Sulfide species and total sulfide toxicity in the shrimp Crangon crangon

Abstract

The toxicity of total sulfide and individual sulfide species at different pH values were studied in Crangon crangon. The toxicity is evaluated both from external concentrations and internal sulfide concentrations and pH. Internal sulfide concentrations are calculated according to a diffusion model. C. crangon is very sensitive to sulfide having a LT 50 of around 1 hour at 20 μM total sulfide (pH 8). During sulfide exposures it is exclusively H 2S which diffuses into C. crangon, and sulfide toxicity is dependent on the concentration of H 2S (i.e., pH dependent). No HS − toxicity was found. The correct quantification of sulfide concentration in exposure experiments are concluded to be H 2S concentration. Exposed to increasing sulfide concentrations, C. crangon shows a distinct pattern of behavior which is correlated to hemolymph H 2S concentration; at 0.1 μM hemolymph H 2S C. crangon starts to swim, at 0.2 μM hemolymph H 2S C. crangon starts to panic (i.e., abdominal constrictions) and at 0.4 μM hemolymph H 2S C. crangon becomes paralysed.