MOLLUSCS, CRUSTACEANS & CEPHALOPODS

Shrimp Shrimp are small animals that

live on the floor of oceans and lakes. There are over 2,000 different species of shrimp worldwide. Shrimp are invertebrates (animals lacking a backbone) that have a tough exoskeleton.

Anatomy: Shrimp range from a small fraction of an inch to 9 inches (a few mm to 23 cm) long. These crustaceans have a thin, smooth, hard, and almost transparent exoskeleton. Shrimp vary widely in color; tropical varieties are often brightly colored. Shrimp have 5 pairs of jointed walking legs on the thorax, and they have 5 pairs of swimming legs (swimmerets) and 3 pairs of maxillae (feeding appendages) on the abdomen. The body, legs, swimmerets, and other appendages are segmented. Shrimp have two pairs of segmented sensory antennae, a tail fan, and compound eyes.

Diet: Shrimp are omnivores; they eat plants and small animals. The unusual pistol shrimp kills or stuns its prey by making a very loud sound with a huge claw with a moveable, snapping appendage.

Life Cycle: Female shrimp lay over a thousand eggs, which are attached to her swimming legs. The shrimp emerge as tiny, floating organisms, a component of zooplankton. After growing, they sink to the bottom, where they will live. As a shrimp grows, it often molts (losing its old shell and growing a new one).

Predators: Shrimp are eaten by many animals, including many fish, many birds (including flamingos and loons), octopi, squid, cuttlefish, and people.

Scallop

Scallops are bivalves; they have two hard shells and a soft body;

they spend most of their time on the sea bottom. Scallops mostly stay in underwater grass beds on a

soft, shallow sea floor. Scallops use jet propulsion to move; they quickly

open and close their shells, squirting the water out of the shells, moving in spurts.

These invertebrate animals have a life span of about 1 1/2 years.

Diet: Scallops eat microscopic food, like algae and plankton that floats through the water.

Predators of the Scallop:Many animals eat scallops, including sea stars, crabs, and people.

Anatomy: The two hard shells (also called valves) are attached by a muscular hinge called the adductor muscle

The Bay Scallop is about 3 inches (8 cm) in diameter; other scallops can reach 8 inches (20 cm) in diameter.

The shell is secreted by the mantle, which is a thin sheet of tissue located between the shell and the body.

Scallops have many primitive eyes; they can only sense changed in light and motion, helping them to detect predators.

Sea Urchin

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.

Diet: Sea urchins eat plant and animal matter, including kelp, decaying matter, algae, dead fish, sponges, mussels, and barnacles.

Predators of Sea Urchins: Sea urchins are eaten by crabs, sunflower stars, snails, sea otters, some birds, fish (including wolf eels), and people.

Adult Anatomy: Adult sea urchins have five-sided radial symmetry. Their skin has hard, chalky plates, and is called the test. Sea urchins have a globular body and long spines that radiate from the body. The spines are used for protection, for moving,and for trapping drifting algae to eat. Among the spines are five paired rows of tiny tube feet with suckers that help with locomotion, capturing food, and holding onto the seafloor. Tiny pedicellarines are small stinging structures that are used for defense and for obtaining food. Like all echinoderms, sea urchins do not have a brain. The mouth is claw-like and is located on the underside; it has 5 tooth-like plates that point inwards and are called Aristotle's lantern. The anus and the genital pores are on the top of the sea urchin.

Oysters

Oysters are soft-bodied animals that have two hard, protective shells (a bivalve). They spend their entire lives in one underwater location.

The shape of the oyster's shells varies, depending mostly upon how crowded they are in the oyster bed.

Pearls: Pearls are sometimes found in oysters. When a grain of sand (or other irritating substance) gets stuck between the oyster's mantle and shell, the oyster secrets nacre. This shiny substance coats the grain of sand, and over the years, forms a lustrous pearl.

Predators of the Oyster: Many animals eat oysters, including whelks, sea stars, and people.

Anatomy: The two hard, rough-textured shells are attached by a muscular hinge (the adductor muscles) at the narrow end.

The shell is generated by the mantle, a thin layer of tissue separating the shell from the soft body.

When an oyster is threatened, it closes its shells, using the very strong adductor muscle. Oysters draw in water through their gills, and extract oxygen and filter out floating algae (which they use for food).

An oyster changes its sex during its life; it starts out as a male and often ends as a female.

