Piraya
| Piraya | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Pygocentrus piraya | ||||||||||||
| ( Cuvier , 1819) |
The Piraya ( Pygocentrus piraya ) is the largest Piranha -Art. It occurs only in northeastern Brazil. It is also called Chupita, Blacktail Piranha, King Emperor Piranha or incorrectly “ Man Eating Piranha ”.
description
The Piraya is the largest piranha species with a body length of 50 centimeters and more. The heaviest specimen caught so far from the Rio São Francisco weighed 5.9 kilograms. Another specimen from the Rio Jatapu in Amazonia weighed 3.23 kilograms. On average, the animals are 35 centimeters long. Even with a length of 12 centimeters, the fish are considered adult. Young fish do not yet have any characteristic features that only develop later. Its morphology is very similar to Natterer's Sägesalmler ( Pygocentrus nattereri ) and can easily be confused with it. A clear distinction can only be made on the basis of the shape of the adipose fin. Adult specimens have elongated fin rays in the adipose fin, which are shaped like tufts and fibers. This distinguishes the Piraya from all other Pygocentrus and Serrasalmus species. The beefy and compact head shape of P. piraya also differs from that of other piranha species. He is one of the most colorful piranhas. The back is mostly dark gray or blue-green in color, interrupted by silvery, strongly iridescent scales. A shoulder spot like that of Pygocentrus notatus is not always developed. The underside of the abdomen is bright orange to yellow, and the eyes can be red or silvery in color. Compared to other Pygocentrus species, it loses the stain color of the youth stage relatively quickly in the course of its development. The color and pigmentation can vary depending on the type of water. There are 22 to 24 toothed scales on the belly keel. As with all piranha species, the body is laterally compressed and almost circular in shape. There are razor-sharp, serrated and three-pointed teeth in its mouth, with the lower jaw being relatively strong, robust and protruding. Sexual dimorphism between the sexes can be detected by examining the gonads under a microscope .
His fin formula is:
- Dorsal II / 15-16
- Anal III / 28-29
- Pectorals 14-16
distribution and habitat
Its occurrence was originally limited to the lower reaches of the Rio São Francisco and its tributaries in the Brazilian states of Alagoas , Sergipe , Pernambuco and Bahia . Together with Serrasalmus brandtii , the piraya is the only piranha species in this river system. It inhabits water sections with water temperatures from 21 to 24 ° C, the ideal pH value is in the range from 6 to 7.8. Its occurrence is also occasionally observed outside the catchment area of the Rio São Francisco.
Way of life
Pirayas are omnivorous , but mainly feed on fish and sick and injured small animals that are attacked in groups or schools. Its food spectrum also includes insects, seeds and plant material. A comparison of the species Pygocentrus piraya and Serrasalmus brandtii showed that both feed mainly on fish and crustaceans, whereas S. brandtii shows a greater plasticity in its diet. The breeding behavior is similar to that of P. natteri . The males are sexually mature with 18 centimeters and the females usually with 28 centimeters. The color of the animals darkens at spawning time. In the Rio São Francisco, the spawning season takes place in October when the water levels are high. The females create a nesting enclosure on the sandy floor in which the eggs are laid. These are then guarded by the females. Intraspecific cannibalism on injured or sick conspecifics is often observed in the Piraya.
Relationship with people
Under certain circumstances, the piraya is one of the more aggressive piranha species that can potentially be dangerous to humans. Through the construction of various reservoirs in the river system of the Rio São Francisco, Pygocentrus piraya was able to multiply and decimated other fish species. The Piraya is sensitive to water pollution and the destruction of its habitat. The city of Piranhas in the Brazilian state of Alagoas was named after the frequent occurrence of the piraya.
Use
Pygocentrus piraya is used locally as food fish, sport fish for anglers and worldwide as aquarium fish. As an aquarium fish, it is very popular because of its lively and colorful drawing. Since its offspring requires certain ecological conditions, the animals are imported from South America. In a community aquarium they can be kept with other similarly sized species. Import into some countries is prohibited. Pygocentrus piraya is kept, for example, in aquariums in the Zoological Gardens in Frankfurt and in Hellabrunn.
literature
- William L. Fink: Revision of the piranha genus Pygocentrus (Teleostei, Characiformes). In: Copeia 1993 (No. 3), pp. 665-687
- RMA Blacksmith, N. Bazzoli, E. Rizzo and Y. Sato: Reproductive aspects of piranha Pygocentrus piraya (Teleostei, Characiformes), a native species from the Rio Sao Francisco basin, Brazil. In: Arquivo Brasileiro de Medicina Veterinaria e Zootecnia. 48 (supl. 1): 71-76, 1996.
- GS Meyers: The Piranha Book. Tropical Fish Hobbyist Magazine, New Jersey, 1972
Web links
- http://www.piranha-info.com/default.php?lang=en&id=p_piraya
- [1] (PDF; 1.2 MB) Phylogeography of the piranha genera Serrasalmus and Pygocentrus: implications for the diversification of the Neotropical ichthyofauna
Notes and individual references
- ↑ See man-eating piranha
- ↑ a b c d Piraya on Fishbase.org (English)
- ^ Fishing World Records
- ↑ Archived copy ( memento of the original from March 10, 2011 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.
- ↑ a b c d e f Günther Sterba: Freshwater fish of the world. Weltbild Verlag, Augsburg 2002, ISBN 3-89350-991-7 , p. 126.
- ↑ a b c d e f g h http://www.angelfire.com/biz/piranha038/piraya.html
- ^ A. Rachow: Handbuch der Zierfischkunde, Wagner Verlag Stuttgart, 1928
- ↑ AMG Cross, Y. Sato, E. Rizzo, E. Saints and GB Bazzoli: Sexual Maturação of piranha Pygocentrus piraya (Cuvier, 1820) (Pisces, Characidae) in the dam of Three Marias, Minas Gerais. Bios, 4 (4): 17-22, 1996 - Sexual dimorphism has been reported for the species via microscopic examination of the gonads. These fish were later raised and sexuality determined by age, sexual maturity and size
- ↑ in the Rio São Francisco the natural pH value fluctuates between 4.8 and 7.8
- ↑ http://www.fishbase.org/museum/OccurrencesList.php?genus=Pygocentrus&species=piraya
- ↑ Márcia Emília de Jesus Trindade, Ricardo Jucá-Chagas: Diet of two serrasalmin species, Pygocentrus piraya and Serrasalmus brandtii (Teleostei: Characidae), along a stretch of the rio de Contas, Bahia, Brazil. In: Neotropical Ichthyology , 6 (4): 645-650, 2008. ( Online ; PDF; 756 kB)
- ↑ "The fish clean out a shallow nest on the sandy bottom and spawn in it. The female guards the nest and viciously attacks any animal or human who comes near. This is said to take place principally in October soon after the rains raise the water level. " in = "Pygocentrus piraya"
- ↑ http://www.agrisustentavel.com/doc/piranhas.htm
- ↑ Archived copy ( Memento of the original from January 28, 2011 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.
- ↑ Archived copy ( memento of the original from September 2, 2010 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.
- ↑ http://www.aqua4you.de/fischart1016.html
