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Back from the dead: The world's rarest toad Adenomus kandianus rediscovered in Sri Lanka

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Adenomus kandianus Günther (1872) was previously known only from two specimens both deposited in the British Museum, the holotype BMNH1947.2.20.63, and the syntype of A. kelaarti BMNH1947.2.20.62. The only record of A. kandianus since the initial description in 1872 was by Ferguson in 1876, who mentions two specimens resembling Bufo kandianus in his collection, making A. kandianus the world's rarest toad. The species had not been reported since, and was considered extinct. Here we report on its rediscovery.
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Accepted by M. Vences: 9 May 2012; published: 15 Jun. 2012
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Copyright © 2012 · Magnolia Press
Zootaxa 3347: 6368 (2012)
www.mapress.com/zootaxa/Article
63
Back from the dead: The world’s rarest toad Adenomus kandianus rediscovered
in Sri Lanka
L. J. MENDIS WICKRAMASINGHE1, 2, DULAN RANGA VIDANAPATHIRANA1 &
NETHU WICKRAMASINGHE1
1Herpetological Foundation of Sri Lanka, 31/5, Alwis Town, Hendala, Wattala, Sri Lanka
2 Corresponding author. E-mail: boiga2000@gmail.com
Abstract
Adenomus kandianus Günther (1872) was previously known only from two specimens both deposited in the British Museum,
the holotype BMNH1947.2.20.63, and the syntype of A. kelaarti BMNH1947.2.20.62. The only record of A. kandianus since
the initial description in 1872 was by Ferguson in 1876, who mentions two specimens resembling Bufo kandianus in his
collection, making A. kandianus the world’s rarest toad. The species had not been reported since, and was considered extinct.
Here we report on its rediscovery.
Key words: Adenomus, extinct amphibian, rediscover, Peak Wilderness, Sri Lanka
Introduction
Adenomus kandianus is one of the 21 amphibian species known to be extinct from Sri Lanka after extensive
searches over a ten-year period failed to locate this species in the wild (Manamendra-Arachchi and Pethiyagoda,
1998, 2005; Manamendra-Arachchi and de Silva, 2004; Stuart, et al., 2008; Meegaskumbura, et al., 2007). A
global amphibian hotspot (Meegaskumbura, et al., 2002), the island of Sri Lanka consists of 111 species of
amphibians described so far, and it also carries the dubious distinction of contributing the highest proportion (60%)
to the global list of extinct amphibians (Manamendra-Arachchi and Pethiyagoda, 1998, 2005; Manamendra-
Arachchi and de Silva, 2004; Stuart, et al., 2008; Meegaskumbura, et al., 2007). These extinctions belong to the
following taxa: one to the family Bufonidae (Adenomous kandianus), one to the family Dicroglossidae
(Nannophrys guentheri), and nineteen species to the family Racophoridae (Pseudophylautus species) (Stuart, et al.,
2008).
The Sri Lankan endemic genus Adenomus is represented by the three species A. dasi, A. kandianus, and A.
kelaarti (Manamendra-Arachchi and Pethiyagoda, 1998) all of which are stream dwelling toads. Gunther first
described A. kandianus from a single specimen under the genus Bufo and provided a concise description with vital
diagnostic characters important in identifying the species. Later publications synonymized A. kandianus as A.
kelaartii Kirtisinghe, (1955), but according to the latest bufonid synopsis A. kandianus was once again considered
a valid yet extinct species. Furthermore, in all publications there after the species was listed as extinct
(Manamendra-Arachchi and Pethiyagoda, 1998; Manamendra-Arachchi and de Silva, 2004; Stuart, et al., 2008;
IUCN and MENR 2007).
The Peak Wilderness Sanctuary is one of the few remaining areas in Sri Lanka with a continuous natural forest
cover of altitudinal graded forest types, ranging from lowland mixed Dipterocarp forests to montane cloud forests,
having its own forest vegetation and is an area of great biological diversity (Singhakumara, 1995). It covers a large
altitudinal range and different climate conditions which is well reflected by its forest type and biodiversity. Forests
ranging from Tropical Lowland Forests (<1050 m) to Tropical Montane Forests (>1650) can be identified within
the area (Fernando and Ranasinghe, 1997). The Peak Wilderness Sanctuary, in particular, harbors the majority of
the endemic and threatened bird species of Sri Lanka (Ranawana and Bambaradeniya, 1998; Wickramasinghe, et
al., 2007). We here report on the rediscovery of A. kandianus during a survey of the Peak Wilderness Sanctuary in
the Central Province, Sri Lanka.
WICKRAMASINGHE ET AL.
