Oxygen Conformity and Metabolic Arrest in Nautilus

Abstract

In 1976 and 1979, two R/V ALPHA HELIX Expeditions to Tañon Strait, Republic of the Philippines, were launched for the purpose of exploring the biochemistry and physiology of Nautilus pompilius. In these studies, only preliminary attempts were made to integrate biochemical information with data obtained from whole organisms (Hochachka et al., 1978; Baldwin, 1982). As a result, the biochemical basis and significance of two rather important metabolic responses in Nautilus to varying O₂ availability were overlooked. One of these responses is O₂ conformity: As O₂ availability in inspired water declines, the rate of O₂ uptake (VO₂) also declines. M. J. Wells (personal communication) has obtained data suggesting that at lower temperatures, O₂ conformity sets in at lower O₂ concentrations, which is perhaps not too surprising.