Piranhas (Pygocentrus) Muller Troschel, 1844
Piranha from Guarani means “evil fish.”
Detachment: Characteristic (Characiformes).
Family: Characteristic (Characidae).
Subfamily: Piranha (Serrasalminae).
Genus: Piranhas (Pygocentrus).
Types: Includes four varieties of true Pyrania.
Known as an insatiable predator, able to quickly tear flesh from bone and dangerous for any animal that has entered its waters, Piranha Bastard is one of the most famous freshwater fish in the world. As a result, the demonstration of this “bloodthirsty” creature, occurring in most public aquariums, terrible Hollywood films were released and the view became popular in the aquarium trade.
According to Herbert Axelrod (1976), the myth began when US President Theodore Roosevelt visited the Amazonia of Brazil in 1913. He was accompanied by numerous journalists, and the Brazilians organized a series of tricks, one of which was that the president allegedly “discovered and discovered” a new river, which was later named after him.
One of the tributaries of the Aripuaná River was chosen, and today it is still referred to as the Rio Roosevelt or the Rio Teodoro.
When Roosevelt arrived at the river, a surprise was prepared by the Brazilians – a stretch of several hundred yards was closed, for several weeks the fishermen released hundreds of piranhas there and isolated them there. They told the president that he and his people should refrain from entering the water, as they would be eaten alive by terribly evil fishes. Naturally, this news was met with skepticism, then the cow was driven there.
This led to a spectacular, frantic fight for the right to get “his piece” among the trapped, hungry piranha. After this event, the newspapers were filled with stories about terrible, carnivorous fish, but there was not a single record of the killing of a man in wild piranhas.
According to information from a number of sites and forums currently devoted to this topic, the captivity of piranhas and their relatives has undergone a relative boom over the past decades. Many different species are now available, but most of them caught in the wild are expensive and not affordable for most amateurs.
Natterer’s piranhas, in contrast, are divorced for commercial purposes; adolescent-sized teens are sold fairly cheaply for fish that require specialized and, ultimately, expensive maintenance and maintenance. For enthusiasts, this is a great aquarium dweller, but serious thinking and learning are essential before buying.
Natterer’s piranha has proven difficult to determine for a number of reasons. For example, Pygocentrus piraya and Pygocentrus cariba are endemics for individual river basins (San Francisco in Brazil and Orinoco in Venezuela / Colombia, respectively) and have pronounced morphological features. Pygocentrus nattereri, has an incredibly wide distribution, and the color can vary significantly even between individuals of the same population.
Fish color also varies with habitat type, fish living in black water / Blackwater, usually darker, with a less red-orange color than those living in clear or white water.
The morphology and structure in adult fish can vary in head and body shape, the presence or absence of dark spots or mesh pattern on the sides and fins.
Piranhas (Pygocentrus) – in all types of living conditions, nutrition and reproduction are similar.
Piranha Natterer / Piranha Ordinary / Bullet-bellied Piranha (Pygocentrus nattereri) Kner, 1858
nattereri: named after the Austrian naturalist Johann Natterer (1787-1843 g).
Currently found throughout most of the Amazon (Brazil, Ecuador, Peru, Bolivia and Colombia), as well as the Essequibo River (Guyana and Venezuela) in the northeast, and further south in the Paraná rivers (Brazil, Paraguay and Argentina) and Uruguay (Brazil, Uruguay and Argentina).
Habitats include large rivers, small tributaries, oxbows, floodplain lakes and ponds.
All members of the Pyranium genus (Pygocentrus) are distinguished by a convex shape of the forehead and a massive lower jaw, a small mouth and very sharp teeth on both jaws.
The wide body compressed from the sides, the pectoral and pelvic fins are small, have an elongated anal fin, a powerful forked tail and small scales make these fish incredibly fast. The belly is all jagged, like a grater.
There is also a fatty fin between the dorsal and caudal fin, a characteristic feature of the Kharatsynovs.
Adults have a bright color. There are various options, but most often the top is gray with a metallic sheen, below the body is silver with gold splashes, the throat, abdomen and anal fin are red-orange.
There are dark spots on the sides and a lot of shiny patches on the scales.
Maximum standard length is 250 – 350 mm.
It is best to keep alone, in a species aquarium, although adult Piranhas do not tend to hunt smaller fish. It is often said that wild P. nattereri hunt in insatiable flocks, but usually only juveniles form clusters.
Older individuals exist in free groups and form hierarchies of dominance, therefore it is recommended to buy either a single instance or a group of 5+, the latter being preferable.
Only suitable for large aquariums.
Some aquarists contain this species without a bottom at the bottom for ease of maintenance, but ordinary aquarium gravel or sand are suitable substrates. Choosing a different decor basically comes down to personal preference, but living plants can be eaten, especially if the fish chooses to spawn.
Lighting is not critical and can be from weak to strong as preferable.
All varieties of real PIRANIES usually produce a lot of waste, so the use of one or more small external filters is important. If there is an opportunity, purchase filters with an integrated / flow-through heater or at least be unbreakable, since adult fish are known to damage scuba equipment.
The sump / sump system works well in this regard.
Temperature: 24 – 28 ° C;
pH: 5.5 – 7.5;
Stiffness: 2 – 12 dHG.
Try to change 30-50% of the volume of the aquarium every week, and also be especially careful when performing maintenance or fishing, for any reason, be careful.
Pygocentrus species are not exclusively carnivorous, more precisely they can be characterized as adaptable universals.
The natural diet consists of live fish plus aquatic invertebrates, insects, nuts, seeds, and fruits. Each jaw has one row of sharp, triangular teeth that are used as blades to pierce, break, grind and crush.
