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Rediscovery of the Ecuadorian snake Atractus dunni Savage, 1955 (Serpentes: Colubridae)

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Rediscovery of the Ecuadorian snake Atractus dunni Savage, 1955 (Serpentes: Colubridae)

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Atractus dunni Savage was known only from the type specimen collected in the 19th century from the type locality "Ecuador", and additional specimens had not been reported. Herein I provide a re-description of the holotype of Atractus dunni, and report new data on its lepidosis, dentition, and col-oration variation, based on additional specimens. The species is endemic to Ecuador, currently known from a few localities in low montane evergreen and montane cloud forests, at altitudes between 1530 to 1900 m, on the western versant of the Andes of Ecuador. Cisneros-Heredia, D. F. (2005) Rediscovery of the Ecuadorian Snake Atractus dunni Savage, 1955 (Serpentes: Colubridae). Journal of the National Museum of Prague, Natural History Series, 174, 1-4, 87–94.
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Rediscovery of the Ecuadorian snake Atractus dunni Savage, 1955
(Serpentes: Colubridae)
Diego F. Cisneros-Heredia
College of Biological and Environmental Sciences, Universidad San Francisco de Quito,
Casilla postal 17-12-841 Quito-Ecuador; e-mail: diegofrancisco_cisneros@yahoo.com
Received 26 May 2005 Accepted 30 May 2005
Abstract: Atractus dunni Savage was known only from the type specimen collected in the 19th century
from the type locality “Ecuador", and additional specimens had not been reported. Herein I provide a re-
description of the holotype of Atractus dunni, and report new data on its lepidosis, dentition, and col-
oration variation, based on additional specimens. The species is endemic to Ecuador, currently known
from a few localities in low montane evergreen and montane cloud forests, at altitudes between 1530 to
1900 m, on the western versant of the Andes of Ecuador.
Reptilia, Serpentes, Colubridae, Atractus dunni, redescription, natural history, distribution, Ecuador
INTRODUCTION
The greatest constraint in conservation planning for either individual species or entire
snake assemblages is the fundamental lack of basic biological information on most
species (Dodd 1993). Unfortunately for some groups, we are deficient at the most basic
levels: taxonomy, distribution, natural history. Several clades are not well studied, and
faulty taxonomy masquerades new species or synonymies; several species are undiscov-
ered or undescribed, and the existence of sibling species and intraspecific variation is
poorly understood (Lovich & Gibbons 1997).
A good example for all these issues is the genus Atractus Wagler, 1828, probably one
of the least-known member of the neotropical herpetofauna. Almost 100 species of
snakes have been assigned to the genus until 2005; however, most were described on the
basis of a single or a few specimens, from single localities (e.g. Atractus depressiocellus
Myers, 2003 known only from Cerro Azul [Cerro Jefe] region, Panama) or too general ar-
eas (e.g. type locality of Atractus dunni Savage, 1955 is “Ecuador”). Furthermore, snakes
of the genus Atractus are rarely registered during routine field research because of their
fossorial and semifossorial habits; therefore they are poorly represented in scientific col-
lections and publications, and even the few specimens in collections are usually not clas-
sified or erroneously named, hiding data on known and undescribed species.
Bocourt (1883) described the species Rhabdosoma maculatum on the basis of two
specimens from “Equateur”, one of them was a female PM 5986 (now MNHN 5986).
Boulenger (1894) transferred R. maculatum in the genus Atractus, placing the female
type specimen in the synonymy of Atractus badius (Boie, 1827) and the male type spec-
imen in his new species A bocourti. Sixty-one years later, Savage (1955) recognized that
the female specimen of R. maculatum represents a valid species different from A. badius,
87
Časopis Národního muzea, Řada přírodovědná
Journal by the National Museum, Natural History Series
Vol. 174 (1–4): 87–114, 2005
and proposed Atractus dunni as a new replacement name for Rhabdosoma maculatum
Bocourt, 1883, which was a secondary homonym of Isocelis maculata Gunther, 1858
(= Atractus maculata). He based his description “on the Bocourt’s original account and
plate and information kindly provided by M. Jean Guibe of the Paris Museum” (Savage
1955, 1960). Because the type locality of A. dunni was so general (Equateur = Ecuador),
Savage (1960) hypothesized that this species was a snake from the eastern slopes of the
Andes. Since Savage’s (1960) revision of the Ecuadorian Atractus, no additional speci-
mens of A. dunni have been reported until now, and the species remained unknown from
any specific locality.
In 1999, while studying specimens of Atractus from western Ecuador deposited in
Ecuadorian collections, it became clear that some were related to Atractus dunni, but
there were discrepancies with the description of Savage (1955, 1960). A revision in 2002
of the holotype of Atractus dunni deposited in Paris and additional material in USA col-
lections clarified the identity of Atractus dunni and elucidated new information on the
taxon known since 1883 from only a single specimen.
The aim of this paper is to provide a redescription of the holotype of Atractus dunni, to
report new data based on new material, including lepidosis, dentition and coloration, and
to clarify the distribution of this species.
MATERIAL AND METHODS
The following specimens of Atractus dunni were examined: ECUADOR: MNHN 5986
(holotype): without specific locality except “Equateur” (= Ecuador). Province of Im-
babura: FHGO 513: Km 8 Apuela – Cotacachi road, near Intag (ca. 00°21’N, 78°35’W,
c. 1980 m); FHGO 461: Hacienda La Florida, near Intag (ca. 00°19’N, 78°34’W, c. 1980
m). Province of Pichincha: DFCH-USFQ G513: Río Guajalito Protection Forest (ca.
