the fish

Other scientific names appearing in the literature of this species:

White Spot Syndrome (WSS); Chinese baculovirus-like virus (CBV) (Lightner, 1996; Tapay et al., 1996). Common Name: White Spot Baculovirus (WSBV), White Spot syndrome (WSS) (Lightner, 1996)

Distinguishing Features:

The White-spot baculovirus is a large, enveloped, rod-shaped to somewhat elliptical, non-occluded virus consisting of double stranded DNA (Lightner, 1996).

Similar Species:

At least three viruses in the white spot syndrome (WSS) or "China Virus" complex have been named in the literature (Lightner, 1996). They appear to be very similar viruses. The names of the viruses and the diseases they cause are: China's hypodermal hematopoietic necrosis baculovirus (HHNBV)--Shrimp Explosive Epidermic Disease (SEED) (Lightner, 1996; Cai et al., 1995); Japan's rod-shaped nuclear virus (RV-PJ) of Peneus japonicus (Inouye et al., 1994; Momoyama et al., 1994; Nakano et al., 1994; Takahashi et al., 1994); and Thailand's systemic ectodermal and mesodermal baculovirus (SEMBV) of Penaeus monodon--red disease; white spot disease (Lightner, 1996; Wang et al., 1995).

Biology:

WSBV is extremely virulent, has a wide host range, and targets various tissues (Chang et al., 1996). The origins of the virus may lay in China (Chou et al., 1995; Tapay et al., 1996), but WSBV was first described in the cultured giant tiger prawn P. monodon and redtail prawn Penaeus penicillatus in Taiwan in 1993. WSBV is known to cause disease in P. japonicus and P. penicillatus and to experimentally infect larval Litopenaeus stylirosturs and L. penaeus (Tapay et al., 1996). Many cell types (ectodermal and mesodermal) are targeted by the virus including the cuticular epithelium from every part of the shrimp's body, connective tissues of some organs, nervous tissue, muscle, lymphoid, and hematopoietic tissue. WSBV also severly damages the stomach, gills, antennal gland, heart and eyes. During late stages of the infection, these organs are destroyed and many cells are lysed (completely broken down) (Chang et al., 1996).

The disease resulting from WSBV infection is highly lethal with cumulative mortality reaching 100% within 2 to 7 days post infection. Diseased shrimp show reddish coloration of the hepatopancreas and white inclusions (spots) on their carapace, appendages and inside surface of the body (Chou et al., 1995). Infected shrimp as noted by Chou et al. (1995) show lethargic behavior.

Most likely means of transmission of the virus is through ingestion of diseased tissue and cohabitation with diseased or latent virus carriers. (Flegel et al., 1996). Vertical transmission of the virus from broodstock to larvae is also a possibility as is the case with other shrimp baculoviruses (Fegan et al., 1991), but more study is necessary (Flegel et al, 1996). Viability of free virus in sea water, as with Yellow-head virus, is 3-4 days (Flegel et al., 1996).

Maximum Size:

70 to 150 nm by 275 to 380 nm (Lightner, 1996; Tapay et al., 1996).

Distribution:

Since its appearance in 1992-1993 in northeast Asia, the Strains of WSBV have spread rapidly throughout most of the shrimp growing regions of Asia and Indo-Pacific (Lightner, 1996). The WSBV complex (WSBV, HHNBV, RV-PJ, and SEMBV) is now found throughout China, Japan, Korea, Indonesia, Taiwan, Vietnam, Malaysia and India (Inouye et al., 1994; Momoyama et al., 1994; Nakano et al., 1994; Takahashi et al., 1994; Chou et al, 1995; Wang et al., 1995). Because the shrimp industry relies on intraregional transport of stocks, the distribution of these viruses may be larger than indicated and may be expanding (Lightner, 1996). White spot disease was first detected in farmed L. setiferus in Texas in 1995.

