Which one of the following is the national aquatic animal of India?

The Gangetic dolphin (Platanista gangetica) was declared the National Aquatic Animal of India on October 5, 2009. It is a freshwater dolphin species primarily found in the Ganges-Brahmaputra-Meghna river system in India, Nepal, and Bangladesh. This declaration aimed to raise awareness about the conservation of the species and its riverine habitat, which is under severe threat from pollution, habitat degradation, and overfishing.