dogtooth tuna
A species of tuna (Gymnosarda unicolor) found in tropical and subtropical waters. In Japanese, it is a specific fish name, not a general term for tuna.
The dogtooth tuna is a type of tuna with sharp teeth.
Standard katakana spelling for this fish name.
Kanji spelling is rare; the word is usually written in kana.
Compound of 磯 (iso, 'rocky shore') and 鮪 (maguro, 'tuna'), referring to a tuna often found near reefs.