Shellfish Knowledge

Shellfish

SHELLFISH CATEGORIES PURCHASING & STORAGE OF FRESH/FROZEN IDENTIFYING CRUSTACEANS IDENTFYING ECHINODERMS IDENTIFYING MOLLUSKS

– UNIVALVE – BIVALVE – CEPHALOPODS

Learning Objectives

Shellfish are aquatic animals protected by some sort of shell. Based on skeletal structure, they can segmented intoCRUSTACEANS

LOBSTERS, SHRIMP, PRAWNS, CRAYFISH, CRAWFISH, CRABS

ECHINODERMS - “spiny skin" SEA URCHIN

SEA CUCUMBERSMOLLUSKS

UNIVALVE – One Shell BIVALVE – Two Shell CEPHALOPODS – No Shell “head & feet”

Shellfish Categories

When purchasing fresh shellfish it is extremely important to ensure that they are alive.

Never use dead shellfish unless they have been purchased frozen.

Never refreeze defrosted shellfish. How do I know they are alive?

All shellfish are potentially hazardous foods, if there is an off smell, such as ammonia, then discard.Crustaceans – will be alert and movingUnivalve – no off smells and opening well closed

Bivalve – shells firmly closed, if open, tap them on counter top and if they do not close then discard.

Purchasing Shellfish

Crab, lobsters and other live shellfish should be packed in seaweed or damp paper upon delivery.

If a lobster tank is not available, store directly in perforated pans at 40F / 4C. DO NOT allow fresh water to come in contact with them.

Clams, mussels and oysters purchased in their shell should be stores in perforated pans.

They SHOULD NOT be iced or sealed in a closed container. Store at 35F - 40F / 2C - 4C.

Storage Shellfish

All crustaceans have an outside articulated shell

Lobster - HomardShrimp – CrevettesPrawn (Dublin Bay) – Langoustine - ScampiCrawfish – Langoust (Spiny Lobster)Crayfish – ÉcrevisseCrab – Crabe

Crustaceans

Maine Lobster - Homarus americanus, also known as “American lobster,” or “Northern Lobster”. From the genus Homarus, of the family Nephropidae.

There are two different species of cold water, clawed lobsters, the American lobster and the European lobster. The two types of lobster are similar in size but the European lobsters typically have a darker color and the claws may be slightly smaller.

The American Lobsters is found in cold, shallow waters as far north as New Found land and as far south as North Carolina, but is generally associated with the waters around the Canadian Maritimes, Maine, Massachusetts, Rhode Island and New Hampshire.

Lobsters

Lobsters

Can be purchased fresh (green shrimp), head on or off. Sold by count (i.e. 21 – 26 count refers to the number per lb – U

10 refers to less than 10 per lb). P & D means peeled and deveined. Warm Water Shrimp – Found in tropical waters. Classified

by color: pink (sweet & tender), brown (briny & firm), white (sweet & mild).

Cold Water Shrimp – Found in North Atlantic & North Pacific. Smaller than warm water shrimp.

Fresh Water Shrimp – Farm raised (Hawaii & CA). Soft & mild.

Tiger Shrimp - Found in South Pacific., Africa & India. Grayish-black strips on grayish-blue shells. Mild & briny.

Rock Shrimp – Hard-shell found in Gulf of Mexico. Flavor & texture close to crawfish & lobster.

Shrimp

Shrimp

Warm Water Spiny Lobster

Panulirus argus, also know as langouste or rock lobsters, from the genius Panulirus and from the family Palinuridae

The are approximately four dozen species of warm water lobsters found in warm waters of the Caribbean, Mediterranean, and the coast of Asia.

They have a tail and a “head” (carapace) that looks similar to those of a cold water lobster, but warm water lobsters do not have claws, and instead have long spiny antennae. The only edible meat in a warm water lobster is found in the lobster’s tail.

Warm Water Spiny Lobster

Dublin Bay Prawns or in Italian, “Scampi” are similar in appearance to shrimp, but are actually related to the spiny lobster and are distinguished by a branching gill structure

Slightly sweet, very delicate flesh.

Prawns

Prawns

Crawfish also known as Spiny Lobster. They are freshwater crustaceans resembling and related to small lobsters but either have very small claws or no claws.

Crawfish/Crayfish

ATLANTIC SPECIESBLUE CRAB - Atlantic Ocean from Cape Cod south to Florida and into the Gulf of Mexico, Blue crabs appear along the Eastern Shore in the spring just before warm weather begins. Blue crab meat is sold either fresh or pasteurized. After the crabs are steamed, the meat is picked over and then packed into cans, sorted as either “lump meat” (solid, whole lump meat from the body), “flake meat” (small pieces of meat from the body), or “claw meat” (meat from the claws that is usually brown in color).

