RCS Sudden Death

[willythewhale]

One of my  Cory grow out tanks has a small number of  RCS as clean up brigade.

I notice they are suddenly afflicted in cruising round in circles ,then eventually lay flinching on the bottom  then die.

This is a very sudden thing .

The tank is established for months & because it houses young fry gets daily water changes.

The Cory fry seem unaffected. 

Can't see any visible clues on the shrimp. Water seems OK.

Only thing ,lots of planaria which has now been mostly cleared. I understand planaria is no threat.

I'd appreciate some guidance on what might have caused this problem & what action to take.

 

Cheers

[fishmosy]

Do you have measurements of the water parameters (pH, temperature, ammonia, nitrite, nitrate, ect.)? Seems like a water quality problem but can't be sure without the values.

Also have their been any sprays used near the tank? Similar symptoms can occur due to poisoning by aersols or insecticides.

[jayc]

One of my  Cory grow out tanks has a small number of  RCS as clean up brigade.

I notice they are suddenly afflicted in cruising round in circles ,then eventually lay flinching on the bottom  then die.

This is a very sudden thing .

The tank is established for months & because it houses young fry gets daily water changes.

The Cory fry seem unaffected. 

Can't see any visible clues on the shrimp. Water seems OK.

Only thing ,lots of planaria which has now been mostly cleared. I understand planaria is no threat.

I'd appreciate some guidance on what might have caused this problem & what action to take.

 

Cheers

 

 

There might be a couple of clues/oddities here...

I'm assuming you are talking about the shrimp that is cruising around in circles, flinch then die? Not the Cory.

That in itself seems unusual. I've never seen sick shrimp swim around in circles aimlessly.

 

If it happens suddenly, ie no sign of the shrimp looking sick and lethargic before ... is also worrying.

 

I know Corys are usually okay with shrimp, but not 100% guaranteed.

How big are the Cory's ? They might not be big enough to fit in their mouths. But it doesn't mean they can't take chomps out of their yummy looking legs or swimmerets. Ever seen a lion swallow wilderbeest whole? No. They take small chunks out of them. Same with fish. This might not be an area of concern if the fish are fry, as you said. But I'm just checking.

If the fish are large enough, check the shrimp for missing limbs or swimmerets - which could explain why they were swimming in circles, if it had a damaged tail, leg or swimmeret.

 

Water seems ok doesn't mean much. The things that would kill a shrimp, but is still okay for fish who are stronger, is not visible to the eye. You can't see ammonia, nitrite or nitrates. You won't be able to see copper, or other toxic substances at the small levels that would kill shrimp. You need to get the water parameters tested as Fishmosy has indicated. I'd add TDS to the list he mentions above.

 

You mentioned planaria, and it's now under control. How did you get it under control?

With medication? What sort?

Did you treat the tank with meds for planaria recently? After all the planaria died, did you do a large water change to get rid of possible ammonia spike from the dead planaria?

 

Hopefully we can help you narrow it down to a possible cause, and save your pets.

Edited February 6, 2015 by jayc

[ineke]

I have had Corys in with shrimp and have seen them attack the shrimp so took them out. As JayC mentioned it is possible that they are getting bitten by the fish.

[BlueBolts]

I'd interrogate the household for use of pesticides/sprays. I'd do a water change immediately.

[inverted]

I'd interrogate the household for use of pesticides/sprays. I'd do a water change immediately.

I did this once...lol

And then realised I'd manually turned on the co2 and left it on for 2 days.