title: First identification of tetrodotoxin (TTX) in the flatworm Stylochoplana sp.; a source of TTX for the sea slug Pleurobranchaea maculata.
abstract: High concentrations of the neurotoxin tetrodotoxin (TTX) were detected by liquid chromatography-mass spectrometry (LC-MS) in the Platyhelminthes Stylochoplana sp. from Pilot Bay (Tauranga, New Zealand). This is the first detection of TTX in this genus. Concentrations were monitored from March to November (2013) and found to significantly decrease from a peak in July (avg. 551 mg kg(-1)) to November (avg. 140 mg kg(-1)). Stylochoplana sp. co-occurred with TTX-containing Pleurobranchaea maculata (Opisthobranchia). A Stylochoplana sp.-specific real-time PCR assay was developed targeting the mitochondrial cytochrome c oxidase subunit I gene to determine if P. maculata consumed Stylochoplana sp. Positive Stylochoplana sp. signals were obtained for 7 of 19 P. maculata tested. Mass calculations indicate Stylochoplana sp. could supply Pilot Bay P. maculata with the TTX required to account for the concentrations reported in previous studies (ca. 1.04 mg TTX per individual) based on an ingestion rate of one individual every 2-3 days throughout their lifetime. However, due to the lack of Stylochoplana sp. in areas with dense P. maculata populations, and high concentration (ca. 1400 mg kg(-1)) of TTX detected in some individuals, it is unlikely that Stylochoplana sp. represent the sole source of TTX in P. maculata.
authors.affiliation: Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
authors.forename: Lauren
authors.initials: L
authors.lastname: Salvitti
authors.affiliation: Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand; Cawthron Institute, Nelson 7042, New Zealand.
authors.forename: Susanna A
authors.initials: SA
authors.lastname: Wood
authors.affiliation: Cawthron Institute, Nelson 7042, New Zealand.
authors.forename: David I
authors.initials: DI
authors.lastname: Taylor
authors.affiliation: Cawthron Institute, Nelson 7042, New Zealand.
authors.forename: Paul
authors.initials: P
authors.lastname: McNabb
authors.affiliation: Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand. Electronic address: caryc@waikato.ac.nz.
authors.forename: S Craig
authors.initials: SC
authors.lastname: Cary
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D018509:DNA, Helminth / Q000235:genetics; D017238:Genes, Helminth; D013058:Mass Spectrometry; D009520:New Zealand; D010865:Pilot Projects; D010986:Platyhelminths / Q000737:chemistry* / Q000235:genetics; D049853:Pleurobranchaea; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013048:Specimen Handling; D013779:Tetrodotoxin / Q000302:isolation & purification*
chemical_list: D018509:DNA, Helminth; D012337:RNA, Ribosomal, 18S; D013779:Tetrodotoxin
keywords: Liquid chromatography–mass spectrometry; Platyhelminthes; Pleurobranchaea maculata; Real-time PCR; Stylochoplana sp.; Tetrodotoxin