Interest to Fisheries:

Pathogenicity studies of WSBV carried out by Tapay et al. (1996) show that L. stylirostris and L. vannamei, penaeids commonly cultured in the Hawaii and the Western hemisphere, are seriously diseased when infected by WSBV and mortalities of up to 100% occur within 4 days post infection. The first reported case of WSBV in the Western Hemisphere involved pond-reared P. setiferus from south Texas in 1995. A shrimp processing plant located within the vicinity was the suspected source of virus; the processor was a major importer and re-processor of shrimp imported from affected areas of Asia (Lightner, 1996).

Recommendations:

To guard against accidental importation of infection to disease-free geographical locations, testing of export shrimp (fresh and frozen) from areas of infection should be carried out (Tapay et al., 1996). Broodstock and postlarvae should be screened using a DNA probe before stocking. If transmission of the virus via broodstock to offspring is found to be possible, infection of grow-out ponds may be blocked by washing the nauplii (a pre-larval stage) after harvesting from spawning tanks (Flegel et al., 1996). Other crustacea have been found to be carrier species of strains of WSBV (Johnson, 1988a, b). A few species noted in work by Johnson (1988) include the crab Rhithropanopeus harrisii (Payen & Bonami, 1979), the bracyuran crab, Callinectes sapidus (Johson, 1976), and the anomuran crab Paralithodes platypus (Sparks & Morado, 1986). Since the virus is easily spread via ingestion of infected tissues, Flegel et al. (1996) recommends not feeding fresh crab to broodstock animals.

It appears that the most effective disinfectant for WSBV is formalin. At 70 ppm (or as little as 20 ppm in aquarium tests) transmission of the virus by water was prevented and at that level there was no harm to the shrimp (Flegel et al, 1996). Flegel et al. (1996) note that the formalin treatment could affect the plankton bloom which in turn may cause a drop in DO (dissolved oxygen) in rearing ponds. Preventing infection by cohabitation is not effective using this method, though applications of formalin every 6 hours may delay infection while other measures are undertaken (Flegel et al., 1996).

As a preventative environmental measure, it is recommended that all effluent used in farming or processing operations where the presence of WSBV is a possibility, should be treated with disinfectant (formalin) before discharge (Flegel et al., 1996).

References:

Cai, S., J. Huang, C. Wang, X. Song, X. Sun, J. Yu, Y. Zhang, and C. Yang. 1995. Epidemiological Studies On The Explosive Epidemic Diseases Of Prawn In 1993-1994. J. Fish China 19:112-117.

Chang, P., C. Lo, Y. Wang and G. Kou. 1996. Identification of white spot syndrome associated baculovirus target organs in the shrimp Penaeus monodon by in situ hybridization. Dis Aquat Org. Vol. 27:131-139.

Chou, H, C. Huang, C. Wang, H. Chiang, and C. Lo. 1995. Pathogenicity of a baculovirus infection causing white spot syndrome in cultured penaeid shrimp in Taiwan. Diseases of Aquatic Organisms, Vol. 23:165-173.

Fegan, D.F., T.W. Flegel, S. Sriurairatana, and M. Waiyakruttha. 1991. The occurrence, development and histopathology of monodon baculovirus in southern Thailand. Aquaculture 96: 205-217.

Flegel, T., S. Boonyaratpalin and B. Withyachumnarnkul. 1997. Progress in Research on Yellow-head Virus and White-Spot Virus in Thailand. In T.W. Flegel and I. H. MacRae (eds), Diseases in asian Aquaculture III. Fish Health Section, Asian Fisheries Society,Manila.

Inouye, K., S. Miwa, N. Oseko, H. Nakano, T. Kimura, K. Momoyama and M. Hiraoka. 1994. Mass mortalities of cultured Kuruma Shrimp Penaeus japonicus in Japan in 1993: Electron Microscopic evidence of the Causative Virus. Fish Pathology, 29(2),148-158.

Johnson, P.T. 1976. A Herpes-like Virus From The Blue Crab, Callinectes Sapidus. J. Invertebr. Pathol. 27:419-420.

Johnson, P.T. 1988. Development And Morphology Of An Unusual Nuclear Virus Of The Blue Crab Callinectes Sapidus. Diseases Of Aquatic Organisms 4:67-75.

