Translation

The Japanese word for "Fish" is sakana 魚.

  • sakana is the common term for fish, while gyorui is the technical term for the animals that are fish.
Romaji sa ka na
Hiraganaさかな
Katakanaサカナ
Kanji 魚
School Level 小2

Loan-word

The word "Fish" katakanized would be fisshu フィッシュ.
Romaji fi sshu
Katakanaフィッシュ
Hiraganaふぃっしゅ

Further Reading

Wikipedia: Fish (魚)
Jellyfish, Swordfish.