Composition and seasonal variability of the suprabenthic reef-fish assemblage in False Bay, South Africa

Abstract

The composition and seasonal variability of a False Bay suprabenthic reef-fish assemblage was investigated monthly at a protected reef site (to a depth of 25 m) for 14 months. In total, 25 484 fish from 28 species (26 demersal) were counted. Sparids dominated the assemblage (50 %of species and 87.3 %of individuals), followed by cheilodactylids (15.4 %of species and 7.5 %of individuals). Pachymetopon blochii (30.6 %), Sarpa salpa (17.7 %), Boopsoidea inornata (16.1 %), Chrysoblephus laticeps (10.4 %) and Spondyliosoma emarginatum (9.2 %)  were the five most abundant species, while the ten most abundant species made up over 93 % of censused individuals. Composition was relatively stable year round, irrespective of water temperature variations, with 16 of the 26 reef-fish species censused encountered during more than 10 monthly censuses. Triakus megalopterus and large Chrysoblephus gibbiceps were the only species whose abundance appeared to vary seasonally.

Key words: census, fish density.