Synonyms: Steatocranus elongatus
Physical description: An elongated fish with a cranial lump that is characteristic to the fish included in the genus. The dorsal fin is very much elongated; running from just behind the hump, back to the beginning of the caudal penuncle. The face is "chubby" and the large, lips barely protrude from the rest of the face. Depending on the mood and water conditions, the body coloring changes from a dark, slate gray to a light gray. On the second color "mood," the body is marked with about five, transverse muddy-yellow stripes. The eyes, in well-maintained water, develop a turquoise colored iris.
Size/Length: Males to 4.7" (12 cm), females to 3" (8 cm)
Similar species: A dwarf species, Steatocranus sp. aff. ubanguiensis, has similar coloration, although it grows no larger than 2.8" (7 cm). This species comes from the rapid sections of the Ubanghi River.
Habitat: Central Africa; in rocky areas of the rapid areas of the lower Zaire (Congo) River.
Aquarium: A tank measuring 30" (76 cm) with a capacity of 20-25 gallons (75-98 L) is sufficient. Use a tank having many sturdy rock formations including caves, overhangs, and crevices. The filter used should create strong current to recreate the environment from which this fish comes. Only robust, potted or weighted plants can be used as either the current or this fish burrowing with uproot them. If possible, the ideal set up would have an area of strong current and an area with little or no current. Use good aeration.
Water chemistry: pH 6-7.5 (6.8), 2-15 dH (6), 75-82°F (24-28°C)
Social behavior: A territorial and pugnacious fish. The Blockhead can be combined with a great range of larger fish. Small fish of the upper swimming levels can be kept in a large tank over 40 gallons). Pairs form monogamous bonds for life. If a mate dies, the remaining one will likely live out its life singly. The Blockhead is easiest kept in pairs. During spawning this fish becomes even more aggressive and territorial.
Suggested companions: Tilapia, "Haplochromis," Hemichromis, Synodontis, Polypterus, Distichodus, "Cichlasoma," Pimelodids, Loricarids (Plecos), Eutropius, Butterfly fish, Barbs.
FOOD: Live; insect larvae, crustaceans, aquatic insects, Tubifex; flakes; tablets; plant matter. A greedy eater. SEX: Males are larger with a larger cranial hump on their forehead. The hump is present on the female, although it is not as conspicuous.
Breeding techniques: Use water with a pH from 6.5-6.9, a water hardness from 4-12 dH, and a temperature from 81-84°F (27-29°C). The pair can be bred in a 24" (61 cm) tank with caves or over-turned flowerpots to serve as spawning sites. As many as 150, but more likely 30-60 eggs are laid in a cave or flowerpot. These are carefully guarded by the female, while the male guards the territory (patriarch/matriarch family). The fry hatch and can be fed on Artemia nauplii and dry foods. The parents continue their care for one or two weeks with the female feeding the young.
Breeding potential: 6. Breeding is not especially difficult.
Remarks: An undemanding and amusing fish. Because of its small swim-bladder, the fish moves in a jerky-hops around the tank.
Difficulty of care: 5. a fish with a strong personality that grows on the keeper. Although it is a bit on the aggressive side, the Blockhead is still recommended for many community tanks. Keep up tank maintenance and perform frequent partial water changes.