A study on the status of shrimp diseases in Iran and whole the world and to present the best practice management in shrimp farms

Shrimp culture in Chabahar in the Sistan and Belochestan province is one of the most important potential for development. From 1386 the white spot syndrome virus (WSSV) observed and collapsed all activity in this area. This virus hugged mortality in the world and in Iran from 1381 in Abadan area this disease induced high mortality in shrimp culture. Different methods applied for prevention WSSV in the world and the main methods consist of used specific pathogen free post larvae, immune stimulant, biosecurity and vaccine. Biosecurity is the best method for prevention the WSSV disease and include different part such as used crab fence, low stocking density, used best quality PL, aeration in the pond and sanitation all equipment and farm. Temperatures play an important role in outbreak of disease. Because in Chabahar area the culture time is in the monsoon season and changing the temperature in this season is trigger factor for WSSV outbreak. In this research study we recommended the season’s culture changing from August to March for prevention the temperature variation in this area and applied biosecurity for control the WSSV outbreak

Assessing the sustainability of Litopenaus vannamei on white spot virus vaccine and fed with yeast Sacchromayces cerevisiae and algae Gracilaria corticata in the face of white spot syndrome virus

Efficacy of G. corticata, S. cerevisiae and gamma irradiation WSSV as immunostimulants to white shrimp L. vannamei was investigated. 1200 healthy shrimp SPF L. vannamei subadult with average weight of 10±1.02 g were collected and divided to four groups. The first group (T1) fed with commercial pellet, second group (T2) fed S. cerevisiae (2 g/ Kg), third group (T3) fed G. corticata powder was mixed with shrimp feed (2 g/Kg) and fourth group (T4) fed commercial pellet and injected intramuscularly gamma irradiant WSSV (1µl/gbw). The shrimp were fed on these diets for a period of 10 days and then challenged injected with WSSV and maintained for 25 days. The control group maintained same manner but without inject with WSSV. Survival rate and immune parameters such as total hemocyte count (THC), total protein plasma (TPP), superoxide dismutase (SOD) activity, peroxidase (POD) activity and phenoloxidas activity (PO) were determined. The result indicated survival rate in shrimp group T4 was 57.05±3.52%, shrimp group T3 was 22.5±0.5% and shrimp group T2 was 15±1.05% and shrimp group T1 was 00.0±0%, respectively. The shrimp group T4 showed higher hematological data, i.e. THC, TPP, SOD, POD and PO at the end of experiment. This study showed that gamma irradiant WSSV are effective immunostimulants in shrimp L. vannamei and perform better than the G. corticata and S. cerevisiae

Evaluation of the immunity factors (THC, TPP, PO, SOD, POD) of shrimp fed with the yeast Saccharomyces cerevisiae compared to shrimp fed without yeast

Effects of S. cerevisiae on immune parameters and the WSSV resistance of the L. vannamei after 10 days of S. cerevisiae feeding were evaluated in this study. The experimental diet has the commercial shrimp composition, but 2 g of S. cerevisiae substituted 2 g of fish meal. Six hundred of subadult shrimp (10±1.02 g) were collected and divided to four groups; the 1st group (T1) and the 2nd group (T2) fed experimental diet for 10 days and T2 after 10 days injected with WSSV, whereas the 3ed group (T3) and 4th group (T4) fed with commercial diet for 10 days as control negative and control positive and T4 after 10 days injected with WSSV and all group maintained for 25 days. The immune parameters such as total hemocyte count (THC), total plasma protein (TPP), phenoloxidase activity (PO), superoxide dismutase (SOD) activity, peroxidase (POD) activity were measured. Shrimp immune parameter in T1 and T2 was significantly increased comparing to T3 and T4, but in T2 the immune response decreased in contrast to T1. The immune parameter in T4 also significantly decreased in contrast to T3. Survival rate in T1 and T3 was higher and significantly different (P<0.05) with T2 and T4, whereas, T2 showed significantly different (P<0.05) survival rate with T4 at the end of experiment. In conclusion these results suggest that the increased survival rate and resistance of shrimp after S. cerevisiae consumption occurs through immune modifications, such as increases in THC, TPP, SOD, SOP and PO activity, against WSSV

The survey and identification source of white spot disease in shrimp Farm in Abadan area

