Sexual dimorphismUploader: Grosida 2 years ago Subscribe 7
Encyclopedia of Aquarium and Pond Fish. Sexual selection is considered the major cause of sexual dimorphism, but recent observations suggest that natural selection may play a more important role in the evolution of sex differentiation than previously recognized. Fish of the size of a siluroid fish, Ompak bimaculatus Block , with particular range between cm are usually intersex. Females often show a preference for exaggerated male secondary sexual characteristics in mate selection. Moreover, during female fish it is round or oval button shaped. In optimal environmental conditions e.