I've had a pistol shrimp with a hi-fin goby for a couple years.. A while back, the goby kicked the bucket, but the pistol shrimp lives on. I consolidated my two tanks into one and mostly forgot about my pistol shrimp in the larger tank, since I rarely see it. I just picked up a Hector's goby at my LFS and he's been awesome. A bit intimidated by the larger clown and wrasse in the tank, but no major aggression toward him. He's been coming out for food, totally chillin so far. Just now, he didn't come out to eat so I started looking around and it turn's out he's now in the hidey hole with my pistol shrimp. I had no idea these guys exhibited host behavior with pistol shrimp as well, but I guess that's a fortunate outcome(except for the fact that he'll become a paranoid weirdo like the hi-fin trying to protect the shrimp)!