Tiger Prawn Cultivation Techniques; Prawn Breeding
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Tiger Prawn Cultivation Techniques, Breeding Information
Today, let us talk about Tiger Prawn Cultivation Techniques and Breeding of Tiger Prawns.
Tiger prawn commonly called the Giant tiger prawn or Asian tiger shrimp is a marine crustacean that is widely reared for food. The scientific name for Tiger prawn is Penaeus monodon.
Common Name of Tiger Prawns:
Black tiger, giant tiger, and jumbo tiger shrimp.
Information On Tiger Prawn:
Tiger prawn is one of the most popular cultured shrimp species in the world. In 2013, worldwide aquaculture produced over 650,000 tones of tiger shrimp (virtually all produced in Asia). Most of these cultured tiger shrimp exports to the European Union. The European market is under pressure due to strong competition from other tiger shrimp species. However, giant tiger shrimp remains an important product in the food service segment in Northern, Western and Southern Europe.
Tiger prawns progress through several life history stages in a short amount of time & mature quickly. Adults exist on soft bottoms. Unlike many aquatic invertebrates, tiger prawns reproduce through internal fertilization. After mating, females release thousands of fertilized eggs, which quickly hatch. Planktonic larvae live in the open ocean, & juveniles live in estuaries, before moving to the preferred adult habitat near the age of maturation. Like in all decapods, the tiger prawn’s shell actually is a skeleton on the outside of its body. The exoskeleton does not expand, & therefore the prawn must molt or shed it regularly in order to grow bigger. Before molting, an individual begins building a new, larger skeleton within the existing one. As it gets too big to be contained, it splits open the outer shell, & the new exoskeleton hardens. During this process, the new exoskeleton can be soft for several hours, & the prawn is highly vulnerable to predation.
Adult tiger prawns are omnivorous & eat a wide variety of food, including algal and plant material, other invertebrates, and decaying organic matter. Most soft-bottom fishes and several invertebrates eat juvenile & adult tiger prawns. This species is the target of a large fishery throughout most of its range. Of concern to conservationists & resource managers is the primary gear with which these species are captured. Black Tiger prawns are captured by bottom trawl. This process is known to cause significant damage to seafloor habitat & known to capture an incredible amount of non-target species. Numerous species of sea turtles, sharks, rays, bony fishes, & other invertebrates are accidentally captured in prawn trawls. The use of prawn traps is an alternative gear type that is more environmentally friendly. Traps do significantly less damage to the seafloor & are not associated with the high levels of incidental bycatch experienced with bottom trawls. Unfortunately, traps are much less lucrative for fishers & may not be a realistic alternative for those who make a living selling tiger prawn.
Another concern related to the tiger prawn is the wide-scale aquaculture for this species. Though aquaculture can lower the fishing pressure on wild populations of some species, tiger Prawn Cultivation is highly destructive to coastal environments. Prawn Cultivation, in general, is the main threat to mangrove forests, which are destroyed when building farms. Discharge of Tiger prawns from farms outside of their native range has resulted in documenting invasive populations in some places around the world. Finally, overfishing of tiger prawns to be raised in ponds & forage fishes to feed the prawns.
Distribution of Tiger Prawn:
The Tiger prawn is widely distributed throughout the greater part of the Indo-Pacific region, ranging northward to Japan and Taiwan, eastward to Tahiti, southward to Australia, & westward to Africa. Tiger prawn completes its life cycle in two environments, namely, marine & estuarine environment.
Tiger prawn is the fastest-growing and largest shrimp in the world. The female prawn grows to a length of 363 mm (440 g), while the maximum size attained by males is 270 mm (180 g). In shrimp culture farms, they are generally harvested at about 160–165 mm (30–35 g) in size. The stocked seed (15–20 mm) reach this harvest size in about 4 months in 15–25 ppt salinity.
