Hagmann's Keelback

distribution

Distribution. Known from Brazil, Colombia, and Venezuela (Plt. 281 A). In Brazil, recorded in Amazonia (Plt. 281 A) at low elevations (Plt. 281 B). Observed in the field in streams and flooded forest areas (Cunha and Nascimento, 1993; Silva Jr., 1993; Martins and Oliveira, 1998).

Atlas of Brazilian Snakes: Verified Point-Locality Maps to Mitigate the Wallacean Shortfall in a Megadiverse Snake Fauna

Diagnosis

Helicops hagmanni is distinguished from all its congeners by having subcaudal keels, 21–29 dorsal scale rows at mid-body (versus 17–20 in H. angulatus ; 21–22 in H. apiaka ; 19 in H. gomesi ; 23–25 in H. pastazae ) and 50–59 subcaudals (compared to 79–103 in H. apiaka ; 72–117 in H. pastazae ); (for information on references, see Suppl. material 3).

Distribution and identification of the species in the genus Helicops Wagler, 1830 (Serpentes, Colubridae, Xenodontinae)

Distribution

The distribution of H. hagmanni ranges from the Estuary of the Amazonas to the Brazilian Provinces Amazonas, Acre, Rondônia and the Venezuelan Province Amazonas. There is also one record from south-western Colombia (Rossman 1975, Fig. 2a).

Distribution and identification of the species in the genus Helicops Wagler, 1830 (Serpentes, Colubridae, Xenodontinae)

Morphology remark

Morphology remark The examined specimens had smooth subcaudal scales on the anterior part of the tail, changing to weakly-keeled scales at the posterior tail, which contrasts with the examination results in Moraes-da-Silva et al. (2019) who reported them to be absent, without further notes on methodology for this character (see also Tables 1, 2).

Distribution and identification of the species in the genus Helicops Wagler, 1830 (Serpentes, Colubridae, Xenodontinae)