My cuttles were introduced into the main tank that at about 2-3 months. Aprrox 3/4" to 1".
First Id like to say that although I have found success with attempting tankmates with bandensis, there is not much other information available on this and there is always a chance that my experiences are isolated.
However, my methods and suggestions to introduce other animals into a sepia tank are the following.
-Have your bandensis settled into the main tank for a couple weeks before introducing new tankmates. This way, the bandensis have already taken on thier territories.
-Place a clear plastic breeder in the main tank where it is clearly visible to the bandensis.
-Place the new tankmate in the breeder and leave in here for a day or two so you can observe the bandensis behaviour.
-For the most part, look for signs of hostility like male flashing of aggression or actually striking at the breeder.
- If none are found, release the animal into the tank
I introduced seahorses about 3-4 inches. I saw no sign of aggression. Actually they didnt seem to even care. I never had problems with them for they outlived the cuttles when they died of old age.
I also introduced a yellow tang and a month later a blue tang. Bandensis showed curiosity, but no aggression at all. If anything, the yellow tang was more aggressive. The tang showed some territorial behaviours with the cuttles, but nothing that ever concerned me.
The blue tang never had any issues with the cuttles as they seemed to live harmoniously.
The clam was in the tank prior to the introduction of the cuttles and was never bothered. Unlike octos, cuttles dont seem interested in snails or clams. Even hermits seem to be uninteresting to them.