Common name: Ray-finned fishes

The enormously diverse Actinopterygii, or the ‘ray-finned fishes’, is one of two living groups of bony fishes.

The ray-finned fishes is the largest and most successful fish and vertebrate group, containing more than half of all living vertebrate species.

Although the other group, the lobe-fins (Sarcopterygii), contains only eight living species (two coelocanths and six lungfishes) it gave rise to the tetrapods - the four-legged vertebrates (including we humans).

Ray-finned fishes have fins made up of membranes with bony supporting structures.They exhibit an amazing array of body forms and adaptations, allowing them to inhabit almost all aquatic environments, including extreme habitats such as mudflats, hot desert springs, subterranean caves, high altitude lakes and streams, polar seas and the depths of the abyss – environments where temperatures, salinities, pH levels, and dissolved oxygen levels may range from one extreme to another.

The fossil record of ray-finned fishes dates back to the Devonian period.

Author: Bray, D.J. 2022

Cite this page as:
Ray-finned fishes, ACTINOPTERYGII in Fishes of Australia, accessed 22 Jun 2024,


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