Can fish distinguish color?

Most fish are colorblind, despite the opinion of many sportfishermen. Fish can see color shadings, reflected light, shape, and movement, which probably accounts for the acceptance or rejection of artificial lures used by fishermen.

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Are all fish edible?

Most kinds encountered by anglers are. The organs of some species are always poisonous to man; other fish can become toxic because of elements in their diets. The latter are most often from tropical regions of both the Atlantic and Pacific Oceans. Scientific literature has pinpointed danger areas in which the disease called "ciguatera" (a disease dangerous to man) may occur in tropical and subtropical fish.

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How can poisonous fish be distinguished from edible ones?

They cannot, without personal knowledge of the types of fish which are at times poisonous. Frequently local customs can be relied upon. A comprehensive three-volume publication on the subject is entitled "Dangerous Marine Animals" by Dr. Bruce Halstead.

Why do food fish sometimes have a strong odor?

For most species, truly fresh fish is almost odorless. Fish begin to smell "fishy" when deterioration sets in, often caused by incorrect storage practices that bring about the release of oxidized fats and acids through bacterial and enzymatic action.

Is there much salt in fish?

Very little in most. More than 240 species contain so little salt that doctors recommend them in salt-free diets. Shark meat is salty - as salty as the sea the shark lives in.