Testing the thermal tolerance of various life stages of fish using the critical thermal method

Authors: Matthew S. Recsetar, Matthew Zeigler, Scott A. Bonar, David L. Ward, Colleen A. Caldwell

Year: 2009 (xli)

Abstract

Increased stream temperatures resulting from global climate change and urbanization will have important implications for fishes worldwide. While there is information on the effects of elevated water temperatures on individual species, there is little information available comparing the susceptibility of different life stages within the same fish species to high temperatures. In our preliminary test, we examined differences in upper temperature tolerances among rainbow trout (Oncorhynchus mykiss) fry (I), fingerling (II), yearling (III) and sub-adult (IV) using critical thermal (CT) tests. Although we found small variations were witnessed, we found little evidence of overwhelming differences in the CTMax of fish at different life stages. In addition to rainbow trout we also tested Rio Grande cutthroat trout (Oncorhynchus clarki virginalis), large mouth bass (Micropterus salmoides), and tilapia at different life stages. This information will be valuable to identify if life stage is an important consideration when estimating temperature tolerance in fish.