Fish Hatchery Management - fisheries & aquaculture

BROODSTOCK, SPAWNING, AND EGC HANDLINCt43this grass provides spawning sites. Aquatic plants are also utilized asspawning sites. If natural vegetation is absent or scarce, hay, straw, or matsof spanish moss may be anchored in shallow areas for spawning purposes.If the eggs are allowed to hatch in the ponds where they are laid, theadults will stop spawning when the pond becomes crowded with youngfish. If the eggs are removed and transferred to clean ponds to hatch, theuncrowded adults will continue to spawn all summer. In general, pondscontaining both young and adults should produce up to 100,000 fingerlingsper acre. In intensive situations, where a heavily stocked brood pond providesfry for eight or ten rearing ponds, production will reach 200,000 to300,000 goldfish per acre.GOLDEN SHINERGolden shiners are widely distributed from eastern Canada to Florida, andwestward to the Dakotas and Texas. They prefer lakes and slack-waterareas of rivers. Young golden shiners eat algae and cladocerans. Adults willconsume a variety of organisms, from algae and zooplankton to mollusksand small fish. Eggs are adhesive and are scattered over filamentous algaeand rooted aquatic plants.Golden shiner breeders should be at least I year old, and 3 8 incheslong. About 5070 of the broodstock should be shorter than 5 inches inlength; otherwise the stock might be predominantly females, as the malesare consistently smaller than females. The stocking rate in large ponds,where the fry will remain with the adults, should range from 2,000 to 3,000fish per acre. In ponds where egg or fry removal is planned, the stockingrate should be 4,000-8,000 adults per acre.Golden shiners start spawning activity when the water temperature risesabove 65'F, but if the temperature exceeds 80'F, spawning ceases. Duringthis period, at least four or five distinct spawning cycles occur, separatedby periods of about 4 or 5 days. Spawning usually starts early in the morningand terminates before noon. The females deposit their eggs on any typeof submerged plants or debris. At temperatures of 75-tt0"F, fertilized eggshatch within four days.Shortly thereafter, fry congregate in schools near the surface along theshoreline, where they can be collected with a fine-mesh net and transferredto growing ponds. Because adults often cannibalize the young if the twoage groups are left together, the fry should be transferred to other ponds atthe rate of 200,000-300,000 fry per acre. Successful production will yield75,000-150,000 2-3-inch fish per acre. In ponds where the fry remain withthe adults, 60,000 shiners per acre is considered good production.Golden shiners, like most other forage species, can be fed a supplementalformulated diet to increase srowth rate.