Role of glucose in enhancing life and potency of Cirrhinus mrigala spermatozoa during cryopreservation

Cryopreservation of fish gametes is an emerging technology and breeding with cryopreserved gametes is advancement in fish seed production. Success of cryopreservation is evaluated by the post - thaw motility of the spermatozoa, an for which energy is required. Cryopreservation is known to cause changes in the seminal plasma that would alter the energy supply for the motility of the spermatozoa. Therefore, energy supplementation is found to be useful during cryopreservation. Cirrhinus mrigala spermatozoa were cryopreserved along with glucose as a co-cryoprotectant after 1:100 dilutions with 0.85% physiological saline as extender and Dimethyl Sulfoxide (DMSO) as cryoprotectant (85:15). The diluents contained glucose at four different concentrations, viz., T1 (0.25%), T2 (0.5%), T3 (0.75%) and T4 (1%). The diluted milt was equilibrated for 10 min at 5? C and loaded into 0.25 ml straws. The loaded straws were then frozen with LN2 vapour for 5 min and immersed in liquid nitrogen. Observations were made once in 7 days for 42 days on motility parameters based on which the duration, score, pattern and percentage were determined. The spermatozoa cryopreserved with glucose at 0.5% concentration showed the highest motility duration of 204±3.6 s whereas Control group showed motility duration of only 83.33± 4.5 s on 42nd day. The difference in motility duration was statistically significant (P>0.025).The present study revealed the benefits of adding glucose a t0.5% during cryopreservation as it could help in maintaining the motility duration and survival of spermatozoa.