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Sample records for stomatopod crustaceans implications

  1. Learning in Stomatopod Crustaceans

    OpenAIRE

    Cronin, Thomas W.; Caldwell, Roy L.; Marshall, Justin

    2006-01-01

    The stomatopod crustaceans, or mantis shrimps, are marine predators that stalk or ambush prey and that have complex intraspecific communication behavior. Their active lifestyles, means of predation, and intricate displays all require unusual flexibility in interacting with the world around them, implying a well-developed ability to learn. Stomatopods have highly evolved sensory systems, including some of the most specialized visual systems known for any animal group. Some species have been de...

  2. The First Complete Mitochondrial Genome Sequences for Stomatopod Crustaceans: Implications for Phylogeny

    Energy Technology Data Exchange (ETDEWEB)

    Swinstrom, Kirsten; Caldwell, Roy; Fourcade, H. Matthew; Boore, Jeffrey L.

    2005-09-07

    We report the first complete mitochondrial genome sequences of stomatopods and compare their features to each other and to those of other crustaceans. Phylogenetic analyses of the concatenated mitochondrial protein-coding sequences were used to explore relationships within the Stomatopoda, within the malacostracan crustaceans, and among crustaceans and insects. Although these analyses support the monophyly of both Malacostraca and, within it, Stomatopoda, it also confirms the view of a paraphyletic Crustacea, with Malacostraca being more closely related to insects than to the branchiopod crustaceans.

  3. Null point of discrimination in crustacean polarisation vision.

    Science.gov (United States)

    How, Martin J; Christy, John; Roberts, Nicholas W; Marshall, N Justin

    2014-07-15

    The polarisation of light is used by many species of cephalopods and crustaceans to discriminate objects or to communicate. Most visual systems with this ability, such as that of the fiddler crab, include receptors with photopigments that are oriented horizontally and vertically relative to the outside world. Photoreceptors in such an orthogonal array are maximally sensitive to polarised light with the same fixed e-vector orientation. Using opponent neural connections, this two-channel system may produce a single value of polarisation contrast and, consequently, it may suffer from null points of discrimination. Stomatopod crustaceans use a different system for polarisation vision, comprising at least four types of polarisation-sensitive photoreceptor arranged at 0, 45, 90 and 135 deg relative to each other, in conjunction with extensive rotational eye movements. This anatomical arrangement should not suffer from equivalent null points of discrimination. To test whether these two systems were vulnerable to null points, we presented the fiddler crab Uca heteropleura and the stomatopod Haptosquilla trispinosa with polarised looming stimuli on a modified LCD monitor. The fiddler crab was less sensitive to differences in the degree of polarised light when the e-vector was at -45 deg than when the e-vector was horizontal. In comparison, stomatopods showed no difference in sensitivity between the two stimulus types. The results suggest that fiddler crabs suffer from a null point of sensitivity, while stomatopods do not. © 2014. Published by The Company of Biologists Ltd.

  4. Fine structure and optical properties of biological polarizers in crustaceans and cephalopods

    Science.gov (United States)

    Chiou, Tsyr-Huei; Caldwell, Roy L.; Hanlon, Roger T.; Cronin, Thomas W.

    2008-04-01

    The lighting of the underwater environment is constantly changing due to attenuation by water, scattering by suspended particles, as well as the refraction and reflection caused by the surface waves. These factors pose a great challenge for marine animals which communicate through visual signals, especially those based on color. To escape this problem, certain cephalopod mollusks and stomatopod crustaceans utilize the polarization properties of light. While the mechanisms behind the polarization vision of these two animal groups are similar, several distinctive types of polarizers (i.e. the structure producing the signal) have been found in these animals. To gain a better knowledge of how these polarizers function, we studied the relationships between fine structures and optical properties of four types of polarizers found in cephalopods and stomatopods. Although all the polarizers share a somewhat similar spectral range, around 450- 550 nm, the reflectance properties of the signals and the mechanisms used to produce them have dramatic differences. In cephalopods, stack-plates polarizers produce the polarization patterns found on the arms and around their eyes. In stomatopods, we have found one type of beam-splitting polarizer based on photonic structures and two absorptive polarizer types based on dichroic molecules. These stomatopod polarizers may be found on various appendages, and on the cuticle covering dorsal or lateral sides of the animal. Since the efficiencies of all these polarizer types are somewhat sensitive to the change of illumination and viewing angle, how these animals compensate with different behaviors or fine structural features of the polarizer also varies.

  5. Crustacean Larvae-Vision in the Plankton.

    Science.gov (United States)

    Cronin, Thomas W; Bok, Michael J; Lin, Chan

    2017-11-01

    We review the visual systems of crustacean larvae, concentrating on the compound eyes of decapod and stomatopod larvae as well as the functional and behavioral aspects of their vision. Larval compound eyes of these macrurans are all built on fundamentally the same optical plan, the transparent apposition eye, which is eminently suitable for modification into the abundantly diverse optical systems of the adults. Many of these eyes contain a layer of reflective structures overlying the retina that produces a counterilluminating eyeshine, so they are unique in being camouflaged both by their transparency and by their reflection of light spectrally similar to background light to conceal the opaque retina. Besides the pair of compound eyes, at least some crustacean larvae have a non-imaging photoreceptor system based on a naupliar eye and possibly other frontal eyes. Larval compound-eye photoreceptors send axons to a large and well-developed optic lobe consisting of a series of neuropils that are similar to those of adult crustaceans and insects, implying sophisticated analysis of visual stimuli. The visual system fosters a number of advanced and flexible behaviors that permit crustacean larvae to survive extended periods in the plankton and allows them to reach acceptable adult habitats, within which to metamorphose. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  6. Morphology of stomatopod larvae from National Parks: Sistema Arrecifal Veracruzano and Arrecife Puerto Morelos, Mexico

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    Sergio Cházaro-Olvera

    2018-03-01

    Full Text Available ABSTRACT The present study provides information on the morphology of stomatopod larvae found in two different reef systems which are also considered national parks: the Sistema Arrecifal Veracruzano (SAVNP and Arrecife Puerto Morelos (APMNP. Zooplankton samples were collected at 26 stations of the SAVNP and four stations of the APMNP. Stomatopod larvae were identified and classified by their larval stage. We found representatives of three stomatopod superfamilies: the superfamily Gonodactyloidea Giesbrecht, 1910 was represented by Neogonodactylus oerstedii (Hansen, 1895, Neogonodactylus wennerae Manning and Heard, 1997, and Pseudosquillidae genus and species indeterminate; the superfamily Lysiosquilloidea Giesbrecht, 1910 was represented by Lysiosquilloidea genus and species indeterminate, Lysiosquilla sp., Lysiosquilla scabricauda (Lamarck, 1818 and Nannosquilla adkisoni Camp and Manning, 1982; the superfamily Squilloidea was represented by larvae of Alima neptuni (Linnaeus, 1768, Squilla spp., and Squilla empusa Say, 1818. We were able to identify and describe four stages of larval development for representatives of these superfamilies. This is the first study describing several stages of larval development of different species of the stomatopods from the Gulf of Mexico and Caribbean Sea.

  7. Re-Engineering the Stomatopod Eye, Nature’s Most Comprehensive Visual Sensor

    Science.gov (United States)

    2013-08-22

    degree of polarisation difference. Stomatopods (Right) also react to similar looming stonuli by retreating or showing eye movements . However, the...N Roberts, NJ Marshall 2013 "Varying degrees of polarization vision in octopus : interaction between degree and angle of polarization in contrast

  8. Biodegradation of the chitin-protein complex in crustacean cuticle

    Science.gov (United States)

    Artur, Stankiewicz B.; Mastalerz, Maria; Hof, C.H.J.; Bierstedt, A.; Flannery, M.B.; Briggs, D.E.G.; Evershed, R.P.

    1998-01-01

    Arthropod cuticles consist predominantly of chitin cross-linked with proteins. While there is some experimental evidence that this chitin-protein complex may resist decay, the chemical changes that occur during degradation have not been investigated in detail. The stomatopod crustacean Neogonodactylus oerstedii was decayed in the laboratory under anoxic conditions. A combination of pyrolysis-gas chromatography/mass spectrometry and FTIR revealed extensive chemical changes after just 2 weeks that resulted in a cuticle composition dominated by chitin. Quantitative analysis of amino acids (by HPLC) and chitin showed that the major loss of proteins and chitin occurred between weeks 1 and 2. After 8 weeks tyrosine, tryptophan and valine are the most prominent amino acid moieties, showing their resistance to degradation. The presence of cyclic ketones in the pyrolysates indicates that mucopolysaccharides or other bound non-chitinous carbohydrates are also resistant to decay. There is no evidence of structural degradation of chitin prior to 8 weeks when FTIR revealed a reduction in chitin-specific bands. The chemical changes are paralleled by structural changes in the cuticle, which becomes an increasingly open structure consisting of loose chitinous fibres. The rapid rate of decay in the experiments suggests that where chitin and protein are preserved in fossil cuticles degradation must have been inhibited.Arthropod cuticles consist predominantly of chitin cross-linked with proteins. While there is some experimental evidence that this chitin-protein complex may resist decay, the chemical changes that occur during degradation have not been investigated in detail. The stomatopod crustacean Neogonodactylus oerstedii was decayed in the laboratory under anoxic conditions. A combination of pyrolysis-gas chromatography/mass spectrometry and FTIR revealed extensive chemical changes after just 2 weeks that resulted in a cuticle composition dominated by chitin. Quantitative

  9. Feeding Partitioning among Tuna Taken in Surface and Mid-water ...

    African Journals Online (AJOL)

    Crustaceans were the almost exclusive food source of surface-swimming bigeye tuna, with the stomatopod (Natosquilla investigatoris) being the sole prey item recorded in this category. The diet of deep-swimming yellowfin tuna was balanced between epipelagic fish, crustaceans and cephalopods. Bigeye tuna fed ...

  10. Market integration in the crustaceans market

    DEFF Research Database (Denmark)

    Ankamah-Yeboah, Isaac; Bronnmann, Julia

    2018-01-01

    are substitutes. Price determination processes for the shrimp markets vary with the level of the value chain. The results imply that the wild and farmed crustaceans markets are interacting through substitution effects. Hence, the markets have the capability to shield volatile and rising prices that would emanate......In this paper the price dynamics and the degree of market integration in the German crustaceans market is examined using cointegration methods. The study focuses on wild caught cold water shrimp, farmed warm water shrimp as well as lobster and derives implications for the fisheries sector....... In the analysis, both the import market and the retail market price reactions are distinguished. Therefore, it is evaluated how price changes affect competing commodities within and between the value chain of a given crustaceans commodity. Evidence of partial market integration is found for all species under...

  11. Respiratory and Metabolic Impacts of Crustacean Immunity: Are there Implications for the Insects?

    Science.gov (United States)

    Burnett, Karen G; Burnett, Louis E

    2015-11-01

    Extensive similarities in the molecular architecture of the crustacean immune system to that of insects give credence to the current view that the Hexapoda, including Insecta, arose within the clade Pancrustacea. The crustacean immune system is mediated largely by hemocytes, relying on suites of pattern recognition receptors, effector functions, and signaling pathways that parallel those of insects. In crustaceans, as in insects, the cardiovascular system facilitates movement of hemocytes and delivery of soluble immune factors, thereby supporting immune surveillance and defense along with other physiological functions such as transport of nutrients, wastes, and hormones. Crustaceans also rely heavily on their cardiovascular systems to mediate gas exchange; insects are less reliant on internal circulation for this function. Among the largest crustaceans, the decapods have developed a condensed heart and a highly arteriolized cardiovascular system that supports the metabolic demands of their often large body size. However, recent studies indicate that mounting an immune response can impair gas exchange and metabolism in their highly developed vascular system. When circulating hemocytes detect the presence of potential pathogens, they aggregate rapidly with each other and with the pathogen. These growing aggregates can become trapped in the microvasculature of the gill where they are melanized and may be eliminated at the next molt. Prior to molting, trapped aggregates of hemocytes also can impair hemolymph flow and oxygenation at the gill. Small shifts to anaerobic metabolism only partially compensate for this decrease in oxygen uptake. The resulting metabolic depression is likely to impact other energy-expensive cellular processes and whole-animal performance. For crustaceans that often live in microbially-rich, but oxygen-poor aquatic environments, there appear to be distinct tradeoffs, based on the gill's multiple roles in respiration and immunity. Insects have

  12. Extreme morphologies of mantis shrimp larvae

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    Carolin Haug

    Full Text Available ABSTRACT Larvae of stomatopods (mantis shrimps are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages, alima and erichthus (the latter two representing later larval stages. These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world 1928-30. These new larval types all represent erichthus-type larvae, especially differing in their shield morphologies. The shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults.

  13. Widespread Wolbachia infection in terrestrial isopods and other crustaceans

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    Richard Cordaux

    2012-03-01

    Full Text Available Wolbachia bacteria are obligate intracellular alpha-Proteobacteria of arthropods and nematodes. Although widespread among isopod crustaceans, they have seldom been found in non-isopod crustacean species. Here, we report Wolbachia infection in fourteen new crustacean species. Our results extend the range of Wolbachia infections in terrestrial isopods and amphipods (class Malacostraca. We report the occurrence of two different Wolbachia strains in two host species (a terrestrial isopod and an amphipod. Moreover, the discovery of Wolbachia in the goose barnacle Lepas anatifera (subclass Thecostraca establishes Wolbachia infection in class Maxillopoda. The new bacterial strains are closely related to B-supergroup Wolbachia strains previously reported from crustacean hosts. Our results suggest that Wolbachia infection may be much more widespread in crustaceans than previously thought. The presence of related Wolbachia strains in highly divergent crustacean hosts suggests that Wolbachia endosymbionts can naturally adapt to a wide range of crustacean hosts. Given the ability of isopod Wolbachia strains to induce feminization of genetic males or cytoplasmic incompatibility, we speculate that manipulation of crustacean-borne Wolbachia bacteria might represent potential tools for controlling crustacean species of commercial interest and crustacean or insect disease vectors.

  14. Scattering of acoustic waves by small crustaceans

    Science.gov (United States)

    Andreeva, I. B.; Tarasov, L. L.

    2003-03-01

    Features of underwater sound scattering by small crustaceans are considered. The scattering data are obtained with the use of unique instrumentation that allows one to measure quantitative scattering characteristics (backscattering cross sections and angular scattering patterns) for crustaceans of different sizes, at different frequencies (20 200 kHz) and different insonification aspects. A computational model of crustaceans is considered with allowance for both the soft tissues of the main massive part of the animal's body and the stiff armour. The model proves to be advantageous for explaining some scattering features observed in the experiments. The scattering cross sections of crustaceans measured by other researchers are presented in a unified form appropriate for comparison. Based on such a quantitative comparison, relatively simple approximate empirical formulas are proposed for estimating the backscattering cross sections of small (within several centimeters) marine crustaceans in a broad frequency range.

  15. Semisubmersible oil platforms: understudied and potentially major vectors of biofouling-mediated invasions.

    Science.gov (United States)

    Yeo, Darren C J; Ahyong, Shane T; Lodge, David M; Ng, Peter K L; Naruse, Tohru; Lane, David J W

    2010-01-01

    Biofouling has long been recognised as a major pathway for the introduction of non-indigenous species. This study records the decapods and stomatopod crustaceans fouling a semisubmersible oil platform dry docked for hull cleaning in Jurong Port, Singapore. Of the 25 species of decapods identified, 13 were non-indigenous and represent new records to Singapore waters. Of these, the crabs Glabropilumnus seminudus and Carupa tenuipes are known to be invasive in other parts of the world. The stomatopod, Gonodactylaceus randalli, is the first mantis shrimp recorded in a biofouling community. The richness and diversity of this fouling community, consisting of many vagile species, highlights the difference between platforms and ships. With the expansion of maritime oil and gas exploration, the threat posed by an expanded fleet of semisubmersible oil platforms translocating non-indigenous fouling communities across biogeographical boundaries is very serious. Scientists, policy-makers, and stakeholders should turn their attention to this growing problem.

  16. Planktonic Crustacean Culture - Live Planktonic Crustaceans as Live Feed for Finfish and Shrimps in Aquaculture

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Syberg, Kristian; Drillet, Guillaume

    2018-01-01

    The cultivation of planktonic crustaceans as live feed is of paramount importance for the aquaculture and aquarium industries. The use of live cladocerans as feed for freshwater fish is limited to the aquarium industry, whereas Artemia and copepods are used to feed edible marine fish larvae...... assessments for hazardous chemicals. Cladocerans are widely used for ecotoxicology testing but Artemia and copepods are emerging new model species. In the present chapter, we review the culturing procedures of these important planktonic crustaceans: Artemia, cladocerans and copepods and discuss their use...

  17. Effects of Organotins on Crustaceans: Update and Perspectives

    Science.gov (United States)

    Vogt, Éverton L.; Model, Jorge F. A.; Vinagre, Anapaula S.

    2018-01-01

    Organotins (OTs) are considered some of the most toxic chemicals introduced into aquatic environments by anthropogenic activities. They are widely used for agricultural and industrial purposes and as antifouling additives on boat hull’s paints. Even though the use of OTs was banned in 2008, elevated levels of OTs can still be detected in aquatic environments. OTs’ deleterious effects upon wildlife and experimental animals are well documented and include endocrine disruption, immunotoxicity, neurotoxicity, genotoxicity, and metabolic dysfunction. Crustaceans are key members of zooplankton and benthic communities and have vital roles in food chains, so the endocrine-disrupting effects of tributyltin (TBT) on crustaceans can affect other organisms. TBT can disrupt carbohydrate and lipid homeostasis of crustaceans by interacting with retinoid X receptor (RXR) and crustacean hyperglycemic hormone (CHH) signaling. Moreover, it can also interact with other nuclear receptors, disrupting methyl farnesoate and ecdysteroid signaling, thereby altering growth and sexual maturity, respectively. This compound also interferes in cytochrome P450 system disrupting steroid synthesis and reproduction. Crustaceans are also important fisheries worldwide, and its consumption can pose risks to human health. However, some questions remain unanswered. This mini review aims to update information about the effects of OTs on the metabolism, growth, and reproduction of crustaceans; to compare with known effects in mammals; and to point aspects that still needs to be addressed in future studies. Since both macrocrustaceans and microcrustaceans are good models to study the effects of sublethal TBT contamination, novel studies should be developed using multibiomarkers and omics technology. PMID:29535684

  18. Effects of Organotins on Crustaceans: Update and Perspectives

    Directory of Open Access Journals (Sweden)

    Éverton L. Vogt

    2018-02-01

    Full Text Available Organotins (OTs are considered some of the most toxic chemicals introduced into aquatic environments by anthropogenic activities. They are widely used for agricultural and industrial purposes and as antifouling additives on boat hull’s paints. Even though the use of OTs was banned in 2008, elevated levels of OTs can still be detected in aquatic environments. OTs’ deleterious effects upon wildlife and experimental animals are well documented and include endocrine disruption, immunotoxicity, neurotoxicity, genotoxicity, and metabolic dysfunction. Crustaceans are key members of zooplankton and benthic communities and have vital roles in food chains, so the endocrine-disrupting effects of tributyltin (TBT on crustaceans can affect other organisms. TBT can disrupt carbohydrate and lipid homeostasis of crustaceans by interacting with retinoid X receptor (RXR and crustacean hyperglycemic hormone (CHH signaling. Moreover, it can also interact with other nuclear receptors, disrupting methyl farnesoate and ecdysteroid signaling, thereby altering growth and sexual maturity, respectively. This compound also interferes in cytochrome P450 system disrupting steroid synthesis and reproduction. Crustaceans are also important fisheries worldwide, and its consumption can pose risks to human health. However, some questions remain unanswered. This mini review aims to update information about the effects of OTs on the metabolism, growth, and reproduction of crustaceans; to compare with known effects in mammals; and to point aspects that still needs to be addressed in future studies. Since both macrocrustaceans and microcrustaceans are good models to study the effects of sublethal TBT contamination, novel studies should be developed using multibiomarkers and omics technology.

  19. The eyes have it: A brief history of crustacean neuroendocrinology.

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    Hopkins, Penny M

    2012-02-01

    To help celebrate the 50th anniversary of General and Comparative Endocrinology, the history of only a small portion of crustacean endocrinology is presented here. The field of crustacean endocrinology dates back to the decades prior to the establishment of General and Comparative Endocrinology and the first article about crustacean endocrinology published in this journal was concerned with the anatomy of neurosecretory and neurohemal structures in brachyuran crabs. This review looks at the history of neuroendocrinology in crustaceans during that time and tries to put perspective on the future of this field. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Structure-activity relationship of crustacean peptide hormones.

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    Katayama, Hidekazu

    2016-01-01

    In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed.

  1. Filtering and polychromatic vision in mantis shrimps: themes in visible and ultraviolet vision.

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    Cronin, Thomas W; Bok, Michael J; Marshall, N Justin; Caldwell, Roy L

    2014-01-01

    Stomatopod crustaceans have the most complex and diverse assortment of retinal photoreceptors of any animals, with 16 functional classes. The receptor classes are subdivided into sets responsible for ultraviolet vision, spatial vision, colour vision and polarization vision. Many of these receptor classes are spectrally tuned by filtering pigments located in photoreceptors or overlying optical elements. At visible wavelengths, carotenoproteins or similar substances are packed into vesicles used either as serial, intrarhabdomal filters or lateral filters. A single retina may contain a diversity of these filtering pigments paired with specific photoreceptors, and the pigments used vary between and within species both taxonomically and ecologically. Ultraviolet-filtering pigments in the crystalline cones serve to tune ultraviolet vision in these animals as well, and some ultraviolet receptors themselves act as birefringent filters to enable circular polarization vision. Stomatopods have reached an evolutionary extreme in their use of filter mechanisms to tune photoreception to habitat and behaviour, allowing them to extend the spectral range of their vision both deeper into the ultraviolet and further into the red.

  2. Host partitioning by parasites in an intertidal crustacean community.

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    Koehler, Anson V; Poulin, Robert

    2010-10-01

    Patterns of host use by parasites throughout a guild community of intermediate hosts can depend on several biological and ecological factors, including physiology, morphology, immunology, and behavior. We looked at parasite transmission in the intertidal crustacean community of Lower Portobello Bay, Dunedin, New Zealand, with the intent of: (1) mapping the flow of parasites throughout the major crustacean species, (2) identifying hosts that play the most important transmission role for each parasite, and (3) assessing the impact of parasitism on host populations. The most prevalent parasites found in 14 species of crustaceans (635 specimens) examined were the trematodes Maritrema novaezealandensis and Microphallus sp., the acanthocephalans Profilicollis spp., the nematode Ascarophis sp., and an acuariid nematode. Decapods were compatible hosts for M. novaezealandensis, while other crustaceans demonstrated lower host suitability as shown by high levels of melanized and immature parasite stages. Carapace thickness, gill morphology, and breathing style may contribute to the differential infection success of M. novaezealandensis and Microphallus sp. in the decapod species. Parasite-induced host mortality appears likely with M. novaezealandensis in the crabs Austrohelice crassa, Halicarcinus varius, Hemigrapsus sexdentatus, and Macrophthalmus hirtipes, and also with Microphallus sp. in A. crassa. Overall, the different parasite species make different use of available crustacean intermediate hosts and possibly contribute to intertidal community structure.

  3. Characteristics and value of the Thukela Banks crustacean and ...

    African Journals Online (AJOL)

    This study describes the Thukela Banks crustacean and linefish fisheries and investigates the potential impacts of reduced flow from the Thukela River on the value of these fisheries. Data were obtained from published and unpublished material, key informants and government records. The crustacean fishery employs ...

  4. Some crustacean zooplankton of Wular lake in Kashmir Himalaya ...

    African Journals Online (AJOL)

    In a taxonomic survey of crustacean zooplankton collected from Wular lake of Kashmir, a pictorial key was developed. Thirty-six (36) pictures of 25 species of crustacean zooplankton, out of which 21 represented 16 Cladocera taxa belonging to Chydoridae (Alona affinis, A. rectangula and A. monacantha, Chydorus ...

  5. Usage of energy reserves in crustaceans during starvation: status and future directions.

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    Sánchez-Paz, Arturo; García-Carreño, Fernando; Muhlia-Almazán, Adriana; Peregrino-Uriarte, Alma B; Hernández-López, Jorge; Yepiz-Plascencia, Gloria

    2006-04-01

    In this paper, we review the current knowledge about the usage of carbohydrates, lipids and proteins as energy source by marine crustaceans during starvation. Crustaceans are a large and diverse group including some economically important species. The efforts to culture them for human consumption has prompted the interest to understand the preferences of energy sources to be applied for feed formulation and cost reduction. Important differences have been found among species and appear to be related not only to the biochemistry and physiology of nutrition, but also to the living environment of the crustaceans. Furthermore, crustaceans undergo morphological, physiological and behavioral changes due to their natural growing process that affect their feeding habits, an aspect that should be carefully considered. We discuss the current information on marine crustaceans about energy usage and describe areas of future research, where starvation studies render important insights.

  6. Modelling gastric evacuation in gadoids feeding on crustaceans

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner; Chabot, Denis; Couturier, C. S.

    2016-01-01

    A mechanistic, prey surface-dependent model was expanded to describe the course and rate of gastric evacuation in predatory fishes feeding on crustacean prey with robust exoskeletons. This was accomplished by adding a layer of higher resistance to the digestive processes outside the inner softer...... parts of a prey cylinder abstraction and splitting up the prey evacuation into two stages: an initial stage where the exoskeleton is cracked and a second where the prey remains are digested and evacuated. The model was parameterized for crustaceans with different levels of armour fed to Atlantic cod...... and Chionoecetes opilio. In accordance with the apparent intraspecific isometric relationship between exoskeleton mass and total body mass, the model described stage duration and rate of evacuation of the crustacean prey independently of meal and prey sizes. The duration of the first stage increased (0-33 h...

  7. Crustacean fauna of a mussel cultivated raft system in the Black Sea

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    Murat Sezgin

    2013-06-01

    Full Text Available The aim of the current study was to make a faunistic analysis of the crustaceans associated with cultivated mussels grown on ropes. Mussel samples from 30 cm ropes were collected from rope-grown mussel beds by hand. The crustacean fauna associated with mussel population were quantified. The density of crustacean fauna associated with mussels was significantly greater within rope-grown mussel assemblages than on other biotopes around.

  8. Bycatch of crustacean and fish bottom trawl fisheries from southern Portugal (Algarve

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    Maria Esmeralda Costa

    2008-12-01

    Full Text Available As part of two research projects for analysing bycatch and discards, we quantified catch composition, catch rates, bycatch and discards in two important commercial bottom trawl fisheries (crustacean and fish trawls off the southern coast of Portugal (Algarve. Stratified sampling by onboard observers took place from February 1999 to March 2001 and data were collected from 165 tows during 52 fishing trips. Commercial target species included crustaceans: blue and red shrimp (Aristeus antennatus, deep-water rose shrimp (Parapenaeus longirostris, Norway lobster (Nephrops norvegicus; and fishes: seabreams (Diplodus spp. and Pagellus spp., horse mackerels (Trachurus spp. and European hake (Merluccius merluccius. The trawl fisheries are characterised by considerable amounts of bycatch: 59.5% and 80.4% of the overall total catch for crustacean and fish trawlers respectively. A total of 255 species were identified, which belonged to 15 classes of organisms (137 vertebrates, 112 invertebrates and 6 algae. Crustacean trawlers had higher bycatch biodiversity. Bony fish (45.6% and 37.8% followed by crustaceans (14.6% and 11.5% were the dominant bycatch components of both crustacean and fish trawlers respectively. The influence of a number of factors (e.g. depth, fishing gear, tow duration and season on bycatch and discards is discussed.

  9. Role of pelagic crustaceans in the diet of the longnose lancetfish ...

    African Journals Online (AJOL)

    The dietary trends of lancetfish are consistent with opportunistic feeding on the most abundant prey. They exploit short food chains based on carnivorous crustaceans, and play an important role in the pelagic trophic functioning of the western Indian Ocean. Keywords: crustaceans, feeding habits, lancetfish, seasonality, ...

  10. Sensitization pattern of crustacean-allergic individuals can indicate allergy to molluscs

    DEFF Research Database (Denmark)

    Vidal, C; Bartolomé, B; Rodríguez, V

    2015-01-01

    This study investigated the sensitization pattern of crustacean-allergic patients according to tolerance to molluscs. Thirty-one patients with anaphylaxis to crustaceans (14 with mollusc allergy and 17 with mollusc tolerance) were studied using skin prick tests (SPTs), specific IgEs (sIgEs) and SDS-PAGE...

  11. Cretaceous and Cenozoic decapod crustaceans of Jamaica

    NARCIS (Netherlands)

    Donovan, Stephen K.; Portell, Roger W.; Collins, Joe S.H.

    2003-01-01

    In the last decade, a rebirth in interest of Jamaican fossil crustaceans has occurred. A summary of known material is provided together with some indications of the directions that future studies should take.

  12. Histological techniques for marine bivalve mollusks and crustaceans, 2nd edition

    OpenAIRE

    Howard, Dorothy W.; Lewis, Earl J.; Keller, B. Jane; Smith, Cecelia S.

    2004-01-01

    Investigators at the Cooperative Oxford Laboratory (COL) diagnose and study crustaceans, mollusks, finfish, and a variety of other marine and estuarine invertebrates to assess animal health. This edition updates the Histological Techniques for Marine Bivalve Mollusks manual by Howard and Smith (1983) with additional chapters on molluscan and crustacean techniques. The new edition is intended to serve as a guide for histological processing of shellfish, principally bivalve mollusks and crustac...

  13. Long-term responses of sandy beach crustaceans to the effects of coastal armouring after the 2010 Maule earthquake in South Central Chile

    Science.gov (United States)

    Rodil, Iván F.; Jaramillo, Eduardo; Acuña, Emilio; Manzano, Mario; Velasquez, Carlos

    2016-02-01

    Earthquakes and tsunamis are large physical disturbances frequently striking the coast of Chile with dramatic effects on intertidal habitats. Armouring structures built as societal responses to beach erosion and shoreline retreat are also responsible of coastal squeeze and habitat loss. The ecological implications of interactions between coastal armouring and earthquakes have recently started to be studied for beach ecosystems. How long interactive impacts persist is still unclear because monitoring after disturbance generally extends for a few months. During five years after the Maule earthquake (South Central Chile, February 27th 2010) we monitored the variability in population abundances of the most common crustacean inhabitants of different beach zones (i.e. upper, medium, and lower intertidal) at two armoured (one concrete seawall and one rocky revetment) and one unarmoured sites along the sandy beach of Llico. Beach morphology changed after the earthquake-mediated uplift, restoring upper- and mid-shore armoured levels that were rapidly colonized by typical crustacean species. However, post-earthquake increasing human activities affected the colonization process of sandy beach crustaceans in front of the seawall. Lower-shore crab Emerita analoga was the less affected by armouring structures, and it was the only crustacean species present at the three sites before and after the earthquake. This study shows that field sampling carried out promptly after major disturbances, and monitoring of the affected sites long after the disturbance is gone are effective approaches to increase the knowledge on the interactive effects of large-scale natural phenomena and artificial defences on beach ecology.

  14. Toward crustacean without chemicals: a descriptive analysis of consumer response using price comparisons

    Directory of Open Access Journals (Sweden)

    Charles Odilichukwu R. Okpala

    2016-10-01

    Full Text Available Background: To date, there seems to be limited-to-zero emphasis about how consumers perceive crustacean products subject to either chemical and or non-chemical preservative treatments. In addition, studies that investigated price comparisons of crustacean products subject to either chemical or chemical-free preservative methods seem unreported. Objective: This study focused on providing some foundational knowledge about how consumers perceive traditionally harvested crustaceans that are either chemical-treated and or free of chemicals, incorporating price comparisons using a descriptive approach. Design: The study design employed a questionnaire approach via interview using a computer-assisted telephone system and sampled 1,540 participants across five key locations in Italy. To actualize consumer sensitivity, ‘price’ was the focus given its crucial role as a consumption barrier. Prior to this, variables such as demographic characteristics of participants, frequency of purchasing, quality attributes/factors that limit the consumption of crustaceans were equally considered. Results: By price comparisons, consumers are likely to favor chemical-free (modified atmosphere packaging crustacean products amid a price increase of up to 15%. But, a further price increase such as by 25% could markedly damage consumers’ feelings, which might lead to a considerable number opting out in favor of either chemical-treated or other seafood products. Comparing locations, the studied variables showed no statistical differences (p>0.05. On the contrary, the response weightings fluctuated across the studied categories. Both response weightings and coefficient of variation helped reveal more about how responses deviated per variable categories. Conclusions: This study has revealed some foundational knowledge about how consumers perceive traditionally harvested crustaceans that were either chemical-treated or subject to chemical-free preservative up to price

  15. Toward crustacean without chemicals: a descriptive analysis of consumer response using price comparisons.

    Science.gov (United States)

    Okpala, Charles Odilichukwu R; Bono, Gioacchino; Pipitone, Vito; Vitale, Sergio; Cannizzaro, Leonardo

    2016-01-01

    To date, there seems to be limited-to-zero emphasis about how consumers perceive crustacean products subject to either chemical and or non-chemical preservative treatments. In addition, studies that investigated price comparisons of crustacean products subject to either chemical or chemical-free preservative methods seem unreported. This study focused on providing some foundational knowledge about how consumers perceive traditionally harvested crustaceans that are either chemical-treated and or free of chemicals, incorporating price comparisons using a descriptive approach. The study design employed a questionnaire approach via interview using a computer-assisted telephone system and sampled 1,540 participants across five key locations in Italy. To actualize consumer sensitivity, 'price' was the focus given its crucial role as a consumption barrier. Prior to this, variables such as demographic characteristics of participants, frequency of purchasing, quality attributes/factors that limit the consumption of crustaceans were equally considered. By price comparisons, consumers are likely to favor chemical-free (modified atmosphere packaging) crustacean products amid a price increase of up to 15%. But, a further price increase such as by 25% could markedly damage consumers' feelings, which might lead to a considerable number opting out in favor of either chemical-treated or other seafood products. Comparing locations, the studied variables showed no statistical differences ( p >0.05). On the contrary, the response weightings fluctuated across the studied categories. Both response weightings and coefficient of variation helped reveal more about how responses deviated per variable categories. This study has revealed some foundational knowledge about how consumers perceive traditionally harvested crustaceans that were either chemical-treated or subject to chemical-free preservative up to price sensitivity using Italy as a reference case, which is applicable to other parts

  16. [Diversity and faunal analysis of crustaceans in Potatso National Park, Shangri-La, China].

    Science.gov (United States)

    Shu, Shu-Sen; Chen, Fei-Zhou; Yang, Jun-Xing; Yang, Xiao-Jun; Chen, Xiao-Yong

    2013-06-01

    Potatso National Park was the first national park in mainland China, preceded by the earlier Bitahai Nature Reserve. Located in the northwest of Yunnan and on the southeast of Qinghai-Tibet plateau, Potatso is a typical low latitude and high elevation wetland nature reserve, with large areas of coniferous forest around alpine lakes and both wetland and water area ecosystems. In August, 2011, we undertook a survey of crustaceans in the park, sampling lakes, ponds, streams, and rivers throughout Potatso. We found a total of 29 species (including varieties) belonging to 24 genera and 11 families. Notable discoveries include Parartemiopsis sp, Arctodiaptomus parvispinus and Simocephalus congener, which are the first examples of these species to be recorded in China. Likewise, Gammarus bitaensis is a unique crustacean found only in Potatso National Park and Thermocyclops dumonti and Gammarus paucispinus are both endemic species to northwestern Yunnan. The overall faunal characteristics of crustaceans in the park also revealed several things about Potatso: (1) Cosmopolitan and Palaearctic elements reach 48.27% and 37.93%, clearly showing the Palaearctic element as the dominant fauna; (2) most of the crustacean, such as Arctodiaptomus parvispinus and Gammarus, are typical alpine types, confirming that Potatso has feature typical of alpine and plateau fauna; and (3) the proportion of endemic and rare crustacean species in Potatso National Park is approximately 10%, suggesting that the Potatso National Park in particular and the northwest of Yunnan in general have a unique geological and evolutionary history.

  17. [Effects of large bio-manipulation fish pen on community structure of crustacean zooplankton in Meiliang Bay of Taihu Lake].

    Science.gov (United States)

    Ke, Zhi-Xin; Xie, Ping; Guo, Long-Gen; Xu, Jun; Zhou, Qiong

    2012-08-01

    In 2005, a large bio-manipulation pen with the stock of silver carp and bighead carp was built to control the cyanobacterial bloom in Meiliang Bay of Taihu Lake. This paper investigated the seasonal variation of the community structure of crustacean zooplankton and the water quality within and outside the pen. There were no significant differences in the environmental parameters and phytoplankton biomass within and outside the pen. The species composition and seasonal dynamics of crustacean zooplankton within and outside the pen were similar, but the biomass of crustacean zooplankton was greatly suppressed by silver carp and bighead carp. The total crustacean zooplankton biomass and cladocerans biomass were significantly lower in the pen (P < 0.05). In general, silver carp and bighead carp exerted more pressure on cladoceran species than on copepod species. A distinct seasonal succession of crustacean zooplankton was observed in the Bay. Many crustacean species were only dominated in given seasons. Large-sized crustacean (mainly Daphnia sp. and Cyclops vicnus) dominated in winter and spring, while small-sized species (mainly Bosmina sp., Ceriodaphnia cornuta, and Limnoithona sinensis) dominated in summer and autumn. Canonical correspondence analysis showed that water transparency, temperature, and phytoplankton biomass were the most important factors affecting the seasonal succession of the crustacean.

  18. Roles of crustacean hyperglycaemic hormone in ionic and metabolic homeostasis in the Christmas Island blue crab, Discoplax celeste.

    Science.gov (United States)

    Turner, Lucy M; Webster, Simon G; Morris, Stephen

    2013-04-01

    There is a growing body of evidence implicating the involvement of crustacean hyperglycaemic hormone (CHH) in ionic homeostasis in decapod crustaceans. However, little is known regarding hormonally influenced osmoregulatory processes in terrestrial decapods. As many terrestrial decapods experience opposing seasonal demands upon ionoregulatory physiologies, we reasoned that these would make interesting models in which to study the effect of CHH upon these phenomena. In particular, those (tropical) species that also undergo seasonal migrations might be especially informative, as we know relatively little regarding the nature of CHHs in terrestrial decapods, and hormonally mediated responses to seasonal changes in metabolic demands might also be superimposed or otherwise integrated with those associated with ionic homeostasis. Using Discoplax celeste as a model crab that experiences seasonal extremes in water availability, and exhibits diurnal and migratory activity patterns, we identified two CHHs in the sinus gland. We biochemically characterised (cDNA cloning) one CHH and functionally characterised (in terms of dose-dependent hyperglycaemic responses and glucose-dependent negative feedback loops) both CHHs. Whole-animal in situ branchial chamber (22)NaCl perfusion experiments showed that injection of both CHHs increased gill Na(+) uptake in a seasonally dependent manner, and (51)Cr-EDTA clearance experiments demonstrated that CHH increased urine production by the antennal gland. Seasonal and salinity-dependent differences in haemolymph CHH titre further implicated CHH in osmoregulatory processes. Intriguingly, CHH appeared to have no effect on gill Na(+)/K(+)-ATPase or V-ATPase activity, suggesting unknown mechanisms of this hormone's action on Na(+) transport across gill epithelia.

  19. Crustacean hyperglycemic hormone (cHH as a modulator of aggression in crustacean decapods.

    Directory of Open Access Journals (Sweden)

    Laura Aquiloni

    Full Text Available Biogenic amines, particularly serotonin, are recognised to play an important role in controlling the aggression of invertebrates, whereas the effect of neurohormones is still underexplored. The crustacean Hyperglycemic Hormone (cHH is a multifunctional member of the eyestalk neuropeptide family. We expect that this neuropeptide influences aggression either directly, by controlling its expression, or indirectly, by mobilizing the energetic stores needed for the increased activity of an animal. Our study aims at testing such an influence and the possible reversion of hierarchies in the red swamp crayfish, Procambarus clarkii, as a model organism. Three types of pairs of similarly sized males were formed: (1 'control pairs' (CP, n = 8: both individuals were injected with a phosphate saline solution (PBS; (2 'reinforced pairs' (RP, n = 9: the alpha alone was injected with native cHH, and the beta with PBS; (3 'inverted pairs' (IP, n = 9: the opposite of (2. We found that, independently of the crayfish's prior social experience, cHH injections induced (i the expression of dominance behaviour, (ii higher glycemic levels, and (iii lower time spent motionless. In CP and RP, fight intensity decreased with the establishment of dominance. On the contrary, in IP, betas became increasingly likely to initiate and escalate fights and, consequently, increased their dominance till a temporary reversal of the hierarchy. Our results demonstrate, for the first time, that, similarly to serotonin, cHH enhances individual aggression, up to reverse, although transitorily, the hierarchical rank. New research perspectives are thus opened in our intriguing effort of understanding the role of cHH in the modulation of agonistic behaviour in crustaceans.

  20. Molecular evolution of the crustacean hyperglycemic hormone family in ecdysozoans

    Directory of Open Access Journals (Sweden)

    Soyez Daniel

    2010-02-01

    Full Text Available Abstract Background Crustacean Hyperglycemic Hormone (CHH family peptides are neurohormones known to regulate several important functions in decapod crustaceans such as ionic and energetic metabolism, molting and reproduction. The structural conservation of these peptides, together with the variety of functions they display, led us to investigate their evolutionary history. CHH family peptides exist in insects (Ion Transport Peptides and may be present in all ecdysozoans as well. In order to extend the evolutionary study to the entire family, CHH family peptides were thus searched in taxa outside decapods, where they have been, to date, poorly investigated. Results CHH family peptides were characterized by molecular cloning in a branchiopod crustacean, Daphnia magna, and in a collembolan, Folsomia candida. Genes encoding such peptides were also rebuilt in silico from genomic sequences of another branchiopod, a chelicerate and two nematodes. These sequences were included in updated datasets to build phylogenies of the CHH family in pancrustaceans. These phylogenies suggest that peptides found in Branchiopoda and Collembola are more closely related to insect ITPs than to crustacean CHHs. Datasets were also used to support a phylogenetic hypothesis about pancrustacean relationships, which, in addition to gene structures, allowed us to propose two evolutionary scenarios of this multigenic family in ecdysozoans. Conclusions Evolutionary scenarios suggest that CHH family genes of ecdysozoans originate from an ancestral two-exon gene, and genes of arthropods from a three-exon one. In malacostracans, the evolution of the CHH family has involved several duplication, insertion or deletion events, leading to neuropeptides with a wide variety of functions, as observed in decapods. This family could thus constitute a promising model to investigate the links between gene duplications and functional divergence.

  1. Relation between physico-chemical limnology and crustacean community in Wular Lake of Kashmir Himalaya.

    Science.gov (United States)

    Shah, Javaid Ahmad; Pandit, Ashok K

    2013-10-01

    The present study scrutinizes the seasonal variation in the distribution of crustacean zooplankton in relation to physico-chemical liminology of Wular lake. Water samples were collected from five study sites during September 2010-August 2011. Remarkable spatial and temporal variations were observed among the different study sites. Among the parameters recorded water temperature showed positive correlation with pH (p<0.01) and orthophosphate (p<0.05).Transparency showed a significant negative correlation with total alkalinity (p<0.01), free carbon dioxide (p<0.01) and ammonical nitrogen (p<0.01). Crustacean zooplankton were collected by filtering 100 L lake water through a 30 microm nytal mesh and preserved in 4% formalin. A total of 42 taxa of crustacean were recorded, among them 23 species belonged to Cladocera, 16 to Copepoda and only 3 to Ostracoda. Species diversity and density depicted an abrupt up surge on the advent of warmer period (extending from March). Among the various sites a maximum of 40 species were recorded from a single biotope (site III) against the minimum of only 17 species being recorded from site I. Bray-Curtis cluster analysis showed close similarity (0.928-0.944%) between summer and autumn in terms of species diversity. Pearson correlation coefficient of the various physico-chemical parameters of water with crustacean zooplankton depicted that not only a single but multiple factors govern over the distribution and diversity of crustacean in the lake.

  2. Fast real-time PCR for the detection of crustacean allergen in foods.

    Science.gov (United States)

    Herrero, Beatriz; Vieites, Juan M; Espiñeira, Montserrat

    2012-02-29

    Crustaceans are one of the most common allergens causing severe food reaction. These food allergens are a health problem, and they have become very important; there are various regulations that establish that labeling must be present regarding these allergens to warn consumers. In the present work a fast real-time PCR, by a LNA probe, was developed. This allows the detection of crustaceans in all kinds of products, including processed products in which very aggressive treatments of temperature and pressure during the manufacturing process are used. This methodology provides greater sensitivity and specificity and reduces the analysis time of real-time PCR to 40 min. This methodology was further validated by means of simulating products likely to contain this allergen. For this, products present on the market were spiked with crustacean cooking water. The assay is a potential tool in issues related to the labeling of products and food security to protect the allergic consumer.

  3. Consumption of crustaceans by megaherbivorous dinosaurs: dietary flexibility and dinosaur life history strategies.

    Science.gov (United States)

    Chin, Karen; Feldmann, Rodney M; Tashman, Jessica N

    2017-09-21

    Large plant-eating dinosaurs are usually presumed to have been strictly herbivorous, because their derived teeth and jaws were capable of processing fibrous plant foods. This inferred feeding behavior offers a generalized view of dinosaur food habits, but rare direct fossil evidence of diet provides more nuanced insights into feeding behavior. Here we describe fossilized feces (coprolites) that demonstrate recurring consumption of crustaceans and rotted wood by large Late Cretaceous dinosaurs. These multi-liter coprolites from the Kaiparowits Formation are primarily composed of comminuted conifer wood tissues that were fungally degraded before ingestion. Thick fragments of laminar crustacean cuticle are scattered within the coprolite contents and suggest that the dinosaurian defecators consumed sizeable crustaceans that sheltered in rotting logs. The diet of decayed wood and crustaceans offered a substantial supply of plant polysaccharides, with added dividends of animal protein and calcium. Nevertheless, it is unlikely that the fossilized fecal residues depict year-round feeding habits. It is more reasonable to infer that these coprolites reflected seasonal dietary shifts-possibly related to the dinosaurs' oviparous breeding activities. This surprising fossil evidence challenges conventional notions of herbivorous dinosaur diets and reveals a degree of dietary flexibility that is consistent with that of extant herbivorous birds.

  4. Fast Real-Time PCR for the Detection of Crustacean Allergens in Foods.

    Science.gov (United States)

    Santaclara, Francisco J; Espiñeira, Montserrat

    2017-01-01

    Crustaceans are one of the most common allergens causing severe food reaction. Hypersensitivity reactions associated with seafood intake are one of the most common food allergies in adults. Crustaceans including shrimps, prawns, crabs, lobster, and crayfish are a common cause of anaphylaxis or hypersensitivity, with shrimps and crabs being the most common causes of allergy. Symptoms occur most often when food or cooking water are ingested.These food allergens are a health problem, and they have become very important; as evidenced by the existence of several regulations that establish that labeling must be present regarding these allergens to warn consumers.The methodology herein exposed allows the detection of crustaceans in any type of product, including those where very aggressive treatments of temperature and pressure are used during the manufacturing process.The main features of this method are its high sensitivity and specificity, and reduced analysis time of real-time PCR (40 min). This assay is a potential tool in issues related to the labeling of products and food security to protect the allergic consumer.

  5. MIO-PLIOCENE CRUSTACEANS FROM THE CANARY ISLANDS, SPAIN

    Directory of Open Access Journals (Sweden)

    JUAN FRANCISCO BETANCORT

    2014-11-01

    Full Text Available There are few previous references to fossil crustaceans for the Neogene marine layers of the Canary Islands (Spain. The Mio-Pliocene marine sedimentary layers in the eastern islands (Gran Canaria, Fuerteventura and Lanzarote were previously characterised by the presence of numerous fossil fauna, mainly anthozoans and molluscs, which correspond to an equatorial-typepalaeoclimate, warmer than the present climate. This Mio-Pliocene transition dated between 9.3 and 4.1 Ma. In this paper, 12 fossil crustacean taxa are identified and classified, including decapods and barnacles: Balanus concavus Bronn, 1831, Balanus spongicola Brown, 1827, Balanus perforatus Bruguière, 1789, Chenolobia testudinaria Linnè, 1767, Tetraclita cf. rubescens Darwin, 1854, Callianassa matsoni Rathbun, 1935, Callianassa sp., Upogebia sp, Eriphia aff. verrucosa (Forskal, 1775 , Maja sp., Scylla michelini Milne-Edwards, 1861 and Ocypode sp. Some of these taxa mean new references for the Atlantic islands and the North African Atlantic and definitely enlarge the palaeographic distribution of Neogene crustaceans beyond the Mediterranean region, extending it to the North Atlantic. Particularly significant are the presence of Tetraclita cf. rubescens ,this being the first reported fossil occurrence of this barnacle outside the North America Pacific coasts, and Chenolobia testudinaria , indicating for the first time the existence of marine turtles in these islands during the Neogene. These results are coherent with previous research hypothesising the existence of a flow of surface water between the Pacific and Atlantic in the Mio-Pliocene transition (Central American Seaway, CAS which explains the arrival of organisms, in larval stage, from Central America to the Canary Islands.

  6. Null models for study Rotifers and Crustaceans Zooplankton species richness in Chilean Patagonian lakes

    OpenAIRE

    Escalante, Patricio de los Ríos

    2016-01-01

    Abstract Aims The Patagonian lakes are characterized by their oligotrophy that is the cause of low species number in their zooplankton assemblage. The aim of the present study is to analyze the crustacean and rotifers species number pattern in Patagonian lakes among a latitudinal gradient (40-51 °S). Results The results revealed that there are direct significant correlations between total species with rotifer species, and chlorophyll concentration with crustacean species number, and an inve...

  7. Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding

    Science.gov (United States)

    Plaisance, L.; Knowlton, N.; Paulay, G.; Meyer, C.

    2009-12-01

    The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two similar-sized dead heads of Pocillopora were sampled at 10 m depth from five central Pacific Ocean localities (four atolls in the Northern Line Islands and in Moorea, French Polynesia). All crustaceans were removed, and partial cytochrome oxidase subunit I was sequenced from 403 individuals, yielding 135 distinct taxa using a species-level criterion of 5% similarity. Most crustacean species were rare; 44% of the OTUs were represented by a single individual, and an additional 33% were represented by several specimens found only in one of the five localities. The Northern Line Islands and Moorea shared only 11 OTUs. Total numbers estimated by species richness statistics (Chao1 and ACE) suggest at least 90 species of crustaceans in Moorea and 150 in the Northern Line Islands for this habitat type. However, rarefaction curves for each region failed to approach an asymptote, and Chao1 and ACE estimators did not stabilize after sampling eight heads in Moorea, so even these diversity figures are underestimates. Nevertheless, even this modest sampling effort from a very limited habitat resulted in surprisingly high species numbers.

  8. Diversity of decapod crustaceans at the interface of unconsolidated ...

    African Journals Online (AJOL)

    The decapod crustacean assemblages from unconsolidated seabed areas located near rocky shores in the Ubatuba region on the south-east coast of Brazil were analysed by investigating the abundance, richness, diversity and dominance of species. The relationships of the sediment and bottom-water temperature to total ...

  9. Occurrence and molecular characterisation of Vibrio parahaemolyticus in crustaceans commercialised in Venice area, Italy.

    Science.gov (United States)

    Caburlotto, Greta; Suffredini, Elisabetta; Toson, Marica; Fasolato, Luca; Antonetti, Paolo; Zambon, Michela; Manfrin, Amedeo

    2016-03-02

    Infections due to the pathogenic human vibrios, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, are mainly associated with consumption of raw or partially cooked bivalve molluscs. At present, little is known about the presence of Vibrio species in crustaceans and the risk of vibriosis associated with the consumption of these products. The aim of the present study was to evaluate the prevalence and concentration of the main pathogenic Vibrio spp. in samples of crustaceans (n=143) commonly eaten in Italy, taking into account the effects of different variables such as crustacean species, storage conditions and geographic origin. Subsequently, the potential pathogenicity of V. parahaemolyticus strains isolated from crustaceans (n=88) was investigated, considering the classic virulence factors (tdh and trh genes) and four genes coding for relevant proteins of the type III secretion systems 2 (T3SS2α and T3SS2β). In this study, the presence of V. cholerae and V. vulnificus was never detected, whereas 40 samples (28%) were positive for V. parahaemolyticus with an overall prevalence of 41% in refrigerated products and 8% in frozen products. The highest prevalence and average contamination levels were detected in Crangon crangon (prevalence 58% and median value 3400 MPN/g) and in products from the northern Adriatic Sea (35%), with the samples from the northern Venetian Lagoon reaching a median value of 1375 MPN/g. While genetic analysis confirmed absence of the tdh gene, three of the isolates contained the trh gene and, simultaneously, the T3SS2β genes. Moreover three possibly clonal tdh-negative/trh-negative isolates carried the T3SS2α apparatus. The detection of both T3SS2α and T3SS2β apparatuses in V. parahaemolyticus strains isolated from crustaceans emphasised the importance of considering new genetic markers associated with virulence besides the classical factors. Moreover this study represents the first report dealing with Vibrio spp. in

  10. External morphology of Lightiella monniotae (Crustacea, Cephalocarida) in the light of Cambrian 'Orsten' crustaceans

    DEFF Research Database (Denmark)

    Olesen, Jørgen; Haug, Joachim T.; Maas, Andreas

    2011-01-01

    The species-poor meiofaunal Cephalocarida have played an important role in discussions of the phylogeny and evolution of Crustacea since their discovery in 1955. One reason may be that the morphology of cephalocarids includes some aspects of putatively ancient appearance, such as the simple roof-...... has again proved to be especially appropriate because of the small size of these animals, and because it permits direct comparisons with other similarly small crustaceans and the ‘Orsten’ crustaceans and their larvae....

  11. Horizontal transfer of transposons between and within crustaceans and insects.

    Science.gov (United States)

    Dupeyron, Mathilde; Leclercq, Sébastien; Cerveau, Nicolas; Bouchon, Didier; Gilbert, Clément

    2014-01-29

    Horizontal transfer of transposable elements (HTT) is increasingly appreciated as an important source of genome and species evolution in eukaryotes. However, our understanding of HTT dynamics is still poor in eukaryotes because the diversity of species for which whole genome sequences are available is biased and does not reflect the global eukaryote diversity. In this study we characterized two Mariner transposable elements (TEs) in the genome of several terrestrial crustacean isopods, a group of animals particularly underrepresented in genome databases. The two elements have a patchy distribution in the arthropod tree and they are highly similar (>93% over the entire length of the element) to insect TEs (Diptera and Hymenoptera), some of which were previously described in Ceratitis rosa (Crmar2) and Drosophila biarmipes (Mariner-5_Dbi). In addition, phylogenetic analyses and comparisons of TE versus orthologous gene distances at various phylogenetic levels revealed that the taxonomic distribution of the two elements is incompatible with vertical inheritance. We conclude that the two Mariner TEs each underwent at least three HTT events. Both elements were transferred once between isopod crustaceans and insects and at least once between isopod crustacean species. Crmar2 was also transferred between tephritid and drosophilid flies and Mariner-5 underwent HT between hymenopterans and dipterans. We demonstrate that these various HTTs took place recently (most likely within the last 3 million years), and propose iridoviruses and/or Wolbachia endosymbionts as potential vectors of these transfers.

  12. Red pigment-concentrating hormone is not limited to crustaceans

    Czech Academy of Sciences Publication Activity Database

    Gäde, G.; Auerswald, L.; Šimek, Petr; Marcoa, H. G.; Kodrík, Dalibor

    2003-01-01

    Roč. 309, - (2003), s. 967-973 ISSN 0006-291X R&D Projects: GA AV ČR IPP1050128; GA AV ČR IAA6007202 Institutional research plan: CEZ:AV0Z5007907 Keywords : Arthropods * Crustaceans * insects Subject RIV: ED - Physiology Impact factor: 2.836, year: 2003

  13. The crustacean zooplankton assemblage of a relatively pristine Utor ...

    African Journals Online (AJOL)

    The water quality and crustacean zooplankton of Utor River, a relatively pristine freshwater body in Edo State, Nigeria was investigated at four stations. The Utor River is slightly acidic, well oxygenated, oligotrophic and low in solids, conductivity, cations and heavy metals. A total of 380 individuals comprising eleven taxa ...

  14. SHELF LIFE OF THAWED CRUSTACEANS TREATED WITH SULPHITES

    Directory of Open Access Journals (Sweden)

    G. Smaldone

    2011-04-01

    Full Text Available The quality of fish and fish products is closely related to their freshness. Aim of this research was to evaluate the shelf life of thawed crustaceans (Aristeomorpha foliacea and Nefrops norvegicus which had been treated with sulphites and frozen on board. Organoleptic characteristics and microbiological and chemical parameters were judged favourably up to day 6 and 7 for the shrimps and Norway lobsters, respectively.

  15. Predation by crustaceans on native and non-native Baltic clams

    NARCIS (Netherlands)

    Ejdung, G.; Flach, E.; Byrén, L.; Hummel, H.

    2009-01-01

    We studied the effect of crustacean predators on native/non-native Macoma balthica bivalves in aquarium experiments. North Sea M. balthica (NS Macoma) were recently observed in the southern Baltic Sea. They differ genetically and in terms of morphology, behaviour and evolutionary history from Baltic

  16. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    OpenAIRE

    Mayorga,Pablo; Pérez,Karen R.; Cruz,Sully M.; Cáceres,Armando

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  17. Ionotropic crustacean olfactory receptors.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Corey

    Full Text Available The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs, the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs, as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

  18. Anticholinesterase effect of eserine (physostigmine in fish and crustacean species

    Directory of Open Access Journals (Sweden)

    Monserrat José M.