64 · Zootaxa 3347 © 2012 Magnolia Press
Materials and methods
Study area: Peak Wilderness was designated a sanctuary on 25th October 1940 (Gazette Notification No. 8,675),
having an area of about 55,300 acres (22,379 ha). According to the current management plan, the geographical area
of the sanctuary is about 24,000 ha, of which 21,175 ha comprises natural or semi-natural vegetation, the rest is no
longer forest and includes tea estate and village settlements (de Alwis, et al., 2007). The sanctuary lies in the centre
of the western ridge of the Central Highlands, north-east of Ratnapura and straddling the border of Central and
Sabaragamuwa provinces. Its eastern boundary is contiguous with Horton Plains National Park. Peak Wilderness
occupies the escarpment that rises steeply from the lowlands to the south and west. Much of the terrain is very rug-
ged, with altitudes ranging from 50 m near Ratnapura to 2,238 m at Adam’s Peak (6° 48' 26.93" N, 80° 30' 03.06"
E), Sri Lanka’s fourth highest peak (de Alwis, et al., 2007).
A systematic survey was carried out in order to document the amphibian diversity across an elevation gradient,
in the Sripada massif, Peak Wilderness (part of the Central Hills World Heritage Site) of the Central province, of
Sri Lanka. Mainly focusing in terrains, where not much light has been shed to the diversity by scientists, because of
the difficulty to reach these sights due to harsh weather conditions and tough trails. The field survey was carried out
over a two year period. A single specimen each from all three congeners were collected, and are deposited in the
Department of Wildlife Conservation (DWC), Girithale National Wildlife Research and Training Center (Adeno-
mus kandianus DWC201201001, SVL 32.24 mm: A. dasi DWC201201002, SVL 28.85 mm: A. kelaarti
DWC201201003, SVL 32.17 mm).
The following morphological characteristics were used in distinguishing each species, and were critically com-
pared against the descriptions for each species: specimen size; shape, and orientation of nostril; shape of internarial
space; shape and orientation of canthus rostralis; shape of snout; loreal region; presence/absence of ridges on head;
size and shape of tympanum; shape and orientation of parotid gland; interorbital area; shape of upper eyelid and
distribution of tubercles; tubercles on head; skin on dorsum; distribution of warts, and granules on dorsum; charac-
ters on ventral aspect (throat, margin of throat, chest, belly, and limbs); tips of fingers, and toes; dermal fringes;
extent of webbing on limbs; presence/absence of tubercles; characteristics of skin on lower and upper parts of
flank.
Series of photographs were made on all members of the genus Adenomus. The extent of webbing on toes were
critically compared with corresponding sketches (Manamendra-Arachchi and Pethiyagoda, 1998) of the respective
holotype specimens except for A. kelaarti which is a lectotype specimen. The original line drawings were given in
black on white background, here we have inverted the colours to fit background. Geographical coordinates were
determined from GPS readings (Gamin eTrex Vista) at the locality where collected.
Results and discussion
Specimens resembling A. kandianus were recorded from the Peak Wilderness Sanctuary (06° 48' 34.16" N, 080°
30' 19.07" E, Altitude 1879 m) on the 23rd October 2009, as a result of a survey carried out in the region to
document the amphibian diversity. During a nocturnal sampling session, about four specimens of an unusual
species were observed, which were sympatric with A. dasi on rocks close to fast flowing streams where a single
specimen was collected in order to taxonomically clarify its identity.
A. kandianus was identified by smooth finger edges, slender habitus and lack of a supraorbital ridge
characteristic of the genus Adenomus (Manamendra-Arachchi and Pethiyagoda, 1998) fully webbed toes diagnostic
of A. kandianus (Günther, 1872) and in addition, a uniform golden yellow venter (absent in A. dasi and A. kelaarti).
Additionally according to its original description (Appendix 1) the following combination of characters; presence
of a cutaneous fold along the edge of tarsus, a long very narrow parotoid gland, hidden tympanum, and yellow
snout confirmed its identity.
A. kandianus can be confused with A. dasi, because of similar body size, morphological characters and geo-
graphical distributions. But the former can be easily distinguished by the presence of complete webbing on toes
(versus half webbed toes), comparatively large warts on dorsum (versus small warts). Apart from the characters
previously mentioned A. kandianus, can be easily distinguished from A. kelaarti by the absence of a cranial ridge
Zootaxa 3347 © 2012 Magnolia Press · 65
REDISCOVERY OF THE RAREST EXTINCT TOAD FROM SRI LANKA
FIGURE 1. Photographic analysis amongst all congeners, and a comparison of the ventral view of foot with the corresponding
type material sketch (Manamendra-Arachchi and Pethiyagoda, 1998). (A) Adenomus kandianus in life. A. kandianus, (B)
holotype BMNH1947.2.20.63, (C) complete webbing of voucher specimen DWC201201001, (D) dorsum with prominent
warts, (E) golden yellow venter, image has been mirrored. A. dasi (F) holotype WHT2267 (G-I) voucher specimen
DWC201201002. A. kelaarti (J) lectotype BMNH1947.2.20.60, (K-M) voucher specimen DWC201201003. Scale bars: 5 mm.
