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Vannamei
Kinds of Vannamei Terms modified by Vannamei Selected AbstractsProtein Hydrolysate of Salted Duck Egg White as a Substitute of Phosphate and Its Effect on Quality of Pacific White Shrimp (Litopenaeus Vannamei)JOURNAL OF FOOD SCIENCE, Issue 8 2009Thammarat Kaewmanee ABSTRACT:, Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P,< 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P,> 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P,< 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties. [source] Effects of low dose gamma irradiation on microbial inactivation and physicochemical properties of fried shrimp (Penaeus vannamei)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2010He Wang Summary Changes in microbiological, physicochemical and sensory properties of shrimp gamma irradiated with 60Co at doses of 0, 1, 3, 6, 9 kGy were investigated. Irradiation at 6 kGy eliminated most of the spoilage microorganisms and did not affect sensory quality. The L* value increased as irradiation dose increased, while a* value decreased as irradiation dose increased. Irradiation had no significant effect on the texture of shrimp samples; however, increasing the dose up to 9 kGy significantly increased the amount of volatile compounds, such as, alcohols, ketones, aldehydes, furans, and oxides. According to the total sensory points, the appearance and flavour of the shrimp product was considered as acceptable by sensory evaluation when irradiated at doses of 0,6 kGy. These results showed that gamma irradiation processing (<6 kGy) had the potential to extend the shelf life of fried shrimp. [source] Inhibition by Cu2+ and Cd2+ of a mu-class glutathione S-transferase from shrimp Litopenaeus vannameiJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2010Alex J. Salazar-Medina Abstract Glutathione S -transferases (GSTs) are a family of detoxifying enzymes that catalyze the conjugation of glutathione (GSH) to electrophiles, thereby increasing the solubility of xenobiotics and aiding its excretion from the cell. The present work presents the inhibition of a mu-class GST of the marine shrimp Litopenaeus vannamei by copper (Cu2+) and cadmium (Cd2+). The protein was overexpressed in bacteria and its enzymatic activity measured using 1-chloro-2,4-dinitrobenzene. The mean inhibitory concentration (IC50) for shrimp GST against Cu2+ was 4.77 ,M and for Cd2+ was 0.39 ,M. A molecular model of the protein based on the crystal structure of a maize GST bound to cadmium showed that the metal binds in the GSH-binding site by coordination with Asp and Gln residues. These results are consistent with the experimental data and suggest that sublethal concentration of metals may affect the capacity of the organism to detoxify pesticides or xenobiotics. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:218,222, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20326 [source] A Mu-class glutathione S -transferase from gills of the marine shrimp Litopenaeus vannamei: Purification and characterizationJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2007Carmen A. Contreras-Vergara Abstract Glutathione S -transferases (GSTs) are a family of detoxifying enzymes that catalyze the conjugation of glutathione (GSH) to electrophiles, thereby increasing the solubility of GSH and aiding its excretion from the cell. In this study, a glutatione S -transferase from the gills of the marine shrimp Litopenaeus vannamei was purified by affinity chromatography using a glutathione,agarose affinity column. GST was purified to homogeneity as judged by reducing SDS-PAGE and zymograms. This enzyme is a homodimer composed of ,25-kDa subunits and identified as a Mu-class GST based on its activity against 1-chloro-2,4-dinitrobenzene (CDNB) and internal peptide sequence. The specific activity of purified GST was 440.12 ,mol/(min mg), and the Km values for CDNB and GSH are very similar (390 and 335 ,M, respectively). The intersecting pattern of the initial velocities of this enzyme in the Lineweaver,Burke plot is consistent with a sequential steady-state kinetic mechanism. The high specific activity of shrimp GST may be related to a highly effective detoxification mechanism necessary in gills since they are exposed to the external and frequently contaminated environment. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:62,67, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20162 [source] Pre-exposure to infectious hypodermal and haematopoietic necrosis virus or to inactivated white spot syndrome virus (WSSV) confers protection against WSSV in Penaeus vannamei (Boone) post-larvaeJOURNAL OF FISH DISEASES, Issue 10 2006J Melena Abstract Larvae and post-larvae of Penaeus vannamei (Boone) were submitted to primary challenge with infectious hypodermal and haematopoietic necrosis virus (IHHNV) or formalin-inactivated white spot syndrome virus (WSSV). Survival rate and viral load were evaluated after secondary per os challenge with WSSV at post-larval stage 45 (PL45). Only shrimp treated with inactivated WSSV at PL35 or with IHHNV infection at nauplius 5, zoea 1 and PL22 were alive (4.7% and 4%, respectively) at 10 days post-infection (p.i.). Moreover, at 9 days p.i. there was 100% mortality in all remaining treatments, while there was 94% mortality in shrimp treated with inactivated WSSV at PL35 and 95% mortality in shrimp previously treated with IHHNV at N5, Z1 and PL22. Based on viral genome copy quantification