Picked up this spotted climbing perch yesterday. Mine's only about 1.5" - 2" but they supposedly get to about 6 - 8" and should make a good centerpiece specimen for a 55g. I've been told they like to hide, but mine seems to enjoy coming out and about in my planted tank. I'm not too sure about your current tankmates, however. I only have guppies with mine so far and I assume he'll help keep the numbers down. lol.