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Shrimp Farming eNews
“A Synthesis of Shrimp News from the International Media, the Internet and the Network of Aquaculture Centres in Asia-Pacific (NACA)”

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Shrimp farming eNews includes the latest news on shrimp farming, trade, environment, and technology and industry development, obtained from Network of Aquaculture Centres in Asian-Pacific (NACA) and its STREAM initiative media monitoring program as well as web-based search engines. This media monitoring service tracks some of the major news items on shrimp aquaculture, market price, events and publications.

Your contributions on research and development, topical stories, market developments, meetings, conferences and other events, and other newsworthy items are welcome. Please send them to


Mr. Koji Yamamoto and Dr. Flavio Corsin

c/o: NACA
P.O. Box 1040, Kasetsart Post Office, Bangkok 10903, Thailand
Tel: 66-2-561 1728 (Ext 120); Fax: 66-2-561 1727
Email: [email protected]

Website: http://www.enaca.org/shrimp/

 

Latest News

NACA Activities News

       Other News

(Source: The Herald, 2 October, 2005)
http://www.brownsvilleherald.com/ts_more.php?id=67393_0_10_0_C

 

Market Price

The figure shows the Spot Price of frozen P.monodon [Yen/1.8kg] produced in North East India, South West India, Indonesia and Vietnam at Japanese market (January-October, 2005).

Source: Kansai Communication Exchange (in Japanese).
The price of other size (21/25 and 26/30) are also available. Send a request to [email protected]

 

Events

 

Publications


(1) NACA Shrimp Publications (http://www.enaca.org/modules/mydownloads/viewcat.php?cid=19)
 

 The International Principles for Responsible Shrimp Farming (Draft 8 Sep 2005) - The outcome from the Consortium Program (the World Bank, NACA, WWF, FAO and UNEP) through stakeholder workshops and consultations has been synthesized into a draft set of The International Principles for Responsible Shrimp Farming. These principles address the technical, environmental, social and economic issues associated with shrimp farming and provide a basis for development and implementation of better farming practices or "better management practices" (BMP) and government policies to guide overall sustainability of shrimp farming at national, regional and global levels.
Download the document.

 

10 steps of simple yet comprehensive guide for successful shrimp farming, developed by NACA, SUMA and DOFI. 4 leaflets are available in both English and Vietnamese.       

·          Leaflet on shrimp pond preparation

·          Leaflet on shrimp seed quality

·          Leaflet on good pond management

·          Leaflet on shrimp health management

Download the documents.
 

A Vietnam Experience on Better Management Practices Implementation – A presentation of Vietnamese experience on Better management Practices (BMP) / Good Aquaculture Practices (GAP) implementation. The result includes profitability of BMP adopted ponds.
Download the document.

 

MPEDA/NACA initiative to put principles into practice among small-scale farmers in India-A presentation on Shrimp Health Management in WAS Meeting in Bali by P. Arun Padiya, B. Vishnu Bhat, Michael Phillips and C.V. Mohan.
Download the document.

 

(2) Aquaculture, Volume 249, Issue 1- 4, Page 1-340 (12 September, 2005) - In this issue several articles which may be of interest and abstracts are provided:
 

Improvement of PCR method for the detection of monodon baculovirus (MBV) in penaeid shrimp
Win Surachetpong, Bonnie T. Poulos, Kathy F.J. Tang and Donald V. Lightner. Page 69-75.

Penaeus monodon-type baculovirus (MBV) infects and causes disease in hatchery-reared larvae and early stages of juvenile P. monodon. In this study, an improved 1-step PCR method was developed for the detection of MBV. The oligonucleotide primers, assigned as 261F and 261R, were designed from a genomic clone of MBV. Using extracted DNA from hepatopancreas or feces of ten geographic isolates of MBV infected shrimp, the PCR reaction yields a 261 bp fragment specific to the MBV sequence. Primers 261F/R did not cross-react with DNA from other shrimp viruses or with uninfected shrimp tissue. The detection limit of this primer pair is 100 copies of positive control plasmid DNA. This improved molecular method provides a diagnostic tool for identification of MBV in infected shrimp tissue collected from different geographic regions.
 

Bacteria attached to suspended particles in Northern White Shrimp (Penaeus vannamei L.) ponds
Wang Yanbo, Xu Zirong, Zhou Xuxia and Xia Meisheng. Page 285-290.

