Coarse fish : Ruffe (Gymnocephalus cernua)

The ruffe (Gymnocephalus cernua) is a small freshwater fish that belongs to the Percidae family.

Resembling the perch, this voracious and slippery fish interests anglers seeking resilient live bait. This article will delve into the characteristics, habitat, behaviour, and fishing techniques related to the ruffe, also known as Gymnocephalus cernua.

Ruffe (Gymnocephalus cernua) - Credit Gilles San Martin on Wikimedia Commons — **Ruffe (Gymnocephalus cernua)** – Credit Gilles San Martin on Wikimedia Commons

Characteristics of the Ruffe (Gymnocephalus cernua)

Determination

Apart from its size, the Ruffe bears a striking resemblance to the Perch. It has an elongated, slightly humped body, with the posterior portion being more compressed than the anterior part. The head of the ruffe is strong, spiny, and scaleless, with large eyes and metallic reflections. Its dorsal fin is long, characteristic of the Percidae family. It is divided into two parts: the anterior part consists of spiny rays, while the posterior portion comprises soft rays. The dorsal and caudal fins are adorned with small dark spots. The ruffe’s colouration is brownish-green on the back, with dark spots covering the body, similar to the gudgeon’s pattern. The flanks are lighter brown, while the belly is yellowish with black spots. The body of the ruffe is covered in small, deeply embedded scales, giving it a rough texture typical of the Percidae family. The fish’s body is also covered in abundant and slippery mucus.

Class

Actinopterygii

Order

Perciformes

Family

Percidae

Genus

Gymnocephalus

Species

G. cernua

Binomial Name

Gymnocephalus cernua (Linnaeus, 1758)

The binomial name for the ruffe is Gymnocephalus cernua, with Linnaeus being credited as the authority who first described it in 1758.

Size and Weight

The ruffe typically measures between 5 and 15 cm in length, with an average weight ranging from 10 to 50 g. The largest specimens can reach up to 25 cm in length and weigh around 200 g.

Longevity

The lifespan of the ruffe is approximately 4 years.

Habitat and Behaviour

Habitat

The Ruffe is native to central and eastern Europe and appeared in Western Europe in the second half of the 18th century. Its habitat now extends from southwest England to the Ural Mountains, including the southern parts of Scandinavia. Its presence in Scotland and North America is likely due to accidental introductions. The ruffe is a gregarious fish that inhabits slow-moving waters, preferably those well-suited to its limited swimming abilities. It thrives in deep waters (up to 25 meters) covered in gravel or sandy bottoms, including ponds, lakes, and calm rivers. The ruffe exhibits a high tolerance to pollution and degraded environments.

Feeding Habits

The ruffe feeds on various organic matter found on the bottom and is considered a benthophagous species. Its highly sensitive lateral line allows it to feed both day and night. It is a voracious fish, active throughout the day, and its diet consists of invertebrates (larvae, zooplankton, etc.), small crustaceans, mollusks, and plant debris. The ruffe also enjoys consuming the eggs of other fish and young fry, which occasionally categorizes it as a nuisance fish.

Reproduction

The ruffe reaches sexual maturity at the age of two. Between April and May, when the water temperature is between 10 and 15°C, the female deposits between 40,000 and 1,000,000 eggs in several batches in shallow areas or on obstacles. The eggs, whitish-yellow in color, form a coiled cord similar to that of the perch, attaching to aquatic plants, branches, or rocks. The incubation period lasts approximately ten days.

Interest of the Ruffe for Anglers

Although the ruffe possesses delicate flesh, akin to other perch species, it is not a highly sought-after fish among anglers. It tends to take bait intended for different fish species, such as predatory species. Anglers commonly use Ruffe for Pike, Zander, Perch, Eels, and occasionally trout, making it primarily valuable as live bait for predator fishing.

Conservation Status of the Ruffe

The Ruffe is classified as “LC” (Least Concern) on the IUCN Red List, indicating that it is widely distributed and abundant.

