Levels In Shrimp Research Articles

Evaluating the Antagonistic Activity of Lactic Acid Bacteria in Cadaverine Production by Vibrio Strains during Co-Culture

Vibrio cholerae and Vibrio parahaemolyticus are common pathogens linked to human gastroenteritis, particularly in seafood like shrimp. This study investigated the impact of lactic acid bacteria on V. cholerae and V. parahaemolyticus regarding the production of cadaverine, a concerning compound. V. cholerae NCCP 13589 and V. parahaemolyticus ATCC 27969 were significant producers of amines in experiments conducted using white-leg shrimp (Litopenaeus vannamei) and lysine decarboxylase broth. Notably, the Lactiplantibacillus plantarum NCIMB 6105 and Leuconostoc mesenteroides ATCC 10830 lactic acid bacteria strains demonstrated a pronounced antagonistic effect on the production of biogenic amines by these food-borne pathogenic bacteria. The presence of lactic acid bacteria led to a substantial reduction in cadaverine production in the lysine decarboxylase broth and shrimp extract. The co-culture of two lactobacilli species reduced the cadaverine production in V. cholerae and V. parahaemolyticus by approximately 77 and 80%, respectively. Consequently, the favorable influence of lactic acid bacteria in curbing cadaverine production by food-borne pathogens presents clear advantages for the food industry. Thus, effectively managing these pathogens could prove pivotal in controlling the biogenic amine levels in shrimp.

Effect of microplastics on oxytetracycline trophic transfer: Immune, gut microbiota and antibiotic resistance gene responses

Microplastics and antibiotics are prevalent and emerging pollutants in aquatic ecosystems, but their interactions in aquatic food chains remain largely unexplored. This study investigated the impact of polypropylene microplastics (PP-MPs) on oxytetracycline (OTC) trophic transfer from the shrimp (Neocaridina denticulate) to crucian carp (Carassius auratus) by metagenomic sequencing. The carrier effects of PP-MPs promoted OTC bioaccumulation and trophic transfer, which exacerbated enterocyte vacuolation and hepatocyte eosinophilic necrosis. PP-MPs enhanced the inhibitory effect of OTC on intestinal lysozyme activities and complement C3 levels in shrimp and fish, and hepatic immunoglobulin M levels in fish (p < 0.05). Co-exposure of MPs and OTC markedly increased the abundance of Actinobacteria in shrimp and Firmicutes in fish, which caused disturbances in carbohydrate, amino acid, and energy metabolism. Moreover, OTC exacerbated the enrichment of antibiotic resistance genes (ARGs) in aquatic animals, and PP-MPs significantly increased the diversity and abundance of ARGs and facilitated the trophic transfer of teta and tetm. Our findings disclosed the impacts of PP-MPs on the mechanism of antibiotic toxicity in aquatic food chains and emphasized the importance of gut microbiota for ARGs trophic transfer, which contributed to a deeper understanding of potential risks posed by complex pollutants on aquatic ecosystems.

The effect of papain hydrolysis on tropomyosin levels in shrimp

Shrimp allergy is a serious public health problem. Epidemiological studies indicated the main cause of food allergy is the ingestion of shrimp and crab. Consequently, reducing the risk of shrimp and crab allergy is a major research focus. Few studies have demonstrated the effect of enzyme hydrolysis on reduction of shrimp allergens in food. In this study, we used papain, a commonly used enzyme in the food industry, as an ingredient to decrease levels of allergen tropomyosin in shrimp. 0–50U of papain was used to treat the shrimp meat, and then heated to measure the levels of tropomyosin, and determined the change of the protein secondary structure. The results showed that 20U of papain decrease the tropomyosin levels up to 80 %, which was further enhanced when combined with 3 min of heating. Furthermore, the result of Fourier-transform infrared spectroscopy (FTIR) showed alteration of secondary protein structure after the processing. The processing developed in this study may be an effective method used to change the levels and structure of tropomyosin.

