Watch out for chinese algae eaters, one of mine, a 10cm one pinned down a 2cm sev and sucked on him, not killing it right away, but it did die from shock, they fight with alot of fish including alot of cichlids, oscars will eat them up right away as well. They are also a cold water fish, and breed in warmer water. But get ready as they are pretty agressive. I was breeding this fish once, dunno how, but just did, i brought 6 and ended up with 18 witch tells me they are not good perants.