Toward the validation of an alternative method for endocrine monitoring in sharks: insights from testosterone analyses in the skin of bycatch individuals.

The present study presents a new technique for measuring steroid hormones in shark skin. Results reveal for the first time that shark skin contains measurable levels of testosterone and that levels can be reliably measured by enzyme immunoassay. We identify the mass threshold below which samples should not be used to avoid inconsistent hormone data and highlight the importance of considering body location when designing future collection protocols.

Proteomic Insights into Seminal Plasma and Spermatozoa Proteins of Small-Spotted Catsharks, : Implications for Reproductive Conservation in Aquariums.

In the ex situ conservation of chondrichthyan species, successful reproduction in aquaria is essential. However, these species often exhibit reduced reproductive success under human care. A key aspect is that conventional sperm analyses do not provide insights into the functional competence of sperm.

New insights into risk variables associated with gas embolism in loggerhead sea turtles () caught in trawls and gillnets.

Tissue and blood gas embolism (GE) associated with fisheries bycatch are likely a widespread, yet underestimated, cause of sea turtle mortality. Here, we evaluated risk factors associated with tissue and blood GE in loggerhead turtles caught incidentally by trawl and gillnet fisheries on the Valencian coastline of Spain. Of 413 turtles (303 caught by trawl, 110 by gillnet fisheries), 54% ( = 222) exhibited GE.

Comparative Study of Semen Parameters and Hormone Profile in Small-Spotted Catshark (): Aquarium-Housed vs. Wild-Captured.

Several chondrichthyan species are threatened, and we must increase our knowledge of their reproductive biology in order to establish assisted reproductive protocols for ex situ or in situ endangered species. The small-spotted catshark () is one of the most abundant shark species of the Mediterranean coast and is easy to maintain in aquaria; therefore, it is considered an ideal reproductive model. This study aimed to compare male reproductive function in aquarium-housed ( = 7) and wild-captured animals, recently dead ( = 17).