Dominance and predator avoidance in domesticated and wild masu salmon Oncorhynchus masou

Abstract

Dominance, aggression and predator avoidance were compared among farmed, sea‐ranched and wild juvenile masu salmon Oncorhynchus masou in laboratory experiments. Domesticated fish (farmed and sea‐ranched), which had been exposed to artificial selection, were not dominant against wild fish in pairwise contests, nor did they show greater aggressiveness. Farmed fish did show greater feeding than wild fish. Under chemically simulated predation risk, farmed fish were more willing to leave cover and feed than wild fish, indicating reduced predator avoidance in the farmed fish. Our results indicate that selection for fast growth (domestication) in masu salmon favors fish that respond to food quickly and ignore predation risk.

Cultured Atlantic salmon in nature: a review of their ecology and interaction with wild fish

“…For example, selection in hatcheries appears to enhance aggression, as indicated by findings for Atlantic salmon , coho salmon (Rhodes and Quinn, 1998), masu salmon (Yamamoto and Reinhardt, 2003), brown trout (Sundström et al, 2003), and rainbow trout (Riley et al, 2005). Greater aggression may be linked to high fish density in hatchery tanks, and Glover et al (2004) showed that the families of brown trout that survive best under conditions in which food was abundant are different from those that survive best on low rations.…”

“…Jonsson et al, 1990;N. Jonsson et al, 1994Risk taking Berejikian, 1995Fleming et al, 2002;Sundström et al, 2004Feeding behaviour Reiriz et al, 1998Reinhardt, 2001;Sundström and Johnsson, 2001;Brown et al, 2003a, c Aggressive behaviour Einum and Fleming, 1997;Rhodes and Quinn, 1998;Sundström et al, 2003;Yamamoto and Reinhardt, 2003 Fleming et al, 1996 River ascent Skilbrei and Holm, 1998;N. Jonsson et al, 1994 Physical Jonsson et al, 1996;Tamate and Maekawa, 2000;Fleming et al, 2003;Quinn et al, 2004 hormone profile, e.g.…”

Variation in Anti-Predator Behavior Among Five Strains of Inbred Guppies, Poecilia reticulata

“…For example, flight distance in red foxes is negatively correlated with mutant coatcolor, docility in Norway rats is correlated with black coat color (reviewed in Price, 1984) and morphology and escape behavior are genetically correlated in garter snakes (Brodie, 1989). With the exception of hatchery-raised salmonids (e.g, Yamamoto and Reinhardt, 2003), the impacts of correlated selection for morphological traits on behavior in fishes have been poorly explored. Ornamental guppy strains have been under strong artificial selection for many morphological traits and may therefore provide a genetic tool for better understanding how correlated selection on morphology or physiology may be expected to impact the evolution of behavior.…”

Experimental selection for body size at age modifies early-life history traits and muscle gene expression in adult zebrafish

“…Adaptation to the novel captive environment (unintended or inadvertent selection) occurs because of differences in food availability, and physical and ecological factors relative to the wild, producing profound effects on numerous behavioural, physiological, morphological and life-history traits (Álvarez and Nicieza, 2003;Robison and Rowland, 2005), sometimes in as little as a single generation (Mayer et al, 2011;Christie et al, 2012). For example, satiation feeding, the surface presentation of food and the absence of predators has been linked to a reduction in stress, loss of the startle response, and an increase in aggression and growth rate in cultured relative to wild populations (Lepage et al, 2000;Yamamoto and Reinhardt, 2003). Breeding programmes involving artificial selection of individuals or families are designed to direct the domestication process to produce stains with desirable characteristics for farming, including high growth rate, delayed sexual maturation, increased disease resistance, etc.…”