Observations on the Glycogen Content of Certain Invertebrates and Fishes

Abstract

THROUGHOUT the animal kingdom, from the Amoeba to Man, carbohydrate is known to be an important constituent of the organism. It is most characteristically represented within the cells by the polysaccharide glycogen, and in the circulating fluids by glucose. In the higher vertebrates the percentage amount of glycogen in the different organs and tissues varies considerably, being usually greatest in the liver. The amount is, however, closely related to the time of feeding and the nature of the food. In the circulating fluids of the animal, on the other hand, there is apparently a tolerably constant percentage of glucose, if the temporary increase which follows immediately upon the ingestion of food (the postprandial rise) be discounted.Here and there in the animal kingdom, however, it has been asserted that very little, if any, glycogen (certain molluscs) or glucose (Selachians)is present. If this should prove to be the case, it would mean either that some other carbohydrate is substituted for glucose and its polysaccharide-such as a pentose,-or that metabolism proceeds in these animals in the absence of any of the higher carbohydrates. Scrutiny of the published researches upon which these generalizations depend shows that the methods employed have been very unequal in value both qualitatively and quantitatively. For the detection of glycogen the microcheinical reaction with iodine has been extensively used, and for the quantitative determination of this substance usually the somewhat uncertain method of Brucke-Kiulz; it is only here and there that the more certain method of Pfluger has been employed. For the detection and measurement of the glucose it has been usual to utilise the reducing power, after precipitation of the proteins by various methods. In consideration of these facts, it was thought advisable to seize the opportunity afforded by several weeks' residence at the Marine Biological Station (situated on the east coast of Vancouver Island, at Nanaimo, B.C.) to determine by standard methods the relative amounts of the abovementioned carbohydrates in selected varieties of marine animals. In planning such an investigation it was recognised that it is decidedly risky

On the function of the two types of myotomal muscle fibre in elasmobranch fish

“…Red muscle values ranged between 1182 mg% and 3612 mg% wet weight; white muscle values between 1439 and 619 mg%. Kilborn & Macleod (1920) observed 180 mg % in dogfish; Suyama, Koike & Suzuki (i960) around 230 mg % in Dasyatis and 330 mg % in Triachis scyllium; most recently Pavlovic, Kekic, Mladjenovic & Vukotic (1965) found 204 mg % in Scyllium stellare, and in the same species Nixon (1965) found 24-620 mg%.…”

The effect of lipid extraction on carbon and nitrogen stable isotope ratios in oyster tissues: Implications for glycogen‐rich species

“…[12,15,[51][52][53][54][55][56][57][58][59] In organisms with different muscle types, the muscle group and function were also important (e.g. greater glycogen content in the tail than in the claw of American lobster [60] ). Other authors have pointed out that C:N is not necessarily reflective of lipid content even in organisms that store lipids, such as fish.…”

Anaerobiosis in invertebrates

“…The maximum is reached when the genital organs are fully developed (Chaigne, 1933a;cf. also Moore, "Whitley and Adams, 1913 ;Kilborn and Macleod, 1920). Only traces of glycogen, however, have been reported in the unfertilized eggs of Arhacia punctulata (Perlzweig and Barron, 1928).…”