Impact of predation by juvenile Clinus superciliosus on phytal meiofauna. are fish important as predators?

Abstract

Clinus superciliosus (L.) is the dominant resident fish of the rocky intertidal around the Cape Peninsula, South Africa. Meiofauna is frequently recorded in the diet of immature individuals. Predation by juvenile fish on communities was examined in a series of laboratory experiments in which the meiofauna was provided with shelter in the form of several species of algae differing in their morpholoqcal complexity. Although algal complexity significantly influenced the success of predators, results suggest that the fish selected their prey on the basis of size. Typically, they took the largest meiofauna or juvenile macrofauna i. e . amphipods, isopods and polychaetes, and unless the fish were starved, smaller components such as copepods were ignored. Using these data and material from the literature it is concluded that permanent members of the meiofaunal community are unaffected by fish predation and that complex algae only become important as a refuge in tidal pools, where fish occur at high densities for relatively long penods of time. This represents the first attempt at estimating the overall impact of fish predation on rocky shore meiofauna.