The rock grenadier is a deep-sea fish that primarily inhabits the North Atlantic Oceans. In Quebec, its presence is limited to the saltwater of the Gulf of St. Lawrence, where it is not particularly sought after for sport fishing due to its depth of habitat and low fighting ability. However, it is of interest to researchers and commercial fishermen because of its flesh. This fish is known to live at depths ranging from 180 to 2,200 meters, making it difficult to target for recreational anglers.

The rock grenadier has an elongated, fusiform body, ending with a slender, pointed tail. Its head is relatively large with prominent eyes adapted to the low light of deep waters. Its body color ranges from gray to dark brown, with a lighter belly. Its dorsal fins are long, and the first is often higher than the second. The scales of the rock grenadier are small and rough. Young grenadiers have a similar appearance to adults, although their body is more slender. There is no obvious sexual dimorphism between males and females, even during the spawning period.

In Quebec, the rock grenadier is primarily found in the Gulf of St. Lawrence, particularly in deep areas off the eastern coast. It is especially abundant in cold, deep waters, beyond the reach of recreational fishermen. Its global distribution extends in the North Atlantic, from New England to Norway, including the seas surrounding Iceland and the Faroe Islands.

The rock grenadier inhabits salty and extremely deep waters. It is mainly found on continental slopes, at depths generally ranging from 180 to 2,200 meters. It prefers cold waters, often around 2 to 4 °C. This fish feeds near the seafloor, where it finds its food among sediments and rocky structures. Fishermen rarely target it due to these difficult access conditions.

The life cycle of the rock grenadier is marked by slow growth and an exceptionally long lifespan for a fish. Spawning occurs in deep waters, where females release floating eggs that drift in the currents. The larvae, once hatched, feed on plankton before descending to the depths. Sexual maturity is reached between 7 and 9 years, and individuals can live up to 30 years. Spring → Spawning → Summer → Larval growth → Fall → Migration to depths → Winter → Sexual maturity

The rock grenadier is a rather solitary fish that is not particularly territorial. It moves slowly in the depths of the ocean in search of food. Due to its habitat, it is little affected by changes in weather conditions or light. It is adapted to live in high-pressure and low-light environments, which influences its discreet and slow behavior.

The diet of the rock grenadier mainly consists of crustaceans, small fish, and cephalopods that it finds near the seafloor. Young grenadiers consume more plankton and small invertebrates before switching to a more carnivorous diet as they grow. Seasons have little influence on its diet, although the availability of certain prey may vary slightly.

The rock grenadier is a deep-sea fish, and its availability for fishing is therefore limited by depth and ocean conditions. It is more active in areas where the temperature remains constant throughout the year, as is the case in the deep waters. Surface weather conditions have little impact on its capture, but commercial fishermen may target this fish in the summer when navigation conditions are more favorable.

To target the rock grenadier, lures are generally not used due to the extreme depth at which it lives. However, if necessary, natural baits such as pieces of fish or squid are preferred. Colors matter little, as light does not penetrate at these depths.

To fish for the rock grenadier, a sturdy rod designed for sea fishing is essential, with a length of 2.4 to 3 meters. A spinning reel capable of handling a line of 50 to 80 lb is recommended. Hooks should be strong, size 4/0 to 7/0, with a leader made of steel or 100 lb monofilament to withstand pressure.

Handling the rock grenadier should be done carefully due to its size and deep habitat. If you plan to release it, do so quickly to minimize stress. Take photos while supporting the fish under its belly to avoid damaging its internal organs.

In the depths of the ocean, the rock grenadier has few natural predators due to its habitat. However, some large sharks and other deep-sea predatory fish may prey on younger grenadiers.

The rock grenadier is not currently considered endangered in Quebec, but its commercial fishing is regulated to avoid overfishing. Quotas are in place to ensure the sustainability of populations. Catch and release is encouraged for incidental captures during commercial fishing.