Yellowtail refers to several species of fish known for their distinctive yellow-colored tails. The most common type is the California yellowtail, a member of the jack family, which is popular among anglers and is often found in the Pacific Ocean. This fish can grow up to 40 inches long and is prized for its firm, flavorful flesh. In addition to the California yellowtail, the term can also refer to yellowtail amberjack, which is found in warmer waters around the world. Both types are sought after for their culinary uses, often served in sushi or grilled, making them favorites in seafood cuisine.