FAQs

The size of a ruffe can vary depending on the species and its location. In general, adult ruffe can measure between 15 and 30 cm in length, but some species can reach sizes of up to 50 cm.

Ruffe are freshwater fish found in various regions worldwide, including Europe, Asia, and North America. They are often found in lakes, rivers, ponds, and canals. Ruffe require clear and cool water to survive and are commonly found in mountainous regions where the water is cooler and the rivers are clearer. They can also be found in coastal areas such as estuaries and deltas, where the water is brackish.

Ruffe are omnivorous fish, feeding on a variety of small aquatic animals such as insects, crustaceans, mollusks, and small fish. They also consume plant matter such as algae, aquatic plants, and organic debris. Ruffe are known to feed on zooplankton and phytoplankton as well. They have a prominent mouth that allows them to easily capture their prey, but they can also graze on plants and algae by scraping the river or lake substrate. Generally, ruffe are opportunistic feeders, adapting to their environment and consuming what is available.

Ruffe can be caught using a variety of baits. Live baits such as worms, larvae, shrimps, crayfish, and small fish are commonly used and mimic the natural prey of the ruffe. Artificial lures such as spinners and soft baits can also be effective. It is recommended to experiment with different types of bait to see what works best in your specific fishing location and conditions.

Ruffe are omnivorous fish, feeding on both animal and plant matter. Their diet consists of insects, crustaceans, mollusks, small fish, algae, aquatic plants, and organic debris. Ruffe also have a preference for consuming fish eggs and young fry, which sometimes categorizes them as nuisance fish.

The weight of a ruffe can vary considerably depending on the species and location. Adult ruffe can weigh from a few grams to several kilograms. Generally, ruffe are relatively small fish, but some species can reach impressive sizes and weights. It is important to respect size and weight limits to protect fish populations and their habitats.

Ruffe are known for their aggressive territorial behavior and can attack other fish that come near their territory. They can also tolerate warmer water temperatures than other ruffe species, allowing them to inhabit larger habitats.

The ruffe can be easily recognized by its distinct physical characteristics. It has an elongated, cylindrical body with a wide head and prominent mouth. Its eyes are situated high on the head, providing a superior view of its prey and surroundings. The ruffe has a gray-green color on its back, with black spots along its sides and a white coloration on its belly. Its dorsal fin is high and pointed, while its anal fin is shorter and rounded. It distinguishes itself from other ruffe species through its color and the black spots on its flanks. Males have longer and more pointed dorsal fins compared to females. Overall, the ruffe is a combative and aggressive fish, often sought after by sport fishermen for its delicious meat and challenging nature.

The ruffe (Gymnocephalus cernua) has an average lifespan of 5 to 7 years. However, under optimal conditions, it can live up to 10 years. The lifespan of ruffe is influenced by factors such as water quality, water temperature, prey availability, and competition with other fish species. Ruffe are also vulnerable to diseases and predators such as birds, snakes, and larger fish. It is important to protect ruffe populations to ensure the sustainability of the aquatic ecosystem. Anglers should adhere to size and weight limits to help protect fish populations and their habitats.

Fishing for ruffe can be an engaging activity for sport fishermen. It is recommended to use live bait such as worms, larvae, and shrimps, which mimic the natural prey of ruffe. Artificial lures such as spoons and soft baits can also be effective. Fishing for ruffe can be practiced from a boat or the shore. It is important to target areas where ruffe are present, such as underwater structures like rocks, tree roots, and debris. Fishing for ruffe can be a fun and rewarding activity, but practicing responsible fishing is crucial to protect fish populations and their habitats. Anglers should adhere to local rules and regulations regarding size, weight, and practice catch-and-release techniques to safely release unwanted fish back into the water.

Coarse fish : Ruffe (Gymnocephalus cernua)

The ruffe (Gymnocephalus cernua) is a small freshwater fish that belongs to the Percidae family.