Over the past two decades, the Tiger prawn, Penaeus monodon Fabricius, has become an important aquatic export product for Southeast Asian countries. In Thailand, which pioneered intensive tiger prawn culture, production was valued at 15.1 billion Thaibahts in 2000 (Fisheries Information Technology Center 2006). However, prawn aquaculture has made some negative impacts, such as environmental deterioration, eutrophication, & frequent outbreaks of bacterial and viral diseases. The declining prawn growth rate is a major problem. Thus, the making of intensively cultured prawns can lead to a number of difficulties in producing countries.
Read: Fish Farming Project Proposal.
Lifespan or Longevity of Tiger Prawn
The life span of wild and captive Tiger prawns is about two years, though it has been suggested that individuals introduced in the Gulf of Mexico have a lifespan closer to 3 years.
Predation:
During their lifetimes, Tiger prawns face a mixture of predators, including birds, comb jellies, crustaceans, and fishes. When adult prawns go from shallow inshore areas to deeper water, their rate of mortality drops.
Tiger prawns have developed a variety of defenses to shield themselves from predation. Prawns have spines on each end of their body (a rostrum above the mouth, & a telson located at the dorsal end of the body). Their distinctive stripes & body color, which is similar to their muddy environment, help to camouflage them from predators. These prawns bury themselves in the substrate, not only hiding their bodies but also masking their waste, which would otherwise likely be noticed by potential fish predators’ chemosensory systems.
Tiger prawn breeding and post-larvae production:
Prawn larvae are formed in hatcheries, which use wild-caught spawners or broodstock collected mainly from the coastal waters between Cook town & Innisfail. The most popular of these spawners are gonadally mature & when they are transferred to the hatchery they either spawn spontaneously or are induced during the use of eyestalk ablation.
Each spawner will make between 200,000 and 500,000 eggs. The eggs are hatched & pass through a number of larval stages until they reach the post-larvae stage. The post-larvae are normally sold to the grow out farms for stocking ponds when they are 15 to 20 days old. The quality of the post-larvae will vary between spawners & the time of the year the spawners are collected.
Females can reach about 33 cm or 13 in length, but are typically 25 cm–30 cm (10–12 in) long and weigh 200–320 g; males are slightly smaller at 20–25 cm (8–10 in) long & weighing 100–170 g. The carapace and abdomen are transversely banded with alternate red & white. The antennae are a grayish brown color. Brown pereiopods & pleopods are present with the fringing site in red.
Tiger Prawn Cultivation techniques:
Lowered stocking density – This can reduce the harvest volume by 20-30%, however, the harvest value could increase by 8%-10% due to bigger size & improved feed conversion. Feeding and nutrient loading is reduced by 20%, & the risk of opportunistic diseases is reduced as well.
Improvement of pond bottom management – This can increase plowing or tilling cost, add net cage construction to the expense, but these costs could be recovered from the sale of the added fish crop. Bacterial profile of sediment is improving, though, as well as water effluent quality. The pathogenic Vibrio count can be reduced.
Crop rotation – One shrimp crop can be lost, but there is some income from fish culture. Crop rotation develops sediment bacterial profile, reduces Vibrio count, reduces the incidence of white spot, & ultimately allow time for organic waste to break down.
Improvement in feed quality –Diet much improved in nutritional quality and lower nitrogen and phosphorus discharges. Farmers can also use probiotics.
Stocking of laboratory-screened fry – There is a cost to fry analysis, screening and waiting time for the results, but the farmer is reducing the risks for white spot & pathogenic Vibrio infections.
Use of green water technology – culture area can be reduced by 25%-50% due to the requirement for a bigger reservoir, but the cost can be recovered from the sale of fishes raised in the reservoir. There is an added expense for modifying the water supply channel. The advantage is more stable water quality, & suppression of growth of pathogenic Vibrio.
Black Tiger Prawn aquaculture:
The Tiger prawn or Penaeus monodon is a fast-growing tropical to subtropical species suited to warm, brackish waters. The black tiger prawn is one of three prawn species farmed in Queensland, and the main species farmed in Australia. Purpose-built earthen ponds, make on coastal lands or adjacent to the estuarine parts of river systems, are used for the intensive culture of marine prawns.
