Pearl oyster

Pearl oyster

Until now the pearl of the moral power can be a sea pearls and freshwater pearls. Product sea pearls are grown in this international market is as follows.

1. Akoya pearl
High-quality pearls produced from P. fucata. A maximum size of 10 mm. White pearl with nuance greenness very beautiful. This type is produced in Japan and China.


2. South sea pearl
pearl is produced in Indonesia and Australia resulting from P. maxima. Groups including pearl white, large up to 18 mm. This type of silvery white, yellowish, pink, and golden.

3. Black pearl
This resulted from a pearl P. margaritifera. Black pearl is very captivating and a jet black color. This type of size is smaller than the size of south sea pearl. Major countries: Tahiti, Hawaii, and Cook Island.


A. Sistematika
Family: Pteridae
Species: Pinctada maxima
P. margaritifera
Trade names: pearl Oyster

Name of the local pearl


B. The characteristics of Biology and the Aspect

1. Physical characteristics
Pearl shell has a pair of body shell together at the back with hinges. Both the body shell
not the same shape. body shell is more convex than the other. In the side of the body shell (nacre) mengilap top.


2. Growth and development
Pearl oyster is a hermaphrodite, protandrous tendency comparison with the male: female = 1: 1, with increase in age. livestock often occur due to extreme temperature changes or changes in the environment that happens suddenly. Livestock pearl oyster in tropical waters is not limited to only one season, but they can throughout the year. P. Margaritifera approaching mature gonad in the second year, whereas P. maxima mature male gonad after measuring 110-120 mm in the body shell of the first year of his life.
growth is an important aspect of the biology of the allegations related to the success of the usaha.Tiram pearl P.margaritifera body shell diameter reached the size of 7-8 cm in the first year, and approaching the size of approximately 11 cm in the second year. Other types of growth, P. maxima, reaching 10-16 cm diameter body shell in the second year.


C. Management of Cultivation
To produce a pearl sea Spat from the hatchery, take about 4 years. Sea pearl cultivation technology, consisting of seeding, seed enlargement, production of pearls, and harvest.

1. Provision of seeds
Early development of the seed used comes from the nature of the arrest. Arrest made using Spat collector nets made of nylon nets eyed halos. Collectors are straightened in the area of distribution of pearl oyster. Within 2-4 weeks, the seed oyster (Spat) will stick to the collector's.


Nowadays, with the progress of science and technology Spat oyster pearls can be produced through the process of farming in the hatchery. The process begins with the selection of parent already mature gonad. Parent-parent should come from different populations to produce high quality seed.

2) maintenance
Nurseri kept in the seed until the adult size of 10-12 cm and 12-18 during the month. on the size of the pearl production process can be implemented. The stage production of pearls as follows.

a) choose to injected adult oyster. selection based on size, age, health condition and oyster.

b) Setting up a snippet of a coat pocket, and about 4-5 mm2 core size of 3,03-9,09 mm. discount coat (shaibo) is taken from the oyster deliberately prepared / sacrificed for such purpose.


c) Preconditioning (weakened) to facilitate the establishment of the oyster body shell during the inject core trasplantasi da discount coat or shaibo.


d) slices on the base of the foot near the gonad. To score in the core is inserted and placed shaibo jog.

e) the wedge and the wedge body shell, and put
to the oyster basket. Cart is made of
net-shaped rectangle. For each basket,
placed 10 oyster head.


f) Caring for how clean the oyster to the basket and outside the body shell, oyster invert, and check if the pearls have or have not been using x-ray diffraction. This treatment is done every 4 hours for 2 weeks, unless the examination with x-ray diffraction.


g) Moving to the oyster in the container have a pocket-shaped basket made of the net. In each piece there are 4 fruit bag. Each bag filled with an oyster. Vessel's swing to the exposition or longline mine. Oyster bags and cleaned every week.


D. Controlling Pests. and Diseases
Pests usually attack the body shell. Hama is a type of barnacle, racing, and is capable of polichaeta body shell oyster drill. The other pests such as animal predators, such as octopus and fish sidat. Prevention efforts with a clean pest-pest with a manual in a period of time.

Pearl oyster disease is generally caused by parasites, bacteria, and viruses. parasite that is often found Haplosporidium nelsoni. Bacteria that are often a problem between enalia other Pseudomonas, Vibrio anguillarum, and Achromobacter sp.

