razorfish; Aeoliscus strigatus
A small, elongated marine fish with a sharp-edged body, found in tropical waters. The Japanese name literally means 'heko sweetfish', but it is not related to ayu.
At the aquarium, the razorfish were swimming upside down.
Katakana spelling is common for this fish name; usually written in kana.
Kanji spelling is rare; the word is usually written in kana.
The name ヘコアユ is a compound of 兵児 (heko, a type of traditional sash) and 鮎 (ayu, sweetfish), but the exact reason for the name is uncertain. The fish is not related to ayu.