Shrimp Culture

Shrimp is an important fisheries resource. It is joint footed invertebrate aquaticanimal. Out of the quantity of fish and fish products that are exported every year 90% is shrimp. Take 3352.89 crore was earned during 2006-2007 by exporting fish and shrimp. Out of this, the amount earned from shrimp is TK 2992.33 crores. At that time, the quantity of fish and fish products exported was 73,704 thousand metric ton. Out of these, the quantity of shrimp was 53,361 thousand metric ton.

Prospect of Shrimp Culture

 There are 2.20 Lac hectares of land suitable for culture in coastal region of the southern part of the country, Out of these; shrimp has been cultured in almost 1.10 Lac hectares of land in traditional method, where annual average production per hectare was only 180-200 kg. During 2006-2007 the average production per hectare in a year has gone up to 399 kgs. This is very low in comparison with other countries. In one season (6 month) 5-6 tons per hectare can be produced if it is cultivated in-semi intensive system. Recently this system of cultivation has been followed in some shrimp farm of the country. If this system is extended, it will be possible to earn a few thousand crores taka of foreign exchange every year by exporting shrimp.

Introduction of Cultivable shrimp 

There are 60 species of shrimp in the reservoirs of water of Bangladesh. Out of these only a few species are profitable for cultivation. Galda prawns are cultured in fresh water. This type prawn becomes very big. One Galda can weigh up to 250-400 gm. Out of saline water shrimps the Bagda shrimps are widely cultivated in coastal region. It is known as "Black Tiger". Chaka shrimps can also be cultivated in saline water.

Culture of Galda Prawns

 Habitat:

 Galda lives in fresh water

Physical Characteristics 

Galda looks like green to almond or blackish colour. 2-5 blackish crosswise belt can be found on the carapace. The rostrum is long and curved and notched in lower side. The number of notches, in case of male Galda the number of upper side and 11-14 in the lower side. In case of female Galda the number of notches is 12-13 in the upper side and 5-7 in the lower side. The cephalothoraxes of the prawn is large. The legs of Galda are long. The first and second pair of legs are spiny. The second pair of legs of male Galda is longer than that of female lobster.

Bagda Shrimp (Tiger Shirmp)

 Habitat: 

Bagda. shrimp lives in saline water.

Physical Characteristics

 The colour of the Bagda is light almond of green. Its body has black strips like tiger. So it is called Black Tiger.
Red stains can be found from the front to the end of the, body of the, young Bangda. The colour of these stains in bigger fries light green. The rostrum of Bangda Shrimp is curved and wide. It has got 8 notches in the upper side and 3 notches in the lower side.

Chaka Shrimp
 Habitat: 

This shrimp also lives in saline water.

Physical Characteristics

 The young Chaka shrimp is light white and the tip of the rostrum is pinkish. The rostrum of the adult shrimp is erect and curved. It has got 8-10 notches in the upper side and more than 3 notches in the lower side.

Farming with Galda Shrimp

 Galda can be cultured in the pond singly of with Ruhi, Katla as mixed culture. Here single farming of Galda is discussed.

Selection of the Pond

 As the pond of shrimp culture requires availability of plenty of oxygen, the water of the pond needs to be changed off and on. For this, the pond area has to be selected near rivers, canals of tube wells. Loam, clay loam or clay soils are suitable of shrimp culture. There should not be big trees on the bank of the pond so that enough sunlight can enter into the pond. The area of the pond should be from 10 decimal to 1 acre-and the depth should be 1-1.5 metre. 

Preparation of the Pond

 First of all the pond should be dried. By doing this, the predator fish and other unwanted fish will be eradicated. As a result of entering sunrays to bottom of the pond poisonous gas and germs of diseases will be destroyed If the pond cannot be dries, rotenon at the rate of 3 gm. per cu metre may, be applied to eradicate the predator fish.

After predator fish are eradicated, lime at the rate of 1 kg per decimal should be applies. After 5-7 days of application of lime cow-dung at the rate of 5 kg/decimal or poultry excreta at the rate of 3 kg/decimal, urea 100 gm. TSP 50 gm. and MP 20 gm should be applied. One day after application of fertilizers the poisonous gas has to be removed by pulling "Harra" 

Stocking of Prawn Fries

 Usually 5-7 days after application of fertilizer when the colour of the water becomes light green prawn fries should be released, the number of fries to be stored depends on fertility of the soil of the pond, quality of water, supplementary  food and management. In cash of single culture of Galda under general management 10,000 fries can be released per acre. Fries can be stored at higher rate if good water management and balanced diet is ensured, Transportation of prawn fries and releasing system in the pond are as like as carp fish as mentioned in the previous chapter. 

