Bandit Cory's kill Panda Cory's?

Backer

Hey guys and gals,

I recently bought a handful of "panda cory's", but when I got home, one was substantially larger than all the others. This leads me to think that the big one may have been a bandit cory, as that is easy enough to do. Anyway long story short after about 2-3 weeks all of the other small cory's died. Now I only have the big one left. I think that this "bandit" cory may have just out competed them for food and picked on the smaller ones. Most of the smaller ones had roughed up tail fins before they died.

Could this be plausible or am I way out to lunch and something else is going on in the tank?

Ps. Tank paramaters are the same they have always been. Housing 11 White Cloud Mountain Minnows.
The day I added the cory's I added more mountain minnows. They are all fine.

JDM

From anything anyone has said about corys, I might doubt you have a bully. How many is a "handful"?

The water parameters may not have changed but you added new fish that died... what are the parameters as they may point to something unusual as it relates to corys?

Jeff.

jentralala

What are the exact parameters? From what I understand corys are incredibly sensitive to ammonia/nitrite/nitrate, conditions in your tank may be adversely affecting them. Another guess would be that you say you added both the corys and mountain minnows at once...this is a lot of impact on the beneficial bacteria. You may have had an ammonia spike that led to their death.

As to roughed up tail fins..I don't know.

Jakiebabie

And Panda Corys are one of the hardest to keep alive. But I would still keep an eye on the other guy.

Backer

The other guy has been fine fro well over a month now, and I didnt see any spikes in levels at all. I will take some today and post them. the tank had been cycled and just the cory's died. I don't really want to buy any more (I had 5) until I have a reasonable idea of what happened. It COULD have been an ammonia spike, and the biggest, hardiest cory was the only survivor.

Byron

The corydoradinae do not have permanent teeth as we understand them, or as fish like the characins (tetra, etc) do. Premaxillary teeth only occur in fry and juveniles and these are then lost since the fish does not need them due to its benthic feeding. So any fin damage is not due to a cory, ever. Plus, I have never heard of a "mean" cory, though one may exist somewhere I suppose; but this has to be the most docile of fish.

As someone mentioned, Corydoras panda is one of the most sensitive species, notwithstanding the fact that they are now being commercially raised. One often expects wild caught fish to be more fussy.

I would get more, but be very slow with acclimating them. This is one of the most social species; mine are together almost all the time.

Byron.

Backer

Beauty, many thanks guys!

My game plan will be as follows:
A) take some readings, make sure we are in the clear.
B) if we are in the clear there, I will go get 4 or so to make a total of five and add them very very slowly.
C) let you guys know how it goes!!

p.s. I didn't know that about panda's, thanks