σέλαχος
σέλαχ-ος, εος, τό, mostly in pl. σελάχη,,
A). the cartilaginous or elasmobranch fishes, sharks and rays, HA 505a1 , 511a5 , al.; ἰχθύσι σελάχεσι Morb. 2.50 , etc. (Some derived the name from σέλας, because fishes of this kind emit a phosphorescent light, 6.737 .)