00°13’S, 78°49’W, c. 1980 m); FHGO 91, 375-6, 379: Estación La Favorita, near
Palmeras (=Río Guajalito Protection Forest) (ca. 00°16’S, 78°46’W, c. 1680 m); USNM
232525: Llambo, camino de Gualea. MCZ-R 175075-78: Las Pampas.
Measurements are based on specimens fixed in formalin and preserved in 75 % ethanol.
Abbreviations used in the text are SVL (snout-vent length), TL (total length), TaL (tail
length), HW (head width), HL (head length), ED (eye diameter), WM (width at mid-
body). Total length and tail length measurements were made to the nearest 1.0 mm with
a metal straight ruler. Other body measurements were made to the nearest 0.05 mm with
a caliper under a dissecting microscope. Color descriptions are based on slides of FHGO
513 and the examination of preserved specimens. Drawings were produced with the aid
of a dissecting microscope or based on digital photographs. Ventral plates were counted
by the method of Dowling (1951). Maxillary teeth were counted in situ (Myers 1974).
The depositories of the quoted material listed in Appendix 1 are abbreviated in the text as
follows: DFCH-USFQ = D.F. Cisneros-Heredia’s collection housed at Universidad San
Francisco de Quito, Quito, Ecuador; FHGO = Fund. Herpetológica G. Orcés’ collection,
Quito, Ecuador; MNHN = Museum National d’Histoire Naturelle, Paris, France; MCZ =
Department of Herpetology, Museum of Comparative Zoology at Harvard University,
USA; USNM = National Museum of Natural History, Smithsonian Institution, Washing-
ton, DC, USA. Localities and their geographic coordinates and elevations were deter-
mined from researcher’s field notes and museum records and revised according to the
2000 physical map of the Republic of Ecuador published by the Instituto Geográfico Mil-
itar and NIMA (2003). Nine diagnostic features are used in order to facilitate the com-
88
parison with other species; these numbered characters for the diagnosis follow Savage
(1960) with modifications by Schargel & García-Pérez (2002).
RESULTS
Atractus dunni Savage, 1955
Rhabdosoma maculatum Bocourt, 1883: 539, pl. 34. Type locality = “Equateur”.
Atractus badius (in part) Boulenger 1894: 308 (Reference to Bocourt's female).
Atractus dunni Savage, 1955: 14. Type locality = Ecuador; Bocourt's female (PM 5986,
now MNHN 5986) was designated as a lectotype of Rhabdosoma maculatum Bocourt,
1883, a secondary homonym of Isocelis maculata Günther, 1858; same specimen is the
holotype of A. dunni.
Redescription of the holotype. The holotype (MNHN 5986) of Rhabdosoma
maculatum Bocourt, 1883 and Atractus dunni Savage, 1955 is rather well preserved, al-
though a little soft in the posterior half. According to the MNHN catalogue, it was col-
lected by “Deyrolle” in “Equateur” [= Ecuador]. The specimen is a female of 320 mm in
SVL and 33 mm in TaL. The SVL measurement differs considerably from data provided
by Savage (1955), and probably it is due to J. Savage getting data from secondary
sources, as he never actually saw this type specimen. Head barely distinct from neck.
Dorsal scales smooth in 17-17-17 rows, no apical pits. 142 ventrals, an undivided anal
plate, 20 subcaudals, all paired. Tail complete, ending in a sharp-tipped terminal scale.
Ventral count cited by Bocourt (1883) and Savage (1955) was 144, difference is due to
different count methods.
Head longer than wide. Rostral smaller than a prefrontal, barely visible from above and
below. Paired small and quadrangular internasals, smaller than prefrontals. Paired big and
rectangular prefrontals longer than broad. Each prefrontal in contact with its mate and
with frontral, supraocular, loreal, nasal, and internasal. Frontal pentagonal, broader than
long, four times bigger than the supraoculars. Parietals almost 2.5 time longer than
frontal, but almost as wide as frontal.
One supraocular on each side, pentagonal and long (twice longer than wide), in touch
with prefrontal, frontal, parietal, and postocular and barely with loreal (Perez-Santos &
Moreno 1991 erroneously cited two supraoculars). No preocular. Nostril between two
nasals. One elongated loreal in touch with eye, almost four times longer than wide. Two
postoculars on each side, the upper one is cuadrangular and slightly smaller than the low-
er which is rectangular. One anterior plus two posterior temporals, the posterior upper
temporal on each side very long, twice longer than wide, 1.75 as long as the parietals; an-
terior temporal touching both postocular, fifth and fourth supralabials and parietal.
Supralabials seven, with third and fourth bordering the orbit, the second and third touch-
ing loreal. Infralabials seven (erroneously reported as five by Savage 1955); first pair in
broad contact between mental and genials; three infralabials touching the genial on each
side. One pair of genials.
Subcircular pupila, six maxillary teeth on the left side, right side broken. Seven
mandibular teeth, although probably more as the mandible is damage. No diastema.
