The
Ganges shark,
Glyphis gangeticus, is a rare species of
fresh water sharkThe river sharks are six rare species of shark in the genus Glyphis, although, due to their secretive habits, other species could easily remain undiscovered. The river sharks are members of the family Carcharhinidae, and thus share the basic characteristics of the group...
that dwells in the
Ganges RiverThe Ganges is one of the major rivers of the Indian subcontinent, flowing east through the Gangetic Plain of northern India into Bangladesh. The river rises in the western Himalayas in the Uttarakhand state of India, and drains into the Sunderbans delta in the Bay of Bengal...
. It should not be confused with the
Bull sharkThe bull shark, Carcharhinus leucas, also known as the whaler shark, Zambezi shark or unofficially known as Zambi in Africa and Nicaragua shark in Nicaragua, is a shark common worldwide in warm, shallow waters along coasts and in rivers. The bull shark is well known for its unpredictable, often...
, which also inhabits the Ganges River and is sometimes referred to as the Ganges shark.
In its external appearance,
G. gangeticus is a typical
requiem sharkRequiem sharks refers to all members of the family Carcharhinidae: this includes migratory, live-bearing sharks of warm seas such as the tiger shark, the blue shark, the bull shark, and the milk shark. The name comes from the French word for shark, "requin". Family members have the usual...
. It is stocky, with a broadly rounded snout and small eyes. The first
dorsal finA dorsal fin is a fin located on the backs of some fish, whales, dolphins, and porpoises, as well as the ichthyosaurs. Depending on the species, an animal can have up to three of them. Its main purpose is to stabilize the animal against rolling and assist in sudden turns...
is over the last third of the pectoral fins, with a free rear tip that is well in front of the pelvic fins.
The
Ganges shark,
Glyphis gangeticus, is a rare species of
fresh water sharkThe river sharks are six rare species of shark in the genus Glyphis, although, due to their secretive habits, other species could easily remain undiscovered. The river sharks are members of the family Carcharhinidae, and thus share the basic characteristics of the group...
that dwells in the
Ganges RiverThe Ganges is one of the major rivers of the Indian subcontinent, flowing east through the Gangetic Plain of northern India into Bangladesh. The river rises in the western Himalayas in the Uttarakhand state of India, and drains into the Sunderbans delta in the Bay of Bengal...
. It should not be confused with the
Bull sharkThe bull shark, Carcharhinus leucas, also known as the whaler shark, Zambezi shark or unofficially known as Zambi in Africa and Nicaragua shark in Nicaragua, is a shark common worldwide in warm, shallow waters along coasts and in rivers. The bull shark is well known for its unpredictable, often...
, which also inhabits the Ganges River and is sometimes referred to as the Ganges shark.
Appearance
In its external appearance,
G. gangeticus is a typical
requiem sharkRequiem sharks refers to all members of the family Carcharhinidae: this includes migratory, live-bearing sharks of warm seas such as the tiger shark, the blue shark, the bull shark, and the milk shark. The name comes from the French word for shark, "requin". Family members have the usual...
. It is stocky, with a broadly rounded snout and small eyes. The first
dorsal finA dorsal fin is a fin located on the backs of some fish, whales, dolphins, and porpoises, as well as the ichthyosaurs. Depending on the species, an animal can have up to three of them. Its main purpose is to stabilize the animal against rolling and assist in sudden turns...
is over the last third of the pectoral fins, with a free rear tip that is well in front of the pelvic fins. The second dorsal fin is much smaller than the first, but is still relatively large. The anal fin is slightly smaller than the second dorsal fin. The pectoral fins are broad and falcate. A longitudinal upper precaudal pit is present, but the interdorsal ridge is absent.
The shark tends to have a uniform gray to
brownBrown is a color term, denoting a wide range of composite colors produced by a mixture of orange, red or yellow with black. The term is from Old English brún, in origin denoting any dusky or dark shade of color....
ish coloration, with no discernible pattern or markings.