    2001-01-01

    Full Text Available The kinetic characteristic (Km of cholinesterase from the crab Chasmagnathus granulata, the shrimp Farfantepenaeus paulensis and the fish Odontesthes bonaeriensis were compared and correlated with the anticholinesterasic effect of eserine (physostigmine. For the crustaceans, the estimated Km values were about 5-8 times higher than that estimated for the fish (0.04 mM. In the crab and the shrimp, the concentration of eserine which inhibited 50% of cholinesterase activity (IC50 was estimated as 5.33x10-4 and 4.33x10-4 mM, respectively. In both cases, it was significantly higher (P < 0.05 than that estimated for the fish larvae (7.43x10-5 mM. A high Km could reflect a lower affinity of the cholinesterase for its natural substrate, acetylcholine, or for substrate analogues such as carbamates and organophosphorous pesticides. If we consider the IC50 for eserine as an index of enzyme susceptibility to pesticide inhibition, the cholinesterase from the fish larvae may be a better useful tool in assays for pesticide biomonitoring than that from crustacean species.

  19. Chitin Extraction from Crustacean Shells Using Biological Methods – A Review

    Directory of Open Access Journals (Sweden)

    Wassila Arbia

    2013-01-01

    Full Text Available After cellulose, chitin is the most widespread biopolymer in nature. Chitin and its derivatives have great economic value because of their biological activities and their industrial and biomedical applications. It can be extracted from three sources, namely crustaceans, insects and microorganisms. However, the main commercial sources of chitin are shells of crustaceans such as shrimps, crabs, lobsters and krill that are supplied in large quantities by the shellfish processing industries. Extraction of chitin involves two steps, demineralisation and deproteinisation, which can be conducted by two methods, chemical or biological. The chemical method requires the use of acids and bases, while the biological method involves microorganisms. Although lactic acid bacteria are mainly applied, other microbial species including proteolytic bacteria have also been successfully implemented, as well as mixed cultures involving lactic acid-producing bacteria and proteolytic microorganisms. The produced lactic acid allows shell demineralisation, since lactic acid reacts with calcium carbonate, the main mineral component, to form calcium lactate.

  20. Decapod crustaceans from the Neogene of the Caribbean: diversity, distribution and prospectus

    NARCIS (Netherlands)

    Collins, J.S.H.; Portell, R.W.; Donovan, S.K.

    2009-01-01

    The Neogene decapod crustaceans are reviewed from Aruba, Bonaire and Curaçao, Anguilla, Barbados, Carriacou, Costa Rica, Cuba, Florida, Hispaniola (Haiti and Dominican Republic), Jamaica, Mexico, Panama, Puerto Rico, St. Kitts, Tintamare Island, Trinidad and Venezuela. The most widely distributed

  1. Disease will limit future food supply from the global crustacean fishery and aquaculture sectors.

    Science.gov (United States)

    Stentiford, G D; Neil, D M; Peeler, E J; Shields, J D; Small, H J; Flegel, T W; Vlak, J M; Jones, B; Morado, F; Moss, S; Lotz, J; Bartholomay, L; Behringer, D C; Hauton, C; Lightner, D V

    2012-06-01

    Seafood is a highly traded food commodity. Farmed and captured crustaceans contribute a significant proportion with annual production exceeding 10 M metric tonnes with first sale value of $40bn. The sector is dominated by farmed tropical marine shrimp, the fastest growing sector of the global aquaculture industry. It is significant in supporting rural livelihoods and alleviating poverty in producing nations within Asia and Latin America while forming an increasing contribution to aquatic food supply in more developed countries. Nations with marine borders often also support important marine fisheries for crustaceans that are regionally traded as live animals and commodity products. A general separation of net producing and net consuming nations for crustacean seafood has created a truly globalised food industry. Projections for increasing global demand for seafood in the face of level or declining fisheries requires continued expansion and intensification of aquaculture while ensuring best utilisation of captured stocks. Furthermore, continued pressure from consuming nations to ensure safe products for human consumption are being augmented by additional legislative requirements for animals (and their products) to be of low disease status. As a consequence, increasing emphasis is being placed on enforcement of regulations and better governance of the sector; currently this is a challenge in light of a fragmented industry and less stringent regulations associated with animal disease within producer nations. Current estimates predict that up to 40% of tropical shrimp production (>$3bn) is lost annually, mainly due to viral pathogens for which standard preventative measures (e.g. such as vaccination) are not feasible. In light of this problem, new approaches are urgently required to enhance yield by improving broodstock and larval sourcing, promoting best management practices by farmer outreach and supporting cutting-edge research that aims to harness the natural

  2. Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle (rhizophoraceae) at Cispata Bay, Cordoba, Colombia

    International Nuclear Information System (INIS)

    Quiros R, Jorge Alexander; Arias, Jorge Enrique

    2013-01-01

    Despite the existing knowledge on the ecology of mangroves at Cispata Bay, few studies have focused on the association of invertebrates on red mangrove roots, so between December 2010 and September 2011, it was characterized Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle in two study sites at Cispata Bay, Colombia. For the collections of biological material were randomly taken three red mangrove roots with a diameter homogeneous by sampling station. Mollusks and crustaceans were obtained from the root surface with a scraping knife then were removed and fixed in 10 % formalin for later identification to species using specialized taxonomic keys. of the 12289 individuals collected in the four samples, 10470 belonged to the phylum Mollusca (85,2 %) and the remaining 1819 to subphylum Crustacea (14,8 %). for mollusks were identified 14 species distributed in 11 families and two classes; bivalvia and gastropoda. for crustaceans were identified 24 species distributed in 16 families and four orders; sessillia, decapoda, isopoda and amphipoda. in both sectors sampling mytella charruana, balanuseburneus and crassostrea rhizophorae were the most important species in terms of abundance, however mollusks like m. charruana and B. eburneus have a great ability to adapt and adjust to changing hydroclimatic, which was reflected in the dominance of these species in the sector with the greatest influence Sinu River. The presence of crustaceans Petrolisthes armatus and Aratus pisonii in the sector with more proximity to the Caribbean Sea indicate that are species with great mobility and physiological adaptation mechanisms.

  3. Inorganic Biominerals in Crustaceans are Structurally Independent of Organic Framework

    Science.gov (United States)

    Mergelsberg, S. T.; Michel, F. M.; Mukhopadhyay, B.; Dove, P. M.

    2015-12-01

    Biomineralization of calcium carbonate (CaCO3) as crystalline calcite or amorphous CaCO3 (ACC) occurs in the exoskeletons of all crustaceans. These cuticles are complex composites of inorganic mineral and organic macromolecules with highly divergent morphologies that are adapted to the extreme variations in environmental pressures within their diverse ecological niches. The remarkable variations and adaptations that form, infer a highly efficient and regulated mechanism for biomineralization that is most likely orchestrated by a myriad of biomacromolecules (Ziegler A 2012). The roles of these peptides and organic metabolites during CaCO3 biomineralization are not well understood. In part, this is due to a lack of knowledge of crustacean homeostasis. In a step toward understanding cuticle mineralization in crustaceans, this study asks: Which molecules affect biomineralization? Do the biomineral-active molecules vary greatly between species and body parts? Recent studies of polysaccharide controls on mineralization also raise the question of whether small heterogeneities in chitin, the most abundant biopolymer of the composite, could be primarily responsible for differences in CaCO3 crystallinity. This study used a novel spectroscopic approach to characterize the mineral and organic components of exoskeletons from three Malacostraca organisms — American Lobster (Homarus americanus), Dungeness Crab (Metacarcinus magister), and Red Rock Crab (Cancer productus). Using high-energy x-ray diffraction and Raman spectroscopy, the cuticles of three major body parts from these organisms were analyzed for the structure and bulk chemistry of its chitin and CaCO3 components. The findings indicate that Raman spectroscopy provides adequate resolution to show that crystallinity of chitin and the CaCO3 mineral component are chemically independent of each other, although their crystallinities co-vary for Brachyura species (Dungeness and Red Rock Crabs). Insights from this study

  4. Algal Diet of Small-Bodied Crustacean Zooplankton in a Cyanobacteria-Dominated Eutrophic Lake.

    Directory of Open Access Journals (Sweden)

    Ilmar Tõnno

    Full Text Available Small-bodied cladocerans and cyclopoid copepods are becoming increasingly dominant over large crustacean zooplankton in eutrophic waters where they often coexist with cyanobacterial blooms. However, relatively little is known about their algal diet preferences. We studied grazing selectivity of small crustaceans (the cyclopoid copepods Mesocyclops leuckarti, Thermocyclops oithonoides, Cyclops kolensis, and the cladocerans Daphnia cucullata, Chydorus sphaericus, Bosmina spp. by liquid chromatographic analyses of phytoplankton marker pigments in the shallow, highly eutrophic Lake Võrtsjärv (Estonia during a seasonal cycle. Copepods (mainly C. kolensis preferably consumed cryptophytes (identified by the marker pigment alloxanthin in gut contents during colder periods, while they preferred small non-filamentous diatoms and green algae (identified mainly by diatoxanthin and lutein, respectively from May to September. All studied cladoceran species showed highest selectivity towards colonial cyanobacteria (identified by canthaxanthin. For small C. sphaericus, commonly occuring in the pelagic zone of eutrophic lakes, colonial cyanobacteria can be their major food source, supporting their coexistence with cyanobacterial blooms. Pigments characteristic of filamentous cyanobacteria and diatoms (zeaxanthin and fucoxanthin, respectively, algae dominating in Võrtsjärv, were also found in the grazers' diet but were generally avoided by the crustaceans commonly dominating the zooplankton assemblage. Together these results suggest that the co-occurring small-bodied cyclopoid and cladoceran species have markedly different algal diets and that the cladocera represent the main trophic link transferring cyanobacterial carbon to the food web in a highly eutrophic lake.

  5. Records of new localities and hosts for crustacean parasites in fish from the eastern Amazon in northern Brazil.

    Science.gov (United States)

    Oliveira, Marcos Sidney Brito; Corrêa, Lincoln Lima; Oliveira Ferreira, Drielly; Neves, Lígia Rigor; Tavares-Dias, Marcos

    2017-06-01

    The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas , Cichla monoculus , Cichla ocellaris , Cichla jariina , Satanoperca jurupari , Leporinus friderici , Leporinus fasciatus , Hoplias malabaricus , Phractocephalus hemioliopterus , Serrasalmus altispinis , Pseudoplatystoma tigrinum and Potamotrygon motoro of the State Amapá and Pará, in northern Brazil. A total of 242 parasites, including Argulus elongatus , Argulus multicolor, Argulus juparanaensis , Argulus nattereri , Dolops discoidalis , Dolops longicauda , Braga patagonica , Braga fluviatilis , Livoneca guianensis and undetermined Lernaeidae, were collected from these hosts. The Argulus species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than D. discoidalis , was most abundant in the integument of A. gigas and P. tigrinum . Finally, the present study reported nine new hosts for the crustacean parasite species and expanded knowledge of the occurrence of some parasite species in the Jari River basin, in eastern Amazon.

  6. A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa.

    Science.gov (United States)

    Chang, Wai Hoong; Lai, Alvina G

    2018-01-01

    The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

  7. 78 FR 9327 - Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2013-02-08

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XC453 Hawaii Crustacean Fisheries; 2013 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce...

  8. 76 FR 4551 - Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2011-01-26

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 665 RIN 0648-XA159 Hawaii Crustacean Fisheries; 2011 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce...

  9. Decapod crustaceans associated with an artificial reef (Adriatic Sea

    Directory of Open Access Journals (Sweden)

    A. SANTELLI

    2013-10-01

    Full Text Available The aim of this study is to increase the knowledge on the distribution of decapod crustaceans associated with an artificial reef positioned on sandy-mud bottoms in the central Adriatic Sea. The reef is constituted of concrete modules assembled in pyramids and concrete poles. Hard and soft bottom samples were collected from 2001, just after reef construction, to 2005 (4 surveys per year. Regarding the soft seabed, three sites close to a pyramid, three inside the reef area at a distance of 10-15 m from the structures, and three 200 m outside the reef (control sites were randomly sampled during each survey. At the same time, three pyramids (vertical and horizontal walls and three poles were also investigated. After taxonomical analysis, decapod crustaceans were analysed using abundance and species richness. Sites and years were compared using a balanced, fixed effect, 2-way ANOVA and PERMANOVA. In addition, SIMPER analysis was performed to identify those species typifying each community inhabiting both the soft bottom and the artificial substrates. The results showed that the artificial reef induced an increase in both abundance and diversity of the decapods of the natural habitat. In fact, man-made substrates may offer new available space for biological colonization and allow the settlement of new species usually living on hard bottoms, thus increasing the complexity of the original benthic communities.

  10. 76 FR 77214 - Hawaii Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2011-12-12

    ... Crustacean Fisheries; 2012 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY: National Marine...: Notification of lobster harvest guideline. SUMMARY: NMFS establishes the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year 2012 at zero...

  11. [Faunal characteristics and distribution pattern of crustaceans in the vicinity of Pearl River estuary].

    Science.gov (United States)

    Huang, Zi-Rong; Sun, Dian-Rong; Chen, Zuo-Zhi; Zhang, Han-Hua; Wang, Xue-Hui; Wang, Yue-Zhong; Fang, Hong-Da; Dong, Yan-Hong

    2009-10-01

    Based on the data of bottom trawl surveys in the vicinity of Pearl River estuary in August (summer), October (autumn), December (winter) 2006, and April (spring) 2007, the faunal characteristics and distribution pattern of crustaceans were analyzed. A total of 54 species belonging to 25 genera, 17 families, and 2 orders were collected, including 22 species of shrimps, 22 species of crabs, and 10 species of squills. Most of the crustaceans were tropical-subtropical warm-water species, a few of them were eurythermal species, and no warm-water and cold-water species occurred. Euryhaline species were most abundant, followed by halophile species, and the low-salinity species were the least. Most of the crustacean species belonged to the fauna of Indian Ocean-western Pacific Ocean. The faunal assemblages were closer to those of the East China Sea, Philippine Sea, Indonesia Sea, and the Japan Sea, and estranger with those of the Yellow Sea, Bohai Sea, and Korea Sea. The dominant species were Metapenaeus joyner, Oratosquilla oratoria, Charybdis miles, Portunus sanguinolentus, Harpiosquilla harpax, Charybdis feriatus, Charybdis japonica, Oratosquilla nepa, Solenocera crassicornis, Portunus trituberculatus, and Calappa philargius. The crustaceans had the largest species number (33) in autumn and the least one (26) in spring, and the highest stock density at the water depth of crabs had the highest stock density (41.81 kg x km(-2)), followed by shrimps (38.91 kg x km(-2)), and squills (18.88 kg x km(-2)). The stock densities of the 3 species groups showed an obvious seasonal variation. Shrimps had the highest stock density (120.32 kg x km(-2)) in summer and the lowest density (0.67 kg x km(-2)) in spring, while crabs and squills had the highest density (62.01 and 29.49 kg x km(-2), respectively) in winter and the lowest density (24.64 and 6.30 kg x km(-2), respectively) in autumn.

  12. Prevalence of Colacium vesiculosum (Colaciales: Euglenophyceae on planktonic crustaceans in a subtropical shallow lake of Argentina

    Directory of Open Access Journals (Sweden)

    Yolanda Zalocar

    2011-09-01

    Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton <53µm. Crustaceans were sampled using a PVC tube (1.2m long and 10cm in diameter, filtering 50L of water through a 53µm-mesh. Microcrustaceans were counted in Bogorov chambers under a stereoscopic microscope. The infested organisms were separated and observed with a photonic microscope to determine density and biovolume of epibionts, by analyzing their distribution on the exoskeleton. The prevalence of C. vesiculosum was higher in adult crustaceans than in their larvae and juveniles. The most infested group was that of calanoid copepods, related to their high density. The attachment sites on the exoskeleton were found to be the portions of the body which have a higher probability of encounter with epibionts during locomotion and feeding, i.e., antennae and thoracic legs in copepods, and thoracic legs and postabdomen in cladocerans. The similar values found in the filtering rate of infested and uninfested individuals of N. spiniger and the constant prevalence (<40% of epibiont algae, suggest that C. vesiculosum does not condition the life of planktonic crustaceans of Paiva Lake. Rev. Biol. Trop. 59 (3: 1295-1306. Epub 2011 September 01.

  13. Late Devonian (Frasnian) phyllopod and phyllocarid crustacean shields from Belgium reinterpreted as ammonoid anaptychi

    Science.gov (United States)

    Goolaerts, Stijn; Denayer, Julien; Mottequin, Bernard

    2017-12-01

    The taxonomic affinities of fossils from the Frasnian succession of Belgium previously described as phyllopod and phyllocarid crustacean shields are discussed. The rediscovery of the holotype of Ellipsocaris dewalquei, the type species of the genus Ellipsocaris Woodward in Dewalque, 1882, allows to end the discussion on the taxonomic assignation of the genus Ellipsocaris. It is removed from the phyllopod crustaceans as interpreted originally and considered here as an ammonoid anaptychus. Furthermore, it is considered to be a junior synonym of the genus Sidetes Giebel, 1847. Similarly, Van Straelen's (1933) lower to middle Frasnian record Spathiocaris chagrinensis Ruedemann, 1916, is also an ammonoid anaptychus. Although ammonoids can be relatively frequent in some Frasnian horizons of Belgium, anaptychi remain particularly scarce and the attribution to the present material to peculiar ammonoid species is not possible.

  14. THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

    Science.gov (United States)

    Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

  15. Crustaceans from bitumen clast in Carboniferous glacial diamictite extend fossil record of copepods.

    Science.gov (United States)

    Selden, Paul A; Huys, Rony; Stephenson, Michael H; Heward, Alan P; Taylor, Paul N

    2010-08-10

    Copepod crustaceans are extremely abundant but, because of their small size and fragility, they fossilize poorly. Their fossil record consists of one Cretaceous (c. 115 Ma) parasite and a few Miocene (c. 14 Ma) fossils. In this paper, we describe abundant crustacean fragments, including copepods, from a single bitumen clast in a glacial diamictite of late Carboniferous age (c. 303 Ma) from eastern Oman. Geochemistry identifies the source of the bitumen as an oilfield some 100-300 km to the southwest, which is consistent with an ice flow direction from glacial striae. The bitumen likely originated as an oil seep into a subglacial lake. This find extends the fossil record of copepods by some 188 Ma, and of free-living forms by 289 Ma. The copepods include evidence of the extant family Canthocamptidae, believed to have colonized fresh water in Pangaea during Carboniferous times.

  16. Chronobiology of deep-water decapod crustaceans on continental margins.

    Science.gov (United States)

    Aguzzi, Jacopo; Company, Joan B

    2010-01-01

    Species have evolved biological rhythms in behaviour and physiology with a 24-h periodicity in order to increase their fitness, anticipating the onset of unfavourable habitat conditions. In marine organisms inhabiting deep-water continental margins (i.e. the submerged outer edges of continents), day-night activity rhythms are often referred to in three ways: vertical water column migrations (i.e. pelagic), horizontal displacements within benthic boundary layer of the continental margin, along bathymetric gradients (i.e. nektobenthic), and endobenthic movements (i.e. rhythmic emergence from the substrate). Many studies have been conducted on crustacean decapods that migrate vertically in the water column, but much less information is available for other endobenthic and nektobenthic species. Also, the types of displacement and major life habits of most marine species are still largely unknown, especially in deep-water continental margins, where steep clines in habitat factors (i.e. light intensity and its spectral quality, sediment characteristics, and hydrography) take place. This is the result of technical difficulties in performing temporally scheduled sampling and laboratory testing on living specimens. According to this scenario, there are several major issues that still need extensive research in deep-water crustacean decapods. First, the regulation of their behaviour and physiology by a biological clock is almost unknown compared to data for coastal species that are easily accessible to direct observation and sampling. Second, biological rhythms may change at different life stages (i.e. size-related variations) or at different moments of the reproductive cycle (e.g. at egg-bearing) based on different intra- and interspecific interactions. Third, there is still a major lack of knowledge on the links that exist among the observed bathymetric distributions of species and selected autoecological traits that are controlled by their biological clock, such as the

  17. 75 FR 1597 - Western Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline

    Science.gov (United States)

    2010-01-12

    ... Pacific Crustacean Fisheries; 2010 Northwestern Hawaiian Islands Lobster Harvest Guideline AGENCY.... ACTION: Notification of lobster harvest guideline. SUMMARY: NMFS announces that the annual harvest guideline for the commercial lobster fishery in the Northwestern Hawaiian Islands (NWHI) for calendar year...

  18. Hypothesis for heritable, anti-viral immunity in crustaceans and insects

    Directory of Open Access Journals (Sweden)

    Flegel Timothy W

    2009-09-01

    Full Text Available Abstract Background It is known that crustaceans and insects can persistently carry one or more viral pathogens at low levels, without signs of disease. They may transmit them to their offspring or to naïve individuals, often with lethal consequences. The underlying molecular mechanisms have not been elucidated, but the process has been called viral accommodation. Since tolerance to one virus does not confer tolerance to another, tolerance is pathogen-specific, so the requirement for a specific pathogen response mechanism (memory was included in the original viral accommodation concept. Later, it was hypothesized that specific responses were based on the presence of viruses in persistent infections. However, recent developments suggest that specific responses may be based on viral sequences inserted into the host genome. Presentation of the hypothesis Non-retroviral fragments of both RNA and DNA viruses have been found in insect and crustacean genomes. In addition, reverse-transcriptase (RT and integrase (IN sequences are also common in their genomes. It is hypothesized that shrimp and other arthropods use these RT to recognize "foreign" mRNA of both RNA and DNA viruses and use the integrases (IN to randomly insert short cDNA sequences into their genomes. By chance, some of these sequences result in production of immunospecific RNA (imRNA capable of stimulating RNAi that suppresses viral propagation. Individuals with protective inserts would pass these on to the next generation, together with similar protective inserts for other viruses that could be amalgamated rapidly in individual offspring by random assortment of chromosomes. The most successful individuals would be environmentally selected from billions of offspring. Conclusion This hypothesis for immunity based on an imRNA generation mechanism fits with the general principle of invertebrate immunity based on a non-host, "pattern recognition" process. If proven correct, understanding the

  19. The biological effects of ionising radiation on Crustaceans: A review

    International Nuclear Information System (INIS)

    Fuller, Neil; Lerebours, Adélaïde; Smith, Jim T.; Ford, Alex T.

    2015-01-01

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  20. The biological effects of ionising radiation on Crustaceans: A review

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Neil; Lerebours, Adélaïde [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom); Smith, Jim T. [School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, Hampshire PO1 3QL (United Kingdom); Ford, Alex T., E-mail: alex.ford@port.ac.uk [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom)

    2015-10-15

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  1. POLYCLONAL ANTISERA AGAINST ESTUARINE CRUSTACEAN VITELLINS: A MOLECULAR APPROACH TO REPRODUCTIVE ENDOCRINOLOGY AND TOXICOLOGY.

    Science.gov (United States)

    To fully elucidate the action of crustacean hormones, or their agonists, on vitellogenesis and reproduction, it has become increasingly important to develop sensitive assays that indicate a stimulatory or inhibitory effect on easily measured endpoints. Because of the relative ab...

  2. Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile).

    Science.gov (United States)

    De Los Ríos-Escalante, P; Acevedo, P

    2016-01-01

    The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.

  3. Effects of temperature and salinity on the development of the amphipod crustacean Eogammarus sinensis

    Science.gov (United States)

    Xue, Suyan; Fang, Jianguang; Zhang, Jihong; Jiang, Zengjie; Mao, Yuze; Zhao, Fazhen

    2013-09-01

    The amphipod crustacean Eogammarus sinensis has useful features that make it suitable for use in the aquaculture of fish and large decapod crustaceans. In this study, we investigated the effects of temperature and salinity on the development, fecundity, survival, and growth rate of E. sinensis. The results show that temperature significantly affected E. sinensis development, but salinity. As temperature increased, the duration of E. sinensis embryonic development decreased. Fecundity was affected significantly by temperature and the combination of temperature and salinity, but by salinity alone. In addition, high temperatures accelerated E. sinensis juvenile growth rates, whereas high salinity reduced it. Therefore, our data suggest that E. sinensis tolerates a wide range of salinities and that temperature has more significant effects than salinity on the embryonic development, fecundity, and growth of E. sinensis. Our results shall be useful for mass production of this species for use in aquaculture.

  4. Ultraviolet Radiation Induces Dose-Dependent Pigment Dispersion in Crustacean Chromatophores

    OpenAIRE

    Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

    2004-01-01

    Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm2 for UVA and 2.15 J/cm2 for UVB. Maximal response was achieved with 10.0 J/cm...

  5. Decapod crustacean assemblages off the West coast of central Italy (western Mediterranean

    Directory of Open Access Journals (Sweden)

    Emanuela Fanelli

    2007-03-01

    Full Text Available Community structure and faunal composition of decapod crustaceans off the west coast of central Italy (western Mediterranean were investigated. Samples were collected during five trawl surveys carried out from June 1996 to June 2000 from 16 to 750 m depth. Multivariate analysis revealed the occurrence of five faunistic assemblages: 1 a strictly coastal community over sandy bottoms at depths

  6. Disease will limit future food supply from the global crustacean fishery and aquaculture sectors

    NARCIS (Netherlands)

    Stentiford, G.D.; Neil, D.M.; Peeler, E.J.; Shields, J.D.; Small, H.J.; Flegel, T.W.; Vlak, J.M.; Jones, B.; Morado, F.; Moss, S.; Lotz, J.; Bartholomay, L.; Behringer, D.C.; Hauton, C.; Lightner, D.V.

    2012-01-01

    Seafood is a highly traded food commodity. Farmed and captured crustaceans contribute a significant proportion with annual production exceeding 10 M metric tonnes with first sale value of $40bn. The sector is dominated by farmed tropical marine shrimp, the fastest growing sector of the global

  7. Hazard identification of contaminated sites. Ranking potential toxicity of organic sediment extracts in crustacean and fish

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, J.; Sundberg, H.; Aakerman, G.; Grunder, K.; Eklund, B.; Breitholtz, M. [Dept. of Applied Environmental Science (ITM), Stockholm Univ. (Sweden)

    2008-09-15

    Background, aim, and scope: It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between compounds with different polarities. Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure (i.e. ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow trout embryos were exposed using nano-injection technique. Results and discussion Clear concentration-response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related pattern. Interestingly, our results indicate that some of the locations contained toxic semi

  8. Fish and crustaceans in northeast Greenland lakes with special emphasis on interactions between Arctic charr (Salvelinus alpinus), Lepidurus arcticus and benthic chydorids

    DEFF Research Database (Denmark)

    Jeppesen, E.; Christoffersen, K.; Landkildehus, F.

    2001-01-01

    We studied the trophic structure in the pelagial and crustacean remains in the surface 1 cm of the sediment of 13 shallow, high arctic lakes in northeast Greenland (74 N). Seven lakes were fishless, while the remaining six hosted a dwarf form of Arctic charr (Salvelinus alpinus). In fishless lakes...... sp. in lakes with Lepidurus, while they were abundant in lakes with fish. The low abundance in fishless lakes could not be explained by damage of crustacean remains caused by Lepidurus feeding in the sediment, because remains of the more soft-shelled, pelagic-living Daphnia were abundant...... in the sediment of these lakes. No significant differences between lakes with and without fish were found in chlorophyll a, total phosphorus, total nitrogen, conductivity or temperature, suggesting that the observed link between Lepidurus arcticus and the benthic crustacean community is causal. Consequently...

  9. Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants

    Czech Academy of Sciences Publication Activity Database

    Mazurová, E.; Hilscherová, Klára; Triebskorn, R.; Kohler, H.R.; Maršálek, Blahoslav; Bláha, Luděk

    2008-01-01

    Roč. 63, č. 2 (2008), s. 139-150 ISSN 0006-3088 Institutional research plan: CEZ:AV0Z60050516 Keywords : crustaceans * reproduction * endocrine disruption Subject RIV: EF - Botanics Impact factor: 0.406, year: 2008

  10. Size of catch, reproduction and feeding of the small-eye smooth-hound, Mustelus higmani (Carcharhiniformes: Triakidae, in Margarita Island, Venezuela

    Directory of Open Access Journals (Sweden)

    Alejandro Tagliafico

    2015-12-01

    Full Text Available Mustelus higmani is categorized as “least concern” according to the red list of the International Union for Conservation of Nature, but gaps in population trends occur in most of its distribution range. In Venezuela, this species has local importance because it is part of typical dishes. The aim of this work is to analyse the population structure, reproduction and feeding of M. higmani from Margarita Island’s artisanal fishery landings for management purposes. Between 2006 and 2008, 2223 specimens were analysed: 1156 females (24.8-88.4 cm total length [TL] and 1067 males (20-69.2 cm TL. Temporal variations in sex ratio and length class structure were detected. Changes in body size were detected throughout different years of sampling. A decrease in TL and an increase in immature specimens in the catch were observed in 2008. Mean length at maturity (L50 was estimated at 46.7 cm TL for females and 47.6 cm TL for males. Female fecundity was 4±1.8 embryos (n=388. Length at birth was between 20 and 29 cm TL, and no differences in sex ratio were detected for embryos. Feeding analyses (n=266 stomachs showed a diet mainly based on decapod crustaceans, small fish, stomatopods and cephalopods. The trophic level was 3.3, which shows feeding based on benthic and demersal species of the continental shelf, especially crustaceans.

  11. Scale Dependence of the Mechanical Properties and Microstructure of Crustaceans Thin Films as Biomimetic Materials

    Science.gov (United States)

    Verma, Devendra; Qu, Tao; Tomar, Vikas

    2015-04-01

    The exoskeletons of crustacean species in the form of thin films have been investigated by several researchers to better understand the role played by the exoskeletal structure in affecting the functioning of species such as shrimps, crabs, and lobsters. These species exhibit similar designs in their exoskeleton microstructure, such as a Bouligand pattern (twisted plywood structure), layers of different thickness across cross section, change in mineral content through the layers, etc. Different parts of crustaceans exhibit a significant variation in mechanical properties based on the variation in the above-mentioned parameters. This change in mechanical properties has been analyzed by using imaging techniques such as scanning electron microscopy and energy-dispersive x-ray spectroscopy, and by using mechanical characterization techniques such as nanoindentation and atomic force microscopy. In this article, the design principles of these biological composites are discussed based on two shrimp species: Rimicaris exoculata and Pandalus platyceros.

  12. 19 CFR 12.26 - Importations of wild animals, fish, amphibians, reptiles, mollusks, and crustaceans; prohibited...

    Science.gov (United States)

    2010-04-01

    ..., reptiles, mollusks, and crustaceans; prohibited and endangered and threatened species; designated ports of..., Birds, and Insects § 12.26 Importations of wild animals, fish, amphibians, reptiles, mollusks, and... crustacea), amphibians, reptiles, or the offspring or eggs of any of the foregoing which the Secretary of...

  13. House dust mite (Der p 10) and crustacean allergic patients may react to food containing Yellow mealworm proteins.

    Science.gov (United States)

    Verhoeckx, Kitty C M; van Broekhoven, Sarah; den Hartog-Jager, Constance F; Gaspari, Marco; de Jong, Govardus A H; Wichers, Harry J; van Hoffen, Els; Houben, Geert F; Knulst, André C

    2014-03-01

    Due to the imminent growth of the world population, shortage of protein sources for human consumption will arise in the near future. Alternative and sustainable protein sources (e.g. insects) are being explored for the production of food and feed. In this project, the safety of Yellow mealworms (Tenebrio molitor L.) for human consumption was tested using approaches as advised by the European Food Safety Authority for allergenicity risk assessment. Different Yellow mealworm protein fractions were prepared, characterised, and tested for cross-reactivity using sera from patients with an inhalation or food allergy to biologically related species (House dust mite (HDM) and crustaceans) by immunoblotting and basophil activation. Furthermore, the stability was investigated using an in vitro pepsin digestion test. IgE from HDM- and crustacean allergic patients cross-reacted with Yellow mealworm proteins. This cross-reactivity was functional, as shown by the induction of basophil activation. The major cross-reactive proteins were identified as tropomyosin and arginine kinase, which are well known allergens in arthropods. These proteins were moderately stable in the pepsin stability test. Based on these cross-reactivity studies, there is a realistic possibility that HDM- and crustacean allergic patients may react to food containing Yellow mealworm proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Crustacean zooplankton release copious amounts of dissolved organic matter as taurine in the ocean.

    Science.gov (United States)

    Clifford, Elisabeth L; Hansell, Dennis A; Varela, Marta M; Nieto-Cid, Mar; Herndl, Gerhard J; Sintes, Eva

    2017-11-01

    Taurine (Tau), an amino acid-like compound, is present in almost all marine metazoans including crustacean zooplankton. It plays an important physiological role in these organisms and is released into the ambient water throughout their life cycle. However, limited information is available on the release rates by marine organisms, the concentrations and turnover of Tau in the ocean. We determined dissolved free Tau concentrations throughout the water column and its release by abundant crustacean mesozooplankton at two open ocean sites (Gulf of Alaska and North Atlantic). At both locations, the concentrations of dissolved free Tau were in the low nM range (up to 15.7 nM) in epipelagic waters, declining sharply in the mesopelagic to about 0.2 nM and remaining fairly stable throughout the bathypelagic waters. Pacific amphipod-copepod assemblages exhibited lower dissolved free Tau release rates per unit biomass (0.8 ± 0.4 μmol g -1 C-biomass h -1 ) than Atlantic copepods (ranging between 1.3 ± 0.4 μmol g -1 C-biomass h -1 and 9.5 ± 2.1 μmol g -1 C-biomass h -1 ), in agreement with the well-documented inverse relationship between biomass-normalized excretion rates and body size. Our results indicate that crustacean zooplankton might contribute significantly to the dissolved organic matter flux in marine ecosystems via dissolved free Tau release. Based on the release rates and assuming steady state dissolved free Tau concentrations, turnover times of dissolved free Tau range from 0.05 d to 2.3 d in the upper water column and are therefore similar to those of dissolved free amino acids. This rapid turnover indicates that dissolved free Tau is efficiently consumed in oceanic waters, most likely by heterotrophic bacteria.

  15. A long-term study on crustacean plankton of a shallow tropical lake: the role of invertebrate predation

    Directory of Open Access Journals (Sweden)

    Marlene S. Arcifa

    2015-06-01

    Full Text Available The primary factor that governs the size and species composition of zooplankton is still a controversial issue and temperature is considered the main factor responsible for latitudinal differences. In waters with a narrow temperature range, such as in the tropics, predation may be a more important factor. Nearly three decades of intermittent studies of the crustacean plankton in a shallow tropical lake revealed that the main event that led to their restructuring was the appearance of a second predator, the water mite Krendowskia sp. The new predator and larvae of the dipteran Chaoborus brasiliensis Theobald exerted a combined, although asymmetrical effect on microcrustaceans. The period when the mite was detected was followed by the restructuring of the crustacean plankton community. Predation by these two invertebrates emerged as the factor responsible for community changes, involving an increased contribution of copepods and decreases in the relative abundance of smaller cladoceran species. In the short term, the mite caused a decrease in species richness and the annual mean instantaneous composition of cladocerans, a predominance of large-sized species (Daphnia ambigua Scourfield and Daphnia gessneri Herbst and the virtual disappearance of small species (e.g., Bosmina tubicen Brehm. The long-term impact resulted in increased species richness and the dominance of large and medium-sized cladocerans, such as D. gessneri and Ceriodaphnia richardi Sars. The larger body size of three cladocerans, the two Daphnia species and B. tubicen, in the long term, may be a response to the dominant predator, Chaoborus. The seasonal variation in the predator abundance, mainly Chaoborus larvae, allowed the prey to recover during the cool season. The copepods Tropocyclops prasinus meridionalis (Fischer and Thermocyclops decipiens Kiefer were less affected by predation than the cladocerans; their contribution to the crustacean plankton increased 12-28% after the

  16. Ontogeny of decapod crustacean hemocyanin: effects of temperature and nutrition.

    Science.gov (United States)

    Terwilliger, N; Dumler, K

    2001-03-01

    Hemocyanin is present throughout the decapod crustacean's life, usually as one-hexamer and two-hexamer oligomers. Hemocyanins of some decapod crustaceans undergo changes in subunit composition and oxygen affinity during development. Maternal hemocyanin is taken up from the hemolymph via endocytosis by the oocyte. Embryo hemocyanin differs in subunit composition from hemocyanin of oocyte and adult crab and may represent the onset of hemocyanin synthesis. Complex changes in expression of hemocyanin subunits occur through megalopa and early juvenile stages of the crab Cancer magister, culminating in the pattern of adult hemocyanin. The influences of food availability and temperature on development, growth and hemocyanin ontogeny in early juvenile C. magister have been studied. Crabs were raised in warm or cold sea water and fed high or low levels of food for 6 months. While intermolt period was shorter in crabs fed high food levels, especially those raised in warm water, crabs reared in cold water with high food levels attained the largest sizes. Thus increased food availability affects growth more than increased temperature. Adult hemocyanin appeared at about the same number of weeks after the start of the experiment for crabs in the warm water/high food, warm water/low food and cold water/high food groups, even though warm water/low food crabs had molted fewer times. Crabs in the cold water/low food group expressed adult hemocyanin much later than the other groups. Molt stage and maturation from juvenile to adult are not absolutely coupled, and food availability has a greater influence than temperature on hemocyanin ontogeny.

  17. Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

    Science.gov (United States)

    McGaw, Iain J; Curtis, Daniel L

    2013-11-01

    Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal

  18. Consumption of crustaceans by megaherbivorous dinosaurs: dietary flexibility and dinosaur life history strategies

    OpenAIRE

    Chin, Karen; Feldmann, Rodney M.; Tashman, Jessica N.

    2017-01-01

    Large plant-eating dinosaurs are usually presumed to have been strictly herbivorous, because their derived teeth and jaws were capable of processing fibrous plant foods. This inferred feeding behavior offers a generalized view of dinosaur food habits, but rare direct fossil evidence of diet provides more nuanced insights into feeding behavior. Here we describe fossilized feces (coprolites) that demonstrate recurring consumption of crustaceans and rotted wood by large Late Cretaceous dinosaurs...

  19. Crustacean plankton communities in forty-five lakes in the experimental lakes area, northwestern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Patalas, K

    1971-01-01

    Zooplankton communities were characterized on the basis of samples taken in summer as vertical net hauls in the central part of lakes. Twenty-eight species of crustaceans were found in the 45 lakes studied. The highest number of species as well as the highest numbers of individuals (per unit of area) usually occurred in the largest deepest lakes with most transparent water.

  20. Long-term effects to ionizing radiation in crustacean Daphnia magna

    International Nuclear Information System (INIS)

    Sarapul'tseva, E.I.

    2016-01-01

    The results of this study have provided strong evidence for the trans generational effects of parental exposure to ionizing radiation in crustacean Daphnia magna. To establish whether parental irradiation can affect the survival, life span and fertility of directly exposed organisms and their non-exposed offspring, D. magna were given 10, 100, 1000 and 10,000 mGy of acute γ-rays. MTT-assay was first applied for the investigation in vivo of the mechanisms of trans generational low doses effects of radiation and development of stress in Daphnia. Our dates strongly support MTT assay results as a good bio marker of survival and fertility effects at D. magna. (authors)

  1. Reproduction in the freshwater crustacean Asellus aquaticus along a gradient of radionuclide contamination at Chernobyl.

    Science.gov (United States)

    Fuller, Neil; Ford, Alex T; Nagorskaya, Liubov L; Gudkov, Dmitri I; Smith, Jim T

    2018-07-01

    Nuclear accidents such as Chernobyl and Fukushima have led to contamination of the environment that will persist for many years. The consequences of chronic low-dose radiation exposure for non-human organisms inhabiting contaminated environments remain unclear. In radioecology, crustaceans are important model organisms for the development of environmental radioprotection. Previous laboratory studies have demonstrated deleterious effects of radiation exposure on crustacean reproduction. However, no studies have documented the effects of chronic radiation exposure on the reproduction of natural crustacean populations. Based on data from laboratory exposures, we hypothesised that populations of the freshwater isopod Asellus aquaticus exposed to radiation for thirty years at Chernobyl would display reduced reproductive output and altered timing of reproduction. To test this hypothesis, A. aquaticus was collected from six lakes at Chernobyl over two years with total dose rates ranging from 0.06-27.1μGy/h. No significant differences in the fecundity, mass of broods or proportion of reproducing female A. aquaticus were recorded. Significant differences in the body mass of gravid females were recorded suggesting different timings of reproduction, however this was not related to radiation contamination. No significant effect of a range of environmental parameters on A. aquaticus reproduction was recorded. Our data suggests current dose rates at Chernobyl are not causing discernible effects on the reproductive output of A. aquaticus. This study is the first to assess the effects of chronic low-dose radiation exposure on the reproductive output of an aquatic invertebrate at Chernobyl. These findings are consistent with proposed radiological protection benchmarks for the maintenance of wildlife populations and will assist in management of environments impacted by radiation. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  2. On the distribution of decapod crustaceans from the Magellan Biogeographic Province and the Antarctic region

    Directory of Open Access Journals (Sweden)

    Enrique E. Boschi

    2005-12-01

    Full Text Available The distribution of decapod crustaceans in the southernmost areas of South America and the Antarctic is assessed considering the Magellan Biogeographic Province instead of the antiboreal region. Possible associations between decapod crustaceans from the Magellan Biogeographic Province and those from the Antarctic region are analysed. Species records were assigned to seven geographic regions that were clustered using multivariate analyses based on species presence/absence and Bray-Curtis similarity. The results showed two well-established clusters, one of which included the Pacific and Atlantic areas of the Magellan Province, the southern tip of South America and the Kerguelen Arc islands, with the highest similarity between the southern tip and the Atlantic area. Another cluster was well separated and included the Antarctic and South Georgia with the highest similarity index. Earlier studies and results obtained here suggest that the faunas of southern Chile and southern Argentina are biogeographically related. There is a low level of association among decapod species from the circum-Antarctic region and the Magellan Province.

  3. Extreme morphologies of mantis shrimp larvae

    OpenAIRE

    Haug, Carolin; Ahyong, Shane T.; Wiethase, Joris H.; Olesen, Jørgen; Haug, Joachim T.

    2016-01-01

    ABSTRACT Larvae of stomatopods (mantis shrimps) are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages), alima and erichthus (the latter two representing later larval stages). These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoolo...

  4. A new genus and two new species of the crustacean order Thermosbaebacea from the West Indies

    NARCIS (Netherlands)

    Stock, Jan H.

    1976-01-01

    Up to now, the crustacean order Thermosbaenacea contained two genera with only six valid species, five from the panmediterranean region, one from Texas. Two new members of this curious group of “living fossils” have been discovered in the West Indies. The one, from two deep wells not far from the

  5. Evolution of body size, vision, and biodiversity of coral-associated organisms: evidence from fossil crustaceans in cold-water coral and tropical coral ecosystems.

    Science.gov (United States)

    Klompmaker, Adiël A; Jakobsen, Sten L; Lauridsen, Bodil W

    2016-06-16

    Modern cold-water coral and tropical coral environments harbor a highly diverse and ecologically important macrofauna of crustaceans that face elevated extinction risks due to reef decline. The effect of environmental conditions acting on decapod crustaceans comparing these two habitats is poorly understood today and in deep time. Here, we compare the biodiversity, eye socket height as a proxy for eye size, and body size of decapods in fossil cold-water and tropical reefs that formed prior to human disturbance. We show that decapod biodiversity is higher in fossil tropical reefs from The Netherlands, Italy, and Spain compared to that of the exceptionally well-preserved Paleocene (Danian) cold-water reef/mound ecosystem from Faxe (Denmark), where decapod diversity is highest in a more heterogeneous, mixed bryozoan-coral habitat instead of in coral and bryozoan-dominated facies. The relatively low diversity at Faxe was not influenced substantially by the preceding Cretaceous/Paleogene extinction event that is not apparent in the standing diversity of decapods in our analyses, or by sampling, preservation, and/or a latitudinal diversity gradient. Instead, the lower availability of food and fewer hiding places for decapods may explain this low diversity. Furthermore, decapods from Faxe are larger than those from tropical waters for half of the comparisons, which may be caused by a lower number of predators, the delayed maturity, and the increased life span of crustaceans in deeper, colder waters. Finally, deep-water specimens of the benthic crab Caloxanthus from Faxe exhibit a larger eye socket size compared to congeneric specimens from tropical reefs, suggesting that dim light conditions favored the evolution of relatively large eyes. The results suggest a strong habitat control on the biodiversity of crustaceans in coral-associated environments and that the diversity difference between deep, cold-water reefs and tropical reefs evolved at least ~63 million years ago

  6. Extinction, recolonization, and dispersal through time in a planktonic crustacean.

    Science.gov (United States)

    Mergeay, Joachim; Vanoverbeke, Joost; Verschuren, Dirk; De Meester, Luc

    2007-12-01

    Dormant propagule banks are important reservoirs of biological and genetic diversity of local communities and populations and provide buffering mechanisms against extinction. Although dormant stages of various plant and animal species are known to remain viable for decades and even centuries, little is known about the effective influence of recolonization from such old sources on the genetic continuity of intermittent populations under natural conditions. Using recent and old dormant eggs recovered from a dated lake sediment core in Kenya, we traced the genetic composition of a local population of the planktonic crustacean Daphnia barbata through a sequence of extinction and recolonization events. This was combined with a phylogeographic and population-genetic survey of regional populations. Four successive populations, fully separated in time, inhabited Lake Naivasha from ca. 1330 to 1570 AD, from ca. 1610 to 1720 AD, from ca. 1840 to 1940 AD, and from 1995 to the present (2001 AD). Our results strongly indicate genetic continuity between the 1840-1940 and 1995-2001 populations, which are separated in time by at least 50 years, and close genetic relatedness of them both to the 1330-1580 population. A software tool (Colonize) was developed to find the most likely source population of the refounded 1995-2001 population and to test the number of colonists involved in the recolonization event. The results confirmed that the 1995-2001 population most probably developed out of a limited number of surviving local dormant eggs from the previous population, rather than out of individuals from regional (central and southern Kenya) or more distant (Ethiopia, Zimbabwe) populations that may have immigrated to Lake Naivasha through passive dispersal. These results emphasize the importance of prolonged dormancy for the natural long-term dynamics of crustacean zooplankton in fluctuating environments and suggest an important role of old local dormant egg banks in aquatic habitat

  7. Decapod crustaceans inhabiting live and dead colonies of three species of Acropora in the Roques Archipelago, Venezuela

    NARCIS (Netherlands)

    Grajal, P. Alejandro; Laughlin, G. Roger

    1984-01-01

    A systematic account is given of the decapod crustaceans found in live and dead colonies of three species of the scleractinian coral Acropora (A. cervicornis, A. palmata, A. prolifera), collected during a 9 month period in a shallow reef flat in the southwestern portion of the Archipelago Los

  8. Resistance to a bacterial parasite in the crustacean Daphnia magna shows Mendelian segregation with dominance.

    Science.gov (United States)

    Luijckx, P; Fienberg, H; Duneau, D; Ebert, D

    2012-05-01

    The influence of host and parasite genetic background on infection outcome is a topic of great interest because of its pertinence to theoretical issues in evolutionary biology. In the present study, we use a classical genetics approach to examine the mode of inheritance of infection outcome in the crustacean Daphnia magna when exposed to the bacterial parasite Pasteuria ramosa. In contrast to previous studies in this system, we use a clone of P. ramosa, not field isolates, which allows for a more definitive interpretation of results. We test parental, F1, F2, backcross and selfed parental clones (total 284 genotypes) for susceptibility against a clone of P. ramosa using two different methods, infection trials and the recently developed attachment test. We find that D. magna clones reliably exhibit either complete resistance or complete susceptibility to P. ramosa clone C1 and that resistance is dominant, and inherited in a pattern consistent with Mendelian segregation of a single-locus with two alleles. The finding of a single host locus controlling susceptibility to P. ramosa suggests that the previously observed genotype-genotype interactions in this system have a simple genetic basis. This has important implications for the outcome of host-parasite co-evolution. Our results add to the growing body of evidence that resistance to parasites in invertebrates is mostly coded by one or few loci with dominance.

  9. Use of the Crustacean Artemia franciscana for Alternative Biotests

    Directory of Open Access Journals (Sweden)

    Petr Dvořák

    2010-01-01

    Full Text Available Use of the crustacean Artemia franciscana for alternative biotests of the second generation was studied, and possible experimental design and applications of such tests outlined. In addition to the classical use in ecotoxicology, the test can be used in pharmacology as well, or to monitor the effects of ionizing radiation in co-exposure with some chemical compounds. The synergistic effect of co-exposure of PCB (DELOR 103, cadmium chloride and potassium dichromate with beta 89Sr irradiation was shown. We also demonstrated the anti-oxidative and pro-oxidative effects of the ascorbic acid in dependence on its concentration. Use of the pharmaco-toxicological screening in search for the novel inhibitors of cyclin-dependent kinases was demonstrated as well, showing that Artemia franciscana may be used as a suitable biosensor instead of the expensive tests on higher vertebrates.

  10. Checklist of fossil decapod crustaceans from tropical America. Part I: Anomura and Brachyura

    Directory of Open Access Journals (Sweden)

    Javier Luque

    2017-10-01

    Full Text Available Abstract Our knowledge of fossil crustaceans from the tropics has increased considerably during recent decades, thanks to novel findings and the re-examination of museum specimens. However, several previous records have been misidentified, numerous museum specimens have never been reported, and many new discoveries are yet to be published. Here, we present a detailed, up-to-date, and revised checklist for every marine, terrestrial, or freshwater fossil decapod crustacean occurrence from tropical America known to us, including their age, geographic occurrences, and related literature. We recognize the occurrence of at least 32 superfamilies, 69 families, 190 genera, and 415 species of brachyurans (‘true’ crabs, and anomurans (‘false’ crabs, hermit crabs, squat lobsters, and allies, several of them previously unknown. The checklist comprises records from three main geographic regions: 1 northern South America (Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela; 2 Central America and southern North America (Belize, Costa Rica, Honduras, Panama, Mexico, southern and central Florida; and 3 the Caribbean Islands + Bermuda (Anguilla, Antigua, Aruba, Bahamas, Barbados, Bermuda, Bonaire, Cuba, Curaçao, Dominican Republic, The Grenadines, Haiti, Jamaica, Puerto Rico, Saint Bartélemy, Saint Martin, Trinidad. Previous findings, new occurrences, and the revised systematic placement for several problematic/misidentified records, indicate that the fossil record of anomurans and brachyurans in tropical America is more diverse than previously envisioned, with a considerable degree of endemism at the genus- and species-levels.

  11. Behavioural indicators of pain in crustacean decapods

    Directory of Open Access Journals (Sweden)

    Francesca Gherardi

    2009-12-01

    Full Text Available Whether invertebrates are able or not to experience pain is a highly controversial issue. An operative way to solve such a controversy might be to investigate their responses to potentially noxious stimuli and to collect evidence of their behavioural complexities as proxies of cognitive capacities. The principle of argument-by-analogy can be then applied to these data: the behaviour displayed by invertebrates is compared with that of "higher" animals, its similarity denoting the former's capacity to have analogous experiences. Here, the author discusses some examples, extracted from the literature on crustacean decapods, that pinpoint their nature of "sentient" animals. This review, however, also shows that research is still scanty in the field. The studies that examine the potential links between stress responses and pain experience are few, and the several papers that help elucidate cognitive abilities in decapods have been limited to a few taxa and are not specifically directed to the question of "sentience". On the contrary, also in the light of the expected revision of the current EU legislation in the matter, more scientific efforts should be expended on exploring the issue of pain experience in invertebrates.

  12. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus

    Science.gov (United States)

    Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-01-01

    Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase. PMID:27391425

  13. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    Full Text Available Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

  14. Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-01-01

    Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

  15. Decapod crustaceans associated with the snakelock anemone Anemonia sulcata. Living there or just passing by?

    Directory of Open Access Journals (Sweden)

    Ricardo Calado

    2007-06-01

    Full Text Available The present work identifies the decapod crustaceans that associate with Anemonia sulcata on the southwestern Atlantic coast of Portugal and characterises their host use pattern. It determines whether the anemone is monopolised by any species, resulting in the exclusion of conspecifics or other decapods and, under laboratory conditions, it evaluates the degree of association between each species and A. sulcata. From all sampled anemones, 79% harboured at least 1 decapod crustacean, with the majority displaying either one or two specimens (32 and 24%, respectively. The most abundant species were the shrimp Periclimenes sagittifer and the crab Inachus phalangium (representing 36 and 31% of collected specimens, respectively, which displayed lasting associations and were commonly recorded among the tentacles of the host. The species Eualus occultus, E. complex cranchii, Clibanarius erythropus, Maja brachydactyla, Pilumnus hirtellus and Polybius (Necora puber displayed short-term associations, were mainly present on the substratum near the base, and avoided the tentacles of A. sulcata. Periclimenes sagittifer and I. phalangium were only recorded alone or in heterosexual pairs, appearing to efficiently defend their host against conspecifics. The majority of recorded species only seem to temporarily associate with A. sulcata, in order to seek protection from predators when other shelters are unavailable.

  16. A TALE of shrimps: Genome-wide survey of homeobox genes in 120 species from diverse crustacean taxa [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Wai Hoong Chang

    2018-01-01

    Full Text Available The homeodomain-containing proteins are an important group of transcription factors found in most eukaryotes including animals, plants and fungi. Homeobox genes are responsible for a wide range of critical developmental and physiological processes, ranging from embryonic development, innate immune homeostasis to whole-body regeneration. With continued fascination on this key class of proteins by developmental and evolutionary biologists, multiple efforts have thus far focused on the identification and characterization of homeobox orthologs from key model organisms in attempts to infer their evolutionary origin and how this underpins the evolution of complex body plans. Despite their importance, the genetic complement of homeobox genes has yet been described in one of the most valuable groups of animals representing economically important food crops. With crustacean aquaculture being a growing industry worldwide, it is clear that systematic and cross-species identification of crustacean homeobox orthologs is necessary in order to harness this genetic circuitry for the improvement of aquaculture sustainability. Using publicly available transcriptome data sets, we identified a total of 4183 putative homeobox genes from 120 crustacean species that include food crop species, such as lobsters, shrimps, crayfish and crabs. Additionally, we identified 717 homeobox orthologs from 6 other non-crustacean arthropods, which include the scorpion, deer tick, mosquitoes and centipede. This high confidence set of homeobox genes will now serve as a key resource to the broader community for future functional and comparative genomics studies.

  17. Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals

    Science.gov (United States)

    Henry, Raymond P.; Lucu, Čedomil; Onken, Horst; Weihrauch, Dirk

    2012-01-01

    The crustacean gill is a multi-functional organ, and it is the site of a number of physiological processes, including ion transport, which is the basis for hemolymph osmoregulation; acid-base balance; and ammonia excretion. The gill is also the site by which many toxic metals are taken up by aquatic crustaceans, and thus it plays an important role in the toxicology of these species. This review provides a comprehensive overview of the ecology, physiology, biochemistry, and molecular biology of the mechanisms of osmotic and ionic regulation performed by the gill. The current concepts of the mechanisms of ion transport, the structural, biochemical, and molecular bases of systemic physiology, and the history of their development are discussed. The relationship between branchial ion transport and hemolymph acid-base regulation is also treated. In addition, the mechanisms of ammonia transport and excretion across the gill are discussed. And finally, the toxicology of heavy metal accumulation via the gill is reviewed in detail. PMID:23162474

  18. Sulfate uptake by crustacean hepatopancreatic brush border membrane vesicles

    International Nuclear Information System (INIS)

    Gerencser, G.A.; Cattey, M.A; Ahearn, G.A.

    1990-01-01

    Purified brush border membrane vesicles (BBMV) were prepared from Atlantic lobster (Homarus americanus) hepatopancreas using differential centrifugation and Mg +2 precipitation techniques. Uptake of 0.1 mM 35 SO 4 -2 was stimulated by pre-loading vesicles with Cl - leading to a transient accumulation of isotope more than twice that at equilibrium. Pre-loading with HCO 3 - or gluconate had no effect on sulfate uptake. No stimulation of 35 SO 4 -2 was observed in the presence of inwardly directed Na + or tetramethylammonium + gradients. Uptake of the divalent anion was strongly stimulated by inwardly directed proton gradients (pH o i ) and markedly inhibited by outwardly directed proton gradients (pH o > pH i ). 35 SO 4 -2 /Cl - exchange was enhanced by imposing a transmembrane inside positive K + diffusion potential and inhibited by a membrane potential of the opposite polarity (K + /valinomycin). Results suggest the presence of a proton-dependent, electrogenic anion antiport mechanism in BBMV isolated from the crustacean hepatopancreas

  19. Crustaceans from a tropical estuarine sand-mud flat, Pacific, Costa Rica, (1984-1988 revisited

    Directory of Open Access Journals (Sweden)

    José A. Vargas-Zamora

    2012-12-01

    Full Text Available The availability of data sets for time periods of more than a year is scarce for tropical environments. Advances in hardware and software speed-up the re-analysis of old data sets and facilitates the description of population oscillations. Using recent taxonomic literature and software we have updated and re-analized the information on crustacean diversity and population fluctuations from a set of cores collected at a mud-sand flat in the mid upper Gulf of Nicoya estuary, Pacific coast of Costa Rica (1984-1988. A total of 112 morphological species of macroinvertebrates was found, of which 29 were crustaceans. Taxonomic problems, maily with the peracarids, prevented the identification of a group of species. The abundance patterns of the crab Pinnixa valerii, the ostracod Cyprideis pacifica, and the cumacean Coricuma nicoyensis were analized with the Generalized Additive Models of the free software R. The models evidenced a variety of population oscillations during the sampling period. These oscillations probably included perturbations induced by external factors, like the strong red tide events of 1985. In additon, early on 1984 the populations might have been at an altered state due to the inpact of El Niño 1982-83. Thus, the oscillations observed during the study period departed from the expected seasonality (dry vs rainy pattern and are thus considered atypical for this tropical estuarine tidal-flat. Crustacean diversity and population peaks were within the range of examples found in worldwide literature. However, abundances of the cumacean C. nicoyensis, an endemic species, are the highest reported for a tropical estuary. Comparative data from tropical tidal flat crustaceans continues to be scarce. Crustaceans (total vs groups had population changes in response to the deployment of predator exclusion cages during the dry and rainy seasons of 1985. Temporal and spatial patchiness characterized the abundances of P. valeri, C. pacifica and C

  20. Risk assessment of pet-traded decapod crustaceans in the Republic of Kazakhstan, the leading country in Central Asia

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    Uderbayev Talgat

    2017-01-01

    Full Text Available The pet trade with decapod crustaceans has been considered one of the main pathway of introduction of these animals worldwide. As the leading markets in this regards are the Czech Republic, Germany and the USA. Central Asia is not perceived as an important market with ornamental decapod crustaceans. Despite this assumption, we found at least 16 species of freshwater shrimp, crayfish and crab species pet-traded in the Republic of Kazakhstan, the largest country in this region. Considering computed risk assessment, the origin of particular species, their availability on the market, the probability of establishment and further aspects, we identified two crayfish Procambarus clarkii and Procambarus fallax f. virginalis being the seriously hazardous taxa with high potential to threaten native crayfish species as well as inhabited ecosystems. To prevent their introductions and to minimize the risks of mentioned species, similarly as in the case of European Union, we recommend the total ban of import, trade and keeping of these high-risk taxa within Central Asia.

