Ichthyol. Also tetraodon, tetradon. [mod.L. (Linnæus, 1766), f. Gr. τετρα- four + ὀδούς ὀδοντ- tooth. So F. tétrodon.] A genus of plectognathic fishes, typical of the family Tetrodontidæ, in which the jaws are divided longitudinally by a groove, giving the appearance of four large teeth; a fish of this family, a globe-fish. Hence Tetrodonic a., of, pertaining to, or derived from fishes of this genus; Chem. applied to a poisonous acid obtained from the roe of a fish of this genus (Cent. Dict. Suppl., 1909); Tetrodonin, a crystalline base obtained with tetrodonic acid. So Tetrodont (also tetraodont), a. having (apparently) four teeth; belonging to the Tetrodontidæ; sb. a tetrodon or globe-fish. Hence Tetrodontid, Tetrodontoid adjs. and sbs.
1774. Goldsm., Nat. Hist. (1776), VI. 237. These are the Sun Fish, the Tetrodon, the Lump Fish.
1822–34. Good’s Study Med. (ed. 4), IV. 214. The genus tetradon, in one species, secretes an electric fluid.
1854. Badham, Halieut., 409. The tetraodons seem as unsafe for food as the diodons.
1858. Baird, Cycl. Nat. Sci., s.v. Diodontidæ, The true diodonts,… the tetraodonts,… and the sun-fishes.
1883. Spectator, 19 May, 639. The tetradon, a knobbly, bladder-shaped creature, used by the Chinese as a lantern, when he has been scooped.
