The fish Pygocentrus piraya often called the piraya piranha or San Francisco piranha, and sometimes sold as the man-eating piranha, is a large, aggressive piranha from the São Francisco River basin in Brazil.

Common name: Piranha, San Francisco piranha, black-tail piranha, piraya, pirania
Maximum in nature 20 inches or 50 cm
In aquarium 15.7 inches or 40 cm
Water values
Temperature: 77 °F – 82 °F, 25 ° – 28 °C
Hardness: 10 ° / 12 ° dGh
PH: 7.5 / 8.5

Pygocentrus piraya has a very squat body, rhomboid in shape strongly compressed laterally; the head is large, rounded, with two pairs of large nostrils located between the eyes; the mouth, short and placed in a terminal position. It is equipped with particularly robust jaws; the teeth are large, monocuspid, very sharp, and replaceable one by one; they protrude from the incredibly full lips; the lower jaw is more developed than the upper jaw; the branchial operculum has a small articulated pre-operculum; the caudal peduncle is thin and well distinct.
The trapezoidal dorsal fin is supported only by 14/18 soft rays and has a slightly rounded distal margin; behind the dorsal fin, there is a small adipose fin, with rays, triangular and with a very rounded distal margin; the caudal fin, with a large delta shape, is slightly incised and divided into two symmetrical lobes with rounded apexes; the anal fin, trapezoidal and supported only by 27/30 soft rays, extends over the whole posterior part of the abdomen and present the first slightly longer rays, forming a sort of comma; the ventral fins, small and triangular, are placed in front of the dorsal fin; the pectoral fins, trapezoidal, long and narrow, are in a jugular position.

It is one of the largest piranhas, reaches a maximum length of 50 cm in nature, and is sometimes considered the most beautiful, with its orange to yellow belly coloring, silver eyes, and radiated fibrous adipose fin. Like most other piranhas, P. piraya is laterally compressed and roughly circular in profile and carries a mouthful of very sharp teeth. The lower jaw is thick, strong, and protruding.


This fish is omnivorous, but when hungry, stressed or looking for live food, it is very aggressive. This feature, combined with its large size, makes it a danger to humans. Piranha attacks on humans are, for the most part, anecdotal. The piraya prefers to eat small fish and insects, along with seeds and aquatic plant material.

In captivity

Piraya is sometimes available as an aquarium fish. It is not generally bred in captivity, so aquarium pirayas are usually imported from South America and expensive. Any other fish that shares an aquarium with a piraya should be of the same or a similar piranha species. Different types of fish will be attacked and eaten.

Pygocentrus Pirayas is Very aggressive fish.

Although a species native to South America, most of the specimens on the market come from breeding and are now not very sensitive to the water’s chemical values ​​. Water condition must only be very well aerated and filtered, preferably through a pressurized external filter, with the flow rate hourly of at least four times the capacity of the aquarium; due to his excessive appetite, it is also advisable to regularly carry out many partial changes preceded by a scrupulous siphoning of the bottom to collect the largest residues and any treatments with ozone. Tank size is least 150 liters per specimen.


There is no information regarding reproductions that took place in captivity. The reproduction of this fearsome fish in the aquarium is made difficult. The size reached by the adult specimens and by their aggressiveness; it is necessary to prepare a specially dedicated tank, of enormous capacity, with very soft and acid water, filtered with peat until it takes on a very intense brown color; a thicket of robust floating plants such as Ceratophyllum demersum is suitable as furniture; low light is also advisable.


By fishexp