전자저널 > 전자저널 > Growth and Survival by the Breeding Method of Early Young Spats of the Hard Clam, Meretrix petechiails (LAMARCK)

Growth and Survival by the Breeding Method of Early Young Spats of the Hard Clam, Meretrix petechiails (LAMARCK)

Byeong Hak Kim, Kee Chae Cho, Young Ju Jee, Soon Gyu Byun, Min Chul Kim

Southeast Sea Fisheries Research Institute, NFRDI, Namhae, Gyeongsangnam-do 668-821, Korea

To establish technical development for artificial seed production, growth and survival for early young spats of the hard clam, Meretrix petechialis, were investigated by breeding methods. Adult clams were collected at Hasa-ri, Baeksu-eup, Yeonggwang-gun, Jeollanam-do on July 13, 2010, and then transported to the indoor aquarium at the laboratory. Eggs which were taken from mother clams, were inseminated, and after they were fertilized in the aquarium, 60 million bottom-clinging spats (198 ± 12 μm in shell length) were produced and bred. The breeding experiments were carried out from July 16 to October 4, 2010 for 80 days. The methods of sand box, sand bottom circulation filter, inclosing net, floor were used for the breeding experiments, and the experimental condition of sea water temperature for larvae were at 25, 28, 31, 34℃. Four marine cultured food organisms were used for this study as follows: Isochrysis galbana, Chaetoceros gracilis, Phaeodactylum tricornutum, Tetraselmis tetrathele. According to the experimental conditions, experimental groups of the spats in the early stage were investigated the growth rate and the survival. As the result, the method of the inclosing net section was the fastest (grew up to 2.64 ± 0.59 μm in shell length), followed by sandbox (2.59 ± 0.64 μm, bottom circulating filter (2.56 ± 0.52 μm), and floor (2.52 ± 0.56 μm). The survival was the highest in the experimental condition of sandbox (35.9%), followed by floor (34.6%), bottom circulating filter (29.5%), and inclosing net (9.3%). Eexperimental condition of water temperature of 34℃ showed the fastest growth rate (grew up to 2.70 ± 0.76 μm in shell length), and showed the latest growth rate (grew up to 2.45 ± 0.41 μm in shell length) at 25℃. The survival (%) was the highest under the water temperature conditions at 31℃, and showed the lowest (14.2%) at 34.℃. The growth rate of the experimental group fed the mixture live food was the fastest with shell length 2.52 ± 0.66 μm, and that of experimental group fed P. tricornutum showed the latest (grew up to 2.29 ± 0.43 μm in shell length). The survival was the highest (36.9%) under the experiment condition fed mixture live food and experimental group fed T. tetrathele showed the lowest rate (16.2%).

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