noun
bluestripe snapper; bluestripe seaperch
A tropical marine fish (Lutjanus kasmira) with distinctive blue stripes, found in the Indo-Pacific. The name is a specific ichthyological term.
沖縄の海でヨスジフエダイの群れを見た。
I saw a school of bluestripe snappers in the sea off Okinawa.
The name is a compound of 四筋 (よすじ, 'four stripes') and 笛鯛 (ふえだい, 'snapper'), referring to the four blue stripes on the fish's body. The exact historical derivation is uncertain.