Ciguatoxin from the flesh and viscera of the barracuda, Sphyraena jello

Abstract

Five of six barracuda, Sphyraena jello, captured in the same area of Queensland as toxic Spanish mackerel ( Scomberomorus commersoni) were found to be toxic. One major lipid-soluble toxin, present in both the flesh and viscera of a pooled sample of barracuda, was chromatographically indistinguishable from Spanish mackerel flesh ciguatoxin. Signs and symptoms induced by toxic barracuda in humans were typical of ciguatera and cats and mice displayed signs indistinguishable from those induced by Spanish mackerel ciguatoxin. Purified barracuda ciguatoxin had an i.p. ld 50 to mice of 55 μg/kg. Barracuda ciguatoxin had a narrow range (0.7 – 1.4 mouse units) of doses between 0% and 100% lethality and its dose vs. death-time relationship was similar to the relationship produced by moray eel and Spanish mackerel ciguatoxin. No water-soluble toxins were detected in the viscera of these barracuda, but a less polar lipid-soluble toxin was found in the viscera. This minor toxin represented 14% of the total viscera lethality and induced signs in mice similar to the major toxin. Barracuda could be an important link in the transfer of ciguatoxin to large Spanish mackerel in southern Queensland waters.