title: Larval pufferfish protected by maternal tetrodotoxin.
abstract: Marine pufferfish contain tetrodotoxin (TTX), an extremely potent neurotoxin. All species of the genus Takifugu accumulate TTX in the liver and ovaries, although the tissue(s) in which it is localized can differ among species. TTX is the major defense strategy the pufferfish appears to use against predators. TTX is also used as a male-attracting pheromone during spawning. Here we demonstrate an additional (and unexpected) use of maternal TTX in the early larval stages of the Takifugu pufferfish. Predation experiments demonstrated that juveniles of all the species of fish used as predators ingested pufferfish larvae, but spat them out promptly. Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS) analysis revealed that the pufferfish larvae contain a small quantity of TTX, which is not enough to be lethal to the predators. Immunohistochemical analysis with anti-TTX monoclonal antibody revealed that the TTX is primarily localized in the body surface of the larvae as a layer of protection. Our study showed the female parent of the Takifugu pufferfish vertically transfers TTX to the larvae through its accumulation in the ovaries, and subsequent localization on the body surface of the larvae.
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan. Electronic address: sitoi@nihon-u.ac.jp.
authors.forename: Shiro
authors.initials: S
authors.lastname: Itoi
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Yoshikawa
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Asahina
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Ishizuka
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Narumi
authors.initials: N
authors.lastname: Takimoto
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Mitsuoka
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Yokoyama
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Detake
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Takayanagi
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Eguchi
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Tatsuno
authors.affiliation: Department of Sea-Farming, Aichi Fish Farming Institute, Tahara, Aichi 441-3618, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kawane
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Kokubo
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Shihori
authors.initials: S
authors.lastname: Takanashi
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Miura
authors.affiliation: Department of Sea-Farming, Aichi Fish Farming Institute, Tahara, Aichi 441-3618, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Suitoh
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takatani
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Arakawa
authors.affiliation: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Sakakura
authors.affiliation: Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Sugita
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001492:Bass / Q000502:physiology; D002853:Chromatography, Liquid; D005260:Female; D005432:Flounder / Q000502:physiology; D007150:Immunohistochemistry; D007564:Japan; D007814:Larva / Q000737:chemistry / Q000254:growth & development; D010053:Ovary / Q000737:chemistry; D010063:Ovum / Q000737:chemistry; D011235:Predatory Behavior / Q000187:drug effects* / Q000502:physiology; D012867:Skin / Q000737:chemistry; D023741:Takifugu / Q000254:growth & development / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D013779:Tetrodotoxin / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000911:Antibodies, Monoclonal; D013779:Tetrodotoxin
keywords: Chemical defense; Pufferfish; Survival strategy; Takifugu; Tetrodotoxin (TTX)