The largest oysters are up to 3 feet (1 m) long, but most are a few inches long.

Clams Clams are animals that burrow under the sea floor.

They are bivalves, mollusks that have two shells that protect a soft body.

There are over 15,000 different species of clams worldwide. The biggest clam is the Giant Clam, Tridacna gigas; it is up to 4.8 feet (1.5 m) long and weighs up to 550 pounds (250 kg).

Most clams are only a few inches long.

Predators of the Clam: Many animals eat clams, including eels, sea stars, whelks, and people.

Anatomy and Diet: Clams come in many colors, including shades of brown, red-brown, yellow, cream, etc.

The two shells are attached by a muscular hinge (the adductor muscle). When a clam is threatened, most clams will pull their soft body into into the shells and close the shells tightly for protection.

The foot is used to burrow into the sand.

Clams use their tube-like siphon to draw in water, from which they extract oxygen and filter plankton (tiny plants that they eat).

CEPHALOPODS CLASSIFICATION: Cephalopods means head-foot. They have tentacles or legs

attached to the head surrounding the mouth. squids, calamari in Italian, calmar in French cuttlefish: larger than a squid with a shorter body octopus NB: The ink of squid or cuttlefish can be used to darken

and enrich a sauce or to make black pasta. CHARACTERISTICS: there are hundreds of species but only few are commonly

eaten. they grow in tropical and warm water. squid is the most widely available edible member of the

family. squid are considered to be the sweeter and the more

tender. octopus or very large squid must be tenderized

MARKET FORM: Frozen whole Frozen cleaned and cut Pickled, canned, canned smoked, dried CHECKING FRESHNESS: sweet smelling and moist meat STORAGE must be well frozen when received. must be thawed according to hygiene

regulations. in refrigerator under cold running water microwave

SQUID

Squid live in salt water. They eat fish, shrimp and other marine animals.

When a squid finds a school of fish, it grabs one. The squid uses its arms to hold the fish near its

mouth, then bites off chunks with its beak. Squids do not have external shells. Their mantles are

easily seen on the outside of their bodies. Squid come in many sizes. They range from less

than an inch to more than sixty feet. Squid can change color. They often change color

when they are disturbed.

HOW TO CLEAN A SQUID:

1. Pull off the head with the interior organs.

2. Pull off the skin

3. Pull out the plastic-like semi trans-parent quill from the body sac.

4. Rinse out the sac to clean it well.

5. Cut off tentacles above the eyes.

6. Discard the head and organs.

7. Remove the hard beak which is found at the center of the tentacles cluster. Rinse well.

8. Prepare and cut according to the recipe.

STANDARD PORTION 6 oz, 180 g cleaned meat COOKING: quick cooking over high heat: stir-fry,

deep frying and sauté slow cooking: braised and stewed when done should be fairly tender TYPICAL DISHES: Grilled squid, with vinaigrette Deep-fried, coated in corn semolina À la majorquine: stewed with bell peppers

and wine Stir-fry in Asia

Cuttlefish The cuttlefish is a marine animal that has eight arms, two

tentacles, and a soft body. It is a cephalopod, a fast-swimming, intelligent mollusk that can change its skin color and spew ink in the water to confuse predators.

The cuttlefish swims by using its fins and by spewing water from its body (a type of jet propulsion). The cuttlefish is nocturnal; it hunts during the night, and it hides and rests during the day. It has a life span of about 18 months.

Diet: Cuttlefish eat fish, small mollusks (snails, clams, other cuttlefish, etc.), worms, crabs, and shrimp. Prey are killed with a venomous bite fom the beak.

Predators and Protection: The cuttlefish is eaten by sharks, fish and other cuttlefish. In order to escape predators, a cuttlefish can squirt black ink into the water, allowing it to escape. Another defense that cuttlefish have is changing their skin color to blend into the background, camouflaging themselves.

Anatomy: Cuttlefish average about 1 ft (30 cm) long. Cuttlefish have eight arms and two tentacles that surround the mouth and beak;

the tentacles are often kept in a pouch under the eyes.

The body of the cuttlefish (the cuttle) is flattened and has fins that extend along the entire length of the mantle.

The skin changes both color and pattern to mimic the environment.

The cuttlebone is a gas-filled shell inside the mantle that lets the cuttlefish regulate its buoyancy (the ability to float or sink).

Cuttlebones are used as calcium supplements for pet birds and for polishing silver (when powdered).