QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by HARRIS, R. R. Search for Related Content PubMed PubMed Citation Articles by HARRIS, R. R.

Journal of Experimental Biology 50,319-326 (1969)
Published by Company of Biologists 1969

Free Amino Acid and Haemolymph Concentration Changes in Sphaeroma Rugicauda (Isopoda) During Adaptation to a Dilute Salinity

R. R. HARRIS ¹

¹ Department of Oceanography, The University, Southampton; Department of Biology, The Royal University of Malta, Msida, Malta

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water.

2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity.

3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities.

4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water.

5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured.

6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer.

7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared.

8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues.

9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.