Oxygen Consumption and Ammonia Excretion by the Abalone Sulculus diversicolor aquatilis in Starved Condition

Abstract

Oxygen consumption and ammonia excretion were investigated during a long term starvation in an abalone Sulculus diversicolor aquatilis. Abalone used in the present study were 14 specimens ranged from 0.14 to 17.10g in wet weight of soft body (W, g). They were kept starved in a closed aquarium at 24°C. Oxygen consumption and ammonia excretion rates were measured by individual in a closed bottle with several days interval until death by starvation. Oxygen consumption rate (R, μl O2/ind./h) of the abalone increased linearly with an increase in W and decreased with the period of starvation (T, days); R=92.019 W0.914. Ammonia excretion rate (E, μmol/ind./h) increased linearly with an increase in W. Until the 17th day from commencement of the experiment E increased with an extention in T, however, it decreased with extention of T after the 17th day and they are expressed as E=0.369 W0.78T0.413 in and E=2.151 W1.012T-0.4b4, respectively. The O/N ratios for abalones just after feeding were relatively high and indicate an apparent dependence upon carbohydrates in the feeding period. After about 2 weeks starvation, the O/N ratios showed relatively low and constant, followed by standard protein energy utilization thereafter. © 1991, The Japanese Society of Fisheries Science. All rights reserved.