The Northern lamprey, or Ichthyomyzon fossor, is a fascinating species, although it is not commonly sought after for sport fishing in Quebec. It is primarily of interest to researchers and aquatic wildlife observers due to its ecological role. Unlike some of its more aggressive relatives, the Northern lamprey is not a threat to sport fish, as it is primarily detritivorous. It can be found in several regions of Quebec, particularly in the freshwater of shallow rivers and lakes. Although its small size and discreet behavior make it difficult to catch, it is an important element of the aquatic ecosystem.

The Northern lamprey is a jawless fish with an elongated, serpentine body, typically reaching lengths of 15 to 25 cm. Its color varies from dark brown to grayish, often with lighter shades on the belly. Unlike the sea lamprey, it does not have sharp teeth. Its mouth is circular, sucker-shaped, adapted for attaching to substrates and feeding on organic debris. The dorsal fins are not prominent, and it lacks pectoral or pelvic fins, which distinguishes it from ray-finned fish. Young individuals, called ammocoetes, are often paler than adults and have a more elongated shape. During the spawning period, there are no marked differences between males and females, although males may develop nuptial crests.

The Northern lamprey is present in several regions of Quebec, particularly around the watersheds of the Saint Lawrence and the Great Lakes. It is mainly found in rivers and streams with sandy or muddy bottoms, as well as in some shallow lakes. It is relatively common in these habitats, but its discreet lifestyle makes it difficult to observe. It is less frequently found in faster or deeper waters. The Northern lamprey prefers clear to slightly turbid waters with good oxygenation.

The Northern lamprey inhabits rivers, streams, and shallow lakes with sandy or muddy bottoms. It prefers areas with moderate currents where it can easily burrow into the substrate. The ideal water temperature for this species is between 10 and 18 °C. It is often found in areas rich in organic debris, which constitutes a significant part of its diet. To observe it, look in clear to slightly turbid waters, often near shorelines where the current is weaker.

The Northern lamprey begins its life as ammocoetes, which resemble small eels and live buried in the substrate. After a few years, they undergo metamorphosis to become adults. Spawning occurs in the spring when adults gather in shallow gravel areas to lay their eggs. Adults usually die after spawning, while young ammocoetes continue to grow in the sediments. With a lifespan of 5 to 7 years, the Northern lamprey spends the majority of its life in the larval stage.

Spring → Spawning → Summer → Larval growth → Autumn → Winter → Metamorphosis

The Northern lamprey is a rather solitary species. It is not territorial and tolerates the presence of other individuals well, particularly in the larval stage where ammocoetes live in groups. It is sensitive to changes in light and prefers shaded or darkened environments. It reacts little to noise, but significant disturbances in its habitat may cause it to move. Weather conditions do not significantly affect its behavior, although it is more active on cloudy days.

The diet of the Northern lamprey varies depending on its developmental stage. Ammocoetes primarily feed on microorganisms and organic matter suspended in the water. Once adults, they continue to consume organic debris and sometimes small animal particles. Unlike some other lampreys, they do not parasitize other fish. Their diet remains relatively stable throughout the year, although they may benefit from a greater abundance of food in spring and summer.

The Northern lamprey is active year-round, but it is easier to observe in spring during the spawning period. In summer, ammocoetes continue their development buried in the substrate. Autumn is a transitional period when young individuals begin to prepare for their metamorphosis. In winter, activity slows down, but the Northern lamprey remains active under the ice. It is more visible early in the morning and late in the afternoon when light is less intense. Weather conditions, such as rain or wind, do not have a major impact on its behavior.

Since the Northern lamprey is not a sought-after species for sport fishing, the choice of lures and colors is not relevant for this species. For researchers or naturalists, direct observation in its natural habitat is preferable.

To observe the Northern lamprey, a simple pair of polarized sunglasses can be useful to reduce glare on the water and see details beneath the surface better. A lightweight wetsuit is recommended for observations in cold water. No specific fishing gear is necessary, as this species is not targeted for capture.

If you need to handle a Northern lamprey for scientific or educational reasons, do so with care. Use wet hands to avoid damaging its sensitive skin. Return it to the water quickly and gently to minimize stress. Avoid excessive handling and only take it out of the water if necessary.

The main predators of the Northern lamprey in Quebec include some larger fish, such as pike and walleye, as well as aquatic birds such as herons. Young ammocoetes can also be preyed upon by small fish and aquatic invertebrates.

The Northern lamprey is not considered threatened in Quebec. It benefits from some protection due to regulations on water quality and the conservation of aquatic habitats. Although it is not targeted by recreational fishing, it is important to respect its habitat to maintain the ecological balance of the rivers and lakes where it lives.