Influence of maternal habitat choice, environment and spatial distribution of juveniles on their propensity for anadromy in a partially anadromous population of rainbow trout (Oncorhynchus mykiss)

LIBEROFF, ANA LAURA; QUIROGA, PAMELA; RIVA ROSSI, CARLA; MILLER, JESSICA ADELE; PASCUAL, MIGUEL

ECOLOGY OF FRESHWATER FISH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 24 p. 424 - 434

0906-6691

This study evaluated the importance of the environment and spatial distribution of juvenile fish for the adoption of alternative migratory tactics in a partially anadromous population of rainbow trout (Oncorhynchus mykiss) from the Santa Cruz River. We captured young-of-the-year fish along the river during autumn 2009, 2010 and spring 2010 and determined their maternal origin (anadromous vs. resident) using strontium-to-calcium ratios in the otolith core. Relative proportion of anadromous offspring, modeled with logistic regression, increased towards headwaters and in areas with deeper channels and larger substrate composition. Body length, modeled with linear multiple regression, varied positively with site depth, water velocity, substrate size and anadromous maternal origin. Based on evidence for limited juvenile movements (