Repeated stressors do not provoke habituation or accumulation of the stress response in the catfish Rhamdia quelen

Abstract

Fish repeatedly experience stressful situations under experimental and aquaculture conditions, even in their natural habitat. Fish submitted to sequential stressors can exhibit accumulation or habituation on its cortisol response. We posed a central question about the cortisol response profiles after exposure to successive acute stressors of a similar and different nature in Rhamdia quelen. We have shown that successive acute stressors delivered with 12-h, 48-h, and 1-week intervals provoked similar cortisol responses in juvenile R. quelen, without any habituation or accumulation. The cumulative stress response is more associated to short acute stressors with very short intervals of minutes to hours. In our work, we used an interval as short as 12h, and no cumulative response was found. However, if the length of time between stressors is of a day or week as used in our work the most common and an expected phenomenon is the attenuation of the response. Thus, also, the absence of both accumulation of the stress response and the expected habituation is an intriguing result. Our results show that R. quelen does not show habituation or accumulation in its stress responses to repeated stressors, as reported for other fish species

Is Habituation Measurable in Lumpfish Cyclopterus lumpus When Used as Cleaner Fish in Atlantic Salmon Salmo salar Aquaculture?

“…Other species including Eurasian perch Perca fluviatillis Linnaeus, 1758 and rainbow trout Oncorhynchus mykiss Walbaum, 1792 showed habituation to mechanical stress after 8 weeks (60). In contrast, studies on catfish Rhamdia quelen Quoy and Gaimard, 1824 did not observe habituation after 3 weeks of exposure to mechanical stress (61). Thus, habituation to predatory presence in a time perspective, should be considered species specific.…”

Short-term exposure to repeated chasing stress does not induce habituation in Senegalese sole, Solea senegalensis

“…For example, Madaro and collaborators (2016b) showed that Atlantic salmon parr and postsmolts showed an attenuated cortisol response to a chasing protocol after being exposed just for a few days to the same stressor. This is not always the case, however, and in other studies with fish submitted to repeated stressors, the physiological response to stress after repeated or prolonged exposure was not reduced (Koakoski et al, 2013;Madaro et al, 2016a;Mugnier et al, 1998),…”

“…Any kind of habituation or sensitization would be of relevance to the assessment of the actual welfare status of the fish in a facility, since habituation ability is part of fish natural robustness against stress exposure (Noakes and Jones, 2012). Some data suggest that fish are able to habituate to certain stressors (Johansson et al, 2016;Madaro et al, 2016b) but not to others (Barcellos et al, 2006;Koakoski et al, 2013). The physiological capacity for habituation in fish seems to depend on the type of stressor, the severity and the species involved.…”

Effect of supplementation of dietary fibre concentrates on biochemical parameters, stress response, immune response and skin mucus of jundiá (Rhamdia quelen )

“…Under experimental conditions, fish are continually subjected to small levels of stress caused by daily feeding and tank cleaning activities, sampling for biometric measurements and verification of disease status. This sequence of stressors can lead to accumulation of response or habituation of cortisol levels (Koakoski et al., ) which remain low even after application of acute stress. Unlike the findings of this study, Jeney et al.…”