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Sample records for brugia malayi larvae

  1. Anti-idiotypic antibodies function as a surrogate surface epitope of Brugia malayi infective larvae.

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    Carlow, C K; Busto, P; Storey, N; Philipp, M

    1990-07-01

    Anti-idiotypic (AB2) antibodies were generated in rabbits following immunization with a murine IgM monoclonal antibody (AB1) recognizing a surface determinant of Brugia malayi infective stage larvae. AB2 specifically inhibited the binding of AB1 to B. malayi larvae. Furthermore, AB2 had the ability to mimic the original antigen since mice immunized with AB2 possessed serum antibodies (AB3) specific for the B. malayi surface determinant. The presence of anti-surface antibodies (AB3 and AB1) induced either by AB2 immunization or by administration of AB1, did not alter the outcome of an intraperitoneal infection of B. malayi larvae in BABL/c mice when compared to untreated animals. AB3 antibodies like AB1, were IgM, thus indicating an isotype restricted response to the B. malayi epitope. There were no detectable cell mediated responses to the surface determinant in mice immunized with AB2, assessed by lymphocyte blastogenesis or IL3 production in vitro in response to the idiotope as presented by living larvae. The lack of cellular responses and/or the previously demonstrated rapid shedding of the epitope may explain the inability of AB1 or AB2 to protect mice against larval challenge in this study.

  2. Detection of Brugia malayi microfilaria/Larvae in mosquito using Polimerase Chain Reaction.

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    Dyah Haryuningtyas

    2008-10-01

    Full Text Available Lymphathic filariasis that is also known as elepanthiasis is caused by infestation of 3 species nematode Wuchereria bancrofti, Brugia malayi and Brugia timori. In Indonesia 70% filariasis case caused by Brugia malayi. Mosquito species from genus Anopheles, Aedes, Culex, Mansonia and Armigeres are known as vector of this disease. Microfilaria detection on mosquito is one methode to know infection rate in vector population in endemic area.The objectives of the research were to study the ability of Hha1 repeat applicable to detect microfilaria/larvae in a pool of mosquitoes and to get description of adult mosquito night biting population lived in endemic area of filariasis brugian. Mosquito as positive control used in this research come from laboratory of parasitology of FKUI. Mosquito sample from the field was from Binawara and Kolam Kiri villages, South Kalimantan province. Mosquito were trapped then identified by its species. DNA of mosquitoes was extracted and then run by the PCR using Hha 1 repeat primer. Result of the research indicated that adult mosquitoes night biting from Binawara village consist of Culex, Mansonia, Anopheles genus and from Kolam Kiri village only from Mansonia genus. Hha 1 repeat primer is applicable to detect 1 mosquito infected with microfilaria/larvae in a pool of negative mosquitoes. Mosquito samplesfrom the two villages showing negative PCR.

  3. Brugia malayi infective larvae fail to activate Langerhans cells and dermal dendritic cells in human skin.

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    Cotton, R N; McDonald-Fleming, R; Boyd, A; Spates, K; Nutman, T B; Tolouei Semnani, R

    2015-02-01

    Filarial infection in humans is initiated when a mosquito deposits third-stage parasite larvae (L3) in the skin. Langerhans cells (LCs) and dermal dendritic cells (DDCs) are the first cells that the parasite encounters, and L3s must evade these highly effective antigen-presenting cells to establish infection. To assess LC and DDC responses to L3 in human skin, we employed three models of increasing physiologic relevance: in vitro-generated LCs, epidermal blister explants and full-thickness human skin sections. In vitro-generated LCs expressed TLR1-10 and robustly produced IL-6 and TNF-α in response to PolyI:C, but pre-exposure to L3s did not alter inflammatory cytokine production or TLR expression. L3s did not modulate expression of LC markers CDH1, CD207, or CD1a, or the regulatory products TSLP or IDO in epidermal explants or in vitro-generated LC. LC, CD14+ DDC, CD1c+ DC and CD141+ DC from human skin sections were analysed by flow cytometry. While PolyI:C potently induced CCL22 production in LC, CD1c+ DC, and CD141+ DC, and IL-10 production in LC, L3s did not modulate the numbers of or cytokine production by any skin DC subset. L3s broadly failed to activate or modulate LCs or DDCs, suggesting filarial larvae expertly evade APC detection in human skin.

  4. Draft genome of the filarial nematode parasite Brugia malayi.

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    Ghedin, Elodie; Wang, Shiliang; Spiro, David; Caler, Elisabet; Zhao, Qi; Crabtree, Jonathan; Allen, Jonathan E; Delcher, Arthur L; Guiliano, David B; Miranda-Saavedra, Diego; Angiuoli, Samuel V; Creasy, Todd; Amedeo, Paolo; Haas, Brian; El-Sayed, Najib M; Wortman, Jennifer R; Feldblyum, Tamara; Tallon, Luke; Schatz, Michael; Shumway, Martin; Koo, Hean; Salzberg, Steven L; Schobel, Seth; Pertea, Mihaela; Pop, Mihai; White, Owen; Barton, Geoffrey J; Carlow, Clotilde K S; Crawford, Michael J; Daub, Jennifer; Dimmic, Matthew W; Estes, Chris F; Foster, Jeremy M; Ganatra, Mehul; Gregory, William F; Johnson, Nicholas M; Jin, Jinming; Komuniecki, Richard; Korf, Ian; Kumar, Sanjay; Laney, Sandra; Li, Ben-Wen; Li, Wen; Lindblom, Tim H; Lustigman, Sara; Ma, Dong; Maina, Claude V; Martin, David M A; McCarter, James P; McReynolds, Larry; Mitreva, Makedonka; Nutman, Thomas B; Parkinson, John; Peregrín-Alvarez, José M; Poole, Catherine; Ren, Qinghu; Saunders, Lori; Sluder, Ann E; Smith, Katherine; Stanke, Mario; Unnasch, Thomas R; Ware, Jenna; Wei, Aguan D; Weil, Gary; Williams, Deryck J; Zhang, Yinhua; Williams, Steven A; Fraser-Liggett, Claire; Slatko, Barton; Blaxter, Mark L; Scott, Alan L

    2007-09-21

    Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design.

  5. Transient effects of levamisole on Brugia malayi microfilariae.

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    Mostafa, Eman; Storey, Bob; Farghaly, Adel Mohammed; Afify, Hany Abd El-Hai; Taha, Afaf Abd El-Raouf; Wolstenholme, Adrian J

    2015-09-01

    Levamisole is an anthelmintic drug that acts by activating nicotinic acetylcholine receptors at the nematode neuromuscular junction and causing paralysis. We measured the in vitro effects of levamisole on the motility of Brugia malayi microfilariae; after 2 h incubation the apparent IC50 was 2.68 mM. Lower drug concentrations, such as 1 mM, caused an immediate total paralysis that lasted for up to 1 h, but was completely reversed by 2 h of incubation. The 'recovered' parasites were still completely susceptible to application of a second nicotinic agonist, pyrantel.

  6. Antifilarial activity of gum from Moringa oleifera Lam. on human lymphatic filaria Brugia malayi

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    V Kushwaha

    2011-01-01

    Full Text Available Aim: Currently available antifilarial drugs diethylcarbamazine, ivermectin and albendazole and their combinations, are not able to control lymphatic filariasis. Therefore, a better antifilarial agent is urgently required for proper management of the disease. Materials and Methods: In this study, we evaluated the antifilarial activity of gum extract of plant Moringa oleifera Lam. against the human lymphatic filarial parasite Brugia malayi using adult worms and microfilariae (mf in two in vitro assays (motility and inhition in MTT reduction for viability and two animal models, primary (Meriones unguiculatus implanted with B. malayi adult worms in the peritoneal cavity and secondary (subcutaneous B. malayi infective larvae induced Mastomys coucha, the model closer to the natural human filarial infection screens. Results: The gum extract inhibited 100% motility (irreversible loss of motility of mf and inhibited more than 56% MTT reduction potential of the adult female worms. The extract was safe in cytotoxicity test using Vero cell line, therefore followed in vivo in primary and secondary screens. In primary screen, the extract (5×500 mg/kg caused 69% macrofilaricidal and 83% sterilization of female worms and 44% macrofilaricidal activity in secondary screen (5 × 1000 mg/kg by oral route. Conclusion: Thus, it is concluded that the gum of the plant is macrofilaricidal in both in vitro and in vivo and may provide valuable leads for design and development of new antifilarial agents. This is the first ever report on the antifilarial efficacy of M. oleifera.

  7. The secreted triose phosphate isomerase of Brugia malayi is required to sustain microfilaria production in vivo.

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    James P Hewitson

    2014-02-01

    Full Text Available Human lymphatic filariasis is a major tropical disease transmitted through mosquito vectors which take up microfilarial larvae from the blood of infected subjects. Microfilariae are produced by long-lived adult parasites, which also release a suite of excretory-secretory products that have recently been subject to in-depth proteomic analysis. Surprisingly, the most abundant secreted protein of adult Brugia malayi is triose phosphate isomerase (TPI, a glycolytic enzyme usually associated with the cytosol. We now show that while TPI is a prominent target of the antibody response to infection, there is little antibody-mediated inhibition of catalytic activity by polyclonal sera. We generated a panel of twenty-three anti-TPI monoclonal antibodies and found only two were able to block TPI enzymatic activity. Immunisation of jirds with B. malayi TPI, or mice with the homologous protein from the rodent filaria Litomosoides sigmodontis, failed to induce neutralising antibodies or protective immunity. In contrast, passive transfer of neutralising monoclonal antibody to mice prior to implantation with adult B. malayi resulted in 60-70% reductions in microfilarial levels in vivo and both oocyte and microfilarial production by individual adult females. The loss of fecundity was accompanied by reduced IFNγ expression by CD4⁺ T cells and a higher proportion of macrophages at the site of infection. Thus, enzymatically active TPI plays an important role in the transmission cycle of B. malayi filarial parasites and is identified as a potential target for immunological and pharmacological intervention against filarial infections.

  8. Susceptibility of eight species members in the Anopheles hyrcanus group to nocturnally subperiodic Brugia malayi

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    Saeung Atiporn

    2013-01-01

    Full Text Available Abstract Background Filariasis, caused by Brugia malayi, is a public health problem in Thailand. Currently, at least two locations in southern Thailand are reported to be active endemic areas. Two and four Mansonia species are primary and secondary vectors, respectively, of the nocturnally subperiodic race, whereas, Coquillettidia crassipes is a vector of the diurnally subperiodic race. Although several Anopheles species have been incriminated extensively as natural and/or suspected vectors of B. malayi, little is known about vector competence between indigenous Anopheles and this filaria in Thailand. Thus, the susceptibility levels of eight species members in the Thai An. hyrcanus group to nocturnally subperiodic B. malayi are presented herein, and the two main refractory factors that affect them in different degrees of susceptibility have been elucidated. Methods Aedes togoi (a control vector, An. argyropus, An. crawfordi, An. nigerrimus, An. nitidus, An. paraliae, An. peditaeniatus, An. pursati and An. sinensis were allowed to feed artificially on blood containing B. malayi microfilariae, and dissected 14 days after feeding. To determine factors that take effect at different susceptibility levels, stain-smeared blood meals were taken from the midguts of Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus immediately after feeding, and their dissected-thoraxes 4 days post blood-feedings were examined consecutively for microfilariae and L1 larvae. Results The susceptibility rates of Ae. togoi, An. peditaeniatus, An. crawfordi, An. nigerrimus, An. argyropus, An. pursati, An. sinensis, An. paraliae and An. nitidus to B. malayi were 70–95%, 70–100%, 80–85%, 50–65%, 60%, 60%, 10%, 5%, and 0%, respectively. These susceptibility rates related clearly to the degrees of normal larval development in thoracic muscles, i.e., Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus

  9. Human Leukocytes Kill Brugia malayi Microfilariae Independently of DNA-Based Extracellular Trap Release

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    Ciaran J. McCoy; Reaves, Barbara J.; Giguère, Steeve; Coates, Ruby; Rada, Balázs; Wolstenholme, Adrian J.

    2017-01-01

    Background Wuchereria bancrofti, Brugia malayi and Brugia timori infect over 100 million people worldwide and are the causative agents of lymphatic filariasis. Some parasite carriers are amicrofilaremic whilst others facilitate mosquito-based disease transmission through blood-circulating microfilariae (Mf). Recent findings, obtained largely from animal model systems, suggest that polymorphonuclear leukocytes (PMNs) contribute to parasitic nematode-directed type 2 immune responses. When expos...

  10. Ultrastructural studies on the microfilaria of Brugia malayi

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    Tongu,Yasumasa

    1974-06-01

    Full Text Available Ultrastructure of microfilaria Brugia malayi was investigated with electron microscope. Microfilariae are covered by a sheath membrane with dense materials on its outer surfaces. The cuticle consists of 3 layers; namely, external cortical, internal cortical and fibrous layer. Beneath these cuticular layers, thin hypodermis is present and the muscle cells are arranged of 4 groups in a crosssection except for the head and tail. A pair of cephalic channel containing several cilial rods opens at the anterior end of the worm. A hook is situated on the anterior edge of one channel orifice, and several spines grow on the opposite side to the hook. Caudal channels paired laterally opening into the both sides of the posterior region differ from cephalic channels by the presence of a single cilial rod. A central canal runs from the buccal cavity to the inner body, and opens into the inner body cell through the filamentous apparatus. The inner body appears to consist of several cells having storage substances and a flat nucleus located on the periphery of the cell. An excretory apparatus, i. e., a cell, is composed of a nucleus and a large vesicle which has many microprojections on the luminal surfaces. The GI cell which occupies the whole width in a cross-section is larger than the R cell. R2-R4 cells appear to be in a close contact with the anal apparatus having many microprojections on the luminal surfaces. These microprojections differ from those of the excretory vesicle in their thickness and length. The characteristic patterns of these organs are compared with other microfilariae.

  11. HYBRIDOMA PRODUCTION USING IMMUNE LYMPHOCYTES AGAINST BRUGIA MALAYI ANTIGEN WITH MYELOMA CELLS

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    Soeyoko Soeyoko

    2012-09-01

    Full Text Available Wuchereria bancrofti, Brugia malayi, and Brugia timori are the causative agents of lymphatic hiariasis in Indonesia, but in some endemic areas, Brugia malayi is the most commonly found,Diagnosis of hiariasis is normally based on clinical and parasitological examinations, but both have limitations. Therefore now the immunological examination plays an important role in the diagnosis of filariasis. The discovery of monoclonal antibodies recently may probably give a firm scientific basis in immunology and add a new dimension to the efforts of developing a specific and sensitive immunological test for various stages of filarial infection. In this study, the production of hybridoma cells to develop monoclonal antibodies against B. malayi integrated a number of techniques: preparations of B. malayi surface antigen, immune lymphocyte cells, NSI myeloma cells and macrophage feeder layers, and a fusion of immune lymphocytes with myeloma cells. The results of this study can be concluded in three points: Protein analysis of the surface antigen was examined by Biureet and SDS-PAGE. A total of fourteen examinations were conducted by using 4000 L3 for each experiment. Three were not detected by Biureet method, but showed five protein fractions by SDS-PAGE. The protein concentration of the surface L3 was varied from 85.0/µg/ml to 769.23/µg/ml, with an average of 297.04/µg/ml.The immunoreactivifies of Balb/c mice antibodies to B. malayi L3 surface antigen were tested by ELISA and showed a gradual increase after four times immunizations at two weeks interval. The optical density (OD after four times immunizations was varied from 0.363 to 0.878 each mouse, where as the positive control sera OD was 0.570.Hybridization using immune lymphocytes against B. malayi L3 surface antigen with myeloma cells yielded 60.41% hybrid cells and none of them produced monoclonal antibodies tested of ELISA.

  12. Characterization of innate immunity genes in the parasitic nematode Brugia malayi.

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    Libro, Silvia; Slatko, Barton E; Foster, Jeremy M

    The filarial nematode Brugia malayi is one of the causative agents of lymphatic filariasis, a neglected tropical disease that affects 120 million people worldwide. The limited effectiveness of available anthelmintics and the absence of a vaccine have prompted extensive research on the interaction between Brugia and its obligate bacterial endosymbiont, Wolbachia. Recent studies suggest that Wolbachia is able to manipulate its nematode host immunity but relatively little is known about the immune system of filarial nematodes. Therefore, elucidation of the mechanisms underlying the immune system of B. malayi may be useful for understanding how the symbiotic relationship is maintained and help in the identification of new drug targets. In order to characterize the main genetic pathways involved in B. malayi immunity, we exposed adult female worms to two bacterial lysates (Escherichia coli and Bacillus amyloliquefaciens), dsRNA and dsDNA. We performed transcriptome sequencing of worms exposed to each immune elicitor at two different timepoints. Gene expression analysis of untreated and immune-challenged worms was performed to characterize gene expression patterns associated with each type of immune stimulation. Our results indicate that different immune elicitors produced distinct expression patterns in B. malayi, with changes in the expression of orthologs of well-characterized C. elegans immune pathways such as insulin, TGF-β, and p38 MAPK pathways, as well as C-type lectins and several stress-response genes.

  13. Diversity and expression of microRNAs in the filarial parasite, Brugia malayi.

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    Catherine B Poole

    Full Text Available Human filarial parasites infect an estimated 120 million people in 80 countries worldwide causing blindness and the gross disfigurement of limbs and genitals. An understanding of RNA-mediated regulatory pathways in these parasites may open new avenues for treatment. Toward this goal, small RNAs from Brugia malayi adult females, males and microfilariae were cloned for deep-sequencing. From ∼ 30 million sequencing reads, 145 miRNAs were identified in the B. malayi genome. Some microRNAs were validated using the p19 RNA binding protein and qPCR. B. malayi miRNAs segregate into 99 families each defined by a unique seed sequence. Sixty-one of the miRNA families are highly conserved with homologues in arthropods, vertebrates and helminths. Of those miRNAs not highly conserved, homologues of 20 B. malayi miRNA families were found in vertebrates. Nine B. malayi miRNA families appear to be filarial-specific as orthologues were not found in other organisms. The miR-2 family is the largest in B. malayi with 11 members. Analysis of the sequences shows that six members result from a recent expansion of the family. Library comparisons found that 1/3 of the B. malayi miRNAs are differentially expressed. For example, miR-71 is 5-7X more highly expressed in microfilariae than adults. Studies suggest that in C.elegans, miR-71 may enhance longevity by targeting the DAF-2 pathway. Characterization of B. malayi miRNAs and their targets will enhance our understanding of their regulatory pathways in filariads and aid in the search for novel therapeutics.

  14. Diversity and expression of microRNAs in the filarial parasite, Brugia malayi.

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    Poole, Catherine B; Gu, Weifeng; Kumar, Sanjay; Jin, Jingmin; Davis, Paul J; Bauche, David; McReynolds, Larry A

    2014-01-01

    Human filarial parasites infect an estimated 120 million people in 80 countries worldwide causing blindness and the gross disfigurement of limbs and genitals. An understanding of RNA-mediated regulatory pathways in these parasites may open new avenues for treatment. Toward this goal, small RNAs from Brugia malayi adult females, males and microfilariae were cloned for deep-sequencing. From ∼ 30 million sequencing reads, 145 miRNAs were identified in the B. malayi genome. Some microRNAs were validated using the p19 RNA binding protein and qPCR. B. malayi miRNAs segregate into 99 families each defined by a unique seed sequence. Sixty-one of the miRNA families are highly conserved with homologues in arthropods, vertebrates and helminths. Of those miRNAs not highly conserved, homologues of 20 B. malayi miRNA families were found in vertebrates. Nine B. malayi miRNA families appear to be filarial-specific as orthologues were not found in other organisms. The miR-2 family is the largest in B. malayi with 11 members. Analysis of the sequences shows that six members result from a recent expansion of the family. Library comparisons found that 1/3 of the B. malayi miRNAs are differentially expressed. For example, miR-71 is 5-7X more highly expressed in microfilariae than adults. Studies suggest that in C.elegans, miR-71 may enhance longevity by targeting the DAF-2 pathway. Characterization of B. malayi miRNAs and their targets will enhance our understanding of their regulatory pathways in filariads and aid in the search for novel therapeutics.

  15. Molecular evidence for a functional ecdysone signaling system in Brugia malayi.

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    George Tzertzinis

    Full Text Available BACKGROUND: Filarial nematodes, including Brugia malayi, the causative agent of lymphatic filariasis, undergo molting in both arthropod and mammalian hosts to complete their life cycles. An understanding of how these parasites cross developmental checkpoints may reveal potential targets for intervention. Pharmacological evidence suggests that ecdysteroids play a role in parasitic nematode molting and fertility although their specific function remains unknown. In insects, ecdysone triggers molting through the activation of the ecdysone receptor: a heterodimer of EcR (ecdysone receptor and USP (Ultraspiracle. METHODS AND FINDINGS: We report the cloning and characterization of a B. malayi EcR homologue (Bma-EcR. Bma-EcR dimerizes with insect and nematode USP/RXRs and binds to DNA encoding a canonical ecdysone response element (EcRE. In support of the existence of an active ecdysone receptor in Brugia we also cloned a Brugia rxr (retinoid X receptor homolog (Bma-RXR and demonstrate that Bma-EcR and Bma-RXR interact to form an active heterodimer using a mammalian two-hybrid activation assay. The Bma-EcR ligand-binding domain (LBD exhibits ligand-dependent transactivation via a GAL4 fusion protein combined with a chimeric RXR in mammalian cells treated with Ponasterone-A or a synthetic ecdysone agonist. Furthermore, we demonstrate specific up-regulation of reporter gene activity in transgenic B. malayi embryos transfected with a luciferase construct controlled by an EcRE engineered in a B. malayi promoter, in the presence of 20-hydroxy-ecdysone. CONCLUSIONS: Our study identifies and characterizes the two components (Bma-EcR and Bma-RXR necessary for constituting a functional ecdysteroid receptor in B. malayi. Importantly, the ligand binding domain of BmaEcR is shown to be capable of responding to ecdysteroid ligands, and conversely, ecdysteroids can activate transcription of genes downstream of an EcRE in live B. malayi embryos. These results together

  16. Mining predicted essential genes of Brugia malayi for nematode drug targets.

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    Sanjay Kumar

    Full Text Available We report results from the first genome-wide application of a rational drug target selection methodology to a metazoan pathogen genome, the completed draft sequence of Brugia malayi, a parasitic nematode responsible for human lymphatic filariasis. More than 1.5 billion people worldwide are at risk of contracting lymphatic filariasis and onchocerciasis, a related filarial disease. Drug treatments for filariasis have not changed significantly in over 20 years, and with the risk of resistance rising, there is an urgent need for the development of new anti-filarial drug therapies. The recent publication of the draft genomic sequence for B. malayi enables a genome-wide search for new drug targets. However, there is no functional genomics data in B. malayi to guide the selection of potential drug targets. To circumvent this problem, we have utilized the free-living model nematode Caenorhabditis elegans as a surrogate for B. malayi. Sequence comparisons between the two genomes allow us to map C. elegans orthologs to B. malayi genes. Using these orthology mappings and by incorporating the extensive genomic and functional genomic data, including genome-wide RNAi screens, that already exist for C. elegans, we identify potentially essential genes in B. malayi. Further incorporation of human host genome sequence data and a custom algorithm for prioritization enables us to collect and rank nearly 600 drug target candidates. Previously identified potential drug targets cluster near the top of our prioritized list, lending credibility to our methodology. Over-represented Gene Ontology terms, predicted InterPro domains, and RNAi phenotypes of C. elegans orthologs associated with the potential target pool are identified. By virtue of the selection procedure, the potential B. malayi drug targets highlight components of key processes in nematode biology such as central metabolism, molting and regulation of gene expression.

