Our objectives were to: 1) compare motility of oyster sperm suspended in artificial seawater (ASW) at five osmotic pressures (22, 203, 403, 601, or 833 mOsm/kg) over 24 h 2) compare motility of sperm suspended in solutions of ASW, Hanks' balanced salt solution (HBSS), or DCSB4 solution (all at 833 mOsm/kg) over 4 days of refrigerated storage 3) compare motility of sperm suspended in ASW or HBSS (833 mOsm/kg) in six ratios of sperm:extender (1:0, 1:1, 1:3, 1:7, 1:15, or 1:31) over 4 days of refrigerated storage, and 4) compare motility and fertilizing capacity of oyster suspended in ASW (200 and 830 mOsm/kg), ASW with 6% glycine (ASW+G), HBSS, and calcium-free HBSS (C-F HBSS) (all at 830 mOsm/kg). We conducted a series of experiments to evaluate refrigerated storage of sperm of the Eastern oyster (Crassostrea viginica). Optimization of conditions for short-term storage of gametes is important for the production of seedstock and genetic management of broodstock in aquaculture. This study demonstrated that conditioning of Crassostrea virginica is possible in a closed, recirculating system, although improvements in nutrition would be useful. These differences were attributed to differences in nutrition available between the field and laboratory. Field controls reached a higher mean gametic stage and were in better physiologic condition at the end of the 8-wk study. Physiologic condition decreased in the laboratory. By week 5, the gonads of 73% of oysters sampled were classified as mature. In the laboratory at week 1, the gonads of all oysters sampled were classified as immature or in early development. Mortality was low (18 of 300 oysters stocked) and not associated with P. Water quality in the system remained within target ranges. At weeks 7 and 8, the laboratory-held oysters were compared with field controls held at Grand Isle, Louisiana. Water quality, mortality, Perkinsus marinus infection, gonad development, and physiologic condition (dry tissue-to-dry shell ratio, dry tissue-to-wet tissue ratio, digestive diverticula tubule ratio) were monitored. ![]() Oysters were fed a diet of algal paste (Isochrysis galbana for the first 6 wks and Chaetocerus calcitrans for the last 2 wks). For conditioning, water temperature in the system was gradually raised with a heat pump from 14☌, and held at 25☌ for 6 wks. Oysters collected in February from public oyster grounds off the coast of Louisiana were maintained in a recirculating system for 8 wks. Techniques were developed for holding and conditioning of eastern oysters, Crassostrea virginica (Gmelin), in a recirculating system.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |