Premium
Cold Tolerance and Potential Overwintering of the Red‐Bellied Piranha Pygocentrus nattereri in the United States
Author(s) -
Bennett Wayne A.,
Currie Rebecca J.,
Wagner Paul F.,
Beitinger Thomas L.
Publication year - 1997
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1997)126<0841:ctapoo>2.3.co;2
Subject(s) - overwintering , brine shrimp , critical thermal maximum , killifish , biology , acclimatization , ecology , fish <actinopterygii> , fishery , zoology
Red‐bellied piranhas Pygocentrus nattereri (also known as red piranhas) acclimated to 15–35°C had critical thermal minima (± SD) from 10.5 ± 0.31°C to 19.7 ± 1.25°C. The chronic thermal minimum (± SD) based on equilibrium loss of fish exposed to decreasing water temperatures of 1°C/d was 10.0 ± 0.15°C. Acclimation temperature incorporated into a second‐order polynomial regression model accounted for 97% of variation in critical thermal minima. Fish in the laboratory were unable to capture live goldfish Carassius auratus at temperatures less than 14°C but accepted frozen adult brine shrimp Artemia sp. attemperatures as low as 12°C. When combined with shallow surface water temperature estimates for January, our temperature tolerance and feeding behavior data suggested that red‐bellied piranhas may overwinter in nine southern states of the USA with varying degrees of success. Red‐bellied piranhas would not overwinter where temperatures fall below 10°C. These fish could overwinter at temperatures of 10–12°C but, owing to climatic variability, would not persist in these areas. Although temperatures between 12°C and 14°C would not be directly lethal, persistence of piranhas may hinge on feeding behavior. Red‐bellied piranhas introduced into areas where winter temperatures remain at 14°C or above, however, would not be physiologically or behaviorally limited by low temperatures and may have the capability to establish permanent populations.