Effects of Laminaria digitata and Aschophylum nodossum in controlling white spot disease (WSD) in white leg shrimp (Litopenaeus vannamei)

Complementary feedstuff extract from Laminaria digitata and Ascophylum nodossum containing 1% alginic acids as stimulator of immune system in Litopenaeus vannamei for controlling WSSV was used in this study. The test shrimps, Litopenaeus vannamei, in larvae stage (Z1-131,1), post larvae stage (PL1-PLO and juvenile (from day 30 to 40) were fed by complimentary feed stuff as the other test conditions in the test and control group were the same. Both groups were exposed to WSSV after 40 days by oral inoculation. The clinical signs and mortality were recorded for 10 days. The results showed the survival rate of the test group was higher than the control group and it was significant (P<0.05). The results also showed that the mortality in the test group occurred 48 hours later than the control group. This study can lead us to new methods for controlling White Spot Disease

Natural source-based graphene as sensitising agents for air quality monitoring

Natural carbon powder has been used as a precursor to prepare two main types of sensitising agents of nitrogen-doped carbon nanoparticles (N-CNPs) and nitrogen-doped graphene quantum dots coupled to nanosheets (N-GQDs-NSs) by using simple treatments of chemical oxidation and centrifugation separation. Characterization based on FTIR, XPS, XRD, Raman spectroscopy, FE-SEM, HR-TEM, AFM, UV-Vis and FL, revealed successful doping carbon nanoparticle with nitrogen with an average plane dimension of 50 nm and relatively smooth surface. The versatility of the prepared samples as sensitising agents was developed and established by exploiting its ability for detection of volatile organic compounds via simple optical fibre based sensing configuration. The comparative experimental studies on the proposed sensor performance indicate fast response achieved at a few tens of seconds and excellent repeatability in exposure to the methanol vapour. The low limit of detection of 4.3, 4.9 and 10.5 ppm was obtained in exposure to the methanol, ethanol and propanol vapours, respectively, in the atmosphere condition. This study gives insights into the chemical/physical mechanism of an enhanced economic optical fibre based gas sensor and illustrates it for diverse sensing applications, especially for chemical vapour remote detection and future air quality monitoring

Convection-diffusion-reaction of CO2-enriched brine in porous media: A pore-scale study

Bureau of Economic Geolog

Effects of light regimes on growth and survival of Penaeus semisuleatus

We investigated the possible effects of light regimes on growth and survival rate of juvenile shrimp Penaeus semisuicants cultured in Bushehr Province, southern Iran. Five light regimes each with three replications were applied for 30 days. The treatments were 24 1 0, 18 / 6, 12 1 12, 6 1 18 and 0 124 hours of light and darkness. We found that the treatment 12 7 12 hours of light and darkness was better than 18 1 6 and significantly superior to other treatments (P<0.05). The lowest growth rate was seen in the treatment 24 / 0 (P<0.001 ). We did not find a significant difference in the survival rate of the shrimps cultured in the light and darkness treatments (P<0.05)

Bioassay of combined hydrogen peroxide and silver ion at four life stages of Indian white shrimp (Fennerop enaeus indicus)

Silver ion and hydrogen peroxide act synergistically as a strong disinfectant. The purpose of this study was to assess the effect of combined hydrogen peroxide 50% and silver ion 0.05% at four life stages of Indian white shrimp (Fenneropenaeus indicus) and to evaluate the feasibility of using this substance in shrimp culture. The Trimmed Spear man karber software was applied for determining EC _(50)/96h and LC sub(50)/96h with 95% confidence limit on the 6000 shrimp based on OECD static method. The experiments were conducted in Iran Shrimp Research Center, Bushehr, during 2005 -2006. The EC _(50) values of 132.5, 67.89, 55.56, 51.95 and 48 .6ppm were obtained in PL15 stage after 12, 24, 48, 72 and 96 hours, respectively. Also these were 147.57, 70.83, 60.01, 54.89, 41.19 for PL_(45) stage, and 306.43, 174.14, 113.62, 78.21, 61.96 for sub adult stage (12 plus or minus 1 grams), res pectively. In addition, the EC _(50) values of 243.25, 130.55, 75.56, 61. 18 and 51.59ppm were obtained at adult stage (20 plus or minus 2 grams), respectively. The LC sub(50) values of 239.81, 101, 74.28, 65.72 and 61.45ppm were obtained in PL _(15) stage after 12, 24, 48, 72 and 96 hours, respectively. Also thes e were 304.56, 160.12, 113.1, 93.69, 79.38 for PL _(45) stage, and 712.13 , 518.44, 265.29, 145.53, 103.76 for sub adult stage, respectively. In addition, the LC _(50) values of 827.75, 508.91, 317.3, 139.44 and 85.88ppm were obtained at adult stage, respectively. The statistical results showed that; no observed effect concentration" (NOEC) of this substance was 20ppm, and the "lowest observed effect concentration" (LOEC) was 40ppm, thus "maximum allowable concentration" (MAC) value was determined 28.8 ppm on the Indian white shrimp. Therefore this combined chemical should be used under determined MAC value with a complete precautionary as a disinfectant for Indian white shrimp

Investigation on effects of ergosan^TM and vibromax^TM in control of white spot disease (WSD) and Vibriosis in shrimp Litopenaeus vannamei

