Morphological diversity and age dependent transformations in progeny of the large barbs (Barbus intermedius complex sensu Banister) of several morphotypes from Lake Tana (Ethiopia). Results of a long-time experiment

Abstract

Results of a long-time (2005–2011) experiment in crossing and rearing the large African barbs from Lake Tana (Ethiopia) are presented. One may conclude that progeny from homonomic crossings of large-mouthed barbs acquire diagnostic traits of their parental morphotype at different age. Some males originated from different crossings reached sexual maturity before acquiring diagnostic traits of a certain morphotype. Siblings from both homonomic and heteronomic crossings living in the same conditions considerably differed both in external and in skull characters. Differences both in external and skull characters between some siblings originated from a homonomic crossing that lived in a pond and those that lived in aquaria were equivalent to the differences between moiphotypes.