First study in cryopreserved Crassostrea angulata sperm.

•Toxicity tests do not take into account the following steps of cryopreservation.•10% DMSO, fast freezing and straws are the best conditions for C.angulata sperm.•Fertilization is the definitive assay to test a cryopreservation protocol in oyster sperm.•Sperm cryopreservation protocol was established in C. angulata for the first time.