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
Our Latest Blog
25 Small Animals in the World: Identification with Pictures
May 2, 2026
Small animals are fascinating because of their diversity, unique adaptations, and important roles in nature. From tiny mammals like the pygmy marmoset to insects like
Read more