In preservative, head uniform brown from the tip of the snout to the posterior edges of
the parietals, proximal half of posterior temporals and upper half of supraoculars; followed
by an incomplete light cream nuchal collar of 1–2 dorsal scales width interrupted mid-dor-
sally by a dark mid-dorsal line. Behind the light collar, a dark shadow suggesting a dark
89
incomplete collar of 1–2 dorsal scales. Dark post ocular stripe. Lower half of supralabials
and distal half of posterior temporals light cream. Light nuchal collar continues into the
light cream throat and infralabials. The following description of dorsal and ventral body
coloration is at mid-body: Dorsal ground color brown, with a dark vertebral shadow, sug-
gesting a mid-dorsal / vertebral stripe. On the forth and fifth dorsal rows a series of dark
spots, usually of one scale wide, occupy the upper border of the forth row and lower bor-
der of the fifth row. On the sixth and seventh dorsal rows, a second series of dark spots
again appears, usually of one scale wide, occupying the upper border of the sixth row and
lower border of the seventh row. In the space between these two series of spots (on row 5
and 6), there is a light cream spot. Sometimes the upper and lower spots get fused and the
light cream spot emerge behind. These two series of spots are distributed fairly uniform
along the entire body, separated from each other by c. 2–3 dorsal rows. On the second and
third dorsal rows a third series of spots occurs, less conspicuous than previous ones, these
spots usually occupy one and a half scale wide, mainly on the second row and on the edges
of the surrounding scales. None series of spots get fused forming a stripe, and there are no
lateral dark stripes in the body of the holotype. Ventral ground color light cream, with dis-
tinct dark marks on the lateral sides of the ventrals, continuous with one another, forming
a pair of irregular ventral stripes, separated from the first row of dorsals by the light cream
margins of the ventrals, which suggesting paired light stripes (Fig. 1).
Variation. Twelve additional specimens assignable to Atractus dunni were examined;
six adult males, five adult females and one juvenile female. The following data include
the holotype in the analysis. Male SVL range was 275–302 mm (n = 2), female SVL
range 205–324 mm (n = 4) and the juvenile female SVL was 119. Tail was 18 % of SVL
in one male and 10–13 % of SVL in five females. Mean number of ventrals in males was
130.7 ±5.0 (range = 125–136, n = 6), mean number of ventral in females was 143.4 ±3.8
(range = 138–150, n = 7). Mean number of subcaudals in males was 33.2 ±4.3 (range =
26–37, n = 6), mean number of subcaudals in females was 20.9 ±1.2 (range = 19–23, n
= 7). Total number of scales (ventrals plus subcaudals, males and females combined) was
164.1 ±2.3 (range 160–173, n = 13). Dorsal scales do not show reduction in most spec-
imens, with 17 scales along the body; however, two specimens have reduced counts on
the neck with 16 scales (MCZ R-175075, 175077). Rostral is usually barely visible from
above and below, but sometimes it is not visible from below (DFCH-USFQ G513) or it
is a little protruding (USNM 232525). Supraoculars are sometimes not in contact with lo-
real (USNM 232525, MCZ R-175077). Prefrontals are in most specimens longer than
broad, but sometimes a little bit broader than long (DFCH-USFQ G513) or as long as
broad (FHGO 461). The relative size of the postoculars is variable, as the upper one can
be greater, equal or smaller than the lower one. Most specimens examined have the pos-
terior upper temporal on each side very long, even as long as the parietals; but two spec-
imens (FHGO 375, MCZ R-175077) have the posterior upper temporal normal in size,
and the scale behind longer. Supralabials can vary from six to seven, with two specimens
(DFCH-USFQ G513, MCZ R-175075) showing seven on the right side and six on the left
side, because of fusion between the second and third supralabials. Infralabials can vary
from six to eight, with one specimen (FHGO 379) having seven infralabials on the right
side and six on the left. Usually three infralabials are in touch with each genial, but in
some specimens four infralabials contact the genial either in both sides or on one side
(FHGO 091, 376). Maxillary teeth vary from 6 to 7 (the last one very small and almost
indistinguishable without a close search); and mandibular teeth vary from 7 to 8 (in both
series of teeth, some specimens with less teeth had broken teeth or damaged / incomplete
90
bones). Some males have small, sometimes inconspicuous cloacal tubercles at the base of
the first subcaudals, its presence probably depends on the reproductive season.
Coloration varies ontogenically and intraspecifically. Dorsal ground color in juveniles
is usually much paler than adults, therefore the dorsal pattern of spots series described for
the holotype is very conspicuous in juveniles, and the nuchal collar is very prominent and
defined. Ventral ground color in juveniles is also paler, almost white; less patterned be-
cause the marks are light brown. Adults are always darker; the dorsal ground color among
adults can varies from light brown to very dark brown. Some individuals show a mid-dor-
sal line, especially towards the anterior part of the body; other specimens show just a ver-
tebral dark shadow or no vertebral mark at all. When the dorsal ground color is dark
brown, the dorsal series of spots are inconspicuous, although sometimes visible under
correct light conditions. The dorsal series of spots can get fused, mainly in the anterior
half of the body or near the tail. Ventral ground color varies from light cream to dark
brown or almost black. Anal plate can be either light or dark brown. Underside of the tail
is always dark, between brown and black. The nuchal collar can be either conspicuous
and defined or barely suggested by a pale shadow.
C o lo r in l if e . The following description of the coloration in life of Atractus dunni is
based on photographs of specimen FHGO 513, and a specimen observed but not collect-
ed at the Bellavista Lodge, northwestern Pichincha: The head is dark brown with a yel-
low nuchal collar. Rostral, nasal, and supralabials yellow with the upper borders dark
brown, other head areas brown, with a dark postocular mark. Dorsum brown with dark
marks in the same pattern described for the holotype (Fig 2).
Diagnosis. Based on the characters discussed below, Atractus dunni differs from oth-
er species of the genus by the following characters: (1) 17-17-17 dorsal scale rows, re-
ductions of one scale in some specimens at the neck; (2) one elongate loreal, three to four
times as long as high; (3) 6 to 7 maxillary teeth, and 7 to 8 mandibular teeth; (4) ventral
scales 138 to 150 in females, 125 to 136 in males; subcaudal scales 19 to 23 in females,
91
Figure 1. Holotype of Atractus dunni Savage MNHN 5986.
