they are commonly known as ritteri nems, they are the hardest nem to keep and about 4 percent of the people that attempt to keep them actually succeed at keeping them more than a year. i have had a few but the tiniest little swing in params can kill them, the one i have now is doing okay, they never seem to fully thrive in a tank like alot of other nems. definitely not a good first nem shatsoever. they are however practically a mansion for a clownfish.