The seasonal distribution of anionic binding sites in the basement membrane of the kidney glomerulus of the winter flounder Pseudopleuronectes americanus

1983 ◽  
Vol 234 (2) ◽  
pp. 271-277 ◽  
Author(s):  
R.B. Boyd ◽  
A.L. DeVries
Keyword(s):  
Basement Membrane ◽  
Binding Sites ◽  
Seasonal Distribution ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Kidney Glomerulus ◽  
Anionic Binding Sites

Localization of Anionic Binding Sites in the Glomerular Basement Membrane of a Cold Water Teleost

1982 ◽  
Vol 40 ◽  
pp. 288-289
Author(s):  
R. B. Boyd ◽  
A. L. DeVries
Keyword(s):  
Binding Sites ◽  
Cold Water ◽  
Sea Water ◽  
Freezing Point ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Anionic Sites ◽  
Glomerular Filtration Barrier ◽  
Filtration Barrier ◽  
Anionic Binding Sites

The blood of the winter flounder, Pseudopleuronectes americanus, a cold water teleost, is characterized by the presence of small (3000-5000d) anionic (pI 4.1-4.5) peptides that lower the freezing point of the blood. These peptides exhibit a seasonal variation, occurring only in the winter when the fish is exposed to temperatures near or below the freezing point of sea water. The antifreeze molecule is retained by the glomerular kidney of the fish even through inulin, of comparable weight, is rapidly filtered from the blood into the urine. We have examined the glomerular filtration barrier in the winter flounder, using the electron-dense ferritins, in order to identify anionic sites that might function to conserve these peptides.

The Winter Flounder (Pseudopleuronectes americanus) in Long Pond, Conception Bay, Newfoundland

1971 ◽  
Vol 28 (8) ◽  
pp. 1153-1165 ◽  
Author(s):  
V. S. Kennedy ◽  
D. H. Steele
Keyword(s):  
Food Intake ◽  
Growth Rates ◽  
Plant Material ◽  
Early Growth ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Food Items ◽  
Fish Remains ◽  
Males And Females ◽  
Conception Bay

Monthly samples of winter flounder taken in Long Pond from November 1962 to October 1963 indicated that the flounder moved into deeper water (7–10 m) during the summer and returned to shallow water (1–2 m) from September to June. These movements corresponded to the end of the spawning season and the ripening of the gonads respectively. Spawning occurred from March until early June, most of it in May and early June. Most males were mature at age 6 and most females at age 7. Fifty percent of the males and females were mature at 21 and 25 cm respectively. The growth rates of the males and females were similar until the age of 8, after which the females apparently outgrew the males. Early growth and fecundity were similar to those reported for other areas. No feeding took place in December or January but the flounder fed in March and continued to feed throughout the summer; food intake decreased in the fall. They were omnivorous and the type of food eaten varied with the locality. Polychaetes, plant material, and molluscs were the most common food items throughout the year. Capelin eggs and fish remains were found only during a few months of the year but were eaten in great quantities.

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