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How do adult flatfishes use their flattened body shape on the ocean bottom?

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Body plan and sexual dimorphism in the common sole (Solea solea) and dusky flounder (Syacium papillosum). — pleuronectiform Body plan and sexual dimorphism in the common sole (*Solea solea*) and dusky flounder (*Syacium papillosum*).

Adult flatfishes (order Pleuronectiformes) utilize their unique, asymmetrical, and strongly compressed body shape to thrive as benthic (bottom-dwelling) organisms.

By habitually resting on one side on the ocean floor, they effectively integrate into their environment. Their flattened morphology allows them to remain close to the substrate, where they move by undulating their bodies or fins. This bottom-living existence is supported by specialized coloration: the side of the fish facing upward is pigmented, while the lower side is typically white.123

To further enhance their survival, many flatfishes employ camouflage by changing their color or pattern to match the specific surface on which they are resting, making them difficult for predators to detect. This combination of physical asymmetry, behavioral adaptation, and physiological color control allows them to remain concealed while navigating or waiting on the seafloor.345