Help!! My Kuhli Loaches are killing all my plecos

Over the past three days I’ve have witnessed my plecos losing parts of its fins. Last night I stayed up watching the tank when I noticed my 3inch kuhlI loach ripping the fins off my plecos. I separated the plecos from the other fish and noticed extreme lack of movement. This is the third time one of my expensive plecos were mortally wounded and died with similar injuries. The kuhlI loaches are now separated from my community tank. Has anyone else experienced the brutality of the kuhlI loach?

 

I find this very peculiar. Kuhli's are generally shy and timid fish. Though they can be verocious predators of very young fry and eggs, I very, very much doubt they would attack a pleco under normal circumstances. Was it an adult pleco?

What are you feeding this tank? Is it possible that they were starving and fighting over morsels of food?
What is the entire stock like? Size? Water parameters?

Edit: Is it possible the plecos were already dead/near dying and the kuhlI was just scavenging? That seems like the most likely explanation in my mind.

 

Over the past three days I’ve have witnessed my plecos losing parts of its fins. Last night I stayed up watching the tank when I noticed my 3inch kuhlI loach ripping the fins off my plecos. I separated the plecos from the other fish and noticed extreme lack of movement. This is the third time one of my expensive plecos were mortally wounded and died with similar injuries. The kuhlI loaches are now separated from my community tank. Has anyone else experienced the brutality of the kuhlI loach?

What size is this tank and how many plecos/khulis are in it?

 

30gal tank, regular morning and nightly feeding of veggI tablets, sinking pellets, and high quality flakes and live blackworms .stocked with Four small angelfish fry, one pearl gourami, two kuhlI loaches and R.I.P three flash Plecos. One pleco was a baby while other two were 3-4 inches. PH was 6.5-7 and no Nitite with low nitrate level. No ammonia. I acted quickly after seeing the kuhlI loach ripping fins off the pleco. Highly planted tank 80-90% cover with four caves and two pots also driftwood

 

Can we get pictures of the loaches and plecos is question? Kuhlis should never be attacking fish unless they are dead/dying or very tiny. I've kept kuhlis for years and the only things they go after are young cherry shrimp and the occasional snail. Fin damage shouldn't be killing an otherwise healthy pleco either.

 

T

What size is this tank and how many plecos/khulis are in it?

Two kuhlI loaches and three flash pleco

30gal

Can we get pictures of the loaches and plecos is question? Kuhlis should never be attacking fish unless they are dead/dying or very tiny. I've kept kuhlis for years and the only things they go after are young cherry shrimp and the occasional snail. Fin damage shouldn't be killing an otherwise healthy pleco either.

The one was missing a chunk out of forehead and the others had barely any fins remaining

Apologies I don't have pictures atm I can acquire kuhlI loach picture once I arrive home

 

Id be eyeing the angels and gourami before the kuhlis.... kuhlis may just be scavenging.

The worst ive ever seen mine do was nose another one out of the way lol

 

Id be eyeing the angels and gourami before the kuhlis.... kuhlis may just be scavenging.

The worst ive ever seen mine do was nose another one out of the way lol

I watched them ripping chunks out at 2am this morning b4 I moved them

Id be eyeing the angels and gourami before the kuhlis.... kuhlis may just be scavenging.

The worst ive ever seen mine do was nose another one out of the way lol

It was latched on the tail fin and was nomming and ripping chunks out

Should I just rehome my loaches because I love plecos and would love to keep them in my tanks

 

I watched them ripping chunks out at 2am this morning b4 I moved them

And the plecos just sit there and take it???? That sounds to me like the plecos are compromised health wise. Or strength wise. Why would they just take it?? They are nocturnal. So its not like they are sleeping and caught off guard.

The behavior you are describing is odd for both the loaches and the plecos!!

 

Pictures of tank and plecos b4 injuries

And the plecos just sit there and take it???? That sounds to me like the plecos are compromised health wise. Or strength wise. Why would they just take it?? They are nocturnal. So its not like they are sleeping and caught off guard.

The behavior you are describing is odd for both the loaches and the plecos!!

I agree I've never had anything like this happen. The one last night was in a cave when the loach was tugging it out

The culprit

 

Those plecos are far too large to have been prey for the kuhli's. Edit: Ninja'd on the kuhlI pics, they look like regular semicincta's to me.

Did you change the stocking of the tank since this picture? Because your list of stocking doesn't match with what I see.

From the way you described it, it sounds to me like the plecos were already dead by the time you saw that scene where the kuhli's were nipping/ripping at them. You just saw kuhli's scavenging on carcasses.

 

I forgotten the farlowella. All the plecos were moving when I removed them and put them in a floating breeder.

I have five tanks and this is the only one that I have issues with

Those plecos are far too large to have been prey for the kuhli's. Edit: Ninja'd on the kuhlI pics, they look like regular semicincta's to me.

Did you change the stocking of the tank since this picture? Because your list of stocking doesn't match with what I see.

From the way you described it, it sounds to me like the plecos were already dead by the time you saw that scene where the kuhli's were nipping/ripping at them. You just saw kuhli's scavenging on carcasses.

Only angles farlowella and pearl gourami now. KuhlI loaches are in 45gal by themselves atm

Rainbows and danios were rehome two weeks ago.

 

I forgotten the farlowella. All the plecos were moving when I removed them and put them in a floating breeder.

