魚類の蛋白質栄養に関する研究-II

コイの代謝性Nおよび内因性N排泄量について

抄録

An apparatus was newly devised to catch the nitrogen excreted in the feces and urine of fish. It consists mainly of three parts, namely, a culture tank for maintenance of fish, a test tube containing chloroform as a fecal N preservative and cupric hydroxide as a protein precipitant, and a column of strongly acidic resin for adsorbing dissolved urinary nitrogen. The test tube is connected to the tank by a siphon and the outlet of the test tube is attached to the resin column. The water, supplied continuously at a slow rate to the tank, first enters the test tube through a siphon and then the column of resin, leaving feces in the test tube. By using this apparatus the metabolic fecal N and endogenous N excretions of carp were determined. These nitrogen fractions excreted by carp were shown to fluctuate depending on experimental tempera-tures.