Macrofauna community structure in extreme temperature and hypersaline waters: Khor Al-Adaid, Arabian Gulf

Arabian Gulf is characterized by hyper saline waters with high temperature levels, which fluctuate seasonally, creating natural stress for marine benthic communities. A study on benthic macrofaunal was conducted at Khor-Al-Adaid, an ‘Inland Sea’. The substratum of the study area is primarily sandy, and supports a macrofaunal community dominated by polychaetes, followed by gastropods and other group of macrofauna such as Demospongia, Stelleroidae, Scaphypoda, Crustacea, Bivalvia as and Ascidiacea in all four seasons (winter, summer, spring and autumn). A total of 108 macrobenthic species from 9 phyla were observed. The polychaetes were dominated by Nephtys sp., Eulalia viridis , Hormothoe dictyophora and Syllis sp. The highest species richness was observed in summer (47) and autumn (44). The diversity indices and statistical analyses including cluster analysis, simper analysis, k - dominance curve and redundancy analysis (RDA) showed significant variations in the community structure.