26 to 37 in males; (5) ventrals plus caudals 160 to 173; (6) Dorsal pattern variable, from
clear brown with a pattern composed of three series of spots to a nearly uniform dark
brown with diffused shadows suggesting the series of spots. Sometimes there is a dark
shadow suggesting a vertebral stripe; in some individuals there is a true vertebral stripe,
but usually it is present just on the anterior part of the body, getting divided into dots or
disappears at the middles and end of the body; (7) ventral pattern with light cream / brown
ground with a pair of irregular dark ventral stripes separated from the first dorsals by a
paired light stripes. The dark stripes get expanded in some specimen covering almost the
entire ventral plates and suggesting a dark venter with clear botches; (8) an incomplete
light nuchal collar, in some specimens weakly defined; (9) six to seven supralabials and
five to seven infralabials; and (10) adults reaching maximum 357 mm TL in males and
353 mm TL in females.
Distribution and natural history. New material (see Material and methods) re-
ported herein indicates that Atractus dunni is a species distributed on the western versant of
the Andes of Ecuador, not supporting Savage’s (1955) hypothesis on its Atlantic versant
provenance. Atractus dunni is endemic to Ecuador, being currently known from a few lo-
calities at altitudes between 1530 to 1900 m in the provinces of Imbabura (surroundings of
Intag), Pichincha (Río Guajalito Protection Forest, La Favorita Reserve, and Bellavista
Lodge near Tandayapa), and Cotopaxi (Las Pampas). A photograph of an individual ob-
served at the Bellavista Lodge, near Tandayapa, confirms the presence of the species there.
All specimens with field data were collected in semifossorial situations, especially under
decay logs or rocks in low montane evergreen forest and montane cloud forest.
Peters & Orejas-Miranda (1970) included Peru in the range of the species without addi-
tional comments; an action followed by Perez-Santos & Moreno (1991) who did not men-
tion or indicate that they examined additional material. In all other references, A. dunni has
been cited as known only from the type locality “Ecuador” (Almendáriz 1991, Coloma et
al. 2000–2004, Peters 1960, Savage 1955, 1960). Carrillo de Espinoza (1989) did not in-
clude A. dunni in the herpetofauna of the country, but Carrillo de Espinosa & Icochea
(1995) and CONAM (1999) cited A. dunni but mention that its distribution in Peru is un-
known. The collection of the Museo de Historia Natural, Universidad Nacional Mayor de
92
Figure 2. A living specimen (not collected) of Atractus dunni Savage from Bellavista (Pichincha,
Ecuador). Photo by Jesse Delia.
San Marcos (Peru) does not hold any spec-
imen of A. dunni (pers. obs. 2003) and there
are no detailed published reports regarding
the presence of A. dunni in Peru. The rea-
sons of Peters & Orejas-Miranda (1970) for
including Peru in the range of A. dunni are
unknown. I considered the inclusion of
Peru in the range of the species erroneous
and there are small chances that the species
could cross the Huancabamba depression
and to reach western Peru. The species
could occur further north in Colombia.
Three specimens (MCZ R-36990-2)
part of a collection from the “Pastaza River,
Canelos to Marañon, Ecuador” (eastern
versant of the Andes of Ecuador) closely
resemble A. dunni. These specimens were
kindly revised by Dr. Jose Rosado at my re-
quest, and showed no differences on most
lepidosis characters, except that they had five to six supralabials, and that two of them had
15 dorsal rows at neck. The coloration is apparently within the range of variation observed
in A. dunni. These specimens would represent first records east of the Andes; however, an-
other species from the western versant of the Andes of Ecuador is also present at the same
collection, Saphenophis bourcieri (Jan, 1867). Therefore, either both species, A. dunni and
S. bourcieri are distributed on both sides of the Andes but recent collections have failed to
locate them in eastern Ecuador; or those specimens were collected in western Ecuador and
get confused in this collection; or the Atractus specimens represent a different species sim-
ilar to A. dunni. Until this material is more thoroughly revised, I suggest keeping this east-
ern locality in question.
DISCUSSION
Atractus dunni is a highly variable species in terms of its coloration, having ontogenic and
intraspecific variation. However, most individual show a pattern clearly discernible from
other Atractus of the region, and the future identification of the species should be fairly
easy. The species is currently assigned to the trilineatus group, as defined by Savage (1955).
Information on new material presented herein confirms A. dunni as a valid species different
from most other species of the trilineatus group recognized by Savage (1955) as present in
Ecuador: A. ecuadorensis Savage, 1955, A. collaris Peracca, 1897, A. gaigae Savage, 1955,
and A. resplendens Werner, 1901. However, the differences between A. lehmanni Boettger,
1898 and A. dunni are still subtle. The color pattern showed by some specimens assigned
to A. dunni in this paper is very dark and almost unpatterned, resembling the color pattern
described for A. lehmanni. Other characters are also very similar. However, ventral counts
of females and males do not overlap between both species, but the sample size in each case
is small, as the only specimens of A. lehmanni are the topotypes. Also, the type locality of
A. lehmanni is “Hoya de Cuenca”, an interandean valley in southern Ecuador, quite distant
from the currently known distribution of A. dunni. As I did not check the types of lehman-
ni and until more material is available, I keep both species separated, however as Savage
93
Figure 3. Known distribution of Atractus dunni
Savage.
(1955) pointed out, they can be conspecific, the variation of ventral count could represent
clinal variation, and the differences in color a condition similar to A. occipitoalbus (Jan,
1862), where there are different color phases in a single population.
