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What's in a Name? A Guide to Understanding Fish Names

A Guide to Understanding Fish Names

If you've ever felt lost at sea in your local seafood market, you're not alone. Navigating the many available seafood options can be tricky, let alone those with multiple names or lookalikes. It’s quite common for a single fish to go by multiple names. This discrepancy can stem from various reasons, including regional nicknames or pronunciations and even commercial influences. Unfortunately, this tangled web of names often results in mislabeling, both in stores and restaurants, leaving shoppers and diners unsure of what they're actually ordering.

To help bring clarity to the chaos of seafood names, the FDA's Seafood List serves as a beacon of guidance, providing standardized names that are permitted to be used for each scientific species classification.

While you can also search for any seafood name you’re used to on our site, we've crafted this comprehensive guide of popular seafood species names and their alter egos so you can confidently sail any seafood aisle with ease, ensuring you bring home exactly what you intended.

How Are Fish Named?

Every fish has a scientific name and at least one common name. Common names for fish often come from local dialects, the fish's appearance, or people's names. The same common name may refer to completely different species in various regions. For instance, "perch" means three separate species around the world, making a scientific name for each fish necessary for scientists to ensure they’re referring to the same species. The FDA seafood list regulates what common names are allowed to be used when labeling seafood.

Scientific names for fish use a two-part naming system called binomial nomenclature. The first part is the genus name that groups related species together. The second part is the species name that uniquely identifies a specific animal. For example, the Pacific halibut is scientifically called Hippoglossus stenolepis- Hippoglossus is the genus, stenolepis is the species that differentiates the fish from Atlantic halibut (Hippoglossus hippoglossus).

As we discuss below, there are also vernacular names that are not permitted in labeling. However, you may hear fish referred to by these as well.

Why Do Some Fish Have So Many Names?

Language disparities contribute significantly to the diverse names associated with seafood species. Localized seafood delicacies earn new namesakes as species, and their cuisines travel globally through export and migration, often leading to questions like “Is calamari squid or octopus?” and “What is Chinook salmon?” Species abundant around the world, like squid, have several interchangeable, localized names. Conversely, species concentrated initially in certain areas, such as European sea bass, frequently retain their original nomenclature (branzino) in their primary local language as they gain popularity worldwide.

Geography and regional naming conventions lead to many cases where completely different species share the same common name. A prime illustration is the confusion around "kingfish." According to the FDA’s Seafood List, kingfish refers to small silver fish in the drum family that resemble whiting and cod. Outside of this list, however, parts of the U.S. informally know kingfish as king mackerel–a long, streamlined fish in the mackerel family. Meanwhile, on the opposite side of the globe, Australians and some Europeans label yellowtail as kingfish. This greenish-yellow fish with bright yellow fins bears no relation to a mackerel or whiting, yet may share a label with them depending on where you are.

Marketing in the commercial seafood industry also plays a role in how certain species are named or rebranded. Sometimes unappetizing original names get swapped out for more marketable monikers. Other times, broad terms are stretched and applied to multiple species to capitalize on recognition and demand. A perfect example of renaming is the Patagonian toothfish. This species, from the depths of South America, is now much better known as "Chilean sea bass" after suppliers struggled to sell such an oddly named fish in the 1980s. Rebranding from Patagonian toothfish to Chilean sea bass made the species feel more familiar to consumers, who still can’t get enough of it some 40 years later. Oysters also benefit from marketing efforts to help consumers differentiate between them. Despite only a handful of oyster species existing for commercial sale, oysters of the same species often taste different because each farm’s water temperature, salinity, nutrients, and other local conditions shape so much of an oyster’s flavors. Oysters are given distinct names like Blue Point and Beau Soleil to better differentiate between the hundreds of flavors that just a few species can bring.

The traits of a species, whether describing appearance or behavior, have notably led to situations where the same name refers to multiple seafoods or multiple names describe the same animal. In some cases, like redfish, different red-hued species around the globe share the same name, while various fish that live amongst the ocean’s rocks are broadly referred to as rockfish.

