Fish Physiology and Biochemistry is an international journal that focuses on all physiological aspects of fish. 

In this Fish Guide, we explore these aquatic, gill-bearing vertebrates, the most diverse group of vertebrates, with over 33,000 known species. They are classified into three groups: bony fish, cartilaginous fish, and jawless fish. Eating fish, as this Fish Guide highlights, offers numerous health benefits, from improved heart health to enhanced brain function. Fish are rich in omega-3 fatty acids and vitamins such as D and B2. Fisheries and aquaculture, as we discuss in this Fish Guide, support the livelihoods of nearly 10% to 12% of the global population. Fish also play a vital role in aquatic ecosystems by balancing the food chain and supporting biodiversity.