Diversification of prey capture techniques among the piscivores in Lake Tana's (Ethiopia) Labeobarbus species flock (Cyprinidae)

• Published in: African zoology Vol. 45; no. 1; pp. 32 - 40
• Main Authors: de Graaf, Martin, van de Weerd, Gerco H., Osse, Jan W.M., Sibbing, Ferdinand A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01-04-2010
• Subjects: Adaptive radiation; Evolution; Functional morphology; Predation; Trophic segregation
• ISSN: 1562-7020; 2224-073X
• DOI: 10.1080/15627020.2010.11657252

Lake Tana harbours the only known intact species flock of large cyprinid fishes (15 Labeobarbus spp.). One of the most curious aspects of this species flock is the large number (8) of piscivorous species. Cyprinids are not well designed for piscivory (i.e. small slit-shaped pharyngeal cavity, lack of teeth in the oral jaws, lack of a stomach), which raises the question how well adapted these labeobarbs actually are to function as piscivores? In this study we analyse the kinematics of prey capture (by varied combinations of suction, swimming and jaw protrusion) among Lake Tana's piscivorous labeobarbs. Suction feeding kinematics were similar to values reported for other piscivorous fish species. A detailed analysis of several Labeobarbus species displayed distinct types of techniques (overswimming, velocity/volume suction with jaw protrusion) suited to capture elusive prey in different macro-habitats. Lake Tana's Labeobarbus species evolved a wide range of piscivorous predation techniques, a unique scenario for cyprinid fishes.