Bristlenose pleco (Ancistrus dolichopterus)

Bristlenose pleco (Ancistrus dolichopterus) is one of the most spread species in the family Loricariidae, it’s a very popular tank fish. Both beginners and experienced aquarists know about it and keep it. Ancistrus has caught such close interest due to its features: the fish is called a “tank cleaner”, it’s easy in care, its behavior is quite extraordinary, its cupule-mouth structure makes it remarkably different from a number of other fishes.

Inhabitance in the wild

The fish is native to South America, especially often it can be seen in the Amazon river basin. In habitat of Loricariidae family catfish the water most of the year has the following parameters: hardness — 4—5 °dH, acidity (рН) — about 6. The flow is relatively fast, the water is oxygen-rich.


Bristlenose catfish has flattened plain body completely covered in polyangular bony plates. Its body has a pair of pectoral and abdominal fins. Its roundish mouth and elongated lips with horn cupule is especially interesting, these cupule help the fish to live in fast flowing waters by sucking on stones and snugs. There are some horn buds on the fish cupule (sometimes they are called a “grater”) meant for scrubbing some plant fouling and animal substance from plants, stones and other surfaces in a tank. In the wild these are the main source of food for Bristlenose catfish.

Ancistrus doesn’t have a sound and that’s why the fish can’t stay for a long time in water as other fishes do. Therefore, to swim for some distance without scrambling any objects with its cupule the catfish has to use its fins rather actively.

Bristlenose catfish is one of the smallest tank catfish: its size is in the range from 8 to 15 cm (3,15-7 inches), but usually even the male fish size doesn’t exceed 15 cm (5 in). Lifespan 5 years and more.T he adult fish body is usually of dark-brown color or more seldom it’s grayish (the coloring also may have some spots of brighter colors) with promiscuously scattered small bright spots which turn into lines on the fish fins. The bottom abdomen side of the fish body is a bit brighter than its back side.
There is also albino bristlenose pleco and longfinned albino bristlenose pleco – it doesn’t differ from the ordinary one but for the coloring and the fins length. Moreover, common Bristlenose catfish may have albino or longfinned Bristlenose pleco in their spawn.


The fish is a territory dependent one, however this concerns only the fish of the same kind. Bristlenose catfish males start fighting for territory and the one that is larger makes the smaller one leave. As a rule bristlenose catfish doesn’t start in with other tank mates, but if the fish is hungry it may suck on fishes without scales. Bristlenose catfish is compatible with any fast and active fishes that swim in the middle water layer.


Ancistrus is considered to be a plant feeder. Namely this feature of the cupule makes this catfish an irreplaceable one to deal with fouling on tank glass and decorations. Due to the unique structure of its mouth Ancistrus scrapes any small fouling. Thus, we can say that the fish isn’t demanding as for the feed and it can find food on its own. However, this doesn’t mean that the aquarist doesn’t have to feed the fish. Ancistrus diet has to consist on 70-80% of plant food and 20-30% of protein. It’s important to have some snag in a tank because by sucking it around the catfish gets lignin, which is important for its digestive system.

When there’s not much fouling in a tank, the fish may start eating tank plants and usually young and soft leaves suffer from this, the fish gnaws holes in them or just eats them completely. To avoid this it’s advisable to give some additional plant feeding to Ancistrus. The easiest way is to feed it with some branded food with plant components. Also you may use some parboiled lettuce leaves (it’s enough to put them into boiling water for 1 minute), or it may be cabbage leaves or a cucumber (cut it into pieces and also put into boiling water on a fork).

Keeping in a tank

Here are the most optimal conditions to keep this fish in a tank successfully: water temperature should be about 24 °C (75 F), dH — up to 20—25°, рН — in the range from 6,5 to 7,5. Water renew should be done at least weekly – ¼ of old tank water should be renewed with fresh water. Tank capacity should be more than 25 gallons, but the tank bottom has to be large with lots of shelters. Ancistrus prefers shadowed tank areas which should be taken into account when designing the tank. This fish swims almost all the time looking for some live or plant food leftovers on the tank bottom. This catfish likes being in the water flow area which is created by the pumps of tank filters. It’s important to keep in mind that the fish may get inside the filter and die, that why it’s recommended to get the filter output tube up at some distance from the tank bottom or close it with some grid.

This catfish gets used to new tank conditions quite easily, and what’s interesting, is that Bristlenose pleco juveniles at the age of 2-6 month adapt faster than adult fish. When buying Bristlenose pleco juveniles you should ask about the tank conditions where they used to live and about the feed they were given there. During their first week in a new tank it’s better to keep the same hydrochemical conditions.

