Order Siluriformes
Family Armored Catfishes ( Loricariidae )
Subfamily Hypostominae
Genus Hypostomus.
Distributed in northern and central parts of South America, from Guyana, Venezuela, Colombia, Peru to Central Argentina. Inhabit water bodies with various water types – white, clear, and black water, as well as mountain streams, ascending up to 1000 m above sea level.
— Hypostomus commersoni [Valenciennes, 1836]. Synonyms: Hypostomus, Plecostomus limosus, Hypostomus, Plecostomus spiniger. Brazil, Paraguay, and Uruguay. 40 cm, in aquarium up to 30 cm. Body brown or dark gray with small spots. Has 2 subspecies. Requires transparent, clean, moving water with high oxygen content. Territorial towards conspecifics.
— Hypostomus plecostomus [Linnaeus, 1758]. (Eng. Armor Plated Catfish, Suckermouth Catfish). Northern part of South America, range from Panama to Uruguay, widely distributed throughout the Amazon River basin. 25-30 cm in aquarium. Has an elongated body covered in 4 rows of bony plates everywhere except the belly. Has a large head that grows larger with age, small eyes set high on the head.
One of the anatomical features of plecostomus is the presence of a special membrane on the eye, resembling the diaphragm of a microscope or camera. This membrane allows controlling the illumination level of the eye: during the day it covers almost the entire eye, while towards night it gradually opens.
Gray-brown, brown, or brownish with a greenish tint body covered with dark spots and patterned stripes. Pectoral, dorsal, and caudal fins are well developed and match the body color. Plecostomus has a tall, long, beautiful dorsal fin and a moon-shaped caudal fin. The first ray of the dorsal and pectoral fins features sharp spines used as a deterrent and defense weapon.
The caudal fin is asymmetrical – the lower lobe is longer than the upper. The male is brighter, leaner than the female, with small spines on the pectoral fins. There are no horn-like growths on the head. Albino and pied forms exist. Similar species include: Pterygoplichthys multiradiatus, Pterygoplichthys pardalis, Glyptoperichthys gibbiceps.
They grow rapidly, hence a large aquarium is necessary, and a 100-liter tank inevitably becomes insufficient. A crepuscular fish, but they are not bothered by bright aquarium lighting during the day. Its daytime apathy is more than compensated by the activity with which this tireless night worker cleans the aquarium of algae. The natural diet of plecostomus consists ofaufwuchs on leaves, stones, and driftwood.
Live foods thrown into the aquarium for other fish do not distract them. Driftwood and other decor are necessary to provide caves and shelters to hide during daylight hours. Driftwood is also needed to obtain cellulose from wood, which is essential for their digestive process.
At the slightest fright, it immediately burrows into the substrate or hides in plant thickets. Soft sandy substrate is preferred. It can spend hours crawling “on its belly” from one shelter to another. With age, the temperament of the plecostomus worsens: it becomes selfish, especially when its territory is infringed upon, and it approaches its aquarium-cleaning duties with considerable laziness.
They will also defend their favorite spots from other fish species with similar habitat requirements. They do not disrupt the decorative composition of plants, stones, and driftwood in the aquarium, and do not harm leaf tissues.
When young, plecostomus is quite tolerant, at least towards fish of other species – only fighting with its own kind all the time (unless raised together from an early age) – whereas in adulthood, it is known for pranks that are not entirely harmless to other fish: it may latch onto someone with its powerful sucker-mouth and cruise around riding on another fish’s back. A large aquarium with hard-leaved plants is required.
This is one of the hardiest and most resilient of all catfishes, growing very quickly. Not particularly demanding regarding maintenance conditions, it nonetheless prefers water with a neutral or slightly acidic pH reaction and medium hardness. Good filtration and regular water changes are essential due to the large amount of waste produced by this catfish. Without plant matter (which should make up at least 60% of the diet), the fish become weak and sometimes simply perish.
The diet should include vegetables, blanched spinach, lettuce, peas. Bloodworms, tubifex, enchytraeids, etc., play only a supplementary role in feeding plecostomuses. Feeding should be done just before lights out. They mature at 3 years of age. Eggs are laid in a pipe or ceramic pitcher placed vertically. The male guards the offspring until the fry leave the shelter. They grow rapidly. Lifespan up to 12 years. pH 6.5-7.5; dH 3-12°; T 22-26°C.
— Hypostomus punctatus [Valenciennes, 1840]. Rivers of southern and southeastern Brazil, acclimatized in Cuba, Indonesia, Thailand. 26 cm. Very similar to the sailfin catfish, but the dorsal fin is less developed, coloration is lighter, without a reticulated pattern. A large number of small brown spots are scattered across the body. The male is leaner than the female, with small spines on the first rays of the pectoral fins. Growths on the head appear only during the spawning period and then disappear. Albino and pied forms exist.
Peaceful, solitary catfish. Lifestyle: crepuscular and nocturnal. Timid. Does not harm even small neighbors. Vegetation and certainly driftwood are needed to provide ballast and cellulose necessary for digestion. Large, robust live plants that should be planted only in pots. Driftwood, stones, and various shelters are necessary. Powerful filtration, aeration, weekly water changes. pH 7.0; dH up to 20°; T 22-28°C.
Identification: Genus Hypostomus.
Peckoltia braueri, brevis, compta, sabaji, vittata.
Aphanotorulus ammophilus, Orinoco Leopard Catfish. 
