The Oxygen Consumption of Newly‐hatched Larvae of Ascaris suum.

Abstract

Summary. Four series of experiments were carried out to determine the oxygen consumption of newly‐hatched larvae of Ascaris suum, using a Barcroft Differential Respirometer. It was found that the consumption curve was divisible into three regions:– A preliminary phase, during which there was a low rate of oxygen consumption, probably due to the fact that the larvae had not settled down to their new conditions of life. An intermediate period, during which the rate of oxygen consumption was very high owing, it is believed, to the larvae making good an oxygen debt incurred during their previous conditions of life inside the egg‐shell due, probably, to the low permeability of the egg‐cases. A final state of constant low oxygen consumption entered into after the larvae have satisfied their oxygen debt and have settled down to their new‐aerobic conditions of life. The actual rate of oxygen consumption during the two later phases was measured and found to be ‐0093 c.c./hr./1000 larvae for the intermediate period and ‐000928 c.c./hr./1000 larvae for the final rate, i. e., during the intermediate phase the rate of oxygen consumption was ten times the normal rate. It is suggested that the larvae can use oxygen if present, but that they can live anaerobically in its absence and build up an oxygen debt during an anaerobic life.