WICKRAMASINGHE ET AL.
66 · Zootaxa 3347 © 2012 Magnolia Press
(present in A. kelaarti), presence of cutaneous fold along the edge of tarsus (versus undulating less prominent
cutaneous fold), long and very narrow parotoid gland (versus short and narrow), hidden tympanum (versus
prominent), comparatively large dorsal warts (versus smaller warts), and chest and belly rough granular (versus
smooth granular) (Fig. 1).
Its characteristic full webbing can only be observed on close examination when the toes are stretched out, and
is not visible when live specimens are hand held. Although Manamendra-Arachchi and Pethiyagoda mentions the
distribution of warts in an hour glass shape as a diagnostic character for A. dasi, this character was not observed on
all specimens of A. dasi, hence we feel that this character should not be used in identifying the species.
Natural History: The species was recorded on rocks of river banks close to fast flowing streams at a very high
altitude above 1800 m asl. All specimens were observed within an area of 200 m2, during nocturnal sampling
sessions from around 1900 h. The canopy cover was that of a montane cloud forest.
Colour in life: Dorsum uniform dark brown, between eyes slightly yellowish tinge, this area sharply defined
by an interorbital dark brown cross bar as stated in original description, light brown band from sacrum to vent mid-
dorsally; laterally dark brown; limbs dorsally light brown, fore limbs, hind limbs, fingers and toes with broad dark
brown cross bands; ventral surface in males uniform golden yellow, and in females dark brown blotching all over
on golden yellow background.
The type locality of A. kandianus is gives as “Ceylon” Günther, (1872) (former Sri Lanka), a vague description
where an area was not specified. The species was originally found in a collection of reptiles and amphibian owned
by Mr. G. H. K. Thwaites, while he was the director of the Royal Botanical Gardens of Peradeniya. Considering the
species epithet and the collector, Manamendra-Arachchi and Pethiyagoda (1998) suggested that the specimen may
have been collected from Kandy. However, the entire central province was referred to as Kandy in the late 19th
Century whereas today it denotes Kandy City and District. Thwaites’ collection includes other specimens not found
in the environs of Kandy. For instance Ixalus femoralis (Pseudophilautus femoralis), I. temporalis (P. temporalis),
and I. schmardanus (P. schmarda) are species found only from the Central Hills at high altitudes above 2000 m asl.
Similar altitudes from the Kandy area are not available, and this collection may well have been collected from all
parts of the country as some other species are only restricted to the dry zone. Therefore, the original specimen of A.
kandianus may have been collected from a high altitude location in the central hills rather than the environs of
Kandy City or District
The species was recorded close to fast flowing streams, at relatively high altitudes, suggesting their preference
to an aquatic life. Also the presence of complete webbing on the toes, most probably facilitates their ease of
swimming in fast flowing streams unlike the other species of the same genus. After the initial sampling session,
close to 100 individuals were recorded in an area of 200 m2.
The Peak Wilderness although is a part of the recently declared Central Hills World Heritage Sites, is polluted
every year from a large number of pilgrims because of its religious importance, especially the streams, and is now
under severe anthropogenic pressures. The highest point of this mountain range, the Adam’s Peak, is a place of
worship by all religions in the country and a place of aesthetic beauty, hence millions visit this site every year
during the pilgrimage season which lasts for a period of 6 months. This is a time when a large amount of garbage
collects, and the natural forest gets over exploited. Illegal gem mining on either side of all major river banks within
the forest have become another potential threat to the amphibian diversity. Tea cultivations in the surrounding areas
are slowly expanding. Illegal tree felling to convert to tea cultivation, has become a major threat in the area. The
survival of this small population of aquatic species re-discovered from a single locality depends on the water
quality, and their breeding habitats. Because they are hyper endemic they are highly vulnerable to environmental
changes such as forest die-back which has spread during the past decade possibly due to pollution and or/ climate
change which has resulted in a decrease of natural forest cover.
