Piaractus brachypomus
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Piaractus brachypomus |
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| ( Cuvier , 1818) |
Piaractus brachypomus , German Gamitana disc tetra or Riesenpacu , port .: Pirapatinga or Caranha , Spanish: Cachama , English: Red-Bellied Pacu , is a large species of saw tetra from tropical South America .
The species was first described by Cuvier in 1818 as Myletes brachypomus and was previously assigned to the genus Colossoma due to its close relationship with the Black Pacu ( Colossoma macropomum ) .
Definition
Pacú is a term used by the Amazonian Indians. Several species of fish fall under this designation. Pacus in the narrower sense are the fish genera Metynnis , Mylossoma and Myleus . The genus Piaractus is represented with its two species, the giant pacu ( Piaractus brachypomus ) and the Paraná pacu ( Piaractus mesopotamicus ).
distribution
Piaractus brachypomus occurs predominantly in the Amazon and Orinoco . The species originally appeared in Brazil , Colombia , Bolivia , Peru , Venezuela , Argentina, and Uruguay . As a result of restocking measures, it was also introduced in the United States , Canada , China , Myanmar , Papua New Guinea, and Taiwan .
description
Piaractus brachypomus has a compact, laterally compressed body shape. The scaling consists of numerous, small round scales , the number of scales on the downward curved side line is 70-89. The abdominal teeth (serrae) typical of the tetras are located on the abdominal keel; the number of ventral scales is 46–63 (Machado-Allison, 1982). Young animals still show a spotted body color. Adult animals vary in color from dirty, whitish blue to almost steel blue and develop a dark back and a red to orange belly. The anal fin is long, there is an adipose fin , but it can be reduced or almost completely absent in adults. While piranhas have pointed, razor-sharp teeth in a pronounced underbite, giant pacus have more compact, angular molar teeth with a slight overbite. The lower jaw is covered by a fleshy lower lip. Giant Pacus grow much larger than piranhas; they reach lengths of 80 to 90 cm with weights of around 20 kilograms. A fish caught at Tamarac , Florida weighed 24.95 kilograms. The animals can live up to 28 years.
Differences between Piaractus brachypomus and Colossoma macroponum
Piaractus brachypomus and Colossoma macropomum inhabit the same habitat and can easily be confused with one another. The habitus of both species is very similar. While Colossoma macroponum often has black spots on the underside of the abdomen, it is reddish in color in Piaractus brachypomus . The two species and their hybrids can be clearly differentiated from one another on the basis of their karyotype .
Way of life
Young animals imitate the behavior of Serrasalmus natteri in order to deter potential predators through mimicry . During the rainy season, the fish migrate into the floodplain forests. They predominantly inhabit rivers with slowly flowing water and lakes with a pH value between 4.8 and 6.8 and water temperatures between 23 and 28 ° C. Milchner become sexually mature at three and Rogner at four. In their natural habitat, the fish spawn at water temperatures of 26 ° C and produce 0.5 to a million fish eggs.
In the Caura River in Venezuela, Piaractus brachypomus feeds on the fruits and seeds of over 100 plants. The life cycle of the fish species is linked to the water level in the water. During the flood months and the large amount of food available from fruits and seeds falling into the water, Piaractus brachypomus gains fat reserves, which it feeds on during the dry season with little food. During the flood season, the fish can be found in the flooded forests and during the dry season mainly at river mouths and faster flowing stretches of water with clear water. During this time, some of the fish also withdraw into the main stream of the Orinoco. Together with Colossoma , Piaractus brachypomus plays a crucial role in the spread of seeds in the flooded rainforest.
nutrition
The extraordinarily strong teeth of Piaractus brachypomus are adapted to cracking nuts, but can lead to serious injuries if the fish is improperly handled. Piaractus brachypomus feeds mainly on nuts and fruits (e.g. seeds of the rubber tree Hevea ssp .), Which fall from trees in the floodplain forests. The sounds of falling seeds and fruits attract Pacus. Young fish still feed on insects, leaves and rotten plant parts.
