PRESERVATION OF SPERMATOZOA AND OVA FROM FRESHWATER FISH (CRYOPRESERVATION, FERTILIZATION, GAMETES, SALMONID, REPRODUCTION)

Gametes from various species of freshwater fishes were examined in order to develop techniques that would allow for the preservation of fish spermatozoa and ova. Individual studies were conducted to examine; (1) physiochemical characteristics of semen and ovarian fluid, (2) factors affecting the in vitro non-frozen preservation of fish gametes, and (3) factors affecting the cryopreservation of fish gametes.; The mean pH and osmotic pressure of trout seminal plasma from minimum damaged samples was 7.85 and 260 m0sm/kg, respectively. The mean sperm concentration of semen collected from 12 freshwater species was 28.7 x 10('9) spermatozoa/ml. Enzymatic constituents of trout seminal plasma were higher in seminal plasma from freeze-damaged samples as compared to minimum damaged samples. With the exception of calcium, the concentration of all inorganic constituents examined changed significantly between seminal plasma from minimum and freeze-damaged samples. The concentration of all 17 amino acids detected in trout seminal plasma increased significantly in freeze-damaged as compared to minimum damaged samples. The mean pH and osmotic pressure of the ovarian fluid of 7 freshwater fishes was 8.56 and 291 m0sm/kg, respectively.; Maximum duration of non-frozen sperm storage was 19 days. The optimal procedure for non-frozen preservation included; (1) 1:2 dilution of neat semen in an extender system (physiological salt solution, pH 7.8, osmotic pressure 320 m0sm/kg), and (2) maintenance at 0 C under an oxygen atmosphere.; Cryopreserved spermatozoa of brown and rainbow trout resulted in post- thaw fertilization rates in excess of 90%. Post-thaw spermatozoa of the brook trout resulted in a maximum of 65% fertility. The optimal procedure for cyropreservation of spermatozoa included; (1) 1:1 dilution of neat semen into an extender containing either 7% dimethyl sulfoxide or ethylene gylcol, and (2) the 0.25ml plastic straw as a freeze configuration.; Eggs of brown trout, brook trout, rainbow trout, and northern pike all survived cooling at -25(DEGREES)C. Attempts to cool the eggs to temperatures below -25(DEGREES)C resulted in the complete loss of egg viability. In all species, post-warming egg viability decreased rapidly after cooling to temperatures below -15(DEGREES)C.