ancistrus It is a gender de peces de sweet water family Loricariidae, order Siluriformes. They are the well-known small plecos that become authentic background protagonists of the aquarium. Their morphology allows them to adhere to surfaces and explore corners where other fish can't reach, earning them a special place in well-planned community aquariums.
They have a mixture of rarity and variety which makes them popular among aquarists of all levels. If you want to know their biology, how to differentiate them by sex, what their ideal parameters are and the key care to keep them healthyBelow you have a complete guide with practical and proven recommendations.
Key features
As bottom fish, they share a stratum with the corydoras, and a pair of ancistrus It is often the perfect complement. In aquariums with dull lower areas, its activity increases the aesthetics and dynamism of the whole, colonizing caves, trunks and nooks.
The body is covered by bony plates (dermal shields) except on the belly, which gives them great protection. The mouth is a subterminal sucker which serves to adhere to currents and scrape biofilm, algae, and wood. This design explains their durability and their role as efficient scrapers of the tank's ecosystem.
In size, males usually reach approx. 15 cm, and the females around 10 cm. In addition to size, the sexual dimorphism It is evident: males develop barbels (odontoids) on the snout; in females, if present, they are shorter and more peripheral. These odontoids may also appear on the spine of the pectoral fin in some adult males.
Other notable morphological features: dorsal fin with eight branched rays, hard spiny rays on several fins (except the adipose and caudal fins), broad head with a downward-curving snout and a robust caudal peduncle. Its coloration varies from brown to dark gray or black, with light spots irregular; they can modulate their tone thanks to retractable chromatophores, adapting to the light and the environment.
In aquarium, many species and varieties are kept between 9 and 10 cm, although there are selected forms (for example, veil) that appear more present. With good handling, its Life expectancy can easily overcome 10 years.
Habitat and area of ​​distribution
Its origin is located in the amazon basin and various rivers of South America. They inhabit stretches with well-oxygenated stream and abundant structure (roots, rocks and trunks), where algae and biofilm proliferate. In many biotopes the water is rich in tannins due to the presence of decomposing plant matter, although there are also species and populations adapted to clearer waters.
They are found in fast-flowing tributaries and areas with islands of vegetation, as well as in substrate areas clayey or silty. These bottoms are interesting for two reasons: they make digging easier burrows and contribute minerals that the fry use during growth. On the South American map, in addition to the Amazon and the Orinoco, there are records in rivers such as Meta and in lakes such as Maracaibo y Valencia.
Ideal aquarium
For optimal conditions, it is important to size the tank well. A conservative guideline is to have 80 liters per copy to allow full growth and avoid conflicts. In aquariums with a large surface area, powerful filtration, and abundant refuges, some keepers keep 1 male with 2-3 females in about 80 liters, although it is more prudent to offer greater volume to ensure stability and reduce the territorial jurisdiction. If desired two males, an aquarium from 300 liters with well-defined areas.
Ancistrus are bottom-dwelling fish with a tendency to establish territoriesIt is essential to offer multiple hiding places (tubes, caves, stable rock mounts, roots), so that each individual can claim an area and reduce stress. oversized filtration and a good oxygenation They are key: they imitate their natural habitat and help manage their significant organic load.
Recommended parameters: pH 5.5-7.5 (slightly acidic to neutral), GH 2-12 (soft to moderate water) and 22-30 ºC, with preference for 24-28 ºC. Tolerates wide ranges if the water quality is stable. Avoid the use of shawl and take extreme precautions with medications, especially those containing copper or elevate phosphates, as they can be harmful.
As noted, the ancistrus they scrape the wood to obtain cellulose and other plant polymers essential for its digestion. Therefore, it includes trunks (mopani, mangrove, redmoor) and replace them every 2-3 years if they deteriorate.
El fine substrate (highly polished sand or gravel) prevents cuts and minimizes accidental ingestion. Although they may peck at some clay for its mineral content, swallowing substrate continuously is a real danger: can damage the intestinal wall and cause bleedingIf you detect feces with excess substrate particles, check your diet and setup.
As for the equipment, they work very well. external filters high-flow or well-aerated sumps. Add water movement (circulation pump) and prioritizes regular maintenance with partial changes to avoid accumulation of nitrates and organic matter.
Plants in the aquarium
They are fond of shaded areas. The plants of broad blade , the Anubias, Echinodorus y Cryptocoryne They provide cover and establish micro-territories. Avoid very delicate groundcovers or fragile stems in passageways, because ancistrus are vigorous scrapers and can break tender leaves as they move.
If the diet provides enough plant matterThey don't usually harm the flora. Secure anubias and ferns to logs or rocks to help them withstand nocturnal activity. Leave clear areas for water flow and prevent dead zones where debris accumulates.