Scientific Name Ancistrus dolichopterus
Common Name Bristlenose Pleco, Bristlenose Catfish, Bushynose Catfish, Brushmouth Pleco, Common Bristlenose, Common Bristlenose Catfish, Veiltail Bristlenose, Piebald Bristlenose, Albino Veiltail, Golden Ancistrus
Tank size 25 gallons (100L) and more
Temperament Territorial, peaceful
Diet Omnivorous bottom feeder
Temperature 75–81 °F (24–27 °C)
pH 6.5-7.5
Size 6 inches (15 cm)

Sex differences

It’s easy to see between Bristlenose pleco female and male! The male fish has some multiple outgrowths along its head, due to which the fish has got its name. The female fish has these outgrowths only along the head edges, they are ill-developed or they are missing at all. Besides, the male fish are much larger than the female one and they are more aggressive.

Male (left) and female

Male (left) and female


It’s easy to breed Ancistrus, quite often they spawn in a community tank, however, as a rule, their juveniles don’t have any chances to survive in such conditions. Usually the fish lays its eggs in some slits in a tank or in tubes, quite often they may do this even behind the water filter and if they can get inside it, so they’ll spawn there. Demolishing the common view that this fish doesn’t have any parental instinct, Ancistrus male eagerly takes care of their eggs and newborn juveniles. After the female fish lays some bright orange large eggs, the male fish starts taking care of them by cleaning them with his mouth, dusting them with his fins and guarding from all possible dangers including the female fish herself.

For purposeful breeding we usually use a separate tank of not less than 20 gallons capacity without any bottom substrate or plants. You should put some ceramic or bamboo tubes, or stones, or snags in it. The moment when the fish is ready to spawn is defined by the level of how Ancistrus female gets fat – if a hungry female fish looks like an aerostate – so, it’s about time to put her spawning. The water for spawning tank is taken from the same tank where Ancistrus used to live. To stimulate spawning add 1/3 of fresh defecated water into it and decrease the water temperature a bit (about 2°C lower). Sometimes the fish start spawning the very next day and more often the male fish spends several days looking for some proper from his point of view tube or slit and cleans it thoroughly this way preparing the place for his future nest. At the same time you can feed the fish right in the spawning tank and it’s better be some plant food. However, don’t forget to remove food leftovers to prevent them from rotting somewhere in the tank.

Bristlenose pleco spawning itself usually happens at night. The female fish lays from about 30 to 200 eggs, their number depends only on the female fish size and age. So, if it’s her first spawning, don’t expect to get high productivity. The eggs stuck to the surface that was prepared by the male fish in advance and after that the female fish is driven out and the male fish starts guarding his spawn. The female fish should be taken away from the tank as fast as possible, since she makes the male fish nervous and he attacks her all the time and may even kill if the tank isn’t spacious enough.

The eggs grow for 4-7 days (it depends on the water temperature, so to speed up the eggs growth you may rise the water temperature after spawning up to 26-28 °C (78-82 F)), and all this time Bristlenose pleco male continuously guards the eggs without even leaving them to get some food.

In case of Bristlenose pleco spontaneous spawning in a community tank you may take the eggs together with the male fish into some separate volume, especially it’s easy when the spawning has happened in a tube. If the eggs were laid directly on the tank glass or somewhere behind the filters or stones (this also happens), you should carefully cut it off with a blade and put into a separate volume.

Don’t be afraid of the fact that the eggs were exposed to air for some short period of time – this won’t do any harm to them. But in this case don’t put the male fish together with eggs, since after the stress he has suffered he stops taking care of the eggs and may even eat them.

Large larvae that hatches out have large yolk sac and for several days they stay together in a bunch, after that they start swimming around the tank little by little. Since this moment you should take away the male fish from the tank, too, and give some first food to the juveniles. You may use different dry feed for juveniles, it’s especially comfortable to feed them with different tablets made for catfish. The juveniles just stick all over the tablet and gnaw it. Those of them, who didn’t get to the tablet, swim fussy around it and eat some crumbles that fall on the tank bottom and try to get closer to the food source.

Provided with regular feed (at least 3 times a day) and daily water renew ( 20% of all water volume) Bristlenose pleco juveniles grow very fast and at the age of 6 month they become almost as large as their parents are. The juveniles become adult and reproductive approximately starting from the age of 10 month, so this is also their breeding age.