Summary
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1.
Blood plasma, urine and rectal fluid compositions, rate of ingestion of sea water and rate of efflux of tritiated water have been determined for the cod.
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2.
The body fluid compositions are like those of other marine teleosts, and allow the combined rectal and urinary flow rates to be estimated as one third of the rate of drinking.
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3.
The mean rate of drinking is 3.89±0.26 (S.E.) ml/kg · h.
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4.
Absorption of ingested sodium and chloride by the gastrointestinal tract exceed 96% and 91% respectively.
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5.
The water permeability measured by osmotic flow exceeds that measured by diffusion by a factor of two or more.
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6.
The possible causes of this discrepancy are discussed briefly.
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Fletcher, C.R. Osmotic and ionic regulation in the cod (Gadus callarias L.). J Comp Physiol B 124, 149–155 (1978). https://doi.org/10.1007/BF00689176
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DOI: https://doi.org/10.1007/BF00689176