Changes in the metabolic rate and quantity of organic acids in the hepatopancreas of the carp, Cyprinus carpio, following feeding.

Abstract

Two experiments were undertaken to divide the metabolic rate due to specific dynamic action (SDA) of carp into several fractions; in one the oxygen uptake, nitrogen and phosphate excretion rates due to SDA were determined, while in the other the organic acids in the hepatopancreas were determined following feeding. The ratio of the oxygen uptake to nitrogen excretion due to SDA (O2/Ni) was in the range of 2.2 to 3.4 in mol. The rates of nitrogen and phosphate excretions increased seven to eight times during 16 hours after feeding. The quantity of organic acids in the hepatopancreas increased six times (0-2, 2-4, 4-7, 7-9, 9-13 and 13-16 hours). The changes in oxygen uptake rate due to SDA were macroscopically in accordance with those in the nitrogen excretion rate and the quantity of organic acids in the hepatopancreas.