  17. Mining predicted essential genes of Brugia malayi for nematode drug targets.

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    Kumar, Sanjay; Chaudhary, Kshitiz; Foster, Jeremy M; Novelli, Jacopo F; Zhang, Yinhua; Wang, Shiliang; Spiro, David; Ghedin, Elodie; Carlow, Clotilde K S

    2007-01-01

    We report results from the first genome-wide application of a rational drug target selection methodology to a metazoan pathogen genome, the completed draft sequence of Brugia malayi, a parasitic nematode responsible for human lymphatic filariasis. More than 1.5 billion people worldwide are at risk of contracting lymphatic filariasis and onchocerciasis, a related filarial disease. Drug treatments for filariasis have not changed significantly in over 20 years, and with the risk of resistance rising, there is an urgent need for the development of new anti-filarial drug therapies. The recent publication of the draft genomic sequence for B. malayi enables a genome-wide search for new drug targets. However, there is no functional genomics data in B. malayi to guide the selection of potential drug targets. To circumvent this problem, we have utilized the free-living model nematode Caenorhabditis elegans as a surrogate for B. malayi. Sequence comparisons between the two genomes allow us to map C. elegans orthologs to B. malayi genes. Using these orthology mappings and by incorporating the extensive genomic and functional genomic data, including genome-wide RNAi screens, that already exist for C. elegans, we identify potentially essential genes in B. malayi. Further incorporation of human host genome sequence data and a custom algorithm for prioritization enables us to collect and rank nearly 600 drug target candidates. Previously identified potential drug targets cluster near the top of our prioritized list, lending credibility to our methodology. Over-represented Gene Ontology terms, predicted InterPro domains, and RNAi phenotypes of C. elegans orthologs associated with the potential target pool are identified. By virtue of the selection procedure, the potential B. malayi drug targets highlight components of key processes in nematode biology such as central metabolism, molting and regulation of gene expression.

  18. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness.

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    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes--6-phosphofructokinase and pyruvate kinase--and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy.

  19. Effects of Doxycycline on gene expression in Wolbachia and Brugia malayi adult female worms in vivo

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    Rao Ramakrishna U

    2012-02-01

    Full Text Available Abstract Background Most filarial nematodes contain Wolbachia symbionts. The purpose of this study was to examine the effects of doxycycline on gene expression in Wolbachia and adult female Brugia malayi. Methods Brugia malayi infected gerbils were treated with doxycycline for 6-weeks. This treatment largely cleared Wolbachia and arrested worm reproduction. RNA recovered from treated and control female worms was labeled by random priming and hybridized to the Version 2- filarial microarray to obtain expression profiles. Results and discussion Results showed significant changes in expression for 200 Wolbachia (29% of Wolbachia genes with expression signals in untreated worms and 546 B. malayi array elements after treatment. These elements correspond to known genes and also to novel genes with unknown biological functions. Most differentially expressed Wolbachia genes were down-regulated after treatment (98.5%. In contrast, doxycycline had a mixed effect on B. malayi gene expression with many more genes being significantly up-regulated after treatment (85% of differentially expressed genes. Genes and processes involved in reproduction (gender-regulated genes, collagen, amino acid metabolism, ribosomal processes, and cytoskeleton were down-regulated after doxycycline while up-regulated genes and pathways suggest adaptations for survival in response to stress (energy metabolism, electron transport, anti-oxidants, nutrient transport, bacterial signaling pathways, and immune evasion. Conclusions Doxycycline reduced Wolbachia and significantly decreased bacterial gene expression. Wolbachia ribosomes are believed to be the primary biological target for doxycycline in filarial worms. B. malayi genes essential for reproduction, growth and development were also down-regulated; these changes are consistent with doxycycline effects on embryo development and reproduction. On the other hand, many B. malayi genes involved in energy production, electron

  20. Suppression of Brugia malayi (sub-periodic larval development in Aedes aegypti (Liverpool strain fed on blood of animals immunized with microfilariae

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    K Athisaya Mary

    2005-07-01

    Full Text Available Preliminary studies were carried out to investigate the role of filarial specific antibodies, raised in an animal model against the filarial parasite, Brugia malayi (sub-periodic, in blocking their early development in an experimental mosquito host, Aedes aegypti (Liverpool strain. In order to generate filarial specific antibodies, Mongolian gerbils, Meriones unguiculatus, were immunized either with live microfilariae (mf of B. malayi or their homogenate. Mf were harvested from the peritoneal cavity of Mongolian gerbils with patent infection of B. malayi and fed to A. aegypti along with the blood from immunized animals. Development of the parasite in infected mosquitoes was monitored until they reached infective stage larvae (L3. Fewer number of parasites developed to first stage (L1 and subsequently to L2 and L3 in mosquitoes fed with blood of immunized animals, when compared to those fed with blood of control animals. The results thus indicated that filarial parasite specific antibodies present in the blood of the immunized animals resulted in the reduction of number of larvae of B. malayi developing in the mosquito host.

  1. In vitro biological evaluation of biguanides and dihydrotriazines against Brugia malayi and folate reversal studies.

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    Bag, Seema; Tawari, Nilesh R; Sharma, Richa; Goswami, Kalyan; Reddy, M V R; Degani, Mariam S

    2010-01-01

    Dihydrofolate reductase (DHFR) is a well-known target for antibacterial and anticancer therapy. DHFR inhibitors are useful for protozoan parasites, but are yet to be explored against metazoan species; hence the present work was designed to evaluate the efficacy of DHFR inhibitors against filariasis, one of the major neglected tropical diseases. Molecules from our in-house library of synthetic antifolate agents (biguanide and dihydrotriazine derivatives) were evaluated along with the antimalarial drug pyrimethamine and the antibacterial drug trimethoprim in an in vitro model against Brugia malayi microfilariae (Mf). Three biguanides and two dihydrotriazines were more potent than trimethoprim and pyrimethamine against B. malayi Mf. Trimethoprim, pyrimethamine and four of the five compounds active against Mf were also active against adult worms. To probe the mechanism of action of the compounds, reversal of activity of active compounds by folic acid and folinic acid was studied. In conclusion, DHFR inhibitors could be used as leads for new antifilarial drugs.

  2. In vitro antifilarial effects of three plant species against adult worms of subperiodic Brugia malayi.

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    Zaridah, M Z; Idid, S Z; Omar, A W; Khozirah, S

    2001-11-01

    Five aqueous extracts from three plant species, i.e., dried husks (HX), dried seeds (SX) and dried leaves (LX) of Xylocarpus granatum (Meliaceae), dried stems (ST) of Tinospora crispa (Menispermaceae) and dried leaves (LA) of Andrographis paniculata (Acanthaceae) were tested in vitro against adult worms of subperiodic Brugia malayi. The relative movability (RM) value of the adult worms over the 24-h observation period was used as a measure of the antifilarial activity of the aqueous extracts. SX extract of X. granatum demonstrated the strongest activity, followed by the LA extract of A. paniculata, ST extract of T. crispa, HX extract and LX extract of X. granatum.

  3. Yeast-Based High-Throughput Screens to Identify Novel Compounds Active against Brugia malayi.

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    Elizabeth Bilsland

    2016-01-01

    Full Text Available Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7-15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases.We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts, and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds, we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi.We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between human and filarial enzymes. Hence, we are confident

  4. Antifilarial activity of Zoanthus species (Phylum Coelenterata, Class Anthzoa) against human lymphatic filaria, Brugia malayi.

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    Lakshmi, V; Saxena, A; Pandey, K; Bajpai, Preeti; Misra-Bhattacharya, Shailja

    2004-07-01

    The chloroform methanol (1:1) extract of an unidentified green zoanthus (Phylum Coelenterata, Class Anthozoa) showed promising in vitro adulticidal activity with a lethal concentration of 125 microg/ml on Brugia malayi. This extract brought about a 52.2% reduction in circulating microfilariae of B. malayi when administered to infected Mastomys coucha at 250 mg/kg, orally for 5 consecutive days. Further fractionation of the extract led to the recovery of four fractions, which were evaluated simultaneously in both in vitro and in vivo systems against B. malayi. The chloroform fraction at 250 mg/kg orally for 5 days exhibited the highest macrofilaricidal action (42.5%), closely followed by the insoluble n-butanol fraction (34.3%), the soluble hexane fraction (32.4%), and the soluble n-butanol fraction (20.4%). In addition, the hexane soluble fraction caused 44.3% sterilization of the surviving female parasites. Two compounds isolated were found devoid of antifilarial activity.

  5. Comparative analysis of ITS1 nucleotide sequence reveals distinct genetic difference between Brugia malayi from Northeast Borneo and Thailand.

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    Fong, Mun-Yik; Noordin, Rahmah; Lau, Yee-Ling; Cheong, Fei-Wen; Yunus, Muhammad Hafiznur; Idris, Zulkarnain Md

    2013-01-01

    Brugia malayi is one of the parasitic worms which causes lymphatic filariasis in humans. Its geographical distribution includes a large part of Asia. Despite its wide distribution, very little is known about the genetic variation and molecular epidemiology of this species. In this study, the internal transcribed spacer 1 (ITS1) nucleotide sequences of B. malayi from microfilaria-positive human blood samples in Northeast Borneo Island were determined, and compared with published ITS1 sequences of B. malayi isolated from cats and humans in Thailand. Multiple alignment analysis revealed that B. malayi ITS1 sequences from Northeast Borneo were more similar to each other than to those from Thailand. Phylogenetic trees inferred using Neighbour-Joining and Maximum Parsimony methods showed similar topology, with 2 distinct B. malayi clusters. The first cluster consisted of Northeast Borneo B. malayi isolates, whereas the second consisted of the Thailand isolates. The findings of this study suggest that B. malayi in Borneo Island has diverged significantly from those of mainland Asia, and this has implications for the diagnosis of B. malayi infection across the region using ITS1-based molecular techniques.

  6. Cross reactive molecules of human lymphatic filaria Brugia malayi inhibit Leishmania donovani infection in hamsters.

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    Verma, Richa; Joseph, Sujith K; Kushwaha, Vikas; Kumar, Vikash; Siddiqi, M I; Vishwakarma, Preeti; Shivahare, Rahul; Gupta, Suman; Murthy, P K

    2015-12-01

    Coinfections are common in natural populations and the outcome of their interactions depends on the immune responses of the host elicited by the parasites. Earlier we showed that immunization with BmAFII (Sephadex G-200 eluted) fraction of human lymphatic filaria Brugia malayi inhibited progression of Leishmania donovani infection in golden hamsters. In the present study we identified cross reactive molecules of B. malayi, and investigated their effect on L. donovani infection and associated immune responses in the host. The sequence alignment and sharing of linear T- and B-cell epitopes in protein molecules of B. malayi and L. donovani counterparts were studied in silico. Hamsters were immunized with robustly cross reactive SDS-PAGE resolved fractions F6 (54.2-67.8kDa) and F9 (41.3-45.0kDa) of B. malayi and subsequently inoculated with amastigotes of L. donovani intracardially. F6 inhibited (∼72%) L. donovani infection and upregulated Th1 cytokine expression, lymphoproliferation, IgG2, IgG2/3 levels and NO production, and downregulated Th2 cytokine expression. Sequences in HSP60 and EF-2 of F6 and L. donovani counterparts were conserved and B- and T-cell epitopes in the proteins shared antigenic regions. In conclusion, leishmania-cross reactive molecules of filarial parasite considerably inhibited leishmanial infection via Th1-mediated immune responses and NO production. Common B- and T-cell epitope regions in HSP60 and EF-2 of the parasites might have contributed to the inhibitory effect on the L. donovani infection. Thus, leishmania-cross reactive filarial parasite molecules may help in designing prophylactic(s) against L. donovani.

  7. Human Leukocytes Kill Brugia malayi Microfilariae Independently of DNA-Based Extracellular Trap Release

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    McCoy, Ciaran J.; Reaves, Barbara J.; Giguère, Steeve; Coates, Ruby; Rada, Balázs

    2017-01-01

    Background Wuchereria bancrofti, Brugia malayi and Brugia timori infect over 100 million people worldwide and are the causative agents of lymphatic filariasis. Some parasite carriers are amicrofilaremic whilst others facilitate mosquito-based disease transmission through blood-circulating microfilariae (Mf). Recent findings, obtained largely from animal model systems, suggest that polymorphonuclear leukocytes (PMNs) contribute to parasitic nematode-directed type 2 immune responses. When exposed to certain pathogens PMNs release extracellular traps (NETs) in the form of chromatin loaded with various antimicrobial molecules and proteases. Principal findings In vitro, PMNs expel large amounts of NETs that capture but do not kill B. malayi Mf. NET morphology was confirmed by fluorescence imaging of worm-NET aggregates labelled with DAPI and antibodies to human neutrophil elastase, myeloperoxidase and citrullinated histone H4. A fluorescent, extracellular DNA release assay was used to quantify and observe Mf induced NETosis over time. Blinded video analyses of PMN-to-worm attachment and worm survival during Mf-leukocyte co-culture demonstrated that DNase treatment eliminates PMN attachment in the absence of serum, autologous serum bolsters both PMN attachment and PMN plus peripheral blood mononuclear cell (PBMC) mediated Mf killing, and serum heat inactivation inhibits both PMN attachment and Mf killing. Despite the effects of heat inactivation, the complement inhibitor compstatin did not impede Mf killing and had little effect on PMN attachment. Both human PMNs and monocytes, but not lymphocytes, are able to kill B. malayi Mf in vitro and NETosis does not significantly contribute to this killing. Leukocytes derived from presumably parasite-naïve U.S. resident donors vary in their ability to kill Mf in vitro, which may reflect the pathological heterogeneity associated with filarial parasitic infections. Conclusions/Significance Human innate immune cells are able to

  8. Brugia malayi excreted/secreted proteins at the host/parasite interface: stage- and gender-specific proteomic profiling.

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    Sasisekhar Bennuru

    Full Text Available Relatively little is known about the filarial proteins that interact with the human host. Although the filarial genome has recently been completed, protein profiles have been limited to only a few recombinants or purified proteins of interest. Here, we describe a large-scale proteomic analysis using microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry to identify the excretory-secretory (ES products of the L3, L3 to L4 molting ES, adult male, adult female, and microfilarial stages of the filarial parasite Brugia malayi. The analysis of the ES products from adult male, adult female, microfilariae (Mf, L3, and molting L3 larvae identified 852 proteins. Annotation suggests that the functional and component distribution was very similar across each of the stages studied; however, the Mf contributed a higher proportion to the total number of identified proteins than the other stages. Of the 852 proteins identified in the ES, only 229 had previous confirmatory expressed sequence tags (ESTs in the available databases. Moreover, this analysis was able to confirm the presence of 274 "hypothetical" proteins inferred from gene prediction algorithms applied to the B. malayi (Bm genome. Not surprisingly, the majority (160/274 of these "hypothetical" proteins were predicted to be secreted by Signal IP and/or SecretomeP 2.0 analysis. Of major interest is the abundance of previously characterized immunomodulatory proteins such as ES-62 (leucyl aminopeptidase, MIF-1, SERPIN, glutathione peroxidase, and galectin in the ES of microfilariae (and Mf-containing adult females compared to the adult males. In addition, searching the ES protein spectra against the Wolbachia database resulted in the identification of 90 Wolbachia-specific proteins, most of which were metabolic enzymes that have not been shown to be immunogenic. This proteomic analysis extends our knowledge of the ES and provides insight into the host-parasite interaction.

  9. The Wolbachia endosymbiont of Brugia malayi has an active pyruvate phosphate dikinase.

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    Raverdy, Sylvine; Foster, Jeremy M; Roopenian, Erica; Carlow, Clotilde K S

    2008-08-01

    Genome analysis of the glycolytic/gluconeogenic pathway in the Wolbachia endosymbiont from the filarial parasite Brugia malayi (wBm) has revealed that wBm lacks pyruvate kinase (PK) and may instead utilize the enzyme pyruvate phosphate dikinase (PPDK; ATP:pyruvate, orthophosphate phosphotransferase, EC 2.7.9.1). PPDK catalyses the reversible conversion of AMP, PPi and phosphoenolpyruvate (PEP) into ATP, Pi and pyruvate. The glycolytic pathway of most organisms, including mammals, contains exclusively PK for the production of pyruvate from PEP. Therefore, the absence of PPDK in mammals makes the enzyme an attractive Wolbachia drug target. In the present study, we have cloned and expressed an active wBm-PPDK, thereby providing insight into the energy metabolism of the endosymbiont. Our results support the development of wBm-PPDK as a promising new drug target in an anti-symbiotic approach to controlling filarial infection.

  10. The Structure and Dynamics of BmR1 Protein from Brugia malayi: In Silico Approaches

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    Bee Yin Khor

    2014-06-01

    Full Text Available Brugia malayi is a filarial nematode, which causes lymphatic filariasis in humans. In 1995, the disease has been identified by the World Health Organization (WHO as one of the second leading causes of permanent and long-term disability and thus it is targeted for elimination by year 2020. Therefore, accurate filariasis diagnosis is important for management and elimination programs. A recombinant antigen (BmR1 from the Bm17DIII gene product was used for antibody-based filariasis diagnosis in “Brugia Rapid”. However, the structure and dynamics of BmR1 protein is yet to be elucidated. Here we study the three dimensional structure and dynamics of BmR1 protein using comparative modeling, threading and ab initio protein structure prediction. The best predicted structure obtained via an ab initio method (Rosetta was further refined and minimized. A total of 5 ns molecular dynamics simulation were performed to investigate the packing of the protein. Here we also identified three epitopes as potential antibody binding sites from the molecular dynamics average structure. The structure and epitopes obtained from this study can be used to design a binder specific against BmR1, thus aiding future development of antigen-based filariasis diagnostics to complement the current diagnostics.

  11. Live Brugia malayi microfilariae inhibit transendothelial migration of neutrophils and monocytes.

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    Jan-Hendrik Schroeder

    Full Text Available Lymphatic filariasis is a major tropical disease caused by the parasite Brugia malayi. Microfilariae (Mf circulate in the peripheral blood for 2-3 hours in synchronisation with maximal feeding of the mosquito vector. When absent from the peripheral blood, Mf sequester in the capillaries of the lungs. Mf are therefore in close contact with vascular endothelial cells (EC and may induce EC immune function and/or wound repair mechanisms such as angiogenesis. In this study, Mf were co-cultured with human umbilical vein EC (HUVEC or human lung microvascular EC (HLMVEC and the transendothelial migration of leukocyte subsets was analysed. In addition, the protein and/or mRNA expression of chemokine, cytokine and angiogenic mediators in endothelial cells in the presence of live microfilariae were measured by a combination of cDNA arrays, protein arrays, ELISA and fluorescence antibody tests.Surprisingly, our findings indicate that Mf presence partially blocked transendothelial migration of monocytes and neutrophils, but not lymphocytes. However, Mf exposure did not result in altered vascular EC expression of key mediators of the tethering stage of extravasation, such as ICAM-1, VCAM-1 and various chemokines. To further analyse the immunological function of vascular EC in the presence of Mf, we measured the mRNA and/or protein expression of a number of pro-inflammatory mediators. We found that expression levels of the mediators tested were predominantly unaltered upon B. malayi Mf exposure. In addition, a comparison of angiogenic mediators induced by intact Mf and Wolbachia-depleted Mf revealed that even intact Mf induce the expression of remarkably few angiogenic mediators in vascular EC. Our study suggests that live microfilariae are remarkably inert in their induction and/or activation of vascular cells in their immediate local environment. Overall, this work presents important insights into the immunological function of the vascular endothelium during

  12. The heme biosynthetic pathway of the obligate Wolbachia endosymbiont of Brugia malayi as a potential anti-filarial drug target.

