Hermaphroditism in the bivalves Anadara tuberculosa and Anadara similis Sowerby 1883 (ARCIDAE) in Colombian Pacific mangroves.

The hermaphrodite condition of the cockles Anadara tuberculosa and Anadara similis, gonochoric species living in mangroves of the Pacific coast of Colombia, are described in this paper. The gonads of 290 individuals of A. tuberculosa and 336 individuals of A.similis collected in five localities of the Colombian Pacific coast were analyzed using histological methods. Our results exposed that 3.1 % of A. tuberculosa and 3.0 % of A. similis analyzed showed signs of both ovules and spermatozoids, as well as simultaneous sexual maturation. Based on this frequency of occurrence of hermaphrodite individuals and the fact that hermaphrodite organisms were present in most of the sampling sites, we conclude that hermaphroditism is a normal rather than casual condition of these two species. We suggest that future studies in the hermaphroditism of these organisms center on the determination of factors potentially affecting this condition.