Nitrogen Budget for the Rotifer Brachionus plicatilis

Nitrogen ingested by the rotifer, Brachionus plicatilis (S type) is balanced by gain in body nitrogen (including reproduction), soluble excreted nitrogen, and nitrogen as egested feces. Every term in the budget was estimated independently, and measured as directly as possible. A comparison of the observed and calculated nitrogen as egested feces yielded a satisfactory result. The nitrogen ingested by the rotifer was distributed as follows: 15.6% for growth and reproduction, 42.0% for metabolic excretion, and 42.4% as feces. From these results, it was concluded that a large proportion (84%) of the nitrogen ingested by the rotifer is transferred to water in various forms and may cause deterioration of the water quality.