Functional responses of five cyprinid species to planktonic prey
- Cite this article as:
- Winkler, H. & Orellana, C.P. Environ Biol Fish (1992) 33: 53. doi:10.1007/BF00002553
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The functional responses of five species of cyprinids (Chalcalburnus chalcoides, Vimba vimba, Abramis brama, Rutilus rutilus, and Scardinius erythrophthalmus) feeding on four planktonic prey types were measured in the laboratory. Although no alternative prey types were present, the response curves were sigmoid in most cases, because attack rates were not independent of prey density. The findings are explained as being the overt expression of the fishes& foraging tactics. The chief way of maximizing food uptake, according to our interpretation, is accelerating attack rates with increasing prey density. The ability of prey to escape or relative prey size may interfere with this strategy. C. chalcoides, the only obligatory planktivore among the species studied, attacks at higher rates and responds most markedly to changes in prey density.