also: ダイアモンドテトラ
noun
diamond tetra
A small freshwater tropical fish (Moenkhausia pittieri) popular in aquariums, known for its shimmering scales.
水槽にダイヤモンドテトラを数匹入れました。
I put a few diamond tetras in the aquarium.
From English 'diamond tetra', referring to the fish's diamond-like reflective scales.