 Epibacteria, i.e. bacteria attached to suspended particles, were studied in ponds, used for the cultivation of Northern White Shrimp (Penaeus vannamei L.), at Hai-yan Farm (Zhejiang Province, China). Four ponds with different surface area and age were used. The water temperature ranged from 24 to 32 °C on the sampling days. Salinity and pH values of all shrimp ponds ranged 10–20‰ and 7.8–8.4, respectively, during the experimental period, from 20 May to 20 August 2004. In this study, the numbers of suspended particles (SP), particles with bacteria attached (BP), epibacteria, i.e. bacteria attached to suspended particles only (EB), and total plate count (TPC) were determined and the concentration of particulate organic carbon (POC) measured. In addition, the correlation between particles, epibacteria and POC was analyzed. Results showed that the average number of SP in four shrimp ponds was 5.41 × 104 ml− 1, with a BP of 3.00 × 104 ml− 1, while the percentage of particles with bacteria attached was 55.41% of the total number of suspended particles. The EB and TPC of the four ponds were 6.33 × 104 per ml and 3.59 × 106 per ml, respectively, while the percentage of EB to TPC was only 1.76%. There were highly significantly lower counts (P < 0.01) of BP, EB and TPC for the first year culture ponds during all phases. However, there was no significant difference (P > 0.01) for POC between the four shrimp ponds. The number of particles to which one, two, three or four bacteria were attached was 46%, 22%, 14% and 9%, respectively, of the total number of particles with bacteria attached. However, the percentage of particles with more than four bacteria attach was only 9%. There was a significant correlation between the number of epibacteria and particles with bacteria attached (r = 0.9920, n = 36; P < 0.01). The number of epibacteria was also correlated with the number of suspended particles (SP) (r = 0.9558, n = 36; P < 0.01) and the total number of bacteria (TPC) (r = 0.8657, n = 36; P < 0.01), but was not correlated with POC (r = 0.1340, n = 36; P > 0.05).

 

Survival, growth and feeding efficiency of Litopenaeus vannamei protozoea larvae fed different rations of the diatom Chaetoceros muelleri
Pablo Pińa, Mario Nieves, Luis Ramos-Brito, Cesar O. Chavira-Ortega and Domenico Voltolina. Page 431-437.

The survival, development and growth of Litopenaeus vannamei protozoea (PZ) larvae were evaluated in three experiments during which they were fed five different rations of the diatom Chaetoceros muelleri, from emerging PZ I larvae until the day of change to mysis I. The total amount of food and energy supplied in 5 days to each larva ranged from 85.5 to 223.2 μg larva− 1 (ash-free dry weight) and between 2.25 and 5.88 J larva− 1. After 2 days, the development index (DI) showed that some of the larvae fed the highest ration had reached the stage of PZ III. At the end of the experiment the mean DI ranged from 2.9 ± 0.2 to 3.2 ± 0.3 and the differences among treatments were not significant. The mean percentages of survival ranged from 35.8% to 51.7% and were not statistically different, but total length was progressively higher with increasing ration. The final values were 1.91 ± 0.54, 2.10 ± 0.53; 2.34 ± 0.36; 2.45 ± 0.37 and 2.55 ± 0.42 mm and were all statistically different with the exception of treatment 4, that was intermediate between treatments 3 and 5. However, the highest final organic weight (26.0 ± 1.7 μg larva− 1) was treatment 4, which was different from the values obtained with the two lower rations. Treatments 3 and 5 had intermediate values. The percentages of the food ingested did not vary with the rations supplied or with the age of the larvae and ranged from 74% to 86%. Food ingestion (Fi) was a function of the food supplied (Fs), according to the equation Fi = 0.848Fs − 4.025 (R2 = 0.992; P < 0.001). Using the amount of food supplied and ingested with each feeding regime and the respective organic weight gains, it was calculated that the percentages of Fs and Fi used for body growth were 14.4% and 17.9% with the lowest ration and 6.9% and 8.3% with the highest, whereas the three intermediate rations gave similar efficiencies (9.8% to 10.2% of Fs and 11.8% to 12.5% of Fi). However, the weight and energy gains obtained with the highest food utilization efficiency were lower than those obtained with the higher rations, indicating that cautious overfeeding is a more convenient alternative for L. vannamei PZ culture

To access to other abstracts visit the website: http://www.sciencedirect.com/science/journal/00448486

 

(3) Abstracts on Shrimp Biosecurity and Health Management from WAS Bali: A selection of abstracts related to shrimp aquaculture from World Aquaculture 2005, Bali, Indonesia, will be included in upcoming issues of the shrimp Media monitor. These abstracts are from the World Aquaculture Society website www.was.org. To access the full list of abstracts for this session visit http://www.was.org/Meetings/SessionAbstracts.asp?MeetingCode=WA2005&Session=62

Increased protection of shrimp against white spot syndrome virus by oral administration of a major envelope protein: Is vaccination a reality?
 J. Witteveldt, MC. W. van Hulten and J.M. Vlak

