Estudo sistemático preliminar do gênero hydrops wagler, 1830, com ênfase nos espécimes da Amazônia oriental (serpentes: colubridae: xenodontinae)

Abstract

The South American water snake genus Hydrops Wagler, 1830, is formed by H. martii (Wagler, 1824) and H. triangularis (Wagler, 1824) with six subspecies: the nominal, H. t. bassleri Roze, 1957, H. t. bolivianus Roze, 1957, H. t.fasciatus (Gray, 1849), H. t. neglectus Roze, 1957, and H. t. venezuelensis Roze, 1957. The distinction between the species is safe, but for the subspecies of H. triangularis it is very confusing, due to the fragility of the characters used, not analyzed at the population level, which has caused publications limited to present identifications at the specific level for the genus. Aiming to support a systematic study of the genus, which will contribute to a better knowledge of the Neotropical ophiological diversity, a preliminary analysis of the Hydrops deposited in the Herpetological Collection of the Museu Paraense Emílio Goeldi (MPEG) was carried out. Through the re-identification of the 1001 specimens from MPEG, all sexed, and preliminary observations on reproductive status and feeding habits, we obtained: 1 - MPEG has 281 specimens of H. martii (127 females and 154 males) from 14 municipalities of Pará, 718 specimens of H. triangularis (369 females and 349 males) from 39 municipalities of Pará and Maranhão, most of the nominal subspecies, 2 - identification for the first time of H. t.fasciatus, from four municipalities of Pará, 3 - presence of 9 to 24 eggs in H. t. triangularis, 4 - variation of anal gland length in females of both species 5 - presence of a Symbranchidae fish (Symbranchus marmoratus) in the diet of H. t. triangularis, which 6 - showed no preference in ingesting prey by the head or tail. The results obtained, although preliminary, make it possible to 1 - hypothesize the invalidation of H. t.fasciatus, and 2 - add new data on feeding and reproduction of H. triangularis.