ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2001
Teresa Castro Simas
Abstract A dynamic model for prediction of bioaccumulation in aquatic macrofauna is described. The model, entitled SHRIMP (Simulation of Heavy-metal Rate of Intake for Macrofaunal sPecies), consists of five coupled submodels, which simulate individual growth, population dynamics, metal transport in the abiotic part of the system, metal bioaccumulation at the organism level, and upscaling of individual contamination to the population scale. The sublethal effects of metal toxicity on individual and population levels are shown to act through the reduction of individual growth rates. The model was tested for cadmium and mercury using epibenthic crustacea from an estuarine system. Individual and population patterns of bioaccumulation were analyzed by comparing the simulated results of five different scenarios of dissolved metal concentrations. Model results suggest that the subtle effect of growth reduction due to metal toxicity is sufficient to cause a decrease on population numbers simply by affecting the growth of the mature females and males. [source]

MAINTENANCE OF ANDRODIOECY IN THE FRESHWATER SHRIMP, EULIMNADIA TEXANA: ESTIMATES OF INBREEDING DEPRESSION IN TWO POPULATIONS

EVOLUTION, Issue 3 2000
Stephen C. Weeks
Abstract., Androdioecy is an uncommon form of reproduction in which males coexist with hermaphrodites. Androdioecy is thought to be difficult to evolve in species that regularly inbreed. The freshwater shrimp Eulimnadia texana has recently been described as both androdioecious and highly selfing and is thus anomalous. Inbreeding depression is one factor that may maintain males in these populations. Here we examine the extent of "late" inbreeding depression (after sexual maturity) in these clam shrimp using two tests: (1) comparing the fitness of shrimp varying in their levels of individual heterozygosity from two natural populations that differ in overall genetic diversity; and (2) specifically outcrossing and selfing shrimp from these same populations and comparing fitness of the resulting offspring. The effects of inbreeding differed within each population. In the more genetically diverse population, fecundity, size, and mortality were significantly reduced in inbred shrimp. In the less genetically diverse population, none of the fitness measures was significantly lowered in selfed shrimp. Combining estimates of early inbreeding depression from a previous study with current estimates of late inbreeding depression suggests that inbreeding depression is substantial (,= 0.68) in the more diverse population and somewhat lower (,= 0.50) in the less diverse population. However, given that males have higher mortality rates than hermaphrodites, neither estimate of inbreeding depression is large enough to account for the maintenance of males in either population by inbreeding depression alone. Thus, the stability of androdioecy in this system is likely only if hermaphrodites are unable to self-fertilize many of their own eggs when not mated to a male or if male mating success is generally high (or at least high when males are rare). Patterns of fitness responses in the two populations were consistent with the hypothesis that inbreeding depression is caused by partially recessive deleterious alleles, although a formal test of this hypothesis still needs to be conducted. [source]

Enigmatic sedimentary,volcanic successions in the central European Variscides: a Cambrian/Early Ordovician age for the Wojcieszów Limestone (Kaczawa Mountains, SW Poland) indicated by SHRIMP dating of volcanic zircons

GEOLOGICAL JOURNAL, Issue 4 2008
Ryszard Kryza
Abstract Metamorphosed volcanic and sedimentary successions in the central European Variscides are, in many areas, poorly biostratigraphically constrained, making palaeotectonic interpretations uncertain. In such instances, geochronological data are crucial. Sensitive high resolution ion microprobe (SHRIMP) dating of volcanic zircons from a quartz,white mica schist (interpreted as deformed metavolcaniclastic/epiclastic rock) within the stratigraphically controversial Wojcieszów Limestone of the Kaczawa Mountains (Sudetes, SW Poland), near to the eastern termination of the European Variscides, has yielded an age of 498,±,5,Ma (2, error), corresponding to late Cambrian to early Ordovician magmatism in that area and constraining the depositional age of the limestones. The new SHRIMP data are not consistent with the recent revision of the age of the Wojcieszów Limestone based on Foraminifera findings that ascribed them to a Late Ordovician,Silurian or even younger interval. They are though, consistent with sparse macrofossil data and strongly support earlier interpretations of the lower part of the Kaczawa Mountains succession as a Cambrian,Early Ordovician extensional basin-fill with associated initial rift volcanic rocks, likely emplaced during the breakup of Gondwana. Copyright © 2008 John Wiley & Sons, Ltd. [source]

