Animal Groups and Number of Species
Here are 10 major animal groups with an approximate number of known species in each:
- Mammals – ~6,500 species
- Birds – ~11,000 species
- Reptiles – ~11,500 species
- Amphibians – ~8,000 species
- Fish – ~34,000 species
- Insects – ~1,000,000+ species
- Arachnids (spiders, scorpions, etc.) – ~100,000 species
- Mollusks (snails, clams, squids) – ~85,000 species
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