Nonindigenous Fishes in Freshwater Systems

Established Nonindigenous Fish Species in Florida

Characidae - Characins

Pirambeba (Serrasalmus humeralis, probably S. rhombeus). The genus Serrasalmus is native to the Rio Orinoco, Rio San Francisco, Rio de la Plata Systems, and the Amazon River in South America (Myers 1972). Importation of any piranha species into Florida is prohibited because of strong concerns that the species could become established in Florida waters (Paul Shafland, Director, Non-native Fish Research Laboratory, Florida Game and Fresh Water Fish Commission, Boca Raton, Florida, personal communication). Myers (1972) edited a monograph on piranhas and discussed relative dangers of the different species of piranha and their relatives. Popularity of this species peaked in 1960 and 1961 and has since declined. Piranha are now on the Prohibited Species List in Florida. Mixed with similar looking species such as the silver dollars (Metynnis hypsauchen) or pacu (Myleus pacu), piranha are still found in shipments into Florida. Although Moe (1964) admitted that not enough was known about the basic biology and life histories of piranhas in their native ranges in South America, he predicted establishment of potential piranhas in Florida if introduced. The temperature range of the pirambeba's native range is similar to temperatures in southern Florida--between 20.0 C and 27.0 C (Moe 1964). His predictions about the piranha's survival in Florida were correct.

In 1977, an established population of Serrasalmus humeralis was found in a display pool--a small confined sinkhole in Monkey Jungle, an amusement park south of Miami--in Florida. The pool was seemingly stocked with them in 1963 or 1964. The pool received water from a small, well-fed stream. In September 1977, personnel of the Florida Game and Fresh Water Fish Commission discovered the fishes and treated the pool with 5% emulsified rotenone. They removed 53 piranha, consisting of three year classes (Shafland and Foote 1979) and verifying that some species of piranha could survive and reproduce in Florida if introduced. Moe (1964) discussed the spawning of this species in captivity in the United States. He found that water conditions, including water temperatures, were suitable for establishment of piranhas in Florida, especially for piranhas from the southern part of their range. Temperature-tolerance tests revealed the lower lethal water temperature was 11 C (Shafland and Foote 1979) and the possible survival of this species in most of Florida. The Florida Game and Fresh Water Fish Commission is concerned about introductions of piranhas into Florida and is engaged in preventing them from entering Florida. Single specimens of a dangerous species, the red piranha (Pygocentrus nattereri; formerly called the red bellied piranha) continue to be taken from the waters of Florida but without evidence of establishment. Red piranhas in waters of Florida are probably released pets who had grown too large for their owners' aquariums or individuals that were released when their owners moved to Florida and discovered that keeping the species is illegal. Although the normal diet of pirambeba includes shrimp, fish, and sometimes other animals, and small amounts of vegetation, they have been known to attack humans and terrestrial animals (Braga 1954).