NITROGEN-EXCRETION BY ARTEMIA-FRANCISCANA

Dry weight and nitrogen content in the San Francisco Bay brine shrimp as well as their ammonia and Kjeldahl nitrogen excretion rates are presented as the log-log linear regressions with respect to the body length. The nitrogen content per dry weight was fairly constant in any size of shrimp (7.8%). However, the slopes of dry weight and nitrogen content changed greatly at the length of 0.8 mm and slightly at about 6 mm. In the smallest group, the slope was -0.2 approximately 0.2, but it was 2.1 approximately 2.2 and 2.7 approximately 2.9 in the middle and the largest groups, respectively. The mature male was heavier than the female of the same length. The ammonia nitrogen was about 68% in the total nitrogen excreted. The total nitrogen turnover rate at 28-degrees-C ranged 6 approximately 22% per day for the shrimp of 4 approximately 10 mm in length and decreased as the shrimp grew.