Spatial and Temporal Distribution of Brachyuran Crabs in Mangroves of the Persian Gulf

The assemblage structure of brachyuran crabs and their relationships with environmental parameters of water and sediment were assessed in the mangrove ecosystem of the northern Persian Gulf. In this study, the spatial distribution and diversity of crabs within two different habitats were studied through four seasons in 2018. A total of 11 species were identified, of which nine species were found in un-vegetated (mudflats) and eleven species in vegetated (mangrove) habitats. Opusia indica, Manningis arabicum, and Nasima dotilliformis were the dominant species in un-vegetated habitats, while O. indica, M. arabicum, and Parasesarma persicum were dominant in vegetated habitats. Nonmetric multidimensional scaling ordinations (nMDS) and a three-way factor PERMANOVA indicated that the crab species assemblage differed significantly between the two habitats, but not among seasons. The vegetated habitats showed higher species richness and Shannon-Weiner diversity index than un-vegetated habitats. However, the species evenness index showed no difference between the habitats. The result of redundancy analysis (RDA), indicated that the sediment grain size and organic matter (OM) content were responsible for the distribution of brachyuran crabs between these two habitats. The results of this study will be useful in the management and conservation of mangrove forests and in understanding the ecological patterns of brachyuran crabs in the Persian Gulf.