Mercury in raw and cooked shrimp and mussels and dietary Brazilian exposure

Seafood is the main source of dietary mercury (Hg) exposure and it can be affected by species, origin, tissue, and processing. The objective of this study was to investigate total Hg in shrimp and mussels from the retail market, compare species, body tissue distribution and cooking time, and to estimate dietary exposure. A total of 126 samples (whiteleg and Atlantic seabob shrimp and South American mussel) were analyzed. Total mercury was quantified by combustion atomic absorption spectrometry with gold amalgamation. Every sample had total Hg lower than maximum legislation levels. Higher mean levels were found in mussels compared to shrimp; and whiteleg shrimp had higher mean Hg levels compared to Atlantic seabob (p < 0.05). Mercury levels in the muscle were higher than in the exoskeleton. Boiling for up to 4 and 6 min did not affect Hg levels in shrimp and mussels, respectively. The estimated methylmercury (MeHg) mean intake from the consumption of shrimp and mussels (0.04–0.09 μg/kg bw for 3 portions/week consumption) was low, less than 6% of the provisional tolerable weekly intake – PTWI.

White spot syndrome virus (WSSV) disturbs the intestinal microbiota of shrimp (Penaeus vannamei) reared in biofloc and clear seawater.

White spot syndrome virus (WSSV) is one of the most virulent pathogens afflicting shrimp farming. Understanding its influence on shrimp intestinal microbiota is paramount for the advancement of aquaculture, since gut dysbiosis can negatively impact shrimp development, physiology, and immunological response. Thereupon, the data presented herein assesses the influence of WSSV infection and different rearing systems on the intestinal microbiota of Penaeus vannamei. Our study aimed to describe and correlate the composition of shrimp (Penaeus vannamei) gut microbiota, when reared in biofloc and clear seawater, before and (48 h) after WSSV experimental infection. Shrimp were kept in two different systems (biofloc and clear seawater) and experimentally infected with WSSV. Intestine and water samples were characterized by 16S rRNA gene sequencing, before and after viral infection. We observed (i) WSSV induced higher mortality among shrimp reared in biofloc; (ii) WSSV led to a loss of intestinal microbiota heterogeneity, at the genus level, in shrimp kept in clear seawater; (iii) there was a prevalence of Cetobacterium and Bacillus in the intestine of shrimp from both systems; (iv) WSSV did not cause significant changes in intestinal microbiota diversity or richness; (v) regardless of the type of system and time of infection, intestinal microbiota was dissimilar to that of the surrounding water, despite being influenced by the type of system. Therefore, WSSV infection leads to punctual dysbiotic changes in shrimp microbiota, although the virus is sufficiently virulent to cause high mortalities even in well-managed systems, such as a balanced experimental biofloc system. KEY POINTS: • WSSV infection leads to a perturbed gut microbiota in shrimp. • WSSV infection greater impacts microbiota of shrimp reared in CSW than those in BFT. • WSSV infection caused higher mortality levels in shrimp reared in BFT than in CSW. • Rearing system influences shrimp gut microbiota composition. Graphical abstract.

Effects of Dietary Probiotic Bacillus sp. D2.2 and Prebiotic Sweet Potato Extract on Growth Performance and Resistance to Vibrio harveyi in Pacific white shrimp, Litopenaeus vannamei

In this study, the effects of oral administration of probiotic Bacillus sp. D2.2 and prebiotic from sweet potato extract on growth performance and resistance against Vibrio harveyi in Pacific white shrimp ( Litopenaeus vannamei) were investigated. During 32-day feeding experiment, 360 individuals of Pacific white shrimp (PL15) with initial weight of 0.02 ± 0.002 g were fed with basal diet as control (A); supplemented with 6% probiotic and 0% prebiotic (B); 6% probiotic and 2% prebiotic (C); 6% probiotic and 4% prebiotic (D). At the end of feeding trial, weight gain (WG), average daily growth (ADG), feed conversion ratio (FCR), and survival rate (SR) were assessed. WG, ADG and FCR of the shrimp were significantly better in treatment D than those of the shrimp in other treatments. Control and treatment D as the best feeding trial were selected for challenge test with infectious V. harveyi . Survival rate and mean time to death (MTD) of the shrimp fed the supplemented diet were not significantly different (P>0.05) to the control. Infection levels in shrimp were evaluated using morphological scoring methods. Infection levels of V. harveyi in shrimp fed the diet were lower compared to the control.

