Ganges Shark

The Ganges shark is a requiem shark known for being the only shark in the entire world to live its life exclusively in freshwater habitats. Researchers believe that the Borneo and Irrawaddy River sharks are either the same species or sub-species of this shark, which would expand its range significantly.

This shark is often confused with the bull shark, which has left it with undeserved notoriety for being extremely deadly to humans.

Ganges Shark Scientific Classification

Kingdom Animalia
Phylum Chordata
Class Chondrichthyes
Order Carcharhiniformes
Family Carcharhinidae
Genus Glyphis
Scientific Name G. gangeticus

Description

The Ganges shark ranges from 70-80 inches in length. It’s a stocky shark with a broad snout. The two dorsal fins lack any spines, with the first one opposite to the wide pectoral fins and the second much smaller than the first. An anal fin can be seen close to the tail, which is smaller than the second dorsal fin.

Its mouth is long and broad, extending up to the minute eyes. Inside the mouth are 32–37 rows of teeth in the upper jaw with serrated, triangular cusps and 31–34 tooth rows in the lower jaw that are hooked and unserrated.

These sharks are brown to gray.

Where do they live

As the name indicates, this shark is found throughout the Ganges River. Other rivers in its range include the Brahmaputra, the Hooghly, and the Mahanadi.

Reports indicate that it lives in the middle to lower river reaches. However, its rarity has led to it being mistaken for other sharks that inhabit the same areas as the Ganges shark.

Behavior

Hunting

Little remains known about the diet of this shark, with experts estimating that it feeds on fish and dasyatid stingrays.

Migratory

Certain researchers believe this shark undergoes mass migrations up to 62.1 miles in both directions.

Reproductive

These sharks are most likely viviparous though the rest of their life cycle is primarily unknown.

Adaptations

Its tiny eyes seem to be developed to navigate the murky, muddy waters of the rivers it inhabits that generally have high turbidity. Additionally, these sharks have protective third eyelids that protect the eye from silt and mud.

Interactions with humans

While having a reputation for being a dangerous man-eating shark, most implied Ganges shark attacks are the work of the bull shark, which often travels into freshwater habitats and is significantly more violent.

Due to a small range and potentially low reproductive rate, the IUCN classifies it as “Critically Endangered” or “CR”, making it one of the 20 sharks to be classified as such. The global population is estimated to be as low as 250. Reasons include habitat degradation, overfishing, dam construction, and similar projects.

To protect the shark, the Indian government banned the fishing of chondrichthyan fish in all ports. However, there remains doubt over the effectiveness of such a ban as restrictions are hard to implement. This isn’t helped by an amendment to ban the landing of only ten species. Thankfully, this shark remains protected under Schedule I, Part II A of the Wildlife Protection Act of India.

Sources

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