So I have a 5 gallon nano tank that currently has a yellowtail damselfish, 4 blue legged hermit crabs, a turbo snail, and a nassarius snail. I've been wanting to get a shrimp but I don't know if the damselfish will get along with it, or if it presents a danger to my crabs. I also have a GSP island with the hopes of adding a duncan coral on its own rubble rock, and I want my main live rock to be a zoa island. If shrimps aren't a good idea, what bout nano starfish?