i dont think either goby will eat your shrimp unless you have bite sized shrimp
sleepers are active sand sifters, stirring everything everywhere
watchmans sift but i think they pretty much dig a tunnel and stay put not doing much sand sifting
the watchman go hand in hand with the
pistol shrimp
im not sure if a sleeper would?? someone will chime in on this one
the
diamond watchman goby is called a watchman but is actually a sleeper goby and a heavy sand sifter
heres a link that divides them into catagories, sleepers and shrimp gobies
http://liveaquaria.com/product/categ.cfm?pCatId=31