Humans depend significantly on the welfare of marine ecosystems, deriving benefits not only from resource harvesting but also from the benefits derived from healthy ecosystems (i.e. natural resources’ quality, biodiversity maintenance, and ecosystem resilience to anthropogenic challenges). Traditionally, marine resource management has focused primarily on morphological traits (e.g. body size) of individuals. However, mounting evidence highlights the critical role of behaviour in biodiversity conservation. Fish behaviour, like other phenotypic traits, is largely determined by genetic factors. Therefore, investigating the genetic mechanisms underlying fish behavioural types is pivotal for fisheries management and biodiversity conservation.
This project uses behavioural data obtained by high-throughput acoustic telemetry to simultaneously measure activity and movement in hundreds of wild individuals. Additionally, behavioural quantification was complemented with studies of the same individuals in captivity, assessing exploration, boldness, activity and aggressiveness. These behavioural traits are linked to fishing vulnerability, as individuals exhibiting specific traits are more susceptible at being captured than others, potentially leading to fisheries-induced selection.
In parallel to the behavioural data, the genomic data from the study individuals was characterized through genotyping by sequencing to identify genetic variants associated with specific behavioural types, and complemented by brain transcriptomics to understand gene expression related to fish behaviour. Moreover, the genomic dataset was expanded by means of the assembly and annotation of the species’ genome and the genotyping of individuals from other populations exposed to varying fishing pressures to broaden the scope of the study and open a follow-up research line.
The multidisciplinary nature of the project, combining novel behavioural data collection with next-generation genomic techniques, offered a comprehensive molecular perspective on behavioural characterization. Notably, an association between the number of amino acid copies in a master gene of the clock system and activity timing in marine fish has been described. Additionally, expression levels on several genes were associated with the activity rhythm in this species. Differential activity preferences among individuals can result in varying exposure to human harvesting, potentially leading to the artificial selection of specific gene variants or regulatory pathways influencing individual activity patterns. Furthermore, the reference genome for the study species has been generated, allowing for a population-level analysis from samples subject to varying fishing pressures. The activities conducted under the scope of this project have opened a new line of research in behavioural molecular ecology unprecedented in marine ecosystems.
