From the beginning, attempts have been made to understand the origins, breadth and complexity of the living world. Classification is an ongoing effort to catalogue life on the basis of evolutionary relationships. The fundamental unit of biological classification is the species, long described as a reproductively isolated population where, under normal circumstances, members only breed with one another. More recently, the species concept is of a single historical lineage having its own unique features that has maintained a separate identity from other such lineages. Classifications group organisms with common ancestry.
All described organisms have scientific names consisting of two italicised words, usually derived from Greek or Latin stems. The first, the generic name, always has the first letter capitalised and is followed by the specific name, which is entirely in lower case. Species with the same generic name are considered to be more closely related to each other than to species in another genus. Genera are, in turn, grouped together into families (whose names end in ‘idae’), families into orders (names ending in ‘iformes’), orders into classes, and so on, to the level of phylum or kingdom. Each of these groupings also implies a shared evolutionary history, in which members of a grouping, such as a family, are more closely related to each other than to members of a separate family. Although complete classifications have many levels, like subfamily or superorder, to aid our understanding of interrelationships, only species, genus, family, subphylum and phylum have regular significance to the general user.
The levels of classification treated here are:
Phylum: Subphylum: Superclass: Class: Subclass: Order: Family: Genus: Species
Browse through the classification of Australia's fishes using the Browse Classification option in the menu at the top of each page.
The classification in Fishes of Australia follows the Australian Faunal Directory’s Catalogue of Fishes. Clicking on a name in the classification on the left will provide information about the group and display names at the next level down.