my teacher's fish tank is being conquered by territorial hillstream loaches

[P3rhaps009]

When hillstream loaches first arrived in the hobby, I got three. One absolutely destroyed all his tankmates. I saw him in action. He was a madly territorial fish - pure aggression. He left a trail of corpses before I caught him in the act. I got rid of them very quickly and wouldn't touch them again with a bargepole.

From what I have seen since, I had a psycho individual, and the species is generally easy going. But the OP is reporting something I have seen before.

It's a fish with a body for really fast water, probably the kind of hillstream that runs downhill sharply. Sometimes if a tank is very slow moving, fast water or rapids/riffle fish can be more aggressive. If I were to get them again, they would be in a tank that had a serious filter outflow.

yeah i think my teacher missed that part when he got them, ill make sure to tell him.

 

[P3rhaps009]

A teacher should know better. I do a lot of research on any fish I might be wanting to keep before I get it. That way I should have a pretty good idea of how big it gets, what it eats, what its temperament is, what range of water parameters it needs, what size it can get to make sure of having a proper tank size. If it is going into a tank where there will be other fish, I need to know if they will get along or eat each other. And then I may even talk to p[eople I know who keep that species if there is anything important I should know/consider.

I am not a teacher and I know to do the above. I think to be a teacher you need to be a good learner first. Tell your teacher I told him to read what I am posting. He/she is responsible for the quality of life in the tank and how the inhabitants fare is completely determined by the care they provide.

BTW pleco is a common term. There is one species of sucker-mouth, armored catfish named Hypostomus plecostomus. From this name evolved the term pleco which, by most, refers to species of armored sucker-mouth catsfish. It may also extend to other members of the Family Loricariidae.
Loricariidae

Hypoptopomatinae

Otocinclus
https://www.planetcatfish.com/common/family.php?subfamily_id=81

okay ill send that to him.

 

[P3rhaps009]

They may eat some of the dead bodies a bit before you find them making it look like they were attacked when in reality the fish died due to being sick and then the snails ate a little... Now usually the snails would still be on the body but that picture of the body didn't show any snails which is a bit surprising.

yeah for some reason they didn't go for that one so it floated but the other ones they got to made me a bit queasy so i never got to taking a picture of them.

 

[P3rhaps009]

This issue is a very clear case of the individual who put the various fish in this tank not knowing much about fish, period.

I suspected the fish being termed a dwarf pleco was probably a Hillstream Loach; in SE Asia particularly this fish is commonly called a "pleco." Another example of the uselessness using common names, no one knows what fish is being considered.

As for the fish themselves, they are indeed territorial. In its habitat it lives in large groups; males will "defend" their territory (selected on the basis of available food) by "topping." When a second male invades another's territory, one fish tries to cover the other in a test of strength, termed "topping." There is rarely any damage inflicted, and one fish eventually retreats. The dominant males claim the best algae areas as their territory, while females tend to congregate in other areas. This fish must be in groups of at least six, or it can be very withdrawn and inactive. Tankmates are difficult to select due to the requirements this species demands with respect to bright lighting (to encourage algae), cooler water and a stronger flow from the filter.

What is happening here is to put it plainly, inhumane.

just so you know he does check the website that sells them i guess that only getting information from there might have been a bad idea, but they are in groups. I fully understand what you are saying and I will make sure to get the message across to him. I'm sure he will understand what to do in the future.

 

[P3rhaps009]

maybe not full grown yet considering a lot of pet stores don't list their fish right could be a different species

they are hillstream loaches, we figured that out earlier.

 

[P3rhaps009]

They are not plecos.

They're generally peaceful, have never once heard of them killing another fish, and I'd be incredibly surprised if it happened. Finding a dead body doesn't prove a thing, fish die for all sorts of reasons, and most fish will eat the body of another fish - it doesn't mean they killed it, they're just not turning down a free meal.

We'd need to know a lot more about the tank to stand a chance of helping. But trying to get another fish that will eat them is kinda sick, and a terrible idea of tank management, which makes me doubt your teacher has any real knowledge or skill in aquarium keeping. Any fish large enough to eat them is also going to eat everything else in the tank, you know...
If he doesn't like them or want them, catch them and return or rehome them. Don't sentence them to death for something they almost certainly didn't do.

Without knowing more about the stocking and water conditions, we cannot possibly know what may have killed other fish. We'd need information to be able to offer any real advice.

oh, that was my idea. I was uneducated about it back then. my bad.

 

[P3rhaps009]

oh, that was my idea. I was uneducated about it back then. my bad.

i actually feel pretty bad about that.

 

[AdoraBelle Dearheart]

oh, that was my idea. I was uneducated about it back then. my bad.

i actually feel pretty bad about that.

This might sound weird, but it's a good thing you feel bad about that? Not that I want you to feel bad! I just mean that it shows you're thinking more about them as living beings that didn't have a choice in the tank they were placed in, or what with, and they're just following natural behaviours they've evolved to do- not that they're mean, bad creatures killing for the fun of it.

