FISH COMPOSITION
REPRODUCTION
- Fish is nutritionally very rich.
- Fish is a rich source of protein, essential oils and minerals.
- The approximate composition of fish is:
- Moisture 40 - 90%
- Protein 06 - 19%
- Oil 01 - 64%
- Ash 0.4 - 1.5%
- Generally fish lay eggs and the fertilization is external.
- In some cases the fish may give birth directly to living young.
- In some sharks, the embryo is completely developed internally (internal fertilization) and the female gives birth to fully developed young one.
- Usually fish lay a very large number of eggs, as they do not exhibit parental care.
FOOD AND FEEDING
·
Based on feeding habits, the fish can be grouped into
1. Herbivorous (sardines
and grass carp)
2. Carnivorous (sharks
and barracuda)
3. Omnivorous (catla)
MIGRATION
·
Most of the fish migrate either for feeding or breeding. Two
most important migrations’ are
1. Anadromous are
those which migrate upstream for spawning. Eg. Salmon and shad
2. Catadramous are
those which migrate from upstream to brackish water. Eg. Eels, fresh water
prawns.
CLASSIFICATION
OF FISH
·
Fishare broadly classified as
1) FIN FISH: They are verte
brates. They are further subdivided into
a) LEAN FISH: are mainly flat, contains oil, only in the
liver. They are mostly deep sea fish. Ex. Pomfret, Sole, Turbot etc.
b) OILY FISH: are
mainly round and contain fat all over the body. Fat varies from 1.5 % - 20% in
different varieties. These are more colourful and move towards the surface. Ex.
Mackerels, sardines, carp, rohu, trout masheer etc.
2) SHELL FISH: have a shell covering the body. They are
invertebrates. They are further subdivided into
a. MOLLUSCS: their
body is enclosed inside the shell. The shells increase at the rate of one ring
per year to allow for the growth of the fish. The age of the mollusk therefore
can be roughly estimated by the number of rings on the shell. Mollusk are of
two types-
¨
UNIVALVES: body is inside one whole shell. Eg. Whelks and Whinkles.
¨
BIVALVES: have two distinctly separate shells joined by a
hinge – like membrane. The movements of the shell are controlled by a strong muscle.
When the muscle relaxes, the two halves of the shell fall open. Eg. Oysters,
scallops, mussels, clams, cockles etc.
b. CRUSTACEANS: these have a segmented, crust like shell. Ex.
Lobsters, crabs, prawns, shrimps. The shells of crustaceans do not grow with
the fish, but are shed each year, with a new one grow with the fish, but are
shed each year, with a new one forming to suit their new size.
SELECTION OF FIN FISH FOR COOKING
·
Eyes should be bright, not sunken.
·
Grills should be red.
·
Tail should be stiff.
·
Flesh should be firm and not flabby.
·
The scales if any should be plentiful.
·
There should be no unpleasant odour (ammonia gas).
·
To test a cut piece, press down with the finger, and if an
impression is left, then the fish is stale.
·
Fish should natural covering of mucous on the body.
·
Should appear heavy in accordance to the size. Light fish
shows signs of de – hydration.
·
Always try to purchase fish without any wounds or bruises.
SELECTION OF
SHELLFISH FOR COOKING
·
It is always advisable to purchase the shellfish alive.
·
Do not buy mollusk with opened shell.
·
Prawns shells should be grayish green.
·
Shells of crustaceans should be firm.
·
Legs of lobsters and crayfish should be firm and claws
springy.
·
In case of live crabs and lobsters, there should be
movement of legs.
·
The lobster tail should be curled under the body.
·
In case of squids, it should have mild odour.
·
Oysters should be plump and should have a natural creamy
colour with clear liquid.
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