Should I take out this one and vent it? Would that help?
-Andrew
Yea if you really need to know that bad. Then put him in a different tank because that one is over stocked and dirty. Question why do you want to know that bad? Are you going to breed? You said you were thinking of getting rid of your stock.
I need to spark up my fish life

Also doesn't have quite such a good body shape. Compatible to my big male.
That could be because s/he is under fed. If you are looking at breeding JDs you might want to take everything else out of the tank. Also wouldn't hurt to put the smaller JD in a decently sized hospital/quarantine tank to bulk him/her up (I keep spare 55s/75s on hand if I ever need to do this - stock up when you see dollar per gallon sales!).
That could be because s/he is under fed. If you are looking at breeding JDs you might want to take everything else out of the tank. Also wouldn't hurt to put the smaller JD in a decently sized hospital/quarantine tank to bulk him/her up (I keep spare 55s/75s on hand if I ever need to do this - stock up when you see dollar per gallon sales!).