Feeding of an Iberian stream cyprinid assemblage: seasonality of resource use in a highly variable environment.

摘要: Food resource use by seven cyprinids from an Iberian stream was analysed over 9 months. Differences in food were found both between species and within seasons. Plant material a more important for carp, nase, goldfish barbel than gudgeon, roach chub, irrespective of the season. Chironomid larvae staple animal former five throughout year. Roach especially latter, displayed large seasonal variations prey use, with chironomid only being during autumn. Ephemerellid nymphs ephemeropteran imagos dominated diet chub spring summer, respectively. Dipteran adults Formicidae most other common ephemerellid hydropsychid larvae. overlap among three dominant (roach, chub) variation. High overlaps observed autumn when these used same resources. During summer much lower each specialising on different prey. The remaining less abundant had amongst themselves barbel, all It is suggested that morphological constraints, habitat partitioning temporal changes limitation may be involved producing patterns use.