Acute toxicity of lead nitrate to red swamp crayfish, Procambarus clarkii

Red crayfish, Procambarus clarkii, is widely farmed in the southern states of Louisiana and Texas. It is the most valuable of commercial crayfish species in the United States, where it is considered a delicacy. In recent years, its availability has decreased due to environmental contamination by toxic chemicals including lead. In the present study, we conducted a ninety-six-hour static renewal bioassay to assess the acute toxicity of lead as Pb(NO3)(2) to adult red swamp crayfish. Study results indicated that Pb(NO3)(2) is toxic to P. clarkii, and its toxicity is both time- and concentration-dependent. The 96-hr LC50 was computed to be 3.95 g/L. During experimentation, erratic behaviors such as restlessness, loss of balance, air gulping, and convulsion were observed in lead-exposed crayfish. Findings from this study have provided a scientific basis for designing subsequent experiments to assess the chronic exposure and biomarkers of lead-induced toxicity in P. clarkii.