C. Rosas, A. Sanchez, E. Diaz-Iglesia, R. Brito, E. Martinez, L.A. Soto-1997
Aquaculture, 152 (1-4) : 259-272 (from Current Contents)
Abstract:
Dissolved oxygen is the most important limiting factor in the intensive cultivation of shrimp species. The critical oxygen level and its effects upon the energy metabolism of postlarvae (PL10-18) Of Penaeus setiferus and Penaeus schmitti exposed to diverse salinities were estimated. In both species the critical oxygen level (COL; estimated as the point of inflection of the curve obtained from the relation between the oxygen consumption and the oxygen concentration) was affected by salinity concentration. In P. schmitti, the COL was 5 mg/l for salinities of 38, 30, 20 and 15 ppt, and 4.5 mg/l for animals kept at 25 ppt salinity. In P. setiferus, the COL was 5.0 mg/l in 37, 30, 25, 20 and 10 ppt salinities and 4.5 mg/l in 15, 5 and 1 ppt salinities. The energy deficit (END; deficit of metabolic energy) caused by the metabolic oxygen critical concentration was in P. schmitti 13.9% (38 ppt salinity) and 26.3% (30 ppt salinity), with intermediate values of 17.2, 22.7 and 24.7% in 25, 20 and 15 ppt salinities, respectively, I:or P. setiferus, the END was between 9.1% (1 ppt salinity) and 25.1% (30 ppt salinity), with intermediate values for the remaining salinities, Based on these data, the optimum salinity for P, setiferus postlarvae was between 5 ppt and 15 ppt, and was 25 ppt for P. schmitti postlarvae. At these salinities the tolerance for the decrease in the oxygen concentration was greater than in the rest of the salinities. The high COL obtained for the postlarvae of both species indicates that the culture conditions must be carefully maintained at this developmental stage to obtain the maximum metabolic performance of the shrimp.
(Natl Autonomous Univ Mexico, Fac Ciencias, Dept Biol, Lab Ecofisiol, Mexico City 04510 DF Mexico)
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