You might think that sharks or whales rule the oceans’ vertebrate life, but in terms of number of species, the prize goes to the perciforms. The largest order of vertebrates in the world,(1,2) the perciformes are a group of over 10,000 species of fish (1,2,3,4) that live all over the globe (3,4)—not just deep in the ocean, (2,3,4) but also in lakes, rivers,(2,3,4) and most of all in coral reefs off of the seashore.(2) From tiny gobies to long, fierce barracudas,(4) from the black and blue wolf-eel to the vivid orange and white clown anemone fish,(5) from shocking electric stargazers to insect-shooting archer fish,(4) perciforms have an endless variety of sizes, shapes, colors, and behaviors.(4) Yet despite their amazing diversity (and the uncertainty about the exact groups belonging in this order of fish (3,4), most perciformes share some important features. These include, among others, pectoral fins on the sides;(2) spines on the dorsal fin (on the fish’s back) and anal fin (on the fish’s underside), probably for self-defense;(3,4) a tail fin that is unconnected to the other fins;(3,4) and a jaw that can be pushed outward to suck food into the mouth.(4) Perciforms have many important interactions with other species, serving as both predators and prey and frequently taking part in relationships that benefit both themselves and other species, as in the case of cleaner fish, which tidy up the mouths and bodies of larger fish and get a tasty meal of small morsels in the process.(4) For thousands of years, perciforms have also been very important for humans, who make use of perciforms such as tuna, mackerel, bass, and many others as major food sources(4)—so much so that some of these are now seriously threatened by overfishing.(2,4) Today many beautiful perciforms are also popular choices for aquariums.(4)