Dugong

The dugong, or sea cow, is a large, grey-brown marine mammal with a torpedo-shaped body, no dorsal fin and no hind limbs. Its front limbs are short, paddle-like flippers, and it swims with a notched, dolphin-like tail fluke, which tells it apart from the manatees. The snout is sharply turned down, an adaptation for feeding on seagrass on the seabed. Males grow a pair of short tusks at puberty. The largest dugong ever recorded, just over 4 m long and about a tonne, was found off the Saurashtra coast of Gujarat (Wikipedia, general species account).

The dugong is the only strictly marine plant-eating mammal. Across its range it depends entirely on seagrass meadows, which limits it to warm, shallow coastal waters, especially wide, sheltered bays and mangrove channels; it can tolerate brackish water. Populations throughout its range have been reduced by hunting for meat and oil, drowning in fishing nets and loss of seagrass, and many are now small and isolated (Wikipedia, general species account).

Palk Bay and the Gulf of Mannar off Tamil Nadu hold India's largest dugong population. A Wildlife Institute of India assessment with the Tamil Nadu Forest Department counted 158 dugongs in Palk Bay and 112 in the Gulf of Mannar, about 270 in total, and recorded mother-and-calf pairs showing that the animals are breeding there (WII, as reported by Deccan Chronicle 2026). India's first Dugong Conservation Reserve in Palk Bay protects 448 km² of core dugong habitat. Smaller numbers survive in the Gulf of Kutch and around the Andaman and Nicobar Islands.