title: Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.
abstract: Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice.
authors.affiliation: Centro de Ciências do Mar (CCMAR), Universidade do Algarve, Campus de Gambelas 8005-139, Faro, Portugal.
authors.forename: Marco
authors.initials: M
authors.lastname: Cerqueira
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Pathfoot Building, Stirling, FK9 4LA, UK.
authors.forename: Sonia
authors.initials: S
authors.lastname: Rey
authors.affiliation: SPAROS Lda., Área Empresarial de Marim, Lote C, 8700-221, Olhão, Portugal.
authors.forename: Tome
authors.initials: T
authors.lastname: Silva
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Pathfoot Building, Stirling, FK9 4LA, UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Featherstone
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Pathfoot Building, Stirling, FK9 4LA, UK.
authors.forename: Margaret
authors.initials: M
authors.lastname: Crumlish
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Pathfoot Building, Stirling, FK9 4LA, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: MacKenzie
mesh_terms: D000818:Animals; D002755:Choice Behavior; D023681:Cichlids / Q000502:physiology*; D005393:Fish Diseases / Q000382:microbiology; D010551:Personality; D011897:Random Allocation; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary; D000070058:Streptococcus iniae / Q000502:physiology; D013696:Temperature
keywords: Nile tilapia; animal personality; behavioural fever; environmental choice; physiological regulation; thermal preference