Economical meaning
Piaractus brachypomus is an important food fish in Amazonia with very tasty meat. It is currently severely affected by overfishing. Pacus are kept in warm water aquacultures around the world . They are very suitable for keeping ponds in tanks with a low oxygen content and have low demands on the protein content of the feed. In Hawaii, studies have been carried out on polycultures of Piaractus brachypomus and other species such as the catfish species Clarius fuscus . In aquaculture, Piaractus brachypomus is characterized by rapid growth, good feed conversion (feed with high carbohydrate and low protein content) and tolerance to poor water quality. It can also be kept in high stocking densities. The highest biomass yields were found in polyculture with the catfish. Since the two species utilize the feed differently, the unit costs of feed decreased with increased efficiency. The time of day feeding also had an effect on weight gain, with night feeding giving the largest increase. This result is explained by the fact that the energy consumption is lower at night than during the day. It was found that Piaractus brachypomus shows its greatest activity during twilight and during the day an acrophase with reduced food intake. In the Peruvian Amazon, pacus are often kept in cages near houseboats. In addition, due to its high weights and fighting behavior, it is a popular sport fish for fly fishermen and is used in many fishing ponds in Brazil and Colombia . Due to its susceptibility to water pollution, Piaractus brachypomus can also serve as a bio-indicator for cadmium contamination of rivers, as is already practiced in Colombia. Piaractus brachypomus are well suited for keeping in an aquarium, where T. achieve high retail prices.
Aquarium fish
Smaller specimens of Piaractus brachypomus can be kept in aquariums at water temperatures of 24 to 27 ° C, for example in association with Hypostomus plecostomus or Osteoglossum bicirrhosum . They can live to be five to 15 years old in captivity.
Piaractus brachypomus as a neozoon
In the meantime, Piaractus brachypomus has been introduced into 16 states in the USA , where it has spread widely in warm temperatures. The US Aquatic Nuisance Species (ANS) Task Force calls on aquarium owners not to release the animals into the wild, but to return them to the appropriate dealers. In Papua New Guinea , this species was introduced into the Sepik River in 1994 and in the Ramu River in 1997 as part of the FAO Fishaid program to improve the protein supply of the local population. The originally herbivorous fish species caused ecological damage to the local flora and fauna in the river system. B. the population of tilapia cichlids and various aquatic plant species in the Sepik River. The introduced Piaractus brachypomus showed increased carnivorous diets in the course of their spread in the new ecosystem . There were even accidents among swimmers who were bitten by large specimens of Piaractus brachypomus . With the local population, the fish is nicknamed " Ball Cutter ". They have also been introduced in other countries, where they are often confused with the related piranhas. Fish of this type have even been caught in Croatia .
literature
- A. Machado-Allison: Studio sobre la subfamilia Serrasalminae (Teleostei, Characidae). Part 1. Estudio comparado de los juveniles de las "cachamas" de Venezuela (generos Colossoma y Piaractus). Acta Biologica Venezuelica, 1982, 11 (3), pp. 1-101
- J. Géry: Characoids of the world. Tropical Fish Hobbyist Publications, Inc., 1977, Neptune City / NJ, USA
- M. Goulding: Fishes of the forest: explorations in Amazonian natural history. University of California Press, 1980, Los Angeles / CA, USA
Web links
- Nutrition of Colossoma macropomum and Piaractus brachypomus
- B. Hintz: 2012. Piaractus brachypomus at Animal Diversity Web.
Notes and individual references
- ↑ Common names of Piaractus brachypomus at Fishbase.org
- ↑ a b c d e f g Piaractus brachypomus on Fishbase.org (English)
- ↑ a b c d e Stephen T. Ross, William M. Brenneman: The Inland Fishes of Mississippi. University Press of Mississippi, 2002, ISBN 978-1578062461 , p. 295.
