[ralphie16]

Lee I posted this question on another forum but really wanted to get your input. I have a 4" Arothron diadematus in my 125 gallon tank for almost a year now. I had him at one point with a Porcupine Puffer but that did not work out because the Porcupine Puffer hurt him one day several times. He was also with a 2" picasso trigger who also started attacking him, so I had to move him out too to my 220. The panda is a very shy fish and lives well with a Teardrop Butterfly and Idol at the moment. I will be moving the Idol out of the tank soon and I was wondering if any other puffer would do well with my Panda Puffer. He is extremely passive and will not do well with any sort of aggression. Would any other Arothron be suitable tankmate for him? A dog-face ok? How about the black-morph Arothron spp? Since the panda is so passive, if it does not work out with another puffer, and as a backup plan can I move the new puffer into my 220 with the porcupine puffer even though he has showed a disliking to the panda would he be fine with a more assertive species or arothron?

[ralphie16]

the last sentence i meant to write "with a more assertive species of arothron"

[leebca]

I don't have any personal experience with this species. However, I can speak only in generalities.

The Panda Puffer is actually a variation of the Dogface Puffer. It should hold up its own against most other assertive fishes. The fact that yours doesn't means there is something about that fish that the other fish sense is 'wrong' (e.g., ill, weak, injured, mal-nourished, etc.) When Mother Nature sends the signal of a fish in trouble, many 'peaceful fishes' will attack the 'wrong' fish.

The second scenario is that the Panda Puffer you have just happens to be a coward, personality-wise and the other fish know.

A third: both of the above are happening at the same time.

In any of the above situations, the tank mate issues go out the door. What should work, may not or will not work. Thus, I can't really say with any confidence what mates it should be setup with. The ones you've listed where it hasn't gotten along are the ones it should get along with. See the problem?

Any thing I could recommend is pure speculation -- a guessing game -- based upon a 'wrong' fish or one that is too shy for its species, or the combo of both.

This leaves only one solution I can see. This Panda you own has to be kept alone or with large fish that are confident (but neither assertive or aggressive) in captivity.

[ralphie16]

Would the standard dog-faced puffer Arothron nigropunctatus fit into the category of large and not aggressive?

And when you say large tankmates does that mean he will eat smaller fish like Pterapogon kauderni (Banggai Cardinalfish) and Midas Blennies?

[ralphie16]

I re-read your post and can answer the question about the dogface but the second question I would still like to know.

[leebca]

The 'usual' Panda Puffer would consider any small fish to be potential food. It would also attack slightly larger fishes to weaken or 'test them' into submission to eat. Unlike many predatory fishes where the rule is smaller than a little bigger than their mouth, the co-habiting fish with the Panda doesn't have to be just larger than the predator's mouth, but large and healthy to keep away from the predator. Preferable tank mates are those that are also predatory and assertive (not so much aggressive).

The normally sized Cardinals of that species would be food.

Since the Puffer watches the substrate for any tasty morsel of the crustacean kind, it might consider any sand sifting or bottom dwelling fish as potential food. The Midas Blenny tends to spend much time perched on rock and, being a carnivore, has predatory and assertive tendencies too. If you get an MB on the large side (over 3") I think it may do well with a Panda Puffer of a small size (under 5"). In the case of your specific Panda, I think it would be a high probability of success to put these two together.