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A story of nasal horns: Two new subspecies of Iguana Laurenti, 1768 (Squamata, Iguanidae) in Saint Lucia, St Vincent & the Grenadines, and Grenada (southern Lesser Antilles)

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Abstract and Figures

The Lesser Antilles, in the Eastern Caribbean, were long considered to have only two species in the genus Iguana Laurenti 1768: the Lesser Antillean iguana Iguana delicatissima, which is endemic to parts of the Lesser Antilles, and the Common green iguana Iguana iguana, which also occurs throughout Central and South America. No subspecies are currently recognised. However, herpetologists and reptile collectors have pointed out strong physical differences between some of the island populations of Iguana iguana and those from the continent. Drawing on both morphological and genetic data, this paper describes two subspecies of the Common green iguana Iguana iguana from the southern Lesser Antilles, specifically the countries of Saint Lucia Iguana iguana sanctaluciae and Iguana iguana insularis from St Vincent & the Grenadines, and Grenada. The form on the island of Saint Vincent has not been identified. The new subspecies are described based on the following unique combination of characters: Presence of high median and medium to small lateral horns on the snout; Small subtympanic plate not exceeding 20% of the eardrum size; Two or three scales of decreasing size anterior to the subtympanic plate; Fewer than ten small to medium triangular gular spikes; Medium sized dewlap; Low number of small to medium dispersed nuchal tubercles; Dark brown iris, with the white of the eye visible; Oval, prominent nostril; Short and relatively flat head; High dorsal spines; No swelling of the jowls in reproductively active males. Iguana iguana sanctaluciae has in adults vertical black stripes on body and tail and a black dewlap whereas Iguana iguana insularis is pale grey or creamy white in adults. Both subspecies are globally threatened by unsustainable hunting (including the pet trade) and by invasive alien species, including hybridization from invasive iguanas from South and Central America (I. iguana iguana and I. rhinolopha, considered here as full species) that have become established in all three countries. The authors call for stronger measures to conserve the remaining purebred Iguana i. insularis and Iguana i. sanctaluciae ssp. nov. throughout their ranges and for further research to identify other cryptic species and subspecies of Iguana in the Lesser Antilles.
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ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Accepted by L. Avila: 27 Mar. 2019; published: 20 May 2019 201
Zootaxa 4608 (2): 201–232
Copyright © 2019 Magnolia Press Article
A story of nasal horns: two new subspecies of Iguana Laurenti, 1768
(Squamata, Iguanidae) in Saint Lucia, St Vincent & the Grenadines,
and Grenada (southern Lesser Antilles)
1Muséum national d’Histoire naturelle, Laboratoire des Reptiles et Amphibiens, Bâtiment 30, 57, rue Cuvier, CP n° 30, 75231 Paris
cedex 05, France. Zoobank:
2Laboratoire Labofarm-Genindexe, 4 rue Théodore Botrel, 22600 Loudéac, France
3 Maison du Soleil, Dauphin Road, La Borne, P O Box GM 1109, Saint Lucia, West Indies
4 Durrell Wildlife Conservation Trust, Les Augres Manor, Trinity, Jersey JE3 5BP, Great Britain
5 Department of Forestry, Ministry of Agriculture, Fisheries, Physical Planning, Natural Resources and Co-operatives, Union, Saint
Lucia, West Indies
6 Fauna & Flora International, David Attenborough Building Pembroke Street, Cambridge CB2 3QZ, UK
7 Forestry Department, Ministry of Agriculture, Industry, Forestry, Fisheries and Rural Transformation, Richmond Hill, Kingstown, St
Vincent & the Grenadines
8Laboratoire Écologie et Biologie des Interactions, équipe EES, UMR CNRS 6556, Université de Poitiers, 5 rue Albert Turpin, 86073
Poitiers Cedex 9, France
9Division of Zoology, Faculty of Sciences, University of Zagreb, Rooseveltov trg 6, 10 000 Zagreb, Croatia
Corresponding author: E-mail:
The Lesser Antilles, in the Eastern Caribbean, were long considered to have only two species in the genus Iguana Laurenti
1768: the Lesser Antillean iguana Iguana delicatissima, which is endemic to parts of the Lesser Antilles, and the Common
green iguana Iguana iguana, which also occurs throughout Central and South America. No subspecies are currently
recognised. However, herpetologists and reptile collectors have pointed out strong physical differences between some
of the island populations of Iguana iguana and those from the continent. Drawing on both morphological and genetic
data, this paper describes two subspecies of the Common green iguana Iguana iguana from the southern Lesser Antilles,
specifically the countries of Saint Lucia Iguana iguana sanctaluciae and Iguana iguana insularis from St Vincent &
the Grenadines, and Grenada. The form on the island of Saint Vincent has not been identified. The new subspecies are
described based on the following unique combination of characters: Presence of high median and medium to small lateral
horns on the snout; Small subtympanic plate not exceeding 20% of the eardrum size; Two or three scales of decreasing
size anterior to the subtympanic plate; Fewer than ten small to medium triangular gular spikes; Medium sized dewlap;
Low number of small to medium dispersed nuchal tubercles; Dark brown iris, with the white of the eye visible; Oval,
prominent nostril; Short and relatively flat head; High dorsal spines; No swelling of the jowls in reproductively active
Iguana iguana sanctaluciae has in adults vertical black stripes on body and tail and a black dewlap whereas Iguana
iguana insularis is pale grey or creamy white in adults.
Both subspecies are globally threatened by unsustainable hunting (including the pet trade) and by invasive alien
species, including hybridization from invasive iguanas from South and Central America (I. iguana iguana and I.
rhinolopha, considered here as full species) that have become established in all three countries. The authors call for
stronger measures to conserve the remaining purebred Iguana i. insularis and Iguana i. sanctaluciae ssp. nov. throughout
their ranges and for further research to identify other cryptic species and subspecies of Iguana in the Lesser Antilles.
202 · Zootaxa 4608 (2) © 2019 Magnolia Press
Key words: Caribbean, endemism, hybridization, Iguana, introgression, Lesser Antilles, microsatellites, mtDNA,
The islands of the Lesser Antilles curve around the Eastern border of the Caribbean Sea between the Greater Antilles
and South America and are noted for their rich diversity of endemic and globally threatened reptiles (Hedges 2018).
Iguanas are among the most iconic animals of this archipelago, but opinions on their nomenclature and distribution
have changed many times over the past few centuries.
Linnaeus (1758) described the Common green iguana as Lacerta iguana, whereas Laurenti (1768) described
the Lesser Antillean iguana as Iguana delicatissima and the common species as I. tuberculata. Both authors based
their descriptions on drawings and specimens (Breuil 2002, 2013, 2016; Pasachnik et al. 2006). Later, Wiegmann
(1834) described a third species with pronounced horns on its snout, I. rhinolopha, from Mexico. Duméril & Bibron
(1837) subsequently recognised three Iguana species, using the names I. tuberculata for the Common green iguana,
I. nudicollis for the Lesser Antillean iguana and I. rhinolopha for the horned Mexican iguana, but found only two
characters to separate I. tuberculata from I. rhinolopha.
The first mention of an iguana on the island of Saint Lucia was by Levacher (1834), but no information was giv-
en to determine the species. Breen (1844) commented that the iguanas were “an excellent sport for the native chas-
seurs (hunters)”. Bonnecour(t), a traveller in the mid-19th Century, caught two specimens in Saint Lucia, which are
now housed in the Muséum National d’Histoire Naturelle (MNHN) in Paris, France (Breuil 2013, 2016). Duméril
& Duméril (1851) recognised some morphological similarities between the horned specimens from Saint Lucia and
the horned iguanas Duméril & Bibron (1837) had described in Mexico. This was corroborated by Boulenger (1885),
who considered that a stuffed specimen from Saint Lucia belonged to the “variety” rhinolopha, together with speci-
mens from Central America. Confusingly, however, Provancher (1890) reported the presence of I. delicatissima on
Saint Lucia on the basis of a stuffed specimen observed in a house (Fig. 1), but his description and drawing of the
specimen were too imprecise to confirm the species’ identity. Dunn (1934) remarked that “The reports of i. rhinolo-
pha from St Kitts and from Sta. Lucia is very strange… Possibly the horned mutation has appeared independently in
that island”. Referring to rhinolopha, Barbour (1935) considered that: “The Antillean specimens are probably based
on specimens incorrectly labelled as to locality” and added “If there really ever were iguanas on these islands, the
mongoose has exterminated them”. (Small Asian mongooses, Herpestes auropunctatus, were widely introduced to
many of the Caribbean islands towards the end of the 19th Century in an attempt to control rats and, possibly in Saint
Lucia’s case, the venomous snake Bothrops caribbaeus: Des Vœux 1903; Nellis & Everard 1983).
FIGURE 1. Drawing by Provancher (1890) of a stuffed iguana on Saint Lucia. Provancher identified it as Iguana delicatissima
(see text), but the body and tail seem to have vertical black stripes, and there are small and scattered tubercular nape scales, and
no subtympanic plate. There is no tympanum and no nasal horns on this drawing, which also shows a forked tongue.
TWO NEW SUBSPECIES OF IGUANA IGUANA Zootaxa 4608 (2) © 2019 Magnolia Press · 203
Farther south, Garmann (1887) remarked “the Grenada specimens are intermediate between tuberculata and
rhinolopha. They have one prominent series of tubercles on the neck, and several scattered ones above the hind
extremities. The tubercles on the snout are not so prominent as in rhinolopha from Central America, but the arrange-
ment is the same. The tubercles on the neck are comparatively few as compared with those on Nicaraguan types”.
Later, Barbour (1914) advised “a careful revision of these two species, made with the aid of extensive collections
from many localities, will be necessary before their exact status can be settled”. He added: “That they are really
distinct I have no doubt whatever, but as yet their ranges cannot be accurately defined. Stejneger suspects that if
intermediates really do exist, they may be explained by the fact that the species have been carried by human agency
‘in innumerable instances’, and that the intermediates may be ‘hybrids from introduced stock, or because of their
geographic distribution’ (ex litt.). I favour the latter explanation, as apparently the accidental introduction of verte-
brates by human agency is a far rarer phenomenon than is often realized”. According to Dunn (1934) and Barbour
(1935), Grenada was inhabited by Iguana iguana iguana.
Following Boulenger’s lead, Dunn (1934) recognised two species in the genus Iguana: I. iguana (with subspecies
iguana and rhinolopha) and I. delicatissima. Lazell (1973) compared 139 “I. iguana” from Central and South America
and the West Indies with 29 I. delicatissima collected between Martinique and Anguilla, and detected only one consis-
tent difference between I. iguana and I. delicatissima: the existence in the former of a subtympanic plate at least 80%
as large as the tympanum. Lazell (1973) rejected rhinolopha as a subspecies because he thought that the nasal horns
were polytopic and polyphyletic characters, having observed them in iguanas from the Grenadines, Saint Lucia and
parts of Central America. Based on their morphology, Lazell (1973) recognized three groups of I. iguana in the Lesser
Antilles (Fig. 2): (1) The Northern group (Montserrat, Saba and, in the Greater Antilles, Saint Croix), distinguished
by a higher proportion of melanistic individuals, large tubercular nape scales and dorsal crest spikes; (2) The Gua-
deloupe group (present only in Les Saintes and Basse Terre in the Sixties) which were “quite ordinary, and resemble
those from northeastern South America. They may be patternless and/or grey: characteristics that are rare or absent in
other parts of the range of I. iguana”; and (3) The Southern group between Saint Lucia and Grenada, characterised by
vertical banding on the body and by nasal horns. Lazell considered the variation between the three groups to be clinal.
For example, iguanas on the islands between Saint Lucia and Grenada have few tubercular nape scales; iguanas from
Guadeloupe have more and larger ones; and those from the Northern group have very large and numerous tubercles.
Owing to their large size, striking colouration and horns, the Southern group is in demand for the international pet trade,
and individuals are being smuggled out of these counties and marketed variously under the trade names “Saint Lucia iguana”
and, from the Grenadines, “pink rhino iguana” and “white zebra rhino iguana” (Daltry pers. obs.; Noseworthy 2017).
In recent decades, this picture has been complicated by the discoveries both of hybridization between the two spe-
cies of Iguana and evidence of multiple invasions by iguanas from Latin America. When Lazell conducted his studies
in the 1960s, both I. delicatissima and I. iguana were abundant and sympatric in Les Saintes (Guadeloupe), but not
syntopic, and at that stage there was no evidence of one species displacing the other. It has since become clear that I.
iguana is an invasive alien species in the Guadeloupean Archipelago (Breuil 2002, 2003), and that frequent interbreed-
ing has taken place between I. delicatissima and I. iguana in Les Saintes, Grande-Terre and Basse-Terre, resulting in
fertile and morphologically intermediate hybrids (Breuil 2002, 2003). Breuil (2013, 2016) reported that I. iguana was
first introduced from French Guiana to Les Saintes in the mid-19th Century, and Breuil (2009) and Breuil et al. (2010)
explained how this species arrived on Basse-Terre. The unfortunate result of this introduction of I. iguana has been the
elimination of the native I. delicatissima through hybridization and competition from Terre-de-Bas and Terre-de-Haut
(Les Saintes) and Grande-Terre, a process that is continuing at present on Basse-Terre (Breuil et al. 2010; Vuillaume et
al. 2015; Breuil 2013, 2016). More recently, Iguana x Cyclura hybrids have been recorded from Little Cayman Island
(Moss et al. 2017), showing the lack of isolating mechanisms between these Caribbean genera.
From Guadeloupe, the alien iguanas have spread North and South. In the Sixties, Father Pinchon brought I.
iguana from Les Saintes to Martinique, and this invasive species now ranges over southern Martinique (Breuil
2011). Following Hurricane Luis in September 1995, dozens of iguanas were carried on rafts composed of logs,
vegetation, house debris and garbage from Guadeloupe to Antigua, Barbuda, and Anguilla (Daltry pers. obs.; Cen-
sky et al. 1998; Hodge et al. 2011): the Guadeloupe origin of these iguanas was inferred from their morphology
(Breuil 1999). Both Anguilla and Barbuda now have growing populations of non-native I. iguana (Henderson &
Breuil 2012). Additional iguanas have arrived in the West Indies as pets, putatively originating from breeding cen-
tres in Central America (Kraus 2009). These iguanas tend to be bigger than the Guadeloupean form, often with a
yellow-orange iris, flat median horns on their snouts, big tubercular nape scales and a very big subtympanic plate.