Stages of life and environment also impact the naming of your seafood. For example, rainbow trout and steelhead are actually the same species (Oncorhynchus mykiss), just at different points in their life cycle. If the fish lives its entire life in freshwater lakes and rivers, it is labeled a rainbow trout. Those that are more mature, having migrated from freshwater to the ocean, are called steelhead. So whether the menu lists rainbow trout, steelhead, or both, understand these refer to the same species at different life stages.

Popular Seafood Names by Fish Family

Common Tuna Species Names

Ahi Tuna: While ahi can also be bigeye tuna, it most commonly addresses the wildly popular yellowfin tuna. The Hawaiian word "ahi" literally translates to "fire," a nod to the powerful yellowfin and bigeye tuna that would pull on Hawaiian fishermen’s lines so hard that smoke would rise from the lines rubbing against the fishing canoes. You can differentiate between ahi tuna species by examining the fat lines and coloration. Yellowfin has minimal, if any, visible fat lines and a lighter red color, while bigeye tuna shows slightly more pronounced fat striations and tends toward a deeper, darker red hue.

Bonito: Bonito classically refers to a distinct genus of tuna (Sarda), though the name bonito is frequently applied to several other species, such as albacore, skipjack, and dogtooth tuna.

  • Skipjack tuna (also called striped tuna) is a more slender tuna with distinctive stripes that break up its dark upper body and pale underside. Though skipjack has its own unique scientific name (Katsuwonus pelamis), it is sometimes mislabeled and sold as "bonito" due to its smaller size compared to larger tunas like bluefin. Skipjack tuna loins are usually quite small (1-2lbs) with intensely red flesh.
  • The mild, white-fleshed albacore tuna (Thunnus alalunga) is also sometimes labeled as bonito, especially when canned in oil or water. Fresh albacore's distinctive pale coloring compared to other species has also earned it the name "white tuna."
  • Dogtooth tuna (Gymnosarda unicolor), though quite different from skipjack and albacore, sometimes ends up lumped under the bonito label commercially as well, despite being closer in size to its ahi tuna relatives at around 5 feet long.

Common Names For Salmon Species

The various species of Pacific salmon boast names that largely reflect their indigenous roots. Sockeye salmon, commonly known as "red salmon," stems from a poor attempt at translating the Coast Salish word "suk-kegh," which simply means "red fish." Coho salmon is the original name for silver salmon, also coined by tribes of British Columbia and Washington. Lastly, king salmon was first known as Chinook salmon, named for the species’ abundance on the Chinook tribe’s traditional fishing grounds in the Pacific Northwest. Keta is widely known today as chum salmon. And the pink or humpback salmon gets its name from the distinctive hump that males develop during spawning season.

Atlantic salmon, on the other hand, are frequently labeled by where they were raised. Scottish salmon, Norwegian salmon, Chilean salmon, and all other geographically named salmon refer to the one Atlantic salmon species. Different regions and farms often raise the salmon differently, leading to different sustainability and taste attributes, which is why farmed salmon are often differentiated based on where they are from. U.S. regulations also require country of origin labeling on all seafood.

Common Names For Snapper Species

Snapper is the common name for fish in the 100+ species Lutjanidae family. The term "snapper" is often improperly extended to describe species like rockfish and hogfish, which are not snapper species. More concerning is the frequent mislabeling of lower-cost whitefish like tilapia or swai as "snapper" on restaurant menus or at seafood counters, whether intentional or not. The bland taste and softer texture of these mislabeled filets bear little resemblance to a snapper's sweet, firm flesh. A simple way to ensure the snapper you’re considering is the real deal is by asking the fishmonger or waitstaff what type of snapper it is and where it comes from. We recommend avoiding it if the answer seems, well, fishy.

  • Both American and Caribbean red snapper species are commonly just called “red snapper” for their reddish-pink skin color. The American red snapper grows up to 24 inches and is prized for its sweet, nutty meat, while the Caribbean red snapper is enjoyed for its smaller size (16-20 inches) and lower cost than its American cousin. We always recommend asking to clarify which species is available to you if it is not clearly shown.
  • The mangrove snapper gets its name from its mangrove habitats and is also commonly labeled as gray snapper or mango snapper.
  • Mutton snapper is also known as mutton fish, king snapper, and virgin snapper. This rich and sweet seafood is guaranteed to please, regardless of how it’s labeled.

