Paralytic shellfish toxins in the xanthid crab Atergatis floridus collected from Australian coral reefs

One hundred and nine specimens of Atergatis floridus (Xanthidae) were collected from coral reefs of the Capricorn Group in the southern region of the Great Barrier Reef, Queensland, Australia. Sixty-five acidified 70% ethanol extracts of whole crabs contained detectable toxicity, quantified with an assay which defines 1 mouse unit (MU) as the intraperitoneal dose which kills a 20 g mouse in 15 min. The most toxic extract contained 3838 MU (108 MUg⁻¹ of crab), which exceeds the suggested human lethal dose. Chromatography and electrophoresis detected toxins similar to the paralytic shellfish toxins (PSTs), namely saxitoxin, neosaxitoxin and gonyautoxins 1 and 2. All of the purified toxins exhibited pharmacoloģical activity consistent with that exhibited by the PSTs. No more than two of these toxins were present in any extract. Statistical analysis demonstrated there were geographic and temporal patterns in the variation of crude toxicity levels. Combined foregut contents from 42 of the crabs comprised fish, crustacean and algal remains, from which 279 MU were extracted from 1.4 g of material (= 199 MUg⁻¹)