Sixty-four of the most common fish likely to be seen on the reef by day or at night are shown in this 32 page chapter. Because the fish are more commonly known than the corals and other invertebrates, both the scientific name and the common name are given for the fish. Most are represented by a single photo, but for some a second or third photo is presented if it can show something more than a single photo can. In keeping with the mostly systematic presentation, the damselfish and angelfish (7) are shown, then chromises (2), butterflyfish (3), and hamlets (5). Other fish are shown, either ones with related species or ones without, that exhibit a variety of body types and life styles, from sand dwelling jawfish and others to poisonous scorpionfish, spiny inflatable balloonfish and burrfish. Predators like the lizardfish, groupers, and the moray eels are shown and discussed. Cleaner fish such as the juvenile bluehead wrasse and cleaning gobies are shown in action, and a look at the peacock flounder and the yellow stingray show how two very different fish have developed a very similar lifestyle, an example of convergent evolution. The chapter is not meant to be exhaustive, but most of the fish that a diver is likely to encounter are included, and many that are related but not seen here are mentioned.