Suppression of the diurnal rhythm of oxygen uptake by eyestalk ablation in the crab Oziotelphusa senex senex Fabricius.

Oxygen uptake of the whole animal, of the isolated hepatopancreas and of some muscles of Oziotelphusa senex senex exhibits a diurnal rhythm with a maximum uptake at 00 h, and a minimum at 12 h. The rhythm is related to the animal's motor function which is active during the night. Bilateral eyestalk ablation increases motor activity and oxygen uptake during the day. The diurnal rhythm of oxygen consumption is suppressed.