Abstract
The perivisceral and ambulacral fluids ofAsterias rubenshave been shown to be not only isosmotic but isoionic with sea water, even if that medium is diluted by nearly half. However, there is a slight accumulation and regulation of calcium in the perivisceral fluid and to a much more marked extent, potassium in the water vascular system. The rapidity with which the potassium diffuses away when the ambulacral fluid is dialysed against sea water suggests that its presence in the water vascular system is due to an active accumulatory mechanism. This mechanism is capable of functioning when the animal encounters sea water of significantly reduced salinity, over the temperature range 0—20° C and extends throughout the season apparently uninfluenced by the breeding cycle or sex of the animal. Smaller animals tend to have a higher concentration of potassium in the water vascular system than do larger ones. Direct and indirect measurements of salt loss under various conditions, together with observations on the rate of lithium transfer, suggests that the integument is very permeable to many ions as well as to water. This supports the hypothesis that the ionic regulation observed results from an active process and not merely from an impermeability of the integument, although measurements with potassium itself have not yet been made.
Publisher
Cambridge University Press (CUP)
Reference40 articles.
1. REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH
2. Regulation osmotiques des liquides internes chez les Echinodermes;Henri;J. Physiol. Path, gen,1904
3. On the Blood of the Invertebrata
4. THE OSMOTIC PRESSURE OF SEA WATER AND OF THE BLOOD OF MARINE ANIMALS
5. Natural history and method of controlling the starfish Asterias forbesi Desor;Galtsoff;Bull. U.S. Bur. Fish,1939
Cited by
38 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献