Fish Hatchery Management - fisheries & aquaculture

BROODSTOCK, SPAWNING, AND EGG HANDLING 133FIGURE 43.Wild northern pike broodstock are trapped for egg-taking purposesthe culturist must provide conditions as optimum as possible for suchthings as pond management, disease control, water quality, and food supply.The salmonid fishes generally reduce their feeding activity prior tospawning, and Pacific salmon discontinue feeding entirely during thespawning run. Trout broodfish usually are fed formulated trout feeds inquantities of 0.7-1.0% of body weight per day at water temperaturesaveraging 48-53"F, and then fed ad libitum as spawning season approaches.Food intake can drop as low as 0.3-0.4% of body weight per day dwing adlibitun feeding, when the fish are fed high-protein diets containing 4B-4g%protein and 1,560-1,600 kilocalories per pound of feed.In some cases, coolwater species are held at the hatchery and a domesticatedbroodstock developed. coolwater fishes all are predators and must beprovided with suitable forage organisms. There has been some recent successin developing formulated diets that cool- and warmwater predatorswill accept, and in developing new strains or hybrids of these species thatwill accept formulated feeds.For predator species such as largemouth 6asq providing a suitable food organismfor growth and maintenance in the amount needed is very important.The rapid growth and development of largemouth bass makes raising