Responses ofcorophium volutatorto sediment sulphide

An apparatus has been developed which allows the complete replacement of interstitial water in sediments without disturbance. In principle, it can be adapted to handle sand or mud, different solutions, and different volumes of sediment. The apparatus was tested with 0·05% (wt/vol.) eosin in sea water. After replacement of the interstitial water, the eosin was evenly distributed throughout the sediment. Interstitial water in samples of sediment was replaced by sulphide solutions in sea water, at a range of concentrations. The responses ofCorophium volutatorto these sediments was tested in choice and non-choice experiments. In the choice experiments, animals avoided burrowing in sediments containing sulphide at concentrations greater than about 5·8 × 10−5M. In the non-choice experiments, animals were progressively inhibited from burrowing when the sediment sulphide concentration was greater than about 5·8 × 10−4M. No mortality occurred during the experiments.