Seafood consumption habits of South Carolina shrimp baiters

ABSTRACTShrimp baiting is a fishing technique used by many South Carolinians and has been regulated in the state since the late 1980s. A postcard survey was developed and included with 400 South Carolina Department of Natural Resources (SCDNR) annual surveys of registered shrimp baiters over a two-year period. The survey contained questions concerning frequency, portion size, baiting locations, and preparation techniques for shrimp as well as other species consumed and demographic information. An overall response rate of 37% was received. The majority of respondents were men over the age of 55 years. Charleston and Beaufort counties were the most common locations for shrimp baiting. Almost half (45.9%) of respondents reported eating locally caught shrimp at least 2–3 times per month. The most common portion size was ½ pound (8 oz. or 277 g), with 44.8% of respondents reporting this as their typical amount of shrimp ingested at one meal. Only 3.7% of respondents reported typically eating the whole shrimp, while all other respondents ingested shrimp with the head removed. The most commonly consumed species besides shrimp were blue crab, oysters, and flounder. According to the US Food and Drug Administration mercury (Hg) guidelines, the majority (97%) of our respondents were not at risk for consuming unsafe levels of Hg from locally caught shrimp. However, this does not take into account other local seafood eaten or other contaminants of concern. These consumption results may be used in conjunction with data on contaminant levels in shrimp to determine potential adverse health risks associated with consumption of locally caught shrimp.

Contribution to the Revision of the Senegalese Law on the Use of Sulfites for the Treatment of Crustaceans: the Case of Shrimp

&lt;p class="jbls"&gt;&lt;span lang="FR"&gt;Shrimp, by its considerable economic importance, is the second shellfish species exported in Senegal. Blackening of untreated sulfites shrimp causes discharges estimated at 10% of the total landed shrimp according to the shrimp processing plant companies. Health problems caused by handling and / or consumption of sulphites (asthmatic subjects) occured. The 2006-52 Directive of 5 July 2006 at Community level and Senegalese Decree No. 00493 of 11 February 2005 governed their use by rules. The Differences in the rules governing SO2 residues could cause Technical trade Barriers in international exchanges. In Senegal, the Competent Authority (CA), a part of its mission of monitoring and inspection of fish products, especially shrimp, cooperate with two chemistry laboratories for detecting residues of SO2. However, the differences noted on the results provided by these two laboratories (Lab1 and 2) make difficult interpretations. This study aims to remove existing ambiguities on the analyzes and interpretation of results regarding to national and community regulations. During the study, more investigations and analyzes of archival data, samples of untreated and treated shrimp sodium metabisulfite were analyzed respectively in the laboratory of the Division of Inspection and Control (DIC) to assess blackening and laboratories 1, 2 and 3 for the detection of residual sulphite in shrimp. Firstly, the results show that the shrimp processing and regulations governing the residual SO2 levels in their flesh can not be effective without taking account of their caliber, and secondly, that the divergence of results provided by the Labo-1 and 2 is more methodological. Thus, the study calls for regulatory oversight in order to harmonize national and international regulations governing the residual SO2 levels in shrimp. It also recommends the creation of a common reference for the determination of residues of SO2 in the flesh of shrimp.&lt;/span&gt;&lt;/p&gt;

Determination of Toxic Metal Accumulation in Shrimps by Atomic Absorption Spectrometry (AAS)

The study was carried out to assess the levels of lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), and mercury (Hg) in different shrimp species. Atomic absorption spectrometry was used to estimate and evaluate the levels of these metals from 11 shrimp samples. The results of this study showed that the average concentrations detected were ranged from <0.1 to 0.202, <0.1 to 0.416, <0.1 to 0.156, <0.1 to 0.21 and <0.1 to 0.28 mg/kg for Pb, Cd, As, Cr and Hg, respectively in river shrimps. In case of Gher, it was ranged from <0.1 to 0.267, <0.1 to 0.166, <0.1 to 0.156, <0.1 to 0.21 and <0.1 to 0.228 mg/kg for Pb, Cd, As, Cr and Hg, respectively. The results show that Pb concentration for both river and Gher samples lies between EU and IAEA limits, Cd concentration in river samples are higher than both EU and IAEA limits. Arsenic is observed only in one river sample that was also below the recommended level. Hg concentration for both Gher and river samples are less than the EU permissible limit. Our study highlights those toxic metals are found to be below the recommended tolerable levels in shrimp of Bangladesh and may not constitute a health hazards for consumers.

