Atractus esepe, Arteaga, Alejandro, Mebert, Konrad, Valencia, Jorge H., Cisneros-Heredia, Diego F., Penafiel, Nicolas, Reyes-Puig, Carolina, Vieira-Fernandes, Jose L. & Guayasamin, Juan M., 2017

Arteaga, Alejandro, Mebert, Konrad, Valencia, Jorge H., Cisneros-Heredia, Diego F., Penafiel, Nicolas, Reyes-Puig, Carolina, Vieira-Fernandes, Jose L. & Guayasamin, Juan M., 2017, Molecular phylogeny of Atractus (Serpentes, Dipsadidae), with emphasis on Ecuadorian species and the description of three new taxa, ZooKeys 661, pp. 91-123 : 102-104

Atractus esepe sp. n.

Proposed standard English name.

Indistinct Groundsnake

Proposed standard Spanish name.

Tierrera indistinta

Holotype.

MZUTI 3758 (Fig. 6), adult male collected by Alejandro Arteaga on September 12, 2014 at Caimito, Esmeraldas Province, Ecuador (N0.69620, W80.090472; 102 m).

Paratopotype.

MZUTI 3759, adult female collected by Jaime Culebras.

Diagnosis.

Atractus esepe is placed in the genus Atractus as diagnosed by Savage (1960), based on phylogenetic evidence (Fig. 1). It is included in the Atractus iridescens group due to its brown dorsal ground color and its phylogenetic position (Figs 1, 6). The species is diagnosed based on the following combination of characters: (1) 17/17/17 smooth dorsals; (2) two postoculars; (3) loreal long; (4) temporals 1+2; (5) seven supralabials, third and fourth contacting orbit; (6) seven infralabials, first four contacting chinshields (7) seven maxillary teeth; (8) 2-3 gular scale rows; (9) 2-3 preventrals; (10) 149 ventrals in the male holotype, 156 in the female paratype; (11) 41 subcaudals in the male holotype, 30 in the female paratype; (12) dorsal ground color brown with a pattern of complete (MZUTI 3759) or broken (MZUTI 3758) (Fig. 6a) dark lines running parallel along each side of the body and separated from each other by a cream line, but rendering the appearance of a row of dorso-lateral blotches in the broken pattern (MZUTI 3758); (13) venter cream faintly speckled with brownish pigment (Fig. 6b); (14) 232-241 mm SVL; (15) 34-53 mm TL.

Comparisons.

Atractus esepe is included in the Atractus iridescens species group and compared to other Pacific lowland congeners who have a brownish ground color (Figs 2, 5): Atractus boulengerii , Atractus cerberus , Atractus dunni , Atractus echidna , Atractus iridescens , Atractus medusa , Atractus microrhynchus , and Atractus occidentalis . From these, Atractus microrhynchus and Atractus occidentalis have striped pattern and cream ventral surfaces similar to that of Atractus esepe , but they occur parapatrically (Fig. 3) and can be distinguished from Atractus esepe by a genetic divergence of 5.3-5.7% in a 506 bp long fragment of the mitochondrial Cytb gene and by having a greater number of subcaudal scales in males (Table 2). Furthermore, adult specimens of Atractus microrhynchus have light brown dorsal surfaces instead of dark brown, and their pattern can be better described as a series of blotches rather than broken longitudinal lines. Specimens of both Atractus esepe and Atractus occidentalis have a pattern of longitudinal lines, but Atractus esepe has a greater number of ventral plus caudal scales than Atractus occidentalis (more than 180 in Atractus esepe ) (Table 2).

Color pattern.

The dorsal ground color is dark brown with either six longitudinal black lines separated by lighter areas or a pattern of dark brown longitudinally arranged spots that correspond to the longitudinal lines. On each side, the line or series of dark spots along the 2nd and 3rd dorsal scale row is feebly visible, but the other lines or spots are conspicuous. The dorsal surface of the head is dark brown and there is a clearly marked dark postocular stripe running from behind the eye to the edge of the mouth (Fig. 6). The ventral surfaces are dingy white, finely speckled with brown pigment that becomes more concentrated towards the tail. The iris is carmine and the pupil is black.

Description of holotype.

Adult male, SVL 232 mm, tail length 53 mm (22.8% SVL); body diameter 7.0 mm; head length 7.9 mm (3.4% SVL); head width 4.8 mm (2.2% SVL); interocular distance 3.4 mm; head slightly distinct from body; snout–orbit distance 3.3 mm; rostral 1.8 mm wide, about one time broader than high; internasals 0.9 mm wide; internasal suture sinistral relative to prefrontal suture; prefrontals 1.9 mm wide; frontal 2.2 mm wide, with a curvilinear triangle shape in dorsal view; parietals 2.1 mm wide, about twice as long as wide; nasal divided; loreal 2.5 mm long, about 3 times longer than high; eye diameter 1.5 mm; pupil round; supraoculars 1.2 mm wide; two postoculars; temporals 1+2, upper posterior temporal elongate, about four times longer than high, and three times as long as first temporal; seven supralabials, 3 rd– 4th contacting orbit; symphisial 0.8 mm wide, separated from chin shields by first pair of infralabials; seven infralabials, 1 st– 4th contacting chin shields; anterior chin shields about three times as long as broad, posterior chin shields absent; three series of gular scales; dorsal scales 17/17/17 rows, smooth without apical pits; preventrals 3; ventrals 149; anal plate single; paired subcaudals 41.

Natural history.

The two known specimens of Atractus esepe were found actively foraging among soil and roots in secondary evergreen lowland forest at least 400 m from the nearest natural body of water. They were found by night at 20h00 after a warm, sunny day.

Distribution.

Known only from the type locality, Caimito, in the Ecuadorian province of Esmeraldas at 102 m (Fig. 3). This locality is 1.3 km airline distance from the shoreline.

Etymology.

The specific epithet esepe is derived from the Spanish pronunciation of “sp.”, which is the abbreviation for the Latin word species. Here, we use this word in allusion to how the majority of Ecuadorian researchers refer to Atractus specimens found in the field.

Conservation status.

We consider Atractus esepe to be Data Deficient following IUCN criteria because it is known only from its type locality but its occurrence in the biogeographic Choco suggests that it might as well be present in other localities. The Chocoan forests of Caimito do not appear to be isolated from other similar habitat by geographical or ecological barriers. Therefore, we consider there is inadequate information to make a direct, or indirect, assessment of its extinction risk based on its scarce distribution data.