Physiological Energetics of Blue Shrimp Penaeus stylirostris (Stimpson) Juveniles Acclimated To Different Salinities

ABSTRACT

The influence of salinity on the energy balance and O:N atomic ratio of the blue shrimp Penaeus stylirostris was determined under laboratory conditions (20, 25 and 30psu). The lowest energy expended for routine metabolism and excretion of nitrogenous products was obtained in the animals maintained at 25psu salinity. The high quantity of energy channeled to scope for growth 2757 J g^-1 day^-1 d.w. was obtained in the shrimp acclimated to a salinity of 25psu. The apparent heat increment fecal production and energy lost in exuviae did not differ significantly (P > 0.05) among the shrimp exposed to the three salinity levels. The O:N atomic ratio calculated for the juveniles indicated a catabolism of carbohydrates as the main energy substrate for the organisms maintained in the isosmotic condition (25psu). We recommend maintaining Penaeus stylirostris juveniles at the salinity level which is isosmotic where they are free of environmental stress; these conditions for blue shrimp juveniles would improve production in the cultivation of this species.

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