Nitrogen Excretion by Artemia franciscana

Abstract

Dry weight and nitrogen content in the San Francisco Bay brine shrimp as well as their am-monia 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 0.8mm and slightly at about 6mm. In the smallest group, the slope was -0.2 ?? 0.2, but it was 2.1-2.2 and 2.7-2.9 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°C ranged 6-22% per day for the shrimp of 4-10mm in length and decreased as the shrimp grew.