|Green, Bartholomew - Bart|
|Rawles, Steven - Steve|
|McEntire, Matthew - Matt|
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2014
Publication Date: 1/12/2015
Citation: Green, B.W., Rawles, S.D., Fuller, S.A., Beck, B.H., Mcentire, M.E. 2015. Hypoxia affects performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis). Aquaculture Research. 47:2266-2275.
Interpretive Summary: Hybrid striped bass, also known as Sunshine bass, reared in intensively managed fingerling or food fish production ponds typically will experience varying degrees of reduced oxygen concentration, or hypoxia, nightly during summer months because photosynthetic oxygen production by algae cease after sunset while all living organisms in the pond continue to respire. It is known generally that fish exposed to hypoxia grow more slowly, but it is not known how low oxygen concentration affects hybrid striped bass. In order to fill this information gap, we conducted a study in tanks where the oxygen concentration was maintained at a constant 25, 40 or 100% of the saturation concentration. Hybrid striped bass growth was higher at higher oxygen concentrations, an improvement that was attributable to higher feed consumption. Higher feed consumption increased yield with no loss in growth efficiency except at the lowest oxygen concentration. The results of this study provide farmers with information they can use to refined pond management practices to ensure pond oxygen concentration is maintained high enough to allow fast fish growth.
Technical Abstract: Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 +/- 2.3%, 39.7 +/- 3.0%, and 105.5 +/- 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole body protein content, whole body compositional indices and nutrient retention efficiencies were linearly related to dissolved oxygen concentration. Results demonstrate that as hypoxia becomes more severe, juvenile hybrid striped bass feed intake is reduced, which affects growth and nutrient retention.