Can red sea bream Pagrus major learn about feeding and avoidance through the observation of conspecific behavior in video playback?

Abstract

The present study investigated whether red sea bream Pagrus major could learn about feeding and avoidance area through video model observation. In Experiment 1, 45-mm standard length (SL) fish were trained to learn about a feeding area in a tank. In Experiment 2, 114-mm SL juveniles were conditioned to avoid a hand net by moving into a shelter. Three treatments were established in each experiment: (i) live model observer: fish observed the behavior of a real fish in an adjacent tank; (ii) video model observer, fish observed video playback of a conspecific on a monitor; and (iii) non-observing control. Ten observational trials were performed in both experiments for the live and video model observer. Afterwards, fish from all treatments were conditioned by feed or avoidance conditioning. In Experiment 1, there was no difference in the feed learning process among treatments. In contrast, in Experiment 2, live and video model observers acquired avoidance learning more quickly than control. The result indicates that the video model can be as efficient as the live model for observational learning in fish. This study suggests that video playback may be useful for anti-predator training of seedlings for stock enhancement.

Angling gear avoidance learning in juvenile red sea bream: evidence from individual-based experiments

“…Red sea bream juveniles learned quickly to avoid angling gear. In a recent study that investigated the ability of red sea bream to learn to escape from net-chasing, they required more trials to acquire escape learning (Takahashi et al, 2015). Red sea bream juveniles may learn avoidance behaviour for angling quicker than they would learn to escape from a net.…”

Reared to become wild-like: addressing behavioral and cognitive deficits in cultured aquatic animals destined for stocking into natural environments—a critical review

“…No-contact visual/chemical predator exposure experiments are also variable in their results, with some studies showing modified antipredation behaviors and improved survival in laboratory predation trials, in both fish and gastropods (Kellison et al 2000, Delgado et al 2002. As with direct exposure, using net-chasing seems to work to improve antipredation behaviors also from a no-contact setting; even exposure to video recordings may have an effect (Takahashi et al 2015). Studies using only chemical predator cues as the training stimuli are often found inefficient (Brokordt et al 2011, Kopack et al 2016, Cámara-Ruiz et al 2019a, effects that hypothetically may depend on predator odor not being innately recognized by some species.…”

“…However, none of these experiments were scaled-up to handle the numbers of fish produced under normal stock-fish culture programs. Takahashi et al (2015) tried both live demonstrators and playback of video-recorded fish to train red seabream (Pagrus major). In this case, the fish learned to forage on live prey rapidly, but without any effect of having observed conspecifics forage being demonstrated.…”

Memory retention capacity using two different training methods, appetitive and aversive learning, in juvenile red sea bream Chrysophrys major

“…Takahashi and Masuda (2018) demonstrated the efficiency of net-chase training in C. major juveniles, showing that these fish can generalize threat experiences during this training to various anti-predator performances such as predator avoidance. Takahashi et al (2015) revealed that C. major juveniles learn threat information through social transmission both with live conspecifics and via video playback, although they do not learn the location of prey in this manner. Sea ranching of C. major has been conducted by conditioning released juveniles with an automatic pellet feeder and sound stimuli in Oita, Japan, since 1980 (Fujiya et al, 1980;Anraku et al, 1997).…”