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

Source: Randy van Dam 2008

15.21 Snow crab legs and claws

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