カジキマグロ

• マグロ

  マグロ refers specifically to tuna, while カジキマグロ is a billfish (marlin/swordfish), not a true tuna despite the name.

• メカジキ

  メカジキ is the specific term for swordfish, whereas カジキマグロ is a broader term often used for marlin.

• カジキマグロUsage37%
  kana-only spelling

  Katakana spelling is standard; the word is usually written in kana.

• かじきまぐろUsage54%

  Hiragana spelling, also common.

• カジキ鮪まぐろUsage9%
  search-only kanji form

  Search-only mixed kanji-katakana form.

• 梶かじ木き鮪まぐろ
  rarely-used kanji form

  Rarely used kanji form; 梶木 is ateji for かじき, 鮪 is まぐろ.

• 旗魚かじき鮪まぐろ
  rarely-used kanji form

  Rarely used kanji form; 旗魚 is ateji for かじき.

Compound of カジキ (marlin/swordfish, from 梶木 or 旗魚) and マグロ (tuna). The exact origin of カジキ is uncertain; it may refer to the fish's resemblance to a boat's oar (梶) or its sail-like fin (旗).