Comportamento Predatório Ex situ do Caranguejo Menippe nodifrons Stimpson, 1859 (Decapoda, Brachyura) sobre Moluscos Gastrópodes

Abstract

Laboratory experiments were used to study the effect predation of the crab Menippe nodifrons Stimpson, 1859 on gastropods Stramonita haemastoma Linnaeus, 1758 Tegula viridula Gmelin, 1791 and Neritina virginea Linnaeus, 1758. The observed aspects had been of prey preference, handling time, predation techniques, prey critical size and chelal biomechanic analysis of the crabs. The crabs and the clams had been collected in the beach of the Pacheco, located in the city of Caucaia-Ce. Menippe nodifrons preferred Neritina virginea over both S. haemastoma and Tegula viridula, and S. haemastoma was strongly preferred over T. viridula. The males crabs preyed more heavily upon Neritina virginea than on both gastropods Stramonita haemastoma and Tegula viridula, while the females had eaten indistinctly the three gastropods. There were differences in hadling times between Neritina virginea, Stramonita haemastoma and Tegula viridula. The mean critical size for Neritina virginea was significantly smaller than for Stramonita haemastoma, which in turn was smaller than for Tegula viridula. The claws of the crab Menippe nodifrons are well designed for breaking shells. Differences in the morphological and mechanical features of crab claws reflect their function and account for many of the observed differences in prey handling techniques and foraging behaviour.