Elevated temperature enhance task performance by improving cognitive abilities in common rudd (Scardinius erythrophthalmus)

Abstract The primary drivers of the thermal sensitivity of ectothermic organisms' task performance remain uncertain, with the potential for changes in mobility, cognitive ability, or the interaction between these factors to be considered. Similarly, it is unclear whether the relationship between these processes varies with experience or task difficulty. These questions were investigated using a common rudd (Scardinius erythrophthalmus) foraging to find a high food density reward (Artemia salina nauplii) in consecutive daily sessions under different task difficulty (short, medium and long distances to the reward and presence or absence of experienced individuals) at two temperatures (16 or 26°C). The results demonstrated that the thermal sensitivity of task performance was within the range of Q10 between 3 and 4 during the first session, rising between second and third sessions, before decreasing to 2 for the subsequent sessions. A positive correlation was observed between thermal sensitivity of task performance and task difficulty. The thermal sensitivity of mobility increased only slightly over consecutive daily sessions, reaching up to Q10 = 2. The discrepancy in thermal sensitivity between task performance and mobility indicates that the improvement in task performance at elevated temperatures is due to enhanced cognition, either independently or through interaction with mobility.