SHRIMP zircon and EPMA monazite dating of granitic rocks from the Maizuru terrane, southwest Japan: Correlation with East Asian Paleozoic terranes and geological implications

ISLAND ARC, Issue 3 2008
Masahiro Fujii
Abstract The Maizuru terrane, distributed in the Inner Zone of southwest Japan, is divided into three subzones (Northern, Central and Southern), each with distinct lithological associations. In clear contrast with the Southern zone consisting of the Yakuno ophiolite, the Northern zone is subdivided into the western and eastern bodies by a high-angle fault, recognized mainly by the presence of deformed granitic rocks and pelitic gneiss. This association suggests an affinity with a mature continental block; this is supported by the mode of occurrence, and petrological and isotopic data. Newly obtained sensitive high mass-resolution ion microprobe (SHRIMP) zircon U,Pb ages reveal the intrusion ages of 424 ± 16 and 405 ± 18 Ma (Siluro,Devonian) for the granites from the western body, and 249 ± 10 and 243 ± 19 Ma (Permo,Triassic) for the granodiorites from the eastern body. The granites in the western body also show inherited zircon ages of around 580 and 765 Ma. In addition, electron probe microanalysis (EPMA) monazite U,Th,total Pb dating gives around 475,460 Ma. The age of intrusion, inherited ages, mode of occurrence, and geological setting of the Siluro,Devonian granites of the Northern zone all show similarities with those of the Khanka Massif, southern Primoye, Russia, and the Hikami granitic rocks of the South Kitakami terrane, Northeast Japan. We propose that both the Siluro,Devonian and Permo,Triassic granitic rocks of the Northern zone are likely to have been juxtaposed through the Triassic,Late Jurassic dextral strike-slip movement, and to have originated from the Khanka Massif and the Hida terrane, respectively. This study strongly supports the importance of the strike-slip movement as a mechanism causing the structural rearrangement of the Paleozoic,Mesozoic terranes in the Japanese Islands, as well as in East Asia. [source]

DRYING METHODS AND QUALITY OF SHRIMP DRIED IN A JET-SPOUTED BED DRYER

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2005
RUNGTIP TAPANEYASIN
ABSTRACT The objective of this study was to experimentally investigate the effects of various parameters, i.e., size of shrimp, level and pattern of inlet drying air temperature, on the drying kinetics and various quality attributes of dried shrimp viz. shrinkage, rehydration ability, texture and color during drying in a jet-spouted bed dryer. It was found that the use of a constant inlet air temperature of 100C yielded dried shrimp of the best quality in terms of low percentage of shrinkage, high percentage of rehydration, low maximum shear force and high value of redness compared to shrimp dried using other conditions. A simple mathematical model that enables prediction of the drying behavior of shrimp in a jet-spouted bed dryer has also been developed. [source]

GAMMA IRRADIATION ON FROZEN AND PACKAGED HEADED SHRIMP

JOURNAL OF FOOD QUALITY, Issue 4 2009
V.K.G. ABREU
ABSTRACT The objective of this work was to evaluate the effects of , irradiation (0, 2, 4 and 6 kGy doses), applied on frozen and packaged headed shrimps, on pathogenic Vibrio cholerae O1 and Salmonella enteritidis bacteria, as well as on some of the physical and sensory characteristics of this kind of food. The 6 kGy dose was highly efficient in inhibiting V. cholerae O1 and S. enteritidis and in decreasing lipid oxidation in shrimps compared with the nonirradiated product. Shrimp texture was not affected by any of the irradiation doses studied, but the lightness of the surface color increased in shrimps irradiated with 6 kGy compared with those irradiated with 2 kGy. Shrimps irradiated with 6 kGy showed lower overall acceptability than those irradiated with 2 kGy or were nonirradiated. The application of , irradiation in doses up to 6 kGy on frozen and packaged headed shrimps could improve the microbiological quality of this commodity. PRACTICAL APPLICATIONS The use of , irradiation has the potential to ensure safety effectively by inactivating bacteria, increasing shelf life and maintaining food quality without significant chemical changes in the food matrix. Besides, this process can be applied to frozen and packaged products. Thus, irradiation of frozen and packaged shrimps could benefit the local processing industry, which could offer the international market a high-quality product, with an additional safety treatment. [source]

