I bought mine from my LFS about six years ago, and since then he has grown so much that people often mistake him as an eel. He's at least a foot long now, and stays mostly in his caves. He occasionally emerges to eat food that floats downward, but like others, he's rarely fully out of his cave. He also ate two of my firefish gobies and who knows what else, so if you're gonna get another goby to be his tankmate, get a big one!