The rock-pool fish community of Koppie Alleen and an assessment of the importance of Cape rock-pools as nurseries for juvenile fish

Abstract

Fishes inhabiting rock-pools at Koppie Alleen on the southern Cape coast were collected quarterly over two years. Clinids (10 species) were numerically dominant with Clinus cottoides (63, 4%) and C. dorsalis (8, 5%) being the most abundant species. Five other species, namely C. superciliosus, Chorlsochismus dentex, Kuhlia mugli, Liza richardsoni and Diplodus sargus each constituted more than 2% of the sample. Species richness varied seasonally, being greater during the summer months owing to an influx of transient species. Comparisons with the eastern and western Cape fish faunas reveal an eastward increase in the total number of species, in the number of subtropical species and in the contribution of transient species, and substantiates previous observations on trends in the composition of the resident component. The importance of the Cape rock-pool habitat as a nursery area Is assessed by comparing the abundance of the fish In rock-pools with available information on other inshore habitats. No species were found to be entirely dependent on rock-pools as a juvenile nursery area although Acanthistius sebastoides, Epinephelus gusza, Sparodon durbanensis, Diplodus cervinus, Chellodactylus fasciatus and Chirodactylus brachydactylus appear to make some use of this habitat.