If you're asking about the serpae's, then the same size as most other tetras, about 1-2 inches. For the Con's, they get to about 4-6". I'd be willing to bet that the cats will eat both (not necessarily all of them, but definitely some of them). And if the cats aren't interested in the tetras, the O's probably will be.mqktandy;4668441; said:I will look into them thanks. How large do they grow? Also convicts size? Luckily my cats ignore other fish. Even the rtc has never shown intrest in the smaller fish. I never feed live to any fish while growing them out. I'll add a bunch of small caves and plants around the sides for them if I get them.