The name Percichthyidae derives from the Ancient Greek words Perca for 'perch' and ichthyos for 'fish' and translated basically means perch-like fishes.
The temperate perches are closely related to the temperate basses of the Moronidae Family, and older literature treats the latter as a belonging to the Percichthyidae Family. Australian freshwater Percichthyids were once placed in the Serranidae (marine grouper) family, and the two families are considered to have some link to each other.
Around 22 species of Percichthyids are now recognised, grouped in around 11 genera. Most but not all are freshwater fishes. They are mainly found in Australasia and South America, though some (notably genus Siniperca, which has the largest number of species) are native to Asia, and some of the marine species are found as far north in the Pacific as California.
Australia has the greatest number of Percichthyid species, where they are represented by the Australian freshwater cods (Maccullochella spp.), which are Murray cod, Mary River cod, eastern freshwater cod and trout cod, by the Australian freshwater blackfishes (Gadopsis spp.), which are river blackfish and two-spined blackfish, and by the Australian freshwater perches (Macquaria spp.), which are golden perch, Macquarie perch, Australian bass and estuary perch.
Several other Australian freshwater species also sit within the Percichthyidae Family while research using mitochondrial DNA suggests the species of the Nannopercidae family are in reality Percichthyids as well. Australia is unique in having a freshwater fish fauna dominated by Percichthyids and allied families/species. This in contrast to Europe and Asia whose fish faunas are dominated by members of the Cyprinidae carp family. (Indeed, Australia does not have a single naturally occurring Cyprinid species; unfortunately the illegal introduction of carp has now established the family's presence in Australia.)
A number of species are or have been important food species; some of these (e.g. the Murray cod, Maccullochella peelii peelii) have become threatened through overfishing and river regulation, while others (e.g. the Chinese perch, Siniperca chuatsi), are now farmed to some extent. Some smaller species (e.g. Balston's pygmy perch, Nannatherina balstoni) are popular in aquaria.