The black dogfish, also known by its scientific name Centroscyllium fabricii, is a small luminescent shark that primarily inhabits the deep, cold waters of the North Atlantic, including areas of the Gulf of Saint Lawrence in Quebec. Although it is not a common target for sport fishing due to its inaccessible habitat and modest size, it still piques the interest of curious anglers and researchers because of its unique adaptations to life in the abyss. Its ability to emit light (bioluminescence) makes it fascinating and mysterious, but it is rarely caught on a line, making it a challenge for anglers passionate about marine diversity.

The black dogfish is a small shark, typically reaching about 60 to 100 cm in length at adulthood. Its body is slender and fusiform, designed for efficient swimming in deep waters. It has a black or dark brown color that allows it to camouflage in the darkness of ocean depths. A distinctive feature is its bioluminescence, with photophores along its body that emit a faint glow, likely used for communication or hunting. Its head is broad with a rounded snout, and its mouth is lined with small, pointed teeth. The pectoral fins are relatively large compared to its body, while its dorsal fin is spiny, without a distinct lower lobe. Males and females are similar in appearance, although females are often slightly larger. Juveniles exhibit similar characteristics to adults but with slightly different body proportions.

In Quebec, the black dogfish is primarily found in the Gulf of Saint Lawrence and the deep waters of the North Atlantic. Although it is widely distributed in these regions, it is rarely observed due to its preferred habitat, often located at depths greater than 200 meters. This species is absent from shallow and coastal waters, preferring cold and dark areas where pressure is high. Outside Quebec, it is found throughout the North Atlantic, from Greenland to the European coasts.

The black dogfish is a deep-sea dweller, preferring areas between 200 and 1500 meters deep. It is generally associated with continental slopes and seamounts, where it can find stable conditions and prey suited to its diet. The water temperature in these habitats is cold, typically between 2 and 6 °C, which corresponds to its optimal environment. To locate it, one must search in waters away from the coast, where daylight does not penetrate, creating a dark environment conducive to its bioluminescence.

The black dogfish has a relatively long life cycle for a small shark, reaching sexual maturity around 6 to 8 years of age. Its reproduction is ovoviviparous, meaning the eggs hatch inside the female's body, which then gives birth to live young. Litters are generally small, with only a few young per reproduction. The growth of the young is slow, allowing them to gradually adapt to their deep and demanding environment. Its longevity can reach 20 to 30 years, allowing it to adjust to variations in its habitat.

Spring → Mating → Summer → Embryonic Development → Autumn → Birth of Young → Winter → Slow Growth in the Depths

The black dogfish is primarily solitary, although it can sometimes be observed in small groups, especially during breeding periods. It is not territorial, which is common among species living in vast and sparsely populated environments. Its reactions to external stimuli like noise or weather changes are limited due to its deep habitat, where light and temperature variations are minimal. However, it may be sensitive to vibrations, which could influence its interactions with other fish or its response to predators.

The diet of the black dogfish primarily consists of small fish, crustaceans, and cephalopods, which it hunts in the dark thanks to its bioluminescence. Juveniles feed on smaller organisms, such as zooplankton and fish larvae, before moving on to larger prey as they grow. Its diet does not vary much according to the seasons, as its deep habitat offers a constant availability of food.

Fishing for the black dogfish is not seasonal in the traditional sense, as it lives at depths where seasonal variations in temperature and light are negligible. However, the best time to attempt to observe or fish it is in the summer, when sea conditions are calmer and access to deep-sea fishing areas is easier. The time of day does not affect its behavior due to the permanent darkness of its habitat. Surface weather conditions, such as atmospheric pressure and wind, have little impact on this species.

For the black dogfish, which lives in darkness, luminous lures are useless. Favor natural baits like squid or dead fish, which emit a strong odor to attract this species. Colors do not play a significant role due to the absence of light in its habitat. However, using materials that emit vibrations in the water can be beneficial to attract the attention of this discreet shark.

To fish for the black dogfish, use a sturdy rod of 2.5 to 3 meters, with heavy power to withstand the pressure of the depths. Opt for a robust drum reel, capable of holding enough line to reach great depths, often beyond 200 meters. A 50 lb line is recommended for its strength. Hooks should be strong, preferably stainless steel to resist corrosion, and steel leaders to prevent cuts from the sharp teeth of the dogfish.

When handling the black dogfish, be cautious with its dorsal spines. Use gloves to avoid injuries. If you wish to photograph it, do so quickly to minimize stress. For a successful release, ensure the fish is well oxygenated before gently releasing it back into the water, head first, to allow it to quickly return to the depths.

The predators of the black dogfish are mainly other larger sharks, such as the Greenland shark. Sperm whales, which dive to great depths, may also feed on these small sharks. Due to its deep habitat, it has no avian predators in Quebec.

The black dogfish is not considered an endangered species in Quebec, but it is sensitive to pressures from commercial deep-sea fishing. The management of this species relies on population monitoring and regulation of bycatch. Release is encouraged for accidentally caught specimens to preserve natural populations.