Paralytic toxin profiles of xanthid crab Atergatis floridus collected on reefs of Ishigaki Island, Okinawa Prefecture, Japan and Camotes Island, Cebu Province, Philippines

Attempts were made to assess the toxicity and to analyze paralytic toxin profiles of xanthid crab Atergatis floridus collected on two reefs on the leftand the right-side, tentatively designated as site A and B, separated by the passage at the outside of Kabira Bay in Ishigaki Island, Okinawa Prefecture, Japan in comparison with those of the same crabs from Camotes Island off the eastern coast of Cebu Island, Cebu Province, Philippines. They were dissected into 4 parts; carapace, viscera, appendage and muscle of appendage. Muscle of appendage was highly toxic, and the maximum toxicity of 4,641±972MU/g as paralytic shellfish poison (PSP) was recorded in the specimens from the right-side reef (site B). Toxicity assays showed that all of them were toxic irrespective of the crab-collecting years, locations, and tissues, and in addition to these, there seemed to be marked narrow regionality and individual variation of toxicity and toxin profiles. Toxicity of Ishigaki specimens was seemed to be higher than that of Camotes specimens. Toxin profiles of the viscera of A.floridus were examined by high performance liquid chromatography-fluorescent detection (HPLC-FLD) analysis. In the viscera of A.floridus from site A in June, 2007, relative abundances (mole %) of carbamoyl-N-hydroxyneosaxitoxin (hyneoSTX), neosaxitoxin (neoSTX), and saxitoxin (STX) were high (98%), and only 2% of gonyautoxin 2(GTX2) were contained in addition to similar amounts (3%) of decarbamoylsaxitoxin (dcSTX). Its viscera from site B in the same month possessed GTX2 (36%) and STX group (63 %) predominantly, and only 1% of GTX1 was contained in addition to similar amount (2%) of STX. Their viscera possessed STX group as the major components (89%) along with the GTX4 (11%) as the minor. On the other hand, PSP compositions of the viscera of Camotes specimen resembled to that of the viscera from the specimens on site A in Kabira Bay with higher GTX4 but lower hyneoSTX. A solitary outstanding difference of toxin profiles in both crabs was the occurrence of tetrodotoxin (TTX) in the Camotes specimen due to the results of HPLC-FLD and gas chromatography-mass spectrometry (GC-MS) analysis.