section_path: Ecology and environment/Fish
section_name: Fish
paragraph_text: Fish
  
  It has been estimated that about 350 fish species live in the entire Ganges drainage, including several endemics. In a major 2007–2009 study of fish in the Ganges basin (including the river itself and its tributaries, but excluding the Brahmaputra and Meghna basins), a total of 143 fish species were recorded, including 10 non-native introduced species. The most diverse orders are Cypriniformes (barbs and allies), Siluriformes (catfish) and Perciformes (perciform fish), each comprising about 50%, 23% and 14% of the total fish species in the drainage.
  
  There are distinct differences between the different sections of the river basin, but Cyprinidae is the most diverse throughout. In the upper section (roughly equalling the basin parts in Uttarakhand) more than 50 species have been recorded and Cyprinidae alone accounts for almost 80% those, followed by Balitoridae (about 15.6%) and Sisoridae (about 12.2%). Sections of the Ganges basin at altitudes above 2,400–3,000 m (7,900–9,800 ft) above sea level are generally without fish. Typical genera approaching this altitude are Schizothorax, Tor, Barilius, Nemacheilus and Glyptothorax. About 100 species have been recorded from the middle section of the basin (roughly equalling the sections in Uttar Pradesh and parts of Bihar) and more than 55% of these are in family Cyprinidae, followed by Schilbeidae (about 10.6%) and Clupeidae (about 8.6%). The lower section (roughly equalling the basin in parts of Bihar and West Bengal) includes major floodplains and is home to almost 100 species. About 46% of these are in the family Cyprinidae, followed by Schilbeidae (about 11.4%) and Bagridae (about 9%).
  
  The Ganges basin supports major fisheries, but these have declined in recent decades. In the Prayagraj region in the middle section of the basin, catches of carp fell from 424.91 metric tons in 1961–1968 to 38.58 metric tons in 2001–2006, and catches of catfish fell from 201.35 metric tons in 1961–1968 to 40.56 metric tons in 2001–2006. In the Patna region in the lower section of the basin, catches of carp fell from 383.2 metric tons to 118, and catfish from 373.8 metric tons to 194.48. Some of the fish commonly caught in fisheries include catla (Catla catla), golden mahseer (Tor putitora), tor mahseer (Tor tor), rohu (Labeo rohita), walking catfish (Clarias batrachus), pangas catfish (Pangasius pangasius), goonch catfish (Bagarius), snakeheads (Channa), bronze featherback (Notopterus notopterus) and milkfish (Chanos chanos).
  
  The Ganges basin is home to about 30 fish species that are listed as threatened with the primary issues being overfishing (sometimes illegal), pollution, water abstraction, siltation and invasive species. Among the threatened species is the critically endangered Ganges shark (Glyphis gangeticus). Several fish species migrate between different sections of the river, but these movements may be prevented by the building of dams.