The round whitefish, also known scientifically as Prosopium cylindraceum, is a freshwater fish from the Salmonidae family. Although it is not the most sought-after fish by sport fishermen in Quebec, it still presents some interest, particularly for those interested in species diversity. This fish is rather discreet, but its presence often indicates good water quality. It is generally found in the clear, cool waters of lakes and rivers in northern Quebec. Its fishing does not offer particularly intense combat, but it requires a technical approach due to its cautious nature and specific habitats.

The round whitefish has an elongated and cylindrical body, typical of several members of its family. Its color varies from silvery gray to brownish on the back, with lighter sides and a white belly. The fins are often transparent to slightly tinted gray. The mouth is small and inferior, adapted for feeding near the bottom. The scales are small and smooth, giving this fish a soft texture to the touch. Young whitefish resemble adults closely, although their color may be brighter. During the spawning period, males may develop more pronounced hues and nuptial tubercles on their heads and fins.

In Quebec, the round whitefish is mainly found in northern regions, such as Baie-James and Nord-du-Québec. It is also found in certain parts of the Côte-Nord and Mauricie. It is much less common in the south of the province. The fish prefers clear, well-oxygenated waters of cold lakes and rivers. Its presence is often an indicator of water quality, as it is sensitive to pollution and environmental changes.

The round whitefish favors deep lakes and rivers with moderate currents where the water is cold and well-oxygenated. It generally stays near the bottom on gravel or sand substrates. The depth at which it is found can vary, but it is often observed between 5 and 20 meters. In summer, it may descend deeper to seek cooler waters. Structures such as rocky reefs or shelf edges are places where it is often present.

Spawning of the round whitefish generally occurs in the fall when the water temperature drops to around 4 to 8 °C. The fish gather in schools to spawn on gravel or sand substrates in shallow waters. The eggs are left unprotected, developing slowly during the winter. The fry hatch in the spring and begin to feed on zooplankton. Growth is relatively slow, reaching sexual maturity around 3 to 4 years of age. Their longevity can reach 9 years.

Spring → Hatching → Summer → Growth → Fall → Spawning → Winter → Egg development

The round whitefish is a social fish, often observed in small groups, especially during the spawning period. It is not particularly territorial, but it can be cautious and avoid areas frequented by predators. It is sensitive to changes in light and prefers cloudy days or low-light hours for feeding. Noise and disturbances in the water can scare it away, hence the importance of a discreet approach.

The diet of the round whitefish primarily consists of benthic invertebrates, such as aquatic insect larvae, small crustaceans, and mollusks. Young fish feed more on zooplankton before transitioning to a more varied diet as they grow. In winter, their feeding activity decreases, but they continue to feed when water temperatures allow. Spring and summer are seasons when their feeding is more active.

In spring, as soon as the ice melts, the round whitefish becomes more active and begins to feed intensively to recover from the winter months. In summer, it generally stays in deeper waters to escape the heat but remains active early in the morning and late in the evening. In fall, before spawning, it feeds abundantly to build reserves. In winter, its activity decreases, but it can be fished in deep waters where the temperature is stable. The best fishing conditions are often on overcast days with little wind, as the fish is then less cautious.

For the round whitefish, natural colors work well, especially in clear waters. Silver or white shades mimic small fish and aquatic insects. In murky waters, brighter colors like yellow or orange can help attract attention. Lures should be chosen based on the depth and clarity of the water. On sunny days, natural colors are preferred, while in overcast conditions, brighter colors may be effective.

A light rod with a moderate action of about 6 to 7 feet is ideal for fishing for round whitefish. A light reel with good line capacity is recommended. Use a 4 to 6 lb line for increased sensitivity. Size 8 to 12 hooks are appropriate, and a fluorocarbon leader can be used for more discretion in clear water.

The round whitefish should be handled with care to avoid removing the protective mucus from its skin. Use wet hands or a damp cloth to hold it. If you release the fish back into the water, do so quickly after capture to minimize stress. For a photo, hold it close to the water and ensure its gills remain moist.

The main predators of the round whitefish in Quebec include fish such as pike and walleye, as well as aquatic birds like the osprey and heron. River otters may also target them when they are in shallow waters.

The round whitefish is not considered endangered in Quebec, but its population depends on water quality. Fishing regulations may vary, so be sure to check local rules before fishing. Catch and release is encouraged to conserve populations, especially in areas where they are less abundant.