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Ganoid scales (or modified ganoid scales) are found in fishes such as the bichirs (Polypteridae), Bowfin (Amia calva), paddlefishes (Polyodontidae), gars (Lepisosteidae), and sturgeons (Acipenseridae).

Ganoid scales are usually rhomboid in shape and have articulating peg and socket joints between them. They are modified cosmoid scales which consist of a bony basal layer, a layer of dentine, and an outer layer of ganoine (an inorganic bone salt).

Ganoid scales are also known from some fossil paleoniscoid fishes.

No fishes with ganoid scales occur in Australian waters.


  • Helfman, G.S., Collette, B.B. & D.E. Facey. 1997. The Diversity of Fishes. Blackwell Science. Pp. 528.