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    Bo Wu

    Full Text Available BACKGROUND: Filarial parasites (e.g., Brugia malayi, Onchocerca volvulus, and Wuchereria bancrofti are causative agents of lymphatic filariasis and onchocerciasis, which are among the most disabling of neglected tropical diseases. There is an urgent need to develop macro-filaricidal drugs, as current anti-filarial chemotherapy (e.g., diethylcarbamazine [DEC], ivermectin and albendazole can interrupt transmission predominantly by killing microfilariae (mf larvae, but is less effective on adult worms, which can live for decades in the human host. All medically relevant human filarial parasites appear to contain an obligate endosymbiotic bacterium, Wolbachia. This alpha-proteobacterial mutualist has been recognized as a potential target for filarial nematode life cycle intervention, as antibiotic treatments of filarial worms harboring Wolbachia result in the loss of worm fertility and viability upon antibiotic treatments both in vitro and in vivo. Human trials have confirmed this approach, although the length of treatments, high doses required and medical counter-indications for young children and pregnant women warrant the identification of additional anti-Wolbachia drugs. METHODS AND FINDINGS: Genome sequence analysis indicated that enzymes involved in heme biosynthesis might constitute a potential anti-Wolbachia target set. We tested different heme biosynthetic pathway inhibitors in ex vivo B. malayi viability assays and report a specific effect of N-methyl mesoporphyrin (NMMP, which targets ferrochelatase (FC, the last step. Our phylogenetic analysis indicates evolutionarily significant divergence between Wolbachia heme genes and their human homologues. We therefore undertook the cloning, overexpression and analysis of several enzymes of this pathway alongside their human homologues, and prepared proteins for drug targeting. In vitro enzyme assays revealed a approximately 600-fold difference in drug sensitivities to succinyl acetone (SA between

  13. Computational prediction of essential genes in an unculturable endosymbiotic bacterium, Wolbachia of Brugia malayi

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    Carlow Clotilde KS

    2009-11-01

    Full Text Available Abstract Background Wolbachia (wBm is an obligate endosymbiotic bacterium of Brugia malayi, a parasitic filarial nematode of humans and one of the causative agents of lymphatic filariasis. There is a pressing need for new drugs against filarial parasites, such as B. malayi. As wBm is required for B. malayi development and fertility, targeting wBm is a promising approach. However, the lifecycle of neither B. malayi nor wBm can be maintained in vitro. To facilitate selection of potential drug targets we computationally ranked the wBm genome based on confidence that a particular gene is essential for the survival of the bacterium. Results wBm protein sequences were aligned using BLAST to the Database of Essential Genes (DEG version 5.2, a collection of 5,260 experimentally identified essential genes in 15 bacterial strains. A confidence score, the Multiple Hit Score (MHS, was developed to predict each wBm gene's essentiality based on the top alignments to essential genes in each bacterial strain. This method was validated using a jackknife methodology to test the ability to recover known essential genes in a control genome. A second estimation of essentiality, the Gene Conservation Score (GCS, was calculated on the basis of phyletic conservation of genes across Wolbachia's parent order Rickettsiales. Clusters of orthologous genes were predicted within the 27 currently available complete genomes. Druggability of wBm proteins was predicted by alignment to a database of protein targets of known compounds. Conclusion Ranking wBm genes by either MHS or GCS predicts and prioritizes potentially essential genes. Comparison of the MHS to GCS produces quadrants representing four types of predictions: those with high confidence of essentiality by both methods (245 genes, those highly conserved across Rickettsiales (299 genes, those similar to distant essential genes (8 genes, and those with low confidence of essentiality (253 genes. These data facilitate

  14. Transcription profiling reveals stage- and function-dependent expression patterns in the filarial nematode Brugia malayi

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    Li Ben-Wen

    2012-05-01

    Full Text Available Abstract Background Brugia malayi is a nematode parasite that causes lymphatic filariasis, a disfiguring and disabiling tropical disease. Although a first draft genome sequence was released in 2007, very little is understood about transcription programs that govern developmental changes required for the parasite’s development and survival in its mammalian and insect hosts. Results We used a microarray with probes that represent some 85% of predicted genes to generate gene expression profiles for seven parasite life cycle stages/sexes. Approximately 41% of transcripts with detectable expression signals were differentially expressed across lifecycle stages. Twenty-six percent of transcripts were exclusively expressed in a single parasite stage, and 27% were expressed in all stages studied. K-means clustering of differentially expressed transcripts revealed five major transcription patterns that were associated with parasite lifecycle stages or gender. Examination of known stage-associated transcripts validated these data sets and suggested that newly identified stage or gender-associated transcripts may exercise biological functions in development and reproduction. The results also indicate that genes with similar transcription patterns were often involved in similar functions or cellular processes. For example, nuclear receptor family gene transcripts were upregulated in gene expression pattern four (female-enriched while protein kinase gene family transcripts were upregulated in expression pattern five (male-enriched. We also used pair-wise comparisons to identify transcriptional changes between life cycle stages and sexes. Conclusions Analysis of gene expression patterns of lifecycle in B. malayi has provided novel insights into the biology of filarial parasites. Proteins encoded by stage-associated and/or stage-specific transcripts are likely to be critically important for key parasite functions such as establishment and maintenance of

  15. A deep sequencing approach to comparatively analyze the transcriptome of lifecycle stages of the filarial worm, Brugia malayi.

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    Young-Jun Choi

    2011-12-01

    Full Text Available BACKGROUND: Developing intervention strategies for the control of parasitic nematodes continues to be a significant challenge. Genomic and post-genomic approaches play an increasingly important role for providing fundamental molecular information about these parasites, thus enhancing basic as well as translational research. Here we report a comprehensive genome-wide survey of the developmental transcriptome of the human filarial parasite Brugia malayi. METHODOLOGY/PRINCIPAL FINDINGS: Using deep sequencing, we profiled the transcriptome of eggs and embryos, immature (≤3 days of age and mature microfilariae (MF, third- and fourth-stage larvae (L3 and L4, and adult male and female worms. Comparative analysis across these stages provided a detailed overview of the molecular repertoires that define and differentiate distinct lifecycle stages of the parasite. Genome-wide assessment of the overall transcriptional variability indicated that the cuticle collagen family and those implicated in molting exhibit noticeably dynamic stage-dependent patterns. Of particular interest was the identification of genes displaying sex-biased or germline-enriched profiles due to their potential involvement in reproductive processes. The study also revealed discrete transcriptional changes during larval development, namely those accompanying the maturation of MF and the L3 to L4 transition that are vital in establishing successful infection in mosquito vectors and vertebrate hosts, respectively. CONCLUSIONS/SIGNIFICANCE: Characterization of the transcriptional program of the parasite's lifecycle is an important step toward understanding the developmental processes required for the infectious cycle. We find that the transcriptional program has a number of stage-specific pathways activated during worm development. In addition to advancing our understanding of transcriptome dynamics, these data will aid in the study of genome structure and organization by facilitating

  16. Cofactor Independent Phosphoglycerate Mutase of Brugia malayi Induces a Mixed Th1/Th2 Type Immune Response and Inhibits Larval Development in the Host

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    Prashant K. Singh

    2014-01-01

    Full Text Available Lymphatic filariasis is a major debilitating disease, endemic in 72 countries putting more than 1.39 billion people at risk and 120 million are already infected. Despite the significant progress in chemotherapeutic advancements, there is still need for other measures like development of an effective vaccine or discovery of novel drug targets. In this study, structural and immunological characterization of independent phosphoglycerate mutase of filarial parasite Brugia malayi was carried out. Protein was found to be expressed in all major parasite life stages and as an excretory secretory product of adult parasites. Bm-iPGM also reacted to all the categories of human bancroftian patient’s sera including endemic normals. In vivo immunological behaviour of protein was determined in immunized BALB/c mice followed by prophylactic analysis in BALB/c mice and Mastomys coucha. Immunization with Bm-iPGM led to generation of a mixed Th1/Th2 type immune response offering 58.2% protection against larval challenge in BALB/c and 65–68% protection in M. coucha. In vitro studies confirmed participation of anti-Bm-iPGM antibodies in killing of B. malayi infective larvae and microfilariae through ADCC mechanism. The present findings reveal potential immunoprotective nature of Bm-iPGM advocating its worth as an antifilarial vaccine candidate.

  17. Expression of five acetylcholine receptor subunit genes in Brugia malayi adult worms.

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    Li, Ben-Wen; Rush, Amy C; Weil, Gary J

    2015-12-01

    Acetylcholine receptors (AChRs) are required for body movement in parasitic nematodes and are targets of "classical" anthelmintic drugs such as levamisole and pyrantel and of newer drugs such as tribendimidine and derquantel. While neurotransmission explains the effects of these drugs on nematode movement, their effects on parasite reproduction are unexplained. The levamisole AChR type (L-AChRs) in Caenorhabditis elegans is comprised of five subunits: Cel-UNC-29, Cel-UNC-38, Cel-UNC-63, Cel-LEV-1 and Cel-LEV-8. The genome of the filarial parasite Brugia malayi contains nine AChRs subunits including orthologues of Cel-unc-29, Cel-unc-38, and Cel-unc-63. We performed in situ hybridization with RNA probes to localize the expression of five AChR genes (Bm1_35890-Bma-unc-29, Bm1_20330-Bma-unc-38, Bm1_38195-Bma-unc-63, Bm1_48815-Bma-acr-26 and Bm1_40515-Bma-acr-12) in B. malayi adult worms. Four of these genes had similar expression patterns with signals in body muscle, developing embryos, spermatogonia, uterine wall adjacent to stretched microfilariae, wall of V as deferens, and lateral cord. Three L-AChR subunit genes (Bma-unc-29, Bma-unc-38 and Bma-unc-63) were expressed in body muscle, which is a known target of levamisole. Bma-acr-12 was co-expressed with these levamisole subunit genes in muscle, and this suggests that its protein product may form receptors with other alpha subunits. Bma-acr-26 was expressed in male muscle but not in female muscle. Strong expression signals of these genes in early embryos and gametes in uterus and testis suggest that AChRs may have a role in nervous system development of embryogenesis and spermatogenesis. This would be consistent with embryotoxic effects of drugs that target these receptors in filarial worms. Our data show that the expression of these receptor genes is tightly regulated with regard to localization in adult worms and developmental stage in embryos and gametes. These results may help to explain the broad effects of

  18. Production of Brugia malayi BmSXP Recombinant Protein Expressed in Escherichia coli

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    Khoo, T. K.

    2010-01-01

    Full Text Available A rapid antibody detection test is very useful for detection of lymphatic filariasis, especially for certification and surveillance of post-mass drug administration. One such kit, panLF RapidTM (commercialized by Malaysian BioDiagnostic Research Sdn. Bhd. had been developed in our laboratory for the detection of all species of filarial infections. It is based on the detection of anti-filarial IgG4 antibodies that react with recombinant Brugia malayi antigens, BmR1 and BmSXP. In this study, the growth of recombinant bacteria that produce BmSXP was optimized under shake flask fermentation for high yield of the recombinant antigen. The optimizations involved selection of suitable growth medium, IPTG concentration and induction time. The medium that yielded the highest biomass as well as total protein was Terrific Broth (TB medium, which is an undefined medium. Initiation of induction of protein expression was found to be best at mid-log phase (OD600 = 1.5, with IPTG concentration of 1.0 mM, and harvest time at 9 h post-induction. This study showed that under the optimized conditions, the shake flask culture produced 4 g/L biomass (dry cell weight of recombinant Escherichia coli BmSXP/pPROEXHTa/TOP10F’, which yielded 2.42 mg/L of purified BmSXP recombinant antigen. The purified antigen was analyzed by SDS-PAGE and the antigenicity of protein was confirmed by Western blot.

  19. Potential involvement of Brugia malayi cysteine proteases in the maintenance of the endosymbiotic relationship with Wolbachia

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    Sara Lustigman

    2014-12-01

    Full Text Available Brugia malayi, a parasitic nematode that causes lymphatic filariasis, harbors endosymbiotic intracellular bacteria, Wolbachia, that are required for the development and reproduction of the worm. The essential nature of this endosymbiosis led to the development of anti-Wolbachia chemotherapeutic approaches for the treatment of human filarial infections. Our study is aimed at identifying specific proteins that play a critical role in this endosymbiotic relationship leading to the identification of potential targets in the adult worms. Filarial cysteine proteases are known to be involved in molting and embryogenesis, processes shown to also be Wolbachia dependent. Based on the observation that cysteine protease transcripts are differentially regulated in response to tetracycline treatment, we focused on defining their role in symbiosis. We observe a bimodal regulation pattern of transcripts encoding cysteine proteases when in vitro tetracycline treated worms were examined. Using tetracycline-treated infertile female worms and purified embryos we established that the first peak of the bimodal pattern corresponds to embryonic transcripts while the second takes place within the hypodermis of the adult worms. Localization studies of the native proteins corresponding to Bm-cpl-3 and Bm-cpl-6 indicate that they are present in the area surrounding Wolbachia, and, in some cases, the proteins appear localized within the bacteria. Both proteins were also found in the inner bodies of microfilariae. The possible role of these cysteine proteases during development and endosymbiosis was further characterized using RNAi. Reduction in Bm-cpl-3 and Bm-cpl-6 transcript levels was accompanied by hindered microfilarial development and release, and reduced Wolbachia DNA levels, making these enzymes strong drug target candidates.

  20. Tissue and stage-specific distribution of Wolbachia in Brugia malayi.

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    Kerstin Fischer

    2011-05-01

    Full Text Available BACKGROUND: Most filarial parasite species contain Wolbachia, obligatory bacterial endosymbionts that are crucial for filarial development and reproduction. They are targets for alternative chemotherapy, but their role in the biology of filarial nematodes is not well understood. Light microscopy provides important information on morphology, localization and potential function of these bacteria. Surprisingly, immunohistology and in situ hybridization techniques have not been widely used to monitor Wolbachia distribution during the filarial life cycle. METHODS/PRINCIPAL FINDINGS: A monoclonal antibody directed against Wolbachia surface protein and in situ hybridization targeting Wolbachia 16S rRNA were used to monitor Wolbachia during the life cycle of B. malayi. In microfilariae and vector stage larvae only a few cells contain Wolbachia. In contrast, large numbers of Wolbachia were detected in the lateral chords of L4 larvae, but no endobacteria were detected in the genital primordium. In young adult worms (5 weeks p.i., a massive expansion of Wolbachia was observed in the lateral chords adjacent to ovaries or testis, but no endobacteria were detected in the growth zone of the ovaries, uterus, the growth zone of the testis or the vas deferens. Confocal laser scanning and transmission electron microscopy showed that numerous Wolbachia are aligned towards the developing ovaries and single endobacteria were detected in the germline. In inseminated females (8 weeks p.i. Wolbachia were observed in the ovaries, embryos and in decreasing numbers in the lateral chords. In young males Wolbachia were found in distinct zones of the testis and in large numbers in the lateral chords in the vicinity of testicular tissue but never in mature spermatids or spermatozoa. CONCLUSIONS: Immunohistology and in situ hybridization show distinct tissue and stage specific distribution patterns for Wolbachia in B. malayi. Extensive multiplication of Wolbachia occurs in the

  1. Efficient in vitro RNA interference and immunofluorescence-based phenotype analysis in a human parasitic nematode, Brugia malayi

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    Landmann Frédéric

    2012-01-01

    Full Text Available Abstract Background RNA interference (RNAi is an efficient reverse genetics technique for investigating gene function in eukaryotes. The method has been widely used in model organisms, such as the free-living nematode Caenorhabditis elegans, where it has been deployed in genome-wide high throughput screens to identify genes involved in many cellular and developmental processes. However, RNAi techniques have not translated efficiently to animal parasitic nematodes that afflict humans, livestock and companion animals across the globe, creating a dependency on data tentatively inferred from C. elegans. Results We report improved and effective in vitro RNAi procedures we have developed using heterogeneous short interfering RNA (hsiRNA mixtures that when coupled with optimized immunostaining techniques yield detailed analysis of cytological defects in the human parasitic nematode, Brugia malayi. The cellular disorganization observed in B. malayi embryos following RNAi targeting the genes encoding γ-tubulin, and the polarity determinant protein, PAR-1, faithfully phenocopy the known defects associated with gene silencing of their C. elegans orthologs. Targeting the B. malayi cell junction protein, AJM-1 gave a similar but more severe phenotype than that observed in C. elegans. Cellular phenotypes induced by our in vitro RNAi procedure can be observed by immunofluorescence in as little as one week. Conclusions We observed cytological defects following RNAi targeting all seven B. malayi transcripts tested and the phenotypes mirror those documented for orthologous genes in the model organism C. elegans. This highlights the reliability, effectiveness and specificity of our RNAi and immunostaining procedures. We anticipate that these techniques will be widely applicable to other important animal parasitic nematodes, which have hitherto been mostly refractory to such genetic analysis.

  2. Molecular characterization of NAD+-dependent DNA ligase from Wolbachia endosymbiont of lymphatic filarial parasite Brugia malayi.

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    Nidhi Shrivastava

    Full Text Available The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD(+-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD(+-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD(+-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies.

  3. DETECTION OF BRUGIA MALAYI INFECTED MOSQUITOES WITH SPECIES SPECIFIC DNA PROBE pBm 15, IN RIAU, INDONESIA

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    L. Kurniawan

    2012-09-01

    Full Text Available A species specific DNA probe (pBm15 was used in a field area where 2 filarial infections coexist: B.malayi in man and B.pahangi in cats. In our laboratory in Jakarta, this DNA probe proved to be sensitive enough to detect 500 ng DNA. One to two infective larvae of B.malayi could be detected with ease. This DNA probe did not react with infective larvae of wuchereria bancrofti, B.pahangi, and Dirofilaria spp. Non specific binding caused by undefined mosquito components was overcome with proteinase K and chitinase treatment. This additional step, made it possible for whole body mosquitoes to be squashed directly onto nitrocellulose paper. A comparative study of experimental infections of laboratory bred mosquitoes infected with B.malayi, showed no difference in infection rate between the group examined by dissection or by DNA probing. Mosquitoes which are vectors in Riau were collected and fed on microfilaremic patients of Riau. The set of mosquitoes were tested in parallel with mosquitoes infected with B.pahangi from cats. All fed mosquitoes were tested after 10-12 days. Only mosquitoes infected with B.malayi reacted in the assay. This study shows a success in applying the DNA probe technique in Jakarta. Further application in the field should be encouraged, with some modification of the DNA probing technique, for cheaper and easier implementation.

  4. Wolbachia endosymbiont of Brugia malayi elicits a T helper type 17-mediated pro-inflammatory immune response through Wolbachia surface protein.

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    Pathak, Manisha; Verma, Meenakshi; Srivastava, Mrigank; Misra-Bhattacharya, Shailja

    2015-02-01

    Wolbachia is an endosymbiotic bacterium of the filarial nematode Brugia malayi. The symbiotic relationship between Wolbachia and its filarial host is dependent on interactions between the proteins of both organisms. However, little is known about Wolbachia proteins that are involved in the inflammatory pathology of the host during lymphatic filariasis. In the present study, we cloned, expressed and purified Wolbachia surface protein (r-wsp) from Wolbachia and administered it to mice, either alone or in combination with infective larvae of B. malayi (Bm-L3) and monitored the developing immune response in infected animals. Our results show that spleens and mesenteric lymph nodes of mice immunized with either r-wsp or infected with Bm-L3 show increased percentages of CD4(+) T helper type 17 (Th17) cells and Th1 cytokines like interferon-γ and interleukin-2 (IL-2) along with decreased percentages of regulatory T cells, Th2 cytokines like IL-4 and IL-10 and transforming growth factor β (TGF-β) levels in culture supernatants of splenocytes. These observations were stronger in mice immunized with r-wsp alone. Interestingly, when mice were first immunized with r-wsp and subsequently infected with Bm-L3, percentages of CD4(+) Th17 cells and Th1 cytokines increased even further while that of regulatory T cells, Th2 cytokines and TGF-β levels decreased. These results for the first time show that r-wsp acts synergistically with Bm-L3 in promoting a pro-inflammatory response by increasing Th17 cells and at the same time diminishes host immunological tolerance by decreasing regulatory T cells and TGF-β secretion.

  5. The Wolbachia endosymbiont of Brugia malayi has an active phosphoglycerate mutase: a candidate target for anti-filarial therapies.

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    Foster, Jeremy M; Raverdy, Sylvine; Ganatra, Mehul B; Colussi, Paul A; Taron, Christopher H; Carlow, Clotilde K S

    2009-04-01

    Phosphoglycerate mutases (PGM) interconvert 2- and 3-phosphoglycerate in the glycolytic and gluconeogenic pathways. A putative cofactor-independent phosphoglycerate mutase gene (iPGM) was identified in the genome sequence of the Wolbachia endosymbiont from the filarial nematode, Brugia malayi (wBm). Since iPGM has no sequence or structural similarity to the cofactor-dependent phosphoglycerate mutase (dPGM) found in mammals, it may represent an attractive Wolbachia drug target. In the present study, wBm-iPGM cloned and expressed in Escherichia coli was mostly insoluble and inactive. However, the protein was successfully produced in the yeast Kluyveromyces lactis and the purified recombinant wBm-iPGM showed typical PGM activity. Our results provide a foundation for further development of wBm-iPGM as a promising new drug target for novel anti-filarial therapies that selectively target the endosymbiont.

  6. Treatment Follow-up of Brugia malayi Microfilaraemic and Amicrofilaraemic Individuals with Serological Evidence of Active Infection

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    Rahmah, N.

    2005-01-01

    Full Text Available Filariasis caused by Brugia malayi and Brugia timori affects ~13 million Asians. In order to ensure elimination of these infections in the context of the Global Programme for Elimination of Lymphatic Filariasis (GPELF, assays which are more sensitive than night blood examination must be employed. IgG4 assay using BmR1 recombinant antigen has been shown to be highly specific and sensitive for diagnosis of brugian filariasis. To provide further evidence of the diagnostic value of this assay, treatment follow-up study was performed on B. malayi microfilaraemic and amicrofilaraemic individuals who were positive by the BmR1-based IgG4-ELISA. Group 1 comprised 22 treated microfilaraemic individuals; group 2A comprised 13 treated amicrofilaraemic individuals and group 2B (control group comprised 16 untreated amicrofilaraemic individuals. Group 1 individuals demonstrated decline in IgG4 levels with treatment and all participants were negative by the end of the 21 months study period. Group 2A also demonstrated IgG4 decline to negativity by 21 months, with re-treatment at 12 months performed on 3 individuals. In group 2B untreated individuals, at 21 months seven participants remained IgG4 positive while nine individuals were IgG4 negative, possibly through spontaneous death of adult worms. Significant difference (p=0.008 was observed when proportions between group 2A and group 2B were compared. This study showed decline of filaria-specific IgG4 post-treatment in both microfilaria positive and microfilaria negative individuals. In addition amicrofilaraemic IgG4 positive individuals were shown to be infected as evidenced by the significant difference between treated and untreated groups of individuals. Therefore, this study strengthened the reported findings that IgG4 assay based on BmR1 recombinant antigen is a good diagnostic tool for brugian filariasis.

