The story
From Japanese + sleeper ray, from its native range in the northwestern Pacific Ocean and its status as a member of the sleeper ray family (Narkidae).
Etymology from Wiktionary, CC BY-SA 4.0.
Japanese sleeper ray
Today it means: Narke japonica, a species of electric ray known for its sedentary lifestyle, found in the northwestern Pacific Ocean from southern Japan to southern China. Full definition →