Consequences and Modes of Morphological Diversification of East African and Eurasian Barbins (genera Barbus, Varicorhinus and Capoeta) with Particular Reference to Barbus Intermedius Complex

Based on results of the comparison of skull proportions and using available data on phylogeny of barbins we discuss patterns of morphological diversity of the present forms and modes of morphological transformations resulting in their emergence. There is no strict correspondence between distance in a character space and genealogical closeness of forms. Similar forms of barbins independently originated from a generalized form in different sites of Africa and western Asia. Regularity of patterns of morphological diversity is thought to be caused by the channeling of morphological transformations. Heterochrony played an important part in evolution of the African large Barbus and Varicorhinus. Extraordinary morphological diversity of the African barbins, Lake Tana barbs in particular, is caused mainly by drastic changes in patterns of relative growth late in ontogeny.