Artificial Insemination from 2 Year-old Cultured Yellowtail Fed with Moist Pellets.

Feeding experiments were carried out for 5 years in order to clarify the use of 2 year old cultured yellowtail Seriola quinqueradiata as spawners.Every year the fish were purchased from private farms and divided into two groups.One was fed with frozen trash fish (TF group) and the other was fed with moist pellets (MP group) in each net cage for 5 months at the Komame Station of the Japan Sea-farming Association.Eggs and milt were stripped from the females and the males after hormone (HCG) injection, and fertilized by the dry method of insemination.Parameters of the MP groups such as maturation rates of the brood stocks, numbers of eggs per spawner, fertilized rates, hatching rates, and survival rates of the larvae were compared with the TP groups'.The results clearly demonstrated that 2 year old cultured yellowtail fed with either trash fish or moist pellets can be used effectively as brood fish for collecting of eggs.Also supplements of vitamin E, squid liver oil, and caro tenoid oil extracted from krill to the moist pellets improved the results of larvae production.