Fish and their families

Fishes have a range of body sizes from the massive whale shark down to the smallest fish under a centimetre in length. Despite this diversity, all fish have a backbone or a notochord, and all breathe using gills. Worldwide there are over 32,000 described species of fish, with over 4,400 from Australia.

Fish are classified into two groups: cartilaginous fish or bony fish. Cartilaginous fish are characterised by their bones made of cartilage, this include sharks and rays. The majority of fish are considered bony fish, it is a much more diverse group with over 28,000 species. Bony fish include the Mackerel tuna and Eastern Australian salmon.

The Australian Museum Ichthyology Collection contains specimens of many of the species listed in the fact sheets.