2. molluscs and
crustaceans
molluscs
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• Shellfish are broadly divided into two
categories
crustaceans
3. Molluscs can be divided
into three categories:
periwinkles whelks limpets
• Uni-valve molluscs have one shell—
periwinkles, whelks and limpets. These
molluscs can be found on the seashore.
4. mussels, oysters and
scallops
mussels oysters
• Bi-valve molluscs have two shells
hingedat one end
scallops
5. Cephalopods
• have no outer shell, just a single internal
one called a pen. Examples include squid
and cuttlefish.
cuttlefish. squid
6. prawns, shrimp, crab
and lobster.
lobster.
• Crustaceans are mobile creatures with crab
hard, segmented shells and flexible joints.
Examples include
shrimp
prawns
7. Finfish
oil-rich fish.
whitefish
• Finfish are divided into whitefish and oil-
rich fish.
8. whitefish
whitefish
• Whitefish are sometimes referred to as
"lean fish" because all the oils are contained
in the liver, which is removed during
gutting.
9. cod,, hake and pollock.
cod, pollock
• Whitefish are further sub-divided into:
Round Whitefish—Examples include
10. Flat Whitefish
plaice
sole brill
• Examples include plaice, lemon sole, brill,
turbot and black sole.
turbot
black sole
lemon
11. T
Cartilaginous Fish
• Examples include ray, dogfish, shark.
dogfish net shark
ray
12. Oil-Rich fish
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• are so called because the oils are
distributed throughout the flesh of the fish.
Mackerel, herring, salmon and trout are
examples.
13. • Finfish are occasionally classified in a
different way—according to where they
swim in the sea.
• Demersal fish are those which live on or
near the seabed. Round and flat whitefish
fall into this category.
• Pelagic fish swim in mid-waters or near the
surface. Examples are oil-rich fish such as
mackerel, herring and tuna.
