Telomere length covaries with personality in wild brown trout

Abstract

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 amongst, 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.

Individual variation in age‐dependent reproduction: Fast explorers live fast but senesce young?

“…Individuals with risky behavioural profiles (as defined above) may thus pay the costs of their fast lifestyle (increased reproductive output per breeding attempt) by reproductively senescing earlier in life. This is in line with laboratory studies showing that bold fish suffer greater oxidative stress and faster telomere attrition (Pauliny, Devlin, Johnsson, & Blomqvist, 2015), while bold fish also have shorter telomeres in the wild (Adriaenssens, Pauliny, Blomqvist, & Johnsson, 2016).…”

Evolutionary ecology of telomeres: a review

“…Likewise, in brown trout ( Salmo trutta ), Adriaenssens et al . (using TRF) showed a relationship between telomere length and individual aggression and exploration, assuming that a shorter life span, as a result of shorter telomeres, selects for a bolder, more aggressive personality (linked to the pace of life syndrome).…”

“…Telomere length declined drastically during the maximal, early nestling growth period, but tail and wing length increased with relative telomere length, more so in males than females. 86 Likewise, in brown trout (Salmo trutta), Adriaenssens et al (using TRF) 87 showed a relationship between telomere length and individual aggression and exploration, assuming that a shorter life span, as a result of shorter telomeres, selects for a bolder, more aggressive personality (linked to the pace of life syndrome).…”

Ectothermic telomeres: it's time they came in from the cold

“… reference species tissue(s) method (telomere; telomerase if applicable) telomere response and effect telomerase? Adriaenssens et al [ 26 ] wild juvenile brown trout ( Salmo trutta ) fin and muscle TRF 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 n.a.…”