Three dead corys in two days

bholt

Still Learning
Apr 28, 2005
7
0
0
Takoma Park, MD
I have lost 3 of my corydoras in the last 2 days. I have never lost any other fish in my main tank before this (only in quarantine).:sad:

I've had 3 sterba's corys that have seemed happy and healthy since I added them to the tank in May. About 2 months ago I bought 3 panda corys. Two of them died during their first week in the quarantine tank. The third survived all 4 weeks of quarantine and is now living happily in my main tank. I wanted to get him some companions, so I bought two more panda corys on Monday. I didn't quarantine them this time (wondered if the starkness of the quarantine tank might have stressed out my previous two lost fish). Found both of the new panda corys dead yesterday. Then I found one of my sterba's corys dead today.

All of the dead corys had their tails chewed down to a nub. Not sure if that is related to the cause of death, or if it happened after they were goners. Anyone know what's going on here? :huh: The only unusual event has been adding the two new panda corys on Monday, and giving the tank some live brine shrimp to eat (which I've only done a few times before).

Tank is 30 gallons, moderately planted, temp 80 degrees, 7.0 pH, Nitrate < 10, Nitrite 0, Ammonia 0, GH 150, KH 120. I add Flourish Excel every other day (amount recommended on bottle) and regular Flourish once or twice a week (again, recommended amount per dose). Regular 33-50% water changes once a week. The other fish are 8 harlequin rasboras, 3 amano shrimp and a siamese algae eater. 2 Sterba's corys and 1 panda cory still surviving. AquaClear 70 filter creates quite a current, and surface disturbance, so I think aeration is OK. Stats have all been consistent through the last 3-4 months.
 
Rasboras harassing the corys?
Eaten fins sounds like something it bothering them. :(
 
how big is your siamese algae eater? true siamese are peaceful, but very often they are actually mislabeled chinese algae eaters, which get big and aggressive, enough to start gnawing on other fish. corys are fairly calm, slow fish, and would be good targets for a hungry CAE
 
Its also just possible you've gotten unlucky :huh: ...Corys can be kind of sensitive and if your tank parameter were much different from the stores, or if they had some sort of problem you couldn't see, the stress of the move might have been too much for them. I just put 3 new corys in a QT tank and was worried about them for a couple of days, they just didn't seem right.
I would definately QT any new ones in the future to safegaurd your main tank
 
I tend to lean towards chicken. SAE do get very aggressive and is know to chew fins, ect off fish.

It is also possible he is eatting them after they die, but still think the SAE is your problem.

H. Rasboras are not fin nippers.
 
Thanks for the feedback

A lot of good answers. Thank you all.

I'll keep an eye on the SAE and look for aggressive tendencies. I'm pretty sure it's a true SAE since I closely examined the pictures on the web that explain how to spot the real SAEs from the CAEs.
 
Oh, Great.... I had No clue that SAE'S were aggressive.... One of my little juvinile cory's has a munched tail.... and i couldn't figure out why.... Now, I will definitly keep and eye peeled............
 
AquariaCentral.com