by real-time PCR, surviving shrimp previously challenged with IHHNV at PL22 contained the lowest load of WSSV (0,1 × 103 copies ,g,1 of DNA). In addition, surviving shrimp previously exposed to inactivated WSSV at PL35 also contained few WSSV (0,2 × 103 copies ,g,1 of DNA). Consequently, pre-exposure to either IHHNV or inactivated WSSV resulted in slower WSSV replication and delayed mortality. This evidence suggests a protective role of IHHNV as an interfering virus, while protection obtained by inactivated WSSV might result from non-specific antiviral immune response. [source] Protein Hydrolysate of Salted Duck Egg White as a Substitute of Phosphate and Its Effect on Quality of Pacific White Shrimp (Litopenaeus Vannamei)JOURNAL OF FOOD SCIENCE, Issue 8 2009Thammarat Kaewmanee ABSTRACT:, Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P,< 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P,> 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P,< 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties. [source] Properties, Translucence, and Microstructure of Pacific White Shrimp Treated with Mixed Phosphates as Affected by Freshness and DeveiningJOURNAL OF FOOD SCIENCE, Issue 1 2008N. Rattanasatheirn ABSTRACT:, Effects of freshness and deveining on some properties, translucence, and microstructure of Pacific white shrimp (Litopenaeus vannamei) soaked in 2.5% NaCl containing different phosphates were studied. Shrimp soaked in all solutions had increases in weight gain and cooking yield with lowered cooking loss, compared with the control (P < 0.05). However, efficacy of mixed phosphates in quality improvement of ice-stored shrimp was lower than fresh shrimp. Deveining resulted in increased weight gain and yield (P < 0.05). Nevertheless, samples treated with phosphates became more translucent. Shrimp stored in ice for 7 d and treated with mixed phosphates were generally more translucent than fresh counterparts (P < 0.05). Shrimp soaked in 2.5% NaCl containing 0.875% sodium acid pyrophosphate (SAPP) and 2.625% tetrasodium pyrophosphate (TSPP) were generally less translucent and had high weight gain and cooking yield along with low cooking loss. The microstructure study revealed that the muscle fibers were less attached with the loss of Z-disks after being treated with mixed phosphates. Cooked meats of fresh shrimp and ice-stored shrimp had more compact fiber arrangement with the shrinkage of sarcomere compared with raw samples. Disintegration was observed at the M-line in ice-stored shrimp treated with mixed phosphates after cooking, while such a phenomenon was not found in the cooked fresh sample treated with phosphates. Tmax and enthalpy of both myosin and actin peaks shifted to lower values when shrimp were treated with mixed phosphates (P < 0.05). Those changes were generally more pronounced in ice-stored shrimp. Therefore, freshness and deveining process had an impact on the quality of Pacific white shrimp treated with phosphates. [source] Validation of a Feeding Stimulant Bioassay Using Fish Hydrolysates for the Pacific White Shrimp, Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2009Michael Grey A protocol for testing feeding stimulants on Pacific white shrimp, Litopenaeus vannamei, is described. Thirty-five rectangular tanks (55 L volume) served as the test system into which ten 5,6 g shrimp were stocked. Every tank contained two bowls, each of which contained either 25 feed pellets of a Reference Diet or Test Diet (consisting of the Reference Diet with one test ingredient added). After 1 h, the difference between the number of pellets consumed of the Test Diet and the Reference Diet was used as the Response. Each of the four Test Diets contained a different salmon hydrolysate made from by-products of the Alaska fish processing industry (included at 50 g/kg). A fifth commercial shrimp diet was also tested. Each Test Diet was tested against the Reference Diet over a 4-d period in seven replicate tanks. The data were subjected to a one-way ANOVA and a confidence interval for each treatment response was calculated. The confidence interval was used to assess the test ingredient as a feeding stimulant. Treatment means were compared using Tukey's test (, = 5%). All the hydrolysates tested were found to act as feeding stimulants. [source] Tail Muscle Free Amino Acid Concentration of Pacific White Shrimp, Litopenaeus vannamei, Fed Diets Containing Protein-bound versus Crystalline Amino AcidsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2009Joe M. Fox Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein-bound amino acids, crystalline lysine as a supplement to protein-bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine-supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine-supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds. [source] Inbreeding Effects on Hatchery and Growout Performance of Pacific White Shrimp, Penaeus (Litopenaeus) vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2008Dustin R Moss In animal breeding programs, selection coupled with a narrow genetic base can cause high levels of inbreeding to occur rapidly (in one or two generations). Although the effects of inbreeding have been studied extensively in terrestrial animals and to a lesser extent in aquaculture species, little is known about the effects of inbreeding on penaeid shrimp. The objective of this study was to investigate the effects of inbreeding on hatchery and growout performance of the Pacific white