Pheromones and the water source preferences of adult coho salmon Oncorhynchus kisutch Walbaum

Abstract

It has been proposed that population‐specific pheromones released by juvenile salmonids guide the adults on their homing migration (Nordeng, 1977). To evaluate this hypothesis, adult coho salmon, Oncorhynchus kisutch, were tested in a two‐choice apparatus with a variety of water sources. Coho salmon preferred home water without coho odours over an unfamiliar water source (city water). Adults preferred water conditioned by juveniles of their own population over plain city water, but did not prefer water conditioned by juveniles of their own population over that of another.