204 · Zootaxa 4608 (2) © 2019 Magnolia Press
FIGURE 2. Distribution of the three iguana groups identified by Lazell (1973). Based on a clinal variation of their morphology,
Lazell (1973) identified at the beginning of the Sixties 3 groups of the Common Iguana Iguana iguana that he thought to be
native in Lesser Antilles. At that time, the central group was known to be present only in Guadeloupe (Les Saintes, Basse-Terre
and Grande-Terre). This group is not native and is the descent of invasive common iguanas from French Guiana (Breuil 2016;
Vuillaume et al. 2015). Now, however, alien iguanas from Central and South America are present throughout most of this region
(van den Burg et al. 2018) except Saint Christopher and Nevis, Petite Terre and some satellites of Saint Barthélemy, Anguilla,
and Martinique.
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During the breeding season the males are often bright orange. These invasive alien iguanas have recently become
established in the wild in Saint Martin, Saint Barthélemy, Martinique and Saint Lucia in the Lesser Antilles (Breuil
2013, 2016). Besides being transported as pets and by storms, invasive iguanas have also spread as stowaways. In
2018, for example, hybrid iguana x delicatissima were detected for the first time near the main port in Dominica,
leading local conservationists to infer that I. iguana had recently arrived with shipping containers from other Carib-
bean islands (Jeanelle Brisbane, WildDominique, pers. comm.). In addition to having become the greatest threat to
the Critically Endangered I. delicatissima in the Lesser Antilles (van den Burg et al. 2018), the invasive I. iguana
have severe negative impacts for other wildlife and humans on other islands, e.g. Puerto Rico, the Caymans and
Dominican Republic (Pasachnik et al. 2012; Falcón et al. 2012, 2013; M. Goetz, pers. comm.).
Invasive alien I. iguana were reportedly smuggled as juveniles into Saint Lucia in the late 1980s. Credible
reports of free-living hatchlings in the vicinity of Soufriere (Southwest Saint Lucia) date back to 2007, putatively
having escaped from a cage in the grounds of a hotel in Soufriere despite warnings from the Forestry Department to
keep the animals and their offspring well secured. As the invasive iguanas began to multiply in spite of efforts by the
Forestry Department and Durrell Wildlife Conservation Trust to catch and cull them, the native iguana population
has become threatened by possible hybridization and competition (Morton & Krauss 2011; Krauss et al. 2014). At
the time of writing, the invasive iguana population is growing in Southwest Saint Lucia, while the indigenous iguana
population is less than 15 km away, in the Northeast. The Government of Saint Lucia recognises the indigenous
Saint Lucia iguana as a distinct and fully protected species, despite it having long been regarded by the scientific
community as merely a variant of Iguana iguana.
The status of the iguanas in Grenada and St Vincent & the Grenadines is less well understood because iguanas
in both countries have long been regarded as a single, relatively abundant game species that can be hunted during
the open season and freely transported by hunters and buyers within their respective borders. Specimens examined
by the authors indicate that invasive I. iguana from Central and South America have invaded and multiplied on the
larger islands at least, including the main islands of Grenada and St Vincent. Unaware of the possible diversity in
iguana taxa, in 2005 the St Vincent & the Grenadines Forestry Department relocated 260 indigenous iguanas from
Palm Island to the nearby Tobago Cays (also in the Grenadines) and the Kingstown botanical gardens on Saint
Vincent in response to complaints from the owners of a resort on Palm Island that the iguanas were becoming a
nuisance. During the hunting season (October to January inclusive), hunters commonly collect and transport live
iguanas from the Grenadine islands to sell as bushmeat on Saint Vincent (G. Gaymes, pers. obs.).
As this narrative shows, understanding the distribution and taxonomy of iguanas in the Lesser Antilles has been
repeatedly frustrated by differences of opinion among scientists on nomenclature and diagnostic characters, the
accidental and deliberate movement of both native and invasive alien iguanas between islands, and hybridisation
between members of the genus Iguana. There have, however, been some recent breakthroughs. Breuil (2002, 2013,
2016) identified more than 15 morphological characters to reliably differentiate I. delicatissima from I. iguana (see
also Vuillaume et al. 2015). Breuil (2013, 2016) also proposed diagnostic characters to distinguish iguanas from
Central America, South America, Montserrat, Saba and Saint Lucia. Malone & Davis (2004) and Stephen et al.
(2013) provided preliminary genetic data that suggested that the Saint Lucia iguana forms an independent radiation
in the Lesser Antilles, but they did not consider the horned iguanas on islands South of Saint Lucia, such as the
Grenadines (which Lazell, 1973, had placed in the same phenotypic group as the Saint Lucia iguana). Vuillaume et
al. (2015) studied the genetic variation of iguanas in the Lesser Antilles from Saint Lucia to Saint Martin (French
West Indies). Following this work, Breuil et al. (in preparation) work on the genetic and morphological originality
of the insular population of Saba and Montserrat.
The objectives of this paper are:
[1] To clarify the taxonomic status of the iguanas of the southern Lesser Antilles using new morphological and
genetic data from Saint Lucia, St Vincent & the Grenadines, and Grenada.
[2] To present new information on the distribution, threats and ecology of this group, and recommendations for
their conservation.
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Materials and methods
Morphological, molecular (i.e. mitochondrial DNA and microsatellites markers), and biological data were used
to characterise the iguanas of Saint Lucia, Grenada and, St Vincent & the Grenadines, and compare them to other
populations of Iguana iguana sensu lato.
Morphological analysis. The morphological characters used to examine the iguanas followed Breuil (2013,
2016), most of which are meristic characters that were easy to record from digital pictures taken by the authors of
wild individuals and from specimens at the Museum of Comparative Zoology (MCZ) in Harvard, USA, and the
Museum National d’Histoire Naturelle (MNHNP) in Paris, France.
We also examined photographs of Iguana found on the Internet using the Google Images search engine for the
islands of Saint Vincent, the Grenadines and, Grenada. The use of Internet images for taxonomic research was advo-
cated by Leighton et al. (2016) for studying spatial patterns in phenotypic traits that are objective, binary and easy to
see, irrespective of the angle, to supplement fieldwork. To identify diagnostic characters, we retained only pictures that
reported precise localities, and eliminated areas known to have iguanas introduced from Central and South America.
Molecular analysis. Collection and preparation of genetic material.
Genomic DNA was isolated from 39 specimens from tissue, shed skin and/or blood samples, using the QIAamp
DNA Mini Kit (QIAGEN, Deutschland) and following the manufacturer’s recommendations (Table 1). Not all
specimens were used for both mtDNA and microsatellites analysis. Samples from the Lesser Antilles were collected
by the authors and from French Guiana by François Catzefis (CNRS, France) and Benoît de Thoisy (Institut Pasteur,
Cayenne, French Guiana).
Mitochondrial DNA (ND4). 903 base pairs (bp) of the ND4 mitochondrial DNA gene were amplified using
GGT AGT CAT AG-3’. A Qiagen multiplex PCR kit was used to conduct each PCR, with a total reaction volume
of 25 µL containing 20 ng DNA template, 12.5 µL Qiagen PCR Master Mix, 2.5 µL Qiagen Q-solution, and 2.5 µL
primer mix at 10 µmM each. PCR reactions were carried out in a SimpliAmp thermal cycler under the following
conditions: initial denaturation at 95°C for 15 min, followed by 35 cycles of denaturation at 95°C for 30 s, annealing
at 52°C for 30 s, and extension at 72°C for 90 s, with a final extension step at 60°C for 30 min. The amplification
was verified by electrophoresis using LabChip GX Analyser (Caliper Life Sciences, USA) and successful PCR
products were then vacuum-purified using MANU 30 PCR plates (Millipore) before being sequenced using the
ABI Big-Dye Terminator v3.1 Cycle Sequencing Kit (Thermo). Cycle sequencing reactions were finally purified
with Sephadex G-50 Fine (GE Healthcare) and sequenced on an ABI 3130xl DNA sequencer (Applied Biosystems).
Sequence chromatograms were analyzed in SEQUENCHER (v5.3; Gene Codes Corp., Ann Arbor). Sequence align-
ment was prepared with MAFFT (v7.187; Katoh et al. 2005). For comparisons we chose a 340-bp fragment of the
ND4 locus common to all our specimens.
Microsatellites. This data set comprised 36 individuals representing seven insular and continental populations
(Table 1). A panel of 16 microsatellite markers were amplified as described by Valette et al. (2012) and Vuillaume
et al. (2015).
Phylogenetic analysis. For ND4 analysis, we aligned our ND4 sequences from the 21 specimens sampled by
the authors (Table 1) with GenBank sequences obtained from previous studies (Malone et al. 2000; Malone & Davis
2004; Stephen et al. 2013; Martin et al. 2015). Phylogenetic trees were constructed using the Maximum Likelihood
(ML) and Bayesian Inference (BI): The best-fit evolutionary model was calculated using the Bayesian Information
Criterion in jModelTest2 (version 2.1.6; Darriba et al. 2012) while the ML analysis was conducted in MEGA6
(Tamura et al. 2013) based on the best-model obtained in jModeltest. Initial tree(s) for the heuristic search were
obtained by applying the Neighbour-Joining method to a matrix of pairwise distances estimated using the Maximum
Composite Likelihood (MCL) approach. A discrete Gamma distribution was used to model evolutionary rate dif-
ferences among sites (5 categories). The BI was performed using MrBayes 3.2 (Ronquist et al. 2012) on the Cipres
Science Gateway. Two independent runs with four MCMC chains were carried out for 50 million generations.
The temperature parameter was set to 0.2 and chains were sampled every 5,000 generations. The first 12.5 million
generations were discarded as burn-in. The effective sample sizes of parameters were checked using TRACER 1.5
(Drummond & Rambaut 2007) and the convergence of runs was checked using AWTY (Nylander et al. 2008). Sup-
ported nodes in phylogram were indicated with bootstrap values P ≥ 70 in ML and posterior probabilities (pp) values
≥ 0.95 in BI.
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TABLE 1. Genetic samples
Locality/Status Microsatellites ND4 GenBank
Soufriere/ Alien iguanas from Central America IGU43
IGU44 IGU44 MK687388
IGU46 IGU46 MK687389
IGU47 IGU47 MK687390
IGU50 MK687391
IGU52 IGU52 MK687392
Grand Anse/ Native iguanas IGU53 IGU53 MK687393
IGU55 IGU55 MK687394
IGU56 IGU56 MK687395
IGU57 IGU57 MK687396
Louvet/ Native iguanas IGU58 IGU58 MK687397
IGU63 IGU63 MK687398
IGU65 MK687399
Union Island/ Native iguanas IGU73 IGU73 MK687400
IGU74 (skin) MK687401
Palm Island/ Native iguanas IGU75 IGU75 MK687402
IGU76 IGU76 MK687403
IGU77 IGU77 MK687404
Trois-Sauts/ Native IGU78 IGU78 MK687405
IGU79 IGU79 MK687406
French Guiana/ Native IGU82 IGU82 MK687407
IGU84 IGU84 MK687408
The Median-Joining (MJ) haplotype network (Bandelt et al. 1999) was constructed to analyze inter- and intra-
specific relations among Iguana lineages. The MJ network was calculated and drawn using PopART (Population
Analysis with Reticulate Trees) v1.7 (Leigh & Bryant 2015).
Genetic diversity. We tested departures from Hardy-Weinberg expectations and linkage disequilibria using
exact tests based on the Markov chain (1,000 permutations) with the software fstat v. (Goudet 2001). We
adjusted the levels of significances for multiple tests using the standard Bonferroni correction (Rice 1989). We
assessed the polymorphism over all loci for each population, computing allelic richness (AR), expected heterozy-
gosity (He), allelic frequencies and inbreeding coefficient (Fis) (Weir & Cockerham 1984) using fstat v.
208 · Zootaxa 4608 (2) © 2019 Magnolia Press
(Goudet 2001) with 1,200 permutations. The allelic frequencies allowed us to deduce private alleles for each popu-
Genetic structure. We estimated pairwise fixation index (FST) values between populations (Weir & Cockerham
1984) using fstat v. (Goudet 2001). Their associated significance was computed and tested using global
tests implemented in fstat v. (Goudet 2001) with a level of significance adjusted for multiple tests using the
standard Bonferroni correction. In addition, relationships among populations were evaluated with a Factorial Cor-
respondence Analysis (FCA) based on individual genotypes and using the FCA procedure implemented in genetix v.
4.05.2 (Belkhir et al. 2004). We also accessed the genetic structure using the individual-based approach implement-
ed by the software structure (Pritchard et al. 2000). This Bayesian clustering approach estimated both the number
(K) of genetic cluster(s) and the admixture coefficient of individuals to be assigned to the inferred clusters. We
choose the admixture model and the option of correlated allele frequencies among populations. As recommended
by Evanno et al. (2005), we replicated 20 independent runs for each value of K (with K varying from 1 to 10) with
a total of 1 million iterations and a burn-in of 10,000. To determine the number of genetic clusters from structure
analyses, we used the structure harvester program (Earl & VonHoldt 2011) to compare the mean likelihood and
variance per K values computed from the 20 independent runs.
Systematic analysis. Based on morphological and genetic analysis, the Southern group of iguanas first identi-
fied by Lazell (1973) is herein recognized as two new subspecies one endemic to St Vincent & the Grenadines,
and Grenada and the other one endemic to Saint Lucia. As a consequence, the continental South American clade is
herein considered as the nominative subspecies. The form of I. iguana on St Vincent remains unverified due to lack
of known pure-bred specimens from here.
These two new subspecies (Figs 3-11) are characterized by the following combination of features and fit Lazell’s
Southern group:
Presence of median and lateral horns on the snout that are generally enlarged at the base;
Small subtympanic plate, not exceeding 20 % of the high of the tympanum;
Two or three scales of decreasing size anterior of the subtympanic plate;
Not more than 8 small to medium triangular gular spikes, exceptionally 10;
Dewlap of medium size;
Low number of small to medium dispersed nuchal tubercles;
Dark brown iris (never yellow to orange), with the white of the eye visible except in the juveniles;
Oval prominent nostril, sometimes triangular;
Short and relatively flat head;
High dorsal spines;
No swelling of the jowls in reproductively active males.
Body of juveniles and young adults is predominantly bright green with 6-8 black vertical bands. The body be-
comes very pale (almost white or cream white) in old individuals and the vertical bands either fade (subspecies
insularis) or remain black (subspecies sanctaluciae).
Black bands on the tail, which typically remain conspicuous throughout life.
Iguana iguana insularis nov. ssp.
Grenadines horned iguana, pink rhino iguana
Figs. 3–6.
Holotype. The holotype of Iguana iguana insularis housed in MCZ under the numbers X-17620/R-79057 (Fig. 3).
