OCCURENCE OF A TOXIC SUBSTANCE IN SKIN OF A SEA BASS POGONOPERCA PUNCTATA

The skin of the sea bass Pogonoperca punctata was found to contain a toxic substance. It caused ciguatera-like effects in cats and showed a resemblance in its pharmacological properties to the toxin from a soapfish, and pahutoxin from a boxfish. It was soluble in acidic water, 70 per cent ethanol, n-butanol and n-amyl alcohol, and insoluble in most fat solvents. It was dialyzed very slowly and precipitated nearly quantitatively as a complex at a half-saturation with NaCl or (NH4)2SO4. On thin-layer chromatography, the preparation partially purified by precipitation with NaCl and subsequent extraction with n-butanol consisted of four or five toxic components, each positive to the Dragendorff reagent and negative to both the biuret and ninhydrin reagents. A toxin obtained from the secretions of another sea bass, Grammistes sexlineatus, was almost identical. A wide distribution of a similar toxin in members of the subfamily Grammistinae is suggested. © 1969.