shrimp, Penaeus vannamei. The experiment was conducted over 2 yr, and data from two successive generations (G2 and G3) of inbred (sibling,sibling mating) and outbred families were analyzed. There were 11 inbred and 12 outbred families in G2 and 9 inbred and 10 outbred families in G3. Inbreeding coefficients (F) for outbred and inbred families were 0.00 and 0.25, respectively, for G2 and 0.00 and 0.375, respectively, for G3. Growth rates for outbreds and inbreds were similar in both G2 and G3. Hatch rate for inbred families was 33.1% lower than for outbred families in G2 and 47.1% lower in G3. Inbreeding depression (IBD) (relative change in phenotype per 0.1 increase in F) ± 95% CI for hatch rate was ,12.3 ± 10.1%. Hatchery survival for inbred families was 31.4% lower than for outbred families in G2 and 38.8% lower in G3. IBD for hatchery survival was ,11.0 ± 5.7%. Growout survival was 1.9% lower for inbred families than for outbred families in G2 and 19.6% lower in G3. IBD for growout survival was ,3.8 ± 2.9%. There was also a significant linear relationship between IBD estimates for survival traits and mean outbred survival. At high outbred survival, IBD was low (e.g., growout survival in G2), but IBD appeared to become more severe when outbred survival was lower. This suggests that stress (related to environment and/or life stage) may worsen IBD for survival traits. Results also indicate that moderate to high levels of inbreeding (>10%) should be avoided in commercial shrimp hatcheries because the cumulative effect of IBD on hatch rate and hatchery survival will significantly reduce postlarvae production. Thus, IBD can be significant enough to justify the use of inbreeding as a germplasm protection strategy (under certain scenarios) for genetic improvement programs. [source] Investigation of the Effects of Salinity and Dietary Protein Level on Growth and Survival of Pacific White Shrimp, Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007Martin Perez-Velazquez It is presumed that in hypo- and hypersaline environments, shrimp's requirements for some specific nutrients, such as protein, may differ from those known in the marine habitat; however, few investigations have been conducted in this area of study. In the present investigation, the effects of salinity and dietary protein level on the biological performance, tissue protein, and water content of Pacific white shrimp, Litopenaeus vannamei, were evaluated. In a 3 × 4 factorial experiment, juvenile shrimp with an average initial weight of 0.36 ± 0.02 g were exposed for 32 d to salinities of 2, 35, and 50 ppt and fed experimental diets with crude protein contents of 25, 30, 35, and 40%. A significant effect of salinity on growth of shrimp was detected, with the growth responses (final weight, weight gain) ranked in the order 2 ppt (3.87, 3.50 g) > 35 ppt (3.40, 3.04 g) > 50 ppt (2.84, 2.47 g). No effects of dietary protein level or an interaction between salinity and protein on growth of shrimp were observed under the experimental conditions of this study. Percent survival of shrimp fed the highest protein content (40%, survival of 74%) was, however, significantly lower than those of shrimp fed the other feeds (25, 30 and 35% protein, survival of 99, 91, and 94%, respectively), a result likely associated with the concentration of total ammonia nitrogen, which increased significantly at increasing protein levels. Final water content of whole shrimp was significantly lower in animals exposed to 50 ppt (70.8%) than in shrimp held at 2 (73.7%) and 35 ppt (72.3%). No effect of salinity, protein, or their interaction was observed on the protein content of whole shrimp. The results of the present study are in agreement with reports of superior and inferior growth of L. vannamei reared in hypo- and hypersaline environments, respectively, as compared to what is generally observed in seawater. [source] The Influence of Artemia and Algal Supplements during the Nursery Phase of Rearing Pacific White Shrimp, Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007Oscar Zelaya A 21-d nursery trial was conducted to evaluate various food supplements on growth and survival of postlarval (PL) Litopenaeus vannamei. Each of four treatments was provided with an equal quantity of a dried commercial feed throughout the study. Three treatments received algae paste (Thalassiosira weissflogii) supplemented every 3 d. These include F, commercial feed plus algae; FAr3, commercial feed plus algae plus Artemia every other day during the first 7 d; and FAr7, commercial feed plus algae plus Artemia every day during the first 7 d. The fourth treatment served as control (FNA); it relied only on the commercial feed plus naturally occurring algae. At the conclusion of the nursery period, there were no significant differences in survival or feed conversion ration for PL nursed in the various treatments. Artemia did have some effect in that PL receiving Artemia supplement for 3 d (FAr3) were significantly larger than those that did not. Algal paste in itself had no significant effect. Overall, results suggest an advantage to supplementing dried feed with Artemia for at least 3 d during the first week of nursery culture but little advantage to the use of a diatom paste as a food supplement. [source] Effects of Gender and Size on Feed Acquisition in the Pacific White Shrimp Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2006Dustin R. Moss Pacific white shrimp, Litopenaeus vannamei, are sexually dimorphic for