Identification and distribution of Gastropods in the east coasts of Qeshm Island (the Persian Gulf, Iran)

Gastropods are considered as the main molluscs of rocky shores and often show marked zonation patterns both horizontally and vertically. Biodiversity and distribution of gastropods were investigated at 8 stations on rocky shores of Qeshm Island during the coldest and warmest months January and August, respectively, in 2018. In the present study, 35 gastropod species were identified. The highest frequency of gastropod (550 +/- 345) was observed at S2 station (Tula 2) and the lowest one was observed at S8 station (Naz Island) (273 +/- 83.70). Planaxis sulcatus was found as the dominant species at all stations (%55.76). The results of the 3-way permutational (MANOVA) test showed that the species' structures of the gastropod community are different at various stations and during sampling months. The results of the nMDS test confirmed these differences in the structure and species composition of the gastropod population during two months. The highest diversity (Shannon index: 3.13) and species richness (Margalef index: 4.53) was observed at the S2 station and the lowest diversity (Shannon index: 2.73, Margalef index: 3.03) was observed at the S8station. According to the results of the SIMPER test, the highest percentage of participation in Bray-Curtis dissimilarity between the two months in summer and winter and at different sampling stations in terms of species density was related to Planaxis sulcatus. The structure of gastropod population at the studied stations can be influenced by the factor of seasonal changes.