SEED RESOURCES OF FINFISH AND SHELLFISH Introduction Estuaries

SEED RESOURCES OF FINFISH AND SHELLFISH

Introduction • Estuaries, mangroves and backwaters serve as nursery grounds for a number of fish and shellfish • Mullet seeds- from coastal waters, estuaries, tidal creeks, tidal canals and lagoons • Milkfish seeds- available in both the east and west coast of India – In the east coast they are available at Vishakapatanam, east Godavari, Krishna, Guntur and Nellore in A. P, Chinglepet, Chennai, south Arcot, Tanjore, Ramnad and Tirnelveli in T. N. – In the west coast they are available from Malabar to the coast of D. K and Udupi dist. – Generally they are abundant during April – June and occasionally in October – December.

Species Locality Months of abundance Mugil cephalus Chilka lake October to February Chanos chanos Pamban, Chennai coast, Pulicate lake. March to May Apr. to May; Nov to Dec. Feb. to Oct. Etroplus suratensis Chilka lake Kerala backwaters Apr. to July; Sept. to Nov. May to June Lates calcarifer Chilka lake Hoogly Matlah estuaries June to Oct. May to Oct. Eleutheronema tetradactylum Mumbai coast T. N. coast Chilka lake Jan to Dec. Oct. to Dec Elops machanta Kerala backwaters T. N. coast Pulicat lake Chilka lake Dec. to Jan Oct. to Nov. ; Apr. to Sept. Megalops cyprinoids Pulicat lake Apr. to Oct.

Shellfish seed resources • Main cultivable species- Penaeus monodon, P. indicus and P. semisulcatus are cultivable • These species breed in offshore waters, but their seeds enter lagoons, creeks, estuaries and backwaters from where they can be easily collected. Species State Penaeus indicus Gujarath Karnataka Kerala Tamil Nadu Andhra Pradesh Orissa Penaeus monodon Karnataka Tamil Nadu Andhra Pradesh Orissa Kerala Occurrence Seasons of abundance Jan - May; Oct. - Dec Jan. - Mar; Sep. to Dec. Jan. – Feb; Apr. – Dec. Jan. – Dec. Feb. -Apr. Feb. - May Dec. - Jan. Oct. - May Feb. - May; Aug-Sept Oct. – Dec. Apr. – July; Nov. – Jan. Feb. – Apr. May – July --Jan. – Dec. Jan. - Dec. Jan. – Dec Jan. – Apr. July – Aug; Oct. – Apr. Mar. – May; Sept. -Dec. Sept. – Apr. – May; Nov. – Feb. Apr. – May Apr.

Factors affecting shrimp seed abundance – – – – Tidal amplitude lunar phases current water depth river discharges rain, substratum suspended matter pollution Ø P. monodon - wider salinity tolerance - available in a wide variety of habitats Ø The seed are particularly abundant during full moon and new moon night tides

Crab seed resources • • The seeds of mud crab, Scylla serrata have a wider distribution in the east rather than the west coast of India Available in Sundarbans, Chilka lake, Vizag, Pulicat, Parangipettai and Tuticorin In the West coast - Cochin Backwaters Seed abundance has been reported during June-August in Tuticorin and October. January in Chilka Lake Lobster seed resources: • Detailed studies – lacking • Spawn throughout the year in deeper waters • Peak breeding is during November to December.

Molluscan seed resources • • • The spats of green mussel Perna viridis are found both along the east and west coast of India In rocky open coasts, harbours and mouth of estuaries where the salinity is as much as that of the seawater Attach themselves to rocks, pilings and other hard objects from intertidal zone to a depth of 15 m depth The spats of brown mussel Perna indica -restricted distribution They are abundant from quilon to Cape Comorin in the south west coast and from Cape Comorin to Tiruchendur in the south east coast of India

Resources of edible oyster seed • The spats of Crossostrea madrasensis are abundant in Deltas of Godavari and Krishna, Pulicat, Chennai, Porto Nov, Mandappam, Keral and Port Blair • The spat available in the south east coast from late September to early May. Pearl oyster seed resources • The seeds of pearl oyster are very scanty and are not available in sufficient quantities • Aquaculture of this group needs to depend solely on hatchery produced seeds

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