A Review on the source of decline of Three Freshwater Species with various Biological Features

White-mauled crawfish, bullhead, and freshwater pearl mussel are diverse model living beings regarding natural attributes. Examining their circulation designs, living space requests, and reasons for decay might along these lines help to determine more extensive structures for protection ventures. This paper incorporates a colossal writing audit for these three undermined freshwater creatures, then utilizations general examples to make proposals about more extensive assurance measures for freshwater species. Every species has a sketchy conveyance, from nearby to wide spatial scales. In any case, we call attention to the trouble to outline such information, in light of the fact that numerous variables were not reliably and/or precisely recorded by specialists, and on the grounds that the scope of colonized environments relies on upon the ecological heterogeneity inside of study regions. Reasons for decrease are essentially identified with human exercises which alter the organic, concoction, and physical components of the sea-going environment, and can be grouped into four sorts: physical territory modifications, interspecific communications, overfishing and poaching, and regular unsettling influence. By dissecting reasons for decay and conceivable activities, we create seven general patterns that could be embraced for a more extensive cluster of species. Then again, security arranges can't be viable without real coordinated efforts between stream chiefs, nearby tenants, and powers. At long last, the re-presentation technique itself (if necessary) relies on upon the species' science under overview, and stays particular. At the same time, further key exploration is expected to sum up connections in the middle of populace and living space motion at diverse spatial and worldly scales.