Surimi, those seafood items that look like crab, scallops, etc. but are really mostly white fish fillets, are thought of by most people as some sort of modern high tech imitation products. They go by such names as 'sea legs', imitation crab or imitation shrimp, etc.
In reality, this process was developed in Japan almost 1,000 years ago when the Japanese discovered that mincing fish flesh, washing it and then heating it, caused a natural gelling of the flesh. If this was then mixed with other ingredients and steamed, the resulting 'fish cake' (kamaboko) stayed together as though it were a natural product.
This is the Japanese term for fish paste. Surimi is restructured fish flesh, usually pollock or some other economically-priced finfish, bound together, and flavored and/or colored.
Surimi products are usually colored and shaped to resemble crab, lobster, scallops, shrimp or other more expensive seafood species, and may contain varying amounts of these shellfish for flavoring.
The FDA recently approved disjunctive ('and/or') labeling for surimi, so the actual proportions of each species may be difficult to determine.