Practice question

Ganges river dolphin Platanista gangetica gangetica, obligate freshwater cetacean, occurs in main channels and tributaries of Ganga-Brahmaputra-Meghna system across Gangetic Plains biogeographic zone from Himalayan foothills to Sundarbans. Functionally blind due to muddy waters, navigates by echolocation clicks, preying on fish, shrimps. Population estimated below 3500, threatened by barrages fragmenting populations, entanglement in fishing nets, pollution and noise. India's National Aquatic Animal since 2009, protected under Wildlife Protection Act Schedule I, Vikramshila sanctuary in Bihar dedicated. This example illustrates how ecological adaptations correlate with biogeographic zonation and conservation prioritization in Indian context.