growth, where subadult and adult females typically are larger than males of the same age. This character may be attributed to physiological and/or behavioral differences between the sexes. To determine if growth differences are the result of a more aggressive feeding behavior by females, four concurrent feeding trials were conducted to study the effects of gender and size on feed acquisition time. Feeding trials consisted of tanks (three replicate tanks per trial) stocked with (1) all females with small- and large-size groups, (2) all males with small- and large-size groups, (3) a random selection of males and females (resulting in larger females than males), and (4) males and females of equal size. Depending on the trial, tanks were stocked with either an equal number of males and females or small and large shrimp. Shrimp were fed a limited ration of squid, and the total feeding time (TFT) of shrimp between groups within a tank was compared. Results show that both gender and size are important factors in TFT as large shrimp out-competed small shrimp in both all-female and all-male feeding trials. Gender is more important than size as males out-competed females for feed even when they were smaller than competing females. These results suggest that sexual growth dimorphism is not the result of more aggressive feeding by females. In fact, males have a competitive advantage over females in acquiring feed. These results are counterintuitive because females typically are larger than males. Additional research is needed to investigate the physiological basis for sexual growth dimorphism in this commercially important shrimp. [source] Production Characteristics of Litopenaeus vannamei in Low-salinity Water Augmented with Mixed SaltsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2006Anthony D. Sowers [source] A Methodology for Evaluation of Dietary Feeding Stimulants for the Pacific White Shrimp, Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2005Dagoberto R. Sanchez A simple and practical method for quantification of feeding stimulation of shrimp Litopenaeus vannamei was developed using feed preference as an index of comparison. Feed preference was defined as the percentage of shrimp observed in each feeding tray. Preliminary trials were undertaken with two commercial feeds (45% protein with 5% squid meal and 40% protein without squid meal). Results indicated the following criteria were suitable for use as methodology for evaluating feeding stimulation in 5-m diameter static flow tanks: shrimp density (2.5 shrimp/m2); observational period (1 or 2 h post-addition of feed to trays), feed rate (2%), and between-trial feed rate (2%). A further investigation was undertaken to evaluate the influence of protein level and source on feed preference using a basal diet consisting of wheat flour, casein, carboxymethyl cellulose binder, and limestone, with or without krill meal as a feeding stimulant. A significant difference was shown in feeding preference for the 16% protein/4% krill meal vs. one without krill meal; however, this relationship was not shown in 45% protein feed comparisons. A second trial comparing 0, 16,30, and 45 % protein/casein-based feeds showed similar results. From these findings, it was postulated that casein, itself, also serves as a feeding stimulant at high dietary inclusion levels. A third trial comparing 16% protein/casein or wheat gluten-based feeds Indicated a delay of at least 2 h in maximum feeding preference response in feeds in which 4% krill meal was added as a feeding stimulant. It was postulated that chemical stimulants from krill meal were more slowly released in wheat gluten-based feeds. Our methodology appears suitable for evaluation of potential feeding stimulants when incorporated into low-protein casein-based or wheat-gluten-based feeds. [source] Nitrite Toxicity to Litopenaeus vannamei in Water Containing Low Concentrations of Sea Salt or Mixed SaltsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2004Anthony Sowers The uptake, depuration and toxicity of environmental nitrite was characterized in Litopenaeus vannamei exposed in water containing low concentrations of artificial sea salt or mixed salts. In 2 g/L artificial sea salts, nitrite was concentrated in the hemolymph in a dose-dependent and rapid manner (steady-state in about 2 d). When exposed to nitrite in 2 g/L artificial sea salts for 4 d and then moved to a similar environment without added nitrite, complete depuration occurred within a day. Increasing salinity up to 10 g/L decreased uptake of environmental nitrite. Nitrite uptake in environments containing 2 g/L mixed salts (combination of sodium, potassium, calcium and magnesium chlorides) was similar to or lower than rates in 2 g/L artificial sea salt. Toxicity was inversely related to total dissolved salt and chloride concentrations and was highest in 2 g/L artificial sea salt (96-h medial lethal concentration = 8.4 mg/L nitrite-N). Animals that molted during the experiments did not appear to be more susceptible to nitrite than animals that did not molt. The shallow slope of the curve describing the relationship between toxicity and salinity suggests that management of nitrite toxicity in low-salinity shrimp ponds by addition of more salts may not be practical. [source] Effects of Artificial Substrate and Stocking Density on the Nursery Production of Pacific White Shrimp Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2004Komarey R. K. Moss Nursery production may be