Invertebrate assemblages associated with seaweeds at different locations in the red sea, egypt

Abstract

The epiphytic organisms play an important role in nutrient cycles and the diversity of the ecosystem in which they occur. The present study investigated the abundance and community structure of invertebrates associated with seaweeds in the Red Sea, Egypt. Six species of seaweeds; Caulerpa racemosa, Sargassum cinereum, Cystoseira myrica, Halimeda tuna, Hormophysa cuneiformis and Digenia simplex were collected from three different locations; Kalawy Bay, Mangrove area and the National Institute of Oceanography and Fisheries (NIOF) at Hurghada. The study was carried out in winter. The distribution of seaweed was different in the investigated locations. Twenty-six invertebrate species were identified from three locations. At the Mangrove area station, amphipods were the most abundant fauna associated with C. myrica and H. cuneiformis, while nematode was the most abundant group associated with C. myrica, H. cuneiformis and S. cinereum at Kalawy Bay. At NIOF station, the most abundant organisms on C. racemosa and S. cinereum were nematode species, while amphipods were the most abundant organisms on C. myrica. The diversity indices revealed that the highest value of species richness was recorded for C. myrica at the Mangrove station, while the highest species richness values for Sargassum cinereum were recorded at Kalawy Bay and NIOF stations. D. simplex and S. cinereum showed the highest similarity according to the abundances of associated epiphytic fauna.