Entering a fishmonger can be a little intimidating if you’re not well versed in seafood terminology.  

Today, we wanted to run you through a few useful definitions, so you know exactly what to ask for on your next trip! 

Don’t forget that if you’re unsure about something, you can always ask the person behind the counter – fishmongers are overwhelmingly friendly and helpful, and they know their stuff! 

Crustacean: In seafood, crustacean refers to a class of arthropods with an exoskeleton and two-parted limbs. Includes Lobsters, Crabs, Crayfish, and Prawns.  

Bivalve: Bivalves are any shellfish with a double hinged shell, many of which are commonly referred to as clams; ‘clam’ once meant ‘shut’ and these creatures can shut their shells tightly to protect themselves from predators. Many of our most popular shellfish, such as Oysters, Scallops and Mussels, are bivalves.   

Mollusc: Scientific term for 'shellfish'. Refers to any of a large phylum (Mollusca) of invertebrate animals (such as Snails, Clams, or Squid) with a soft unsegmented body usually enclosed in a calcareous shell.  

Cephalopod: A class of marine molluscs including Squid, Cuttlefish, and Octopus, which have a group of muscular (usually sucker-bearing) arms around the front of the head, highly developed eyes, and usually a sac containing ink which is ejected for defense or concealment.  

Whole Fish: A fish which has not been filleted, and is thus sold completely intact, exactly how it was caught. In most seafood retailers, whole fish will be sold pre-cleaned, however you may need to ask to have them gilled, gutted, and scaled.  

Gilled: A fish with the gills removed. Gills are removed because they can impart a bitter flavour to fish.  

Gutted: A fish with the guts (viscera) removed. Ready to cook whole after a simple wipe down of the inner cavity.  

Scaled: A fish with its scales removed. This is generally done by your fishmonger, using a special tool.  

Cleaned: A fish that has been scaled, gilled, and gutted.  

Fillett: A fillet is the whole side of a fish cut away from the central back bone and rib cage. You may need several fillets from a very small fish, such as Sand Whiting, to serve 1 person, while those from a larger fish, such as an 800g Snapper, may be an ideal portion size for 1 person.  

Cutlet: Cutlets are a section sliced horizontally through the whole fish, leaving the bones in; Salmon and Blue-eye Trevalla are often seen as cutlets. When used in relation to Prawns, this term refers to a peeled Prawn with the tail left attached.  

Steak: Fillets from very large fish, such as Swordfish or Tuna, are usually sliced vertically into boneless 'steaks' that are a suitable portion size for 1 person.   

Trunk: A whole fish sold with the head removed. Ocean Jacket are a species commonly sold as 'trunks'.   

Butterflied: Butterflying is another way of filleting a whole fish. Rather than taking the fillets away from the backbone, the bone is taken out. The result is two fillets that stay connected, usually with the head and tail left on, to hold the finfish together during cooking. Butterflied fish are great for stuffing.  

Skin On/Skin Off: Your fishmonger will generally have fillet options available with both the skin on and skin off. If you are looking to pan-fry or BBQ your fish, you would usually purchase it with skin on, so that you can crisp up the skin in the pan. You can always ask for skin to be removed if you perfer not to eat it.  

Pin boned: Fish with the bones meticulously removed using specialised tweezers. Not all fish available at your chosen retailer will be pin boned; if you are nervous about bones, it is worthwhile to ask your fishmonger about them. Sometimes pin boning will come at an additional cost.  

Sashimi-grade: Very fresh seafood, suitable for eating raw is labelled ‘sashimi-grade’. It’s caught and handled in such a way that peak freshness and quality are maintained. Sashimi-grade Tuna, and other large wild-caught fish, are line-caught, landed onto a mattress (to minimise bruising) and killed instantly by brain-spiking (ike jime). This prevents the fish from struggling and releasing stress hormones and helps keep the body temperature low. The fish is then bled immediately, removing heat and waste products, and put into an ice slurry to drop the body temperature as close to 0ºC as quickly as possible. If you are planning on eating your chosen seafood raw or rare, make sure to check with your fishmonger whether it is sashimi-grade.  

Wild-Caught: Refers to seafood caught in natural marine environments, such as oceans, lakes, and rivers.  

Farmed: Refers to a seafood species reared and harvested in controlled water environments. Some popular aquaculture species are: Barramundi (Queensland, NT and WA), Eel (mainly Victoria and Queensland), freshwater Crayfish (Yabby, Redclaw and Marron), Murray Cod (Victoria and NSW), Oysters (Sydney rock, Pacific and Native), Prawns (especially banana and black tiger), Silver Perch (mainly NSW and Queensland), Trout (mainly Rainbow Trout grown in freshwater, or in sea cages and marketed as Ocean Trout), and Yellowtail kingfish and Mulloway (mostly from Port Lincoln, SA). Also available in Australia is Chinook Salmon (farmed in New Zealand and marketed as King Salmon).  

Responsibly sourced: A term used in the seafood industry to mean 'sustainable'. While overfishing has been a serious problem globally and continues to be an issue in some regions, since the turn of this century Australian fisheries have been internationally recognised as among the best-managed in the world. Both State and Commonwealth legislation requires that our fisheries be sustainable, and that the environmental impacts of fishing activities be regularly assessed. Stocks of even previously overfished species continue to increase under careful supervision; recovery plans for such species are mandatory and have been proven to work. The best way to be sure you’re buying sustainable or 'responsibly-sourced' seafood is to buy Australian.