After hatching, free-swimming nauplii are obtained, which further passes through protozoea, mysis and then to postlarval stage, which resembles the adult prawn. Saudi Arabia was the largest producer in at nearly 11, tonnes with Vietnam not far behind with 10, tonnes. In India F. Although the Indian prawn itself is not threatened, the methods used to capture it result in a large amount of bycatch , which includes endangered species such as sea turtles.
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In adult petasma males, third maxilliped with distal segment about as long as second ventral view segment which bears a tuft of dense long hairs same length as distal segment attip. Petasma of males with distomedian projections strongly curved and overhanging distal margin of costae.
Thelycum of females formed by 2 semi-circular lateral plates, with their median margins forming tumid lips; anterior process slightly rounded and slightly convex; posterior process elongated and inserted between anterior part of lateral plates; both anterior and posterior processes rather distinct. Telson lacking lateral spines. Colour: body semi-translucent, somewhat yellowish white small specimens or greyish green and covered with numerous minute dark brown dots; eyes light brown and covered with some dark brown mesh-like stripes; rostral and abdominal dorsal crests reddish brown to dark brown; antennal flagella yellowish; antennular flagella of same colour as body and covered with many dark spots; legs translucent and somewhat whitish, pleopods yellowish to pinkish; distal part of uropods yellowish with red margins.
Size: Maximum body length 23 cm females and Profile Historical background Traditional methods of brackish water aquaculture exist in four maritime states in India, namely West Bengal, Kerala, Karnataka and Goa.
In Kerala, on the southwest coast of India, traditional shrimp farming is practiced with one crop of salt tolerant paddy during the rainy season June to September and one crop of shrimp during the summer season November to April. These ponds are tidal; auto-stocking of mixed varieties of shrimp and fish takes place during high tide. Within the shrimp harvest, Indian white prawn constituted percent. Juveniles completely depend upon natural food and harvesting is periodical, during full and new moon periods.
Commercial shrimp farming, with selective stocking of shrimp seeds, was initiated with the establishment of shrimp hatcheries in the government and private sectors in India in he late s; these hatcheries produced Penaeus indicus and Penaeus monodon seeds. In India, P. The contribution of P. Currently P. Adults are normally found at depths less than 30 m but have also been caught from 90 m. The shrimp mature and breed mostly in marine habitats and spend the juvenile and sub-adult stages of 30 to mm total length TL in coastal estuaries, backwaters or lagoons.
On the southwest coast of India the juveniles support a good commercial fishery in the backwaters and paddy fields. Geographic variations in size at first maturity are evident and vary from to mm TL. There are five stages in ovarian maturation: immature, early maturing, late maturing, mature and spent. During mating, which normally occurs at night, the sperm packs spermatheca are deposited by the hard-shelled male into the thelycum of the newly moulted, soft-shelled female.
The females carry the spermatheca during ovarian maturation and the sperms are dispensed at the time of spawning. Fertilization is external as the ripe ova released by the female become fertilized by the sperm extruding simultaneously from the stored spermatheca in the thelycum.
Depending upon the temperature, hatching takes place within hours after spawning. The nauplii are free swimming and non-feeding and pass through six moults. The larvae further pass through protozoea 3 stages , mysis 3 stages , and then to postlarvae, which resemble the adult shrimp. The postlarvae migrate into the estuaries, settle and feed on benthic detritus, polychaete worms and small crustaceans, and remain there until they attain mm TL.
These sub-adults then return to the sea and get recruited into the fishery. Production Production cycle of Penaeus indicus Production systems Seed supply In the traditional paddy-cum-filtration systems, juveniles congregating around the sluice gate are allowed to enter into the extensive fields during high tide.
Earlier, wild seeds were also caught and sold to shrimp farmers. However, with the establishment of hatcheries and also due to overfishing, the dependence on wild seeds has been reduced. When wild spawners are used, they are carefully transported to the hatchery and maintained in flow-through systems in order to recover from the stress. The size of P. The tanks are covered and kept in a dark room.
Three tanks of the above size can meet the broodstock requirements of a hatchery of 18 million capacity. Shrimp are fed with intertidal oligochaetes and clam and squid meat daily. Female eyestalks are unilaterally ablated by an electrocautery apparatus for endocrine stimulation. Shrimp mature within days after ablation and the interval between two consecutive spawnings may be days.