I have five tanks and this is the only one that I have issues with

I'd move the plecos to a safe tank OR the khulis to a tank where they're the only bottom dwellers. This whole thing is just weird!

 

Peculiar. But I still maintain something else caused the plecos to be in terrible condition and the kuhlI were just being opportunistic. As far as I know I've never heard anyone witness genuine predatory behaviour on anything even half the size of the kuhli, and lots of people have them.
It is always possible naturally to have a peculiar individual that behaves differently... but it is strange that they would do it to all of the plecos and not just one. Which suggests territorial aggression, which is just completely unheard of in kuhli. The only genuine reason I can think of is that they were starving (they are shy and easily outcompeted)...

If it is territorial aggression I would expect them to be out and about chasing off the other fish as well, but on the picture it seems like they are hiding in the underbrush as is usual.

Have you had anything else strange happening in this tank? Deaths?

 

This is all very odd and not at all normal behavior. Like others have said it seems as if the Plecos must have already had some other problems going on and the kuhlies realized he was basically dead. Why would a healthy Pleco just sit there and let itself get eaten? Something else has to be amiss here.

 

Peculiar. But I still maintain something else caused the plecos to be in terrible condition and the kuhlI were just being opportunistic. As far as I know I've never heard anyone witness genuine predatory behaviour on anything even half the size of the kuhli, and lots of people have them.
It is always possible naturally to have a peculiar individual that behaves differently... but it is strange that they would do it to all of the plecos and not just one. Which suggests territorial aggression, which is just completely unheard of in kuhli. The only genuine reason I can think of is that they were starving (they are shy and easily outcompeted)...

If it is territorial aggression I would expect them to be out and about chasing off the other fish as well, but on the picture it seems like they are hiding in the underbrush as is usual.

Have you had anything else strange happening in this tank? Deaths?

One of my amanos died while molting other than that nothing out of the ordinary. The loaches were out almost 24/7 tho swimming in the bubbles and patrolling the perimeter of the tank. I never really had to look for them.

 

only one other thing comes to mind- most khulis like to be in groups of 6 or more. Wonder if this could be part of the problem???

 

Maybe I only had a male and female at the same age and the female is by far the most active and the aggressor

 

One of my amanos died while molting other than that nothing out of the ordinary. The loaches were out almost 24/7 tho swimming in the bubbles and patrolling the perimeter of the tank. I never really had to look for them.

But have you seen them attacked and/or display threatening behaviour towards the other fish? The farlowella?

only one other thing comes to mind- most khulis like to be in groups of 6 or more. Wonder if this could be part of the problem???

That should only make them more timid, I would think. I can't imagine it bringing out aggression. If anything they should feel strong in numbers. I would be more nervous about keeping a young bottom-dwelling fish with 30 kuhli...

Maybe I only had a male and female at the same age and the female is by far the most active and the aggressor

Oh! This gave me an idea. Could it be possible that they bred and the plecos were trying to eat the eggs? Maybe they were defending eggs?
I've not heard of that behaviour either, but it would make sense, and little is known about breeding habits of kuhli.

 

This is all very odd and not at all normal behavior. Like others have said it seems as if the Plecos must have already had some other problems going on and the kuhlies realized he was basically dead. Why would a healthy Pleco just sit there and let itself get eaten? Something else has to be amiss here.

I’ve been doing all the tests and the water peramiters check out... also my angelfish are doing great. My rescue angel has about two inches of fin growth since I got her from a cichlids tank at a chain store

But have you seen them attacked and/or display threatening behaviour towards the other fish? The farlowella?


That should only make them more timid, I would think. I can't imagine it bringing out aggression. If anything they should feel strong in numbers. I would be more nervous about keeping a young bottom-dwelling fish with 30 kuhli...


Oh! This gave me an idea. Could it be possible that they bred and the plecos were trying to eat the eggs? Maybe they were defending eggs?
I've not heard of that behaviour either, but it would make sense, and little is known about breeding habits of kuhli.

That makes a lot of sense! What should I do?


The female gourami and farlowella stay away from them

 

That makes a lot of sense! What should I do?

Maybe move the Plecos to another tank and watch for KuhlI fry?

 

Kuhlis are not predatory or aggressive in any sense and are too dumb to be protective over their own fry. As far as I know, only pangio oblonga are known to spawn in gravel and have fry survive in captivity. Most, if not all, striped species of kuhlI that i've seen spawn in floating plants at the top of the water which is very rare in captivity and they probably wouldn't with angels in the tank anyway.

I'd be inclined to think the pleco's health declined or was shedding some kind of slime coat/had deterioration of the fins and the kuhlis took advantage. I'd be looking at disease and figuring out what caused the plecos to die. Did you quarantine them? How long did you have them in the tank?

 

Most, if not all, striped species of kuhlI that i've seen spawn in floating plants at the top of the water which is very rare in captivity

Ooh, this is news to me. Do you happen to know of a casus description or source available online on this? I would love to read more details
I was recently wondering to someone why my kuhlI (semicincta) seem to hang out in my floating plants when I rarely hear them do that....

 

Ooh, this is news to me. Do you happen to know of a casus description or source available online on this? I would love to read more details
I was recently wondering to someone why my kuhlI (semicincta) seem to hang out in my floating plants when I rarely hear them do that....

Hopefully i'm allowed to link this: here is a great article. Mark Duffill has also managed to get them to spawn.