Parnaíba River

Not to be confused with Paranaíba River.

The Parnaíba River (Portuguese: Rio Parnaíba [paɾnaˈibɐ]) is a river in Brazil, which forms the border between the states of Maranhão and Piauí. Its main course is 1,400 km (870 mi) long and the Parnaíba River Basin covers 330,000 km² (130,000 sq mi).^[1] The Parnaíba River rises in the Chapada das Mangabeiras range, and flows northeastward to empty into the Atlantic Ocean, being the longest river entirely located within Brazil's Northeast Region.^[2] The middle and upper regions of this river are separated by the Portuguese: Boa Esperança Hydroelectric Power Plant dam, but is otherwise navigable.^[3]

Parnaíba
Piauí side of Parnaíba River
Parnaíba River watershed (Interactive map)
Location
Country	Brazil
State	Piauí, Maranhão
Region	Northeast
Physical characteristics
Source	Áqua Quente
• location	Barreiras do Piauí, Piauí
• coordinates	10°19′37″S 45°55′16″W
• elevation	786 m (2,579 ft)
2nd source	Rio das Lontras
• location	Barreiras do Piauí, Piauí
• coordinates	10°08′28″S 45°43′16″W
• elevation	723 m (2,372 ft)
Mouth	Atlantic Ocean
• location	near Parnaíba (city), Maranhão / Piauí border
• coordinates	2°45′01″S 41°49′15″W
• elevation	0 m (0 ft)
Length	1,400 km (870 mi)
Basin size	344,112 km2 (132,862 sq mi)

Ecology

The fish species richness in the Parnaíba River Basin has traditionally been considered impoverished, but this has been disproven by recent surveys, which have recorded about 140 native species (including several that remain undescribed) and about 40% of these are endemic.^[1] One of the basin endemics is the freshwater stingray Potamotrygon signata.^[4] More than 70% of the fish species in the basin are members of either Characiformes or Siluriformes.^[1] The fauna in the headwaters has not yet been thoroughly surveyed. In addition to the natives, there are seven introduced fish species in the basin.^[1]

The river delta is protected by the 313,800 hectares (775,000 acres) Delta do Parnaíba Environmental Protection Area, created in 1996.^[5] The river's delta has large stands of mangrove,^[6] as well as dunes, beaches, marshes and other habitats.^[7] The delta is considered an Important Bird Area and is home to species such as scarlet ibis (Eudocimus ruber) and rufous crab hawk (Buteogallus aequinoctialis).^[7]

Two species of aquatic turtles are endemic to the general region, the Maranhão slider (Trachemys adiutrix) that is found in the delta and the side-necked turtles Mesoclemmys perplexa found inland, but neither is entirely restricted to the Parnaíba River Basin.^[8][9]

References

1. Ramos, T.P.A.; Ramos, R.T.C.; and Ramos, S.A.Q.A. (2014). Ichthyofauna of the Parnaíba river Basin, Northeastern Brazil. Biota Neotrop. 14(1).
2. Knepper, Christian (October 2005). "Rumo ao delta" (in Portuguese). National Geographic. Archived from the original on 15 April 2012. Retrieved 3 December 2011.
3. "Hidrovia do Parnaíba". gov.br - Departamento Nacional de Infraestrutura de Transportes (in Brazilian Portuguese). 2018-12-27. Retrieved 2021-09-19.
4. Moro, G.I; Charvet, P.; and Rosa, R.S. (2012). Insectivory in Potamotrygon signata (Chondrichthyes: Potamotrygonidae), an endemic freshwater stingray from the Parnaíba River basin, northeastern Brazil. Braz. J. Biol. 72(4).
5. APA Delta do Parnaíba (Federal) (in Portuguese), ISA: Instituto Socioambiental, retrieved 2017-02-09
6. Lacerda, L.D., eds. (2002). Mangrove Ecosystems: Function and Management. p. 53. ISBN 978-3-662-04713-2
7. BirdLife International: Delta do Parnaíba. Retrieved 28 July 2014.
8. Batistela, A.M. (2008). Biologia de Trachemys adiutrix (Vanzolini, 1995) (Testudines, Emydidae) no litoral do nordeste - Brasil. INPA/Biologia de Água Doce e Pesca Interior.
9. Bour, R.; and Zaher, H. (2005). A new species of Mesoclemmys, from the open formations of northeastern Brazil (Chelonii, Chelidae). Pap. Avulsos Zool. (São Paulo) 45(24).