The largest order of fishes, comprising 20 suborders, 160 families, about 1540 genera, and over 10,000 species, which is about 36% of all fish species. Eighty percent of the perciforms are marine species; in contrast, the Ostariophysi, which comprise the next three largest orders (Cypriniformes, ~3300 species; Characiformes, ~1700 species; and Siluriformes, ~2900 species), are virtually all freshwater inhabitants. The ostariophysans are dominant in the freshwaters of the world; the perciforms are dominant in the oceans.