In the summer of 2002 high mortality occurred in farm shrimp in Abadan area due to white spot disease. The main objective of this study was detection and identification the source of white spot syndrome virus. For this reason from 2004/11/4 until 2005/120/6 about 190 samples consisted of wild shrimp, crab, fish, and plankton collected and preserved in alcohol 90-75% for polymerase chain reaction (PCR).The samples transferred to the South Iranian Aquaculture Center in Ahwaz. The samples examined by commercial WSSV detection kit (Fast Target) and new kit design by Iranian Fisheries Research Organization (IFRO) and Biotechnology Research Center from Iran. The result from PCR showed the samples of Penaeus indicus brood stock and postlarvea, Parapenaeopsis stylifrus and Metapenaeus affinis was positive. The rest of samples did not show any sign of virus and they was negative by PCR. Because the disease outbreak occurred in 2002 and the samples collected in 2004, the situation of environmental in the area was changed and may be the virus disappears in the samples and died

Immunization of cultured shrimp against WSSV by use of produced recombinant vaccine (In vitro)

Shrimp diseases, especially viral diseases are the major limiting factors of shrimp farming activities in the world. White spot disease is one of the most pernicious viral disease that lead to serious loss in all shrimps of penaeids family. In Iran during 2002 to 2004 in Khuzestan province and in 2005 in Bushehr province, the most ponds and farms infected with white spot and the entire industry faced threat of closure. Surface proteins of virus has important role in the early stages of virus with host cell interaction, because these proteins usually enumerated as a candidate to produce a subunit and recombinant vaccines. On the other hand, these proteins can use as an important virus antigen and produce virus-specific antibodies in the preparation of diagnostic kits. In several studies proteins in the form of injection or oral vaccine has shown promising results. This study was designed in order to gain these proteins for immunization of white leg shrimp. To achieve the white spot virus genome, sampling and DNA extraction of moribund shrimps with clinical signs was done from Choebdeh farms. VP28 and VP19 protein-coding gene-specific primers were selected, and after amplification and purification were cloned in E.coli TG1. Protein expression evaluated and commercial plates were coated with inactivated bacteria containing the recombinant protein. White leg shrimp post larvae (PL30) were fed with recombinant food for 7 days then two times in 9th and 23th day after beginning of plate feeding and was challenged by white spot disease virus. The results of the first exposure (end of the seventh day after the shrimp fed with recombinant plate) showed that the lowest mortality at day 14 after exposure in different groups belong to VP28 group with cumulative mortality percent %30 ± 3.84 and the highest percentage of the Group TG1 equal to %72.22±2.93, also The highest and lowest relative percent survival, belong to the group of VP28 (60.29± 5.09%) and TG1 (4.41 ± 2.94%), respectively. In terms of mortality percent and relative percent survival, VP28 and VP 28+19 has significant difference with other groups while there was no significant difference between the groups VP19, TG1 and pMal. In the second exposure experiment (21 days after end of plate feeding) results showed that the lowest cumulative mortality in different groups belong to VP28 (%50 ± 5.09) and the highest percentage was owned by Group TG1 equal to %75.55±2.22, also the highest and the lowest of relative percent survival belong to VP28 (%32.86± 6.83) and TG1 (%0.00 ± 2.98) groups respectively. Similar to the first experiment, VP28 showed significant differences in cumulative mortality and relative percentage of survival in contrast to other group. As a general conclusion it can be noted that recombinant protein VP28 in any form that delivered to shrimp was able to protect shrimp against white spot virus. On the contrary VP19 has no this ability. The survival rate is directly related to the duration of the presence of recombinant protein in the diet

(Fenneropenaeus indicus) study on protozoa emerging diseases of shrimp

Certain diseases such as bacterial , viruses, parasirtic ones Protozoa parasites Could severe mortalities in farmed shrimp last decades. Two hundred and seventy Fenneropenaeus indicus with the weight of 10± 1.09 were selected, transferred to Iran Shrimp Center and distributed to the treatmentsand controls (3 groups). The objective of our study was to describe the signs, prevalence, and intensity of Hemocytosis, a new disease in shrimp, Fenneropenaeus indicus. The experimental design included three groups, one treatment as infected shrimp or group B and 2 controls with non-infected but exposure to White Spot Syndrom Virus (WSSV) shrimp as group A and non-infected non- exposure to WSSV shrimp as group C in triplicate. The results revealed that Hemocytosis associated with a decrease in hyalinocytes and large-granulocytes (less than 8%) and a considerable increase in semi-granulocytes in group A and B in contrast to group C that Hyalinocyte increased. This infection made the shrimp susceptible to WSSV disease. It is believed that Hemocytosis causes a condition which can result in a rapid mortality among susceptible species, F. indicus when exposure to WSSV is occurred

Identification of WSSV, TSV & IHHNV in wild and cultured shrimps and crustaceans in Khuzestan province - Abadan and investigation of its pathogenicity

