First CPD causualty today

[seangee]

I have had a group of around 25 for about 15 months. Today I discovered this one spiralling around and spending a lot of time on his side. He was also quite bent (laterally). Nothing has been added to the tank recently and the only other tankmates are red cherry shrimp, malaysian trumpet snails and a single nerite snail. I have now put him out of his misery. I am assuming it was natural causes and the hole in his side was either from a physical injury or his tankmates having a go when he was down and out. Basic parameters:
dGH: 6
dKH: 3
Ammonia: 0
Nitrite: 0
Nitrate: <5ppm
pH: 7
Temp: 27C (usually kept at 23 but its been a bit warm in the UK for the last week or so).
I change 75% water weekly and the only other thing I have changed in the last month is to put in a more powerful pump to ensure adequate oxygenation through the warmer months

Everything else in the tank appears normal and healthy. Just posting the pic in case somebody tells me my diagnosis is wrong and I should be treating something.

As an aside I have seen conflicting info on their lifespan, with some sources suggesting as low as 1-2 years. Guess I had better get on with breeding the next generation if that's true.

 

[Colin_T]

Fish spinning or spiralling through the water normally have a protozoan or bacterial infection in the brain. This is usually caused by a dirty tank. High water temperatures encourage bacteria, protozoa and other microscopic organisms to grow faster.

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Wipe the inside of the glass down and do a 75% water change and gravel clean the substrate every day for 2 weeks. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. Wash filter media in a bucket of tank water.

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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.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 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, 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 but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

 

[seangee]

Fish spinning or spiralling through the water normally have a protozoan or bacterial infection in the brain. This is usually caused by a dirty tank. High water temperatures encourage bacteria, protozoa and other microscopic organisms to grow faster.

12 hours later and all still seems well. Have done a w/c today (tank was done as usual on Friday).

My concern was more about the nature of the wound, its a lot more than skin deep. It does look like its been eaten. The spiralling was minimal, there was some swimming in circles and plenty of lying on its side, both on the substrate and near the surface. The fish was completely exhausted.

Will continue to keep a close eye on things.