Every Seafood Type Explained

Finfish. Finfish are the most common type of seafood worldwide, and humans have been catching them for at least 40,000 years. This category includes everything with fins and a backbone, from salmon and tuna to cod and tilapia. They're divided into two main groups, freshwater fish like trout and catfish, and saltwater fish like halibut and snapper. Wild-caught finfish tend to have better flavor than farm varieties, but aquaculture now produces about half of all finfish consumed globally. The texture varies wildly, some are oily and rich, like sardines and mackerel, while others are mild and flaky, like cod or sole. Crustaceans. Crustaceans have been considered a delicacy since ancient Roman times, when wealthy citizens would pay enormous sums for fresh lobster. This group includes lobsters, crabs, shrimp, prawns, and crayfish. They have hard shells, jointed legs, and live on the sea floor or near it. Interestingly, lobsters were so abundant in colonial New England that they were fed to prisoners and used as fertilizer. Today, they're luxury items. Most crustaceans turn red or pink when cooked, because heat breaks down proteins that normally hide the red pigment astaxanthin in their shells. They're sweet, firm, and usually cooked since most are unsafe to eat raw. Mollusks. Mollusks are one of the oldest food sources on Earth. Archaeological evidence shows humans were eating them over 165,000 years ago. This category includes clams, oysters, mussels, and scallops, all soft-bodied animals usually protected by shells. Oysters were so popular in the 19th century New York that they were cheaper than chicken, and oyster bars were common as hot dog stands. They're also incredible filter feeders. A single oyster can filter up to 50 gallons of water per day, making them vital for ocean health. Most are eaten raw or lightly cooked to preserve their delicate briny flavor. Cephalopods. Cephalopods are the most intelligent invertebrates in the ocean. This group includes squid, octopus, and cuttlefish. They have no shells, strong beaks, and advanced nervous systems. Octopuses can solve puzzles, use tools, and some species can change color in milliseconds to communicate or camouflage. In Mediterranean and Asian cuisines, they've been eaten for thousands of years, but they only gained popularity in Western countries relatively recently. The key to cooking them is going either very fast or very slow. Anything in between makes them rubbery. Squid ink, which they use as a defense mechanism, is also harvested and used to color pasta and risotto. Sea vegetables. Sea vegetables are edible seaweeds like nori, kelp, wakame, and dulse. These have been a staple in East Asian diets for centuries and are packed with iodine and minerals. In Japan, nori farming is so sophisticated that farmers seed nets with spores and suspend them in shallow bays. Some varieties of kelp can grow up to two feet per day, making them one of the fastest-growing organisms on Earth. The umami flavor in many sea vegetables comes from naturally occurring glutamates, and many experts consider sea vegetables the most sustainable food source on the planet. Echinoderms. This group includes sea urchins, sea cucumbers, and starfish, though only the first two are commonly eaten. The most famous part of the sea urchin is the uni, which many people think is roe, but it's actually the animal's reproductive organs. In Mediterranean countries, sea urchins are often eaten fresh right on the beach, split open with scissors. Sea cucumbers are prized in Chinese cuisine, where they've been eaten for over 1,000 years. They have almost no flavor on their own, but absorb whatever they're cooked with, and their chewy, gelatinous texture is the main appeal. Cartilaginous fish. These are fish with skeletons made of cartilage instead of bone, primarily sharks, rays, and skates. Shark has been eaten for centuries, though it requires special preparation, because sharks urinate through their skin, which can make the meat taste of ammonia if not handled properly. This is why some cultures ferment shark meat, like the Icelandic dish haukarl, which takes months to prepare and smells so strong that it's been called one of the most challenging foods. Skate wings are popular in French cuisine, with a delicate flavor and a texture that separates into long strands when cooked. Derived seafood. Derived seafood covers products made from seafood rather than whole seafood itself. Fish sauce has been produced since ancient Roman times, when it was called garum, and was so valuable it was traded across the empire. Modern fish sauce is made by fermenting anchovies or other small fish with salt for months or even years. Fish oil supplements are another derived product, extracted for their omega-3 fatty acids. Caviar, the salt-cured eggs of sturgeon, was once so common in America that it was given away free in bars to encourage drinking. Overfishing made it rare and expensive by the 20th century. Other examples include batarga, which is salted and dried fish roe often grated over pasta, and ambergris, a waxy substance from sperm whales historically used in high-end perfumes and occasional historical recipes. Processed seafood. Humans have been preserving seafood for millennia, and this category includes anything that has been preserved or altered to last longer or change texture. Surimi, the fake crab meat in California rolls, was invented in Japan in the 1970s, and is made by washing and pulverizing white fish until it becomes a paste, then adding flavoring and shaping it. Canning became popular in the 1800s and helped seafood reach inland populations. While some processed seafood is highly refined, others, like smoked fish, are traditional preservation methods that go back centuries. Tunicates. Tunicates, also called sea squirts or pineapples of the sea, are a niche seafood mostly found in Korea and Japan. The only one regularly eaten is the sea squirt, popular in Korea where it's called munggae. They spend their adult lives attached to piers or reefs, and have a very intense, bitter, and medicinal flavor that tastes like a concentrated shot of seawater. When you cut them open, they literally squirt water, hence the name. In some parts of France and Italy, they're also eaten raw as a delicacy, though they're definitely an acquired taste. Marine worms. Marine worms aren't common in western cuisine, but they're eaten in various coastal cultures around the world. In Samoa, paolo worms are harvested when they rise to the surface once a year, and are eaten raw or fried. They taste salty and slightly fishy. In some Asian markets, you can find sand worms, which are used in soups and are prized for their supposed medicinal properties. They have a crunchy texture when fried, and need to be prepared carefully to remove any grit. Marine mammals. Marine mammals like whales, seals, and dolphins have been hunted for food by indigenous Arctic peoples for thousands of years, where they're a crucial source of calories and nutrients in an environment where little else grows. Whale meat was also common in Japan and Norway historically. Today, most whale hunting is restricted or illegal by international regulations, due to conservation concerns. Indigenous communities in Alaska, Canada, and Greenland maintain traditional subsistence hunting rights. The meat is very dark, almost black, because marine mammals have huge amounts of myoglobin in their muscles to store oxygen for long dives. It has a flavor that sits somewhere between beef and liver, with a fishy undertone due to the animal's diet. Jellyfish. Jellyfish have been eaten in China for over 1700 years. Since they're about 95% water, they don't have much flavor on their own, so preparing them involves a long process of salting and drying to remove moisture and firm up the texture. Once processed, dried jellyfish can last for months. To serve, they're rehydrated and typically dressed in sesame oil, vinegar, and soy sauce. Only a few species out of thousands are edible, and they must be carefully prepared to remove their stinging cells. As ocean temperatures rise and fish stocks dwindle, some scientists suggest we might be seeing a lot more jellyfish on our menus in the future.