Given the high degree of microendemism and species diversity in Sri Lanka, it cannot be fully excluded that
the toad population on which we here report might represent a new, undescribed species rather than Adenomus
kandianus. However, because no molecular data are available on the types of A. kandianus, its type locality is
doubtful as we argue herein, and the encountered specimens agree most closely with the A. kandianus types in
morphology, it is the taxonomically most parsimonious solution to actually consider these toads as A. kandianus
and this species thus rediscovered. Of the six known extinct bufonids of the world (Stuart, et al., 2008), A.
kandianus seems to be the only toad where a live specimen has never been documented since the initial type
description in 1872, for nearly 137 years. Except for Ferguson in 1876, where he mentioned two specimens
Zootaxa 3347 © 2012 Magnolia Press · 67
REDISCOVERY OF THE RAREST EXTINCT TOAD FROM SRI LANKA
resembling Bufo kandianus in his collection, where nothing else has been known, about this species until now, thus
making A. kandianus the world’s rarest toad.
Acknowledgments
The authors wish to acknowledge the Biodiversity Secretariat of the Ministry of Environment for funding and
collaborating the project, to Mr. Gamini Gamage (former Director, Bio diversity), Mr. K. A. I. de Silva (Director
Biodiversity), Mr. R. H. S. S. Samarathunga (Secretary-Ministry of Environment), Mr. N. K. G. K. Nannawaththa
(Additional Secretary-Natural Resources), Mr. R. A. R. Roopasinghe (Additional Secretary administration), Mrs
Dakshini Perera, and Mrs. Hasula Wickramasinghe for all their support rendered. The Department of Wildlife
Conservation for permission granted to carry out the survey (Permit no. WL/3/3/354), the Director of Operations
Mr. H. D. Rathnayake, and the Deputy Director Mr. S. R. B. Dissanayake (Research and Training) for all their
support. Staff of the Nallathanniya and Palabaddala Wildlife range offices, and also for partial funding received
from the Nagao Environment Fund. Heartfelt thanks goes to Dr. Channa Bambaradeniya, Dr. Prithiviraj Fernando,
Mr. Jerome Kiel for their valuable comments, and moral support. Mr. Lalith Senanayake for editing of images. Mr.
Jagath Krishantha, Mr. Ruwan Chinthaka and the late Dr. Amith Munindradasa are fondly remembered for their
support and encouragements. We also like to thank Mr. Sameera Suranjan, Mr. Gayan Chathuranga, Dr. M. D.
Gehan Rajeev, Mr. S. Chathuranga Ariyarathne, Mr. A. W. Amila Chanaka, Mr. L. L. Dharshana Priyantha, for
their support in the field work and our colleagues at the Herpetological Foundation of Sri Lanka for various
courtesies.
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C.J. (2002) Sri Lanka: an amphibian hotspot. Science, 298, 379.
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Appendix 1
Günther, A. (1872) Descriptions of some Ceylonese reptiles and batrachians. Annals and Magazine of Natural History, Series
4, (9), 87.
Bufo kandianus.
Crown flat, without bony enlargement. Snout rather obtuse, with angular canthus rostralis. Limbs and fingers of moderate
length; the fourth finger longer than the second. Toes rather short, completely webbed. Metatarsus with two small flat cal-
losities: a cutaneous fold along the edge of tarsus. Skin with small tubercles in small number. Parotoid long and very nar-
row. Tympanum entirely hidden by the skin. Inner nares narrow; Eustachian tubes very narrow. Upper parts uniform
brownish grey, except the snout, which is yellowish, the yellowish part being sharply defined by an interorbital line. Lower
parts yellowish.
One specimen, apparently immature, is 30 millims. long; hind limb 40 millims.
... Sri Lanka has 120 amphibian species (Appendix 1; Table 3), of which 107 (~90.0%) are endemics and more than 80% are restricted to rain forests (Manamendra-Arachchi and Pethiyagoda, 2006;Fernando et al., 2007;Meegaskumbura et al., 2009;Meegaskumbura and Manamendra-Arachchi, 2011;Wickramasinghe et al., 2012a, b;Wickramasinghe et al., 2013a;Batuwita et al., 2019b). Eighteen endemic species of amphibians are currently confirmed as extinct (Manamendra-Arachchi and Meegaskumbura et al., 2007;Wickramasinghe et al., 2012b;2013b, c), which includes a single species from a relic genus, Nannophrys Günther, 1869 and 17 species from Pseudophilautus. Thus, once the extinct species are excluded, the total number of amphibian species are 102 (including 89 endemics). ...
