Premium
Rate of Acclimation of Juvenile Channel Catfish, Ictalurus punctatus, to High Temperatures
Author(s) -
Allen Kenneth O.,
Strawn Kirk
Publication year - 1971
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(1971)100<665:roaojc>2.0.co;2
Subject(s) - ictalurus , catfish , acclimatization , zoology , fish <actinopterygii> , juvenile , biology , ecology , fishery
Experiments were designed to determine the rate of temperature acclimation, measured in terms of change in heat resistance, when fish were changed between three temperatures—26.0, 30.0, and 34.0 C. Approximately 2300 juvenile channel catfish, Ictalurus punctatus (Rafinesque), were tested. Fish acclimated to each of the three temperatures were exposed to each of the other two temperatures. The length of time required to acclimate to the new temperature was then monitored by testing samples of fish at 0, 1, 3, 9 hours, and then daily after the temperature change was made. Fish were tested at three lethal temperatures of 38.5, 39.0, and 40.0 C. Changes in average resistance time were used to determine progress toward acclimation. Fish changed from lower to higher temperatures were nearly reacclimated in 1 to 3 days. However, fish changed from higher to lower temperatures required from 4 to 14 days to approach acclimation to the new temperature. In both changes, complete reacclimation required at least 12 days. Acclimation was accelerated at higher temperatures. A strong cyclic effect in the mean daily resistance time was noted. A maximum or minimum in resistance time occurred about every 2 to 4 days. These oscillations in resistance time were tested by utilizing multiple regression analysis. The equations derived were found to be quartic (P .01). No explanation was found for this rhythm. These findings indicate that tempering for a few hours would increase heat tolerance to some extent, but upwards of one day would be required to significantly increase heat tolerance. On the other hand channel catfish could be held in cold water for one or two days with only a partial loss of heat tolerance. Fish exposed to fluctuating temperature should retain a relatively high heat tolerance.