Paratrygon aiereba
| Paratrygon aiereba | ||||||||||||
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Underside of Paratrygon aiereba |
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| Paratrygon | ||||||||||||
| Duméril , 1865 | ||||||||||||
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| Paratrygon aiereba | ||||||||||||
| Müller & Henle , 1841 |
Paratrygon aiereba ( English : Discus Ray, Spanish : Raya disco) is a large representative of the freshwater stingrays livingin South America . It is the only species in the Paratrygon genus.
features
Paratrygon aiereba can reach a height of 130 centimeters and 60 kilograms of body weight. The circular shape is reminiscent of a discus disc. The body color of the rays living near the bottom is light to gray-brown in the basic pattern, with the top being marked with a dark net pattern. It is thus optimally adapted to its natural environment. The ray has a tail that, like all freshwater stingrays, has poisonous spines.
Occurrence
Paratrygon aiereba is a species of ray that is widespread in the Amazon basin . The distribution area extends to the Amazon, or Rio Solimões and its tributaries such as. B. Ucayali , Rio Branco , Rio Madeira , and the Rio Orinoco . Paratrygon aiereba occurs in Brazil , Venezuela , northern Bolivia , Peru and Ecuador . Especially in the Rio Negro and its 42 tributaries, the ray is still relatively widespread.
Way of life
The ray lives in shallow waters with water temperatures around +25 ° C. While the juvenile fish are predominantly in stretches of water with a sandy bottom, estuaries and small streams, adult specimens prefer the deep channels of large rivers and streams. At Paratrygon aiereba on the Rio Negro, migratory movements between deep and shallow sections of water were observed during the day. The fish are mostly nocturnal and seek out shallow and sandy stretches of water, where they prey on small fish, crustaceans, worms and insect larvae close to the bottom.
The reproductive biology of Paratrygon aiereba has been studied in Brazil and Venezuela. The fish are viviparous (matrotrophic viviparity ). The reproductive cycle lasts two years. The fry, usually two per female, are around 16 centimeters long at birth and reach sexual maturity at 60 centimeters.
Endangerment status
Habitat destruction and overfishing endanger the species. Despite its wide distribution, the population of Paratrygon aiereba is considered endangered, especially because of its low rate of reproduction. The population is also threatened by tourism and net fishing. So far there are no catch restrictions. Maria Lúcia Góes de Araújo has been investigating the effects of tourism on freshwater ray populations on the central Rio Negro since 1998 and selected the Mariuá Archipelago, consisting of 1,200 islands, on the central Rio Negro, as the region for her study. The island's shores consist mainly of flat sandy beaches and are preferred by the ray species Potamotrygon orbignyi and Paratrygon aiereba . Their population was deliberately decimated in order not to endanger bathing tourism through accidents with stinging rays.
Economic use
The export of Paratrygon aiereba as an ornamental fish is prohibited in Brazil. Export is legal in Peru and Colombia .
Relationship with people
Due to its short tail and the position of the spines, dangerous accidents with people are relatively rare. The effect of the poison on humans is described with local symptoms on the affected part of the body, but is not fatal.
literature
- Renata G. Frederico, Izeni P. Farias, Maria Lúcia Góes de Araújo, Patricia Charvet-Almeida and José A. Alves-Gomes: Phylogeography and conservation genetics of the Amazonian freshwater stingray Paratrygon aiereba Müller & Henle, 1841 (Chondrichthyes: Potamotrygonidae). In: Neotropical Ichthyology, Volume 10, No. 1, Porto Alegre 2012.
Web links
Notes and individual references
- ↑ a b c d e f g h i IUCN Red List
- ↑ a b c Paratrygon aiereba on Fishbase.org (English)
- ↑ matrotrophy is a form of development in which the embryo is supplied with additional nutrition from the mother (eg through a placenta).
- ↑ matrotrophic viviparity: internal fertilization of eggs with the mother providing some nutrition to developing embryos and with the young born as larvae
- ↑ Convention on International Trade in Endangered Species of Wild Fauna and Flora - Inclusion of Paratrygon aiereba in Appendix II ( Memento of the original from June 27, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ On the occasion of the 16th CITES conference, NABU Factsheet COP16 - Colombia applied for the Manzana ray ( Paratrygon aiereba ) to be listed in Appendix II.
- ↑ VH Junior, JL Cardoso, DG Neto: Injuries by marine and freshwater stingrays: history, clinical aspects of the envenomations and current status of a neglected problem in Brazil. In: The journal of venomous animals and toxins including tropical diseases. Volume 19, number 1, 2013, p. 16, doi : 10.1186 / 1678-9199-19-16 , PMID 23895313 , PMC 3735412 (free full text).
- ↑ Clinical Toxinolgy Resources
