Assessing the impact of captivity on the growth and development of pyjama sharks (Poroderma africanum)

The pyjama shark ( Poroderma africanum ) is a Scyliorhinid species endemic to South Africa. Even though it is kept in captivity in many aquariums, there is a lack of research on its growth and development. In this study, we investigated the fertilization rate of eggs, growth, and age at female sexual maturation in captive pyjama sharks, and compared their growth to that of wild individuals. The fertilization rate of 319 eggs was 18.8%, and total length ( L t ) and body weight ( W t ) at hatching were 14.65 ± 0.26 cm and 16.6 ± 0.8 g, respectively. Both in captivity and in the wild, males showed negative allometric growth and females showed isometric growth. The growth performance (Φ') was also greater in captive sharks compared to wild sharks regardless of sex. One female laid fertilized eggs (85.2 cm L t and 3300 g W t at laying) 2419 days (6.6 years) after hatching and was considered sexually mature. It was suggested that the difference in growth was due to the difference in habitat depth preference between males and females. This is the first study to compare the growth of captive and wild catsharks as well as the first study to compare growth in male and female pyjama sharks. Therefore, this study provides a greater insight into the effects of captivity on different elasmobranch families, as well as aiming to inform differential husbandry techniques depending on sex.