  7. Filaria-induced immune evasion: suppression by the infective stage of Brugia malayi at the earliest host-parasite interface.

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    Semnani, Roshanak Tolouei; Law, Melissa; Kubofcik, Joseph; Nutman, Thomas B

    2004-05-15

    To assess the physiologic interactions between the infective stage of Brugia malayi--one of the extracellular parasites responsible for lymphatic filariasis in humans--and the APC with which they come in contact during their development and routes of travel, we have investigated the interaction between the infective stage (L3) of B. malayi and human Langerhans cells (LC) in the skin. Our data indicate that live L3 result in increased migration of LC from the epidermis without affecting the viability of these cells and up-regulation of the IL-18 cytokine involved in LC migration. Live L3 also result in down-regulation of MHC class I and II on the LC cell surface. Additionally, microarray data indicate that live L3 significantly down-regulated expression of IL-8 as well as of multiple genes involved in Ag presentation, reducing the capacity of LC to induce CD4(+) T cells in allogeneic MLR, and thus resulting in a decreased ability of LC to promote CD4(+) T cell proliferation and production of IFN-gamma and IL-10. These data suggest that L3 exert a down-regulatory response in epidermal LC that leads to a diminished capacity of these cells to activate CD4(+) T cells.

  8. Immunological evaluation of an rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi.

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    Rana, Ajay Kumar; Kushwaha, Susheela; Singh, Prashant Kumar; Misra-Bhattacharya, Shailja

    2016-02-01

    Wolbachia is a wonderful anti-filarial target with many of its enzymes and surface proteins (WSPs) representing potential drug targets and vaccine candidates. Here we report on the immunologic response of a drug target, rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi. The recombinant protein generated both humoral and cell-mediated response in BALB/c mice but compromised its immunity. The humoral response was transient and endured barely for six months in mice with or without B. Malayi challenge. In splenocytes of mice, the key humoral immunity mediating cytokine IL4 was lowered (IL4↓) while IFNγ, the major cytokine mediating cellular immunity was decreased along with upregulation of IL10 cytokine (IFNγ↓, IL10↑). The finding here indicates that the enzyme has low immunogenicity and triggers lowering of cytokine level in BALB/c mice. Interestingly the overall immune profile can be summed up with equivalent response generated by WSP or whole Wolbachia.

  9. Immunization with Brugia malayi Myosin as Heterologous DNA Prime Protein Boost Induces Protective Immunity against B. malayi Infection in Mastomys coucha

    Science.gov (United States)

    Gupta, Jyoti; Misra, Sweta; Misra-Bhattacharya, Shailja

    2016-01-01

    The current control strategies employing chemotherapy with diethylcarbamazine, ivermectin and albendazole have reduced transmission in some filaria-endemic areas, there is growing interest for complementary approaches, such as vaccines especially in light of threat of parasite developing resistance to mainstay drugs. We earlier demonstrated recombinant heavy chain myosin of B. malayi (Bm-Myo) as a potent vaccine candidate whose efficacy was enhanced by heterologous DNA prime/protein boost (Myo-pcD+Bm-Myo) vaccination in BALB/c mice. BALB/c mouse though does not support the full developmental cycle of B. malayi, however, the degree of protection may be studied in terms of transformation of challenged infective larvae (L3) to next stage (L4) with an ease of delineating the generated immunological response of host. In the current investigation, DNA vaccination with Bm-Myo was therefore undertaken in susceptible rodent host, Mastomys coucha (M. coucha) which sustains the challenged L3 and facilitates their further development to sexually mature adult parasites with patent microfilaraemia. Immunization schedule consisted of Myo-pcD and Myo-pcD+Bm-Myo followed by B. malayi L3 challenge and the degree of protection was evaluated by observing microfilaraemia as well as adult worm establishment. Myo-pcD+Bm-Myo immunized animals not only developed 78.5% reduced blood microfilarial density but also decreased adult worm establishment by 75.3%. In addition, 75.4% of the recovered live females revealed sterilization over those of respective control animals. Myo-pcD+Bm-Myo triggered higher production of specific IgG and its isotypes which induced marked cellular adhesion and cytotoxicity (ADCC) to microfilariae (mf) and L3 in vitro. Both Th1 and Th2 cytokines were significantly up-regulated displaying a mixed immune response conferring considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges as a

  10. Immunogenicity and Protective Efficacy of Brugia malayi Heavy Chain Myosin as Homologous DNA, Protein and Heterologous DNA/Protein Prime Boost Vaccine in Rodent Model.

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    Jyoti Gupta

    Full Text Available We earlier demonstrated the immunoprophylactic efficacy of recombinant heavy chain myosin (Bm-Myo of Brugia malayi (B. malayi in rodent models. In the current study, further attempts have been made to improve this efficacy by employing alternate approaches such as homologous DNA (pcD-Myo and heterologous DNA/protein prime boost (pcD-Myo+Bm-Myo in BALB/c mouse model. The gene bm-myo was cloned in a mammalian expression vector pcDNA 3.1(+ and protein expression was confirmed in mammalian Vero cell line. A significant degree of protection (79.2%±2.32 against L3 challenge in pcD-Myo+Bm-Myo immunized group was observed which was much higher than that exerted by Bm-Myo (66.6%±2.23 and pcD-Myo (41.6%±2.45. In the heterologous immunized group, the percentage of peritoneal leukocytes such as macrophages, neutrophils, B cells and T cells marginally increased and their population augmented further significantly following L3 challenge. pcD-Myo+Bm-Myo immunization elicited robust cellular and humoral immune responses as compared to pcD-Myo and Bm-Myo groups as evidenced by an increased accumulation of CD4+, CD8+ T cells and CD19+ B cells in the mouse spleen and activation of peritoneal macrophages. Though immunized animals produced antigen-specific IgG antibodies and isotypes, sera of mice receiving pcD-Myo+Bm-Myo or Bm-Myo developed much higher antibody levels than other groups and there was profound antibody-dependent cellular adhesion and cytotoxicity (ADCC to B. malayi infective larvae (L3. pcD-Myo+Bm-Myo as well as Bm-Myo mice generated a mixed T helper cell phenotype as evidenced by the production of both pro-inflammatory (IL-2, IFN-γ and anti-inflammatory (IL-4, IL-10 cytokines. Mice receiving pcD-Myo on contrary displayed a polarized pro-inflammatory immune response. The findings suggest that the priming of animals with DNA followed by protein booster generates heightened and mixed pro- and anti-inflammatory immune responses that are capable of

  11. Structure of the trehalose-6-phosphate phosphatase from Brugia malayi reveals key design principles for anthelmintic drugs.

    Science.gov (United States)

    Farelli, Jeremiah D; Galvin, Brendan D; Li, Zhiru; Liu, Chunliang; Aono, Miyuki; Garland, Megan; Hallett, Olivia E; Causey, Thomas B; Ali-Reynolds, Alana; Saltzberg, Daniel J; Carlow, Clotilde K S; Dunaway-Mariano, Debra; Allen, Karen N

    2014-07-01

    Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP) from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s) of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible.

  12. Functional analysis of the cathepsin-like cysteine protease genes in adult Brugia malayi using RNA interference.

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    Louise Ford

    Full Text Available BACKGROUND: Cathepsin-like enzymes have been identified as potential targets for drug or vaccine development in many parasites, as their functions appear to be essential in a variety of important biological processes within the host, such as molting, cuticle remodeling, embryogenesis, feeding and immune evasion. Functional analysis of Caenorhabditis elegans cathepsin L (Ce-cpl-1 and cathepsin Z (Ce-cpz-1 has established that both genes are required for early embryogenesis, with Ce-cpl-1 having a role in regulating in part the processing of yolk proteins. Ce-cpz-1 also has an important role during molting. METHODS AND FINDINGS: RNA interference assays have allowed us to verify whether the functions of the orthologous filarial genes in Brugia malayi adult female worms are similar. Treatment of B. malayi adult female worms with Bm-cpl-1, Bm-cpl-5, which belong to group Ia of the filarial cpl gene family, or Bm-cpz-1 dsRNA resulted in decreased numbers of secreted microfilariae in vitro. In addition, analysis of the intrauterine progeny of the Bm-cpl-5 or Bm-cpl Pro dsRNA- and siRNA-treated worms revealed a clear disruption in the process of embryogenesis resulting in structural abnormalities in embryos and a varied differential development of embryonic stages. CONCLUSIONS: Our studies suggest that these filarial cathepsin-like cysteine proteases are likely to be functional orthologs of the C. elegans genes. This functional conservation may thus allow for a more thorough investigation of their distinct functions and their development as potential drug targets.

  13. Development of an in vivo RNAi protocol to investigate gene function in the filarial nematode, Brugia malayi.

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    Chuanzhe Song

    Full Text Available Our ability to control diseases caused by parasitic nematodes is constrained by a limited portfolio of effective drugs and a paucity of robust tools to investigate parasitic nematode biology. RNA interference (RNAi is a reverse-genetics tool with great potential to identify novel drug targets and interrogate parasite gene function, but present RNAi protocols for parasitic nematodes, which remove the parasite from the host and execute RNAi in vitro, are unreliable and inconsistent. We have established an alternative in vivo RNAi protocol targeting the filarial nematode Brugia malayi as it develops in an intermediate host, the mosquito Aedes aegypti. Injection of worm-derived short interfering RNA (siRNA and double stranded RNA (dsRNA into parasitized mosquitoes elicits suppression of B. malayi target gene transcript abundance in a concentration-dependent fashion. The suppression of this gene, a cathepsin L-like cysteine protease (Bm-cpl-1 is specific and profound, both injection of siRNA and dsRNA reduce transcript abundance by 83%. In vivo Bm-cpl-1 suppression results in multiple aberrant phenotypes; worm motility is inhibited by up to 69% and parasites exhibit slow-moving, kinked and partial-paralysis postures. Bm-cpl-1 suppression also retards worm growth by 48%. Bm-cpl-1 suppression ultimately prevents parasite development within the mosquito and effectively abolishes transmission potential because parasites do not migrate to the head and proboscis. Finally, Bm-cpl-1 suppression decreases parasite burden and increases mosquito survival. This is the first demonstration of in vivo RNAi in animal parasitic nematodes and results indicate this protocol is more effective than existing in vitro RNAi methods. The potential of this new protocol to investigate parasitic nematode biology and to identify and validate novel anthelmintic drug targets is discussed.

  14. Structure of the trehalose-6-phosphate phosphatase from Brugia malayi reveals key design principles for anthelmintic drugs.

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    Jeremiah D Farelli

    2014-07-01

    Full Text Available Parasitic nematodes are responsible for devastating illnesses that plague many of the world's poorest populations indigenous to the tropical areas of developing nations. Among these diseases is lymphatic filariasis, a major cause of permanent and long-term disability. Proteins essential to nematodes that do not have mammalian counterparts represent targets for therapeutic inhibitor discovery. One promising target is trehalose-6-phosphate phosphatase (T6PP from Brugia malayi. In the model nematode Caenorhabditis elegans, T6PP is essential for survival due to the toxic effect(s of the accumulation of trehalose 6-phosphate. T6PP has also been shown to be essential in Mycobacterium tuberculosis. We determined the X-ray crystal structure of T6PP from B. malayi. The protein structure revealed a stabilizing N-terminal MIT-like domain and a catalytic C-terminal C2B-type HAD phosphatase fold. Structure-guided mutagenesis, combined with kinetic analyses using a designed competitive inhibitor, trehalose 6-sulfate, identified five residues important for binding and catalysis. This structure-function analysis along with computational mapping provided the basis for the proposed model of the T6PP-trehalose 6-phosphate complex. The model indicates a substrate-binding mode wherein shape complementarity and van der Waals interactions drive recognition. The mode of binding is in sharp contrast to the homolog sucrose-6-phosphate phosphatase where extensive hydrogen-bond interactions are made to the substrate. Together these results suggest that high-affinity inhibitors will be bi-dentate, taking advantage of substrate-like binding to the phosphoryl-binding pocket while simultaneously utilizing non-native binding to the trehalose pocket. The conservation of the key residues that enforce the shape of the substrate pocket in T6PP enzymes suggest that development of broad-range anthelmintic and antibacterial therapeutics employing this platform may be possible.

  15. Inflammatory mediator release byBrugia malayi from macrophages of susceptible hostMastomys coucha andTHP-1 andRAW 264.7 cell lines

    Institute of Scientific and Technical Information of China (English)

    Shiv Kumar Verma; Vikas Kushwaha; Vijaya Dubey; Kirti Saxena; Aakanksha Sharma; Puvvada Kalpana Murthy

    2011-01-01

    Objective:To investigate which life stage of the parasite has the ability to stimulate release of pro- or anti-inflammatory mediators from macrophages.Methods: The human macrophage/monocyte cell lineTHP-1, the mouse macrophage cell lineRAW 264.7 and naive peritoneal macrophages(PM)from the rodent hostMastomys coucha (M. coucha)were incubated at37 ℃in 5% CO2atmosphere with extracts of microfilariae(Mf), third stage infective larvae(L3) and adult worms (Ad)ofBrugia malayi. After48 hr post exposure,IL-1β, IL-6, TNF-α, IL-10 and nitric oxide (NO) in cell-free supernatants were estimated.Results: Extracts of all the life stages of the parasite were capable of stimulating pro-(IL-1β, IL-6 andTNF-α) and anti-inflammatory (IL-10)cytokines in both the cell lines and peritoneal macrophages ofM. coucha. Mf was the strongest stimulator of pro-inflammatory cytokines followed by L3 and Ad; however, Ad was a strong stimulator ofIL-10 release. Mf was found to have potential to modulateLPS-inducedNO release inRAW cells. Ad-inducedNO release was concentration dependent with maximum at 20 μg/mL in bothRAW andPMs.Conclusions:The results show that parasites at all life stages were capable of stimulating pro- (IL-1β, IL-6 and TNF-α) and anti-inflammatory(IL-10) cytokines andNO release from macrophages of susceptible hostM. coucha, human and mouse macrophage cell lines.Mf can suppress theLPS-inducedNO release inRAW cells. The findings also show that the two cell lines may provide a convenientin vitro system for assaying parasite-induced inflammatory mediator release.

  16. A 22-nucleotide spliced leader sequence in the human parasitic nematode Brugia malayi is identical to the trans-spliced leader exon in Caenorhabditis elegans.

    OpenAIRE

    Takacs, A M; Denker, J A; Perrine, K G; Maroney, P A; Nilsen, T W

    1988-01-01

    The mRNAs encoding a 63-kDa antigen in the human parasitic nematode Brugia Malayi contain a spliced leader sequence of 22 nucleotides (nt) that is identical to the trans-spliced leader found on certain actin mRNAs in the distantly related nematode Caenorhabditis elegans. The 22-nt sequence does not appear to be encoded near the 63-kDa genes but is present in multiple copies in several locations within the parasite genome, including the 5S rRNA gene repeat. The 5S-linked copies of the 22-nt se...

  17. Detection of enzymes dehydrogenases and proteases inBrugia malayi filarial parasites.

    Science.gov (United States)

    Bhandary, Y P; Krithika, K N; Kulkarni, Sandeep; Reddy, M V R; Harinath, B C

    2006-03-01

    Lymphatic filariasis caused mainly by infection fromW. bancrofti andB. malayi remains a major cause of clinical morbidity in tropical and subtropical countries. Analysis ofB. malayi mf, infective larval and adult worm lysates for the activity of enzymes led to the demonstration of activities of three key enzymes of carbohydrate metabolism viz., Malate dehydrogenase (MDH), Malic enzyme (ME) and Glucose-6-phosphate dehydrogenase (G6PDH) in all the three stages of the parasite. The specific activity of all the three dehydrogenases was significantly high in mf lysate compared to their activity in lysates of the other two stages (PFlouride (PMSF). In sodium do-decyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), using gelatin copolymerized gel, the microfilarial lysate showed 3 protease molecules of 40 kDa, 180 kDa and 200 kDa and the L(3) larval lysate had 6 protease molecules of 18, 25, 37, 49, 70 and 200 kDa size.

  18. Characterization of transcription factors that regulate the type IV secretion system and riboflavin biosynthesis in Wolbachia of Brugia malayi.

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    Zhiru Li

    Full Text Available The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium Wolbachia (wBm that is required for parasite survival. Consequently, targeting wBm is a promising approach for anti-filarial drug development. The Type IV secretion system (T4SS plays an important role in bacteria-host interactions and is under stringent regulation by transcription factors. In wBm, most T4SS genes are contained in two operons. We show the wBm is active since the essential assembly factor virB8-1, is transcribed in adult worms and larval stages, and VirB8-1 is present in parasite lysates. We also identify two transcription factors (wBmxR1 and wBmxR2 that bind to the promoter region of several genes of the T4SS. Gel shift assays show binding of wBmxR1 to regions upstream of the virB9-2 and wBmxR2 genes, whereas wBmxR2 binds to virB4-2 and wBmxR1 promoter regions. Interestingly, both transcription factors bind to the promoter of the ribA gene that precedes virB8-1, the first gene in operon 1 of the wBm T4SS. RT-PCR reveals ribA and virB8-1 genes are co-transcribed as one operon, indicating the ribA gene and T4SS operon 1 are co-regulated by both wBmxR1 and wBmxR2. RibA encodes a bi-functional enzyme that catalyzes two essential steps in riboflavin (Vitamin B2 biosynthesis. Importantly, the riboflavin pathway is absent in B. malayi. We demonstrate the pathway is functional in wBm, and observe vitamin B2 supplementation partially rescues filarial parasites treated with doxycycline, indicating Wolbachia may supply the essential vitamin to its worm host. This is the first characterization of a transcription factor(s from wBm and first report of co-regulation of genes of the T4SS and riboflavin biosynthesis pathway. In addition, our results demonstrate a requirement of vitamin B2 for worm health and fertility, and imply a nutritional role of the symbiont for the filarial parasite host.

  19. Characterization of transcription factors that regulate the type IV secretion system and riboflavin biosynthesis in Wolbachia of Brugia malayi.

    Science.gov (United States)

    Li, Zhiru; Carlow, Clotilde K S

    2012-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium Wolbachia (wBm) that is required for parasite survival. Consequently, targeting wBm is a promising approach for anti-filarial drug development. The Type IV secretion system (T4SS) plays an important role in bacteria-host interactions and is under stringent regulation by transcription factors. In wBm, most T4SS genes are contained in two operons. We show the wBm is active since the essential assembly factor virB8-1, is transcribed in adult worms and larval stages, and VirB8-1 is present in parasite lysates. We also identify two transcription factors (wBmxR1 and wBmxR2) that bind to the promoter region of several genes of the T4SS. Gel shift assays show binding of wBmxR1 to regions upstream of the virB9-2 and wBmxR2 genes, whereas wBmxR2 binds to virB4-2 and wBmxR1 promoter regions. Interestingly, both transcription factors bind to the promoter of the ribA gene that precedes virB8-1, the first gene in operon 1 of the wBm T4SS. RT-PCR reveals ribA and virB8-1 genes are co-transcribed as one operon, indicating the ribA gene and T4SS operon 1 are co-regulated by both wBmxR1 and wBmxR2. RibA encodes a bi-functional enzyme that catalyzes two essential steps in riboflavin (Vitamin B2) biosynthesis. Importantly, the riboflavin pathway is absent in B. malayi. We demonstrate the pathway is functional in wBm, and observe vitamin B2 supplementation partially rescues filarial parasites treated with doxycycline, indicating Wolbachia may supply the essential vitamin to its worm host. This is the first characterization of a transcription factor(s) from wBm and first report of co-regulation of genes of the T4SS and riboflavin biosynthesis pathway. In addition, our results demonstrate a requirement of vitamin B2 for worm health and fertility, and imply a nutritional role of the symbiont for the filarial parasite host.

  20. Brugia malayi microfilariae induce a regulatory monocyte/macrophage phenotype that suppresses innate and adaptive immune responses.

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    Noëlle Louise O'Regan

    2014-10-01

    Full Text Available Monocytes and macrophages contribute to the dysfunction of immune responses in human filariasis. During patent infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive.To determine whether blood microfilariae directly act on blood monocytes and in vitro generated macrophages to induce a regulatory phenotype that interferes with innate and adaptive responses.Monocytes and in vitro generated macrophages from filaria non-endemic normal donors were stimulated in vitro with Brugia malayi microfilarial (Mf lysate. We could show that monocytes stimulated with Mf lysate develop a defined regulatory phenotype, characterised by expression of the immunoregulatory markers IL-10 and PD-L1. Significantly, this regulatory phenotype was recapitulated in monocytes from Wuchereria bancrofti asymptomatically infected patients but not patients with pathology or endemic normals. Monocytes from non-endemic donors stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and cytokine production (IFN-γ, IL-13 and IL-10. IFN-γ responses were restored by neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate expressed high levels of IL-10 and had suppressed phagocytic abilities. Finally Mf lysate applied during the differentiation of macrophages in vitro interfered with macrophage abilities to respond to subsequent LPS stimulation in a selective manner.Conclusively, our study demonstrates that Mf lysate stimulation of monocytes from healthy donors in vitro induces a regulatory phenotype, characterized by expression of PD-L1 and IL-10. This phenotype is directly reflected in monocytes from filarial patients with asymptomatic infection but not patients with pathology or endemic normals. We suggest that suppression of T cell functions typically seen in lymphatic filariasis is caused by microfilaria-modulated monocytes in an IL

  1. Brugia malayi Microfilariae Induce a Regulatory Monocyte/Macrophage Phenotype That Suppresses Innate and Adaptive Immune Responses

    Science.gov (United States)

    Venugopal, Gopinath; Rao, Gopala B.; Lucius, Richard; Srikantam, Aparna; Hartmann, Susanne

    2014-01-01

    Background Monocytes and macrophages contribute to the dysfunction of immune responses in human filariasis. During patent infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive. Aim To determine whether blood microfilariae directly act on blood monocytes and in vitro generated macrophages to induce a regulatory phenotype that interferes with innate and adaptive responses. Methodology and principal findings Monocytes and in vitro generated macrophages from filaria non-endemic normal donors were stimulated in vitro with Brugia malayi microfilarial (Mf) lysate. We could show that monocytes stimulated with Mf lysate develop a defined regulatory phenotype, characterised by expression of the immunoregulatory markers IL-10 and PD-L1. Significantly, this regulatory phenotype was recapitulated in monocytes from Wuchereria bancrofti asymptomatically infected patients but not patients with pathology or endemic normals. Monocytes from non-endemic donors stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and cytokine production (IFN-γ, IL-13 and IL-10). IFN-γ responses were restored by neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate expressed high levels of IL-10 and had suppressed phagocytic abilities. Finally Mf lysate applied during the differentiation of macrophages in vitro interfered with macrophage abilities to respond to subsequent LPS stimulation in a selective manner. Conclusions and significance Conclusively, our study demonstrates that Mf lysate stimulation of monocytes from healthy donors in vitro induces a regulatory phenotype, characterized by expression of PD-L1 and IL-10. This phenotype is directly reflected in monocytes from filarial patients with asymptomatic infection but not patients with pathology or endemic normals. We suggest that suppression of T cell functions typically seen in lymphatic

  2. Rapid detection and identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in mosquito vectors and blood samples by high resolution melting real-time PCR.

