Perciformes

Perciformes, commonly called perch-like fishes, is the largest order of ray-finned fishes (Actinopterygii). It contains thousands of species in numerous families and is found in nearly all aquatic environments, from tropical reefs and estuaries to temperate rivers and lakes, in both marine and freshwater zones.

Anatomy and variation: Perciformes are typically laterally compressed with dorsal and anal fins that often have both spiny and soft-rayed portions. In many species the dorsal fin is divided into an anterior spiny part and a posterior soft-rayed part; the pectoral fins are usually placed low on the body. Scales are commonly cycloid or ctenoid. Mouth position is typically terminal or slightly superior, and many species have a protrusible jaw.

Ecology and life history: The order encompasses a wide range of trophic strategies, from planktivores to apex predators. Habitats range from coral reefs and rocky shores to freshwater lakes and rivers. Reproductive modes are diverse, including guarding of eggs in nests and, in some families, mouthbrooding or broadcast spawning.

Taxonomy and systematics: Perciformes is a traditional, highly diverse grouping within the ray-finned fishes. Modern molecular analyses have challenged the monophyly of Perciformes, and several lineages have been reclassified into separate orders in some taxonomic schemes. As a result, the exact circumscription of Perciformes varies among sources.

Importance: The group includes many species of ecological and economic importance, including components of commercial fisheries and the aquarium trade, and they play key roles in both marine and freshwater ecosystems.