plSSN : 0374-8111 | elSSN : 2287-8815
plSSN : 0374-8111 | elSSN : 2287-8815
plSSN : 0374-8111elSSN : 2287-8815
Culture Characteristics and Feed Suitability of Four Korean CoastalMicroalgal Isolates for Crassostrea gigas Larvae
이상백1,2·박정은1·천민우1·김강래1·박수진1·이덕찬1·정귀택2·김소희1,2*
1국립수산과학원 남동해수산연구소, 2국립부경대학교 생물공학과
Four microalgal isolates from Korean oyster farming areas were evaluated for their culture characteristics and suitability for Pacific oyster Crassostrea gigas larvae. Molecular analyses identified the isolates as Dunaliella bioculata (SA; Sinan-gun, Jeollanam-do), Picochlorum aff. costavermella (WD; Wando-gun, Jeollanam-do), Porphyridium aff. purpureum (GH; Goheung-gun, Jeollanam-do), and Tetraselmis chuii (TY; Tongyeong-si, Gyeongsangnam-do). Responses to salinity (0-40 psu) and temperature (10-30°C) were assessed after 8 days of cultivation. All isolates grew in 2 m³ paddlewheel-driven raceway tanks, reaching day 7 cell densities of 31.7±2.1×104, 2,173.3±30.6×104, 60.0±1.0×104, and 47.0±2.0×104 cells/mL for SA, WD, GH, and TY, respectively. The specific growth rates during exponential growth were 0.412, 0.838, 0.908, and 0.545 d-1, respectively. Larval ingestion was evaluated 2 h post-feeding across four developmental stages: D-shaped, early umbo, middle umbo, and late umbo. WD showed ingestion rates above 90% across all stages. SA was ingested from the D-shaped stage onward, whereas GH and TY showed limited ingestion during the early stages, but were ingested by all late umbo larvae. These results demonstrated isolate-specific culture characteristics and stage-dependent ingestion. However, long-term feeding trials are required to evaluate larval growth, survival, metamorphosis, and settlement and to confirm the suitability of these isolates for hatchery applications.
Microalgal isolates, Feed organism, Mass cultivation, Pacific oyster larvae, Ingestion rate