    Science.gov (United States)

    Thanchomnang, Tongjit; Intapan, Pewpan M; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej; Maleewong, Wanchai

    2013-12-01

    A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.5±0.2℃, 79.0±0.3℃, 76.8±0.1℃, and 79.9±0.1℃, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors.

  3. Designing, synthesis of selective and high-affinity chalcone-benzothiazole hybrids as Brugia malayi thymidylate kinase inhibitors: In vitro validation and docking studies.

    Science.gov (United States)

    Sashidhara, Koneni V; Avula, Srinivasa Rao; Doharey, Pawan Kumar; Singh, L Ravithej; Balaramnavar, Vishal M; Gupta, Jyoti; Misra-Bhattacharya, Shailja; Rathaur, Sushma; Saxena, Anil K; Saxena, Jitendra Kumar

    2015-10-20

    In our continuing search for safe and efficacious antifilarials, a series of novel chalcone-benzothiazole hybrids have been synthesized and evaluated for their Brugia malayi thymidylate kinase (BmTMK) enzyme inhibition activity. Their selectivity towards BmTMK was studied and compared to the human TMK (HsTMK) by an in silico method. Out of seventeen derivatives, compounds 34 and 42 showed higher interactions with the BmTMK active site. MolDock docking model revealed the interactions of these two derivatives and the results corroborated well with their in vitro antifilarial activities. Our studies suggest that these hybrids are selective towards the BmTMK enzyme and may serve as potential therapeutic agents against filariasis.

  4. Low positive predictive value of anti-Brugia malayi IgG and IgG4 serology for the diagnosis of Wuchereria bancrofti.

    Science.gov (United States)

    Chanteau, S; Glaziou, P; Moulia-Pelat, J P; Plichart, C; Luquiaud, P; Cartel, J L

    1994-01-01

    Enzyme-linked immunosorbent assays (ELISAs) for anti-Brugia malayi immunoglobulin (Ig) G and IgG4 were evaluated on sera from 1561 subjects in French Polynesia for the serodiagnosis of Wuchereria bancrofti filariasis, compared with the test for Onchocerca gibsoni circulating antigen (Og4C3) as a 'gold standard'. The sensitivity of the ELISA-IgG and ELISA-IgG4 assays was 90.8% and 94.5%, and the specificity was 45.9% and 50.7%. The positive predictive values were 41% and 45% respectively for an antigen prevalence rate of 30%. Thus antibody prevalences exceeded by two-fold the antigen prevalence, which itself exceeded by two-fold the prevalence of microfilaraemia.

  5. Experimental chemotherapy of filariasis: comparative evaluation of the efficacy of filaricidal compounds in Mastomys coucha infected with Litomosoides carinii, Acanthocheilonema viteae, Brugia malayi and B. pahangi.

    Science.gov (United States)

    Zahner, H; Schares, G

    1993-01-01

    Eleven types/classes of compound with antifilarial activity were comparatively evaluated in Mastomys coucha infected with Litomosoides carinii, Acanthocheilonema viteae, Brugia malayi or B. pahangi. The paper deals with the efficacy of (i) predominantly microfilaricidal compounds [diethylcarbamazine, levamisole, avermectins (ivermectin, milbemycin), nitrofurans (nitrofurantoin, hydroxymethylnitrofurantoin, nifurtimox, furazolidone, furapyrimidone), organophosphorals (metrifonate, haloxon), and aminophenyl-amidines], (ii) predominantly macrofilaricidal compounds [suramin, benzimidazoles (flubendazole, mebendazole, oxfendazole, ciclobendazole, albendazole, cambendazole, fenbendazole), and arsenicals (thiacetarsamide, Mel PH, R7/45)], and (iii) micro- and macrofilaricidal compounds [benzazole derivatives (CGP 20376 and other benzothiazoles) and nitrophenylamines (amoscanate, CGP 6140)]. Minimum effective doses against microfilariae and minimum curative doses against adult filariae as well as detailed data on dose-efficacy relationships are reported for the various drugs. The results obtained in M. coucha are compared with those published for other experimental in vivo filarial systems, thus attempting to describe a general status of in vivo antifilarial activity of the compounds.

  6. A recombinant plasmid of composite cysteine proteinase inhibitor/glyceraldehyde-3-phosphate dehydrogenase gene of periodic Brugia malayi functions on DNA immunity in the host

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    Z Fang

    2016-01-01

    Full Text Available Objectives: Both cysteine proteinase inhibitors (CPIs and glyceraldehyde-3-phosphate dehydrogenase (GAPDH play important roles in the pathogenesis of parasites and their relationship with the hosts. We constructed a new eukaryotic recombinant expression plasmid pcDNA3.1(+-BmCPI/BmGAPDH of periodic Brugia malayi for investigation of the DNA vaccine-elicited immune responses. Materials and Methods: We cloned a gene encoding the CPIs and GAPDH from periodic B. malayi into vector pcDNA3.1. The composited plasmid or the control was injected into the tibialis anterior muscle of the hind leg in BALB/c mice, respectively. The target genes were detected by reverse transcription-polymerase chain reaction in muscle tissues. The stimulation index (SI of T-lymphocyte proliferation and the levels of interferon-gamma (INF-g and interleukin-4 ( IL-4 in serum were detected by thiazolyl blue tetrazolium blue and enzyme-linked immunosorbent assays. Results: The pcDNA3.1(+-BmCPI/BmGAPDH was amplified from muscle tissues of the mice after immunisation. The SI of the immunised group was significantly higher than that of the two control groups (P < 0.05. The levels of INF-g and IL-4 of pcDNA3.1(+-BmCPI/BmGAPDH group were both higher than those of the two control groups (P < 0.05. The level of INF-g of pcDNA3.1(+-BmCPI/BmGAPDH group was significantly higher than that of pcDNA3.1(+-BmCPI/CpG group (P < 0.05. Conclusions: We conclude that the recombinant plasmid pcDNA3.1(+-BmCPI/BmGAPDH could elicit specific humoural and cellular immune responses in mice.

  7. Cloning, expression and characterization of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA from Wolbachia endosymbiont of human lymphatic filarial parasite Brugia malayi.

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    Mohd Shahab

    Full Text Available Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for treatment of lymphatic filariasis. Although functional characterization of the Wolbachia peptidoglycan assembly has not been fully explored, the Wolbachia genome provides evidence for coding all of the genes involved in lipid II biosynthesis, a part of peptidoglycan biosynthesis pathway. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA is one of the lipid II biosynthesis pathway enzymes and it has inevitably been recognized as an antibiotic target. In view of the vital role of MurA in bacterial viability and survival, MurA ortholog from Wolbachia endosymbiont of Brugia malayi (wBm-MurA was cloned, expressed and purified for further molecular characterization. The enzyme kinetics and inhibition studies were undertaken using fosfomycin. wBm-MurA was found to be expressed in all the major life stages of B. malayi and was immunolocalized in Wolbachia within the microfilariae and female adults by the confocal microscopy. Sequence analysis suggests that the amino acids crucial for enzymatic activity are conserved. The purified wBm-MurA was shown to possess the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase like activity at a broad pH range with optimal activity at pH 7.5 and 37°C temperature. The apparent affinity constant (Km for the substrate UDP-N-acetylglucosamine was found to be 0.03149 mM and for phosphoenolpyruvate 0.009198 mM. The relative enzymatic activity was inhibited ∼2 fold in presence of fosfomycin. Superimposition of the wBm-MurA homology model with the structural model of Haemophilus influenzae (Hi-MurA suggests binding of fosfomycin at the same active site. The findings suggest wBm-MurA to be a putative antifilarial drug target for screening of novel compounds.

  8. Exome and Transcriptome Sequencing of Aedes aegypti Identifies a Locus That Confers Resistance to Brugia malayi and Alters the Immune Response

    KAUST Repository

    Juneja, Punita

    2015-03-27

    Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait.

  9. Homology modeling of NAD+-dependent DNA ligase of the Wolbachia endosymbiont of Brugia malayi and its drug target potential using dispiro-cycloalkanones.

    Science.gov (United States)

    Shrivastava, Nidhi; Nag, Jeetendra K; Pandey, Jyoti; Tripathi, Rama Pati; Shah, Priyanka; Siddiqi, Mohammad Imran; Misra-Bhattacharya, Shailja

    2015-07-01

    Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD(+)-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD(+)-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD(+) cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates.

  10. PENENTUAN JENIS NYAMUK MansoniaSEBAGAI TERSANGKA VEKTOR FILARIASIS Brugia malayi DAN HEWAN ZOONOSIS DI KABUPATEN MUARO JAMBI

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    Santoso Santoso

    2015-01-01

    Full Text Available AbstrakFilariasis merupakan penyakit yang tidak mudah menular. Filariasis adalah penyakit yang ditularkan oleh nyamuk sebagai vector. Jenis nyamuk yang dapat berperan sebagai vector filariasis dipengaruhi oleh jenis cacing penyebab filaria. Brugia spp. umumnya ditularkan oleh nyamuk Mansonia spp dan Anopheles spp. Vektor dan hewan zoonosis merupakan salah satu factor yang dapat perlu mendapat perhatian dalam pengendalian filariasis. Penelitian terhadap vector dan hewan zoonosis telah dilakukan di Kabupaten Muaro Jambi untuk mengidentifikasi bionomik vektor dan kemungkinan adanya hewan zoonosis yang berperan sebagai penular filariasis. Desain penelitian adalah observasi, yaitu dengan melakukan penangkapan nyamuk dan pemeriksaan darah terhadap kucing. Jumlah kucing yang diperiksa sebanyak 18 ekor. Kucing yang positif microfilaria sebanyak 1 ekor. Jumlah nyamuk Mansonia spp. tertangkap sebanyak 1,167 ekor yang terdiri dari 6 species. Spesies nyamuk tertangkap paling banyak adalah Mansonia uniformis sebanyak 1.010 ekor dengan angka kekerapan 1,0. Berdasarkan hasil tersebut, maka diperlukan peran serta masyarakat untuk mengurangi kepadatan nyamuk dengan membersihkan genangan air dan mencegah gigitan nyamuk. Selain itu diperlukan juga penanganan terhadap hewan yang bertindak sebagai zoonosis dengan memberikan pengobatan terhadap kucing agar tidak menjadi sumber infeksi.Keywords : filariasis, Mansonia, vektor, zoonosis, Muaro Jambi.AbstractFilariasisis noteasily transmitted diseases. Filariasisis transmitted by mosquito vectors. Various types of mosquitoes can act as vectors of filariasis, depending on the type of microfilaria. Brugia spp. are generally transmitted by Mansonia spp and Anopheles spp. Vector and zoonotic animal are the factors that can transmit filariasis and need to have attention for controlling filariasis. Research on vector and zoonotic had been done in Muaro Jambi to determine bionomic vector and the possibility of animals can

  11. Bm-CPI-2, a cystatin from Brugia malayi nematode parasites, differs from Caenorhabditis elegans cystatins in a specific site mediating inhibition of the antigen-processing enzyme AEP.

    Science.gov (United States)

    Murray, Janice; Manoury, Bénédicte; Balic, Adam; Watts, Colin; Maizels, Rick M

    2005-02-01

    The filarial parasite Brugia malayi survives for many years in the human lymphatic system. One immune evasion mechanism employed by Brugia is thought to be the release of cysteine protease inhibitors (cystatins), and we have previously shown that the recombinant cystatin Bm-CPI-2 interferes with protease-dependent antigen processing in the MHC class II antigen presentation pathway. Analogy with vertebrate cystatins suggested that Bm-CPI-2 is bi-functional, with one face of the protein blocking papain-like proteases, and the other able to inhibit legumains such as asparaginyl endopeptidase (AEP). Site-directed mutagenesis was carried out on Bm-CPI-2 at Asn-77, the residue on which AEP inhibition is dependent in vertebrate homologues. Two mutations at this site (to Asp and Lys) showed 10-fold diminished and ablated activity respectively, in assays of AEP inhibition, while blocking of papain-like proteases was reduced by only a small degree. Comparison of the B. malayi cystatins with two homologues encoded by the free-living model organism, Caenorhabditis elegans, suggested that while the papain site may be intact, the AEP site would not be functional. This supposition was tested with recombinant C. elegans proteins, Ce-CPI-1 (K08B4.6) and Ce-CPI-2 (R01B10.1), both of which block cathepsins and neither of which possess the ability to block AEP. Thus, Brugia CPI-2 may have convergently evolved to inhibit an enzyme important only in the mammalian environment.

  12. Physicochemical properties of the modeled structure of astacin metalloprotease moulting enzyme NAS-36 and mapping the druggable allosteric space of Heamonchus contortus, Brugia malayi and Ceanorhabditis elegans via molecular dynamics simulation.

    Science.gov (United States)

    Sharma, Om Prakash; Agrawal, Sonali; Kumar, M Suresh

    2013-12-01

    Nematodes represent the second largest phylum in the animal kingdom. It is the most abundant species (500,000) in the planet. It causes chronic, debilitating infections worldwide such as ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis, filariasis and trichinosis, among others. Molecular modeling tools can play an important role in the identification and structural investigation of molecular targets that can act as a vital candidate against filariasis. In this study, sequence analysis of NAS-36 from H. contortus (Heamonchus contortus), B. malayi (Brugia malayi) and C. elegans (Ceanorhabditis elegans) has been performed, in order to identify the conserved residues. Tertiary structure was developed for an insight into the molecular structure of the enzyme. Molecular Dynamics Simulation (MDS) studies have been carried out to analyze the stability and the physical properties of the proposed enzyme models in the H. contortus, B. malayi and C. elegans. Moreover, the drug binding sites have been mapped for inhibiting the function of NAS-36 enzyme. The molecular identity of this protease could eventually demonstrate how ex-sheathment is regulated, as well as provide a potential target of anthelmintics for the prevention of nematode infections.

  13. The n-hexane and chloroform fractions of Piper betle L. trigger different arms of immune responses in BALB/c mice and exhibit antifilarial activity against human lymphatic filarid Brugia malayi.

    Science.gov (United States)

    Singh, Meghna; Shakya, Shilpy; Soni, Vishal Kumar; Dangi, Anil; Kumar, Nikhil; Bhattacharya, Shailja-Misra

    2009-06-01

    Modulation of immune functions by using herbal plants and their products has become fundamental regime of therapeutic approach. Piper betle Linn. (Piperaceae) is a widely distributed plant in the tropical and subtropical regions of the world and has been attributed as traditional herbal remedy for many diseases. We have recently reported the antifilarial and antileishmanial efficacy in the leaf extract of Bangla Mahoba landrace of P. betle which is a female plant. The present report describes the in vivo immunomodulatory efficacy of the crude methanolic extract and its n-hexane, chloroform, n-butanol fractions of the female plant at various dose levels ranging between 0.3 and 500 mg/kg in BALB/c. Attempts were also made to observe antifilarial activity of the active extracts and correlate it with the antigen specific immune responses in another rodent Mastomys coucha infected with human lymphatic filarial parasite Brugia malayi. The crude methanol extract and n-hexane fraction were found to potentiate significant (p<0.001) enhancement of both humoral (plaque forming cells, hemagglutination titre) as well as cell-mediated (lymphoproliferation, macrophage activation, delayed type hypersensitivity) immune responses in mice. The flow cytometric analysis of splenocytes of treated mice indicated enhanced population of T-cells (CD4(+), CD8(+)) and B-cells (CD19(+)). The n-hexane fraction (3 mg/kg) was found to induce biased type 2 cytokine response as revealed by increased IL-4(+) and decreased IFN-gamma(+) T-cell population while the chloroform fraction (10 mg/kg) produced a predominant type 1 cytokines. Crude methanolic extract (100 mg/kg) demonstrated a mixed type 1 and type 2 cytokine responses thus suggesting a remarkable immunomodulatory property in this plant. The induction of differential T-helper cell immune response appears ideal to overcome immunosuppression as observed in case of lymphatic, filarial Brugia malayi infection which may also be extended to other

  14. Genomes of parasitic nematodes (Meloidogyne hapla, Meloidogyne incognita, Ascaris suum and Brugia malayi) have a reduced complement of small RNA interference pathway genes: knockdown can reduce host infectivity of M. incognita.

    Science.gov (United States)

    Iqbal, Sadia; Fosu-Nyarko, John; Jones, Michael G K

    2016-07-01

    The discovery of RNA interference (RNAi) as an endogenous mechanism of gene regulation in a range of eukaryotes has resulted in its extensive use as a tool for functional genomic studies. It is important to study the mechanisms which underlie this phenomenon in different organisms, and in particular to understand details of the effectors that modulate its effectiveness. The aim of this study was to identify and compare genomic sequences encoding genes involved in the RNAi pathway of four parasitic nematodes: the plant parasites Meloidogyne hapla and Meloidogyne incognita and the animal parasites Ascaris suum and Brugia malayi because full genomic sequences were available-in relation to those of the model nematode Caenorhabditis elegans. The data generated was then used to identify some potential targets for control of the root knot nematode, M. incognita. Of the 84 RNAi pathway genes of C. elegans used as model in this study, there was a 42-53 % reduction in the number of effectors in the parasitic nematodes indicating substantial differences in the pathway between species. A gene each from six functional groups of the RNAi pathway of M. incognita was downregulated using in vitro RNAi, and depending on the gene (drh-3, tsn-1, rrf-1, xrn-2, mut-2 and alg-1), subsequent plant infection was reduced by up to 44 % and knockdown of some genes (i.e. drh-3, mut-2) also resulted in abnormal nematode development. The information generated here will contribute to defining targets for more robust nematode control using the RNAi technology.

  15. Brugia malayi Antigen (BmA Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    Directory of Open Access Journals (Sweden)

    Emily E I M Mouser

    Full Text Available One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA and excretory-secretory product 62 (ES-62 from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs.

  16. AMPLIFICATION, CLONING AND SEQUENCE ANALYSIS OF CYSTEINE PROTEASE GENE FROM PERIODIC Brugia Malayi%周期型马来丝虫半胱氨酸蛋白酶基因的扩增、克隆及序列分析

    Institute of Scientific and Technical Information of China (English)

    黄为群; 方政; 陈阳; 姜声扬; 吴建军; 谢东方

    2007-01-01

    [目的]克隆周期型马来丝虫半胱氨酸蛋白酶(cysteine protease of periodic Brugia malayi,BmCP)基因到原核载体中,测定其序列,为进一步的研究奠定基础.[方法]从周期型马来丝虫虫体中抽提总RNA,以mRNA为模板,采用RT-PCR法体外扩增出BmCP基因序列,扩增产物经初步鉴定后将其克隆入pMD18-T载体,转化大肠杆菌(E. coli)DH5α,筛选阳性克隆,进行双酶切及PCR扩增签定,获得阳性重组质粒pMD18-T-BmCP,经测序验证,并进行同源性比较.[结果]RT-PCR扩增出一条约1 201 bp大小的特异性条带,重组质粒双酶切和以质粒为模板的PCR结果与预期相符,DNA序列分析与GeneBank已知的基因序列同源性为99%.[结论]成功构建了周期型马来丝虫半胱氨酸蛋白酶重组质粒pMD18-T克隆载体,为进一步研究该基因的功能提供了条件.

  17. 周期型马来丝虫复合基因重组质粒和相应表达蛋白的免疫学研究%Immunology comparision of composite gene recombinant plasmid and expressed protein of periodical Brugia malayi

    Institute of Scientific and Technical Information of China (English)

    王慧; 方政; 徐倩; 陆施娟; 钱一言; 徐怿琳; 方浩; 徐邦生

    2014-01-01

    粒/复合重组蛋白/CpG组小鼠淋巴细胞刺激增殖指数(1.629±0.235)高于复合重组蛋白组(1.248±0.110,P<0.05);免疫4、6周后,复合重组质粒/复合重组蛋白/CpG组和复合重组质粒/CpG组小鼠血清IFN-γ水平[(101.660±5.101)、(178.265±7.139)mg/L,(102.067±3.722)、(115.148±6.031)mg/L]均高于复合重组蛋白组[(75.438±2.102)、(82.004±3.777) mg/L,P均<0.05];免疫后6周,复合重组质粒/复合重组蛋白/CpG组和复合重组蛋白/CpG组的小鼠血清IL-4水平[(75.385±3.318)、(46.363±3.672)mg/L]均明显高于复合重组质粒/CpG组[(36.691±3.443)mg/L,P均<0.05).结论 pcDNA3.1-BmCPI/BmGAPDH核酸疫苗和相应蛋白疫苗均可诱导BALB/c小鼠产生特异性体液和细胞免疫应答反应.核酸疫苗-蛋白疫苗联合免疫效果有明显的优势.%Objective To construct a plasmid DNA vector expressing cysteine protease inhibitor and glyceraldehydes-3-phosphate dehydrogenase of periodic Brugia malayi(BmCPI/BmGAPDH),and purify the recombinant protein after transfecting the vector into human cervical carcinoma cells(Hela) for expression.To make a comparison of immunity efficacy between the recombinant plasmid and the homologous protein and to a lay theoretic and experimental basis for developing novel anti-filarial genetic engineering vaccines.Methods The amplified genes BmCPI and BmGAPDH and a plasmid vector were double enzymes digested and ligated to construct a recombinant plasmid pcDNA3.1 (+)-BmCPI/BmGAPDH,and this plasmid was transfected to Hela cells after being identified.G418 was used for screening transfectants,and the monoclonal resistant cell strain was determined by RT-PCR and SDS-PAGE.The recombinant protein was purified by affnity chromatography and identified by Western blotting.Sixty BALB/c mice were divided into 5 groups,12 per group,and they were immunized at 2,4,and 6 weeks.Mice in control groups were injected with PBS 100 μ1 or pcDNA3.1 100 μg/CpG 30 μg,and mice in

  18. Detection of filaria-specific IgG4 antibodies using Brugia Rapid test in individuals from an area highly endemic for Brugia timori.

