Help please - rasbora fins shredded

Hi,

I woke up overnight and found that a few of my purple harlequin rasbora now have shredded or ripped tails.

The tank is a three foot wall aquarium so narrow. Occupants are: 6 harlequin rasbora, 1 otocinclus, 3 pygmy cories, 1 chilli rasbora and 1 sparkling gourami. The chilli and sparkling are leftovers from previous schools.

I did clean the tank yesterday and stirred up some junk in the substrate but have just tested the water this morning and everything looks good. 0 ammonia and 0 nitrite, 5 nitrate. So i don't think it's bacterial or water related.

The only thing I can think of is maybe the sparkling gourami attacked the Harlequins over night? I used to have a group of spaklings and they hunted all the shrimp I had in the tank to extinction so maybe it was just used to hunting things? The second last sparkling only died a couple weeks ago so maybe it's lonely?

If it's not the sparkling then maybe the Harlequins attacked each other? I always thought they were pretty peaceful though. I can't imaging the chilli rasbora, oto or pygmy cories nipping at tails.

What do you think? How do I help the Harlequins? Photo attached.




Thanks for any help or advice offered

put the gourami in a separate tank or breeding net with some plants and see how the rasboras go. if it happens again, it is not the gourami. sparkling gouramis aren't renown for fin nipping.

DeanoL83 said:

Hi,

I woke up overnight and found that a few of my purple harlequin rasbora now have shredded or ripped tails.

The tank is a three foot wall aquarium so narrow. Occupants are: 6 harlequin rasbora, 1 otocinclus, 3 pygmy cories, 1 chilli rasbora and 1 sparkling gourami. The chilli and sparkling are leftovers from previous schools.

I did clean the tank yesterday and stirred up some junk in the substrate but have just tested the water this morning and everything looks good. 0 ammonia and 0 nitrite, 5 nitrate. So i don't think it's bacterial or water related.

The only thing I can think of is maybe the sparkling gourami attacked the Harlequins over night? I used to have a group of spaklings and they hunted all the shrimp I had in the tank to extinction so maybe it was just used to hunting things? The second last sparkling only died a couple weeks ago so maybe it's lonely?

If it's not the sparkling then maybe the Harlequins attacked each other? I always thought they were pretty peaceful though. I can't imaging the chilli rasbora, oto or pygmy cories nipping at tails.

What do you think? How do I help the Harlequins? Photo attached.

View attachment 152756
View attachment 152757

Thanks for any help or advice offered

Click to expand...

Geeze! I’m sorry that’s happening. It reminds me of when I had 45 newborn platies in a breeder box. The bigger ones started eating the smaller ones tails. I think it’s happing again now that I’ve released the remaining 27 into the 10g with the smallest getting their tails picked on, but I can’t catch the culprit hope your rasboras get better!

foxgirl158 said:

Geeze! I’m sorry that’s happening. It reminds me of when I had 45 newborn platies in a breeder box. The bigger ones started eating the smaller ones tails. I think it’s happing again now that I’ve released the remaining 27 into the 10g with the smallest getting their tails picked on, but I can’t catch the culprit hope your rasboras get better!

Click to expand...

Sorry to hear about your platies! So annoying to not be able to see it happen and catch the culprit. Tank and all fish always look so peaceful whenever I am looking lol

Colin_T said:

put the gourami in a separate tank or breeding net with some plants and see how the rasboras go. if it happens again, it is not the gourami. sparkling gouramis aren't renown for fin nipping.

Click to expand...

Thanks Colin, I think I will separate the gourami for a bit. I'm surprised too cause nothing I've read said that they would nip.

Can you think of any other logical explanation though?

Also, is ther anything I can do to help the rasboras tails grow back or will they just heal over time?

Cheers

DeanoL83 said:

is there anything I can do to help the rasboras tails grow back or will they just heal over time?

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Keep the tank and filter clean with big daily water changes and gravel cleaning for a week.

Clean the filter if it hasn't been done in the last 2 weeks. Just wash the filter media/ materials in a bucket of tank water and re-use the media. Tip the dirty water on the lawn.

Feed the fish well on a varied diet.

They should heal up on their own. If it looks worse then add some salt.

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SALT
You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria, fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

If you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

DeanoL83 said:

Sorry to hear about your platies! So annoying to not be able to see it happen and catch the culprit. Tank and all fish always look so peaceful whenever I am looking lol

Click to expand...

Here’s my poor little one, his tail looks almost exactly like your rasboras!