Effects of temperature on oxygen consumption and nitrogenous excretion of juvenile Macrobrachium rosenbergii

Abstract

Oxygen consumption (O-2 mg g(-1) h(-1)) and ammonia-N, urea-N, organic-N and total nitrogen excretion (N mu g g(-1) h(-1)) of juvenile Macrobrachium rosenbergii increased directly with temperature in the range of 17-32 degrees C. No urea-N excretion was found at 17 degrees C. The proportion of ammonia-N excretion to total nitrogen excreted by prawns was inversely related to temperature, whereas the proportion of urea-N excretion to total nitrogen excreted increased directly with temperature. At 32 degrees C, the amount of ammonia-N, urea-N and organic-N excreted by prawns accounted for 70.2%, 4.2% and 25.6%, respectively of total nitrogen. Relationships between cumulative amount of oxygen consumed, ammonia-N excreted, organic-N excreted, and total nitrogen excreted, temperature and time are given.