Sole

Presentation

The common Sole (Solea Solea) is a marine flatfish characteristic of the sandy and muddy bottoms of the Atlantic and Mediterranean coast. Its oval and flattened body, its two eyes located on the right side and its mimic grayish-brown coloring make it a discreet and well camouflaged species. It lives buried in sediment during the day and feeds mainly at night. Highly appreciated in gastronomy, it constitutes an economically important fishing resource, particularly in Tunisia where it is fished along the coasts.

The body of the Sole is oval, very laterally flattened and asymmetrical, with the two eyes grouped on the right side of the body. The skin is covered with small rough scales and has a mottled grayish-brown coloring on the oculated side, while the blind side remains whitish. The dorsal and anal fins are long and border almost the entire body.

Characteristics

Indicative values: they vary by subspecies, sex and region.

Habitat and distribution

Sole frequents sandy and muddy bottoms of shallow coastal areas, as well as brackish estuaries and lagoons. It particularly likes coastal waters up to a hundred meters deep. Juveniles are often found in very coastal areas and estuarine wetlands.

Behaviour

The Sole is a benthic, solitary and mainly nocturnal fish. During the day, it remains buried in the sand or mud, with only its eyes visible, which protects it from predators. It carries out seasonal migrations between shallow coastal areas and deeper waters depending on the season and reproduction.

Reproduction

Breeding occurs in winter and early spring, usually in deeper waters. The female lays several hundred thousand pelagic eggs which drift with the currents before hatching. The larvae, initially symmetrical like a classic fish, undergo a spectacular metamorphosis during which one eye migrates to the other side of the body.

Peculiarities

The most striking feature of Sole is ocular migration during larval development, transforming a symmetrical fish into an asymmetrical flatfish. Its exceptional camouflage allows it to blend almost completely into the surrounding sediment.

Threats and conservation

Sole is subject to significant fishing pressure due to its high commercial value. The degradation of coastal and estuarine habitats, essential areas for juveniles, constitutes an additional threat. Quota management measures exist in certain areas to limit overfishing.

References

Profile updated 29 August 2026 · Reviewed by the TunisieVet editorial team.