Bristlenose Plecos are odd looking fish, with bushy beards and beady eyes that deserve a place in your aquarium.
They are top tier algae eaters, peaceful community residents, and fascinating to watch as they busily grazy their way across a tank!
If you’re unfamiliar with these smaller Plecos I think it’s time you got to know them better! This guide covers everything you need to know about Bristlenose Pleco care.
What Are Bristlenose Plecos?
South America is home to several popular aquarium fish. All Plecos call this continent home and are found mostly in the tropical regions of the Amazon and Orinoco River basins.
Bristlenose Plecos are part of the Loricariidae group, which is actually the largest family of catfish of all! These fish are specialized for life in the main current of streams and rivers.
Their rounded, downturned mouths not only securely attach them to hard surfaces in swift current but also work for rasping away at algae and detritus, food sources relatively few fish compete for.
Like Common Plecos, Bristlenose Plecos are excellent algae eaters and easy to find in most pet stores. However they are a better choice for most aquarists and well worth your attention!
Bristlenose vs Common Plecostomus
Since both are members of the family Loricariidae and are commonly sold in the trade as algae eaters it’s worth getting to know the differences between the two types of plecos.
I use the word “type” loosely because both are a mess of different species that are sold under the same name. “Common Plecos” typically refers to Hypostomus plecostomus but there are around half a dozen species sharing that label.
They are all some of the largest species of suckermouth catfish, reaching 18-24 inches when fully mature. As true tank busters and vegetarians that produce copious amounts of waste, adult Common Plecos are unsuitable for all but the largest of aquaria.
Bristlenose Plecos, on the other hand, are mature from 4 to 6 inches, depending on the species. They are also gentler on plants and decorations, whereas Plecostomus have a tendency to eat softer leaves and knock over decorations, especially when startled. Bristlenose Plecos are also less territorial and can even be kept in groups.
Bristlenose Plecos are usually a bit more expensive than Common Plecos in the trade. However their manageable size and personality makes them the better option for the majority of aquariums.
Bristlenose Pleco Care
Medium sized and hardy, Bristlenose Plecos are an attractive alternative for aquarists looking for an algae eater! Here are the essentials to Bristlenose Pleco care!
While not particularly large, Bristlenose Plecos are chunky enough that they need a bit of space, especially when keeping pairs or groups. 20 gallons of space is a minimum for a single 4-6 inch adult, with an additional Pleco per 10 gallons of space.
Bristlenose Plecos are found throughout tropical South America and Panama in tropical streams and rivers. Ancistrus species can be found in both swift flowing headwaters, sluggish forest streams, and the winding course of the Amazon itself.
They can be found even in blackwater habitats along with Discus and Cardinal Tetras, making them great algae eaters for these specialized biome tanks. Water parameters should thus be tropical in temperature, from 74-82F, with a soft to neutral pH (5.5-7.0).
Since many, if not most, Bristlenose Plecos are captive bred these days they are tolerant of water on the hard side as well, up to pH 7.5. Still, soft water improves immunity, appetite, and is essential for reproduction.
Ammonia, nitrite, and nitrate should be close to 0ppm, as always, however Bristlenose Plecos are hardy and can tolerate briefly elevated levels with little stress.
Bristlenose Plecos (and Plecostomus in general) are good indicators of dissolved oxygen levels. They are facultative air breathers, meaning they can absorb atmospheric oxygen in times of need, but otherwise prefer to breathe through their gills.
Occasionally, you’ll see your Pleco rush to the surface for a quick splashing gulp, before swiftly returning to the bottom. This is normal behavior but if it happens a few times per hour it may be a sign aquarium dissolved oxygen levels are lower than they should be.
Investing in a curtain bubbler, powerhead, or adjusting the flow of your hanging filter to create additional surface agitation is the best solution for low oxygen levels. Live plants also provide supplemental O2 for your fish while locking away toxic nitrates!
Plants and Driftwood
One reason Bristlenose Plecos are so popular in the hobby is because they are some of the Best Algae Eaters For Your Freshwater Aquarium. While they don’t touch brown diatoms they will eat nearly all kinds of green algae, polishing rocks, driftwood, plant leaves, and aquarium glass in the process.
Since they are so good at their jobs algae can reach levels too low to keep them properly fed. If you see your Bristlenose Plecos actively eating plant leaves it’s a sign you aren’t feeding them enough.
They preferentially eat algae, detritus, driftwood, and decaying plant material but will switch to live plants if there’s nothing else available.
It’s rare but sometimes a Pleco will simply take a liking to the taste of a particular plant even if they are well fed! Stocking an aquarium with bitter, tough leaved epiphytes like Java Fern, Anubias, and African Water Fern will discourage even the most persistent grazer.
Bristlenose Plecos Tank Mates
As a rule, Bristlenose Plecos are model community tank inhabitants, even better than Common Plecostomus. Bristlenose Plecos never rasp on the sides of broad bodied fish like Discus nor are they aggressive to other bottom dwellers. Although they will certainly eat any eggs they come across they are no threat to free swimming fry.
