Are Corys Safe With Male Bettas?

[andyw823]

Got 3 Corys to keep with my male Betta in a 25 litre tank, they have been in the tank now for approx 5 hours. Just spotted one upside down at the bottom of the tank half dead, its side is swollen and red, could the Betta have done this?

 

[wuvmybetta]

He *could* have, it's only been 5 hours so did you notice if he was especilly aggressive towards them? Some males don't care, some think it's a new plaything. It all depends on the male.

But, since it happened so quickly, I would imagine it was most likely the betta judging by the description of the wound. What's he doing now, stalking out the other ones?

 

[andyw823]

He never seemed interested in them when i first put them in. He is just resting near the top of the tank as normal!

 

[wuvmybetta]

Maybe it wasn't him then, poor guy,guilty before proven innocent!

Has the tank been cycled? Are the others doing okay?
I've never kept cories so I'm not sure how they react to a dead fish, I know some cats have NO problems eating or gnawing on deadies, could the cory have died due to shock and the others gave him the red marks afterwards?

 

[andyw823]

The tank is new but ive used 80-90% of the water from my community tank, also before i added the Betta to his new home the filter sponge was in the communtiy fiter for a day or so to collect some bacteria .
Well the little cory has just gone to fishy heaven poor thing. The other 2 seem fine and have just had some bloodworm, so who knows if he was guilty or not!!

 

[wuvmybetta]

Tough call, just watch the others closely, typically bettas are fine with cories.

 

[dwarfgourami]

Red marks are likely to have been from a bacterial infection, which corys are quite prone too. You want to watch the remaining ones, especially as that is quite a small tank you've got them in (c. 6 gallons). Keep the substrate clean. And keep an eye on the state of their barbels.

Hang on, just spotted something. Your tank wasn't cycled! Adding water from another tank is not going to do it as most of the bacteria live on the filter media+ some on the substrate, very little in the actual water column. And a day won't have been enough to seed the filter media in the ohter tank, you;d need about 2 weeks for that probably. And the tank was most likely overstocked as well, what with 3 corys and the betta.

What are your water stats now? You probably need to keep doing water changes.