Abstract:

The overall status of seedling production in Korea is discussed. In shellfish culture, such as oyster and ark shell, seedlings are obtained by natural seedling collection. Shellfish seedling production has been decreasing rapidly due to coastal pollution and continuous dense culture over the years. This has lead to the development of artificial production of shellfish seedlings. However, the mass production of seedlings in the hatchery is not yet fully developed in Korea. Isochrysis, Pavlova, Chaetoceros and Thalassiosira are the main live food organisms for the artificial seedling production. These species can be cultured indoors, but the technology for their outdoor culture is not established. Marine fish culture production is growing fast. With regard to seedling production of marine fish, flounder and rockfish are the most important commercial species. For seedling production of these species, rotifers and Artemia are the main live food organisms. Marine Chlorella for rotifer culture is unstable at temperatures over 30 degrees C. Nannochloris oculate, which grows faster than marine Chlorella at temperatures over 30 degrees C is widely used in the summer season as an alternative. A natural Artemia strain exists in small quantities in areas of restricted salt fields. However, the mass production of Korean Artemia cysta is not economically feasible. The Korean Artemia strain seems to have originated from the Shandong Pennisula in China, because of similarities such as the hatching ecology, chromosome number and nutrient composition. Currently, research is carried out to identify a new live food organism that can substitute rotifers and Artemia. The cost of feed including live food organisms is 30-60% of the total production cost for seedling production of marine fish in Korea. Therefore, new and inexpensive artificial formulated feeds should be developed.
(Pukyong Natl. Univ., Dept. Aquaculture, Pusan 608737, South Korea)
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