The 'Barbus' intermedius species flock in Lake Tana (Ethiopia):: II -: Morphological diversity of "large barbs" from Lake Tana and neighbouring areas:: homoplasies or synapomorphies?

In the Lake Tana barbs the PCA of skull measurements reveals "ontogenecic channels" within which individual ontogenetic trajectories are located. Some individuals seem to acquire slates of characters specific for a certain morphotype quite late when they are 20-25 cm SL and 3-5 years old. Morphologically different sympatric forms of large barbs are also found in the Didessa (Blue Nile basin), Genale (Wabi Shebeli basin), and Gibe (Omo basin) rivers. In all the three rivers barbs resembling certain morphotypes of the Lake Tana barbs occur. Most probably, allopatric big-mouthed forms originated independently from sympatric forms which have no conspicuous specific traits and that their similarity results from homoplasies.