[hackujin]

Kosher Jews say the same about shellfish and pork. Calling those sources of protein quote "bottom feeders" and therefor unpure.

[wavefunction]

I suspect that's a historical tradition made religious due to the fact that it's easy to get "poisonous" pork or shellfish that will kill you if not sourced or prepared correctly.

[i386]

If your culture lives in a hot desert then not eating shell fish makes a lot of sense.

Pork was full of parasites until the advent of some relatively modern farming practices.