  1. Obesogens beyond Vertebrates: Lipid Perturbation by Tributyltin in the Crustacean Daphnia magna

    Science.gov (United States)

    Jordão, Rita; Casas, Josefina; Fabrias, Gemma; Campos, Bruno; Piña, Benjamín; Lemos, Marco F.L.; Soares, Amadeu M.V.M.; Tauler, Romà

    2015-01-01

    Background The analysis of obesogenic effects in invertebrates is limited by our poor knowledge of the regulatory pathways of lipid metabolism. Recent data from the crustacean Daphnia magna points to three signaling hormonal pathways related to the molting and reproductive cycles [retinoic X receptor (RXR), juvenile hormone (JH), and ecdysone] as putative targets for exogenous obesogens. Objective The present study addresses the disruptive effects of the model obesogen tributyltin (TBT) on the lipid homeostasis in Daphnia during the molting and reproductive cycle, its genetic control, and health consequences of its disruption. Methods D. magna individuals were exposed to low and high levels of TBT. Reproductive effects were assessed by Life History analysis methods. Quantitative and qualitative changes in lipid droplets during molting and the reproductive cycle were studied using Nile red staining. Lipid composition and dynamics were analyzed by ultra-performance liquid chromatography coupled to a time-of-flight mass spectrometer. Relative abundances of mRNA from different genes related to RXR, ecdysone, and JH signaling pathways were studied by qRT-PCR. Results and Conclusions TBT disrupted the dynamics of neutral lipids, impairing the transfer of triacylglycerols to eggs and hence promoting their accumulation in adult individuals. TBT’s disruptive effects translated into a lower fitness for offspring and adults. Co-regulation of gene transcripts suggests that TBT activates the ecdysone, JH, and RXR receptor signaling pathways, presumably through the already proposed interaction with RXR. These findings indicate the presence of obesogenic effects in a nonvertebrate species. Citation Jordão R, Casas J, Fabrias G, Campos B, Piña B, Lemos MF, Soares AM, Tauler R, Barata C. 2015. Obesogens beyond vertebrates: lipid perturbation by tributyltin in the crustacean Daphnia magna. Environ Health Perspect 123:813–819; http://dx.doi.org/10.1289/ehp.1409163 PMID

  2. Ensamble de crustáceos bentónicos en un lago salino tropical Benthic crustaceans assemblage in a tropical, saline lake

    Directory of Open Access Journals (Sweden)

    Ma. del Carmen Hernández

    2010-10-01

    Full Text Available El presente trabajo reconoce la composición, estructura y distribución espacial del ensamble de crustáceos bentónicos de Alchichica, un lago salino tropical ubicado en el extremo oriental del altiplano mexicano. El lago presenta una riqueza taxonómica de crustáceos bentónicos compuesta por 1 anfípodo (Hyalella azteca, 1 isópodo (Caecidotea williamsi y 2 ostrácodos (Limnocythere inopinata y Candona sp.. Comparada con otros lagos tropicales, la riqueza de especies es reducida. A pesar de lo anterior, es importante mencionar el grado elevado de endemismo representado por C. williamsi, recientemente descrita para el lago Alchichica; adicionalmente, es factible que tanto Candona como H. azteca sean especies nuevas y endémicas del lago. Los crustáceos bentónicos se distribuyen desde la zona litoral hasta la zona más profunda del lago (62 m con abundancias y riqueza taxonómica variables. Los ostrácodos fueron los crustáceos que con mayor frecuencia se recolectaron en el lago, en la zona litoral, en el talud, y en la zona profunda de la que son habitantes exclusivos. Los anfípodos constituyeron el segundo grupo en abundancia de la zona litoral y talud y estuvieron ausentes en la zona profunda. Los isópodos sólo se encuentran asociados a los depósitos de tufa, hábitat característico del lago que se extiende a lo largo del talud, por lo que con las técnicas de muestreo tradicional empleadas en el presente estudio no fueron capturados. En este ensamble de crustáceos predominan las especies de desarrollo directo y con posiciones tróficas que incluyen componentes herbívoros (H. azteca, omnívoros (C. williamsi y bacterívoros (L. inopinata y Candona sp..This work acknowledges the composition, structure and spatial distribution of the benthic crustaceans assemblage of Alchichica, a tropical saline lake located in the easternmost portion of the Mexican highlands. The benthic crustaceans' assemblage was comprised by 1 amphipod

  3. Extended parental care in crustaceans: an update Cuidado parental extendido en crustáceos: conocimiento actual

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    MARTIN THIEL

    2003-06-01

    Full Text Available Many crustacean species show extended parental care (XPC for fully developed juvenile offspring. Herein, the present state of knowledge of the major patterns and consequences of XPC is reviewed, and furthermore important future research topics are identified. Crustaceans with XPC are found in marine, freshwater and terrestrial environments, but care for late juvenile stages appears to be more common in terrestrial environments. In all species, females participate or even take the main share of XPC activities. Crustaceans that carry their offspring during XPC commonly release early juvenile stages, while species inhabiting particular microhabitats may host offspring until these have reached subadult or adult stages. Apart from providing a suitable and safe microhabitat to small offspring, parents share food with, groom or actively defend their juveniles. Some of the most important benefits of XPC include improved juvenile growth and survival. XPC may also lead to conflicts among developing offspring or between parents and offspring, especially during later phases of XPC when resources (food and space become increasingly limiting. Similarly, during long-lasting cohabitation, epibionts (e.g., parasites may be transferred from parents to offspring, as is indicated by observational evidence. For several species, local recruitment, where juveniles recruit in the immediate vicinity of their parents, has been observed. Under these conditions, local populations may rapidly increase, potentially leading to intra-specific competition for space, thereby possibly causing a decrease in reproductive activity or a reduction in length of XPC. Another consequence of XPC and local recruitment could be limited dispersal potential, but some marine crustaceans with XPC and local recruitment nevertheless have a wide geographic distribution. It is hypothesized that the existence of suitable dispersal vectors such as floating macroalgae or wood can lead to a substantial

  4. Fatty acid trophic markers and trophic links among seston, crustacean zooplankton and the siphonophore Nanomia cara in Georges Basin and Oceanographer Canyon (NW Atlantic

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    Sergio Rossi

    2008-06-01

    Full Text Available Fatty acid concentrations expressed as percentages of total fatty acid pools in seston, stage V copepodites of Calanus finmarchicus, adults of the euphausiid Meganyctiphanes norvegica, and the physonect siphonophore Nanomia cara were used to elucidate trophic links in Georges Basin and Oceanographer Canyon in September 2003. Seston at both locations was refractory and comprised mainly of saturated fatty acids. Phytoplankton did not contribute significantly to the fatty acid composition of seston or higher trophic levels. Only four fatty acids, i.e. 14:0, 16:0, 16:1 (n–7 and 18:1 (n–7, were transferred from seston to C. finmarchicus or M. norvegica, which suggested weak trophic interactions. Fatty acids transferred from the two species of crustaceans to N. cara included the same four fatty acids, along with three polyunsaturated fatty acids found in relatively high concentrations in both crustaceans, i.e. 20:3 (n–6, 20:5 (n–3 and 22:6 (n–3. In addition, 18:1 (n–9, which occurred in relatively high concentrations only in M. norvegica, and 18:0 and 18:2 (n–6, which were found in low concentrations in both crustaceans, also appeared to be transferred to N. cara. Overall, fatty acid trophic markers proved useful for identifying trophic links to N. cara.

  5. Cardioacceleratory Neurons of the Isopod Crustacean, Ligia exotica : Visualization of Peripheral Projection onto the Heart Muscle

    OpenAIRE

    Akira, Sakurai; Hiroshi, Yamagishi; Institute of Biological Sciences, University of Tsukuba; Institute of Biological Sciences, University of Tsukuba

    1998-01-01

    Innervation of the heart muscle by the cardioacceleratory neurons was morphologically and electrophysiologically examined in the isopod crustacean, Ligia exotica. Intracellular injection of neurobiotin into the first and second cardioacceleratory neurons(CA1 and CA2)revealed their peripheral axonal projections. Inside the heart, the CA1 and CA2 axons ran along the trunk of the cardiac ganglion. Finely arborized branches with many varicosities arose from the axon and projected over the heart m...

  6. Structural prediction and analysis of VIH-related peptides from selected crustacean species.

    Science.gov (United States)

    Nagaraju, Ganji Purna Chandra; Kumari, Nunna Siva; Prasad, Ganji Lakshmi Vara; Rajitha, Balney; Meenu, Madan; Rao, Manam Sreenivasa; Naik, Bannoth Reddya

    2009-08-17

    The tentative elucidation of the 3D-structure of vitellogenesis inhibiting hormone (VIH) peptides is conversely underprivileged by difficulties in gaining enough peptide or protein, diffracting crystals, and numerous extra technical aspects. As a result, no structural information is available for VIH peptide sequences registered in the Genbank. In this situation, it is not surprising that predictive methods have achieved great interest. Here, in this study the molt-inhibiting hormone (MIH) of the kuruma prawn (Marsupenaeus japonicus) is used, to predict the structure of four VIHrelated peptides in the crustacean species. The high similarity of the 3D-structures and the calculated physiochemical characteristics of these peptides suggest a common fold for the entire family.

  7. Hábitos alimentarios de Lutjanus peru (Pisces: Lutjanidae en las costas de Guerrero, México

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    Apolinar Santamaría Miranda

    2003-06-01

    snapper (Lutjanus peru in the southern coast of Guerrero state, Mexico. This data could be relevant to local fisheries management. In total 385 full stomachs (206 from females and 179 from males were collected monthly in 1993 and 1994, from commercial catches. Stomach contents were identified to species level when possible. Food items were grouped into taxonomically coherent groups, and their numbers, weight and frequency of occurrence obtained. The index of relative importance (IRI was calculated for the total sample, by month, sex and size class. In 1993, a total of 42 different food items were obtained, and 43 in 1994. Food items consisted of fishes, crustaceans, and mollusks. The grouping of prey species, genera, or families rendered 14 food groups, as follows: Mollusks, Amphipods, Copepods, Stomatopods, Penaeus vannamei, Brachiuran Larvae, Stomatopods Larvae, Family Albuneidae Larvae, Other crustaceans, Anchoa ischana, Anchoa lucida, Other fishes, Salps and Unidentified organic matter. Anchoa ischana dominated the trophic spectrum in both years. Although, Amphipods, Anchoa lucida and Other fishes had important indexes in 1994. There was high variability in the diet composition by month. Nevertheless, in 1993, from February to August, crustaceans as a whole dominated the diet. In 1994, crustaceans only dominated in March and August. No differences in food habits were found between immature fish, males and females. The diet of the Red snapper varies as they grow, although the same food groups are found always. At the adult phase, in length classes over 261 mm FL, there is some degree of specialization, as they consume more fish, particularly engraulids.

  8. Effects of habitat structure on the epifaunal community in Mussismilia corals: does coral morphology influence the richness and abundance of associated crustacean fauna?

    Science.gov (United States)

    Nogueira, Marcos M.; Neves, Elizabeth; Johnsson, Rodrigo

    2015-06-01

    Coral habitat structures increase abundance and richness of organisms by providing niches, easy access to resources and refuge from predators. Corals harbor a great variety of animals; the variation in coral species morphology contributes to the heterogeneity and complexity of habitat types. In this report, we studied the richness and abundance of crustaceans (Decapoda, Copepoda, Peracarida and Ostracoda) associated with three species of Mussismilia exhibiting different growth morphologies, in two different coral reefs of the Bahia state (Caramuanas and Boipeba-Moreré, Brazil). Mussismilia hispida is a massive coral; M. braziliensis also has a massive growth pattern, but forms a crevice in the basal area of the corallum; M. harttii has a meandroid pattern. PERMANOVA analysis suggests significant differences in associated fauna richness among Mussismilia species, with higher values for M. harttii, followed by M. braziliensis and later by M. hispida. The same trend was observed for density, except that the comparison of M. braziliensis and M. hispida did not show differences. Redundancy and canonical correspondence analysis indicated that almost all of the crustacean species were more associated with the M. harttii colonies that formed a group clearly separated from colonies of M. braziliensis and M. hispida. We also found that the internal volume of interpolyp space, only present in M. harttii, was the most important factor influencing richness and abundance of all analyzed orders of crustaceans.

  9. A Phylogenomic Solution to the Origin of Insects by Resolving Crustacean-Hexapod Relationships.

    Science.gov (United States)

    Schwentner, Martin; Combosch, David J; Pakes Nelson, Joey; Giribet, Gonzalo

    2017-06-19

    Insects, the most diverse group of organisms, are nested within crustaceans, arguably the most abundant group of marine animals. However, to date, no consensus has been reached as to which crustacean taxon is the closest relative of hexapods. A majority of studies have proposed that Branchiopoda (e.g., fairy shrimps) is the sister group of Hexapoda [1-7]. However, these investigations largely excluded two equally important taxa, Remipedia and Cephalocarida. Other studies suggested Remipedia [8-11] or Remipedia + Cephalocarida [12, 13] as potential sister groups of hexapods, but they either did not include Cephalocarida or used only Sanger sequence data and morphology [9, 12]. Here we present the first phylogenomic study specifically addressing the origins of hexapods, including transcriptomes for two species each of Cephalocarida and Remipedia. Phylogenetic analyses of selected matrices, ranging from 81 to 1,675 orthogroups and up to 510,982 amino acid positions, clearly reject a sister-group relationship between Hexapoda and Branchiopoda [1-7]. Nonetheless, support for a hexapod sister-group relationship to Remipedia or to Cephalocarida-Remipedia was highly dependent on the employed analytical methodology. Further analyses assessing the effects of gene evolutionary rate and targeted taxon exclusion support Remipedia as the sole sister taxon of Hexapoda and suggest that the prior grouping of Remipedia + Cephalocarida is an artifact, possibly due to long branch attraction and compositional heterogeneity. We further conclude that terrestrialization of Hexapoda probably occurred in the late Cambrian to early Ordovician, an estimate that is independent of their proposed sister group [4, 8, 12, 14]. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Immunochemical and immunocytochemical studies of the crustacean vitellogenesis-inhibiting hormone (VIH).

    Science.gov (United States)

    Meusy, J J; Martin, G; Soyez, D; van Deijnen, J E; Gallo, J M

    1987-09-01

    Immunochemical investigations, using dot immunobinding assay (DIA) and enzyme-linked immunosorbent assay (ELISA), and immunocytochemical studies reveal the following new information about crustacean vitellogenesis-inhibiting hormone (VIH): (1) The structure of VIH is sufficiently different from that of the other sinus gland neuropeptides to allow a selective recognition of VIH by polyclonal antibodies. (2) From immunochemical criteria, VIH does not seem strictly species specific. The antisera raised against VIH of Homarus americanus cross-react with sinus gland extracts of Palaemonetes varians, Palaemon serratus, Macrobrachium rosenbergii, Carcinus maenas, and Porcellio dilatatus. (3) In the sinus gland of H. americanus, VIH immunoreactivity is localized mainly in electron-dense granules of medium size (110-185 nm in diameter) while, in P. dilatatus, the labeling is mostly on the largest granules (200-270 nm in diameter).

  11. Crustáceos decápodos asociados a arrecifes de Phragmatopoma sp. (Polychaeta: Sabellariidae en playa El Horcón, Isla de Margarita, Venezuela | Decapod crustaceans associated with Phagmatopoma sp. (Polychaeta: Sabellariidae in Horcón Beach, Margarita Island, Venezuela

    Directory of Open Access Journals (Sweden)

    Marcel Velásquez

    2017-11-01

    Full Text Available At Horcón beach, Margarita Island, there are sand reefs formed by polychaetes belonging to the Family Sabellariidae, which until now have not been studied, despite their importance as habitat providers for setting and larval settlement of various species, mainly decapod crustaceans. In this sense, the present study aimed to survey decapod crustaceans associated with these reefs. For this, monthly samplings were taken between February and July 2008 and pieces of reef from the subtidal zone were manually collected, at an average between 0.5 and 1 m deep. Samples were transported to the laboratory for processing, extraction and taxonomic determination of the decapod crustaceans present. A total of 1517 individuals of decapod crustaceans were analyzed, belonging to ten families, 15 genera and 27 species. The best represented families were Porcellanidae and Mithracidae with 928 and 298 individuals respectively, followed by Alpheidae (159 ind., while Processidae, Paguridae and Xanthidae were represented by a single individual each. Moreover, the finding of Alpheus thomasi is the first record for the coast of Venezuela. These reefs appear to be of great importance as substrate protection and shelter for decapod crustaceans.

  12. Composición y superposición de dietas en cuatro especies de Diplectrum (Perciformes: Serranidae en el Pacífico central mexicano

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    Bernabé Aguilar Palomino

    2010-12-01

    function. To assess this in four Diplectrum species, we analyzed the stomach contents of 397 individuals caught using shrimp trawling nets off the coasts of Jalisco and Colima, Mexico. Main food component of D. eumelum were fish of the Order Pleuronectiformes, followed by shrimps (Metapenaeopsis spp. D. euryplectrum feeds mainly on crustaceans, with stomatopods (Squilla mantoidea as main food items followed by shrimps and brachyurans. Fish and polychaetes had a low representation in the diet of this species. D. labarum feeds mainly on crustaceans, mollusks and fish. The stomatopod Eurysquilla veleronis contributed to with a high diet percentage by weight, followed by shrimps (mostly Solenocera florae and brachyurans, as well as the squid Lolliguncula diomedae. Fishes (Ophidion spp. were also an important component of the diet of this species. The most common preys of D. rostrum were crustaceans, mollusks, polychaetes and fish. The squid Lolliguncula diomedae and fishes of genus Ophidion were also well represented in the diet. Diet breadth index yielded significant differences between species. The number of diet items varied from 16 in D. euryplectrum to 6 in D. eumelum. The average value of overlap (0.247 was not significantly different (p=0.118 from the expected one for a null model (0.174. The observed variance of the overlap index (0.071 was significantly higher (V=0.025, p=0.0004 than the value expected for a null model. Rev. Biol. Trop. 58 (4: 1189-1198. Epub 2010 December 01.

  13. Bioaccumulation of "2"1"0Po and "2"1"0Pb in the crustaceans of Pichavaram mangrove ecosystem, Tamil nadu, India

    International Nuclear Information System (INIS)

    Raja, P.; Shahul Hameed, P.

    2017-01-01

    It was observed that the concentrations of "2"1"0Po in water and sediment were 1.64mBq/l and 5.92 Bq/kg and "2"1"0Pb in water and sediment samples 3.10 mBq/l and 2.45 Bq/kg respectively. The muscle of crabs registered a higher level of "2"1"0Po (152 Bq/kg) than that of prawns (71.87 Bq/kg) and lobster (49.3Bq/kg). Conversely the exoskeleton of crustacean species analyzed, accumulated a higher level of "2"1"0Pb (range 5.7-9.11 Bq/kg) as compared to level of accumulated "2"1"0Pb in muscle (range 1.62-2.54 Bq/kg). The study reveals the base line data on the levels of naturally occurring radionuclides such as "2"1"0Po and "2"1"0Pb in the prestart environment of Pichavaram Mangrove Ecosystem with special reference to the crustaceans. (author)

  14. Astakine 2--the dark knight linking melatonin to circadian regulation in crustaceans.

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    Apiruck Watthanasurorot

    2013-03-01

    Full Text Available Daily, circadian rhythms influence essentially all living organisms and affect many physiological processes from sleep and nutrition to immunity. This ability to respond to environmental daily rhythms has been conserved along evolution, and it is found among species from bacteria to mammals. The hematopoietic process of the crayfish Pacifastacus leniusculus is under circadian control and is tightly regulated by astakines, a new family of cytokines sharing a prokineticin (PROK domain. The expression of AST1 and AST2 are light-dependent, and this suggests an evolutionarily conserved function for PROK domain proteins in mediating circadian rhythms. Vertebrate PROKs are transmitters of circadian rhythms of the suprachiasmatic nucleus (SCN in the brain of mammals, but the mechanism by which they function is unknown. Here we demonstrate that high AST2 expression is induced by melatonin in the brain. We identify RACK1 as a binding protein of AST2 and further provide evidence that a complex between AST2 and RACK1 functions as a negative-feedback regulator of the circadian clock. By DNA mobility shift assay, we showed that the AST2-RACK1 complex will interfere with the binding between BMAL1 and CLK and inhibit the E-box binding activity of the complex BMAL1-CLK. Finally, we demonstrate by gene knockdown that AST2 is necessary for melatonin-induced inhibition of the complex formation between BMAL1 and CLK during the dark period. In summary, we provide evidence that melatonin regulates AST2 expression and thereby affects the core clock of the crustacean brain. This process may be very important in all animals that have AST2 molecules, i.e. spiders, ticks, crustaceans, scorpions, several insect groups such as Hymenoptera, Hemiptera, and Blattodea, but not Diptera and Coleoptera. Our findings further reveal an ancient evolutionary role for the prokineticin superfamily protein that links melatonin to direct regulation of the core clock gene feedback loops.

  15. Exoskeleton Heterogeneity in Crustaceans: Quantifying Compositional and Structural Variations Across Body Parts

    Science.gov (United States)

    Ulrich, R. N.; Mergelsberg, S. T.; Dove, P. M.

    2016-12-01

    Crustacean exoskeletons are a complex biocomposite of organic macromolecules and calcium carbonate minerals. The highly divergent functions and diverse morphologies of these biominerals across taxa raise the question of whether these differences are systematically reflected in exoskeleton composition and structure. Previous studies that investigated element concentrations in exoskeletons used spectroscopic methods. However, the findings were largely inconclusive because of analytical limitations and most studies concluded that magnesium, phosphorus, and other trace elements are mostly contained in the mineral fraction because concentrations in the organic framework could not be resolved. This experimental study was designed to quantify the distributions of Ca, P, Mg, and Sr in the mineral versus organic fractions of exoskeletons from the American Lobster (H. americanus), Dungeness Crab (M. magister), and Red Rock Crab (M. productus). Samples of exoskeleton from 10 body parts were collected in triplicate and dissolved using three procedures specific to extracting the 1) mineral, 2) protein, and 3) chitin phases separately. Chemical analyses of the resulting effluents using ICP-OES show the mineral fraction of the skeleton can contain significant amounts of mineralized Mg and P particularly for body parts associated with a significant difference in mineral structural ordering. The protein fraction contains more Mg and P than expected based on estimates from previous studies (Hild et al., 2008). While the element distributions vary greatly depending on the location, in body parts with thicker cuticle (e.g. claw) the mineral component appears to control overall composition. The findings have implications for paleoenvironmental reconstructions based upon exoskeleton composition. First, the chemical composition of an exoskeleton cannot be assumed constant across the different body parts of an entire organism. This is particularly true when the exoskeleton of the claw is

  16. Global diversity of marine isopods (except Asellota and crustacean symbionts.

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    Gary C B Poore

    Full Text Available The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10-1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species

  17. Crustacean zooplankton species richness in Chilean lakes and ponds (23°-51°S

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos-Escalante

    2013-07-01

    Full Text Available Chilean inland-water ecosystems are characterized by their low species-level biodiversity. This study analyses available data on surface area, maximum depth, conductivity, chlorophyll-α concentration, and zooplankton crustacean species number in lakes and ponds between 23° and 51°S. The study uses multiple regression analysis to identify the potential factors affecting the species number. The partial correlation analysis indicated a direct significant correlation between chlorophyll-α concentration and species number, whereas the multiple regression analysis indicated a direct significant response of species number to latitude and chlorophyll-α concentration. These results agree with findings from comparable ecosystems in Argentina and New Zealand.

  18. Ontogenetic changes in the olfactory antennules of the shore crab, Hemigrapsus oregonensis, maintain sniffing function during growth.

    Science.gov (United States)

    Waldrop, Lindsay D; Hann, Miranda; Henry, Amy K; Kim, Agnes; Punjabi, Ayesha; Koehl, M A R

    2015-01-06

    Malacostracan crustaceans capture odours using arrays of chemosensory hairs (aesthetascs) on antennules. Lobsters and stomatopods have sparse aesthetascs on long antennules that flick with a rapid downstroke when water flows between the aesthetascs and a slow return stroke when water is trapped within the array (sniffing). Changes in velocity only cause big differences in flow through an array in a critical range of hair size, spacing and speed. Crabs have short antennules bearing dense arrays of flexible aesthetascs that splay apart during downstroke and clump together during return. Can crabs sniff, and when during ontogeny are they big enough to sniff? Antennules of Hemigrapsus oregonensis representing an ontogenetic series from small juveniles to adults were used to design dynamically scaled physical models. Particle image velocimetry quantified fluid flow through each array and showed that even very small crabs capture a new water sample in their arrays during the downstroke and retain that sample during return stroke. Comparison with isometrically scaled antennules suggests that reduction in aesthetasc flexural stiffness during ontogeny, in addition to increase in aesthetasc number and decrease in relative size, maintain sniffing as crabs grow. Sniffing performance of intermediate-sized juveniles was worse than for smaller and larger crabs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  19. Role of cellular compartmentalization in the trophic transfer of mercury species in a freshwater plant-crustacean food chain.

    Science.gov (United States)

    Beauvais-Flück, Rebecca; Chaumot, Arnaud; Gimbert, Frédéric; Quéau, Hervé; Geffard, Olivier; Slaveykova, Vera I; Cosio, Claudia

    2016-12-15

    Mercury (Hg) represents an important risk for human health through the food webs contamination. Macrophytes bioaccumulate Hg and play a role in Hg transfer to food webs in shallow aquatic ecosystems. Nevertheless, the compartmentalization of Hg within macrophytes, notably major accumulation in the cell wall and its impact on trophic transfer to primary consumers are overlooked. The present work focusses on the trophic transfer of inorganic Hg (IHg) and monomethyl-Hg (MMHg) from the intracellular and cell wall compartments of the macrophyte Elodea nuttallii - considered a good candidate for phytoremediation - to the crustacean Gammarus fossarum. The results demonstrated that Hg accumulated in both compartments was trophically bioavailable to gammarids. Besides IHg from both compartments were similarly transferred to G. fossarum, while for MMHg, uptake rates were ∼2.5-fold higher in G. fossarum fed with the cell wall vs the intracellular compartment. During the depuration phase, Hg concentrations in G. fossarum varied insignificantly suggesting that both IHg and MMHg were strongly bound to biological ligands in the crustacean. Our data imply that cell walls have to be considered as an important source of Hg to consumers in freshwater food webs when developing procedures for enhancing aquatic environment protection during phytoremediation programs. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Two quantitative real-time PCR assays for the detection of penaeid shrimp and blue crab, crustacean shellfish allergens.

    Science.gov (United States)

    Eischeid, Anne C; Kim, Bang-hyun; Kasko, Sasha M

    2013-06-19

    Food allergen detection methods must be able to specifically detect minute quantities of an allergenic food in a complex food matrix. One technique that can be used is real-time PCR. For the work described here, real-time PCR assays were developed to detect penaeid shrimp and blue crab, crustacean shellfish allergens. The method was tested using shrimp meat and crab meat spiked into several types of foods, including canned soups, deli foods, meat, seafood, and prepared seafood products. Foods were spiked with either shrimp or crab at levels ranging from 0.1 to 10⁶ parts per million (ppm) and analyzed either raw or cooked by a variety of methods. Real-time PCR data were used to generate linear standard curves, and assays were evaluated with respect to linear range and reaction efficiency. Results indicate that both assays performed well in a variety of food types. High reaction efficiencies were achieved across a linear range of 6-8 orders of magnitude. Limits of detection were generally between 0.1 and 1 ppm. Cooking methods used to simulate thermal processing of foods had little effect on assay performance. This work demonstrates that real-time PCR can be a valuable tool in the detection of crustacean shellfish.

  1. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening

    Directory of Open Access Journals (Sweden)

    Pablo Mayorga

    2010-10-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.

  2. Decapod crustaceans on the Gökçeada (Imbros island continental shelf (north-eastern Aegean Sea

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    A.S. ATES

    2006-12-01

    Full Text Available The present composition of decapod crustaceans found at the sublittoral depths (5-104 m off the coast of the island of Gökçeada (north-eastern Aegean Sea is presented. A total of 28 species (11 caridean shrimps, 1 thalassinid ghost crab, 7 anomurans and 9 brachyuran crabs and 277 specimens were recorded. The caridean shrimp, Athanas nitescens had the highest abundance with a dominance value of 20.94% in samples. The dominant group is caridean, represented by a total of 11 species and an occurrence frequency of 39.29%.

  3. Visualization of ecdysteroid activity using a reporter gene in the crustacean, Daphnia.

    Science.gov (United States)

    Asada, Miki; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

    2014-02-01

    Ecdysone is a hormone known to play a pivotal role in crustaceans and insects. In order to evaluate the ecdysone activities in the environment and within the organism, we have developed a biomonitoring Daphnia strain by introducing a reporter gene. In this study, the ecdysone response element was inserted in the upstream region of a reporter gene, and the DNA construct was injected into Daphnia eggs. The expression of the reporter gene was detected during the early embryonic development stage. In addition, when the eggs expressing the reporter gene were exposed to ecdysone, there was enhanced expression of the reporter gene at detectable levels, while the presence of an antagonist led to its downregulation. These results suggested that this system could be potentially developed for monitoring ecdysone activities in media. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Seasonal abundance of crustaceans associated with artisanal fishery of blue crab (Callinectes sapidus) in Sisal, Yucatan, Mexico

    OpenAIRE

    Celis-Sánchez, José Alfredo; Estrella-Canto, Arely de Jesús; Poot-López, Gaspar Román; González-Salas, Carlos; López-Rocha, Jorge Alberto

    2014-01-01

    Seasonal abundance and selectivity of the main crustacean species associated with blue crab fishing was studied at the port of Sisal, Yucatan, Mexico. For this purpose, 52 crab traps were used, which were divided into four parallel transects placed 100, 150, 200 and 250 m of the shoreline. Each transect consisted of 13 traps 20 m from each other. Traps were set at dusk and checked at dawn, standardizing the fishing effort to 17 hours/trap/day. A total of 832 organisms from eight species were ...

  5. Glutathione S-Transferase (GST Gene Diversity in the Crustacean Calanus finmarchicus--Contributors to Cellular Detoxification.

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    Vittoria Roncalli

    Full Text Available Detoxification is a fundamental cellular stress defense mechanism, which allows an organism to survive or even thrive in the presence of environmental toxins and/or pollutants. The glutathione S-transferase (GST superfamily is a set of enzymes involved in the detoxification process. This highly diverse protein superfamily is characterized by multiple gene duplications, with over 40 GST genes reported in some insects. However, less is known about the GST superfamily in marine organisms, including crustaceans. The availability of two de novo transcriptomes for the copepod, Calanus finmarchicus, provided an opportunity for an in depth study of the GST superfamily in a marine crustacean. The transcriptomes were searched for putative GST-encoding transcripts using known GST proteins from three arthropods as queries. The identified transcripts were then translated into proteins, analyzed for structural domains, and annotated using reciprocal BLAST analysis. Mining the two transcriptomes yielded a total of 41 predicted GST proteins belonging to the cytosolic, mitochondrial or microsomal classes. Phylogenetic analysis of the cytosolic GSTs validated their annotation into six different subclasses. The predicted proteins are likely to represent the products of distinct genes, suggesting that the diversity of GSTs in C. finmarchicus exceeds or rivals that described for insects. Analysis of relative gene expression in different developmental stages indicated low levels of GST expression in embryos, and relatively high expression in late copepodites and adult females for several cytosolic GSTs. A diverse diet and complex life history are factors that might be driving the multiplicity of GSTs in C. finmarchicus, as this copepod is commonly exposed to a variety of natural toxins. Hence, diversity in detoxification pathway proteins may well be key to their survival.

  6. The first venomous crustacean revealed by transcriptomics and functional morphology: remipede venom glands express a unique toxin cocktail dominated by enzymes and a neurotoxin.

    Science.gov (United States)

    von Reumont, Björn M; Blanke, Alexander; Richter, Sandy; Alvarez, Fernando; Bleidorn, Christoph; Jenner, Ronald A

    2014-01-01

    Animal venoms have evolved many times. Venomous species are especially common in three of the four main groups of arthropods (Chelicerata, Myriapoda, and Hexapoda), which together represent tens of thousands of species of venomous spiders, scorpions, centipedes, and hymenopterans. Surprisingly, despite their great diversity of body plans, there is no unambiguous evidence that any crustacean is venomous. We provide the first conclusive evidence that the aquatic, blind, and cave-dwelling remipede crustaceans are venomous and that venoms evolved in all four major arthropod groups. We produced a three-dimensional reconstruction of the venom delivery apparatus of the remipede Speleonectes tulumensis, showing that remipedes can inject venom in a controlled manner. A transcriptomic profile of its venom glands shows that they express a unique cocktail of transcripts coding for known venom toxins, including a diversity of enzymes and a probable paralytic neurotoxin very similar to one described from spider venom. We screened a transcriptomic library obtained from whole animals and identified a nontoxin paralog of the remipede neurotoxin that is not expressed in the venom glands. This allowed us to reconstruct its probable evolutionary origin and underlines the importance of incorporating data derived from nonvenom gland tissue to elucidate the evolution of candidate venom proteins. This first glimpse into the venom of a crustacean and primitively aquatic arthropod reveals conspicuous differences from the venoms of other predatory arthropods such as centipedes, scorpions, and spiders and contributes valuable information for ultimately disentangling the many factors shaping the biology and evolution of venoms and venomous species.

  7. FRESHWATER FISH AND DECAPOD CRUSTACEAN POPULATIONS ON RÉUNION ISLAND, WITH AN ASSESSMENT OF SPECIES INTRODUCTIONS.

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    KEITH P.

    2002-01-01

    Full Text Available Streams of Réunion Island shelter with 26 fish species and 11 decapod crustacean species. Some species have been introduced (18%, some other are endemic to the island or to the Madagascar-Mascarenes region (16.2%, are originated from Indo-Pacific area (35.2% or from Indo-African area (27%. Gobiidae and Palaemonidae are the prevailing family in freshwaters, with the highest number of species. 16 species were introduced, mainly fishes, beginning at the turn of the 19th century, but only 4 of those have become acclimatised, while 7 have disappeared and the status of the other is uncertain.

  8. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    OpenAIRE

    Pablo Mayorga; Karen R. Pérez; Sully M. Cruz; Armando Cáceres

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  9. New records of Decapod Crustaceans (Decapoda: Pontoniinae and Inachidae associated with sea anemones in Turkish waters

    Directory of Open Access Journals (Sweden)

    Z. DURIS

    2013-10-01

    Full Text Available Three anemone-associated decapod crustaceans, two shrimp species, Periclimenes amethysteus and P. aegylios (Caridea: Palaemonidae: Pontoniinae, and the crab Inachus phalangium (Brachyura: Inachidae, all collected from the Dardanelles, are reported for the first time from Turkish coasts. Another inachid crab, Macropodia czernjawskii is also reported for the first time to occur in association with the sea anemone, Anemonia viridis. Periclimenes scriptus was the fifth decapod species recorded associated with sea anemones within the present study, and while this species has already been reported from Turkish waters, this is the first time it is recorded from the Dardanelles (the Turkish Straits System.

  10. Acute and chronic toxicity of cadmium to different life history stages of the freshwater crustacean Asellus aquaticus (L)

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.J.; Williams, K.A.; Pascoe, D.

    1986-09-01

    Different life-history stages of the freshwater isopod crustacean Asellus aquaticus were exposed to a range of cadmium concentrations using a semi-static toxicity testing procedure. Median lethal concentrations (96-hr LC50) ranged from 80 ..mu..g Cd/L for juveniles to > 2000 ..mu..g Cd/L for embryos. Pre-treatment of eggs with cadmium did not increase their tolerance to the metal as juveniles. The responses of each stage are discussed in relation to the use of macroinvertebrate toxicity test data in predicting the hazardous effects of pollutants.

  11. Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects

    Science.gov (United States)

    Dugan, Jenifer E.; Hubbard, David M.; Contreras, Heraldo; Duarte, Cristian; Acuña, Emilio; Schoeman, David S.

    2017-01-01

    Predicting responses of coastal ecosystems to altered sea surface temperatures (SST) associated with global climate change, requires knowledge of demographic responses of individual species. Body size is an excellent metric because it scales strongly with growth and fecundity for many ectotherms. These attributes can underpin demographic as well as community and ecosystem level processes, providing valuable insights for responses of vulnerable coastal ecosystems to changing climate. We investigated contemporary macroscale patterns in body size among widely distributed crustaceans that comprise the majority of intertidal abundance and biomass of sandy beach ecosystems of the eastern Pacific coasts of Chile and California, USA. We focused on ecologically important species representing different tidal zones, trophic guilds and developmental modes, including a high-shore macroalga-consuming talitrid amphipod (Orchestoidea tuberculata), two mid-shore scavenging cirolanid isopods (Excirolana braziliensis and E. hirsuticauda), and a low-shore suspension-feeding hippid crab (Emerita analoga) with an amphitropical distribution. Significant latitudinal patterns in body sizes were observed for all species in Chile (21° - 42°S), with similar but steeper patterns in Emerita analoga, in California (32°- 41°N). Sea surface temperature was a strong predictor of body size (-4% to -35% °C-1) in all species. Beach characteristics were subsidiary predictors of body size. Alterations in ocean temperatures of even a few degrees associated with global climate change are likely to affect body sizes of important intertidal ectotherms, with consequences for population demography, life history, community structure, trophic interactions, food-webs, and indirect effects such as ecosystem function. The consistency of results for body size and temperature across species with different life histories, feeding modes, ecological roles, and microhabitats inhabiting a single widespread coastal

  12. Ultraviolet radiation induces dose-dependent pigment dispersion in crustacean chromatophores.

    Science.gov (United States)

    Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

    2004-10-01

    Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm(2) for UVA and 2.15 J/cm(2) for UVB. Maximal response was achieved with 10.0 J/cm(2) UVA and 8.6 J/cm(2) UVB. UVA was more effective than UVB in inducing pigment dispersion. Soon after UV exposure, melanophores once again reached the initial stage of pigment aggregation after 45 min. Aggregated erythrophores of shrimps adapted to a white background showed significant pigment dispersion with 2.5 J/cm(2) UVA and 0.29 J/cm(2) UVC. Dispersed erythrophores of shrimps adapted to a black background did not show any significant response to UVA, UVB or UVC radiation. UVB did not induce any significant pigment dispersion in shrimps adapted to either a white or a black background. As opposed to the tanning response, which only protects against future UV exposure, the pigment dispersion response could be an important agent protecting against the harmful effects of UV radiation exposure.

  13. Ectoparasitic crustaceans on mullet, Mugil curema (Osteichthyes: Mugilidae in the coastal waters of Rio Grande do Norte State, Brazil - doi: 10.4025/actascibiolsci.v33i3.6796 Ectoparasitic crustaceans on mullet, Mugil curema (Osteichthyes: Mugilidae in the coastal waters of Rio Grande do Norte State, Brazil - doi: 10.4025/actascibiolsci.v33i3.6796

    Directory of Open Access Journals (Sweden)

    Sathyabama Chellappa

    2011-07-01

    Full Text Available White mullet is a commercial fish species abundant in the coastal waters of Brazil. This study investigated the occurrence of crustacean ectoparasites on white mullet, Mugil curema captured from the littoral waters of Rio Grande do Norte State, Brazil. From 2006 to 2007, 31 individuals of M. curema were captured and encountered ectoparasites were observed, identified and counted. M. curema was parasitized by ectoparasitic crustaceans, caligid copepods, Caligus bonito and Caligus sp.; ergasilid copepods, Ergasilus versicolor and E. lizae; and isopod Cymothoa spinipalpa. Of the caligids detected, 66.66% were C. bonito and 33.33% Caligus sp. C. bonito occurred on males of M. curema during the drought season and Caligus sp. occurred on females during the rainy season. The prevalence of both caligid species was 3.23%. Of the ergasilids detected, E. versicolor (91.67% occurred during the drought and rainy seasons, whereas E. lizae (8.33% occurred during the rainy season. Prevalence of E. versicolor was 35.48% and E. lizae was 3.23%. C. spinipalpa was detected during the drought and rainy seasons with a prevalence of 16.13%. The preferred site of fixation by the parasites was the branchial chambers.White mullet is a commercial fish species abundant in the coastal waters of Brazil. This study investigated the occurrence of crustacean ectoparasites on white mullet, Mugil curema captured from the littoral waters of Rio Grande do Norte State, Brazil. From 2006 to 2007, 31 individuals of M. curema were captured and encountered ectoparasites were observed, identified and counted. M. curema was parasitized by ectoparasitic crustaceans, caligid copepods, Caligus bonito and Caligus sp.; ergasilid copepods, Ergasilus versicolor and E. lizae; and isopod Cymothoa spinipalpa. Of the caligids detected, 66.66% were C. bonito and 33.33% Caligus sp. C. bonito occurred on males of M. curema during the drought season and Caligus sp. occurred on females during the rainy

  14. Genotyping of white spot syndrome virus on wild and farm crustaceans from Sonora, Mexico

    Directory of Open Access Journals (Sweden)

    González-Galaviz José Reyes

    2013-01-01

    Full Text Available White spot syndrome is a viral disease affecting wild and farm crustaceans that serve as reservoirs. Previous reports have demonstrated high genomic variation in WSS viruses (WSSV isolated from distinct geographical regions. In this study, we collected wild shrimps (Litopenaeus stylirostris, crabs (Callinectes arcuatus and farmed shrimp (L. vannamei in Sonora, Mexico, between 2008 and 2010. DNA was extracted, and the variable regions and transposase genes were subjected to PCR and sequencing. Compared to strains of WSSV from other sites, Mexican samples exhibited a distinct number of repeat units (RUs in ORF94, ORF75 and ORF125, which ranged between 1-11, 3-15, and 8-11 RUs respectively, and a unique single nucleotide polymorphism (SNP at position 48 of ORF94. A total of six Mexican genotypes were found in organism from shrimp farm and natural environment.

  15. Signal information available for plume source tracking with and without surface waves and learning by undergraduates assisting with the research

    Science.gov (United States)

    Wiley, Megan Beth

    Autonomous vehicles have had limited success in locating point sources of pollutants, chemicals, and other passive scalars. However, animals such as stomatopods, a mantis shrimp, track odor plumes easily for food, mates, and habitat. Laboratory experiments using Planar Laser Induced Fluorescence measured odor concentration downstream of a diffusive source with and without live stomatopods to investigate their source-tracking strategies in unidirectional and "wave-affected" (surface waves with a mean current) flows. Despite the dearth of signal, extreme temporal variation, and meandering plume centerline, the stomatopods were able to locate the source, especially in the wave-affected flow. Differences in the two plumes far from the source (>160 cm) appeared to help the animals in the wave-affected flow position themselves closer to the source (fluid mechanics, and there was little evidence of learning by participation in the RAship. One RA's conceptions of turbulence did change, but a group workshop seemed to support this learning more than the RAship. The documented conceptions could aid in curriculum design, since situating new information within current knowledge seems to deepen learning outcomes. The RAs' conceptions varied widely with some overlap of ideas. The interviews also showed that most RAs did not discuss molecular diffusion as part of the mixing process and some remembered information from course demonstrations, but applied them inappropriately to the interview questions.

  16. Role of crustacean hyperglycemic hormone (CHH) in the environmental stressor-exposed intertidal copepod Tigriopus japonicus.

    Science.gov (United States)

    Kim, Bo-Mi; Jeong, Chang-Bum; Han, Jeonghoon; Kim, Il-Chan; Rhee, Jae-Sung; Lee, Jae-Seong

    2013-09-01

    To identify and characterize CHH (TJ-CHH) gene in the copepod Tigriopus japonicus, we analyzed the full-length cDNA sequence, genomic structure, and promoter region. The full-length TJ-CHH cDNA was 716 bp in length, encoding 136 amino acid residues. The deduced amino acid sequences of TJ-CHH showed a high similarity of the CHH mature domain to other crustaceans. Six conserved cysteine residues and five conserved structural motifs in the CHH mature peptide domain were also observed. The genomic structure of the TJ-CHH gene contained three exons and two introns in its open reading frame (ORF), and several transcriptional elements were detected in the promoter region of the TJ-CHH gene. To investigate transcriptional change of TJ-CHH under environmental stress, T. japonicus were exposed to heat treatment, UV-B radiation, heavy metals, and water-accommodated fractions (WAFs) of Iranian crude oil. Upon heat stress, TJ-CHH transcripts were elevated at 30 °C and 35 °C for 96 h in a time-course experiment. UV-B radiation led to a decreased pattern of the TJ-CHH transcript 48 h and more after radiation (12 kJ/m(2)). After exposure of a fixed dose (12 kJ/m(2)) in a time-course experiment, TJ-CHH transcript was down-regulated in time-dependent manner with a lowest value at 12h. However, the TJ-CHH transcript level was increased in response to five heavy metal exposures for 96 h. Also, the level of the TJ-CHH transcript was significantly up-regulated at 20% of WAFs after exposure to WAFs for 48 h and then remarkably reduced in a dose-dependent manner. These findings suggest that the enhanced TJ-CHH transcript level is associated with a cellular stress response of the TJ-CHH gene as shown in decapod crustaceans. This study is also helpful for a better understanding of the detrimental effects of environmental changes on the CHH-triggered copepod metabolism. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Sequence Conservation and Sexually Dimorphic Expression of the Ftz-F1 Gene in the Crustacean Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Nur Syafiqah Mohamad Ishak

    Full Text Available Identifying the genes required for environmental sex determination is important for understanding the evolution of diverse sex determination mechanisms in animals. Orthologs of Drosophila orphan receptor Fushi tarazu factor-1 (Ftz-F1 are known to function in genetic sex determination. In contrast, their roles in environmental sex determination remain unknown. In this study, we have cloned and characterized the Ftz-F1 ortholog in the branchiopod crustacean Daphnia magna, which produces males in response to environmental stimuli. Similar to that observed in Drosophila, D. magna Ftz-F1 (DapmaFtz-F1 produces two splicing variants, αFtz-F1 and βFtz-F1, which encode 699 and 777 amino acids, respectively. Both isoforms share a DNA-binding domain, a ligand-binding domain, and an AF-2 activation domain and differ only at the A/B domain. The phylogenetic position and genomic structure of DapmaFtz-F1 suggested that this gene has diverged from an ancestral gene common to branchiopod crustacean and insect Ftz-F1 genes. qRT-PCR showed that at the one cell and gastrulation stages, both DapmaFtz-F1 isoforms are two-fold more abundant in males than in females. In addition, in later stages, their sexual dimorphic expressions were maintained in spite of reduced expression. Time-lapse imaging of DapmaFtz-F1 RNAi embryos was performed in H2B-GFP expressing transgenic Daphnia, demonstrating that development of the RNAi embryos slowed down after the gastrulation stage and stopped at 30-48 h after ovulation. DapmaFtz-F1 shows high homology to insect Ftz-F1 orthologs based on its amino acid sequence and exon-intron organization. The sexually dimorphic expression of DapmaFtz-F1 suggests that it plays a role in environmental sex determination of D. magna.

  18. Molecular identification of a Drosophila G protein-coupled receptor specific for crustacean cardioactive peptide

    DEFF Research Database (Denmark)

    Cazzamali, Giuseppe; Hauser, Frank; Kobberup, Sune

    2003-01-01

    The Drosophila Genome Project website (www.flybase.org) contains the sequence of an annotated gene (CG6111) expected to code for a G protein-coupled receptor. We have cloned this receptor and found that its gene was not correctly predicted, because an annotated neighbouring gene (CG14547) was also...... part of the receptor gene. DNA corresponding to the corrected gene CG6111 was expressed in Chinese hamster ovary cells, where it was found to code for a receptor that could be activated by low concentrations of crustacean cardioactive peptide, which is a neuropeptide also known to occur in Drosophila...... and other insects (EC(50), 5.4 x 10(-10)M). Other known Drosophila neuropeptides, such as adipokinetic hormone, did not activate the receptor. The receptor is expressed in all developmental stages from Drosophila, but only very weakly in larvae. In adult flies, the receptor is mainly expressed in the head...

  19. Re-Engineering the Stomatopod Eye

    Science.gov (United States)

    2016-09-21

    Biology 25: R1-R3. 17. J. Marshall, K.L. Carleton and T. Cronin. 2015. Colour vision in marine organisms. Current Opinion in Neurobiology 34:86-94...20130032. http://dx.doi.org/10.1098/rstb.2013.0032 34. *N.J. Marshall, M.F. Land, and T.W. Cronin. 2014. Shrimps that pay attention : Saccadic...Marshall, K.L. Carleton and T. Cronin. 2015. Colour vision in marine organisms. Current Opinion in Neurobiology 34:86-94. K. Feller, J. Cohen, and T.W

  20. Ingestion and selection of suprabenthic crustaceans by small-sized fishes in a lower saltmarsh system

    Directory of Open Access Journals (Sweden)

    Yoko Wakabara

    1996-01-01

    Full Text Available This study was performed in the lower saltmarsh system of the Arrozal, in the Cananéia lagoon estuarine region (25º02'S - 47º56'W, Brazil. Suprabenthic fauna was surveyed Wlth a small sledge and fishes were captured with casting and set nets to analyse: crustacean fauna as food for local fish species; difference in the diet at different times of the year; if there is diet overlap between species and the feeding behaviour of the species analysed. The fauna of Arrozal is poor in species, dominated mainly by Metamysidopsis alongata atlantica, Acartia lilljeborgi, Atylus minikoi, decapod larvae, and reveals a strong seasonal variation. The fishes were ali camivorous with suprabenthic crustacean as their main food resource. Seasonal changes in food supply are also reflected in the diet. Of the 12 flSh species collected six were opportunistlc feeders whereas six others were selective feeders. Food overlap value of 0.08 for ali of the fish community indicates an almost completely distinct food niches. The increased overlapping of summer food between Cathorops spixii and species of Group 11 and between Oligoplites sp and species of Group I seems to have two different explanations: 1 the mmIDishing of food supply for species feeding on benthic originated suprabenthic crustaceans and 2 overabundance of planktonic forms of suprabenthos as well as a period of high feeding activity of fishes with such diet.O presente estudo foi realizado no infralitoral contíguo à marisma, na Ponta do Arrozal, região estuarina lagunar de Cananéia (25º02'S - 47º56'W, Brasil. A fauna suprabêntica foi amostrada com uma pequena draga e os peixes capturados com tarrafa e rede de espera, com a finalidade de analisar: a composição de espécies dos crustáceos suprabênticos como itens alimentares dos peixes; diferenças na dieta em diferentes época do ano; se ocorre sobreposição alimentar entre as espécies e o comportamento alimentar: das espécies de peixes

  1. Crystallization and X-ray diffraction studies of crustacean proliferating cell nuclear antigen

    International Nuclear Information System (INIS)

    Carrasco-Miranda, Jesus S.; Cardona-Felix, Cesar S.; Lopez-Zavala, Alonso A.; Re Vega, Enrique de la; De la Mora, Eugenio; Rudiño-Piñera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

    2012-01-01

    Proliferating cell nuclear antigen from Litopenaeus vannamei was recombinantly expressed, purified and crystallized. Diffraction data were obtained and processed to 3 Å. Proliferating cell nuclear antigen (PCNA), a member of the sliding clamp family of proteins, interacts specifically with DNA replication and repair proteins through a small peptide motif called the PCNA-interacting protein or PIP box. PCNA is recognized as one of the key proteins involved in DNA metabolism. In the present study, the recombinant PCNA from Litopenaeus vannamei (LvPCNA) was heterologously overexpressed and purified using metal ion-affinity chromatography. Crystals suitable for diffraction grew overnight using the hanging-drop vapour-diffusion method. LvPCNA crystals belong to space group C2 with unit-cell parameters a = 144.6, b = 83.4, c = 74.3 Å, β = 117.6°. One data set was processed to 3 Å resolution, with an overall R meas of 0.09 and a completeness of 93.3%. Initial phases were obtained by molecular replacement using a homology model of LvPCNA as the search model. Refinement and structural analysis are underway. This report is the first successful crystallographic analysis of a marine crustacean decapod shrimp (L. vannamei) proliferating cell nuclear antigen

  2. Biomechanical properties of predator-induced body armour in the freshwater crustacean Daphnia.

    Science.gov (United States)

    Kruppert, Sebastian; Horstmann, Martin; Weiss, Linda C; Witzel, Ulrich; Schaber, Clemens F; Gorb, Stanislav N; Tollrian, Ralph

    2017-08-29

    The freshwater crustacean Daphnia is known for its ability to develop inducible morphological defences that thwart predators. These defences are developed only in the presence of predators and are realized as morphological shape alterations e.g. 'neckteeth' in D. pulex and 'crests' in D. longicephala. Both are discussed to hamper capture, handling or consumption by interfering with the predator's prey capture devices. Additionally, D. pulex and some other daphniids were found to armour-up and develop structural alterations resulting in increased carapace stiffness. We used scanning transmission electron microscopy (STEM) and confocal laser scanning microscopy (CLSM) to identify predator-induced structural and shape alterations. We found species specific structural changes accompanying the known shape alterations. The cuticle becomes highly laminated (i.e. an increased number of layers) in both species during predator exposure. Using nano- and micro-indentation as well as finite element analysis (FEA) we determined both: the structure's and shape's contribution to the carapace's mechanical resistance. From our results we conclude that only structural alterations are responsible for increased carapace stiffness, whereas shape alterations appear to pose handling difficulties during prey capture. Therefore, these defences act independently at different stages during predation.

  3. Armadillidin H, a glycine-rich peptide from the terrestrial crustacean Armadillidium vulgare, displays an unexpected wide antimicrobial spectrum with membranolytic activity.

    Directory of Open Access Journals (Sweden)

    Julien Verdon

    2016-09-01

    Full Text Available Antimicrobial peptides (AMPs are key components of innate immunity and are widespread in nature, from bacteria to vertebrate animals. In crustaceans, there are currently 15 distinct AMP families published so far in the literature, mainly isolated from members of the Decapoda order. Up to now, armadillidin is the sole non-decapod AMP isolated from the haemocytes of Armadillidium vulgare, a crustacean isopod. Its first description demonstrated that armadillidin is a linear glycine-rich (47% cationic peptide with an antimicrobial activity directed towards Bacillus megaterium. In the present work, we report identification of armadillidin Q, a variant of armadillidin H (earlier known as armadillidin, from crude haemocyte extracts of A. vulgare using LC-MS approach. We demonstrated that both armadillidins displayed broad spectrum antimicrobial activity against several Gram-positive and Gram negative bacteria, fungi, but were totally inactive against yeasts. Membrane permeabilization assays, only performed with armadillidin H, showed that the peptide is membrane active against bacterial and fungal strains leading to deep changes in cell morphology. This damaging activity visualized by electronic microscopy correlates with a rapid decrease of cell viability leading to highly blebbed cells. In contrast, armadillidin H does not reveal cytotoxicity towards human erythrocytes. Furthermore, no secondary structure could be defined in this study (by CD and NMR even in a membrane mimicking environment. Therefore, armadillidins represent interesting candidates to gain insight into the biology of glycine-rich AMPs.

  4. Biodiversity patterns of crustacean suprabenthic assemblages along an oligotrophic gradient in the bathyal Mediterranean Sea

    Science.gov (United States)

    Almeida, Mariana; Frutos, Inmaculada; Tecchio, Samuele; Lampadariou, Nikolaos; Company, Joan B.; Ramirez-Llodra, Eva; Cunha, Marina R.

    2017-03-01

    Crustacean suprabenthic abundance, community structure, α-diversity (both taxonomic and trophic) and β-diversity were studied along a West-East gradient of oligotrophy in the deep Mediterranean Sea. The assemblages were sampled with a suprabenthic sledge in three regions (western, central and eastern basins) at three water depths (1200, 2000 and 3000 m) in May-June 2009. Environmental data were obtained at each sampling location including sediment properties, oceanographic variables near the seafloor and in the water column, and proxies of epipelagic productivity at the surface. Our results, concerning the crustacean component of the suprabenthos, showed complex trends in community structure and biodiversity across different spatial scales (longitudinal, bathymetric, and near-bottom distribution). A decrease in the number of species and abundance, accompanied by changes in the trophic structure of the assemblages were observed from West to East. In the eastern region the assemblages were impoverished in number of trophic guilds and trophic diversity. The West-East oligotrophic gradient was identified as the main driver in community structure as shown by the significant correlation with trophic environmental variables. Differences in community structure across regions were more marked at greater depths, while at the shallower sites assemblages were more similar. Within each basin, abundance, number of species and number of trophic groups decreased with depth, showing high turnover rates between 1200 and 2000 m depths. The small-scale (0-150 cm) vertical distribution of the suprabenthos was interpreted in relation to the species' functional traits (e.g. swimming activity, migratory behaviour, bottom dependence, feeding habits). Bottom-dependent and more mobile components of the suprabenthos were apparently responding differently to the various environmental challenges imposed by the large-scale longitudinal and bathymetric gradients. We propose that the bathyal

  5. Extreme morphologies of mantis shrimp larvae

    DEFF Research Database (Denmark)

    Haug, Carolin; Ahyong, Shane T.; Wiethase, Joris H.