Blue crab meat has a sweet, buttery flavor, but its texture depends on what part of the crab the meat comes from.

NOTE: During their normal growing cycle, all crabs must shed their shells. A softshell crab is a Blue crab that has shed its hard outer shell. For five to six hours, until its hard outer shell grows back, the crab has only a soft shell. Soft-shell crabs (once cleaned) are usually eaten whole and are never picked over for meat.

Crab

ATLANTIC SPECIESJONAH CRAB - Nova Scotia to Long Island. Also know as “Peeky Toe crab,” in the same family as the Dungeness crab, but has less meat than its West Coast cousin.

STONE/SPIDER CRAB - Stone crab is a type of Spider crab found in the Atlantic Ocean from North Carolina southward through the Florida Keys and into the Caribbean. It has a rock-like, oval-shaped outer shell inspire.

Stone crab season begins on October and ends on April. To protect the species, commercial fishermen are only allowed to keep one claw and release the rest of the catch. This does not harm the crab and in no way inhibits the crab’s feeding capabilities, since claws are used for only defensive purposes. It can take up to two years for the crab to regenerate another claw. Stone Crab claw meat is sweet and delicate with a flavor and texture similar to the claw meat of the Maine lobster.

PACIFIC SPECIESDUNGENESS CRAB - A native of cold Pacific Ocean waters from Mexico to Alaska. The harvest season begins in November and runs through August. Production usually peaks in December through March. To protect the breeding population.

Only male crabs larger than a set minimum size (6¼-in) can be harvested and fishing is prohibited during the breeding season. The circular pots used to catch Dungeness crab are highly selective traps, meaning that by catch is not an issue.

Dungeness crab meat is sold either fresh or frozen (crabs are steamed, the meat is picked and then canned), as “leg meat” (usually the most prized and most expensive),or as “broken leg meat” or “body meat.

Dungeness crab meat has a light, slightly nutty flavor anda delicate sweetness.

ALASKA KING CRAB - British Columbia north through Northern Alaska. There are three commercial King crab species: Red King crabs, Blue King crabs and Golden King crabs. Each species is harvested from late autumn through early winter.

King crab is sold either whole or as “legs and claws” (individual whole legs and claws that have been separated at the shoulder), “split legs” (individual whole legs that have been split in half lengthwise), “select portions” (the meatiest section of the leg, considered by crab lovers to be the most desirable part of the crab), or “broiler claws” (single claws scored around the top so the shell can be easily removed to expose the tender white meat).

King crab meat is firm and sweet with a bright membrane and white flesh. Red King

Crab is the most prized of the three species.

PACIFIC SPECIES

PACIFIC SPECIESSNOW CRAB - Found primarily in Alaskan and Canadian waters. The Alaskan

Snow crab harvest usually runs mid January through March. Both the King crab and Snow crab fisheries are closely managed by Alaska Department of Fish and Game.

Snow crab meat is a good substitute for King crab, but its subtle flavor is lesssweet than King crab and the meat is not as red.

Stone Crab

ATLANTIC SPECIES

Jonah Crab

Blue Crab/Rajungan

Snow CrabPACIFIC SPECIES

DUNGENESS CRAB

King Crab

The sea urchin is a spiny, hard-shelled animal that lives on the rocky seafloor, from shallow waters to great depths. These globular marine invertebrates move very slowly along the seabed.

There are about 700 different species of sea urchins worldwide. Many sea urchins have venomous spines.

The biggest sea urchin is the red sea urchin (Strongylocentratus franciscanus); it has a test about 7 inches (18 cm) in diameter.

RED SEA URCHINPURPLE SEA URCHINGREEN SEA URCHIN

Sea Urchin

Sea Urchin

Elongated body and leathery skin, which is found on the sea floor worldwide. Prized for its gelatinous texture and supposed aphrodisiac qualities, the sea cucumber is a delicacy in Chinese cuisine. Rather bland on their own, sea cucumbers absorb and accentuate the flavors of the ingredients in which they are cooked.

