I've got 2 bronze cories and 2 'leopard' cories (pretty sure they're trilineatus), in a fairly new tank with 4 small zebra danios and 2 tiny otos. The cories have been in there nearly a month. All 4 cories were very nervous at first, and would hide if anyone came near the tank, but now the bronze cories are always out and about, digging and dancing, usually together but not always. But the leopards are so shy. Except at feeding time, they're almost always together, generally hiding under a plant or decor near the back of the tank. They come out to eat and scoff their food enthusiastically, shoving the greedy danios out of the way when necessary, they look healthy and they've definitely grown since I got them. They're a little more active in the evening, but not anything like as busy as the bronzes. I read that cories of different species will swim together, but these rarely mix with the bronzes.
My water isn't perfect (due to nitrite in the tap water (thanks Anglian Water
) so I get a slight nitrite reading after every water change, nitrate around 30, pH about 7.9, 24.5C) but no ammonia, and the nitrite has never gone above 0.1. The tank is under-stocked as it's new. None of the other fish have any signs of illness or discomfort, and when one of the bronzes cut himself a couple of weeks ago, it healed really quickly, so they seem to be doing OK. Do you think the leopards are just naturally shyer than the bronzes, or should I be worried about them? Would they be more sociable if I got more of the same or are the tank conditions stressing them? Would they be showing other signs if they were unhappy?
My water isn't perfect (due to nitrite in the tap water (thanks Anglian Water
) so I get a slight nitrite reading after every water change, nitrate around 30, pH about 7.9, 24.5C) but no ammonia, and the nitrite has never gone above 0.1. The tank is under-stocked as it's new. None of the other fish have any signs of illness or discomfort, and when one of the bronzes cut himself a couple of weeks ago, it healed really quickly, so they seem to be doing OK. Do you think the leopards are just naturally shyer than the bronzes, or should I be worried about them? Would they be more sociable if I got more of the same or are the tank conditions stressing them? Would they be showing other signs if they were unhappy?
they are always at the front of the tank dancing about....the bronze when I first got them were very shy but since adding a lot more cory to the tank...they have tended to venture out more....(mind you with my face stuck up against the tank) I am not surprised they do not wanna come out sometimes 
) and I don't have a huge tank so need to be careful...
The Pulchers although wild caught also come to the front and line up at the glass and watch me, but they run and hide when I come to their tank, watching me from the undercover. The julii/trilis line up at the back and face the other way with their tank mates the areio. The blacks which have not been wild for many generations couldn't care less. The long fin albino peppers also hang and hardly move when I appear, other than to beg for food.
- even for a small tank!