QUALITY OF FROZEN SHRIMP THAWED BY RECIRCULATING AIR VERSUS WATER IMMERSION

JOURNAL OF FOOD QUALITY, Issue 1 2003
C. S. LIN
ABSTRACT The quality of shrimp thawed using a constant temperature thawing chamber compared with running water was studied. Shrimp thawed in room temperature air was used as the control. Shrimp thawed using the thawing chamber had lower drip loss, higher yield and moisture content than shrimp thawed by running water. However, the differences were not statistically significant. There were also no significant differences in press juice and shear force between control and shrimp thawed using either thawing method. Shrimp thawed using the thawing chamber had lower aerobic bacterial counts than either control or shrimp thawed using running water. Shrimp thawed using the thawing chamber did not exceed ,1C throughout the thawing experiment, and microbial growth during thawing was also avoided. Results indicated that the thawing chamber has potential for the foodservice industry to produce uniformly thawed products under sanitary conditions. [source]

U-Pb Age Determination for Seven Standard Zircons using Inductively Coupled Plasma,Mass Spectrometry Coupled with Frequency Quintupled Nd-YAG (, = 213 nm) Laser Ablation System: Comparison with LA-ICP-MS Zircon Analyses with a NIST Glass Reference Material

RESOURCE GEOLOGY, Issue 2 2008
Yuji Orihashi
Abstract This paper evaluates the analytical precision, accuracy and long-term reliability of the U-Pb age data obtained using inductively coupled plasma,mass spectrometry (ICP-MS) with a frequency quintupled Nd-YAG (, = 213nm) laser ablation system. The U-Pb age data for seven standard zircons of various ages, from 28 Ma to 2400 Ma (FCT, SL13, 91500, AS3, FC1, QGNG and PMA7) were obtained with an ablation pit size of 30 ,m diameter. For 207Pb/206Pb ratio measurement, the mean isotopic ratio obtained on National Institute of Standards and Technology (NIST) SRM610 over 4 months was 0.9105 ± 0.0014 (n = 280, 95% confidence), which agrees well with the published value of 0.9096. The time-profile of Pb/U ratios during single spot ablation showed no significant difference in shape from NIST SRM610 and 91500 zircon standards. These results encouraged the use of the glass standard as a calibration standard for the Pb/U ratio determination for zircons with shorter wavelength (, = 213 nm) laser ablation. But 206Pb/238U and 207Pb/235U ages obtained by this method for seven zircon standards are systematically younger than the published U-Pb ages obtained by both isotope dilution,thermal ionization mass spectrometry (ID-TIMS) and sensitive high-resolution ion-microprobe (SHRIMP). Greater discrepancies (3,4% younger ages) were found for the 206Pb/238U ages for SL13, AS3 and 91500 zircons. The origin of the differences could be heterogeneity in Pb/U ratio on SRM610 between the different disks, but a matrix effect accuracy either in the ICP ion source or in the ablation-transport processes of the sample aerosols cannot be neglected. When the 206Pb/238U (= 0.2302) newly defined in the present study is used, the measured 206Pb/238U and 207Pb/235U ages for the seven zircon standards are in good agreement with those from ID-TIMS and SHRIMP within ±2%. This suggests that SRM610 glass standard is suitable for ICP-MS with laser ablation sampling (LA-ICP-MS) zircon analysis, but it is necessary to determine the correction factor for 206Pb/238U by measuring several zircon standards in individual laboratories. [source]

Neoproterozoic Tectonic Setting of Southeast China: New Constraints from SHRIMP U-Pb Zircon Ages and Petrographic Studies on the Mamianshan Group

