A New Aquatic Snake From Brazil's Mato Grosso

Helicops apiaka sp. nov. (UFMT-R 8180), live specimen from
aranaíta municipality, Mato Grosso State, Brazil, with a detail of
ventral coloration (lower right corner).

The aquatic snake genus Helicops Wagler, 1830, is widely distributed in South America  and of closely related to Hydrops and Pseudoeryx. Currently, 15 species of Helicops are recognized with five species (H. danieli, H. pastazae, H. petersi, H. scalaris, and H. yacu) endemic to northwestern Amazonia in Ecuador, Colombia, Peru, and Venezuela. Ten species are known to occur in Brazil, with four of them restricted to southeastern and southern regions (H. carinicaudus, H. gomesi, H. infrataeniatus, and H. modestus). The remaining six species occur in the Brazilian Amazon (H. angulatus, H. hagmanni, H. leopardinus, H. polylepis, H. tapajonicus, and H.trivittatus).

Kawashita-Ribeiro and colleagues (2013) recently collected specimens that resemble the  widespread H. angulatus from the Brazilian state of Mato Grosso, but which differed  in color pattern and scalation. They named it Helicops apiaka, and it is from the type locality of Paranaíta, in the state of Mato Grosso, Brazil. It is distinguished from all other Helicops by its dorsal scales in 21/21/19 rows in males and 23/21/19 rows in females; as well as other scale characters, and its blotched ventral surface.

Citation
Kawashita-Ribeiro, R.A, Ávila, R. W., Morais, D.H.. 2013. A New Snake of the Genus Helicops Wagler, 1830 (Dipsadidae, Xenodontinae) from Brazil. Herpetologica 69(1):80-90.