Habitat selection, parasites and injuries in Amazonian crocodilians

Abstract

Caiman crocodilus is found most frequently in relatively warm, shallow or grassy areas in the larger rivers, lakes and canals of Amazonia. The habitats that it uses are increasing in area because of human activities. Paleosuchus trigonatus appears to be restricted to small forest streams in dense forest. Water temperatures are relatively low and constant in the streams and opportunities to bask are limited in the forest. Paleosuchus palpebrosus and M. niger are both found most commonly in the parts of major lakes, rivers and canals which have steep banks and little floating grass. To what extent the present distributions are influenced by intensive hunting of M. niger is unknown. Animals had similar injury rates in all habitats but in the Lago Amanã area individuals in the lake had higher leech, and lower nematode infestation than individuals in the surrounding canals. The giant rotifer Limnias ceratophylli is reported for the first time as an epizoic on the ventral surfaces of M. niger