enhanced by the addition of artificial substrate to increase the surface area upon which shrimp graze and to serve as refuge. The objective of this study was to assess the effects of the artificial substrate, AquaMatsTM, on the performance of postlarval Pacific white shrimp Litopenaeus vannamei stocked at three densities. Eighteen 230-L tanks were stocked with 10-d postlarvae (mean weight < 0.01 g). Six treatments were evaluated and consisted of shrimp stocked at three densities (778 shrimp/m2, 1,167 shrimp/ m2, and 1,556 shrimp/m2) with and without access to artificial substrate. Shrimp in all treatments received a commercial diet ad libitum. After 6 wk, shrimp were harvested from each nursery tank, counted, and batch weighed. Mean final weight, survival, production, feed conversion ratio, and water quality parameters were analyzed by 2-way ANOVA. There were highly significant (P < 0.001) density and substrate effects on final weight, but there was no significant interaction effect. Final weight was 26.0, 17.4, and 34.5% greater in treatments with substrate than without substrate when stocked at 778, 1,167, and 1,556 shrimp/m2, respectively. There was no significant density, substrate, or interaction effect on survival or water quality. Mean survival was ± 89.1% for all treatments. Increased shrimp growth in the presence of added substrate was likely due to the availability of attached particulate organic matter on the AquaMatsTM that served as an additional food source. Results from this study indicate that artificial substrate can be used to mitigate the potential negative effects of high stocking density on growth of L. vannamei in nursery systems. [source] Acute and Chronic Effects of Nitrite on White Shrimp, Litopenaeus vannamei, Cultured in Low-Salinity Brackish WaterJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2004Amit Gross The marine white shrimp Litopenaeus vannamei is widely cultured. Recently, farmers have begun to culture this shrimp in low-salinity brackish water (< 6 g/L). The intensification of shrimp culture often results in occurrences of elevated nitrite concentration during the growing season. Nitrite is toxic to shrimp and exposure to high concentrations may cause retarded growth and mortalities. The current study was aimed at investigating the acute and chronic toxicity of nitrite to L. vannamei grown in low-salinity (2 g/L) brackish water. Studies of the 96-h EC50 and LC50 values of nitrite were performed to determine the acute toxicity, and an aquarium growth study (2 d post exposure to elevated nitrite concentrations) was conducted to evaluate the chronic effects of nitrite on shrimp production. The 96-h EC50 and LC50 values for juvenile L. vannamei grown in water of 2 g/L salinity was about 9 mg/L NO2 -N, suggesting a safe concentration for shrimp production in ponds to be less than 0.45 mgIL NO2 -N. Exposing shrimp to nitrite concentration of 4 mg/L for 2 d reduced their growth but did not affect their survival. [source] A Profound Effect of Hyperthermia on Survival of Litopenaeus vannamei Juveniles Infected with White Spot Syndrome VirusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2001Oscar M. Vidal This study was conducted to examine the effect of increasing seawater temperature on White Spot Syndrome Virus (WSSV) infection in juvenile Pacific White shrimp (Litopenaeus vannamei). Infection by WSSV was achieved using two methods, intramuscular injection and per os (oral) administration. Forty injected and 20 per os infected animals were kept in heated tanks at 32.3 ± 0.8 C, and the same number of WSSV infected animals were maintained in tanks at ambient temperature (25.8 ± 0.7 C). Despite the route of exposure, there were no survivors among the animals kept at ambient temperature; whereas, in heated tanks the survival of the WSSV infected juvenile shrimp was always above 80%, suggesting the existence of a beneficial effect from hyperthermia that mitigated the progression of WSSV disease. Moreover, this beneficial effect was not attributable to viral inactivation. Infected animals kept at 32 C had histologically detectable lymphoid organ spheroids suggestive of a chronic viral infection but were PCR negative (hemolymph) for WSSV. These findings might be related to low viral replication in WSSV-infected shrimp held at the higher environmental temperature. When the WSSV-infected shrimp were transferred from 32 C to ambient temperature, the mortality from WSSV ensued and was always 100%. Although the mechanism related to the beneficial effect of heating was not determined, our results indicate that increasing the water temperature modifies dramatically the natural history of the WSSV disease and the survival curves of WSSV-infected juvenile Pacific White shrimp. [source] Effect of Low Salinity on Growth and Survival of Postlarvae and Juvenile Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2001Susan Laramore The effect of low salinity on survival and growth of the Pacific white shrimp Litopenaeus vannamei was examined in the laboratory due to the interest of raising shrimp inland at low salinities. In three separate experiments, individual L. vannamei postlarvae (, 0.1 g) were cultured at salinities of either 0.5, 1, 1.5, 2, or 3 ppt (N= 5 or 10/treatment) for 18 to 40 d at 30 C in individual 360-mL containers. In each experiment controls of 0 and 30 ppt were run. There was no postlarval survival at salinities < 2 ppt. Survival was significantly different (P < 0.01) at 2 ppt (20%) compared