Although many South and Central American cichlids live in multiple species communities, haitiensus is the only endemic cichlid to its island. This is a fairly unique situation, and may give an indication why it does not play well with others.
It also tends to prefer a unique temperature requirement.
Its natural waters usually hover in the high 80s to low 90s.
http://www.cichlidae.com/article.php?id=55
This is quite different than the mid to high 70s that most mainland cichlids live in, making haitiensus a bit of a special case.
Through trial and error, many deaths, and research I was able to maintain a healthy group, and breeding pair
When first working with haitiensus, I found if they could not kill tank mates, the stress would lead them to bloat.
And at any temps lower than the low 80s, bloat and ich were also issues.
They may have evolved to digest protein at higher temps than normal, and may be why at lower temps they seem to become lethargic, and whither away.
Of course there may be exceptions, as aquarium strains become more tolerant, but a few generations in an aquarium compared with a million years or evolution in a certain environment, make me believe that research into special needs, leads to a happier aquarium end.
Saving the few individuals of a spawn that survive lower temps, and breeding them together, may at some point select for a lower temp haitiensus strain.
Or selecting only less belligerent individuals, and breeding those together could at some point produce a community type.
I believe xCichlsoma beani is also the only cichlid in its natural waters, and in temperament, very much mirrors the same aggressive quality as haitiensus.
Where it differs however, (being the most northern reaching cichlid on the Mexican Pacific coast) it seems to require lower temps. At high temps, they seem be susceptible to the bacteria Flexibactor columnaris.