Meanwhile, the type of virus that is usually pearl oyster is menginfeksi herpes virus. Efforts to reduce the attack on the disease, among others, the pearl oyster
a) always monitors the salinity to be in the range needed to maintain health oyster,

b) ensure that the water temperature fluctuation is not too high, such as maintenance oyster does not close the surface of the water during the winter,

c) the location of body with the power selected brightness is good, and

d) does not choose a location on the basis of the muddy sand.


G. Harvest
After a period of 18-24 months, the pearl is harvested can be done. Next, harvest cleaned and choose quality.
source: PenebarSwadaya, 2008

Disease Prevention Strategies for Penaeid Shrimp Culture

By Shaun M. Moss, Steve M. Arce, Dustin R. Moss and Clete A. Otoshi, The Oceanic Institute - Penaeid shrimp aquaculture expanded significantly over the past two decades. However, shrimp farmers have suffered significant economic losses because of viral diseases.

Abstract

Researchers from the U.S. Marine Shrimp Farming Program (USMSFP) have developed novel approaches to mitigate the devastating impact of shrimp viruses, including the use of specific pathogen free (SPF) and specific pathogen resistant (SPR) shrimp, as well as the establishment of biosecure production systems that rely on pathogen exclusion. These approaches have evolved over the past decade in response to changing disease problems faced by U.S. shrimp farmers.

In the late 1980’s and early 1990’s, U.S. farmers observed Runt Deformity Syndrome (RDS), an economically significant and frequent disease problem of cultured Pacific white shrimp, Litopenaeus vannamei. RDS is characterized by reduced growth rates and cuticular deformities and is caused by Infectious hypodermal and hematopoietic necrosis virus (IHHNV). The increasing incidence of RDS on commercial farms catalyzed USMSFP researchers to develop SPF stocks of L. vannamei that were free of IHHNV. High health offspring from these SPF stocks were made available to U.S. shrimp farmers, resulting in a significant increase in U.S. farmed shrimp production from 1992 - 1994.

However, in mid-1995, Taura syndrome virus (TSV) was identified in south Texas, the major shrimp farming region in the U.S., and the resulting TSV epizootic contributed to a 164% decline in Texas shrimp production from 1994 to 1995. USMSFP researchers responded by initiating a selective breeding program to develop TSV-resistant L. vannamei. The use of these high-health SPR stocks, in conjunction with on-farm biosecurity practices, resulted in incremental increases in U.S. shrimp production from 1998 to the present.

Although TSV-resistant shrimp improved production and profitability for those farmers who were experiencing crop losses from TSV, breeding shrimp for resistance to a single viral pathogen, using current selective breeding strategies, may not be the most effective course of action for the long-term viability of the shrimp farming industry. USMSFP researchers are now developing biosecure shrimp production systems which rely on pathogen exclusion, and research results indicate that it is possible to produce > 5 kg of market-sized shrimp (~ 20 g) per m2 of raceway in about 12 weeks, using < 400 L of water per kg of shrimp.

With advanced biosecure technologies available, the U.S. shrimp farming industry will be able to expand into areas away from the coast with greater control against the spread of disease and without adversely affecting the environment.

Shrimp Pond Waste Management

By U Win Latt, Aquaculture Asia - Intensive shrimp farming developed rapidly in the mid 1980's, especially in the Southeast Asian region. Shrimp production levels increased mainly due to expansion of farming areas and adoption of intensive farming practices.

Improvements in water and waste management during the last decade have been a response to a wide range of problems in the shrimp farming sector. Most management issues have focused on water and wastewater management, while little attention has been paid to improving the management of solid and semisolid shrimp pond waste.

At the same time, the environmental impact of shrimp farming has been highlighted especially with regard to farm wastewater discharge. This has lead to the development of improved water management techniques, including water pre-treatment and recirculating systems.

Both researchers and farmers have worked to improve pond management techniques. Yet complete sludge management has not received much attention. After years of culture operation, disposal of accumulated sludge is posing a problem.

Farmers are concerned about the initial capital cost and limited area is available on farm, so further post-culture management of shrimp pond waste (SPW) has not been well pursued although it has long term gain.

The results of a recent farm survey I conducted on shrimp pond waste management in three southern provinces (Ranong, Phang Nga and Chumpon) show that most farm operators are willing to improve their waste management techniques.

However, they don't have enough information to enable them to make effective changes. Therefore, a systematic waste management strategy that includes treatment, disposal and recycling is needed for sustainable shrimp farming management.