Atractus tamessari KOK, 2006
Can you confirm these amateur observations of Atractus tamessari?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Atractus tamessari KOK 2006|
Atractus tamessari — RIVAS et al. 2012: 39
Atractus tamessari — GOWER et al. 2012: 133
Atractus tamessari — WALLACH et al. 2014: 81
|Distribution||Guyana (Kaieteur National Park, Potaro-Siparuni District), Venezuela (Bolivar)|
Type locality: “along a tributary of Elinkwa River, ESE Kaieteur National Park, ca. 500 m elevation, Potaro-Siparuni District.” 05°08’09’’N, 59°25’28’’W
|Types||Holotype: IRSNB 2640, adult male|
Paratypes: Subadult (IRSNB 2641) and adult (IRSNB 2642) females; same data as the holotype.
|Diagnosis||Diagnosis. An Atractus species with 15 dorsal scale rows that can be distinguished from all other congeners by the following combination of characters: (1) medium size, adults reaching about 400 mm in TTL; (2) loreal much longer than high and touching the eye; (3) two postoculars; (4) eight supralabials, fourth and fifth touching the eye; (5) seven to eight infralabials, four in contact with chinshield; (6) six maxillary teeth; (7) 153–163 ventrals; (8) 28–31 subcaudals; (9) dorsal color pattern of irregular red or pale red markings, sometimes forming an incomplete broken dorsolateral stripe, on a medium brown to brownish black ground color; (10) venter yellowish cream, heavily mottled with brownish black. The new species can be referred to the genus Atractus because it possesses the following combination of characters: medium size; head small, slightly distinct from neck; eye small, with semi-elliptical pupil; scales smooth; dorsal scales in 15 rows without reduction; loreal present, touching the eye and separating prefrontals and supralabials; nostril between two scales; single pair of chinshields; anal single; subcaudals divided; maxillary teeth decreasing in size posteriorly; occurring in northern South America (Boulenger 1894, Hoogmoed 1980). By having 15 dorsal scale rows at midbody, Atractus tamessari differs from all Atractus species having 17 scale rows in the Guiana Shield (Silva Haad 2004, Avila-Pires 2005): A. alphonsehogei Cunha & Nascimento 1983, A. badius (Boie 1827), A. charitoae Silva Haad 2004, A. duidensis Roze 1961, A. favae (Filippi 1840), A. flammigerus (Boie 1827), A. latifrons (Günther 1868), A. lucilae Silva Haad 2004, A. major Boulenger 1894, A. riveroi Roze 1961, A. schach (Boie 1827), A. snethlageae Cunha & Nascimento 1983, A. steyermarki Roze 1958, A. torquatus Duméril, Bibron & Duméril 1854, and A. zidoki Gasc & Rodrigues 1979. Among the few Atractus species with 15 dorsal scale rows found in the region, Atractus tamessari differs from A. elaps (Günther 1858) by having two postoculars (one in A. elaps), eight supralabials (six), and no red or yellow rings on body (present); from A. franciscopaivai Silva Haad 2004by having eight supralabials, three contacting the loreal (five supralabials, two contacting the loreal in A. franciscopaivai), seven to eight infralabials (five), two postoculars (one), 1+2 temporals (1+1), and a yellowish cream venter heavily mottled with brownish black blotches (banded black and orange or black and yellow); from A. heliobelluomini Silva Haad 2004by having eight supralabials, three contacting the loreal (seven supralabials, two contacting the loreal in A. heliobelluomini), two postoculars (one), 1+2 temporals (1+1), and a yellowish cream venter heavily mottled with brownish black blotches (immaculate cream); from A. insipidus Roze 1961 by having eight supralabials, three contacting the loreal (seven supralabials, two contacting the loreal in A. insipidus), and a yellowish cream venter heavily mottled with brownish black blotches (immaculate cream); from A. poeppigi (Jan 1862) by having eight supralabials (six in A. poeppigi), 1+2 temporals (0+1 or 0+2), the loreal much longer than high (slightly higher than long), and a yellowish cream venter heavily mottled with brownish black blotches (reddish cream or red and black); and from A. trilineatus Wagler 1828 by having 28–31 subcaudal scales (11–19 in A. trilineatus), a yellowish cream venter heavily mottled with brownish black blotches (cream with light brown spots on posteriormost ventrals and anal), and by lacking well-defined longitudinal stripes (3–4 well-defined stripes present). [from KOK 2006].|
|Comment||Similar species: Atractus tamessari has been confused with Atractus insipidus (e.g. Schargel and García- Pérez, 2002).|
Habitat: rainbforest and cloud forest between 500- and 2200-m elevation.
|Etymology||Named after Michael Tamessar, retired Senior Scientific Officer of the Department of Biology at the University of Guyana (UG).|