Since the 1990s shrimp culture has been hampered by mass mortalities in ponds throughout the world. Penaeid shrimp are affected by many infectious agents, mainly of bacterial and viral origin, and especially by white spot syndrome virus (WSSV). The latter has had a major impact on shrimp culture since its discovery in 1992 and continues to be a major problem. The only measures presently used to control WSSV are rigorous sanitation and adequate health management practices. Alternative intervention strategies such as vaccination should be and are currently being explored.
Recent experiments in the shrimp Penaeus monodon revealed that oral administration of the major envelope protein VP28 over expressed in bacteria results in high protection levels compared to control groups (Fig. 1). Though these results are promising for the further development of a practical disease prevention strategy, the mechanism of the protection is unclear and it is important to understand it from a biological viewpoint. Shrimp and crustaceans in general are thought to lack a specific-immune system and thus to be unable to recognize, let alone respond specifically to, foreign proteins. Nevertheless, increased protection against disease has been observed by oral administration and intramuscular injection of WSSV structural proteins and this has been called a quasi-immune response.
As long as the nature of these observed responses is unknown, we can only speculate on the processes involved. Is it a specific-immune response or is it the result of something different like competition for receptors? Another question is whether the protection is durable. Experiments designed to tackle these questions and answers to them will be discussed.
 

Research progress on Monodon Slow Growth Syndrome (MSGS) in Thailand
T.W. Flegel and B. Withyachumnarnkul

During 2002, slow growth of farmed P. monodon (Monodon Slow Growth Syndrome or MSGS) was reported throughout shrimp growing areas of Thailand and indicated that annual production volume was down by approximately 36%. Although the etiology is still uncertain, a working case detection of MSGS has been developed for surveillance and epidemiological purposes. By this detection, a suspected population must have a coefficient of variation (CV = Standard deviation/Mean) of more than 35% by weight and absence of hepatopancreatic parvovirus (HPV) or of other severe hepatopancreatic infections by known agents while also complying with any 3 out of the 5 following gross signs: 1) unusually dark color, 2) average daily weight gain of less than 0.1 g/day at 4 months, 3) unusually bright yellow markings, 4) bamboo abdominal segments, 5) brittle antennae. Preliminary trials using bacteria-free substrates from slow growing P. monodon caused slow growth in laboratory injection experiments with P. monodon but not with P. vannamei. This suggested that an infectious agent might be involved.
P. monodon broodstock from Thailand by DV Lightner (personal communication) in late 2002. Ultracentrifuge bands of tissue homogenates from MSGS shrimp have shown 2 previously unreported viral-like particles, and extracts of these bands give products by random RT-PCR but not by PCR, suggesting possible involvement by an RNA virus(es). As of now, there is no tested management approach to tackle this problem. However, it is well known that exotic viruses can move easily amongst crustacean species. Implementing the following recommendations might help to reduce the impact of slow growth syndrome. Imported crustaceans and especially exotic species should be reared separately from native species particularly at the hatchery phase and importations should follow the full ICES protocol with the addition of co-habitation tests employing important, endemic crustacean species. This will reduce the risk of importing exotic viral pathogens that may damage local aquaculture or fisheries.
 

Incidence of bruises and black marks in L.vannamei: Factors involved and possible solutions
N. Taw and Kastitonif

In shrimp farming, producing quality shrimp is crucial. Amongst shrimp species cultured in Indonesia, Pacific white shrimp (L. vannamei) was introduced only in 2001. At present, the species has adapted well in the Indonesian environment and production of the species has become stable (Nyan Taw, et.al, 2002; Nyan Taw & Rudyan Kopot, 2004). However, as culture has intensified, constraints concerning quality have surfaced. One of the major problems in terms of quality was a high incidence of black (melanized) bruises on the shrimp shell and in rare cases, encysted within shrimp which is termed as black mark. Initially, black mark was thought to be a human health issue. This issue was cleared after a thorough laboratory study. Bruises, black bruises and black marks are caused by melanized, hemocyte-insurfaces or puncture wounds (D. Lightner, pers. comm.)
A study was conducted on incidence of bruises, black bruises and black marks during commercial culture operation and at harvest and considering different post larval stocking densities (70 to 130 PL/m2) and pond construction types (high-density/poly-ethylene lined and earthen) and culture operation systems (minimum water exchange and bacteria sampling of shrimp for each pond started from DOC (Day of Culture) 35 and continued weekly with a minimum of 400 specimens taken per pond. However, at harvest a minimum of 2,000 specimens per pond was taken. High incidence was significantly correlated (P<0.05) with older DOC, either in earthen or semi-HDPE ponds. Animal density also had an affect on the incidence of bruises and black marks. It was significantly higher (P<0.05) at high density (100pcs/m2) than at normal density (70-80pcs/m2). However, in the bacterial system, a lower incidence was observed even at high density (130pcs/ m2). This indicated that good, non-pathogenic bacteria in pond water could somehow reduce the incidence. At present the solution to control the incidence in normal culture systems is to use molasses to promote good bacterial growth and to use HDPE lined ponds.