i kept 1 for maybe a year. but took some serious extra effort. i bought a "pair" but the bigger one killed off the smaller one.
then fed live brine allmost dailey, with the pumps off, they wriggle around just above the sand bed and the gobies would pick them off, but had to feed the rest of the tank first. then i would dig some frozen diy mix into the sand around his burrow.
awsome fish, but hard work! really hard work!
oh yeh, he lived untill i lost my entire tank when the power went out from the fridge catching fire over an easter long weekend.... but i wont buy another.