shellfish generally refers to shrimp, crab, lobster, oysters, clams etc..  Other fish is different. However I would recommend proceeding with extreme caution, as these fish are often likely to come in contact with shellfish and in the case of some extreme allergies this can be enough to trigger a reaction. I would check with an allergist, or a doctor who is familiar with your situation to see if fish bother you, and what they recommend. My mom has a severe aspirin allergy and even something remotely salicalte related can cause a reaction,even if it is just somebody handling it after handling an aspirin or other salicilate. I would also make sure to have an epi pen or other emergency treatment at all times as well as a card or necklace stating your allergies in case you are in a situation where you can't talk for yourself