A whitefish is a broad term that refers to a category of fish that generally live near the bottom of water sources, such a lakes, oceans, ponds, and aquariums. They are equipped to comfortably reside in close proximity to loose sand and debris. Due to being located near the bottom of water sources near sand, members of this fish category generally have a dry and flaky texture to their flesh when they are cooked and consumed, especially compared to fish who reside closer to the surface of the water and tend to have an oilier texture. Some common types of whitefish are cod, pollock, and halibut.
Since whitefish remain as close to the bottom of a water source as possible, they are commonly referred to as bottom feeders. Bottom feeders are typically exposed to sand, pebbles, and other loose debris. In order to comfortably adapt to this environment, bottom feeder fish use a process to filter out any debris they inhale. As these fish inhale the water and any debris, their internal breathing mechanism — known as a gill — filters out all non-water materials out of the body through a slit.
Whitefish generally live in a wide variety of water sources, such as rivers, lakes, and oceans. They also reside in various geographical locations throughout the world, including North America, Europe, and Asia. Their diets can vary depending on the specific type of fish, but can range from insect larvae to other small fish.
When whitefish is caught by fisherman and packaged and sold for food, its proximity to the bottom of the water source provides its distinctive texture once it is cooked. The fish has a drier texture, which adds firmness and allows the fish to maintain its shape while it cooks. Fish that live closer to the surface of water sources have an oil content that can make it too delicate to withstand high temperatures during cooking. The firm texture of whitefish makes it able to hold up during many cooking methods, especially deep frying in hot oil.
This variety of fish is most commonly used in the traditional British recipe of fried fish and chips, as well as commercial fish sticks, because it is firm enough to keep its shape and allow a batter or coating to stick to it. It can also be processed into a gel and formed into sticks to be sold as imitation crabmeat. The fish is also a common ingredient in traditional Jewish cuisine, especially served with bagels.