Taxonomy & naming
Ogilby and McCulloch described the species in 1916, and it is now placed in Hephaestus, the genus Gill erected for the large Australian and New Guinean freshwater grunters of the family Terapontidae. The type locality is the upper Gregory River in northern Queensland. Older books file it in Hephaestus or in Scortum; the Catalog of Fishes lists the current genus.
Morphology
A heavy-bodied grunter, dark grey to nearly black in life, which is the source of the common name. FishBase gives a maximum length of 13 in TL. Grunters take the name from the sound they make with the pharyngeal teeth.
Habitat
FishBase lists the habitat as freshwater and benthopelagic, with a temperature range of 25 to 30 C, and describes the species as endemic to Australia. It occurs in rivers and streams of the tropical north.
Feeding
The species is carnivorous. In captivity it takes whole prawns, earthworms, fish pieces and live fish small enough to swallow, and it accepts large sinking pellets once settled.
Mating
Courtship and spawning behaviour are not described in the sources available to the atlas.
Breeding
FishBase notes that the eggs are guarded and fanned by the male parent. Clutch size and incubation time are not recorded.
In the aquarium
A species for a large tank, from about 80 US gal for a single fish, with strong filtration, hiding places and robust decor. It will eat any tank mate small enough to swallow and can bully others of similar size, so keep it with large, fast fishes or on its own. Keep it warm, within the 25 to 30 C that FishBase gives.
Conservation
The IUCN Red List classes Hephaestus carbo as Least Concern, last assessed in February 2019.