Aquaculture Fisheries Development :
Spawning WHITE SHRIMP (Penaeus vannamei)
Penaeus vannamei, also called white shrimp and into Penaidae families. Members of this family to hatch their eggs outside the body after the egg released by the female shrimp. Penaeid shrimp can be distinguished from other types of shapes and number of teeth on rostrumnya. Penaeid vannamei has 2 teeth on the edge of the rostrum and 8-9 ventral teeth on the edge of the dorsal part of rostrum
Penaeus vannamei culture has
superior characteristics. This shrimp weight can be increased more than 3 grams per week in culture with high density (100 udang/m2). Adult shrimp weight can reach over 20 grams and the weight, Penaeus vannamei grow slowly at around 1 gram / week. Shrimp females grow faster than the male shrimp
Penaeus vannamei has a wide salinity tolerance, that is from 2 to 40 ppt, but will grow faster at a lower salinity, the environment and the blood isoosmotik. Taste the shrimp can be influenced by the level of free amino acids is high in muscle resulting taste sweeter. During the process of post-harvest, only water with high salinity, which is used to maintain the natural sweetness of the shrimp. Temperature also has a great influence on the growth of shrimp. Penaeus vannamei will die if lying in water with a temperature below or above 15 oC 33 oC for 24 hours or more. Subletal stress can occur in 15-22 and 30-33 oC oC. Temperature suitable for the growth of Penaeus vannamei is 23-30 oC. The influence of temperature on growth of Penaeus vannamei is the stage specificity and size. The young shrimp can grow well in warm water with temperature, but the larger the shrimp, then the optimum water temperature would decrease.
B. Life Cycle of Penaeus vannamei
Prawns mate in the shallow offshore. The process involves the transfer of mating shrimp shrimp spermatophore from male to female shrimp. Nesting place in offshore areas deeper. Eggs removed and fertilized externally in the water. A female shrimp can produce half to one million eggs per spawn. Within 13-14 hours, these small eggs develop into microscopic larvae called sized nauplii / nauplius. Stage nauplii was eating egg yolk stored in the body and then metamorphosed into Zoea. This second phase of eating algae and after a few days longer metamorphosed into mysis. Mysis beginning to look like tiny shrimp and eat the algae and zooplankton. After 3 to 4 days, mysis metamorphosed into postlarva. Postlarva stage is the stage when the shrimp have started to have the characteristics of adult shrimp. The entire process from nauplii stage to postlarva took about 12 days. In its natural habitat, migration toward postlarva will estuarin rich nutrients and low salinity. They grew up there and will return to the open sea as adults. Shrimp bentik adults are animals that live on the seabed
C. Main Characteristics of Shrimp
Shrimp is used as the parent (broodstock) should be SPF (Specific pathogen free). Shrimp can be purchased from service providers who have a parent shrimp SPF certificate. Shrimp advantage is resistance to some common diseases that attack the shrimp, such as white spot, and others. Shrimp are obtained from a large number of families with the selection of each generation uses a combination of family selection, mass selection (WFS) and marker-assisted selection. Parent shrimp are descendants of a selected group of relatives and having rapid growth characteristics, resistant to TSV and the survival of life on the high pool. Main characteristics of the other good shrimp is shrimp male and female characteristics have a very good reproduction. Spermatophore well-developed male and white pearls. Shrimp sexually mature females and showed a natural development of the ovary. The weight of male and female shrimps around 40 grams and was 12 months.
D. Shrimp Reproduction
Penaeus vannamei reproductive system consists of a pair of female ovary, oviduct, genital opening, and thelycum. Oogonia produced by mitosis of the germinal epithelium during the reproductive life of female shrimp. Oogonia experienced meiosis, differentiate into the oocyte, and becomes surrounded by follicle cells. Oocytes produced will absorb the yolk material from the mother's blood through the follicle cells. The main reproductive organs of male shrimp is the testes, vasa derefensia, petasma, and appendix maskulina. Shrimp sperm have a nucleus that is not condensed and does not have nonmotil because flagella. During the journey through the vas deferens, differentiated sperm were collected in the liquid and the surrounding fluid in a chitinous spermatophore. The number of spermatozoa in direct contact with body size of males.
E. Mating and egg-laying
Mating behavior in Penaeus vannamei in the maturation tank influenced by several environmental factors such as water temperature, depth, light intensity, fotoperiodisme, and some biological factors such as aerial density and sex ratio. mating behavior in crustaceans due to the pheromones. Male shrimp will only mate with females that had shrimp mature ovary. Contact antennas made by male shrimp in the shrimp is intended for the introduction of female sexual receptors in shrimp. The process of natural mating in most shrimp usually occur at night. However, the shrimp Penaeus vannamei most active mating at sunset. Penaeus vannamei species have closed so thelycum type shrimp shrimp mating when females at intermolt stage or after the completion of ovarian maturation, and the shrimp will lay their eggs in one or two hours after mating
Nesting occurs when the female shrimp out mature eggs. The process lasted for about two minutes. Penaeus vannamei usually lay eggs at night or several hours after mating. Shrimp females alone should be conditioned to natural mating behavior appears.
