APPLICATION OF A DIGITAL PATTERN-RECOGNITION SYSTEM TO DINOPHYSIS-ACUMINATA AND DINOPHYSIS-SACCULUS COMPLEXES

An image discrimination technique was developed to improve specific id entification of some toxic Dinophysis cells (marine dinoflagellates in volved in diarrhoeic shellfish poisoning), especially the ''acuminata' ' and ''sacculus'' groups, which can be present at different ratios in natural sea-water samples collected during toxic episodes. This work was performed with image analysis software SAMBA (TITN Alcatel) using preserved cells directly observed through an inverted microscope and r ecorded with a video camera before further processing. All morphometri c parameters used for discrimination of 7 different species or morphot ypes of Dinophysis were tested with discriminant analysis. This study indicates that Dinophysis sp. and D. pavillardi seem well classified a t the species level, whereas D. cf. acuminata and D. sacculus appear t o be morphotypes of D. acuminata.