魚類

1. Origins, structure, and basic meaning

• Structure: 魚類 is read as ぎょるい and is a noun for fish considered collectively as a zoological group or category.
• Basic usage: Use 淡水の魚類 for freshwater fish as a group and 魚類の体の形 for the body shapes of fish.

2. Common pitfalls and similar expressions

• Difference between 魚類 and 魚
  • The former treats fish as a biological class or collective group, whereas the latter is the everyday word for individual fish and can also refer to fish as food.