Complementary feedstuff extract from Laminaria digitata and Ascophylum nodosum that containing 1% alginic acids as shrimps stimulating of immune system for control of WSSV is used in this study. The test shrimps Litopenaeus vannamei in larvae stage (Z1-PL1), post larvae stage (PL1-PL10) and juvenile (from 30th day to 40th day) fed by complimentary feedstuff comprised control group. The other condition in test and control group was the same manner. Both groups after 40 days exposed to WSSV by oral inoculation. The clinical sign and mortality recorded for 10 days. The results showed the survival rate of exposed group was higher than the control group and it was significant (p<0/05). The result also show the mortality observed in exposed group 48 hours later than the control group. This study can led us to new methods for control of White spot disease

A survey on the effects of the Cochlodinium sp. bloom on the survival of the Litopenaeus vannamei shrimp

Red tide event a product of micro algae abundance has elevated in last few years. Loss of aquatic life due to HAB, and its effect on human health, has caused tremendous damage in the world. In this research the effect of (1, 2, 3, 9, and 30) ×10^3 Cells ml^-1 densities of Cochlodinium polykrikoides on survival and histopathological effect on hepatopancreas and gills of Litopenaeus vannamei postlarvae (PLs) and juvenile stages has been investigated. Results showed 100% survival with (1, 2, and 3) ×10^3 Cells ml-1 densities but accumulative mortality in 9×10^3 Cells ml^-1 density were 1.33% and 2.22%, in PLs and juvenile stages respectively, and there is no significant difference between control and treatment groups. accumulative mortality in 3×10^4 Cells ml^-1 density was 4.44% and 17.8% in PLs and juveniles respectively which have significant different with control groups. According to histopathological investigation in this density the infiltration of blood cells in connective tissue of hepatopancreatic tubules and gills lamellae of PLs and juvenile stages were low but high in 3×10^4 Cells ml^-1. The intensity of infiltration in juvenile stages was higher than PLs, which indicate incensement of hepatopancreatic and gills blood cells in higher densities of this phytoplankton. The end result of the study indicates that in high densities of C. polykrikoides survival rate in PLs and juveniles decreased and according to histopathological study the most important possible factor in shrimp mortality when exposure to C. polykrikoides was settlement of phytoplankton on gills lamellae and preventing oxygen exchange of shrimp

Study on effect of enriched Artemia with (HUFA) on reproductive parameters and comparing with current method (used marine worm) in Litopenaeus vannamei

Nowadays, the use of live food enrichment is very common in aquaculture and as a practical method introduced. Artemia a potential food source and quality is suitable, it will have used for feeding fish and crustaceans (shrimp). In this study, Artemia enriched with unsaturated fatty acids used for increase the sexual maturity of the white leg shrimp (Litopenaeus vannamei). Thus, the young brood stocks transferred to Bandarga Research station. In order to achieve optimal weight, Brood stocks were feeding by food concentrate and food frozen fresh. In this study such as 3 treatments each with 3 replicates, which brood stocks were stocking in the fiberglass thank with density 2 to 3 (pieces/m^2). They were feeding with meals different including 1) squid , pen shale and marine polychaeta worm (Perinereis nuntia), 2) squid , pen shale and Artemia biomass "fransiscan", 3) squid , pen shale and Artemia biomass enriched with unsaturated fatty acid (HUFA) SPARI SELCO solution after were eye ablation. The results showed that sexual maturity increased in the brood stocks fed with Artemia enriched which with significantly higher brood stocks fed with Artemia biomass and the marine worm (P 0.05). The other hand, histological studies showed that brood stocks fed with Artemia enriched than other two treatments contain were many mature follicles ready for ovulation. However, there was more absolute fecundity in the brood stocks fed with Artemia enriched, but don't found any significant differences in competition with other two treatments (P>0.05). In addition, during this period, measured and recorded all factors physicochemical water and environment daily. Following this study showed that if the Artemia enriched as part of the diet can both caused eliminate unsaturated fatty acid deficiency diet and improved ovarian development and increase sexual maturity brood stocks female in a short interval. Finally, the results analyzed with statistical software spss 9.0, one way ANOVA and Tukey test

Development gene data bank of cultured shrimp species in Iran

DNA barcode is a short, standard well known sequence of cytochrome oxidase І gene. By using this DNA sequence can be realized that each animal, plant or fungus belongs to which species. in this research, samples were collected from imported cultured shrimp Litopenaeus vannamei and and 6 Persian Gulf and Oman Sea shrimp species which classified based on traditional systematically as: Penaeus semisulcatus, Fenneropenaeus merguiensis, Metapenaeus affinis, Parapenaeopsis Stylifera and Fenneropenaeus indicus. After examination of DNA barcode sequence, molecular and bioinformatics operations of each sequence in the Consortium for the Barcode of Life (CBOL) and National Center for Biotechnology Information (NCBI), phylogenetic analysis of each sample was determined and similarity of each sample with NCBI and CBOL database was checked and the closest species to each sample were specified. According to the results different samples of L. vannamei, . banded P.semisulcatus, F. merguiensis and F. indicus have more than 97% similarity to the same species of other countries. non banded P.semisulcatus had 80.07% similarity to banded P.semisulcatus, M. affinis samples had 90.3% similarity to Metapenaeus ensis and Parap. Stylifera had 93.44% similarity to Parapenaeopsis coromandelica in the CBOL. This funding confirmed the need for further investigation and possible announcement of new species