This specimen was caught by James Lazell on Bequia, St Vincent & the Grenadines (10 April 1964).
Sex: Undetermined.
Age: Young, possibly 2 years old, based on its size.
Morphological measurements: Total length: 51.5 cm, SVL: 13.5 cm, tail length: 38 cm. Height and width of
the left subtympanic plate: 3.2 mm, 4.3 mm.
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FIGURE 3. Holotype of Iguana iguana insularis ssp. nov. MCZ X-17620/R-79057 © Museum of Comparative Zoology, Har-
vard University. © President and Fellows of Harvard College. Specimen in alcohol with discolouration. Annotations: 1. Small
size of subtympanic plate ± 10-20% of the eardrum. 2. Two or three scales of decreasing size anterior to subtympanic plate.
3. Juxtaposed elongated sublabial scales 5. Median and lateral horns on the snout. 6. Horns with enlarged bases. 7. Oval and
prominent nostrils. 9. Flat and triangular gular spikes. 10. Six gular spikes. 11. Scattered nuchal tubercles. 12. Low number of
nuchal tubercles. 13. Small size of nuchal tubercles. 15. Dewlap of medium size.
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FIGURE 4. Examples of adult male Iguana iguana insularis ssp. nov. A. Adult male (Palm island) sequenced under the number
IGU75 (SVL 41 cm); B and C, adult male (Palm Island) sequenced under the number IGU77 (SVL 45 cm) (Palm Island). An-
notations: 1. Small size of subtympanic plate ± 10-20% of the eardrum. 2. Two or three scales of decreasing size anterior to
subtympanic plate. 3. Juxtaposed elongated sublabial scales. 4. No apparent swelling of the jowls in breeding males. 5. Median
and lateral horns on the snout. 6. Horns with enlarged bases. 7. Oval and prominent nostrils. 8. Brown eyes with visible white.
9. Flat and triangular gular spikes. 10. Seven or eight gular spikes. 11. Scattered nuchal tubercles. 12. Low number of nuchal
tubercles. 13. Small size of nuchal tubercles. 14. Orange in dorsal scales in breeding animals. 15. Creamy white dewlap of me-
dium size. 16. Creamy white body with faint to no black banding in old individuals.
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FIGURE 5. Nasal horns of Iguana iguana insularis ssp. nov. View of the snout of IGU75 (A) and IGU77 (B) from Palm Island
(same individuals as Fig. 4). Annotations: 0. Frontal scale not developed into a horn. 1. Median horns with enlarged bases. 2.
Lateral horns. 3. Oval prominent nostril. Note the differing forms and disposition of cephalic scales, and that IGU75 (a younger
male) has flat scales whereas IGU77 (an older, larger male) has more prominent scales.
Meristics: Number of gular spikes, 5 medium + 2 small. Number of dorsal spikes to cloaca: 54 ± 1.
Paratypes. Two other young specimens MCZ X-17619/R-79056 and X-17621/R-79058) from the same loca-
tion and the same collector.
Diagnosis of Iguana iguana insularis (Figs 4, 5). We define the typical morphology of this new taxon based on
our own observations on both adults and juvenile specimens on Palm and Union Islands (St Vincent & the Grena-
dines), complemented by the specimens from MCZ R-79056-57-58 collected on Bequia (also in St Vincent & the
Grenadines) and R-79747 from Sandy Bay, Grenada. The latter four are young individuals with SVL from 128 mm
to 135 mm, and thus lack some details specific to adults.
The iguanas from the Grenada Bank, including the Grenadines, are characterised by the following association
of characters in adults compared with iguanas from Saint Lucia (I. iguana sanctaluciae ssp. nov., see below).
In most old adults (both males and females), the green colouration and black bands fade to an almost uniform
light cream to nearly white, except on the posterior end of the tail where the black banding persists;
In old adults, the head is nearly light cream to white;
The dewlap is predominantly white but may have some black scales;
There are no black margins on the subtympanic plate and on the sublabial scales;
The snout has 2 to 5 median horns (usually 3 or 4) and 2 to 6 less developed lateral horns on each side;
The horns may or may not remain black throughout the animal’s life;
There are light yellow scales on the head and on the dewlap in old adults;
The tips of the dorsal spikes of mature adults during the breeding season are light yellow to light orange;
The anterior part of the dewlap is rounded.
Size. The largest purebred I. iguana insularis measured by the authors had an SVL of 45 cm (IGU77, an adult
male on Palm Island, Fig. 4). Its tail was incomplete.
Another large individual fitting the morphology of this subspecies (but not genetically tested) on Petit Bateau
had a total length of 136 cm.
Geographical distribution (Fig. 6). Of the c. 30 islands of Grenada Bank, including the Grenadine islands and
the main island of Grenada, 26 have been reported to have iguanas (Henderson & Powell 2018). The entire bank is
inferred to have been originally inhabited by I. iguana insularis but morphological (e.g. Henderson & Powell 2018,
212 · Zootaxa 4608 (2) © 2019 Magnolia Press
photograph p. 50) and genetic data indicate that several islands, including the main island of Grenada, have had
incursions of iguanas from South American and/or Central American lineages.
From our collection of photographs of specimens captured by the authors and obtained from internet searches,
it is clear that most Grenadine islands still have the indigenous white, horned and more or less black-banded pheno-
type, but there is the Central America phenotype with various hybrids among them that make it difficult to confirm
which islands still have purebred populations of this subspecies. Further genetic testing is required to accurately
map the present distribution of I. iguana insularis and invasive iguanas.
Etymology. The subspecific name refers to the numerous islands in the southern Lesser Antilles where the new
subspecies lives.
FIGURE 6. Distribution of iguanas in the Grenadine islands. Locations are mapped to the nearest 2 × 2 km square representing
groups of islands in the Grenadines. We have deliberately avoided being specific to protect the animals (see Auliya et al. 2016).
Note that there are alien iguanas on some islands and not all of the island clusters shown here have purebred populations of
Iguana iguana insularis. We have no confirmed specific localities for the main island of Grenada, although a museum specimen
(MCZ R-79747) confirms this subspecies occurred here. Henderson & Breuil (2012), Henderson & Powell (2018), Baldwin
(2012) and Baldwin & Mahon (2011), G. Gaymes and J. Daltry (pers. obs.; the Grenadines). While iguanas are present on St.
Vincent, these have not been identified to subspecies level and cannot be assumed to be identical to those on the Grenada Bank.
The grey line just south of St Vincent marks the brake between the St. Vincent Bank to the north and the Grenada Bank to the
south. The black line between Petit Saint Vincent and Petit(e) Martinique shows the political boundary between St. Vincent and
the Grenadines to the north and Grenada to the south. The Grenadine islands form an archipelago from the south of St. Vincent
to the north of Grenada.
Iguana iguana sanctaluciae nov. ssp.
Saint Lucia horned iguana
Figs 7–11.
Holotype. The holotype of Iguana iguana sanctaluciae housed in MNHN Paris under the number MNHN2362 and
collected by Bonnecour(t) between 1850–1851. (Fig. 7)
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FIGURE 7. Holotype and paratype of Iguana iguana sanctaluciae. The holotype MNHN2362 (A, C, D, E) and the paratype
MNHN1996.8276 (B) Both specimens collected by Bonnecour(t) in 1850-51 in Saint Lucia. Note the nasals (median and lateral
horns), the small subtympanic plate, the low number of small nuchal tubercles, the 7 gular spikes, the prominent oval nostril,
the banded body.
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FIGURE 8. Ontogenetic change in colour of Iguana iguana sanctaluciae. Young male (A), old male (B). Annotations: 1. Small
subtympanic plate ± 10% of the eardrum. 2. Two or three scales of decreasing size anterior to subtympanic plate. 3. Low number
of sublabial scales with black margins. 4. No swelling of the jowls in breeding males. 5. Lateral and median horns. 6. Median
horns with enlarged bases. 7. Oval to rounded nostril. 8. Brown eye with the white of the eye visible. 9. Triangular gular spikes.
10. 7 gular spikes. 11. Dispersed nuchal tubercles. 12. Low number of nuchal tubercles. 13. Small size of nuchal tubercles. 14.
Orange in first dorsal spikes in breeding animals. 15. Entirely black dewlap in old adults. 16. Body and tail black and bright
green in young individuals and very light green to almost pale greenish grey in old adults. Old individuals may look nearly
“black and white”. The brilliant colouration of the young male results from the flash of the camera.
This specimen is rigid, curved in its jar and it is nearly impossible to take accurate measurements.
Sex: Male
Age: Adult
Morphological measurements: total length: 132 cm; SVL: 38.5 cm; tail length 93.5 cm; height and width of
left subtympanic plate: 16.7/14.6; height and width of right subtympanic plate: 16.4/15.5, height of 4th dorsal spike:
47.5 mm.
Meristic characteristics: Number of gular spikes 7; Number of horns 2 median with very enlarged base + 3
small lateral on each side; Number of dorsal spikes to cloacae: 54
Colouration: type in alcohol with discolouration, the ground colouration is green light grey with dark banding,
6 on the body and 10 on the tail, the scale of the dewlap are dark or half dark, the dorsal spikes are ochre but seem
to have lost their original colour.
Type locality: Saint Lucia, West Indies. No more information is known for this individual.
Paratype. The stuffed specimen MNHN 1996.8276 (Fig. 7) from the same island (Saint Lucia) and the same
Diagnosis of Iguana iguana sanctaluciae (Figs 7–9). Iguana iguana sanctaluciae resembles I. iguana insu-
laris, but differs by the following association of characters:
the scales of the jowls sometimes overlap;
there are 7 or fewer triangular gular spikes of moderate size (cf. 8 or 9 exceptionally 10 gular spikes in I. iguana
the vertical bands on the body are thicker, black and remain well developed in old individuals (cf. narrow bands
on the body that fade with age in I. iguana insularis);
the dewlap is black in old individuals (cf. creamy white in I. iguana insularis);
the subtympanic plate and the associated 2–3 anterior scales have black pigmentation on their margins;
TWO NEW SUBSPECIES OF IGUANA IGUANA Zootaxa 4608 (2) © 2019 Magnolia Press · 215
Only the anterior dorsal spikes are orange in males (cf. most dorsal spikes have an orange hue in I. iguana insu-
Size. The largest adult male to be measured on Saint Lucia was 160 cm in length (50 cm SVL) and weighed
over 5 kg (Fig. 10). A sample of 30 adults in Saint Lucia had a mean total length of 110 cm (30 cm SVL) and mass
of 1.3 kg.
Geographical distribution (Fig. 11). The distribution of native Saint Lucia horned iguanas (Iguana iguana
sanctaluciae) and introduced alien iguanas (Iguana rhinolopha) on Saint Lucia is shown in figure 16, redrawn from
Morton & Krauss (2011) with minor updates, after an island-wide, systematic survey (Morton et al. 2007).
FIGURE 9. Horned iguanas from the Central American clade of the “rhinolophaphenotype. Photographed from invasive
introduced populations in the Lesser Antilles: old male caught in Saint Lucia (A). young male caught on Saint Maarten (B);
Annotations: 1. Huge subtympanic plate, 2 to 3 times the size of the eardrum. 2. A half crown of sublabial scales around the
subtympanic plate and the first scale anterior to subtympanic plate. 3. Mosaic of sublabial scales. 4. Swelling of the jowls in
breeding male. 5. Generally 2-3 small median horns and no lateral horns. 6. Flat small horns. 7. Triangular nostril. 8. Yellow to
dark orange eye with not the white visible. 9. Triangular gular spikes. 10. Number of gular spikes ≥ 10. 11. Nuchal tubercles
appear to be organised in rows. 12. High number of nuchal tubercles. 13. Very large nuchal tubercles. 14. Yellow, orange to red
dorsal scales on the whole body in breeding males. 15. Variable size and colour of the dewlap but often large and not uniform
black (cf. I. iguana sanctaluciae) or creamy white (cf. I. iguana insularis). 16. Body orange to red in breeding males, green in
other individuals, and not heavily banded. This phenotype is recognised in this paper as a full species, I. rhinolopha, native to
Central America (see text).
Etymology: The subspecific name is given in reference to Saint Lucia which is the only island inhabited by this
new taxon.
Comparison to other species. Because in the field there is greatest risk of confusing the new subspecies with
invasive alien I. rhinolopha, which also has nasal horns, figures 8, 9 and 10 highlight the main morphological dif-
ferences between the anterior parts of I. iguana sanctaluciae and I. rhinolopha. The two new subspecies are distin-
guished from I. iguana iguana, I. rhinolopha (considered here as a full species, see below) and I. delicatissima by
the following combination of characters.
Colour hue and pattern. The head, body and tail are bright green in young individuals, becoming very pale
greenish grey or creamy white with age (unlike I. iguana iguana, I. rhinolopha and I. delicatissima, which vary
widely in hue but are rarely as pale). The body has 6–8 thin or thick vertical black bands (except in old adult I.
iguana insularis, in which only faint traces of the vertical bands remain). These vertical black bands are present
on the newborn I. i. sanctaluciae whereas they are generally absent in newborn Iguana iguana iguana and iguana
216 · Zootaxa 4608 (2) © 2019 Magnolia Press
rhinolopha. According to Henderson & Powell (2018), juveniles most frequently are uniform green but this point
has to be checked for Iguana iguana insularis. The tail has black bands that are conspicuous at all ages (unlike I.
delicatissima, which does not have vertical bands on the body or tail). The legs are not black even in old individuals
(unlike the indigenous iguanas of Saba and Montserrat). Although the body of pale adults may have a pinkish hue,
the body colouration of breeding males is never orange as in I. rhinolopha from Central America (Fig. 10).
FIGURE 10. Adult breeding males I. iguana sanctaluciae and I. rhinolopha. The endemic Saint Lucia horned iguana (I.
iguana sanctaluciae, photo from Grand Anse, A) is clearly different from the Central America horned iguana (I. rhinolopha:
this specimen was photographed from an introduced population on Sint Maarten by M. Yokoyama, B) by size, body proportion,
body colour, size and form of the horns, eye colouration, scalation of the jowls, and dewlap size, colour and form.
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FIGURE 11. Distribution of iguanas on Saint Lucia. Locations are mapped to the nearest 1×1 km square. Data come from
Morton et al. (2007). Grey squares, Saint Lucia endemic iguana, Black squares, alien iguana from Central America clade. “False
absences” were minimized by interviewing persons about iguana presence in grid squares confirmed independently, through
sightings and captures by us, to have iguanas present. We rejected some reported sightings of native iguanas, shown here as open
grid squares, as being iguanas captured for food or pets or reports based on misidentification (for example on the islet of Maria
Major off the far south of Saint Lucia; J. Lazell, in litt. 2010). Some of the reports that were accepted from the interior of the
northern half of Saint Lucia may also be suspect, though they are all below 300 m ASL. These patterns of distribution suggest
that the mountainous interior of Saint Lucia may create at least a partial barrier to direct east-west movements of iguanas.
