A preliminary report on the application of Macrobrachium amazonicum Heller, 1862 (Decapoda: Palaemonidae) as a biomarker

A method is described for the rapid evaluation of water quality through monitoring the respiratory response of Macrobrachium amazonicum a dominant benthic macroinvertebrate of Northeast Brazil constituting a source of nutrients for fish and humans. By maintaining the organism in a respiratory chamber supplied with test water (gravity-feed) at a rate of 10 ml min-1, it is possible to identify when the organism is in stress. Respiration rates were determined before (control) and after test concentrations were introduced. The herbicide paraquat was used because of its popularity with sugar cane cultivators and reported low toxicity. There was a discrete increase in respiration associated with acute toxicity at all concentrations tested above 0.035 μg l-1. At 0.01 μg l-1 no increase in respiration was observed and prawn survival continued until the experiment was terminated (25 days).