Abundance Of Molluscs (Gastropods) At Mangrove Forests Of Iran

Abstract

This study determined the abundance and diversity of molluscs (focused on gastropod) at Hara Protected Area (HPA) and Gaz and Hara Rivers Delta (GHRD) mangroves, southern of Iran. Point count sampling method was employed in this study. A total of 1581 individual of gastropods, representing 28 species and 21 families, were observed in the two sites. The PCA plot indicated that all species have correlation with winter excluding species namely Ethalia sp., Haminoea sp., Trichotropis sp. and Tibia insulaechorab curta at HPA and Telescopium telescopium, Stocsicia annulata, and Stenothyra arabica at GHRD. The mean number of species was estimated 6.88±2.77 (per plot) versus 9.65±6.63 (per plot) at HPA and GHRD respectively. The results of X 2 test indicated that there was a high significant difference between total gastropod population observed at 4 seasons (X 2 3, 1 =31.9, p 0.05). The results of diversity comparisons indicated that the highest diversity was in the HPA as compared to GHRD. Furthermore, the SIMPER analysis indicated that mangroves of HPA and GHRD were dominated with Asseminea sp., although the number of population was much higher at R. mucronata habitat. Eight species namely Asseminea sp., Stenothyra arabica, Cerithidium cerithinum, Littoria intermedia, Telescopium telescopium, Iravadia quadrasi, Atys cylindrica and Cyclostrema ocrinium represented more than 91% of observations at HPA, while at GHRD, there were only three species namely Asseminea sp., Stenothyra arabica and Cerithidea cingulata which represented more than 90% of observations. The result states that the great importance of HPA and GHRD for gastropod assemblages as main food resource for wading birds must be recognized and the protection of these sites from threats must be thoroughly enhanced.