Supply of Supplementary Feed 

Total nutrition can not be available from the natural food produced as a result of application of fertilizer. Supplementary food should be supplied for their quick growth and nourishment. Really the success of prawn culture depends on the supply of supplementary feed.

Amount of Daily Food Supply

 Food should be supplied daily the rate, 4% of the total weight of the stored prawn. The required food should be given in the evening.  

Application of Fertilizer

 Fertilizer should, be applied to the pond to supply natural food in addition to supplying supplementary food. After every two weeks cow dung 15 kg, urea 6 kg. TSP 2.5 kg. and M.P. 1 kg. Per acre should be applied. These fertilizers should be soaked in water, 3 times in quantity of fertilizer in a pot. For 12 hours and then, after mixing properly should be spread in the pond after 2-3 hours of sunrise.

Establishing Shelters 

The prawn becomes weak after they change their sloughs. At this there is apprehension o attack by other creatures. For this reason some leafless branches of trees and bamboo may be fixed in the ground of the pond. Shrimps take their shelters in those places.

Prawn Collection and Marketing

 Generally prawns become suitable for marketing within 6-7 months. When 10-15 prawns weigh 1 kg. Then can be sold out. Using nets of wider loops can catch beg prawns. The suitable time for catching prawns are during the time of full moon and having new moon. This time the sloughs become hard. During collection of prawns those should be kept with ice under shade and to be sold out quickly. 

Production

 Production of Galdas at the rate of 8-10 kg per decimal is possible if cultivated as per above-mentioned management

Shrimp Culture in Coastal-Areas

 There are vast coastal areas in the southern part of Bangladesh. This area extends from Satkhira to Cox's Bazar.

3 methods of shrimp culture are followed in the coastal regions- 

1.    Traditional method of culture. 

2.    Improved light culture.

 3.    Semi-intensive culture.

Traditional Method of Culture

 Culture together of the fries of shrimps and fish those come, with of tide in the coastal embankments areas is called traditional method of shrimp culture. Per decimal production, in this case, is about 700 gm. Such type of culture does not require change of water, supply of food or fertilizer. The duration of culture is 5-6 month and the area of the farm is 40-50 hectare. 

Improved Shrimp Culture 

Culture of shrimps like Bagda, Chaka etc. in saline water after controlling predator fish and other unwanted creatures is called improved light culture. In this case water is filtered through a net place in the mouth of the enclosure during high tide. The water has to be, changed off and on. The enclosure prepared by applying lime and fertilizer and afterwards food is supplied. This system is also called improved traditional method.

Semi-intensive Shrimp Culture

 In this method fishes are cultured after controlling predator fish, the detrimental, creatures and other lives. Bagda fries are released at the rate of 7500- 15000 numbers per acre and nursed. In this case management like pond preparation, release of good young shrimps, application of required food, change of water and supply of oxygen to the water are done. This type of farming produced shrimps up to 20 kg per decimal.

Shrimp Culture in Enclosure (Gher) by Improved Shrimp Culture Method

 It is not possible now to introduce semi-intensive or intensive culture method in the extensive areas of shrimp, culture. So attempts have been taken to increase production by improving the traditional, method of culture. This type of culture is called improved light culture. 

Generally, shrimp culture is practice in big enclosure of saline water in the embankments of the southern coastal region. For effective management the big enclosure is divided into small ponds of 2-3 acres each by making ridges. This type of  pond is called enclosure of "Gher". In improved light culture method an arrangement for setting net in the entrance of the 'Gher' has to be done to avoid entry of predators or unwanted fish. The environment of the 'Gher can be kept well if the depth of water of the 'Gher' maintained at 0.80-1 metre , After preparing the 'Gher'. by controlling  predators and applying lime and fertilizer young Bagdas fries are stored. Generally young, shrimps Bagdas are stored during the month of February; Young Bagdas are stored up to 200 numbers per decimal. After storing the fries supplementary food is supplied at the same time natural food is also ensured by applying fertilizers. The water has to be changed every month to maintain the quality of water salinity and environment of the 'Gher' in right condition. 

Following this method of culture 8-10 kg of Bagda shrimp per decimal can be produced in 7-8 months.