Antennae regeneration of marine amphipod Parhyale Hawaiensis as endpoint in ecotoxicology

Abstract

The marine amphipod Parhyale hawaiensis is able to regenerate its appendages, limbs and tissues. The objective of this study was: (i) verify whether the regeneration of P. hawaiensis antenna can be used as an endpoint in a miniaturized toxicity test system (12 well microplates, 5 mL) and, (ii) apply this endpoint in the toxicity assessment of dimethyl sulfoxide (DMSO), a organic solvent commonly used in toxicity tests, and diflubenzuron (DFB), a growth regulator insecticide. The average regeneration time of fifty percent of the population (RT50) in reconstituted saltwater tests was 16.7 days. DMSO induced the regeneration concentrations above 0.02%. As expected for chitin syntesis inhibitor, DFB strogly inhibited the antenna regeneration with a 28 d-EC50 = 0.5 μg/L. Thefore, we conclude that regeneration time can be used as endpoint in a cost effective miniaturized toxicity test, with time < 35 d. Moreover, DMSO should not be used as a solvent.