ACKNOWLEDGMENTS
I am grateful to the following institutions and their curators for giving access to material under their care:
J.-M. Touzet and A. M. Velasco (FHGO), Roy McDiarmid, George Zug, and Ron Heyer (USNM), Ivan Ineich and
J. C. de Massary (MNHN), Jose Rosado and James Hanken (MCZ). I thank John Simmons, Marinus Hoogmoed
and the Savanna River Ecology Laboratory for providing useful literature; to Ana Peñaherrera, Mónica Naranjo,
J.-M. Touzet, A. León for laboratory assistance and useful discussions; to Jesse Delia for information on his sur-
vey of the herpetofauna of Bellavista and for the photograph in Figure 2; and to Vlastimil Zak for granting DFCH
access to Guajalito. Universidad San Francisco de Quito provided institutional and in-kind support. My deepest
gratitude goes to María Elena Heredia and Laura Heredia for their continuous moral and financial support.
REFERENCES
Almendáriz A., 1991: Anfibios y reptiles. In: Barriga R., Almendáriz A. & Albuja L. (eds.): Lista de Verte-
brados de Ecuador. – Revista Politécnica (Quito) 16: 89–162.
Bocourt F., 1883: Études sur les reptiles et les batraciens. In: Mission scientifique au Mexique et dans
l’Amérique centrale, Recherches Zoologiques 9: 529–659. Paris: Imprimerie Imperiale.
Boulenger G. A., 1894: Catalogue of the snakes in the British Museum (Natural History). Vol. II. – London:
Taylor and Francis, xi + 382 pp.
Carrillo de Espinoza N., 1989: List of Peruvian Colubridae. Lima: Museo de Historia Natural, Universidad
Nacional Mayor de San Marcos, 4 pp.
Carrillo de Espinosa N. & Icochea J., 1995: Lista taxonómica de los reptiles vivientes de Perú. – Publicaciones
del Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos (A) 49: 1–27.
Coloma L. A., Quiguango A. & Ron S., 2000–2004: Reptiles de Ecuador: lista de especies y distribución.
Crocodylia, serpentes y testudines. [on line]. Ver. 1.1. (25 May 2000). Museo de Zoología, Pontificia
Universidad Católica del Ecuador, Quito. http://www.puce.edu.ec/Zoologia/repecua.htm [Last ac-
cessed on 22 May 2005].
CONAM, 1999: Lista de especies de reptiles de Perú. In: Estrategia Nacional de Diversidad Biológica de
Perú. Lima: CONAM, 7 pp.
Dodd C. K. Jr., 1993: Strategies for Snake Conservation. – In: Seigel R. A. & Collins J. T. (eds.): Snakes: ecol-
ogy and behavior: 363–393. New York: McGraw-Hill.
Dowling H. G., 1951: A proposed standard system of counting ventrals in snakes. – British Journal of Her-
petology 1: 97–99.
Lovich J. E. & Gibbons J.W., 1997: Conservation of covert species: protecting species we don’t even know. –
In: Van Abbema J. (ed.): Conservation, restoration and management of tortoises and turtles: 426–429.
New York: New York Turtle and Tortoise Society.
Myers C. W., 1974: The systematics of Rhadinaea (Colubridae), a genus of New World snakes. – Bulletin of
the American Museum of Natural History 153 (1): 1–262.
NIMA, 2003: Geonet names server GNS. Geographic names data base: official standard names approved by the
United States Board on Geographic Names. National Imagery and Mapping Agency. [on line: 29 august
2003]. USA. – http://earth-info.nga.mil/gns/html/ = part of www.nima.mil [Last accessed on 10 May 2004].
Pérez-Santos C. & Moreno A., 1991: Serpientes de Ecuador. – Museo Regionale di Scienze Naturali Torino,
Monografie 11, 538 pp.
Peters J. A., Orejas-Miranda B. & Vanzolini P. E., 1986: Catalogue of the Neotropical Squamata, Part I: Snakes.
Revised Edition. – Washington: Smithsonian Institution Press, 347 pp.
Peters J. A., 1960: The snakes of Ecuador. A check-list and key. – Bulletin of the Museum of Comparative Zool-
ogy 122: 491–541.
Savage J., 1955: Description of new colubrid snakes, genus Atractus, from Ecuador. – Proceedings of the Bio-
logical Society of Washington 68: 11–20.
Savage J., 1960: A revision of the Ecuadorian snakes of the colubrid Genus Atractus. – Museum of Zoology,
University of Michigan, Miscellaneous Publications 112: 1–86.
Schargel W. E. & García-Pérez J. E., 2002: A new species and a new record of Atractus (Serpentes: Colubri-
dae) from the Andes of Venezuela. – Journal of Herpetology 36: 398–402.
Sierra R., ed., 1999: Propuesta preliminar de un sistema de clasificación de vegetación para el Ecuador conti-
nental. – Quito: Proyecto INEFAN/GEF-BIRF y EcoCiencia.
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... Finally, a mention should be made about the importance of using a biogeographical framework that includes molecular data and species distribution models (when the number and quality of locality records is sufficient for these analyses; see van Proosdij et al. 2015) when defining species limits within Atractus. Finding ground snakes along the Andes has showed us (Arteaga et al. 2013(Arteaga et al. , 2017 and other authors (Savage 1955(Savage , 1960Cisneros-Heredia 2005;Salazar-Valenzuela et al. 2014) that snakes in this genus have lower dispersal capacity than other colubrids and many species are endemic to a single mountain range or restricted to an isolated inter-Andean valley. Thus, the presence of the same Atractus species in two geographically isolated areas that are climatically and floristically distinct and are separated from each other by tens or even hundreds of kilometers of discontinuous habitat is unlikely. ...