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010
Ganguo WU
Abstract: Precambrian tectonic history of Zhejiang, Fujian, and Jiangxi provinces of south China is important for understanding the tectonic evolution of South China but its magmatic activity, petrogenesis, stratigraphic sequence of the Mamianshan Group is still strongly controversial. Here we present new sensitive high resolution ion micro-probe (SHRIMP) U-Pb zircon geochronological data for the Mamianshan Group and petrographical data to constrain the tectonic framework of the regions. Our results showed that the SHRIMP U-Pb zircon age of green schists of the Dongyan Formation is 796.544.3 Ma, the Daling Formation is 756.2±7.2 Ma, and mica-quartz schist of the Longbeixi Formation is 825.5±9.8 Ma. These data indicate that the Mamianshan Group was formed not in the Mesoproterozoic, but in the Neoproterozoic and its stratigraphic sequences should be composed of Longbeixi, Dongyan, and Daling Formations from the bottom to the top. Rocks from this Group, from Zhejiang, Fujian and Jiangxi provinces, constituted the upper basement of the Cathaysia Block that overlay the lower basement of the Mayuan Group. Detailed petrographic studies demonstrate that the amphibole schists of the Dongyan Formation in the Mamianshan Group were formed within an intra-arc rift setting rather than a continental rift as previously suggested. Rather, this island-arc type formation was developed by collision and/or subduction between various blocks resulting from the breakup of the supercontinent Rodinia at c.850,750 Ma. The Zhuzhou conglomerate, distributed near Dikou Town, Jian'ou City, Fujian Province and previously considered as evidence of the Mesoproterozoic Dikou movement, is shown here not to be the basal conglomerate above the angular unconformity between the upper and lower basements. Our conclusions have important implications for understanding the Precambrian tectonics of South China. [source]

40Ar/39Ar Dating of Xuebaoding Granite in the Songpan-Garzê Orogenic Belt, Southwest China, and its Geological Significance

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010
Yan LIU
Abstract: Thus far, our understanding of the emplacement of Xuebaoding granite and the occurrence and evolution of the Songpan-Garzê Orogenic Belt has been complicated by differing age spectra results. Therefore, in this study, the 40Ar/39Ar and sensitive high resolution ion micro-probe (SHRIMP) U-Pb dating methods were both used and the results compared, particularly with respect to dating data for Pankou and Pukouling granites from Xuebaoding, to establish ages that are close to the real emplacements. The results of SHRIMP U-Pb dating for zircon showed a high amount of U, but a very low value for Th/U. The high U amount, coupled with characteristics of inclusions in zircons, indicates that Xuebaoding granites are not suitable for U-Pb dating. Therefore, muscovite in the same granite samples was selected for 40Ar/39Ar dating. The 40Ar/39Ar age spectrum obtained on bulk muscovite from Pukouling granite in the Xuebaoding, gave a plateau age of 200.1±1.2 Ma and an inverse isochron age of 200.6±1.2 Ma. The 40Ar/39Ar age spectrum obtained on bulk muscovite from Pankou granite in the Xuebaoding gave another plateau age of 193.4± 1.1 Ma and an inverse isochron age of 193.7±1.1 Ma. The 40Ar/39Ar intercept of 277.0±23.4 (2,) was very close to the air ratio, indicating that no apparent excess argon contamination was present These age dating spectra indicate that both granites were emplaced at 200.6±1.3 Ma and 193.7±1.1 Ma, respectively. Through comparison of both dating methods and their results, we can conclude that it is feasible that the muscovite in the granite bearing high U could be used for 40Ar/39Ar dating without extra Ar. Based on this evidence, as well as the geological characteristics of the Xuebaoding W-Sn-Be deposit and petrology of granites, it can be concluded that the material origin of the Xuebaoding W-Sn-Be deposit might partially originate from the Xuebaoding granite group emplacement at about 200 Ma. Moreover, compared with other granites and deposits distributed in various positions in the Songpan-Garzê Orogenic Belt, the Xuebaoding emplacement ages further show that the main rare metal deposits and granites in peripheral regions occurred earlier than those in the inner Songpan-Garzê. Therefore, 40Ar/39Ar dating of Xuebaoding granite will lay a solid foundation for studying the occurrence and evolution of granite and rare earth element deposits in the Songpan-Garzê Orogenic Belt. [source]

THERMAL PROPERTIES OF SHRIMPS, FRENCH TOASTS AND BREADING

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2000
M.O. NGADI
ABSTRACT Thermal properties of fried products namely butterfly and popcorn shrimp, French toast and breading were determined for a wide range of temperature (20 to 140C), moisture content (3.3 to 87.4% w.b.) and fat content (0.005 to 0.618 kg/kg dry weight) typically encountered during deep-fat frying. Solid density of the products ranged from 1034 to 1508 kg/m3. Solid density increased with decreasing moisture content of product. Thermal conductivity ranged from 0.03 to 0.85 W/mC. Specific heat ranged from 1.51 to 4.67 kJ/kgC. The results were in the range of published data for similar products. Temperature, moisture and fat content affected variations of thermal conductivity and specific heat. Regression equations were used to fit experimental data. [source]

