Ossubtus xinguense
| Ossubtus xinguense | |
|---|---|
| Not evaluated (IUCN 3.1) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Serrasalmidae |
| Genus: | Ossubtus Jégu, 1992 |
| Species: | O. xinguense |
| Binomial name | |
| Ossubtus xinguense Jégu, 1992 | |
Ossubtus xinguense is a species of serrasalmid and the only species of the genus Ossubtus. It has an unusual downturned mouth that gives the appearance of a beak.
Distribution
It originates from the Xingu River basin, but is restricted to the rapids area around Altamira City, Pará, Brazil.[1]
Description
This species reaches 17.6 cm (6.9in) in standard length (SL). The body is ovoid. The profile of the snout is blunt. In young fish, the mouth is terminal (pointing forward); however, as the fish grows, the mouth turns downward and becomes strictly ventral in individuals longer than 5 cm (2 in).[1] This gives the mouth a beak-like appearance.[1]
Ecology
O. xinguense is a strictly rheophilic species. Young specimens of up to 4 cm (1.6 in) SL could be observed in schools of 20–30 individuals, sheltered under broad stones.[1] This species is omnivorous. Shrimp, dead or alive, blood worm, vegetable matter, brine shrimp, and daphnia are consumed in captivity. In captivity, it exhibits high territoriality which results in a strong aggressiveness towards conspecifics. This species is parasitized by Anphiira xinguensis, an isopode of the family Cymothoidae. This parasite lives in the gill chamber of the fish and develops a contorted morphology, presumably in response to its host's cursive ontogeny.[2] The female is far more dominant than the male and will often seek caves into which no other fish may enter. This is believed to be due to reproductive dominance (protecting the young), once a suitable breeding location is found, the female will not surrender it.
Conservation
This fish is endangered.[1] It has not been rated by the IUCN.[3]
O. xinguense is endemic to the rapids of Xingu River around Altamira City. The planned construction of a large hydroelectric plant, the Belo Monte Dam in the lower Xingu River at the limit of the rapids and the main Amazon floodplain may result in a highly negative impact to the population of O. xinguense and numerous other rheophilic (and apparently endemic) fish species occurring in the Xingu River rapids.[1]
References
- 1 2 3 4 5 6 Jégu, Michel; Zuanon, Jansen (2005). "Threatened fishes of the world: Ossubtus xinguense (Jégu 1992) (Characidae: Serrasalminae)". Environmental Biology of Fishes 73 (4): 414. doi:10.1007/s10641-004-4230-5.
- ↑ Thatcher, E. (1995) Anphiira xinguensis sp. nov. (Isopoda, Cymothoiclae) a gill chamber parasite of an Amazonian serrasalmid fish, Ossubtus xinguense Jegu, 1992. Amazoniana XIII(314): 293-304.
- ↑ Froese, Rainer and Pauly, Daniel, eds. (2007). "Ossubtus xinguense" in FishBase. July 2007 version.
4. Calum and Jock Chalmers - Keepers and Breeders