to 30 ppt (80%). Growth was also significantly different (P < 0.01) at 2 and 3 ppt compared to 30 ppt (416%, 475%, and 670%, respectively). A fourth experiment compared juveniles (, 8 g) and postlarvae (, 0.05 and 0.35 g). Shrimp were cultured at salinities of 0, 2, 4, and 30 ppt for 40 d at 25 C, in individual 360-mL and 6-L containers (N= 7/treatment). There was no postlarval survival at < 2 ppt. Postlarval survival at 4 ppt (86%) was not significantly different (P > 0.05) from 30 ppt (100%). Juveniles exhibited better survival at lower salinities (100% at 2 ppt) than 0.05 and 0.35 g postlarvae (29% and 14% respectively, at 2 ppt). The effects of salinity on growth varied with sizdage. Final growth of 0.05 g postlarvae at 2 ppt (693%) was significantly less (P < 0.01) than at 4 ppt (1085%) and 30 ppt (1064%). Growth of 0.35 g postlarvae was significantly less (P < 0.01) for 4 ppt (175%) than for 30 ppt (264%). There was no growth data for juveniles (8 g). It appears from these experiments that the culture of L. vannamei poses risks when performed in salinities less than 2 ppt. [source] Effects of Diet and Water Source on the Nursery Production of Pacific White Shrimp Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2001Clete A. Otoshi Penaeid shrimp reared in eutrophic pond water grow significantly faster than shrimp in clear well water, and this growth enhancement is especially pronounced in postlarval shrimp. The objective of this study was to determine if the nutritional benefits of pond water could supplement a lower protein feed for postlarval Pacific white shrimp Litopenaeus vannamei. Sixteen 230-L tanks were stocked with 10-d postlarvae at a density of 350 shrimp/tank. Four treatments (four replicates/treatment) were tested for 6 wk and consisted of: 1) shrimp grown in well water and fed a commercially available 45%-protein feed (W/45); 2) shrimp grown in pond water and fed the same 45%-protein feed (P/45); 3) shrimp grown in well water and fed a commercially available 52%-protein feed (W/ 52); and 4) shrimp grown in pond water and fed the same 52%-protein feed (P/52). At the end of the experiment. mean weight gain (± SE) for shrimp in pond water (1.85 ± 0.03 g) was significantly greater (P > 0.0001) than shrimp in well water (0.98 ± 0.10 g). Mean weight gain for shrimp fed the 52%-protein feed (1.56 ± 0.13 g) was significantly greater (P > 0.0001) than shrimp fed the 45%-protein feed (1.26 ± 0.20 g). In addition, there was a significant interaction effect between water source and feed (P > 0.0001). Mean weight gain for shrimp in the W/52 treatment (1.23 ± 0.04 g) was 68% greater than shrimp in the W/45 treatment (0.73 ± 0.03 g). However, mean weight gain for shrimp in the P/52 treatment (1.90 ± 0.03 g) was only 5% greater than shrimp in the P/45 treatment (1.80 ± 0.04 g). These results suggest that organically rich pond water provides postlarval shrimp with sufficient nutrients to compensate for nutritional deficiencies associated with a lower protein feed. [source] Relative Abundance and Species Composition of Gram-Negative, Aerobic Bacteria Associated with the Gut of Juvenile White Shrimp Litopenaeus vannamei Reared in Oligotrophic Well Water and Eutrophic Pond WaterJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2000Shaun M. Moss Gut bacteria may contribute significantly to the growth and survival of cultured shrimp, although little is known about factors that affect bacterial community structure in shrimp guts. The objective of this study was to determine the abundance and species composition of gut bacteria in juvenile white shrimp Litopenaeus vannamei reared in two different environments. Eight 120-L tanks were stocked at a density of 8 shrimphank. Two treatments were tested for 10 d and consisted of tanks receiving flow-through water from one of two sources: 1) well water pumped from a sea-water aquifer (Well treatment), and 2) pond water pumped from an intensive shrimp pond (Pond treatment). Shrimp mid- and hindguts were excised on days 1, 3, 6, and 10 for enumeration of gram-negative, aerobic bacteria by quantifying colony-forming units (CFU) using standard microbiological plating techniques. Identification of bacterial isolates was made using the Biologa® GN Microplate system. Bacterial numbers were significantly greater (P > 0.05) in Well shrimp than in Pond shrimp on days 1 and 3. Following day 3, a decrease in bacterial numbers occurred in the Well shrimp, and no significant differences between treatments were observed on days 6 or 10. Guts from Well shrimp were dominated by Vibrio and Aero-monas, and these two genera accounted for 80,851 of the bacteria on each sampling day. Guts from Pond shrimp exhibited a greater bacterial diversity and were dominated by Vibrio, Aeromonas, and Pseudomonas. Flavobacterium were identified in the guts of Pond shrimp on days 3 and 10, but were not identified in any of the Well shrimp. A greater understanding of gut bacteria-shrimp interactions could lead to increased production and profitability for shrimp farmers through the development of more cost-effective feeds and novel disease control strategies. [source] Correlation Between Two Size Classes of Pacific White Shrimp Litopenaeus vannamei and Its Potential Implications for Selective Breeding ProgramsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2000Brad J. Argue Breeders may assume that the largest brood-stock shrimp were also the largest market shrimp. In this study, 120 market shrimp were