Johnson, P.T. 1988. Rod-shaped Nuclear Viruses Of Crustaceans: Hemocyte-infecting Species. Diseases Of Aquatic Organisms 5:111-122.

Lightner, D.V. 1996. A Handbook Of Shrimp Pathology And Diagnostic Procedures For Disease Of Cultured Penaeid Shrimp. World Aquaculture Society, Baton Rouge, Lousisana, USA.

Lo, C.F., J.H. Leu, C.H. Ho, C.H. Chen, S.E. Peng, Y.T. Chen, C.M. Chou, P.Y. Yeh, C.J. Huang, H.Y. Chou, C.H. Wang, and G.H. Kou. 1996. Detection Of Baculovirus Associated With White Spot Syndrome (WSBV) In Penaeid Shrimps Using Polymerase Chain Reaction. Diseases Of Aquatic Organisms 25:133-141.

Momoyama, K., M. Hiraoka, H. Nakano, H.Koube, K. Inouye, and N. Oseka. 1994. Mass Mortalities Of Cultured Kuruma Shrimp Penaeus Japonicus, In Japan In 1993: Histopathological Study. Fish Pathology 29:141-148.

Nakano, H., H. Koube, S. Umezaea, K Momoyama, M. Hiraoka, K. Inouye, and N. Oseko. 1994. Mass Mortalities Of Cultured Kuruma Shrimp Penaeus Japonicus, In Japan In 1993: Epizootiological Survey And Infection Trials. Fish Pathology 29:135-139.

Payen, G.G. And J.R. Bonami. 1979. Mise En Evidence De Particles D'allure Virale Associees Aux Noyaux Des Cellules Mesodermiques De La Zone Germinative Testiculaire Du Crabe Rhithropanopeus Harrisii (Gould) (Brachyoure, Xanthide). Rev. Trav. Inst. Pech. Marit. 43:361-365.

Sano, T., T. Nishimura, K. Oguma, K. Momoyama, and N. Takeno. 1981. Baculovirus infection of cultured Kuruma shrimp, Penaeus japonicus in Japan. Fish Pathology 15: 185-191.

Sparks, A.K. And J.F. Morado. 1986. A Herpes-like Virus Disease In The Blue King Crab Paralithodes Platypus. Diseases Of Aquatic Organisms 1:115-122.

Takahashi, Y., T. Itama, M. Kondo, M. Maeda, R. Fujii, S. Tomonaga, K. Supamattaya, and S. Boon 1994. Electron Microscopic Evidence of Bacilliform Virus Infection in Kuruma Shrimp (Penaeus japonicus). Fish Pathology, 29(2) 121-125.

Tapay, L.M., Y. Lu, R.B. Gose, J.A. Brock and P.C. Loh. 1997. Infection of white spot baculvirus-like virus in two species of penaied shrimp penaeus stylirostis (stimpson) and P. Vannamei (Boone) In T.W. Flegel and I.H. MacRae editors. Diseases in Aquaculture III. Fish Health Section, Asian Fisheries Society, Manila

Van Hoa, N., B.Q. Te, L.T.T. Loan, L.T.P. Yen, and L.M. Thanh. 1996. Pathogens In Cultured Shrimp In Southern Vietnam. In Diseases In Asian Aquaculture III, Proceedings Of The Third Symposium On Diseases In Asian Aquaculture. 29 January To 2 February 1996. Bangkok, Thailand.

Wang, C., C. Lo, J. Leu, C. Chou, P. Yeh, H. Chou, M. Tung, C. Chang, M. Su and G. Kou. 1995. Purification and genomic analysis of baculovirus associated with white spot syndrome of Penaeus monodon. Diseases of Aquatic Organisms, Vol. 23:239-242.

Source: Gulf States Marine Fisheries Commission - Last Modified March 2005

Introduction

Bag shipment requires placing a prescribed weight of fish in 1.5 to 2 gallons of water in 3 ml polyethylene bags, 18 by 32 inches. Excess air is removed from the bag and replaced with pure oxygen. The bag is sealed, placed in an insulated container and finally into a cardboard shipping box and shipped.