... Subsequently, Van Bocxlaer et al. (2009) showed that Bufo atukoralei, B. kotagamai and B. scaber are in fact members of Duttaphrynus. Apart from the above mentioned species, two other species from the family Bufonidae exist and they belong to an endemic genus Adenomus, sc., A. kelaartii and A. kandianus (Wickramasinghe et al., 2012b;Meegaskumbura et al., 2015). Until Wickramasinghe et al. (2012b) rediscovered the latter species, it was considered as an extinct species (Manamendra-Arachchi and . ...
... Apart from the above mentioned species, two other species from the family Bufonidae exist and they belong to an endemic genus Adenomus, sc., A. kelaartii and A. kandianus (Wickramasinghe et al., 2012b;Meegaskumbura et al., 2015). Until Wickramasinghe et al. (2012b) rediscovered the latter species, it was considered as an extinct species (Manamendra-Arachchi and . Moreover, Meegaskumbura et al. (2015) showed that previously described Adenomus dasi Manamendra-Arachchi and Pethiyagoda, 1998 is a new junior synonym of A. kandianus. ...
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... Most importantly, the discovery of this critically endangered restricted range species of frog outside its previously known range highlights the importance of taxon specific biodiversity surveys of vertebrate groups in Sri Lanka. Hence, future surveys may even shed light on species that are considered to be extinct such as N. guentheri similar to the other studies that have rediscovered other species of amphibians that were thought to be extinct Wickramasinghe et al., 2012;Wickramasinghe et al., 2013aWickramasinghe et al., , 2013b. ...
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... Meanwhile falling into the same error as Manamendra-Arachchi and Pethiyagoda (1998), Wickramasinghe et al. (2012) had announced the rediscovery of A. kandianus from the same locality as 'A. dasi' and heralded it as " world's rarest toad " on the brink of extinction. ...
... Based on field records from this study and published literature (Gabadage et al. 2014; Karunarathna et al. 2012; Wickramasinghe et al. 2012), seven presence locations from two regions (Table S1) were used to produce the predicted distribution map of Adenomus kandianus using MaxEnt version 3.3.3k (Phillips et al. 2004). ...
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Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, following several years of surveying, a few A. kandianus were found in 2012 and referred to as "the world's rarest toad." However, tadpoles of A. kandianus bearing unique ventral suckers were soon discovered, but the rarity of the adult and the profusion of tadpoles were never explained. Here, using ecological methods, niche modeling and DNA-barcoding, we aim to understand the ecology, natural history and distribution of this rare toad. Following a two-year study of occurrence, habits and habitat associations of adults and larvae, we show this to be a secretive species with a patchy distribution. During non-mating periods female toads (N = 23) were found in primary forests habitat up to 650 m away from the breeding streams, and predominantly males in the riparian zone (12 males, 2 females). Following heavy rain they form large (N = 388) but patchy mating congregations in torrential streams (six sites; range 0−95 mating pairs; mean = 25, SD = 38.16, CV = 152%). Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but ability to dive, vocalize underwater, and characteristics of the eggs, suggests that they lay eggs in dark recesses of the stream. Quadrat sampling of tadpoles show microhabitat partitioning (in depth, flow-rate and substrate conditions) within the stream: the greatest diversity of larval developmental stages (25-42) in slow-flowing (depth, 0.75−1.5 m) rocky areas; more robust stages (31−39) bearing sucker discs utilize rocky-rapids (depth, 0.25−0.75 m); metamorphic stages (43-45) use stream margins (depth, <0.25 m); slow flowing silt covered areas of the stream were unoccupied, irrespective of the depth. DNA barcoding of the 16S rRNA gene fragment from the two known localities confirms the identity of the Pedro population also as A. kandianus. The uncorrected pairwise genetic distance of 0.1−0.7% suggests historical gene flow between the two populations. Distribution modeling (using MaxEnt), with forest-cover layers added, predicts a very small remaining area of suitable habitats (an area of occupancy of 16 km2 and an extent of occurrence of 128 km2) isolated by habitats that are not conducive to these toads. While the healthy population recorded at one site gives hope for the survival of the species, long-term conservation of this climatically and ecologically restricted species hinges largely on the preservation of cloud and riparian forests and the unpolluted high-flow torrents.
... Notably, several of these extinct frogs have been rediscovered in recent years. For example, the first frog to be rediscovered was Raorchestes travancoricus in India (Last seen (Ls): 1891 -Rediscovery (R): 2004) (Biju and Bossuyt, 2009 (Wickramasinghe et al., 2012(Wickramasinghe et al., , 2013a(Wickramasinghe et al., , 2013b. ...
