The European flounder (Platichthys flesus), commonly referred to as the common flounder or plaice, is an intriguing fish species found in various aquatic habitats. Belonging to the Pleuronectidae family, it showcases distinctive anatomical and behavioral adaptations, capturing the attention of ichthyologists.
With a flattened body structure and both eyes positioned on one side, the European flounder typically measures between 20 and 50 centimeters (8 to 20 inches) in length, although larger individuals can reach up to 70 centimeters (28 inches). Regarding weight, these fish exhibit significant variation, weighing anywhere from 200 to 2,000 grams (7 to 70 ounces). They have an average lifespan of 7 to 15 years, although exceptional cases have recorded individuals living up to 20 years. Such precise data provides valuable insights into the life history of this species, enriching our understanding of its biology.
The European flounder demonstrates distinct preferences for optimal fishing conditions, which depend on factors such as time of day, weather, and seasons. Familiarizing oneself with these patterns can greatly enhance the success of anglers targeting this species.
During the spring season, the European flounder exhibits heightened activity levels, particularly in the early morning and late afternoon. They display greater receptiveness towards bait or lures when the water temperature ranges from 10°C to 14°C (50°F to 57°F). As summer approaches, the ideal fishing times shift to the early morning and evening hours, with water temperatures ranging between 14°C and 20°C (57°F and 68°F).
In autumn, the European flounder remains active, although its feeding behavior becomes less aggressive. The high tide and early morning or late afternoon periods offer better chances of successful fishing, especially when the water temperature falls within the range of 10°C to 16°C (50°F to 61°F). During the winter season, this species displays reduced activity due to the colder temperatures. The late afternoon, accompanied by water temperatures between 4°C and 10°C (39°F and 50°F), presents the most productive fishing opportunities.
The European flounder enjoys an extensive geographical range, primarily inhabiting the coastal waters of the northeastern Atlantic Ocean. Its distribution spans from the northernmost regions of the Baltic Sea and the White Sea to the western coast of France, including the English Channel and the North Sea. These fish can be found in both shallow and deeper areas, reaching depths of up to 200 meters (656 feet).
Multiple countries, including Norway, Sweden, Denmark, the United Kingdom, France, and Germany, host populations of the European flounder. The coastal regions within these countries provide suitable habitats for the species, characterized by sandy or muddy substrates with optimal water temperatures.
The European flounder engages in spawning activities during the late winter to early spring period, typically occurring from February to April. Successful reproduction is closely tied to the water temperature, with the preferred spawning range falling between 6°C and 10°C (43°F and 50°F).
Females of this species produce a substantial number of eggs, with an average of 100,000 to 500,000 eggs per individual. The buoyancy of these fertilized eggs enables their dispersal across vast areas through ocean currents. Following hatching, the larvae spend time drifting in open waters before eventually settling on the seabed. This strategic spawning method ensures the dispersion and survival of the European flounder population.
As a predator, the European flounder exhibits a diverse diet consisting primarily of small fish, crustaceans, and various bottom-dwelling organisms. Its feeding preferences adapt based on the availability of prey species within different habitats. Young European flounder initially feed on small invertebrates like amphipods and polychaetes, gradually transitioning to larger prey as they mature.
Employing a stealthy hunting technique, the European flounder patiently lies in wait for suitable prey, seizing the opportunity to strike swiftly when within reach. This hunting behavior allows for efficient prey capture without expending excessive energy. However, it's important to note that the European flounder is an opportunistic feeder, adjusting its diet to the availability of food resources in its immediate environment.
The European flounder plays a crucial ecological role within its native habitats. Its predatory nature aids in regulating populations of small fish and other aquatic organisms, ensuring a balanced ecosystem by preventing overpopulation.
Furthermore, the presence of the European flounder serves as an indicator of a healthy and diverse aquatic ecosystem. Changes in its abundance or decline can reflect the overall condition of the environment. Hence, the preservation of European flounder habitats and populations holds utmost importance for the conservation of biodiversity and the sustainability of aquatic ecosystems.