While listing exactly 20 definitively agreed-upon "branches" of zoology is difficult due to overlap and evolving specializations, here is a list encompassing many key areas within the field, drawing from common classifications and incorporating the reference material:
- Anatomy: The study of the structure of organisms and their parts.
- Physiology: The study of the functions and mechanisms within a living system.
- Ecology: The study of the interactions between organisms and their environment.
- Ethology: The study of animal behavior.
- Genetics: The study of heredity and the variation of inherited characteristics.
- Evolutionary Biology: The study of the evolutionary processes that have produced the diversity of life on Earth.
- Paleozoology: The study of prehistoric animals through fossils.
- Embryology: The study of the development of an animal from a zygote to birth or hatching.
- Systematic Zoology (Taxonomy): The science of classifying and naming organisms.
- Entomology: The study of insects.
- Ichthyology: The study of fish.
- Herpetology: The study of amphibians and reptiles.
- Ornithology: The study of birds.
- Mammalogy: The study of mammals.
- Malacology: The study of mollusks.
- Arachnology: The study of arachnids (spiders, scorpions, mites, etc.).
- Nematology: The study of nematodes (roundworms).
- Parasitology: The study of parasites and their relationships with their hosts.
- Cytology: The study of cells, their structure, function, and behavior.
- Histology: The study of the microscopic structure of tissues.
It's important to note that many zoological fields are highly interdisciplinary and may overlap considerably. Additionally, emerging fields like behavioral ecology, conservation biology, and molecular zoology represent important modern specializations within zoology.
