Biol. Bull. Sign up for etocs!
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Biol Bull 73: 261-279. (October 1937)
© 1937 Marine Biological Laboratory
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by TYLER, A.
Right arrow Articles by HUMASON, W. D.
Right arrow Search for Related Content
PubMed
Right arrow Articles by TYLER, A.
Right arrow Articles by HUMASON, W. D.

ON THE ENERGETICS OF DIFFERENTIATION, VI

COMPARISON OF THE TEMPERATURE COEFFICIENTS OF THE RESPIRATORY RATES OF UNFERTILIZED AND OF FERTILIZD EGGS

ALBERT TYLER 1 and W. D. HUMASON 1

1 From the William G. Kerckhoff Laboratories of the Biological Sciences, California Institute of Technology, Pasadena, California

1. The effect of temperature on the rate of oxygen consumption of unfertilized and fertilized eggs of Urechis, Strongylocentrotus, Ciona and Dendraster was investigated.

2. The unfertilized eggs exhibit a rising rate of respiration with time in allfour species. The rise is much more rapid in Strongylocentrotus and in Dendraster than in Urechis and in Ciona. This rise appears to be correlated with the loss of fertilizability on the part of the eggs.

3. Methods of determining the temperature coefficients in such a way as to take into account the general rise (which is a significant factor in prolonged runs) and other variations are described.

4. Only the temperature coefficients for the same temperature intervals are compared, the respiration being determined at two temperatures in each experiment. With Urechis and with Strongylocentrotus eggs, experiments were run at temperatures between 22° and 5°; with Ciona, between 25° and 12°; and with Dendraster, 22° and 12°. The experiments with Urechis and Strongylocentrotus thus included low temperatures at which the fertilized eggs fail to cleave.

5. No significant differences between the temperature coefficients of the respiratory rate of unfertilized and of fertilized eggs of the four animals investigated are found over most of the temperature range in which development is possible. At the lower temperatures, there are differences that are possibly significant, the unfertilized eggs giving consistently lower values.

6. Comparison of the absolute rates of respiration of the unfertilized and fertilized eggs shows in Strongylocentrotus and Dendraster the rise in respiration upon fertilization typical of the echinoids; in Ciona a less than two-fold rise is manifest; in Urechis, the rate may rise considerably, remain constant or decrease slightly, depending upon the particular batch of eggs employed. Eggs from animals kept some time in captivity give lower unfertilized rates and manifest a rise upon fertilization; eggs from freshly collected animals give higher unfertilized rates and no rise or even a slight decrease upon fertilization.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1937 by the Marine Biological Laboratory.