22 MARCH 2016 • WORLD AQUACULTURE • WWW.WAS.ORG Gosrybcenter. The farm incubates eggs of two strains of C. peled, industrial hybrid C. peled and C. nasus, C. muksun, C. nasus, C. lavaretus pidschian, C. tugun and S. l. nelma. In the fall of 2015, the incubation facility at Tobolsk incubated 969 million whitefish eggs, which is the third top result in its half-century history and is the best performance in Russia at the moment. Whitefish eggs are incubated in 8-L Weiss jars (Fig. 5). During a recent season the incubation facility used about 1,200 hatching devices. Usually the incubation season lasts from 10 October to 30 May. Water temperature in the incubation facility is typical for similar whitefish hatcheries. Average long-term incubation temperature during the whole season is 1.6 C, while the water temperature in the incubation facility during the main part of the season, from December 1 to April 1, does not exceed 0.4 C. The incubation facility at Tobolsk incubated and hatched 612 million whitefish larvae in April-May 2015. The main share (78.9 percent) was C. peled, hybrids of whitefish accounted for 14.3 percent; C. muksun 3.1 percent; C. nasus 2.3 percent, C. lavaretus pidschian 1.3 percent and C. tugun 0.1 percent. The survival rate of larvae from live eggs was about 80 percent. A short period of providing larvae with Artemia nauplii for 3-18 days is carried out at the Tobolsk incubation facility. Whitefish larvae are transported to lakes or fish farms in plastic bags with oxygen, live-fish containers, and live-fish boats. Release of larvae is the most difficult stage technologically. Larvae must be taken, accumulated, packed and transported over long distances, up to 1000 km, in the shortest possible time during the mass hatching. The larvae of whitefish are supplied for stocking of floodplain reservoirs and nurseries in the Ob and Irtysh River basins to replenish natural populations and for commercial growing in lakes. Several million eggs before hatching or larvae are sent to China and Kazakhstan every year. In addition to the Tobolsk Regional Fish Farm, the Ugra hatchery has been in operation in the region for 5 years (Fig. 1). Three small hatcheries operate in the area of Chelyabinsk and each produces up to 100 million larvae annually. A whitefish hatchery on the Sob River in Kharp (Yamalo-Nenets Autonomous District) will initiate operation in 2016 with a projected capacity of 208 million eggs. Egg Collection The need for eggs for hatcheries is satisfied through collection of eggs in 5-7 fish breeding locations. A specific feature of FIGURE 5. Egg incubation system at Tobolsk Regional Fish Farm. FIGURE 6. Traditional method of whitefish egg collection. Manual collection of C. muksun eggs (left). Hydration of C. peled eggs (right).
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