II ‐ Morphological diversity of “large barbs”; from Lake Tana and neighbouring areas: Homoplasies or synapomorphies?

Abstract

In the Lake Tana barbs the PCA of skull measurements reveals "ontogenetic channels" within which individual ontogenetic trajectories are located. Some individuals seem to acquire states 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 bigmouthed forms originated independently from sympatric forms which have no conspicuous specific traits and that their similarity results from homoplasies.

Adaptive radiation of barbs of the genusLabeobarbus(Cyprinidae) in an East African river

“…This riverine assemblage of the Genale barbs was comprised of fewer distinct forms than those found in the lacustrine species flock from Lake Tana (Golubtsov, ). Divergent morphology and preliminary gut content analysis of these forms suggested trophic specialisation (Golubtsov, ; Mina et al., ). Specifically, five different forms were reported, which included generalised, thick‐lipped, large‐mouthed (piscivorous), as well as two scraping forms with different jaw scrapers (Golubtsov, ; Mina et al., ).…”

“…Divergent morphology and preliminary gut content analysis of these forms suggested trophic specialisation (Golubtsov, ; Mina et al., ). Specifically, five different forms were reported, which included generalised, thick‐lipped, large‐mouthed (piscivorous), as well as two scraping forms with different jaw scrapers (Golubtsov, ; Mina et al., ). These same five forms were recently sampled again, along with an additional new form named short due to its short body (Figure ).…”

“…A putative riverine species flock was discovered over 20 years ago in the Ethiopian cyprinid genus Labeobarbus in the Genale River of Ethiopia (Golubtsov, 1993;Mina, Mironovsky, Golubtsov, & Dgebuadze, 1998). This riverine assemblage of the Genale barbs was comprised of fewer distinct forms than those found in the lacustrine species flock from Lake Tana (Golubtsov, 1993).…”

Adaptive radiation of barbs of the genusLabeobarbus(Cyprinidae) in the East African river

“…A putative riverine species flock was discovered over twenty years ago in the Ethiopian cyprinid genus Labeobarbus in the Genale River of Ethiopia (Golubtsov 1993;Mina et al 1998).…”

“…This riverine assemblage of the Genale barbs was comprised of fewer distinct forms than those found in the lacustrine species flock from Lake Tana (Golubtsov 1993). Divergent morphology and preliminary gut content analysis of these forms suggested trophic specialization (Mina et al 1998;Golubtsov 2010). Specifically, five different forms were reported, which included generalized, thick-lipped, large-mouthed (piscivorous), as well as two scraping forms with different jaw scrapers (Golubtsov 1993;Mina et al 1998).…”