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The genus Atractus includes 146 species of cryptozoic snakes occurring from Panama to northeastern Argentina. Here, a molecular phylogeny of this genus is presented, which encompasses 29% (= 42; six are included here for the first time) of the species currently recognized. Morphological and phylogenetic support is found for three new species of ground snakes, which are described here based on their unique combination of molecular, meristic, and color pattern characteristics. The name A. arangoi Prado, 1939 is revalidated for a Colombian snake species previously subsumed under A. major Boulenger, 1894 based on new material collected in Ecuador. Reidentifications are provided for Atractus voucher specimens and sequences deposited in GenBank. With these changes, the number of Atractus reported in Ecuador increases from 27 to 31 species. Finally, attention is given to the importance of using a biogeographical framework that includes molecular data and a comprehensive geographic sampling when proposing species limits in complex taxonomic groups.
... Atractus is the most speciose alethinophidian snake genus, with about 130 valid species, most of them known only from their type specimens (Myers 2003;Passos et al. 2005;Passos & Fernandes 2008;Prudente & Passos 2008;Passos et al. 2009a, b). Although the number of Atractus specimens available in collections has increased through the years, the proper identification of material belonging to several poorly known taxa has been achieved only in recent detailed studies (Cisneros-Heredia 2005b;Passos et al. 2007a;Passos et al. in press a, b, c;Prudente & Passos in press). To date, the taxonomic status of several species remains unclear, and there have been attempts of taxonomic revisions only for some countries (Savage 1960;Roze 1961;Myers 2003), and geographically restricted regions of Amazonia (Cunha & Nascimento 1983;Martins & Oliveira 1993;Silva 2004) or the Andes (Esqueda & La Marca 2005;Myers & Schargel 2006;Passos et al. 2009a, b). ...
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The taxonomic status of the Pacific lowland Atractus is revised on the basis of meristic, morphometric, colour pattern, and hemipenial characters. Geographical variation is reported for six Atractus species (A. boulengerii, A. clarki, A. iridescens, A. melas, A. multicinctus, and A. paucidens). Atractus boulengerii is rediscovered and redescribed from a specimen from the Colombian coast. The first voucher specimens are reported for A. melas. The current status of A. microrhynchus is maintained based on the discovery of new material referrable to that species. Three new species of Atractus are described from the Pacific lowland of Colombia: A. echidna sp. nov., A. medusa sp. nov., A. typhon sp. nov. Two new Atractus species groups (multicinctus and paucidens) are proposed based on external morphology, maxillary dentition, and hemipenial characters. A new key to Pacific lowland species of Atractus is provided.
... However, this scenario has been gradually changing with a series of studies based on the faunal elements of countries (Savage 1960;Myers 2003), biogeographic provinces from trans-Andean (Passos & Lynch 2011;Passos et al. 2009e) or cis-Andean portions of South America (Passos et al. 2013b), broad ecoregions (Passos et al. 2010c), as well as directed toward to certain species complex (Passos & Prudente 2012). As an expected result, old taxa poorly characterized in the past were resurrected (Passos et al. 2010b), rediscovered as misidentified specimens in scientific collections (Cisneros 2005;Passos & Lynch 2011;Passos et al. 2013d) or obtained through fieldwork carried out in poorly sampled regions (Passos et al. 2009a(Passos et al. , 2010aVanegas-Guerrero et al. 2014). On other hand, evaluation of many recently described species has revealed an astonishing amount of junior synonymies (Kok et al. 2007;Passos et al. 2009a,d;Passos et al. 2010c;Passos & Prudente 2012;Passos et al. 2013d), adding more difficulties to the already challenging task towards achieving the taxonomic accuracy in the genus Atractus (Passos et al. 2016b). ...
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We reassessed the taxonomic status of the species in the Atractus collaris complex (A. alphonsehogei, A. collaris, A. limitaneus, and A. gaigeae) on the basis of congruence between quantitative and qualitative morphological characters (meristic, morphometric, color pattern, hemipenis, and scale microdematoglyphics) along its wide geographical distribution. Our results support the recognition of three species with apparently fixed diagnostic characters. We propose the synonymization of Atractus limitaneus with A. collaris based on the wide overlap of all morphological character systems here analyzed, as well as on the basis of examination of the holotype and two topotypes of A. limitaneus. Finally, we discuss the geographical variation and morphological distinction of A. alphonsehogei, A. collaris and A. gaigeae. Furthermore, we provide a dichotomous key for all recognized species in the A. collaris species group.
... The remaining individuals were detected by turning over logs, rocks and other surface objects. All specimens included in the genetic analyses were morphologically identified according to Savage (1955Savage ( , 1960, Cisneros-Heredia (2005), Passos et al. (2009a), Arteaga et al. (2013), Schargel et al. (2013) and Salazar-Valenzuela et al. (2014). We generated sequence data for samples marked with an asterisk under Appendix I, which includes museum vouchers at the Museo de Zoología de la Universidad Tecnológica Indoamérica (MZUTI), the División de Herpetología del Museo Ecuatoriano de Ciencias Naturales (DHMECN) and the Fundación Herpetológica Gustavo Orcés (FHGO). ...
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We present a molecular phylogeny of snake genus Atractus, with an improved taxon sampling that includes 30 of the 140 species currently recognized. The phylogenetic tree supports the existence of at least three new species in the Pacific lowlands and adjacent Andean slopes of the Ecuadorian Andes, which we describe here. A unique combination of molecular, meristic and color pattern characters support the validity of the new species. With the newly acquired data, we propose and define the A. iridescens species group, as well as redefine the A. roulei species group. The species A. iridescens is reported for the first time in Ecuador, whereas A. bocourti and A. medusa are removed from the herpetofauna of this country. We provide the first photographic vouchers of live specimens for A. multicinctus, A. paucidens and A. touzeti, along with photographs of 19 other Ecuadorian Atractus species. The current status of A. occidentalis and A. paucidens is maintained based on the discovery of new material referable to these species. With these changes, the species number reported in Ecuador increases to 27, a number that is likely to increase as material not examined in this work becomes available and included in systematic studies.
