IMHO- Pearl gouramis aka Trichogaster leeri!!! You should really look at
doing a species specific pearl gourami tank- they are gorgeous!!!
That being said my Mom has a 30g and she has 3 spot (she calls them blue
gouramis), and the gold ones. I've informed her they are the bigger gouramis
and she needs more space but she says they are happy and she's not gonna do
it right now (I think she's waiting for me to upgrade from my 55g so she can
inherit it). Anyway- she has a couple of each and I don't even think they
are pairs or anything like that. She probably has either all males or
females but she has nothing for them to bubblenest with in the tank so I
guess they wouldn't breed anyway.
So anyway... moral of the story? 4 fish in 30g and they all get along with
no major power struggles. Ergo... opaline (supposedly a spotless 3 spot), 3
spot and goldens are compatable tank mates (when not in breeding behavior).
They all get to be a pretty good size... 5-6" so maybe just breeding pairs
of opaline or 3 spot (maybe one of each?), snake-skinned (these guys are
sometimes hard to find), pearl and gold gouramis for your 55g? That's all
that would fit in your tank at mature size. Plus if you go by the 1":1g rule
that gives you about 5" of fish to play with... might I suggest some
Corydoras for bottom cleaning duties?
I've read somewhere on the net that the males will tear up plants at
breeding time. I would love to ask those who had this problem if they had
any floating type of plants (pennywort, duckweed, etc.) for the males to
bubble with? They may have been trying to make a nest and had no floating
plants to do this with so they were tearing up plants to get some nesting
material???
Here's a link for more info on labyrinth fish which has an "okay" pic of a
Pearl:
http://www.animalatlas.com/encyclo/f.../labyrinth.htm