    2016-01-01

    Larvae of stomatopods (mantis shrimps) are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages), alima and erichthus (the latt er two representing later larval stages). These categories, however, do not refl ect the existing morphological...

  6. A study of the uptake and toxicity of some stable and radioactive pollutants in marine organisms: antimony, silver, cobalt and strontium in mollusks, crustaceans and teleosts

    International Nuclear Information System (INIS)

    Amiard, J.-C.

    1978-10-01

    Qualitative and quantitative results following direct aquatic contamination of mollusks, crustaceans and teleosts by 125 Sb, 110 Ag, 60 Co, 85 Sr are reported. The effects of a number of biotic and abiotic parameters on the contamination of the various organisms and the distribution and elimination of the radionuclides in the tissues were investigated. The transfer of sup(110m)Ag, 60 Co and 125 Sb was studied in several benthic food chains. The transfer factor (F.T.) between a given trophic level and the initial environment (seawater) was determined as well as various physiological parameters (percentages ingested, assimilated, eliminated via the feces or urine and/or the gills. Elimination and tissue uptake were followed in mollusks and crustaceans. The consequences of contamination by stable and radioactive pollutants on plants and animals were considered. Acute (lethal) toxicity of various metals or metalloids on marine organisms were quantified. More sensitive sublethal tests considering physiological functions or behaviour were used. Irradiation doses to experiment animals were calculated, showing the importance of the (internal or external distribution of radionuclides and individual geometries on the total exposure dose [fr

  7. A mutation in the receptor Methoprene-tolerant alters juvenile hormone response in insects and crustaceans.

    Science.gov (United States)

    Miyakawa, Hitoshi; Toyota, Kenji; Hirakawa, Ikumi; Ogino, Yukiko; Miyagawa, Shinichi; Oda, Shigeto; Tatarazako, Norihisa; Miura, Toru; Colbourne, John K; Iguchi, Taisen

    2013-01-01

    Juvenile hormone is an essential regulator of major developmental and life history events in arthropods. Most of the insects use juvenile hormone III as the innate juvenile hormone ligand. By contrast, crustaceans use methyl farnesoate. Despite this difference that is tied to their deep evolutionary divergence, the process of this ligand transition is unknown. Here we show that a single amino-acid substitution in the receptor Methoprene-tolerant has an important role during evolution of the arthropod juvenile hormone pathway. Microcrustacea Daphnia pulex and D. magna share a juvenile hormone signal transduction pathway with insects, involving Methoprene-tolerant and steroid receptor coactivator proteins that form a heterodimer in response to various juvenoids. Juvenile hormone-binding pockets of the orthologous genes differ by only two amino acids, yet a single substitution within Daphnia Met enhances the receptor's responsiveness to juvenile hormone III. These results indicate that this mutation within an ancestral insect lineage contributed to the evolution of a juvenile hormone III receptor system.

  8. Integration of physiological responses of crustaceans to ...

    African Journals Online (AJOL)

    1997-09-02

    Sep 2, 1997 ... end-products have been implicated as effectors of behaviour and thereby ... cular function, relative perfusion of gills v. lungs, gas transport in the blood, the ..... pendent changes in haemolymph flow through separate arte-.

  9. Combined toxicity of mercury and plastic wastes to crustacean and gastropod inhabiting the waters in Kuwait.

    Science.gov (United States)

    Bu-Olayan, A H; Thomas, B V

    2015-11-01

    The present study determined total mercury (T-Hg) in crustacean Portunus pelagicus (blue crab) and mollusc Tapes sulcarius (Furrowed Venus: Cockle) following suspected rise in beach plastic wastes and their effect on marine organisms. Live samples were collected from beaches representing six Kuwait Governorate areas and exposed to toxicity (96hr) and bio accumulation tests for 180 d with inclusion of plastic wastes and environmental conditions simulated in laboratory. Results revealed high T-Hg concentrations in T sulcarius (1.44ng l(-1)) compared to P. pelagicus (1.03ng l(-1)) during winter than summer, with bio accumulation factor (BAF) > 1 labelled these species as hyper-accumulators. Significantly, combination of T-Hg concentrations from plastic wastes and in seawater validated the possibilities of detrimental effects of other marine lives besides deteriorating the aesthetic values of scenic beaches and likelihood of invasive species in such coastal areas.

  10. Studies on the planktonic Decapoda and Stomatopoda (Crustacea) from the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Nair, V.R.; Goswami, S.C.

    Abundance and distribution of decapods and stomatopods were studied, based on 90 samples collected from the western Bay of Bengal (Lat. 09 degrees 58' and 20 degrees 50'N and long. 80 degrees 00'E) between 24 August and 2 October, 1976. The decapod...

  11. Melanization and Pathogenicity in the Insect, Tenebrio molitor, and the Crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3

    Science.gov (United States)

    Noonin, Chadanat; Jiravanichpaisal, Pikul; Söderhäll, Irene; Merino, Susana; Tomás, Juan M.; Söderhäll, Kenneth

    2010-01-01

    Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS), bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish) and Tenebrio molitor larvae (mealworm). The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core) is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT) containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the proPO system

  12. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    Directory of Open Access Journals (Sweden)

    Chadanat Noonin

    Full Text Available Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS, bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish and Tenebrio molitor larvae (mealworm. The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the

  13. Differential protein expression using proteomics from a crustacean brine shrimp (Artemia sinica) under CO2-driven seawater acidification.

    Science.gov (United States)

    Chang, Xue-Jiao; Zheng, Chao-Qun; Wang, Yu-Wei; Meng, Chuang; Xie, Xiao-Lu; Liu, Hai-Peng

    2016-11-01

    Gradually increasing atmospheric CO 2 partial pressure (pCO 2 ) has caused an imbalance in carbonate chemistry and resulted in decreased seawater pH in marine ecosystems, termed seawater acidification. Anthropogenic seawater acidification is postulated to affect the physiology of many marine calcifying organisms. To understand the possible effects of seawater acidification on the proteomic responses of a marine crustacean brine shrimp (Artemia sinica) three groups of cysts were hatched and further raised in seawater at different pH levels (8.2 as control and 7.8 and 7.6 as acidification stress levels according to the predicted levels at the end of this century and next century, respectively) for 1, 7 and 14 days followed by examination of the protein expression changes via two-dimensional gel electrophoresis. Searches of protein databases revealed that 67 differential protein spots were altered due to lower pH level (7.6 and 7.8) stress in comparison to control groups (pH 8.2) by mass spectrometry. Generally, these differentially expressed proteins included the following: 1) metabolic process-related proteins involved in glycolysis and glucogenesis, nucleotide/amino acid/fatty acid metabolism, protein biosynthesis, DNA replication and apoptosis; 2) stress response-related proteins, such as peroxiredoxin, thioredoxin peroxidase, 70-kDa heat shock protein, Na/K ATPase, and ubiquinol-cytochrome c reductase; 3) immune defence-related proteins, such as prophenoloxidase and ferritin; 4) cytoskeletal-related proteins, such as myosin light chain, TCP1 subunit 2, tropomyosin and tubulin alpha chain; and 5) signal transduction-related proteins, such as phospholipase C-like protein, 14-3-3 zeta, translationally controlled tumour protein and RNA binding motif protein. Taken together, these data support the idea that CO 2 -driven seawater acidification may affect protein expression in the crustacean A. sinica and possibly also in other species that feed on brine shrimp in the

  14. Epidemiological, evolutionary, and coevolutionary implications of context-dependent parasitism.

    Science.gov (United States)

    Vale, Pedro F; Wilson, Alastair J; Best, Alex; Boots, Mike; Little, Tom J

    2011-04-01

    Abstract Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster-growing parasites do not appear to cause more damage, and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa, we show how easily an interaction can shift from a severe interaction, that is, when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modeling pathogen evolution and disease spread under different levels of infection severity and found that environmental shifts that promote tolerance ultimately result in populations harboring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus, our results suggest two mechanisms that could underlie coevolutionary hotspots and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection.

  15. Cloning and expression of the recombinant crustacean hyperglycemic hormone isoform B2 (rCHH-B2) and its effects on the metabolism and osmoregulation of the Pacific white shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Camacho-Jiménez, Laura; Sánchez-Castrejón, Edna; Díaz, Fernando; Aguilar, Manuel B; Muñoz-Márquez, Ma Enriqueta; Ponce-Rivas, Elizabeth

    2017-11-01

    Crustacean hyperglycemic hormones (CHHs) are multifunctional neuropeptides ubiquitous in crustaceans. In Litopenaeus vannamei, CHH-B2 is a CHH eyestalk isoform whose expression has been shown to vary with enviromental conditions, suggesting its relevance for ecophysiological performance of shrimp, controlling processes related to metabolism and osmo-ionic regulation. To study the involvement of CHH-B2 in these processes, we cloned and expressed a recombinant version with a free C-terminal glycine (rCHH-B2-Gly) in the methylotrophic yeast Pichia pastoris. The rCHH-B2-Gly peptide secreted to the culture medium was purified by RP-HPLC and used for in vivo glucose, triglyceride, and osmoregulation dose-response analyses with juvenile shrimp. The peptide was also amidated at the C-terminus using an α-amidating enzyme to produce rCHH-B2-amide. The shrimp showed a dose-dependent effect of rCHH-B2-Gly to hemolymph glucose and triglyceride levels, inducing maximal increases by injecting 500 and 1000pmol of hormone, respectively. Additionally, 10pmol of hormone was sufficient to reduce the hypo-osmoregulatory capacity of shrimp at 35‰. These findings suggest that CHH-B2 has regulatory roles in carbohydrate and lipid metabolism, and a potential involvement in osmoregulation of L. vannamei. Injection of 100pmol of rCHH-B2-amide increased glucose and triglyceride levels by 15 and 28%, respectively in comparison with rCHH-B2-Gly, suggesting an important role for the C-terminal amidation. Additionally, an in silico structural analysis done with the CHH-B1 and rCHH-B2-Gly peptides suggests that the C-terminal region may be relevant for the activity of the L. vannamei isoforms and explain the functional divergence from other crustacean CHH/CHH-like peptides. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Fitness and virulence of a bacterial endoparasite in an environmentally stressed crustacean host.

    Science.gov (United States)

    Coors, Anja; De Meester, Luc

    2011-01-01

    Host-parasite interactions are shaped by the co-evolutionary arms race of parasite virulence, transmission success as well as host resistance and recovery. The virulence and fitness of parasites may depend on host condition, which is mediated, for instance, by host energy constraints. Here, we investigated to what extent stress imposed by predation threat and environmental pollutants influences host-parasite interactions. We challenged the crustacean host Daphnia magna with the sterilizing bacterial endoparasite Pasteuria ramosa and simultaneously exposed the host to fish kairomones, the pesticide carbaryl or both stressors. While parasite virulence, measured as impact on host mortality and sterilization, increased markedly after short-term pesticide exposure, it was not influenced by predation threat. Parasite fitness, measured in terms of produced transmission stages, decreased both in fish and pesticide treatments. This effect was much stronger under predation threat than carbaryl exposure, and was attributable to reduced somatic growth of the host, presumably resulting in fewer resources for parasite development. While the indirect impact of both stressors on spore loads provides evidence for host condition-dependent parasite fitness, the finding of increased virulence only under carbaryl exposure indicates a stronger physiological impact of the neurotoxic chemical compared with the effect of a non-toxic fish kairomone.

  17. Studies on planktonic decapoda and stomatopoda (Crustacea) from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Goswami, S.C.; Nair, V.R.

    and longitudes 66 degrees 00' and 78 degrees 00'E and depths ranging from 25 to 500 m. Only 40 samples out of 93, contained planktonic decapods and stomatopods. Maximum number of larvae (1501/100 m3) was obtained from Station 228 (Ga. Cr. 13), a very shallow...

  18. Alloxenic distribution of cystacanths of two Profilicollis species in sympatric crustacean hosts in Chile.

    Science.gov (United States)

    Balboa, L; Hinojosa, A; Riquelme, C; Rodríguez, S; Bustos, J; George-Nascimento, M

    2009-10-01

    The taxonomic status of Profilicollis ( = Falsifilicollis Webster, 1948) species in crustaceans in Chile is examined. Mole crabs, Emerita analoga (Stimpson 1857), living in the splash zone of a sandy beach at Lenga off the coast of central Chile, harbor Polymorphus (Profilicollis) bullocki Mateo, Córdova and Guzmán 1982, while the estuarine crabs, Hemigrapsus crenulatus (Milne-Edwards, 1837), living in an oligohaline inlet at the same site, harbor Profilicollis spp. cystacanths which cannot be distinguished specifically to either Profilicollis antarcticus or P. chasmagnathi Holcman-Spector, Mañé-Garzón and Dei-Cas 1977. We found no morphological data supporting records of P. altmani along the coast of Chile. Therefore, and after examination of both their morphology and the literature, we consider that P. bullocki must be reinstated as a valid species in the genus. There is a widespread distribution of habitats, such as sandy beaches and inlets, as well as a variety of host taxa involved in the life cycle of Profilicollis spp. Consequently, they provide an interesting scenario for testing hypotheses regarding the coevolution and host specificity of these parasites.

  19. Epidemiological, evolutionary and co-evolutionary implications of context-dependent parasitism

    Science.gov (United States)

    Vale, Pedro F.; Wilson, Alastair J.; Best, Alex; Boots, Mike; Little, Tom J.

    2013-01-01

    Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster growing parasites do not appear to cause more damage and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa we show how easily an interaction can shift from a severe interaction, i.e. when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modelling pathogen evolution and disease spread under different levels of infection severity, and find that environmental shifts that promote tolerance ultimately result in populations harbouring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus our results suggest two mechanisms that could underlie co-evolutionary hot- and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection. PMID:21460572

  20. Uptake and effects of microplastic textile fibers on freshwater crustacean Daphnia magna.

    Science.gov (United States)

    Jemec, Anita; Horvat, Petra; Kunej, Urban; Bele, Marjan; Kržan, Andrej

    2016-12-01

    Microplastic fibers (MP) from textile weathering and washing are increasingly being recognized as environmental pollutants. The majority of studies on the bioavailability and effects of microplastic focused on small polystyrene spherical plastic particles, while less data are available for fibers and for other materials besides polystyrene. We investigated the ingestion and effects of ground polyethylene terephthalate (PET) textile microfibers (length range: 62-1400 μm, width 31-528 μm, thickness 1-21.5 μm) on the freshwater zooplankton crustacean Daphnia magna after a 48 h exposure and subsequent 24 h of recovery in MP free medium and algae. The majority of ingested fibers by D. magna were around 300 μm, but also some very large twisted MP fibers around 1400 μm were found inside the gut. Exposure to these fibers results in increased mortality of daphnids after 48 h only in the case where daphnids were not pre-fed with algae prior to experiment, but no effect was found when daphnids were fed before the experiments. Regardless of the feeding regime, daphnids were not able to recover from MP exposure after additional 24 h incubation period in a MP free medium with algae. The uptake and effects of PET textile MP on D. magna are presented here for the first time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Transgenerational deleterious effects of ocean acidification on the reproductive success of a keystone crustacean (Gammarus locusta).

    Science.gov (United States)

    Borges, Francisco O; Figueiredo, Cátia; Sampaio, Eduardo; Rosa, Rui; Grilo, Tiago F

    2018-07-01

    Ocean acidification (OA) poses a global threat to marine biodiversity. Notwithstanding, marine organisms may maintain their performance under future OA conditions, either through acclimation or evolutionary adaptation. Surprisingly, the transgenerational effects of high CO 2 exposure in crustaceans are still poorly understood. For the first time, the present study investigated the transgenerational effect of OA, from hatching to maturity, of a key amphipod species (Gammarus locusta). Negative transgenerational effects were observed on survival of the acidified lineage, resulting in significant declines (10-15%) compared to the control groups in each generation. Mate-guarding duration was also significantly reduced under high CO 2 and this effect was not alleviated by transgenerational acclimation, indicating that precopulatory behaviours can be disturbed under a future high CO 2 scenario. Although OA may initially stimulate female investment, transgenerational exposure led to a general decline in egg number and fecundity. Overall, the present findings suggest a potential fitness reduction of natural populations of G. locusta in a future high CO 2 ocean, emphasizing the need of management tools towards species' sustainability. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Description of two new associated infaunal decapod crustaceans (Axianassidae and Alpheidae from the tropical eastern Pacific

    Directory of Open Access Journals (Sweden)

    Arthur Anker

    2015-08-01

    Full Text Available Two new species of infaunal decapod crustaceans are described based on material collected in Bahía Málaga, Pacific coast of Colombia, in 2009. The mud-shrimp Axianassa darrylfelderi sp. nov. (Axianassidae appears to be most closely related to A. australis Rodrigues & Shimizu, 1992, A. canalis Kensley & Heard, 1990, and A. jamaicensis Kensley & Heard, 1990. The new species may be distinguished from each of them by a combination of morphological features, mainly on the uropodal exopod, antennal acicle, third maxilliped and first pleonite. The shrimp Leptalpheus canterakintzi sp. nov. (Alpheidae, associated with burrows of A. darrylfelderi sp. nov., undoubtedly represents the eastern Pacific sister species of the western Atlantic L. axianassae Dworschak & Coelho, 1999, which lives exclusively in burrows of A. australis. The two species are reliably distinguishable only by the proportions of the merus and propodus of the third pereiopod. Leptalpheus azuero Anker, 2011, previously known only from the Pacific coast of Panama, is reported for the first time from Bahía Málaga, Colombia.

  3. The immune-related fatty acids are responsive to CO2 driven seawater acidification in a crustacean brine shrimp Artemia sinica.

    Science.gov (United States)

    Gao, Yan; Zheng, Shu-Cheng; Zheng, Chao-Qun; Shi, Yue-Chen; Xie, Xiao-Lu; Wang, Ke-Jian; Liu, Hai-Peng

    2018-04-01

    The gradual increase of CO 2 concentration in the atmosphere, absorbed by the ocean surface water through air to sea equilibration termed ocean acidification (OA), leads to the decline of pH in seawater. It is not clear so far how the composition of fatty acids, particular the immune-related, in marine crustacean and the subsequent energy supply in marine ecosystem are affected by OA. The brine shrimp Artemia sinica is an open and common feed that provide essential fatty acids for mariculture. In this study, the fatty acids profiles of brine shrimp cultured under different lower pH levels of CO 2 driven seawater were investigated. The results showed a significant reduction of the proportion of total saturated fatty acids under the pH7.6 within one week. Meanwhile, the percentage of total monounsaturated fatty acids was significantly decreased at day 14 under pH7.8, and this percentage gave a significant increase of proportion within one week under pH7.6. Furthermore, the relative content of total polyunsaturated fatty acids (PUFAs) was found to be clearly increased with exposure to different seawater acidification at day 1, suggesting that the brine shrimp immune response was likely to be affected by acidified seawater as the PUFAs have been well known to be involved in immunomodulatory effects through alterations on cell membrane fluidity/lipid mediators and gene expression of cell signaling pathways. Notably, eicosapentaenoic acid and docosahexaenoic acid, which have essential effect on various physiological processes such as inflammatory cytokines production and cell structural stability, were strongly increased under two lower pH treatments within one week and with the significant increase at day 1 under pH7.6. These data clearly supported the hypothesis that OA might affect fatty acids composition, likely also the innate immunity, in crustacean and the subsequent energy transfer by food-chain system in the marine ecosystem. Copyright © 2017 Elsevier Ltd. All

  4. Environmental sex determination in the branchiopod crustacean Daphnia magna: deep conservation of a Doublesex gene in the sex-determining pathway.

    Directory of Open Access Journals (Sweden)

    Yasuhiko Kato

    2011-03-01

    Full Text Available Sex-determining mechanisms are diverse among animal lineages and can be broadly divided into two major categories: genetic and environmental. In contrast to genetic sex determination (GSD, little is known about the molecular mechanisms underlying environmental sex determination (ESD. The Doublesex (Dsx genes play an important role in controlling sexual dimorphism in genetic sex-determining organisms such as nematodes, insects, and vertebrates. Here we report the identification of two Dsx genes from Daphnia magna, a freshwater branchiopod crustacean that parthenogenetically produces males in response to environmental cues. One of these genes, designated DapmaDsx1, is responsible for the male trait development when expressed during environmental sex determination. The domain organization of DapmaDsx1 was similar to that of Dsx from insects, which are thought to be the sister group of branchiopod crustaceans. Intriguingly, the molecular basis for sexually dimorphic expression of DapmaDsx1 is different from that of insects. Rather than being regulated sex-specifically at the level of pre-mRNA splicing in the coding region, DapmaDsx1 exhibits sexually dimorphic differences in the abundance of its transcripts. During embryogenesis, expression of DapmaDsx1 was increased only in males and its transcripts were primarily detected in male-specific structures. Knock-down of DapmaDsx1 in male embryos resulted in the production of female traits including ovarian maturation, whereas ectopic expression of DapmaDsx1 in female embryos resulted in the development of male-like phenotypes. Expression patterns of another D. magna Dsx gene, DapmaDsx2, were similar to those of DapmaDsx1, but silencing and overexpression of this gene did not induce any clear phenotypic changes. These results establish DapmaDsx1 as a key regulator of the male phenotype. Our findings reveal how ESD is implemented by selective expression of a fundamental genetic component that is

  5. Symbiotic bacteria contribute to increasing the population size of a freshwater crustacean, Daphnia magna.

    Science.gov (United States)

    Peerakietkhajorn, Saranya; Tsukada, Koji; Kato, Yasuhiko; Matsuura, Tomoaki; Watanabe, Hajime

    2015-04-01

    The filter-feeding crustacean Daphnia is a key organism in freshwater ecosystems. Here, we report the effect of symbiotic bacteria on ecologically important life history traits, such as population dynamics and longevity, in Daphnia magna. By disinfection of the daphniid embryos with glutaraldehyde, aposymbiotic daphniids were prepared and cultured under bacteria-free conditions. Removal of bacteria from the daphniids was monitored by quantitative polymerase chain reaction for bacterial 16S rRNA gene. The population of aposymbiotic daphniids was reduced 10-folds compared with that of the control daphniids. Importantly, re-infection with symbiotic bacteria caused daphniids to regain bacteria and increase their fecundity to the level of the control daphniids, suggesting that symbiotic bacteria regulate Daphnia fecundity. To identify the species of symbiotic bacteria, 16S rRNA genes of bacteria in daphniids were sequenced. This revealed that 50% of sequences belonged to the Limnohabitans sp. of the Betaproteobacteria class and that the diversity of bacterial taxa was relatively low. These results suggested that symbiotic bacteria have a beneficial effect on D. magna, and that aposymbiotic Daphnia are useful tools in understanding the role of symbiotic bacteria in the environmental responses and evolution of their hosts. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Uncovering three-dimensional gradients in fibrillar orientation in an impact-resistant biological armour

    Science.gov (United States)

    Zhang, Y.; Paris, O.; Terrill, N. J.; Gupta, H. S.

    2016-05-01

    The complex hierarchical structure in biological and synthetic fibrous nanocomposites entails considerable difficulties in the interpretation of the crystallographic texture from diffraction data. Here, we present a novel reconstruction method to obtain the 3D distribution of fibres in such systems. An analytical expression is derived for the diffraction intensity from fibres, explaining the azimuthal intensity distribution in terms of the angles of the three dimensional fibre orientation distributions. The telson of stomatopod (mantis shrimp) serves as an example of natural biological armour whose high impact resistance property is believed to arise from the hierarchical organization of alpha chitin nanofibrils into fibres and twisted plywood (Bouligand) structures at the sub-micron and micron scale. Synchrotron microfocus scanning X-ray diffraction data on stomatopod telson were used as a test case to map the 3D fibre orientation across the entire tissue section. The method is applicable to a range of biological and biomimetic structures with graded 3D fibre texture at the sub-micron and micron length scales.

  7. The lunar-tide cycle viewed by crustacean and mollusc gatherers in the State of Paraíba, Northeast Brazil and their influence in collection attitudes

    Directory of Open Access Journals (Sweden)

    Alves Rômulo RN

    2006-01-01

    Full Text Available Abstract Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20 crab gatherers and 30 mollusc gatherers was recorded through open interviews and structured questionnaires. The results showed that the gatherers have an accurate comprehension of tidal phenomenon based on their exploitation of natural resources, which perpetuates through generations.

  8. Behaviour of fish by-catch in the mouth of a crustacean trawl.

    Science.gov (United States)

    Queirolo, D; Gaete, E; Montenegro, I; Soriguer, M C; Erzini, K

    2012-06-01

    The behaviour of fish by-catch was recorded and characterized by in situ observations in the mouth of a crustacean trawl using an underwater camera system with artificial light, at depths between 106 and 461 m, along the central coast of Chile. The groups or species studied were rattails (family Macrouridae), Chilean hake Merluccius gayi gayi, sharks (orders Carcharhiniformes and Squaliformes), skates (family Rajidae), flatfishes (genus Hippoglossina) and small benthopelagic and demersal fishes (orders Osmeriformes, Stomiiformes, Gadiformes, Ophidiiformes and Perciformes). The fish behaviour was categorized in terms of (1) position in the water column, (2) initial orientation with respect to the trawl, (3) locomotion and (4) swimming speed with respect to the trawl. Rattails, sharks, skates and flatfishes were passive in response to the trawl and showed similar behavioural patterns, with most fishes observed sitting or touching the bottom with no swimming or other activity. Merluccius gayi gayi was the most active species, displaying a wide combination of behavioural responses when the trawl approached. This species showed several behavioural patterns, mainly characterized by swimming forward at variable speed. A fraction of small bentho-pelagic and demersal fishes also showed an active behaviour but always at lower speed than the trawl. The species-specific differences in behaviour in the mouth of the trawl suggest that improvements at the level of the footrope can be made to reduce by-catch, especially of passive species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  9. Comparative cation dependency of sugar transport by crustacean hepatopancreas and intestine

    Directory of Open Access Journals (Sweden)

    Ada Duka

    2014-06-01

    Full Text Available Glucose is transported in crustacean hepatopancreas and intestine by Na+-dependent co-transport, while Na+-dependent D-fructose influx has only been described for the hepatopancreas. It is still unclear if the two sugars are independently transported by two distinct cation-dependent co-transporter carrier systems. In this study, lobster (Homarus americanus hepatopancreas brush border membrane vesicles (BBMV were used to characterize, in detail, the cation-dependency of both D-[3H]-glucose and D-[3H]-fructose influxes, while in vitro perfused intestines were employed to determine the nature of cation-dependent sugar transport across this organ. Over the sodium concentration range of 0–100 mM, both [3H]-glucose and [3H]-fructose influxes (0.1 mM; 1 min uptakes by hepatopancreatic BBMV were hyperbolic functions of [Na+]. [3H]-glucose and [3H]-fructose influxes by hepatopancreatic BBMV over a potassium concentration range of 15–100 mM were hyperbolic functions of [K+]. Both sugars displayed significant (p<0.01 Na+/K+-dependent and cation-independent uptake processes. Transepithelial 25 µM [3H]-glucose and [3H]-fructose fluxes across lobster intestine over luminal sodium and potassium concentration ranges of 0–50 mM and 5–100 mM, respectively, were hyperbolic functions of luminal [Na+] and [K+]. As with hepatopancreatic sugar transport, transepithelial intestinal sugar transport exhibited both significant (p<0.01 Na+/K+-dependent and cation-independent processes. Results suggest that both D-glucose and D-fructose are transported by a single SGLT-type carrier in each organ with sodium being the “preferred”, high affinity, cation for both sugars in the hepatopancreas, and potassium being the “preferred”, high affinity, cation for both sugars in the intestine.

  10. Transforming nanostructured chitin from crustacean waste into beneficial health products: a must for our society

    Directory of Open Access Journals (Sweden)

    Morganti P

    2011-12-01

    Full Text Available P Morganti1, G Morganti2, A Morganti3,41Department of Dermatology, Second University of Naples, Naples, Italy; 2Centre of Nanoscience, Mavi Sud s.r.l, Aprilia, Italy; 3Max Planck Institute for Intellectual Property and Competition Law, Munich, Germany; 4Lextray, Milan, ItalyAbstract: Chitin, obtained principally from crustacean waste, is a sugar-like polymer that is available at low cost. It has been shown to be bio- and ecocompatible, and has a very low level of toxicity. Recently, it has become possible to industrially produce pure chitin crystals, named "chitin nanofibrils" (CN for their needle-like shape and nanostructured average size (240 × 5 × 7 nm. Due to their specific chemical and physical characteristics, CN may have a range of industrial applications, from its use in biomedical products and biomimetic cosmetics, to biotextiles and health foods. At present, world offshore disposal of this natural waste material is around 250 billion tons per year. It is an underutilized resource and has the potential to supply a wide range of useful products if suitably recycled, thus contributing to sustainable growth and a greener economy.Keywords: chitin nanofibrils, biomimetic cosmetics, biomedical products, food, nanotechnology, waste

  11. Chronic toxicity of selected polycyclic aromatic hydrocarbons to algae and crustaceans using passive dosing.

    Science.gov (United States)

    Bragin, Gail E; Parkerton, Thomas F; Redman, Aaron D; Letinksi, Daniel J; Butler, Josh D; Paumen, Miriam Leon; Sutherland, Cary A; Knarr, Tricia M; Comber, Mike; den Haan, Klaas

    2016-12-01

    Because of the large number of possible aromatic hydrocarbon structures, predictive toxicity models are needed to support substance hazard and risk assessments. Calibration and evaluation of such models requires toxicity data with well-defined exposures. The present study has applied a passive dosing method to generate reliable chronic effects data for 8 polycyclic aromatic hydrocarbons (PAHs) on the green algae Pseudokirchneriella subcapitata and the crustacean Ceriodaphnia dubia. The observed toxicity of these substances on algal growth rate and neonate production were then compared with available literature toxicity data for these species, as well as target lipid model and chemical activity-based model predictions. The use of passive dosing provided well-controlled exposures that yielded more consistent data sets than attained by past literature studies. Results from the present study, which were designed to exclude the complicating influence of ultraviolet light, were found to be well described by both target lipid model and chemical activity effect models. The present study also found that the lack of chronic effects for high molecular weight PAHs was consistent with the limited chemical activity that could be achieved for these compounds in the aqueous test media. Findings from this analysis highlight that variability in past literature toxicity data for PAHs may be complicated by both poorly controlled exposures and photochemical processes that can modulate both exposure and toxicity. Environ Toxicol Chem 2016;35:2948-2957. © 2016 SETAC. © 2016 SETAC.

  12. Trace elements in several species of crustaceans of Amami Island Group in Japan determined by activation analysis

    International Nuclear Information System (INIS)

    Fukushima, M.; Tamate, H.; Nakano, Y.

    2001-01-01

    Concentration levels of trace elements were determined in several species of subtropical crustaceans from Amami Islands in Japan in order to evaluate the levels of specific accumulation of elements among species. Tissue samples prepared from gill, muscle, hepatopancreas, and testis were irradiated for photon activation analysis (PAA) and neutron activation analysis (NAA). By PAA and NAA, eighteen elements could be determined. The levels of Br and I were extremely high in gills of spiny lobster and shovel-nosed lobster, respectively. A high concentration of Ag was found in the hepatopancreas of spiny lobsters collected from the Amami Island, while this element was not detected in the same species collected from Toba. The results suggest that the distribution of the trace elements in different tissues and species varies according to both species and environmental differences. To study the molecular forms of the elements in tissue, fractions that contained protein-bound elements from the hepatopancreas of spiny lobsters were separated by ultracentrifugation and gel filtration chromatography. Elution profiles of the chromatography suggest that Cu, Fe, and Se were bound to proteins, while Ag was not. (author)

  13. Status of selected bottomfish and crustacean species in Prince William Sound following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Armstrong, D.A.; Dinnel, P.A.; Orensanz, J.M.

    1995-01-01

    Exposure and possible adverse effects of the Exxon Valdez oil spill (EVOS) at depth were studied between 1989 and 1991 on several species of crustaceans, molluscs, and finfish that are characterized by ontogenetic shifts in distribution from meroplanktonic larvae to benthic and demersal juveniles and adults. The authors approach was to search for (1) evidence of exposure to Exxon Valdez crude oil (EVC) at depth (generally between 20 to 150 m) and (2) measurable perturbations at both the individual and population levels. Primary species targeted were Tanner crab (Chionoecetes bairdi), several pandalid shrimps (Pandalus platyceros, P. hypsinotus, P. borealis), flathead sole (Hippoglossoides elassodon), and several bivalves including scallops (Chlamys rubida) and infaunal clams (Nuculana, Yoldia, and Macoma spp.). The survey design provided a comparison between variables measured in oiled bays around Knight Island and non-oiled bays at other locations within Prince William Sound. Polycyclic aromatic hydrocarbons (PAHs) of petrogenic origin were measured in all bays sampled in this study and levels of PAHs derived from EVC were elevated in the oiled bays following the spill, yet attenuated to less than 200 ng/g sediment by 1991. 95 refs., 22 figs., 6 tabs

  14. The influence of finfish aquaculture on benthic fish and crustacean assemblages in Fitzgerald Bay, South Australia

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    Jason E. Tanner

    2015-09-01

    Full Text Available The influence of sea-cage aquaculture on wildfish assemblages has received little attention outside of Europe. Sea-cage aquaculture of finfish is a major focus in South Australia, and while the main species farmed is southern bluefin tuna (Thunnus maccoyii, there is also an important yellowtail kingfish (Seriola lalandi industry. Yellowtail kingfish aquaculture did not appear to have any local or regional effects on demersal assemblages (primarily fish, but also some crustaceans surveyed by baited remote underwater video (BRUV in Fitzgerald Bay. We did, however, detect small scale spatial variations in assemblages within the bay. The type of bait used strongly influenced the assemblage recorded, with significantly greater numbers of fish attracted to deployments where sardines were used as the bait to compared to those with no bait. The pelleted feed used by the aquaculture industry was just as attractive as sardines at one site, and intermediate between sardines and no bait at the other. There was significant temporal variability in assemblages at both farm sites and one control site, while the second control site was temporally stable (over the 9 weeks of the study. Overall, the results suggested that aquaculture was having little if any impact on the abundance and assemblage structure of the demersal macrofauna in Fitzgerald Bay.

  15. Assessment of radionuclide concentration in three crustaceans species of the bay of Bengal; Mesure de la concentration de radionucleides dans trois especes de crustaces du golfe du Bengale

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, C.K.; Zafar, M. [Chittagong Univ., Institute of Marine Sciences (Bangladesh); Chowdhury, M.I.; Kamal, M. [Radioactivity Testing and Monitoring Laboratory, Bangladesh Atomic Energy Commission, Chittagong (Bangladesh)

    2006-10-15

    The natural ({sup 226}Ra, {sup 228}Th, {sup 232}Th and {sup 40}K) and anthropogenic ({sup 137}Cs) radionuclides concentrations in three crustaceans species (Penaeus monodon, Metapenaeus monoceros and Panulirus versicolor), collected from the bay of Bengal, were determined with an aim of assessing any internal radiation hazard due to consumption of the shell fishes and establishing a database for radioactivity levels of the species. Very low level of radioactivity was observed in all the species. The average activity of {sup 226}Ra observed in P. monodon was 1.21 {+-} 0.27 Bq kg{sup -1} fw; in M. monoceros was 0.70 {+-}0.08 Bq kg{sup -1} fw, and in Panulirus versicolor was 1.04 {+-} 0.09 Bq kg{sup -1} fw. The activity of {sup 232}Th observed in these species was 1.30 {+-} 0.37, 0.76 {+-} 0.34 and 1.32 {+-} 0.70 Bq kg{sup -1} fw, and {sup 228}Th was 0.55 {+-} 0.26, 0.31 {+-} 0.14 and 0.74 {+-} 0.22 Bq kg{sup -1} fw, respectively. The average activity of {sup 40}K observed in these species was 12.56 {+-} 1.18, 6.38 {+-}1.02 and 10.07 {+-} 1.52 Bq kg{sup -1} fw, respectively. The activity of radiocaesium ({sup 137}Cs) was below detection limit. The results indicate that the natural and artificial radionuclides observed in three crustaceans species are safe for human health. A significant relationship was observed between {sup 226}Ra and {sup 232}Th in both the P. monodon (r = 0.839, p {<=} 0.05, df = 4) and the Panulirus versicolor (r = 0.906, p {<=} 0.05, df = 4). (authors)

  16. Taxonomic richness and abundance of cryptic peracarid crustaceans in the Puerto Morelos Reef National Park, Mexico

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    Luz Veronica Monroy-Velázquez

    2017-06-01

    Full Text Available Background and Aims Cryptic peracarids are an important component of the coral reef fauna in terms of diversity and abundance, yet they have been poorly studied. The aim of this study was to evaluate the taxonomic richness and abundance of cryptic peracarids in coral rubble in the Puerto Morelos Reef National Park, Mexico (PMRNP, and their relationship with depth. Methods Three reef sites were selected: (1 Bonanza, (2 Bocana, and (3 Jardines. At each site six kilograms of coral rubble were collected over four sampling periods at three depths: 3 m (back-reef, 6–8 m (fore-reef, and 10–12 m (fore-reef. Results A total of 8,887 peracarid crustaceans belonging to 200 taxa distributed over five orders and 63 families was obtained; 70% of the taxa were identified to species and 25% to genus level. Fifty species of those collected represent new records for the Mexican Caribbean Sea. Isopoda was the most speciose order while Tanaidacea was the most abundant. Discussion Cryptic peracarid taxonomic richness and abundance were related to depth with higher values of both parameters being found in the shallow (3 m back-reef, possibly due to a higher reef development and a greater accumulation of coral rubble produced during hurricanes. Peracarid data obtained in the present study can be used as a baseline for future monitoring programs in the PMRNP.

  17. Evidence for a cost of immunity when the crustacean Daphnia magna is exposed to the bacterial pathogen Pasteuria ramosa.

    Science.gov (United States)

    Little, Tom J; Killick, Stuart C

    2007-11-01

    The deployment of the immune system has the obvious potential to ameliorate infection outcomes, but immune responses can also harm hosts by either damaging host tissues or monopolizing resources, leading to enhanced mortality. To gain insight into such a 'cost of immunity' when the crustacean Daphnia magna is challenged with the bacterium Pasteuria ramosa, we measured survivorship among hosts that resisted infection following exposure to various strains and doses of the parasite. In the first of two experiments, these exposures were: single exposures with relatively non-aggressive strains, double exposures with non-aggressive strains, and exposure to aggressive strains. Mortality increased across this gradient of exposure. In a second experiment, we varied the dose of the most aggressive P. ramosa strain and found that resisting infection when a large dose was applied resulted in greater mortality than when a medium or low dose was applied. Assuming that resistance is accomplished with an immune response, and that more aggressive parasites and/or larger doses of parasites are more immunostimulatory, these data are compatible with a cost of immunity. Indeed, in terms of survival, resisting parasites can be more harmful than infection.

  18. Using DNA Barcoding and Standardized Sampling to Compare Geographic and Habitat Differentiation of Crustaceans: A Hawaiian Islands Example

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    M. Julian Caley

    2011-09-01

    Full Text Available Recently, the Census of Marine Life has explored methods to assess coral reef diversity by combining standardized sampling (to permit comparison across sites with molecular techniques (to make rapid counts of species possible. To date, this approach has been applied across geographically broad scales (seven sites spanning the Indian, Pacific and Atlantic Oceans, focusing on similar habitats at all sites (10–12 m forereef. Here we examine crustacean spatial diversity patterns for a single atoll, comparing results for four sites (comprising forereef, backreef, and lagoon habitats at French Frigate Shoals (FFS, Northwestern Hawaiian Islands, Hawaii, USA, within the Papahanaumokuakea Marine National Monument. The Bray-Curtis index of similarity across these habitats at FFS was the same or greater than the similarity between similar habitats on Heron Island and Lizard Island in the Great Barrier Reef and much greater than similarity between more widely separated localities in the Indo-Pacific Ocean (e.g., Ningaloo, Moorea, French Polynesia or the Line Islands. These results imply that, at least for shallow reefs, sampling multiple locations versus sampling multiple habitats within a site maximizes the rate at which we can converge on the best global estimate of coral reef biodiversity.

  19. Chronic toxicity of contaminated sediments on reproduction and histopathology of the crustacean Gammarus fossarum and relationship with the chemical contamination and in vitro effects

    Energy Technology Data Exchange (ETDEWEB)

    Mazurova, Edita; Hilscherova, Klara; Sidlova-Stepankova, Tereza; Blaha, Ludek [Faculty of Science, RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk Univ., Brno (Czech Republic); Koehler, Heinz R. [Animal Physiological Ecology, Univ. of Tuebingen (Germany); Triebskorn, Rita [Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Rottenburg (Germany); Jungmann, Dirk [Inst. of Hydrobiology, Dresden Univ. of Tech. (Germany); Giesy, John P. [Dept. of Veterinary Biomedical Sciences and Toxicology Centre, Univ. of Saskatchewan, Saskatoon (Canada); Zoology Dept., National Food Safety and Toxicology Center, and Center for Integrative Toxicology Center, and Center for Integrative Toxicology, Michigan State Univ., East Lansing, MI (United States); Biology and Chemistry Dept., City Univ. of Hong Kong, Kowloon, Hong Kong (China); School of the Environment, Nanjing Univ. (China)

    2010-04-15

    The aim of the present study was to investigate possible relationships between the sediment contaminants and the occurrence of intersex in situ. Two of the studied sediments were from polluted sites with increased occurrence of intersex crustaceans (Lake Pilnok, black coal mining area in the Czech Republic, inhabited by the crayfish Pontastacus leptodactylus population with 18% of intersex; creek Lockwitzbach in Germany with Gammarus fossarum population with about 7% of intersex). Materials and methods Sediments were studied by a combined approach that included (1) determination of concentrations of metals and traditionally analyzed organic pollutants such as polychlorinated biphenyls, pesticides, and polycyclic aromatic hydrocarbons (PAHs); (2) examination of the in vitro potencies to activate aryl hydrocarbon (AhR), estrogen (ER), and androgen receptor-mediated responses; and (3) in vivo whole sediment exposures during a 12-week reproduction toxicity study with benthic amphipod G. fossarum. (orig.)

  20. Intersexuality in Crustacea: an environmental issue?

    Science.gov (United States)

    Ford, Alex T

    2012-02-01

    This paper aims to give a historical overview of current understanding about intersexuality in crustaceans, assesses gaps in our knowledge and asks whether it should be an environmental concern. The oldest known cases of intersexuality come from 70 million year old fossil crabs whilst the oldest published case of intersex crustacean stems from a 1730 Royal Society report of a gynandromorph lobster. Many crustacean species are sequential hermaphroditic or simultaneous hermaphrodites. Consequently, there has been confusion as to whether accounts of intersex in the literature are correct. Intersexuality is fairly common throughout the Crustacea and it has been suggested that intersex may arise through different mechanisms. For example, sexual gynandromorphism may arise through disruption in early embryonic development whereas intersexuality may also arise through perturbations of androgenic gland hormone and sexual differentiation in later development. The causes of intersex are multifaceted and can occur through a number of mechanisms including parasitism, environmental sex determination, genetic abnormalities and increasingly pollution is being implicated. Despite many studies on the effects of endocrine disrupters on crustaceans, very few have focussed on wild populations or male related endpoints; rather many laboratory studies have been attempting to assess biomarkers of feminisation. This is surprising as many of the seminal papers on endocrine disruption focussed on effects found in the wild and male specimens. This paper argues that we might have been addressing the right questions (i.e. pollution induced intersex), but in the wrong way (feminisation); and therefore gives recommendations for future directions for research. Biomarker development has been hampered by paucity of genomic and endocrine knowledge of many crustacean model species; however this is rapidly changing with the advent of cheaper affordable genomic techniques and high throughput sequencing

  1. Simultaneous Sampling of Flow and Odorants by Crustaceans can Aid Searches within a Turbulent Plume

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    Swapnil Pravin

    2013-12-01

    Full Text Available Crustaceans such as crabs, lobsters and crayfish use dispersing odorant molecules to determine the location of predators, prey, potential mates and habitat. Odorant molecules diffuse in turbulent flows and are sensed by the olfactory organs of these animals, often using a flicking motion of their antennules. These antennules contain both chemosensory and mechanosensory sensilla, which enable them to detect both flow and odorants during a flick. To determine how simultaneous flow and odorant sampling can aid in search behavior, a 3-dimensional numerical model for the near-bed flow environment was created. A stream of odorant concentration was released into the flow creating a turbulent plume, and both temporally and spatially fluctuating velocity and odorant concentration were quantified. The plume characteristics show close resemblance to experimental measurements within a large laboratory flume. Results show that mean odorant concentration and it’s intermittency, computed as dc/dt, increase towards the plume source, but the temporal and spatial rate of this increase is slow and suggests that long measurement times would be necessary to be useful for chemosensory guidance. Odorant fluxes measured transverse to the mean flow direction, quantified as the product of the instantaneous fluctuation in concentration and velocity, v’c’, do show statistically distinct magnitude and directional information on either side of a plume centerline over integration times of <0.5 s. Aquatic animals typically have neural responses to odorant and velocity fields at rates between 50 and 500 ms, suggesting this simultaneous sampling of both flow and concentration in a turbulent plume can aid in source tracking on timescales relevant to aquatic animals.

  2. CRISPR/Cas-mediated knock-in via non-homologous end-joining in the crustacean Daphnia magna.

    Science.gov (United States)

    Kumagai, Hitoshi; Nakanishi, Takashi; Matsuura, Tomoaki; Kato, Yasuhiko; Watanabe, Hajime

    2017-01-01

    The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system (Cas) is widely used for mediating the knock-in of foreign DNA into the genomes of various organisms. Here, we report a process of CRISPR/Cas-mediated knock-in via non-homologous end joining by the direct injection of Cas9/gRNA ribonucleoproteins (RNPs) in the crustacean Daphnia magna, which is a model organism for studies on toxicology, ecology, and evolution. First, we confirmed the cleavage activity of Cas9 RNPs comprising purified Cas9 proteins and gRNAs in D. magna. We used a gRNA that targets exon 10 of the eyeless gene. Cas9 proteins were incubated with the gRNAs and the resulting Cas9 RNPs were injected into D. magna eggs, which led to a typical phenotype of the eyeless mutant, i.e., eye deformity. The somatic and heritable mutagenesis efficiencies were up to 96% and 40%, respectively. Second, we tested the CRISPR/Cas-mediated knock-in of a plasmid by the injection of Cas9 RNPs. The donor DNA plasmid harboring the fluorescent reporter gene was designed to contain the gRNA recognition site. The co-injection of Cas9 RNPs together with the donor DNAs resulted in generation of one founder animal that produced fluorescent progenies. This transgenic Daphnia had donor DNA at the targeted genomic site, which suggested the concurrent cleavage of the injected plasmid DNA and genomic DNA. Owing to its simplicity and ease of experimental design, we suggest that the CRISPR/Cas-mediated knock-in method represents a promising tool for studying functional genomics in D. magna.

  3. Alternative mitochondrial respiratory chains from two crustaceans: Artemia franciscana nauplii and the white shrimp, Litopenaeus vannamei.

    Science.gov (United States)

    Rodriguez-Armenta, Chrystian; Uribe-Carvajal, Salvador; Rosas-Lemus, Monica; Chiquete-Felix, Natalia; Huerta-Ocampo, Jose Angel; Muhlia-Almazan, Adriana

    2018-04-01

    Mitochondrial ATP is synthesized by coupling between the electron transport chain and complex V. In contrast, physiological uncoupling of these processes allows mitochondria to consume oxygen at high rates without ATP synthesis. Such uncoupling mechanisms prevent reactive oxygen species overproduction. One of these mechanisms are the alternative redox enzymes from the mitochondrial respiratory chain, which may help cells to maintain homeostasis under stress independently of ATP synthesis. To date, no reports have been published on alternative redox enzymes in crustaceans mitochondria. Specific inhibitors were used to identify alternative redox enzymes in mitochondria isolated from Artemia franciscana nauplii, and the white shrimp, Litopenaeus vannamei. We report the presence of two alternative redox enzymes in the respiratory chain of A. franciscana nauplii, whose isolated mitochondria used glycerol-3-phosphate as a substrate, suggesting the existence of a glycerol-3-phosphate dehydrogenase. In addition, cyanide and octyl-gallate were necessary to fully inhibit this species' mitochondrial oxygen consumption, suggesting an alternative oxidase is present. The in-gel activity analysis confirmed that additional mitochondrial redox proteins exist in A. franciscana. A mitochondrial glycerol-3-phosphate dehydrogenase oxidase was identified by protein sequencing as part of a branched respiratory chain, and an alternative oxidase was also identified in this species by western blot. These results indicate different adaptive mechanisms from artemia to face environmental challenges related to the changing levels of oxygen concentration in seawater through their life cycles. No alternative redox enzymes were found in shrimp mitochondria, further efforts will determine the existence of an uncoupling mechanism such as uncoupling proteins.

  4. Parasitic manipulation and neuroinflammation: Evidence from the system Microphallus papillorobustus (Trematoda - Gammarus (Crustacea

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    Thomas Frederic

    2010-04-01

    Full Text Available Abstract Background Neuropathological consequences of neuroinflammatory processes have been implicated in a wide range of diseases affecting the central nervous system (CNS. Glial cells, the resident immune cells of the CNS, respond to tissue injury by releasing proinflammatory cytokines and free radicals such as nitric oxide. We explored the possibility that neuroimmune responses are involved in parasitic manipulation of host behavior in a trematode-crustacean association. The cerebral larva of the flatworm Microphallus papillorobustus alters responses to environmental stimuli - and thus reflex pathways - in the crustacean Gammarus insensibilis, in a way that enhances predation of the crustacean by birds, definitive hosts of the parasite. Results Immunocytochemical experiments followed by confocal microscopy were performed to study the distribution of glutamine synthetase, a glial cell marker, and nitric oxide synthase in the brain of gammarids. Astrocyte-like glia and their processes were abundant at the surface of the parasites while levels of nitric oxide synthase were elevated at the host-parasite interface in the brain of gammarids harboring mature cerebral larvae and demonstrating altered behavior. Conclusion Taken together these results lend support to the neuroinflammation hypothesis whereby a chronic CNS specific immune response induced by the parasite plays a role in the disruption of neuromodulation, neuronal integrity, and behavior in infected hosts.

  5. Sediment nickel bioavailability and toxicity to estuarine crustaceans of contrasting bioturbative behaviors--an evaluation of the SEM-AVS paradigm.

    Science.gov (United States)

    Chandler, G Thomas; Schlekat, Christian E; Garman, Emily R; He, Lijian; Washburn, Katherine M; Stewart, Emily R; Ferry, John L

    2014-11-04

    Robust sediment quality criteria require chemistry and toxicity data predictive of concentrations where population/community response should occur under known geochemical conditions. Understanding kinetic and geochemical effects on toxicant bioavailability is key, and these are influenced by infaunal sediment bioturbation. This study used fine-scale sediment and porewater measurement of contrasting infaunal effects on carbon-normalized SEM-AVS to evaluate safe or potentially toxic nickel concentrations in a high-binding Spartina saltmarsh sediment (4%TOC; 35-45 μmol-S2-·g(-1)). Two crustaceans producing sharply contrasting bioturbation--the copepod Amphiascus tenuiremis and amphipod Leptocheirus plumulosus--were cultured in oxic to anoxic sediments with SEM[Ni]-AVS, TOC, porewater [Ni], and porewater DOC measured weekly. From 180 to 750 μg-Ni·g(-1) sediment, amphipod bioturbation reduced [AVS] and enhanced porewater [Ni]. Significant amphipod uptake, mortality, and growth-depression occurred at the higher sediment [Ni] even when [SEM-AVS]/foc suggested acceptable risk. Less bioturbative copepods produced higher AVS and porewater DOC but exhibited net population growth despite porewater [Ni] 1.3-1.7× their aqueous [Ni] LOEC. Copepod aqueous tests with/without dissolved organic matter showed significant aqueous DOC protection, which suggests porewater DOC attenuates sediment Ni toxicity. The SEM[Ni]-AVS relationship was predictive of acceptable risk for copepods at the important population-growth level.

  6. Effect of some biological factors on the chitin yield of two crustacean species inhabiting the Egyptian waters

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    Amira Talaat Abo-Hashesh

    2017-11-01

    Full Text Available Objective: To investigate the chitin yield of two commercial crustacean species that are exploited in the Suez Canal region, the Red Sea crab Charybdis natator (C. natator and the Mediterranean mantis shrimp Erugosquilla massavensis (E. massavensis, and to assess the effect of some biological factors such as sex, size and maturity stages of females' ovaries on this yield. Methods: A total of 64 specimens of crabs were collected from the Red Sea and 1 377 mantis shrimps were collected from the Mediterranean Sea. Chitin was obtained after the deproteinization, de-mineralization and de-colorization of 5 g oven dried exoskeletons and values were expressed as g/5 g and percentages. Results: Chitin yield was significantly higher in E. massavensis than C. natator (22.1%, 14.22%, respectively. No significant difference in the yield was recorded between males and females of C. natator (12.9%, 14.9%, respectively, while the yield in E. massavensis males was significantly higher than females (25.3%, 21.2%, respectively. Significant variations in the chitin yield were observed between the different sizes of E. massavensis with the maximum being from the individuals falling in the size range 90–130 mm body length. The yield was at its lowest in the immature stage of C. natator females' ovaries (9.29%. However, the values increased and remained constant for the remaining stages (≥ 18%. Conclusions: The study recommends the use of the mantis shrimp for the production of chitin on commercial scale particularly medium sized males.

  7. A 5' UTR-Overlapping LncRNA Activates the Male-Determining Gene doublesex1 in the Crustacean Daphnia magna.

    Science.gov (United States)

    Kato, Yasuhiko; Perez, Christelle Alexa G; Mohamad Ishak, Nur Syafiqah; Nong, Quang D; Sudo, Yuumi; Matsuura, Tomoaki; Wada, Tadashi; Watanabe, Hajime

    2018-06-04

    Long noncoding RNAs (lncRNAs) are pervasively transcribed in the eukaryotic genome [1] and are important for the control of master regulatory genes that are involved in cell differentiation and development [2, 3]. Here, we show that a 5' UTR-overlapping lncRNA regulates the male-specific expression of the DM-domain gene doublesex1 (dsx1) in the crustacean Daphnia magna, which produces males in response to environmental stimuli. This lncRNA, named doublesex1 alpha promoter-associated long RNA (DAPALR), is transcribed upstream the transcription start site (TSS) in a sense orientation and subjected to 5' end capping and 3' end processing at a stem-loop structure before the dsx1 coding exon. Similar to dsx1, its expression is only activated in males by the juvenile hormone (JH) and basic-leucine zipper (bZIP) transcription factor Vrille (Vri) and is maintained during embryogenesis. Knockdown of DAPALR in males silenced dsx1 and led to feminization, including egg production, whereas ectopic expression of DAPALR in dsx1-silenced females resulted in the de-repression of dsx1. We further demonstrate that the DAPALR transcript overlaps the dsx1 5'-UTR, and this overlapping region is required for dsx1 activation. Our results suggest that DAPALR can transactivate and possibly maintain dsx1 expression. This might be important for converting transient environmental signals into stable male development, controlled by the continuous expression of dsx1. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. The decapod and stomatopod Crustacea of St Paul's Rocks

    NARCIS (Netherlands)

    Holthuis, L.B.

    1980-01-01

    INTRODUCTION Saint Paul's Rocks (Penedos de São Pedro e São Paulo) are a small group of rocky islets on the mid-Atlantic ridge near the equator, occupying an area of roughly 250 by 425 m. There is no vegetation and, apart from birds and invertebrates, the islands are uninhabited. The Cambridge

  9. A Study of Fish Lice (Argulus Sp.) Infection in Freshwater Food Fish

    OpenAIRE

    Aalberg K.; Koščová L.; Šmiga Ľ.; Košuth P.; Koščo J.; Oros M.; Barčák D.; Lazar P.

    2016-01-01

    Argulus sp., commonly referred to as fish lice, are crustacean ectoparasites of fishes. The hematophagous parasites attach to and feed off the integument of their hosts. Outbreaks of epizootics have been reported worldwide, causing mass mortalities and having serious economic implications for fish farms and culture efforts. Argulus fish lice may also serve as vectors of infectious diseases and as intermediate hosts of other parasites. Two native European species, A. foliaceus and A. coregoni,...

  10. Distribución y abundancia de crustáceos en humedales de Tabasco, México Abundance and distribution of crustaceans in wetlands of Tabasco

    Directory of Open Access Journals (Sweden)

    Everardo Barba

    2010-10-01

    Full Text Available El estado de Tabasco presenta una compleja y alta diversidad de humedales que incluye tipos palustres (20.72%, costeros (3.93%, lacustres (1.74% y ribereños (1.37%, los cuales cubren el 27% del territorio estatal. La diversidad faunística en estos ambientes comprende invertebrados y vertebrados, donde la mayor parte de los registros son de especies de interés comercial. Se presenta el inventario de crustáceos recolectados desde 2003 hasta la fecha en las subregiones Sierra, Ríos y Pantanos. La recolección fue diurna, en 14 localidades (ambientes lóticos y lénticos, mediante nucleador y draga para la infauna, y arrastres con diferentes artes para la epifauna. Se obtuvieron 2 370 organismos que pertenecen a 4 órdenes, 15 familias, 17 géneros y 17 especies. Las especies más abundantes fueron Discapseudes holthuisi Bacescu y Gutu, 1975 (62%, Macrobrachium acanthurus (Wiegmann, 1836 (12%, Leptochirus sp. Zaddach, 1844 (8% y Palaemonetes vulgaris (Say, 1818 (7%, sumando el 89% del total. El 67% de la abundancia correspondió a la infauna y el 33% a la epifauna. El 81% de los crustáceos se capturaron en sistemas lénticos y el resto en sistemas lóticos. Este trabajo contribuye con nuevos registros de crustáceos en humedales de Tabasco.The state of Tabasco is characterised by complex and diverse wetlands of different types: palustrine (20.72%, coastal (3.93%, lacustrine (1.74% and riverine (1.37%, covering 27% of its surface. Faunal diversity of these wetlands includes invertebrates and vertebrates, most of the available records come from species with commercial importance. The list of crustaceans collected from 2003 to date in the subregions Sierra, Ríos and Pantanos, is presented. The sampling at 14 localities was diurnal (lotic and lentic environments, using cores and dredges for the infauna and different nets for epifauna. A total of 2 370 organisms belonging to 4 orders, 15 families, 17 genera and 17 species, was obtained. The most

  11. Behind the impact of introduced trout in high altitude lakes: adult, not juvenile fish are responsible of the selective predation on crustacean zooplankton

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    Rocco Tiberti

    2014-05-01

    Full Text Available Introduced fish seriously affect zooplankton communities in mountain lakes, often leading to the loss of large species. Selective predation is recognized to be the ultimate cause of such a strong impact. Here we describe the selection of zooplankton prey by analyzing the stomach contents of more than 300 brook trout (Salvelinus fontinalis inhabiting seven alpine lakes in the Gran Paradiso National Park (western Italian Alps. Our results show that planktivory is much more common in young fish, which feed on a larger number of taxa, but also adult fish maintain the ability to feed on zooplankton. There is a direct dependence between the length of zooplankton prey and the length of their fish predators, and adult, not juvenile fish are responsible of the selective predation on large crustacean zooplankton, which drive the impact of introduced fish throughout the entire zooplankton community. In some rare cases, large zooplankton populations develop in the presence of brook trout, and planktivory can become an important temporary resource for adult fish during the ice-free season. Thus, in the early stages of the establishment of non-native trout in alpine lakes, large-bodied zooplankton may represent an important food resource.

