Morphological variation of Gomesophis brasiliensis and Ptychophis flavovirgatus (Serpentes, Dipsadidae, Xenodontinae)

Autor(es)

Gonzalez, Rodrigo Castellari ^[1] ; da Costa Prudente, Ana Lucia ^[2] ; Franco, Francisco Luis ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Rio de Janeiro, Museu Nacl, Dept Vertebrados, BR-20940040 Rio De Janeiro - Brazil

^[2] Museu Paraense Emilio Goeldi, Dept Zool, BR-66017970 Belem, Para - Brazil

^[3] Inst Butantan, Lab Colecoes Zool, BR-05503900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SALAMANDRA; v. 50, n. 2, p. 85-98, JUN 30 2014.
• Citações Web of Science: 1

Resumo

Gomesophis and Ptychophis are both monotypic, poorly known genera. They are small, viviparous, opistoglyphous snakes with a semi-aquatic lifestyle. They belong to the tribe Tachymenini and occur in the highlands of southern and southeastern Brazil. Here we present a redescription of their holotypes and expand the species' diagnoses. We report on intraspecific variation, testing the differences amongst disjunctive subpopulations of Ptychophis flavovirgatus, and reporting on the sexual dimorphism of both species. We examined 155 Gomesophis brasiliensis and 52 Ptychophis flavo-virgatus for meristic and morphometric character states. Ptychophis flavovirgatus is found in lotic-, clear-and cold-water environments in the Brazilian states of Minas Gerais, Paran, Santa Catarina, and Rio Grande do Sul. Gomesophis brasilien-sis is found in areas with slow-flowing waters, in the mud of wetlands, and along the margins of streams and ponds in the Federal District and Brazilian states of Minas Gerais, Sao Paulo, Paran, Santa Catarina, and Rio Grande do Sul. Both species can be distinguished from all other Tachymenini genera by following combination of characters: 17/17/15 dorsal scale rows, round pupils, and three scales in contact with the eye. Externally, they can be distinguished from each other by colouration and the presence of keeled dorsal scales in P. flavovirgatus and smooth dorsal scales in G. brasiliensis. We found sexual dimorphism in both species mainly with respect to the number of ventral scales. Amongst the Tachymenini, both Ptychophis and Gomesophis are the only ones that present characters related to the usage of aquatic habitats, although further studies are necessary to assess their phylogenetic relationship and position within Tachymenini. (AU)

• Processo FAPESP: 11/50313-0 - Diversidade e evolução de répteis no estado de São Paulo
• Beneficiário: Francisco Luís Franco
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular