Using individual-specific conditioning to reduce stereotypic behaviours: A study on smooth dogfish Mustelus canis in captivity

Abstract

Despite how frequently stereotypic behaviours are discussed in the field of animal behaviour and welfare, research on stereotypies in captive elasmobranchs is far less represented in the literature compared to studies on mammalian species. This is particularly unfortunate as aquatic species exhibited in aquariums may be just as likely to perform stereotypic behaviours as other taxa. This study focused on documenting the stereotypic behaviours exhibited by a female smooth dogfish Mustelus canis housed in an aquarium, and the resulting effects of two specific interventions on the performance of those behaviours. The behaviour of the smooth dogfish and her location within the exhibit was monitored for approximately 11 months (5 months of baseline, and 6 months following interventions) using focal scan sampling. Following initial observations, two individual-specific interventions were implemented: 1) the smooth dogfish was removed from her normal exhibit and relocated into a less dynamic medical pool (‘modified social-isolation’); and 2) a more individualised feeding and conditioning method was established to reinforce performance of species-specific behaviours (‘food-based conditioning’). Results indicate that the smooth dogfish not only performed stereotypic behaviours far less frequently following the interventions, but also began performing increased species-specific behaviours (namely resting), and utilised her exhibit space more ubiquitously, suggesting that the interventions had a positive impact. The specific interventions discussed may not be a ‘one-size-fits-all’ solution for stereotypic behaviours displayed in other captive smooth dogfish. However, this study highlights the importance of taking action when stereotypic behaviours are noted, provides initial suggestions for possible interventions, and demonstrates the efficacy of utilising individual-specific approaches for addressing animal care and welfare concerns in captive aquatic species.