I recently added 4 new multi's to my multi tank. There is 1 new male and 3 new females in the tank now, along with the pair I already had in the tank (tank is a bowfront Eclipse 12). Both of the older inhabitants are much more lively now having more tankmates, and the two males seem to constantly shift control of the tank. However, two of the new females are always at the surface. They eat better than the others and have just as healthy fins and body shape. Should I be concerned that they aren't staking out claims in the shells like the rest?