vertical-striped cardinalfish; Indian perch; coral fish
Refers to the fish species Apogon lineatus. In everyday contexts, the katakana form テンジクダイ is standard.
I saw a school of vertical-striped cardinalfish at the aquarium.
Kanji form is rare and mainly seen in taxonomic or specialized contexts.
The name テンジクダイ (天竺鯛) literally means 'Indian sea bream', from 天竺 (India) and 鯛 (sea bream), though the fish is not a true sea bream. The exact derivation is uncertain.