The Herpetological Journal

pp. 171-176
Authors: Martins, Marcio

Abstract: The semi-aquatic teiid lizard Crocodilurus amazonicus (local name jacarerana) inhabits lakes and rivers throughout Amazonia. Although it is a common species in many areas, very little information is available on its biology. I provide information on the ecology of C. amazonicus in areas of flooded forests in central Amazonia, Brazil. Most field observations were made at two igapó (blackwater swamp) forest in the Negro River basin, from 1992 to 1995. Lizards were found accidentally or during time-constrained searches by boat or on foot. More than 100 individuals were observed in both areas. Lizards were either swimming in shallow waters or exposed on the ground or on low vegetation. During low water, when large expanses of shoreline became exposed, C. amazonicus foraged and basked on these margins. When the water began to rise and several ponds were formed in the igapó forests, the lizards moved into the flooded forest. They were much easier to find during low water. The jacarerana feeds on several prey types, but eats more crustaceans and other aquatic animals than terrestrial teiids. I found 85 prey items in 26 stomachs. Arthropods (insects, shrimps, crabs and spiders) comprised about two thirds of total prey volume and vertebrates (fish and frogs, including tadpoles) about one third. Because most prey were aquatic, C. amazonicus probably forages mainly in the water. The jacarerana may be the only Neotropical lizard that feeds frequently on fish (23% of total prey volume) and crabs (16%). The occurrence of C. amazonicus in many protected areas in Brazil and adjacent countries may offset population declines associated with development in the future.

Keywords: TEIIDAE, AMAZONIA, AQUATIC LIZARD, PISCIVORY, SWAMP FOREST