Good Tank Mates for Bristlenose Plecos
- Middle and Upper Water Schooling Fish (Tetras, Rasboras, Barbs, Danios, etc)
- Most Cichlids
What’s more important is choosing fish that won’t bother your Bristlenose Pleco. They actually do well in a Cichlid tank thanks to their armored flanks and defensive cheek spines. However their bushy beards can be tempting for some fish to pick at, such as Puffers and Tiger Barbs! These wounds can result in both stress and open routes for infection to take hold.
Poor Tank Mates for Bristlenose Plecos
- Aggressive to Large Cichlid
- Puffer Fish
- Nippy Barbs (ex: Tiger Barbs)
- Larger, Aggressive Plecostomus species
When kept together Bristlenose Plecos will occasionally act territorially towards one another, especially males, but never viciously so. For one they don’t have sharp teeth to do battle with.
Males do have cheek spines that they use when displays get heated but they rarely do lasting harm to one other. So long as there is ample room for grazing and hiding places for all they can be kept in groups without fear.
Feeding Bristlenose Plecos
Once aquarium algae runs low you’ll want to start providing vegetables in as much variety as you can! Spirulina flakes and algae formulated sinking wafers are perfect for Bristlenose Plecos. HIKARI Tropical Algae Wafers are undoubtedly the best choice as they are formulated for algae eaters and appropriately sized for different species.
- Hikari tropical Algae Wafer 8.8oz
- Algae Wafers were specifically developed for the hard to feed plecostomus and other algae eating bottom feeders.
- Hikari was the originator of this diet, now copied by many.
Feel free to also offer blanched terrestrial vegetables like peas, carrots, spinach, and cauliflower. They provide valuable nutrients and roughage for healthy digestion.
Bristlenose Plecos are a bit unusual for fish in that they absolutely LOVE waterlogged driftwood. As driftwood ages the outer layers soften and slowly decay, creating a tasty mush of detritus, algae, and micro organisms that Bristlenose Plecos will spend all day grazing on.
While driftwood isn’t essential, providing a nicely aged piece goes a long way towards their general health and happiness! Driftwood also provides hiding places, slowly releases tannins that buffer the pH towards acidity and provides stable rooting places for the epiphytic plants mentioned above. If you’re interested in learning more about choosing the right kind, have a look at my Driftwood Guide here!
Bristlenose Plecos do need a small amount of protein-based food and usually get enough in prepared formulas. They will also eat live and frozen foods like Bloodworms and Tubifex but these should never be more than 20% of their diet relative to vegetable matter.
Breeding Bristlenose Plecos
While not super easy to breed, Bristlenose Plecos are mostly captive bred now. It takes a bit of knowledge of their natural rhythms, combined with extra food and space for the father to rear the eggs!
Sexing Brislenose Plecos
Unlike most catfish, telling male Bristlenose Plecos from females is a relatively simple affair once they are sexually mature. Males have a more prominent bushy “beard” as well as long cheek spines that they use both to spar with each other and defend against predators.
If you need to net a Bristlenose Pleco beware these spines, which can get tangled up in nets or even prick a careless finger. While not poisonous they are certainly painful.
Males are also more territorial, especially when you start replicating the breeding season for them. You should keep around 2 females per male for a Bristlenose breeding project.
Spawning & Raising Bristlenose Pleco Fry
One of the best ways to condition them is to do a 50-75% water change while allowing temperatures to cool to 72-74F. Note: we still want to maintain our pH levels, so adjust the parameters as necessary when adding fresh water to the tank – sudden, drastic shifts in pH can be lethal to fish.
The sudden influx of fresh water mimics the rainy season floods, which are the normal period for breeding in the world. Additional large water changes can be done biweekly, while providing a good selection of prepared and blanched vegetable matter for your Plecos.
Eventually, you should see an increase in territorial spats among males and displays made towards female Plecos. Males usually choose a cave along the flooded riverbank in nature; a driftwood hollow or overturned clay pot can work just as well in aquaria.
Once the female swells with eggs and is receptive to his advances, copulation is a brief affair. The male guides her into his cave where she attaches the eggs to a hard surface. He then fertilizes them and swiftly ejects her.
Male Bristlenose Plecos are good parents, aerating the developing eggs with their fins and guarding the cave from intruders for the 5 to 10 days it takes for the Pleco fry to hatch.
Your water quality should be top notch, with small frequent water changes during this period. Like most fish eggs they are sensitive to fungal infections and once a single egg gets infected the disease can spread to the entire clutch.
Infected eggs turn opaque and fuzzy while viable eggs are a translucent yellow or orange. Usually the father will eat infected eggs but if you see eggs beginning to fuzz it’s worth taking tweezers and removing them despite his wrath. You can also try antifungal agents like Pimafix but these agents are better used in hospital tanks.
Once the Bristlenose Pleco fry hatch they are vulnerable and immobile for their first 4 days as they absorb their yolk sack. Once they are no longer weighed down they begin foraging for algae and detritus and leave their cave for good! Over the course of 6-10 months they develop until they are as large as their parents and ready to begin the cycle anew!