K. Nogami, K. Hamasaki, M. Maeda, K. Hirayama-1998
Hydrobiologia, 358: 291-295 (from Current Contents)
Abstract:
The aim of this work is to control the water environment for culturing larvae of the swimming crab, Portunus trituberculatus, using microorganisms. The bacterial strain PM-4 (Thalassobacter utilis) improved the survival rate of crab larvae and repressed the growth of Vibrio anguillarum (bacterium) and Haliphthoros sp.(fungus) in seawater. PM-4 was cultured and added daily to seawater during the first to third zoean growth stage of the crab with diatoms and rotifers. Numbers of PM-4 decreased in culture water during the first 3 days, because of feeding by the first zoean stage of larvae. The final concentration of PM-4 was 10(5) to 10(6) cells/ml according to the plate count method in larval rearing water. During 1989 to 1993, we tried seed productions of a swimming crab in 200 m(3) containers at Tamano Station, Japan Sea-Farming Association. In 33 trials of the biocontrol methods, average survival rate of crab larvae was 28.3% when the bacterial strain PM-4 was added. In 42 trials in which the strain PM-4 was not added, average survival rate of crab larvae was 15.6%. We conclude that the bacterial strain PM-4 is effective as a biocontrol agent.
(Japan Sea Farming Assoc., Obama Stn., Tomari 26, Obama 91701, Japan)