Cooling of curimba (Prochilodus lineatus) embryos using different concentrations of dimethyl sulphoxide and methanol

ABSTRACT This study aimed to evaluate the effect of using different concentrations (5, 7.5, 10, and 12.5%) of two permeating cryoprotectants, dimethyl sulphoxide (DMSO) and methanol, on Prochilodus lineatus embryos while being subjected to cooling for 2, 4, 6, and 8 h at 4 °C. We analyzed the hatching rate, viable larvae, and counts of hatched and spoiled eggs and those that did not complete their development after cooling. We observed a significant interaction among variables, permeable cryoprotectant concentration, and cooling time, having the increase of these factors caused a reduction in hatching rate. The curimba embryos showed a higher sensitivity to cold at a temperature of 4 °C for 6 and 8 h, directly influencing the production of viable larvae. We did not observe a significant difference in the variables analyzed when comparing the cryoprotectant solutions containing DMSO, methanol, and solutions containing only water and sucrose (0.5M). An increase in the concentration of cryoprotectant and cooling time promotes a reduction in the hatching rate and in the percentage of viable curimba larvae.