The effects of dietary algal and lipid supplements on the gonadal and larval development of Crassostrea gigas kumamoto (Thunberg)

• Main Author: Robinson, Anja M.
• Other Authors: Tubb, Richard A., Yamada, Sylvia B., Brown, P., Weber, L. J., Lannan, J. E., Fisheries and Wildlife, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Oyster culture; Crassostrea gigas > Feeding and feeds; Crassostrea gigas
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/z603r259p

Under laboratory conditions, elevated temperatures accelerated production of gametes. However, when conditioning for spawning at elevated temperatures was initiated early in the season (January-March), larval survival and number of spat collected were significantly lower than when conditioning was initiated in may or June. At elevated temperatures, broodstock oysters were fed on algal or lipid supplements consisting of menhaden oil, egg phosphatidylcholine and partially hydrogenated vegetable oil (Kaomel, Durkee) in the ratio (by weight) 5:2:3. Oysters fed on supplemental algae or lipid mixtures during conditioning resulted in larger numbers of eggs than non-fed broodstock oysters. After conditioning from March to early April, the proportion of spat was higher in progeny derived from algal- or lipid-supplemented broodstock compared to that from non-fed oysters. The same conditioning treatments initiated in May resulted in no change in the percent of spat collected. Supplemental feeding had no effect on the fatty acid composition of broodstock oysters, but it affected the fatty acid profile of eggs. The w3 fatty acid content was significantly higher in the eggs from algal-supplemented oysters than in eggs from lipid-supplemented or non-fed broodstock oysters. Enrichment of the w3 fatty acid composition of the eggs from algal- supplemented oysters probably increased the success rate in egg development and metamorphosis. The effects of supplemental feeding on broodstock were similar for oysters conditioned for spawning in either flow-through or recirculating systems. The optimum temperature for larval rearing varied from 24 to 28C and optimum salinity ranged from 20 to 3096.