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The Physiological Effect of Sodium Chloride upon Brook Trout
Author(s) -
Phillips Arthur M.
Publication year - 1947
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1944)74[297:tpeosc]2.0.co;2
Subject(s) - sodium , trout , zoology , chemistry , salinity , chloride , excretion , body weight , endocrinology , fish <actinopterygii> , biology , biochemistry , fishery , ecology , organic chemistry
Feeding sodium chloride in gelatin capsules to brook trout caused a rise in blood salt when amounts of 10, 15, 20, and 25 milligrams were ingested. No effect on the chloride level was found when 5 milligrams were fed. An edema resulted from feeding the two higher levels. This disappeared in the 20 milligram experiment with no loss of fish, but caused a mortality in the 25 milligram level. The absorption curves for salt were similar to those described for carbohydrates. Excretion curves were found to be curvilinear, but showed a break in the two higher levels with the appearance of edema. It was necessary to feed between 0.91 and 1.82 grams of salt per kilogram of body weight to produce a rise in blood salt and between 2.72 and 3.64 grams per kilogram to cause an edema. Salt baths of 3.0 and 5.0 per cent caused an increase in salinity of the blood of trout. A 2.5 bath had no such effect. For the shorter periods of immersion, an increase in blood salt was quickly eliminated upon return of the fish to fresh water, but the baths of longer duration produced a more prolonged effect. The concentration of a salt bath determines the period of immersion since the greater the concentration, the more rapid the change of blood salinity and the fish is unable to make the proper adjustments. The level of blood chlorides reached appears secondary to the rate of change of salinity.