: Each scale consists of three distinct layers: a bony basal layer, a middle layer of dentine (similar to human teeth), and a hard, enamel-like outer layer called ganoine .
Today, only a few groups of fish still possess these primitive scales: ganoid fish
: Due to their thick, bony nature, these scales make the fish's body relatively rigid compared to more modern teleost fish. Representative Living Species : Each scale consists of three distinct layers:
: In these species, the scales are often modified into large, bony plates called scutes rather than a full body covering. : Unlike the overlapping "shingle-like" scales of common
: Unlike the overlapping "shingle-like" scales of common fish, ganoid scales are rhomboidal and connect via peg-and-socket joints . This creates an interlocking, nearly impenetrable surface that is highly resistant to predators.
The defining feature of these fish is their scales, which act like a suit of chainmail.
: Species like the Alligator Gar are famous for their diamond-shaped armor.