Fish and Shellfish
Chapter 15
Objectives
• List methods for harvesting seafood
• Explain the purpose of the green sheet
• Summarize the many quality points that
should be inspected when receiving
seafood
• Differentiate between shellfish and
bonefish
Objectives (cont’d.)
• Define the term mollusks
• Compare the differences between
univalves and bivalves
• Define the terms crustaceans and
cephalopods
• Distinguish among roundfish, flatfish,
winged fish, and eels
Objectives (cont’d.)
• Identify the various market forms for
shrimp and crab
• List the various market forms for fish
• Describe the proper method for icing
fish for storage
Harvesting Seafood
• Seafood harvesting methods
– Foraging for them in their natural habitat
– Raising them in pens, ponds, or tanks
• Harvesting method has an impact on
fish habitat and product
• Some methods selectively capture
certain species; others are nonselective
Fish Harvesting
• Harvesting methods
– Gillnetting
– Handline
– Harpooning
– Purse seine
– Hook and line
– Trawling and trapping
Fish Harvesting (cont’d.)
15.2a A purse seine loosely
surrounds a school of fish
15.2b The seine net is
“pursed” to capture the fish
Fish Harvesting (cont’d.)
• Fish aquaculture
– Open-ocean cages or net pens
• Used to hold large stocks of fish
• Method can pollute surrounding waters and
threaten wild stock with disease
– Tanks, ponds, and raceways
• Free-flowing water from rivers and streams are
diverted into raceways
• Pumps aerate water in ponds and tanks
Shellfish Harvesting
• Harvesting methods
– Diving
– Dredging
– Trapping and pots
– Tongs and rakes
15.5 Trapping fish in pots
Shellfish Harvesting (cont’d.)
• Shellfish aquaculture
– Beach culture
• Uses sand filled pens; minimal habitat impact
– Suspended cable or bags
• Uses suspended surface areas upon which
filter-feeding shellfish grow
• No impact on surrounding habitat or other
species
Buying and Storing
• Green sheet
– Name for market news reports issued by
the National Marine Fisheries Service
• Lists weekly prices of fresh and frozen seafood
• Similar reports include:
– Boston blue sheet (fish blocks and fillets)
– Seattle sheet (salmon)
Buying and Storing (cont’d.)
• Similar reports include: (cont’d.)
– New Orleans sheet (shrimp)
– Los Angeles sheet (tuna)
• Seafood grading is voluntary
– Grades are A, B, and C
• Food service establishments should
inspect fresh fish upon arrival
Buying and Storing (cont’d.)
• Inspection factors
– Smell
– For whole fish: inspect eyes, gills, gut
cavity, slime, skin, and temperature
– For shellfish, ensure shells are closed
• Tap an open shell to see if it closes (indicates
product is still alive)
Packaging
• Most common seafood packaging
methods
– Block frozen
– Cello wraps
– Individually quick frozen (IQF)
– Layer packs
– Shatterpack
Caviar
• Sturgeon roe (eggs)
• Major types of caviar
– Beluga, osetra, and sevruga
• Fish roe is harvested from fish while it is
still alive
– Then mixed with salt to keep eggs from
clumping (malossol)
American Caviar
• Types of caviar made from U.S.
freshwater fish include:
– American and lake sturgeon
– Hackleback and white sturgeon
– Paddlefish, salmon and whitefish roe
– Trout, bowfin and lobster roe
Imported Caviar
• Caspian Sea provides 90 percent of
caviar available on the world market
• Types
– Beluga, sevruga, and osetra sturgeon
– Tobico sushi, wasabi, and kaluga caviar
Fish
• A vital food source for people worldwide
• 20,000 known species of fish
• Identified in many ways
– Freshwater or saltwater
– Large or small
– Oily or flaky
– Thin or meaty
Roundfish
• Most common types of fish
– Populate salt and fresh waters
• Common types of roundfish
– Smallmouth and largemouth bass, carp,
European pike perch, sauger, walleye,
perch, trout, mullet, monkfish
Roundfish (cont’d.)
• Common types of roundfish (cont’d.)
