Malformation in the crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae), in São Vicente (SP), Brazil

In the seventies, the region known as Baixada Santista was a large repository of environmental contamination mainly resulting from industrial waste. In effect, the contaminated residues came from different toxic substances including chemical, biochemical and others. Industrial waste was dumped or even stored in inadequate fragile ecological sites without any previous treatment and it resulted in significant amounts of air, soil and water pollution. A male specimen of U. cordatus presenting a malformation of the pollex (immovable finger) of its major claw (left) was captured in São Vicente city, raising concern to the local press and community. The immovable finger of the propodus segment in the claw of this specimen was modified into a structure in the form of a talon. This structure resembling an avian claw was comprised of five fixed ends united at the base. This might be a result from an injury of the original corpus structure while in a confrontation with another specimen. The newly found sample showed a high incidence of micronucleated cells in the haemolymph, approximately three times higher than normally reported. Perhaps this suggests the effect of an environmental influence in the morphology of the organism, most likely linked to the several sources of pollution in the region (public dump of Alemoa/Sambaiatuba, and the industrial conglomerate of Cubatão). We propose that similar measurements could be used in the estuarine area to assess and evaluate ecological risks and adverse biological effects.