  12. Airborne seafood allergens as a cause of occupational allergy and asthma.

    Science.gov (United States)

    Lopata, Andreas L; Jeebhay, Mohamed F

    2013-06-01

    Occupational allergy and asthma is a serious adverse health outcome affecting seafood-processing workers. Allergic reactions are directed to two major seafood groups: fish and shellfish, with the latter group comprising crustaceans and molluscs. Several allergenic proteins have been identified in these different groups, but few have been characterised on a molecular level. Parvalbumin appears to be the major fish allergen, while tropomyosin the major crustacean allergen. Other IgE-binding proteins have also been identified in molluscs and other seafood-associated agents (e.g. Anisakis sp), although their molecular nature has not been characterised. Aerosolised allergens can be identified and quantified using immunological and chemical approaches, detecting levels as low as 10 ng/m(3). This contemporary review discusses interesting and recent findings in the area of occupational seafood allergy including high-risk occupations, environmental risk factors for airborne exposures, major and minor allergens implicated and innovative approaches in diagnosing and managing occupational allergy and asthma associated with seafood processing.

  13. A gastric evacuation model for three predatory gadoids and implications of using pooled field data of stomach contents to estimate food rations

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    2001-01-01

    evacuation rate was related by a negative power function to energy density of fish prey,) er an extended range from 3(.)4 to 11(.)5 kJ g (1) of the effector variable. Gastric evacuation of crustacean prey seemed to depend on the characteristics of their exoskeleton, Gastric evacuation of mixed meal, composed...

  14. Increasing salinity drastically reduces hatching success of crustaceans from depression wetlands of the semi-arid Eastern Cape Karoo region, South Africa.

    Science.gov (United States)

    Mabidi, Annah; Bird, Matthew S; Perissinotto, Renzo

    2018-04-13

    Salinity is an important factor affecting freshwater aquatic species distribution and diversity. The semi-arid Eastern Cape Karoo region of South Africa has been earmarked for shale gas development through hydraulic fracturing. The process uses large amounts of water and produces briny wastewater. When not managed properly, these wastewaters may lead to salinisation of surface freshwater bodies in the region. Therefore, the effect of salinity on the hatching success of crustacean resting eggs was examined using sediments from four depression wetlands found in the region. The sediments were exposed for 28 days to salinity levels of 0.5 g L -1 , 2.5 g L -1 , 5 g L -1 and 10 g L -1 . Control aquaria in which no salt was added were also set up. There was a significant decrease in the emerged taxa richness and abundances at salinities of 2.5 g L -1 and above. Anostraca, Notostraca and Spinicaudata hatchlings were abundant at salinities of 0.5 g L -1 and below, while Copepoda, Daphniidae (Cladocera) and Ostracoda were observed in the highest salinity, but their densities were still lower with increased salinities. Given the importance of large branchiopods in the trophic balance of depression wetlands, their loss may alter the ecological balance and function of these ecosystems.

  15. Fatty acids in six small pelagic fish species and their crustacean prey from the mindanao sea, southern Philippines.

    Science.gov (United States)

    Metillo, Ephrime Bicoy; Aspiras-Eya, Anna Arlene

    2014-08-01

    Fatty acids are important in human health and useful in the analysis of the marine food web, however information on tropical pelagic organisms is scarce. Six zooplanktivorous small pelagic fish species (Decapterus kurroides, Decapterus macarellus, Selar crumenophthalmus, Sardinella lemuru, Spratilloides gracilis and Stolephorus insularis) and four of their zooplanktonic crustacean prey [three sergestoid species (Acetes erythraeus, Acetes intermedius and Lucifer penicillifer) and one calanoid copepod (Acartia erythraea)] were collected from the Mindanao Sea, and their fatty acids were profiled. The resulting profiles revealed 17 fatty acids that were specific to certain species and 9 {myristic acid [C14:0], palmitic acid [C16:0], stearic acid [C18:0]; palmitoleic acid [C16:1], oleic acid [C18:1n9c], linoleic acid [C18:2n6c], linolenic acid [C18:3n3], eicosapentaenoic acid (EPA) [C20:5n3] and docosahexaenoic acid (DHA) [C22:6n3]} that were common to all species. Cluster analysis and non-metric multidimensional scaling (NMDS) of fatty acids indicate a high similarity in profiles in all species, but separate fish and zooplankton clusters were obtained. Mackerel species (D. macarellus, D. kurroides and S. crumenophthalmus) had concentrations of total n-3 fatty acids that match those of their Acetes prey. The copepod A. erythraea and the sergestoid L. penicillifer exhibited the lowest values of the EPA:DHA ratio, which was most likely due to their phytoplanktivorous feeding habits, but the occurrence of the highest values of the ratio in Acetes suggests the inclusion of plant detritus in their diet. DHA values appear to affirm the trophic link among copepod, Lucifer, Acetes and mackerel species.

  16. Implicative Algebras

    African Journals Online (AJOL)

    Tadesse

    In this paper we introduce the concept of implicative algebras which is an equivalent definition of lattice implication algebra of Xu (1993) and further we prove that it is a regular Autometrized. Algebra. Further we remark that the binary operation → on lattice implicative algebra can never be associative. Key words: Implicative ...

  17. Aridity promotes bet hedging via delayed hatching: a case study with two temporary pond crustaceans along a latitudinal gradient.

    Science.gov (United States)

    Pinceel, Tom; Vanschoenwinkel, Bram; Hawinkel, Wouter; Tuytens, Karen; Brendonck, Luc

    2017-05-01

    Climate change does affect not only average rainfall and temperature but also their variation, which can reduce the predictability of suitable conditions for growth and reproduction. This situation is problematic for inhabitants of temporary waters whose reproductive success depends on rainfall and evaporation that determine the length of the aquatic phase. For organisms with long-lived dormant life stages, bet hedging models suggest that a fraction of these should stay dormant during each growing season to buffer against the probability of total reproductive failure in variable environments. Thus far, however, little empirical evidence supports this prediction in aquatic organisms. We study geographic variation in delayed hatching of dormant eggs in natural populations of two crustaceans, Branchinella longirostris and Paralimnadia badia, that occur in temporary rock pools along a 725 km latitudinal aridity gradient in Western Australia. Consistent with bet hedging theory, populations of both species were characterised by delayed hatching under common garden conditions and hatching fractions decreased towards the drier end of the gradient where the probability of reproductive success was shown to be lower. This decrease was most pronounced in the species with the longer maturation time, presumably because it is more sensitive to the higher prevalence of short inundations. Overall, these findings illustrate that regional variation in climate can be reflected in differential investment in bet hedging and hints at a higher importance of delayed hatching to persist when the climate becomes harsher. Such strategies could become exceedingly relevant as determinants of vulnerability under climate change.

  18. Distribution of heavy metals in muscles and internal organs of Korean cephalopods and crustaceans: risk assessment for human health.

    Science.gov (United States)

    Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Shim, Kil Bo; Lee, Tae Seek; Kim, Ji Hoe

    2014-12-01

    Samples of seven species of cephalopods and crustaceans were collected from major fish markets on the Korean coast and analyzed for mercury (Hg) using a direct Hg analyzer and for the metals cadmium (Cd), lead (Pb), chromium, silver, nickel, copper, and zinc using inductively coupled plasma mass spectrometry. The distributions of heavy metals in muscles, internal organs, and whole tissues were determined, and a risk assessment was conducted to provide information concerning consumer safety. The heavy metals accumulated to higher levels (P octopus (relatively large cephalopods), red snow crab, and snow crab exceeded the European Union limits. The estimated dietary intake of Cd, Pb, and Hg for each part of all species accounted for 1.73 to 130.57%, 0.03 to 0.39%, and 0.93 to 1.67%, respectively, of the provisional tolerable daily intake adopted by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives; the highest values were found in internal organs. The hazard index (HI) is recognized as a reasonable parameter for assessing the risk of heavy metal consumption associated with contaminated food. Because of the high HI (>1.0) of the internal organs of cephalopods and the maximum HI for whole tissue of 0.424, consumers eating internal organs or whole tissues of cephalopods could be at risk of high heavy metal exposure. Therefore, the internal organs of relatively large cephalopods and crabs (except blue crab) are unfit for consumption. However, consumption of flesh after removing internal organs is a suitable approach for decreasing exposure to harmful metals.

  19. Reproductive patterns in demersal crustaceans from the upper boundary of the OMZ off north-central Chile

    Science.gov (United States)

    Gallardo, María de los Ángeles; González López, Andrés E.; Ramos, Marcel; Mujica, Armando; Muñoz, Praxedes; Sellanes, Javier; Yannicelli, Beatriz

    2017-06-01

    Pleuroncodes monodon (Crustacea: Munididae) supports one of the main trawling fisheries over the continental shelf off Chile between 25°S and 37°S within the upper boundary of the oxygen minimum zone (OMZ). Although the reproductive cycle of P. monodon has been described, the relationship between this key biological process and the variability of the OMZ has not been comprehensibly addressed neither for P. monodon nor for other OMZ resident species. In this study a set of 14 quasi-monthly oceanographic cruises carried out between June 2010 and November 2011 were conducted over the continental shelf off Coquimbo (30°S) to investigate the temporal variability of: i) dissolved oxygen concentration, temperature and chlorophyll-a at relevant depths ii) the presence and proportion of occurrence of P. monodon ovigerous females and juveniles from benthic trawls; iii) the presence of different stage larvae in the plankton, and iv) similar biological data for other species from the OMZ and shallower depths crustaceans. During summer months oxygen levels and bottom temperature were lower than in winter, while chlorophyll-a concentration was maximum in summer coinciding with an active (but not maximum) upwelling season. P. monodon maximum egg carrying occurred in winter during periods of increased oxygenation. Egg carrying females were never found at depths where oxygen concentration was below 0.5 ml L-1, while over 50% of the autumn and spring cohorts of juveniles occurred at oxygen concentrations below that level. The depth range occupied by ovigerous females was more restricted than the rest of the population and their depth of occurrence followed the variability of the upper OMZ. The larval release period of OMZ resident species extends over late winter and spring, and its main peak precedes that of coastal species (spring) and the spring-summer chlorophyll-a maximum. We propose that for OMZ resident species, brood carrying during warmer and more oxygenated conditions

  20. Trophic transfer of trace metals: Subcellular compartmentalization in a polychaete and assimilation by a decapod crustacean

    Science.gov (United States)

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    The chemical form of accumulated trace metal in prey is important in controlling the bioavailataility of dietary metal to a predator. This study investigated the trophic transfer of radiolabelled Ag, Cd and Zn from the polychaete worm Nereis diversicolor to the decapod crustacean Palaemonetes varians. We used 2 populations of worms with different proportions of accumulated metals in different subcellular fractions as prey, and loaded the worms with radiolabelled metals either from sediment or from solution. Accumulated radiolabelled metals were fractionated into 5 components : metal-rich granules (MRG), cellular debris, organelles, metallothionein-like proteins (MTLP), and other (heat-sensitive) proteins (HSP). Assimilation efficiencies (AE) of the metals by P. varians were measured from the 4 categories of prey (i.e. 2 populations, radiolabelled from sediment or solution). There were significant differences for each metal between the AEs from the different prey categories, confirming that origin of prey and route of uptake of accumulated trace metal will cause intraspecific differences in subsequent metal assimilation. Correlations were sought between AEs and selected fractions or combinations of fractions of metals in the prey-MRG, Trophically Available Metal (TAM = MTLP + HSP + organelles) and total protein (MTLP + HSP). TAM explained 28% of the variance in AEs for Ag, but no consistent relationships emerged between AEs and TAM or total protein when the metals were considered separately. AEs did, however, show significant positive regressions with both TAM and total protein when the 3 metals were considered together, explaining only about 21 % of the variance in each case. A significant negative relationship was observed between MRG and AE for all metals combined. The predator (P. varians) can assimilate dietary metal from a range of the fractions binding metals in the prey (N. diversicolor), with different assimilation efficiencies summated across these

  1. Concentrations and human health implications of heavy metals in wild aquatic organisms captured from the core area of Daya Bay's Fishery Resource Reserve, South China Sea.

    Science.gov (United States)

    Gu, Yang-Guang; Huang, Hong-Hui; Lin, Qin

    2016-07-01

    Heavy metal concentrations in edible organisms from the core area of Daya Bay's Fishery Resource Reserve, South China Sea, were determined. Samples of 14 crustacean, fish, and shellfish species were collected and analyzed. The As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn concentrations were 0.18-1.16, 0.002-0.919, 0.40-2.85, 0.07-4.10, 0.004-0.055, 0.14-1.19, 0.014-0.070, and 4.57-15.94μg/g wet weight, respectively. The As concentrations were higher than the Chinese maximum permissible levels in all of the fish and shellfish species and two crustacean species, indicating that consumption of these wild species by humans may pose health risks. However, calculations of the health risks posed to humans indicated that no significant adverse health effects would be associated with consuming these species. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Recommended reporting standards for test accuracy studies of infectious diseases of finfish, amphibians, molluscs and crustaceans: the STRADAS-aquatic checklist

    Science.gov (United States)

    Gardner, Ian A; Whittington, Richard J; Caraguel, Charles G B; Hick, Paul; Moody, Nicholas J G; Corbeil, Serge; Garver, Kyle A.; Warg, Janet V.; Arzul, Isabelle; Purcell, Maureen; St. J. Crane, Mark; Waltzek, Thomas B.; Olesen, Niels J; Lagno, Alicia Gallardo

    2016-01-01

    Complete and transparent reporting of key elements of diagnostic accuracy studies for infectious diseases in cultured and wild aquatic animals benefits end-users of these tests, enabling the rational design of surveillance programs, the assessment of test results from clinical cases and comparisons of diagnostic test performance. Based on deficiencies in the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines identified in a prior finfish study (Gardner et al. 2014), we adapted the Standards for Reporting of Animal Diagnostic Accuracy Studies—paratuberculosis (STRADAS-paraTB) checklist of 25 reporting items to increase their relevance to finfish, amphibians, molluscs, and crustaceans and provided examples and explanations for each item. The checklist, known as STRADAS-aquatic, was developed and refined by an expert group of 14 transdisciplinary scientists with experience in test evaluation studies using field and experimental samples, in operation of reference laboratories for aquatic animal pathogens, and in development of international aquatic animal health policy. The main changes to the STRADAS-paraTB checklist were to nomenclature related to the species, the addition of guidelines for experimental challenge studies, and the designation of some items as relevant only to experimental studies and ante-mortem tests. We believe that adoption of these guidelines will improve reporting of primary studies of test accuracy for aquatic animal diseases and facilitate assessment of their fitness-for-purpose. Given the importance of diagnostic tests to underpin the Sanitary and Phytosanitary agreement of the World Trade Organization, the principles outlined in this paper should be applied to other World Organisation for Animal Health (OIE)-relevant species.

  3. Delayed metamorphosis in decapod crustaceans: evidence and consequences Retraso de la metamorfosis en crustáceos decápodos: evidencias y consecuencias

    Directory of Open Access Journals (Sweden)

    PAULINA GEBAUER

    2003-06-01

    Full Text Available Most marine invertebrate species exhibit a complex life cycle including a planktonic larval phase and a benthic juvenile-adult phase. Metamorphosis and settlement are the links between these phases of development. In many species, metamorphosis is triggered by specific chemical and/or physical cues, mainly associated with the adult habitat. In the absence of such cues, competent larvae can delay their metamorphosis by a few days to several months. Most investigations on the delay of metamorphosis have been realised on sessile or sedentary species. In relation to mobile decapod crustaceans, the number of such studies is low, probably because the members of this group retain their mobility after metamorphosis, and hence, may depend less on enviromental cues for the induction of settlement and metamorphosis. Nevertheless, the larvae of some decapod species have been shown to depend on metamorphosis-stimulating cues. These include special types of substrates, physical or chemical traits of particular (e.g., estuarine water bodies, as well as odors from conspecific or congeneric adults. The capacity for delay is, in the decapod species studied so far, limited and may normally end with spontaneous metamorphosis. An extended time of larval development presents the advantage of enhancing the probability for locating a suitable habitat, but it may imply, as a disadvantage, a reduction of juvenile growth or survival and a prolonged development time preceding benthic life. This paper reviews the available evidence for delayed metamorphosis in decapod crustaceans, indentifed cues, the importance of larval age at the time of contact with a cue, and costs of delayed metamorphosis. Additionally, we propose new frontiers for future investigations on delayed metamorphosis in decapod crustaceans, including the molecular identification of chemical cues, the identification of the stage(s of the moulting cycle that is or are sensitive to such cues, the study of

  4. Structural characterization of recombinant crustacyanin subunits from the lobster Homarus americanus

    International Nuclear Information System (INIS)

    Ferrari, Michele; Folli, Claudia; Pincolini, Elisa; McClintock, Timothy S.; Rössle, Manfred; Berni, Rodolfo; Cianci, Michele

    2012-01-01

    The two recombinant apo subunits H1 and H2 from H. americanus have been structurally characterized. Reconstitution studies with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits. Crustacean crustacyanin proteins are linked to the production and modification of carapace colour, with direct implications for fitness and survival. Here, the structural and functional properties of the two recombinant crustacyanin subunits H 1 and H 2 from the American lobster Homarus americanus are reported. The two subunits are structurally highly similar to the corresponding natural apo crustacyanin CRTC and CRTA subunits from the European lobster H. gammarus. Reconstitution studies of the recombinant crustacyanin proteins H 1 and H 2 with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits from H. gammarus in complex with astaxanthin. Moreover, correlations between the presence of crustacyanin genes in crustacean species and the resulting carapace colours with the spectral properties of the subunits in complex with astaxanthin confirmed this genotype–phenotype linkage

  5. Trophic transfer of trace metals from the polychaete worm Nereis diversicolor to the polychaete N. virens and the decapod crustacean Palaemonetes varians

    Science.gov (United States)

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    Diet is an important exposure route for the uptake of trace metals by aquatic invertebrates, with trace metal trophic transfer depending on 2 stages - assimilation and subsequent accumulation by the predator. This study investigated the trophic transfer of trace metals from the sediment-dwelling polychaete worm Nereis diversicolor from metal-rich estuarine sediments in southwestern UK to 2 predators - another polychaete N. virens (Cu, Zn, Pb, Cd, Fe) and the decapod crustacean Palaemonetes varians (Cu, Zn, Pb, Cd, Fe, Ag, As, Mn). N. virens showed net accumulation of Cu, Zn, Pb and Cd from the prey; accumulation increased with increasing prey concentration, but a coefficient of trophic transfer decreased with increasing prey concentration, probably because a higher proportion of accumulated metal in the prey is bound in less trophically available (insoluble) detoxified forms. The trace metal accumulation patterns of P. varians apparently restricted significant net accumulation of metals from the diet of N. diversicolor to just Cd. There was significant mortality of the decapods fed on the diets of metal-rich worms. Metal-rich invertebrates that have accumulated metals from the rich historical store in the sediments of particular SW England estuaries can potentially pass these metals along food chains, with accumulation and total food chain transfer depending on the metal assimilation efficiencies and accumulation patterns of the animal at each trophic level. This trophic transfer may be significant enough to have ecotoxicological effects. ?? Inter-Research 2006.

  6. Parasites in the fossil record: a Cretaceous fauna with isopod-infested decapod crustaceans, infestation patterns through time, and a new ichnotaxon.

    Directory of Open Access Journals (Sweden)

    Adiël A Klompmaker

    Full Text Available Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels are available. Here we provide this type of data for a mid-Cretaceous (upper Lower Cretaceous, upper Albian reef setting at Koskobilo, northern Spain, on the basis of 874 specimens of anomurans and brachyurans. Thirty-seven specimens (4.2%, arranged in ten species, are infested. Anomurans are more heavily infested than brachyurans, variability can be high within genera, and a relationship may exist between the number of specimens and infestation percentage per taxon, possibly suggesting host-specificity. We have also investigated quantitative patterns of infestation through geological time based on 88 infested species (25 anomurans, 55 brachyurans, seven lobsters, and one shrimp, to show that the highest number of infested species can be found in the Late Jurassic, also when corrected for the unequal duration of epochs. The same Late Jurassic peak is observed for the percentage of infested decapod species per epoch. This acme is caused entirely by infested anomurans and brachyurans. Biases (taphonomic and otherwise and causes of variability with regard to the Koskobilo assemblage and infestation patterns through time are discussed. Finally, a new ichnogenus and -species, Kanthyloma crusta, are erected to accommodate such swellings or embedment structures (bioclaustrations.

  7. Ontogenetic food resource partitioning and feeding strategy in ...

    African Journals Online (AJOL)

    Results revealed that juveniles fed more on immature and adult insects, plant materials, detritus and small crustaceans. Medium size categories fed more on crustaceans, frogs, tadpoles and piscivorous materials. The bigger fishes consumed mostly fish and crustaceans, and showed more specialization in feeding, followed ...

  8. Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city region, China

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Haruhiko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)]. E-mail: nakata@sci.kumamoto-u.ac.jp; Hirakawa, Yuko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kawazoe, Masahiro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, (Japan); Nakabo, Tetsuji [Kyoto University Museum, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Arizono, Koji [Faculty of Environmental and Symbiotic Sciences, Kumamoto Prefectural University, 3-1-100 Tsukide, Kumamoto 862-8502 (Japan); Abe, Shin-Ichi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kitano, Takeshi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Hideaki [Faculty of Education, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Watanabe, Izumi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchuu-city, Tokyo 183-8509 (Japan); Li Weihua [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China); Ding Xucheng [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China)

    2005-02-01

    Contamination by persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) were examined in sediments, soils, fishes, crustaceans, birds, and aquaculture feed from Lake Tai, Hangzhou Bay, and in the vicinity of Shanghai city in China during 2000 and 2001. OCs were detected in all samples analyzed, and DDT and its metabolites were the predominant contaminants in most sediments, soils and biota. Concentrations of p,p'-DDT and ratio of p,p'-DDT to {sigma}DDTs were significantly higher in marine fishes than those in freshwater fishes. While the use of DDTs has been officially banned in China since 1983, these results indicate a recent input of technical DDTs into the marine environment around Hangzhou Bay. Comparison of organochlorine concentrations in fishes collected from Lake Tai and Hangzhou Bay suggests the presence of local sources of HCHs, chlordanes and PCBs at Lake Tai. Higher proportions of penta- and hexa-PCB congeners in fishes at Lake Tai may suggest the use of highly chlorinated PCB product, such as PCB{sub 5}, around this lake. To our knowledge, this is a first comprehensive study to examine the present status of organochlorine contamination in various environmental media, such as sediments, soils and wildlife, in China. - Elevated concentrations of DDTs were detected in sediments, soils, and wildlife collected from China.

  9. Putative pacemakers in the eyestalk and brain of the crayfish Procambarus clarkii show circadian oscillations in levels of mRNA for crustacean hyperglycemic hormone.

    Directory of Open Access Journals (Sweden)

    Janikua Nelson-Mora

    Full Text Available Crustacean hyperglycemic hormone (CHH synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress.

  10. Long-term changes of the crustacean zooplankton community in Lake Mjøsa, the largest lake in Norway

    Directory of Open Access Journals (Sweden)

    Jarl Eivind LØVIK

    2003-08-01

    Full Text Available Lake Mjøsa has been subject to an accelerating eutrophication from the 1950s to the mid 1970s, but comprehensive nutrient reduction efforts caused marked reductions of phytoplankton production and biomass during the 1980s, a process that continued during the 1990s. Zooplankton biomass and species composition was considerably affected during the eutrophication and subsequent oligotrophication. Total crustacean zooplankton biomass decreased along with decreasing algal biomass during the 1980s and 1990s. The seasonal means of zooplankton biomass were positively correlated with seasonal means of phytoplankton biovolume and chlorophyll-a, indicating a primarily bottom up regulation of the zooplankton biomass. Several herbivorous and omnivorous zooplankton species (Daphnia galeata, Bosmina longispina, Limnocalanus macrurus and Cyclops lacustris were probably negatively affected by reduced algal biomass, whereas other species (Holopedium gibberum and Thermocyclops oithonoides/Mesocyclops leuckarti seemed to be positively affected. H. gibberum disappeared in the 1960s, but reappeared in the 1980s after the significant reduction in algal biomass and primary production. The temporal trend of T. oithonoides/M. leuckarti indicated a strong competition with cladocerans (mainly B. longispina and D. galeata in periods with high algal biomass. Early warming of the lake could also have promoted a biomass increase of T. oithonoides/M. leuckarti in later years, although the mean epilimnion temperature did not correlate with seasonal mean biomass of these species. The seasonal mean biomass of Eudiaptomus gracilis, the dominant calanoid, showed substantial fluctuations with 6-7 years between tops, but a decreasing trend during the 1990s. However, there were no significant correlations between this species and any of the environmental variables. The study indicated that dominant cladocerans (D. galeata and B. longispina are decisive for the success of cisco

  11. [Groundwater quality in an arid area of Morocco: impact of pollution on the biodiversity and relationships between crustaceans and bacteria of health interest].

    Science.gov (United States)

    Hallam, F; Yacoubi-Khebiza, M; Oufdou, K; Boulanouar, M

    2008-11-01

    In the north of Marrakesh (Morocco), the high anthropogenic activity and the permeable nature of the geological ground makes the water of Jbilet vulnerable to contamination. The results of physico-chemical analyses conducted in 2006 showed that two groups of wells could be distinguished. Groundwater of wells located on the right bank of the Tensift River, which are far from any source of pollution, is of fairly good quality, well oxygenated, at neutral pH and with rather weak levels of organic compounds. In contrast, in the other wells in the area of the landfill of the city of Marrakesh and those in the peri-urban area demonstrate deteriorated water quality. The nutriment and organic matter content is quite high. Results of bacteriological analyses of water showed a fairly high faecal contamination. In this area the soil is highly permeable and promotes infiltration of organic pollutants and minerals as well as of pathogen and opportunistic bacteria into groundwater. After their penetration, these microorganisms form films around grain particles. The movements of the stygofauna in the interstices allow bacteria to settle on their exoskeleton and seep into their gut, thus being a potential source of groundwater contamination. An analysis of bacterial flora showed that the rate of bacteria is high in the digestive tract of two crustacean species of the stygobites Typhlocirolana haouzensis and Metacrangonyx spinicaudatus, and that it depends on the species and the bacteria. Bacteria may be one of the potential nutritional resources for stygobites.

  12. The eyes of mesopelagic crustaceans. III. Thysanopoda tricuspidata (Euphausiacea).

    Science.gov (United States)

    Meyer-Rochow, V B; Walsh, S

    1978-12-14

    The compound eyes of the mesopelagic eupausiid Thysanopoda tricuspidata were investigated by light-, scanning-, and transmission electron microscopy. The eyes are spherical and have a diameter that corresponds to 1/6 of the carapace length. The hexagonal facets have strongly curved outer surfaces. Although there are four crystalline cone cells, only two participate in the formation of the cone, which is 90-120 micrometer long and appears to have a radial gradient of refractive index. The clear zone, separating dioptric structures and retinula, is only 90-120 micrometer wide. In it lie the very large oval nuclei of the seven retinula cells. Directly in front of the 70 micrometer long and 15 micrometer thick rhabdom a lens-like structure of 12 micrometer diameter is developed. This structure, known in only a very few arthropods, seems to be present in all species of Euphausiacea studied to date. It is believed that the rhabdom lens improves near-field vision and absolute light sensitivity. Rod-shaped pigment grains and mitochondria of the tubular type are found in the plasma of retinula cells. The position of the proximal screening pigment as well as the microvillar organization in the rhabdom are indicative of light-adapted material. The orthogonal alignment of rhabdovilli suggests polarization sensitivity. Behind each rabdom there is a cup-shaped homogenous structure of unknown, but possibly optical function. Finally, the structure and the function of the euphysiid eye are reviewed and the functional implications of individual components are discussed.

  13. Linking Insects with Crustacea: Physiology of the Pancrustacea: An Introduction to the Symposium.

    Science.gov (United States)

    Tamone, Sherry L; Harrison, Jon F

    2015-11-01

    Insects and crustaceans represent critical, dominant animal groups (by biomass and species number) in terrestrial and aquatic systems, respectively. Insects (hexapods) and crustaceans are historically grouped under separate taxonomic classes within the Phylum Arthropoda, and the research communities studying hexapods and crustaceans are quite distinct. More recently, the hexapods have been shown to be evolutionarily derived from basal crustaceans, and the clade Pancrustacea recognizes this relationship. This recent evolutionary perspective, and the fact that the Society for Integrative and Comparative Biology has strong communities in both invertebrate biology and insect physiology, provides the motivation for this symposium. Speakers in this symposium were selected because of their expertise in a particular field of insect or crustacean physiology, and paired in such a way as to provide a comparative view of the state of the current research in their respective fields. Presenters discussed what aspects of the physiological system are clearly conserved across insects and crustaceans and how cross-talk between researchers utilizing insects and crustaceans can fertilize understanding of such conserved systems. Speakers were also asked to identify strategies that would enable improved understanding of the evolution of physiological systems of the terrestrial insects from the aquatic crustaceans. The following collection of articles describes multiple recent advances in our understanding of Pancrustacean physiology. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  14. Assessing the environmental hazard of individual and combined pharmaceuticals: acute and chronic toxicity of fluoxetine and propranolol in the crustacean Daphnia magna.

    Science.gov (United States)

    Varano, Valentina; Fabbri, Elena; Pasteris, Andrea

    2017-08-01

    Pharmaceuticals are widespread emerging contaminants and, like all pollutants, are present in combination with others in the ecosystems. The aim of the present work was to evaluate the toxic response of the crustacean Daphnia magna exposed to individual and combined pharmaceuticals. Fluoxetine, a selective serotonin re-uptake inhibitor widely prescribed as antidepressant, and propranolol, a non-selective β-adrenergic receptor-blocking agent used to treat hypertension, were tested. Several experimental trials of an acute immobilization test and a chronic reproduction test were performed. Single chemicals were first tested separately. Toxicity of binary mixtures was then assessed using a fixed ratio experimental design. Five concentrations and 5 percentages of each substance in the mixture (0, 25, 50, 75, and 100%) were tested. The MIXTOX model was applied to analyze the experimental results. This tool is a stepwise statistical procedure that evaluates if and how observed data deviate from a reference model, either concentration addition (CA) or independent action (IA), and provides significance testing for synergism, antagonism, or more complex interactions. Acute EC50 values ranged from 6.4 to 7.8 mg/L for propranolol and from 6.4 to 9.1 mg/L for fluoxetine. Chronic EC50 values ranged from 0.59 to 1.00 mg/L for propranolol and from 0.23 to 0.24 mg/L for fluoxetine. Results showed a significant antagonism between chemicals in both the acute and the chronic mixture tests when CA was adopted as the reference model, while absence of interactive effects when IA was used.

  15. Boring crustaceans damage polystyrene floats under docks polluting marine waters with microplastic.

    Science.gov (United States)

    Davidson, Timothy M

    2012-09-01

    Boring isopods damage expanded polystyrene floats under docks and, in the process, expel copious numbers of microplastic particles. This paper describes the impacts of boring isopods in aquaculture facilities and docks, quantifies and discusses the implications of these microplastics, and tests if an alternate foam type prevents boring. Floats from aquaculture facilities and docks were heavily damaged by thousands of isopods and their burrows. Multiple sites in Asia, Australia, Panama, and the USA exhibited evidence of isopod damage. One isopod creates thousands of microplastic particles when excavating a burrow; colonies can expel millions of particles. Microplastics similar in size to these particles may facilitate the spread of non-native species or be ingested by organisms causing physical or toxicological harm. Extruded polystyrene inhibited boring, suggesting this foam may prevent damage in the field. These results reveal boring isopods cause widespread damage to docks and are a novel source of microplastic pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Induced thermal stress on serotonin levels in the blue swimmer crab, Portunus pelagicus

    OpenAIRE

    Rajendiran, Saravanan; Muhammad Iqbal, Beema Mahin; Vasudevan, Sugumar

    2016-01-01

    The temperature of habitat water has a drastic influence on the behavioral, physiological and biochemical mechanisms of crustaceans. Hyperglycemia is a typical response of many aquatic animals to harmful physical and chemical environmental changes. In crustaceans increased circulating crustacean hyperglycemic hormone (CHH) and hyperglycemia are reported to occur following exposure to several environmental stress. The biogenic amine, serotonin has been found to modulate the CHH levels and oxid...

  17. Prevalence of Colacium vesiculosum (Colaciales: Euglenophyceae on planktonic crustaceans in a subtropical shallow lake of Argentina

    Directory of Open Access Journals (Sweden)

    Yolanda Zalocar

    2011-09-01

    Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton Colacium vesiculosum Ehrenberg (Euglenophyceae es un epibionte común en microcrustáceos del plancton de aguas continentales. La interacción epibiontes y organismo substrato es poco conocida, particularmente en ambientes subtropicales de América del Sur. Se analiza la prevalencia, densidad, biomasa y sitios de adhesión de C. vesiculosum en microcrustáceos planctónicos de un lago subtropical de Argentina. Con el fin de evaluar si los epibiontes afectan la tasa de filtración de Notodiaptomus spiniger Brian, crustáceo dominante del zooplancton, se realizaron bioensayos utilizando el fitoplancton <53µm. Los crustáceos fueron muestreados con un tubo de PVC (1m de largo, 10cm de diámetro filtrándose 50L de agua a través de una red de 53µm de abertura de malla. El recuento de los microcrustáceos se realizó en cámaras de Bogorov bajo microscopio estereoscópico. Los organismos infectados fueron separados y observados al microscopio fotónico para determinaciones de densidad y biovolumen de los epibiontes, y su distribución en el exoesqueleto. La prevalencia de C. vesiculosum fue mayor en crustáceos adultos que en estadíos larvales y juveniles. El grupo más infestado fue el de los copépodos calanoideos en relación con su alta densidad. Los sitios de adhesión sobre el exoesqueleto fueron las regiones del cuerpo que durante la

  18. Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions.

    Science.gov (United States)

    Veldhoen, Nik; Ikonomou, Michael G; Buday, Craig; Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa; Dubetz, Cory; Chamberlain, Jon; Pittroff, Sabrina; Vallée, Kurtis; van Aggelen, Graham; Helbing, Caren C

    2012-02-01

    The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1-4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K(p)) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, β-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions

    International Nuclear Information System (INIS)

    Veldhoen, Nik; Ikonomou, Michael G.; Buday, Craig; Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa; Dubetz, Cory; Chamberlain, Jon; Pittroff, Sabrina; Vallée, Kurtis; Aggelen, Graham van; Helbing, Caren C.

    2012-01-01

    The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1–4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K p ) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, β-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean.

  20. Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Nik [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, Stn CSC, Victoria, BC, V8W 3P6 (Canada); Ikonomou, Michael G. [Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Sidney, BC, V8L 4B2 (Canada); Buday, Craig [Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, BC, V7H 1V2 (Canada); Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, Stn CSC, Victoria, BC, V8W 3P6 (Canada); Dubetz, Cory; Chamberlain, Jon [Institute of Ocean Sciences, Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Sidney, BC, V8L 4B2 (Canada); Pittroff, Sabrina; Vallee, Kurtis [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, Stn CSC, Victoria, BC, V8W 3P6 (Canada); Aggelen, Graham van [Pacific Environmental Science Centre, Environment Canada, 2645 Dollarton Highway, North Vancouver, BC, V7H 1V2 (Canada); Helbing, Caren C., E-mail: chelbing@uvic.ca [Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055, Stn CSC, Victoria, BC, V8W 3P6 (Canada)

    2012-02-15

    The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1-4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K{sub p}) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, {beta}-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean.

  1. Brain architecture in the terrestrial hermit crab Coenobita clypeatus (Anomura, Coenobitidae, a crustacean with a good aerial sense of smell

    Directory of Open Access Journals (Sweden)

    Hansson Bill S

    2008-06-01

    Full Text Available Abstract Background During the evolutionary radiation of Crustacea, several lineages in this taxon convergently succeeded in meeting the physiological challenges connected to establishing a fully terrestrial life style. These physiological adaptations include the need for sensory organs of terrestrial species to function in air rather than in water. Previous behavioral and neuroethological studies have provided solid evidence that the land hermit crabs (Coenobitidae, Anomura are a group of crustaceans that have evolved a good sense of aerial olfaction during the conquest of land. We wanted to study the central olfactory processing areas in the brains of these organisms and to that end analyzed the brain of Coenobita clypeatus (Herbst, 1791; Anomura, Coenobitidae, a fully terrestrial tropical hermit crab, by immunohistochemistry against synaptic proteins, serotonin, FMRFamide-related peptides, and glutamine synthetase. Results The primary olfactory centers in this species dominate the brain and are composed of many elongate olfactory glomeruli. The secondary olfactory centers that receive an input from olfactory projection neurons are almost equally large as the olfactory lobes and are organized into parallel neuropil lamellae. The architecture of the optic neuropils and those areas associated with antenna two suggest that C. clypeatus has visual and mechanosensory skills that are comparable to those of marine Crustacea. Conclusion In parallel to previous behavioral findings of a good sense of aerial olfaction in C. clypeatus, our results indicate that in fact their central olfactory pathway is most prominent, indicating that olfaction is a major sensory modality that these brains process. Interestingly, the secondary olfactory neuropils of insects, the mushroom bodies, also display a layered structure (vertical and medial lobes, superficially similar to the lamellae in the secondary olfactory centers of C. clypeatus. More detailed analyses with

  2. A deep transcriptomic resource for the copepod crustacean Labidocera madurae: A potential indicator species for assessing near shore ecosystem health.

    Directory of Open Access Journals (Sweden)

    Vittoria Roncalli

    Full Text Available Coral reef ecosystems of many sub-tropical and tropical marine coastal environments have suffered significant degradation from anthropogenic sources. Research to inform management strategies that mitigate stressors and promote a healthy ecosystem has focused on the ecology and physiology of coral reefs and associated organisms. Few studies focus on the surrounding pelagic communities, which are equally important to ecosystem function. Zooplankton, often dominated by small crustaceans such as copepods, is an important food source for invertebrates and fishes, especially larval fishes. The reef-associated zooplankton includes a sub-neustonic copepod family that could serve as an indicator species for the community. Here, we describe the generation of a de novo transcriptome for one such copepod, Labidocera madurae, a pontellid from an intensively-studied coral reef ecosystem, Kāne'ohe Bay, Oahu, Hawai'i. The transcriptome was assembled using high-throughput sequence data obtained from whole organisms. It comprised 211,002 unique transcripts, including 72,391 with coding regions. It was assessed for quality and completeness using multiple workflows. Bench-marking-universal-single-copy-orthologs (BUSCO analysis identified transcripts for 88% of expected eukaryotic core proteins. Targeted gene-discovery analyses included searches for transcripts coding full-length "giant" proteins (>4,000 amino acids, proteins and splice variants of voltage-gated sodium channels, and proteins involved in the circadian signaling pathway. Four different reference transcriptomes were generated and compared for the detection of differential gene expression between copepodites and adult females; 6,229 genes were consistently identified as differentially expressed between the two regardless of reference. Automated bioinformatics analyses and targeted manual gene curation suggest that the de novo assembled L. madurae transcriptome is of high quality and completeness. This

  3. A deep transcriptomic resource for the copepod crustacean Labidocera madurae: A potential indicator species for assessing near shore ecosystem health

    Science.gov (United States)

    Christie, Andrew E.; Sommer, Stephanie A.; Cieslak, Matthew C.; Hartline, Daniel K.; Lenz, Petra H.

    2017-01-01

    Coral reef ecosystems of many sub-tropical and tropical marine coastal environments have suffered significant degradation from anthropogenic sources. Research to inform management strategies that mitigate stressors and promote a healthy ecosystem has focused on the ecology and physiology of coral reefs and associated organisms. Few studies focus on the surrounding pelagic communities, which are equally important to ecosystem function. Zooplankton, often dominated by small crustaceans such as copepods, is an important food source for invertebrates and fishes, especially larval fishes. The reef-associated zooplankton includes a sub-neustonic copepod family that could serve as an indicator species for the community. Here, we describe the generation of a de novo transcriptome for one such copepod, Labidocera madurae, a pontellid from an intensively-studied coral reef ecosystem, Kāne‘ohe Bay, Oahu, Hawai‘i. The transcriptome was assembled using high-throughput sequence data obtained from whole organisms. It comprised 211,002 unique transcripts, including 72,391 with coding regions. It was assessed for quality and completeness using multiple workflows. Bench-marking-universal-single-copy-orthologs (BUSCO) analysis identified transcripts for 88% of expected eukaryotic core proteins. Targeted gene-discovery analyses included searches for transcripts coding full-length “giant” proteins (>4,000 amino acids), proteins and splice variants of voltage-gated sodium channels, and proteins involved in the circadian signaling pathway. Four different reference transcriptomes were generated and compared for the detection of differential gene expression between copepodites and adult females; 6,229 genes were consistently identified as differentially expressed between the two regardless of reference. Automated bioinformatics analyses and targeted manual gene curation suggest that the de novo assembled L. madurae transcriptome is of high quality and completeness. This

  4. One precursor, three apolipoproteins: the relationship between two crustacean lipoproteins, the large discoidal lipoprotein and the high density lipoprotein/β-glucan binding protein.

    Science.gov (United States)

    Stieb, Stefanie; Roth, Ziv; Dal Magro, Christina; Fischer, Sabine; Butz, Eric; Sagi, Amir; Khalaila, Isam; Lieb, Bernhard; Schenk, Sven; Hoeger, Ulrich

    2014-12-01

    The novel discoidal lipoprotein (dLp) recently detected in the crayfish, differs from other crustacean lipoproteins in its large size, apoprotein composition and high lipid binding capacity, We identified the dLp sequence by transcriptome analyses of the hepatopancreas and mass spectrometry. Further de novo assembly of the NGS data followed by BLAST searches using the sequence of the high density lipoprotein/1-glucan binding protein (HDL-BGBP) of Astacus leptodactylus as query revealed a putative precursor molecule with an open reading frame of 14.7 kb and a deduced primary structure of 4889 amino acids. The presence of an N-terminal lipid bind- ing domain and a DUF 1943 domain suggests the relationship with the large lipid transfer proteins. Two-putative dibasic furin cleavage sites were identified bordering the sequence of the HDL-BGBP. When subjected to mass spectroscopic analyses, tryptic peptides of the large apoprotein of dLp matched the N-terminal part of the precursor, while the peptides obtained for its small apoprotein matched the C-terminal part. Repeating the analysis in the prawn Macrobrachium rosenbergii revealed a similar protein with identical domain architecture suggesting that our findings do not represent an isolated instance. Our results indicate that the above three apolipoproteins (i.e HDL-BGBP and both the large and the small subunit of dLp) are translated as a large precursor. Cleavage at the furin type sites releases two subunits forming a heterodimeric dLP particle, while the remaining part forms an HDL-BGBP whose relationship with other lipoproteins as well as specific functions are yet to be elucidated.

  5. Re-Engineering the Stomatopod Eye, Nature’s Most Comprehensive Visual Sensor

    Science.gov (United States)

    2017-02-22

    evolutionary trajectory for the past 400 million years. We want to learn from this evolutionarily based design. As their closest existing, artificial...of the Anterior Cruciate Ligament. The American Journal of Sports Medicine 0363546514566192. T. Charanya, T. York, S. Bloch, G. Sudlow, R. Tang, W

  6. The food and feeding habits of five freshwater and brackish-water ...

    African Journals Online (AJOL)

    % nematodes, 14% diatoms and 8% crustaceans, while adults were planktotrophic, consuming 23% diatoms, 33% Chlorophyceae and 22% crustaceans. Synodontis nigrita juveniles fed almost exclusively (91%) on nematodes, while adults ...

  7. Uptake of cadmium from a dietary and soluble source by the crustacean Daphnia magna

    International Nuclear Information System (INIS)

    Carney, G.C.; Shore, P.; Chandra, H.

    1986-01-01

    Daphnia were exposed to radioactively labeled cadmium in solution and in the presence of Chlorella which had been preloaded with the metal to varying extents. Illuminated algal cells retained the cadmium and greatly reduced its availability to the daphnids. Autoradiographic evidence was obtained which implicated the exoskeleton as a major sink for the cadmium taken up from solution. Cadmium in solution at a concentration close to the 48 hr LC 50 level did not affect respiration during the first 6 hr of exposure. Retention patterns were similar, regardless of the source of cadmium, but ecdysis resulted in a considerable loss of body burden provided that this had been acquired via a predominantly soluble route

  8. Timing sexual differentiation: full functional sex reversal achieved through silencing of a single insulin-like gene in the prawn, Macrobrachium rosenbergii.

    Science.gov (United States)

    Ventura, Tomer; Manor, Rivka; Aflalo, Eliahu D; Weil, Simy; Rosen, Ohad; Sagi, Amir

    2012-03-01

    In Crustacea, an early evolutionary group (∼50 000 species) inhabiting most ecological niches, sex differentiation is regulated by a male-specific androgenic gland (AG). The identification of AG-specific insulin-like factors (IAGs) and genomic sex markers offers an opportunity for a deeper understanding of the sexual differentiation mechanism in crustaceans and other arthropods. Here, we report, to our knowledge, the first full and functional sex reversal of male freshwater prawns (Macrobrachium rosenbergii) through the silencing of a single IAG-encoding gene. These "neofemales" produced all-male progeny, as proven by sex-specific genomic markers. This finding offers an insight regarding the biology and evolution of sex differentiation regulation, with a novel perspective for the evolution of insulin-like peptides. Our results demonstrate how temporal intervention with a key regulating gene induces a determinative, extreme phenotypic shift. Our results also carry tremendous ecological and commercial implications. Invasive and pest crustacean species represent genuine concerns worldwide without an apparent solution. Such efforts might, therefore, benefit from sexual manipulations, as has been successfully realized with other arthropods. Commercially, such manipulation would be significant in sexually dimorphic cultured species, allowing the use of nonbreeding, monosex populations while dramatically increasing yield and possibly minimizing the invasion of exotic cultured species into the environment.

  9. Feeding habits of Barbul de piedra (ariopsis sp.) in the Sinu River, Colombia

    International Nuclear Information System (INIS)

    Olaya Nieto, Charles W; Arellano Padilla, John J; Martinez Gonzalez, Angel L

    2012-01-01

    The feeding habits of Barbul de piedra in the Sinu River were studied. the stomach content was analyzed using the proportion of empty stomachs, grade of digestion, frequency of occurrence, numerical frequency, gravimetry, relative importance index and the gut length total length relationship. Only 18.8% of stomachs were empty, most of preys were half digested and five food groups were identified: crustaceans, fishes, vegetable rests, molluscs and others. Crustaceans were the most frequent, abundant and greater weight composition group. The relative importance index indicated that crustaceans and fishes were secondary relative importance groups and vegetable rests, molluscs and others were occasional or circumstantial groups. The results achieved in this work indicate that Barbul de piedra is a fish that keeps your feeding habits as they grow and along the hydrological cycle, although shows carnivorous preference, especially by crustaceans.

  10. Epidemiology of a Daphnia-multiparasite system and its implications for the red queen.

    Science.gov (United States)

    Auld, Stuart K J R; Hall, Spencer R; Duffy, Meghan A

    2012-01-01

    The Red Queen hypothesis can explain the maintenance of host and parasite diversity. However, the Red Queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes) and strongly virulent effects of infection on host fitness. A European crustacean (Daphnia magna)--bacterium (Pasteuria ramosa) system typifies such specificity and high virulence. We studied the North American host Daphnia dentifera and its natural parasite Pasteuria ramosa, and also found strong genetic specificity for infection success and high virulence. These results suggest that Pasteuria could promote Red Queen dynamics with D. dentifera populations as well. However, the Red Queen might be undermined in this system by selection from a more common yeast parasite (Metschnikowia bicuspidata). Resistance to the yeast did not correlate with resistance to Pasteuria among host genotypes, suggesting that selection by Metschnikowia should proceed relatively independently of selection by Pasteuria.

  11. Mining TCGA data using Boolean implications.

    Directory of Open Access Journals (Sweden)

    Subarna Sinha

    Full Text Available Boolean implications (if-then rules provide a conceptually simple, uniform and highly scalable way to find associations between pairs of random variables. In this paper, we propose to use Boolean implications to find relationships between variables of different data types (mutation, copy number alteration, DNA methylation and gene expression from the glioblastoma (GBM and ovarian serous cystadenoma (OV data sets from The Cancer Genome Atlas (TCGA. We find hundreds of thousands of Boolean implications from these data sets. A direct comparison of the relationships found by Boolean implications and those found by commonly used methods for mining associations show that existing methods would miss relationships found by Boolean implications. Furthermore, many relationships exposed by Boolean implications reflect important aspects of cancer biology. Examples of our findings include cis relationships between copy number alteration, DNA methylation and expression of genes, a new hierarchy of mutations and recurrent copy number alterations, loss-of-heterozygosity of well-known tumor suppressors, and the hypermethylation phenotype associated with IDH1 mutations in GBM. The Boolean implication results used in the paper can be accessed at http://crookneck.stanford.edu/microarray/TCGANetworks/.

  12. A parameter for detecting estrogenic exposure in the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Andersen, Henrik Rasmus; Halling-Sørensen, Bent; Kusk, Kresten Ole

    1999-01-01

    Literature on the basic endocrinology of crustaceans, such as crab, lobster and shrimp, suggest that estrogens, e.g., 17 beta-estradiol, are stimulating hormones in female sexual maturation and egg production in crustaceans. The copepod Acartia tonsa, has continuous egg production. A profile...

  13. Nutrient Discharge from aquaculture operations in function of system design and production enviorment

    NARCIS (Netherlands)

    Verdegem, M.C.J.

    2013-01-01

    In aquaculture, nutrient loading is defined as the difference between nutrients supplied with fertilizers and feed and nutrients harvested in the form of finfish, crustaceans, molluscs and seaweeds. On average, the production of finfish and crustaceans results in a net nutrient loading, while for

  14. Disposition of phenanthrene and octachlorostyrene in spiny lobsters, Panulirus argus, after intragastric administration

    International Nuclear Information System (INIS)

    Solbakken, J.E.; Knap, A.H.

    1986-01-01

    Spiny lobster (Panulirus argus) is a commercial crustacean in Bermuda. It was therefore of interest to study the fate of xenobiotics in the species as very little attention has been paid to toxicological studies with spiny lobsters. Earlier it was found that the temperate crustacean, Nephrops norveqicus (Norway lobster) had the ability to accumulate and eliminate phenanthrene. The aim of this investigation was to gain a better understanding of the fate of xenobiotics in crustaceans under different environmental conditions, and to compare the polycyclic aromatic hydrocarbon, phenenthrene, with the more environmentally persistent chlorinated compound octachlorostyrene, a by-product of magnesium metal production

  15. Biodiversity of microcrustaceans (Cladocera, Copepoda in a lowland river ecosystem

    Directory of Open Access Journals (Sweden)

    Maciej Karpowicz

    2016-06-01

    Full Text Available This study presents comprehensive research on microcrustacean diversity in different types of aquatic environments in the Upper Narew Valley over five years. A total of 559 samples were analyzed, and 74 species of crustacean zooplankton were identified. Metacyclops planus (Gurney, 1909 is a new species for the fauna of Poland and was found in oxbow lakes and tributary streams. The results of the study suggest that oxbow lakes, with more than 80% of all recorded species, may significantly contribute to the regional biodiversity of floodplain rivers. The highest crustacean community diversity was observed in the semi-lotic oxbow lakes, which emphasizes the role of intermediate disturbance in enhancing biodiversity of water bodies in river valleys. Generally, more “heterogeneous” habitats, such as small oxbow lakes and tributary streams, had higher crustacean species richness. However, a sampling station that was quite “homogeneous”, the Narew River upstream the Siemianówka Reservoir, had high crustacean species richness. The species accumulation curves revealed that approximately 50 - 100 zooplankton samples taken from different environments of river valley are required to establish crustacean species richness. These data could be important for river catchment management and could act as pilot survey data for monitoring plans.

  16. The diversity of coral reefs: what are we missing?

    Directory of Open Access Journals (Sweden)

    Laetitia Plaisance

    Full Text Available Tropical reefs shelter one quarter to one third of all marine species but one third of the coral species that construct reefs are now at risk of extinction. Because traditional methods for assessing reef diversity are extremely time consuming, taxonomic expertise for many groups is lacking, and marine organisms are thought to be less vulnerable to extinction, most discussions of reef conservation focus on maintenance of ecosystem services rather than biodiversity loss. In this study involving the three major oceans with reef growth, we provide new biodiversity estimates based on quantitative sampling and DNA barcoding. We focus on crustaceans, which are the second most diverse group of marine metazoans. We show exceptionally high numbers of crustacean species associated with coral reefs relative to sampling effort (525 species from a combined, globally distributed sample area of 6.3 m(2. The high prevalence of rare species (38% encountered only once, the low level of spatial overlap (81% found in only one locality and the biogeographic patterns of diversity detected (Indo-West Pacific>Central Pacific>Caribbean are consistent with results from traditional survey methods, making this approach a reliable and efficient method for assessing and monitoring biodiversity. The finding of such large numbers of species in a small total area suggests that coral reef diversity is seriously under-detected using traditional survey methods, and by implication, underestimated.

  17. Functional Assessment of Residues in the Amino- and Carboxyl-Termini of Crustacean Hyperglycemic Hormone (CHH in the Mud Crab Scylla olivacea Using Point-Mutated Peptides.

    Directory of Open Access Journals (Sweden)

    Chun-Jing Liu

    Full Text Available To assess functional importance of the residues in the amino- and carboxyl-termini of crustacean hyperglycemic hormone in the mud crab Scylla olivacea (Sco-CHH, both wild-type and point-mutated CHH peptides were produced with an amidated C-terminal end. Spectral analyses of circular dichroism, chromatographic retention time, and mass spectrometric analysis of the recombinant peptides indicate that they were close in conformation to native CHH and were produced with the intended substitutions. The recombinant peptides were subsequently used for an in vivo hyperglycemic assay. Two mutants (R13A and I69A rSco-CHH completely lacked hyperglycemic activity, with temporal profiles similar to that of vehicle control. Temporal profiles of hyperglycemic responses elicited by 4 mutants (I2A, F3A, D12A, and D60A Sco-CHH were different from that elicited by wild-type Sco-CHH; I2A was unique in that it exhibited significantly higher hyperglycemic activity, whereas the remaining 3 mutants showed lower activity. Four mutants (D4A, Q51A, E54A, and V72A rSco-CHH elicited hyperglycemic responses with temporal profiles similar to those evoked by wild-type Sco-CHH. In contrast, the glycine-extended version of V72A rSco-CHH (V72A rSco-CHH-Gly completely lost hyperglycemic activity. By comparing our study with previous ones of ion-transport peptide (ITP and molt-inhibiting hormone (MIH using deleted or point-mutated mutants, detail discussion is made regarding functionally important residues that are shared by both CHH and ITP (members of Group I of the CHH family, and those that discriminate CHH from ITP, and Group-I from Group-II peptides. Conclusions summarized in the present study provide insights into understanding of how functional diversification occurred within a peptide family of multifunctional members.

  18. Epidemiology of a Daphnia-multiparasite system and its implications for the red queen.

    Directory of Open Access Journals (Sweden)

    Stuart K J R Auld

    Full Text Available The Red Queen hypothesis can explain the maintenance of host and parasite diversity. However, the Red Queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes and strongly virulent effects of infection on host fitness. A European crustacean (Daphnia magna--bacterium (Pasteuria ramosa system typifies such specificity and high virulence. We studied the North American host Daphnia dentifera and its natural parasite Pasteuria ramosa, and also found strong genetic specificity for infection success and high virulence. These results suggest that Pasteuria could promote Red Queen dynamics with D. dentifera populations as well. However, the Red Queen might be undermined in this system by selection from a more common yeast parasite (Metschnikowia bicuspidata. Resistance to the yeast did not correlate with resistance to Pasteuria among host genotypes, suggesting that selection by Metschnikowia should proceed relatively independently of selection by Pasteuria.

  19. Family Common Name Scientific name Main food Main Guild Beach ...

    African Journals Online (AJOL)

    NICKSON

    Spur-winged Plover, Vanellus spinosus, crustaceans, insects, worms, Invertebrate, 1.38, 0.6, 3.4, 0.59, RES. Kittlits Plover, Charadrius ... Great Snipe, Gallinago media, crustaceans, worms, insects, Invertebrate, 0.34, PM. Common ... Red-eyed Dove, Streptopelia semitorquata, seeds, grains, Granivore, 1.38, 0.62, 0.59, RES.

  20. The Crustacea Decapoda Macrura (the Alpheidae excepted) of Easter Island

    NARCIS (Netherlands)

    Holthuis, L.B.

