Like with any species the temperament varies with the individual, the last one I kept years ago was anything but placid. Regularly pushing all the other inhabitants around. It did not attempt to kill the smaller tankmates, haps, nimbos etc until they got over the six inch mark but I failed to stock anything above that size with the Milomo in the aquarium. This was a bulky 8-9" specimen. Beautiful but problematic in the future I will only keep species like this in larger aquariums as my 180 wasn't enough.