Piranha Explained... 🐟💥🔍
A piranha or piraña (/pɪˈrɑːnjəˌ -ræn/, or /pɪˈrɑːnə/; Portuguese: [piˈɾɐ̃ɲɐ], Spanish: [piˈɾaɲa]) is any of a number of freshwater fish species in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, floodplains, lakes and reservoirs. Although often described as extremely predatory and mainly feeding on fish, their dietary habits vary extensively, and they will also take plant material, leading to their classification as omnivorous.
The name originates from the indigenous Tupi people and their respective Tupi language. It is formed from two words, pirá meaning 'fish' and sainha meaning 'tooth'; the same word is used by Indians to describe a pair of scissors. Another possible derivation is from pira nya, probably literally 'biting-fish'. In the mid 18th century the Portuguese merged the word into piranha. Finally, the word may also come from the combination of pirá 'fish' and ánha 'cut' (which also meant 'bad' or 'devil' in Tupi-Guarani).
Piranhas belong to the family Serrasalmidae, which includes closely related omnivorous[8] fish such as pacus.[9] Traditionally, only the four genera Pristobrycon, Pygocentrus, Pygopristis, and Serrasalmus are considered to be true piranhas, due to their specialized teeth. However, a recent analysis showed, if the piranha group is to be monophyletic, it should be restricted to Serrasalmus, Pygocentrus, and part of Pristobrycon, or expanded to include these taxa plus Pygopristis, Catoprion, and Pristobrycon striolatus. Pygopristis was found to be more closely related to Catoprion than the other three piranha genera.
The total number of piranha species is unknown and contested, and new species continue to be described. Estimates range from fewer than 30 to more than 60.
Piranhas are indigenous to the Amazon basin, in the Orinoco, in rivers of the Guianas, in the Paraguay–Paraná, and the São Francisco River systems, but there are major differences in the species richness. In a review where 38–39 piranha species were recognized, 25 were from the Amazon and 16 from Orinoco, while only three were present in Paraguay–Paraná and two in São Francisco. Most species are restricted to a single river system, but some (such as the red-bellied piranha) occur in several. Many species can occur together; for example, seven are found in Caño Maporal, a stream in Venezuela.
Aquarium piranhas have been unsuccessfully introduced into parts of the United States. In many cases, however, reported captures of piranhas are misidentifications of pacu (e.g., red-bellied pacu or Piaractus brachypomus is frequently misidentified as red-bellied piranha or Pygocentrus nattereri). Piranhas have also been discovered in the Kaptai Lake in southeast Bangladesh. Research is being carried out to establish how piranhas have moved to such distant corners of the world from their original habitat. Some rogue exotic fish traders are thought to have released them in the lake to avoid being caught by antipoaching forces. Piranhas were also spotted in the Lijiang River in China.
Depending on the exact species, most piranhas grow to between 12 and 35 cm (5–14 in) long. A few can grow larger, with the largest living species, the red-bellied, reaching up to 50 cm (20 in). There are claims of São Francisco piranhas at up to 60 cm (24 in), but the largest confirmed specimens are considerably smaller. The extinct Megapiranha which lived 8–10 million years ago reached about 71 cm (28 in) long, and possibly even 128 cm (50 in).
Serrasalmus, Pristobrycon, Pygocentrus, and Pygopristis are most easily recognized by their unique dentition. All piranhas have a single row of sharp teeth in both jaws. The teeth are tightly packed and interlocking (via small cusps) and are used for rapid puncture and shearing. Individual teeth are typically broadly triangular, pointed, and blade-like (flat in profile). The variation in the number of cusps is minor. In most species, the teeth are tricuspid with a larger middle cusp which makes the individual teeth appear markedly triangular. The exception is Pygopristis, which has pentacuspid teeth and a middle cusp usually only slightly larger than the other cusps.
iranhas have one of the strongest bites found in bony fishes. Relative to body mass, the black piranha (Serrasalmus rhombeus) produces one of the most forceful bites measured in vertebrates. This extremely powerful and dangerous bite is generated by large jaw muscles (adductor mandibulae) that are attached closely to the tip of the jaw, conferring the piranha with a mechanical advantage that favors force production over bite speed. Strong jaws combined with finely serrated teeth make them adept at tearing flesh.
Piranhas vary extensively in ecology and behavior depending on exact species. Piranhas, especially the red-bellied (Pygocentrus nattereri), have a reputation as ferocious predators that hunt their prey in schools.