Divergence in behavioural responses to stress in two strains of rainbow trout () with contrasting stress responsiveness

Abstract

The aim of this study was to establish whether two lines of rainbow trout divergent for their plasma cortisol response to a standardized stressor would show consistent differences in their behavioural response to a range of challenging situations. Our results show that the high-and low-responding (HR and LR) lines of rainbow trout did not differ in the aggression shown towards an intruder or in their response to the introduction of a novel object to their home environment. However, there was a difference in behaviour between the two selection lines when they were exposed to two unfamiliar environments. These results suggest that the behaviour of the HR and LR fish differs when they are challenged in unfamiliar environments, while their behaviour does not differ when they are challenged in their home environment. These observations are in agreement with studies on mammals thatshow that individuals with reactive coping styles perform similarly to proactive animals when they are challenged in a familiar environment, while they show different behaviour when they are challenged in unfamiliar environments. Thus, these results provide further evidence that the HR and LR selection lines of rainbow trout exemplify the two different coping styles described in mammals.

Behavioral plasticity in rainbow trout (Oncorhynchus mykiss) with divergent coping styles: When doves become hawks

“…In addition, following transfer from group rearing to isolation in an unfamiliar tank, trout from the LR strain resumed feeding earlier than did fish from the HR strain (Øverli et al, 2002a). It was later shown that rapid resumption of feeding following transfer to a novel environment also predicts social dominance and level of aggression towards territorial intruders in non-selected aquaculture strains of rainbow trout (Øverli et al, 2004;Schjolden et al, 2005a). Most of the behavioural characteristics of the HR line are consistent with previously reported effects of the steroid hormone cortisol in non-mammalian vertebrates (Gregory and Wood, 1999;Øverli et al, 2002b;DiBattista et al, 2005).…”

Modulation of Fgfr1a Signaling in Zebrafish Reveals a Genetic Basis for the Aggression–Boldness Syndrome

“…According to the aggression-boldness syndrome, animals that are more aggressive will also be bolder and more explorative in novel environments (Huntingford, 1976). Aggression-boldness has been described in many animals, including mammals (Benus et al, 1991), birds , and fish (Huntingford, 1976;Brick and Jakobsson, 2001;Schjolden et al, 2005;Moretz et al, 2007;Bourne and Sammons, 2008). However, the mechanism underlying its formation is not well understood and has been suggested to be caused by either pleiotropic genetic (Deng et al, 1994;Dingemanse et al, 2007) or hormonal (Koolhaas et al, 1999;Veenema et al, 2003) constraint or selection driven by optimal adaptation to the environment (Bell, 2005;Bell and Sih, 2007), with each behavioral component having a separate genetic basis.…”

The Integration of Sociality, Monoamines, and Stress Neuroendocrinology in Fish Models: Applications in the Neurosciences

“…For example, Pottinger & Carrick (1999) selected rainbow trout (Oncorhynchus mykiss) selected for responsiveness of the HPI axis by assessing cortisol responses to repeated confinement stress, and selectively breeding animals at extremes of the endocrine response. These lines show divergent behavioural profiles, with high responding (HR) fish more frequently becoming subordinate (Øverli et al, 2005), habituating more slowly to transfer to a new tank (Øverli et al, 2005;Ruiz-Gomez et al, 2008), showing more behavioural arousal after the introduction of an intruder (Øverli et al, 2005) and more attacks to the intruder (Schjolden et al, 2005a) than low responding (LR) fish. Interestingly, differences were also observed in the intestinal mucosal barrier: Rosengren et al (2017) identified high responding trout in an ordinary hatchery population that show lower intestinal permeability during basal conditions, but this was reversed after stress.…”