lookdown (Selene vomer)
A species of marine fish in the family Carangidae, known for its silvery, laterally compressed body. The name is a specific ichthyological term.
I saw a lookdown at the aquarium.
Katakana spelling is standard for this fish name; usually written in kana.
Kanji spelling is rare; the fish is almost always written in kana.
The name シロガネアジ literally means 'silver horse mackerel', from 白銀 (しろがね, 'silver') and アジ (horse mackerel), referring to its shiny appearance.