Bag shipment may be the best choice for the shipper for several reasons. First, very small fish and fry could be damaged by being shipped in large tanks. Second, due to the extreme distances involved, bag shipment may offer economic advantages over standard tank transportation. This fact sheet will focus on transport of fish. With minor modifications the techniques and principals discussed also apply to shellfish.

Water quality during shipping
Fish health is affected by changes in water quality parameters while in the plastic bags during the transportation process. The parameters to be considered are temperature, dissolved oxygen, pH, carbon dioxide, ammonia and the salt balance of the fish's blood. The rate of change of each parameter is affected by the weight and size of fish to be transported and the duration of transport.

Temperature

Fish are cold-blooded, so the metabolic rate of fish is affected by the temperature of the environment. The metabolic rate of fish will double for each 18 degree F increase in temperatures and be reduced by half for each 18 degree F decrease in temperature. A reduced metabolic rate will decrease the oxygen consumption, ammonia production and carbon dioxide production. Therefore, it is essential to transport fish as low temperatures. For cool and warm water species a temperature of 55 degrees to 60 degrees F is recommended. For species such as tilapia and red drum temperatures should be nearer to 60 degrees F. Cold water fish, such as trout, inhabit colder water and should be transported at even colder temperatures, such as 45 to 50 degrees F.

To achieve the desired transport temperature, fish should be held in tanks of cool water. By holding the fish in tanks for two days, the water temperature can be gradually reduced by adding cool water. After loading the fish into bags, final decreases and maintenance of temperatures during transport can be accomplished by adding ice or (more commonly) gel packs.

Ice or gel packs often are used during transport, especially over longer transport periods that might allow increases in temperature. One-half pound of ice will reduce the temperature of one gallon of water by about 10 degrees F. Insulated Styrofoam shipping boxes also are used to prevent outside temperatures from affecting the temperature of transport water. In some instances, 20 to 40 quart coolers are used for transport.

Dissolved oxygen

The most important single factor in transporting fish is the provision of adequate concentrations of dissolved oxygen (DO). The importance of supplying adequate levels of DO cannot be overemphasized. Failure to do so results in severe stress which may contribute to fish kills two to three days after transport.

The amount of oxygen that can be dissolved in fresh water is based primarily on water temperature. The water is referred to as 100 percent saturated when the upper saturation level is reached. DO saturation is higher for cool water than for warm water. For example, at sea level DO saturation of 45 degrees F water is 12.1 parts per million (ppm) but at 60 degrees F, saturation is 10.0 ppm. Because pure oxygen is used during bag transport, DO levels in the water will be saturated and the low oxygen levels usually will not be a problem unless the bag is improperly sealed or develops holes caused by the spines of large fish. It is important to have a 75 percent volume of oxygen in the bag to ensure adequate diffusion of oxygen at the surface of the water.

The quantity of hydrogen ions (H+) in the water will determine if it is acidic or basic. The scale for measuring the degree of acidity is called the pH scale, which ranges from 1 to 14. A value of 7 is considered neutral, neither acidic nor basic; values below 7 are considered acidic; above 7 basic. The acceptable range for fish growth is between pH 6.5 and 9.0. The pH of water will be influenced by the alkalinity (buffering capacity) and the amount of free carbon dioxide. The pH of the transport water will also affect the toxicity of ammonia. Even in well-buffered transport water the pH will sometimes decrease by one pH unit.

Carbon dioxide

As fish respire they produce carbon dioxide as a byproduct. Carbon dioxide reacts with water to form a weak acid. This weak acid will in turn decrease the pH of the water. High levels of carbon dioxide (greater than 20 ppm) will interfere with the oxygen uptake in the fish's blood. High levels of carbon dioxide sometimes are found in well water. Excess carbon dioxide in well water can be reduced by mechanical aeration or by passing the water through a degassing column.

