Thanks for the reply. I was thinking of adding the cats not only for more variety to the tank, but for population control of the fry. My concern was more for the cats getting bullied by the shellies.
As for tank size, I was thinking a 20L would be good for the shellies, but perhaps too small to add a few cats as well. If so, perhaps a 30 gallon, or 40 breeder. Thoughts?
I like the lamprologus occelatus.