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Influence of Upper and Lower Temperature Extremes on the Swimming Performance of Tilapia mossambica
Author(s) -
Kutty M. N.,
Sukumaran N.
Publication year - 1975
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(1975)104<755:ioualt>2.0.co;2
Subject(s) - acclimatization , tilapia , fish <actinopterygii> , critical thermal maximum , zoology , environmental science , fishery , biology , ecology
Abstract Tilapia mossambica (mean size: 13 cm) acclimated to 30 C in fresh water and forced to swim at current speeds of 36, 66, and 82 cm/s in Blazkaˈs activity apparatus failed to swim at 39.7, 38.4, and 37.0 C respectively, when the temperature of ambient water was gradually increased from the acclimation temperature. The lower critical temperatures of swimming failure at the same three swimming speeds were 17.4, 18.8, and 19.8 C, respectively. The pattern of swimming failure at the critical temperature was similar to that at critical ambient oxygen concentrations. At both the upper and lower critical zones fish swam steadily again when the temperature stress was reduced. The upper avoidance temperature of T. mossambica in relatively quiet water was much lower than the upper critical temperatures of swimming failure. Since such failures do not incapacitate the fish from further performance and since the critical temperatures can be considered as points in a temperature gradient in running water, it appears that these temperatures are indicative of a thermal avoidance in running water.