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We report the rediscovery of a declared extinct frog, Craugastor escoces, at the edge of a protected forest in the Juan Castro Blanco National Park, Alajuela, Costa Rica. This species, which is endemic to Costa Rica, had not been observed since 1986. The rediscovery of this species comes after 30 years without being seen and 12 years of being declared extinct. The site where we found the species is located in the west of the central mountain region of Costa Rica, which is >15 km away from its known distribution. Our finding adds another species to the list of the few rediscovered frogs declared extinct. Knowing that C. escoces can still be found triggers the need for conservation strategies to help the species survive.
... Habitat loss, water pollution, and loss of vegetation are the most significant factors for restricted distribution of highland amphibians. Two of the very rare amphibian species were recently rediscovered from the Peak Wilderness, in Central Hills of Sri Lanka (Wickramasinghe et al. 2012(Wickramasinghe et al. , 2013. Nannophrys marmorata, an endemic and critically endangered amphibian species, is restricted to the rock strewn streams of the Knuckles Forest Reserve (200-1200 m amsl). ...
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Wetland ecosystems are among the most productive ecosystems that support many kinds of life. They are valuable in terms of hydrology, plant and animal survival, and biodiversity. National Wetland Directory of Sri Lanka describes 62 important wetlands, with their status. The central highland complex of Sri Lanka is a unique ecosystem and the most important catchment area of major rivers. Therefore, it is identified as a super biodiversity hotspot and a world heritage site. The major wetland types in the central highland ecosystem are freshwater marshes, streams, waterfalls, human-made lakes, reservoirs, and springs. In Sri Lanka, most of the threatened species, which are associated with aquatic habitats, are found in the central highlands with very restricted distribution. Habitat deterioration and degradation, encroachments, clearing of vegetation, water pollution, and spread of invasive alien species are the most significant threats to the highland wetlands. Therefore, demarcation of wetlands, protection of buffer zones, increased public awareness, and implementation of good agricultural practices would certainly bring beneficial changes to the ecosystems.
... Of the 35 globally extinct amphibians prior to 2012, 21 alone were declared from Sri Lanka (Stuart et al. 2008). But after the rediscovery of three species (Wickramasinghe et al. 2012b(Wickramasinghe et al. , 2013b, now the total number of extinct amphibians stands at 18. Out of the predicted 18 extinct species, 17 belong to the genus Pseudophilautus (see Manamendra-Arachchi & Pethiyagoda 1998, 2005Manamendra-Arachchi & de Silva 2004;IUCN & MENR 2007;Meegaskumbura et al. 2007;Stuart et al. 2008). ...
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A new species of shrub frog Pseudophilautus dilmah is described from the Central Hills of Sri Lanka. This unique species is distinguished from all the other congeners from a combination of characters; snout rounded in lateral aspect, bluntly pointed in dorsal and ventral aspect, canthus rostralis rounded, vomerine teeth, lingual papilla and nuptial pads absent, dermal fringe distinct on inside of fingers III and IV, small blunt tubercles on metacarpal and ulnar folds, toes basally webbed, interorbital area smooth, upper eyelid prominent tubercles present, anterior and posterior dorsum without horny spinules but tubercles present, upper part of flank weakly granular, supratympanic fold distinct, prominent small calcar present at the distal end of the tibia, throat granular, chest and belly coarsely granular. Based on comparison of 16s rRNA gene we also show that the species is genetically distinct from other members of Pseudophilautus for which gene sequences are available. The high rate of deforestation and anthropogenic activities threaten this population in its natural habitat.
... Die Konsequenz daraus ist, dass beinahe 65 % aller Amphibien als vom Aussterben bedroht angesehen werden müssen, und 19 Arten scheint dieses Schicksal bereits ereilt zu haben (Manamendra-Arachchi & Meegaskumbura 2012). Andererseits haben jüngste Untersuchungen dann doch wieder drei dieser Arten zutage gebracht (Wickramasinghe et al. 2012, Wickramasinghe et al. 2013a). Angesichts der derzeitigen Entwicklungen ist der Verlust an Lebensräumen die Hauptbedrohung für Amphibien. ...
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The southern and southeastern parts of Asia host high amphibian biodiversity and comprise four biodiversity hotspots. 285 amphibian species are endemic to South Asia, 342 are distributed in India and 119 in Sri Lanka. Here we document the distribution, threats, and conservation status of amphibians in the major countries of southern and southeastern Asia (India, Bangladesh, Sri Lanka, Pakistan, and China) and list smaller countries with species numbers. Conservation is an umbrella concept that is fundamental yet paradoxical. Training programmes, workshops for students, bio-banking, and the publication of field guides in local languages are urgently needed to conserve amphibian biodiversity in this part of the world.
