Conservações e áreas afins - Pôsteres - 30/11/2023 - 15:30 h às 16:30 h

Coral reefs are one of the most important ecosystems to sustain marine life. However, corals worldwide are facing severe environmental pressures and high mortalities at a rate that spontaneous recovery seems no longer to be effective. Thus, efforts to develop strategies for the conservation of coral reefs must be immediate, and gamete cryopreservation could be a promising tool. This study aimed to develop a cryopreservation protocol for sperm of the Brazilian coral Mussismilia harttii. To understand the sensitivity of the spermatozoa to cryoprotectants and the freezing process, we investigated different cryoprotectants, concentrations, and cryopreservation techniques. Colonies (n=50) were placed in 1000-L tanks with a semi-open capture system connected to the ocean and were monitored until spawning. After collection, spermatic quality was assessed and sperm pool from groups of three colonies was obtained and distributed among treatments. Spermatozoa were exposed to the cryoprotectants dimethyl sulfoxide (DMSO) and methanol at concentrations of 10, 15, and 20% and cryopreserved by vitrification and controlled slow freezing. The successful combination of 20% DMSO associated with controlled slow freezing resulted in samples with 83.57 ± 2.22% viable spermatozoa. This study marks the history of cryobiology applied to genetic conservation of Brazilian corals, leaving as legacy the first coral gamete bank in the South Atlantic, containing 2.4 billion spermatozoa from the endemic coral M. harttii.