Amano's arched bridge designs

[matti]

I've had one of my smallest Amanos arching its back in my 60L for over two weeks now, and it hasn't gone back to normal. My Amanos in that tank are getting up there in age - over three years old. I'm wondering if this could be a sign of old age, especially since my largest one passed away a few days ago, which I'm assuming was due to old age.

Any ideas on what might have caused it?

I've been thinking - could it be Muscular Necrosis?

[coltin]

Is its body colour normally arched like that or did that start a few weeks ago too? What did the other one that died look like in terms of its body colour?

If the muscle tissue is turning a milky white or cream colour, then I'm worried it might be a microsporidian infection. That would be a concern since it can spread to other fish or shrimp that have come into contact with the infected body.

If that's the case, I'd suggest treating it with salt. I'd use rock salt, swimming pool salt, or non-iodised salt - just 2 heaped tablespoons per 20 litres for at least 2 weeks but no more than 4. I've heard that can cause kidney damage if left for too long, especially for fish from soft water like tetras or Corydoras.

When I add the salt, I'll make sure to mix it in a small bucket of tank water first, then slowly pour it into the tank near the filter outlet over a couple of minutes. And if I do water changes while using salt, I'll treat the new water with salt before adding it to the tank to keep the salt level stable.

After the treatment, I'll do 10% water changes each day for a week using fresh, dechlorinated water, then 20% water changes each day for a week, and then bigger water changes after that to slowly dilute the salt out of the tank.

[matti]

Is its body colour normally arched like that or did that start a few weeks ago too? What did the other one that died look like in terms of its body colour?

If the muscle tissue is turning a milky white or cream colour, then I'm worried it might be a microsporidian infection. That would be a concern since it can spread to other fish or shrimp that have come into contact with the infected body.

If that's the case, I'd suggest treating it with salt. I'd use rock salt, swimming pool salt, or non-iodised salt - just 2 heaped tablespoons per 20 litres for at least 2 weeks but no more than 4. I've heard that can cause kidney damage if left for too long, especially for fish from soft water like tetras or Corydoras.

When I add the salt, I'll make sure to mix it in a small bucket of tank water first, then slowly pour it into the tank near the filter outlet over a couple of minutes. And if I do water changes while using salt, I'll treat the new water with salt before adding it to the tank to keep the salt level stable.

After the treatment, I'll do 10% water changes each day for a week using fresh, dechlorinated water, then 20% water changes each day for a week, and then bigger water changes after that to slowly dilute the salt out of the tank.

1. The colour change actually coincided with its back arching - happened around a week or two ago.

2. As for the one that passed away, it went into hiding for a few days, then I found it during a water change. It had turned a bright pink colour and had a strong smell. I did an 80% water change that day, knowing the carcass would've caused a spike in ammonia levels.

If the muscle tissue changing colour and turning milky white/cream is a sign of microsporidian infection, then that's probably what's going on here. And if that's the case, salt treatment might be the way to go.

It's likely that's the issue, and I do have salt on hand, which is a plus. The challenge now is catching the affected shrimp.