Haptosquilla glyptocercus are long lived and tough. I have had some in the lab for 4 years. THey don't get that large - usually only 35-40 mm total length, so it will be fine in your system. I often keep them in 1 liter tubs with no circulation or filtration and they do fine for years as long as I change the water twice a week after feeding.
Generally, females are dark and males are a cream and green or brown mottle color.
This species occurs higher in the intertidal than almost any other stomatopod, so they are adapted to periods of hot, foul water. For someone who wants a small, desktop stomatopod, this is the perfect species.
They also have one behavior that I have described that is particularly unusual. If you get a chance to see it, the telson is very heavily armored with lots of crenulations. They use this in fighting and when they are attempting to evict another animal from a cavity. An intruder will approach an occupied cavity, coil in front using the telson as a shield agains the blows of the resident, than strike. As the resident retreats inside, the H. g. will force its telson into the entrance and wedge it in place. You can hear the resident striking, but it is not effective against this heavy armor. After a few minutes, the intruder will step aside and allow the resident to flee. Why does the occupant bail out? This is where it gets interesting. I have observed what I call "aggressive defication". The intruder deliberately fouls the water in the cavity and with the entrance blocked, it probably gets pretty nasty inside. (H. g. usually live in cavities with a single entrance.) Most time the resident gives up and flees leaving the cavity to the "deficator".
Roy