    1972-01-01

    So far the Crustacean fauna of Easter Island has received but very little attention. In most early narratives of expeditions visiting the island no mention is made of any Crustacean. Behrens (1908: 135) who accompanied Jacob Roggeveen on the voyage during which, in 1722, the island was discovered,

  1. Decapod crustaceans used as food by the Yanomami Indians of the Balawa-ú village, State of Amazonas, Brazil Crustáceos decápodos usados na alimentação pelos índios Yanomami da aldeia de Balawa-ú, Estado do Amazonas, Brasil

    Directory of Open Access Journals (Sweden)

    Célio Magalhães

    2006-01-01

    Full Text Available The Yanomami are a group of South American Indians that live in the rainforest along the borderlands of Brazil and Venezuela. They depend on hunting, gardening and wild food for survival; crustaceans are a highly prized food item in their diet. Taxonomical and ethnozoological aspects of the Yanomami Indians of the Balawa-ú village, state of Amazonas, Brazil, related to the crustaceans are described. Information and specimens were obtained from August to December, 2003. Interviews were conducted with residents of the village and focused on questions about species exploited, indigenous names, modes of capture and use of the species. One shrimp species of the family Palaemonidae (Macrobrachium brasiliense and two crab species of Trichodactylidae (Sylviocarcinus pictus, Valdivia serrata as well as two of Pseudothelphusidae (Fredius fittkaui, F. platyacanthus were recorded. The indigenous names applied to these species are: shuhu, for shrimp, oko and peimatherimi for each of the two pseudothelphusid crabs, and hesiki tôtôrema for both trichodactylid crabs.Os Yanomami são um grupo de índios que habitam a floresta tropical úmida ao longo da fronteira entre Brasil e Venezuela. Eles dependem da caça, da agricultura e da coleta de produtos da floresta para a sua sobrevivência, sendo os crustáceos um dos itens alimentares mais apreciados. São descritos aspectos taxonômicos e etnozoológicos dos índios Yanomami da aldeia de Balawa-ú, no estado do Amazonas, Brasil, relacionados aos crustáceos. Informações e espécimes foram coletados de agosto a dezembro de 2003. Foram realizadas entrevistas com habitantes da aldeia com enfoque nas espécies exploradas, nomes indígenas, modos de captura e utilização. Foram registradas uma espécie de camarão da família Palaemonidae (Macrobrachium brasiliense, duas espécies de caranguejos da família Trichodactylidae (Sylviocarcinus pictus, Valdivia serrata e duas da família Pseudothelphusidae (Fredius

  2. Size-dependent responses of zooplankton to submerged macrophyte restoration in a subtropical shallow lake

    Science.gov (United States)

    Zeng, Lei; He, Feng; Zhang, Yi; Liu, Biyun; Dai, Zhigang; Zhou, Qiaohong; Wu, Zhenbin

    2018-03-01

    To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans (cladocerans and copepods). The rotifers were grouped into three size classes (400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis (RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl- a, but negative correlations between macrophytes and COD or Chl- a, and between crustaceans and Chl- a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.

  3. Implicative Algebras | Kolluru | Momona Ethiopian Journal of Science

    African Journals Online (AJOL)

    In this paper we introduce the concept of implicative algebras which is an equivalent definition of lattice implication algebra of Xu (1993) and further we prove that it is a regular Autometrized Algebra. Further we remark that the binary operation → on lattice implicative algebra can never be associative. Keywords: Implicative ...

  4. Toxicity of seaweed-synthesized silver nanoparticles against the filariasis vector Culex quinquefasciatus and its impact on predation efficiency of the cyclopoid crustacean Mesocyclops longisetus.

    Science.gov (United States)

    Murugan, Kadarkarai; Benelli, Giovanni; Ayyappan, Suganya; Dinesh, Devakumar; Panneerselvam, Chellasamy; Nicoletti, Marcello; Hwang, Jiang-Shiou; Kumar, Palanisamy Mahesh; Subramaniam, Jayapal; Suresh, Udaiyan

    2015-06-01

    Nearly 1.4 billion people in 73 countries worldwide are threatened by lymphatic filariasis, a parasitic infection that leads to a disease commonly known as elephantiasis. Filariasis is vectored by mosquitoes, with special reference to the genus Culex. The main control tool against mosquito larvae is represented by treatments with organophosphates and insect growth regulators, with negative effects on human health and the environment. Recently, green-synthesized nanoparticles have been proposed as highly effective larvicidals against mosquito vectors. In this research, we attempted a reply to the following question: do green-synthesized nanoparticles affect predation rates of copepods against mosquito larvae? We proposed a novel method of seaweed-mediated synthesis of silver nanoparticles using the frond extract of Caulerpa scalpelliformis. The toxicity of the seaweed extract and silver nanoparticles was assessed against the filarial vector Culex quinquefasciatus. Then, we evaluated the predatory efficiency of the cyclopoid crustacean Mesocyclops longisetus against larval instars of C. quinquefasciatus in a nanoparticle-contaminated water environment. Green-synthesized silver nanoparticles were characterized by UV-vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In mosquitocidal assays, the LC₅₀ values of the C. scalpelliformis extract against C. quinquefasciatus were 31.38 ppm (I), 46.49 ppm (II), 75.79 ppm (III), 102.26 ppm (IV), and 138.89 ppm (pupa), while LC₅₀ of silver nanoparticles were 3.08 ppm, (I), 3.49 ppm (II), 4.64 ppm (III), 5.86 ppm (IV), and 7.33 ppm (pupa). The predatory efficiency of the copepod M. longisetus in the control treatment was 78 and 59% against I and II instar larvae of C. quinquefasciatus. In a nanoparticle-contaminated environment, predation efficiency was 84 and 63%, respectively. Predation was higher against first instar larvae over other instars

  5. Gene expression profiling of cuticular proteins across the moult cycle of the crab Portunus pelagicus

    Directory of Open Access Journals (Sweden)

    Kuballa Anna V

    2007-10-01

    Full Text Available Abstract Background Crustaceans represent an attractive model to study biomineralization and cuticle matrix formation, as these events are precisely timed to occur at certain stages of the moult cycle. Moulting, the process by which crustaceans shed their exoskeleton, involves the partial breakdown of the old exoskeleton and the synthesis of a new cuticle. This cuticle is subdivided into layers, some of which become calcified while others remain uncalcified. The cuticle matrix consists of many different proteins that confer the physical properties, such as pliability, of the exoskeleton. Results We have used a custom cDNA microarray chip, developed for the blue swimmer crab Portunus pelagicus, to generate expression profiles of genes involved in exoskeletal formation across the moult cycle. A total of 21 distinct moult-cycle related differentially expressed transcripts representing crustacean cuticular proteins were isolated. Of these, 13 contained copies of the cuticle_1 domain previously isolated from calcified regions of the crustacean exoskeleton, four transcripts contained a chitin_bind_4 domain (RR consensus sequence associated with both the calcified and un-calcified cuticle of crustaceans, and four transcripts contained an unannotated domain (PfamB_109992 previously isolated from C. pagurus. Additionally, cryptocyanin, a hemolymph protein involved in cuticle synthesis and structural integrity, also displays differential expression related to the moult cycle. Moult stage-specific expression analysis of these transcripts revealed that differential gene expression occurs both among transcripts containing the same domain and among transcripts containing different domains. Conclusion The large variety of genes associated with cuticle formation, and their differential expression across the crustacean moult cycle, point to the complexity of the processes associated with cuticle formation and hardening. This study provides a molecular entry path

  6. Zoogeografía de los crustáceos decápodos chilenos marinos y dulceacuícolas Zoogeography of Chilean marine and freshwater decapod crustaceans

    Directory of Open Access Journals (Sweden)

    Marco A Retamal

    2010-01-01

    Full Text Available Sobre la base de 77 familias, más de 200 géneros y 431 especies que habitan aguas chilenas, se ha tratado de revelar el patrón zoogeográfico subyacente a estos taxa comparando áreas sobre la base del número de especies, géneros y familias que las comparten. Para obtener este patrón zoogeográfico se dividió la costa y las islas oceánicas en 16 áreas, que abarcan la mayor parte de la placa de Nazca, incluyendo la isla de Pascua, isla Salas y Gómez, islas Desventuradas y archipiélago de Juan Fernández, así como las cordilleras submarinas de Salas y Gómez y Nazca (5 áreas, la costa sudamericana occidental desde Arica (ca., 18°S hasta el cabo de Hornos (56°S (10 áreas y la península Antartica y áreas adyacentes (1 área. Los cuatro dendrogramas obtenidos coinciden en mostrar seis áreas provinciales: a Chileno-Peruana (18°-42°S; b Magallánica (42°-56°S; c Antartica, que incluye la península Antartica y los archipiélagos del arco de Escocia; d Archipiélago de Juan Fernández (33°40'S, 79°00'W, incluyendo las islas Desventuradas (ca. 26°20'S, 80°W; e Isla de Pascua (27°09'S, 109°25'S; y, f cordilleras sumergidas de Salas y Gómez & Nazca (ca. 25°S; ca. 75°W-100°W. El dendrograma que se basa exclusivamente en las familias compartidas entre las diversas áreas geográficas muestra dos grandes conjuntos: el primero reúne a todas las áreas oceánicas sobre la placa de Nazca y el segundo las diez áreas sudamericanas y la Antartica. Adicionalmente, los decápodos del cono sur de América del Sur se extienden desde el Pacífico suroriental magallánico hasta el Atlántico suroccidental magallánico, llegando hasta el archipiélago de las islas Kerguelen en el límite de los océanos índico y Antartico.Using more than 200 genera and 431 species that comprise the 77 families of decapods crustaceans inhabiting Chilean waters, we attempted to reveal the underlying zoogeographical pattern of these taxa by comparing areas

  7. Prime implicants in dynamic reliability analysis

    International Nuclear Information System (INIS)

    Tyrväinen, Tero

    2016-01-01

    This paper develops an improved definition of a prime implicant for the needs of dynamic reliability analysis. Reliability analyses often aim to identify minimal cut sets or prime implicants, which are minimal conditions that cause an undesired top event, such as a system's failure. Dynamic reliability analysis methods take the time-dependent behaviour of a system into account. This means that the state of a component can change in the analysed time frame and prime implicants can include the failure of a component at different time points. There can also be dynamic constraints on a component's behaviour. For example, a component can be non-repairable in the given time frame. If a non-repairable component needs to be failed at a certain time point to cause the top event, we consider that the condition that it is failed at the latest possible time point is minimal, and the condition in which it fails earlier non-minimal. The traditional definition of a prime implicant does not account for this type of time-related minimality. In this paper, a new definition is introduced and illustrated using a dynamic flowgraph methodology model. - Highlights: • A new definition of a prime implicant is developed for dynamic reliability analysis. • The new definition takes time-related minimality into account. • The new definition is needed in dynamic flowgraph methodology. • Results can be represented by a smaller number of prime implicants.

  8. Establishment of two invasive crustaceans (Copepoda: Harpacticoida) on the nearshore sands of Lake Michigan

    Science.gov (United States)

    Horvath, Thomas G.; Whitman, Richard L.; Last, Laurel L.

    2001-01-01

    Benthic copepods (Copepoda: Harpacticoida) in the nearshore sediments of southern Lake Michigan appear to be dominated by two new invasive species. We report the first occurrence in North America of Schizopera borutzkyi Montschenko, a native to the Danube River delta, and Heteropsyllus nr. nunni, likely a new species that is morphologically similar to the marine species Heteropsyllus nunni and represents the first occurrence of this genus in freshwater. Schizopera borutzkyi is a euryhaline species occurring in shallow sands in its native habitat and in deeper sands (6-15 m) in southern Lake Michigan. Based on the absence of these species from previous studies, we suggest that they are recent introductions. Heteropsyllus nr. nunni dominated (55-100%) the harpacticoid abundance to depths of 9 m, but S. borutzkyi comprised 75% of the harpacticoid abundance at 15 m. Native harpacticoids were always greatly outnumbered by invasive harpacticoids in our samples, which suggests that the natives are being replaced rapidly or that the invasive species are finding unused resources. The ecological implications of these introductions are not known, but these invasions may represent continued 'invasional meltdown' in Lake Michigan.

  9. L'analyse implicative bayésienne multivariée d'un questionnaire binaire : quasi-implications et treillis de Galois simplifié

    OpenAIRE

    Bernard, Jean-Marc; Poitrenaud, Sébastien

    2006-01-01

    We propose a new method for simplifying the Galois lattice associated to a binary questionnaire (n units classified according to q binary questions). The method consists in weakening the implications borne by the lattice into quasi-implications. At the descriptive level, the method involves a new measure for quasi-implications (the "multivariate implicative index") which satisfies some requirements of invariance by logical equivalence. At the inductive level, uncertainty about the patterns' t...

  10. Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2011

    Science.gov (United States)

    2012-05-01

    variation in digestion rates, feeding habits , seasonal or diel collection times, fish size, and individual dietary whims (Bowen 1983). Food sources are not...frequency that fish could access the marsh edge for feeding . Total Site Channel Density Stream channel length per unit area calculated by dividing the...DOSalinity Prey Epibenthic micro crustaceans Macro crustaceans InsectsWorms Zooplankton Primary production Microbenthic algae Estuarine

  11. Structural and functional comparisons and production of recombinant crustacean hyperglycemic hormone (CHH) and CHH-like peptides from the mud crab Scylla olivacea.

    Science.gov (United States)

    Chang, Chih-Chun; Tsai, Kuo-Wei; Hsiao, Nai-Wan; Chang, Cheng-Yen; Lin, Chih-Lung; Watson, R Douglas; Lee, Chi-Ying

    2010-05-15

    Sco-CHH and Sco-CHH-L (CHH-like peptide), two structural variants of the crustacean hyperglycemic hormone family identified in the mud crab (Scylla olivacea), are presumably alternatively spliced gene products. In this study, Sco-CHH and Sco-CHH-L were isolated from the tissues using high performance liquid chromatography. Identity of the native peptides was confirmed using mass spectrometric (MS) analyses of purified materials and of trypsin-digested peptide fragments. Additionally, characterizations using circular dichroism (CD) spectrometry revealed that the 2 peptides have similar CD spectral profiles, showing they are composed mainly of alpha-helices, and are similarly thermo-stable with a melting temperature of 74-75 degrees C. Results of bioassays indicated that Sco-CHH exerted hyperglycemic and molt-inhibiting activity, whereas Sco-CHH-L did not. Further, recombinant Sco-CHH-Gly (rSco-CHH-Gly, a glycine extended Sco-CHH) and Sco-CHH-L (rSco-CHH-L) were produced using an Escherichia coli expression system, refolded, and purified. rSco-CHH-Gly was further alpha-amidated at the C-terminal end to produce rSco-CHH. MS analyses of enzyme-digested peptide fragments of rSco-CHH-Gly and rSco-CHH-L showed that the two peptides share a common disulfide bond pattern: C7-C43, C23-C39, and C26-C52. Circular dichroism analyses and hyperglycemic assay revealed that rSco-CHH and rSco-CHH-L resemble their native counterparts, in terms of CD spectral profiles, melting curve profiles, and biological activity. rSco-CHH-Gly has a lower alpha-helical content (32%) than rSco-CHH (47%), a structural deviation that may be responsible for the significant decrease in the biological activity of rSco-CHH-Gly. Finally, modeled structure of Sco-CHH and Sco-CHH-L indicated that they are similarly folded, each with an N-terminal tail region and 4 alpha-helices. Putative surface residues located in corresponding positions of Sco-CHH and Sco-CHH-L but with side chains of different properties

  12. Maritime Violence : Implications to Malaysia

    OpenAIRE

    Zubir, Nurulizwan Ahmad

    2012-01-01

    Abstract Maritime Piracy has been a serious threat to the international community especially in the SoutheastAsia region. This threat has caused tremendous implications towards the world economy, environment,political stability of the nations involved because 45% of the shipping company passes through theSoutheast Asia. The worrying fact is that these attacks were committed by terrorists as well as traditionalmaritime pirates. This paper examines on the implications of maritime crime in M...

  13. The privacy implications of Bluetooth

    OpenAIRE

    Kostakos, Vassilis

    2008-01-01

    A substantial amount of research, as well as media hype, has surrounded RFID technology and its privacy implications. Currently, researchers and the media focus on the privacy threats posed by RFID, while consumer groups choose to boycott products bearing RFID tags. At the same, however, a very similar technology has quietly become part of our everyday lives: Bluetooth. In this paper we highlight the fact that Bluetooth is a widespread technology that has real privacy implications. Furthermor...

  14. Quantum histories and their implications

    International Nuclear Information System (INIS)

    Kent, A.

    2000-01-01

    Classical mechanics and standard Copenhagen quantum mechanics respect subspace implications. For example, if a particle is confined in a particular region R of space, then in these theories we can deduce that it is confined in regions containing R. However, subspace implications are generally violated by versions of quantum theory that assign probabilities to histories, such as the consistent histories approach. I define here a new criterion, ordered consistency, which refines the criterion of consistency and has the property that inferences made by ordered consistent sets do not violate subspace relations. This raises the question: do the operators defining our observations form an ordered consistent history? If so, ordered consistency defines a version of quantum theory with greater predictive power than the consistent histories formalism. If not, and our observations are defined by a non-ordered consistent quantum history, then subspace implications are not generally valid. (orig.)

  15. Towards an internationally harmonized test method for reproductive and developmental effects of endocrine disrupters in marine copepods

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Wollenberger, Leah

    2007-01-01

    with marine copepods (Acartia tonsa, Nitocra spinipes, Tisbe battagliai, and Amphiascus tenuiremis). The present paper gives an overview on the endocrine system of crustaceans with special emphasis on development and reproduction, which are targets for endocrine disruption, and reviews available methods......New and updated methods to detect and characterize endocrine disrupting chemicals (EDCs) are urgently needed for the purpose of environmental risk assessment since these substances are often not detected using existing chronic toxicity tests. Numerous reports on the effects of EDCs on crustacean...... development and reproduction have been published and the development of life-cycle tests with crustaceans has been prioritized within the OECD work program for endocrine disrupter testing and assessment. As a result, Sweden, and Denmark initiated a proposal for development of a full life-cycle test...

  16. Ophthalmic implications of seasonal affective disorder

    International Nuclear Information System (INIS)

    Paramore, J.E.; King, V.M.

    1989-01-01

    A review of seasonal affective disorder (SAD) is presented with a discussion of its standard treatment of phototherapy. A number of ophthalmic implications related to SAD are proposed. These implications relate to both the condition and the phototherapy used in its treatment, especially the use of full spectrum light which contains ultraviolet and near ultraviolet radiation. 12 references

  17. Fuzzy implicative hyper BCK-ideals of hyper BCK-algebras

    OpenAIRE

    Jun, Young Bae; Shim, Wook Hwan

    2002-01-01

    We consider the fuzzification of the notion of implicative hyper BCK-ideals, and then investigate several properties. Using the concept of level subsets, we give a characterization of a fuzzy implicative hyper BCK-ideal. We state a relation between a fuzzy hyper BCK-ideal and a fuzzy implicative hyper BCK-ideal. We establish a condition for a fuzzy hyper BCK-ideal to be a fuzzy implicative hyper BCK-ideal. Finally, we introduce the notion of hyper homomorphisms of hyper ...

  18. Implications of deforestation and desertification on sustainable ...

    African Journals Online (AJOL)

    This paper examines the implications of deforestation and desertification in sustainable agriculture. The problems of deforestation and desertification were examined as they affect land and agricultural productivity. The socio-economic implications of deforestation and desertification in sustainable agriculture were equally ...

  19. Effect Of GAMMA-Irradiation On Production And Characteristics Of Chitosan Produced From Crustacean Waste By Using Some Bacterial Strains

    International Nuclear Information System (INIS)

    INAS ISMAIL MAHMOUD RAAFAT

    2015-01-01

    The main study focused on separation of chitin from crustacean waste (shrimp shell) using some proteolytic bacterial isolates. After that, chitosan was obtained by deactylation and its characteristics were studied using some characterizing tools. The produced chitosan was degraded to different molecular weights and evaluated as an antibacterial agent. Seventy bacterial isolates were obtained from different sources (soil, plant roots and shrimp shell waste) and tested for their ability to produce proteolytic enzymes. One isolate was selected, due its high proteolytic activity and ability to grow using shrimp as carbon and nitrogen source on shrimp shell agar medium and identified as Bacillus subtilis NA12 by 16S-rRNA gene sequences with a high degree of similarity (99 %) as a gene bank database. Factors affecting deproteinization (DP) and demineralization (DM) efficiency of shrimp shell waste (SSW) (carbon source and its optimal concentration, shrimp shell waste concentration, inoculum size and fermentation time) were studied. The most efficient DP (92.40 %) and DM (81.37 %) of SSW by B. subtilis NA12 were sucrose 10 % (w/v) and inoculum size 15 % (v/v 35 x 108 CFU/ml ) to ferment shrimp shell waste 5 % (w/v) for 6 days of fermentation time. The effect of γ-irradiation on the performance of selected bacterial strain was studied to maximize chitin yield. Box-Behnken design using response surface methodology was employed to establish the relationship between the previous variables, implied that the model was highly significant. It was found that a sucrose concentration of 5 % (w/v), SSW of 12.5 % (w/v), inoculum size of 10 % (v/v) and fermentation time of 7 days; had a predicted value of DP of 97.65 % whereas the actual experiment gave 96.37 %. The predicted value of DM was 82.94 % whereas the actual experiment gave 82.19 %. Chitosan polymer was successfully prepared by the deacetylation reaction from fermented shrimp shell waste (SSW) by Bacillus subtilis NA12

  20. Risk Implications of Energy Policy Instruments

    DEFF Research Database (Denmark)

    Kitzing, Lena

    papers and a working paper), based on a combination of micro-economic and policy analysis. Financial theory is used for the quantitative analysis of investment problems under uncertainty, including mean-variance portfolio theory, real option analysis, Monte Carlo simulations and time series analysis...... show, both qualitatively and quantitatively, that policy makers cannot neglect risk implications when designing RES support instruments without compromising either on effectiveness or cost-efficiency of energy policy. The central research questions are: how can risk implications of RES policy...... instruments be integrated into policy design, so that the policies provide adequate investment incentives? And can the consideration of such risk implications in policy design make overall energy policy more successful? These questions are answered in seven research papers (four journal papers, two conference...

  1. Economic and policy implications of pandemic influenza.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Braeton J.; Starks, Shirley J.; Loose, Verne W.; Brown, Theresa Jean; Warren, Drake E.; Vargas, Vanessa N.

    2010-03-01

    Pandemic influenza has become a serious global health concern; in response, governments around the world have allocated increasing funds to containment of public health threats from this disease. Pandemic influenza is also recognized to have serious economic implications, causing illness and absence that reduces worker productivity and economic output and, through mortality, robs nations of their most valuable assets - human resources. This paper reports two studies that investigate both the short- and long-term economic implications of a pandemic flu outbreak. Policy makers can use the growing number of economic impact estimates to decide how much to spend to combat the pandemic influenza outbreaks. Experts recognize that pandemic influenza has serious global economic implications. The illness causes absenteeism, reduced worker productivity, and therefore reduced economic output. This, combined with the associated mortality rate, robs nations of valuable human resources. Policy makers can use economic impact estimates to decide how much to spend to combat the pandemic influenza outbreaks. In this paper economists examine two studies which investigate both the short- and long-term economic implications of a pandemic influenza outbreak. Resulting policy implications are also discussed. The research uses the Regional Economic Modeling, Inc. (REMI) Policy Insight + Model. This model provides a dynamic, regional, North America Industrial Classification System (NAICS) industry-structured framework for forecasting. It is supported by a population dynamics model that is well-adapted to investigating macro-economic implications of pandemic influenza, including possible demand side effects. The studies reported in this paper exercise all of these capabilities.

  2. Balancing tissue perfusion demands: cardiovascular dynamics of Cancer magister during exposure to low salinity and hypoxia.

    Science.gov (United States)

    McGaw, Iain J; McMahon, Brian R

    2003-01-01

    acclimation to hypoxic conditions, apart from an increased heart rate, there were no other cardiovascular changes associated with the low salinity episode. The implications of these changes in cardiovascular dynamics are discussed in relation to physiological mechanisms and the ecology of decapod crustaceans, in hypoxic or low salinity environments. Copyright 2003, Wiley-Liss, Inc.

  3. Predicting predatory impact of juvenile invasive lionfish (Pterois volitans) on a crustacean prey using functional response analysis: effects of temperature, habitat complexity and light regimes

    KAUST Repository

    South, Josie; Dick, Jaimie T. A.; McCard, Monica; Barrios-O’ Neill, Daniel; Anton, Andrea

    2017-01-01

    The ecological implications of biotic interactions, such as predator-prey relationships, are often context-dependent. Comparative functional responses analysis can be used under different abiotic contexts to improve understanding and prediction

  4. Current Status and New Perspectives on Chitin and Chitosan as Functional Biopolymers.

    Science.gov (United States)

    Philibert, Tuyishime; Lee, Byong H; Fabien, Nsanzabera

    2017-04-01

    The natural biopolymer chitin and its deacetylated product chitosan are found abundantly in nature as structural building blocks and are used in all sectors of human activities like materials science, nutrition, health care, and energy. Far from being fully recognized, these polymers are able to open opportunities for completely novel applications due to their exceptional properties which an economic value is intrinsically entrapped. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal and insect sources. Significant efforts have been devoted to commercialize chitosan extracted from fungal and insect sources to completely replace crustacean-derived chitosan. However, the traditional chitin extraction processes are laden with many disadvantages. The present review discusses the potential bioextraction of chitosan from fungal, insect, and crustacean as well as its superior physico-chemical properties. The different aspects of fungal, insects, and crustacean chitosan extraction methods and various parameters having an effect on the yield of chitin and chitosan are discussed in detail. In addition, this review also deals with essential attributes of chitosan for high value-added applications in different fields and highlighted new perspectives on the production of chitin and deacetylated chitosan from different sources with the concomitant reduction of the environmental impact.

  5. Decapod crustacean chelipeds: an overview

    Indian Academy of Sciences (India)

    Unknown

    The dimorphic growth pattern of chelae can be adversely affected by factors such as parasitic ... upward, (iv) merus, (v) carpus, (vi) propodus, and (vii) dac- tyl. The basis and ...... Hazlett B A and Winn H E 1962 Sound production and associ-.

  6. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    International Nuclear Information System (INIS)

    Stockdale, Anthony; Tipping, Edward; Lofts, Stephen; Fott, Jan; Garmo, Øyvind A.; Hruska, Jakub; Keller, Bill; Löfgren, Stefan; Maberly, Stephen C.; Majer, Vladimir; Nierzwicki-Bauer, Sandra A.; Persson, Gunnar; Schartau, Ann-Kristin; Thackeray, Stephen J.

    2014-01-01

    The WHAM-F TOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F TOX ), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H + TOX to relate combined toxic effects of protons and metal cations towards lake crustacean zooplankton. • The fitted results give toxic potencies increasing in the order H + TOX model has been applied to field data for pelagic lake crustacean zooplankton. The fitted results give metal toxic potencies increasing in the order H + < Al < Cu < Zn < Ni

  7. Transformation of University Organizations:Leadership and Managerial Implications

    Directory of Open Access Journals (Sweden)

    Cemil ULUKAN

    2005-10-01

    Full Text Available Transformation of University Organizations:Leadership and Managerial Implications Cemil ULUKAN, Ph.D Anadolu UniversityOpen Education Faculty Eskisehir-TURKEYABSTRACT Technology and globalization are forcing higher education institutions to transform themselves. This paper aims to contribute to a better understanding the leadership and managerial implications of recent developments for higher education. Reviewing unique characteristics and the fundamental changes shaping higher education, the paper examines the need for organizational transformation and the major managerial implications.

  8. New functions of arthropod bursicon: inducing deposition and thickening of new cuticle and hemocyte granulation in the blue crab, Callinectes sapidus.

    Directory of Open Access Journals (Sweden)

    J Sook Chung

    Full Text Available Arthropod growth requires molt-associated changes in softness and stiffness of the cuticle that protects from desiccation, infection and injury. Cuticle hardening in insects depends on the blood-borne hormone, bursicon (Burs, although it has never been determined in hemolymph. Whilst also having Burs, decapod crustaceans reiterate molting many more times during their longer life span and are encased in a calcified exoskeleton, which after molting undergoes similar initial cuticle hardening processes as in insects. We investigated the role of homologous crustacean Burs in cuticular changes and growth in the blue crab, Callinectes sapidus. We found dramatic increases in size and number of Burs cells during development in paired thoracic ganglion complex (TGC neurons with pericardial organs (POs as neurohemal release sites. A skewed expression of Burs β/Burs α mRNA in TGC corresponds to protein contents of identified Burs β homodimer and Burs heterodimer in POs. In hemolymph, Burs is consistently present at ∼21 pM throughout the molt cycle, showing a peak of ∼89 pM at ecdysis. Since initial cuticle hardness determines the degree of molt-associated somatic increment (MSI, we applied recombinant Burs in vitro to cuticle explants of late premolt or early ecdysis. Burs stimulates cuticle thickening and granulation of hemocytes. These findings demonstrate novel cuticle-associated functions of Burs during molting, while the unambiguous and constant presence of Burs in cells and hemolymph throughout the molt cycle and life stages may implicate further functions of its homo- and heterodimer hormone isoforms in immunoprotective defense systems of arthropods.

  9. Knowledge and Awareness Implication on E-Waste Management ...

    African Journals Online (AJOL)

    Knowledge and Awareness Implication on E-Waste Management among ... and Awareness Implication on E-Waste Management among Nigerian Collegiate ... with e-waste may pose potential threat to human health and the environment.

  10. cis-Canthaxanthins: unusual carotenoids in the eggs and the reproductive system of female brine shrimp Artemia

    OpenAIRE

    Nelis, H.J.C.F.; Lavens, P.; Moens, L.; Sorgeloos, P.; Jonckheere, J.A.; Criel, G.R.J.; De Leenheer, A.P.

    1984-01-01

    The significance of carotenoid accumulation in crustacean eggs remains obscure, particularly because neither eggs nor female animals have been found to display specific pigment patterns in relation to reproduction. We report here the first example of carotenoids found exclusively in the ovaries, the eggs, and the hemolymph, but not in the carcass of a female, reproductively active crustacean, i.e. the brine shrimp Artemia . These pigments are virtually absent in males and in immature animals ...

  11. Implications of social structure

    DEFF Research Database (Denmark)

    Brask, Josefine Bohr

    Social systems in nature are characterised by heterogeneous social structures. The pattern of social interactions or associations between individuals within populations (i.e. their social network) is typically non-random. Such structuring may have important implications for the expression...... and evolution of behaviour, and for individual fitness. In this thesis I investigated implications of social structure for fitness and behaviour, with focus on three main areas: social structure & fitness, social structure & communication, and social structure & cooperation. These areas were investigated......, we investigate empirically the role of the social environment of individuals for their communication patterns. Our study species is a song bird, the black-capped chickadee (Poecile atricapillus). The results suggest that individual communication in this species is influenced by features of the local...

  12. Ectoparasitic crustaceans on mullet, Mugil curema (Osteichthyes: Mugilidae in the coastal waters of Rio Grande do Norte State, Brazil = Crustáceos ectoparasítos em tainha, Mugil curema (Osteichthyes: Mugilidae nas águas costeiras do Estado do Rio Grande do Norte, Brasil

    Directory of Open Access Journals (Sweden)

    Elizete Teresinha Santos Cavalcanti

    2011-07-01

    Full Text Available White mullet is a commercial fish species abundant in the coastal waters of Brazil. This study investigated the occurrence of crustacean ectoparasites on white mullet, Mugil curema captured from the littoral waters of Rio Grande do Norte State, Brazil. From 2006 to 2007, 31 individuals of M. curema were captured and encountered ectoparasites were observed, identified and counted. M. curema was parasitized by ectoparasitic crustaceans, caligid copepods, Caligus bonito and Caligus sp.; ergasilid copepods, Ergasilus versicolor andE. lizae; and isopod Cymothoa spinipalpa. Of the caligids detected, 66.66% were C. bonito and 33.33% Caligus sp. C. bonito occurred on males of M. curema during the drought season and Caligus sp. occurred on females during the rainy season. The prevalence of both caligidspecies was 3.23%. Of the ergasilids detected, E. versicolor (91.67% occurred during the drought and rainy seasons, whereas E. lizae (8.33% occurred during the rainy season. Prevalence of E. versicolor was 35.48% and E. lizae was 3.23%. C. spinipalpa was detected during the drought and rainy seasons with a prevalence of 16.13%. The preferred site of fixation by the parasites was the branchial chambers.As tainhas são peixes marinhos de valor comercial, abundantes em águas costeiras brasileiras. O presente estudo investigou a ocorrência de crustáceos ectoparasitos na tainha, Mugil curema no litoral do Rio Grande do Norte. Foram capturados 31 exemplares de M. curema no período de março de 2006 a março de 2007 e os ectoparasitos encontrados foram coletados, observados, identificados e quantificados. M. curema foi parasitado por vários crustáceosectoparasitos: caligídeos: Caligus bonito e Caligus sp.; ergasilídeos: Ergasilus versicolor e E. lizae; e isópode Cymothoa spinipalpa. Dos caligídeos detectados 66,66% foi de C. bonito e 33,33% de Caligus sp. Caligus bonito ocorreu somente nos machos de M. curema durante a estação seca e Caligus sp

  13. THE ACTUAL IMPLICATIONS OF INFLATION

    Directory of Open Access Journals (Sweden)

    Murăriţa Ilie

    2011-12-01

    Full Text Available The authors have started from the idea that inflationary phenomenon is a companion, the cause and the effect of the globalization of poverty in the broader context of world economy globalization. Therefore, starting from a common definition of inflation, the first objective was to identify causal relationships that singularize contemporary inflationary process. After that, attention was focused on the implications of inflation in the current stage, bearing in mind that monetary financial theory and practice are operating with perfectly anticipated inflation or imperfectly anticipated inflation. Inflation has great implications on the long-term contracts and wage contracts.

  14. Positive Implicative Ideals of BCK-Algebras Based on Intersectional Soft Sets

    Directory of Open Access Journals (Sweden)

    Eun Hwan Roh

    2013-01-01

    Full Text Available The aim of this paper is to lay a foundation for providing a soft algebraic tool in considering many problems that contain uncertainties. In order to provide these soft algebraic structures, the notion of int-soft positive implicative ideals is introduced, and related properties are investigated. Relations between an int-soft ideal and an int-soft positive implicative ideal are established. Characterizations of an int-soft positive implicative ideal are obtained. Extension property for an int-soft positive implicative ideal is constructed. The ∧-product and ∨-product of int-soft positive implicative ideals are considered, and the soft intersection (resp., union of int-soft positive implicative ideals is discussed.

  15. Epigenetics: ambiguities and implications.

    Science.gov (United States)

    Stotz, Karola; Griffiths, Paul

    2016-12-01

    Everyone has heard of 'epigenetics', but the term means different things to different researchers. Four important contemporary meanings are outlined in this paper. Epigenetics in its various senses has implications for development, heredity, and evolution, and also for medicine. Concerning development, it cements the vision of a reactive genome strongly coupled to its environment. Concerning heredity, both narrowly epigenetic and broader 'exogenetic' systems of inheritance play important roles in the construction of phenotypes. A thoroughly epigenetic model of development and evolution was Waddington's aim when he introduced the term 'epigenetics' in the 1940s, but it has taken the modern development of molecular epigenetics to realize this aim. In the final sections of the paper we briefly outline some further implications of epigenetics for medicine and for the nature/nurture debate.

  16. Surface metal adsorption on zooplankton carapaces: implications for exposure and effects in consumer organisms

    International Nuclear Information System (INIS)

    Robinson, K.A.; Baird, D.J.; Wrona, F.J.

    2003-01-01

    Metals adsorbed to prey surfaces may be a mechanism of exposure in predators. - The current study aimed to determine the potential of two important aquatic invertebrate crustacean species, Daphnia magna and Ceriodaphnia dubia, to adsorb cadmium on to their carapaces from aqueous solution. Using the Langmuir equation to model data outputs, it was shown that cadmium readily became associated with the carapace surfaces of both species, with uptake being dependent on exposure time and concentration. Maximum carapace-adsorption potential was found to be directly related to surface area, so that at predicted carapace saturation, D. magna neonates bound approximately five times more cadmium than the smaller C. dubia neonates. However, adsorption per unit surface area was found to be similar under the same exposure conditions. Results of surface metal adsorption studies in C. dubia suggested that short term exposures to high concentrations of aqueous cadmium would lead to similar levels of adsorption as obtained with long-term exposures to low concentrations. The study illustrates that contaminants adsorbed to prey surfaces may be an important mechanism of exposure to predators, and highlights some potential problems of feeding organisms during long-term toxicity tests

  17. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    Directory of Open Access Journals (Sweden)

    Pablo Mayorga

    2010-12-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.Três bioensaios de letalidade com o crustáceo de água salgada Artemia salina Leach, Artemiidae, (teste convencional em microplaca de 96 poós Artoxkit microbiotest M e o crustáceo de água doce Thamnocephalus platyurus Packard, Thamnocephalidae (Thamnotoxkit microbiotest F, foram comparados utilizando extratos de dez espécies de plantas da Guatemala. Foi previamente observado que cinco delas possuem atividade anti

  18. Industrial implications of hydrogen

    International Nuclear Information System (INIS)

    Pressouyre, G.M.

    1982-01-01

    Two major industrial implications of hydrogen are examined: problems related to the effect of hydrogen on materials properties (hydrogen embrittlement), and problems related to the use and production of hydrogen as a future energy vector [fr

  19. Implications of U.S. electricity deregulation

    International Nuclear Information System (INIS)

    Gottfried, D.A.

    1997-01-01

    This article is a concise summary of the potential impacts of electric utility deregulation, including the resolution of stranded costs, impact on electricity rates, reformation of utilities, and reshuffling of the nation's fuel portfolio. The national and state implications of the deregulation of the electricity industry are monumental and overwhelming. The implications occur on many fronts, including monetary, quality, reliability, and environmental issues. Many significant changes will occur as a result--some will be positive and others may be more disturbing

  20. Expression of collier in the premandibular segment of myriapods: support for the traditional Atelocerata concept or a case of convergence?

    Directory of Open Access Journals (Sweden)

    Budd Graham E

    2011-02-01

    Full Text Available Abstract Background A recent study on expression and function of the ortholog of the Drosophila collier (col gene in various arthropods including insects, crustaceans and chelicerates suggested a de novo function of col in the development of the appendage-less intercalary segment of insects. However, this assumption was made on the background of the now widely-accepted Pancrustacea hypothesis that hexapods represent an in-group of the crustaceans. It was therefore assumed that the expression of col in myriapods would reflect the ancestral state like in crustaceans and chelicerates, i.e. absence from the premandibular/intercalary segment and hence no function in its formation. Results We find that col in myriapods is expressed at early developmental stages in the same anterior domain in the head, the parasegment 0, as in insects. Comparable early expression of col is not present in the anterior head of an onychophoran that serves as an out-group species closely related to the arthropods. Conclusions Our findings suggest either that i the function of col in head development has been conserved between insects and myriapods, and that these two classes of arthropods may be closely related supporting the traditional Atelocerata (or Tracheata hypothesis; or ii alternatively col function could have been lost in early head development in crustaceans, or may indeed have evolved convergently in insects and myriapods.

  1. Green synthesis approach: extraction of chitosan from fungus mycelia.

    Science.gov (United States)

    Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur; Verma, Mausam

    2013-12-01

    Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields.

  2. On two reports associated with James Wood-Mason and Alfred William Alcock published by the Indian Museum and the Indian Marine Survey between 1890 and 1891: implications for malacostracan nomenclature.

    Science.gov (United States)

    Huys, Rony; Low, Martyn E Y; De Grave, Sammy; Ng, Peter K L; Clark, Paul F

    2014-01-29

    conclusively attributable to a specific author, it is considered to be written anonymously and should therefore be cited as Anonymous (1891). A number of names in Appendix No. XIII are available since they are accompanied by a brief description of the taxa they denote, and are either attributable to James Wood-Mason or remain with anonymous authorship; others are nomina nuda without a diagnosis or indication, or have been diagnosed previously in the "Natural History Notes from H.M. Indian Marine Survey Steamer Investigator". The nomenclatural implications for eight names made available in Anonymous (1891) are discussed: Glyphocrangon caeca, Glyphocrangon sculptus var. coecescens, Psalidopodidae, Psalidopus, Psalidopus mirabilis, Psathyrocaris, Psathyrocaris fragilis and Psopheticus crepitans. The nomenclatural history of various other taxa, initially denoted by unavailable names in Anonymous (1891), is also documented. The authorships of the various crustacean taxa collected by the Indian Marine Survey Steamer Investigator during the seasons 1889-1890 and 1890-1891, and published in two series of connected parts in the Annals and Magazine of Natural History, are also re-assessed and summarised. A rare document containing the list of R.I.M.S. Investigator stations for the period 1884-1913 is reproduced for the future benefit of the scientific community. 

  3. Radiological implications from the temporal development of radioactivity in marine food from the North Sea

    International Nuclear Information System (INIS)

    Kanisch, G.; Nagel, G.; Krueger, A.; Kellermann, H.-J.

    2000-01-01

    A subject of the revision of authorised limits in 1994 for the discharge of liquid radioactive waste by the reprocessing plant Sellafield (UK) was an increase of these limits for certain radionuclides ( 3 H, 14 C, 60 Co, 99 Tc and 129 I). It is investigated now how the radioactivity in marine biota from the North Sea and subsequently the public radiation exposure of seafood consumers has developed in the years since 1994. This is based on a compartment model for dispersion in the North-East Atlantic. Discharges from the reprocessing plants Dounreay (UK) and La Hague (F) are included in the assessment. It is deduced that about 60% of 137 Cs in the North Sea originate presently in the remobilisation of old Sellafield discharges from the Irish Sea sediment. A comparison with measured biota data shows that the model is conservative in most cases. The public radiation exposure (artificial radionuclides) from ingestion of fish, crustaceans and molluscs from the central North Sea as the sum over 12 considered radionuclides has decreased from 1992 to 1998 from 0.13 to 0.08 μSv y -1 . (orig.)

  4. A Note on One Less Known Class of Generated Residual Implications

    Directory of Open Access Journals (Sweden)

    Vojtěch Havlena

    2016-12-01

    Full Text Available This paper builds on our contribution [Havlena and Hlinena, 2016] which studied modelling of the conjunction in human language. We have discussed three different ways of constructing conjunction. We have dealt with generated t-norms, generated means and Choquet integral. In this paper we construct the residual operators based on the above conjunctions. The only operator based on a t-norm is an implication. We show that this implication belongs to the class of generated implications I^g_N which was introduced in [Smutna, 1999] and studied in [Biba and Hlinena, 2012]. We study its properties. More, we investigate this class of generated implications. Some important properties, including relations between some classes of implications, are given.

  5. Psoriasis : implications of biologics

    NARCIS (Netherlands)

    Lecluse, L.L.A.

    2010-01-01

    Since the end of 2004 several specific immunomodulating therapies: ‘biologic response modifiers’ or ‘biologics’ have been registered for moderate to severe psoriasis in Europe. This thesis is considering the implications of the introduction of the biologics for psoriasis patients, focusing on safety

  6. Concentrations of polycyclic aromatic hydrocarbons in four species of bottom dwelling fish and two species of crustaceans from the Estuary and Gulf of Saint-Lawrence and from the Saguenay fjord; Concentrations d`hydrocarbures aromatiques polycycliques chez quatre especes de poissons de fond et deux especes de crustaces de l`estuaire et du golfe du Saint-Laurent et du fjord du Saguenay

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, E.; Canuel, G.; Padros, J.; Clermont, Y. [Quebec Univ., INRS-Oceanologie, Rimouski, PQ (Canada); Gobeil, C. [Fisheries and Oceans Canada, Mont-Joli, PQ (Canada). Maurice Lamontagne Inst.

    1999-08-01

    An update was presented on the levels of polycyclic aromatic hydrocarbon (PAH) contamination in bottom dwelling fish and crustaceans in the Gulf of St. Lawrence and the Saguenay fjord. Attempts were made to detect specific compounds including fluoranthene, pyrene, benzo-b-fluoranthene, benzo-k-fluoranthene, benzo-a-pyrene, dibenzo-a,h-anthracene, benzo-g,h,i-perylene, naphtalene, acenaphtene, fluorene, phenanthrene, and anthracene. Concentrations of all PAHs in the muscle tissue of cod, plaice, skate and halibut were found to be below analytical detection limits. Concentrations of most PAHs were also below detection limits in halibut liver tissue and crab. The exception was benzo-a-anthracene. Shrimp muscle contained measurable levels of many PAHs. The levels were detected by fluorimetry but could not be confirmed by mass spectroscopy. Based on these results, it was concluded that the fish can be considered safe for human consumption. 3 refs., 13 tabs., 1 fig.

  7. From Blood to Brain: Adult-Born Neurons in the Crayfish Brain Are the Progeny of Cells Generated by the Immune System

    Directory of Open Access Journals (Sweden)

    Barbara S. Beltz

    2017-12-01

    Full Text Available New neurons continue to be born and integrated into the brains of adult decapod crustaceans. Evidence in crayfish indicates that the 1st-generation neural precursors that generate these adult-born neurons originate in the immune system and travel to the neurogenic niche via the circulatory system. These precursors are attracted to the niche, become integrated amongst niche cells, and undergo mitosis within a few days; both daughters of this division migrate away from the niche toward the brain clusters where they will divide again and differentiate into neurons. In the crustacean brain, the rate of neuronal production is highly sensitive to serotonin (5-hydroxytryptamine, 5-HT levels. These effects are lineage-dependent, as serotonin's influence is limited to late 2nd-generation neural precursors and their progeny. Experiments indicate that serotonin regulates adult neurogenesis in the crustacean brain by multiple mechanisms: via direct effects of serotonin released from brain neurons into the hemolymph or by local release onto target cells, or by indirect influences via a serotonin-mediated release of agents from other regions, such as hormones from the sinus gland and cytokines from hematopoietic tissues. Evidence in crayfish also indicates that serotonin mediates the attraction of neural precursors generated by the immune system to the neurogenic niche. Thus, studies in the crustacean brain have revealed multiple roles for this monoamine in adult neurogenesis, and identified several pathways by which serotonin influences the generation of new neurons.

  8. Global cooling as a driver of diversification in a major marine clade

    Science.gov (United States)

    Davis, Katie E.; Hill, Jon; Astrop, Tim I.; Wills, Matthew A.

    2016-10-01

    Climate is a strong driver of global diversity and will become increasingly important as human influences drive temperature changes at unprecedented rates. Here we investigate diversification and speciation trends within a diverse group of aquatic crustaceans, the Anomura. We use a phylogenetic framework to demonstrate that speciation rate is correlated with global cooling across the entire tree, in contrast to previous studies. Additionally, we find that marine clades continue to show evidence of increased speciation rates with cooler global temperatures, while the single freshwater clade shows the opposite trend with speciation rates positively correlated to global warming. Our findings suggest that both global cooling and warming lead to diversification and that habitat plays a role in the responses of species to climate change. These results have important implications for our understanding of how extant biota respond to ongoing climate change and are of particular importance for conservation planning of marine ecosystems.

  9. Strategic Implications of Global Health

    National Research Council Canada - National Science Library

    Monaghan, Karen

    2008-01-01

    "Strategic Implications of Global Health" responds to a request from the Undersecretary of State for Democratization and Global Affairs for an intelligence assessment on the connections between health and U.S. national interests...

  10. Paradoxical implications of personal social media use for work

    NARCIS (Netherlands)

    van Zoonen, W.; Rice, R.E.

    2017-01-01

    New information and communication technologies can have paradoxical implications: they may be liberating and constraining at the same time. This field study examines the direct implications of personal social media use for work on employees’ autonomy and work pressure, and the indirect effects on

  11. Motivation and Gifted Students: Implications of Theory and Research

    Science.gov (United States)

    Clinkenbeard, Pamela R.

    2012-01-01

    An analysis of contemporary motivation theories reveals implications for gifted and talented students. The expectancy-value framework, intrinsic-extrinsic motivation theories, goal orientations, self-efficacy and other self-perceptions, and attribution theory are described and discussed with respect to implications for the psychology and education…

  12. The Technological Society: Implications for Women in the Workplace.

    Science.gov (United States)

    Cianni, Mary; Weitz, Anna D.

    1986-01-01

    Although increased technology is altering the nature of work, familiar barriers continue to exist for women. Examines the equity of access to technology, the career implications for those employed at home, and the realities of newly promised occupational opportunities. Implications for counselors are discussed. (Author/BL)

  13. Uranium ore deposits: geology and processing implications

    International Nuclear Information System (INIS)

    Belyk, C.L.

    2010-01-01

    There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique set of geological characteristics which may also result in unique processing implications. Primary uranium production in the past decade has predominantly come from only a few of these deposit types including: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic ones. Processing implications can vary widely between and within the different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy, ore hardness, porosity, uranium mineral morphology and carbon content. Processing difficulties may occur as a result of one or more of these characteristics. In order to meet future uranium demand, it is imperative that innovative processing approaches and new technological advances be developed in order that many of the marginally economic traditional and uneconomic non-traditional uranium ore deposits can be exploited. (author)

  14. Effects of the pyrethroid insecticide, cypermethrin, on a freshwater community studied under field conditions. I. Direct and indirect effects on abundance measures of organisms at different trophic levels

    Energy Technology Data Exchange (ETDEWEB)

    Friberg-Jensen, Ursula; Wendt-Rasch, Lina; Woin, Per; Christoffersen, Kirsten

    2003-05-29

    The effects of the pyrethroid insecticide cypermethrin on a natural freshwater community were studied in small in situ enclosures over an 11-day period. The experiment was conducted in a eutrophic lake using a regression design that included three untreated controls and a gradient of six unreplicated cypermethrin concentrations, ranging from 0.01 to 6.1 {mu}g/l. This paper is the first in a series of two, and describes the fate of cypermethrin and its effects on the abundance of crustaceans, rotifers, protozoans (cilliates and heterotrophic nanoflagellates (HNF)) and bacteria and the biomass of periphytic and planktonic algae. The concentration of cypermethrin decreased quickly during the experiment, with a half-life of 48 h for the total and 25 h for the dissolved fractions of cypermethrin, respectively. Cypermethrin proved to be acutely toxic to crustaceans in enclosures receiving nominal cypermethrin concentrations of {>=}0.13 {mu}g/l. No Effect Concentration (NEC) and median Effect Concentration (EC{sub 50}) for the total crustacean community and cladoceran and copepod subgroups ranged between 0.02-0.07 and 0.04-0.17 {mu}g/l, respectively, with copepods being less sensitive than cladocerans. The abundance of rotifers, protozoans and bacteria and the chlorophyll-a concentration of planktonic and periphytic algae was significantly related to the concentration of cypermethrin. All groups proliferated within 2-7 days after the cypermethrin application in those enclosures where the abundance of crustaceans was seriously affected by cypermethrin (i.e. {>=}0.13 {mu}g/l). We hypothesise that the proliferation of rotifers, protozoans, bacteria and algae was due to a reduced grazer control from crustaceans and thereby mediated indirectly by cypermethrin. The results of this experiment provide knowledge on how an entire microplankton community may respond to pyrethroids in nature, and the indirect effects observed on the community clearly demonstrates the necessity of

  15. Effects of the pyrethroid insecticide, cypermethrin, on a freshwater community studied under field conditions. I. Direct and indirect effects on abundance measures of organisms at different trophic levels

    International Nuclear Information System (INIS)

    Friberg-Jensen, Ursula; Wendt-Rasch, Lina; Woin, Per; Christoffersen, Kirsten

    2003-01-01

    The effects of the pyrethroid insecticide cypermethrin on a natural freshwater community were studied in small in situ enclosures over an 11-day period. The experiment was conducted in a eutrophic lake using a regression design that included three untreated controls and a gradient of six unreplicated cypermethrin concentrations, ranging from 0.01 to 6.1 μg/l. This paper is the first in a series of two, and describes the fate of cypermethrin and its effects on the abundance of crustaceans, rotifers, protozoans (cilliates and heterotrophic nanoflagellates (HNF)) and bacteria and the biomass of periphytic and planktonic algae. The concentration of cypermethrin decreased quickly during the experiment, with a half-life of 48 h for the total and 25 h for the dissolved fractions of cypermethrin, respectively. Cypermethrin proved to be acutely toxic to crustaceans in enclosures receiving nominal cypermethrin concentrations of ≥0.13 μg/l. No Effect Concentration (NEC) and median Effect Concentration (EC 50 ) for the total crustacean community and cladoceran and copepod subgroups ranged between 0.02-0.07 and 0.04-0.17 μg/l, respectively, with copepods being less sensitive than cladocerans. The abundance of rotifers, protozoans and bacteria and the chlorophyll-a concentration of planktonic and periphytic algae was significantly related to the concentration of cypermethrin. All groups proliferated within 2-7 days after the cypermethrin application in those enclosures where the abundance of crustaceans was seriously affected by cypermethrin (i.e. ≥0.13 μg/l). We hypothesise that the proliferation of rotifers, protozoans, bacteria and algae was due to a reduced grazer control from crustaceans and thereby mediated indirectly by cypermethrin. The results of this experiment provide knowledge on how an entire microplankton community may respond to pyrethroids in nature, and the indirect effects observed on the community clearly demonstrates the necessity of multispecies

  16. Stem cell terminology: practical, theological and ethical implications.

    Science.gov (United States)

    Shanner, Laura

    2002-01-01

    Stem cell policy discussions frequently confuse embryonic and fetal sources of stem cells, and label untested, non-reproductive cloning as "therapeutic." Such misnomers distract attention from significant practical and ethical implications: accelerated research agendas tend to be supported at the expense of physical risks to women, theological implications in a multi-faith community, informed consent for participation in research, and treatment decisions altered by unrealistic expectations.

  17. Structuralism and Its Heuristic Implications.

    Science.gov (United States)

    Greene, Ruth M.

    1984-01-01

    The author defines structuralism (a method for modeling and analyzing event systems in a space-time framework), traces its origins to the work of J. Piaget and M. Fourcault, and discusses its implications for learning. (CL)

  18. The SANE Research Project: Its Implications for Higher Education.

    Science.gov (United States)

    Harrison, Andrew; Dugdale, Shirley

    2003-01-01

    Describes a 2-year research program called Sustainable Accommodation for the New Economy (SANE), which is exploring the implications of the distributed workplace. Its focus is on the creation of sustainable, collaborative workplaces for knowledge workers across Europe, encompassing both virtual and physical spaces. Discusses its implications for…

  19. Rubella Deaf-Blind Child: Implications of Psychological Assessment. Proceedings.

    Science.gov (United States)

    Rouin, Carole

    Presented are proceedings of a conference involving authorities in testing and evaluating the blind, deaf, and deaf-blind. In a paper titled "Psychological Implications of Assessing the Deaf", C. Goetzinger discusses references used in audiology, anatomy and physiology of the ear, degrees of hearing impairment, and implications of the various…

  20. Acid Mucopolysaccharide of the Crustacean Cuticle.

    Science.gov (United States)

    Meenakshi, V R; Scheer, B T

    1959-10-30

    The acid mucopolysaccharide found in the crab Hemigrapsus nudus and containing glucose, galactose, and fucose residues is found both in the cuticle and in the digestive gland of the crab. The concentration of mucopolysaccharide is somewhat higher in the cuticle, where it it the only soluble polysaccharide, than in the digestive gland, where it makes up 10 to 25 percent of the total polysaccharide content.

  1. The protozoan associates of some crustaceans

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.; Gopalan, U.K.

    produced by high turbidity and low oxygen tension in the infested tanaidacean were carried out. Most of the infested tanaidaceans were found dead, showing the potentially harmful nature of this ciliate...

  2. Physician-Rating Web Sites: Ethical Implications.

    Science.gov (United States)

    Samora, Julie Balch; Lifchez, Scott D; Blazar, Philip E

    2016-01-01

    To understand the ethical and professional implications of physician behavior changes secondary to online physician-rating Web sites (PRWs). The American Society for Surgery of the Hand (ASSH) Ethics and Professionalism Committee surveyed the ASSH membership regarding PRWs. We sent a 14-item questionnaire to 2,664 active ASSH members who practice in both private and academic settings in the United States. We received 312 responses, a 12% response incidence. More than 65% of the respondents had a slightly or highly unfavorable impression of these Web sites. Only 34% of respondents had ever updated or created a profile for PRWs, although 62% had observed inaccuracies in their profile. Almost 90% of respondents had not made any changes in their practice owing to comments or reviews. One-third of respondents had solicited favorable reviews from patients, and 3% of respondents have paid to improve their ratings. PRWs are going to become more prevalent, and more research is needed to fully understand the implications. There are several ethical implications that PRWs pose to practicing physicians. We contend that it is morally unsound to pay for good reviews. The recourse for physicians when an inaccurate and potentially libelous review has been written is unclear. Some physicians have required patients to sign a waiver preventing them from posting negative comments online. We propose the development of a task force to assess the professional, ethical, and legal implications of PRWs, including working with companies to improve accuracy of information, oversight, and feedback opportunities. It is expected that PRWs will play an increasing role in the future; it is unclear whether there will be a uniform reporting system, or whether these online ratings will influence referral patterns and/or quality improvement. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Kierkegaardian Implications of Punishment, Guilt, and Forgiveness for Education.

    Science.gov (United States)

    Senyshyn, Yaroslav

    1998-01-01

    Explores Soren Kierkegaard's notion of punishment, which should interest educators because it provides a way to avoid the pitfalls of unjust punishment by viewing it in conjunction with the implications of guilt and forgiveness. The paper notes the need to question the notion of punishment closely and seek to understand its implications. (SM)

  4. Feeding ecology of the beach silverside Atherinella blackburni (Atherinopsidae in a tropical sandy beach, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Júlio Guazzelli Gonzalez

    Full Text Available Abstract The feeding ecology of the beach silverside (Atherinella blackburni in the surf zone of a tropical sand beach, located in the southeastern Brazil, was accessed through the gut content analysis of 198 fish. Factors such as fish's size, season and day period were analysed to understand how these variables affect the diet composition of the species. Results show that A. blackburni is a coastal neritic fish with a broad feeding niche. Most recurrent prey were zooplanktonic crustaceans, insects and benthic molluscs, in which Copepoda crustaceans were the dominant dietary item in occurrence and abundance. A. blackburni appears to have a slight ontogenetic shift in its diet, changing from benthic molluscs to crustaceans and insects along its life cycle. The diel activity also reveals to be an important factor to the A. blackburni feeding ecology. The predominant occurrence of small fish during the morning, along with the main preys for this size class, suggests that small individuals use shallower waters as feeding grounds during the morning and, during the night, they move to deeper waters for protection against predators.