... Several of the species we recorded were described recently, including Riama yumborum (Aguirre-Peñafiel et al., 2014), Alopoglossus viridiceps (Torres-Carvajal & Lobos, 2014), Atractus gigas (Myers & Schargel, 2006;Tolhurst et al., 2010) and Echinosaura brachycephala (Köhler et al., 2004). Some are believed to be rare, such as A. dunni (Cisneros-Heredia, 2005;Arteaga et al., 2013) and others e.g., Lepidoblepharis conolepis and R. oculata are reported from a limited locale (Ávila-Pires, 2001;Cisneros-Heredia, 2009). Conservation status has been assigned to only three of the species we report: R. oculata, Anolis gemmosus and A. fraseri. ...
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The cloud-forests of the Western Ecuadorean Andes are highly diverse and under threat from anthropogenic habitat disturbance. Reptiles are sensitive to habitat change and are therefore useful indicators of ecosystem state. Overall diversity has been shown to be highest in old-growth (primary) forest, although older secondary forests can recover to near pre-disturbance levels. We systematically surveyed leaf-litter lizard diversity along a gradient of disturbance in a montane cloud-forest fragment whilst controlling for the potentially confounding effect of elevation. We deployed 21 pitfall trap-lines equally between primary forest, secondary forest of mid-age (18–30 years), and agroforestry, between three altitudinal bands for ten days each over a period of three years. We investigated diversity patterns using Chao 1 and 2 indices (estimated richness), effective species number (ESN), relative abundance of individual species, relative abundance of pooled species, and observed species richness. We also conducted an opportunistic inventory of reptile species. We recorded 7 species of leaf-litter lizards and 15 other species of squamate, the majority of which are rare, recently described and/or of restricted distribution. Elevation was strongly negatively correlated with diversity. Richness and most indices of diversity were higher in primary forest but abundance was similar in primary forest and agroforestry. ESN followed a negative linear response to disturbance but for all other measures agroforestry supported diversity that was either higher than or equal to secondary forest. We conclude that, particularly at high elevations, mid-aged secondary forest is depauperate of leaf-litter lizards but agroforestry potentially supports relatively large populations of generalist species. Lizard diversity in response to human-induced disturbance in Andean Ecuador.
... Atractus is the most speciose alethinophidian snake genus, with about 130 valid species, most of them known only from their type specimens (Myers 2003;Passos et al. 2005;Passos & Fernandes 2008;Prudente & Passos 2008;Passos et al. 2009a, b). Although the number of Atractus specimens available in collections has increased through the years, the proper identification of material belonging to several poorly known taxa has been achieved only in recent detailed studies (Cisneros-Heredia 2005b;Passos et al. 2007a;Passos et al. in press a, b, c;Prudente & Passos in press). To date, the taxonomic status of several species remains unclear, and there have been attempts of taxonomic revisions only for some countries (Savage 1960;Roze 1961;Myers 2003), and geographically restricted regions of Amazonia (Cunha & Nascimento 1983;Martins & Oliveira 1993;Silva 2004) or the Andes (Esqueda & La Marca 2005;Myers & Schargel 2006;Passos et al. 2009a, b). ...
Article
Full-text available
The taxonomic status of the Pacific lowland Atractus is revised on the basis of meristic, morphometric, colour pattern, and hemipenial characters. Geographical variation is reported for six Atractus species (A. boulengerii, A. clarki, A. iridescens, A. melas, A. multicinctus, and A. paucidens). Atractus boulengerii is rediscovered and redescribed from a specimen from the Colombian coast. The first voucher specimens are reported for A. melas. The current status of A. microrhynchus is maintained based on the discovery of new material referrable to that species. Three new species of Atractus are described from the Pacific lowland of Colombia: A. echidna sp. nov., A. medusa sp. nov., A. typhon sp. nov. Two new Atractus species groups (multicinctus and paucidens) are proposed based on external morphology, maxillary dentition, and hemipenial characters. A new key to Pacific lowland species of Atractus is provided.
... although several authors correlated the apparent rarity of most species of Atractus with its secretive habits or restricted endemism (savage, 1960;roze, 1961;schargel and Garcia-pérez, 2002;Myers, 2003;Myers and schargel, 2006), recent studies based on museum specimen's or increasing fieldwork efforts revealed that some taxa are relatively common within certain geographical and/or altitudinal ranges of distribution (Cisneros-Heredia, 2005b;Zaher et al., 2005;passos et al., 2007a;loebmann et al., 2009;passos et al., 2009a,e). nevertheless, sometimes the scarcity of certain species really reflects lacking of regional samples due to logistic difficulties (passos et al, 2009e), rapid habitats disturbance (passos and prudente and passos, 2010), and narrow endemic taxa (passos et al., 2009c,e). ...
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Zoologisches Forschungsmuseum Alexander Koenig, sektion Herpetologie, Konrad Adenauer Alee 53 Bonn, germany. 3 División de Herpetología, cOrBiDi (centro de Ornitología y Biodiversidad) santa rita 105, of. 202, Huertos de san Antonio, surco, Lima, Peru. 4 current Address, Laboratório de Herpetologia, instituto Butantan, Avenida Vital Brazil, 1.500, Butantã, 05503‑900, são Paulo, sP, Brasil. 5 corresponding author: atractus@gmail.com. abstract. Atractus gigas was described based on a single specimen from western andes of ecuador. although recently, a second specimen of A. gigas was reported close to the type locality just on the basis of photographic vouchers. during the examination of ecuadorian and peruvian collections, we found additional specimens of this poorly known snake. We also collected new individuals of Atractus gigas during fieldwork carried out on northeastern portion of the peruvian andes. in this paper, we report new specimens, localities, and data on meristic, morphometric and color pattern variation for the species. We associate the variation displayed by these character systems with sexual, geographic, and ontogenetic phenomena respectively. We provide detailed comparisons and diagnosed Atractus gigas from all others members of this highly diverse and complex genus, and comment on their natural history and ontogeny.
