Spiny-finned Fishes

Abstract

The Acanthopterygii are the peak of teleostean evolution and, like all groups of animals that have successfully radiated in comparatively recent times, they are both very numerous and enormously diverse. In consequence, their classification is difficult and far from satisfactory. The 8000 or so described species fall into 12 orders, one of which, the Perciformes, contains three-quarters of them, arranged in over 20 suborders. Here, one finds many of the fishes familiar to the layman. Some of these are of great economic importance, such as the mackerel, tunny and barracuda, or are prized by sportsmen as, for example, the marlin, bonito and swordfish. Others have become common aquarium fishes, such as the cichlids, fighting fish and fire eels. Acanthopterygians in general, and Perciformes in particular, have established themselves almost everywhere in the sea, fresh water and brackish regions, with a bewildering range of form and colour. Their common names, parrot fish, stargazers, ragfish, mudskippers, unicorn fish, surgeon fish and sailfish, are indicative of this.