Renal water and solute excretion in the Atlantic stingray in fresh water |
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| Authors: | M G Janech P M Piermarini |
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| Institution: | Grice Marine Laboratory, College of Charleston, SC, 205 Fort Johnson, Charleston, SC 29412, U.S.A.;Department of Zoology, University of Florida, Bartram Hall, Gainesville, FL 32611, U.S.A. |
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| Abstract: | Freshwater, male Atlantic stingrays Dasyatis sabina , from Lake Jesup, Florida, U·S·A·, excreted a dilute urine similar in composition to freshwater teleosts and lampreys with the exception that urea was the primary osmolyte. Urine flow rate was 2·5 to 10 fold higher than that reported for freshwater teleosts resulting in high free-water clearance. Mass-specific free-water clearance values from euryhaline elasmobranchs inhabiting freshwater environments greatly exceed those for freshwater teleosts and are nearly equivalent to those of freshwater lampreys. |
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| Keywords: | Dasyatis sabina euryhaline elasmobranch urine free-water clearance |
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