So that you feel bad about it and want to find a better solution is a good thing. Don't beat yourself up too much though, you've been great about taking in the advice given here, which isn't easy! And it means a lot. Shows you're really a caring person who wants the fish in the tank to survive.

 

[P3rhaps009]

Ok, i think I have come to a conclusion. I will see if there are any diseases or rehome the hillstream loaches. thank you very much for your help in helping me solve this problem. it probably is a diseas or something like that. I think I was to hard on the loaches earlier. but i think checking for diseases or possibly rehoming the loaches would be a good idea. thank you very much for your help but i am very busy and will be unable to be checking my messages very often. i feel very privileged to have had the opportunity of speaking with you. thank you.

 

[P3rhaps009]

This might sound weird, but it's a good thing you feel bad about that? Not that I want you to feel bad! I just mean that it shows you're thinking more about them as living beings that didn't have a choice in the tank they were placed in, or what with, and they're just following natural behaviours they've evolved to do- not that they're mean, bad creatures killing for the fun of it.

So that you feel bad about it and want to find a better solution is a good thing. Don't beat yourself up too much though, you've been great about taking in the advice given here, which isn't easy! And it means a lot. Shows you're really a caring person who wants the fish in the tank to survive.

thanks!

 

[AdoraBelle Dearheart]

Ok, i think I have come to a conclusion. I will see if there are any diseases or rehome the hillstream loaches. thank you very much for your help in helping me solve this problem. it probably is a diseas or something like that. I think I was to hard on the loaches earlier. but i think checking for diseases or possibly rehoming the loaches would be a good idea. thank you very much for your help but i am very busy and will be unable to be checking my messages very often. i feel very privileged to have had the opportunity of speaking with you. thank you.

I understand!
Good luck, and thanks for making an interesting thread! If you get a chance later on, we'd love to hear an update on how you and the teacher resolved the issue!

 

[GaryE]

A teacher should know better. I do a lot of research on any fish I might be wanting to keep before I get it. That way I should have a pretty good idea of how big it gets, what it eats, what its temperament is, what range of water parameters it needs, what size it can get to make sure of having a proper tank size. If it is going into a tank where there will be other fish, I need to know if they will get along or eat each other. And then I may even talk to p[eople I know who keep that species if there is anything important I should know/consider.

I am not a teacher and I know to do the above. I think to be a teacher you need to be a good learner first. Tell your teacher I told him to read what I am posting. He/she is responsible for the quality of life in the tank and how the inhabitants fare is completely determined by the care they provide.

That's a bit righteous. This forum would not exist if it weren't for people buying on trust, and putting their faith in pet store expertise. In an ideal world, everyone would do what they should before making decisions. This teacher, at this time of year, probably wants to do a little extra for the kids by setting up a tank, probably with his/her own money. He/she is probably coaching (unpaid), dealing with large class sizes, and earning less than a whole lot of other trades. When you have 120 compositions to correct, with constructive and educational comments on each, specialized programs for kids with learning or behavioural difficulties to design, regular lessons to design, parents to be answered promptly and most likely, your own classroom to clean, fact checking a clerk is the least of your 'to do list' things.

Don't undermine people who are trying. Provide useful advice.

 

[Alice B]

That's a bit righteous. This forum would not exist if it weren't for people buying on trust, and putting their faith in pet store expertise. In an ideal world, everyone would do what they should before making decisions. This teacher, at this time of year, probably wants to do a little extra for the kids by setting up a tank, probably with his/her own money. He/she is probably coaching (unpaid), dealing with large class sizes, and earning less than a whole lot of other trades. When you have 120 compositions to correct, with constructive and educational comments on each, specialized programs for kids with learning or behavioural difficulties to design, regular lessons to design, parents to be answered promptly and most likely, your own classroom to clean, fact checking a clerk is the least of your 'to do list' things.

Don't undermine people who are trying. Provide useful advice.

I put 3 kids thru public schools. I took a lot of class pets home for the summer, and rescued starving parakeet from a kindergarten 3 times before telling my kid to mention aspca to the teacher, at which point she replied keep the bird. Teachers are overwhelmed, parents volunteer less and less when they work more and more, and it's rough. I think the most successful class pet we ever did of all my kids classes was the youngest daughter's first grade teacher, I set up a half full 10 gallon with 19 cents worth of grocery store crayfish. Eventually the king of the tank managed to take the other 2 out but he lived for years, came home for the summer you know.

This teacher is over is head, and needs constructive help, and his student is trying to provide it.

 

[seannx]

huh, that actually makes a lot of sense. but i don't know if it's gonna be easy in a densely planted 40 gallon, i'll ask him.

I took my plecos back to the fish store. They were the biggest chow hounds at feedings, and aggressively chased and ate any of my baby and small cherry shrimp the rest of the time.

 

[DoubleDutch]

We'll wait for

Hillstream loaches - how on earth are they dominating the tank?

Got 5 of these. They are trying to rule our household. Think they'll try to take over the world.