With age the dewlap changes from green to entirely creamy white (I. iguana insularis) or completely black (I.
iguana sanctaluciae) as the indigenous iguanas of Saba and Montserrat, but never orange (cf. I. rhinolopha, Fig. 9).
The dorsal crest is often high, especially in males (unlike I. delicatissima), and of the same colour as the light part
of the body and often pink-orange towards the tips. The iris is dark brown, not yellow to orange, and the white part
of the eye is visible (unlike I. iguana iguana, I. rhinolopha and I. delicatissima). There is no black patch between
the eye and the tympanum, and no pink on the jowls, as in Saba and Montserrat (Breuil 2013, 2016, Breuil et al. in
prep.) but some breeding males have pale golden yellow on the jowls.
Scalation. Several scales between the nostrils are elongated to form horns (whereas nasal horns are absent from
I. delicatissima and I. iguana iguana). There are 2 to 5 horns (usually 3–4) on the axial plane, and 1 to 3 smaller
horns and sometimes up to 6 for I. iguana insularis on each side in adults (whereas lateral horns absent in I. rhino-
lopha). The horns are broad at their bases and the tallest are sometimes curved back (whereas the horns of I. rhino-
lopha are thin, straight and shorter). However, hatchlings and young juveniles of the two new subspecies have only
very small horns.
The nostrils are prominent; their openings are from oval to circular, sometimes triangular in Iguana iguana in-
sularis, looking from the side. There are some small to rarely medium conical scales on the occiput. There are 6–10
medium-sized gular spikes on the dewlap that extend to the half lower part. In adults, these spikes are triangular. A
subtympanic plate is present (cf. absent in I. delicatissima) but it is relatively small: even in old adults the diameter
218 · Zootaxa 4608 (2) © 2019 Magnolia Press
of the subtympanic plate is no more than ± 20% the height of the tympanum (cf. 2–3 times the size of the tympanum
in I. rhinolopha).
There are 2–3 scales of decreasing size anterior to the subtympanic plate, a characteristic not found in other
species systematically present in I. i. sanctaluciae and sometimes in I. i. insularis. (This trait however resembles a
feature of F1 hybrids between I. iguana iguana/Iguana rhinolopha and I. delicatissima: Breuil 2013, 2016). There
are only few tubercular nape scales: fewer than 10 in I. i. sanctaluciae and up to 20 in I. i. insularis, small, not very
prominent and dispersed, i.e. not arranged in more or less conspicuous rows as in I. rhinolopha (Fig. 10) and the
largely melanistic iguanas of Saba and Montserrat populations (I. cf. iguana). This distinguishing character is pres-
ent in hatchlings and throughout life, unlike some of secondary sex characteristics noted above.
Head. The head is relatively short and flat, and the dewlap is of medium size (cf. the large dewlap in I. rhino-
lopha). The scales anterior to the subtympanic plate overlap slightly in some individuals. The jowls do not appear
swollen even in reproductively active males (cf. very well-developed jowls in breeding male I. rhinolopha).
FIGURE 12. Phylogenetic tree. Based on mtDNA of 23 iguanas (21 from this study, 2 from GenBank). Four clades are iden-
tified. Iguana delicatissima (AF217783) serves as the outgroup. The monophyly of Lazell’s southern Lesser Antilles group,
characterised by horns, is described here as two new subspecies Iguana iguana insularis and Iguana iguana sanctaluciae. The
horned iguanas from Central America are also considered here as a full species I. rhinolopha. The sister group of I. iguana
insularis and Iguana iguana sanctaluciae is I. iguana iguana (based on specimens shown here from French Guiana). This phy-
logenetic tree shows that I. iguana iguana is present as an invasive alien species in the Grenadines (IGU74) and that there is I.
delicatissima mitochondrial DNA in some specimens of I. iguana sanctaluciae. The ML tree with the highest log likelihood is
shown. Node supports were indicated by bootstrap values from ML (>70) and posterior probability from BI (>0.95).
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Results of genetic analysis
Phylogeny. The intra- and interspecific relationships among Iguana species are shown in the phylogram (Fig. 12)
and in the Median-Joining haplotype network (Fig. 13). Four clades can be observed:
Clade 1, the most basal, corresponds to I. delicatissima (GB: AF217783), which clustered with mtDNA from
two iguanas from Grand Anse in Saint Lucia (IGU55, IGU56) that had been identified in the field as pure endemic
iguanas (see Discussion). IGU53, from the same locality, shows a haplotype that was found nowhere else.
Clade 2 corresponds to the mtDNA haplotypes shared by the alien iguanas on Saint Lucia, identified by their
phenotypes as iguanas from Central America, likely originating from the pet trade (Fig. 9). These haplotypes are
close to those of the Central American clade of Stephen et al. (2013) and Vuillaume (2012). This clade forms the
sister group of the iguanas from French Guiana (South America) and from the southern Lesser Antilles.
Clade 3 groups the Common green iguana (I. iguana iguana) from French Guiana but also contains a specimen
known only from a piece of shed skin (IGU74) found on Union Island (St Vincent & the Grenadines).
Clade 4 is consistent with our morphological analysis and shows the existence of an endemic group that inhabits
Saint Lucia and the Grenadines (Grenada Bank).
FIGURE 13. Median-Joining haplotype network. Based on 23 mtDNA sequences of Iguana (21 from this study, 2 from Gen-
Bank). Black circles are median vectors that represent extinct or unsampled haplotypes. Numbers of mutational steps are indi-
cated by hatch marks.
Genetic diversity. No linkage disequilibrium was detected after Bonferroni correction (adjusted P-value thresh-
old = 0.0004). Only 5 of the 64 population-locus combinations deviated significantly from Hardy-Weinberg expec-
tations (adjusted P-value threshold after Bonferroni correction = 0.0008). These deviations occurred for population
of individuals endemic of Saint Lucia and so seem to be inherent to it. All microsatellite loci were polymorphic with
an allelic richness (AR) ranging from 1 to 3.552 and a genetic diversity (He) ranging from 0 to 0.821 across popu-
lations (Table 2). Moreover, based on allelic frequencies, individuals introduced in Saint Lucia and those coming
from French Guiana revealed the presence of several private alleles suggesting a specific genetic signature and so
populations well genetically differentiated.
Genetic structure. Results revealed significant genetic differentiation between populations. After applying
the Bonferroni correction (adjusted P-value threshold = 0.0083), significant FST values were found between several
pairwise populations (mean FST value = 0.495) (Table 3). This significant variation was corroborated by both FCA
(Fig. 14) and the Bayesian individuals-based approach. Indeed, based on the individuals’genotypes, FCA clearly
distinguishes four different populations and, furthermore, shows the low genetic diversity within the native Saint
220 · Zootaxa 4608 (2) © 2019 Magnolia Press
Lucia population (only 7 circles are shown because many individuals from Louvet and one from Grand Anse had
the same genotypes based on 16 microsatellites). The structure and structure harvester software revealed a high-
est delta K value of 3 (Figs 15, 16). According to these results, individuals from introduced iguana populations in
Saint Lucia and those from French Guiana were mainly assigned to the first and second genetic cluster respectively
(clades 3 and 2 from the phylogram, Fig. 12). Individuals native to Saint Lucia and the Grenadine islands were
mainly assigned to the third genetic cluster (clade 4 of the phylogram). However, we can also distinguish three indi-
viduals (IGU53, IGU55, IGU56) that showed intermediate admixture coefficients, even though they were assumed
to be of pure native origin. These intermediate admixture coefficients (Fig. 16, Table 4) and FCA results (Fig. 14)
suggest hybridization has occurred in Grand Anse, where three out of the four individuals sampled are considered
as hybrids between endemic and introduced individuals from different clades. Moreover, IGU55 and IGU56 have I.
delicatissima haplotypes for ND4, and IGU53 has a unique haplotype closely related to I. delicatissima (Fig. 13).
TABLE 2. Genetic diversity parameters for each locus. Expected heterozygosity (He); number of private alleles (PA);
allelic richness (AR); and inbreeding coefficient (Fis) have been computed for each population and each locus using
FSTAT ver. software (Goudet 2001). In italics and bold: the Fis with significant departures from Hardy-Weinberg
expectations (i.e. significantly different from 0; P<0.0008 after Bonferroni adjustment).
Saint Lucia
Iguana rhinolopha
Saint Lucia
Iguana iguana
Iguana iguana
French Guiana
Iguana iguana
All populations
n 8 17 4 7 36
L2 He 0 0.265 0 0.262 0.132
PA 0 0 0 0 -
AR 1 1.647 1 1.692 1.91
Fis NA 0.778 NA -0.091 0.343
L3 He 0.125 0 0 0 0.031
PA 1 0 0 0 -
AR 1.375 1 1 1 1.768
Fis 0 NA NA NA 0
L5 He 0.690 0.272 0 0.524 0.371
PA 2 0 0 0 -
AR 2.874 1.779 1 1.99 2.738
Fis -0.448 0.351 NA -0.091 -0.063
L6 He 0.429 0.217 0 0.524 0.2925
PA 0 0 0 1 -
AR 1.930 1.559 1 1.972 2.299
Fis -0.333 0.458 NA 0.727 0.284
L8 He 0.667 0 0 0.262 0.232
PA 1 0 0 1 -
AR 2 1 1 1.692 1.453
Fis 0.5 NA NA -0.091 0.204
L9 He 0.652 0.217 0.75 0.607 0.556
PA 0 0 0 1 -
AR 2.604 1.559 2.929 2.692 2.972
Fis 0.233 0.458 0.333 -0.412 0.153
L13 He 0 0.217 0.5 0 0.179
PA 0 0 0 0 -
AR 1 1.559 1.964 1 1.975
Fis NA 0.458 1 NA 0.729
......continued on the next page
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TABLE 2. (Continued)
Saint Lucia
Iguana rhinolopha
Saint Lucia
Iguana iguana
Iguana iguana
French Guiana
Iguana iguana
All populations
L14 He 0.125 0.116 0 0.143 0.096
PA 0 1 0 1 -
AR 1.375 1.353 1 1.429 1.959
Fis 0 -0.016 NA 0 -0.005
L15 He 0.393 0.059 0 0.679 0.28275
PA 1 0 0 1 -
AR 1.885 1.176 1 2.774 1.893
Fis -0.273 0 NA 0.158 -0.038
L16 He 0.81 0 0.25 0.143 0.301
PA 2 0 1 0 -
AR 3.375 1 1.75 1.429 2.06
Fis 0.824 NA 0 0 0.275
L17 He 0.548 0.224 0 0.488 0.315
PA 1 0 0 2 -
AR 1.99 1.652 1 2.275 3.055
Fis 0.478 0.475 NA 0.415 0.456
L18 He 0.339 0 0 0.533 0.218
PA 1 0 0 1 -
AR 1.786 1 1 1.998 1.667
Fis 0.632 NA NA -0.25 0.191
L19 He 0.125 0.272 0 0.524 0.230
PA 0 0 0 0 -
AR 1.375 1.779 1 1.995 2.439
Fis 0 0.351 NA -0.364 -0.004
L20 He 0.571 0.224 0 0.655 0.3625
PA 1 0 0 3 -
AR 2.348 1.652 1 2.827 3.213
Fis -0.094 0.475 NA -0.091 0.097
L23 He 0.4 0.272 0 0.821 0.373
PA 0 0 0 3 -
AR 1.909 1.779 1 3.552 3.071
Fis -0.25 0.351 NA 0.304 0.135
L24 He 0 0 0 0 0
PA 0 0 0 0 -
AR 1 1 1 1 1
He 0.367 0.147 0.094 0.385 0.248
PA 10 1 1 14 -
AR 1 1 1 1 1
Fis 0.156 0.425 0.5 0.034 0.279
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TABLE 3. Pairwise Fst values for each population comparison (below diagonal) and their significance level (above di-
agonal). P-value threshold is adjusted with the Bonferroni correction, P= 0.0083.
Saint Lucia
Iguana rhinolopha
Saint Lucia endemic
Iguana iguana
Iguana iguana
French Guiana
Iguana iguana
Introduced Saint Lucia - 0.0083 0.1083 0.0667
Saint Lucia endemic 0.6846 - 0.0583 0.0083
Grenadines endemic 0.6448 0.1051 - 0.0083
French Guiana 0.5048 0.5472 0.4832 -
TABLE 4. Admixture coefficient inferred by STRUCTURE software for the four studied populations.
Cluster 1 Cluster 2 Cluster 3
Introduced Saint Lucia Iguana rhinolopha 0.941 (±0.153) 0.056 (±0.151) 0.003 (±0.002)
Saint Lucia endemic
Iguana iguana sanctaluciae
0.064 (±0.142) 0.072 (±0.196) 0.864 (±0.324)
Grenadines endemic
Iguana iguana insularis
0.011 (±0.015) 0.025 (±0.025) 0.964 (±0.037)
French Guiana
Iguana iguana iguana
0.003 (±0.001) 0.994 (±0.001) 0.003 (±0.001)
FIGURE 14. Factorial Correspondence Analysis (FCA) of the genotypes of samples from four populations. Black squares:
individuals introduced in Saint Lucia (Iguana rhinolopha) [n=8] circles: individuals endemic to Saint Lucia (Iguana iguana
sanctaluciae), with white circles for individuals from Louvet (n=13) and hatched circles for individuals from Grand Anse (n=4);
white triangles: individuals endemic to Grenadines (Iguana iguana insularis), [n=4]; and grey stars: individuals from French
Guiana (Iguana iguana iguana) [n=7]. Only 7 circles are shown for the 17 ‘native’ individuals from Saint Lucia because many
individuals from Louvet and one from Grand Anse had the same genotypes.
TWO NEW SUBSPECIES OF IGUANA IGUANA Zootaxa 4608 (2) © 2019 Magnolia Press · 223
FIGURE 15. Results from the Evanno’s Method using the STRUCTURE HARVESTER software. This analysis reveals a
maximum likelihood for K=3.
FIGURE 16. STRUCTURE bar plot showing admixture coefficient of each individual to the three inferred genetic clusters.
This bar plot was produced using the distruct program (Rosenberg 2004).