However, ablated females produce ten, eight and six times as many spawns, eggs and nauplii, respectively, compared to unablated females. Estimates of the total number of eggs spawned are made by sampling. The eggs are allowed to hatch in the same tank. After estimating the total number of nauplii hatched, they are collected, washed and stocked into larval rearing tanks. Small-scale hatcheries purchase the nauplii from nauplii producing centres for further rearing to postlarvae because broodstock maturation facilities require higher investments and infrastructure.
Hatchery production Smaller indoor tanks of tonnes capacity are used for rearing larvae up to PL Larval rearing trials without the inclusion of the expensive Artemia nauplii have been successful but higher survival is achieved when Artemia is fed. Nursery The postlarvae PL5 from each larval rearing tank are transferred into a nursery tank of 10 tonnes capacity for further rearing to PL From PL5 onwards, artificial diets are commonly used to reduce water quality deterioration.
Twelve larval cycles can be obtained in 8 months. PL20 postlarvae can be directly stocked into grow-out ponds for farming.
Ongrowing techniques The culture practices followed are traditional, extensive, modified extensive, semi-intensive or intensive. Traditional farming practices are still practiced in tidal ponds along the Southwest coast of India.
Commercial semi-intensive farming has been adopted in Middle Eastern and in the Gulf countries. Semi-intensive farming of P. Traditional This system of shrimp farming, which involves the trapping and holding of juvenile shrimp brought in by tidal water, is practiced in Bangladesh, India, Indonesia, Myanmar, the Philippines and Viet Nam.
On the southwest coast of India, paddy fields ranging in size from 0. These fields are seasonally used for a single crop of paddy during the monsoon season June- September. Very large fields with deeper areas ranging in size from 2 to 75 ha, where paddy cultivation is impossible, are also used for shrimp filtration throughout the year.
Indicus forms percent of the total yield of shrimp. Modified extensive Ponds of 1 to 2 ha in size are constructed with separate inlet and outlet facilities on elevated sites to allow complete pond drainage. The shrimp feed on natural foods enhanced by pond fertilization, and supplemented by artificial diets.
Water exchange of percent is carried out daily. Water exchange is regularly carried out by pumping. Intensive Intensive farming of P. Heavy aeration and water exchange to minimize environment deterioration was practiced. Feed supply In India farmers use locally manufactured commercial shrimp feeds not specifically designed for this species as well as imported feeds designed for Penaeus monodon.
Some farmers prepare their own feeds but these are qualitatively poor. The cost of imported feeds is generally higher. In Saudi Arabia, the National Prawn Company prepares feeds specifically for Penaeus indicus as it is exclusively culturing this species. Harvesting techniques In traditional farming, harvesting starts 2 months after stocking and is carried out from dusk to dawn for days around every full moon and new moon period.
Close-meshed conical nets are fitted to the sluice gates during low tide to harvest the stock. Final harvesting from extensive farming is carried out after months of ongrowing. Water is drained out during low tide and further reduced by pumping, using mobile diesel-powered equipment.
The remaining shrimp are harvested by cast netting. In modified extensive systems and semi-intensive systems, harvesting is carried out by complete draining of the pond, the shrimp escaping through the sluice gate being collected by bag nets. The remaining stock is harvested by hand picking. In Saudi Arabia, mechanical harvesting techniques are employed.
The rectangular crates in which they are placed are then transported to the processing plants by insulated trucks. In the processing plants, the shrimp are cleaned and sorted into various grades to suit export requirements. Depending on market requirements, shrimp may be processed into several forms, such as simple block frozen, ready-to-eat, whole chilled, IQF, and cooked products, which are exported by container ship or air cargo. Production costs Production costs depend upon the site, the type of culture system, the scale of production, the number of production cycles per year, and the incidence of diseases, etc.
The cost of adult shrimp produced in a modified extensive system was estimated in to be USD 4. The production costs for this species, as reared in Saudi Arabia, are not available. Diseases and control measures The major disease problems for this shrimp species are shown in the table below.
Viral infections cannot be treated by drugs but can be managed by screening for viral pathogens in broodstock and postlarvae by the PCR technique and by adopting good farming practices such as regulated stocking, feeding protocols and effective pond management. However, outbreaks of shrimp viruses may occur due to sudden changes in water quality and poor pond bottom environment In some cases antibiotics and other pharmaceuticals have been used in treatment but their inclusion in this table does not imply an FAO recommendation.
FENNEROPENAEUS INDICUS PDF
Fenneropenaeus indicus (H.Milne Edwards, 1837)