individually tagged and grown to broodstock in an earthen pond. There was a significant relationship between market and broodstock weight (P < 0.001) but it was not highly correlated (r = 0.42). There was no correlation between market weight and post-market weight gain (P= 0.477; r= 0.08). Of the largest 20 broodstock, only seven were among the top 20 at market weight. If the goal of a breeding program is to select the fastest growing individuals to market, shrimp should be individually selected at market weight and not as broodstock. [source] Isolation and characterization of microsatellites in Pacific white shrimp Penaeus (Litopenaeus) vannameiMOLECULAR ECOLOGY RESOURCES, Issue 3 2002P. Cruz Abstract Five polymorphic microsatellite loci were characterized for Penaeus (Litopenaeus) vannamei. Loci were isolated using a partial Sau3A1 genomic library by the sequencing of randomly selected clones and by a biotinylated (CT)10 and (GT)10 probes screening procedure. The last strategy resulted in the most useful data. About 40% of the clones showed a previously reported satellite/microsatellite (PVS1), reducing the chance of finding new microsatellite regions. Whereas two of the microsatellite loci with more than 10 alleles will be useful for mating analysis in a breeding program, the others might prove useful for population genetic studies. [source] Proteomic analysis of differentially expressed proteins in Penaeus vannamei hemocytes upon Taura syndrome virus infectionPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2007Phattara-orn Chongsatja Abstract To understand molecular responses of crustacean hemocytes to virus infection, we applied 2-DE proteomics approach to investigate altered proteins in hemocytes of Penaeus vannamei during Taura syndrome virus (TSV) infection. At 24,h postinfection, quantitative intensity analysis and nano-LC-ESI-MS/MS revealed 11 forms of 8 proteins that were significantly up-regulated, whereas 9 forms of 5 proteins were significantly down-regulated in the infected shrimps. These altered proteins play important roles in host defense (hemocyanin, catalase, carboxylesterase, transglutaminase, and glutathione transferase), signal transduction (14-3-3 zeta), carbohydrate metabolism (acetylglucosamine pyrophosphorylase), cellular structure and integrity (beta-tubulin, beta-actin, tropomyosin, and myosin), and ER-stress response (protein disulfide isomerase). Semiquantitative RT-PCR and Western blot analysis confirmed the upregulation of 14-3-3 at both mRNA and protein levels. Interestingly, several altered protein spots were identified as fragments of hemocyanin. Mass spectrometric analysis showed that the hemocyanin spots at acidic and basic regions represented the C- and N-terminal hemocyanin fragments, respectively. As three-quarters of C-terminal fragments were up-regulated, whereas two-thirds of N-terminal hemocyanin fragments were down-regulated, we therefore hypothesize that C- and N-terminal hemocyanin fragments may have differential roles in hemocytes. Further investigation of these data may lead to better understanding of the molecular responses of crustacean hemocytes to TSV infection. [source] A gene-based SNP linkage map for pacific white shrimp, Litopenaeus vannameiANIMAL GENETICS, Issue 3 2010Z.-Q. Du Summary Pacific white shrimp (Litopenaeus vannamei) are of particular economic importance to the global shrimp aquaculture industry. However, limited genomics information is available for the penaeid species. We utilized the limited public information available, mainly single nucleotide polymorphisms (SNPs) and expressed sequence tags, to discover markers for the construction of the first SNP genetic map for Pacific white shrimp. In total, 1344 putative SNPs were discovered, and out of 825 SNPs genotyped, 418 SNP markers from 347 contigs were mapped onto 45 sex-averaged linkage groups, with approximate coverage of 2071 and 2130 cm for the female and male maps, respectively. The average-squared correlation coefficient (r2), a measure of linkage disequilibrium, for markers located more than 50 cm apart on the same linkage group, was 0.15. Levels of r2 increased with decreasing inter-marker distance from ,80 cm, and increased more rapidly from ,30 cm. A QTL for shrimp gender was mapped on linkage group 13. Comparative mapping to model organisms, Daphnia pulex and Drosophila melanogaster, revealed extensive rearrangement of genome architecture for L. vannamei, and that L. vannamei was more related to Daphnia pulex. This SNP genetic map lays the foundation for future shrimp genomics studies, especially the identification of genetic markers or regions for economically important traits. [source] A major SNP resource for dissection of phenotypic and genetic variation in Pacific white shrimp (Litopenaeus vannamei)ANIMAL GENETICS, Issue 1 2010D. C. Ciobanu Summary Bioinformatics and re-sequencing approaches were used for the discovery of sequence polymorphisms in Litopenaeus vannamei. A total of 1221 putative single nucleotide polymorphisms (SNPs) were identified in a pool of individuals from various commercial populations. A set of 211 SNPs were selected for further molecular validation and 88% showed variation in 637 samples representing three commercial breeding lines. An association analysis was performed between these markers and several traits of economic importance for shrimp producers including resistance to three major viral diseases. A small number of SNPs showed associations with test weekly