Sea Cucumber

Univalve (one shell) - Winkles, conch, abalone, whelk, land snail

Bivalve (two shells) - Oysters, mussels, scallops, clams, cockle

Cephalopods (no shell, “head-foot”) - Octopus, squid, cuttlefish

Mollusks

A class of mollusks typically having a 1-piece coiled shell and flattened muscular foot with a head bearing stalked eyes

Univalve

Periwinkles

ConchAbalone

Snail

Univalve

Bivalve

Bivalve mollusks (e.g., clams, oysters, mussels, scallops) have an external covering that is a two-part hinged shell that contains a soft-bodied invertebrate.Like fish, bivalve mollusks breathe through their gills. As filter feeders, bivalves gather food through their gills. Some bivalves have a pointed, retractable "foot" that protrudes from the shell and digs into the surrounding sediment, effectively enabling the creature to move or burrow.

e.g., clams, oysters, mussels, scallops

BIVALVE

Most oysters clams and mussels on the US market are farm-raised. They are raised in estuaries, (where fresh and salt water meet and mingle). Oysters feed at their leisure, filtering up to eight gallons of salt water per hour to collect food.

An oyster’s entire reproductive cycle is based on water temperature, not mood. When the water gets warm enough, oysters become reproductive and spawny.

There are three factors that contribute to the taste of oysters: SPECIES, METHOD OF CULTIVATION LOCATION OF CULTIVATION

OYSTERS

SPECIESEdible species of oysters can be divided up into two genera, the genus

crassostrea and the genus ostrea. Oysters in the genus crassostrea have cupped shells that house the bulk of the meat. Fertilization occurs outside the shell. Oysters in the genus ostrea have flatter shells and fertilization

takes place inside the female shell.

PACIFIC (Crassostrea gigas) — Native to Japan. Gigas are the most common oyster in the world, making up over 90% of all oysters produced. They are fast-growing, with anoblong shape and a deep cup. They are a highly adaptable species and have beenbrought into area that either have no commercial oyster crop or where the native oysters have, for some reason, failed.

ATLANTIC (Crassostrea virginica) — Native to eastern United States, Gulf Coast and Canada. Approximately 85 percent of all of the oysters grown in the United States are Atlantic oysters. They have a round, somewhat flat, shell. A large amount of these oysters are processed in various ways and never reach the table as half-shell oysters.

KUMAMOTO (Crassostrea sikamea) — Native to the Far East; cultivated in the PacificNorthwest. “Kumos” are a very slow-growing oyster.

OLYMPIA (Ostrea lurida) — the only oyster native to the West Coast United States. Olympia oysters are extremely small in size with a tiny, round shell and a metallic taste.

EUROPEAN FLAT (Ostrea edulisi) — Native to northwestern Europe. European flats have a flat, round shell with a coppery taste.

PORTUGUESE (Crassostrea angulata) — Native to northwestern Europe.

SYDNEY ROCK (Crassostrea commercialis) — Native to Australia.

CHILOE (Ostrea chilensis) — Native to Chile.

COON OR GULF (Ostrea frons) — Native to southeastern United States.

PEARL OYSTERS gold-lip (Pinctada maxima), black-lip (Pinctada margaritifera) and penguin oyster (Pteria penguin) — These are inedible oysters from which fine pearls are obtained.

OYSTERS

Belon /European Flat Pacific

METHOD OF CULTIVATION

While wild oysters grow on rocks, cultivated oysters are raised naturally in different ways. Some oyster growers buy oyster larvae and place the larvae in huge fiberglass tanks, along with strings of adult oyster shells. Others put oysters, the size of peas, in floating wire cylinders, where the rolling tides smooth and round their shells. They are then transferred to flats of wire bags attached to iron trestles where they continue to grow until they are large enough to be harvested. Still others place seed oysters in wire bags attached to racks. The ebb and flow of the tides continuously rotates the oysters inside the bags with a movement similar to a washing machine.

LOCATION OF CULTIVATIONOysters of the same species (or different species) take on a subtle and sometimes not-so-subtle difference when grown in different beds. The action of tides, salinity of the water, availability of food, presence of algae, the amount of fresh water coming into the saltwater marshes, and the mineral content are all contributing factors that cause the variance in oysters’ shape, color and flavor.

Tasting Oysters There are three factors to consider:

SALINITY (degree of saltiness) •Mild•Medium•Salty

TEXTURE •Crunchy•Creamy

FINISH•Mineral•Buttery•Fruity•Vegetable

Squid, Octopus and Cuttlefish belong to this family. Tough and require long cooking times or mechanical

tenderization. They have a thin internal bone called a pen or cuttlebone.

CEPHALOPODS

CEPHALOPODSOctopus, Squid, Cuttlefish