The Age of Aquariums: Managing Elasmobranch Behaviour in a Mixed-Species Habitat

Managing elasmobranchs in mixed-species aquarium exhibits presents unique welfare challenges. With many species facing conservation threats, optimising behaviour in managed care is critical. This study investigated the effects of modified feeding events and positive reinforcement training on sharks, rays, and bony fish in Singapore Oceanarium's Open Ocean Habitat. Experiment 1 employed a reversal design, transitioning from single daily feeding to three feedings a day while maintaining the total food quantity. Sharks showed a significant reduction in undesired responses; however, rays showed an increase in such behaviours. Bony fish showed minimal effects due to the manipulations. Experiment 2 targeted undesired responses in the rays through a target training intervention. Javanese cownose rays ( Rhinoptera javanica ) received positive reinforcement training using stretcher conditioning, while spotted eagle rays ( Aetobatus narinari) received fixed location feeding. Training significantly reduced the cownose ray’s undesired responses. Eagle rays showed improvements, though not statistically significant. Results demonstrated that live-feeding modifications effectively reduced undesired responses in sharks but required additional reward-focused interventions for rays. Positive reinforcement training successfully addressed welfare challenges, providing practical management tools for aquarium professionals working with diverse elasmobranch collections.