Beheaded fish in tank

Hi there,

I'm a newbie to the forum, and was wondering if anyone can help me out on this issue. I have had 3 fish in total now over the course of a couple of months, brutally attacked and killed. 2 of my sucker fish had their heads clean ripped off (none of the fish was eaten), and this morning I awoke to one of my baby juli cories dying with its whole tail torn off (not just the fins being torn, line the whole back of the fish).

I like to think I have a peaceful tank, but I guess i have been proven wrong. I believe the only fish in my tank capable of doing this are my clown loaches, but I'm not 100% sure.

Tank Size 300L. There are plenty of hiding spaces, and there are plants also
My tank consists of:
2 clown loaches
9 Corydoras (all different species)
3 suckers
3 zebra danios
5 ember tetras
5 cato river rainbow fish
1 platy
1 swordtail

Any help appreciated

define "3 suckers"

mikey11 said:

define "3 suckers"

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Hi Mikey,

They are like the regular sucker fish from the LFS, and they are gold in colour. I hope that helps?

are you talking about a pleco?....how big are they?

No they are not plecos, I'll try find a pic for you

these are the ones I have

mikey11 said:

are you talking about a pleco?....how big are they?

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As for the size they are only like 5 or 6cm long

I believe the pictured fish is an albino Chinese Algae Eater. This is certainly one likely culprit, as this fish is known to sometimes become a real terror with its aggression, which increases as it ages. Substrate level fish are often not even tolerated in time, so you clown loaches are in trouble, and cories likely the same. I would remove the three of them (back to the store if at all possible).

Your clown loaches have an issue too, and they also might be the culprits due to stress which usually makes fish more aggressive. Loaches are shoaling fish that need to live in groups, and they are highly social fish. They develop hierarchies, and with only two, three, sometimes even just four, they can eventually kill one another out of frustration. They need a group of five (or more), but this means at least a 6-foot tank and preferably an 8-foot tank. I'm afraid a 300 liter (80 gallon) tank is not going to be sufficient, so unless there is a much larger tank, these should be re-homed soon.

I do not recommend loaches with cories, primarily because they will be in each other's area and the cories are likely the losers. Mature clown loaches, or any loach species that gets this large (12 inches, 30 cm) is not going to ignore bumbling cories.

BTW, welcome to TFF.

Byron.

Lina88 said:

these are the ones I have

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It is a chinese algae eater....they can become very aggressive in community type tanks....even at a small size

Byron said:

I believe the pictured fish is an albino Chinese Algae Eater. This is certainly one likely culprit, as this fish is known to sometimes become a real terror with its aggression, which increases as it ages. Substrate level fish are often not even tolerated in time, so you clown loaches are in trouble, and cories likely the same. I would remove the three of them (back to the store if at all possible).

Your clown loaches have an issue too, and they also might be the culprits due to stress which usually makes fish more aggressive. Loaches are shoaling fish that need to live in groups, and they are highly social fish. They develop hierarchies, and with only two, three, sometimes even just four, they can eventually kill one another out of frustration. They need a group of five (or more), but this means at least a 6-foot tank and preferably an 8-foot tank. I'm afraid a 300 liter (80 gallon) tank is not going to be sufficient, so unless there is a much larger tank, these should be re-homed soon.

I do not recommend loaches with cories, primarily because they will be in each other's area and the cories are likely the losers. Mature clown loaches, or any loach species that gets this large (12 inches, 30 cm) is not going to ignore bumbling cories.

BTW, welcome to TFF.

Byron.

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Hi Byron,

Thank you for your help.

I only recently was informed about how large clown loaches get, and that they should be kept in a minimum school of 5. Which I was quite disappointed about, that the LFS had not given me this sort of information, so now I have to try and give them away.

As for the sucker fish, i had no idea they could be aggressive like this, as my family always kept them in the past. So would they really be capable of ripping a head clean off another sucker fish?

Thanks in advance

Lina88 said:

Hi Byron,

Thank you for your help.

I only recently was informed about how large clown loaches get, and that they should be kept in a minimum school of 5. Which I was quite disappointed about, that the LFS had not given me this sort of information, so now I have to try and give them away.

As for the sucker fish, i had no idea they could be aggressive like this, as my family always kept them in the past. So would they really be capable of ripping a head clean off another sucker fish?

Thanks in advance

Click to expand...

You're welcome. It is one possibility that one of the Chinese AE (or maybe one of the clown loaches, less likely though) killed the fish (they are known to attach to a fish, this could have been during the night) and having killed it, any of the other fish would feast on it. Nothing mentioned would be likely to take off a head from a live fish in one go. But once a fish is severely weakened or dead, it may not take long for large parts of it to get eaten.

Byron said:

You're welcome. It is one possibility that one of the Chinese AE (or maybe one of the clown loaches, less likely though) killed the fish (they are known to attach to a fish, this could have been during the night) and having killed it, any of the other fish would feast on it. Nothing mentioned would be likely to take off a head from a live fish in one go. But once a fish is severely weakened or dead, it may not take long for large parts of it to get eaten.

