1.1. The effect of temperature on the respiratory metabolism of zoeae I, postlarvae and adult freshwater shrimps, Macrobrachium olfersii and M. heterochirus, was examined.2.2. Zoeal and adult metabolic responses of both species were very similar, although each stage inhibits a different biotope; postlarval metabolic responses were the most sensitive to temperature variation.3.3. Regression analyses indicated that b values ranged from 0.67 to 0.71 for M. olfersii and from 0.70 to 0.73 for M. heterochirus; a values increased with temperature increase.4.4. Ontogenetic stages crossing the marine-fluvial interface exhibit markedly different metabolism-temperature response patterns.