11. Feeding ecology of the neotropical worm snake Atractus reticulatus in southern Brazil

Analyses of the gut content of 126 specimens of Atractus reticulatus from the eastern Central Depression of Rio Grande do Sul State, southern Brazil, indicate that this species feeds exclusively on annelids, and primarily on oligochaetes of the family Megascolecidae. Thirty-two stomachs presented 52 items, of which 84.6% were oligochaetes (75.0% family Megascolecidae, 7.7% family Glossoscolecidae, and 1.9% unidentified families), 7.7% were Hirudinea and 7.7% unidentified annelids. Chaetae of oligochaetes were also found in the intestines of 40 additional specimens. Among 20 individuals of A. reticulatus of different size classes captured with some content in the gut, 85.0% were captured at night or in the early hours of morning, indicating foraging activity in these periods. About 83% of the ingested prey were free- living, epigeic annelids, which indicates that A. reticulatus forages mainly on the ground. Prior to swallowing, the annelids were usually oriented and ingested from the anterior portion of the body, a method probably related to autotomy of the prey, which may occur if they are captured from the posterior.