    Science.gov (United States)

    Supali, T; Rahmah, N; Djuardi, Y; Sartono, E; Rückert, Paul; Fischer, P

    2004-05-01

    The filarial parasite Brugia timori is of great public health importance in some islands of Eastern Indonesia. To establish a simple serological test for the identification and post-treatment monitoring of areas endemic for B. timori, a rapid immunochromatographic dipstick test (Brugia Rapid, BR) was evaluated on microfilaraemic and amicrofilaraemic individuals. This test is based on the detection of anti-filarial IgG4 antibodies that react with a recombinant Brugia malayi antigen (BmR1). In our study area on Alor island the prevalence of microfilaraemia was 26%. With the BR test, 100% of 196 sera from microfilaraemic persons and 76% of 563 sera from amicrofilaraemic persons, either symptomatic or asymptomatic, reacted positive. All 50 control sera from areas non-endemic for lymphatic filariasis gave negative BR test results. This study showed that the BR test can be also used to detect antibodies against B. timori. Due to the high prevalence of IgG4 antibodies as detected by the BR test (81%), no significant correlation with the prevalence of microfilaraemia could be detected within the endemic village. The BR test also shows great promise to be employed as a monitoring tool for B. timori in the framework of the Global Program to Eliminate Lymphatic Filariasis (GPELF).

  19. Effects of gamma radiation on development of Brugia pahangi in a susceptible strain of Aedes aegypti

    Energy Technology Data Exchange (ETDEWEB)

    Richey, T.J.; Rodriguez, P.H.

    1976-08-01

    Female mosquitoes were fed on an infected jird having a microfilarial density of 201 per mm/sup 3/ of blood. Mosquitoes were exposed to doses of 3,000 and 5,000 rads of gamma radiation before and after infection. Mosquitoes were dissected 8 to 10 days later and the number of active larvae was recorded. Results indicated that postinfection radiation affected the development of Brugia pahangi. (HLW)

  20. Novel drug designing rationale againstBrugia malayi microfilariae using herbal extracts

    Institute of Scientific and Technical Information of China (English)

    SharmaRD; PetareS; ShindeGB; KalyanGoswami; ReddyMVR

    2010-01-01

    Objective:To explore the effect of herbal polyphenolics on filariasisin vitro.Methods: Two herbal extracts, methanolic extracts of roots ofVitex negundo Linn. (Nirgundi) and leaves ofAegle marmelos Juss. (Beal) in different concentrations ranging from40-80ng/mL were tested for their antifilarial activity either alone or in combination with diethyl carbonate (DEC)(300μg/mL) and/orH2O2 (0.5 mM).Results:Combination of DEC and each extract had significant anti-filarial effect. And fractions of both extracts were not effective as crude herbal extract.Conclusions:Such unique pharmacodynamics reported in this study might provide new drug development stratagem against filariasis.

  1. Immune responses in human infections with Brugia malayi: specific cellular unresponsiveness to filarial antigens.

    Science.gov (United States)

    Piessens, W F; McGreevy, P B; Piessens, P W; McGreevy, M; Koiman, I; Saroso, J S; Dennis, D T

    1980-01-01

    We evaluated the cellular immune competence of 101 subjects living in an area of South Kalimantan (Borneo) where Malayan filariasis is endemic. All patients with elephantiasis but none with other clinical stages of filariasis reacted with adult worm antigens. The majority of subjects without clinical or parasitological evidence of filariasis and approximately one-half of those with amicrofilaremic filariasis reacted with microfilarial antigens. In contrast, most patients with patent microfilaremia did not respond to microfilarial antigens. The in vitro reactivity of all patient categories to nonparasite antigens was similar to that of the distant control group. These results indicate that patent microfilaremia is associated with a state of specific cellular immune unresponsiveness and are consistent with the current hypothesis that the various clinical manifestations of filariasis result from different types of immune responses to distinct antigens associated with different developmental stages of filarial worms. PMID:7350196

  2. Proinflammatory Cytokine Gene Expression by Murine Macrophages in Response to Brugia malayi Wolbachia Surface Protein

    Directory of Open Access Journals (Sweden)

    Chantima Porksakorn

    2007-01-01

    Full Text Available Wolbachia, an endosymbiotic bacterium found in most species of filarial parasites, is thought to play a significant role in inducing innate inflammatory responses in lymphatic filariasis patients. However, the Wolbachia-derived molecules that are recognized by the innate immune system have not yet been identified. In this study, we exposed the murine macrophage cell line RAW 264.7 to a recombinant form of the major Wolbachia surface protein (rWSP to determine if WSP is capable of innately inducing cytokine transcription. Interleukin (IL-1β, IL-6, and tumor necrosis factor (TNF mRNAs were all upregulated by the rWSP stimulation in a dose-dependant manner. TNF transcription peaked at 3 hours, whereas IL-1β and IL-6 transcription peaked at 6 hours post-rWSP exposure. The levels of innate cytokine expression induced by a high-dose (9.0 μg/mL rWSP in the RAW 264.7 cells were comparable to the levels induced by 0.1 μg/mL E. coli-derived lipopolysaccharides. Pretreatment of the rWSP with proteinase-K drastically reduced IL-1β, IL-6, and TNF transcription. However, the proinflammatory response was not inhibited by polymyxin B treatment. These results strongly suggest that the major Wolbachia surface protein molecule WSP is an important inducer of innate immune responses during filarial infections.

  3. Detection of filaria-specific IgG4 antibodies and filarial DNA, for the screening of blood spots for Brugia timori.

    Science.gov (United States)

    Fischer, P; Bonow, I; Supali, T; Rückert, P; Rahmah, N

    2005-01-01

    The establishment of simple, sensitive and specific tools for the diagnosis of brugian lymphatic filariasis is a prerequisite for a successful intervention to control the disease. In the simple and rapid Brugia Rapid (BR) test, an immunochromatographic dipstick is used to detect IgG(4) antibodies that are reactive with a recombinant Brugia malayi antigen. When sera from 109 individuals with Brugia microfilaraemias (12 with B. malayi and 97 with B. timori) were investigated using the BR test, all were found positive. In contrast, all of the 150 sera from individuals with Onchocerca volvulus or Mansonella infections investigated were found negative in BR tests. Some unwelcome cross-reactions were observed, however, with sera from individuals infected with Wuchereria bancrofti (three of 12 test-positive) and Dirofilaria (one of nine test-positive). In an attempt to facilitate sample collection and detect any cross-reactions, the BR dipstick was used to screen blood spots, that had been allowed to dry on filter paper, for B. timori microfilariae, before the dipstick-positive samples were tested with a PCR-based assay. Of the 66 individuals so tested, 37 (56%) were found positive by the BR test used on dry blood spots and eight (22%) by the filtration of fresh blood samples. Only nine of the 37 dipstick-positive samples were found PCR-positive. The combined use of BR tests and PCR-based assays, for testing blood spots in areas where brugian filariasis is endemic, appears to be a promising method not only for post-treatment monitoring but also for the certification activities planned within the framework of the Global Programme to Eliminate Lymphatic Filariasis.

  4. Rapid Diagnosis of Brugia malayi and Wuchereria bancrofti Filariasis by an Acridine Orange/Microhematocrit Tube Technique

    Science.gov (United States)

    1990-01-01

    cyte monophenol oxida uviN in mos- thme laboratory biology and mai nance of-ti-des quitoescexposed to microfil ac ofiof’ aria mm. fri vilfofus. Mosquito...h aaie r detected in samples diluted to alevel ofappr-dmately 18;Rcmne l,18) h aaie r 50/mI. K \\/i )’c cl stained by the acridine orange dye and can...Ridley, Department of ratory Medicin, College of teninary Medicine; *Division of Biology and ji~epartment of Anatomy anid Phys , College of Veterinary

  5. Gene : CBRC-TTRU-01-0063 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available AMILY PROTEIN [Brugia malayi] gb|EDP39170.1| PPE FAMILY PROTEIN, putative [Brugia malayi] 6e-73 33% METVHMVKVPRVTLPMVTVLMVT...MPMVMVLMVKLPIVTVPMVIVPVVTVLTVKVPMVTLPTVITLKVTELTVIVAMLTVPLLRVLMVILLTVTVPMVRVLMLRLLMMTTLMVAVPMVT...MLIVAVLMVIVLMLTVLPVTLSMVSVSMVTVLTMILLTVAVLLVTLLRVTVCTVPMVSVPTVTFPMVTVPTVTVSMVRVCMETVHIVTFPTVKMPMVT...VLTMTVPMVTVPMVTVPMVIVPMVTVLMVTVPMVRVLMVTVPMVTVTTVTMPMLTVLTIKMLIVTVPMVILPMGSVLTVKVPMVTLPTVIVHKVRVLTVLVPMVT...VPMVAVPMVTVPMVIVLMVIEPMVTVPMVAVPMVTMFTVSMPMVTLLMVTVLTVKVLTVLVLTVIVLMVIAPW ...

  6. Possible implication of oxidative stress in anti filarial effect of certain traditionally used medicinal plants in vitro against Brugia malayi microfilariae

    Directory of Open Access Journals (Sweden)

    R D Sharma

    2010-01-01

    Full Text Available Introduction: Tropical disease research scheme of World Health Organization has duly recognized traditional medicine as alternative for antifilarial drug development. Polyphenolic compounds present in traditionally used herbal medicines are natural antioxidants; however, paradoxically they may exert pro-oxidant effect. Popular drug diethyl carbamazine citrate harnesses the innate inflammatory response and the consequent oxidative assault to combat invading microbes. Methods: With this perspective, extracts of Vitex negundo L. (roots, Butea monosperma L. (leaves, Aegle marmelos Corr. (leaves, and Ricinus communis L. (leaves were selected to explore the possible role of oxidative rationale in the antifilarial effect in vitro. Results: Apart from the last, other three plant extracts were reported to have polyphenolic compounds. Dose-dependent increase was found in the levels of lipid peroxidation and protein carbonylation for all the three plant extracts except Ricinus communis L. (leaves. Such increase in oxidative parameters also showed some degree of plant-specific predilection in terms of relatively higher level of particular oxidative parameter. High degree of correlation was observed between the antifilarial effect and the levels of corresponding oxidative stress parameters for these three plants. However, extracts of Ricinus communis L. (leaves which is relatively deficient in polyphenolic ingredients recorded maximum 30% loss of motility and also did not show any significant difference in various stress parameters from corresponding control levels. Conclusion: These results reveal that targeted oxidative stress might be crucial in the pharmacodynamics.

  7. Brugia timori INFECTION IN LEKEBAI, FLORES: clinical aspects

    Directory of Open Access Journals (Sweden)

    Arbain Joesoef

    2012-09-01

    Full Text Available Pengamatan filariasis pada penduduk Nualolo-Lekebai, Pulau Flores telah dilakukan pada bulan Februari 1975. Kampung Nualolo-Lekebai berpenduduk 680 jiwa, pekerjaan bertani dan menganut agama Nasrani. Kebiasaan hidup di antara penduduk di daerah ini adalah menyerahkan pelaksanaan pekerjaan berat pada kaum wanita, baik di rumah ataupun di kebun. Dalam perjalanan jauh baik ke kebun atau ke pasar, kaum wanitanya selalu berjalan kaki sedangkan kaum prianya menunggang kuda. Sejumlah 80% dari penduduk kampung ini telah diperiksa terhadap infeksi parasit filaria dan terhadap gejala filariasis. Dari hasil yang ditemukan ternyata penduduk kampung ini menderita infeksi Brugia timori dengan angka derajat infeksi sebesar 7.0% dan angka derajat elephantiasis sebesar 10.3%. Hal yang menarik yang ditemukan dalam pengamatan ini adalah tingginya angka derajat elephantiasis pada kaum wanita dibandingkan dengan pada kaum pria. Fenomena ini mungkin disebabkan oleh kebiasaan hidup kaum wanita di daerah ini sehari-hari yang bekerja lebih berat dan berjalan kaki lebih sering dan lebih jauh dibandingkan kaum prianya.

  8. [Larva migrans].

    Science.gov (United States)

    Chabasse, D; Le Clec'h, C; de Gentile, L; Verret, J L

    1995-01-01

    Larbish, cutaneous larva migrans or creeping eruption, is a serpiginous cutaneous eruption caused by skin penetration of infective larva from various animal nematodes. Hookworms (Ancylostoma brasiliense, A. caninum) are the most common causative parasites. They live in the intestines of dogs and cats where their ova are deposited in the animal feces. In sandy and shady soil, when temperature and moisture are elevated, the ova hatch and mature into infective larva. Infection occurs when humans have contact with the infected soil. Infective larva penetrate the exposed skin of the body, commonly around the feet, hands and buttocks. In humans, the larva are not able to complete their natural cycle and remain trapped in the upper dermis of the skin. The disease is widespread in tropical or subtropical regions, especially along the coast on sandy beaches. The diagnosis is easy for the patient who is returning from a tropical or subtropical climate and gives a history of beach exposure. The characteristic skin lesion is a fissure or erythematous cord which is displaced a few millimeters each day in a serpiginous track. Scabies, the larva currens syndrome due to Strongyloides stercoralis, must be distinguished from other creeping eruptions and subcutaneous swelling lesions caused by other nematodes or myiasis. Medical treatments are justified because it shortens the duration of the natural evolution of the disease. Topical tiabendazole is safe for localized invasions, but prolonged treatment may be necessary. Oral thiabendazole treatment for three days is effective, but sometimes is associated with adverse effects. Trials using albendazole for one or four consecutive days appear more efficacious. More recent trials using ivermectine showed that a single oral dose can cure 100% of the patients; thus, this drug looks very promising as a new form of therapy. Individual prophylaxis consists of avoiding skin contact with soil which has been contaminated with dog or cat feces

  9. Larvae for layers

    DEFF Research Database (Denmark)

    Bjerrum, Lotte; Fischer, Christian Holst; Nordentoft, Steen

    2013-01-01

    Companies and researchers are in close collaboration developing a container- based system for cultivating fly larvae at organic poultry farms. In a one week process, manure will be converted to compost and the live larvae will be harvested and used for feeding laying hens. The larvae are expected...

  10. A PRELIMINARY STUDY OF MALAYAN FILARIASIS IN PUDING VILLAGE, JAMBI PROVINCE (SUMATERA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Sudomo M.

    2012-09-01

    Full Text Available Beberapa daerah di Propinsi Jambi akan dikembangkan menjadi daerah transmigrasi, satu di antara­nya adalah daerah Kumpeh yang terletak berdekatan dengan daerah endemik filariasis malayi. Desa yang paling dekat dengan lokasi transmigrasi tersebut adalah desa Puding. Penelitian pendahuluan tentang penyakit filariasis telah dikerjakan di desa Puding untuk mengetahui tingkat endemisitas, periodisitas B. malayi, fauna nyamuk, jenis nyamuk yang potensial menjadi vektor filariasis, hospes reservoir dan keadaan sosial-ekonomi-budaya penduduk setempat. Mf rate pada penduduk desa Puding adalah 18,7% dan dari B. malayi jenis subperiodiknokturna. Nyamuk yang tertangkap terdiri dari enam genera yaitu genus Anopheles, Aedes, Culex, Coquilletidia, Mansonia dan Tripteroides. Dari enam genera tersebut yang potensial untuk menjadi vektor filariasis adalah genus Mansonia dan ini didukung dengan diketemukannyd larva stadium L3 (infektif Brugia sp di tubuh nyamuk tersebut. Keadaan sosial-ekonomi-budaya, khususnya menyangkut adat istiadat dan kebiasaan penduduk setempat, telah dipelajari.

  11. Mosquito infection responses to developing filarial worms.

    Directory of Open Access Journals (Sweden)

    Sara M Erickson

    Full Text Available Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in transcript abundance in response to the different stages of B. malayi infection were diverse. At the early stages of midgut and thoracic muscle cell penetration, a greater number of genes were repressed compared to those that were induced (20 vs. 8. The non-feeding, intracellular first-stage larvae elicited few differences, with 4 transcripts showing an increased and 9 a decreased abundance relative to controls. Several cecropin transcripts increased in abundance after parasites molted to second-stage larvae. However, the greatest number of transcripts changed in abundance after larvae molted to third-stage larvae and migrated to the head and proboscis (120 induced, 38 repressed, including a large number of putative, immunity-related genes (approximately 13% of genes with predicted functions. To test whether the innate immune system of mosquitoes was capable of modulating permissiveness to the parasite, we activated the Toll and Imd pathway controlled rel family transcription factors Rel1 and Rel2 (by RNA interference knockdown of the pathway's negative regulators Cactus and Caspar during the early stages of infection with B. malayi. The activation of either of these immune signaling pathways, or knockdown of the Toll pathway, did not affect B. malayi in Ae. aegypti. The possibility of LF parasites evading mosquito immune responses during successful development is discussed.

  12. Enzootic Brugia infection in a two-year-old Colombian girl.

    Science.gov (United States)

    Kozek, W J; Reyes, M A; Ehrman, J; Garrido, F; Nieto, M

    1984-01-01

    Mature male and female filarial worms were present in a lymphatic vessel near a retro-auricular lymph node removed from a 2-year old Colombian girl. Although apparently mature microfilariae were present in the uterus of the female, none was detected in blood samples (Knott's) of peripheral blood taken during day or night. The identification of the worms as a species of Brugia is suggested by their location in a dilated lymphatic vessel, morphology of adults, and the distribution pattern of tail nuclei of the microfilariae. This case is similar to another Colombian case reported from the Departamento del Santander del Sur, and suggests that zoonotic filarial infections may not be uncommon in Colombia.

  13. NCBI nr-aa BLAST: CBRC-TTRU-01-1053 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-1053 ref|XP_001901891.1| endoplasmic reticulum multispan transmembrane... protein [Brugia malayi] gb|EDP29450.1| endoplasmic reticulum multispan transmembrane protein, putative [Brugia malayi] XP_001901891.1 0.15 23% ...

  14. NCBI nr-aa BLAST: CBRC-TTRU-01-0887 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-0887 ref|XP_001902801.1| Transmembrane amino acid transporter protein ...[Brugia malayi] gb|EDP28347.1| Transmembrane amino acid transporter protein [Brugia malayi] XP_001902801.1 0.065 28% ...

  15. NCBI nr-aa BLAST: CBRC-CREM-01-1342 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CREM-01-1342 ref|YP_198592.1| Predicted permease [Wolbachia endosymbiont strai...n TRS of Brugia malayi] gb|AAW71350.1| Predicted permease [Wolbachia endosymbiont strain TRS of Brugia malayi] YP_198592.1 2e-05 25% ...

  16. NCBI nr-aa BLAST: CBRC-FCAT-01-1234 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-FCAT-01-1234 ref|YP_198404.1| 50S ribosomal protein L13 [Wolbachia endosymbion...t strain TRS of Brugia malayi] gb|AAW71162.1| Ribosomal protein L13 [Wolbachia endosymbiont strain TRS of Brugia malayi] YP_198404.1 3.4 26% ...

  17. Og4C3 circulating antigen, anti-Brugia malayi IgG and IgG4 titers in Wuchereria bancrofti infected patients, according to their parasitological status.

    Science.gov (United States)

    Chanteau, S; Glaziou, P; Luquiaud, P; Plichart, C; Moulia-Pelat, J P; Cartel, J L

    1994-09-01

    This study involved 221 microfilaremic (Mf+), 302 amicrofilaremic (Mf-) antigen positive (AG+) and 1454 Mf-antigen negative (AG-) individuals living in endemic villages. Whatever the group considered, antigen and antibody titers were widely distributed. Og4C3 antigen, detected both in Mf- and Mf+ patients, was significantly higher in Mf+ patients. The Mf parasitological status did not significantly influence the antifilarial antibodies levels in the infected AG+ individuals, although IgG4 was more discriminant. In the supposedly uninfected individuals (Mf-AG-), anti-filarial IgG and IgG4 could be detected in a large proportion of the group. Og4C3 circulating antigen test was confirmed to be a good marker of active Wuchereria bancrofti infection.

  18. Working with dauer larvae.

    Science.gov (United States)

    Karp, Xantha

    2016-07-14

    Dauer diapause is a stress-resistant, developmentally quiescent, and long-lived larval stage adopted by Caenorhabditis elegans when conditions are unfavorable for growth and reproduction. This chapter contains methods to induce dauer larva formation, to isolate dauer larvae, and to study pre- and post-dauer stages.

  19. Key to marine arthropod larvae

    Directory of Open Access Journals (Sweden)

    John A. Fornshell

    2012-03-01

    Full Text Available The scope of this key is restricted to the larvae of marine arthropods. The key is based solely on their morphology, patterns of body segmentation, numbers of appendages, and mode of locomotion. An effort has been made to treat all traditionally named larval forms, both planktonic and benthic. It is intended that this key be useful for a researcher working with archived museum specimens and therefore, does not include habitat information as a identifying trait, even though this information is usually available in the archived records. Within the phylum Arthropoda there are two sub-phyla and eleven classes having larval stages in the marineenvironment. Where feasible the original names of the various larval types have been used. Because this nomenclature is less commonly used today compared to the past, the more recent taxonomic affinities are included in parentheses after the original larval name. The key includes the following thirty-four larvae: Branchhiopoda nauplii; Cephalocarida nauplii; Mystacocarida nauplii; trilobite larva; protonymphon; hexapod larvae; Remipedia nauplii; nauplius - Y larvae; Cirripedia nauplii; Ascothoracida nauplii; Ostracoda nauplii; Euphausiacea nauplii; Penaeidea nauplii; Cyclopoida nauplii; Calanoida nauplii; Harpacticoida nauplii;Polyarthra nauplii; cypris larva; eryonecius larva; cypris-Y larva; elapthocaris larvae; mysis larvae; lucifer zoea; acetes zoea; acanthosoma larva; phyllosoma; antizoea larva; anomuran zoea; brachyuran zoea; calyptopis larvae; furcilia larva; crytopia larva; puerulus larva; alima larva.

