Aggressive Shrimp?

[Bluelily54]

I've had my betta (Captain Barbossa) for a little over two weeks now, and everything has been going great thanks to the information I found here as a lurker.
I bought a couple of ghost shrimp as little house cleaners the same day, and there hadn't been any trouble until this morning. When I went to feed Barbossa, the bigger of the two shrimp was swimming around. No big deal. But a few minutes after I had finished feeding him the shrimp swam straight for Barbossa and tried to latch on to his side! Barbossa, being the brave fish he is, fought off the shrimp before any kind of visible damage had been done, but I immediately fished out the offending shrimp and there he remains in a cup next to the aquarium.
I've also noticed that Barbossa's tail fin has been looking a little more tattered the last couple of days. Am I right in thinking the shrimp could be the culprit?

My question is, could this shrimp be one of the "imposter ghost shrimp" I've heard about? Would I be able to introduce it back into the aquarium (which I'm not so keen on doing), or should I take it back to the store? What are my other options?

[Kwomais]

It could be an imposter ghostie. Check the whiskers for orange/pink banding (like 1 stripe) if you don't see the banding, you likely have an imposter and I would recommend returning it to the store so as to keep Cap'n Barbossa safe!

[tekkguy]

Doesn't even necessarily have to be an "imposter" ... there are actually several species of shrimp that are sold as "ghost shrimp," and some stores (especially the "big box" stores) are completely indiscriminate. Those orange bands that Kwomais mentioned will help you figure out if you have an aggressive shrimp.

See this site for more info and a picture of the type of shrimp you DON'T want.

[Bluelily54]

Good to know, I'll be sure and keep an eye on the other one for any future mishaps. Thanks to both of you for the advice!