Systematic Diversity, Population Abundance and Ecological Significance of Shellfish Fauna in Bihar, India

Freshwater shellfishes, despite their ecological and economic importance, remain poorly studied in many parts of India, particularly in the northeastern region of Bihar. This study was undertaken to document the taxonomic diversity, abundance, and economic value of shellfishes in the Mahananda-Koshi basin. Shellfishes were collected from both lentic and lotic water bodies using hand-picking and dredging techniques. Systematic identification was carried out using standard taxonomic keys and reference literature. Species were categorized into three groups-abundant, common, and rare-based on their frequency of occurrence. In addition, market surveys were conducted to assess the economic significance of different taxa. A total of 24 taxa, including gastropods, bivalves, and crustaceans, were recorded. Out of the 24 taxa recorded, the most abundant species group accounted for 16.7%, whereas the least abundant (rare) group represented 20.8% of the total diversity. Market analysis revealed that M. gangeticum and other small-sized Macrobrachium species had the highest economic value, followed by Paratelphusa and edible gastropods (Pila and Bellamya). Overall, the study highlights the rich ecological diversity and considerable economic potential of freshwater shellfishes in the region, underscoring the urgent need for their sustainable exploitation, management, and conservation to maintain ecological balance and support rural livelihoods.