– Sea bass, sardine, anchovy, herring,
mackerel, swordfish, salmon, cod,
haddock, smelt
– Tuna
• May be labeled white tuna (albacore) or light
tuna (bluefin or yellowfin)
Flatfish
• Named because eyes are on same side
of the head
• Types of flatfish
– Plaice, flounder, halibut, sole, turbot
Winged Fish
• Skate
– Thin fish with long tail and fins that look like
wings
– Edible portions are the wings, the cheeks,
and the liver
– Boneless flesh is pinkish or off-white;
resembles scallops
Eel
• Has cylindrical body with small oval
scales embedded in the skin
• Popular in Japan
• Cut into fillets, slices or pieces
– Sold fresh, smoked, marinated, or in cans
• Flesh is firm and fatty
– Easy to debone; extremely perishable
Market Forms of Fish
•
•
•
•
•
Whole fish
Drawn
Dressed
H&G
Loin
• Fillet
– Thin, medium,
and thick
• Steak
• Fish sticks and
patties
Crustaceans
• Shellfish with external skeletons and
jointed legs
• Thousands of species, but only a few
are commercially viable
– Crab, shrimp, lobster, crayfish
Crab
15.9 Dungeness crab
15.21 Snow crab legs and claws
Source: Randy van Dam 2008
Shrimp
• Various market forms of shrimp
– Green head-on
– Green headless
– Peeled
– PUD
– P&D
– Shell-on cooked
Lobster
• Market forms of lobsters
– Maine lobster (American or true lobster)
– Spiny lobsters (Rock or Florida lobsters)
• Should be kept alive until needed for
cooking
• Does not freeze well
• Tails may be cold or warm water
Crayfish
• Known as freshwater lobsters,
crawdads and mudbugs
– Most come from Louisiana
– Available live or frozen whole
• Meat may be kept frozen up to two
months
– Live crayfishes in refrigerator for 24 hours
Mollusks (Molluscs)
• Types of mollusks
– Bivalves
• Clams, oysters, mussels, and scallops
– Univalves
• Conch and abalone
– Cephalopods
• Squid, octopus, and cuttlefish
Clams
• Found in sand or mud close to shore
– Harvested with hand tools
• Species of hardshell clams
– Southern quahog, Northern quahog
• Littleneck, Cherrystone, and Chowder
– Steamer clams
• Sold live, fresh, or frozen
Oysters
• Grow mainly in tidal mudflats
• Shellfish sanitation program
– Monitors oysters for contamination from
viruses, bacteria, and “red tide” toxins
• Popular standard types
– Eastern oyster
– European flat oyster
Oysters (cont’d.)
• Popular standard types (cont’d.)
– Kumamoto
– Olympia
– Pacific (Japanese)
• Oysters have a fairly long shelf life
– Up to two weeks
– Should be consumed when fresh
Mussels
• Subject to controls of
Shellfish Sanitation
Program
• Cheap and plentiful
• Sold by the bushel
bag
– Weighs about 45 lb.
15.29a Mussels
Source: Randy van Dam 2008
Scallops
• Muscle holding the two halves of the
scallop shell together
• Only available as chucked
– Whole scallops cannot be opened without
commercial equipment
• Large quantities of frozen scallops are
thawed and sold as fresh
Conch
• Large sea snails
– Bahamian or
Caribbean
– New-England type
• Becomes more tender
with extended cooking
15.31 Conch shell and conch meat
Source: Randy van Dam 2008
Abalone
• One of the most expensive varieties of
seafood
– Prime target for cheaper substitutions
– Giant squid or cuttlefish may be passed off
as abalone
• Sold cut into round steaks
• Must be cooked briefly, or it toughens
Squid (Calamari)
• Available in a variety of market forms
– Fresh, frozen, dried, and canned
– Fresh squid should be moist, but firm
• With a faint seawater odor
• Clean the squid prior to use
– When sold fresh or thawed
• Very long shelf life if handled with care
Octopus
• Flesh is firm and flavorful
– Small animals are best
– Pound tough flesh of large octopus with a
mallet
– Flesh of certain species is poisonous
• Usually cleaned and tenderized before it
is sold
Cuttlefish
• Common in Europe and Asia
• Measures between six and ten inches
• Choose fresh cuttlefish with moist, firm
flesh that smells faintly of the sea
– Also sold frozen or canned
• White flesh is very firm; slippery skin is
difficult to remove
Sea Urchin
• Edible portion of the sea urchin is
located under its mouth
– Consists of five sexual organs known as
the “coral”
• Sold whole or ready to serve and
extremely perishable
– Look for firm spines and tightly closed
mouth holes
Sea Cucumbers
• Found on the sea floor worldwide
• Considered a delicacy in Far East
countries
• Often purchased dried and rehydrated
before use
• Used in soups, stews, and braised
dishes
Smoked Seafood
• Process by which salted seafood are
flavored in a drying oven
– Dense smoke passes around and through
the product
• Good product made from good fish
• Basic methods of smoking include hot
and cold
Market Varieties of
Smoked Seafood
• Includes:
– Bloaters, buckling, cod and haddock fillets,
eels, finnan haddock, herrings, kippers,
mackerel, oysters, pollock, sablefish, trout,
whitefish
– Smoked salmon: most popular; several
varieties
Seafood Analogs
• Substitutes for meat-based proteins
– Burgers
– Hams and loaves
– Hot dogs
– Sausages
Summary
• There are various methods of seafood
harvesting
• Fish may be categorized as roundfish,
flatfish, winged fish, eel, and shellfish
• Visually inspect incoming fresh fish
• Shellfish Sanitation Program monitors
shellfish safety