Effect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp, a Beninese food condiment

Smoked shrimp is a food condiment widely used in Beninese local cooking practices. A previous study revealed that this product is highly contaminated with polycyclic aromatic hydrocarbons (PAH). The present study explored possibilities to reduce PAH levels in shrimp smoked using cottage industry smoking techniques with barrel and chorkor kilns, by replacing wood by charcoal from Acacia auriculiformis and Mangifera indica, as fuels. Results showed that only shrimp smoked using acacia charcoal in a chorkor kiln had PAH levels (benzo[a]pyrene = 5 µg kg−1 and sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene = 28 µg kg−1) in accordance with a European standard of 5 and 30 µg kg−1, respectively, and suitable physicochemical characteristics for good storage (moisture content = 11.9% ± 1.5%; water activity = 0.46 ± 0.03). However, further investigations still needs to be done to reduce the duration of product contact with combustion gasses in order to reduce the PAH content of smoked shrimp to safer levels, largely below standards.

Uptake and depuration of PCB-153 in edible shrimp Palaemonetes varians and human health risk assessment

A medium-term mesocosm exposure study was conducted to elucidate bioaccumulation and depuration of polychlorinated biphenyl congener 153 (PCB-153) in edible shrimp Palaemonetes varians. Over the 15-day exposure period, shrimp under different exposure concentrations exhibited a significant increase in PCB-153 concentration compared with control organisms. Distinct bioaccumulation patterns and uptake rates were observed depending on the exposure concentrations. For low PCB-153 exposure levels (0.25μgL−1), accumulation followed a saturation model, reaching an apparent steady state after fifteen days exposure. For intermediate (2.5μgL−1) and high PCB-153 levels (25μgL−1), accumulation was faster and linear. In addition, the bioaccumulation rate was not proportional to PCB-153 concentration, and the bioaccumulation was higher at intermediate exposure concentrations. Regarding the depuration phase, P. varians lost up to 30% of PCB-153 after 72h and levels continued slowly to decrease until the end of the 30-d experimental period. However, PCB-153 levels in shrimp did not reach background values, and those exposed to moderate and high PCB-153 concentrations presented contamination levels much higher than the regulatory limit for human food consumption (75ngg−1 ww for Σ6 PCB).

Dietary effect of squid and fish meals on growth and survival of Pacific white shrimpLitopenaeus vannameiin the presence or absence of phytoplankton in an indoor tank system

This study was conducted in 36 indoor 40-L fibreglass aquaria to determine the weight gain and survival of Litopenaeus vannamei fed different dietary levels of fish (FM) and squid meal (SM) and to evaluate the potential of phytoplankton to reduce FM and SM levels in shrimp feeds. Six experimental isonitrogenous (35% protein) and isocaloric (17.5 kJ g−1) diets were formulated to contain either 5%, 10% or 20% SM combined with either 6.5% or 12% FM. Dietary effects on growth and survival were compared in two systems: a ‘CLEAR water system’ (CWS) without the presence of microalgae and a ‘GREEN water system’ (GWS) with microalgae in the culture water. Shrimp cultured in the GWS had 28–57% greater weight gain than those cultured in the CWS, regardless of dietary treatment. However, survival was not different. Shrimp cultured in the CWS or the GWS, and fed diets containing combinations of FM and SM did not show differences in weight gain and feed conversion ratio. These results suggest that under the conditions existing during this research, 6.5% FM and 5% SM can be used as a cost-effective combination in commercial feeds for shrimp production and that growth can be enhanced in the presence of primary productivity.