Ammonia

Ammonia build up occurs in transport water as a result of fish metabolism and, to a lesser extent, bacterial action on fish waste excreted into the water. Two forms of ammonia occur in transport water: ionized (NH4+), and un-ionized (NH3). Unlike the ionized form, the un-ionized form of ammonia is extremely toxic at concentrations as low as 0.2 ppm. In tests for ammonia, both forms are grouped together as "total ammonia nitrogen" (TAN). The percent of ammonia that is un-ionized will depend on both temperature and pH (Table 1).

Total ammonia concentrations may reach more than 14 ppm during transport. However, using Table 1, the percent of the total ammonia which is un-ionized at pH 6.5 and 55 degrees F is only 0.07 percent. Therefore, the un-ionized ammonia concentration at 14 ppm is 14 x 0.0007 = 0.0098 ppm. Un-ionized concentrations greater than 0.05 ppm should be handled with caution.

The easiest way to reduce toxic ammonia buildup in transport water is to lower the temperature of the transport water and to stop feeding several days before transporting. Fish up to eight inches long should not be fed for 48 hours before loading and transporting and those larger than eight inches should not be fed 72 hours before transporting.

Table 1.
Percent of ammonia in the un-ionized form of different temperatures (degrees F) and pH values

Chemical additives

Numerous chemical additives can be added to the transport water to alleviate several problems associated with transporting fish in bags. Since overdoses of chemical can cause death, care must be taken when measuring the dosage of each chemical. It is essential to double check every calculation and to use an accurate balance when weighing chemicals.

The most common chemical added to transport water is salt (NaCl). Salt is used to relieve stress associated with maintaining a water balance in the fish. Freshwater fish have a blood salt concentration higher than the salts of the transport water. As a result, the fish are continually losing salts to the surrounding water. Concentrations of 5,000 ppm (0.5 percent) are commonly used. A 5,000 ppm concentration can be made by adding 19 grams (one tablespoon) of salt per gallon to water used during transport. Use non-iodized salt that contain no anti-caking compounds. Canning salt is a good example.

If the alkalinity of the transport water is less than 100 ppm, some type of buffering compound should be added to the water. Properly buffered water will help remove freed carbon dioxide which causes drops in pH. Sodium bicarbonate (Na2CO3) is one of the fastest reacting buffers and should be added at a rate of 1 g per gallon. of water. Finally, the fish will suffer some stress because they are transported in crowded conditions. Sometimes a chemical anesthetic may be beneficial by producing a light sedation. The only anesthetic approved by Food and Drug Administration (FDA) for food fish is Finquel (tricaine methanesulfonate). Finquel may be used at a rate of 0.06 to 0.25 g per gallon. of water.

Carrying capacity

The maximum weight of fish that can be safely transported within a given period of time is the carrying capacity. The carrying capacity depends on the duration of haul, water temperature, fish size and fish species. If water quality conditions such as temperature, oxygen, carbon dioxide, alkalinity and ammonia are constant, then carrying capacity will depend on the fish species. In general, fewer pounds of smaller fish can be transported per gallon of water than larger fish. General carrying capacity guidelines are given in Table 2. It is important that first-time or experienced shippers handling a new species test-run a batch before undertaking a large shipment.

Table 2.
Carrying capacity in pounds of warm water fish transported in 18- x 32- inch polyethylene bags containing 2 gallons of water (about 15 pounds). Water should be moderately hard (80 to 100 ppm total hardness) and have a temperature range of 55-60 degrees F (Dupree and Hunter, 1984)

Transport procedure

Days before the fish are loaded and transported, the shipper should determine the carrier to be used, time of departure, time of arrival and shipping costs. This information needs to be communicated to the receiver well before the shipping date. All loading should be planned to allow boxes to be shipped as soon after loading as possible. With proper planning, unnecessary delays in delivery and pickup can be avoided. The receiver is responsible for contacting the shipper if any deaths occur.

Procedure for shipping fish:

• Carefully add the proper weight of fish to 1.5 to 2 gallons of clean high quality water. Water contained in the bag needs to be within two degrees of the holding water. Chemicals, if any, need to be added at this time.
  
• Deflate to remove air and then fill with pure oxygen. Approximately 75 percent of the volume in the bag should be oxygen.
  
