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Thursday, November 21, 2024
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മലയാളം
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Seed Collection
Since milkfish does not mature and breed in confined waters and culture ponds, development
of a hatchery technology has been difficult. However, induced breeding has been
successfully carried out in this species, but the final survival rate has been less
and hatchery operations hence are not economical. In this respect the most suitable
method is collection of seeds from natural sources. In India, the seeds of milkfish
measuring 2-7 cm in length occur along the coast of Orissa, Andhra Pradesh, Tamil
Nadu, Kerala and Karnataka. The main fry season extends from March to June. Milkfish
seeds prefer clear calm inshore waters of gently sloping beaches including tidal
creeks, estuaries, brackishwater bodies and mud flat areas where the temperature
is about 23-25 oC and salinity varies between 10 and 32 ppt.
The seeds are collected from low-lying areas using scoop nets, dip nets and hand
nets. In estuaries and lagoons, drag nets or seine nets may be used, while in mud
flat areas, a scare line made of coir rope of about 3-3.5 m length with palmyrah
leaves attached is dragged below the water surface and seeds collected in fine meshed
cloth. Soon after collected the seeds are conditioned by keeping in a limited volume
of clear water for a definite period without food. Seeds are transported in containers
with diluted seawater of 10-15 ppt salinity and at a rate of about 100 fry/L.
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