Meals
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Their nutritional needs are simple if you understand their basis: they are omnivores with a strong herbivorous inclination. Approximately 80% of your diet should be vegetable (algae, biofilm, leaves and vegetables), supplemented with protein occasionallySpecific loricariid tablets and plant-based tablets are useful, but the natural variety makes a difference in color y vitality.
Suitable vegetables: cucumber, zucchini, spinach, peeled peas, pumpkin, carrotYou can blanch them for a few seconds to soften them and secure them with tongs or suction cups. Remove any leftovers after 12-24 hours to avoid ammonia spikes. As a protein supplement, offer it sporadically. Artemia, Daphnia or frozen/freeze-dried foods in small portions.
La wood In the aquarium it is not decorative: it contributes cellulose, vital to the digestive physiology of loricariids. In addition, they require certain minerals; in nature, they obtain them from clay substrates. In aquariums, a complete diet and access to quality logs usually cover these needs. If you detect an appetite for substrate, check dietary deficiencies.
The heces are a good indicator: they should be brown or greenish and somewhat soft. Excessively reddish stools or stools containing grains from the substrate suggest problems. Adjusting the diet immediately prevents serious gastrointestinal damage.
With fry, offers finely chopped vegetables, smooth porridges and micronutrients, always keeping pieces of wood accessible. They feed above all the to become night, so scheduling a main shot at the end of the photoperiod usually works very well.
Reproduction
They are one of the most species accessible to reproduce in captivity. The macho is responsible for the laying care, ventilating and protecting the eggs in a cave of single entryThe female deposits 60 to 150 eggs (deep orange) of around 1.5-2.5 mm, that hatch in 5-6 days depending on temperature. When the fry absorb the yolk sac, they begin to feed themselves and the male abandons custody.
To maximize productivity, you can keep a pair in a separate aquarium. 120 liters, with a lot of wood and several caves (ceramic pipes, PVC or logs with cavities). In large tanks of more than 300 liters, it is feasible to maintain two males with several females if there is sufficient territory. The slightly acidic water and soft usually favors regular laying, which can be repeated every 4-6 weeks if nutrition and environment are adequate.
During spawning, the aggressiveness males' behavior toward other males increases. Ensure shelters and visual separations to avoid direct collisions. If you keep the fry in a community, make sure there are no opportunistic predators. Alternatively, you can remove the cave with eggs to be incubated in a farrowing pen with gentle ventilation, always maintaining identical parameters so as not to compromise embryonic development.
Behavior and compatibility
In communities, they are generally fish peaceful, assets especially of nightThey spend the day in hiding places and emerge when the light fades. With sufficient resources, they rarely cause problems. They are compatible with corydoras, peaceful characids, viviparous calm and other mid-upper column fish that do not compete for bottom position.
The Males They can be territorial with each other. If you keep several loricarids, provide many shelters and visually separate areas from the background. Avoid combinations with background species. highly territorial if the aquarium is small. As a rule, it is not advisable to put them together with fish capable of ingest them due to size difference.
Most common types and varieties
Multiple options are offered in stores color varieties and morphologies: albinos (white or yellowish), gold, super network (orange-reddish) and the velo (elongated fins). You will also see references to codes L (from the specialized literature) as L144 o L183 Starlight (dark body with light spots and edges), and names like Ancistrus hoplogenys (L059)These names refer to populations and patterns specific within the trade and hobby.
It's important not to confuse Ancistrus with species from other genera that are sometimes listed alongside them. For example, Hypancistrus (such as L046 zebra or L333) belong to another evolutionary line, with different requirements and behaviors. If you're looking for an ancistrus for its role as a primarily herbivorous scraper and its easy handling, check out the gender and source information before purchasing.
Maintenance and health
The key to success is in clean and oxygenated water, a diet rich in vegetables and constant availability of wood. Avoid treatments with copper unless strictly indicated and dosed; they are also salt-sensitive. With any medication, reduce the dose and observe the response. Try not to manipulate them with fine mesh nets: odontoids They can get caught; use soft containers or nets.
Watch the heces: Normal color and texture indicate good digestive function. Changes toward persistent whitish stools may suggest parasites intestinal; consult a specialist before medicating. Maintain a routine partial changes regular and siphon the bottom to remove debris without excessively disturbing their territories.
Quick guide to parameters and assembly
Volume: 80 l per specimen as a conservative guide; if forming a harem (1/2-3), more volume and a wider base are preferable.
Parameters: pH 5.5-7.5; GH 2-12; 24-28 ºC recommended.
Filtration: oversized, with good ventilation and some flow.
Decoration: essential logs, caves, stable rocks and broad-leaved plants.
Substratum: fine and smooth; be careful not to ingest too much.
Diet: 80% plant-based (vegetables and tablets) + occasional protein; remove leftovers.
With these guidelines you will have active ancistrus, with intense color y natural behaviors. Planning shelters, providing cellulose and maintaining good water quality are the pillars to enjoy this genre for years, even with regular reproductions in the home aquarium.