Notes on the herpetofauna of Surinam : VII. Revision of the genus Atracus in Surinam, with the resurrection of two species (Colubridae, Reptilia) (original) (raw)

With 17 text-figures, 6 plates and 1 table ABSTRACT A re-examination of old specimens of the genus Atractus, preserved in the Rijksmuseum van Natuurlijke Historie resulted in the discovery of syntypes of Brachyorrhos badius F. Boie, B. flammigerus F. Boie, B. schach F. Boie and Rabdosoma torquatus Dumeril, Bibron & Dumeril. Lectotypes for all these species are designated. B. flammigerus and B. schach have been considered synonyms of Atractus badius since 1837. This proved to be wrong, they turned out to be valid taxa exhibiting differences in scale counts, body size, hemipenial morphology and colour pattern. Among recently collected material from Surinam the recently described A. zidoki Gasc & Rodrigues was discovered and described on the basis of seven specimens. Both A. latifrons (Günther) and A. favae (Filippi) are reported for the first time from Surinam. Including A. elaps (Günther) the total number of species now known from Surinam is eight. Data gathered in Surinam indicate that the existence of many localised forms in Atractus is real and that under the name A. badius probably several other taxa are hiding. A revision of the entire genus is badly needed. RESUMEN En el estudio de ejemplares viejos del género Atractus, conservados en el Rijksmuseum van Natuurlijke Historie se descubrieron los sintipos de Brachyorrhos badius F. Boie, B. flammigerus F. Boie, B. schach F. Boie y Rabdosoma torquatus Duméril, Bibron & Dumeril. Se indican lectotipos para todas esas especies. B. flammigerus y B. schach han sido considerados como sinónimos de Atractus badius desde 1837. Se descubrió que era un error y resulto que esas especies eran taxa valida y que presentan diferencias con respecto al numero de escamas, al tamano, a la morfologia del hemipenis y al diseno de color. Entre el material recientemente recogido en Surinam se ha tambien descubierto la especie A. zidoki Gasc & Rodrigues que se describe a base de siete ejemplares. A. latifrons (Günther) y A. favae (Filippi) se mencionan por la primera vez de Surinam. Inclusive A. elaps (Günther) el numero total de especies conocidas de Surinam es ocho. Datos obtenidos en Surinam indican que muchas formas localizadas de Atractus existen de veras y que bajo el nombre de A. badius probablemente se ocultan algunas taxas diferentes. Una revision de todo el género Atractus es sumamente necesaria. KEY TO THE SURINAM SPECIES OF ATRACTUS 1. Pair of chin shields not in contact with mental, separated from it by the first pair of infralabials, forming a suture behind the mental, subcaudals less than 50, preocular never present, tail short 2 Pair of chin shields in contact with mental, first pair of infralabials not forming a suture, subcaudals 57-67, sometimes a small preocular present, tail long . Atractus favae 2. Most specimens with one postocular, only exceptionally two postoculars present 3 All specimens with two postoculars 5 3. Supralabials six, third and fourth entering the orbit, loreal short, pattern of black rings around the body 4 Supralabials eight, fourth and fifth entering the orbit, loreal elongate, back with small darker spots, arranged in four longitudinal rows, sometimes forming transverse bands, no black rings Atractus torquatus 4. Scales on body in 15 rows, internasals forming a suture, tail without sharp dorsal ridge Atractus elaps Scales on body in 17 rows, internasals separated, tail with a sharp dorsal ridge . Atractus latifrons 5. Loreal very narrow, elongated; ventrals less than 160; pattern without longitudinal stripes or series of spots 6 Loreal not elongated; ventrals 173-182; pattern of paravertebral rows of spots and a black stripe along the edges of the ventrals Atractus zidoki 6. Head wide, blunt; chin shields in contact with four infralabials, subcaudals 19-32 back brown with transverse, black bars or light spots 7 Head narrow, pointed; chin shields in contact with three (exceptionally four) infralabials, subcaudals 33-50, anterior part of back red with pairs of black bands, the members of each pair separated by narrow white bands, bands not continuous on belly Atractus badius 7. Upper labials eight, fourth and fifth entering the orbit; infralabials seven or eight, scales on posterior part of back and on tail smooth to strongly keeled, back brown with alternating black-edged light spots Atractus flammigerus Upper labials seven, third and fourth entering the orbit; infralabials eight, all scales on body and tail smooth, back light brown with alternating, rectangular black spots and a black vertebral line Atractus schach SPECIES ACCOUNTS Atractus badius (F. Boie) (pl. 1 fig. b, pl. 2 figs. a, b)