Refrigerated storage of channel catfish sperm

Refrigerated storage of sperm is useful for genetic study and artificial breeding of fishes. Due to the potential loss of donor males, storage is important in species such as channel catfish Ictalurus punctatus from which sperm cannot be stripped. This study addresses short-term storage (at 4 C) of channel catfish sperm by evaluation of storage methods employed for other species and for cryopreservation of channel catfish sperm. The objectives were to evaluate: 1) storage of intact testes and storage of sperm suspended in an extender solution; 2) use of various storage containers with and without supplemental oxygen; 3) use of extender solution with and without the addition of an antibiotic/antimycotic cocktail; 4) use of extender solution with and without the addition of methanol; and 5) use of extender solution with and without the addition of glucose and methanol. Sperm suspended in extender solution retained motility significantly longer (9 d) than did sperm in intact testis (2 d). Sperm stored in Zip-loc(R) plastic bags inflated with pure oxygen retained motility significantly longer (12 d) than did sperm stored in Zip-loc(R) plastic bags without supplemental oxygen (7 d), or sperm stored in plastic beakers (8 d) or test tubes (8 d) without supplemental oxygen. Sperm stored with the addition of antibiotic/antimycotic cocktail or methanol retained motility significantly longer (10-12 d) than did sperm stored without additives (6-8 d). Sperm stored in extender solution without glucose retained motility significantly longer (19-21 d) than did sperm stored in extender with glucose (13-16 d). Motility was retained for as long as 21 d in sperm stored in extender solution with 5% methanol and without glucose. In each experiment, loss of motility was associated with bacterial growth.