Pleco and Hilstream Laoch

[FishRBeautiful]

I have a BN Pleco and Hilstream Loach (sold as butterfly loach but looks like reticulated hilstream loach to me) in a 20 gallon high. Maybe it’s all in my head but the Pleco seems to be hiding a lot and loach not so much. Can the loach possibly be aggressive when I’m not watching? Are these two fish not compatible? I always research fish before adding but I may have  forgotten to research these two together. 

Edited February 28 by FishRBeautiful

[Tony s]

Don’t think it’s aggression, bn’s are mostly nocturnal. It may be you’re not as active when it is 

[Trigri]

I myself, am pretty new to keeping both plecos and hillstream loaches, so anyone that is more experienced can correct me if I'm wrong. I have a lot to learn about keeping these species too.

I have a rubber lip pleco and a reticulated hillstream loach in a 30 gallon tank and they do just fine together. Mine don't display any aggression towards one another, and I often find them hiding together near the sponge filter or my pleco cave, just chilling. They also sometimes clean the same area of the glass near each other and don't appear bothered by one other. I've never seen them fight over food and I even watch them late at night to watch their nighttime behaviors. I'd say mine are similar to yours, the pleco hiding a lot and the loach not hiding as much, but that is pretty normal for these fish.

Hillstream loaches aren't typically aggressive towards other fish, but they can sometimes be with their own kind. Even then, they can't really hurt each other and it's more of a display. A BN pleco may be a little aggressive over food, but that also depends on the individual. Neither of these fish can really hurt one another if they are being aggressive for whatever reason, but they could possibly prevent the other from eating if they are being too aggressive. I would watch them and try to see how they behave with each other during feeding and see whether or not they show any aggression. Most of the time though, they should be perfectly fine to keep together.

[Cinnebuns]

I have both butterfly and reticulated hillstream loaches. They can look pretty similar. Butterfly are bigger and have spots whereas reticulated has swirls or stripes. Neither butterfly or reticulated are aggressive. Even when multiple males of the same species are together their scuffles rarely get very aggressive with each other. It's more likely the fact that plecos are nocturnal than anything. 

On 2/27/2024 at 11:20 PM, Trigri said:

Hillstream loaches aren't typically aggressive towards other fish, but they can sometimes be with their own kind. Even then, they can't really hurt each other and it's more of a display.

This is worded better than I said it lol. I typed mine before reading other responses. 

On 2/27/2024 at 11:20 PM, Trigri said:

A BN pleco may be a little aggressive over food

I will caution this though. Although plecos are not by nature aggressive, they have been known to attack and even kill fish by sucking off their slime coat if they are not fed properly. As they age they become more carnivorous. Many people don't understand this and don't feed them enough protein. This causes them to try to get protein from other fish. 

Edited February 28 by Cinnebuns

[FishRBeautiful]

Thanks for your replies. It’s super helpful. Yesterday I saw the two darting like crazy on the back wall of the tank. I didn’t know if they had uncontrollable spurts of energy (my kitten gets those LOL) or if they were fighting. The Pleco does those darts a lot and scares other fish away but I don’t know if it’s intentional. 
The Pleco definitely likes to hog sinking food. But the snail got his algae wafer once and the Pleco swam away in defeat. I have seen the Pleco and snail fighting aggressively with each other before.  And once a kuhli loach tried to get some sinking food and the Pleco sucked on its head and then it swam away. Pleco also keeps sticking its spines in its cheeks out but I haven’t seen it do that to other fish yet. My fish hide a lot so sometimes I wonder if the loach scares them but it may just be that the loach is the least shy creature in my tank. I plan to get some black neon tetras as dither fish. And most of my fish are nocturnal because they’re my favorite. 

[Trigri]

@FishRBeautiful I don't know enough about plecos and their behaviors to say much more that could help you. Your plecos behavior seems a bit worrying to me, so you might want to continue to watch it and make sure it's not being overly aggressive and hurting or trying to kill your other fish. Hopefully someone with more experience with plecos can chime in and give their opinion and help you out.

[FishRBeautiful]

Thanks! I’ll watch the pleco as it gets older. I’ve had it maybe 4 or 6 months so it’s still like 2.5 inches. I’ve found overfeeding sinking food helps with hogging food so the pleco and snail can each have their own not to share. And then cleaning the tank every week which seems crazy. 

[Lennie]

The two should be fine together. Is your bristlenose a male? Males usually tend to claim a cave and spend most of their time inside/around. Females and fry/juveniles seem to be more outgoing and also wander around during day time in my experience. I had my borneo loach with my L199 for a long time with no issues in a similar sized tank

[FishRBeautiful]

So I measured the Pleco tonight (take a ruler up to it against the outside of the glass) and it’s about 2.25 inches. Not sure what age/size males grow “bristles” on their “noses”. This is my Pleco. Don’t know its sex. From your description, it may be a female based on behavior. No cave claiming.

This is also a pic of the loach.