According to the white spot disease during 2002 until 2005 and the damages caused by the disease to the farmers a new species L.vannamei were introduced to the farming region of Abadan Choebdeh from 2006. Hight mortality occurred in Khuzestan province farms in 2007 and 2008 again. Probably viral agent was transferred to native shrimps or other aquatic animals, therefore it is very important that presence of viruses in local aquatic animals and its vectors detected. Detection of WSSV, TSVand IHHNV in aquatic animal from Khuzestan costal region imphasis to wild shrimp and craps is the main objectives of this study. So samples were taken from 10 active farms twice a week and 100 postlarves from 3 active breeding center befor stocking. Samples for viral detection were studied by molecular and histopathology asseys. Results was shown presence of the White spot virus in cultured and wild shrimp and TSV infection in only two cultured shrimps but there was negative result for IHHN virus. To study the pathogenesis of white spot virus isolated from wild and farmed shrimps, exposure method was used. Results of challenge showed that WSSV can be transmited from diseased cultured and wild shrimp to cultured shrimp. Mean mortality percent in the treatment that fed with infected wild shrimp was 38.33±10.4 and treatment that fed with infected cultured shrimp 61.66±7.63 and in the positive control treatment was 87.5±3.5

Preparation of inactivated vaccine to induce resistance against white spot syndrome virus by nuclear & non nuclear techniques

The inactivated of white spot syndrome virus (WSSV) by Gama and Electron radiation and chemical material such as Formalin with antigen property have been done during last year. At the first time the stock of virus prepared and purred it. Six hundred of shrimp Fenneropenaus indicus with average weight 7 to 12 gram collected from shrimp research station in Heleh area and transported to Shrimp Research Institute in Boushehr province. Vibrio parahemolyticus obtained from Veterinary University of Tehran and then lyophilized it. The bacterial V. parahemolyticus inactivated with Gamma, electron and formalin and then injected to shrimp for activated the immune system. The source of viruses was identified through PCR, TEM and histopathology methods from the shrimp infected in 2009 occurrence of boushehr province. The virus injected to crayfish and collected the hemlymph for prepared the stock of WSSV virus. The virus was lyophilized and then exposed to gamma and electron radiation and formalin with optimal dose for inactivated the virus. The shrimp divided to 25 groups and each group consist of six shrimp and the vaccine exposed to shrimp with injected and bathroom methods and the documented the result after 15 days. In vivo virus titration was performed in Penaeus indicus. Inactivation of WSSV was carried out by a gamma cell instrument Nordian, model 220 with dose rate: 4.8 Gy/sec and activity: 20469 Ci. The LD50 of live virus stock was calculated 10 5.4 / ml and the optimum dose of gamma radiation beam to inactivate WSSV was obtained 14-15 kGy. The LD50 of live virus stock was calculated 10 5.4 / ml and the optimum dose of electron beam to inactivate WSSV was obtained 12-13 kGy and and the virus inactivated by formalin 0.5% V/V during 10 minutes.The LD50 of live virus stock was calculated by Karber method 10 3.29 /ml and 10 5.35 /ml, respectively. The V. parahemolyticus was inactivated with 8 KG. The result showed all vaccine during 2 hours have a good effect to shrimp viruses with the 102.4 LD50 / 50 l titre. The result showed if the Gamma and electron vaccine increase to feed of shrimp the effect of vaccine is better than when used without feed. The end of experiment our study showed that the Gamma vaccine has the better effect to control WSSV during 2 hours with comparing the others

Knowledge acquisition and technology transfer for the mass production of specific pathogen free (SPF) shrimp, towards independent on foreign production

In this study we collected the adult shrimp from farm in Bouhsher province based on the pedigree information and screening by PCR for 10 shrimp pathogen as well viral diseases and transported to the shrimp research station for first quarantine. Three different families were selected and crossed them and obtained the larval and produced F1generation. The F1 shrimp had reach an average weight (33±2g) and crossed together for produced F2 generation. The larval from F2 generation transferred to second quarantine and maintained in different tank. The postlarvae from F2 transferred to nuclear breeding center and cultured until the adult size. During F1 and F2 period we screened the shrimp for 10 pathogen and for prevention the inbreeding and transferring the growth and survival gen we used selection breeding with 12 primers by microsatellite technique during each generation. After 3 year we produced 8 thousand shrimp SPF and the shrimp are free of important viral disease as well WSSV

Supply and protected different population of Litopenaeus vannamei subadult zero foster (F_0) from difference provinces Iran

Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free