Broodstock

Aquaculturists may elect to purchase animals for stocking or maintain their own broodstock and hatchery. The decision may rest on such factors as the availabihty and cost of fry fish, post-larval fish, oyster spat, or other eady life history stages in the location selected for the aquaculture venture. 

The University of Idaho and USFWS, with funds from the Bonneville Power Administration, are also gathering data for registration of erythromycin. Erythromycin is intended for control of bacterial kidney disease in salmonid fingerlings that can also be transmitted by broodstock to the eggs (9). If research is completed on schedule and data indicate that the compound is safe and effective, registration is scheduled for 1994 (see Antibiotics, MACROLIDES). 

Anesthetics. Ethyl amiaobenzoate [94-09-7] (benzocaiae), C2H22NO2, is the only anesthetic candidate that might allow spawned-out broodstock carcasses to be used for pet or human food. Studies are still required to determine which residues remain ia the carcasses (9). Electronarcosis is an alternative to chemical anesthesia that uses varying electrical frequencies to rapidly anesthetize fishes and allow gentie recovery. Electronarcosis has been used effectively on tilapia (Oreochromis sp.) and the common carp Cyprinus carpid) and the technique is being tested with other fishes (23,24). 

Sandnes, K, Ulgenes, Y., Braekkan, O.R. and Utne, F. (1984). The effect of ascorbic acid supplement in broodstock feed on reproduction of rainbow trout (Salmo gairdneri). Aquaculture 43,167-177. 

Watanabe, T., Ohhashi, S., Itoh, A., Kitajima, C. and Fujita, S. (1984). Effect of nutritional composition of diets on chemical components of red sea bream broodstock and eggs produced. Bulletin of the Japanese Society of Scientific Fisheries 50,503-515. 

P.D. Delorme. The effects of toxaphene, chlordane and 2,3,4,7,8-pentachlorodibenzofuran on lake trout and white sucker in an ecosystem experiment and the distribution and effects of 2,3,4,7,8-pentachlorodibenzo-furan on white suckers and broodstock rainbow trout in laboratory experiments. PhD Thesis, University of Manitoba, Winnipeg, Man., 1995. 

Principles of finfish broodstock management in aquaculture control of reproduction and genetic improvement... 

Key words finfish, broodstock management, genetic improvement, reproduction, gamete quality. 

Critical points in the control of reproduction forming a broodstock, culture environment and nutrition... 

Large tanks with <5 kg/m, environment natural winter-spring photoperiod (LD9 15-J-LD12 12) and temperature (13-J-15 °C). Hormone induction may be needed for captivity bred broodstock. 

Ponds, spring, increasing photoperiod (->LD14 10) and temperature (15 20 °C 1-2000 degree days). Hormone induction also routinely used for broodstock transferred to the hatchery... 

On arrival of new fish at the hatchery, care needs to be taken with quarantine and acclimatisation to the new holding conditions. The entrance of new broodstock is a path through which diseases can enter into a hatchery. Therefore, a quarantine period should be managed before entering the fish into the broodstock unit and the broodstock unit should be managed as an area quarantined from the other hatchery facilities. Ideally, the quarantine should be in tanks with an environment similar or identical to that in the broodstock unit. Three classes of disease should be considered parasites, bacteria and virus. All fish should be examined for external parasites and if the fish have wounds from capture, the wounds should be treated with an... 

In practice, the framework indicates that water quality, temperature, tank environment and feeding should be optimal, while invasive manipulation of the stock should be minimal. Therefore, for a broodstock or potential broodstock, the water quaUty should be the best available, oxygen levels, pH and contaminants (ammonia, nitrates and pollutants such as fertilisers, herbicides and pesticides) need to be in optimal ranges for the species. 

---