Metabolic effects following short-term cyclic hypoxia in a penaeid shrimp (juvenile and adult) and a caridean shrimp (under different salinities) (Crustacea: Decapoda)

Estuarine environments often undergo fluctuations in dissolved oxygen and salinity. Two experiments were performed, one with the penaeid shrimp Penaeus aztecus at two life stages (juvenile, adult) under constant normoxia conditions or diel cycled hypoxia for 2 weeks. The second experiment was with the caridean shrimp Palaemon pugio at two salinity levels (15 g kg⁻¹ and 5 g kg⁻¹) under constant normoxia conditions or diel cycled hypoxia for 2 weeks. After experimentation, partial bioenergetic composition and oxygen consumption were quantified. Cycled hypoxia had no effect on body composition (protein or lipid in P. aztecus, protein in P. pugio), or oxygen consumption in both experiments, suggesting both species are well adapted to short-term fluctuations in dissolved oxygen. Juvenile P. aztecus had higher percent lipid compared to adults, with no difference in percent protein composition. Palaemon pugio in the 5 g kg⁻¹ salinity group had higher oxygen consumption compared to the 15 g kg⁻¹ salinity group. Salinity had no effect on bioenergetic composition. There were no interactions between the factors in both experiments. Hyposalinity may be a stressor for P. pugio; however, the occurrence of salinity stress and short-term cyclic hypoxia together do not appear to affect one another.