title: First report of saxitoxin in octopi.
abstract: We report for the first time, the presence of saxitoxin (STX) in a common cephalopod, Octopus (Abdopus) sp. 5, collected from Cooke Point on the northern coastline of Western Australia. Sodium channel and saxiphilin based radio-receptor assays detected saxitoxin-like binding in octopi extracts. Further analysis by liquid chromatography-fluorescence detection (LC-FLD) identified STX as the major contributing toxin in these samples. The presence of STX was confirmed by LC-mass spectrometry and comparison of fragmentation patterns with an authentic STX standard. LC-FLD quantitation and conversion of the Octopus sp. 5 extracts revealed toxin concentrations as high as 246 microg STX/100g tissue, more than three times the US, European and Australian regulatory limit for human consumption of shellfish of 80 microg STX/100g tissue. There was no evidence of tetrodotoxin or other paralytic shellfish toxin derivatives. This level and distribution of STX in octopi poses a potential public health risk, particularly when routine toxin screening of wild catch is not regulated.
authors.affiliation: Department of Biochemistry and Molecular Biology, James Cook University, Townsville, Qld 4811, Australia. a.robertson@aims.gov.au
authors.forename: Alison
authors.initials: A
authors.lastname: Robertson
authors.forename: David
authors.initials: D
authors.lastname: Stirling
authors.forename: Cedric
authors.initials: C
authors.lastname: Robillot
authors.forename: Lyndon
authors.initials: L
authors.lastname: Llewellyn
authors.forename: Andrew
authors.initials: A
authors.lastname: Negri
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D005453:Fluorescence; D013058:Mass Spectrometry; D049831:Octopodiformes / Q000737:chemistry*; D011869:Radioligand Assay; D012530:Saxitoxin / Q000378:metabolism*; D012758:Shellfish / Q000032:analysis*; D014904:Western Australia
chemical_list: D012530:Saxitoxin