Body shape variation of three species of Percichthys in relation to their coexistence in the Limay River basin, in northern Patagonia

• Published in: Environmental biology of fishes Vol. 53; no. 2; pp. 143 - 153
• Main Authors: CUSSAC, V. E, RUZZANTE, D, WALDE, S, MACCHI, P. J, OJEDA, V, ALONSO, M. F, DENEGRI, M. A
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.10.1998; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fish; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Morphology; Percichthys; Percichthys colhuapiensis; Percichthys trucha; Percichthys vinciguerrai; Predation; Prey; Reservoirs; River basins; Rivers; Synecology; South America; Argentina; America; Argentina, Limay R; Morphological variation; Trophic relation; Reservoir; Coexistence; River basins; Freshwater environment; Vertebrata; Buccal apparatus; Geographic distribution; Pisces; Interspecific competition; Intraspecific comparison; Morphometry
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1023/A:1007492101376

We describe morphological variation within and among three species of Percichthys (Perciformes, Percichthyidae) inhabiting two reservoirs within a single river drainage (Limay River) in Argentina. Two small-mouthed percas', P. vinciguerrai and P. trucha were found in both reservoirs (Alicura and Piedra del Aguila), and a third species, the large-mouthed perca, P. colhuapiensis, was found in Piedra del Aguila. There was some specialization in diet where the three species coexisted. The large-mouthed perca ate a higher proportion of large prey (>25 mm) and a smaller proportion of small prey (< 15 mm) than did the small-mouthed species, suggesting some diet specialization based on prey size. Percichthys trucha and P. vinciguerrai had smaller gapes, as indicated by shorter heads and jaws, and narrower mouths, in Piedra del Aguila where they coexisted with the large-mouthed species, than in Alicura where the competitor was virtually absent. Thus the direction of morphological changes in trophic-related characters in P. trucha and P. vinciguerrai is consistent with the hypothesis of character shift due to interspecific competition.[PUBLICATION ABSTRACT]