Abstract
In most ecological studies, traditional biodiversity indices such as the Shannon have generally been used in assessing species diversity. New taxonomic distinctness indices have been considered phylogenetic relatedness of species and provide more information for ecologists. In the present contribution traditional species richness index along taxonomic distinctness indices were used to evaluate amphipods communities of Chabahar Bay. Sampling was carried out in 19 stations during December 2016. We identified 21 species belong to 14 genera and 12 families. Amplisidae was the most abundant family. Shannon index was 0-2.9 with average value of 1.2. The highest distribution of amphipod communities was on the east, northeast and southwest coasts of the bay. The highest average taxonomic distinctness index (AvTD) was calculated for west, southwest and southeast. Therefore, considering that higher taxonomic distinctness indices indicate more suitable ecological conditions, it can be concluded that the middle part of Chabahar Bay has more unfavourable ecological conditions for amphipods and other macrobenthos.