Shrimp,a dynamic model of heavy-metal uptake in aquatic macrofauna

Effects of Social Structure on the Behaviour and Performance of Alternative Reproductive Phenotypes in Male Rock Shrimp, Rhynchocinetes typus

ETHOLOGY, Issue 4 2008
Stefan Dennenmoser
Males that adopt alternative mating tactics within a conditional strategy often undergo costly morphological changes when switching to the next phenotype during ontogeny. Whether costs of changing to a subsequent reproductive phenotype are outweighed by a higher mating probability may depend on the frequencies of different phenotypes in a group of competitors. Benefits and costs associated with different phenotype frequencies depend on interactions within and between alternative phenotypes, but the underlying behavioural mechanisms have rarely been studied. Herein, we used the rock shrimp Rhynchocinetes typus as a model: ontogenetic male stages of this species differ in morphological and behavioural traits that indicate alternative reproductive phenotypes. The small, subordinate, male stage (typus) develops via several intermediate stages (intermedius) to the dominant male stage (robustus): in competitive interactions the typus males usually employ the sneaking tactic, while the robustus males invariably employ the monopolizing fighter tactic. In laboratory experiments, we manipulated phenotype frequencies to examine whether there are frequency-dependent effects on searching behaviour, aggressiveness and mating probability. With increasing frequency of robustus males, the rate of aggressive interactions among them increased. Furthermore, robustus males increased walking velocity when more than one robustus male was present. In contrast, typus males did not adjust their searching or aggressive behaviour. The increase of aggressive interactions among robustus males provided more opportunities for typus males to seize a temporarily unguarded female. While typus males exploit fights among robustus males that produce mating opportunities for them, robustus males benefit from typus males, which reveal the presence of receptive females. We suggest that each phenotype benefits from the presence of the other phenotype and suffers costly interference among individuals of the same phenotype. Whether frequency-dependent effects on the mating probability of subordinates also affect their ontogenetic switchpoint should be examined in future studies. [source]

Shrimp (Pandalus borealis) growth and timing of the spring phytoplankton bloom on the Newfoundland,Labrador Shelf

FISHERIES OCEANOGRAPHY, Issue 2 2007
C. FUENTES-YACO
Abstract We examined latitudinal and temporal changes in the availability of food for young shrimp (Pandalus borealis) on the Newfoundland,Labrador Shelf, using a suite of quantitative characteristics of the spring phytoplankton bloom determined from satellite ocean colour data, including bloom initiation time, maximum chlorophyll concentration, timing of the maximum, and bloom duration. We found significant correlations between bloom intensity, timing, and the size of young shrimp. The results are discussed in relation to the observation that, since the early 1990s, carapace lengths of shrimp have been decreasing in many Northwest Atlantic stocks. [source]

The influence of reproductive state on cardiac parameters and hypoxia tolerance in the Grass Shrimp, Palaemonetes pugio

FUNCTIONAL ECOLOGY, Issue 6 2005
J. A. GUADAGNOLI
Summary 1In many crustaceans, female reproduction represents a time of increased metabolic demand. Palaemonetes pugio are typically hypoxia tolerant; but the energetic demands of reproduction may compromise their ability to tolerate hypoxic conditions. Given the correlation between cardiac output and metabolic demand, we used cardiac output (CO) to measure differences in metabolic demand in the life-history stages of P. pugeo. 2We hypothesized that (1) the cost of egg production would result in an increased CO for gravid females compared with non-gravid females; (2) those females that were both ovigerous and gravid would have an additional metabolic demand due to brooding behaviour (pleopod fanning) and hence an even greater CO; and (3) hypoxia tolerance would decrease with increasing reproductive demand. To test these hypotheses, we compared cardiac output across three reproductive states and at decreasing water oxygen tensions. 3Ovigerous females had significantly greater pleopod fanning frequency than non-ovigerous females at all oxygen tensions. Additionally, ovigerous/gravid females had significantly higher cardiac output at all oxygen tensions than gravid only or non-gravid females. 4Changes in cardiac output indicate that females became more sensitive to environmental oxygen tension with increasing reproductive demand. Non-gravid females were able to maintain cardiac output down to 15 mm Hg O2, whereas gravid and ovigerous/gravid females maintained cardiac output down to 50 mm Hg and 75 mm Hg O2, respectively. 5These differences in CO suggest that metabolic demands of females change with reproductive state and, while gravid and ovigerous/gravid females appear more sensitive to low oxygen tensions, they are able to physiologically tolerate low environmental oxygen conditions. [source]