gain, grow-out survival and resistance to Taura Syndrome Virus. Very low levels of linkage disequilibrium were revealed between most SNP pairs, with only 11% of SNPs showing an r2 -value above 0.10 with at least one other SNP. Comparison of allele frequencies showed small changes over three generations of the breeding programme in one of the commercial breeding populations. This unique SNP resource has the potential to catalyse future studies of genetic dissection of complex traits, tracing relationships in breeding programmes, and monitoring genetic diversity in commercial and wild populations of L. vannamei. [source] SNP discovery in Litopenaeus vannamei with a new computational pipelineANIMAL GENETICS, Issue 1 2009D. M. Gorbach Summary Litopenaeus vannamei (Pacific white shrimp) have been farmed in the Americas for many years and are growing in popularity in Asia with the development of specific pathogen-free stocks. The full genomic sequence of this species might not be available in the near future, so other tools are needed to discover the location of polymorphic sites for quantitative trait loci mapping, association studies and subsequent marker-assisted selection. Currently, 25 937 L. vannamei expressed sequence tags (ESTs) are publicly available. These sequences were manually screened, masked for tandem repeats and inputted into CAP3 for clustering. The resulting 3532 contigs were analysed for possible single nucleotide polymorphisms (SNPs) with snpidentifier, a newly developed computer program for predicting SNPs. snpidentifier is designed for ESTs without accompanying chromatogram sequence quality information, and therefore it performs quality control checks on all data. snpidentifier sets a threshold such that the sequences used have a poor quality nucleotide (N) frequency <0.1, and it trims off the first 10 bases of every sequence to ensure higher sequence quality. For a base to be predicted as an SNP, the minor nucleotide (allele) frequency must be >0.1, it must be observed at least four times and the 15 bases on either side must exactly match the consensus sequence. Using these conservative parameters, 504 SNPs were predicted from 141 contigs for L. vannamei. A small sample of 18 individuals from three lines have been sequenced to verify prediction results and 17 of 39 (44%) of the tested SNPs have been confirmed. [source] Effects of dietary protein and lipid levels on growth and energy productive value of pacific white shrimp, Litopenaeus vannamei, at different salinitiesAQUACULTURE NUTRITION, Issue 4 2010X.Z. ZHU Abstract A 8-week feeding experiment was conducted to evaluate the effect of different dietary protein and lipid levels on growth and energy productive value of juvenile Litopenaeus vannamei, at 30 and 2 ppt, respectively. Nine practical diets were formulated to contain three protein levels (380, 410 and 440 g kg,1) and three lipid levels (60, 80 and 100 g kg,1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The effects of salinity and an interaction between dietary protein level and lipid level on growth and energy productive value of shrimp were observed under the experimental conditions of this study. At 30 ppt seawater, shrimp fed with 440 g kg,1protein diets had significantly higher weight gain (WG) than those fed with 380 g kg,1 protein diets at the same dietary lipid level, and the 60 g kg,1 lipid group showed higher growth than 80 g kg,1and 100 g kg,1 lipid groups at the same dietary protein level. At 2 ppt seawater, the growth of shrimp was little affected by dietary protein treatments when shrimp fed the 80 and 100 g kg,1 lipid, shrimp fed the 80 g kg,1 lipid diets had only slightly higher growth than that fed 60and 100 g kg,1 lipid diets when fed 380 and 410 g kg,1 dietary protein diets. A significant effect of salinity on growth of shrimp was detected with the growth responses at 30 ppt > 2ppt (P < 0.05). Final body lipid content, body protein content and energy productive value of shrimp was significantly higher in animals exposed to 30 ppt than in shrimp held at 2 ppt. [source] Comparison of Ulva clathrata and the kelps Macrocystis pyrifera and Ascophyllum nodosum as ingredients in shrimp feedsAQUACULTURE NUTRITION, Issue 4 2009L.E. CRUZ-SUÁREZ Abstract Three experimental diets were formulated to contain 33 g kg,1 seaweed meals, made of wild brown algae (kelps) Macrocystis pyrifera (MAC) and Ascophyllum nodosum (ASC) or of a cultivated green alga Ulva clathrata (ULVA). The diets were fed to juvenile white shrimp Litopenaeus vannamei (1.6 g) for 28 days. Loss of dry matter (LDM) and loss of protein (LP) after 1 hour immersion in seawater, and distilled water absorption (WA) were analyzed in the pelleted diets, as well as shrimp weight gain, feed intake, feed conversion ratio (FCR), survival, protein efficiency ratio (PER) and body pigmentation. Feed intake, FCR and PER were corrected for nutrients preprandial losses in seawater. ULVA diet resulted in lower LDM, but a higher LP and also higher WA, indicating a modification of the pellet physical quality (better hydro stability). No significant differences in feed consumption and survival were found, but ULVA diet resulted in a slightly higher final weight (4.8 for ULVA versus 4.6 and 4.3 g for ASC and MAC), and better FCR (1.7 versus 1.9 and 2.1) and PER (2.0 versus 1.7 and 1.5), the differences with MAC diet being significant (Duncan, , = 0.05). Red color after cooking was markedly darker in the ULVA fed shrimp. [source] | ||||||||||||||||