F. The Conventional Germ Process
Seeding process is usually done in most hatchery commercial shrimp is by natural spawn to produce larvae. Natural marriage benefits compared to artificial insemination is the number of nauplii produced per female was laying eggs shrimp more than nauplii produced by artificial insemination methods.
Parent shrimp Penaeus vannamei collected and maintained in normal conditions for the maturation and natural mating. Every afternoon examination to see the shrimp females married and moved to the tank nesting (spawning tank.) The married females will show a spermatophore attached. As the morning, females are nesting in the tanks moved back into the tank maturation (maturation tanks). Within 12-16 hours, the egg-laying eggs in the tank will develop into larvae without a segment or nauplii.
Ova in the female shrimp usually experience reabsorb without laying again. These problems can be reduced by ablation of one eye stalks that provide hormone that serves as a stimulus for reabsorbed ova. Several researchers have shown that ablation can also increase the growth of shrimp. Ablation is done by burning, remove the contents from one of the rod eye out through the eyeball, and injuring the eye with scissors bar.
Shrimp that will ablated prepared to enter the reproductive peak. If ablation performed during premolting stage, it will cause molting, ablation immediately after molting shrimp can cause death, and ablation during the intermolt causes ova development.
G. System maturation
Parent shrimp need a quiet atmosphere for a good maturation. Therefore, maturation facility should be divided into three separate rooms, namely the maturation tank, the tank nesting (spawning tanks), and space for food preparation.
The tank space maturation (maturation Tanks)
Each tank maturation is facilitated by a pipe for water supply. Flow and water used in each supply line to control the exchange of water. Air channels located in the middle of the tank to provide air into the tank. Airways are also used to keep the water into the tank remains at 18 inches. 75-watt light box suspended above the tank. Plastic diffuser on the light box functions to spread the light, and prevent excessive light into the tank underneath. Machine sunrise / sunset (lights are controlled by time and rheostat) fotoperiodisme control in each tank and gradually increase the light from the dark into the full light of mid day. Maturation tank was painted black to create an atmosphere rather dark. Room maturation tank was also kept at a temperature of 27oC to create environmental conditions resembling the natural environment Penaeid shrimp
Tank space nesting (Spawning Tanks)
Spawning tanks have a flat base. Each tank containing sea water and air channels in the middle of the tank. Glass fiber is added in the tank so that the six tail shrimp married can lay eggs immediately.
Water quality should be regulated and maintained in conditions resembling the natural environment Penaeid shrimp. Sea water entered into the tank maturation and spawning tanks should have some first treatment, including removal of dissolved organic matter by filtration and sedimentation, ozonisasi to eliminate most microorganisms, and cooling water (25oC - 28oC) in order to obtain the temperature-like Penaeid shrimp natural habitat. Thermostat is set at 27oC temperature and daily temperature fluctuation is set to less than 0.5 oC.
Alarm systems that monitor several important parameters in the maturation system. An alarm is connected to the depth of water in the reservoir. If water fell as much as 15 cm in the tank, an alarm will sound. Another alarm system connected to the air supply
H. Systems Management maturation Stocking
Each tank is occupied by shrimp maturation more males than females of shrimp (5-6 shrimp / m 2). Shrimp males should weigh 40 grams or more. Because the male shrimp growth slow, heavy 40 gram shrimp under shrimp is usually the cause of the productive series. Shrimp melanisasi male with a severe petasma or spermatophore not included in the maturation tank .. Female shrimp weight should reach 48 grams or more.
Every parent should be marked so that each individual can be counted and identified. Marker inserted in the rod eye. This system also works to find some animals to eliminate.
After a week in the maturation tank, the mother shrimp ablation done on the rod eye. Cutting rod eye with a knife or scissors that were burned before so sterile. When the shrimp have been marked females and ablated, the operating system into the daily routine activities
Refunds shrimp Married females
Shrimp females mating on the previous night from spawning tanks moved into the maturation tank.
Maturation tank cleaned before the first feeding by siphoning. Tank cleaned from the rest of molting, food remains, feces and dead shrimp. Air flow in the non-enabled for siphoning to collect all the dirt that is in the tank to increase the visibility.
