Brutalized guppies

[Townie]

Hi,

My wife has a community tank with guppies, tetras, platties, panda catfish and a pleco. She used to have striped danios too but assumed they were the issue and re-homed them.

However we keep finding guppies with their fins/tails bitten off (esp the ones with big tails). One guppy is now bent. Any ideas where the aggression might be coming from or what to do? We’ve never seen it happen. Right now we have them segregated from in a small net breeder box in the corner.

I have suggested a small 2nd tank but she figures she’ll kill them all getting it to cycle given how long it took her to cycle our current tank.

Any suggestions?

 

[Aiken Drum]

The most likely cause is aggression between the guppies rather than one of the other fish causing this. But, the only way really to see what is happening is to observe it.

Are you certain its torn fins rather than fin rot being caused by poor water quality? Fin rot tends to look mushy and happens gradually whereas torn fins are cleaner and happen more quickly.

What size tank? How many, what type of fish do you have? Do you know if your guppies are M/F?

 

[Townie]

The most likely cause is aggression between the guppies rather than one of the other fish causing this. But, the only way really to see what is happening is to observe it.

Are you certain its torn fins rather than fin rot being caused by poor water quality? Fin rot tends to look mushy and happens gradually whereas torn fins are cleaner and happen more quickly.

What size tank? How many, what type of fish do you have? Do you know if your guppies are M/F?

Hi Aiken,

The water quality is/has been fine. We check it twice per week and have also had it checked at the pet store last week. All the guppies are male.

We have a 36 gallon tank with a 50 gal over the side filter and a 40 gal sponge filter.

 

[Aiken Drum]

Going back over your previous thread you have serpae tetras which you are calling red minor tetras. These are often considered fin nippers and not good tank mates for fish with flowing fins and tails. You also reported only having 3 of these fish.

Tetras are social fish and do better in groups of their own species. When kept in small numbers they can be stressed and this stress can manifest in a number of ways including aggression towards other of their own species or other species. When kept in bigger groups, any aggession tends to be kept within the group.

Adding more serpaes might help calm them down. It might not. The only surefire way to stop serpaes attacking other fish is to not keep them together.

The best thing for your guppies recovery will be pristine water and a stressfree environment. The breederbox doesnt provide this. Get them onto a tank on their own where you can do daily water changes until they recover. May as well make this tank their permanent home while you are at it. Once the fish have recovered, there is no reason why cycling the tank cant be done in a safe manner.

The best thing for your serpaes would get another 3 or 4 of them. Another 6 would be better still.

 

[Townie]

When we re-homed the danios, my wife got three more of the red tetras. One died a few days later but there are still 5 of them.

I keep telling her she either needs a small guppies only tank or not to keep guppies at all. For 8 small male guppies, is a 5 gal tank too small?

 

[Aiken Drum]

5g would be ok as a temporary hospital tank, but id go 10g for a permanent home.

 

[Andy Sager]

Hi,

My wife has a community tank with guppies, tetras, platties, panda catfish and a pleco. She used to have striped danios too but assumed they were the issue and re-homed them.

However we keep finding guppies with their fins/tails bitten off (esp the ones with big tails). One guppy is now bent. Any ideas where the aggression might be coming from or what to do? We’ve never seen it happen. Right now we have them segregated from in a small net breeder box in the corner.

I have suggested a small 2nd tank but she figures she’ll kill them all getting it to cycle given how long it took her to cycle our current tank.

Any suggestions?

Danios are not generally fin nippers so she rehomed the wrong fish. The Tetras are the most likely suspects ( as Aiken mentioned.) No fish with frilly colorful fins are safe with the majority of entire Tetra family.

To rapidly cycle a new aquarium, adding some filter material from an established tank or the squeezings from a sponge filter from an established tank will be adding the nitrifying bacteria immediately into the tank so the bacteria bed will establish and grow quickly ( unlike starting a new tank from scratch where you add nothing but ammonia. ) There are also products like Fritzyme #7 or Fritz Turbostart 700 which are live nitrifying bacteria cultures and will help establish a bacteria bed quite quickly.

One thing about keeping guppies by themselves: if you keep males only, they will be more colorful because they are trying to improve themselves over the other males in case a female happens to come along. There may be some fin nips when doing this but generally they are minor and are really rips more than nips and will heal quickly with good water and good diet. If you try to keep males and females together, you want to keep at least 2 -3 females to every male as they will constantly be harassing the females trying to breed. Without enough females to spread the attention, females can get stressed and die off. It's actually easier to keep 20 male guppies in a 10 gallon tank than it is 10 in a 5 gal. 5s are just too small for that kind of quantity. I would do no more than 3 males in a 5 gal.

Hope this helps.

 

[Colin_T]

What sort of tetras do you have?
Serpae, red-eye and black skirt/ widow tetras are all renown fin nippers and will rip guppies apart. Most tetras also come from water that is soft and acidic (pH below 7.0) whereas guppies come from harder water with a pH above 7.0. They should not be kept together because of water chemistry requirements and temperament.

Most tetras also need to be kept in groups of 10 or more. If you only have small numbers they stress and become much more aggressive when stressed out. Small tanks also contribute to stress because each fish needs its own personal space, and this applies to schooling fishes like tetras where every fish has its own space in the group.

If your unsure about what species of tetra you have, post pictures of them and we will try to identify them for you.

 

[Townie]

What sort of tetras do you have?
Serpae, red-eye and black skirt/ widow tetras are all renown fin nippers and will rip guppies apart. Most tetras also come from water that is soft and acidic (pH below 7.0) whereas guppies come from harder water with a pH above 7.0. They should not be kept together because of water chemistry requirements and temperament.

Most tetras also need to be kept in groups of 10 or more. If you only have small numbers they stress and become much more aggressive when stressed out. Small tanks also contribute to stress because each fish needs its own personal space, and this applies to schooling fishes like tetras where every fish has its own space in the group.

If your unsure about what species of tetra you have, post pictures of them and we will try to identify them for you.

Hi Colin,

Agreed, it’s definitely the Tetras (Serpaes and Red Eye’s).

 

[Townie]

Our daughter is taking the tetras and re-homing in her 125g aquarium. That’ll work best for everyone.