Water dispersal of Amphisbaena alba and Amphisbaena amazonica (Squamata: Amphisbaenia: Amphisbaenidae) in Brazilian Amazonia

Information on the use of aquatic environments by two species of amphisbaenids (Amphisbaena amazonica Vanzolini, 1951 and Amphisbaena alba Linnaeus, 1758) are presented. These findings suggest that aquatic environments are not a barrier to these animals, until now considered as strictly fossorial. New studies on amphisbaenians in natural conditions are needed in order to better understand which species may use water environment during dispersal events and the frequency of this behavior in the group

Reproduction and diet of Imantodes cenchoa (Dipsadidae: Dipsadinae) from the Brazilian Amazon

Imantodes cenchoa (Linnaeus, 1758) is distributed from the east coast of Mexico to Argentina. In Brazil, it occurs in the north, central-west and northeast regions. We present information on the reproductive biology and diet of I. cenchoa from analysis of 314 specimens deposited in the Herpetological Collection of the Museu Paraense Emílio Goeldi (MPEG). Imantodes cenchoa displays sexual dimorphism in the snout-vent length, where sexually mature females are larger than mature males (t = 4.02, p < 0.01; N males = 150, N females = 71), head length (f1.218 = 98.29, p < 0.01; N males = 150, N females = 71), and head width (f1.218 = 112.77, p < 0.01, N males = 150; N females = 71). Bi-sexual maturity is observed, with males becoming sexually mature earlier than females. Females with eggs were recorded from November to January (rainy season) and from April to July (dry season), suggesting two reproductive peaks throughout the year, with recruitment occurring mainly during the rainy season, when there is a greater supply of food. Imantodes cenchoa is a nocturnal active forager, capturing prey that are asleep on the vegetation. In 32.80% of the analyzed specimens, food contents were present, of which 84.11% were lizards of the genera Norops (69.16%, N = 74) and Gonatodes (14.95%, N = 16). The other 15.89% of the contents were made up of items in an advanced state of digestion, preventing their identification. Some specimens had more than one food item in their digestive tract, accounting for 107 prey items in total. There was no ontogenetic variation in the diet of I. cenchoa, and the predominant direction of prey ingestion was antero-posterior (71.96%). Larger snakes tended to feed on larger prey, although these did not exclude small prey from their diet

Food habits of Anilius scytale (Serpentes: Aniliidae) in the Brazilian Amazonia

Information on the diet of Anilius scytale is provided based on the analysis of 162 specimens from the Brazilian Amazonia. Amphisbaenians (Aulura anomala Barbour, 1914; Leposternon polystegumn [Duméril, 1951] and Amphisbaena sp.), which are highly specialized for a fossorial life, accounted for 81.25% of the recorded items, followed by snakes - Anilius scytale (Linnaeus, 1758), and Tantilla melanocephala (Linnaeus, 1758): 12.5% - and caecilians - Caecilia cf. gracilis Shaw, 1802: 6.25%. We found a positive, although not significant, relationship between the snout-vent length of A. scytale and the total length of the prey and a tendency for smaller specimens to ingest proportionately larger prey. Anilius scytale forages mainly on the ground, at night, as well as in aquatic environments. The non-selective capture of either proportionately large or small prey by A. scytale may reflect the opportunistic nature of the encounters. A tendency of the juveniles of this species to ingest proportionately larger prey may be associated with either a low availability of prey with a size compatible to that of the juveniles, or with their inexperience in selecting prey. Ingestion of prey headfirst may be an attempt to minimize the risk of injury the prey could cause through their rigid, pointed and sharp structures or powerful bites