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Ratnagiri coast, when large catches are landed, they are carefully cured
and despatched to flourishing markets for iternal consumption.
(29) TUNAS
Tunas have lately come into importance in world fisheries because of the
vast potential resources which till very recently remained untapped.
Canned tuna, considered as a luxury fish in many western countries and
especially in U.S.A., commands highest price. Treated in the manner of
thekl canning process, the tuna develops a consistency and flavour not
unlike chicken, and is frequently referred to as “ chicken of the sea”.
As sharks are rovers of open ocean, the tunas are masters of all the three
oceans the Atlantic, the Indian and the Pacific. They are widely distributed
in tropical as well as temperate regions of the immense marine expanses.
They are powerful swimmers, every line of their body or contour
suggestive of rapid motion through water, like that of a torpedo. The
streamlined body, bullet-shaped head, close-set jaws, spinous dorsal,
pectoral and pelvic fins fitting into grooves and depressions, minimise the
resistance in water to a great extent. The soft dorsal, and anal finlets set as
stabilizers, and the powerful caudal fin actuated by muscular movements
of the body, are all adapted to provide speedy motion cutting through
water like a torpedo; they are known to have a speed of about 20 knots (or
23 miles per hour). Another unique feature of tunas is that their body
temperature is higher, sometimes by 8° C than that of the surroundings. As
such, they are essentially stenothermal living in a temperature range
between 14°C to 20°C.
Tuna were well-known from ancient times as great migratory fishes. The
migrations of common tuna was a subject of interest and speculation since
Aristotle's time. " Whence they come and where they go" was a mystery
and many theories were advanced to account for their seasonal occurrence.
It is now known, fairly well, that the tuna undertake a migration for
spawning and after spawnning a migration for feeding.
FAUNA 119