  5. [Feeding habits of Lutjanus guttatus (Pisces: Lutjanidae) at Los Cóbanos and Puerto La Libertad, El Salvador].

    Science.gov (United States)

    Rodrigo Rojas, José; Maravilla, Erick; Chicas, Francisco

    2004-03-01

    Abstract: A total of 175 spotted snapper Lutjanus guttatus were collected monthly in the Los Cobanos and Puerto La Libertad, El Salvador, from January to December 2000 to determine its feeding habits. The fishes studied ranged 9.8 - 58.0 cm in total length. Were collected using push-net and hook and line. This snapper is a bentonic opportunistic carnivorous predator. The total biomass of the stomach contents was 260.5 g. Crustaceans (Squillidae, Portunidae, Dynomenidae. Penaeidae, Sicyoniidae, Callianassidae), were the most abundant group: they accounted for 50.4% of the total biomass. Numerically, Portunus asper was the most abundant prey. Ontogenic differences were observed in the diet. In juveniles (16 cm TL). at any time of the year, the most frequent and abundant components were crustaceans and in adults were crustaceans, fishes and mollusks. The relative importance of different components of the diet was assessed with two indexes that combine. in different ways. percentage frequency of occurrence, percentage number and percentage weight of prey categories. The commercial use this resource and the absence of management strategies are discussed.

  6. Poverty and Brain Development in Children: Implications for Learning

    Science.gov (United States)

    Dike, Victor E.

    2017-01-01

    Debates on the effect of poverty on brain development in children and its implications for learning have been raging for decades. Research suggests that poverty affects brain development in children and that the implications for learning are more compelling today given the attention the issue has attracted. For instance, studies in the fields of…

  7. Investigating Variations in Gameplay: Cognitive Implications

    Directory of Open Access Journals (Sweden)

    Kamran Sedig

    2015-01-01

    Full Text Available There is increasing interest in creating computer games for learning, problem solving, and other high-level cognitive activities. When investigating whether gameplay is conducive to such activities, gameplay is often studied as a whole. As a result, cognitive implications can be linked to the game but not to its structural elements. Given that gameplay arises from interaction between the player and the game, it is the structural components of interaction that should be investigated to better understand the design of gameplay. Furthermore, minor variations in the components of interaction can have significant cognitive implications. However, such variation has not been studied yet. Thus, to gain a better understanding of how we can study the effect of interaction on the cognitive aspect of gameplay, we conducted an exploratory investigation of two computer games. These games were isomorphic at a deep level and only had one minor difference in the structure of their interaction. Volunteers played these games and discussed the cognitive processes that emerged. In one game, they primarily engaged in planning, but in the other game they primarily engaged in visualizing. This paper discusses the results of our investigation as well as its implications for the design of computer games.

  8. Shopper marketing implications on communication strategies and actions

    OpenAIRE

    Silveira, Paulo Duarte; Marreiros, Cristina

    2013-01-01

    Comunicação apresentada em 15th IAMB Conference, Lisboa Shopper marketing is an international recent concept and approach to marketing. Since shopper marketing is in the early stages of development, it is also an emerging research field, and consequently questions and challenges acrossall the marketing-mix variables are emerging. This paper addressesshopper marketing implications on one of those variables – communication.Specifically, the purpose of this paper is to study the implications ...

  9. Pacific white shrimp (Litopenaeus vannamei) vitellogenesis-inhibiting hormone (VIH) is predominantly expressed in the brain and negatively regulates hepatopancreatic vitellogenin (VTG) gene expression.

    Science.gov (United States)

    Chen, Ting; Zhang, Lv-Ping; Wong, Nai-Kei; Zhong, Ming; Ren, Chun-Hua; Hu, Chao-Qun

    2014-03-01

    Ovarian maturation in crustaceans is temporally orchestrated by two processes: oogenesis and vitellogenesis. The peptide hormone vitellogenesis-inhibiting hormone (VIH), by far the most potent negative regulator of crustacean reproduction known, critically modulates crustacean ovarian maturation by suppressing vitellogenin (VTG) synthesis. In this study, cDNA encoding VIH was cloned from the eyestalk of Pacific white shrimp, Litopenaeus vannamei, a highly significant commercial culture species. Phylogenetic analysis suggests that L. vannamei VIH (lvVIH) can be classified as a member of the type II crustacean hyperglycemic hormone family. Northern blot and RT-PCR results reveal that both the brain and eyestalk were the major sources for lvVIH mRNA expression. In in vitro experiments on primary culture of shrimp hepatopancreatic cells, it was confirmed that some endogenous inhibitory factors existed in L. vannamei hemolymph, brain, and eyestalk that suppressed hepatopancreatic VTG gene expression. Purified recombinant lvVIH protein was effective in inhibiting VTG mRNA expression in both in vitro primary hepatopancreatic cell culture and in vivo injection experiments. Injection of recombinant VIH could also reverse ovarian growth induced by eyestalk ablation. Furthermore, unilateral eyestalk ablation reduced the mRNA level of lvVIH in the brain but not in the remaining contralateral eyestalk. Our study, as a whole, provides new insights on VIH regulation of shrimp reproduction: 1) the brain and eyestalk are both important sites of VIH expression and therefore possible coregulators of hepatopancreatic VTG mRNA expression and 2) eyestalk ablation could increase hepatopancreatic VTG expression by transcriptionally abolishing eyestalk-derived VIH and diminishing brain-derived VIH.

  10. MARITIME VIOLENCE : IMPLICATIONS TO MALAYSIA

    Directory of Open Access Journals (Sweden)

    Nurulizwan Ahmad Zubir

    2014-04-01

    Full Text Available Abstract Maritime Piracy has been a serious threat to the international community especially in the SoutheastAsia region. This threat has caused tremendous implications towards the world economy, environment,political stability of the nations involved because 45% of the shipping company passes through theSoutheast Asia. The worrying fact is that these attacks were committed by terrorists as well as traditionalmaritime pirates. This paper examines on the implications of maritime crime in Malaysia and discusseswhether the definition of piracy under the International Law could be applied to these attacks. Thispaper concludes that cooperation between the region’s states and the enhancement of a good securitysystem of one state are needed to combat maritime violence. Thus it is imperative that the internationallaw need to be changed in order to enhance the meaning of piracy and also to include sea terrorism. Key words: piracy, maritime, terrorist

  11. Postgraduate diploma collaborative assignment: Implications for ...

    African Journals Online (AJOL)

    Postgraduate diploma collaborative assignment: Implications for ESL students ... and collaborative teaching/learning model involving the major course convenors. ... The quality of the work and mood of all concerned improved tremendously.

  12. The economic implications of carbon cycle uncertainty

    International Nuclear Information System (INIS)

    Smith, Steven J.; Edmonds, James A.

    2006-01-01

    This paper examines the implications of uncertainty in the carbon cycle for the cost of stabilizing carbon dioxide concentrations. Using a state of the art integrated assessment model, we find that uncertainty in our understanding of the carbon cycle has significant implications for the costs of a climate stabilization policy, with cost differences denominated in trillions of dollars. Uncertainty in the carbon cycle is equivalent to a change in concentration target of up to 100 ppmv. The impact of carbon cycle uncertainties are smaller than those for climate sensitivity, and broadly comparable to the effect of uncertainty in technology availability

  13. Implications of SNOMED CT versioning

    NARCIS (Netherlands)

    Lee, Dennis; Cornet, Ronald; Lau, Francis

    2011-01-01

    To determine the changes each Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) release undergoes and the implications of those changes. (1) We reviewed the SNOMED CT Component History documentation and analyzed the Component History table in detail. (2) We outlined a list of semantic

  14. Cosmological implications of grand unified theories

    International Nuclear Information System (INIS)

    Nanopoulos, D.V.

    1982-01-01

    These lectures, mainly devoted to the cosmological implications of GUTs, also include the essential ingredients of GUTs and some of their important applications to particle physics. Section 1 contains some basic points concerning the structure of the standard strong and electroweak interactions prior to grand unification. A detailed expose of GUTs is attempted in sect. 2, including their basci principles and their consequences for particle physics. The minimal, simplest GUT, SU 5 is analysed in some detail and it will be used throughout these lectures as the GUT prototype. Finally, sect. 3 contains the most important cosmological implications of GUTs, including baryon number generation in the early Universe (in rather lengthy detail), dissipative processes in the very early Universe, grand unified monopoles, etc. (orig./HSI)

  15. Deep-ocean disposal of high-activity nuclear wastes: a conservative assessment of the seafood critical pathway

    International Nuclear Information System (INIS)

    Baxter, M.S.; Economides, B.

    1984-01-01

    This paper applies conventional 'worst-case' assumptions to modelling the effects of possible future disposal of high-activity wastes in the oceans. It otherwise uses previously published and generally accepted data to assess the possible intakes of the waste nuclides via consumption of seaweeds, molluscs, crustaceans, plankton and fish. Model-predicted intakes for critical groups generally exceed ICRP-recommended limits, with 244 Cm, 241 Am and 137 Cs being the most potentially hazardous nuclides. The various seafood consumption pathways are found to rank, in decreasing order of potential hazard, as seaweeds > molluscs > plankton > fish > crustaceans. (Auth.)

  16. Zooplankton grazing in a eutrophic lake: implications of diel vertical migration

    International Nuclear Information System (INIS)

    Lampert, W.; Taylor, B.E.

    1985-01-01

    During summer and fall, depth profiles of zooplankton community grazing were determined in situ during day and night in the Schoehsee, a small eutrophic lake. Labeled algae of two different sizes were mixed with the natural suspension of phytoplankton in a grazing chamber. A small blue-green alga (Synechococcus, 1 μm) was labeled with 32 P; a larger green alga (Scenedesmus, 4-15 μm) was labeled with 14 C. During summer, grazing in the upper 5 m was negligible during day but strong at night. Hence, algae grow relatively unimpeded by grazing during daytime but are harvested at night. Vertical and diel differences in grazing rates disappeared when the vertical migration ceased in fall. Selectivity of grazing was controlled by the zooplankton species composition. Eudiaptomus showed a strong preference for Scenedesmus. Daphnia showed a slight preference for Scenedesmus, but Ceriodaphnia preferred Synechococcus. Cyclopoid copepodites did not ingest the small blue-green. Because Daphnia and Eudiaptomus were dominant, grazing rates on larger cells were usually higher than grazing rates on the small cells. Negative electivity indices for scenedesmus occurred only when the biomass of large crustaceans was extremely low (near the surface, during day). Zooplankton biomass was the main factor controlling both vertical and seasonal variations in grazing. Highest grazing rates (65%/d) were measured during fall when zooplankton abundance was high. Because differential losses can produce substantial errors in the results, it was necessary to process the samples on the boat immediately after collection, without preservation

  17. Effect of magnetic pulses on Caribbean spiny lobsters: implications for magnetoreception.

    Science.gov (United States)

    Ernst, David A; Lohmann, Kenneth J

    2016-06-15

    The Caribbean spiny lobster, Panulirus argus, is a migratory crustacean that uses Earth's magnetic field as a navigational cue, but how these lobsters detect magnetic fields is not known. Magnetic material thought to be magnetite has previously been detected in spiny lobsters, but its role in magnetoreception, if any, remains unclear. As a first step toward investigating whether lobsters might have magnetite-based magnetoreceptors, we subjected lobsters to strong, pulsed magnetic fields capable of reversing the magnetic dipole moment of biogenic magnetite crystals. Lobsters were subjected to a single pulse directed from posterior to anterior and either: (1) parallel to the horizontal component of the geomagnetic field (i.e. toward magnetic north); or (2) antiparallel to the horizontal field (i.e. toward magnetic south). An additional control group was handled but not subjected to a magnetic pulse. After treatment, each lobster was tethered in a water-filled arena located within 200 m of the capture location and allowed to walk in any direction. Control lobsters walked in seemingly random directions and were not significantly oriented as a group. In contrast, the two groups exposed to pulsed fields were significantly oriented in approximately opposite directions. Lobsters subjected to a magnetic pulse applied parallel to the geomagnetic horizontal component walked westward; those subjected to a pulse directed antiparallel to the geomagnetic horizontal component oriented approximately northeast. The finding that a magnetic pulse alters subsequent orientation behavior is consistent with the hypothesis that magnetoreception in spiny lobsters is based at least partly on magnetite-based magnetoreceptors. © 2016. Published by The Company of Biologists Ltd.

  18. Water fleas require microbiota for survival, growth and reproduction.

    Science.gov (United States)

    Sison-Mangus, Marilou P; Mushegian, Alexandra A; Ebert, Dieter

    2015-01-01

    Microbiota have diverse roles in the functioning of their hosts; experiments using model organisms have enabled investigations into these functions. In the model crustacean Daphnia, little knowledge exists about the effect of microbiota on host well being. We assessed the effect of microbiota on Daphnia magna by experimentally depriving animals of their microbiota and comparing their growth, survival and fecundity to that of their bacteria-bearing counterparts. We tested Daphnia coming from both lab-reared parthenogenetic eggs of a single genotype and from genetically diverse field-collected resting eggs. We showed that bacteria-free hosts are smaller, less fecund and have higher mortality than those with microbiota. We also manipulated the association by exposing bacteria-free Daphnia to a single bacterial strain of Aeromonas sp., and to laboratory environmental bacteria. These experiments further demonstrated that the Daphnia-microbiota system is amenable to manipulation under various experimental conditions. The results of this study have implications for studies of D. magna in ecotoxicology, ecology and environmental genomics.

  19. Astrophysical implications of periodicity

    International Nuclear Information System (INIS)

    Muller, R.A.

    1988-01-01

    Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed

  20. Military Implications of Global Warming.

    Science.gov (United States)

    1999-05-20

    U.S. environmental issues also have important global implications. This paper analyzes current U.S. Policy as it pertains to global warming and climate...for military involvement to reduce global warming . Global warming and other environmental issues are important to the U.S. military. As the United

  1. Cosmological implications of Heisenberg's principle

    CERN Document Server

    Gonzalo, Julio A

    2015-01-01

    The aim of this book is to analyze the all important implications of Heisenberg's Uncertainty Principle for a finite universe with very large mass-energy content such as ours. The earlier and main contributors to the formulation of Quantum Mechanics are briefly reviewed regarding the formulation of Heisenberg's Principle. After discussing “indeterminacy” versus ”uncertainty”, the universal constants of physics are reviewed and Planck's units are given. Next, a novel set of units, Heisenberg–Lemaitre units, are defined in terms of the large finite mass of the universe. With the help of Heisenberg's principle, the time evolution of the finite zero-point energy for the universe is investigated quantitatively. Next, taking advantage of the rigorous solutions of Einstein's cosmological equation for a flat, open and mixed universe of finite mass, the most recent and accurate data on the “age” (to) and the expansion rate (Ho) of the universe and their implications are reconsidered.

  2. Safety implications of control systems

    International Nuclear Information System (INIS)

    Smith, O.L.

    1983-01-01

    The Safety Implications of Control Systems Program has three major activities in support of USI-A47. The first task is a failure mode and effects analysis of all plant systems which may potentially induce control system disturbance that have safety implications. This task has made a preliminary study of overfill events and recommended cases for further analysis on the hybrid simulator. Work continues on overcooling and undercooling. A detailed investigation of electric power network is in progress. LERs are providing guidance on important failure modes that will provide initial conditions for further simulator studies. The simulator taks is generating a detailed model of the control system supported by appropriate neutronics, hydraulics, and thermodynamics submodels of all other principal plant components. The simulator is in the last stages of development. Checkout calculations are in progress to establish model stability, robustness, and qualitative credibility. Verification against benchmark codes and plant data will follow

  3. Increasing pressure on freshwater resources due to terrestrial feed ingredients for aquaculture production.

    Science.gov (United States)

    Pahlow, M; van Oel, P R; Mekonnen, M M; Hoekstra, A Y

    2015-12-01

    As aquaculture becomes more important for feeding the growing world population, so too do the required natural resources needed to produce aquaculture feed. While there is potential to replace fish meal and fish oil with terrestrial feed ingredients, it is important to understand both the positive and negative implications of such a development. The use of feed with a large proportion of terrestrial feed may reduce the pressure on fisheries to provide feed for fish, but at the same time it may significantly increase the pressure on freshwater resources, due to water consumption and pollution in crop production for aquafeed. Here the green, blue and gray water footprint of cultured fish and crustaceans related to the production of commercial feed for the year 2008 has been determined for the major farmed species, representing 88% of total fed production. The green, blue and gray production-weighted average feed water footprints of fish and crustaceans fed commercial aquafeed are estimated at 1629 m3/t, 179 m3/t and 166 m3/t, respectively. The estimated global total water footprint of commercial aquafeed was 31-35 km3 in 2008. The top five contributors to the total water footprint of commercial feed are Nile tilapia, Grass carp, Whiteleg shrimp, Common carp and Atlantic salmon, which together have a water footprint of 18.2 km3. An analysis of alternative diets revealed that the replacement of fish meal and fish oil with terrestrial feed ingredients may further increase pressure on freshwater resources. At the same time economic consumptive water productivity may be reduced, especially for carnivorous species. The results of the present study show that, for the aquaculture sector to grow sustainably, freshwater consumption and pollution due to aquafeed need to be taken into account. Copyright © 2015. Published by Elsevier B.V.

  4. Hydrology and water resources in Caspian Sea

    Science.gov (United States)

    Haddadi Moghaddam, Kourosh

    2016-10-01

    Precipitation is the main driver of the water balance variability of the water over space and time, and changes in precipitation have very important implications for hydrology and water resources. Variations in precipitation over daily, seasonal, annual, and decadal time scales influence hydrological variability over time in a catchment. Flood frequency is affected by changes in the year-to-year variability in precipitation and by changes in short-term rainfall properties. Desiccation of the Caspian Sea is one of the world's most serious ecosystem catastrophes. The Persian Sturgeon (Acipenser persicus) caught under 10 m depth using bottom trawl net by research vessel during winter 2012, summer and winter 2013 and spring 2014 in east, central and west of southern parts of Caspian Sea, then, their diets were investigated. During 136 trawling in the aimed seasons, Persian sturgeon with 1 to 2 years old and 179.67 × 0.2 g (body weight) and 29.97 ± 0.4 cm (Total length) captured. Examination of stomach contents in the sturgeon specimens revealed that the food spectrum was composed of bony fishes (Neogobius sp., Atherina sp. and Clupeonella delicatula), invertebrates belonging to the family Ampharetidae polychaeta worms including (Hypanai sp. and Nereis diversicolor), various crustaceans (Gammarus sp. and Paramysis sp.). Investigation on stomach contents of sturgeon Acipenser persicus caught under 10 m depth in 2012 to 2013 surveys showed that there is significant difference in the consumed food. The most food diversity have been observed in winter 2013, also Polychaeta is the primary consumed food and crustacean is the secondary one (P > 0.05), no new types of food (such as bony fishes or benthics) have been observed on food chain of Acipenser persicus and shows no significant difference (P > 0.05).

  5. Theoretical analyses of the refractive implications of transepithelial PRK ablations.

    Science.gov (United States)

    Arba Mosquera, Samuel; Awwad, Shady T

    2013-07-01

    To analyse the refractive implications of single-step, transepithelial photorefractive keratectomy (TransPRK) ablations. A simulation for quantifying the refractive implications of TransPRK ablations has been developed. The simulation includes a simple modelling of corneal epithelial profiles, epithelial ablation profiles as well as refractive ablation profiles, and allows the analytical quantification of the refractive implications of TransPRK in terms of wasted tissue, achieved optical zone (OZ) and induced refractive error. Wasted tissue occurs whenever the actual corneal epithelial profile is thinner than the applied epithelial ablation profile, achieved OZ is reduced whenever the actual corneal epithelial profile is thicker than the applied epithelial ablation profile and additional refractive errors are induced whenever the actual difference centre-to-periphery in the corneal epithelial profile deviates from the difference in the applied epithelial ablation profile. The refractive implications of TransPRK ablations can be quantified using simple theoretical simulations. These implications can be wasted tissue (∼14 µm, if the corneal epithelial profile is thinner than the ablated one), reduced OZ (if the corneal epithelial profile is thicker than ablated one, very severe for low corrections) and additional refractive errors (∼0.66 D, if the centre-to-periphery progression of the corneal epithelial profile deviates from the progression of the ablated one). When TransPRK profiles are applied to normal, not previously treated, non-pathologic corneas, no specific refractive implications associated to the transepithelial profile can be anticipated; TransPRK would provide refractive outcomes equal to those of standard PRK. Adjustments for the planned OZ and, in the event of retreatments, for the target sphere can be easily derived.

  6. American alligator digestion rate of blue crabs and its implications for stomach contents analysis

    Science.gov (United States)

    Nifong, James C.; Rosenblatt, Adam E.; Johnson, Nathan A.; Barichivich, William; Silliman, Brian; Heithaus, Michael R.

    2012-01-01

    Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats

  7. Clinical Ethics Consultation After God: Implications for Advocacy and Neutrality.

    Science.gov (United States)

    Parker, J Clint

    2018-06-01

    In After God: Morality and Bioethics in a Secular Age, H. Tristram Engelhardt, Jr. explores the broad implications for moral reasoning once a culture has lost a God's-eye perspective. In this paper, I focus on the implications of Engelhardt's views for clinical ethics consultation. I begin by examining the question of whether clinical ethics consultants (CECs) should advocate a particular viewpoint and/or process during consultations or adopt a neutral stance. I then examine the implications of Engelhardt's views for this question. Finally, I discuss some of Engelhardt's foundational ontological, metaphysical, meta-ethical, and epistemological commitments and how these commitments connect to his views on clinical ethics consultation.

  8. Gastrointestinal Motility Disorders and Their Clinical Implications in Cirrhosis

    Directory of Open Access Journals (Sweden)

    Eleni Theocharidou

    2017-01-01

    Full Text Available Gastrointestinal motility is impaired in a substantial proportion of patients with cirrhosis. Cirrhosis-related autonomic neuropathy, increased nitric oxide production, and gut hormonal changes have been implicated. Oesophageal dysmotility has been associated with increased frequency of abnormal gastro-oesophageal reflux. Impaired gastric emptying and accommodation may result in early satiety and may have an impact on the nutritional status of these patients. Small intestinal dysmotility might be implicated in small intestinal bacterial overgrowth and increased bacterial translocation. The latter has been implicated in the pathophysiology of hepatic encephalopathy and spontaneous bacterial peritonitis. Enhanced colonic motility is usually associated with the use of lactulose. Pharmacological interventions aiming to alter gastrointestinal motility in cirrhosis could potentially have a beneficial effect reducing the risk of hepatic decompensation and improving prognosis.

  9. Education System Reform in China after 1978: Some Practical Implications

    Science.gov (United States)

    Sun, Miantao

    2010-01-01

    Purpose: This paper aims to provide an overview of education system reform in China since 1978, and its practical implications. Design/methodology/approach: Data were collected from literature review and interview. An overview of education system reform and its practical implications was found through data analysis. Findings: There has been two…

  10. Clinical implications of contemporary gender theory.

    Science.gov (United States)

    Kulish, Nancy

    2010-04-01

    The current intellectual scene in psychoanalysis is marked by vigorous theoretical controversies about gender. The ideas being debated have important implications for clinical work, which have not been thoroughly explicated or integrated into common practice. These implications include the following: gender can accrue idiosyncratic meanings; gender identity is considered fluid and rigidity of gender identity deemed problematic; gender-related conflicts are typically described as divergent; analysis of superego conflicts related to gender becomes particularly important; and, finally, gender-related biases are seen as inevitable and must be taken into account in the clinical situation. A detailed clinical example illustrates the application of these ideas. While the more dramatic cases related to gender have been more frequent subjects of study, conflicts about gender are everyday occurrences for our patients and deserve further attention.

  11. Implication of Information and Communication Technologies for the Internationalisation of Services

    DEFF Research Database (Denmark)

    Henten, Anders; Skouby, Knud Erik

    1997-01-01

    Paper on the implications of ICTs on the internationalisation of services - with an emphasis on factors affecting this development.......Paper on the implications of ICTs on the internationalisation of services - with an emphasis on factors affecting this development....

  12. Public health implications of post-harvest fish handling practices in ...

    African Journals Online (AJOL)

    A wide range of handling practices for harvested fish exists and they have economic as well as public health implications. This paper is a review of the existing problems in fish handling technologies at post-harvest in Nigeria. The public health aspects with the associated implications are highlighted. Status of policy on fish ...

  13. Myasthenia Gravis and Its Aeromedical Implications.

    Science.gov (United States)

    Jagathesan, Tania; O'Brien, Michael D

    2017-01-01

    Myasthenia gravis is an autoimmune condition where antibodies form against the acetylcholine receptors at the neuromuscular junction, eventually causing damage to the motor end plate. The clinical features include muscle fatigability as well as ocular, bulbar, and limb weakness, which can have implications on the role of a pilot or air traffic controller. This retrospective study reviewed the United Kingdom Civil Aviation Authority (UK CAA) experience of myasthenia gravis. A search of the United Kingdom Civil Aviation Authority medical records database from 1990 to 2016 identified 11 individuals with a diagnosis of myasthenia gravis. Data were extracted for the class of medical certificate, age at diagnosis, symptoms, acetylcholine receptor antibody status, treatment, the time from diagnosis to loss of medical certification, and the reasons for loss of certification. There were two Class 1 certificate holders (for professional flying) and six Class 2 certificate holders (for private pilot flying) and three air traffic controllers. The mean and median ages at diagnosis were 53 and 57 yr, respectively, with a range of 28-67 yr. The mean and median intervals from diagnosis to loss of certification were 22 and 11 mo, respectively, with a range of 0 to 108 mo. The aeromedical implications of myasthenia gravis, including complications, types of treatment, and functional impact, are considered. A policy for medical certification following a diagnosis of myasthenia gravis is proposed.Jagathesan T, O'Brien MD. Myasthenia gravis and its aeromedical implications. Aerosp Med Hum Perform. 2017; 88(1):30-33.

  14. Radioecological studies of activation products released from a nuclear power plant into the marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, M.; Mattsson, S.; Holm, E.

    1984-01-01

    The Barseback nuclear power plant, located on the Oresund sound between Denmark and Sweden, consists of two boiling water reactors. The release of radionuclides, mainly activation products, is quite low during normal operation. During the summer, when annual overhaul and partial refuelling take place, the discharge is much higher. Samples of seaweeds and crustaceans collected along the coast were analyzed for radionuclides. Seaweeds (Fucus vesiculosus, F. Serratus, Ascophyllum nodosum and Cladophora glomerata) and crustaceans (Idothea and Gammarus) proved to be excellent bioindicators for radioactive corrosion products released from the nuclear power plant into the marine environment. These bioindicators have been used to map the spatial and temporal distribution of the released radioactivity. The activity has been followed up to 150 km from the power plant, and the decrease in activity concentration in the bioindicators with distance can be expressed by a power function. The variation with time of activity concentration reflects the amount of activity discharged from the power plant, with good resolution in time. The bioindicators exhibit different uptake patterns of the radionuclides detected. The crustacean Idothea showed variations in the Co/sup 60/ activity concentration between winter and summer. 9 references, 12 figures, 2 tables.

  15. Chinese Cultural Implications for ERP Implementation

    Directory of Open Access Journals (Sweden)

    Mukesh Srivastava

    2009-05-01

    Full Text Available Implementation of an enterprise resource planning (ERP system in a global environment can be fragmented due to the internal enterprise culture, which is representative of societal culture. In China, this is especially true due to the nationalistic culture of business. The way ERP systems are perceived, treated, and integrated within the business plays a critical role in the success or failure of the implementation. When a Western developed ERP system is implemented in a country where the culture differs greatly from that of the developer, implementation may require localization in order to be successful. In doing so, strategic benefits of ERP systems may be diminished. This research paper looks into the characteristics of Chinese localization by Western vendors and the implications to the Chinese enterprise. Keywords: ERP, Chinese Cultural Implications, Societal Culture, Strategy

  16. Hypertext, Hypermedia, and Metacognition: Research and Instructional Implications for Disabled Readers.

    Science.gov (United States)

    Balajthy, Ernest

    1990-01-01

    The article examines the potential impact of computer-based text technologies, called hypermedia, on disabled readers. Discussed are hypertext, the hypercard, and implications of metacognitive research (such as author versus user control over text manipulations), instructional implications, and instructional text engineering. (DB)

  17. Implications for Forest Resource Degradation and Deforestation ...

    African Journals Online (AJOL)

    Effects of Socio-Economic Status and Food Consumption Pattern on Household Energy uses: Implications for Forest Resource Degradation and Deforestation around Wondo Genet Catchments, South-Central Ethiopia.

  18. OSHA: Implications for Higher Education.

    Science.gov (United States)

    National Association of College and University Business Officers, Washington, DC.

    Presented in this document are several articles concerning recommendations about the Occupational Safety and Health Act of 1970 (OSHA) and its implications for higher education. It is time for an educated look at facilities and programs and the beginning of plans which, in the long run, will bring colleges and universities into compliance with…

  19. Energy Drinks: Implications for the Breastfeeding Mother.

    Science.gov (United States)

    Thorlton, Janet; Ahmed, Azza; Colby, David A

    2016-01-01

    Breastfeeding women may experience disrupted sleep schedules and be tempted to turn to popular energy drinks to reduce fatigue and enhance alertness, prompting the question: What are the maternal and child health implications for breastfeeding mothers consuming energy drinks? Caffeine and vitamin-rich energy drinks contain a variety of herbal ingredients and vitamins; however, ingredient amounts may not be clearly disclosed on product labels. Interactions between herbal ingredients and caffeine are understudied and not well defined in the literature. Some infants can be sensitive to caffeine and display increased irritability and sleep disturbances when exposed to caffeine from breastmilk. Breastfeeding women who consume energy drinks may be ingesting herbal ingredients that have not undergone scientific evaluation, and if taking prenatal vitamins, may unknowingly exceed the recommended daily intake. Caffeinated products are marketed in newer ways, fueling concerns about health consequences of caffeine exposure. We present implications associated with consumption of caffeine and vitamin-rich energy drinks among breastfeeding women. Product safety, labeling, common ingredients, potential interactions, and clinical implications are discussed. Healthcare providers should encourage breastfeeding women to read product labels for ingredients, carbohydrate content, serving size, and to discourage consumption of energy drinks when breastfeeding and/or taking prenatal vitamins, to avoid potential vitamin toxicity.

  20. Ambiguity and Volatility : Asset Pricing Implications

    NARCIS (Netherlands)

    Pataracchia, B.

    2011-01-01

    Using a simple dynamic consumption-based asset pricing model, this paper explores the implications of a representative investor with smooth ambiguity averse preferences [Klibano¤, Marinacci and Mukerji, Econometrica (2005)] and provides a comparative analysis of risk aversion and ambiguity aversion.

  1. A treaty banning nuclear weapons and its implications for the Netherlands

    NARCIS (Netherlands)

    Güven, O.; van der Meer, S.

    2015-01-01

    International support for a new multilateral treaty banning nuclear weapons is increasing. What implications would such a treaty have for the Netherlands? This policy brief describes the legal and political context of such a treaty and examines the implications of two scenarios: one in which the

  2. Federalism and social justice: implications for social work.

    Science.gov (United States)

    Linhorst, Donald M

    2002-07-01

    Federalism is a system of government that divides power between two or more levels of government. During the current conservative political climate in the United States, power has shifted increasingly from the federal government to states, a move that has implications for the achievement of social justice. Consequently, it is now necessary for social workers to engage in political activity at the state and local levels, in addition to the federal level, to promote social justice. Implications for social work policy practice, research, and education for advancing social justice within the federal system of government are explored.

  3. Climate Change: Generic Implications for Agriculture

    Indian Academy of Sciences (India)

    Climate Change: Generic Implications for Agriculture. Increasing carbon dioxide: Good for most crops. Increase in mean temperature: orter ... Increasing rainfall intensity and dry days- more floods and droughts: Higher production variability. Himalayan glaciers to recede: irrigation in IGP gradually becomes less dependable ...

  4. Practical and Scholarly Implications of Information Behaviour Research: A Pilot Study of Research Literature

    Science.gov (United States)

    Koh, Kyungwon; Rubenstein, Ellen; White, Kelvin

    2015-01-01

    Introduction: This pilot study examined how current information behaviour research addresses the implications and potential impacts of its findings. The goal was to understand what implications and contributions the field has made and how effectively authors communicate implications of their findings. Methods: We conducted a content analysis of 30…

  5. Personal Narratives: Cultural Differences and Clinical Implications

    Science.gov (United States)

    Bliss, Lynn S.; McCabe, Allyssa

    2008-01-01

    A study was conducted to examine the misdiagnosis of cultural difference deficits and how mistaking deficits in narrative production for cultural differences can be avoided. Findings reveal the implications for intervention.

  6. The CHARGE Association: Implications for Teachers.

    Science.gov (United States)

    Jones, Thomas W.; Dunne, Michele T.

    1988-01-01

    CHARGE association is described as a diagnostic label for a group of congenital malformations, including coloboma, heart defects, atresia choanae, retarded postnatal growth/central nervous system defects, genital hypoplasia, and ear deformities. Etiology and characteristics of the CHARGE association are discussed, along with implications for…

  7. Cassava production and consumption: Health implications

    African Journals Online (AJOL)

    Mr A. O. Akinpelu

    HEALTH IMPLICATIONS OF CASSAVA PRODUCTION AND CONSUMPTION. AKINPELU, A.O. ... huge potential for the export market (Egesi et al., 2007). In urban areas ... farmer's/ household income and economic growth. Stakeholders in ..... dissertation submitted to the school of graduate studies in partial fulfilment of the.

  8. Some Implications of Human-Structure Interaction

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2013-01-01

    On structures, humans may be active which may cause structural vibrations as human activity can excite structural vibration modes. However, humans may also be passive (sitting or standing on the structure). The paper addresses this subject and explores the implications of having passive humans...

  9. Evolving Conceptualization of Leadership and Its Implication for Vocational Technical Education

    Science.gov (United States)

    Boateng, Christina

    2012-01-01

    Leadership has been conceptualized variedly in the literature with various implications for those who lead and the people and organizations they lead. In this paper a thorough appraisal of the literature on the evolving conceptualization of leadership and its specific implication for leadership in vocational technical education is presented. A…

  10. Forestry implications of agricultural short-rotation woody crops in the USA

    Science.gov (United States)

    Peter J. Ince; Alexander N. Moiseyev

    2002-01-01

    The purpose of this chapter is to discuss forestry implications of SRWC based on an economic analysis. As with the development of paper recycling, anticipating forestry implications of agricultural SRWC will depend in part on anticipating market conditions and economic impacts of technological developments. This chapter presents an analytic framework and market outlook...

  11. Socio-economic implications of structural changes in plantations in Asian countries.

    OpenAIRE

    Sircar KN; Navamukundan, A; Sajhau JP; Sukarja R

    1985-01-01

    ILO pub. Working paper on the economic implications and social implications of restructuring in plantations in India, Indonesia, Malaysia and Sri Lanka - covers agricultural production, employment, working conditions of plantation workers, wages, management, and public ownership or private ownership of tea, coffee, rubber, etc. Plantations; comments on labour legislation. Bibliography, statistical tables.

  12. A novel homozygous truncating GNAT1 mutation implicated in retinal degeneration.

    LENUS (Irish Health Repository)

    Carrigan, Matthew

    2016-04-01

    The GNAT1 gene encodes the α subunit of the rod transducin protein, a key element in the rod phototransduction cascade. Variants in GNAT1 have been implicated in stationary night-blindness in the past, but unlike other proteins in the same pathway, it has not previously been implicated in retinitis pigmentosa.

  13. Climate Change Communication Research: Trends and Implications ...

    African Journals Online (AJOL)

    Climate Change Communication Research: Trends and Implications. ... African Journal of Sustainable Development ... with a specific focus on the themes that have dominated current studies, major research methods in use, major theories that ...

  14. Business ethics: implications for managed care contracts.

    Science.gov (United States)

    Stahl, D A

    1997-01-01

    Business ethics is a specialized study that emphasizes how moral standards apply to organizations, policies, procedures and behavior. Moral standards must be considered to understand the implications of business ethics in subacute care.

  15. Business development - the function, research propositions, and managerial implications

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe

    and executives from high-tech firms and venture capitalists in North America, Asia, and Europe to provide a foundation for future research. Business development is an emerging staff function providing an added level of sophistication to the firms' overall strategic management with interesting performance...... implications. The business development function is typically found in progressive firms especially within high-tech industries, but is argued to become critical for all types of firms across industries wishing to grow and accumulate wealth. Research propositions and managerial implications are discussed....

  16. Assisted Reproductive Technologies : Implications for Women's ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Assisted Reproductive Technologies : Implications for Women's Reproductive Rights and Social Citizenship. There is a general perception that assisted reproductive technologies (ARTs) affect only a small number of affluent women in India. However, the ART industry - tied as it is to the vigorously pushed medical tourism ...

  17. Changing business environment: implications for farming

    OpenAIRE

    Malcolm, Bill

    2011-01-01

    The natural, technological, economic, political and social environment in which farmers farm constantly changes. History has lessons about change in agriculture and about farmers coping with change, though the future is unknowable and thus always surprising. The implication for farm operation is to prepare, do not predict.

  18. Clinical Implications Of Childhood Bilingualism | Southwood ...

    African Journals Online (AJOL)

    Stellenbosch Papers in Linguistics Plus. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 32 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Clinical Implications Of Childhood Bilingualism.

  19. Exposure Through Runoff and Ground Water Contamination Differentially Impact Behavior and Physiology of Crustaceans in Fluvial Systems.

    Science.gov (United States)

    Steele, Alexandra N; Belanger, Rachelle M; Moore, Paul A

    2018-06-19

    Chemical pollutants enter aquatic systems through numerous pathways (e.g., surface runoff and ground water contamination), thus associating these contaminant sources with varying hydrodynamic environments. The hydrodynamic environment shapes the temporal and spatial distribution of chemical contaminants through turbulent mixing. The differential dispersal of contaminants is not commonly addressed in ecotoxicological studies and may have varying implications for organism health. The purpose of this study is to understand how differing routes of exposure to atrazine alter social behaviors and physiological responses of aquatic organisms. This study used agonistic encounters in crayfish Orconectes virilis as a behavioral assay to investigate impact of sublethal concentrations of atrazine (0, 40, 80, and 160 µg/L) delivered by methods mimicking ground water and surface runoff influx into flow-through exposure arenas for a total of 23 h. Each experimental animal participated in a dyadic fight trial with an unexposed opponent. Fight duration and intensity were analyzed. Experimental crayfish hepatopancreas and abdominal muscle tissue samples were analyzed for cytochrome P450 and acetylcholinesterase levels to discern mechanism of detoxification and mode of action of atrazine. Atrazine delivered via runoff decreased crayfish overall fight intensity and contrastingly ground water delivery increased overall fight intensity. The behavioral differences were mirrored by increases in cytochrome P450 activity, whereas no differences were found in acetylcholinesterase activity. This study demonstrates that method of delivery into fluvial systems has differential effects on both behavior and physiology of organisms and emphasizes the need for the consideration of delivery pathway in ecotoxicological studies and water-impairment standards.

  20. Exploring ethical implications of personal relationships in dyadic business exchanges

    OpenAIRE

    Davidrajuh, Reggie

    2007-01-01

    This paper explores the ethical implications of the existence of personal relationships in business exchanges. Firstly, this paper introduces personal relationship in business exchanges. Secondly, three normative theories of business ethics that are related to the issue of personal relationship are presented. Finally, this paper explores the ethical implications on personal relationships according to the three theories. The main recommendation of this paper is that an analysis of ...

  1. The CH/π hydrogen bond: Implication in chemistry

    Science.gov (United States)

    Nishio, M.

    2012-06-01

    The CH/π hydrogen bond is the weakest extreme of hydrogen bonds that occurs between a soft acid CH and a soft base π-system. Implication in chemistry of the CH/π hydrogen bond includes issues of conformation, crystal packing, and specificity in host/guest complexes. The result obtained by analyzing the Cambridge Structural Database is reviewed. The peculiar axial preference of isopropyl group in α-phellandrene and folded conformation of levopimaric acid have been explained in terms of the CH/π hydrogen bond, by high-level ab initio MO calculations. Implication of the CH/π hydrogen bond in structural biology is also discussed, briefly.

  2. Transcriptome and peptidome characterisation of the main neuropeptides and peptidic hormones of a euphausiid: the Ice Krill, Euphausia crystallorophias.

    Directory of Open Access Journals (Sweden)

    Jean-Yves Toullec

    Full Text Available BACKGROUND: The Ice krill, Euphausia crystallorophias is one of the species at the base of the Southern Ocean food chain. Given their significant contribution to the biomass of the Southern Ocean, it is vitally important to gain a better understanding of their physiology and, in particular, anticipate their responses to climate change effects in the warming seas around Antarctica. METHODOLOGY/PRINCIPAL FINDINGS: Illumina sequencing was used to produce a transcriptome of the ice krill. Analysis of the assembled contigs via two different methods, produced 36 new pre-pro-peptides, coding for 61 neuropeptides or peptide hormones belonging to the following families: Allatostatins (A, B et C, Bursicon (α and β, Crustacean Hyperglycemic Hormones (CHH and MIH/VIHs, Crustacean Cardioactive Peptide (CCAP, Corazonin, Diuretic Hormones (DH, the Eclosion Hormone (EH, Neuroparsin, Neuropeptide F (NPF, small Neuropeptide F (sNPF, Pigment Dispersing Hormone (PDH, Red Pigment Concentrating Hormone (RPCH and finally Tachykinin. LC/MS/MS proteomics was also carried out on eyestalk extracts, which are the major site of neuropeptide synthesis in decapod crustaceans. Results confirmed the presence of six neuropeptides and six precursor-related peptides previously identified in the transcriptome analyses. CONCLUSIONS: This study represents the first comprehensive analysis of neuropeptide hormones in a Eucarida non-decapod Malacostraca, several of which are described for the first time in a non-decapod crustacean. Additionally, there is a potential expansion of PDH and Neuropeptide F family members, which may reflect certain life history traits such as circadian rhythms associated with diurnal migrations and also the confirmation via mass spectrometry of several novel pre-pro-peptides, of unknown function. Knowledge of these essential hormones provides a vital framework for understanding the physiological response of this key Southern Ocean species to climate change

  3. Committed effective dose from naturally occuring radionuclides in shellfish

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226Ra, 19.3 to 39.1 μSv for 228Ra and 17.0 to 40.4 μSv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values.

  4. Feminist Developmental Theory: Implications for Counseling.

    Science.gov (United States)

    Wastell, Colin A.

    1996-01-01

    Discusses the importance of counseling guided by a life-span development model. Emphasizes that one popular theory should be modified by taking into account a broader understanding of life-span development in terms of commonalities and differences in male and female development. Examines implications with borderline personality disorder and…

  5. Implications of Risk Management Practices on Financial ...

    African Journals Online (AJOL)

    Implications of Risk Management Practices on Financial Performance of Sugar ... The respondents were functional heads of the companies under the survey. ... of downside losses in order to minimize the negative impact of risk on returns.

  6. Corporal punishment contestations, paradoxes and implications for ...

    African Journals Online (AJOL)

    Corporal punishment contestations, paradoxes and implications for school leadership: A case study of two South African high schools. ... South African Journal of Education. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current ...

  7. Immune functions in crustaceans: lessons from flies

    NARCIS (Netherlands)

    Stet, R.J.M.; Arts, J.A.J.

    2005-01-01

    In recent years insects, notably Drosophila, have emerged as a popular model for studying immune responses to bacterial and fungal pathogens. Due to the availability of the complete genome sequence, genome-wide scans of immune responses have been performed using microarray analyses. These analyses

  8. Metamorphosis in the Cirripede Crustacean Balanus amphitrite

    Science.gov (United States)

    Maruzzo, Diego; Aldred, Nick; Clare, Anthony S.; Høeg, Jens T.

    2012-01-01

    Stalked and acorn barnacles (Cirripedia Thoracica) have a complex life cycle that includes a free-swimming nauplius larva, a cypris larva and a permanently attached sessile juvenile and adult barnacle. The barnacle cyprid is among the most highly specialized of marine invertebrate larvae and its settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex and critical to the survival of the barnacle. Here we use video microscopy to present a timeline and description of morphological events from settled cyprid to juvenile barnacle in the model species Balanus amphitrite, representing an important step towards both a broader understanding of the settlement ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle cavity, building of the juvenile musculature, contraction of antennular muscles, raising of the body, shedding of the cypris cuticle, shell plate and basis formation and, possibly, a further moult to become a suspension feeding barnacle. We compare these events with developmental information from other barnacle species and discuss them in the framework of barnacle settlement ecology. PMID:22666355

  9. Metamorphosis in the cirripede crustacean Balanus amphitrite

    DEFF Research Database (Denmark)

    Maruzzo, Diego; Aldred, Nick; Clare, Anthony S.

    2012-01-01

    settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex...... ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle...

  10. Integration of physiological responses of crustaceans to ...

    African Journals Online (AJOL)

    It is established that metabolic end products such as lactate, intermediates including urate, and monoamine and peptide neurohormones can have important regulatory roles. These include effects on ventilation and heart function, blood perfusion, respiratory gas transport, as well as water and salt homeostasis providing an ...

  11. The Military Coup and its Implications for the Thai Economy

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    The paper analyses the regional and international implications of the Thai military coup in September 2006. Focus is furthermore  attached to the economic consequences and the geo-political and geo-economic aspects related to the coup.......The paper analyses the regional and international implications of the Thai military coup in September 2006. Focus is furthermore  attached to the economic consequences and the geo-political and geo-economic aspects related to the coup....

  12. Relaciones tróficas de cinco peces costeros comunes en el área submareal del norte de Chile (20°11'-20°20'S

    Directory of Open Access Journals (Sweden)

    Mauricio Vargas

    1999-09-01

    Full Text Available The trophic relations of five coastal Perciformes at northern Chile were analyzed on the basis of 151 specimens of Acanthistius pictus, Paralabrax humeralis, Pinguipes chilensis, Anisotremus scapularis and Cheilodactylus variegatus collected off Iquique, in April 1996, as a preliminary way to identify trophic guilds of subtidal fishes; A. pictus, P. humeralis and C. variegatus, had the crustaceans Rhynchocynetes typus, Pseudosquillopsis lessoni and Allopetrolisthes angulosus, respectively, as the best represented items. In A. scapularis and P. chilensis the best represented items were the mollusks; however for the last species, the main food was the crustacean Cancer setosus. These fish are essentially benthophagous carnivores with a variable trophic spectrum(8 to 36 items.

  13. Integrating animal health surveillance and food safety: the example of Anisakis.

    Science.gov (United States)

    Pozio, E

    2013-08-01

    Nematodes of the genera Anisakis and Pseudoterranova (family Anisakidae) are zoonotic parasites for which marine mammals (e.g., whales, dolphins, porpoises, seals, sea lions, walruses) act as final hosts, and crustaceans, cephalopods and fish as intermediate and/or paratenic hosts. In humans, the ingestion of Anisakidae larvae can result in infection with live larvae, an allergic reaction to Anisakidae allergens (even when dead larvae are ingested), or both. Worldwide, more than 2000 infections are diagnosed in humans every year, yet most of the infections and allergic reactions are undiagnosed. A very high prevalence of anisakid larvae has been found in many commercially important species of fish, cephalopods and crustaceans. Preventive measures for anisakiosis focus on post-harvest handling.

  14. Isolation of TDA-producing Phaeobacter strains from sea bass larval rearing units and their probiotic effect against pathogenic Vibrio spp. in Artemia cultures

    DEFF Research Database (Denmark)

    Grotkjær, Torben; Bentzon-Tilia, Mikkel; D'Alvise, Paul

    2016-01-01

    V. harveyi, which is the major bacterial pathogen in crustaceans and Mediterranean sea bass larvae cultures. Concomitantly, they significantly improved survival of V. harveyi-infected brine shrimp. 16S rRNA gene sequence homology identified the antagonists as Phaeobacter sp., and in silico DNA...... Vibrio anguillarum and reduce mortality in V. anguillarum-infected cod and turbot larvae. In this study, it was demonstrated that antagonistic Roseobacter-clade bacteria could be isolated from sea bass larval rearing units. In addition, it was shown that they not only antagonized V. anguillarum but also......-producing Phaeobacter isolated from Mediterranean marine larviculture are promising probiotic bacteria against pathogenic Vibrio in crustacean live-feed cultures for marine fish larvae....

  15. 134Cs-transport in an experimental ecological system

    International Nuclear Information System (INIS)

    Mocsy, Ildiko; Uray, Ildiko; Salagean, Stefania

    1986-01-01

    An experimental aquatic ecosystem was developed consisting of river water, slurry, algae and crustaceans. The change of the cesium concentration factor (F c ) of two alga species were measured using 20 Bq/ml of 134 CsCl. Measurements were performed in the 6th, 12th, 24th, 48th and 72nd hour after irradiation. F c in crustaceans was found to be 1300 in the 12th hr, then decreased rapidly down to 275. The temporal dependence of cesium accumulation in slurry increased consistently. It was found that algae accumulated cesium variously. Owing to its high accumulation, Cladophora glomerata can be used as a biological indicator of cesium concentration in surface waters. (K.I.)

  16. Kinetic Model of Growth of Arthropoda Populations

    Science.gov (United States)

    Ershov, Yu. A.; Kuznetsov, M. A.

    2018-05-01

    Kinetic equations were derived for calculating the growth of crustacean populations ( Crustacea) based on the biological growth model suggested earlier using shrimp ( Caridea) populations as an example. The development cycle of successive stages for populations can be represented in the form of quasi-chemical equations. The kinetic equations that describe the development cycle of crustaceans allow quantitative prediction of the development of populations depending on conditions. In contrast to extrapolation-simulation models, in the developed kinetic model of biological growth the kinetic parameters are the experimental characteristics of population growth. Verification and parametric identification of the developed model on the basis of the experimental data showed agreement with experiment within the error of the measurement technique.

  17. The pedagogical implications of information and communication ...

    African Journals Online (AJOL)

    The pedagogical implications of information and communication technology on adult education: a case study of the osun state colleges of ... Finally, the department should give individual students access to the use of 1C1 equipment.

  18. Implications of the "My School" Website for Disadvantaged Communities: A Bourdieuian Analysis

    Science.gov (United States)

    Mills, Carmen

    2015-01-01

    Drawing on the theoretical constructs of Pierre Bourdieu, this article explores implications of the Australian "My School" website for schools located in disadvantaged communities. These implications flow from the legitimisation of certain cultural practices through the hidden linkages between scholastic aptitude and cultural heritage…

  19. Corporal Punishment: Legalities, Realities, and Implications.

    Science.gov (United States)

    Hinchey, Patricia H.

    2003-01-01

    Presents a quiz that will help readers determine the reliability of their own perceptions relating to corporal punishment in schools. Discusses U.S. Courts and corporal punishment, worldwide and nationwide legality, and the realities of corporal punishment in the United States. Discusses implications for what teachers can do to address corporal…

  20. The response of zooplankton communities to the 2016 extreme hydrological cycle in floodplain lakes connected to the Yangtze River in China.

    Science.gov (United States)

    Zhang, Kun; Xu, Mei; Wu, Qili; Lin, Zhi; Jiang, Fangyuan; Chen, Huan; Zhou, Zhongze

    2018-06-04

    The Huayanghe Lakes play an important role in the Yangtze floodplain in China and had extremely high water levels during the summer of 2016. Monitoring data was collected in an effort to understand the impact of this change on the crustacean zooplankton composition and abundance and the biomass variation in the Huayanghe Lakes between a regular hydrological cycle (RHC) and an extreme hydrological cycle (EHC). The crustacean zooplankton community composition, abundance, and biomass in the floodplain lakes were markedly affected by the water-level disturbance. The number of species was lower in the RHC, but the mean density and biomass decreased from 93.84 ± 13.29 ind./L and 6.11 ± 0.89 mg/L, respectively, in the RHC to 66.62 ± 10.88 ind./L and 1.22 ± 0.26 mg/L, respectively, in the EHC. Pearson correlations and redundancy analyses revealed the environmental factors with the most significant impact on the crustacean zooplankton community differed between the RHC and EHC cycles. Little previous information exists on the zooplankton in these lakes, and the present study provides data on the zooplankton composition, abundance, and biomass, both at baseline and in response to hydrological changes.

  1. Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi.

    Science.gov (United States)

    Ventura, Tomer; Fitzgibbon, Quinn P; Battaglene, Stephen C; Elizur, Abigail

    2015-08-27

    The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation.

  2. The versatile biopolymer chitosan: potential sources, evaluation of extraction methods and applications.

    Science.gov (United States)

    Kaur, Surinder; Dhillon, Gurpreet Singh

    2014-05-01

    Among the biopolymers, chitin and its derivative chitosan (CTS) have been receiving increasing attention. Both are composed of randomly distributed β-(1-4)-linked d-glucosamine and N-acetyl glucosamine units. On commercial scale, CTS is mainly obtained from the crustacean shells. The chemical methods employed for extraction of CTS from crustacean shells are laden with many disadvantages. Waste fungal biomass represents a potential biological source of CTS, in fact with superior physico-chemical properties, such as high degree of deacetylation, low molecular weight, devoid of protein contamination and high bioactivity. Researchers around the globe are attempting to commercialize CTS production and extraction from fungal sources. Fungi are promising and environmentally benign source of CTS and they have the potential to completely replace crustacean-derived CTS. Waste fungal biomass resulting from various pharmaceutical and biotechnological industries is grown on inexpensive agro-industrial wastes and its by-products are a rich and inexpensive source of CTS. CTS is emerging as an important natural polymer having broad range of applications in different fields. In this context, the present review discusses the potential sources of CTS and their advantages and disadvantages. This review also deals with potential applications of CTS in different fields. Finally, the various attributes of CTS sought in different applications are discussed.

  3. Selectively enhanced expression of prophenoloxidase activating enzyme 1 (PPAE1 at a bacteria clearance site in the white shrimp, Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Jang In-Kwon

    2011-12-01

    Full Text Available Abstract Background The prophenoloxidase-activating (PO activating system plays an important role in the crustacean innate immunity, particularly in wound healing and pathogen defense. A key member of this system is prophenoloxidase-activating enzyme (PPAE, which is the direct activator of prophenoloxidase (proPO. Despite their importance in crustacean PO activating system, the studies on them remain limited. Results Here we report on a PPAE of white shrimp, Litopenaeus vannamei (lvPPAE1, which showed 94% similarity to PPAE1 of Penaeus monodon. We found that lvPPAE1 in fluid hemocytes was down regulated after challenge by Vibrio harveyi but was enhanced when shrimps were exposed to a bacteria-rich environment for long-term. In vivo gene silence of lvPPAE1 by RNAi can significantly reduce the phenoloxidase activity (PO and increase the susceptibility of shrimps to V. harveyi. Although lvPPAE1 was down-regulated in fluid hemocytes by Vibrio challenge, its expression increased significantly in gill after bacteria injection, which is the primary bacteria-clearance tissue. Conclusion Suppressed expression in fluid hemocytes and enhanced expression in gill indicates selectively enhanced expression at the bacterial clearance site. This is a novel feature for PPAE expression. The results will contribute to our understanding of the PO activating system in crustaceans.

  4. Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi

    Science.gov (United States)

    Ventura, Tomer; Fitzgibbon, Quinn P.; Battaglene, Stephen C.; Elizur, Abigail

    2015-01-01

    The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation. PMID:26311524

  5. Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

    Science.gov (United States)

    Babin, A; Saciat, C; Teixeira, M; Troussard, J-P; Motreuil, S; Moreau, J; Moret, Y

    2015-04-01

    The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supplementation with carotenoids and immune challenge on immune defences and the activity of the antioxidant enzymes SOD and CAT, in the amphipod crustacean Gammarus pulex. Dietary supplementation increased the concentrations of circulating carotenoids and haemocytes in the haemolymph, while the immune response induced the consumption of circulating carotenoids and a drop of haemocyte density. Interestingly, supplemented gammarids exhibited down-regulated SOD activity but high CAT activity compared to control ones. Our study reveals specific interactions of dietary carotenoids with endogenous antioxidant enzymes, and further underlines the potential importance of carotenoids in the evolution of immunity and/or of antioxidant mechanisms in crustaceans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Phytochemical Profile of Brown Rice and Its Nutrigenomic Implications

    Directory of Open Access Journals (Sweden)

    Keneswary Ravichanthiran

    2018-05-01

    Full Text Available Whole grain foods have been promoted to be included as one of the important components of a healthy diet because of the relationship between the regular consumption of whole-grain foods and reduced risk of chronic diseases. Rice is a staple food, which has been widely consumed for centuries by many Asian countries. Studies have suggested that brown rice is associated with a wide spectrum of nutrigenomic implications such as anti-diabetic, anti-cholesterol, cardioprotective and antioxidant. This is because of the presence of various phytochemicals that are mainly located in bran layers of brown rice. Therefore, this paper is a review of publications that focuses on the bioactive compounds and nutrigenomic implications of brown rice. Although current evidence supports the fact that the consumption of brown rice is beneficial for health, these studies are heterogeneous in terms of their brown rice samples used and population groups, which cause the evaluation to be difficult. Future clinical studies should focus on the screening of individual bioactive compounds in brown rice with reference to their nutrigenomic implications.

