DIMORFISMO SEXUAL, REPRODUCCIÓN Y BIOLOGÍA ALIMENTARIA DE Helicops angulatus (LINNAEUS, 1758) (COLUBRIDAE: HYDROPSINI) EN LA AMAZONIA ORIENTAL, BRASIL

Abstract

We described natural history traits of the brownbanded water snake Helicops angulatus from Eastern Brazilian Amazon, one of the most threatened areas in Amazonia. We recorded morphometric information, feeding habits, and reproductive strategies from 97 mature females, 58 mature males, and 40 juveniles. Females are larger than males, although males have longer tail length. Females and males mature at different sizes, with males becoming mature at smaller sizes. We observed the presence of follicles and secondary eggs throughout the year. However, we found two reproductive peaks, in July and October, corresponding to the dry season in the Amazon region. Diet consists mainly of fishes, followed by frogs that use water bodies for reproduction. Most prey were ingested headfirst (82.35%), possibly to decrease risk of injuries during the capture and ingestion. We found a positive relationship between total length of the prey and snout-vent length of snakes. Compared to other species, H. angulatus ingests proportionally larger prey (22-44% of the snout-vent length of snakes), probably optimizing energy gain.

First record of Sebekia oxycephala (Pentastomida: Sebekidae) infecting Helicops angulatus (Reptilia: Colubridae) in Northeast Brazil

“…Infection with Sebekia oxycephala may be related to the semiaquatic habit and piscivorous diet of this host, since the nymphs of Sebekia species use fishes with intermediate hosts (Junker et al, 1998;Almeida et al, 2010;Santos-Costa et al, 2022), suggesting the use of Helicops angulatus as a second intermediate host in the life cycle of this parasite. The Sebekia species has already been registered infecting other species of Helicops, such as H. leopardinus (Schlegel, 1837) in Pantanal, state of Mato Grosso (Rego & Vicente, 1988) and H. infrataeniatus (Jan, 1865) in the state de São Paulo (Silva et al, 2015).…”

“…In addition, there are is a water snake, widely distributed in Brazil (Uetz et al, 2023). It primarily feeds on fish and amphibians (Santos-Costa et al, 2022) although records have shown the occurrence of lizards and earthworms in its diet (Strussmann et al, 2011;Teixeira et al, 2017).…”