σέλαχος

English (LSJ)

εος, τό, mostly in pl. σελάχη, τά,

   A the cartilaginous or elasmobranch fishes, sharks and rays, Arist.HA505a1, 511a5, al.; ἰχθύσι σελάχεσι Hp.Morb.2.50, etc. (Some derived the name from σέλας, because fishes of this kind emit a phosphorescent light, Gal. 6.737.)