Hi Cyndi -- The type of shrimp advertised as a bryopsis-eater is Heteropenaeus longimanus according to on-line sources. Penaeids can be difficult to identify correctly and lots of species - even genera - look alike. I suspect that very few LFS employees or their suppliers are capable of correctly identifying H. longimanus, which would mean very few of the shrimp sold are actually this species, and that most of these badly-id'ed shrimp are not primarily algae eaters. It's true that some penaeids do favor algae but most of them are omnivores & predators that prefer animal prey. Also, I was unable to find any clear evidence that true H. longimanus (if you even got one) are vegetarians. Penaeids usually bury themselves in soft bottoms during the day & only come out at night or when the light is low. You'll need to watch the tank with the lights out to see what it's eating. A flashlight covered with transparent red plastic will help as many animals can't see red light & won't react to it as they would to regular light.
I really hope the shrimp does turn out to be an algae eater as advertised otherwise you just bought a very expensive micro-predator.
