Corrigendum to: ‘Shy trout grow faster: do personality traits predict fitness of brown trout in the wild?’ by Bart Adriaenssens and Jörgen I. Johnsson. 22:135–143

No abstract available

Telomere length covaries with personality in wild brown trout

The prevalence of consistent among-individual differences in behaviour, or personality, makes adaptive sense if individuals differ in stable state variables that shift the balance between the costs and benefits of their behavioural decisions. These differences may give rise to both individual differences in, and covariance among, behaviours that influence an individual's exposure to risks. We here study the link between behaviour and a candidate state variable previously overlooked in the study of state-dependent personality variation: telomere length. Telomeres are the protective endcaps of chromosomes and their erosion with age is thought to play a crucial role in regulating organismal senescence and intrinsic lifespan. Following evidence that shorter telomeres may reduce the lifespan of animals in a wide range of taxa, we predict individuals with shorter telomeres to behave more boldly and aggressively. In order to test this, we measured telomere length and behaviour in wild juvenile brown trout (Salmo trutta). We found individuals with shorter fin telomeres to behave consistently more boldly and aggressively under controlled conditions in the laboratory. No such relationship was found with muscle telomere length 3–4 months after the behavioural assays. We suggest that telomere dynamics are an important factor integrating personality traits with other state variables thought to be important in the regulation of behaviour, such as metabolism, disease resistance and growth

Behavioural adjustment of fish to temporal variation in fishing pressure affects catchability: an experiment with angled trout

In passive fisheries, such as angling, the fishing success depends on the ultimate decision of a fish to ingest the bait, based on an individual’s internal state, previous experience and threat perception. Fish surviving capture by anglers are known to be less vulnerable, and catch rates usually quickly decline with increasing fishing effort. Previous theoretical models have thus suggested fishing closures as a means to recover responsiveness of fish to angling gear and maintain catch rates, yet empirical support remains limited. In a controlled replicated pond experiment, we evaluated the effects of temporal variation in fishing pressure on catch rates of rainbow trout (Oncorhynchus mykiss) by simulating short term fishing closures. These fishing closures increased catch rates and population-level catchability, by reducing threat perception at the population level and allowing released individuals to return to a vulnerable state. Our experimental results show that periodic fishing closures benefit catch-rates but at the risk of aggravating the likelihood of overharvesting

IBEROAMÉRICA 1979 [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Learning and context-specific exploration behaviour in hatchery and wild brown trout

In this study we investigate whether rearing environment (wild vs. hatchery) affects the ability of brown trout parr (Salmo trutta) to learn two foraging tasks. Hatchery- and wild-reared brown trout were trained in two different foraging tasks: locating food hidden in a maze and finding a cryptic prey, and their performance within and across tasks was compared. Fish reduced their search time for cryptic prey, but not maze search time, by learning. In contrast to most previous studies hatchery-reared trout generally tended to be more successful feeders and showed faster learning than wild trout when foraging on cryptic prey. This appeared to be due to motivational effects rather than based on cognitive skills. In addition, we examine whether exploration behaviour in brown trout is repeatable across time and context (i.e. reflecting a behavioural syndrome). Individual exploration tendency was repeatable within tasks, suggesting the occurrence of personality in brown trout. However, individuals that were fast explorers in the cryptic prey task were not necessarily fast to explore the maze. Thus, a context-specific behavioural syndrome was found to best explain exploratory behaviour for both hatchery and wild trout. However, repeatability of exploration behaviour within tasks differed between hatchery and wild trout, where wild trout were found to be more consistent in their exploration strategy

Natural selection, plasticity and the emergence of a behavioural syndrome in the wild

Individuals often show consistent behavioural differences where behaviours can form integrated units across functionally different contexts. However, the factors causing and maintaining behavioural syndromes in natural populations remain poorly understood. In this study, we provide evidence for the emergence of a behavioural syndrome during the first months of life in wild brown trout (Salmo trutta). Behavioural traits of trout were scored before and after a 2-month interval covering a major survival bottleneck, whereupon the consistency and covariance of behaviours were analysed. We found that selection favoured individuals with high activity levels in an open-field context, a personality trait consistent throughout the duration of the experiment. In addition, a behavioural syndrome emerged over the 2 months in the wild, linking activity to aggressiveness and exploration tendency. These novel results suggest that behavioural syndromes can emerge rapidly in nature from interaction between natural selection and behavioural plasticity affecting single behaviours

Mixed support for sexual selection theories of mate preference in the Swedish population

Evolutionary theory predicts the existence of relatively stable sex differences in partner preferences with, for example, males being more concerned with traits predicting high fertility and females with traits predicting high resource availability. We tested three predictions using personal advertisements from both traditional newspapers and internet dating services. In accordance with predictions, men offered resources more often than did women, and women requested resources more often than men. Males in all age-categories preferred young partners. Young females preferred older males, but the pattern was reversed for the majority of females past their fertile period. In contrast to predictions, there was no difference between males and females in the degree to which they offered, or asked for, physical attractiveness. Based on our results and a review of previous studies, we suggest that sex differences in factual or advertised preference for physical attractiveness may be more labile than sex differences in preference for resources and status across societies