Digestive plasticity in Mallard ducks modulates dispersal probabilities of aquatic plants and crustaceans

FUNCTIONAL ECOLOGY, Issue 3 2005
I. CHARALAMBIDOU
Summary 1The consequences of plastic responses of the avian digestive tract for the potential of birds to disperse other organisms remain largely uninvestigated. 2To explore how a seasonal diet switch in Mallard (Anas platyrhynchos L.) influences their potential to disperse plants and invertebrates, we recorded the retention time of markers, following exposure to two diets of contrasting digestibility (trout chow vs seeds). 3We then recorded the retrieval and germination of Fennel Pondweed (Potamogeton pectinatus L.) seeds and Brine Shrimp (Artemia franciscana Kellogg) cysts ingested by the same birds. 4Gut passage rates of markers were increasingly longer in birds on the seed-based, high-fibre diet and shorter in birds on the animal-based, low-fibre one. 5Propagule digestibility, and thus survival to gut passage, differed between diet groups, with more seeds and fewer cysts retrieved from ducks on the animal-based diet. Germination decreased with retention time, but was not affected by diet. 6Differences in passage rates of markers but not of seeds and cysts suggest no change in dispersal distances of plants and invertebrates between seasons, while differences in digestibility would affect the numbers of propagules dispersed. [source]

Synthesis and Odor Evaluation of Stereoisomers of Imine Derivatives in Roasted Spotted Shrimp

HELVETICA CHIMICA ACTA, Issue 2 2003
Toru Tachihara
All possible stereoisomers of imine derivatives 1,4, which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood. [source]

A New Species of Streptocephalus Fairy Shrimp (Crustacea, Anostraca) with Tetrahedral Cysts from Central Thailand

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 3 2006
La-Orsri Sanoamuang
Abstract A new species of fairy shrimp, Streptocephalus siamensis n. sp., is described from five temporary pools in Suphan Buri and Kanchana Buri Provinces, central Thailand. It sometimes co-occurs with its congener, S. sirindhornae . This new species belongs to the subgenus Parastreptocephalus which is defined by bearing tetrahedral cysts. This is the third anostracan species reported from Thailand. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Structure and Functioning of the "Egg Bank" of a Fairy Shrimp in a Temporary Pool: Chirocephalus ruffoi from Pollino National Park (Southern Italy) as a Case Study

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 1 2004
Graziella Mura
Abstract To investigate their distribution and total numbers, resting eggs of the anostracan Chirocephalus ruffoi were collected from the bed of a temporary pool in southern Italy. Samples were taken at 0.5 m intervals along six transects oriented at 30° from each other, by means of a cylindrical core sampler. The horizontal distribution of intact resting eggs was extremely patchy, with cyst number per core ranging from 191 to 1,400 (CV = 32.7%), corresponding to a mean of between 0.8 and 4.3 cysts cm,3. Differences observed were related to core position and transect orientation, total cyst numbers being markedly higher in the leeward area of the pool compared to the windward area. Marked variation was also evident in vertical distribution, a significant, though weak correlation was recorded between egg density and sediment depth. Cyst-bank size (± 95% confidence limits) of the pool bed, estimated from the mean cyst number cm,3 obtained for the 6 transects, ranged between 1.0 × 108 and 1.3 × 108 cysts. Hatching in the laboratory was very erratic. Despite significant differences in hatching, the observed variation was unrelated to most of the variables considered (position within sections, cores and transects, pre-incubation treatment) and was explained only by initial sediment conditions (moist/dry). In none of the experimental conditions tested was synchronous hatching obtained. Possible causal factors (mixing of the bottom sediments by cattle, egg age, storage conditions, differential exposure to environmental cues as well as variability in hatching response even at clutch level) are discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

