Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2011
Publication Date: 2/29/2012
Citation: Green, B.W., Mcentire, M.E., Rawles, S.D., Beck, B.H. 2012. Effect of dissolved oxygen concentration on growth of fingerling hybrid striped bass [abstract]. Book of Abstracts Aquaculture America 2012: Bringing all the Players to the Table. p.207.
Technical Abstract: Management of dissolved oxygen (DO) concentration in production ponds is important because fish growth and yield are greater in ponds with higher DO concentrations. The purpose of this study was to evaluate growth and metabolic responses of hybrid striped bass (Morone chrysops x M. saxatilis; HSB) fingerlings exposed to a constant DO concentration of 30%, 50%, or 100% of saturation at ambient water temperature (23.0 +/- 0.8 C; mean +/- SD). Tanks were operated in flow-through mode and inlet water flow was 39 L/min. Thirty fingerlings (29.6 +/- 5.3 g/fish; 3.8 kg HSB/m3) were stocked into each of 12 250-L fiberglass tanks. Fish were fed twice daily as much 46% protein (12% lipid) feed as they would consume in a 30-min period. Tanks were harvested by draining after 90 d. Survival averaged 98.9%. Hybrid striped bass fingerling growth was impacted by dissolved oxygen concentration. At harvest, HSB reared at 30% DO saturation averaged 63.6 g/fish, significantly smaller than fish reared at 50% (97.3 g/fish) or 100% (101.2 g/fish) DO saturation. Cumulative weight gain averaged 104.6%, 194.1%, or 226.65 for the 30%, 50%, or 100% DO saturation treatments, respectively. Muscle ratio and visceral somatic index were affected by DO concentration, whereas hepatosomatic index was not. Evaluation of aerobic respiration and glycolysis in freshly isolated liver slices showed that oxygen consumption rate did not differ significantly between fish maintained at hypoxia versus normoxia. However, the extracellular acidification rate (a marker of glycolysis) was significantly higher in fish maintained under chronic hypoxic conditions.