Taxonomic and systematic implications. The presence of horns on the iguanas of Central America first prompted
the description of Iguana rhinolopha, by Wiegmann (1834), based on specimens caught in Mexico, and Duméril
& Duméril (1851) and Boulenger (1885) subsequently applied the same name to iguanas from Saint Lucia because
of their horns. No other morphological traits were used to distinguish I. rhinolopha apart from a small difference
224 · Zootaxa 4608 (2) © 2019 Magnolia Press
in number and size of spikes on the dorsal crest, identified by Duméril & Bibron (1837) based on a very small
number of specimens (Figs 9, 10). Later, with the widespread use of the subspecies concept, Dunn (1934) proposed
that rhinolopha was merely a subspecies of I. iguana, and Barbour (1935) also followed this position. This was the
consensus until the work of Lazell (1973), who considered that the presence of horns on the snout was inconsistent
and, because it occurs polytopically, he rejected the taxon rhinolopha. Lazell realised that the indigenous iguanas
on Saint Lucia possessed horns that were generally well developed on mature adult individuals, and this is also
confirmed by our observations. However, while horns can be found in Central American iguanas, they differ from
the arrangement of horns found in the Lesser Antilles as we have demonstrated in this work.
This paper describes two new subspecies of horned iguana known only from the southern Lesser Antilles. All
the indigenous iguanas from Saint Lucia, St Vincent & the Grenadines and Grenada, described herein possess me-
dian and lateral horns. Moreover they have a combination of morphological traits that makes them unique, includ-
ing: low number and small size of nuchal tubercles, small subtympanic plate, brown iris colour with the white of
the eye visible, no subtympanic swelling, colour hue and pattern of the body, etc. (Figs 4, 5, 7, 8). With about 2%
divergence in the ND4-Leu sequence, I. iguana insularis and I. iguana sanctaluciae show a level of differentiation
from I. iguana iguana from French Guiana that is within the interval of divergence of subspecies recognition among
Cyclura (Malone & Davis 2004). So, should we regard this Southern group as a full species with two subspecies,
or simply two horned differently coloured subspecies of Iguana iguana? In recent years, the subspecies concept has
become unpopular in herpetology, and almost every subspecies in the Caribbean has now been upgraded to a full
species (e.g. Breuil 2002) in accordance with the phylogenetic species concept that treats populations as separate
species if they are on separate evolutionary trajectories (see e.g. Torstrom et al. 2014), as is usually the case for
animals confined to separate islands. For example, the same basis was used by Hawlittsckek et al. (2012) for distin-
guishing species and subspecies of Comoran snakes.
As there are enough distinct and consistent morphological and genetic differences (Figs 12, 13, 14, 15) to
recognise the native southern Lesser Antillean iguanas as a full species we nevertheless chose to consider them
only as subspecies of Iguana iguana. We proceed as that to prevent too many changes in the taxonomy of the genus
Iguana but proceeding as that we loose the information that this two subspecies have a unique common ancestor.
Further research is also needed on the island of St Vincent to determine whether any purebred (i.e. non-hybrid) na-
tive iguanas remain here, and whether they belong to either of the aforementioned subspecies or a third, undescribed
When did this southern lineage diverge from other lineages in this genus? Studies of iguana morphology (Breuil
2013, 2016) and genetics (Stephen et al. 2013; Vuillaume et al. 2015) have shown there are at least three ancient
lineages (I. delicatissima and the iguanas of Central America and South American) in the genus Iguana, with a
genetic divergence approximated by a molecular clock of 1.29 million years for every 1% sequence divergence at
the ND4-Leu Locus (Malone et al. 2000). With approximately 10% divergence (Malone & Davis, 2004) between I.
iguana and I. delicatissima, the age of separation of these two species is therefore about 11–12 My; but according
to Hedges et al. (2015), the two lineages could have diverged as much as 22.8 My ago. If we take the lower value
of the molecular clock, I. iguana insularis and I. iguana sanctaluciae diverged about 2.2 My ago. This timeframe is
compatible with the ages of Saint Lucia and Grenada, where the oldest rocks date from the Miocene and belong to
the intermediate volcanic arc (Bouysse & Garrabé 1984; Germa 2008).
Evolution in isolation over millions of years does not automatically mean the taxa cannot interbreed. Even
the most distantly related species in the genus Iguana – I. delicatissima and I. iguana – can interbreed to produce
healthy, fertile offspring (Breuil 2013, 2016; Vuillaume et al. 2015). This is not very unusual among even more
distantly related taxa: For example, even crocodiles in the genus Crocodylus from opposite sides of the globe can
interbreed to produce fertile hybrids that have a competitive advantage (e.g. Daltry et al. 2016a). Judging from their
nesting periods (Fig. 17), there is some overlap between the breeding seasons of I. iguana sanctaluciae, I. delicatis-
sima and introduced I. iguana from South America, which might enable these species to interbreed.
Where does this leave the horned iguanas of Central America? Stephen et al. (2013) recognized two well sup-
ported genetic groups in Iguana iguana as evolutionary significant units: Central America (México to Panamá)
and South America (excluding Curaçao) and the Lesser Antilles) but declined to propose any taxonomic changes
pending further sampling across Panamá and South America and a better understanding of the basal position of the
populations of Curacao (Buckley et al. 2016). The divergence between Central and South American clades based
on ND4-Leu is about 4.3%, similar to the 4% divergence between Cyclura species (Malone & Davis 2004). We
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therefore accept I. rhinolopha (Wiegmann 1834) as a full species native to Central America, distinguished not only
by its unique arrangement of nasal horns but numerous other morphological and genetical characters, as shown by
Breuil (2013, 2016), Stephen et al. (2013) and Vuillaume et al. (2015). By sampling more areas across this region,
it is likely other new cryptic species or subspecies will be identified (Bickford et al., 2007; Buckley et al. 2016).
Indeed, the melanistic iguanas from Saba and Montserrat have been shown to be morphologically and genetically
distinct (Breuil 2013, 2016; Stephen et al. 2013; Vuillaume et al. 2015) and will be considered in another work.
Nevertheless, further studies elsewhere in this region are unlikely to change our conclusions regarding the original-
ity of Iguana iguana insularis and Iguana iguana sanctaluciae vs Iguana. rhinolopha and Iguana iguana iguana in
the Lesser Antilles.
FIGURE 17. Nesting periods of various iguana populations. Monthly mean precipitation is indicated in mm. Precipitation var-
ies according to altitude and aspect, but the important point is that after a 3 months incubation period, the eclosions occur at the
beginning or during the rainy season. The brackets indicate the main laying period for the different species at different insular
and continental locations. Note that the nesting period of Iguana iguana sanctaluciae overlaps the laying periods of both Iguana
delicatissima and Iguana iguana iguana, which suggests that mating periods could also overlap, potentially enabling all three
species to interbreed.
The most unexpected revelation from our genetic study is that two iguanas (IGU55, IGU56) from Grand
Anse, Northeast Saint Lucia, had delicatissima ND4 haplotypes, while a third (IGU53) had an unknown haplotype
that also clustered with delicatissima in addition to the microsatellites from both I. iguana iguana and I. rhinolopha
(Figs 12, 13, 16). The samples used to characterise the population of Grand Anse were juveniles caught 10 years
ago, when the morphological differences between the different clades of Iguana were less well understood, and
the animals were erroneously registered as pure native Saint Lucia iguanas (Table 1). As reported in our introduc-
tion, Provencher (1880) had mentioned the presence of I. delicatissima on Saint Lucia, but the only evidence was a
poorly executed drawing (reproduced in Fig. 1). Our discovery of Iguana delicatissima unique haplotypes in Saint
Lucia may be explained by either an ancient delicatissima population on Saint Lucia that persists only as a maternal
lineage or by the recent arrival of a female with this unknown haplotype from another island that has reproduced
226 · Zootaxa 4608 (2) © 2019 Magnolia Press
with Iguana iguana sanctaluciae. Currently, however, we have insufficient data to support one or other hypoth-
Conservation status of the new subspecies. These new subspecies of iguana are at risk throughout their ranges
in the southern Lesser Antilles due to habitat loss, hunting (both for bushmeat and the pet trade) and invasive alien
species, especially alien predators and non-native Iguana species.
Of the two new subspecies described in this paper, the Saint Lucia horned iguana (I. iguana sanctaluciae) ap-
pears to be most scarce and vulnerable to extinction. These iguanas are a fully protected species under the Wildlife
Protection Act (Laws of Saint Lucia 2010), but they continue to be hunted and eaten at a significant level (Morton &
Haynes, pers. obs.) and have been illegally exported and sold to collectors overseas (J. Daltry, pers. obs.). The range
of the native iguana population on Saint Lucia is now restricted to that part of the island without good road access
(Fig. 16), putatively because of over-hunting in the more accessible areas.
Habitat conversion for development (in particular the proposed tourism developments on the three large estates
of Louvet, Grand Anse and Marquis, and the proposed North East Corridor highway) is currently considered the
most severe threat facing the remaining population. Illegal mining of beach sand threatens the iguanas’ nesting sites
and their seasonal deciduous forest habitat is also especially vulnerable to wildfires (Robbins et al. 2008). Develop-
ments in the Northeast are also likely to exacerbate threats from introduced mammalian predators: Feral cats (Felis
catus), southern opossums (Didelphis marsupialis) and small Asian mongooses (Herpestes auropunctatus) are all
known to kill hatchling iguanas in Saint Lucia (Morton et al. 2007). Mongooses also take iguana eggs, and the
mutilation of hatchlings whilst still in the nest chamber has been attributed to rats (Rattus rattus or R. norvegicus)
(Morton pers. obs.). Both feral and domestic dogs (Canis familiaris) prey on iguanas, especially nesting females that
are especially vulnerable whilst on the ground (Morton et al. 2007).
Invasive alien iguanas also pose a serious threat, having become well established in Southwest Saint Lucia.
Despite numerous efforts to catch and cull the invasive iguanas (Morton & Krauss 2011; Krauss 2013; Krauss et
al. 2014), it is proving prohibitively expensive and difficult to limit their spread and prevent contact with the indig-
enous Iguana iguana sanctaluciae in Northeast Saint Lucia (Fig. 11), especially with the risk of human-mediated
transport across the country. The alien iguanas appear to originate from the Central America clade (Iguana rhino-
lopha), characterised by its greatly enlarged subtympanic plate, yellow iris, numerous and conspicuous tubercular
nape scales, orange colouration in breeding male, huge dewlap with more than ten spikes but also small horns on
the stout (Breuil 2013, 2016). The invasive iguanas on Saint Lucia (Fig. 9) also have larger clutches than the native
species: mean clutch size for the former is 40 (n = 4 clutches) and mean clutch size for I. iguana sanctaluciae is
only 23 eggs (n = 14 clutches). The same invasive iguanas from Central America have clutch sizes of 8–75 in Puerto
Rico (Lopez-Torres et al. 2012) and 20–63 in Hawaii (McKeon 1996). It is very likely that the alien iguanas could
hybridize as suggested by the genetic analysis (Fig. 16) with and outcompete Iguana iguana sanctaluciae, leading to
its elimination (as occurred with I. delicatissima in Les Saintes, Basse-Terre and Grande-Terre: Breuil 2002, 2013,
2016; Vuillaume et al. 2015).
The status and threats to the Grenada Bank subspecies is less well understood because iguanas have been less
closely studied and existing literature on iguanas has failed to distinguish between the native and invasive alien
iguanas. Given that iguanas in general are considered to be fairly abundant and widespread on Grenada and St Vin-
cent & the Grenadines, adult iguanas may still be lawfully hunted for several months of the year (typically October
through December or January) for personal consumption and local sale (Laws of Saint Vincent & the Grenadines
1990; Laws of Grenada 1990, Henderson & Powell 2018). Unlike Saint Lucia, the national laws here do not distin-
guish between native and introduced or hybrid iguanas, nor define any populations that may not be hunted or moved
within national borders. It is therefore not uncommon for hunters to collect iguanas from the Grenadine islands
for sale on St Vincent or Grenada during the hunting season (G. Gaymes, pers. obs.). Hunting is frequent on the
uninhabited island of Baliceaux, for example, where hunters from Bequia and Saint Vincent “carry away dozens of
iguanas” (Daudin & Da Silva 2011). In this context of numerous translocations, it is uncertain how many purebred
populations of Iguana iguana insularis remain.
Not surprisingly, considering the lack of any concerted effort to prevent incursions, alien iguanas appear to have
become very widespread in Grenada and St Vincent & the Grenadines, with perhaps no purebred (i.e. non-hybrid)
native iguanas remaining anywhere on the main islands of St Vincent or Grenada. We suspect that the most intact
native populations are restricted to some of the smallest islands in the Grenadines, including Palm Island and Union
Island, where genetic samples were analysed for this study. It is noteworthy that in this context that IGU74 collected
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as a shed skin has a ND4 haplotype that clusters with Iguana iguana from South America. Like the iguanas of Saint
Lucia, even these populations are at substantial risk from invasive alien predators (dogs, cats, opossums, etc.) and
coastal deforestation and development (Daltry et al. 2016b).
Under the national laws of all three countries – Saint Lucia, St Vincent & the Grenadines and Grenada the
export of iguanas or their products is prohibited without permits from their respective chief wildlife wardens. Fur-
thermore, on the basis that the iguanas were classified as Iguana iguana, listed on CITES Appendix II, exports have
required an export certificate from the CITES Management Authority. Nevertheless, recent years have seen a rise
in young iguanas being smuggled from these islands and sold under various trade names, including the Saint Lucia
iguana, pink rhino iguana (originating from Union Island) and white zebra rhino iguana (from the Tobago Cays).
Iguanas from Saint Lucia and the Grenadines have been offered for sale in the USA, Japan and Europe, for prices
of up to $10,000 per pair, with traders often claiming to have CITES permits, even though no such export permits
have been issued by these countries (Noseworthy 2017).
The Saint Lucia iguana (Iguana iguana sanctaluciae) is Critically Endangered under criteria B1ab(i–iii): Its
extent of occurrence is approximately 30 km2, it exists in only one location (Northeast Saint Lucia), and a continu-
ing decline is observed and projected in the (i) extent of occurrence, (ii) area of occupancy, and (iii) area, extent
and quality of habitat due to tourism developments, sand-mining, livestock grazing and other documented threats
(Daltry 2009).
The Grenadines horned iguana (Iguana iguana insularis) has been less closely studied but qualifies as Vul-
nerable and possibly Endangered under criteria B1ab(i–iii): Its area of occupancy is less than 20 km2, it exists at
not more than 10 locations (only two locations the 9 km2 Union Island and 0.55 km2 Palm Island have been
confirmed to have reasonably intact, non-hybrid populations) and estimates indicate continuing decline, observed,
inferred or projected, in the (i) extent of occurrence, (ii) area of occupancy and (iii) area, extent and quality of habitat
due to tourism developments, livestock grazing, bushfires and other threats (Daltry et al. 2016).
International trade in horned iguanas from the Grenadine islands (specifically, Union Island, Palm Island and the
Tobago Cays) and Saint Lucia has been confirmed in recent years at a level that could present a serious risk to both
subspecies. By formally describing the two subspecies, we recognise that the demand from reptile collectors could
increase (Auliya et al. 2016). We therefore recommend that as an urgent precaution the two new subspecies Iguana
iguana insularis and Iguana iguana sanctaluciae, should be placed on Appendix I of CITES at the next Confer-
ence of Parties to monitor and control illegal international trade. As an interim measure, we urge Saint Lucia, Saint
Vincent & the Grenadines and Grenada to jointly request the CITES Secretariat to place these two new subspecies
on Appendix III. This is necessary to help to ensure that iguanas cannot be sold overseas without a CITES export
permit from the country of origin.
Nationally, Iguana iguana sanctaluciae is fully protected in Saint Lucia, where the Wildlife Protection Act
distinguishes between the native Saint Lucia iguana and the (non-protected) invasive alien iguanas. We recommend
Grenada and St Vincent & the Grenadines also consider increased levels of protection for the native horned igua-
nas and ensure that any future exploitation of I. iguana insularis populations is monitored closely and sustainable.
Considering the outstanding importance of the apparently purebred and growing population of I. iguana insularis
on Palm Island (St Vincent & the Grenadines), technical assistance should be offered to the landowners to find solu-
tions to complaints that the iguanas are causing a nuisance.
Because invasive alien iguanas have already become well established in all three countries (Saint Lucia, St
Vincent and the Grenadines, and Grenada), it is also imperative to safeguard all remaining native iguana populations
from hybridisation and competition. Active biosecurity measures must be developed to prevent non-native iguanas
from successfully spreading to Northeast Saint Lucia, Palm Island, Union Island and any other areas known to have
purebred (non-hybrid) I. iguana insularis, including monitoring these native populations regularly to ensure any
incursions are detected and dealt with swiftly. Further surveys are required on St Vincent and Grenada to determine
whether any purebred native iguanas remain on these islands. If alien iguanas continue to increase unchecked on
Saint Lucia, it may be necessary to separate them from the native iguanas with a physical barrier. With this in mind,
plans are currently being developed to create a ‘mainland island’ sanctuary for native Saint Lucian wildlife, sur-
228 · Zootaxa 4608 (2) © 2019 Magnolia Press
rounded by a pest-proof fence (Saint Lucia Forests and Land Resources Department, 2015) that could potentially
conserve several hundred I. iguana sanctaluciae in strict isolation from alien iguanas.
To support all these recommendations, it will be necessary to develop illustrated identification materials for
researchers, enforcement officials and other stakeholders to reliably distinguish I. iguana insularis and I. iguana
sanctaluciae at all ages from I. iguana iguana, I. rhinolopha and other species.
Thus, we hope that the recognition of this two subspecies will ultimately facilitate their protection and conser-
This project was financed mainly by the Direction Régionale de l’Environnement et du Logement de Martinique to
study the origin of invasive Common green iguanas in Martinique and their relationships to the Saint Lucia iguana.
The genetic study formed part of Barbara Vuillaume’s Master’s degree. The genetic analyses were initially con-
ducted at Genindexe in La Rochelle (France) and completed by David Schikorski in Genindexe Labofarm (France),
which financed part of this study.
Specimens were collected from Palm Island and Union Island, in the Grenadines, by JD and GG with kind
permission from the Palm Island Resort and the St Vincent & the Grenadines Forestry Department. Fieldwork was
supported with funding from the FFI Species Fund, Disney Conservation Fund, National Geographic, US Fish &
Wildlife Service (#F18AP00796), and the St Vincent & the Grenadines Preservation Fund. We are most grateful
to Roseman Adams, Katrina Adams and other members of the Union Island Environmental Attackers for their as-
sistance. Special thanks also to F. Catzefis (CNRS, Montpellier) and Benoît de Thoisy (Institut Pasteur, Cayenne,
French Guiana), who provided samples from French Guiana and Mark Yokoyama for the picture of Iguana rhino-
lopha (Fig. 10).
All Saint Lucia samples were collected by the Durrell Wildlife Conservation Trust and the Saint Lucia Forestry
Department. Many members of the Forestry Department were closely involved in project work on the biology of
the iguana on Saint Lucia, including especially Alwin Dornelly, Timotheus Jean Baptiste, Brian James, Lyndon
John, Stephen Lesmond, Michael Bobb, Adams Toussaint, Michael Andrew, Feria Narcisse-Gaston, Rebecca Rock,
George Antoine, Mary James and Richard Regis. Martin Satney and Dunley Auguste provided much appreciated
support from the Ministry of Agriculture. Special thanks are due to Donald Anthony (Saint Lucia Forestry Depart-
ment), John Hartley and John Fa (Durrell Wildlife Conservation Trust) for developing the project work on Saint
Lucia, and most especially to Anthony ‘Seako’ Johnny for countless hours of assistance with field work and shar-
ing his extensive local knowledge. Many hours of field assistance in Saint Lucia were also contributed by Bradley
Abraham, Curtis Mathurin, Neil Oculi, Nazza Gustave, Fendley Estephane, Kissinger Henry and Greg Alexander
from Saint Lucia, along with the tireless voluntary efforts of most of the co-authors of Morton et al. (2007) plus Jane
Huston. Catherine Stephen, Bill Toone, Rich Young, Sarah Seymour, Roger Graveson, Melvin Smith, Chris Pilgrim
and most especially Karen Graham all provided much-valued support and insight. The farmers at Sankofa Rainbow
Roots Farm and Roots Farm Zimbabwe, along with the owners of Louvet Estate, the Laule family, kindly facilitated
access to their lands. This part of our work was funded by the Balcombe Trust.
Pictures and measurements of MCZ specimens were kindly provided by Joseph Martinez. We thank two anony-
mous reviewers for their remarks on an earlier version of this manuscript. We thank Catherine Stephen for discus-
sion concerning the status of these iguanas.
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... Currently, IUCN guidelines designate I. delicatissima as 'critically endangered', whereas I. iguana is of 'least concern' [12,13]. Recently, several insular I. iguana populations in the Caribbean Lesser Antilles were proposed for full species recognition: I. insularis, constituting native populations from St. Lucia, St. Vincent and the Grenadines and Grenada, as well as I. melanoderma, which includes native melanistic populations from Saba, Montserrat, and St. Croix and St. Thomas [14][15][16]. However, these populations are currently designated as subspecies, with only I. iguana insularis (St. ...
... Lucia) recognized by the Iguana Taxonomy Working Group, whereas I. melanoderma is still considered part of I. i. iguana (for details, see ITWG [17]). Although these remain currently unassessed under IUCN guidelines, the numerous threats faced by these island I. iguana populations is likely to result in them being designated as threatened [14,16,18]. ...
... Despite its 'least concern' assignment, regional assessments across I. iguana indicate that local populations can be threatened due to a range of factors. Whereas mainland populations are also locally endangered [19,20], the most at-risk are insular populations in the Lesser Antilles, given a range of prominent threats, e.g., hunting, invasive species, and the spread of non-native iguanas [12,14,15,21,22]. Overall, I. iguana are among the most traded reptiles globally [23,24], with native populations being harvested for trade, often without restrictions [20,25]. ...
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Lizards within the Iguana iguana species complex are among the most common reptilian pets, with the widest natural geographic range among iguanids. Deep phylogenetic divergence distinguishes multiple mitochondrial clades, and several taxonomic changes have recently been proposed. These small populations, typically island endemics, are threatened by numerous factors, including the international pet trade. Recent investigations reveal the absence of required CITES permits for lawful export of animals, providing evidence of ongoing illegal trade. Additional monitoring of trade in iguanas can be achieved through the application of forensic molecular techniques. In this study, two captive melanistic iguanas were genotyped for molecular markers for which geographic distributions of alleles have been established. Mitochondrial sequencing indicates that both animals carry a haplotype known to originate from the islands of Saba and Montserrat, populations taxonomically proposed to be Iguana melanoderma. Genotypes at 15 microsatellite loci are equally consistent with this origin, given the results of a principal component analysis. This first forensic genetic assessment within the extensive I. iguana pet trade highlights the presence of illegal activity. The need for additional forensic assessments of pet‐trade iguanas is evident, especially given that their value is driven by variety and rarity, which is further intensified by recent taxonomic changes.
... However, Buckley et al. (2016) acknowledged that found significant morphological differences between the Saba, St. Lucia, and South American populations. Taxonomic interpretation across the global range may be much more complicated than the conclusions drawn from our Lesser Antilles samples (Breuil et al. 2019 as suggested by recent research on the ABC Islands and Colombia (van den Burg and Malone 2018). In addition, numerous iguana translocations have occurred in the Lesser Antilles since the Caribbean period (Bochaton et al. 2015;Vuillaume et al. 2015;De Jésus Villanueva et al. 2021) and have altered the original endemic populations. ...
... The iguanas used by Breuil et al. (2019Breuil et al. ( , 2020 to differentiate Lesser Antillean taxa from continental iguanas originate from northern South America (French Guiana), representing only 1% of the global range. Furthermore, van den Burg et al. (2021) showed that these French Guiana iguanas do belong to the same genetic group as those from Surinam, Trinidad, Venezuela (Bolivar Rio Caroni) and Brazil (Alter do Chao), a conclusion previously reached by Stephen et al. (2013) using three nuclear genes and one mitochondrial gene. ...
... Furthermore, van den Burg et al. (2021) showed that these French Guiana iguanas do belong to the same genetic group as those from Surinam, Trinidad, Venezuela (Bolivar Rio Caroni) and Brazil (Alter do Chao), a conclusion previously reached by Stephen et al. (2013) using three nuclear genes and one mitochondrial gene. We therefore considered that these French Guiana iguanas correspond to the species Iguana iguana (Breuil , 2016Breuil et al. 2019Breuil et al. , 2020 described by Linnaeus (1758) based on the type locality assigned to this species by Hoogmoed (1973) "confluence of the Cottica River and Perica Creek, Surinam" and Duellman (2012) "vicinity of Paramaribo, Surinam". Thus, the common iguanas of northern South America do belong to the species Iguana iguana described by Linnaeus without prejudging the taxonomic status of populations in the rest of South America. ...
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The newly described horned iguana Iguana insularis from the southern Lesser Antilles is separated in two easily recognized subspecies: I. insularis sanctaluciae from St. Lucia and I. insularis insularis from the Grenadines. Its former description is completed by the use of 38 new samples for genetic and morphological analysis. Seventeen microsatellites were used to estimate genetic diversity, population structure and the level of introgression with other Iguana species over nearly the whole range of the species. ND4 and PAC sequences were also used to better characterize hybridization and to complete the description of this lineage. The I. insularis population of St. Vincent shows a high level of introgression from I. iguana whereas in the Grenadines, most islands present pure insularis populations but several show evidence of introgressions. Of the two remaining populations of I. insularis sanctaluciae, only one is still purebred. The recent identification of this and other distinct insular species and subspecies in the eastern Caribbean, and evaluation of where hybridization has occurred, are timely and important because the native iguanas are in urgent need of conservation action. Among the greatest threats is the ongoing human-mediated spread of invasive iguanas from Central and South America, which are destroying the endemic insular lineages through multiple diachronic introgression events.
... Taxonomically, this genus consists of two well defined lineages, I. delicatissima and the I. iguana complex. Within the latter, hypotheses of species boundaries are unresolved, though are currently under investigation, see Table 1 for nomenclature and geographic ranges (Stephen et al. 2013;Breuil et al. 2019. ...
... As is true for many Iguanids (IUCN 2020), insular lineages within Iguana are highly endangered. The main threat to these species is the continuous spread and recurrent incursion of non-native iguanas, both through natural events and, since at least the 19th Century (Breuil 2003(Breuil , 2013, anthropogenic assistance, which is expected to continue in the absence of stricter biosecurity measures (Falcón et al. 2012;Bock et al. 2018;van den Burg et al. 2018avan den Burg et al. , 2020avan den Burg et al. , 2020bvan den Burg et al. , 2021bBreuil et al. 2019Breuil et al. , 2020Knapp et al. 2020). These invasive, non-native iguanas have profoundly impacted native insular iguana populations throughout the Lesser Antilles, as the former have larger clutch and body sizes and show higher aggressiveness than native iguanas (van den Burg et al. 2018a; van Wagensveld and van den Burg 2018; Breuil et al. 2019). ...
... The main threat to these species is the continuous spread and recurrent incursion of non-native iguanas, both through natural events and, since at least the 19th Century (Breuil 2003(Breuil , 2013, anthropogenic assistance, which is expected to continue in the absence of stricter biosecurity measures (Falcón et al. 2012;Bock et al. 2018;van den Burg et al. 2018avan den Burg et al. , 2020avan den Burg et al. , 2020bvan den Burg et al. , 2021bBreuil et al. 2019Breuil et al. , 2020Knapp et al. 2020). These invasive, non-native iguanas have profoundly impacted native insular iguana populations throughout the Lesser Antilles, as the former have larger clutch and body sizes and show higher aggressiveness than native iguanas (van den Burg et al. 2018a; van Wagensveld and van den Burg 2018; Breuil et al. 2019). These incursions from different nonnative sources have resulted in region-wide hybridization, best documented for the Critically Endangered I. delicatissima (Vuillaume et al. 2015;van den Burg et al. 2018avan den Burg et al. , 2018bPounder et al. 2020), and to a lesser extent for the distinct lineages within the I. iguana complex (Breuil et al. 2019). ...
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Biodiversity and wild populations are globally threatened by a wide range of actors. The genus Iguana, widely distributed throughout the Americas, is under threat by invasive species, hybridization, the global pet trade, and habitat destruction. This holds especially true for the insular lineages, with the Critically Endangered I. delicatissima having experienced a > 75% range decrease, primarily through hybridization with non-native iguanas. We collated published microsatellite data and genotyped samples from new localities to construct a distribution-wide Iguana dataset built from 190 individuals for 17 microsatellite loci. This enabled us to identify patterns of genetic differentiation within and among populations, and identify key loci and private alleles for use in conservation management. Our analyses reveal clear separation between I. delicatissima and the I. iguana complex, highlighting the power of eight key microsatellite loci for the study of hybridization dynamics. Genetic differentiation within I. delicatissima identifies four clusters that aid decision making for conservation management action. Within the I. iguana complex, we increase mainland localities by 11-fold and recover 3.5 × more alleles across all loci than previously known. Overall, we identify 112 (48% private) and 76 (25% private) alleles for mainland and island lineages, respectively. We highlight loci sets to identify (1) non-native or hybrid iguanas in insular populations and their genetic origin, and (2) genetic origin of insular iguanas in the global pet trade. Overall, we provide a reference for Iguana microsatellite loci in order to allow standardization and comparison among studies, aiding broader assessment of research and conservation hypotheses.