QUALITY OF FROZEN SHRIMP THAWED BY RECIRCULATING AIR VERSUS WATER IMMERSION

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 2009
Thammarat 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 Deveining

JOURNAL OF FOOD SCIENCE, Issue 1 2008
N. 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]

Recovery of Components from Shrimp (Xiphopenaeus kroyeri) Processing Waste by Enzymatic Hydrolysis

JOURNAL OF FOOD SCIENCE, Issue 5 2006
Helenice Duarte De Holanda
ABSTRACT:, Industrial shrimp waste is a good source of protein, chitin, and carotenoids. In general, this waste is discarded with no attempt to use it, thus contributing to environmental pollution. This study was aimed at recovering the 3 main components of industrial shrimp waste, protein, chitin, and astaxanthin, using enzymatic treatment with Alcalase and pancreatin. An increase in the degree of hydrolysis (DH) from 6% to 12% resulted in 26% to 28% protein recovery. Alcalase was more efficient than pancreatin, increasing the recovery of protein from 57.5% to 64.6% and of astaxanthin from 4.7 to 5.7 mg astaxanthin/100 g of dry waste, at a DH of 12%. The enzymatic hydrolysis of the industrial waste from Xiphopenaeus kroyeri shrimp using Alcalase allowed for 65% protein recovery in the form of hydrolysates, in addition to providing suitable conditions for the recovery of astaxanthin and chitin. [source]

Effects of Dietary Heat-killed Lactobacillus plantarum on Larval and Post-larval Kuruma Shrimp, Marsupenaeus japonicus Bate

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2010
Ha Thanh Tung
Two feeding trials were conducted to evaluate the effects of heat-killed Lactobacillus plantarum (HK-LP) on larval and post-larval kuruma shrimp, Marsupenaeus japonicus Bate. Five microbound diets were formulated to contain levels of a preparation containing 20% HK-LP (HK-LP Prep): 0, 0.001, 0.01, 0.1, and 1 g/kg. In the first experiment, zoea1 stage larvae were fed test diets for 8 d. Some parameters such as survival, developmental stage, metamorphosis to post-larvae, and formalin stress resistance were evaluated. In second trial, post-larval shrimp (16 ± 0.04 mg) were fed test diets for 30 d. Survival, body weight gain, specific growth rate, feed efficiency ratio, individual dry weight, total body length, osmotic and formalin stress resistances, and protease activity were evaluated. Results indicated that the larvae that received HK-LP Prep at 0.1 and 1 g/kg diets showed significantly (P < 0.05) higher survival than that of the control group. For the post-larval trial, shrimp that received HK-LP Prep at 1 g/kg diet were significantly higher than the control group in most of the growth parameters and stress resistance. However, shrimp that received HK-LP Prep at 0.1 g/kg diet were significantly higher than the control group in survival only. For protease activity, there was no significant difference detected among groups. [source]

Validation of a Feeding Stimulant Bioassay Using Fish Hydrolysates for the Pacific White Shrimp, Litopenaeus vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2009
Michael 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 Acids

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2009
Joe 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]

A Microsatellite DNA Marker Developed for Identifying Disease-resistant Population of Giant Black Tiger Shrimp, Penaeus monodon

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2009
Kuntal Mukherjee
White spot disease caused by white spot syndrome virus (WSSV) poses major problems that result in huge economic losses each year in shrimp aquaculture throughout the world. In the present study, microsatellite-based DNA fingerprints have been compared between naturally occurring WSSV disease-resistant and susceptible populations of giant black tiger shrimp, Penaeus monodon, to find DNA markers. For the first time, we report here a microsatellite locus, which, after amplification by polymerase chain reaction, provides a highly statistically significant DNA fingerprint of 71 bp, only in disease susceptible populations but not in disease-resistant shrimp populations, whereas a 317 bp band is common in both. The absence of the former DNA marker will be very useful to identify disease-resistant broodstock of P. monodon for marker-assisted selection in breeding programs to generate disease-free shrimps (P. monodon) in the aquaculture industry. [source]

Inbreeding Effects on Hatchery and Growout Performance of Pacific White Shrimp, Penaeus (Litopenaeus) vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2008
Dustin 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 vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007
Martin 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 vannamei

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2007
Oscar 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]