Some Clarification on Seafood:
Seafood can be divided into four categories, with some categories universally accepted as halal, whereas others accepted by some people and not by others.
Category one — includes fish with scales and fins such as cod, flounder, haddock, halibut, herring, mackerel, perch, pollock, salmon, sea bass, whiting, buffalo fish, carp, trout, tuna, orange roughy, and snapper. This category is acceptable by all the Muslim consumers.
Category two — includes fish or fishlike animals which may have fins but not removable scales. Some of these may breathe oxygen from air rather than water, but live in water all the time. Examples are catfish, shark, swordfish, eel, monkfish, cusk, and blowfish. This category is acceptable to the majority of Muslim consumers, but not all denominations accept them as halal. They might consider them makrooh (disliked or detested).
Category three — comprises several unrelated species, mobile or not, of various shapes and sizes, that cannot survive without being in water. These are generally either molluscs or crustaceans, including clams, mussels, lobsters, shrimp, oysters, octopus, scallops, and squid. This group also includes marine mammals that live totally in the sea such as whales and dolphins. The majority of Muslim consumers eat them; however, others consider them either haram or makrooh. Shrimp seems to be in a special category: some only eat them but not the rest of category.
Category four — includes many of the animals generally falling under the definition of seafood. They live in and around water most of their life cycle, but are capable of living outside water because they can breathe air. These are generally not considered halal although some Islamic scholars are of the opinion that they are from the seas because they live in and around water. These include crabs, snails, turtles, alligators, and frogs.