... Recent field work and revisions of museum holdings has yielded additional specimens of some of these species. Examples are A. dunni Savage 1955(Cisneros-Heredia 2005, A. modestus Boulenger 1894 (Passos et al. 2007a), A. wagleri Prado 1945(Passos & Arredondo 2009), A. bocki (Passos et al. 2009a), A. gigas Myers & Schargel 2006), A. microrhynchus Cope 1868), and A. riveroi Roze 1961(Passos et al. 2013b. For other species of this genus that were previously thought to be small-scale endemics, the known geographic distribution was considerably expanded recently: A. ronnie Passos et al. 2007b(Loebmann et al. 2009), A. natans Hoogmoed & Prudente 2003, A. tamessari Kok 2006(Passos et al. 2013b, and A. caxiuana Prudente & Santos-Costa 2006(Passos et al. 2013b. ...
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We describe two new species of Atractus from Colombia: one from the Serrania de la Lindosa, south of San José de Gua- viare in the province Guaviare, and another from Punta de Betin in the province Magdalena, close to the Caribbean coast. The first new species differs from all congeners by having a combination of 17 smooth dorsal scale rows; loreal present, approximately as long as high; temporals 1+2; seven supralabials; seven infralabials; five maxillary teeth; four gular scale rows; four pre-ventrals; 187 ventrals in single male; 29/31 subcaudals in single male; dorsum of body with longitudinal stripes; venter uniformly dark gray. The second new species differs from all congeners by having a combination of 17 smooth dorsal scale rows; loreal absent; temporals 1+2; seven supralabials; six or seven infralabials; eight maxillary teeth; three gular scale rows; three pre-ventrals; 146 ventrals in single male; 31/32 subcaudals in single male; dorsum of body and tail reddish brown with paired, occasionally slightly alternating lateral vertical cream blotches, approximately one dorsal scale broad, not contacting in vertebral region; venter cream with reddish brown blotches, forming two parallel se- ries on anterior body and a checkered pattern on the rest of body.
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ABSTRACT: The Neotropical dipsadid snake genus Atractus contains more species than any other genus of serpents. The type species for the genus, Three-lined Snakes (Atractus trilineatus), occurs in northern South America, as well as in the islands of Trinidad and Tobago. Little is known about the phylogenetic position of this fossorial snake. Here, we examine the genetic variation of this species. Phylogenetic analyses suggest that A. trilineatus is an early branch within Atractus, and is deeply divergent from all of the other 31 species within the genus included in our analyses. Populations of A. trilineatus from Trinidad and Tobago show a close genetic affinity with mainland populations from Guyana, and indicate recent vicariance following Late Pleistocene sea-level rises. Overwater dispersal events cannot be ruled out, however, especially for the colonization of Tobago. Our results add to the understanding of the complexity of the hylogeographic events in the eastern Caribbean with this ecologically constrained species.
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Atractus carrioni was described based on two specimens from Loja, in the western versant of Cordillera Real, Ecuador. Posteriorly, 13 additional individuals were reported in the literature, but this entire sample was obtained in the neighborhood of Loja, and indeed comprises topotypes of A. carrioni. Thus, despite the fact that we are acquainted with some aspects of the intra-populational variability of the species (few merestic and morphometric features), nothing is known about its ontogenetic, sexual and geographical variation, as well as its natural history. During the examination of Ecuadorian and Peruvian collections, we found 28 additional specimens of this poorly known snake. In this paper, we report new localities and data on meristic, morphometric, color pattern, and hemipenis variation for the species. We associate the variation displayed by these character systems with sexual, geographic, and ontogenetic phenomena. We provide detailed comparisons of the former taxon with their putative closely related species (A. roulei), and propose a new species group to accommodate A. carrioni and A. roulei. Additionally, we provided the first data on reproduction for Andean species of Atractus.
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A new species of Atractus is described from the Cordillera de Mérida, Venezuela. The new species can be distinguished from all other congeners by the combination of 15 dorsal scale rows at midbody and a color pattern consisting of two pale dorsolateral stripes on a dark ground color. Additionally Atractus pamplonensis is reported for the first time for Venezuela. /// Una nueva especie de Atractus es descrita para la Cordillera de Mérida, Venezuela. Esta nueva especie difiere del resto de los Atractus por la combinación de 15 hileras de escamas dorsales y un patrón de coloración de dos líneas claras dorsolaterales sobre un dorso oscuro. Adicionalmente se reporta Atractus pamplonensis por primera vez para Venezuela.
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http://deepblue.lib.umich.edu/bitstream/2027.42/56356/1/MP112.pdf
1883: Études sur les reptiles et les batraciens
  • F Bocourt
Bocourt F., 1883: Études sur les reptiles et les batraciens. In: Mission scientifique au Mexique et dans l'Amérique centrale, Recherches Zoologiques 9: 529-659. Paris: Imprimerie Imperiale.
Reptiles de Ecuador: lista de especies y distribución. Crocodylia, serpentes y testudines Museo de Zoología
  • L A Coloma
  • A Quiguango
  • S Ron
Coloma L. A., Quiguango A. & Ron S., 2000–2004: Reptiles de Ecuador: lista de especies y distribución. Crocodylia, serpentes y testudines. [on line]. Ver. 1.1. (25 May 2000). Museo de Zoología, Pontificia Universidad Católica del Ecuador, Quito. – http://www.puce.edu.ec/Zoologia/repecua.htm [Last accessed on 22 May 2005].