Successful Prawn Cultivation requires a sustainable & clean coastal resource. The industry is currently regulated by local, state & in some areas, commonwealth laws to ensure a high standard of protection for the environment. Prawns are harvested early in the year & also on demand. Most of the Tiger prawn crop is sold on the domestic market.
Growing and harvesting black tiger prawns:
Pond preparation:
Between harvests, stocking ponds are dried out & accumulated sediments from the previous crop are removed. These sediments contain organic matter (dead plankton, uneaten food & old moults) & mineral matter. Prior to filing, the ponds are limed to encourage plankton growth & minimize disease problems. The ponds are filled through screening inlets, fertilized with both organic and inorganic fertilizers and allowed to stand for 7 to 10 days to allow the plankton to develop.
Seed supply:
Due to their larger size & better survival, captured wild seeds were used generally in south Asia for extensive ponds, which want a minimal amount of seed for stocking. Though, the use of wild seeds has been reduced, due to overfishing & the outbreak of white spot disease in shrimp nursery grounds. Therefore, most Tiger prawn grows-out farms now rely solely on hatchery-produced seeds.
Feeding:
Ponds are stocked with post-larvae at rates varying from 25 to 40 per square meter. The post-larvae are weaned from plankton to manufacture feed over the first four weeks.
Prawns are fed 3 to 4 times per day, with the last feed being given close to dark. The feed is blown into the pond with an engine-driven blower. Consumption is calculated at each feed by using feed trays that are submerged along the pond edges. Growth rates are monitored by the weekly sampling of the prawns. This feed management enables farms to minimize feed wastage & maintain good feed conversion rates. Feed conversion ratios (kilogram of feed to produce 1kg of prawns) from 1.6:1 to 2.2:1.
Water quality:
Stable pond conditions & good water quality are necessary to maximize survival and growth rates. Paddlewheels and aspirators are generally used for aeration. The aeration generates a current causing the sediments to gather in the centre of the pond. This keeps a clean feeding area around the pond edge. As the quantity of prawns increases, the level of aeration necessary increases to maintain the levels of dissolved oxygen in the water. A minimum of one kilowatt of aeration is required for each tone of prawns in the pond.
Exchanging water controls the density of algal blooms & ammonia levels in the ponds. Water exchange is minimized to help keep stable water conditions. Wastewater is removed from the bottom of the pond & drained into sedimentation or treatment ponds before being reused or released to the environment.
Harvesting:
Crops are normally ready for harvest in 120 to 150 days; however, the time will depend on stocking rates and water temperature.
Ponds are sometimes moderately harvested using traps or seine nets, but more often a drain harvest is used. The water is released during the outlet structure, which has a net fitted over the pipe and the prawns are then caught in this net. Partial harvests can be used early in the season to reduce the density of prawns in the pond & allow the prawns remaining to grow to a larger size.
Normally, prawns are harvested when they are 25 to 35 grams each. Prawns are washed, graded & generally cooked before marketing. Some prawns are sold green & others are individually quick-frozen for storage and sale at a later date.
Read: Organic Livestock Farming.
Harvesting techniques:
Bamboo traps are traditionally used for the partial harvest of preferred large shrimp in extensive culture. Semi-intensive ponds are generally harvested by draining the pond by tide through a bag net installed at the outlet sluice gate. Intensive ponds are generally harvested similar to semi-intensive ponds. If the tide does not allow harvesting, the drainage canal can be blocked to allow the water to be pumped out to decrease the water level. It is still essential to pick the remaining shrimp by hand after the pond has been drained.
