Bristlenose Plecostomus

Here's a picture of a young female Bristlenose Plecostomus taken by littleme3333. This little pleco seems to be enjoying her lunch!


The Bristlenose Pleco belongs to the genus Ancistrus. Within that genus, there are about 60 recorded species. Primarily bottom dwellers, don't be surprised to catch the Bristlenose Plecostomus sucking the algae off the sides of your fish tank. They love it. When they've cleaned the algae up, feed them zucchini or algae wafers. I like to steam my zucchini and keep it in the fridge to use as needed.

Here are a few facts to keep in mind if you're thinking about stocking your aquarium with a Bristlenose Plecostomus:

  • Minimum tank size: 30 gallons
  • Easy to care for
  • Adults can reach up to 4" (it varies among Ancistrus species)
  • The Bristlenose Pleco is a peaceful fish (loves to 'chill')

The nice thing about the Bristlenose Plec is that it has a voracious appetite for algae, but won't grow as large as the Plecostomus usually sold at your local pet store. Those can grow as large as one to two feet!

Breeding the Bristlenose Plecostomus is fairly easy, so have plenty of fish loving friends if you're going to try that. Bristlenose have whisker-like appendages around their nose and mouth. It's fun to watch when they flare them out.

The Bristlenose Plecostomus is a great fish tank addition for an aquarium enthusiast looking for a fish that can get a little tank cleaning done. Do you have a favorite Bristlenose Pleco species?

137 thoughts on “Bristlenose Plecostomus”

  1. I had two plecs and one of them liked to go in the small barrel I had bought for my neons but on Thursday night he got stuck in it and seemed to be squashed. My dad got hold of his tail and pulled him out but when he came out he was dead. Is my dad heavy handed and killed him by accident or would it have died because of the panicing anyway of being stuck and because its shy? I was so upset that I cried. I have one plec left now and hope he lives a long life.

  2. hi, i was wondering why do these fish eat so much and also how do they digest all of there food since there stomachs are so small.

  3. Hi Don,

    The eggs would probably be vulnerable to other fish in the community. I haven’t bred them, but think it would be easier seperate. Also, I’ve read that a 75% water change is needed to help the process get going, which would be better seperate.


  4. Hey Mike,
    I have a question about an albino BNP I got a few days ago. I’ve been reading up on them and must say I’m hooked. I’m having some trouble sexing him/her though. I’ve read about sexing based on the “bristles” and I’ve also seen mention of a pink spot on the back and I think this may be associated with the male but I can’t find anything that tells me for sure. My “guy” is still relatively small (almost 3 inches) and I can’t decide if it’s a female or a male that’s not quite developed yet it has a line of very small bristles around the mouth and two “protrusions” on the head just between and below the eyes that may just be nostrils (I’ve seen pics of females with similar structures). Do you know of any other way to determine the gender?
    Thanks, Scott

  5. hey, i have 5 african cichlids (all under 2 inches) with a 5 inch Pleco (type unknown), and a small catfish (about 3 inches) all in my 55 gallon tank. the tank is very roomy but my catfish has not left the castle and it has been nearly a week… i have not seen it once. I know it is still alive for i have checked and my pleco hardly ever comes out… what should i do to know if they are eating?

  6. Hi Matt,
    They’re eating. My pleco hides all the time. Try checking the tank when the lights off at night.

  7. hello
    can anyone explain how come plecos arent compatible with freshwater plants??

  8. I am looking to get a bristlenose pleco and I was wondering how you tell the difference between male and female?

  9. Hello, do Plecos attack Goldfish? I saw my bristle-nose Pleco sort of jumping at my two 2 1/2 inch Fan-tails, he didn´t actually manage to bite them, but sort of chased them off. I wasn´t too worried. But they are in a make-shift 11g at the moment, my 29 g is still cycling. Do Plecos exhibit terretorial behaviour? I ask because I also noticed the tails of my Fan-tails are both shredded.

  10. My plecos have always stayed under rocks or driftwood. The male plecos can get territorial with other males. I’ve never heard of them getting aggressive enough to actually bite other fish.

    If that’s the only 2 species you have together, you can’t rule it out I guess.

  11. I’ve just put my 3 BN Plecos into my new 4ft Amazon tank and was wondering if i could add my 2 Pictus and a Featherfin which are currently residing in my 280l Mbuna tank.

