How to ask for "no shellfish"
We are taking our 16-year-old cousin to Tokyo this week; none of us have ever been. He can eat fish but not shellfish, no meat, no poultry. (I am hoping he takes a don't ask, don't tell approach.) Our phrasebook doesn't have a word for "shellfish" -- how might we say this?
Watashi wa niku, tori niku, seafoodo no kai ga taberaremasen. Sakana wa OK desu.
"I cannot eat meat, poultry, and shellfish. Fish is OK."
...Just some advice- if these are health related dining requirements, you're going to have to be very careful about many things such as broths, sauces, condiments, side dishes, etc. Also, at most places, you don't order one dish and eat it yourself. It's more toward communal style dining.
I'm splitting hairs, but I'd simplify Silverjay's phrase to this:
Watashi wa niku, tori niku, seafoodo ga taberaremasen. Sakana wa OK desu.
Also: good advice on the broths, sauces, etc. Since sweetpotater wasn't the one that brought up allergies, I'm assuming there's no medical imperatives, just dietary preferences for the cousin in question.
貝 "kai" refers specifically to clams, not shellfish in the broader sense that includes shrimp, crabs, etc.
シーフード "seafood" is transliterated directly from English, and is commonly used instead of some other native word.
Here's the ultimate in clarity and politeness:
Watashi wa sakana ga taberaremasu ga, kai, ebi, kani ga taberaremasen. Sore kara, mata nikurui mo issai taberaremasen. Doozo yoroshiku onegai itashimasu.
I can eat fish. However, I cannot eat shelled fish, shrimp, and crab. On top of that, I cannot eat any type of meat. Thank you for your understanding.
The restrictions are because he keeps kosher, not for any medical reason. He is not super-religious, though, so I am not going to mention that minefields lie everywhere. If he cared enough, he'd look into it. But I think just avoiding the obvious will suffice.
You guys are the best - thanks!