2 research outputs found
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
Evaluation growths and survival indexes of vaccinated Litopenaeus vannamei against white spot virus syndrome
Nowadays, white spot virus disease is serious threat for breeding and culture industry of shrimp. In this study was increasing resistance of shrimp against white spot virus by using modern methods such as shrimp vaccination with inactivated viruses and recombinant proteins. The aim of this study were determine the growth and survival rates vaccinated and non-vaccinated of Litopenaeus vannamei (5 to 15 and 12 to 26 day), that were challenged with white spot virus in 40 and 60 day rearing. This study consisted two separate groups were vaccinated and non-vaccinated with 11 treatments experimental and each of replicate was stocked 1000 pieces by post larva of 5 to15 and 12 to 26 day. After vaccination, two groups of post larvae exposed to the white spot virus at 40 and 60 day, one groups no exposure to the virus. Samplings were randomly of shrimp in 40, 60 and 80 days 10 pieces each of treatment experimental and measured mean of weight and length. Also, number of deaths was recorded at morning and evening daily and calculated survival rate at the end of study. The results showed growth rate of post larvae vaccinated (5 to15 day) which exposed to white spot virus at 40 and 60 was significantly lower than non-vaccinated of post larval, while the growth rate of post larval exposed to virus in 60 day was significantly increased. On the other hand, growth rate of post larval vaccination (12 to 26 day) exposed to virus in 60 day compared with post larval vaccination (5 to 15 and 12 to 26) exposed to virus in 40 and 60 days was significantly increased. Hence, growth rate was significantly increased in post larval vaccinated (5 to 15 and 12 to 26) which non-exposed to virus. Although the survival rate was post larval vaccinated (12 to 26 days) exposed to virus Post larvae in 60 day higher than post larval were exposed to virus in 40 and 60, but no significant differences were observed. However, relative mortality of post larval vaccination in 12 to 26 day compared with post larval vaccination in 5 to 15 days exposed to virus were significantly lower. Considering growth and survival index was improved of post larval vaccination can be concluded that the optimum age for vaccination against white spot virus of L.vannamei was 12 to 26 day