Individual personality does not predict spatial learning ability in farmed crucian carp ( Carassius auratus )

Animal personality is a concept in behavioural ecology that describes consistent inter-individual variation in behavior. These behavioral tendencies are stable across different contexts and throughout an individual’s life. Increasing evidence shows that variation in individual personality of animals is related to variation in their cognitive ability (e.g. spatial learning), but the findings on such links are contradictory among and even within species. This study examined how personality traits (boldness and activity) relate to spatial learning in crucian carp (Carassius auratus), specifically to determine their reliance on allocentric (landmark-based) navigation. Fish were trained under two conditions: a visual landmark absent and present. As trials progressed, latency to complete the foraging task and theG number of fish turn-backs decreased in both treatments. However, the percentage of correct choices increased significantly only in the landmark present condition, with no marked improvement in the landmark absent condition. This indicates that the presence of a landmark enhanced learning efficiency, suggesting a reliance on allocentric navigation. Despite this, neither boldness nor activity predicted individual learning performance in landmark present context. Our findings demonstrate that environmental structure, specifically the presence of landmarks, is a critical factor in spatial learning for crucian carp, but the personality traits measured here do not underpin individual variation in this cognitive ability within the tested contexts.