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Aim The diversity of brood size across animal species exceeds the diversity of most other life‐history traits. In some environments, reproductive success increases with brood size, whereas in others it increases with smaller broods. The dominant hypothesis explaining such diversity predicts that selection on brood size varies along climatic gradients, creating latitudinal fecundity patterns. Another hypothesis predicts that diversity in fecundity arises among species adapted to different microhabitats within assemblages. A more recent hypothesis concerned with the consequences of these evolutionary processes in the era of anthropogenic environmental change predicts that low‐fecundity species might fail to recover from demographic collapses caused by rapid environmental alterations, making them more susceptible to extinctions. These hypotheses have been addressed predominantly in endotherms and only rarely in other taxa. Here, we address all three hypotheses in amphibians globally. Location Global. Time period Present. Major taxa studied Class Amphibia. Methods Using a dataset spanning 2,045 species from all three amphibian orders, we adopt multiple phylogenetic approaches to investigate the association between brood size and climatic, ecological and phenotypic predictors, and according to species conservation status. Results Brood size increases with latitude. This tendency is much stronger in frogs, where temperature seasonality is the dominant driver, whereas salamander fecundity increases towards regions with more constant rainfall. These relationships vary across continents but confirm seasonality as the key driver of fecundity. Ecologically, nesting sites predict brood size in frogs, but not in salamanders. Finally, we show that extinction risk increases consistently with decreasing fecundity across amphibians, whereas body size is a “by‐product” correlate of extinction, given its relationship with fecundity. Main conclusions Climatic seasonality and microhabitats are primary drivers of fecundity evolution. Our finding that low fecundity increases extinction risk reinforces the need to refocus extinction hypotheses based on a suggested role for body size.
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The tropical island nation of Sri Lanka is a biodiversity hotspot with a high diversity and endemism of amphibians. The endemic, stream-dwelling Kandian torrent toad Adenomus kandianus is Critically Endangered and was considered to be extinct until its rediscovery in 2012. The species is now known from two localities in tropical montane forests. We conducted a 4-year study using transect surveys and opportunistic excursions to assess habitat associations, demographics and abundance of A. kandianus in and around Pidurutalagala Conservation Forest. We recorded a mean of 44.25 post-metamorphs per year, with a density of < 1 individual per 100 m ² , with occurrence within a narrow extent (c. 0.005 km ² ) of the stream channel. Behaviour and microhabitat selection varied depending on sex and stage of maturity. The species preferred moderately sized montane streams with rocky substrates and woody debris, colder temperatures, and closed-canopy, intact riparian forests. We noted size-based reversed sexual dimorphism and a strong ontogenetic relationship between snout–vent length and body weight. Anthropogenic activities such as intensive crop farming deterred the species; proximity to croplands had a negative influence on abundance. We recommend re-delineation of the boundary of Pidurutalagala Conservation Forest to incorporate the toad's habitat into the core of the reserve and thus limit the impacts of human activities. Conservation and management actions such as ex-situ breeding, population monitoring, and restoration of degraded habitats could also contribute towards the persistence of this toad. Our findings provide useful insights into ecological research on and conservation of range-restricted aquatic amphibians.
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Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, a few A. kandianus were rediscovered in 2012 and redescribed as "the world's rarest toad". Here we report the results of a two-year study of the occurrence, habits and habitat associations of adult and larval A. kandianus using both general surveys and quadrat sampling. We show this to be a secretive species with a patchy distribution. Non-breeding female toads dwell in primary-forest habitats, but after heavy and sudden downpours they form large mating congregations in large streams. Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but the ability to dive and vocalize underwater, and characteristics of the eggs, suggest that they lay eggs in dark recesses of the stream. Tadpoles show microhabitat partitioning within the stream, with the greatest diversity of stages in slow-flowing rocky areas. The more robust stages possessing sucker discs exploit rocky-rapids, while metamorphic stages inhabit stream margins. We use DNA-barcoding to show the existence of two disparate toad populations. Distribution modeling with forest-cover layers added, predict a very small remaining area of suitable habitats. Conservation of this climatically and ecologically restricted species hinge largely on the preservation of high-elevation primary and riparian forests and unpolluted torrents.
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The present work describes two new species of Lankascincus from the Sripada Sanctuary (Peak Wilderness Sanctuary) of Sri Lanka. Lankascincus sripadensis sp. nov. is the largest member in the genus and it is morphologically closely related to L. deignani (Taylor 1950). But Lankascincus sripadensis sp. nov. can be clearly distinguished from other members of the genus, by having three loreal scales, posterior loreals larger than the anterior in longitudinal axis, prefrontal and upper anterior preocular touching posterior loreal; 2 nd, 3rdsupralabials and 1st subocular scale touching lower posterior loreal; males with pale brown throat and the ventral head; a dark brown stripe in the light brown background on the dorsal body, divided nasal. The other new species, Lankascincus munindradasai sp. nov. is morphologically closely related to L. taprobanensis (Kelaart, 1854) and can be clearly distinguished from other member of the genus, by having one loreal scale, the loreal is touching the prefrontal, frontonasal, nasal, 1st and 2nd supralabial scales, upper and lower preoculars; the loreal is larger than the longitudinal axis.
