An assessment of the feasibility of using image analysis in the oyster embryo-larval development test

In this study the feasibility of using the latest image capture, processing , and analysis techniques in the oyster embryo-larval development (OEL) tes t was assessed. This initially involved determining whether the OEL test co uld be carried out in multiwell plates (which would assist in the applicati on of the image analysis technique), based on data from tests with the refe rence toxicant zinc and industrial effluents. The study then ascertained wh ich of the 31 image analysis parameters of the Image Pro Plus software used was most appropriate for differentiating between the D larvae and non-D la rvae at the end of the test procedure in a manner similar to that of visual observations. On the basis of the zinc reference toxicant and effluent tes t data derived in this study, the OEL test can be effectively carried out i n 24 chamber multiwell plates, which provides the opportunity to count obje cts with image analysis software. The use of the image analysis parameters area and size (length) in combination resulted in mean control abnormalitie s and EC,, values in zinc reference toxicant tests which were not significa ntly different statistically from corresponding values derived using visual observations. Discrimination using the area and length parameters may be i mproved by the inclusion of other parameters in a suite of measurements whi ch would reduce interference from extraneous material or lighting artefacts . Furthermore, the use of multiwell plates and image analysis can eliminate the variability associated with sub-sampling and inter-operator difference s in the counts of D larvae and non-D larvae which is evident with the curr ent visual observation method. (C) 2001 by John Wiley & Sons, Inc.