Studies on the littoral seaweed epifauna of St Croix Island. 3. Gelidium pristoides (Rhodophyta) and its epifauna

Abstract

The distribution of Gelidium pristoides, a commercially important seaweed in South Africa, was investigated on St Croix Island in Algoa Bay. Total area of the midlittoral G. pristoides belt was 4241 m² and total summer standing crop of this perennial seaweed was 265 kg (dry mass). Monthly numerical composition of G. pristoides epifauna at three sites on St Croix is presented and discussed. Nematodes dominated the epifauna throughout the year with harpacticoids the second most abundant taxon. The presence of nauplius, annelid and Diptera larvae as well as juvenile amphipods and molluscs in the epifauna indicates the role of seaweeds as nursery areas for littoral fauna. G. pristoidesepifauna averaged 1,77 x 10⁵ animals m^-2. Total summer standing stock of G. pristoides epifauna on St Croix was determined by two methods which yielded 6,4 x 10⁸ and 7,3 x 10⁸ animals respectively.