Insights into the Diversity and Distribution of Gastropods in River Kana Damodar (Kaushiki), West Bengal, India: A Spatial Perspective

This study aimed to assess the spatial distribution, diversity, and community composition of gastropods in the anthropogenically altered Kana Damodar River (Kaushiki), West Bengal, India. Monthly collections of gastropods were conducted at five sampling sites (KD1-KD5) during the 2019-20 and 2021-22 sampling periods using various sampling methods. Three diversity indices were computed: dominance index, Shannon-Weiner index, and Margalef’s richness index. Hierarchical cluster analysis using the Bray-Curtis similarity matrix and one-way analysis of similarities (ANOSIM) were employed to evaluate the spatial organization and dissimilarity of gastropod assemblages across the sampling sites. Eleven (11) gastropod species, distributed across eight (8) families, were recorded from five sampling stations. The study revealed significant spatial variability in species composition, with Filopaludina bengalensis and Radix rufescens being the most dominant species. The dominance index showed a prevalence of a few opportunistic species, with values ranging from 0.24 to 0.46. The Shannon-Weiner index (H') ranged from 0.55 to 1.98, indicating low species diversity across all stations, which suggests potential vulnerabilities in ecosystem stability of the studied river. Margalef's richness index showed notable variation in species richness, with values ranging from 0.79 to 1.55, suggesting reduced gastropod diversity in the studied river. Hierarchical cluster analysis and ANOSIM further underscored the spatial heterogeneity of gastropod communities across the studied river. The findings of this study highlight the urgent need for targeted conservation and site-specific management strategies to address the unique ecological challenges at each sampling station in the River Kana Damodar (Kaushiki).