Parent-laying ability could be enhanced by way of the feeding of marine animals, fresh or frozen, such as oysters, squid, or polichaeta. Parent shrimps fed by these organisms have the ability to reproduce higher than shrimp fed dry feed. Good nutrition can improve the reproduction of shrimp by increasing the synthesis of a steroid hormone, egg yolk, egg yolk and transportation of hepatopankreas to the ovary. During the reproductive period, shrimp need more vitamin C which plays an important role in the change of cholesterol to steroid
The feed was given four times a day to feed an alternative form of squid and blood worms. Blood worms are made into semi-liquid and cut into one-third its length, while the squid cut boxes. This was done to minimize water turbidity.
Water Quality Monitoring
Dissolved oxygen or DO and temperature are measured every day using a DO meter. water pH was also measured . Besides salinity, concentration of ammonium, and nitrite was also monitored every day. According to Treece and Fox (1993), sea water has an average concentration of NH4-N of 0.02-0.04 mg / L (ppm), concentrations of NO2-N (nitrite) of 0.01-0.01 mg / L (ppm), and the concentration of NO3 -N (nitrate) of 0.1-0.2 mg / L (ppm). According to Chen and Chin (1988) that the concentration of nitrite 0.1 m / L (ppm) or more can damage reproduction.
Counting eggs and nauplii
Eggs and nauplii in each spawning tanks is calculated by taking five samples (each 100 ml) and then calculated by using the help desk lamp. The number of eggs and nauplii in each sample is calculated and the average calculated from five samples and then extrapolated to the volume of water in the spawning tanks to determine the total number of eggs and nauplii.
Nauplii harvesting is done by opening a pipeline located in the middle of the tank. Light above the pipe is lit to attract the nauplii which are positive so fototaxis nauplii swim toward the pipes. Nauplii are harvested and put into plastic bags.
Preparation Spawning Tanks
After the nauplii harvested and counted, spawning treated chlorination tanks to clean the tank and then dried. After that, the tank rinsed with water and washed with soap or detergent. Air ducts cleaned is also entirely. Then, spawning tanks filled with 200 liters lag sea water and aerated. Three ppm EDTA added to each spawning tanks. Treflan added to the spawning tanks with a concentration of 0.1 ppm to prevent the growth of fungus epizootik.
Control of Water Supply
Total air exchange every day about 200% of the volume of the tank. y may occur when the exchange of water is lower than 200% volume of the tank
Supervision Level Light Intensity
Maturation Fotoperiodic in space is 13 hours light and 11 hours dark. Male shrimp will begin to marry more than one hour after lights out. Gradual lighting changes intended to make the shrimp do not experience stress
Search's Shrimp Married females
During this process, the channel off the air for maximum visibility. Shrimp females with developing ovaries would look outs. Selection of female shrimp is done by using the net. Spermatophore can easily be lost by taking the mother who is married to quickly and carefully.
If you look at the shrimp spermatophore females, the female shrimp are transferred to one of the spawning tanks. Color markers, number, time, number spawning tanks, the color of the ovary, and the condition of each shrimp spermatophore females mating recorded. After all female shrimp with a developing ovary examined and removed, unmarried females are released and the air channel is activated again. Females each day inspection is useful for detecting patterns of ovarian development.
Every day, final inspection must be done on aeration systems, flow of water, feed, timers, and general cleaning. Everything was done to ensure that all systems worked well.
I. Hatchery Way Artificial Insemination
Used artificial insemination performed by main supplier of shrimp that is superior, such as shrimp with certified SPF (Specific pathogen free). This technique should be done in order to obtain offspring that can be ascertained from the mother superior and there is no inbreeding. Techniques to produce this excellent parent and procedures require highly sophisticated equipment and expensive, one way is to use fingerprinting techniques, and others. In addition, the number of eggs and nauplii produced much less when compared with natural spawning
First, female prawns were captured and seen the development of ovaries. Females who already have developed ovaries will have a greenish color on ovarian lobes located at the bottom of the carapace. Spermatophore that has developed from a male shrimp issued manually by pressing spermatophore carefully out of the spermatophore to the genital opening. healthy spermatophore did not indicate any melanitation, white, slightly swollen, and hard to the touch. Shrimp females developed ovaries was held quietly until thelycum visible. Thelycum is dried with paper towels. Spermatophore placed between the finger and index finger and pressed the tip of spermatophore closed to the open end. The pressure makes the sperm sacs burst and release sperm that formed droplets between the finger and index finger. It also separates the sperm mass of gelatinous material and spermatophore
Female shrimp meetings held last drop of sperm is placed into the thelycum . After the sperm is placed in the right position, the position poreopod returned to the starting position that helps 'lock' of sperm. Female shrimp are placed in spawning tanks all night. This process must be completed in less than 1 minute to reduce the pressure on the female shrimp.
Aquaculture Fisheries Development.