- ↑ the species inhabits the river system of the Rio Paraná
- ↑ a b Marko Ćaleta et al. : How was a Pirapitinga, Piaractus brachypomus (Serrasalmidae) introduced in Croatian freshwaters? In: Cybium 2011, 35 (3): 259-261. ( Online ; PDF; 860 kB)
- ↑ IGFA World Record Piaractus brachypomus ( Memento of the original from July 7, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ M. Nirchio, AS Fenocchio, AC Swarça, JE Pérez, A. Granado, A. Estrada and E. Ron: Cytogenetic characterization of hybrids offspring between Colossoma macropomum (Cuvier, 1818) and Piaractus brachypomus (Cuvier, 1817) from Caicara del Orinoco, Venezuela. In: Caryologia. Vol. 56, pp. 405-411, 2003 ( Online ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice .; PDF; 4, 1 MB)
- ↑ a b The Quiet Invasion: A Guide to Invasive Species of the Galveston Bay Area
- ↑ Tributary of the Orinoco
- ↑ Michael E. Mc Clain: The Ecohydrology of South American Rivers and Wetlands. In: IAHS Special Publication No. 6, 2002, pp. 100–101 ( Online ; PDF; 114 kB)
- ↑ a b Development of sustainable Pond Aquaculture for Piaractus brachypomus in the Peruvian Amazon (PDF; 102 kB)
- ↑ Konrad Dabrowski, Jacques Rinchard, Joseph S. Ottobre, Fernando Alcantara, Palmira Padilla, Andrzej Ciereszko, Marcos J. De Jesus, Christopher C. Kohler: Effect of Oxygen Saturation in Water on Reproductive Performances of Pacu Piaractus brachypomus. ( Abstract online )
- ↑ Clyde Tamaru, RuthEllen Klinger-Bowen, Robert Howerton, Bradley Fox and Kathleen McGovern-Hopkins: Performance of Red Pacu, Piaractus brachypomus, cultured alone or co-cultured with Chinese Catfish, Clarius fuscus. ( Online ; PDF; 3.7 MB)
- ↑ E. Barasa, C. Mélarda, JC Grignarda and X. Thoreau: Comparison of Food Conversion by Pirapatinga piaractus brachypomus under Different Feeding Times. In: The Progressive Fish-Culturist , Volume 58, Issue 1, 1996 doi : 10.1577 / 1548-8640 (1996) 058 <0059: COFCBP> 2.3.CO; 2
- ↑ Definition of acrophase: time between midnight and the point in time with the daily maximum value of the body temperature; Maximum value with circadian rhythmically varying parameters
- ↑ Etienne Baras: Day – night alternation prevails over food availability in synchronizing the activity of Piaractus brachypomus (Characidae). In: Aquatic Living Resources , 2000, 13, pp. 115–120 ( online )
- ↑ B. Fernando Alcantara, V. Carlos Chavez, Luciano Rodríguez, Christopher C. Kohler, Susuan T. Kohler, William Camargo N., Marco Colace and S. Tello: Gamitana (Colossoma macroponum) and Paco (Piaractus brachypomus) culture in floating cages in the Peruvian Amazon. , World Aquaculture Magazine, Vol. 34 No. 4, December 2003 ( Contents Online ( Memento of the original dated August 30, 2006 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. )
- ↑ Y. Rojas, K. Barbosa and J. Gonzalez: White Cachama (Piaractus brachypomus) as a bioindicator of cadmium-polluted waters. ( Online ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice .; PDF; 3.2 MB)
- ^ Aquarium Fish Information
- ^ Environmental Institute of Houston Invasive Species Inventory
- ↑ Leo Nico, Pam Fuller: Piaractus brachypomus In: USGS Nonindigenuous Aquatic Species Database
- ↑ http://www.habitattitude.net/
- ↑ Ursula M. Kolkolo: Quarantine Practices used in Papua New Guinea for Introductions and Transfers of Live Fish. ( Online )
- ^ Piaractus brachypomus introduced to Papua New Guinea from Malaysia. Introduced Species Fact Sheets
- ^ JD Bell, JE Johnson and AJ Hobday: Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change. Secretariat of the Pacific Community, Noumea, New Caledonia, 2011 ( Online ( Memento of the original from April 17, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note .; PDF; 6.3 MB)
- ↑ Castrator
- ^ The Telegraph - Piaractus brachypomus
- ^ Angler snares deadly fish that killed two men by biting off their testicles
- ↑ Scientists dispel fears of piranha invasion in Cat Tien Reserve ( Memento of the original from July 16, 2006 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.
