Ganges river dolphin
The Ganges river dolphin (''Platanista gangetica'') is a species of toothed whale classified in the family Platanistidae. It lives in the Ganges and related rivers of South Asia, namely in the countries of India, Nepal, and Bangladesh. It is rel ...
, or "susu" occur in the
Ganges
The Ganges ( ) (in India: Ganga ( ); in Bangladesh: Padma ( )). "The Ganges Basin, known in India as the Ganga and in Bangladesh as the Padma, is an international river to which India, Bangladesh, Nepal and China are the riparian states." is ...
and
Brahmaputra
The Brahmaputra is a trans-boundary river which flows through Tibet, northeast India, and Bangladesh. It is also known as the Yarlung Tsangpo in Tibetan, the Siang/Dihang River in Arunachali, Luit in Assamese, and Jamuna River in Bangla. It ...
, south Asia's largest
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
systems. It is among the most endangered
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s of the region.
The
Ganges river dolphin
The Ganges river dolphin (''Platanista gangetica'') is a species of toothed whale classified in the family Platanistidae. It lives in the Ganges and related rivers of South Asia, namely in the countries of India, Nepal, and Bangladesh. It is rel ...
ranges from 2.3 to 2.6 meters in length. The tail fluke is on average 46 cm in width.
Female
Female (Venus symbol, symbol: ♀) is the sex of an organism that produces the large non-motile ovum, ova (egg cells), the type of gamete (sex cell) that fuses with the Sperm, male gamete during sexual reproduction.
A female has larger gamet ...
s are larger than
male
Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization.
A male organism cannot reproduce sexually without access to ...
s. The color of this
dolphin
A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...
varies from lead-colored to black. The undersides are lighter in color. The rostrum is 18 to 21 cm in length and the forehead is steep and rises abruptly from the base of the snout. The dorsal fin is rudimentary and ridge-like, and the ends of the pectoral
fin
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
s are squared instead of tapered. The neck is visibly constricted and the blowhole is a longitudinal slit. There are 28 to 29 teeth on either side of the jaw. The eye and optic nerve of the Ganges river dolphin are degenerate. The eye lacks a lens and is therefore incapable of forming images on the retina. However, it functions in light-detection. It is believed that the lack of a true visual apparatus in the river dolphin is related to its habitat; the water in which it lives is so muddied that vision in essentially useless.
Valmiki National Park
Valmiki National Park is a Tiger Reserve in the West Champaran District of Bihar, India. It is the only national park in Bihar. Valmiki Tiger Reserve covers , which is 17.4% of the total geographical area of the district. As of 2018, there wer ...
,
West Champaran district
West Champaran is an administrative district in the state of Bihar in India, located just west of Birgunj. It is the largest district in Bihar with an area of 5,228 km²(2,019sq mi). It is a part of Tirhut Division. The district headquarte ...
, covering about 800 km2 of forest, is the 18th tiger reserve of India, and is ranked fourth in terms of density of
tiger
The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus '' Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on u ...
population. It has diverse landscapes, sheltering rich wildlife habitats and floral and faunal composition, with the prime protected carnivores.
See also
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Flora of Bihar
The Indian state of Bihar contains sub-Himalayan foothills and mountains with moist deciduous forests. Rainfall may exceed 1600 millimeters per year. Common trees include ''Shorea robusta'' (''sal''), ''Toona ciliata'', ''Diospyros melanoxylon' ...
*
Protected areas of Bihar
Bihar is a state in East India. It is bounded by Uttar Pradesh to the west, Nepal to the north, West Bengal to the east and Jharkhand to the south. About 7% of the state is protected forest area.
Geography
Bihar has notified forest area of 6,764. ...
Flora of India
The flora of India is one of the richest in the world due to the wide range of climate, topology and habitat in the country. There are estimated to be over 18,000 species of flowering plants in India, which constitute some 6-7 percent of the to ...
*
Fauna of India
India is the world's 8th most biodiverse region with a 0.46 BioD score on diversity index, 102,718 species of fauna and 23.39% of the nation's geographical area under forest and tree cover in 2020. India encompasses a wide range ...
Bihar
Bihar (; ) is a state in eastern India. It is the 2nd largest state by population in 2019, 12th largest by area of , and 14th largest by GDP in 2021. Bihar borders Uttar Pradesh to its west, Nepal to the north, the northern part of West Be ...