... The Green Iguana Iguana rhinolopha (Wiegemann 1834) is a large lizard, exceeding two meters (males) in total length, although females are considerably smaller at 1.4 m in total length (Breuil et al. 2019;Leenders 2019). It possesses a conspicuous crest of comb-like spines down the neck, back, and tail, and a greatly enlarged smooth scale near the posterior margin of the head below the ear opening, on the side of the throat (Savage 2002;Leenders 2019). ...
... The distribution of the Green Iguana extends from northern Mexico to Panamá, from near sea level to 1000 m in elevation (Breuil et al. 2019;Leenders 2019). It occurs in the forest and along forest margins in lowland rainforests, as well as in riparian forests and vegetation in lowland dry forests (Savage 2002). ...
... In Iguana Laurenti 1768, current research aims to understand intraspecific variation within the Iguana iguana complex which holds four major mitochondrial clades (Stephen et al. 2013). Although no further genetic data have been published on the extent and boundaries of native populations between these four clades, studies focusing mostly on morphological characteristics have recently proposed two new species, Iguana melanoderma and Iguana insularis (Breuil et al. 2019(Breuil et al. , 2020. Breuil et al. (2020) (ITWG 2022), in which these populations are considered as part of Iguana iguana iguana while awaiting more data from the entire species complex to better assess its taxonomic position. ...
... Finally, a catremoval campaign that followedDebrot et al. (2014) was only temporary and local in focus, suggesting that feral cats still occur across the island, however recent data are lacking and should be the focus of a future research effort.Development.-Coastal development threatens iguana populations throughout the LesserAntilles (van denBurg et al. 2018b;Breuil et al. 2019). Not only are the warmer, dryer and lessvegetated coastal zones generally better habitats for the iguana in terms of sunning opportunities but on many islands the coastal zone has better soil accumulations for nesting. ...
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Intraspecific diversity is among the most important biological variables, although still poorly understood for most species. Iguana iguana is a Neotropical lizard known from Central and South America, including from numerous Caribbean islands. Despite the presence of native melanistic I. iguana populations in the Lesser Antilles, these have received surprisingly little research attention. Here we assessed population size, distribution, degree of melanism, and additional morphological and natural history characteristics for the melanistic iguanas of Saba, Caribbean Netherlands based on a one-month fieldwork visit. Using Distance sampling from a 38-transect dataset we estimate the population size at 8233 ±2205 iguanas. Iguanas mainly occurred on the southern and eastern sides of the island, between 180-390 m (max altitude 530 m), with highest densities both in residential and certain natural areas. Historically, iguanas were relatively more common at higher altitudes, probably due to more extensive forest clearing for agricultural reasons. No relationship was found between the degree of melanism and elevation, and few animals were completely melanistic. Furthermore, we found that body-ratio data collection through photographs is biased and requires physical measuring instead. Although the population size appears larger than previously surmised, the limited nesting sites and extremely low presence of juvenile and hatchling iguanas (2.4%), is similarly worrying as the situation for I. delicatissima on neighboring St. Eustatius. The island's feral cat and large goat population are suspected to impact nest site quality, nest success, and hatchling survival. These aspects require urgent future research to guide necessary conservation management.
... Recently, two additional taxa have been proposed from the Eastern Caribbean: The Southern Antilles horned iguana I. insularis (subspp. insularis from St Vincent and the Grenadines and Grenada, and sanctaluciae from Saint Lucia) and Saban black iguana I. melanoderma from Montserrat, Saba, and northern Venezuela [2,3]. Ongoing genetic and morphological research led by the first author indicates that the taxonomy of the Iguana iguana species complex is not yet fully resolved. ...
... All three Iguana species considered to be endemic to the Eastern Caribbean (I. delicatissima, I. insularis and I. melanoderma) are declining, have been illegally traded, and are threatened by the introduced non-native I. iguana [2,5,15,16]. ...
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Lizards in the Neotropical genus Iguana are heavily traded for the international pet trade, with unusual colour morphs and rare species commanding high prices. Recent research aimed to understand the taxonomy and phenotypic variation of Iguana in the Lesser Antilles, with those populations now severely threatened by this trade. Although the entire Iguana genus has been on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II since 1977, current levels of trade regulation are proving to be inadequate for the Caribbean Iguana populations, which are declining. This paper presents the case for immediately halting regional commercial trade to safeguard the most vulnerable island populations. We further provide recommendations for trade regulations of other species complexes where the nomenclature used in legislation and the trade industry fall temporarily out of step with new taxonomic changes.
... Not only do IAGI introductions pose a major danger to I. delicatissima on St. Eustatius and other islands of the Lesser Antilles, but also to other regional endemic iguana species and/or subspecies, three of which have only recently been described, namely Iguana melanoderma, from the nearby Caribbean Netherlands island of Saba, I. i. sanctaluciae from St. Lucia and I. i. insularis from St. Vincent and Grenada (Breuil et al. 2019. In order to give these last few large endemic island vertebrates a chance of survival, it will be essential to keep their island refuges free of the IAGI. ...
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The Invasive Alien Green Iguana (IAGI), Iguana iguana, has spread worldwide via the pet trade, as stowaways and via other means and has become a pest species of global concern. It also represents a major threat to the endemic Lesser Antillean Iguana, Iguana delicatissima, on St. Eustatius. Following the capture of an adult female IAGI on St. Eustatius in early 2016, we conducted a Rapid Response Removal Campaign (RC) from April 2016 to January 2017. Three sets of directed visual surveys totaling 409.5 observer hours and covering a combined trajectory of 114.2 km realized only a single detection of a hybrid that was later removed. During the remainder of the campaign period, an additional four IAGI hybrids were opportunistically detected and removed thanks to park staff or community involvement. Since the end of the campaign, eight additional detections and removals have been realized, three of which were IAGIs caught while offloading freight in the harbour and five of which were hybrids caught in surrounding suburban areas. We suggest that at least four distinct IAGI introductions to St. Eustatius occurred between 2013 and 2020. Our results show the value of motivating and mobilizing stakeholders and the public at an early stage of an invasion. Since the program’s initiation, eight of the 13 iguanas detected for culling were thanks to public and key stakeholder support and involvement. Four years after our campaign, the number of IAGIs and their hybrids still appear to be limited and concentrated in and around inhabited areas. Additional removal campaigns should be initiated as soon as possible, firmly based in public outreach, motivation and engagement. New legislation is needed to prohibit the importation, possession and harbouring of IAGIs or hybrids and to provide a framework for long-term structural funding required for effective control and removal. Routine fumigation and rigorous inspection of arriving cargo to eliminate the risk of stowaway IAGIs are also recommended. Culling of IAGIs is recommended for the port of St. Maarten, which serves as a major point of dispersal of IAGIs to St. Eustatius and likely also other islands in the region.
... We refer to the population of Iguana iguana in Oaxaca as I. rhinolopha based on Breuil et al. (2019), who recognized the populations in Mexico and Central America as a different taxon from I. iguana; which now is endemic to South America. McCranie et al. (2020) examined the genus Marisora in Mexico and Central America. ...
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A substantial number of changes to the composition of the herpetofauna of the Mexican state of Oaxaca, including taxonomic additions and deletions, have occurred in the five years since our original assessment of this region. These changes now establish a herpetofauna of 480 species for the state. A number of taxonomic and nomenclatural changes involving the Oaxacan herpetofauna also are discussed. Updated patterns of physiographic distribution, endemism, and conservation status of the members of the state herpetofauna are examined.
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Invasive alien species are among the main drivers of the ongoing sixth mass extinction wave, especially affecting island populations. Although the Caribbean is well-known for its high species richness and endemism, also for reptiles, equally important is the regional contribution of non-native species to island biodiversity. The Lesser Antilles encompass high genetic diversity in Iguana , though most native populations either have gone extinct or are declining following competitive hybridization with invasive non-native iguanas. Here we assessed non-native presence in two poorly-studied native melanistic Iguana iguana populations using available genetic tools, and explored utilizing size-dependent body measurements to discriminate between native and non-native iguanas. Genetic samples from Saba and Montserrat were genotyped across 17 microsatellite loci with STRUCTURE and multivariate analyses indicating non-native iguanas presence only on Saba. This was corroborated by mtDNA and nDNA sequences, highlighting a non-native origin in Central America and the ABC islands. We identified preliminary evidence suggestive of hybridization. Morphological variation among size-dependent characteristics showed that non-native iguanas have significantly larger subtympanic plates than native iguanas. Non-native individuals also differed in scalation and coloration patterns. Overall, our findings demonstrate the need for continuous monitoring for non-native iguanas within remaining native Iguana populations in the Lesser Antilles, with those not directly threatened by non-native iguanas restricted to only 8.7% of the historic range. Although genetic data allows for identification of non-native or hybrid iguana presence, this field-to-lab workflow is time consuming. Rapid in-situ identification of non-native individuals is crucial for conservation management, and besides scale and coloration patterns, we have highlighted the utility of size-dependent variables for rapid diagnosis. We urge regional partners to build morphometric databases for native Iguana populations that will help to quickly detect future incursions of non-native iguanas and allow the rapid implementation of effective countermeasures during the early phase of invasion.
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The morphological reexamination of specimens previously identified as Laonice bahusiensis Söderström, 1920 from North European and Mediterranean collections, supported by the molecular analysis of freshly collected material, enabled the recognition of four different species in the region: the genuine L. bahusiensis, L. irinae n. sp. from North European waters, and L. grimaldii n. sp. and L. mediterranea n. sp. from the Mediterranean Sea. The morphology of these species is described and illustrated, and their distributions are clarified based on old and new materials. A key for their identification is also provided. The Bayesian analysis of the COI sequences (483 bp) showed that these four species form a clade, namely the L. bahusiensis species complex, morphologically characterized by the continuous dorsal crests on postbranchiate chaetigers in the adults. The genetic p-distances between the species of the complex ranged from 13.27% to 17.99%, while the intraspecific variability ranged from 0.6% to 1.57%. Together with the sister species Laonice cirrata (Sars, 1851), the L. bahusiensis complex formed the Laonice (Laonice) clade, which is morphologically characterized by the prostomium fused with the anterior peristomial margin. However, the monophyly of the L. bahusiensis complex, as well as that of the clade Laonice (Laonice), needs to be further supported through the analysis of a greater set of genes from a larger number of species.
