Fig. 6. Aerobic and anaerobic ATP turnover rates (_ATP) at 32°C in North Sea and White Sea Littorina saxatilis acclimated at 13°C and 4°C. The rate of ATP turnover during anaerobiosis (amount of ATP consumed per g wet mass per hour) was calculated from end product accumulation and ATP and phospho-L-arginine (PLA) depletion as described in the text, assuming an ATP equivalent of 2.75 µmol per µmol of succinate. The aerobic ATP turnover rate was calculated from routine oxygen consumption rates, assuming that 6 mol ATP produced 1 mol O₂.