Hostname: page-component-5c6d5d7d68-ckgrl Total loading time: 0 Render date: 2024-08-19T02:21:33.005Z Has data issue: false hasContentIssue false
  • English
  • Français

The Hydrogen Ion Concentration in the Gut of certain Lamellibranchs and Gastropods

Published online by Cambridge University Press:  11 May 2009

O. M. Yonge
O. M. Yonge
Affiliation:
Temporary Assistant Naturalist at the Plymouth Laboratory
Get access Rights & Permissions [Opens in a new window]

Extract

1. In the Lamellibranchs, as typified by Pecten maximus, Mya arenaria and Ensis siliqua, the entire, gut has an acid reaction, the stomach being the most acid region and the pH rising along the mid-gut and rectum.

2. The origin of the acidity of the gut lies in the style. This has a low pH (5·4 in Pecten and Mytilus, 4·6 in Ensis and 4·45 in Mya), and, after it has been artificially extracted from Mya or induced to disappear, by keeping the animals under abnormal conditions, in Mytilus, Tapes and Pecten, the pH of the stomach invariably rises (by as much as 0·825 in Mya and 0·72 in Tapes), although the pH in the mantle cavity has fallen.

3. The style, which dissolves rapidly in alkaline or weakly acid media, is not dissolved in fluids below a certain pH—4·4 for Ensis, 4·2 for Mya, 3·6 for Pecten and Mytilus.

4. The style is never absent, even though animals are starved, so long as they are kept under otherwise healthy conditions. The disappearance of the style under abnormal conditions is probably due to a lowering of the vital activities, which include the secretion of the style substance, and the consequent dissolution of the style by the less acid contents of the stomach.

5. The style is only maintained as a result of a balance between the rate of its secretion and the rate of its dissolution.

6. There is a well-marked correlation between the tolerance of the presence of hydrogen ions possessed by the cilia from the various regions of the gut and the degree of acidity of the fluid with which they are normally surrounded.

7. The pH of the gut in five Gastropods has been investigated. The fore-gut and stomach have invariably the lowest pH.

8. This acidity may be caused by the salivary glands (Patella and Buccinum), the digestive gland (Doris and Aplysia), or the style (Crepidula).

9. The mid-gut and rectum have a high pH, except in Doris, where there is little secretion of mucus, the gut being free and muscular.

10. The style of Orepidula has similar properties to those of the Lamellibranchs. It has a pH of 5·8, and is not dissolved in fluid of pH 3·6 or lower.

11. The cilia from the gut of Buccinum and Doris can function in a pH of 5·0, but there is little difference in the toleration of the various cilia to the presence of hydrogen ions.

Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 13 , Issue 4 , October 1925 , pp. 938 - 952
Copyright
Copyright © Marine Biological Association of the United Kingdom 1925

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

BIBLIOGRAPHY

1Allen, W. R. 1914. The Food and Feeding Habits of Freshwater Mussels. Biol. Bull., XXVII, p. 127.Google Scholar
2Berkeley, C. 1923. On the Crystalline Style as a possible factor in the Anaerobic Respiration of certain Marine Mollusks. Jour. Exp. Zool., XXXVII, p. 477.CrossRefGoogle Scholar
3Dakin, W. J. 1909. Pecten. L.M.B.C. Memoir, No. XVII.Google Scholar
4Edmondson, C. H. 1920. The Reformation of the Crystalline Style in Mya arenaria. Jour. Exp. Zool., XXX, p. 259.Google Scholar
5Gray, J. 1920. The Effects of Ions upon Ciliary Movement. Q.J.M.S., LIV, p. 345.Google Scholar
6Haseloff, B. 1888. Über den Krystallstiel der Muscheln nach Untersuchung verschiedener Arten der Kieler Bucht. Biol. Centr., VII, p. 683.Google Scholar
7Hazay, J. 1881. Die Molluskenfauna von Budapest. Malak. Bl. L. Pfeiffer. N.F., IV, p. 195.Google Scholar
8Hirsch, G. C. 1914. Die Emährungsbiologie fleischfressender Gastropoden. Zool. Jahr. Abt. Zool. u. Physiol., XXXV, p. 357.Google Scholar
9Mackintosh, N. A. 1925. The Crystalline Style in Gastropods. Q.J.M.S., LXIX, p. 317.Google Scholar
10Nelson, T. C. 1918. On the Origin, Nature, and Function of the Crystalline Style of Lamellibranchs. Jour. Morph., XXXI, p. 53.Google Scholar
11Orton, J. H. 1923. Fishery Investigations. Series II, Vol. VI, No. 3, p. 54.Google Scholar
12Yonge, C. M. 1923. The Mechanism of Feeding, Digestion, and Assimilation in the Lamellibranch Mya. Brit. Jour. Exp. Biol., I, p. 15.Google Scholar