yesterday I found 6 small, brownish Otocinclus-like fish, and since I have a soft spot for rare fish, I could not resist (the fact the only cost 2 euro's a piece probably also played a role, though

I'd like to know what species they are, and how to take proper care of them (water chemistry, temperature, food, tank set-up).
The pictures aren't that great, as the fish are not really cooperative. But hopefully they're clear enough.




Thanks in advance!