A person who specializes in the study of animals is called a zoologist . Zoologists who study certain kinds of animals have their own names. Anthropologists study human beings.
Entomologists study insects.
Herpetologists study reptiles and amphibians. Ichthyologists specialize in fish. Malacologists study mollusks, like snails and clams. Mammalogists specialize in mammals. Nematologists study round worms.