European flounder

Species of fish

The European flounder (Platichthys flesus) is a species of flatfish in the family Pleuronectidae. It is native to the coastal waters of Europe and is known for its distinctive ability to adapt to both saltwater and freshwater environments.

Description

European flounder in Estonia

The European flounder is a demersal fish, meaning it lives and feeds on or near the bottom of seas or lakes. It has a laterally compressed body, which allows it to lie flat on the seabed. The flounder typically has a brownish-green coloration on its upper side, which is the side that faces upwards when it is lying on the seabed. This coloration provides excellent camouflage against the sandy or muddy bottoms where it resides. The underside of the flounder is usually white.

The eyes of the European flounder are located on the right side of its body, a characteristic feature of the family Pleuronectidae. The fish can grow up to 60 cm in length, although most individuals are smaller.

Distribution and Habitat

The European flounder is found in the northeast Atlantic Ocean, from the White Sea and Iceland in the north, down to the Mediterranean Sea and the Black Sea in the south. It inhabits a variety of environments, including estuaries, coastal lagoons, and river mouths. The species is euryhaline, meaning it can tolerate a wide range of salinities, which allows it to thrive in both marine and freshwater habitats.

Behavior and Diet

The European flounder is primarily a nocturnal feeder, preying on a variety of benthic organisms. Its diet consists mainly of polychaete worms, small crustaceans, and mollusks. The flounder uses its well-developed sense of smell to locate prey buried in the sediment.

Reproduction

Spawning occurs in the spring and early summer. The European flounder migrates to deeper waters to spawn, where females release eggs that are fertilized by males. The eggs are pelagic, meaning they float in the water column. After hatching, the larvae are planktonic and undergo a transformation where one eye migrates to the other side of the head, a process typical of flatfish development.

Fisheries and Conservation

Fishing boats in Niechorze, Poland

The European flounder is an important species for commercial and recreational fisheries in many parts of its range. It is caught using various methods, including trawling and gillnetting. While the species is not currently considered threatened, overfishing and habitat degradation pose potential risks to its populations.

Related pages

• Flatfish
• Pleuronectidae
• Demersal fish