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See thats the strange thing, the fish were not eaten at all, they were just perfectly beheaded, and no signs of other fish eating them.

Also with the baby cory that was recently killed, it was still alive when I found it, and the whole tail ripped off, however the fish was healthy, and I was only watching them the night before it happened, that's why I assumed it would be the clown loaches since they have large mouths. But I must say I have noticed the sucker fish being aggressive toward each other

So since I now need to re home all the suckers and loaches, what could you recommend for my tank would be good to replace them with? As I got the loaches to control my snail problem (due to having plants).
As for the suckers, what would be good algae eaters aside from plecos? I have had plecos before, but have bad luck with them dying (so do not want to get them again, alss they get too large for my tank)

Lina88 said:

See thats the strange thing, the fish were not eaten at all, they were just perfectly beheaded, and no signs of other fish eating them.

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Lina88 said:

Also with the baby cory that was recently killed, it was still alive when I found it, and the whole tail ripped off, however the fish was healthy, and I was only watching them the night before it happened, that's why I assumed it would be the clown loaches since they have large mouths. But I must say I have noticed the sucker fish being aggressive toward each other

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I would assume a fish had to chomp off the head, and this could occur rapidly during darkness if not during daylight, as I explained. I have had fish die, we all do; sometimes I see the corpse, often not. When I do, it may be partially consumed, or not at all. Snails as well as fish will deal with dead fish, and snails are the best for this, eating organics.

Lina88 said:

So since I now need to re home all the suckers and loaches, what could you recommend for my tank would be good to replace them with? As I got the loaches to control my snail problem (due to having plants).

Click to expand...

Snails are not bad, they are your best friend in an aquarium. They eat organics, which includes fish excrement, breaking it down faster for the bacteria to handle. And they get places you (we, the aquarist) cannot. Be glad you have them. The small species that arrive with plants are harmless to plants but beneficial to the biological system. Different people define "snail problem" differently; I have hundreds in some tanks, over a thousand in the larger. If you/I overfeed, this will increase them, true, but otherwise they will bee at a level needed to handle the organics.

Lina88 said:

As for the suckers, what would be good algae eaters aside from plecos? I have had plecos before, but have bad luck with them dying (so do not want to get them again, alss they get too large for my tank)

Click to expand...

The Chinese Algae Eaters have another problem...they rarely eat algae, especially as they mature. No fish will really control "algae" though some are good at keeping it under control along with you. Algae is normal and natural, and no healthy aquarium will be algae-free--it won't be healthy if it is without any algae. But we control it, especially with live plants (without plants, algae performs a similar function to plants, using nutrients and producing oxygen). If you have problem algae, you need to do something to deal with that, re the light/nutrient balance. But if it is just common algae, there are fish that will deal with this, as will snails.

Byron said:

I would assume a fish had to chomp off the head, and this could occur rapidly during darkness if not during daylight, as I explained. I have had fish die, we all do; sometimes I see the corpse, often not. When I do, it may be partially consumed, or not at all. Snails as well as fish will deal with dead fish, and snails are the best for this, eating organics.



Snails are not bad, they are your best friend in an aquarium. They eat organics, which includes fish excrement, breaking it down faster for the bacteria to handle. And they get places you (we, the aquarist) cannot. Be glad you have them. The small species that arrive with plants are harmless to plants but beneficial to the biological system. Different people define "snail problem" differently; I have hundreds in some tanks, over a thousand in the larger. If you/I overfeed, this will increase them, true, but otherwise they will bee at a level needed to handle the organics.



The Chinese Algae Eaters have another problem...they rarely eat algae, especially as they mature. No fish will really control "algae" though some are good at keeping it under control along with you. Algae is normal and natural, and no healthy aquarium will be algae-free--it won't be healthy if it is without any algae. But we control it, especially with live plants (without plants, algae performs a similar function to plants, using nutrients and producing oxygen). If you have problem algae, you need to do something to deal with that, re the light/nutrient balance. But if it is just common algae, there are fish that will deal with this, as will snails.

Click to expand...

Thank you so much for all the helpful information, and sorry for all the questions haha.

This all makes sense, and as for the algae eaters, I just need something that will control the algae on the plants, so they are not being taken over. Would something like a mystery snail help?

Lina88 said:

Thank you so much for all the helpful information, and sorry for all the questions haha.

This all makes sense, and as for the algae eaters, I just need something that will control the algae on the plants, so they are not being taken over. Would something like a mystery snail help?

Click to expand...

While snails do eat algae, it is minimal, meaning, they cannot deal with a problem of increasing algae. The only safe way to deal with this is by tweaking the balance between light and nutrients so the plants use all the light/nutrients and algae is left out.

In order to assess the balance, we will need to have data on the light (type, watts, spectrum, etc) and what if any fertilizers you are adding and how often.

[Just so you know, I will be signing off momentarily and back here tomorrow, so don't think I am ignoring you if you give this and I don't respond.]

And questions are never the problem; we are all here to learn and share what we have learned.