Here's a nice glossaryof fish used as an ingredient in our beloved sushi, from thenibble.com:
ABALONE or AWABI
The “king of clams,” has exquisite pearlized coloring on the inside of its shell that is used for jewelry and decorative items. The meat has a crisp, chewy texture. See awabi, below.
Horse mackerel, also known as saurel. It is filleted and marinated in vinegar to cure it before serving. There are three types of mackerel commonly found at sushi bars: aji, saba and sawara.
Anago refers to any type of salt water ee. It is often translated as “conger eel” on sushi menus; but the latter is more accurately the white-spotted conger eel, found in the waters around Japan.
Monkfish liver, also known as angler fish or goosefish. Monkfish liver is similar to a fine pâté in texture. It is the Japanese “foie gras,” and much more affordable! The liver is typically smoked or steamed and garnished with scallions, daikon radish and a marinade made from grated daikon radish and mild red chiles