Echinology is a relatively obscure term, meaning the study of spiny animals like sea urchins and sand dollars. It's a niche field, but there are several related terms that better-known scientists and animal lovers may recognize. For instance, the broader study of sea creatures is known as marine biology; ichthyology specifically focuses on fish, while herpetology is the study of reptiles and amphibians. Entomology is the study of insects, while arachnology is dedicated to spiders and other arthropods. Though these fields may overlap with echinology, they each have their own distinct focus and methods of research.