The single one in the tank with the grama appears to have settled his differences, and is getting along nicely now. Of the two remaining in the 50, one is a little larger, and has staked out a territory. Unfortunately that territory is owned by the Lemonpeel. He occasionally tries to put the run on the Lemonpeel, but that only results in getting the Lemonpeel PO"d. He then gets chased until the Lemonpeel can no longer see him. It really appears to be a somewhat fruitless bit of exercise for both combatants.
