Shellfish knowledge - Food Commodities

1. Shellfish Knowledge

2. Shellfish

3.  SHELLFISH CATEGORIES
 PURCHASING & STORAGE OF FRESH/FROZEN
 IDENTIFYING CRUSTACEANS
 IDENTFYING ECHINODERMS
 IDENTIFYING MOLLUSKS
 – UNIVALVE
 – BIVALVE
 – CEPHALOPODS
Learning Objectives

4. Shellfish are aquatic animals protected by some sort of shell. Based
on skeletal structure, they can segmented into
CRUSTACEANS
 LOBSTERS, SHRIMP, PRAWNS, CRAYFISH, CRAWFISH,
CRABS
ECHINODERMS - “spiny skin"
SEA URCHIN
 SEA CUCUMBERS
MOLLUSKS
 UNIVALVE – One Shell
 BIVALVE – Two Shell
 CEPHALOPODS – No Shell “head & feet”
Shellfish Categories

5. 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 moving
Univalve – 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

6.  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

7. All crustaceans have an outside articulated shell
Lobster - Homard
Shrimp – Crevettes
Prawn (Dublin Bay) – Langoustine - Scampi
Crawfish – Langoust (Spiny Lobster)
Crayfish – Écrevisse
Crab – Crabe
Crustaceans

9. 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

10. Lobsters

11.  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

12. Shrimp

13. 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.

14. Warm Water Spiny Lobster

15. 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

16. Prawns

17. 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

18. ATLANTIC SPECIES
BLUE 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

19. ATLANTIC SPECIES
JONAH 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.

20. PACIFIC SPECIES
DUNGENESS 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 and
a delicate sweetness.

21.  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

22. PACIFIC SPECIES
SNOW 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 less
sweet than King crab and the meat is not as red.

23. Stone Crab
ATLANTIC SPECIES

24. Jonah Crab

25. Blue Crab/Rajungan

26. Snow Crab
PACIFIC SPECIES

27. DUNGENESS CRAB

28. King Crab

29. 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 URCHIN
PURPLE SEA URCHIN
GREEN SEA URCHIN
Sea Urchin

30. Sea Urchin

31. 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

32. 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

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

34. Periwinkles
ConchAbalone
Snail
Univalve

35. 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

36. BIVALVE

37. 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

38. SPECIES
Edible 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
an
oblong shape and a deep cup. They are a highly adaptable species and have been
brought 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
Pacific
Northwest. “Kumos” are a very slow-growing oyster.

39.  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.

40. OYSTERS

41. Belon /European Flat
Pacific

42. 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.

43. LOCATION OF CULTIVATION
Oysters 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.

44. Tasting Oysters
There are three factors to consider:
SALINITY (degree of saltiness)
•Mild
•Medium
•Salty
TEXTURE
•Crunchy
•Creamy
FINISH
•Mineral
•Buttery
•Fruity
•Vegetable

45. 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

46. CEPHALOPODS
Octopus, Squid, Cuttlefish