ClassACTINOPTERYGII Ray-finned fishes
A large and distinctive group of highly compressed bottom-dwelling fishes with more than 800 species. Flatfishes have both eyes on one side of the skull – to the right side of the head in most species.
Larval flatfishes are pelagic, swim upright and are bilaterally symmetrical until one eye migrates over the top of the head during larval development - so that one eye doesn't point down into the sediment once the larvae settle onto the bottom.
Flatfishes are not only asymmetrical in the placement of their eyes, they also have asymmetrical dentition, paired fins and scale coverings.
During metamorphosis, considerable changes also occur to the head bones, and associated nerves and muscles in readiness for life on the seafloor.
Flatfishes are usually well-camouflaged, matching the soft sediments on which they live. They are ambush predators, often burying themselves leaving only their eyes exposed.
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