Prosymna angolensis Boulenger, 1915

Conradie, Werner, Baptista, Ninda L., Verburgt, Luke, Keates, Chad, Harvey, James, Júlio, Timóteo & Neef, Götz, 2021, Contributions to the herpetofauna of the Angolan Okavango-Cuando-Zambezi river drainages. Part 1: Serpentes (snakes), Amphibian & Reptile Conservation (e 292) 15 (2), pp. 244-278 : 265

Prosymna angolensis Boulenger, 1915

Angola Shovel-snout Snake ( Fig. 27 , Map 25) Material: PEM R27381, Quembo River bridge camp, Trap 4, Moxico Province, -13.52658° 19.27810°, 1,248 m asl; PEM R23456–8, Quembo trap 4, Moxico Province, -13.13586° 19.04709°, 1,368 m asl; PEM R23483, Cuando River Source Trap 4, Moxico Province, -13.00164° 19.1296°, 1,372 m asl; PEM R23510–2, Cuito Source Lake, Moxico Province, -12.68866° 18.36025°, 1,426 m asl. Description: Dorsal scales smooth and in 15 rows at midbody; 116–124 smooth ventrals; 18–26 paired subcaudals; 1 (rarely 2) preoculars; 2 postoculars; temporals mostly 1+2; 6 supralabials, with 2 nd –4 th entering the orbit; 7 infralabials, the first three in contact with the anterior chin shield; cloacal scale entire; 21–36 fused dark dorsal spots. Largest female: 200 + 21 mm (PEM R23456); largest male: 198 + 25 mm (PEM R23458). Habitat and natural history notes: All specimens were captured in traps in sandy areas next to source lakes. Comment: Boulenger (1915) described this species from Angola, but did not designate a precise type locality. Loveridge (1958) was the first to propose designating Huíla as the type locality, but it was Broadley (1980) that finally restricted it to Caconda, since the Huíla material could not be found. This species is mostly distributed in central and western Angola, with isolated records from western Zambia, the Zambezi Region (= Caprivi Strip) in north-eastern Namibia, and northern Botswana ( Broadley 1980). Material from south-eastern Angola exhibits the same dorsal coloration (large black fused blotches, similar to P. janii , which is restricted to Mozambique and north-eastern South Africa), lower ventral and subcaudal scale counts, and two postoculars as described for specimens from western Zambia, which differ from the type material from Caconda ( Broadley 1980). Despite these differences, Broadley (1980) did not make any taxonomic changes but stated that a larger series was needed to resolve this issue. The taxonomic status of this material is under investigation, and it may prove to be a separate species from the western and southern populations.

Figures

Fig. 27. Prosymna angolensis from Cuando River source. Photo by Werner Conradie.