Short-term low-salinity response in lead-exposed lobsters, Homarus americanus (Milne Edwards)

The only effect attributable solely to lead exposure (50μg·l^?1, 30 days) in lobsters, Homarusamericanus (Milne Edwards), was decreased pentose shunt activity (G6PDH) in the antennal gland, which contained the greatest concentration of lead taken up by the tissues analyzed. Similarly-exposed lobsters were subsequently held for 2 days in clean, aerated sea water at either ambient or low salinity (27 or 17%., respectively), after which time the lead concentration in the antennal gland had dropped by one-third and G6PDH had returned to control values. Low-salinity effects far outnumbered lead-induced effects and were found primarily in the tail muscle, corroborating findings in an earlier study with cadmium. In that earlier study, cadmium produced more metabolic disturbance than did the lead exposure reported here. Lead exposure at low salinity abolished several normal hyposaline reactions seen in control animals.