@Scrbblechick -- According to my research, shellfish is kind of open to debate as to whether it's halal or not. You're right that it's not kosher at all, ever, but some Muslims, Shi-ites among them, think eating shrimp or prawns is OK.
I'm not sure why this is so, other than it's not specifically forbidden in the Qu'ran, as far as I could tell. The Bible is pretty specific about what's kosher and what isn't. It says only fish with "scales and fins" can be eaten. That rules out shellfish pretty definitively. But I'm not sure if the Qu'ran ever gets that specific.