Order Siluriformes
Family Loricariidae
Subfamily Ancistrinae
Genus Ancistrus.
— Ancistrus hoplogenys [Gunther, 1864]. Synonym: Ancistrus alga, tectirostris, Chaetostomus hoplogenys, alga, malacops, tectirostris, Xenocara hoplogenys. (L 059, L 182). Amazon River. 12 cm. Main background is dark brown or black with white spots scattered across it, which become brownish-white with age; the caudal and dorsal fins have a white border.
With age, the white border on the fins disappears, but the “starlight” pattern becomes more distinct — numerous small whitish-bluish dots with a black halo scattered across the dark body and fins. Females are paler and plumper than males, moreover, the latter begin to develop skin growths on the tip of the snout at 7-10 months of age. Ancistrus leucostictus is very similar to this species. There is also A. hoplogenys “Red” – Red starlight Ancistrus. Their dorsal and caudal fins have scarlet or intensely red borders.
A peaceful fish, but intraspecific aggression may occur, especially in case of food scarcity or in small aquariums during spawning. Males are territorial. Unpretentious. These are nocturnal fish; they become active at dusk and during the day when atmospheric pressure drops. In a brightly lit aquarium during daytime hours, they tend to hide in plant thickets or driftwood hollows. Vegetation and mandatory driftwood are needed to provide ballast and cellulose necessary for digestion. Plant food should make up at least half of the diet.
The catfish not only helps combat certain algae, but also eats up food particles that have fallen to the bottom and been ignored by other fish. Aeration, filtration, and water changes are mandatory. When kept on a light substrate and when frightened, the coloration changes to brown with dark brown spots. Filtration, aeration, weekly water change. They grow slowly. Fish reach sexual maturity after one year. pH 5.5-7.5; dH 2-20°; T 22-26°C.
— Ancistrus ranunculus [Muller, Rapp Py-Daniel & Zuanon, 1994]. (Medusa Pleco). (L 034). Brazil, Xingu River, Tocantins. 12-14 cm. A somewhat strange species with a characteristic large wide head taking up almost the entire body and a flat body profile; it received the name medusa due to the large and numerous tentacles in 3 rows on its snout. Only males fully develop dense tentacles on the head. Healthy catfishes are completely black, without any spots. A faint red-brown sheen may appear on the tentacles.
Unfortunately, this fish is not the easiest to keep in an aquarium and is not suitable for inexperienced aquarists. The species is very secretive, leads a nocturnal lifestyle, and can go unnoticed for weeks. They prefer narrow crevices and small passages among underwater rocks, or hide under flat rocks at the bottom. Hiding places should match the body shape, very low flat caves made of clay or slate. Males occupy caves and decisively defend them against other males. Territorial from a very early age.
Optimal keeping conditions are of great importance — strong filtration, enhanced water flow, weekly water changes, and good nutrition. The water should be soft, slightly acidic, well oxygenated with strong current from a pump. Unlike other ancistruses, they prefer food richer in proteins, so they are fed tablets and pellets with regular servings of live and frozen foods such as bloodworms, chopped mussels, shrimp, etc. Aquarium glass is not cleaned. pH 6.0-7.0; T 25-29°C.
— Ancistrus temminckii [Valenciennes, 1840]. (Bristle Nose Pleco, Bristle Nosed Catfish) Brazil, Guiana, Suriname. 11 cm. Beige-brown with a dark honeycomb pattern and light spots on the body and fins. The belly is lighter in color, but also with contrasting spots. The male has a brush of whiskers on his cheeks. Albino and pied forms exist.
Vegetation and mandatory driftwood are needed to provide ballast and cellulose necessary for digestion. With age, they scrape off algae less effectively, especially if overfed with live food. These are nocturnal fish; they become active at dusk and during the day when atmospheric pressure drops. Aeration, filtration, and water changes (at least a third of the volume weekly) are mandatory. They mature at 10-15 months. pH 6.5-7.5; T 22-30°C.
Ancistrus leucostictus, Ancistrus multispinis.
Ancistrus cirrhosus, claro, dolichopterus. 
