Differences in the effects of mercury on telson regeneration in two populations of the grass shrimp Palaemonetes pugio.

Abstract

AdultPalaemonetes pugio were collected from two tidal creek systems, Piles Creek (PC), a mercury polluted estuary, and Big Sheeps head Creek (BSC), a relatively non-polluted creek in New Jersey. Telsons were ablated from shrimp in each population. Twenty ablated individuals from each population were placed in each of the following concentrations: 20 g/L artificial sea water (ASW), 20 g/L ASW with 0.01 mg/L mercuric chloride (HgCl2), or 20 g/L ASW with 0.01 mg/L methyl-mercuric chloride (meHg). In addition, 20 BSC shrimp were pre-treated with each of the following prior to ablatement: 0.01 mg/L HgCl2 or 0.01 mg/L meHg. No significant difference between the control group and treated animals was noted in the PC population with respect to all parameters examined. Significant differences (P < 0.05) existed between BSC controls and BSC shrimp treated with HgCl2, which had not been pre-treated, with respect to survival at molt, in that controls had a greater survival rate. No such difference was noted between BSC control animals, and animals pretreated with HgCl2. In addition, BSC shrimp treated with meHg had a significantly (P < 0.05) shorter intermolt period when compared to BSC control shrimp, and BSC meHg pre-treated shrimp had a significantly shorter intermolt period than did meHg-treated shrimp which had not been pretreated.