To elaborate on what's already been said, I wouldn't recommend even one of these for any tank under 100 gallons. And that's only if you REALLY want a dead sandbed. They eat all the stuff that makes the sandbed live and useful.
And yes, they do tend to starve and die under the sand. Dont even have the common courtesy to die where we can see them! It is my personal opinion that these shouldn't even be sold. But that is just my opinion.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef