Osteology, morphology, and female choice in species of the genus Cynolebias (Cyprinodontiformes: Rivulidae)

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the utility of different osteological and morphological characters for phylogenetic analyses was done using clear and double stained specimens and measurements of morphometric parameters respectively. Scanning electron microscopy was used to study the morphology of the egg chorion. Female choice tests were also conducted to test male traits that may be preferred by females. The osteological analysis showed that some characters previously unreported may be phylogenetically useful. Head scalation patterns were found to be intraspecifically variable, making them inappropriate to use in systematics. Each morphometric parameter analyzed resulted in different species clusters. The analysis of the eggs chorion showed that eggs characteristics are species-specific and useful in species diagnosis. Females of C. constanciae showed no preference on male traits considered, while females of C. whitei showed preference for males that exhibited more courtship displays