corydora attacked a guppy?!

My fiance has a 10 gal . In it were 4 guppies, and 1 bronze cory, and 1 albino cory. Tuesday I bought him 2 female guppies, and he bought a female guppy. He took them and the albino and bronze cories from my tank that had 3 fancy guppies, 3 common guppies, 2 female bettas, and 3 spotted cories. He texted me about 3-4 am this morning that one of his cories was attacking one of the female guppies! the cories had eaten the fins completely off of one female and were chewing on the other. He's been feeding mostly betta food (he has a solitary female betta and his dad gave him the leftover food when his mom's betta died) flakes, pellets, and f-d bloodworms. Any ideas what would cause the attacks?

 

I would think the guppies must have died and the cories were scavenging them as I've personally never heard of them being agressive. However, maybe someone with more experience may have some insight.

 

That does sound extremely unusual for a cory...no idea what could be causing it, if he actually attacked it. Chances are, as Matt said, it was dead already and being scavenged.

 

He said the guppy was still trying to swim away as the cory was attacking. I double checked that when he first freaked out about it.

 

I would have to see it first hand and then I still probably wouldnt believe it. I have never heard of a cory attacking another fish. Agree with the other answers that the guppy was dead.

 

So really you're saying that because YOU've never seen it, it couldn't have happened to someone else? Anything with a mouth is capable of biting, simply because you've never heard of it happening doesn't mean it's impossible. And I believe my fiance when he said the guppy was STILL SWIMMING during the attacks. If this is the kind of answers I'm going to get, then I can see that joining this forum was a waste of time. thanks.

 

I think people are balking at the idea because your cories don't really have the dentition to attack and kill a healthy fish. Another possibility is you don't have cories at all but rather "mimics". Some species of predatory catfish mimic cories at a young age and can and will kill and eat other fish. Do a google search on cory mimics and see if that is a possibility. Again, hopefully a more experienced member will come along with some more insight.

 

How are his fish now? Hopefully the guppy is ok.

 

Possibly, the guppy was sick, the cory is taking advantage of that. Yes, it can still be swimming, but if its sick, then its down for the count. Cory don't have the ability to actually take out a fish, no real teeth there . Now of course, the tank, both hers and yours are over stocked, so that may have aided the issue. You can have maybe 6 guppys in a tank, that's stock. Cory don't belong in anything less then 20gals, with 6 of their own species. WITH the exception of pygmy cory and dwarf cory species. Female bettas are SOLITARY fish. They don't particularly like having another female around unless its in a divided tank, or a large sorority tank. Regardless of how they seems to be doing fine, they are simply tolerating. At no point in time are 2 bettas in the same undivided tank happy with each other, ever(breeding may be an exception, still pretty violent.). Cory are also omnivores. They need more then betta food to survive, so do gups. Bettas need Protein, they are carnivores, a good betta food is not a good cory or guppy food.

 

Betta food is only one of a few food types her partner is feeding, according to the first post. Also pellets, flakes and freeze dried blood worms are on the menu. It's a pretty rounded diet, and unlikely causing any issues

 

Cories are unlikely to attack other fish. There is always an exception to every rule. My guess would be that the guppy was either ill or was attacked by another fish in the tank. Because cories are scavengers and because the fish was weakened, they went in for the kill. It's kind of like Darwin's theory of evolution.....

If you walk into a pet store of ill repute and see dying fish in the tank but that are still swimming, observe the tank. You will see other fish picking, nipping, biting, and eating the ill fish that is still alive. It's gross, but a part of nature.

Hopefully you don't have a mutant zombie cory!

 

So really you're saying that because YOU've never seen it, it couldn't have happened to someone else? Anything with a mouth is capable of biting, simply because you've never heard of it happening doesn't mean it's impossible. And I believe my fiance when he said the guppy was STILL SWIMMING during the attacks. If this is the kind of answers I'm going to get, then I can see that joining this forum was a waste of time. thanks.

You join a forum to hear what people with some experience have to say about the issue. Nobody was being rude about it and I don't think any of the responses you received warranted you to be rude either. Nobody was calling your boyfriend a liar just simply stating that it is unheard of for a cory to attack another fish. I guess the answer you were looking for is maybe your cory has rabies?

 

My fiance has a 10 gal . In it were 4 guppies, and 1 bronze cory, and 1 albino cory. Tuesday I bought him 2 female guppies, and he bought a female guppy. He took them and the albino and bronze cories from my tank that had 3 fancy guppies, 3 common guppies, 2 female bettas, and 3 spotted cories. He texted me about 3-4 am this morning that one of his cories was attacking one of the female guppies! the cories had eaten the fins completely off of one female and were chewing on the other. He's been feeding mostly betta food (he has a solitary female betta and his dad gave him the leftover food when his mom's betta died) flakes, pellets, and f-d bloodworms. Any ideas what would cause the attacks?

Welcome to fishlore. I'm sorry your fiance had such an unpleasant experience. Can you take the cories back until your fiance can get a more suitable tank with room for the cories to be in a school of 6?

 

Yeah, I didn't mean he was lying...just that sometimes things can be mistaken, and that I have never heard of a cory attacking another fish...if he did, he did, but I have to say I wouldn't know why.

 

I'm sorry to hear about your fish.

I too am going to have to agree that the guppy was probably sick and or dying and that's what was happening. Cory's are usually very peaceful but I am sure, like any other fish, if it saw something dying, it would probably go after it like food.

Hopefully you will be able to rehome some of the fish - they may be stressed due to being overstocked and also the issue with Bettas being a solitary fish.

Good luck!