The black scabbardfish is bathypelagic by day, but moves upwards in the water column at night to feed at middle depths on crustaceans, cephalopods, and other fishes, mostly grenadiers, codlings (family Moridae) and naked heads (family Alepocephalidae).

The narrow, elongated body of the black scabbardfish, along with its pointed head and long dorsal fin, is adapted for fast swimming.

[4] In general, the size distribution moves towards higher values from north to south of the Northeast Atlantic.

The lifecycle of black scabbardfish is unknown, but the most common hypothesis is that one single stock undertakes a large-scale clockwise migration around the Northeast Atlantic.

The juvenile black scabbardfish stay to feed and grow for a few years in the fisheries south of the Faroe Islands and the west of the British Isles.

It is also a total spawner, meaning that it releases all of its eggs in one single event per breeding season.

The mature and spawning adult fish have only been observed in the last quarter of the year in certain locations including Madeira, the Canaries, and the northwest coast of Africa.

The gonadosomatic index is higher for the same body length in the black scabbardfish located around Madeira as opposed to off mainland Portugal or to the west of the British Isles.

[10] Consumption of raw or undercooked black scabbard fish can result in health complications for humans.

The only reliable treatment for a human affected with anisakiasis is the removal of the nematodes through endoscopy, or surgery.

Upon reaching adulthood, they then move south again to the waters off Portugal until they are of reproductive maturity age and return to their spawning grounds.

[12] The black scabbardfish is of economic importance to fisheries associated with countries of the Iberian Peninsula, and especially the Madeira Islands, where they are prized for food.

The black scabbardfish, along with the crab, are the two most sought-after sea products for consumption in the Madeira Islands and Portugal, so play a significant economic role in these locations.

[14] Despite having huge market value and a strong hold in the typical Southern European diet, several health risks are associated with consumption of the black scabbardfish due to the presence of several toxic metals found within the fish, including lead, mercury, and cadmium.

Eating raw or undercooked black scabbardfish could result in a parasitic infection known as anisakiasis, and the only way this condition can be treated is by removal of the nematodes through endoscopy, or surgery.

They are mainly caught in mixed trawl fisheries along with other deep-water species, and are highly vulnerable to overfishing.