Susceptibility of native perca (Percichthys trucha) and exotic rainbow trout (Oncorhynchus mykiss) to high temperature in Patagonia: different physiological traits and distinctive responses

J. AIGO; M.E. LATTUCA; V.E. CUSSAC

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2014

0018-8158

The aim of this work was to explore for the existence of a physiological basis for the apparentexclusion of salmonid fish from the littoral zone of lakes in Patagonia in response toincreasing water temperature, to the benefit of the native perca (Percichthys trucha). Weconducted experiments on the thermal preferences of juvenile perca and rainbow troutcollected in three sites of Northern Patagonia. We characterized the relationship betweenpreferred and acclimation temperature (PT, AT) for perca and trout and analyzed betweensitesvariations in PTs. Both species responded with increasing PT to higher AT, but withdifferences in overall PT for perca from different sites (lower PTs for fish from cooler lake).In general, rainbow trout displayed lower PT and a narrower range of PT than perca. Ourresults provide the first comparative view of PTs of one important native fish and the mainsport fish species of Patagonia. Native perca may be better equipped to cope with warmerwaters than exotic rainbow trout, in agreement with their geographic distribution. Also, percamay have an advantage at the local level, particularly in littoral areas of lakes, through thealleviation of predation by and trophic competition with trout.