They sometimes attack sick or dying fish, eat remnants of the skeletons of large species, but attacks on live animals that get into the water are very rare and mainly relate to random bites or cases in which a large number of these fish remain in small bodies of water during dry periods. .
In the aquarium, fry can be offered to bloodworms, small earthworms, shredded shrimps, and the like, while adults will take pieces of fish flesh, whole shrimps, mussels, large earthworms, etc.
This species should not be fed with mammals or poultry meat, since some of the lipids contained in them cannot be properly absorbed by fish and can cause excess body fat and even organ degeneration. In addition, there is no benefit in feeding such fish as viviparous or small goldfish, which carry the risk of disease and, as a rule, do not have a high nutritional value.
Females tend to grow larger in adulthood and have a more rounded body shape than males.
Wild populations undergo two annual breeding periods, the first during the rising water level at the beginning of the rainy season, and the second during the low water period in November and December, when there is a sudden temporary increase in the water level. Flooded coastal vegetation and floodplain meadows of floodplain lakes are preferred spawning grounds.
Natterer’s piranhas are relatively easy to breed in an aquarium. Sexual maturity occurs approximately at the age of the year, with a body length of 100-150 mm.
If you cannot find a pair of producers, then perhaps the best place to start is with a group of 6+ fish, which allows you to form pairs in a natural way. In some documented cases, spawning was initiated by large changes of cold water, while in others this occurred without intervention.
When males are ready for breeding, they become territorial, using the mouth and caudal fin to create a depression in the soil in the center of the selected area. Aquatic plants can also be “mown”, and the resulting “nest” is protected from other males.
Ready to spawn females show interest in what is happening, at this moment both the male and the female become darker in color. Caviar is deposited in several portions and is guarded by a male, sometimes the female helps with this.
In very large aquariums, several pairs can spawn simultaneously.
Larvae hatch within 2-3 days, begin free swimming on the fifth. At the moment, it is considered the best for transplanting fry into smaller, rearing aquariums.
Artemia nauplii, a microworm or equivalent will be suitable as the initial food, and about 10% of the volume of the aquarium should be changed every day.
Fry due to the difference in growth rate become cannibals, when this starts to happen they must be moved to larger aquariums, in batches of equal size.
Think carefully before you start breeding, you could eventually raise more than 1000 fry, which later will simply have nowhere to go.
Pygocentrus Ordinary / Piranha from the San Francisco River / Piranha Cuvier (Pygocentrus Piraya) Cuvier, 1819
A distinctive feature of this piranha – orange-red color rises along the entire length of the body of the fish, reaches the lateral line, sometimes higher.
It is bounded by the San Francisco River Basin in eastern Brazil, including major tributaries such as the Velhas and Grande Rivers.
It inhabits large river channels, small tributaries, floodplain lakes and large artificial reservoirs formed by dams.
Only suitable for public demo or largest private aquariums.
Temperature: 20 – 28 ° C;
pH: 6.0 – 8.0.
Not recorded, but probably uses a similar reproductive strategy as their relatives P. nattereri.
Black Piranha / Black-dotted Piranha / Piranha Kariba (Pygocentrus cariba) Humboldt, 1821
The distinctive feature of this piranha is a black spot on the body, right behind the gill cover.
Limited in the Orinoco River Basin in Colombia and Venezuela, including major tributaries such as the Inirida, Guaviare, Meta, Tomo, Casanare, Apure and Guarico rivers.
It lives in large river channels, smaller tributaries and floodplain lakes, many of which contain acidic, slightly mineralized “Black Water”, although it is also found in clean water.
Many of its habitats are within Venezuela and Colombia, seasonally flooded plains and in forests, the total area of which is almost 600 thousand square kilometers.
There are well-defined weather conditions with pronounced wet and dry seasons and high temperatures throughout the year.
Suitable only for public demonstration or the largest private aquariums, ranging in size from 240 * 90 * 60 cm or equivalent, these are the minimum requirements for a group of fish.
Temperature: 20 – 28 ° C;
pH: 4.0 – 7.0.
Piranha Palometa (Pygocentrus palometa) Valenciennes, 1850
The species was described by Valenciennes, but at present no evidence of this has been found.
Orinoco River Basin, Venezuela.
The existence of this species has not been reliably established / confirmed.
The only source of discovery of this kind are the surviving entries on paper.
The Piranhaev family (Serrasalmidae) contains 16 genera including piranhas, pacu and relatives.
Their characteristic features include a compressed body shape, a long dorsal fin with 16 or more rays, and a variable number of sharp notches formed by modified ventral scales.
They are found in numerous habitats, from lowland floodplains and flooded forests to upstream sources, and are also found in all major river systems of South America east of the Andes. Some species perform unique ecological functions, such as spreading seeds or maintaining inland fisheries.
Representatives show three main feeding characteristics: predators (carnivores), fruit-eating (feeding on fruits and seeds) and lepidophages (eating scales and fins of other fish). Predatory species usually have one row of trihedral teeth on each jaw, frugivorous tend to have two rows of incisors or molar teeth (pressing and chewing) on the premaxilla, while lepidophages have tubercular teeth and are located on the outer edge of the premaxillary.
The evolutionary history of the Piranjevs (Serrasalmidae) has been studied by various authors, including the most recent studies (Thompson and co-authors, 2014), supporting the existence of three major genera in the family. The genus ”Paku” contains the species Colossoma, Mylossoma and Piaractus, “Piranhas” include Metynnis, Pygopristis, Pygocentrus, Pristobrycon, Catoprion and Serrasalmus and the genus “Mileus” includes the species Myleus schomburgkii.