Aquatic Animals of Sundarbans: A Wildlife Explorer’s Guide

The Sundarbans, the world’s largest mangrove forest, is a dynamic and ever-changing ecosystem, where freshwater rivers meet the salty waters of the Bay of Bengal. This unique blend of estuaries, tidal rivers, creeks, and mudflats supports an extraordinary diversity of aquatic life. From migratory fish and endangered dolphins to venomous sea snakes and massive estuarine crocodiles, the waters of the Sundarbans are teeming with biodiversity.

As a wildlife explorer, zoologist, and naturalist, I have spent years studying and documenting the aquatic animals of the Sundarbans. Below is a carefully compiled list of aquatic species, categorized for better understanding.

List of Aquatic Animals Found in the Sundarbans

1. Marine and Freshwater Mammals

• Ganges River Dolphin (Platanista gangetica gangetica) – An endangered freshwater dolphin, blind in the traditional sense, relying on echolocation to navigate the murky waters.
• Irrawaddy Dolphin (Orcaella brevirostris) – A rare, shy dolphin species with a rounded head, often seen in the estuarine waters.

2. Reptiles (Crocodiles, Turtles, and Sea Snakes)

• Saltwater Crocodile (Crocodylus porosus) – The apex predator of the mangrove waters, growing up to 6 meters in length.
• Olive Ridley Sea Turtle (Lepidochelys olivacea) – A seasonal visitor known for its mass nesting behavior.
• Green Sea Turtle (Chelonia mydas) – Occasionally spotted in the coastal waters of the Sundarbans.
• Beaked Sea Snake (Enhydrina schistosa) – One of the most venomous sea snakes, found in brackish and marine waters.
• Yellow-bellied Sea Snake (Hydrophis platurus) – A fully marine snake that drifts with ocean currents.
• Dog-faced Water Snake (Cerberus rynchops) – A semi-aquatic snake commonly found in tidal creeks.

3. Crustaceans (Crabs, Prawns, and Shrimps)

• Mud Crab (Scylla serrata) – One of the most commercially valuable crabs in the Sundarbans.
• Fiddler Crab (Uca spp.) – Recognizable by their asymmetrical claws, they are found on mudflats.
• Mangrove Crab (Sesarma mederi) – Plays a crucial role in the mangrove ecosystem by aerating the soil.
• Giant Tiger Prawn (Penaeus monodon) – A major part of the local fishing industry.
• Whiteleg Shrimp (Litopenaeus vannamei) – Cultivated in estuarine farms.

4. Mollusks (Shellfish and Snails)

• Mangrove Oyster (Saccostrea cucullata) – Found clinging to mangrove roots.
• Blood Clam (Tegillarca granosa) – A species of edible saltwater clam.
• Mudwhelk (Telescopium telescopium) – A common gastropod found on mudflats.

5. Fish (Freshwater, Brackish, and Marine Species)

Catfish Family (Siluriformes)

• Giant Catfish (Pangasius pangasius) – A large fish found in brackish water.
• Walking Catfish (Clarias batrachus) – Can survive out of water for short periods, moving across mud.

Sharks and Rays (Chondrichthyes)

• Bull Shark (Carcharhinus leucas) – Known for entering freshwater rivers.
• Ganges Shark (Glyphis gangeticus) – A rare and endangered species.
• Mottled Eagle Ray (Aetomylaeus maculatus) – Occasionally seen in the deeper waters of the delta.

Common Fish of the Sundarbans

• Hilsa (Tenualosa ilisha) – The national fish of Bangladesh, famous for its taste.
• Bhetki (Barramundi) (Lates calcarifer) – A sought-after fish for both local cuisine and sport fishing.
• Mangrove Goby (Mugilogobius tigrinus) – A small fish adapted to brackish water.
• Mudskipper (Periophthalmus spp.) – Amphibious fish that can “walk” on mud using their pectoral fins.

The aquatic life of the Sundarbans plays an essential role in maintaining the balance of this fragile ecosystem. The interdependent relationships between predators, prey, and scavengers ensure the mangrove’s survival. However, threats like climate change, rising salinity, illegal fishing, and pollution pose serious dangers to this incredible biodiversity.

Conservation efforts, including sustainable fishing practices, habitat protection, and anti-poaching measures, are necessary to protect the rich aquatic fauna of the Sundarbans.