The Absorption of Oxygen by Plaice Eggs

1928 ◽  
Vol 5 (3) ◽  
pp. 177-184
Author(s):  
S. T. BURFIELD

1. The rate of oxygen absorption by plaice eggs, contained in a closed volume of sea water, falls when the eggs and water are allowed to remain relatively quiescent. This fall takes place even when a large volume of water is used. 2. It has been shown that small changes in the partial pressure of dissolved oxygen do not appreciably affect the rate of absorption, so that this is not the factor concerned in the fall. 3. The rate of oxygen absorption in a closed volume of sea water does not fall if the eggs be frequently moved. 4. The removal of eggs to a closed volume of fresh sea water at the end of a period prevents the rate of absorption from falling during a second equal period. 5. The removal of eggs to a closed volume of "used" sea water at the end of a period causes the rate of absorption to fall during a second equal period. 6. The addition of urea in small quantities to the sea water has no effect on oxygen absorption. 7. The addition of carbon dioxide to the sea water has a marked effect in lowering the rate of oxygen absorption, and the accumulation of excreted carbon dioxide is probably the factor causing the fall in absorption mentioned under paragraphs 1 and 5. 8. This effect is possibly directly due to the alteration in the hydrogen ion concentration produced by the carbon dioxide. 9. The Respiratory Quotient of young plaice eggs is about .75.

1926 ◽  
Vol 10 (2) ◽  
pp. 345-358 ◽  
Author(s):  
Laurence Irving

The normal reaction of the cœlomic fluid in Patiria miniata and Asterias ochraceus is pH 7.6, and of the cæca, 6.7, compared with sea water at 8.3, all without salt error correction. A medium at pH 6.7–7.0 is optimum for the cæca for ciliary survival and digestion of protein, and is maintained by carbon dioxide production. The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It does not represent an elimination gradient for carbon dioxide. Because the normal excised cæca maintain a definite hydrogen ion concentration and change their internal environment toward that as an optimum during life, there exists a regulatory process which is an important vital function.


Author(s):  
W. R. G. Atkins

It has long been known that sea water is alkaline and numerous determinations of its alkalinity have been made. The method adopted was the usual one for mixtures of carbonates and bicarbonates, or some modification of it. Those waters which give no colour with phenolphthalein contain bicarbonate only, but for the most part ocean waters have a small amount of carbonate also. Owing to the presence of larger amounts of carbonates and bicarbonates the reaction of sea water is more stable than that of rain or river water, inasmuch as it has a greater alkaline reserve which acts as a “buffer.” The significance of this has been pointed out by Moore, Prideaux, and Herdman (1915) and by other workers. The measurement of alkalinity was carried out by the above named using N/100 hydrochloric acid and titrating to the end points with phenol phthalein and methyl orange. The results are recorded in cubic centimetres of centinormal acid per 100 c.c. of sea water; this is convenient as it is what is measured directly, but others adopt the perhaps more rational notation of milligram equivalents of hydroxyl per litre (Buch, 1914). One cubic centimetre of N/100 acid per 100 c.c. corresponds to 0.1 milligram equivalent per litre. Some workers on fresh waters, Birge and Juday (1911) for example, consider water as acid if it contains more carbon dioxide than that sufficient to convert the carbonate into bicarbonate, and titrate back to a pink with phenolphthalein. Their acid water is, however, still alkaline to methyl orange.


Nature ◽  
1923 ◽  
Vol 111 (2778) ◽  
pp. 132-133
Author(s):  
J. J.

Author(s):  
C. F. A. Pantin ◽  
Lancelot T. Hogben

1. A simple colorimetric method for plotting the dissociation curve of haemocyanin is indicated. The limits of error are within 5 per cent. The simplicity of the method commends it for laboratory class work.2. The effect of hydrogen ion concentration on the dissociation of the hsemocyanins of the crustacean Palinurus and the pulmonate Helix have been compared. In the snail change of hydrogen ion concentration over a wide range was not found to affect the dissociation of the hsemocyanin: in 'the crustacean there is a marked effect similar to that seen in the dissociation of hæmoglobin.3. The similarity of crustacean hsemocyanin to haemoglobin is also seen in that increasing temperature depresses the dissociation curve. The effects of certain salts upon haemocyanin. have also been recorded.


Author(s):  
W. R. G. Atkins

The present paper is a continuation of the work already published under the above general title and should be considered in relation to the results previously recorded. The method of performing the measurements remained unchanged; xylenol blue was used to check the determinations made with cresol red in the more alkaline regions—namely, around pH 8.24. The water was tested immediately after being drawn, or within a few hours, unless otherwise stated in the tables.


1922 ◽  
Vol 4 (3) ◽  
pp. 305-317 ◽  
Author(s):  
Edwin B. Powers

1. The ability of marine fishes to absorb oxygen at low tension from the sea water is more or less dependent upon the hydrogen ion concentration of the water. 2. The ability of fishes to withstand wide variations in the range of hydrogen ion concentration of the sea water can be correlated with their habitats. The fishes that are most resistant to a wide variation in the hydrogen ion concentration are most cosmopolitan in their habitat. Those that are least resistant to a variation in the hydrogen ion concentration are the most restricted in their range of habitat. 3. There is a close correlation between the optimum condition of the sea water for the absorption of oxygen at low tension by the herring (Clupea pallasii), the condition of the sea water to which they react positive and that in which they are found most abundantly. 4. It is suggested that the variation in the ability to absorb oxygen at low tension at a given pH of individuals of a species is dependent upon the alkaline reserve of the blood of the individual fish.


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