Multivariate ecological assessment of ten Indigenous IUCN threatened and near threatened freshwater fishes from South-West Regions of West Bengal, India

The freshwater fish diversity is significant in the food chain and is a nutrient source. Our study sites are home to diversified freshwater fishes due to their varied geography. For the first time, length–weight relationships of ten Indigenous International Union for Conservation of Nature-threatened fish species (were collected from the different sites from November 2019 to December 2022 in 3-month intervals. There were various types of nets with varying sizes of mesh, including gill net (0.5 to 4 cm), scoop net (0.3 × 0.3 to 0.5 × 0.5 cm), and cast net (up to 1 × 1 cm in a mesh up to 3.0 m² coverage). The “b” values range from 2.615 (Wallago attu) to 3.287 (Channa orientalis), and the correlation coefficient (r²) is ≥0.90. In contrast, native fishes have negative allometric growth, and the condition factor (K_n) of these species’ ranges (mean value ±SD) from 0.138 ± 0.04 (Anguilla bengalensis) to 0.793 ± 0.09 (Clarius magur). A new TL_max of Parambassis lala has been found (4.2 cm). Depending on the species available in this region, the species distribution modeling and non-metric dimensional scaling have been prepared, which will help build an area-specific conservation policy to restore the vulnerability. We also established a conservation strategy to develop sustainable fishery management guidelines based on the results.