title: Confirmation and distribution of tetrodotoxin for the first time in terrestrial invertebrates: two terrestrial flatworm species (Bipalium adventitium and Bipalium kewense).
abstract: The potent neurotoxin tetrodotoxin (TTX) is known from a diverse array of taxa, but is unknown in terrestrial invertebrates. Tetrodotoxin is a low molecular weight compound that acts by blocking voltage-gated sodium channels, inducing paralysis. However, the origins and ecological functions of TTX in most taxa remain mysterious. Here, we show that TTX is present in two species of terrestrial flatworm (Bipalium adventitium and Bipalium kewense) using a competitive inhibition enzymatic immunoassay to quantify the toxin and high phase liquid chromatography to confirm the presence. We also investigated the distribution of TTX throughout the bodies of the flatworms and provide evidence suggesting that TTX is used during predation to subdue large prey items. We also show that the egg capsules of B. adventitium have TTX, indicating a further role in defense. These data suggest a potential route for TTX bioaccumulation in terrestrial systems.
authors: Department of Biology, California State University, Bakersfield, California, United States of America.
authors: Amber N
authors: AN
authors: Stokes
authors: Biological Sciences Department, State University of New York, Cortland, New York, United States of America.
authors: Peter K
authors: PK
authors: Ducey
authors: Department of Biology, Utah State University, Logan, Utah, United States of America.
authors: Lorin
authors: L
authors: Neuman-Lee
authors: Department of Biology, Utah State University - Uintah Basin, Vernal, Utah, United States of America.
authors: Charles T
authors: CT
authors: Hanifin
authors: Department of Biology, Utah State University, Logan, Utah, United States of America.
authors: Susannah S
authors: SS
authors: French
authors: Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America.
authors: Michael E
authors: ME
authors: Pfrender
authors: Mountain Lake Biological Station and Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America.
authors: Edmund D
authors: ED
authors: Brodie
authors: Department of Biology, Utah State University, Logan, Utah, United States of America.
authors: Edmund D
authors: ED
authors: Brodie
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007124:Immunoenzyme Techniques; D009929:Organ Size; D009928:Organ Specificity; D013779:Tetrodotoxin / Q000378:metabolism*; D014419:Turbellaria / Q000378:metabolism*
chemical_list: D013779:Tetrodotoxin