Susceptibility of native perca (Percichthys trucha) and exotic rainbow trout (Oncorhynchus mykiss) to high temperature in Patagonia

AIGO JUANA; CUSSAC VICTOR

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2013 p. 1 - 27

0018-8158

We determined the relationship between preferred temperature (PT) and acclimationtemperature (AT) for the native Percichthys trucha and the exotic rainbow trout(Oncorhynchus mykiss) collected in two different lakes of Patagonia, by exposingindividual fish to an experimental thermal gradient. We fitted a general regressionmodel, with PT as a response variable of one continuous variable, AT, and twocategorical variables, species and population of origin. Both species responded withincreasing PT to higher AT, but with inter-population differences in overall PT for P.trucha (lower PTs for fish from cooler lake). In general and for a similar range of AT,rainbow trout displayed a narrower range of PT than P. trucha. Our results provide thefirst comparative view of PTs of one of the most important native fish species ofPatagonia and rainbow trout. Our findings indicate that P. trucha may be betterequipped to cope with warmer waters than rainbow trout. P. trucha may have anadvantage, particularly in littoral areas of lakes, through the alleviation of predation byand trophic competition with salmonids.