Handling and processing:
If shrimp is sold directly to giving out plants, particular teams for harvesting & handling are used to ensure the first grade quality of their raw materials. After rough sorting, shrimp is washed, weighed & immediately killed in iced water at 0 °C. The hardest job is to clean the shrimp picked by hand from pond bottoms at the end of the harvest. Because they contain a lot of mud, organic matter & debris. Shrimp is then kept in ice in insulated containers & transported by small pick-up trucks for short distances or by large insulated trucks over long distances, either to processing plants or shrimp markets. For transportation of live shrimp from farms directly to aquarium tanks in restaurants, the shrimp are kept in aerated plastic containers at a density of 0.2 to 0.3 kg/litre of water. The containers are normally placed on small pickup trucks with a roof. For the export of live shrimp from Thailand to Hong Kong & China, water temperature is gradually reduced to 16 to 17°C until the shrimp become inactive. The dormant shrimp is then packed alternately in layers of chilled sawdust beads in insulated boxes for export by air. This dry packing can minimize freight costs & shrimp can survive for 12 to 15 hours. Domestic markets mostly require chilled product supplied directly from farms or from shrimp markets.
In processing plants, shrimp is properly cleaned & sorted according to export standard sizes. Depending on market conditions, Tiger prawn is the method in several categories before quick freezing at -10°C and stored below -20°C for further export by ship or air cargo. Due to an increasing demand & higher profit margin, many processing plants increasingly operate value-added product lines.
Development:
Expansion in aquaculture production of Tiger prawn has not been as great as was initially expected, including major problems with viral disease outbreaks, market competition & trade barriers. Several farmers that originally reared Penaeus monodon have replaced this species with Litopenaeus vannamei, in which culture & domestication technologies are much simpler. L. vannamei disease problems are less severe, mostly for culture in inland freshwater ponds. Due to its lower cost, this new species can be increasingly sold in domestic markets, which ensures stable incomes for farmers on the unstable export price. Tiger Prawn Cultivation will be more sustainable if farmers can shift production to other species when the existing cultured species faces problems. Decreasing Tiger prawn production can also improve the status of its broodstock in the wild in the future because less will be caught and less disease from grow-out ponds will be introduced into the sea. Due to these different species, the growth of P. monodon or Tiger prawn production is predicted to slow in the immediate future. Later, it can increase, thus improving the sustainability of production & reducing operational costs.
Cost of Tiger prawns:
Cost of Tiger Prawns approximately Rs. 700/Kilogram – 1,500/Kilogram.
Prawn Health Benefits:
Nutrition Facts of Prawn:
Calories | 106 |
Fat Calories | 15.3 |
Total Fat | 1.7 g |
Saturated Fat | 0.3 g |
Cholesterol | 152 mg |
Sodium | 148 mg |
Protein | 20.3 g |
Omega 3 | 0.53 g |
Eating prawns regularly will give the following nutritional benefits:
Prawns are a great source of high-quality protein, & provide some of the most important vitamins and minerals that make up a healthy diet. They are surprisingly low in calories & are made up of extremely healthy cholesterol. In fact, according to the American Journal of Clinical Nutrition, eating prawns is a component of a heart-healthy diet. And because they are common throughout the world, there are healthy prawn dishes within about every style or type of cuisine.
- Eating prawns provide a total protein, which means it includes all nine amino acids in the right proportion for the body to function properly. In fact, 100 grams of prawns contain about 25 grams of protein, roughly the same as a similar amount of chicken or beef.
- Prawns are particularly low in calories. The same 100 grams of prawns have only about 115 calories.
- Prawns have higher than average amounts of cholesterol; they do not lead to higher cholesterol levels in the body due to their healthy fat profile. This is because they have almost three times more Omega 3 Fatty Acid than they do Omega 6 Fatty Acid. In fact, the cholesterol contained in prawns is essential for a healthy diet.
- Prawns are a great source of Vitamins B-6, B-12 & Niacin, which help the body produce energy, build muscle & replenish red blood cells.
- Prawns contain important amounts of iron, a mineral that is essential for the body to effectively distribute oxygen. And because it is in only a few types of food, iron deficiencies that cause severe exhaustion are surprisingly widespread, particularly for women.
- Prawns are a rich source of selenium, one of the most efficient antioxidants in maintaining healthy cells. They contain high levels of Zinc, which is important to develop a healthy immune system
- Eating prawns help build strong bones because they contain phosphorous, copper & magnesium.
Read: Goat Farming.