Preference and selection of prey by creek chub (Semotilus atromaculatus) inhabiting the Mink River, Manitoba

Abstract

Listen

Translate article

In the Mink River, Manitoba, adult creek chub were observed to be selective feeders consuming brook stickleback in early summer and crayfish in late summer despite an abundance of other potential prey fishes, particularly johnny darters and a number of cyprinids. Laboratory experiments conducted to investigate preference, utilizing creek chub from two isolated populations, Mink River and Norquay Channel, Manitoba, demonstrated that both brook stickleback and crayfish were preferred least, ranking behind johnny darters and two species of cyprinids, pearl dace, and common shiners, respectively. Subsequent experiments were conducted to examine a number of possible factors which might reduce or increase the accessibility of potential prey species. Results revealed that the johnny darter, although preferred, was protected from predation by creek chub by the presence of a rocky substrate. Similarly the presence of simulated rooted aquatic vegetation reduced the accessibility of brook stickleback. The inaccessibility of cyprinids was not attributable to a pheromone-induced fright reaction but possibly to their countershading.