Does parental angling selection affect the behavior or metabolism of brown trout parr?

Abstract

Acknowledgements 21We thank the staff of Kainuu Fisheries Research Station for their help in catching, breeding 22 and rearing fish, Dr. Hannu Huuskonen for advice in setting up the respirometry, and Dr. 23Chris Elvidge for comments on the manuscript. J.M.P., Abstract 27The behavior of organisms can affect their vulnerability to human induced selection, 28 including recreational angling. Angling is expected to select fish with bold behavior, which 29 may be linked to low stress responses through stress coping styles. Brown trout (Salmo trutta) 30 is an intensively fished salmonid, and thus provides a relevant model to study artificial 31 human-induced selection by angling. We used a selection experiment with fish possessing 32 high or low vulnerability to angling to understand the consequences on traits related to stress 33 coping styles and metabolic rate. We produced selection lines in two populations of brown 34 trout -one wild and one reared in captivity for several generations-and reared the offspring in 35 common garden conditions. We then assessed minimum and average metabolic rates, 36 boldness and sensitivity to stress in juveniles at the age of 1 year. Angling selection had 37 population-specific effects on risk taking -related latency and exploration tendency, and 38 populations differed on average in several measured traits, which could be due to a 39 combination of genetic and non-genetic effects. Our study provides evidence for angling 40 induced selection in fish personality and suggests that metabolic rate and stress sensitivity 41 might also be affected. The results can be explained by contrasting frequencies of proactive 42 and reactive stress coping style in the two populations. 43 44 Significance statement: 45Hunting and fishing by humans, as any predation, can select individuals with bold behaviors, 46 which potentially leads to an increase in shyness in prey populations. Because this is expected 47 from highly vulnerable parents, but having only a weak effect on in juveniles from the wild 52 population. Our study implies that angling selection can lead to accumulating behavioral, 53 stress sensitivity and metabolic change over time.

Genetic coupling of life-history and aerobic performance in Atlantic salmon

“…Other studies in salmonids have found sex differences in the performance of 2+ yearold or mature individuals, including a higher aerobic scope, but not SMR, and a higher cost of swimming in males than in females (Clark et al 2011;Makiguchi et al 2017;Archer et al 2020). The lack of sex differences in metabolic phenotypes in our study both across and within age-at-maturity genotypes, therefore, supports the conclusion that sex-dependent lifehistory variation is not reflected in metabolic rates during the juvenile stage, as suggested by a few other studies (Regnier et al 2015;Prokkola et al 2021;Åsheim et al 2021). Recently, it was also shown that salmon females have a higher size threshold for maturation after one year at sea compared to males (Tréhin et al 2021), and further studies are required to link the performance differences and sex-specific maturation schedules of salmon at sea.…”

Post-release exploration and diel activity of hatchery, wild and crossbred strain brown trout in semi-natural streams

“…We used fish from two originally philopatric populations, one captured from the wild, the other reared in a hatchery for stocking purposes for over five decades, and their reciprocal F1 crosses. Previous studies have demonstrated that these strains differ in personality traits and in migration tendency (Alioravainen et al 2018, Prokkola et al 2019, Lemopoulos et al 2019b) the hatchery strain being the boldest and the most migratory. Here, we hypothesized that the experimental populations would be strongly diverged in their behaviour, and that the hatchery population would represent a more (downstream) dispersive phenotype and display higher day-time activity than the wild strain.…”