Stress and mortality associated with truck transport of largemouth bass Micropterus salmoides were characterized during and after simulated hauling periods of up to 30 hours at a density of 180 g fish/liter of water. Generally, "transported" fish had significantly elevated concentrations of plasma glucose and corticosteroids and decreased plasma chloride concentrations and oso molality. Significant mortality was associated with hauls of 24 and 30 hours (38% and 83-92%, respectively). Plasma characteristics returned to near-normal values 3-28 days after being hauled; recovery time generally was related to length of haul and associated mortality. Stress was reduced significantly and mortality was eliminated when fish were treated for diseases, held 72 hours without food before they were loaded, anesthetized before they were loaded, hauled at a cool temperature in physiological concentrations of salts with an antibiotic and a mild anesthetic, and allowed to recover in the same medium less the anesthetic.

We developed methods for cryopreserving sperm of channel catnsh Ictalurus punctatus and evaluated the use of cryopreserved sperm for reproduction. Five Cryoprotectants were evaluated: methanol, glycerol, dimethyl sulfoxide (DMSO), sucrose, and polyvinylpyrrolidone. We measured the motility of sperm that had been stored at 4°C in three concentrations of Cryoprotectants (5%, 10%, 15%) dissolved in a modified Hank's balanced salt solution. All Cryoprotectants reduced motility within 6 h; 5% methanol and 5% DMSO caused the smallest reduction. After sperm were frozen at -80°C and stored for 2 d at -196°C, motility was highest (5-10%) in samples cryopreserved with 5% and 10% solutions of methanol. Sperm cells cryopreserved in methanol solutions (5%, 10%, and 15%) were used to fertilize channel catfish eggs from three females. Fertilization ranged from 24% to 97%, and no difference in fertilization success was found between cryopreserved sperm and untreated sperm from the same males. Growth of channel catfish produced with cryopreserved sperm was not different from the growth of siblings produced with untreated sperm. Sperm cryopreservation offers utility as a routine method for gamete storage and genetic improvement of catnsh.

Plasma values of corticosteroids, glucose, chloride, and osmolality were determined in largemouth bass Micropterus salmoides under various environmental conditions. No differences were observed in quiescent fish due to sex, size, time of day, or the types of holding facilities tested (tanks, raceways, ponds). Differences were observed in plasma glucose, chloride, and osmolality values among fish acclimated to 10, 16, and 23 C. Abrupt temperature changes caused elevations in plasma corticosteroid and glucose concentrations and reduced plasma chloride and osmolality. Confinement in a net, for up to 48 hours, caused elevated glucose and corticosteroids and reduced chloride and osmolality values. After 48 hours of confinement, fish required up to 14 days to recover normal plasma characters. Generally, short-term exposure to poor water quality (high concentrations of CO2 and NHs, and low concentrations of dissolved oxygen) altered plasma corticosteroids and glucose but had little effect on plasma chloride or osmolality. Net confinement plus poor water quality caused additional stress. Plasma glucose and corticosteroid values were good indicators of stress during application of acute stressors whereas chloride and osmolality were useful indicators of long-term stress and patterns of recovery after stressors were removed.

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