|Could a seasonal-like reduction in light radiation intensity affect cultured shrimp (Penaeus stylirostris Stimpson) yield?|
Garen, P.; Martin, J.-L.M. (2002). Could a seasonal-like reduction in light radiation intensity affect cultured shrimp (Penaeus stylirostris Stimpson) yield? Aquacult. Int. 10(1): 43-55
In: Aquaculture International. Springer: London. ISSN 0967-6120, more
Dissolved organic matter; Growth; Nutrients (mineral); Phytoplankton; Shrimp culture; Litopenaeus stylirostris (Stimpson, 1871) [WoRMS]; Marine
|Authors|| || Top |
- Garen, P., correspondent
- Martin, J.-L.M.
Experiments were carried out to establish the effect of a simulated decrease in daylight intensity on the yield of the cultured shrimp Penaeus stylirostris. The purpose of these experiments was to simulate the periods in intertropical regions, which may last for several days, when solar radiation levels fall due to seasonal cloud cover. After 4 weeks of culture, the light reduction resulted in lower shrimp yields compared to unshaded tanks. Survival rates ranged from 54.9 to 71.1% for shaded tanks and from 77.0 to 83.0% for unshaded tanks. Growth rates varied between 0.091 and 0.110 g.d-1 for shaded tanks and between 0.189 and 0.224 g.d-1 for unshaded tanks. In unshaded tanks, variation in growth rate is related to initial shrimp stocking densities. The light reduction led to a reduced phytoplankton growth with, as a consequence, an increase in the concentration of dissolved mineral nitrogen [(NO3- + NO2-)-N, (NH4++NH3)-N] and dissolved organic nitrogen (DON). The higher mortality and lower growth observed in the shaded tanks cannot be entirely explained by the concentrations of mineral nutrients, the temperature, the pH or the O2 concentration. The lower results obtained with the shaded tanks could be most likely a consequence of the toxicity of dissolved organic matter.