  20. Baylisascaris Larva Migrans

    Science.gov (United States)

    Kazacos, Kevin R.; Abbott, Rachel C.; Van Riper, Charles

    2016-05-26

    SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.

  1. Baylisascaris larva migrans

    Science.gov (United States)

    Kazacos, Kevin R.; Abbott, Rachel C.; Van Riper, Charles

    2016-05-26

    SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.

  2. Excretory-secretory and somatic antigens in the diagnosis of human filariasis.

    Science.gov (United States)

    Kaushal, N A; Hussain, R; Ottesen, E A

    1984-06-01

    In order to compare the immunodiagnostic value of excretory-secretory (E-S) antigens derived from adult Brugia malayi worms with somatic antigens derived from adults, microfilariae (Mf) and infective larvae (L3) of these parasites, well defined serum pools from patients with filarial (brugia, bancrofti, loa and perstans) and non-filarial (ascaris, stronglyoides, toxocara, echinococcus, cysticercus and schistosoma) helminth infections were tested against antigens derived from these different life cycle stages of B. malayi in a Staphylococcus aureus radioimmunoprecipitation assay (S. aureus RIA). The adult brugia antigens proved significantly more discriminatory than those of the other parasite stages, with the homologous brugia serum pool also showing greater reactivity to adult than to L3 and Mf antigens. Similar results were obtained when individual sera from patients (rather than serum pools) were tested in the same assay. The most surprising finding was the minimal reactivity seen between the adult filarial antigens and the non-filarial serum pools despite the presence in these pools of strong antibody reactivity with their homologous antigens. The reasons underlying the unexpected specificity of this S. aureus RIA for discriminating among sera from filarial and non-filarial infections were analysed qualitatively by immunoprecipitation techniques. It was found that use of the chloramine-T method for radioiodination resulted in preferential labelling of the low molecular weight (mol. wt) proteins (10-70,000 daltons) in the B. malayi adult somatic antigen and that these antigens were bound primarily by the filarial and not the non-filarial serum pools. These findings suggest that lower mol. wt helminth antigens may show greater species specificity than those with higher mol. wt, and those with higher mol. wt, greater cross-reactivity. If substantiated by further analysis, such results would have important implications for the subsequent isolation of diagnostically

  3. PENGETAHUAN, SIKAP DAN PERILAKU PENDERITA FILARIASIS MALAYI SELAMA PELAKSANAAN PENGOBATAN DI KABUPATEN TABALONG KALSEL

    Directory of Open Access Journals (Sweden)

    Anorital Anorital

    2012-10-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui sampai seberapa jauh pengetahuan, sikap, dan perilaku para penderita filariasis malayi yang sedang menjalani pengobatan. Kabupaten Tabalong dipilih sebagai daerah pelaksanaan penelitian karena pada wilayah ini filariasis merupakan penyakit endemis pada beberapa desa dan mayoritas penduduk terdiri atas suku Banjar dan Daya Maanyan. Penelitian dilaksanakan secara prospektif yaitu dengan cara mencari kasus melalui mikrofilaria survei. Penderita yang ada selanjutnya diberi pengobatan selama 3 bulan dan sebelum pem­ berian obat, penderita diwawancarai untuk mengetahui pengetahuan dan sikap mereka terhadap penyakit filaria. Selama pemberian obat, penderita diikuti dan dicatat perilaku mereka terhadap reaksi samping pengobatan dan berbagai faktor yang terkait dengan kepatuhan dalam menjalani pengobatan. Sebelum dan selama masa pemberian obat (3 bulan tidak dilakukan intervensi yang berupa penyuluhan. Dari survei ini diperoleh 46 kasus mikrofilaremia yang akan menjadi subyek penelitian (SP, namun jumlah kasus/subyek penelitian yang dapat diana/isis adalah 42 kasus/SP karena 4 kasus/SP mengundurkan diri sebelum masa pengobatan selesai. Hasil penelitian menunjukkan bahwa 58, 7% kasus berpendidikan di bawah SD (tamat SD, tidak tamat, dan tidak sekolah, dan 73,9% sebagai petani. Dari aspek pengetahuan dan sikap diketahui bahwa kasus/SP menyatakan bahwa penyebab kaki gajah adalah karena menginjak daerah terlarang (50,0%, dan jika sakit kasus/SP berobat ke petugas kesehatan/Puskesmas (52,2% sedangkan jika kaki telah membesar kasus/SP menyatakan bahwa hanya dengan pengobatan modern kaki gajah dapat diobati (82,6%. Untuk mencegah gigitan nyamuk hanya 15,2% dari kasus/SP yang tidur tidak menggunakan kelambu atau obat nyamuk bakar. Bagi kasus/SP yang  bekerja sebagai petani penyadap karet untuk melindungi diri dari gigitan nyamuk dengan menggunakan baju lengan panjang adalah 38,2%. Sebelum pelaksanaan pengobatan, gejala

  4. Perreyia flavipes larvae toxicity

    Directory of Open Access Journals (Sweden)

    Djeison L. Raymundo

    2012-08-01

    Full Text Available Fresh or thawed Perreyia flavipes larvae were ground and mixed with water and orally ad ministered to sheep. At 5mg/kg, neither clinical nor enzymatic changes were observed. Unique do ses of 7.5 and 10mg/kg induced characteristic clinical signs of Perreyia sp. larvae poisoning, increased GGT and AST values, and decreased glycemic curves. However, doses of 5, 10, and 15mg/kg repeated at 30 or 15 days intervals caused no disease and mild disease followed by death, respectively. These fin dings indicate that these animals probably developed some degree of tolerance to the toxins in P. flavipes larvae. Ultrastru ctural examination of liver revealed proliferation of the smooth endoplasmic reticulum in the hepatocytes, which may be associated with an increased ability to metabolize toxins and could consequently lead to the tolerance observed in the present study. Further investigations may elucidate whether such tolerance effects could be applied as a control measure for P. flavipes poioning or other hepatotoxic diseases. In addition, clinicopathological findings were discussed.

  5. Midgut barrier imparts selective resistance to filarial worm infection in Culex pipiens pipiens.

    Directory of Open Access Journals (Sweden)

    Michelle L Michalski

    Full Text Available Mosquitoes in the Culex pipiens complex thrive in temperate and tropical regions worldwide, and serve as efficient vectors of Bancroftian lymphatic filariasis (LF caused by Wuchereria bancrofti in Asia, Africa, the West Indies, South America, and Micronesia. However, members of this mosquito complex do not act as natural vectors for Brugian LF caused by Brugia malayi, or for the cat parasite B. pahangi, despite their presence in South Asia where these parasites are endemic. Previous work with the Iowa strain of Culex pipiens pipiens demonstrates that it is equally susceptible to W. bancrofti as is the natural Cx. p. pipiens vector in the Nile Delta, however it is refractory to infection with Brugia spp. Here we report that the infectivity barrier for Brugia spp. in Cx. p. pipiens is the mosquito midgut, which inflicts internal and lethal damage to ingested microfilariae. Following per os Brugia exposures, the prevalence of infection is significantly lower in Cx. p. pipiens compared to susceptible mosquito controls, and differs between parasite species with <50% and <5% of Cx. p. pipiens becoming infected with B. pahangi and B. malayi, respectively. When Brugia spp. mf were inoculated intrathoracically to bypass the midgut, larvae developed equally well as in controls, indicating that, beyond the midgut, Cx. p. pipiens is physiologically compatible with Brugia spp. Mf isolated from Cx. p. pipiens midguts exhibited compromised motility, and unlike mf derived from blood or isolated from the midguts of Ae. aegypti, failed to develop when inoculated intrathoracically into susceptible mosquitoes. Together these data strongly support the role of the midgut as the primary infection barrier for Brugia spp. in Cx. p. pipiens. Examination of parasites recovered from the Cx. p. pipiens midgut by vital staining, and those exsheathed with papain, suggest that the damage inflicted by the midgut is subcuticular and disrupts internal tissues. Microscopic studies

  6. CalCOFI Larvae Stages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Developmental stages (yolk sac, preflexion, flexion, postflexion, or transformation) of selected fish larvae captured in CalCOFI icthyoplankton nets.

  7. BIOTECHNOLOGY OF THE FILARIA OF INDONESIA

    Directory of Open Access Journals (Sweden)

    F. Partono

    2012-09-01

    Full Text Available More than 90 million people were currently infected with lymphatic filariasis and mo-third of them lived in China, India and Indonesia. Filariasis is endemic throughout the entire Indonesian Archipelago. More than 20 million people lived in endemic areas and 3-4 million people were estimated to have the infection. Control measures have reduced the prevalence of infections in some areas, but the disease remained a public health problem in many outer islands of Indonesia. Recent development in monoclonal antibodies and recombinant technology of DNA have made it possible to apply these new tools in the studies of filariasis, and three groups in Indonesia are currently using these new technology. The studies with the Imperial College of London will be presented by Dr. Rick Maizels. Collaboration with the New England Biolabs and Smith College involve the use of a stage and species-specific monoclonal antibody against the infective larvae of Brugia malayi, a double blind comparison of conventional methods and DNA probes for the diagnosis of brugian filariasis, and phylogentic studies of the brugian parasites. The ELISA using the monoclonal antibody has been adapted for field use in Jakarta. It is simple to use, does not cross-react with the infective stage of Brugia pahangi, but does so with the infective stage of the non-sympatric Brugia timori. The reagent is useful to acurately monitor the progress of control programs in endemic areas of brugian filariasis. The oligonucleotide DNA probes for B.malayi and B.pahangi were both qualitatively and quantitatively comparable to the conventional methods for the diagnosis of brugian parasites in cats and man. Sequencing data of the repeated DNA sequences of various brugian parasites indicated their homologies and divergences. The anthropophilic strain of B.malayi and B.timori showed similarity in their biological characteristics and repeated DNA sequences and they are phylogenically probably closely related

  8. Diversity in parasitic nematode genomes: the microRNAs of Brugia pahangi and Haemonchus contortus are largely novel

    Directory of Open Access Journals (Sweden)

    Winter Alan D

    2012-01-01

    Full Text Available Abstract Background MicroRNAs (miRNAs play key roles in regulating post-transcriptional gene expression and are essential for development in the free-living nematode Caenorhabditis elegans and in higher organisms. Whether microRNAs are involved in regulating developmental programs of parasitic nematodes is currently unknown. Here we describe the the miRNA repertoire of two important parasitic nematodes as an essential first step in addressing this question. Results The small RNAs from larval and adult stages of two parasitic species, Brugia pahangi and Haemonchus contortus, were identified using deep-sequencing and bioinformatic approaches. Comparative analysis to known miRNA sequences reveals that the majority of these miRNAs are novel. Some novel miRNAs are abundantly expressed and display developmental regulation, suggesting important functional roles. Despite the lack of conservation in the miRNA repertoire, genomic positioning of certain miRNAs within or close to specific coding genes is remarkably conserved across diverse species, indicating selection for these associations. Endogenous small-interfering RNAs and Piwi-interacting (piRNAs, which regulate gene and transposon expression, were also identified. piRNAs are expressed in adult stage H. contortus, supporting a conserved role in germline maintenance in some parasitic nematodes. Conclusions This in-depth comparative analysis of nematode miRNAs reveals the high level of divergence across species and identifies novel sequences potentially involved in development. Expression of novel miRNAs may reflect adaptations to different environments and lifestyles. Our findings provide a detailed foundation for further study of the evolution and function of miRNAs within nematodes and for identifying potential targets for intervention.

  9. Workbook on the Identification of Mosquito Larvae.

    Science.gov (United States)

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable public health workers identify larvae of some important North American mosquito species. The morphological features of larvae of the various genera and species are illustrated in a programed booklet, which also contains illustrated taxonomic keys to the larvae of 11 North American genera and to…

  10. Repurposing auranofin as a lead candidate for treatment of lymphatic filariasis and onchocerciasis.

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    Christina A Bulman

    2015-02-01

    Full Text Available Two major human diseases caused by filariid nematodes are onchocerciasis, or river blindness, and lymphatic filariasis, which can lead to elephantiasis. The drugs ivermectin, diethylcarbamazine (DEC, and albendazole are used in control programs for these diseases, but are mainly effective against the microfilarial stage and have minimal or no effect on adult worms. Adult Onchocerca volvulus and Brugia malayi worms (macrofilariae can live for up to 15 years, reproducing and allowing the infection to persist in a population. Therefore, to support control or elimination of these two diseases, effective macrofilaricidal drugs are necessary, in addition to current drugs. In an effort to identify macrofilaricidal drugs, we screened an FDA-approved library with adult worms of Brugia spp. and Onchocerca ochengi, third-stage larvae (L3s of Onchocerca volvulus, and the microfilariae of both O. ochengi and Loa loa. We found that auranofin, a gold-containing drug used for rheumatoid arthritis, was effective in vitro in killing both Brugia spp. and O. ochengi adult worms and in inhibiting the molting of L3s of O. volvulus with IC50 values in the low micromolar to nanomolar range. Auranofin had an approximately 43-fold higher IC50 against the microfilariae of L. loa compared with the IC50 for adult female O. ochengi, which may be beneficial if used in areas where Onchocerca and Brugia are co-endemic with L. loa, to prevent severe adverse reactions to the drug-induced death of L. loa microfilariae. Further testing indicated that auranofin is also effective in reducing Brugia adult worm burden in infected gerbils and that auranofin may be targeting the thioredoxin reductase in this nematode.

  11. Isolamento de esporos de Paenibacillus larvae subsp. larvae no Brasil Detectionof Paenibacillus larvae subsp. larvae spores in Brazil

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    Dulce Maria Tocchetto Schuch

    2003-03-01

    Full Text Available Este trabalho objetivou detectar presença de esporos de Paenibacillus larvae subsp. larvae em produtos de um entreposto do interior do Estado do Rio Grande do Sul, a identificação de possíveis fontes de contaminação e a avaliação da possibilidade da transferência de esporos para colméias de apiários adjacentes a partir de produtos importados contaminados. Foram analisados mel e pólen importados disponíveis no entreposto, favo do ninho (crias, pólen e mel colhido de uma colméia sadia, mel estocado em um dos apiários e abelhas adultas. Os resultados foram positivosem relação ao mel e pólen importados, a três grupos de abelhas adultas e ao mel do favo.The objective of this work was to detect the presence of Paenibacillus larvae subsp. larvae spores in products from a warehouse located in Rio Grande do Sul State, Brazil, the identification of possible contamination sources, and the assessment of spores transference possibility from contaminated imported products from the warehouse to apiaries located in the surrounding area. Samples of imported pollen and bulk honey stocked in the warehouse, and honeycomb (brood, honey and pollen from a healthy hive, honey from one apiary and adult bees were analyzed. Imported honey and pollen, and three groups of adult bees and the honey collected from the honeycomb resulted positive.

  12. Radiosensitivity of spores of Paenibacillus larvae ssp. larvae in honey

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Wanderley Mendes de [Ministerio da Agricultura, Pecuaria e Abastecimento, Rio de Janeiro, RJ (Brazil). Servico de Inspecao de Produtos de Origem Animal]. E-mail: sipa-rj@agricultura.gov.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito CTEx, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Schuch, Dulce Maria Tocchetto [Ministerio da Agricultura, Pecuaria e Abastecimento, Porto Alegre, RS (Brazil)]. E-mail: micro-lara-rs@agricultura.gov.br

    2007-07-01

    Irradiation, usually used in combination with other conventional methods of conservation, has been proven to be an efficient tool to ensure the safety of many types of foods by destroying pathogenic microorganisms and extending their shelf-lives. This work has investigated the efficacy of gamma irradiation to inactivate spores of the bacterium Paenibacillus larvae that causes the 'American foulbrood', a highly contagious disease still exotic in Brazil that kills bees and contaminates honey, preventing its commercialization and causing great economical losses. In this study, 60 g samples of two types of honey inoculated with 3.5x10{sup 3} spores/mL of that bacterium were irradiated with doses of 0, 5, 7.5, 10, 12.5 and 15 kGy and counted. The analyses indicated a mean reduction of 97.5{+-}0.7% in the number of viable spores exposed to 5 kGy. The application of doses of 7.5 kGy or higher yielded no viable spores above the detection threshold (10/mL). In addition the value of D{sub 10} (3.1{+-}0.3 kGy) was estimated and the logarithm of the population of viable spores of Paenibacillus larvae subsp. larvae was determined as linear and quadratic polynomial functions of the radiation dose. The results indicated that the dose of 10 kGy could be insufficient to assure complete sterilization of honey in some cases while suggesting that 25 kGy would perform such task adequately. (author)

  13. Taste processing in Drosophila larvae

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    Anthi A. Apostolopoulou

    2015-10-01

    Full Text Available The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances.

  14. Simultaneous Larva Migrans and Larva Currens Caused by Strongyloides stercoralis: A Case Report

    OpenAIRE

    Liliam Dalla Corte; Mariana Vale Scribel da Silva; Paulo Ricardo Martins Souza

    2013-01-01

    Strongyloidiasis is an infectious disease caused by the Strongyloides stercoralis larvae, which penetrate the skin, go through the lymphatic circulation, and migrate to the lungs before reaching the intestines. They mature and may cause cutaneous strongyloidiasis, known as larva currens because of the quick migratory rate of the larva. The authors describe a case in which the larvae did not follow their natural lymph route, and after penetrating into the intertriginous area, they migrated to ...

  15. Workbook on Identification of Aedes Aegypti Larvae.

    Science.gov (United States)

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable yellow fever control workers to identify the larvae of "Aedes aegypti." The morphological features of mosquito larvae are illustrated in this partially programed text, and the distinguishing features of "A. aegypti" indicated. A glossary is included. (AL)

  16. Coral larvae move toward reef sounds

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Marhaver, K.L.; Huijbers, C.M.; Nagelkerken, I.; Simpson, S.D.

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to ob

  17. Kemampuan Larva Oryctes Rhinoceros (Coleoptera: Scarabaeidae) Menularkan Cendawan Metarhizium Anisopliae Ke Larva Sehat Di Pertanaman Kelapa Sawit

    OpenAIRE

    Perabu Jaya Sitepu

    2009-01-01

    Perabu Jaya Sitepu, Kemampuan larva Oryctes rhinoceros menularkan Metharizium anisopliae ke larva sehat di pertanaman kelapa sawit. Penelitian bertujuan untuk mengetahui kemampuan larva O. rhinoceros menularkan M. anisopliae ke larva O. rhinoceros yang lain di lapangan. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) Non Faktorial yang terdiri dari 4 perlakuan dan enam ulangan yaitu : L1 (kontrol), L2 (5 larva dilumuri M. anisoplioae), L3 (10 larva dilumuri M. anisoplioae), L4 (15 la...

  18. Behavior of Settling Marine Larvae in Flow

    Science.gov (United States)

    Hernandez, J.; Koehl, M. A.

    2012-12-01

    Many bottom-dwelling marine animals produce microscopic larvae that are dispersed by ambient water currents. These larvae can only recruit to habitats on which they have landed if they can resist being washed away by ambient water flow. We found that larvae on marine surfaces do not experience steady water flow, but rather are exposed to brief pulses of water movement as turbulent eddies sweep across them. We made video recordings of larvae of the tube worm, Hydroides elegans, (important members of the community of organisms growing on docks and ships) on surfaces subjected to measured realistic flow pulses to study factors that might affect their dislodgement from surfaces in nature. We found that the response of a larva of H. elegans to a realistic pulse of water flow depended on its behavior at the time of the pulse and on its recent history of exposure to flow pulses, and that stationary larvae were less likely than locomoting larvae to be blown away when hit by the first pulse of water flow.; ;

  19. TIME management by medicinal larvae.

    Science.gov (United States)

    Pritchard, David I; Čeřovský, Václav; Nigam, Yamni; Pickles, Samantha F; Cazander, Gwendolyn; Nibbering, Peter H; Bültemann, Anke; Jung, Wilhelm

    2016-08-01

    Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue.

  20. Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

    Science.gov (United States)

    Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

    2010-10-01

    We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers.

  1. 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...... 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 diff ering in their shield morphologies. Th e shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae...

  2. CalCOFI Larvae Counts Positive Tows

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  3. Extreme morphologies of mantis shrimp larvae

    DEFF Research Database (Denmark)

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

    2016-01-01

    1928–30. These new larval types all represent erichthus-type larvae, especially diff ering in their shield morphologies. Th e shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae......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...... 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...

  4. Ocular larva migrans: a case report.

    OpenAIRE

    Lyness, R. W.; Earley, O E; Logan, W C; Archer, D B

    1987-01-01

    A case of intraocular toxocara larva migrans occurring in a 12-year-old boy is presented. Motility is inferred from the nature of multiple intraocular lesions observed. Possible mechanisms preventing a conclusive immunological response to the organism are discussed.

  5. Extreme morphologies of mantis shrimp larvae

    Directory of Open Access Journals (Sweden)

    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.

  6. Coral larvae move toward reef sounds.

    Directory of Open Access Journals (Sweden)

    Mark J A Vermeij

    Full Text Available Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency.

  7. Tingkat Kepadatan Larva Anopheles spp. di Delta Lakkang Kecamatan Tallo Makassar

    OpenAIRE

    Mardilah

    2016-01-01

    Telah dilakukan penelitian tentang tingkat kepadatan larva Anopheles spp di Delta Lakkang Kecamatan Tallo. Penelitian bertujuan untuk mengetahui tingkat kepadatan larva dan faktor-faktor yang mempengaruhi. Metode yang digunakan adalah metode observasi dengan mengambil larva nyamuk selanjutnya dipelihara kemudian dilakukan perhitungan tingkat kepadatan larva. Hasil penelitian menunjukkan bahwa tingkat kepadatan larva Anopheles tertinggi ditemukan di bagian barat dengan jumlah larva 179 larva p...

