The oxygen consumption of Gasterosteus aculeatus L. in toxic solutions.

INTRODUCTION The respiratory exchange of entire organisms, isolated organs and tissues is a widely explored field in physiology, dating back to the classic work of Lavoisier, and in recent times still presents fresh problems for study, as, for instance, the work of Davis & Fraenkel (1940) on the oxygen consumption of flies during flight. Literature prior to 1916 is reviewed and catalogued in the monograph by Krogh (1916); since then the principal work dealing with the respiration of fishes appears to be that of van Dam (1938). This and other previous work on the respiratory exchange of fishes has been mainly occupied with the design of apparatus, the effects of variation in oxygen and carbon dioxide tension, and of temperature, age, size and starvation; and though in recent years river pollution problems have stimulated the study of the toxicity to fish of a vast range of toxic substances (see Ellis, 1937) there has been surprisingly little study of the effect of dissolved toxic substances on fish respiration. Powers (1917) made the first comprehensive study of the effect and degree of toxicity of a wide range of toxic substances to Carassius and (1922) investigated the effect of variations in the />H of the medium on the physiology of respiration in fishes. Carpenter (1927,1930), in investigations of the effects of metallic pollution, concluded that the death of fish in dilute solutions of heavy metals is due to asphyxia consequent upon the metal ion precipitating the mucus upon the gill filaments, thus preventing their movement and impeding gas exchange; but, apart from one experiment (Carpenter, 1927, p. 385) in which it was shown that Gasterosteus immersed in a lead nitrate solution evolved carbon dioxide at rather less than 40 % the normal rate, and the general observation that the opercular movements of fish so treated were more rapid than normal, Carpenter submitted no detailed evidence of the extent and rapidity of this asphyxiation effect. The present work was begun as a general study of the effect of toxic solutions on the respiration of fish and deals with heavy metal salts, chloroform and hydrogen cyanide and hydrogen sulphide.