(aka) river shark
Distribution
The Ganges shark, as its name suggests, is largely restricted to the rivers of Eastern and North-Eastern India, particularly the Hooghly River of
West BengalWest Bengal is a state in eastern India. With Bangladesh, which lies on its eastern border, the state forms the ethno-linguistic region of Bengal. To its northeast lie the states of Assam and Sikkim and the country Bhutan, and to its southwest, the state of Orissa...
, the Ganges, Brahmaputra,
MahanadiThe Mahanadi in EastCentral India. It drains an area of around 132,100 km
2 and has a total course of 900 km. . The river flows through the states of Chhattisgarh and Orissa.-Source:...
in
AssamAssam ) is a northeastern state of India with its capital at Dispur located in the Guwahati city. Located south of the eastern Himalayas, Assam comprises the Brahmaputra and the Barak river valleys and the Karbi Anglong and the North Cachar Hills with an area of 30,285 square miles...
,
BiharBihar is a state in eastern India. Bihar is the 12th largest state in terms of geographical size at 38,202 sq mi , and 3rd largest by population. Close to 85 percent of the population lives in villages...
and
OrissaOrissa , is a state of India, located on the east coast of India, by the Bay of Bengal. It is the modern name of ancient republican nation of Kalinga, which was invaded by the Indian Emperor Ashoka in 261 BC, that led to a turning point in the Emperor's life when deeply saddened by the bloodshed...
respectively. Bengalis call it
Baagh Maach which means tiger fish. It is typically found in the mid to lower reaches of a river.
Biology
The shark, though poorly documented, is known to inhabit only
freshwaterFreshwater is naturally occurring water on the surface such as bogs, ponds, lakes, rivers and streams, and underground in aquifers and underground rivers. Freshwater is characterized by having low concentrations of dissolved salts...
, inshore marine and
estuarineAn estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries are thus subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of...
systems. Its feeding habits are unknown. Its maximum size is probably in the area of 2 m. It is probably viviparous, measuring 55 to 60 cm at birth.
A related species is the
speartooth sharkThe speartooth shark, Glyphis glyphis, is a shark of the family Carcharhinidae, found in the tropical waters of the western Pacific Ocean between latitudes 5° N and 21° S. This little-known species has an uncertain occurrence in Malaysia, Papua New Guinea, and Queensland, Australia. The...
,
Glyphis glyphis, although its distribution is different.
Danger to humans
The shark appears to pose a threat to
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
s, but this has not been proven. Though some consider the Ganges shark to be "extremely dangerous", it has so far been impossible to separate its attacks from those of
bull sharkThe bull shark, Carcharhinus leucas, also known as the whaler shark, Zambezi shark or unofficially known as Zambi in Africa and Nicaragua shark in Nicaragua, is a shark common worldwide in warm, shallow waters along coasts and in rivers. The bull shark is well known for its unpredictable, often...
s.(Allen, 107) Most likely the shark is a specialized species that feeds primarily on small fish. Amongst deadly sharks inhabiting the Ganges, the bull shark represents a greater definite danger than this extremely endangered and elusive species. According to the International Union for Conservation of Nature and Natural Resources, the Ganges shark is one of 20 sharks on the "Red List" of endangered shark species. (from the
San Diego Union-Tribune, August 31, 2006, p. E8).
It has been known to attack small land mammals which it chances upon and also take swipes at humans, though it wouldn't pose a real threat to a full grown human. It forms a vital part of the river's ecosystem. Most of the Eastern and North-eastern Indian rivers are prone to flooding. This causes widespread loss of animal and human lives. These sharks scavenge the carcasses and help keep the river clean. However, widespread and rampant fishing has depleted the population of these sharks. Their oil, along with that of the
Gangetic DolphinThe Ganges River Dolphin and Indus River Dolphin are two sub-species of freshwater or river dolphins found in Bangladesh, India, Nepal and Pakistan...
is highly sought after.