Conservation of Commercial Kumamoto Oyster....
NOAA Fisheries Logo


GRANT NUMBER:  NA66FD0110           NMFS NUMBER:   95-SWR-007

REPORT TITLE:  Conservation of Commercial Kumamoto Oyster Broodstock

AUTHOR:  Anja Robinson

PUBLISH DATE:  November 12, 1998

AVAILABLE FROM:  National Marine Fisheries Service, Northwest Region, 7600 Sand Point Way NE, BIN C15700, Bldg #1, Seattle, WA 98115.   TELEPHONE: (206) 526-6115


In order to establish a true Kumamoto oyster (Crasosstrea sikamea) broodstock for a commercial scale production of larvae in hatcheries, Kumamoto-type oysters with characteristics features of deep cupped, fluted valves and small adult size were collected on commercial growing grounds from California to Washington. Samples of gill tissue were analyzed by comparing the patterns in DNA. According the results, only the true Kumamoto oysters and their offspring were kept for future stock commercial broodstock.

More than two decades ago Kumamoto oyster Crasosstrea sikamea was crossed with pacific oyster Crassostrea gigas in a commercial hatchery in the hope to produce a oyster with good qualities of both species. Despite of the continuous efforts to select the broodstock oyster by morphology hatchery produced seed of Kumamoto oyster has been reported to grow up resembling Pacific Oyster. The technology to distinguish genetic differences between Kumamoto and Pacific oysters was developed at Dr. Hedgecock’s laboratory at Bodega Bay, California. In this study, the molecular markers were used to select pure Kumamoto oysters for future commercial broodstock. Audactor muscles of the oysters were relaxed by holding the oysters in a magnesium chloride solution in order to remove a small peice of gill tissue for DNA analysis. Each oyster and sample of gill tissue were numbered accordingly and oysters placed into running sea water for recovery. According to the results of the DNA analysis, true Kumamoto oysters were conditioned for spawning, spawned, mated pair-wise by selecting individuals from different origin in the hope of genetic diversity, larvae was reared through metamorphasis, set and delivered to commercial growing grounds for future commercial broodstock oysters. A total of 810 oysters were analyzed and 730 were identified as true Kumamoto oysters which have been sent to commercial hatcheries for pure Kumamoto oyster broodstock.

Privacy Statement | Disclaimer | Employee Locator

NOAA Fisheries, 1315 East West Highway, SSMC3, Silver Spring, MD  20910