2.3. Cryoprotectant stock solution preparation
Stock solutions of dimethyl sulfoxide (DMSO) and glycerol (purchased from Sigma-Aldrich Pty Ltd) were freshly prepared in 0.5 μm filtered seawater at a concentration twice that of the final concentration required in the experiment. When the stock solution was mixed with sperm at a volume ratio of 1:1 in a single step, the required final concentration was produced.