Fig. 3. A representative 26 h record of cumulative urea-N and ammonia-N from an individual juvenile toadfish (14 mm TL). Urea pulsing was noted in all juvenile toadfish tested (N=7) but the intensity and frequency of the pulse varied among individuals. This individual was collected as a fertilized egg in Biscayne Bay and was used within 1 week of full yolk-sac absorption. Note the urea pulse at 10–12 h and that the ammonia excretion rate was relatively constant.