Asymmetry of the olfactory system in the brain of the winter flounder,Pseudopleuronectes americanus

1984 ◽  
Vol 225 (4) ◽  
pp. 492-510 ◽  
Author(s):  
P. D. Prasada Rao ◽  
Thomas E. Finger
Keyword(s):  
Olfactory System ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
The Brain

How does the brain control the pituitary's release of antifreeze synthesis inhibitor?

1984 ◽  
Vol 62 (5) ◽  
pp. 839-844 ◽  
Author(s):  
G. L. Fletcher ◽  
M. J. King ◽  
C. L. Hew
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Antifreeze Proteins ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Synthesis Inhibitor ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
The Brain ◽  
Antifreeze Activity

Previous studies of winter flounder (Pseudopleuronectes americanus) demonstrated that the pituitary inhibits the synthesis of antifreeze proteins during the summer and that the inhibition is removed with the approach of winter. Assuming that the pituitary is under the control of the central nervous system, the question posed was, Does the central nervous system stimulate the release of the pituitary antifreeze inhibitory factor during the summer or inhibit its release during the winter? Two experiments were carried out. In the first, flounder were hypophysectomized and a number of them were given pituitary autotransplants prior to the spring loss of plasma antifreeze. During July, flounder containing functional autotransplants had lost the capacity to synthesize antifreeze proteins and their plasma antifreeze activity had disappeared. In the second experiment, hypophysectomy and pituitary transplantation was carried out in the fall prior to the winter onset of antifreeze biosynthesis. Flounder containing functional auto- or homo-transplants showed no evidence of plasma antifreeze activity, whereas intact controls and hypophysectomized flounder had levels typical of winter fish. These results indicate that the central nervous system normally inhibits the pituitary glands release of antifreeze inhibitor during the winter.

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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