• Twist mouth of bag tightly and secure with heavy-duty rubber bands. Castration rings or heat sealing may also be used. Place bag inside a second bag, which has a frozen gel pack, and seal the bag.
  
• Place the sealed bag inside a cardboard shipping box and seal the box. The shipping box must be clearly labeled "Live Fish," with the name and address of the shipper and receiver displayed prominently. In the case of trips which may expose the bags to extremes of heat or cold, the bags may need to be placed inside a Styrofoam cooler before being packed into the shipping box.

Procedure for unpacking fish

Unpacking is as important as packing fish in bags. Guidelines for proper unpacking are as follows.

• Float unopened bags in a shaded area of the receiving water for at least 30 minutes to allow temperature to equalize. Check water temperatures and watch for mortalities.
  
• Open bags and add 2 to 3 gallons of receiving water to the bag.
  
• Gently and slowly pour fish into the receiving water.

Suggested Readings

Dupree, H.K. and J.V. Huner, 1984. Third Report to Fish Farmers. U.S. Fish and Wildlife Service, Washington, D.C.

Piper, R. G., I.B. McElwain, L.E. Orme, J.P. McCraren, L.G. Fowler, and J.R. Leonard, 1982. Fish Hatchery Management. U.S. Fish and Wildlife Service, Washington, D.C. 517 pp.

S.K. Johnson, 1988. Transport of Fish and Crustaceans in Sealed Containers. Inland Aquaculture Handbook. Texas Aquaculture Association, College Station, TX. A1504-A1509.

Privacy Policy for http://the-fishfarm.blogspot.com/

If you require any more information or have any questions about our privacy policy, please feel free to contact us by email at zherokib@gmail.com.

At http://the-fishfarm.blogspot.com/, the privacy of our visitors is of extreme importance to us. This privacy policy document outlines the types of personal information is received and collected by http://the-fishfarm.blogspot.com/ and how it is used.

Log Files
Like many other Web sites, http://the-fishfarm.blogspot.com/ makes use of log files. The information inside the log files includes internet protocol ( IP ) addresses, type of browser, Internet Service Provider ( ISP ), date/time stamp, referring/exit pages, and number of clicks to analyze trends, administer the site, track user’s movement around the site, and gather demographic information. IP addresses, and other such information are not linked to any information that is personally identifiable.

Cookies and Web Beacons
http://the-fishfarm.blogspot.com/ does use cookies to store information about visitors preferences, record user-specific information on which pages the user access or visit, customize Web page content based on visitors browser type or other information that the visitor sends via their browser.

DoubleClick DART Cookie
.:: Google, as a third party vendor, uses cookies to serve ads on http://the-fishfarm.blogspot.com/.
.:: Google's use of the DART cookie enables it to serve ads to users based on their visit to http://the-fishfarm.blogspot.com/ and other sites on the Internet.
.:: Users may opt out of the use of the DART cookie by visiting the Google ad and content network privacy policy at the following URL - http://www.google.com/privacy_ads.html

Some of our advertising partners may use cookies and web beacons on our site. Our advertising partners include ....
Google Adsense
Commission Junction
Widget Bucks
Adbrite
Clickbank
Azoogle
Chitika
Linkshare
Amazon
Kontera


These third-party ad servers or ad networks use technology to the advertisements and links that appear on http://the-fishfarm.blogspot.com/ send directly to your browsers. They automatically receive your IP address when this occurs. Other technologies ( such as cookies, JavaScript, or Web Beacons ) may also be used by the third-party ad networks to measure the effectiveness of their advertisements and / or to personalize the advertising content that you see.

http://the-fishfarm.blogspot.com/ has no access to or control over these cookies that are used by third-party advertisers.

You should consult the respective privacy policies of these third-party ad servers for more detailed information on their practices as well as for instructions about how to opt-out of certain practices. http://the-fishfarm.blogspot.com/'s privacy policy does not apply to, and we cannot control the activities of, such other advertisers or web sites.

If you wish to disable cookies, you may do so through your individual browser options. More detailed information about cookie management with specific web browsers can be found at the