Physiology of acute silver toxicity in the starry flounder (Platichthys stellatus) in seawater

J Comp Physiol B. 1999 Oct;169(7):461-73. doi: 10.1007/s003600050243.


Physiological effects of exposure to silver (AgClnn-1; 250 micrograms Ag l-1 or 1000 micrograms Ag l-1) in seawater fish were investigated using adult starry flounders. While all fish survived up to 10 days in 250 micrograms Ag l-1, flounders started to die after day 4 in 1000 micrograms l-1. Dose-dependent increases in plasma and hepatic silver concentrations showed that silver was available for uptake. There were minimal negative effects on hematological parameters, acid-base status, and blood gases. Plasma ammonia showed a pronounced (three- to four-fold), but transient increase in flounders exposed to either 250 micrograms Ag l-1 or 1000 micrograms Ag l-1. Whole body ammonia and acid equivalent efflux measurements indicated that ammonia retention was due to a combination of stimulated production and inhibited excretion. In the 1000-microgram Ag l-1 group there was a similar transient increase in plasma [magnesium], which was restored by day 4. In contrast, plasma chloride and sodium levels increased gradually towards the point when fish began to die. At 250 micrograms Ag l-1, the Na+/K(+)-ATPase activity of the intestine was unaffected but there was a two-fold increase in branchial Na+/K(+)-ATPase activity. The latter effect was interpreted as compensation for an elevated chloride and sodium load. The increases in plasma chloride and sodium concentrations were accompanied by a marked suppression of drinking, thereby indicating that acute silver toxicity was likely caused by a combination of elevated electrolyte concentrations and dehydration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / analysis
  • Acids / metabolism
  • Ammonia / analysis
  • Ammonia / blood
  • Animals
  • Behavior, Animal / drug effects
  • Blood Gas Analysis
  • Blood Glucose
  • Blood Urea Nitrogen
  • Body Fluids / chemistry
  • Body Fluids / metabolism
  • Carbon Dioxide / blood
  • Chlorides / blood
  • Dehydration / chemically induced
  • Drinking Behavior / drug effects
  • Flounder / physiology*
  • Gills / enzymology
  • Hematocrit
  • Hemoglobins
  • Hydrocortisone / blood
  • Intestines / enzymology
  • Magnesium / blood
  • Oxygen / blood
  • Seawater
  • Silver / toxicity*
  • Sodium-Potassium-Exchanging ATPase / metabolism
  • Water-Electrolyte Balance / drug effects*


  • Acids
  • Blood Glucose
  • Chlorides
  • Hemoglobins
  • Carbon Dioxide
  • Silver
  • Ammonia
  • Sodium-Potassium-Exchanging ATPase
  • Magnesium
  • Oxygen
  • Hydrocortisone