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Guadeloupe and nearby dependencies (la Désirade, Petite Terre, Marie-Galante, les Saintes, Marie-Galante) are situated in the middle of the Lesser Antilles Arc, whereas Saint-Martin and Saint-Barthélemy lie at the Northern end. Together with Anguilla and their satellites, these northern islands belong to the same bank, the Anguilla Bank. Thus they formed a unique piece of land 12000 years ago, before the ice melted. The same situation occurs on the Guadeloupian Bank where Basse-Terre, Grande-Terre, and nearby satellites (Kahouanne, Fajou, Goyaves ... ), la Désirade, and Petite Terre appear to belong to the same terrestrial unit. The different islands forming les Saintes are on another bank, but they form an isolated island before the last ice melting, as did Marie-Galante that stands alone. The herpetofauna of aIl these islands is richer than assumed by Schwartz and Henderson (1991) and following researchers. While prospecting, we found numerous herps yet undiscovered by other naturalists. With historical data drawn from earlier naturalists (L'Herminier, Plée ... ) in conjunction with the descriptions written by historical chroniclers, we propose a quite different vision of the Guadeloupian herpetofauna. Because of their small size and low altitude, and because they lie so far away from South America, Saint-Barthélemy and Saint-Martin are considered to have an impoverished fauna. This is partially true. Saint-Barthélemy has Chelonoidis carbonaria (introduced), Iguana delicatissima, Anolis gingivinus, Hemidactylus mabouia (introduced), Sphaerodactylus sputator, S. parvus, Thecadactylus rapicauda, Ameiva plei plei, Mabuya sloanii, Ramphotyphlops braminus (introduced), Typhlops annae, Alsophis rijgersmaei. Moreover, according to Plée's manusctipt, it is possible to asselt that an Eleutherodactylus species lived in Saint-Barthélemy in 1821. This presumably endemic species disappeared for unknown reasons and, at the beginning of 1980, E. martinicensis arrived on this island. In the Middle of the nineties, we found E. johnstonei in gardens and greenhouses, together with the Cuban Treefrog (Osteopilus septentrionalis), originating from Florida. This last species is invasive and poses a great threat to the whole ecosystem. In addition, Saint-Barthélemy is said to have Mabuya mabouya but it has not been found for decades, and possibly Anolis cf. pogus. In Saint-Martin, Eleutherodactylus johnstonei is everywhere, but it is possible that the same Eleutherodactylus species found in Saint-Barthélemy in the nineteenth century lived there as well. This endemic whistling frog may have been eliminated by the opportunistic E. johnstonei. E. martinicensisis known from collections dating from the eighties, and was later reintroduced with plants from Guadeloupe. Osteopilus septentrionalis is present in great numbers on the French side, and it is a predator of Eleutherodactylus. Chelonodis carbonaria is present on Tintamarre. There is a clear-cut ecological separation between S. sputator, which is xerophilic, and S. parvus that is mesophilic. Hemidactylus mabouia became rupicolous and lives under rocks, as does Anolis gingivinus in grasslands, whereas Thecadactylus rapicauda is truly arboricolous or edificarian. Anolis gingivinus that is found everywhel'e with the exception of grasslands lives in some places alongside with Anolis pogus. This last species was also present on Anguilla but it disappeared from there in the twentieth centul'y. The reason may have been the reduction of land surface with the ice cap melting and the competition with A. gingivinus. Iguana delicatissima is very rare and could be found in the highlands of Saint-Martin. Iguana iguana is also there as an escapee from pet shops. Ameiva plei analifera inhabits lowlands (mainly beach areas) and is very abundant despite the presence of mongooses. Same as on Saint-Barthélemy, it is Ameiva plei plei that is present on Tintamane, with a huge population. Alsophis rijgersmaei is still present on the Dutch side, but it was not found recently on the French side, and the same is true for Mabuya mabouya that seems to no longer exist. This snake inhabits Saint-Barthélemy but it is killed by people and by cars. The herpetofauna of SaintBarthélemy- Saint-Martin shows affinities with Greater Antilles (Sphaerodactylus parvus, Mabuya sloanii, Alsophis rijgersmaei). At the beginning of the volcanic activity in this region, about 6-4 M. years ago, there were only 3 islands: Proto-Guadeloupe (= the Northern part of Basse-Terre), Proto-Désirade and Proto-Saintes. Proto-Montserrat was there as weIl as ProtoDominica and Proto-Martinique. During the following period (between 1,6 and 0,6 M.y.) Tene-de-Bas, Grande-Terre (2 islands) and Marie-Galante emerged. Because, Les Saintes and Marie-Galante belong to "Guadeloupe", naturalists tend to consider them as natural parts of Guadeloupe, irrespective of their situation on two other independent banks. It is traditionaIly thought that these herps had not reached species level, although they would have been isolated for a very long time. Meanwhile, S. fantasticus, A. marmoratus and Alsophis antillensis have differentiated on these independent islands. With the fragmentation of the original island of Les Saintes when the sea level rose, they differentiated again for a second time. With S. fantasticus excepted, it is suggested here that Alsophis and Anolis from Les Saintes are two species (Alsophis sanctonum and Anolis terraealtae) with two subspecies each. Basse-Terre has two endemic Eleutherodactylus (E. barlagnei, E. pinchoni and perhaps two more) and E. martinicensis. E. johnstonei is also there and seems to have arrived recently. This whistling frog is an invasive species of great potential threat. Chelonoidis carbonaria and C. denticulata are present in Guadeloupe as pets, but also as feraI animaIs. Trachemys stejnegeri is abundant on Marie-Galante, but also on Terre-de-Haut and Terre-de-Bas des Saintes, and there are some individuais in ponds in Grande-Terre. Pelusios castaneus is abundant in Grande-Terre but is also found on Basse-Terre and one shell was found· on Grand-Ilet des Saintes. Anolis marmoratus is found as 4 endemic subspecies on Basse-Terre and 3 more on satellites (Kahouanne, Petite Terre, Désirade). The differentiation of the populations to the subspecies or species level on the satellites of the same bank is probably due to recent isolation by water. For example, Ameiva major -which was caught by Félix-Louis L' Herminier in 1825, on the islands of la Petite Terre (a nature reserve since 1998 for its huge Iguana delicatissima population) and therefore not on Martinique, as always stated, under the name "Lézard pilori" which was the French name of Ameiva erythrocephala from Saint-Christophe - is different from A. cineracea whereas they belonged to the same bank. The differentiation of the populations of Anolis marmoratus to subspecies level on Basse-Terre was traditionally correlated with climatic zonation. Here we suggest an allopatric subspeciation model for this species, with geological events as the main constraint. During the Pleistocene, Grande-Terre was in the state of two independent islands (Grands Fonds and plateau du Nord) where subspeciation occurred for Anolis marmoratus and Sphaerodactylus fantasticus. Monts Caraïbes and Morne Liquin (South of BasseTerre) where also two independent islands which began to be connected about 100000 years ago with Proto-Guadeloupe, when the Soufrière volcano began its formation. It is possible to find there the prints of subspeciation or speciation events as in Martinique in the same geological context with Montagne Pelée and Mont Conil. La Désirade seems to have expanded since the rniddle of the Pliocene, and Marie-Galante during the Pleistocene, before Grande-Terre. The uplift of the Guadeloupian bank appears to have been the consequence of the Soufrière's activity, which began about 100000 years ago, and with ice melting at the end of Würm, there was a decrease of lowland surfaces which led to the formation of small islands where isolation occurred for sorne thousands of years, which seems to have been sufficient for sorne species to give rise to at least subspecies (Anolis marmoratus) but not in other (S. macrolepis, S. sputator, A. gingivinus, Ameiva plei, Alsophis rijgersmaei) with the fragmentation of the Anguilla bank. Together with Dominica, Grande-Terre, BasseTerre and Marie-Galante are the only islands where a Liophis (coming from South-America) lives alongside an Alsophis (coming from Greater Antilles), but on the French islands these two snakes are on the verge of extinction and are probably extinct on Marie Galante. With climatic changes and cyclones, colonisation, invasive species and introduced predators, the Guadeloupian Archipelago lost a great part of its original biodiversity. Since the beginning of colonisation, the Guadeloupian bank lost Ameiva major, Ameiva cineracea, Ameiva spp. (la Désirade, Les Saintes), Leiocephalus cf. cuneus, Ceslestus or Diploglossus sp., Mabuya mabouya (7), Clelia sp. and perhaps Boa constrictor. Alsophis antillensis, Liophis juliae and Iguana delicatissima are nearly extinct on Basse-Terre and Grande-Terre. Iguana delicatissima is still abundant in Petite Terre and La Désirade. In Les Saintes, Basse-Terre and GrandeTerre I. delicatissima has been elirninated through competition and hybridization by Iguana iguana which was very rare (except in Les Saintes) in the Seventies-Eighties. This last species is found nearly everywhere in Basse-Terre and Grande-Terre.
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Green iguanas (Iguana iguana) are invasive throughout the West Indies and co-occur on several islands with native rock iguanas (Genus Cyclura). In August 2016, three hybrid hatchlings were captured on Little Cayman Island, providing the first evidence for a successful crossbreeding event between I. iguana and any Cyclura rock iguana species in the wild. Hybrid status was confirmed with morphological and genetic character analysis. This discovery prompts new concerns for biosecurity in the Caribbean.
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(Conclusions): The saltwater crocodile case study from Australia is this region’s best example of a well-managed industry that generates significant revenue from crocodile products in tandem with conserving wild populations. This is mirrored by equally impressive successes in the United States, where the American alligator has rebounded to 2–3 million individuals in the wild, while farms and ranches contain some 650,000 alligators and reap over USD 70 million annually (Elsey and Woodward 2010). These impressive cases are frequently cited as proof that exploitation is a powerful tool for both crocodile conservation and economic development. Importantly, such success is not restricted to wealthy countries: the case study from PNG— albeit underpinned with considerable international support— shows how organized hunting and ranching encouraged thousands of villagers to restore and protect crocodile habitats. On the other hand, legalizing exploitation through crocodile farming in Thailand, Vietnam, and Cambodia has coincided with the near-total extirpation of saltwater and Siamese crocodiles in these and neighboring countries. Illicit harvesting to supply farms is still among the greatest threats to the few crocodiles that remain (Simpson and Bezuijen 2010). This industry benefited hundreds of farmers, traders, and fishers, but why has it failed to conserve wild populations as well? At their worst, crocodile farms and other authorized forms of exploitation not only deplete wild stocks, but create an illusion that action is being taken, even as wild populations disappear. This is evident in Indochina and the Philippines where, for many years, well-intentioned efforts and funds were invested in farming on the assumption this would help crocodiles in some way, and hardly any attention was paid to safeguarding wild crocodiles or their habitats. Similarly, the head-starting program that initially rescued the gharial in India and Nepal has side-lined the pressing need to tackle sand mining, illegal fishing, and other detrimental activities affecting wild populations in the Chambal and Ghagra rivers (Hussain and Badola 2001; Hussain 2009). The “feel good” measures of collecting eggs and releasing hatchlings have been the government’s priority in India (Nair et al. 2012). Drawing upon our experiences from Asia Pacific and other published cases, table 21.2 highlights a number of conditions that enable exploitation (hunting, farming, or ranching) to realize positive or negative outcomes for wild crocodilians. The most important factors are the standards of governance and levels of corruption in the country: if law enforcement and compliance are weak, exploitation can be open to abuse (National Research Council 1983; Laurance 2004). The countries covered in this chapter vary enormously in this regard; for example, while Australia ranked 9th in the world (very clean), Cambodia ranked a poor 160th in 2013. Aside from the range country’s ability to manage exploitation sustainably, variation among species in terms of their production costs and market value affects the types of initiatives that are economically viable. In PNG, for example, ranching of New Guinea freshwater crocodiles waned because their hides were less profitable than those of the saltwater crocodile. Tighter profit margins translate into hunters, farmers, and ranchers being less willing or able to “give something back” to conservation. However, the commercial skin trade is not the only way to promote the conservation of wild crocodilians, or indeed one that can achieve positive results in isolation. The case study from Australia demonstrates the need for effective law enforcement to protect wild stocks and highlights the importance of public education to mitigate human-crocodile conflict— especially among people who are not landowners or consumers, and hence see no personal economic gain from these dangerous animals. While saltwater crocodiles continue to be harvested, it is noteworthy that Australian freshwater crocodiles have recovered without exploitation. Similarly in India, the recovery of mugger crocodiles was achieved mainly through captive breeding, law enforcement, and protected areas, without commercial exploitation. Meanwhile in the Philippines, local communities are being successfully encouraged to tolerate and protect crocodiles for their intrinsic or cultural values, rather than material benefits. While some countries have found crocodile management strategies that work for them, this region is undergoing rapid changes in terms of human population growth, economic development, and ever-mounting pressures on wild habitats. Even countries that have achieved commercial and conservation success must continually re-examine and adapt their management strategies to meet the changing threats and opportunities. India, PNG, and Australia, for example, report rising attacks on humans, which urgently need to be addressed if wild crocodiles are to continue to be tolerated by local residents and their leaders. Not all of the power lies in the hands of range countries. The skin trade is a volatile business, subject to the global economy and the whims of fashionistas, many of them outside of the Asia Pacific region (Thorbjarnarson 1999). Yet the latter could become a powerful force for good if they favored crocodile leather produced according to sustainable and “fair trade” principles. As CITES certificates do not tell buyers the whole story, perhaps it is time to establish standards for crocodile products that meet high standards of sustainability, similar to the Forest Stewardship Council scheme for timber. This could enable conscientious consumers to choose products from farms or ranches that are genuinely sustainable and support crocodile conservation. For certain species and countries, controlled commercial exploitation will undoubtedly remain an important part of the crocodile management toolkit in the future. Consumer demand for crocodile skins, meat, and other products is unlikely to fall, and nobody could wish to return to the dark days of widespread illegal hunting. As the diverse experiences in this chapter demonstrate, however, any legalized exploitation must be firmly rooted in good governance, effective habitat protection, capacity building, monitoring, education, and community outreach if Asia Pacific’s remarkable crocodilians are to survive.
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The article “Morphological characterization of the common iguana Iguana iguana (Linnaeus, 1758), of the Lesser Antillean iguana, Iguana delicatissima, Laurenti, 1768 and of their hybrids” by Michel Breuil was originally published in the Bulletin de la Société herpétologique de France, (2013) 147:309–346 in French. The document details the impact and significance of the invasive Iguana iguana on the populations of Iguana delicatissima in the Lesser Antilles. To support the dissemination of the document to a broader audience for the purpose of awareness, the International Reptile Conservation Foundation (IRCF), non-profit 501(c)(3), has translated the document into English. While best efforts have been made in the translation, no warranties or representations are made with respect to accuracy of the translation. The IRCF thanks Tri Luu for his assistance, time and efforts in translating the original document.
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Of the 10,272 currently recognized reptile species, fewer than 8% are regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the European Wildlife Trade Regulations (EWTR). However, The International Union for Conservation of Nature (IUCN) Red List has assessed 45% of the world’s reptile species and determined that at least 1390 species are threatened by “biological resource use.” Of these, 355 species are intentionally targeted by collectors, including 194 non-CITES-listed species. Herein we review impacts of the global reptile pet trade, and its contribution to the over-harvesting of species and populations, in light of current international law. Findings are based on examination of relevant professional observations, online sources and literature (e.g., applicable policies, taxonomy [reptile database], trade statistics [EUROSTAT], and conservation [IUCN Red List]). Case studies are presented from the following countries and regions: Australia, Central America, China, Galapagos Islands (Ecuador), Germany, Europe, India, Indonesia (Kalimantan), Islamic Republic of Iran, Japan, Madagascar, Mexico, the Netherlands, New Zealand, the Philippines, South Africa, Sri Lanka, Vietnam, Western Africa, and Western Asia. Between 2004 and 2014 (the period under study), the European Union (EU) member states officially reported the import of 20,788,747 live reptiles. Illegal trade activities involve species regulated under CITES, but concerns are also raised about the provenance of species that are not CITES-regulated but are nationally protected in their country of origin and are openly offered for sale in the EU. Analysis of trade data and examples suggest that law and enforcement in several countries may be inadequate to prevent the overexploitation of species and to halt illegal trade activities.
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Summary: 1. Describing spatial patterns of phenotypic traits can be important for evolutionary and ecological studies. However, traditional approaches, such as fieldwork, can be time-consuming and expensive. Information technologies, such as Internet search engines, could facilitate the collection of these data. Google Images is one such technology that might offer an opportunity to rapidly collect information on spatial patterns of phenotypic traits. 2. We investigated the use of Google Images in extracting data on geographical variation in phenotypic traits visible from photographs. We compared the distribution of visual traits obtained from Google Images with four previous studies: colour morphs of black bear (Ursus americanus); colouration and spottiness in barn owl (Tyto alba); colour morphs of black sparrowhawk (Accipiter melanoleucus) and the distribution of hooded (Corvus corone) and carrion crows (Corvus cornix) across their European hybrid zone. Additionally, we develop and present a web application (morphic), which facilitates the human data capture process of this method. 3. We found good agreement between fieldwork data and Google Images data across all studies. Indeed, there was strong agreement between the data obtained from the original study and from the Google Images method for the colour morphs of black bear (R2 = 80%) and for two barn owl plumage traits (R2 = 64% and 53%). Our approach also successfully matched the clinal variation of black sparrowhawks morphs across South Africa. Our method also gave a good agreement between the distribution of hooded and carrion crows (with 86% placed on the correct side of the hybrid zone line). 4. Our results suggest that this method can work well for visible traits of common and widespread species that are objective, binary, and easy to see irrespective of angle. The Google Images method is cost-effective and rapid and can be used with some confidence when investigating patterns of geographical variation, as well as a range of other applications. In many cases, it could therefore supplement or replace fieldwork.
We describe a model-based clustering method for using multilocus genotype data to infer population structure and assign individuals to populations. We assume a model in which there are K populations (where K may be unknown), each of which is characterized by a set of allele frequencies at each locus. Individuals in the sample are assigned (probabilistically) to populations, or jointly to two or more populations if their genotypes indicate that they are admixed. Our model does not assume a particular mutation process, and it can be applied to most of the commonly used genetic markers, provided that they are not closely linked. Applications of our method include demonstrating the presence of population structure, assigning individuals to populations, studying hybrid zones, and identifying migrants and admixed individuals. We show that the method can produce highly accurate assignments using modest numbers of loci—e.g., seven microsatellite loci in an example using genotype data from an endangered bird species. The software used for this article is available from