  7. Deeply discounted medications: Implications of generic prescription drug wars.

    Science.gov (United States)

    Czechowski, Jessica L; Tjia, Jennifer; Triller, Darren M

    2010-01-01

    To describe the history of generic prescription pricing programs at major pharmacy chains and their potential implications on prescribing, quality of care, and patient safety. Publicly available generic prescription discount program drug lists as of May 1, 2009. Fierce competition among major pharmacy chains such as Walgreens, CVS, and Walmart has led to a generic prescription pricing war with unclear public health implications. Introduced in 2006, currently 7 of the 10 largest pharmacy chains advertise a version of a deeply discounted medication (DDM) program, accounting for more than 25,000 locations nationally. By early 2008, almost 70 million Americans had used these programs. Although DDM programs lower drug costs for many patients, DDM formularies include potentially ineffective or harmful medications, have the potential to influence physician prescribing behavior, and may impair pharmacists' ability to review complete drug-dispensing records. DDMs are widespread but have the potential for unintended consequences on patients, providers, and the health care system. A systematic review of DDMs needs to evaluate the clinical, economic, and system-level implications of such programs.

  8. [Gut microbiota: Description, role and pathophysiologic implications].

    Science.gov (United States)

    Landman, C; Quévrain, E

    2016-06-01

    The human gut contains 10(14) bacteria and many other micro-organisms such as Archaea, viruses and fungi. Studying the gut microbiota showed how this entity participates to gut physiology and beyond this to human health, as a real "hidden organ". In this review, we aimed to bring information about gut microbiota, its structure, its roles and its implication in human pathology. After bacterial colonization in infant, intestinal microbial composition is unique for each individual although more than 95% can be assigned to four major phyla. The use of culture independent methods and more recently the development of high throughput sequencing allowed to depict precisely gut microbiota structure and diversity as well as its alteration in diseases. Gut microbiota is implicated in the maturation of the host immune system and in many fundamental metabolic pathways including sugars and proteins fermentation and metabolism of bile acids and xenobiotics. Imbalance of gut microbial populations or dysbiosis has important functional consequences and is implicated in many digestive diseases (inflammatory bowel diseases, colorectal cancer, etc.) but also in obesity and autism. These observations have led to a surge of studies exploring therapeutics which aims to restore gut microbiota equilibrium such as probiotics or fecal microbiota transplantation. But recent research also investigates biological activity of microbial products which could lead to interesting therapeutics leads. Copyright © 2015 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  9. Validation of a Mathematical Model for Green Algae (Raphidocelis Subcapitata Growth and Implications for a Coupled Dynamical System with Daphnia Magna

    Directory of Open Access Journals (Sweden)

    Michael Stemkovski

    2016-05-01

    Full Text Available Toxicity testing in populations probes for responses in demographic variables to anthropogenic or natural chemical changes in the environment. Importantly, these tests are primarily performed on species in isolation of adjacent tropic levels in their ecosystem. The development and validation of coupled species models may aid in predicting adverse outcomes at the ecosystems level. Here, we aim to validate a model for the population dynamics of the green algae Raphidocelis subcapitata, a planktonic species that is often used as a primary food source in toxicity experiments for the fresh water crustacean Daphnia magna. We collected longitudinal data from three replicate population experiments of R. subcapitata. We used this data with statistical model comparison tests and uncertainty quantification techniques to compare the performance of four models: the Logistic model, the Bernoulli model, the Gompertz model, and a discretization of the Logistic model. Overall, our results suggest that the logistic model is the most accurate continuous model for R. subcapitata population growth. We then implement the numerical discretization showing how the continuous logistic model for algae can be coupled to a previously validated discrete-time population model for D. magna.

  10. Cultural Implications of Human Resource Development.

    Science.gov (United States)

    Hiranpruk, Chaiskran

    A discussion of the cultural effects of economic and, by extension, human resource development in Southeast Asia looks at short- and long-term implications. It is suggested that in the short term, increased competition will affect distribution of wealth, which can promote materialism and corruption. The introduction of labor-saving technology may…

  11. Understanding predation: implications toward forest management

    Science.gov (United States)

    Harvey R. Smith

    1991-01-01

    It is generally accepted that when gypsy moths rest in the litter survival is low due to predation by ground-foraging generalist predators and that predation can maintain these populations indefinitely. Forest Service research on predators of gypsy moth continues to focus on population dynamics, the mechanisms of predation and forest management implications.

  12. First Planck results and cosmological implications

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    The Planck satellite has measured CMB anisotropies over the full sky with unprecedented sensitivity. The collaboration has released its first CMB temperature maps and cosmological analysis on the 21st of March. I will present a summary of these new CMB results, focusing mainly on their implications for our understanding of the Universe.

  13. Implications of alternative fuel cycles

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The United States is re-examining alternative fuel cycles and nuclear power strategies, and doubtful attempts are being made to justify the economics of the 'throw-away' fuel cycle. At an international forum on 'An acceptable nuclear energy future for the world' at Fort Lauderdale, Karl Cohen of General Electric and a leading authority on this topic put the implications into perspective. Extracts from his address are presented

  14. Tobacco, politics and economics: implications for global health.

    Science.gov (United States)

    Stebbins, K R

    1991-01-01

    This paper examines the expanding presence of multinational cigarette companies into almost every country in the world, and discusses the health implications of this global penetration. Cigarettes deserve special attention because tobacco is the only legally available consumer product that is harmful to one's health when used as intended. A temptation exists to blame governments for the existence of health-threatening products within their borders. However, this paper illustrates the extent to which extra-national forces influence domestic policies and circumstances. Cigarette smokers are often blamed for their lethal habit, despite billion-dollar promotional schemes which attract people to smoking, obscuring the harmful consequences of consuming a highly addictive drug. Multinational cigarette companies are increasingly targeting Asian and Third World populations. To facilitate this market penetration, political avenues are often pursued with considerable success, disregarding the health implications associated with cigarette tobacco. The use of tobacco in development programs (e.g. the U.S. 'Food for Peace' program) has political and economic implications for donor and recipient countries, and lucrative advantages for the tobacco companies. However, this paper recommends that corporate profits and foreign policy should not be pursued at the expense of tobacco-related diseases and premature deaths among Third World peoples.

  15. Gender Equity Issues in CTE and STEM Education: Economic and Social Implications

    Science.gov (United States)

    Toglia, Thomas V.

    2013-01-01

    Title IX of the Educational Amendments of 1972 has significant implications for gender equity in career and technical education (CTE) and science, technology, engineering, and mathematics (STEM) programs--and the relatively low number of women and girls pursuing nontraditional careers has significant economic and social implications. From an…

  16. Fukushima Daiichi: implications for carbon-free energy, nuclear nonproliferation, and community resilience.

    Science.gov (United States)

    Hall, Howard L

    2011-07-01

    Implications of the nuclear power plant accidents at Fukushima Daiichi are explored in this commentary. In addition to questions of nuclear reactor regulatory standards, broader implications on noncarbon-emitting energy production, nuclear nonproliferation objectives, and community resilience and emergency response against catastrophic events are explored. Copyright © 2011 SETAC.

  17. Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

    Directory of Open Access Journals (Sweden)

    Gerhard MAIER

    2005-08-01

    Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

  18. The complete mitochondrial genome of the common sea slater, Ligia oceanica (Crustacea, Isopoda bears a novel gene order and unusual control region features

    Directory of Open Access Journals (Sweden)

    Podsiadlowski Lars

    2006-09-01

    Full Text Available Abstract Background Sequence data and other characters from mitochondrial genomes (gene translocations, secondary structure of RNA molecules are useful in phylogenetic studies among metazoan animals from population to phylum level. Moreover, the comparison of complete mitochondrial sequences gives valuable information about the evolution of small genomes, e.g. about different mechanisms of gene translocation, gene duplication and gene loss, or concerning nucleotide frequency biases. The Peracarida (gammarids, isopods, etc. comprise about 21,000 species of crustaceans, living in many environments from deep sea floor to arid terrestrial habitats. Ligia oceanica is a terrestrial isopod living at rocky seashores of the european North Sea and Atlantic coastlines. Results The study reveals the first complete mitochondrial DNA sequence from a peracarid crustacean. The mitochondrial genome of Ligia oceanica is a circular double-stranded DNA molecule, with a size of 15,289 bp. It shows several changes in mitochondrial gene order compared to other crustacean species. An overview about mitochondrial gene order of all crustacean taxa yet sequenced is also presented. The largest non-coding part (the putative mitochondrial control region of the mitochondrial genome of Ligia oceanica is unexpectedly not AT-rich compared to the remainder of the genome. It bears two repeat regions (4× 10 bp and 3× 64 bp, and a GC-rich hairpin-like secondary structure. Some of the transfer RNAs show secondary structures which derive from the usual cloverleaf pattern. While some tRNA genes are putative targets for RNA editing, trnR could not be localized at all. Conclusion Gene order is not conserved among Peracarida, not even among isopods. The two isopod species Ligia oceanica and Idotea baltica show a similarly derived gene order, compared to the arthropod ground pattern and to the amphipod Parhyale hawaiiensis, suggesting that most of the translocation events were already

  19. Fabrication of Novel Porous Chitosan Matrices as Scaffolds for Bone Tissue Engineering

    National Research Council Canada - National Science Library

    Jiang, Tao; Pilane, Cyril M; Laurencin, Cato T

    2005-01-01

    .... Chitosan, a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton, is a potential candidate for bone tissue engineering due to its excellent osteocompatibility...

  20. The Professional-Bureaucratic Conflict: Origins, Implications, Resolution.

    Science.gov (United States)

    Angona, Judith; Williams, Leonard B.

    1981-01-01

    Examines the literature on the inevitable conflict in modern organizations between the professional's training for self-administration and bureaucratic denial of individual initiative and draws implications for administrative techniques that can help win the loyalty of a professional staff. (Author/WD)

  1. Surveillance theory and its implications for law

    NARCIS (Netherlands)

    Timan, Tjerk; Galic, Masa; Koops, Bert-Jaap; Brownsword, Roger; Scotford, Eloise; Yeung, Karen

    2017-01-01

    This chapter provides an overview of key surveillance theories and their implications for law and regulation. It presents three stages of theories that characterise changes in thinking about surveillance in society and the disciplining, controlling, and entertaining functions of surveillance.

  2. Epistemological and Treatment Implications of Nonlinear Dynamics

    Science.gov (United States)

    Stein, A. H.

    The treatment implications of understanding mind as solely epiphenomenal to nonlinearly founded neurobiology are discussed. G. Klimovsky's epistemological understanding of psychoanalysis as a science is rejected and treatment approaches integrating W. R. Bion's and D. W. Winnicott's work are supported.

  3. Insecurity and national economic development implications for ...

    African Journals Online (AJOL)

    Insecurity and national economic development implications for Nigeria's vision 20: 2020. ... International Journal of Development and Management Review ... These social menace trigger off a worrisome sense of insecurity that challenge Nigeria's efforts towards national economic development and consequently its vision ...

  4. Gender equality mainstreaming: Implications for poverty reduction ...

    African Journals Online (AJOL)

    Gender equality mainstreaming: Implications for poverty reduction and sustainable development in Abia State of Nigeria. ... Empowerment of women when pursued beyond mere rhetoric and instrumentation, it will improve their wellbeing, self esteem, resource allocation, political voice and increased productivity generally.

  5. Darwin and Darwinism: the (alleged) social implications of the origin of species.

    Science.gov (United States)

    Orr, H Allen

    2009-11-01

    Most scientific theories, even revolutionary ones, change the practice of a particular science but have few consequences for culture or society at large. But Darwinism, it has often been said, is different in this respect. Since the publication of The Origin of Species, many have claimed that Darwinism has a number of profound social implications. Here, I briefly consider three of these: the economic, the political, and the religious. I suggest that, for the most part, these supposed implications have been misconstrued or exaggerated. Indeed, it is reasonably clear that the chain of implication sometimes primarily ran in the opposite direction-from, for instance, economics and political theory to Darwinism.

  6. Applying a Cognitive Neuroscience Perspective to Disruptive Behavior Disorders: Implications for Schools.

    Science.gov (United States)

    Tyler, Patrick M; White, Stuart F; Thompson, Ronald W; Blair, R J R

    2018-02-12

    A cognitive neuroscience perspective seeks to understand behavior, in this case disruptive behavior disorders (DBD), in terms of dysfunction in cognitive processes underpinned by neural processes. While this type of approach has clear implications for clinical mental health practice, it also has implications for school-based assessment and intervention with children and adolescents who have disruptive behavior and aggression. This review articulates a cognitive neuroscience account of DBD by discussing the neurocognitive dysfunction related to emotional empathy, threat sensitivity, reinforcement-based decision-making, and response inhibition. The potential implications for current and future classroom-based assessments and interventions for students with these deficits are discussed.

  7. Proof complexity of intuitionistic implicational formulas

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil

    2017-01-01

    Roč. 168, č. 1 (2017), s. 150-190 ISSN 0168-0072 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : proof complexity * intuitionistic logic * implicational fragment Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.647, year: 2016 http://www.sciencedirect.com/science/article/pii/S0168007216301154

  8. Cost Characteristics of Telecom Networks and their Implications for Market Structures

    DEFF Research Database (Denmark)

    Falch, Morten

    1997-01-01

    The paper analyses the cost structure of telecom operators and test the hypotheses of economies of scale and economies of density. The impact of new technologies and the regulatory implications are analysed.......The paper analyses the cost structure of telecom operators and test the hypotheses of economies of scale and economies of density. The impact of new technologies and the regulatory implications are analysed....

  9. Medicare Part D Roulette, Potential Implications of Random..

    Data.gov (United States)

    U.S. Department of Health & Human Services — Medicare Part D Roulette, Potential Implications of Random Assignment and Plan Restrictions Dual-eligible (Medicare and Medicaid) beneficiaries are randomly assigned...

  10. Software Maintenance and Evolution: The Implication for Software ...

    African Journals Online (AJOL)

    Software Maintenance and Evolution: The Implication for Software Development. ... Software maintenance is the process of modifying existing operational software by correcting errors, ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  11. Development Implications of Liberalization of Trade in Services ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Development Implications of Liberalization of Trade in Services ... disseminated by the United Nations Conference on Trade and Development (UNCTAD). ... The Honourable Chrystia Freeland, Minister of International Trade, announced a ...

  12. International University Research Ventures: Implications for U.S. Economic Competitiveness National Security

    Science.gov (United States)

    2018-03-31

    NTERNATIONAL UNIVERSITY RESEARCH VENTURES: IMPLICATIONS FOR US ECONOMIC COMPETITIVENESS AND NATIONAL SECURITY The views, opinions and/or findings...UNIVERSITY RESEARCH VENTURES: IMPLICATIONS FOR US ECONOMIC COMPETITIVENESS AND NATIONAL SECURITY Report Term: 0-Other Email: mzak@gatech.edu...expected to inform political and economic theories about technology transfer, innovation, economic competitiveness, and democratization/civil

  13. Explicit Memory among Individuals with Mild and Moderate Intellectual Disability: Educational Implications

    Science.gov (United States)

    Lifshitz, Hefziba; Shtein, Sarit; Weiss, Itzhak; Svisrsky, Naama

    2011-01-01

    We previously reported a meta-analysis of explicit memory studies in populations with intellectual disability (ID). The current study discusses the educational implications of this meta-analysis. The main factors at the core of these implications can be divided into two categories: those related to task characteristics (e.g., depth of processing,…

  14. Implications for global energy markets: implications for non-fossil energy sources

    International Nuclear Information System (INIS)

    Grubb, Michael

    1998-01-01

    This paper highlights the recent developments concerning non-fossil energy and examines the impact of the Kyoto Protocol on non-fossil energy sources, and the implications for non-fossil sources in the implementation of the Kyoto Protocol. The current contributions of fossil and non-fossil fuels to electricity production, prospects for expansion of the established non-fossil sources, new renewables in Europe to date, renewables in Europe to 2010, and policy integration in the EU are discussed. Charts illustrating the generating capacity of renewable energy plant in Britain (1992-1966), wind energy capacity in Europe (1990-2000), and projected renewable energy contributions in the EU (wind, small hydro, photovoltaic, biomass and geothermal) are provided. (UK)

  15. Pacific Islands Region Fishing Permits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sustainable Fisheries Division Permits Program issues around 300 permits annually for pelagic longline and troll & handline, bottomfish, crustacean (lobster...

  16. A review of the clinical implications of bisphosphonates in dentistry.

    Science.gov (United States)

    Borromeo, G L; Tsao, C E; Darby, I B; Ebeling, P R

    2011-03-01

    Bisphosphonates are drugs that suppress bone turnover and are commonly prescribed to prevent skeletal related events in malignancy and for benign bone diseases such as osteoporosis. Bisphosphonate associated jaw osteonecrosis (ONJ) is a potentially debilitating, yet poorly understood condition. A literature review was undertaken to review the dental clinical implications of bisphosphonates. The present paper briefly describes the postulated pathophysiology of ONJ and conditions with similar clinical presentations. The implications of bisphosphonates for implantology, periodontology, orthodontics and endodontics are reviewed. Whilst bisphosphonates have potential positive applications in some clinical settings, periodontology particularly, further clinical research is limited by the risk of ONJ. Prevention and management are reviewed, including guidelines for reducing cumulative intravenous bisphosphonate dose, cessation of bisphosphonates prior to invasive dental treatment or after ONJ development, and the use of serum beta-CTX-1 in assessing risk. In the context of substantial uncertainty, the implications of bisphosphonate use in the dental clinical setting are still being determined. © 2010 Australian Dental Association.

  17. Environmental conflicts: Key issues and management implications ...

    African Journals Online (AJOL)

    Environmental crises and problems throughout the world are widespread and increasing rapidly. In relation to these concerns, the article discusses the following aspects: people and the environment, environmental conflicts, climate change and environmental conflicts, and management implications. The section on people ...

  18. Shame, Guilt and Remorse: Implications for Offender Populations

    Science.gov (United States)

    Tangney, June Price; Stuewig, Jeff; Hafez, Logaina

    2011-01-01

    The emotions shame and guilt may represent a critical stepping stone in the rehabilitation process. Often referred to as “moral” emotions owing to their presumed role in promoting altruistic behavior and inhibiting antisocial behaviors, shame and guilt provide potentially exciting points of intervention with offenders. In this article, we describe current psychological theory and research that underscores important differences between shame and guilt. We note parallels between psychologists’ conceptions of guilt and shame, and criminologists’ conceptions of reintegrative and disintegrative shaming. We summarize recent research investigating the implications of these moral emotions for criminal and risky behavior, with special emphasis on the handful of studies conducted with actual offenders. We conclude with a discussion of implications for treatment in criminal justice settings. PMID:22523475

  19. Teacher's experiences in PBL: implications for practice

    Science.gov (United States)

    Alves, Anabela C.; Sousa, Rui M.; Fernandes, Sandra; Cardoso, Elisabete; Carvalho, Maria Alice; Figueiredo, Jorge; Pereira, Rui M. S.

    2016-03-01

    Project-Based Learning (PBL) has been implemented in the first year of the Industrial Engineering and Management programme at the University of Minho, Portugal, since 2004/2005. The purpose of this paper is to analyse and discuss teachers' experiences in PBL in this programme and to explore its implications for student learning and for teaching practices in higher education. For data collection, the research method used was written narratives to these teachers, at the end of the PBL semester. Findings suggest that teachers express a positive view of PBL as a learning approach. They identify student motivation and engagement, along with a better understanding of the application of concepts in real-life situations, as important outcomes of the project for students. Besides this, teachers also highlight the importance of the development of transversal skills by students throughout the project. Recommendations for future work and implications for practice will also be discussed.

  20. How do local stakeholders respond to the uncertain implications of an innovative flood infrastructure project?

    Science.gov (United States)

    van den Hoek, Ronald; Brugnach, Marcela; Hoekstra, Arjen

    2013-04-01

    In the 20th century, flood management was dominated by rigid structures - such as dikes and dams - which intend to strictly regulate and control water systems. Although the application of these rigid structures has been successful in the recent past, their negative implications for ecosystems and natural processes is often not properly taken into account. Therefore, flood management practices are currently moving towards more nature-inclusive approaches. Building with Nature (BwN) is such a new approach of nature-inclusive flood management in the Netherlands, which aims to utilize natural dynamics (e.g., wind and currents) and natural materials (e.g., sediment and vegetation) for the realization of effective flood infrastructure, while providing opportunities for nature development. However, the natural dynamics driving a project based on BwN design principles are inherently unpredictable. Furthermore, our factual knowledge base regarding the socio-ecological system in which the BwN initiative is implemented is incomplete. Moreover, in recent years, it is increasingly aimed for by decision-makers to involve local stakeholders in the development of promising flood management initiatives. These stakeholders and other actors involved can have diverging views regarding the project, can perceive unanticipated implications and could choose unforeseen action paths. In short, while a project based on BwN design principles - like any human intervention - definitely has implications for the socio-ecological system, both the extent to which these particular implications will occur and the response of stakeholders are highly uncertain. In this paper, we study the Safety Buffer Oyster Dam case - a BwN pilot project - and address the interplay between the project's implications, the uncertainties regarding these implications and the action paths chosen by the local stakeholders and project team. We determine how the implications of the Safety Buffer project are viewed by local

  1. Implications of social judgement theory for persuasive advertising ...

    African Journals Online (AJOL)

    Implications of social judgement theory for persuasive advertising campaigns. ... The way the consumers perceive an advertising campaign will, therefore, determine how they will respond to the advertisement. ... AJOL African Journals Online.

  2. Dynamic patterns of zooplankton transport and migration in Catuama Inlet (Pernambuco, Brazil, with emphasis on the decapod crustacean larvae Patrones dinámicos de transporte y migración de zooplancton en el estuario Catuama (Pernambuco, Brasil, con énfasis en las larvas de crustáceos decápodos

    Directory of Open Access Journals (Sweden)

    Ralf Schwamborn

    2008-01-01

    Full Text Available The objective of this study was to quantify and to model zooplankton transport with emphasis on decapod crustacean larvae. Sampling was carried out at three depths with a plankton pump coupled to a 300-/¿m mesh. Current data were obtained with an ADCP. Our data showed the existence of vertically and horizontally heterogeneous current and transport fields. We identified 27 groups of Decapoda (larvae of Sergestidae, Porcellanidae, Upogebiidae, Cari dea, Brachyura. Most of the species and larval phases showed characteristic vertical migration patterns, in phase with the diurnal tidal cycles, thus enhancing retention or export from the estuary.Esta investigación tiene como objetivo cuantificar y modelar el transporte de zooplancton, con énfasis en las larvas de Crustacea Decapoda. El muestreo se realizó a tres profundidades con una bomba de plancton acoplada a una red con malla de 300 /¿m. Se obtuvieron los datos de corrientes con un ADCP. Los datos mostraron la existencia de campos de corrientes y de transporte vertical y horizontal heterogéneos. Se identificaron 27 grupos de Decapoda (larvas de Sergestidae, Porcellanidae, Upogebiidae, Caridea, Brachyura. La mayoría de las especies y fases larvales mostraron patrones de migración vertical característicos, en fase con los ciclos de la marea diurnos, favoreciendo la retención o exportación del estuario.

  3. Language practice as games: Implications for sociology of ...

    African Journals Online (AJOL)

    Language practice as games: Implications for sociology of translation in development contexts in Africa. ... Abstract. Drawing from Game Theory, the article conceptualises language practice as games, that is ... AJOL African Journals Online.

  4. Current Trends In Educational Technology: Implication On ...

    African Journals Online (AJOL)

    This paper presents the current trends in educational technology and the implication on educational managers in Nigeria. The current trends in the field of educational technology are centred on the influence of information and communication technology on the development of educational management. Various challenges ...

  5. African Regional Integration: Implications for Food Security

    NARCIS (Netherlands)

    Dijk, van M.

    2011-01-01

    This report looks at the African regional trade, regional integration agreements (RIAs) and the implications for food security. An overview is presented on the present state of African regional integration and the determinants of regional trade in agriculture and food commodities. In particular the

  6. Implications of Telecommuting in a Library Environment.

    Science.gov (United States)

    Meglio, Delores

    1991-01-01

    Discussion of telecommuting possibilities focuses on a program at Information Access Company that allows indexers and abstractors to work at home. Employer and employee expectations are discussed, equipment provisions are described, employee benefits are examined, and implications for the library environment are suggested. (LRW)

  7. Energy policy in China: implications for global climate change

    Energy Technology Data Exchange (ETDEWEB)

    ZhongXiang Zhang [University of Groningen, Groningen (Netherlands)

    1998-12-31

    This is the first systematic and comprehensive analysis of the economic implications of carbon abatement for the Chinese economy. It evaluates the economics of climate change and provides national, cost-effective policies for climate change. The book consists of three main parts, firstly, an analysis of the Chinese energy system to increase awareness of the implications of this sector for China`s future carbon dioxide emissions, secondly, a macroeconomic analysis of carbon dioxide emissions limits using a newly-developed computable general equilibrium model of the Chinese economy; and finally, a cost-effective analysis of carbon abatement options by means of a technology-oriented dynamic optimization model.

  8. ISSUES ABOUT THE EVALUATION OF THE FINANCIAL INSTRUMENTS AND TAX IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Camelia-Catalina, MIHALCIUC

    2014-11-01

    Full Text Available Accounting assessment is a process with tax implications on accounting figures. In fact, when it comes to evaluation, we need to clarify exactly what is being refered to: it s about the individual assessment of an asset or liability, or about the global assessment of a business. So, in a narrower approach, in accounting we are particularly interested in the individual assessment of assets and liabilities. In the evaluation, the concept of value is the primary element, accounting, especially along with the application of the principle of economic prevalence over the juridic, managed to convey the best measure those interested, information about how to create, to mesure and how to comunicate to business partners the value. The tax implication that arise after the evaluation of the individual elements of the asset, influence the result of the exercise by including the expenditure in the total expenses generated by the evaluation. The main asset elements, which following the evaluation generate tax implications are the tangible fixed asset, financial and stocks. Based on this consideration, one of the main objectives of this paper is to highlight the tax implications arising from the evaluation of financial instruments that generate tax liabilities.

  9. Aquatic ecotoxicity and biodegradability of cracked gas oils. Summary of relevant test data

    Energy Technology Data Exchange (ETDEWEB)

    Comber, M.I.H.; Den Haan, K.; Djemel, N.; Eadsforth, C.V.; King, D.; Parkerton, T.; Leon Paumen, M.; Dmytrasz, B.; Del Castillo, F.

    2013-09-15

    This report describes the experimental procedures and the results obtained in acute and chronic ecotoxicity tests as well as a biodegradation study on cracked gas oil samples. In a CONCAWE study, three samples were tested for toxicity to the crustacean zooplankter, Daphnia magna and the algae, Pseudokirchneriella subcapitata (alternatively known as Selenastrum capricornutum) using water accommodated fractions. In addition, another sample was tested in a separate API study for toxicity to the fish, Oncorhynchus mykiss, the crustacean zooplankter, Daphnia magna (acute and chronic) and the algae, Pseudokirchneriella subcapitata using water accommodated fractions. The API sample was also tested for ready biodegradability in a manometric respirometry test. All these results assist in determining the environmental hazard posed by cracked gas oils.

  10. Irish and Scandinavian objection to Sellafield; Norden protesterer

    Energy Technology Data Exchange (ETDEWEB)

    Haaland, Leif

    2001-07-01

    The article deals with the objection of Ireland and the Scandinavian countries to the radioactive emissions from the Sellafield reprocessing plant. This contamination follows the sea currents northward and radioactive material from this plant has been found in seaweed and crustaceans along the coast of Norway. The concentration in lobster from the Irish Sea is much higher than in Norwegian crustaceans and above the action limit set by the EU for the radioactive isotope Technetium 99 in the event of a new atomic accident. British authorities have refused to stop the pollution and even plan to start production of MOX fuel at Sellafield. They say new purification techniques will be developed within three or five years. For Norway, the opposition against Sellafield is a priority.

  11. Irish and Scandinavian objection to Sellafield

    International Nuclear Information System (INIS)

    Haaland, Leif

    2001-01-01

    The article deals with the objection of Ireland and the Scandinavian countries to the radioactive emissions from the Sellafield reprocessing plant. This contamination follows the sea currents northward and radioactive material from this plant has been found in seaweed and crustaceans along the coast of Norway. The concentration in lobster from the Irish Sea is much higher than in Norwegian crustaceans and above the action limit set by the EU for the radioactive isotope Technetium 99 in the event of a new atomic accident. British authorities have refused to stop the pollution and even plan to start production of MOX fuel at Sellafield. They say new purification techniques will be developed within three or five years. For Norway, the opposition against Sellafield is a priority

  12. The End of Hypergamy: Global Trends and Implications.

    Science.gov (United States)

    Esteve, Albert; Schwartz, Christine R; Van Bavel, Jan; Permanyer, Iñaki; Klesment, Martin; Garcia, Joan

    2016-12-01

    The gender gap in education that has long favored men has reversed for young adults in almost all high and middle-income countries. In 2010, the proportion of women aged 25-29 with a college education was higher than that of men in more than 139 countries which altogether represent 86% of the world's population. According to recent population forecasts, women will have more education than men in nearly every country in the world by 2050, with the exception of only a few African and West Asian countries (KC et al. 2010). The reversal of the gender gap in education has major implications for the composition of marriage markets, assortative mating, gender equality, and marital outcomes such as divorce and childbearing (Van Bavel 2012). In this work, we focus on its implications for trends in assortative mating and, in particular, for educational hypergamy: the pattern in which husbands have more education than their wives. This represents a substantial update to previous studies (Esteve et al. 2012) in terms of the number of countries and years included in the analysis. We present findings from an almost comprehensive world-level analysis using census and survey microdata from 420 samples and 120 countries spanning from 1960 to 2011, which allow us to assert that the reversal of the gender gap in education is strongly associated with the end of hypergamy and increases in hypogamy (wives have more education that their husbands). We not only provide near universal evidence of this trend but extend our analysis to consider the implications of the end of hypergamy for family dynamics, outcomes and gender equality. We draw on European microdata to examine whether women are more likely to be the breadwinners when they marry men with lower education than themselves and discuss recent research regarding divorce risks among hypogamous couples. We close our analysis with an examination of attitudes about women earning more money than their husbands and about the implications

  13. The Atom in a Molecule: Implications for Molecular Structure and Properties

    Science.gov (United States)

    2016-05-23

    Briefing Charts 3. DATES COVERED (From - To) 01 February 2016 – 23 May 2016 4. TITLE AND SUBTITLE The atom in a molecule: Implications for molecular...For presentation at American Physical Society - Division of Atomic , Molecular, and Optical Physics (May 2016) PA Case Number: #16075; Clearance Date...10 Energy (eV) R C--H (au) R C--H(au) The Atom in a Molecule: Implications for Molecular Structures and Properties P. W. Langhoff, Chemistry

  14. miRNAs in inflammatory skin diseases and their clinical implications

    DEFF Research Database (Denmark)

    Løvendorf, Marianne B; Skov, Lone

    2015-01-01

    biological processes. The clinical implications of miRNAs are intriguing, both from a diagnostic and a therapeutic perspective. Accordingly, there is emerging evidence for the clinical potential of miRNAs as both biomarkers and possible therapeutic targets in skin diseases. Future studies will hopefully...... incomplete; however, it is known that miRNAs are implicated in various cellular processes of both normal and diseased skin. Some miRNAs appear to be consistently deregulated in several different inflammatory skin diseases, including psoriasis and atopic dermatitis, indicating a common role in fundamental...

  15. The nuclear and its psychological implications

    International Nuclear Information System (INIS)

    Blanc, D.

    2001-01-01

    From the 13. to 15. january 1977, the S.F.R.P. has organised at Paris, with the patronage of The National Institute of Health and Medical Research, the French Society of Radiology, a colloquium devoted to the nuclear and its psycho-implications sociological. It is a second edition, realised at the demand of the Antoine Beclere Center. (N.C.)

  16. Origin of comets - implications for planetary formation

    International Nuclear Information System (INIS)

    Weissman, P.R.; Arizona Univ., Tucson)

    1985-01-01

    Primordial and episodic theories for the origin of comets are discussed. The implications of the former type for the origin of the solar system are considered. Candidate sites for the formation of comets are compared. The possible existence of a massive inner Oort cloud is discussed

  17. Investigating Teachers' Personal Visions and Beliefs: Implications ...

    African Journals Online (AJOL)

    Investigating Teachers' Personal Visions and Beliefs: Implications for Quality in Language Teacher Education. ... attitude, focus and performance. The growing influence of constructivism in teacher education and the increase in the amount of research into teacher cognition has put the notion of beliefs and vision into central ...

  18. Alternative Families and Children: Implications for Education.

    Science.gov (United States)

    Alexander, Jannette; Eiduson, Bernice T.

    1980-01-01

    Since 1973, the UCLA Family Styles Project has studied a sample of nontraditional Caucasian families (single mothers, social contract families, communal families) plus a comparison group of conventional nuclear families. Findings are reported on parents' personal/social values and changes in childrearing practices. Implications for education are…

  19. Mycobacterial Species Identification and Public Health Implications ...

    African Journals Online (AJOL)

    Mycobacterial Species Identification and Public Health Implications of Tuberculosis Among Nomadic Pastoralists in Three Local Governments of Plateau State, North ... Bovine and human tuberculosis is endemic in Nigeria, and apart from meat inspection at the abattoir, which is not very effective, no control measures are ...

  20. Managerialism and higher education governance: Implications for ...

    African Journals Online (AJOL)

    This article identifies some of the implications of corporate forms of higher education governance for the management of South African universities. It explores corporate higher educational governance with reference to institutional autonomy incorporating academic freedom. It is the contention of this article that the primary ...

  1. Environmental conflicts: Key issues and management implications

    African Journals Online (AJOL)

    main manifestations and implications of these conflicts are examined in the next section ... with invasive or alien species. This special ... the majority of potential pest species. ... Production of goods: food, durable materials and industrial products, ... well as a remarkably stable life support system that has allowed human.

  2. Transnational Education: Current Developments and Policy Implications

    Science.gov (United States)

    Gu, Jianxin

    2009-01-01

    Ever since the transnational education trend took off since the 1980s, transnational education has come to bearing political, economic and cultural implications. Different approaches have been formulated to achieve specific policy objectives by both importing and exporting countries. Such approaches demonstrate a four dimensional composition,…

  3. Implications of ecological and social characteristics to community ...

    African Journals Online (AJOL)

    Implications of ecological and social characteristics to community livelihoods in the coastal ... African Journal of Environmental Science and Technology ... This will further address conflicts over resource uses that may arise due to livelihood ...

  4. implications of decision making process on agricultural employees

    African Journals Online (AJOL)

    This study was designed to determine the implications of decision making process on employees' turnover in the Institute of ... Involvement in Decision Making and Agricultural Employees' Turnover in Ibadan, Nigeria 37 ..... Lack of motivation.

  5. Dependence on carbonated water: Clinical and policy implications

    Directory of Open Access Journals (Sweden)

    Sumit Kumar Gupta

    2015-01-01

    Full Text Available A case of caffeine dependence syndrome with preference for a specific brand of carbonated water (popularly known as soft drinks or colas is discussed to highlight the clinical and policy implications.

  6. Awareness of Health Implications of Agrochemical Use: Effects on Maize Production in Ejura-Sekyedumase Municipality, Ghana

    Directory of Open Access Journals (Sweden)

    Franklin N. Mabe

    2017-01-01

    Full Text Available This study assessed factors that affect awareness of health implications of agrochemical use and its effects on maize production in Ejura-Sekyedumase Municipality of Ashanti Region, Ghana. One hundred and fifty-four (154 maize farmers were randomly sampled from the municipality. The study used awareness indicators to estimate an index representing farmers’ awareness levels of health implications of agrochemical use. An ordered logit compliment with multivariate linear regression model was used to identify the drivers of farmers’ awareness level of health implications of agrochemical use. Also, a multivariate linear regression model was used to analyze the effects of health implications of agrochemical use on maize output. On average, the respondents have the moderate awareness level of health implications of agrochemical use (0.578. The awareness level was significantly explained by education, the number of children in school, ownership of TV/radio, experience in agrochemicals use, and farm size. The multivariate linear regression results showed that awareness levels of health implications of agrochemical use increase maize output. It is therefore recommended that interventions aimed at increasing farmers’ awareness levels of health implications of agrochemicals use should focus on educating farmers through interactive radio discussion and training sessions on the field and incorporate safety use of agrochemical in our educational curriculum.

  7. Biotic and abiotic influences on rocky intertidal biomass and ...

    African Journals Online (AJOL)

    composition of these zones, noting the characteristic dominants. Subtidal fringe ... algae and contains an extremely rich associated fauna of small crustaceans, errant polychaetes ..... by most authors (Brown & Jarman 1978), and Stephenson.

  8. Adsorptive removal of cationic dye from aqueous solution using ...

    African Journals Online (AJOL)

    PROF HORSFALL

    Received 15 October 2017, received in revised form 03 December 2017, accepted 31 December 2017. Keywords: African Border Tree, ... to remove dyes include flocculation, oxidation, ..... estuarine algae, crustaceans and fishes. Environ.

  9. Climate Change and Interacting Stressors: Implications for ...

    Science.gov (United States)

    EPA announced the release of the final document, Climate Change and Interacting Stressors: Implications for Coral Reef Management in American Samoa. This report provides a synthesis of information on the interactive effects of climate change and other stressors on the reefs of American Samoa as well as an assessment of potential management responses. This report provides the coral reef managers of American Samoa, as well as other coral reef managers in the Pacific region, with some management options to help enhance the capacity of local coral reefs to resist the negative effects of climate change. This report was designed to take advantage of diverse research and monitoring efforts that are ongoing in American Samoa to: analyze and compile the results of multiple research projects that focus on understanding climate-related stressors and their effects on coral reef ecosystem degradation and recovery; and assess implications for coral reef managment of the combined information, including possible response options.

  10. The estrogen hypothesis of schizophrenia implicates glucose metabolism

    DEFF Research Database (Denmark)

    Olsen, Line; Hansen, Thomas; Jakobsen, Klaus D

    2008-01-01

    expression studies have indicated an equally large set of candidate genes that only partially overlap linkage genes. A thorough assessment, beyond the resolution of current GWA studies, of the disease risk conferred by the numerous schizophrenia candidate genes is a daunting and presently not feasible task....... We undertook these challenges by using an established clinical paradigm, the estrogen hypothesis of schizophrenia, as the criterion to select candidates among the numerous genes experimentally implicated in schizophrenia. Bioinformatic tools were used to build and priorities the signaling networks...... implicated by the candidate genes resulting from the estrogen selection. We identified ten candidate genes using this approach that are all active in glucose metabolism and particularly in the glycolysis. Thus, we tested the hypothesis that variants of the glycolytic genes are associated with schizophrenia...

  11. The implicit contract: implications for health social work.

    Science.gov (United States)

    McCoyd, Judith L M

    2010-05-01

    Identifying common patient dynamics is useful for developing social work practice sensitivity in health social work. This article draws on findings from a study of women who terminated desired pregnancies because of fetal anomalies and identifies dynamics that may be applicable to many health settings. Data suggest that women have expectations that submission to medical care, particularly high-tech medical care, should ensure a positive outcome--in this case a healthy baby. Analysis of data reveals the presence of an implicit contract that the women hold with the medical system,"Mother Nature," or society. The analysis carries an implication that health social work should help patients develop realistic expectations about health care. The presence of implicit contracts may have further implications for liability and litigation. Social work roles and interventions are addressed.

  12. DMPD: Innate immunity and toll-like receptors: clinical implications of basic scienceresearch. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15069387 Innate immunity and toll-like receptors: clinical implications of basic science...te immunity and toll-like receptors: clinical implications of basic scienceresearch. PubmedID 15069387 Title... Innate immunity and toll-like receptors: clinical implications of basic sciencer

  13. Technical limitations of African prints and their implications

    African Journals Online (AJOL)

    User

    THEIR IMPLICATIONS ON GARMENT CONSTRUCTION IN. GHANA ... economic growth throughout the world. In. 2001, the sector ... and its exports represent 45 billion Euros, mak- ing it the world's ..... Unpublished BA Thesis,. College of Art ...

  14. Introducing change in organization: implication for human resource ...

    African Journals Online (AJOL)

    Introducing change in organization: implication for human resource ... that one of the most obvious and urgent problems at management level in organizations is ... to change their attitude and behavior as rapidly as their organization requires.

  15. attitudes of women to menopause: implications for counselling

    African Journals Online (AJOL)

    Elizabeth

    conforms to society's standards of youth and beauty include low self- esteem, depression and anxiety. .... issue in understanding her attitudes or perception of menopause. Fifty- .... Lippert, L. (1997). Women at midlife: Implications for theories of.

  16. Mainstreaming academic literacy teaching: Implications for how ...

    African Journals Online (AJOL)

    This article draws on research into the role of academic literacies within a range of disciplines and its implications for academic literacy teaching in Higher Education. The study explored ways of transforming current academic literacy teaching practices with a view to developing better synergy between the academic ...

  17. Implications of the behavioral approach to hypnosis.

    Science.gov (United States)

    Starker, S

    1975-07-01

    The findings of behaviorally oriented research regarding the importance of cognitive-motivational variables in hypnosis are examined and some clinical and theoretical implications are explored. Hypnosis seems usefully conceptualized as a complex configuration or gestalt of interacting variables on several different levels, for example, cognitive, motivational, social, physiologic.

  18. Total Quality Management: Implications for Educational Assessment.

    Science.gov (United States)

    Rankin, Stuart C.

    1992-01-01

    Deming's "System of Profound Knowledge" is even more fundamental than his 14-principle system transformation guide and is based on 4 elements: systems theory, statistical variation, a theory of knowledge, and psychology. Management should revamp total system processes so that quality of product is continually improved. Implications for…

  19. Federal Tax Implications of Charitable Gift Annuities

    Science.gov (United States)

    Teitell, Conrad

    1975-01-01

    Surveys the federal tax implications of "immediate" charitable gift annuities (annuity payments beginning within one year of transfer) and "deferred payment" charitable gift annuities (beginning at a specified date), both of which enable individuals to make a charitable gift, retain a form of life income, and achieve federal…

  20. Forensic implications: adolescent sexting and cyberbullying.

    Science.gov (United States)

    Korenis, Panagiota; Billick, Stephen Bates

    2014-03-01

    Adolescence is marked by establishing a sense of identity, core values, a sense of one's relationship to the outside world and heightened peer relationships. In addition, there is also risk taking, impulsivity, self exploration and dramatic increase in sexuality. The dramatic increase in the use of cell phones and the Internet has additional social implications of sexting and cyberbullying. Sexting refers to the practice of sending sexually explicit material including language or images to another person's cell phone. Cyberbullying refers to the use of this technology to socially exclude, threaten, insult or shame another person. Studies of cell phone use in the 21st century report well over 50% of adolescents use them and that text messaging is the communication mode of choice. Studies also show a significant percentage of adolescents send and receive sex messaging, both text and images. This paper will review this expanding literature. Various motivations for sexting will also be reviewed. This new technology presents many dangers for adolescents. The legal implications are extensive and psychiatrists may play an important role in evaluation of some of these adolescents in the legal context. This paper will also make suggestions on future remedies and preventative actions.

  1. Generic implications of the Chernobyl accident

    International Nuclear Information System (INIS)

    Sege, G.

    1989-01-01

    The US Nuclear Regulatory Commission (NRC) staff's assessment of the generic implications of the Chernobyl accident led to the conclusion that no immediate changes in the NRC's regulations regarding design or operation of US commercial reactors are needed. However, further consideration of certain issues was recommended. This paper discusses those issues and the studies being addressed to them. Although 24 tasks relating to light water reactor issues are identified in the Chernobyl follow-up research program, only four are new initiatives originating from Chernobyl implications. The remainder are limited modifications of ongoing programs designed to ensure that those programs duly reflect any lessons that may be drawn from the Chernobyl experience. The four new study tasks discussed include a study of reactivity transients, to reconfirm or bring into question the adequacy of potential reactivity accident sequences hitherto selected as a basis for design approvals; analysis of risk at low power and shutdown; a study of procedure violations; and a review of current NRC testing requirements for balance of benefits and risks. Also discussed, briefly, are adjustments to ongoing studies in the areas of operational controls, design, containment, emergency planning, and severe accident phenomena

  2. changing stm curricula for the information age: implications

    African Journals Online (AJOL)

    TONIA CLARE

    information age, rationale and strategies for changing STM curricular, implications for the teacher and then conclusion. ... learner under the guidance of a school to effect a change in the ..... education international conference. Ofele, C. N. ...

  3. Satirical drama, political corruption and development implications for ...

    African Journals Online (AJOL)

    Satirical drama, political corruption and development implications for Nigeria: a reflection on Ola Rotimi's Our husband has gone mad again. ... The corrupt tendencies of this select few, which come in various forms, have ... from 32 Countries:.

  4. Keystone Life Orientation (LO) teachers: Implications for educational ...

    African Journals Online (AJOL)

    Keystone Life Orientation (LO) teachers: Implications for educational, social, and ... characteristics and support networks needed by keystone Life Orientation (LO) ... In this study “keystone” refers to LO teachers who make a positive impact in ...

  5. A novel homozygous truncating GNAT1 mutation implicated in retinal degeneration

    OpenAIRE

    Carrigan, Matthew; Duignan, Emma; Humphries, Pete; Palfi, Arpad; Kenna, Paul F; Farrar, G Jane

    2015-01-01

    Background The GNAT1 gene encodes the ? subunit of the rod transducin protein, a key element in the rod phototransduction cascade. Variants in GNAT1 have been implicated in stationary night-blindness in the past, but unlike other proteins in the same pathway, it has not previously been implicated in retinitis pigmentosa. Methods A panel of 182 retinopathy-associated genes was sequenced to locate disease-causing mutations in patients with inherited retinopathies. Results Sequencing revealed a ...

  6. Species identification of ciguatoxin-carrying grouper implicated in food poisoning.

    Science.gov (United States)

    Hsieh, Cheng-Hong; Hwang, Ken-Lin; Lee, Ming-Ming; Lan, Chi-Hsun; Lin, Wen-Feng; Hwang, Deng-Fwu

    2009-11-01

    Food poisoning due to ingestion of an unknown red grouper occurred in southern Taiwan. To identify the species of toxic red grouper implicated in food poisoning, a 475-bp sequence of the cytochrome b gene from six species of fresh red grouper meat was amplified by using a pair of primers (L14735/H15149). This fragment could be amplified when fish meat was treated with different heating processes. After sequencing, it was found that no variation in sequences was detected among individuals within each species. The species of toxic red grouper meat implicated in food poisoning was judged to be Lutjanus bohar based on sequence analysis. In addition, restriction enzyme analysis with HaeIII rapidly distinguished these six species of red grouper and the two samples implicated in food poisoning. No toxicity of viscera in 18 specimens of six red grouper species was detected, but two food poisoning samples were found to be toxic. This study indicated that DNA sequence and restriction enzyme analysis are powerful methods for identifying potentially toxic red grouper species as L. bohar.

  7. Bioenergy and its implication for yoga therapy

    Directory of Open Access Journals (Sweden)

    Chathapuram Rajan Narayanan

    2018-01-01

    Full Text Available Electro photonic imaging (EPI is being researched relative to its application for yoga therapy. Three parameters of interest in EPI measurements are as follows: Communication energy (C, integral or normalized area (IA, and Entropy (E. It is important to note that C indicates the total energy of communication for the organ system; IA is an indication of total amount of energy that is available for the organ system while entropy is an indication of the amount of coherence of the energy. Coherence and entropy are inversely related; this means less the entropy, more the coherence and vice versa. Illustrative cases of successful therapy with yoga practices in a wide variety of abnormal conditions are examined, and in every case, entropy is shown to decrease for the affected organ system while communication energy stays within stable range. Relative to the electromagnetic (Rubik and living matrix (Oschman models, it is suggested that the regulation of energy, its coherence in the biological system and interaction with life processes provide the basis for model building and design of health-promoting procedures. Further, this approach is examined relative to yoga theory, traditional medicine systems, and scientific developments in the field of gene expression and neuroplasticity and a generalized model that we call Unified System of Medicine is proposed. This model has direct implications on methods used to control the environmental factors to get robust results from EPI application for therapeutic purposes. Implications for furthering research in yoga therapy using EPI and implications of EPI as a translational technology between traditional medicine systems and modern medicine is discussed.

  8. AFSC/RACE/SAP/Swiney: Effects of holding space on juvenile red king crab growth and survival

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rearing crustaceans communally for aquaculture, stock enhancement or research often results in high rates of cannibalism and low yields. One potential strategy to...

  9. systems, pelagic fish of the southern Benguela are dominated

    African Journals Online (AJOL)

    denise

    cyclopoid copepods, anchovy eggs and crustacean eggs being the primary prey types. ... Key words: feeding, phytoplankton, sardine, southern Benguela, zooplankton. * Marine ...... KAWASAKI, T. and A. KUMAGAI 1984 — Food habits of the.

  10. Comparative morphology of the feeding appendages of four ...

    African Journals Online (AJOL)

    The morphology of feeding appendages of the coexisting estuarine copepods, Pseudodiaptomus hessei and ..... are indicative of a predominantly herbivorous feeding habit; an EI value of ..... of a mysid crustacean, Hemimysis lamornae. Trans.

  11. Body mass management of lightweight rowers: nutritional strategies and performance implications.

    Science.gov (United States)

    Slater, Gary; Rice, Anthony; Jenkins, David; Hahn, Allan

    2014-11-01

    The majority of lightweight rowers undertake acute weight loss prior to competition. Given the competitive advantage afforded to larger, more muscular rowers over their smaller counterparts, the use of moderate, acute weight loss may be justified, at least among larger, leaner athletes who struggle to achieve the specified body mass requirement and have limited potential for further body mass loss via reductions in body fat. The performance implications of moderate acute weight loss appear to be small on the ergometer and may be even less on water, at least when aggressive recovery strategies are adopted between weigh-in and racing. Furthermore, any performance implications of acute weight loss are not exacerbated when such weight loss is undertaken repeatedly throughout the course of a regatta, and may even be eliminated when aggressive recovery strategies are introduced before and after racing. The combination of adequate sodium, fluid and carbohydrate in line with current guidelines results in the best performances. While the performance implications of modest acute weight loss may still need to be considered in regard to competition outcome, chronic body mass strategies may not be without performance implications. This is especially the case for athletes who have very low levels of body fat and/or athletes who decrease their body mass too quickly. Further studies are needed to address the degree of weight loss that can be tolerated with minimal health and/or performance implications, and the optimal time frame over which this should occur. Possible adaptation to the physiological state that accompanies acute weight loss also warrants investigation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. The dental public health implications of cosmetic dentistry: a scoping review of the literature.

    Science.gov (United States)

    Doughty, J; Lala, R; Marshman, Z

    2016-09-01

    The popularity of cosmetic surgery has seen a rapid increase recently, with the trend mirrored in dentistry. The Department of Health expressed concerns about the potential for biological and psychosocial harm of these cosmetic procedures. Furthermore, the dental public health implications (DPH) of the growing uptake of cosmetic dental procedures have not been explored. Conduct a scoping review to explore the DPH implications of cosmetic dentistry and identify gaps for future research. A fivestage scoping review was conducted of studies identified using the search terms cosmetic AND dentistry. Data from the studies meeting the inclusion criteria were extracted, collated and summarised into themes. Fifty-seven papers met the inclusion criteria (11 cross-sectional studies, 10 literature reviews and 36 opinion pieces). The DPH implications were summarised into five emergent themes: dento-legal and ethical, marketing, psychosocial, biological and workforce. These themes revealed patients' increased expectations, expanding commercialisation of the profession, psychological risks to vulnerable patients, the iatrogenic consequences of invasive cosmetic dental procedures and workforce implications of the current trends. The scoping review found that existing literature on cosmetic dentistry is predominately anecdotal - professional opinions and discussions. Despite this, our findings demonstrated workforce training and governance implications due to increased demand for cosmetic dentistry. Further empirical research is needed to understand the DPH implications of the increasing demand and uptake of cosmetic dental procedures to guide evidence-based policy to safeguard patients and improve the quality of dental services. Copyright© 2016 Dennis Barber Ltd

  13. Nuclear debate and its implications in Latin America

    Energy Technology Data Exchange (ETDEWEB)

    Huacuz V, J M

    1977-09-01

    The controversy associated with nuclear power has been grouped into three areas: safety, economics, and availability of uranium. Implications of these factors are discussed in terms of their effects on Third World countries, particularly in Latin America.

  14. Bioavailability: implications for science/cleanup policy

    Energy Technology Data Exchange (ETDEWEB)

    Denit, Jeffery; Planicka, J. Gregory

    1998-12-01

    This paper examines the role of bioavailability in risk assessment and cleanup decisions. Bioavailability refers to how chemicals ''behave'' and their ''availability'' to interact with living organisms. Bioavailability has significant implications for exposure risks, cleanup goals, and site costs. Risk to human health and the environment is directly tied to the bioavailability of the chemicals of concern.

  15. 2014 and beyond: implications for displacement

    Directory of Open Access Journals (Sweden)

    Aidan O’Leary

    2014-05-01

    Full Text Available 2014 marks a watershed for Afghanistan, with the withdrawal of the International Security Assistance Force after twelve years, and the very real risks this withdrawal poses to the capacity of the Afghan state to meet the many internal and external challenges faced by the country. These challenges have significant implications for displaced and returning Afghans and for the potential for displacement in the future.

  16. Civil implications of commercial nuclear power

    International Nuclear Information System (INIS)

    Wilkinson, P.; Gallie, N.

    1985-01-01

    The following aspects are discussed; spent fuel transport by rail, routes and possible accidents; reactors, possible accidents and effects of radioactive releases to the environment; possible effects of sabotage and terrorist attacks; possible hazards from fuel reprocessing plants; radioactive wastes, inventories and possible effects of escape to environment; biological radiation effects; civil war effects and democratic freedoms; the miners' strike and its implications. (U.K.)

  17. The acute toxicity of thallium to freshwater organisms: Implications for risk assessment.

    Science.gov (United States)

    Tatsi, Kristi; Turner, Andrew; Handy, Richard D; Shaw, Benjamin J

    2015-12-01

    The acute toxicity of Tl(I) to the microalga, Pseudokirchneriella subcapitata, the planktonic crustaceans, Daphnia magna and Daphnia pulex, and early-life stage of the zebrafish, Danio rerio, has been studied according to OECD protocols. Toxicological end-point concentrations for the microalga ranged from 17 μg l(-1) for a 72 h EyC25 (yield inhibition) to 80 μg l(-1) for a 72 h ErC50 (growth inhibition). Daphnia were less sensitive to Tl, with 48 h EC50s of about 1000 μg l(-1) and 1200 μg l(-1) for D. magna and D. pulex, respectively; however, end-point concentrations were reduced considerably (to about 510 μg l(-1) and 730 μg l(-1), respectively) when experiments were repeated in dechlorinated Plymouth tap water (rather than OECD medium). The 96 h LC50 for D. rerio was 870 μg l(-1) but a variety of sub-lethal effects, including enlargement of yolk sac and reduction in heart beat rate, were observed when larvae were exposed to lower concentrations. Based on these results, a predicted no effect concentration (PNEC) for Tl in freshwaters of 0.087 μg l(-1) is proposed. The PNEC is an order of magnitude lower than the only (Canadian) water quality guideline for Tl that appears to exist, and is lower than Tl concentrations reported in freshwaters impacted by historical or contemporary metal mining. Our results are also consistent with previous studies that employ different organisms and end-points in that Tl toxicity is dependent on the concentration of K+, the biogeochemical analogue of Tl+. Accordingly, regulation of Tl in the freshwater environment should factor in the relative abundance of K. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Estuary-ocean connectivity: fast physics, slow biology.

    Science.gov (United States)

    Raimonet, Mélanie; Cloern, James E

    2017-06-01

    Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1-3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary-ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to changing

  19. Allergic risks of consuming edible insects: A systematic review.

    Science.gov (United States)

    Ribeiro, José Carlos; Cunha, Luís Miguel; Sousa-Pinto, Bernardo; Fonseca, João

    2018-01-01

    The expected future demand for food and animal-derived protein will require environment-friendly novel food sources with high nutritional value. Insects may be one of such novel food sources. However, there needs to be an assessment of the risks associated with their consumption, including allergic risks. Therefore, we performed a systematic review aiming to analyse current data available regarding the allergic risks of consuming insects. We reviewed all reported cases of food allergy to insects, and studied the possibility of cross-reactivity and co-sensitisation between edible insects, crustaceans and house dust mites. We analysed a total of 25 articles - eight assessing the cross-reactivity/co-sensitisation between edible insects, crustaceans and house dust mites; three characterizing allergens in edible insects and 14 case reports, describing case series or prevalence studies of food allergy caused by insects. Cross-reactivity/co-sensitisation between edible insects and crustaceans seems to be clinically relevant, while it is still unknown if co-sensitisation between house dust mites and edible insects can lead to a food allergy. Additionally, more information is also needed about the molecular mechanisms underlying food allergy to insects, although current data suggest that an important role is played by arthropod pan-allergens such as tropomyosin or arginine kinase. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Local knowledge of traditional fishermen on economically important crabs (Decapoda: Brachyura) in the city of Conde, Bahia State, Northeastern Brazil.

    Science.gov (United States)

    de Magalhães, Henrique Fernandes; Costa Neto, Eraldo Medeiros; Schiavetti, Alexandre

    2012-07-02

    This article records the traditional knowledge of crab gatherers in the city of Conde, in the North Coast Region of Bahia State, Northeastern Brazil. Data on biological and ecological aspects of economically important brachyuran crustaceans have been obtained from semi-structured interviews and in loco observations conducted from September 2007 to December 2009. A total of 57 fishermen of both genders, aged between 10 and 78 years have been interviewed (individually or collectively) in different contexts; interviewees were asked about aspects such as external morphology, life cycle, trophic ecology, and spatial and temporal distribution of the major economically important brachyuran crustaceans in the region. Seven fishing communities were visited: Siribinha, Sítio do Conde, Poças, Ilha das Ostras, Cobó, Buri and Sempre Viva. Data were analyzed by comparing the information provided by participants with those from the specialized academic literature. The results show that artisanal fishermen have a wide ranging and well-grounded knowledge on the ecological and biological aspects of crustaceans. Crab gatherers of Conde know about growth and reproductive behavior of the animals they interact with, especially with regard to the three major biological aspects: "molt", "walking dance" and "spawning". This knowledge constitutes an important source of information that should be considered in studies of management and sustainable use of fishery resources in the North Coast Region of Bahia State.