Sparing effect of pond water on vitamins in shrimp diets

A 10-wk experiment was conducted to determine whether shrimp pond water has a sparing effect on vitamins, trace minerals, and protein levels in diets fed to juvenile Pacific white shrimp, Litopenaeus vannamei. Twenty-four 52-L aquaria were stocked with 0.7-g shrimp at a density of 24 shrimp/aquaria (100 shrimp/m 2 equivalent). Shrimp were exposed to flow-through seawater from one of two sources: clear well water from a seawater aquifer or organically rich water from a pond used for intensive shrimp culture. In addition, four diets were evaluated in each of the two water sources (three replicates/treatment), including: 1) a 35%-protein diet with vitamin and trace mineral premixes, 2) the same 35%-protein diet minus the vitamin premix, 3) the 35%-protein diet minus the trace mineral premix, and 4) a 25%-protein diet with vitamin and trace mineral premixes. Shrimp grown in well water without vitamins in their diet had a significantly lower ( P < 0.05) final weight, growth rate, and survival, and a significantly higher FCR, than shrimp grown in well water with vitamins. However, there was no significant difference in final weight, growth rate, survival, or FCR between pond-water reared shrimp with and without vitamins, indicating that removal of vitamins from the diet of pond water-reared shrimp had no effect on shrimp performance. In contrast to vitamins, there was no sparing effect of pond water on trace minerals or protein levels. As expected, growth rates of shrimp reared in pond water were greater than those in well water for each of the four diets. The largest difference in growth rate was seen with the 35%-protein diet minus vitamins. Shrimp fed this diet grew 306% faster in pond water than in well water. It appears that the growth enhancing effect of pond water is more pronounced when shrimp are fed diets of inferior quality. Results from this study indicate that pond water has a sparing effect on vitamins in shrimp diets, and microbes likely contributed significantly to this effect. By exploiting endogenously produced microbes and associated detritus, shrimp farmers and feed manufacturers can reduce substantially vitamin levels in shrimp feeds, resulting in reduced feed costs without compromising shrimp growth, survival, or FCR.

Effect of Dietary Phosphorus on Growth and Its Excretion in Tiger Shrimp, Penaeus monodon

Six semi-purified diets were formulated with supplemented phosphorus levels of 0, 0.5, 1.0, 1.5, 2.0 and 2.5% at a fixed calcium level of 1.25% and the effect of dietary phosphorus on growth, FCR, body phosphorus and its excretion in shrimp Penaeus monodon was studied. The results of a 45 day feeding trial, in triplicate, on the juveniles of P. monodon (initial average live –weight 2.54 ±0.28g) had shown that phosphorus is indispensable in the diet and the best performance (147.3 and 154.5% increase in live-weight and 1.44 and 1.57 FCR) was recorded by the diet supplemented with 1.0 and 1.5% phosphorus which was significantly (P&lt;0.05) higher than the performance of the other diets tested. Higher phosphorus supplementation suppressed growth and increased FCR. The shrimp maintained body phosphorus and calcium levels in a ratio of 1:3 irrespective of dietary levels of phosphorus. There was no significant change in the proximate composition of post feeding trial shrimp. Phosphorus excretion in faeces of P. monodon increased proportionately with dietary phosphorus while the excretion level far exceeded the body phosphorus level in the shrimp fed with diets having supplemented phosphorus level above 1.5%. Even the shrimp fed with 0% phosphorus diet had 0.10% phosphorus in their faeces. The phosphorus levels in shrimp feeds vis-a-vis its excretion into aquaculture environment have been discussed.

Exposure patterns of perfluorooctane sulfonate in aquatic invertebrates from the Western Scheldt estuary and the southern North Sea.

Over the past decades little research has been conducted on the environmental behavior and effects of fluorinated organochemicals (FOCs). Recently it has been reported that perfluorooctane sulfonic acid (PFOS) is occurring worldwide. Little is known about the PFOS levels in organisms originating from the southern North Sea and the Western Scheldt estuary. In this study, we determined, for the first time, the PFOS-exposure levels in Crangon crangon, Carcinus maenas, and Asterias rubens from these ecosystems. Concentrations on a wet-weight basis in soft tissues of shrimp, crab, and starfish ranged from 19 to 520 ng/g, from 24 to 877 ng/g, and from 9 to 176 ng/g, respectively. These results show the existence of a PFOS pollution gradient in organisms along the Western Scheldt estuary, with the highest concentrations near Antwerp. The range of PFOS levels in shrimp and crab are slightly higher in coastal regions compared with sampling sites in open water. This study shows widespread distribution of PFOS in the Belgian and Dutch marine and estuarine environment at rather high concentrations.

Concentrations of Cd, Zn and Cu in sediments and brown shrimp (Crangon crangon L.) from the Severn Estuary and Bristol Channel, UK

Cd, Zn and Cu levels were determined in sediments and Crangon crangon from 9 sites in the Severn Estuary/Bristol Channel during winter 1999. Metal levels in both shrimp and sediments varied significantly between sites and were related to proximity of input and/or sediment type. In the upper Estuary, Cd levels in shrimp were 100x higher than other reported values whereas sediment Cd contamination was comparable. It is suggested that high Cd levels in shrimp are due to the high inputs and enhanced bioavailability of metal during winter.

