Biologia reprodutiva e alimentar de helicops angulatus (linnaeus, 1758) (serpentes: colubridae) na Amazônia oriental, Brasil.

Abstract

The objective of the work is to study the reproductive and feeding biology of Helicops angulatus, from the Eastern Amazon, Pará. We analyzed 240 specimens from the Herpetological Collection of the Museu Paraense Emílio Goeldi. In the study of sexual dimorphism, morphometric and meristic analysis were performed. The gonads and stomach contents were examined through abdominal incision, and males were considered mature if the duetus deferens were tangled and/or opaque and females with secondary vitellogenic follicles (> 10mm), eggs, enlarged oviduct or with egg marks. Food items were identified to the lowest possible taxonomic level and the direction of prey ingestion (anteroposterior/post-anterior) was observed. Mature females showed greater rostro-cloacal length than mature males (t= 6.12; p<0.05). Tail length of males was relatively longer than females (t=6, 1; p<0.05). Females have greater numbers of ventral scales than males (t= 3.5; p<0.05). and these numbers of subcaudal scales greater than females (t= 6.0; p<0.05). Females with vitellogenic follicles, eggs and pups were found throughout the year, indicating seasonal reproductive cycles. Most individuals presented anteroposterior direction of intake. There was a predominance of fish in the diet composed of the following Orders and Families: Gymnotiformes-Gymnotidae; Perciformes-Cichludae, Cichlidae; Siluriformes-Callfchthyidae; Characiformes-Erythrinidae, Lebiasinidae, Curimatidae. All fish species identified occur in lentic environments and most forage at the bottom of the water column. Three individuals had anurans in their stomach contents, belonging to the following Families and Genera: Leptodactylidae Adenomera; Bufonidae-Bufo and Hylidae- Hyla. These genera are found in the leaf litter and shrubs, indicating eventual foraging on the ground.