  12. hi Matt
    my 6 inch pleco, draco, is lovely and was in hiding for the first three days but now is swimming all over my 200litre tank he is with small comunity fish and does not interact with them or spottie my baby pleco who is about 2 inches but i read how plecos don’t like to come out is this a bad thing he is doing this and do you know what their normal lifespan is

  13. Hi! I have a 37gal tank (biggest I could afford and store) and 2 plecos-1 sized at 9.5″ and the other at 6″. They usually live great in my outside pond, but brought them in as it;s gettting too cold for them and I want these guys to live. Problem: I don’t know if to set up gravel at the bottom of tank for them and of course, the pooper masters are at work. So how much should I feed them? The water has been cloudy as it’s a new tank set up, but I’m gravel vacuuming everyday, changing water if necessary. Main concern is correct quantity of food and setup. Also, the bigger one has gotten competitive when it comes to food. Help! These plecos were used to being hand fed peas in the pond. I just want them to be healthy enough through the winter so they can go back in the pond when it’s the right temp outside. Any and all advice welcomed!!!

  14. Your plecos are spoiled… ha ha.. hand fed peas.

    Make sure your water quality is good.. ammonia and nitrite levels.

    Probably happier with a few places to hide.. plants, caves, driftwood.

    I never feed mine anymore.. period algae wafers or shrimp pellets. Mine eat the algae.

    Main thing is watch water quality, since it’s now a closed environment. Weekly water changes.. 1/3 is what i do with my 37 gallon tank.


  15. I have a few BN pleco’s albino longfin and short fin- I got a pair of regular short fin and put them in a 55 gl tank that had a adult short fin male in it and they got in a fight..had to pull them apart -have a hook by their mouth found out the hard way you can’t keep 2 males with a fertile female in one tank.
    Also if you want to get a lot of alge fast -keep light on in tank 24 hours around… have a 20 gl tank with 2 BN albino and about 10 guppies… now have another 50 ” BN babies” does anyone know why they line the top about 10-15 days after they are born.. made it easy to count

  16. love to sell them.. when they get big enough,, Started with 2 albino’s m/f and by chance have figured out how to get them to breed… First batch 20- then 6… now this time 50!!!! they turn out about 1/2 long fin and 1/2 short fin… have a few tanks when they get growing… so they can all get something to eat… they don’t take to zucchini, beans and things that other people feed theirs… so I make sure there is algae so they have something to eat…

  17. If I could figure out how to post a picture, I would… with them all hanging around the top of the tank…

  18. I have 3 molly’s I got them last week and I’m thinking about getting a pleco how long will it be before I should get one? I figured I should wait about 4 months but I’m not sure…

  19. If I get a pleco what temp will it have to be at because I keep my tank at 80 degrees because I have 3 mollies do I have to to lower the tempreture?


  20. Hi Jade,

    A pleco should be fine with your mollies. 80 degrees is ok too. A pleco should help if you have any algae buildup.


  21. Not sure if I actually GOT a bristle nose or not. This pleco was recommended at the store because I wanted an algae eater for a 33gal tank. I was informed that this one will grow to about 4″-6″ max and to expect his nose to grow the whiskers. So now, I’ve had him…. 6 months? He’s grown fairly fast to about 3″ right now, he’s beautiful, chocolate brown with tan colored leopard type spots, but hasn’t developed the whiskers at all. I’m starting to worry about the speed at which he’s grown compared to other fish I have in there, and if this might end up being a large pleco that my tank just can’t hold. I have another pleco in there that hasn’t grown at all (no clue on the type at all) and he’s much smaller than the bristlenose.

    Are there varieties of bristlenoses that don’t get the whiskers? Is he/she just too young? I’m just worried like I said that I have something that will outgrow my tank. It’d be a shame cause he’s beautiful; although very shy.

  22. I found my answer> In case someone else has the same question, the female does not have the bristles. That simple.

  23. I have a Pleco in a 10-15 gallon tank and we have had it for a few years. The Goldfish we had in there died several months ago so, the Pleco is alone. It never comes out even at night and I found that it’s was stuck in a hole in the log. We got it out and plugged up the hole and it found another smaller hole to stick it’s head in. Should we get it out and plug up all of the holes? We never see it come out even at night, there is never algae in the tank becasue there isn’t any other fish (the tank has a filter) and, it doesn’t eat the wafers. Also, should I take the light off of the lid or is that ok? I think the light probably heat the tank but, I wasn’t sure if maybe it doesn’t like the light and that is why it never comes out and never sticks to the side of the tank like alot of Plecos I have seen. Any advice would be appreciated!

