title: Investigating diet as the source of tetrodotoxin in Pleurobranchaea maculata.
abstract: The origin of tetrodotoxin (TTX) is highly debated; researchers have postulated either an endogenous or exogenous source with the host accumulating TTX symbiotically or via food chain transmission. The aim of this study was to determine whether the grey side-gilled sea slug (Pleurobranchaea maculata) could obtain TTX from a dietary source, and to attempt to identify this source through environmental surveys. Eighteen non-toxic P. maculata were maintained in aquariums and twelve were fed a TTX-containing diet. Three P. maculata were harvested after 1 h, 24 h, 17 days and 39 days and TTX concentrations in their stomach, gonad, mantle and remaining tissue/fluids determined using liquid chromatography-mass spectrometry. Tetrodotoxin was detected in all organs/tissue after 1 h with an average uptake of 32%. This decreased throughout the experiment (21%, 15% and 9%, respectively). Benthic surveys at sites with dense populations of toxic P. maculata detected very low or no TTX in other organisms. This study demonstrates that P. maculata can accumulate TTX through their diet. However, based on the absence of an identifiable TTX source in the environment, in concert with the extremely high TTX concentrations and short life spans of P. maculata, it is unlikely to be the sole TTX source for this species.
authors.forename: Serena
authors.initials: S
authors.lastname: Khor
authors.affiliation: Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand. susie.wood@cawthron.org.nz.
authors.forename: Susanna A
authors.initials: SA
authors.lastname: Wood
authors.forename: Lauren
authors.initials: L
authors.lastname: Salvitti
authors.forename: David I
authors.initials: DI
authors.lastname: Taylor
authors.forename: Janet
authors.initials: J
authors.lastname: Adamson
authors.forename: Paul
authors.initials: P
authors.lastname: McNabb
authors.forename: Stephen Craig
authors.initials: SC
authors.lastname: Cary
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D004777:Environment; D005612:Freeze Drying; D009520:New Zealand; D049853:Pleurobranchaea / Q000737:chemistry / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D013779:Tetrodotoxin / Q000032:analysis* / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D013779:Tetrodotoxin