• 金魚きんぎょ — goldfish
• 人魚にんぎょ — mermaid
• 魚屋さかなや — fish shop
• 淡水魚かいぎょ — freshwater fish

魚 is a pictographic character that resembles the shape of a fish, with fins and tail. It directly represents "fish" and is frequently used in words related to seafood, species, and fishing.