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An extensive survey of amphibians in Sri Lanka, a 65,000 km 2 continental island, has recently served to uncover ~100 new species of amphibians, mostly Oriental shrub-frogs of the endotrophic genus Philautus. Comparison of specimens acquired in the course of this survey with type and other historical collections have previously shown that 19 species have disappeared from the island. The final two extinct species, Philautus pardus and P. maia, known only from collections made in the island prior to 1876, are described herein as new. A contemporaneous account of the latter species reported that the female carried its clutch of eggs adhered to its belly, a behaviour which, if true, is unique in Anura. The remarkable extinction of anurans in Sri Lanka appears to be largely a result of the loss of c. 95 % of the island's perhumid forests. Sri Lanka's amphibian extinctions have been detectable only because of the baseline offered by specimens collected in the period 1850–1940 and preserved in overseas natural-history museums. Historical biodiversity collections in the world's natural history museums thus offer outstanding value as baselines for contemporary biodiversity conservation assessments.
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Full-text available
An extensive survey of amphibians in Sri Lanka, a 65,000 km 2 continental island, has recently served to uncover ~100 new species of amphibians, mostly Oriental shrub-frogs of the endotrophic genus Philautus. Comparison of specimens acquired in the course of this survey with type and other historical collections have previously shown that 19 species have disappeared from the island. The final two extinct species, Philautus pardus and P. maia, known only from collec-tions made in the island prior to 1876, are described herein as new. A contemporaneous account of the latter species reported that the female carried its clutch of eggs adhered to its belly, a behaviour which, if true, is unique in Anura. The remarkable extinction of anurans in Sri Lanka appears to be largely a result of the loss of c. 95 % of the island's perhumid forests. Sri Lanka's amphibian extinctions have been detectable only because of the baseline offered by specimens col-lected in the period 1850–1940 and preserved in overseas natural-history museums. Historical biodiversity collections in the world's natural history museums thus offer outstanding value as baselines for contemporary biodiversity conserva-tion assessments.
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Dramatic population declines have affected frogs worldwide ([1][1]), and, although new species continue to be described ([2][2]), the discovery of large new species radiations is rare. Here, we report the discovery of an endemic radiation of >100 species of Old World tree frogs (Rhacophorinae) from
Article
The present work describes two new species of Lankascincus from the Sripada Sanctuary (Peak Wilderness Sanctuary) of Sri Lanka. Lankascincus sripadensis sp. nov. is the largest member in the genus and it is morphologically closely related to L. deignani (Taylor 1950). But Lankascincus sripadensis sp. nov. can be clearly distinguished from other members of the genus, by having three loreal scales, posterior loreals larger than the anterior in longitudinal axis, prefrontal and upper anterior preocular touching posterior loreal; 2 nd , 3 rd supralabials and 1 st subocular scale touching lower posterior loreal; males with pale brown throat and the ventral head; a dark brown stripe in the light brown background on the dorsal body, divided nasal. The other new species, Lankascincus munindradasai sp. nov. is morphologically closely related to L. taprobanensis (Kelaart, 1854) and can be clearly distinguished from other member of the genus, by having one loreal scale, the loreal is touching the prefrontal, frontonasal, nasal, 1 st and 2 nd supralabial scales, upper and lower preoculars; the loreal is larger than the longitudinal axis.
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A team of dedicated technical staff from IUCN was involved in implementing this extremely important national task. The work spanned across several years, and involved a comprehensive literature survey of fauna and flora in Sri Lanka, data compilation and analysis of the status of species using IUCN global red list criteria and preparation of the digital database on the species assessed. Although the team faced several constraints in attending to this task, they were able to address these issues with the active support of the experts who assisted in reviewing the draft lists of threatened fauna and flora.
Reptile fauna of Ceylon. Government printer
  • W Ferguson
Ferguson, W. (1877) Reptile fauna of Ceylon. Government printer, Ceylon, 42 pp.
1872) Descriptions of some Ceylonese reptiles and batrachians
  • A Günther
Günther, A. (1872) Descriptions of some Ceylonese reptiles and batrachians. Annals and Magazine of Natural History, Series 4 (9), 85-88.