The survey of molluscan fauna of Ashtamudi estuary of the southwest coast of India recorded the presence of 119 species classified under 3 classes (Polyplacophora, Gastropoda and Bivalvia), 57 families and 96 genera. The species diversity was dominated by the Gastropoda (69 species), followed by the Bivalvia (49 species) and the Polyplacophora (1 species). The report includes four species recorded for the first time from India: Desmaulus edgarianus (Melvill, 1898), Pilosabia trigona (Gmelin, 1791), Nassarius javanus (Schepman, 1891) and Jorunna labialis (Eliot, 1908). The true diversity of the mangrove region was as good as that of a community with 31.380 (= 31) equally common species; the respective values for the bar mouth and lake regions were 15.516 and 8.997, respectively, indicating that the molluscan species assemblage of the mangrove was the most diverse and of the lake, the least. True β-diversity across this gradient registered 1.792, which means that though there were three communities, they were equivalent to only 1.792 (= 2) effective communities, i.e., the three actual communities were as different from each other as 2 with equal weights and no species in common.

印度西南海岸阿什塔木迪河口软体动物区系的调查记录了119个物种的存在，该物种分为3类（聚斑，腹足纲和双壳纲），57个科和96属。物种多样性以腹足纲动物（69种）为主，其次是双壳纲（49种）和多菌斑（1种）。该报告包括四个种类记录首次从印度：Desmaulus edgarianus（Melvill，1898年），Pilosabia TRIGONA（格梅林，1791），织纹螺javanus（Schepman，1891年）和Jorunna口唇（艾略特，1908年）。红树林地区的真实多样性与拥有31.380（= 31）个同样常见物种的群落的真实多样性一样好。坝口和湖泊区域的相应值分别为15.516和8.997，表明红树林的软体动物种类组合最多，湖泊的最少。该梯度上的真实β多样性记录为1.792，这意味着尽管存在三个社区，但它们仅等效于1.792（= 2）个有效社区，即，三个实际社区彼此之间的权重相同，彼此相同，为2。没有共同的物种。