首页 | 本学科首页   官方微博 | 高级检索  
   检索      


An experimental study of body size and food size relations in crucian carp,Carassius carassius
Authors:Cynthia A Paszkowski  William M Tonn  Ismo J Holopainen
Institution:(1) Department of Zoology, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada;(2) Department of Biology, University of Joensuu, P.O. Box 111, SF-80101 Joensuu, Finland
Abstract:Synopsis In dense, single-species assemblages of crucian carp, competition is intense and results in populations of stunted fish. To explore mechanisms underlying this competition, we measured handling times, return rates, and prey choice for five sizes of crucian carp feeding on six sizes of a standardized food. Handling times increased with prey size and decreased with fish size. Return rates (dry mass ingested per unit handling time) increased dramatically with fish size, and generally decreased with increasing prey size, especially for small fish. Patterns of return rates among size-classes suggested that one or more size-related shifts in feeding efficiency exist for crucian carp; combined with physiological stresses related to winter anoxia, the inability of fish to make these shifts may contribute to size structures observed in high-density populations. Comparisons of relations among fish size, prey size, and return rates for crucian carp and bluegill, Lepomis macrochirus, suggest that similar intraspecific competitive relations exist between generalist species with size-structured populations. Despite differences in return rates among prey sizes, the extent of food selectivity based on prey size exhibited by crucian carp in two types of choice trials was less than predicted. Crucian carp commonly take in several items before mechanically processing food with their pharyngeal apparatus; this multiple prey processing may contribute to disparities between observed choice patterns and those predicted based on return rates for single prey.
Keywords:Feeding behavior  Handling time  Intraspecific competition  Multiple prey processing  Prey choice  Stunting  Cyprinidae
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号