Effect of experience on behavior and parameter correlation in juvenile seabass (Dicentrarchus labrax)

Abstract:

Learning and information transfer are two important parts of fish cognitive processes. This study aimed to compare the time and behavioral parameters of juvenile seabass (Dicentrarchus labrax) with or without experienced individuals under a specific environmental condition. The experimental device was “L”-shaped and consisted of three 60 cm×60 cm test compartments made of PVC material. The two adjacent compartments were connected by a cylinder channel with an inner diameter of 12 cm (i.e., first channel and second channel). The experiment comprised two trials: The first tested the time and behavior of an alone fish (AF) to complete the task, and the second tested the time and behavior of inexperienced fish (SF) in the presence of experienced fish to complete the task and the correlation of behavioral parameters between pairs of fish. The results showed that the time for the AF and SF to pass through the second channel was significantly lower than that through the first channel (P<0.05), regardless of the presence of experienced fish. Over the entire experiment, no significant difference was observed between the times taken for AF and SF to pass through the second channel (P>0.05), but less time was taken in the second trial. The pairs of fish showed similar motion trends within 10 min after they first met and kept the relative movement distance within one total length. There were significant correlations between the pairs of fish in terms of the distance moved, velocity, acceleration, turn angle, and activity. These results suggested that inexperienced fishes’ behavior might be influenced by an experienced individual, and that inexperienced fish might obtain more complex information in the process of exploring their environment.