Now, I am observing all of them better (turn lights down on low anyway) and notice that sometimes when at rest the others have their fins down a bit as well. The other cories I have (bronze and some sort of spotted one) I have not seen this in before. They are all active, eating well, so could it be that a certain type behaves differently when at rest? At any rate, have set up hospital tank with same water et al, just in case. Thanks for any thoughts from worry wart me. Best Sherry

Top fins don't always stand up high.

I've found with my cories if I see something going on, water changes help out. They're hardy little fish - but they do get hit every once in a while (sometimes fungus, sometimes ich seems to strike one or another - usually when I've neglected the tank a bit)

Bronze cories are very hardy.

Here's a good link:

Here is a link that might be useful: planet catfish - corydoras

Thanks Skygee, I think he is ok, and again, don't see any other signs. He swims around a lot, but rest on this one leaf... guess I am used to the bronze cories which rest on the bottom... these have spots and bands... guess I thought they have to stand straight up, lol... will watch carefully. (did the usual partial water change, guess I am nervous as to where they came from, lfs tank with fungus).

Just reading that due to the nature of bottom feeders ie catfish, they have pretty hardy immune systems. Like rats! I am pretty good at tank maintanence. Thanks for link Sherry

Sherry......I am wondering if you are stressing yourself out for nothing. Cories will sit with their fins up, down and part way in-between.

Now having said that....When you bring in new fish....I HIGHLY recomment quarantine for 6 weeks to 2 month or longer.....even if you think they look healthy. Sometimes once they have been exposed to something in the pet stores...it doesn't show up right away......sometimes it takes a good 2 months to see signs and symptoms.

Are your corys ...Corydoras punctatus?

If you still suspect a problem with your cories.....put them in a seperate tank.....and do small partial water changes daily......watch when you feed to make sure they are all eating.

Sierra