Effects of cryopreservation on the physiological characteristics and enzyme activities of yellowfin seabream sperm, Acanthopagrus latus (Houttuyn 1782)

Abstract

This study uses the CASA system and enzyme activity kit to detect movement parameters and enzyme activities of fresh and cryopreserved yellowfin seabream (Acanthopagrus latus) sperm, which could provide theoretical support for the protection of the germplasm resources of yellowfin seabream and the sustainable and healthy development of its aquacultural industry. The results showed that MOT, ALH, BCF and other indices were significantly reduced after cryopreservation (P < 0.05). VCL, VSL and WOB and others indicators were not significantly different (P > 0.05). CAT, SOD, CK and other enzyme activities of fresh sperm decreased significantly after cryopreservation (P < 0.05), and there was no significant difference in the enzyme activity of ATP and SDH (P > 0.05). After the second freezing treatment, the enzyme activities of SOD, T-GSH, ATP, CK and SDH of sperm were significantly reduced (P < 0.05), and there was no significant difference in the enzyme activities of CAT, GR, GSH-Px and LDH (P > 0.05). When the cryopreservation time was extended from 5 days to 20 days, the enzyme activities of CAT, SOD, ATP and CK in sperm tended to increase first and then decrease, while the enzyme activities of GSH-Px and LDH tended to remain stable first and then decreased. This study indicates that cryopreservation has some effect on sperm motility parameters and that the activity compared with fresh sperm is slightly reduced. Cryopreservation causes damage to the antioxidant system of sperm to some extent. It also reduces the antioxidant capacity of antioxidant enzymes and energy metabolizing enzymes to generate energy.