Common Seafood Names FAQs

Is There a Difference Between Crayfish and Crawfish?

There is no difference! Crayfish and crawfish are the same species. Whether you pronounce it crayfish, crawfish, crawdad, or mudbug, you can feel confident about ordering this lobster-like southern delicacy.

Is Caviar Fish Eggs?

Traditionally, only the eggs of the sturgeon are caviar. The term caviar being more broadly used across fish eggs is a case of commercial simplification and upselling. While traditionally referring only to sturgeon roe, some companies have expanded "caviar" to encompass fish eggs of many species to capitalize on sturgeon caviar's cachet and consumer recognition. So what is the real difference between roe and caviar? True caviar only comes from sturgeon, while roe is a generic term describing the fully ripe eggs of any sea life

Like caviar, many species have unique names for their eggs. For example, ikura is the name used for salmon eggs, and tobiko describes flying fish eggs.

Is Mahi Mahi Dolphin?

No, mahi mahi is not actually a dolphin! It is believed that sometimes mahi mahi is called “dolphin” because of the fish's sleek, tapered shape and acrobatic behavior when hooked, resembling playful dolphins jumping in the water. Whether you see it labeled mahi mahi, dolphin, dorado, or simply mahi on a menu or at the market, these all refer to the same delicious species of tropical fish. The name mahi mahi hails from the Hawaiian language, meaning "very strong," while “mahi” is just a convenient abbreviation. Dorado is the Spanish term for the same fish, translating to "golden" in reference to its brilliant colors.

Is Calamari Squid or Octopus?

Calamari is the Italian word for squid, and only squid. While squid and octopus are both delicious cephalopods, calamari refers solely to squid, while polpo refers solely to octopus.

Is Branzino Sea Bass?

Another common seafood name out of Italy is branzino (sometimes spelled bronzino), which has grown popular in the U.S. in recent years. Branzino is merely the Italian name for European sea bass. We are starting to see branzino gain global recognition by its other names like loup de mer (French) and lubina (Spanish).

What’s The Difference Between Shrimp and Prawns?

While shrimp and prawns are close crustacean relatives, there are some distinctions to note. Prawns are generally larger with segmented bodies that carry their front legs extended, while shrimp curve smoothly and tuck their legs inward. However, the terms are often used interchangeably at stores and restaurants, with "prawn" inconsistently applied across regions. Learn more in our Essential Guide to Shrimp.

Are Fluke and Flounder the Same?

Though their names are often used interchangeably, flounder is a family of flatfish with both eyes on one side, while fluke is specifically a species of summer flounder. Fluke tend to be larger and more oval-shaped than other flounder species and are a very popular target species for fishermen and seafood lovers alike.

Is a Marlin a Swordfish?

Although both species share notable attributes like long sword-like bills and bodies, the marlin is not a swordfish. Swordfish are more compressed with flat bills used for slashing prey. Marlin have taller, more rounded bodies and use their lengthy spear-like snouts to stun fish. To differentiate between marlin and swordfish meat, look for marlin's lighter ivory color compared to swordfish's slightly darker peach-toned meat.


Seafood species labels can be as varied as the creatures themselves. Yet, regardless of whether it's called mahi mahi or dorado, Chilean sea bass or Patagonian toothfish, the ultimate goal remains constant: choosing seafood of the highest quality from trustworthy sources. To avoid any confusion surrounding an ambiguous seafood name when shopping, we recommend referring to the FDA's Seafood List.

To ensure you always receive authentic seafood, purchase from reputable purveyors with a deep understanding of seafood. At Fulton Fish Market, we use our centuries of experience to ensure you get exactly what you want. Take a look at our product pages for detailed information on each product we offer, and don’t hesitate to reach out if you have any questions.

Let your taste buds guide you, and prioritize freshness and sustainability above all else when making your seafood selections. After all, the joy of seafood lies not in its name, but in its exquisite flavor and texture.

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