Ruffe

Gymnocephalus cernuus Pärnu River Estonia 2010-01-06

Ruffe (Gymnocephalus cernua) is a species of freshwater fish in the family Percidae, which also includes perch and darters. It is native to Eurasia and is known for its distinctive appearance and behavior.

Description

The ruffe is a small fish, typically reaching lengths of 10-15 cm, though some individuals can grow up to 25 cm. It has a laterally compressed body with a spiny dorsal fin. The coloration of the ruffe is generally brownish or olive with darker spots, which provides camouflage against the substrate of its habitat.

Habitat

Ruffe are commonly found in lakes, rivers, and reservoirs with slow-moving or still waters. They prefer habitats with sandy or muddy bottoms where they can easily find food. The species is highly adaptable and can tolerate a range of environmental conditions, including varying levels of salinity and temperature.

Diet

Ruffe are opportunistic feeders, primarily consuming benthic invertebrates such as insect larvae, crustaceans, and mollusks. They use their well-developed sense of smell to locate prey in the substrate.

Reproduction

The spawning season for ruffe typically occurs in the spring, when water temperatures rise. Females lay their eggs on submerged vegetation or other structures, and the eggs hatch within a few days. The larvae are planktonic at first, but they soon settle to the bottom and begin feeding on small invertebrates.

Distribution

Ruffe are native to a wide range of Eurasia, including parts of Europe and Asia. They have been introduced to other regions, such as the Great Lakes in North America, where they are considered an invasive species due to their impact on local ecosystems.

Impact as an Invasive Species

In regions where ruffe have been introduced, they can have significant ecological impacts. They compete with native fish species for food and habitat, and their presence can lead to declines in native fish populations. Management efforts are ongoing to control the spread of ruffe in non-native areas.

Related Pages

• Percidae
• Perch
• Darters
• Invasive species
• Great Lakes