  24. Forgot to ask if maybe I have to much water in the tank. The Pleco is about 3″ and the tank is 10-15 gallons and filled about 6″ from the top.

  25. You just have a very shy pleco! Don’t feed it. It’s getting enough food from the algae. You could plug up those holes, but do leave it some type of hiding spot.

  26. I have 4 1 inch bristlenose plecos in a 15 gallon tank. how fast do the grow?
    Like for example how many inches per month.
    Would this tank be large enough for the 4 plecos which are supposed to be smaller than common plecos

  27. I have a 15 gallon tank with 10 fish (tetras & danios, all an inch or less). Used to have a pleco but it died. Got another and it died too – both apparently of the same thing, but I haven’t been able to figure out what. Both of them seemed quite well for several months. No outward signs of disease or stress (all the other fish remain in excellent health). We fed them algae wafers, zucchini, and cucumber bits, which they ate with great appetite until about a week before they died. They basically seemed to just stop eating. Water tests revealed no detectable ammonia, nitrites, or nitrates. The pH was a BIT low (5.5) but stable – and again, NO issues with any of the other fish, even our tiny blue-green tetras which are supposedly terribly sensitive to such things. Could the plecos have eaten too much, gotten some kind of intestinal blockage? Accidentally sucked up a snail? I am really hoping to get a bristlenose but I worry that the same thing will happen to it, any ideas/advice?

  28. You’re obviously diligent at keeping safe water parameters. The only suggestion I’d have, you mentioned; maybe feed them less. I rarely give my plecos anything anymore. My gold nugget is extremely shy, but comes out now when I feed my other fish flakes once a day. Also, if you have any type of algae growth, the plecos should find it. Good luck.


  29. hi, i have a red eared slider turtle, we just got him a much bigger tank and he seems lonley so we are probably going to get one more turtle and a couple of fish. he is still a very tiny baby only about 2 inches. i was wondering if he would attack this fish? could the fish hurt him?

  30. what will the babies if you have a longfin and a regular fin pleaco? I have a pair of albinos and a bunch of new babies. Cant tell yet

  31. Hi! My name is Tee, from Malaysia. There are a few species of pleco had been imported to my country since years ago. ‘Zebra Pleco’ is one of the most expensive species. I have ‘Sailfin Pleco’, ‘Albino’ as well ‘Dwarf Bristlenose Pleco’, it’s about 4 inches in length. But, my Dward Bristlenose is totally difference as this one you showing above. Mine is more to ‘Medusa Pleco’ look alike, dark brown with a few tiny white spot in color. I got it by accidentally among a group of mixing pleco in the pet shop. I am now looking for more medusa pleco and the dwarf species exactly the same as yours. Hopefully can find it in Malaysia, so that I can try to breed them in a colony ;o)

  32. We have four of these – all albino. Two of them got a little cuddly and we have scads of babies. Anyone want some plecos?

    I’d like to put them in my outdoor pond during the summer.

    Anyone know what temp will be too cold for them?

  33. We have a fish tank at work with about 9 fish and a pleco. They other day when we came in our pleco had no EYES!!! We read online that the type of fish we have can become aggressive and do this sort of thing. Will our little Pleco be okay?

  34. Judy,
    I would guess your pleco will be ok… unless the other aggressive fish continue to pick at your pleco.

    Make sure the pleco has a good hiding spot.


  35. I have one angle fish with it looks like from the photos I hope a bristlenose,it is spotted no bristles I just changed tanks to a smaller one. It is now a ten gallon one. I realize that the anglefish will out grow and now I am thinking so will the bristlenose. the bristlenose seemed to be acting strange staying up on the sides not usual for this one. I went to get some algee did not eat. later I foumd some eggs in the tank on a shell, the anglefish was eating them. I don’t know it the eggs are from the bristlenose or the anglefish. How can I tell what fish the eggs are from??

  36. Bristlenose Pleco eggs are amber or orange colored. Anglefish eggs are very tiny. A hundred would probably fit on your fingernail.

    Do an image search on Google for “bristlenose eggs”, and “anglefish eggs” to see the difference.

  37. Hi
    I have a 70 litre (I think thats about 18 Gallons) tank. I have 5 goldfish (2 are fan-tails) all under 2 inches, 5 danio’s and 5 red minnows all under an inch and I also have 1 Borneo Sucker who is tiny at the moment (only about an inch at the most). I was just wondering if it is safe to get a Pleco in there as well? And what is the smallest type you can get? I don’t want it to get to big for the tank.

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