On Sat, 29 Dec 2007 23:42:59 -0600, Reel McKoi wrote:

Are you sure they not those small
snail eggs? Are there any small snails in your tank? Most smaller fish
scatter their eggs all over plants, they don't stick them to glass like
Angel fish and a few others. Also, any that are stuck where other fish can
find them are quickly eaten.

In my experience (YMMV) snail eggs tend to be a mass. Catfish eggs may be
attached to the glass in close proximity to each other, but each is a
separate entity.

And I have sat and watched my albino cory cats attach each egg singly to
the glass. They mate and the female carries an egg to the glass in her
fins and ataches it. If the original poster watches in the morning before
the tank lights come he may observe that behavior.