Is my betta fish afraid of cory catfish?

[Surly]

I just set up a 10-gallon tank with my betta and some Emerald cory catfish, but now he's freaking out whenever the cories make sudden moves. I'm not sure what to do - should I just give him space and let him get accustomed to their behavior or is there something I can do to help him feel more at ease?

[boomer]

I must advise against housing a male betta with other fish. It's not uncommon for bettas to take a dislike to tankmates, or for those tankmates to harass the betta, particularly if they're sedate and have long fins. While cories are generally a safer choice, I wouldn't personally recommend it. The cories can't inflict the same damage as mid-water swimmers, but their sudden movements may still be irritating the betta. If your betta was previously living alone, the sudden introduction of other fish could be unsettling for him. It's essential to monitor the situation closely, as things could escalate quickly - it really depends on the individual fish.

By the way, I'm curious - which species are your "Emerald Corys"? I've seen this name used to describe both Corydoras aeneus and Corydoras (Brochis) splendens. The latter grows larger and requires more space.

[Surly]

I must advise against housing a male betta with other fish. It's not uncommon for bettas to take a dislike to tankmates, or for those tankmates to harass the betta, particularly if they're sedate and have long fins. While cories are generally a safer choice, I wouldn't personally recommend it. The cories can't inflict the same damage as mid-water swimmers, but their sudden movements may still be irritating the betta. If your betta was previously living alone, the sudden introduction of other fish could be unsettling for him. It's essential to monitor the situation closely, as things could escalate quickly - it really depends on the individual fish.

By the way, I'm curious - which species are your "Emerald Corys"? I've seen this name used to describe both Corydoras aeneus and Corydoras (Brochis) splendens. The latter grows larger and requires more space.

thanks for the advice, and to answer your question, i'm pretty sure mine are the aeneus cory - i've had them for a while now, got them at petsmart and they were labeled as 'emerald green cory'

[boomer]

I just set up a 10-gallon tank with my betta and some Emerald cory catfish, but now he's freaking out whenever the cories make sudden moves. I'm not sure what to do - should I just give him space and let him get accustomed to their behavior or is there something I can do to help him feel more at ease?

I'll post some pics of the two species for comparison. The dorsal fin is quite distinct between them, so that's the key thing to look for. Don't worry too much about the body color of the C. aeneus, as it can vary quite a bit - the size and dorsal fin shape are the main giveaways.