COMPARATIVE-STUDY ON PARALYTIC SHELLFISH TOXIN PROFILES OF THE DINOFLAGELLATE GYMNODINIUM-CATENATUM FROM 3 DIFFERENT COUNTRIES

Paralytic shellfish toxin profiles of the dinoflagellate Gymnodinium c atenatum Graham were investigated as a possible biochemical marker to distinguish different geographic populations of this species. Isolates obtained between 1986 and 1988 from Japan, Tasmania (Australia) and G alicia (Spain) were cultured under similar conditions and the toxins p roduced were analyzed using HPLC. Variations in temperature, salinity, and nitrate and phosphate levels in the culture medium had no signifi cant effect on the toxin profile, suggesting that toxins can be used a s a stable biochemical marker for this dinoflagellate. All the isolate s produced mainly toxins of the N-sulfocarbamoyl group (C1-C4, gonyaut oxins 5 and 6) but their relative abundance differed according to thei r geographic origin. Furthermore, only the Australian population produ ced the newly found 13-deoxydecarbamoyl toxins, and these could readil y be used to distinguish the Australian populations from those of the other two countries.