noun
Pacific blackdragon
A deep-sea fish, Idiacanthus antrostomus. The Japanese name literally means 'three-pronged spear fish', referring to its appearance.
ミツマタヤリウオは深海に生息する魚だ。
The Pacific blackdragon is a fish that lives in the deep sea.
Compound of 三つ又 (mitsumata, 'three-pronged') + 槍魚 (yariuo, 'spearfish'), describing the fish's shape. The exact derivation is uncertain beyond the descriptive name.