Cryodiluents optimization of Glossogobius giuris (hamilton-buchanan) spermatozoa

Biodiversity conservation by germplasm maintenance by cryobanks is an accepted way of saving species. The edible fish Glossogobius giuris is reported to be threatened in India and needs rehabilitation measures to improve their numbers in natural waters.

To investigate the standardization of cryoprotectants for the preservation of male gametes of this species.

Four different cryoprotectants were used: DMSO, glycerol, ethylene glycol and methanol. Different combinations of diluents and milt were processed inside a cold handling unit at -5 degree C and stored for the short-term.

Prior to exposure to cryoprotectants, the motility of fresh sperm was 98.3 ± 2.5%. After 10 min equilibration at room temperature in 7.5 % glycerol, sperm motility was 95.6 1.5%, and 93 , 3.2% after 180 min at -5 degree C in this cryoprotectant. In contrast, motility was 65C3% after equilibration in 12.5 % methanol, and survivability fell to 30.7 0.9% after 180 min storage at -5 degree C. Analysis by Bonferroni and Holm Multiple Comparison showed highly significant variations between the effect of methanol and the other cryoprotectants. There was a statistically significant fall in motility when using methanol compared to glycerol.

Glycerol provides greater protection to spermatozoa during cold storage at -5 degree C, possibly as a result of its membrane stabilizing power.