| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Zoology, University of California at Los Angeles, Department of Chemistry, Harvard University, and Scripps Institution of Oceanography, University of California, San Diego
1. The occurrence of small degrees of supercooling and the presence in the blood of organic antifreeze compounds are confirmed in arctic populations of short-horned sculpins (Myoxocephalus scorpius) and fjord cod (Gadus ogac) captured at Hebron Fjord, Labrador, in early spring. The quantity of antifreeze added seems variable, however.
2. Although significantly supercooled, these same fishes were found to be very resistant to freezing even though seeded with ice. Possible explanations for this resistance are discussed.
3. Non-arctic populations of the sculpin and of the tomcod (Microgadus tomcod, a close relative of the fjord cod) also studied in early spring were found to lack both the resistance to freezing when supercooled and also the antifreeze substances found in the arctic fishes. Very few of the non-arctic sculpins were able to develop any resistance to freezing even after several days' exposure to arctic water temperatures.
4. The antifreeze substance added to the blood of the fjord cod is indicated to be a member of the non-protein nitrogen fraction. There is no evidence that it is an amino acid, an amine or an amine oxide.
5. The antifreeze substance added to the blood of the short-horned sculpin is also unidentified. It apparently contains neither nitrogen nor phosphorus, is not glycerol or a related alcohol and probably is not a reducing or a non-reducing sugar, an aldehyde or ketone, a carboxylic acid (lipid or other), an ester or an aromatic compound.
6. Tomcod exposed to arctic water temperatures show increases in plasma non-protein nitrogen levels similar to those which occur in the fjord cod in winter.
This article has been cited by other articles:
|
|
 |
|
  P. A. Cziko, C. W. Evans, C.-H. C. Cheng, and A. L. DeVries Freezing resistance of antifreeze-deficient larval Antarctic fish J. Exp. Biol., February 1, 2006; 209(3): 407 - 420. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. R. Hargens Freezing Resistance in Polar Fishes Science, April 14, 1972; 176(4031): 184 - 186. [Abstract] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
