I got a couple of these little guys a few months ago, interesting little guys and good snail eaters.
There is one in the plants under the shrimp which gives an idea of how samll they are.
Fishbase lists them as brackish while fishprofiles list them as freshwater. I have kept them in fresh
since I got them and the LFS told me they were fresh water which is what they kept them in. They
are doing fine anyway.