Fish physiology refers to the study of how fish function biologically. While fish physiology encompasses a wide range of topics, including respiration, circulation, and digestion, there are several synonyms that can be used to reference this field of study. These include ichthyology, fish biology, and fish anatomy. Ichthyology focuses on the study of fish in general, including their behavior, genetics, and ecology. Fish biology specifically focuses on the biology of fish and their characteristics, such as reproduction, growth, and adaptations. Finally, fish anatomy is concerned with the structural and functional features of fish, including their organs and body systems.