Participamos en el International Congress of Zoology

 

Entre el 22 y el 24 de noviembre se ha desarrollado el International Congress of Zoology (ICZ2021) en Cape Town (Sudáfrica) que ha sido un evento que ha combinado sesiones presenciales y on-line.

Pablo García-Salinas ha presentado una comunicación oral titulada: Novel tools for sharks and rays conservation strategies: fresh storage and cryopreservation protocols for elasmobranch sperm, con parte de los resultados de su tesis doctoral. El texto del abstract correspondiente es el siguiente:

Elasmobranchs (sharks, rays, and their relatives) are one of the most endangered group of vertebrates on the planet, but despite this situation the use of reproductive techniques in elasmobranch conservation strategies has been scarce. Among these techniques, sperm preservation is a potential tool for ex situ conservation breeding programs. However, there are no widespread preservation protocols for elasmobranch sperm, and shark sperm cryopreservation has never been achieved before. Here we present the establishment of successful cryopreservation protocols for elasmobranch sperm, tested in 10 species including sharks and rays considered Critically Endangered. We have formulated a sperm extender that can be used for different species, capable of maintaining sperm motility for 36 days at 4 °C. The cryopreservation of sperm was achieved by supplementing the extender with different combinations of cryoprotectants: methanol, dimethyl sulfoxide (DMSO) and fresh egg yolk. Samples were frozen inside a styrofoam box using vapour of liquid nitrogen and preserved into liquid nitrogen. Sperm quality was assessed by studying the motility and membrane integrity post-thawing, demonstrating its effectiveness in the 10 species tested. In rays the use of 10% DMSO or 10% methanol rendered post-thawing motility values higher than 40%. In sharks the best post-thawing motility values were obtained with a combination of 5% DMSO, 5% methanol and 10% egg yolk, which induced mean values close to 35%. Overall, the addition of egg yolk increased the post-thawing motility values, by up to 42% in samples with initial motility values of 70%. This is the first time that shark sperm cryopreservation has been reported, broadening our knowledge on the reproductive techniques that can be applied to elasmobranchs, and laying the foundations for the first cryobanks for their sperm.