The black-spotted goby is an invasive species that has appeared in the waters of Quebec, particularly in the Saint Lawrence River and its tributaries. Native to the Black Sea and the Caspian Sea, this small fish has rapidly colonized the Great Lakes and has spread to Quebec. Although it is not a prized target for sport fishing due to its small size and weak fight, the black-spotted goby plays an important role in the ecosystem as an aggressive competitor for food resources. Its presence is a concern for local biodiversity, but it can offer an interesting catch for anglers curious to discover this invasive species.

The black-spotted goby is a small fish, typically measuring between 12 and 20 cm, with an elongated and robust body. Its color varies from brown to gray, often with distinct black spots that give it its name. Its head is broad and flattened, with a large mouth oriented downward, equipped with thick lips. The pectoral fins are large and fan-shaped, while the dorsal fins are separated into two distinct parts. The caudal fin is rounded. The scales are small and rough to the touch. Young gobies are often paler than adults and have fewer spots. During the spawning period, males develop darker coloration and more pronounced nuptial spots to attract females.

In Quebec, the black-spotted goby is primarily found in the Saint Lawrence River and its tributaries. It is also found in some lakes where it has been accidentally introduced. This species is particularly abundant in areas where the bottom consists of rocks and gravel, as it uses these structures for hiding and feeding. The black-spotted goby is absent from waters far from urban and industrial areas where its introduction has not yet occurred.

The black-spotted goby prefers freshwater and slightly brackish waters with a rocky or sandy bottom. It is often found at depths ranging from 1 to 15 meters, although it can venture deeper in search of food. This fish is highly adaptable and can survive in varying temperature and salinity conditions, allowing it to quickly colonize new habitats. To locate it, look for it near submerged structures like docks, rocks, and debris, where it feeds and hides.

The life cycle of the black-spotted goby begins in the spring when water temperatures rise. Spawning occurs between May and July, when males dig nests in the rocky or sandy substrate. Females then lay hundreds of adhesive eggs that males guard jealously until hatching, about 10 to 15 days later. Young gobies grow rapidly and reach sexual maturity in one to two years. The longevity of this species is relatively short, with an average lifespan of four to six years.

Spring → Spawning → Summer → Growth → Fall → Hibernation → Winter → Lethargy

The black-spotted goby is a territorial and aggressive fish, especially during the breeding season. It is often solitary but can be observed in small groups when feeding. This fish is very resistant to environmental changes, allowing it to quickly adapt to new conditions. It reacts little to noise and disturbances but prefers calm waters that are not disturbed by currents or strong winds. Light does not seem to have a significant impact on its behavior, although it is more active at dusk and dawn.

The diet of the black-spotted goby is varied and opportunistic. Young gobies primarily feed on zooplankton and small aquatic invertebrates. As they grow, their diet expands to include mollusks, crustaceans, aquatic insects, and even small fish. In winter, feeding activity decreases, but they continue to feed on available prey in their immediate environment.

The black-spotted goby is active year-round, although its activity is more pronounced during the warm months. In spring, it prepares for spawning by seeking partners and defending nests. In summer, it is easier to spot due to its constant search for food. In fall, its activity decreases slightly, but it continues to actively feed to build reserves for winter. In winter, it becomes more lethargic and often hides under rocks or debris to protect itself from the cold. The best times to fish for it are early in the morning and late in the afternoon, especially in overcast weather or just after a light rain.

For the black-spotted goby, natural-colored lures like brown, olive green, and gray are the most effective. In murky waters, opt for brighter colors or lures with shiny elements to attract attention. In clear water, stick to neutral tones and mimic natural prey as closely as possible. Small-sized lures are preferable to match the size of the food it usually consumes.

To fish for the black-spotted goby, a light to ultra-light rod of 6 to 7 feet is ideal. Opt for a rod with a fast action to better feel delicate bites. A light reel with a line capacity of 4 to 8 lb is sufficient. Use small hooks, between #8 and #12, and a fluorocarbon leader for discretion. Ensure your gear is sensitive enough to detect the subtle bites of this small fish.

When handling the black-spotted goby, use wet hands to minimize stress and avoid damaging its delicate skin. For release, ensure it is well-oxygenated before letting it go. For a photo, hold it firmly but gently, avoiding pressure on its internal organs.

The main predators of the black-spotted goby in Quebec include yellow perch, pike, and some piscivorous birds like herons. Young gobies are also vulnerable to larger predatory fish such as bass.

The black-spotted goby is an invasive species in Quebec, and its management is crucial to protect local ecosystems. It is often recommended not to release it back into the water once caught to limit its spread. Check local regulations, as they may vary depending on the areas and conservation goals.