NEUROTOXIN PRODUCTION BY A CHLOROMONAD FIBROCAPSA-JAPONICA (RAPHIDOPHYCEAE)

The ichthyotoxicity and toxin composition of a red-tide producing chlo romonad Fibrocapsa japonica (Toriumi and Takano) were examined. The fl agellate showed the highest toxicity in mid-logarithmic phase and the lowest in the stationary phase with increased number of spherical-shap ed cells. Five neurotoxic components, FjTx-I, FjTx-II, FjTx-IIIa, FjTx -IIIb and FjTx-IV, which corresponded to brevetoxin components, PbTx-1 , PbTx-2, PbTx-9, PbTx-3 and oxidized PbTx-2 were tentatively identifi ed from analysis of F. japonica toxins on TLC and HPLC. The quantity o f each component fluctuated with the age and growth stage of the cultu re. Among the five toxic components the yield of FjTx-II per cell was highest in both logarithmic and stationary phases.