|Vol. 5 (No. 4), pp. 103-143, 2012||doi:10.5047/absm.2012.00504.0103|
Salmon and Freshwater Fisheries Research Institute, Fisheries Research Department, Local Independent Administrative Agency Hokkaido Research Organization, 3-373, Kitakashiwagi, Eniwa, Hokkaido 061-1433, Japan
(Received on January 10, 2012; Accepted on June 21, 2012; Online published on December 21, 2012)
Abstract: Anadromous salmonids and osmerids are artificially propagated in Japan by release of their seeds. However, there are many unsolved problems in the techniques of their propagation. In the present monograph, studies on the improvement of seed production techniques in 4 fishes (masu salmon Oncorhynchus masou, chum salmon O. keta, shishamo smelt Spirinchus lanceolatus and Japanese smelt Hypomesus nipponensis) were outlined. Techniques to evaluate dorsal fin pigmentation during smoltification as an external seed quality, and to improve seed quality of hatchery-reared fish, and the discovery of metabolic problems in hatchery-reared fish were described in yearling masu salmon. In underyearling masu salmon, techniques to evaluate nutritional conditions using kidney melano-macrophage density was developed, and applied to the evaluation of the nutritional condition in hatchery-reared fish after release. In chum salmon fry, the development of techniques to monitor the physical condition and to find its appropriate culture conditions was reviewed. In egg cultures of shishamo and Japanese smelt, techniques to eliminate egg adhesiveness with treatments of kaolin or scallop shell powder suspension were established in order to improve hatching rates. In addition, the appropriate embryogenetic stage for the release of shishamo smelt embryos was demonstrated. Consequently, this monograph reveals that these techniques contribute directly to the development of artificial propagation in some salmonids and osmerids.
Keywords: culture condition, hatchery-reared fish, hatching rate, Hypomesus nipponensis, kaolin, Oncorhynchus keta, Oncorhynchus masou, physical condition, scallop shell powder, seed production, seed quality, Spirinchus lanceolatus
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