Mercury bioaccumulation in organisms from three Puerto Rican estuaries

We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site. Mercury levels were also below detection limits in Tilapia, except for specimens collected at Frontera Creek, allegedly contaminated with mercury. However, mercury levels ranged from 92-238 μg/kg (wet weight) in Tarpon, a predaceous fish that feeds on smaller fish. Few of the birds had detectable levels of mercury. Our results indicate relatively low concentrations of mercury in biota collected in all of the three estuaries at most trophic levels, although 10 of 12 Tarpon fillet samples from Frontera had detectable mercury compared to 3 of 12 fillet samples for the other two lagoons.

Natural tracers in dietary studies: data for 210Po and 210Pb in decapod shrimp and other pelagic organisms in the Northeast Atlantic Ocean

Measurements of the concentrations of the naturally-occurring radioactive nuclides 210Po and 210Pb in a large number of pelagic organisms from the Atlantic Ocean made in the spring/summer of 1984 and 1985 are reported. Marine shrimp are particularly well represented, and in many cases data were obtained for shrimp hepatopancreas, stomach-contents, and posterior intestine plus contents, as well as for whole individuals. The wide ranges found in 210Po concentrations group into categories: the shrimp, for example, divide into four categories, two penaeid and two carid. These groupings are explained on the basis of variations in diet between the different categories. A clear difference was also observed between the 210Po levels in shrimp of similar species and size from opposite sides of an oceanographic front; this difference too can be explained plausibly in terms of a change in certain penaeid shrimp, and attention is drawn to the need for investigation of cytological and/or genetic effects which could possibly be caused by the very high natural radiation doses to which such organisms are exposed.

High Pressure Liquid Chromatographic Method for Indole in Shrimp: Development of Method and Collaborative Study

A collaborative study on the determination of indole in shrimp was conducted in which a high pressure liquid chromatographic (HPLC) method and a spectrofluorometric method were compared with the AOAC gas-liquid chromatographic (GLC) method (18.075-18.078, 13th ed.). In the HPLC method, 10 g shrimp was blended with methanol, an internal standard was added, and the extract was filtered. Indole was separated on an octadecylsilane reverse phase column, using 60% MeOH-H2O, and quantitated with a fluorescence detector (excitation 280 nm, emission 330 nm) by comparing the indole peak height with that of an internal standard, 2-methyl-indole. Recoveries at a 25 micrograms/100 g level averaged 104% with a range of 90-127%, and at a level of 35 micrograms/100 g averaged 102% with a range of 93-112%. In the spectrofluorometric method, 25 g shrimp was extracted with 2% EtOAc-hexane. After several washes, indole was partitioned into a saturated NaCl-MeOH solution and its fluorescence was measured (excitation 280 nm, emission 332 nm). Recoveries at a 25 micrograms/100 g level averaged 93% with a range of 0-255% and at a level of 35 micrograms/100 g averaged 64% with a range of 0-107%. Recoveries obtained by the AOAC-GLC method at a level of 25 micrograms/100 g averaged 96% with a range of 81-116% and at a level of 35 micrograms/100 g averaged 101% with a range of 81-119%. The coefficients of variation were 20, 10, and 64% at a 25 micrograms/100 g level for the GLC method, the HPLC method, and the spectrofluorometric method, respectively. The HPLC method was adopted as official first action for indole levels in shrimp exceeding 1 microgram/100 g.

Microbial Flora of Pond-Reared Shrimp (Penaeus stylirostris, Penaeus vannamei, and Penaeus setiferus)

Aerobic plate counts of fresh pond-reared shrimp (Penaeus stylirostris, Penaeus vannamei, and Penaeus setiferus) ranged from 1.5 × 103 to 1.3 × 104 per gram. Coryneform bacteria and Vibrio spp. dominated the microbial flora of shrimp. Aerobic plate counts of pond waters ranged from 6.1 × 102 to 2.2 × 104 per milliliter. Vibrio spp. usually were dominant in pond waters. Enterococci and coliform levels in shrimp were low. Fecal coliforms were present in only one of 11 shrimp samples. No Escherichia coli was recovered from pond-reared shrimp. Salmonella, Vibrio parahaemolyticus, Bacillus cereus, and Clostridium perfringens were not recovered from either shrimp or pond waters. No relationship could be established between changes in numbers and types of microorganisms in pond-reared shrimp or pond waters and changes in characteristics of the pond waters such as temperature, salinity, dissolved oxygen, and pH.