クルマエビの呼吸に関する研究-II

Abstract

1) The oxygen uptake rate of Penaeus japonicus BATE was studied by a flowing water method both in the case in which prawns lay hidden motionlessly in the sand, and in the case in which they were prevented from burrowing, thus being in an excited, active state. Animals used ranged in body weight from 3 to 18 gm. All experiments were performed at about 23°C. 2) Immediately after burrowing into the sand prawns showed a comparatively high rate of oxygen uptake, which gradually subsided, and reached a steady resting rate after about 3 hours. The resting oxygen uptake rates per unit weight varied with the size of animals, ranging from 77 to 135 cc./kg./hr. Increase in size was accompanied by a decrease in resting rate. 3) The following relationship was observed between external oxygen content and resting oxygen uptake rate, except in the case of large prawns. Above a certain oxygen level the resting rate is independent of the oxygen content. Below this level the rate gradually increases with decrease in oxygen content, and reaches a maximum at a certain low oxygen level, below which the rate falls rapidly. 4) The active rate of oxygen uptake is more than three times as large as the resting rate. The active rate also tended to drop with increase in size. 5) The active rate is dependent on the external oxygen content over a wide range from near air saturation down to 1 cc./1. 6) From a combination of the resting and active rates of oxygen uptake it seems that the so-called incipient lethal level for this prawn lies between 1.0 and 0.5 cc./1.