The role of aquaria in the advancement of elasmobranch reproductive biology

Abstract

Public aquaria showcase aquatic life while raising awareness and educating the public on biodiversity and the need for conservation. Recently, aquaria have followed in the footsteps of zoos by taking more directed approaches in species conservation as well as leveraging animals in their collection to fill biological knowledge gaps through research. Similar to zoos, aquaria are able to house animals that are not feasible to care for in traditional academic settings, allowing important life history information to be gained. In particular, our understanding of reproductive aspects of large migratory fishes such as elasmobranchs (sharks, skates and rays) have benefited from information gleaned in aquarium settings that would otherwise be difficult or impossible to study in the natural environment. For example, the ability of elasmobranchs to reproduce parthenogenetically was discovered through observation of sharks maintained in public aquaria. Since its discovery, parthenogenesis has been observed for many ex situ shark and ray species. Aquaria have made other important contributions to characterizing elasmobranch reproductive biology such as understanding reproductive cycling and trialing assisted reproductive techniques, among others. Here, we review the role aquaria have played in the field of elasmobranch reproductive biology and discuss how zoos and aquariums can continue to contribute to this field in the future.

Husbandry conditions of spotted ratfish (Hydrolagus colliei, Chimaeriformes) in aquaria for successful embryonic development and long‐term survival of juveniles

“…The pathologies observed in POM captive specimens, and the corresponding treatments are also detailed. We hope this work again proves the crucial need for collaboration between aquaria and academia to tackle challenging research questions on animals rarely studied in the wild (Feldheim et al, 2022; Harahush et al, 2007; Toledo et al, 2022). We expect long‐term breeding of H. colliei to facilitate access to selected ontogenetic stages to update previous descriptive studies (Dean, 1906; Didier et al, 1998) on this topic and pave the way for future work on holocephalan development.…”

Costs of parthenogenesis on growth and longevity in ex situ zebra sharks Stegostoma tigrinum

“…For most other vertebrates, observations of parthenogenesis have been documented repeatedly among vertebrate species held in human care across academic, private hobbyist, and zoo and aquarium collections (Booth & Schuett 2016, Ryder et al 2021. For elasmobranchs (sharks, skates and rays), parthenogenesis has al most exclusively been observed for animals in human care and when females are maintained in single-sex groups (Feldheim et al 2022), with the exception of 1 observation in a wild smalltooth sawfish Pristis pec tinata (Fields et al 2015). The unexpected birth of a shark or ray in the absence of a male prompts a re productive investigation, and genetics are used to confirm parentage.…”

Development and Application of Techniques for the Control of Captive Breeding in Elasmobranchs

“…Aquaria are able to house animals that are difficult to care maintain in traditional research facilities and academic facilities. In addition, aquaria are able to monitor the same animals over long periods of time, which is especially important when trying to fill in certain gaps in their life histories (Daly and Jones, 2017;Penfold and Wyffels, 2019;Feldheim et al, 2022).…”

“…Additional observations have expanded knowledge on growth rates, longevity, captivity-related aspects (pathologies, social behavior, nutrition, bioenergetics) (Henningsen et al, 2004b;Smale et al, 2004). Moreover, techniques such as tagging, handling, and sampling, initially tested in aquaria, have been applied in the wild to gather data from wild populations (Smale et al, 2004;Daly and Jones, 2017;Penfold and Wyffels, 2019;Feldheim et al, 2022).…”

“…These advancements, coupled with non-lethal information-gathering procedures, are reducing the impact on studied animals, even in the field. Being beyond the scope of this thesis a detailed review of all these applications can be found in the works of Penfold and Wyffels (2019), Mylniczenko et al (2017), andFeldheim et al (2022). Unfortunately, one of the areas of study that has not received much attention has been the use of reproductive breeding technologies.…”