  8. PERKEMBANGAN AWAL LARVA KERAPU KERTANG (Epinephelus lanceolatus

    Directory of Open Access Journals (Sweden)

    Philip Teguh Imanto

    2016-11-01

    Full Text Available Observasi pada larva kerapu kertang (E. lanceolatus dilaksanakan di Balai Besar Riset Perikanan Budidaya Laut (BBRPBL, Gondol-Bali, untuk mengumpulkan informasi dasar tentang perkembangan awal morfologi larva yang penting untuk menunjang keberhasilan pembenihannya. Larva berasal dari telur hasil pemijahan yang dirangsang dengan hormon (di Taiwan dan ditransportasikan segera setelah menetas (D-0 melalui transportasi udara ke laboratotium pembenihan BBRPBL, Gondol. Pengamatan dilakukan dengan memanfaatkan fasilitas tangki 500 L dengan sistem air resirkulasi. Dari data yang dihimpun diketahui bahwa rata-rata panjang total larva (D-1 2,48 mm; D-8 3,17 mm; dan tumbuh dengan cepat mencapai 10,79 mm pada D-19. Kuning telur larva yang berumur sehari (D-1 rata-rata bervolume 150,3 x 10-4 mm3 dan pada hari ketiga terserap 42,61% dan habis pada hari keempat (D-4. Butir minyak larva D-1 sebesar 41,9 x 10-4 mm3 dan masih tersisa sebesar 0,34 x 10-4 mm3 sampai dengan D-6. Mulut larva diperhitungkan sudah mencapai lebar sebesar 200 μm pada D-2. dan mampu untuk memangsa rotifer sejalan dengan pigmentasi mata yang mulai terjadi pada D-2 dan sempurna pada D-3. Dari analisis pertumbuhan terjadi titik belok (flexion point pada D-8 dan setelah itu terjadi kurva pertumbuhan yang cepat y= 0,6747x-2,5508. Berdasarkan hasil observasi tersebut maka pemberian pakan awal untuk larva kerapu kertang sudah bisa diberikan pada D-2 akhir (sore, pada D-8 komposisi pakan alami sudah harus diubah dengan memberikan pakan yang lebih besar dan bernutrisi tinggi. Observation on early development of E. lanceolatus larvae have been conducted in laboratory condition at Gondol Research Institute for Mariculture (GRIM Bali; the purpose was to gain basic data mainly on the larval development stage to support both larval rearing and aquaculture technique of this species. The larvae from egg were produced by induced spawning technique and transported on D-0 to GRIM. Observation have been

  9. Quantifying and predicting Drosophila larvae crawling phenotypes

    Science.gov (United States)

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-06-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design.

  10. Incidence of ascaridoid larvae in Kuwaiti food fishes.

    Science.gov (United States)

    Sey, O; Petter, A J

    1997-01-01

    Three hundred and six fish of 83 species were carefully examined in Kuwait during the period from October 1992 to September 1995 for ascaridoid larvae. Thirty-nine fishes (12.7%) belonging to 23 species were infected with 9 types of ascaridoid third-stage larvae: Anisakis simplex, Terranva spp, Contracaecum spp and 6 different types of Hysterothylacium spp (KA-KF). Hysterothylacium larvae (including all types) were found in all the infected fish except one (94.6%); Terranova larvae were found in 12 fishes (10 species, 56.1%); Anisakis simplex larvae occurred in 2 fishes (2 species, 8.6%) and Contracaecum spp larvae in one fish only.

  11. Attraction to and learning from social cues in fruitfly larvae.

    Science.gov (United States)

    Durisko, Zachary; Dukas, Reuven

    2013-09-22

    We examined the use of social information in fruitfly larvae, which represent an ideal model system owing to their robust learning abilities, small number of neurons and well-studied neurogenetics. Focal larvae showed attraction to the distinct odour emanating from food occupied by other larvae. In controlled learning experiments, focal larvae preferred novel odours previously paired with food occupied by other larvae over novel odours previously paired with unoccupied food. When we gave groups of larvae a choice between food patches differing in quality, more larvae aggregated on the higher-quality food, suggesting that attraction to and learning about cues associated with other larvae can be beneficial. Furthermore, larvae were more likely to find the best available food patch in trials when that food patch was occupied by other larvae than in trials when that food patch was unoccupied. Our data suggest, however, that the benefits from joining others may be at least partially offset by the fitness costs of increased competition, because larvae reared in isolation did as well as or better than larvae reared in groups on three key fitness parameters: developmental rate, survival rate and adult dry body mass. Our work establishes fruitfly larvae as a highly tractable model species for further research on the mechanisms that modulate behaviour and learning in a social context.

  12. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  13. Evolution of foraging behavior in Drosophilid larvae

    Science.gov (United States)

    Rivera-Alba, Marta; Kabra, Mayank; Branson, Kristin; Mirth, Christen

    2015-03-01

    Drosophilids, like other insects, go through a larval phase before metamorphosing into adults. Larvae increase their body weight by several orders of magnitude in a few days. We therefore hypothesized that foraging behavior is under strong evolutionary pressure to best fit the larval environment. To test our hypothesis we used a multidisciplinary approach to analyze foraging behavior across species and larval stages. First, we recorded several videos of larvae foraging for each of 47 Drosophilid species. Then, using a supervised machine learning approach, we automatically annotated the video collection for the foraging sub-behaviors, including crawling, turning, head casting or burrowing. We also computed over 100 features to describe the posture and dynamics of each animal in each video frame. From these data, we fit models to the behavior of each species. The models each had the same parametric form, but differed in the exact parameters. By simulating larva behavior in virtual arenas we can infer which properties of the environments are better for each species. Comparisons between these inferred environments and the actual environments where these animals live will give us a deeper understanding about the evolution of foraging behavior in Drosophilid larvae.

  14. CalCOFI Larvae Counts, Scientific Names SJ to ST

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  15. Bothid larvae (Pleuronectiformes-Pisces) of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    the Indian Ocean, their regional, seasonal as well as diurnal variations. Engyprosopon grandisquamis dominated contributing to 23.2% of the total larvae. Numerically the incidence of bothid larvae suggested a uniform pattern of distribution during the two...

  16. CalCOFI Larvae Counts, Scientific Names OY to PI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  17. CalCOFI Larvae Counts, Scientific Names V to Z

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  18. CalCOFI Larvae Counts, Scientific Names DH to EC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  19. CalCOFI Larvae Counts, Scientific Names BCE to BZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  20. CalCOFI Larvae Counts, Scientific Names SU to TE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  1. CalCOFI Larvae Counts, Scientific Names LB to LI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  2. CalCOFI Larvae Counts, Scientific Names SD to SI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  3. CalCOFI Larvae Counts, Scientific Names AS to BA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  4. CalCOFI Larvae Counts, Scientific Names MB to MO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  5. CalCOFI Larvae Counts, Scientific Names SB to SC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  6. CalCOFI Larvae Counts, Scientific Names CI to CO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  7. CalCOFI Larvae Counts, Scientific Names LJ to MA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  8. CalCOFI Larvae Counts, Scientific Names EV to GN

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  9. CalCOFI Larvae Counts, Scientific Names A to AM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  10. CalCOFI Larvae Counts, Scientific Names Q to SA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  11. CalCOFI Larvae Counts, Scientific Names HJ to ID

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  12. CalCOFI Larvae Counts, Scientific Names PP to PZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  13. CalCOFI Larvae Counts, Scientific Names ED to EU

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  14. CalCOFI Larvae Counts, Scientific Names PL to PO

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  15. CalCOFI Larvae Counts, Scientific Names C to CE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  16. CalCOFI Larvae Counts, Scientific Names HB to HI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  17. CalCOFI Larvae Counts, Scientific Names AN to AR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  18. CalCOFI Larvae Counts, Scientific Names MP to NA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  19. ISOLASI BACILLUS THURINGIENSIS DARI LARVA DAN PENGUJIAN PATOGENISITASNYA TERHADAP LARVA NYAMUK VEKTOR

    Directory of Open Access Journals (Sweden)

    Blondine Ch. P.

    2012-09-01

    Full Text Available A study to evaluate pathogenic organisms as cause of mosquito larvae death was conducted at Wonokerto and Pabelan villages, Salatiga Luar Kota subdistrict, Semarang regency in Central Java from May 1991 through December 1991. Bacterial isolation from dead larvae showed that 31 B. thuringicnsis isolates were obtained from 31 larvae samples collected from 2 location e.g Wonokerto village (3 samples, Pabelan village (28 samples. Nineteen isolates (61,3% showed a pathogenicity of more than 50% to third toward instar larvae of Aedes aegypti and Culex quinquefasciatus respectively 24 hours after exposure. This study shows the possible use of B. thuringiensis for biologic control of mosquitoes which can act as vectors for human diseases.

  20. Appetitive associative olfactory learning in Drosophila larvae.

    Science.gov (United States)

    Apostolopoulou, Anthi A; Widmann, Annekathrin; Rohwedder, Astrid; Pfitzenmaier, Johanna E; Thum, Andreas S

    2013-02-18

    In the following we describe the methodological details of appetitive associative olfactory learning in Drosophila larvae. The setup, in combination with genetic interference, provides a handle to analyze the neuronal and molecular fundamentals of specifically associative learning in a simple larval brain. Organisms can use past experience to adjust present behavior. Such acquisition of behavioral potential can be defined as learning, and the physical bases of these potentials as memory traces. Neuroscientists try to understand how these processes are organized in terms of molecular and neuronal changes in the brain by using a variety of methods in model organisms ranging from insects to vertebrates. For such endeavors it is helpful to use model systems that are simple and experimentally accessible. The Drosophila larva has turned out to satisfy these demands based on the availability of robust behavioral assays, the existence of a variety of transgenic techniques and the elementary organization of the nervous system comprising only about 10,000 neurons (albeit with some concessions: cognitive limitations, few behavioral options, and richness of experience questionable). Drosophila larvae can form associations between odors and appetitive gustatory reinforcement like sugar. In a standard assay, established in the lab of B. Gerber, animals receive a two-odor reciprocal training: A first group of larvae is exposed to an odor A together with a gustatory reinforcer (sugar reward) and is subsequently exposed to an odor B without reinforcement. Meanwhile a second group of larvae receives reciprocal training while experiencing odor A without reinforcement and subsequently being exposed to odor B with reinforcement (sugar reward). In the following both groups are tested for their preference between the two odors. Relatively higher preferences for the rewarded odor reflect associative learning--presented as a performance index (PI). The conclusion regarding the associative

  1. Larva migrans visceral: relato de caso Visceral larva migrans: case report

    Directory of Open Access Journals (Sweden)

    Alexandre Bortoli Machado

    2003-04-01

    Full Text Available Larva migrans visceral é doença infecciosa, adquirida por ingestão de ovos provenientes dos vermes Toxocara canis e/ou Toxocara cati que infestam cães e gatos; as larvas penetram a parede intestinal e migram através dos tecidos levando a alterações diversas, conseqüentes a uma resposta inflamatória imune.¹ Os autores descrevem um caso clínico de larva migrans visceral com apresentação clínica atípica.Visceral larva migrans is an infectious human disease that occurs following ingestion of eggs from the environment originating from roundworms which commonly infect dogs and cats, Toxocara canis and Toxocara cati. The larvae penetrate the gut wall and migrate through the tissues causing disorders consequent to an inflammatory immune response¹. The authors describe a clinical case of visceral larva migrans with an unusual clinical presentation and also its clinical aspects, diagnosis and treatment are reviewed.

  2. Larva of Palaemnema brasiliensis Machado (Odonata: Platystictidae), from Amazonas, Brazil.

    Science.gov (United States)

    Neiss, Ulisses Gaspar; Hamada, Neusa

    2016-02-09

    The larva of Palaemnema brasiliensis Machado, 2009 is described and illustrated based on last-instar larvae and exuviae of reared larvae collected in a blackwater stream in Barcelos and Presidente Figueiredo municipalities, Amazonas state, Brazil. The larva of P. brasiliensis can be distinguished from the two South American species of the genus with described larvae (P. clementia Selys and P. mutans Calvert), mainly by presence of a single obtuse cusp on the labial palp, the presence and configuration of setae in the caudal lamellae, and the proportional length of terminal filaments of the caudal lamellae. The family is recorded here for the first time in Brazilian state of Amazonas.

  3. Predatory cannibalism in Drosophila melanogaster larvae.

    Science.gov (United States)

    Vijendravarma, Roshan K; Narasimha, Sunitha; Kawecki, Tadeusz J

    2013-01-01

    Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

  4. The early stress responses in fish larvae.

    Science.gov (United States)

    Pederzoli, Aurora; Mola, Lucrezia

    2016-05-01

    During the life cycle of fish the larval stages are the most interesting and variable. Teleost larvae undergo a daily increase in adaptability and many organs differentiate and become active. These processes are concerted and require an early neuro-immune-endocrine integration. In larvae communication among the nervous, endocrine and immune systems utilizes several known signal molecule families which could be different from those of the adult fish. The immune-neuroendocrine system was studied in several fish species, among which in particular the sea bass (Dicentrarchus labrax), that is a species of great commercial interest, very important in aquaculture and thus highly studied. Indeed the immune system of this species is the best known among marine teleosts. In this review the data on main signal molecules of stress carried out on larvae of fish are considered and discussed. For sea bass active roles in the early immunological responses of some well-known molecules involved in the stress, such as ACTH, nitric oxide, CRF, HSP-70 and cortisol have been proposed. These molecules and/or their receptors are biologically active mainly in the gut before complete differentiation of gut-associated lymphoid tissue (GALT), probably acting in an autocrine/paracrine way. An intriguing idea emerges from all results of these researches; the molecules involved in stress responses, expressed in the adult cells of the hypothalamic-pituitary axis, during the larval life of fish are present in several other localizations, where they perform probably the same role. It may be hypothesized that the functions performed by hypothalamic-pituitary system are particularly important for the survival of the larva and therefore they comprises several other localizations of body. Indeed the larval stages of fish are very crucial phases that include many physiological changes and several possible stress both internal and environmental.

  5. Learning and Memory in Zebrafish Larvae

    OpenAIRE

    Adam Christopher Roberts; Bill, Brent R; Glanzman, David L

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promisi...

  6. Learning and memory in zebrafish larvae

    OpenAIRE

    Roberts, Adam C.; Bill, Brent R; Glanzman, David L

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promisin...

  7. The Identification of Congeners and Aliens by Drosophila Larvae

    Science.gov (United States)

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles. PMID:26313007

  8. The Identification of Congeners and Aliens by Drosophila Larvae.

    Directory of Open Access Journals (Sweden)

    Francisco Del Pino

    Full Text Available We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b, Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles.

  9. Self-mixing of fly larvae during feeding

    Science.gov (United States)

    Shishkov, Olga; Johnson, Christopher; Zhang, Bryan; Hu, David

    2016-11-01

    How do we sustainably feed a growing world population? One solution of increasing interest is the use of black solider fly larvae, pea-sized grubs envisioned to transform hundreds of tons of food waste into a sustainable protein source. Although startups across the world are raising these larvae, a physical understanding of how they should be raised and fed remains missing. In this study, we present experiments measuring their feeding rate as a function of number of larvae. We show that larger groups of larvae have greater mixing which entrains hungry larvae around the food, increasing feeding rate. Feeding of larvae thus differs from feeding of cattle or other livestock which exhibit less self-mixing.

  10. Modeling peripheral olfactory coding in Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Derek J Hoare

    Full Text Available The Drosophila larva possesses just 21 unique and identifiable pairs of olfactory sensory neurons (OSNs, enabling investigation of the contribution of individual OSN classes to the peripheral olfactory code. We combined electrophysiological and computational modeling to explore the nature of the peripheral olfactory code in situ. We recorded firing responses of 19/21 OSNs to a panel of 19 odors. This was achieved by creating larvae expressing just one functioning class of odorant receptor, and hence OSN. Odor response profiles of each OSN class were highly specific and unique. However many OSN-odor pairs yielded variable responses, some of which were statistically indistinguishable from background activity. We used these electrophysiological data, incorporating both responses and spontaneous firing activity, to develop a bayesian decoding model of olfactory processing. The model was able to accurately predict odor identity from raw OSN responses; prediction accuracy ranged from 12%-77% (mean for all odors 45.2% but was always significantly above chance (5.6%. However, there was no correlation between prediction accuracy for a given odor and the strength of responses of wild-type larvae to the same odor in a behavioral assay. We also used the model to predict the ability of the code to discriminate between pairs of odors. Some of these predictions were supported in a behavioral discrimination (masking assay but others were not. We conclude that our model of the peripheral code represents basic features of odor detection and discrimination, yielding insights into the information available to higher processing structures in the brain.

  11. Learning and Memory in Zebrafish Larvae

    Directory of Open Access Journals (Sweden)

    Adam Christopher Roberts

    2013-08-01

    Full Text Available Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory.

  12. Learning and memory in zebrafish larvae.

    Science.gov (United States)

    Roberts, Adam C; Bill, Brent R; Glanzman, David L

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory.

  13. PEMIJAHAN DAN PEMELIHARAAN LARVA IKAN BERONANG (Siganus guttatus

    Directory of Open Access Journals (Sweden)

    Samuel Lante

    2007-12-01

    Full Text Available Untuk menghasilkan benih ikan beronang Siganus guttatus yang baik, maka penanganan induk yang meliputi: pemeliharaan, pematangan gonad dengan implan pelet hormon LHRH-a, dan penambahan vitamin C dalam pakan serta pemeriksaan siap pijah sangat penting. Pengamatan perkembangan embrio dalam telur dan larva pada tahap awal, penyediaan pakan alami serta pemeliharaan larva merupakan tahap lanjutan dari pemeliharaan larva yang baik, maka benih-benih ikan Siganus guttatus yang dihasilkan juga akan baik.

  14. Larvae of Nearshore Fishes in Oceanic Waters near Oahu, Hawaii

    OpenAIRE

    Clarke, Thomas A.

    1991-01-01

    Larvae of over 50 families of nearshore fishes were taken in oceanic waters about 13 km offshore of the leeward (southwest) coast of Oahu, Hawaii during 1977-78, The five most frequently taken families (Labridae, Parapercidae, Serranidae, Gobiidae, and Carangidae) made up over 50% of the total nearshore larvae. Most other families were taken very infrequently. Comparison of catch data from three types of nets indicated that 1.25-m diameter bongo nets often sampled larvae as well or better tha...

  15. GenBank blastx search result: AK289222 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK289222 J100067E05 AF030944.1 AF030944 Brugia malayi microfilarial sheath protein ...SHP3a (Bmshp3a) and microfilarial sheath protein SHP3 precursor (Bmshp3) genes, complete cds. INV 0.0 0 ...

  16. AcEST: DK953053 [AcEST

    Lifescience Database Archive (English)

    Full Text Available .18 sp|Q01202|MYSP_BRUMA Paramyosin OS=Brugia malayi PE=2 SV=2 33 1.6 sp|Q11IG3|Y1416_MESSB UPF0283 membrane...ct: 168 DQLKKDKHLAEKAAERFEAQTVELSNKVEDLNRHVNDLAQQRQRLQAENNDL 219 >sp|Q11IG3|Y1416_MESSB UPF0283 membrane pro

  17. AcEST: DK949163 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 36 2.3 tr|A8P3K7|A8P3K7_BRUMA Retinitis pigmentosa GTPase regulator-lik... 35 3.... 92 FGGGGN 97 >tr|A8P3K7|A8P3K7_BRUMA Retinitis pigmentosa GTPase regulator-like protein OS=Brugia malayi GN

  18. Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

    Energy Technology Data Exchange (ETDEWEB)

    Law, A.T.; Yeo, M.E. [Universiti Kolej Terengganu (UPM), Darul Iman (Malaysia)

    1997-03-01

    Literature on the toxicities of phenol on aquatic organisms is very limited. USEPA reported that the acute and chronic toxicities of phenol to freshwater aquatic life occur at concentrations as low as 10.2 mg/L and 2.56 mg/L, respectively. While for the saltwater aquatic life the acute toxicity occurs at concentrations as low as 5.8 mg/L. No data are available for the chronic toxicity of phenol to saltwater aquatic life. Sublethal concentrations of phenol have significant effects on the physiological and histological processes of the aquatic organisms: such as gill necrosis; destruction of erythrocyte cells; inhibition of sexual activities; suppression on growth and reduction of resistance to diseases. Macrobrachium rosenbergii(de Man) is the sole freshwater prawn cultured in Malaysia. Occasionally, the hatcheries are unable to produce the post-larvae because of undefined pollutants present in the water supplies. It has been observed that the use of cracked fiberglass tanks for larvae rearing is correlated with high mortality. This high mortality is probably due to the toxicity of the phenolic compounds which are leached out from the fiber glass tank into the water. This study was undertaken to evaluate the toxicity of phenol on eggs, larvae and post-larvae of M. rosenbergii and to set the water quality criteria of phenol for the said species. 16 refs., 3 tabs.

  19. Fate of pharmaceuticals and pesticides in fly larvae composting

    Energy Technology Data Exchange (ETDEWEB)

    Lalander, C., E-mail: cecilia.lalander@slu.se [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Senecal, J.; Gros Calvo, M. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Ahrens, L.; Josefsson, S.; Wiberg, K. [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (Sweden); Vinnerås, B. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden)

    2016-09-15

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

  20. Reindeer warble fly larvae found in red deer

    Directory of Open Access Journals (Sweden)

    A. C. Nilssen

    1988-06-01

    Full Text Available Seven third instar larvae of the reindeer warble fly (Hypoderma (=Oedemagena tarandi were found in a 2-3 year old male red deer {Cervus elaphus shot on 14 November 1985 at Todalen, western Norway. This it, the first report of H. tarandi from red deer. In reindeer third instar larvae are found from February to June, and the unusual date of this record indicates a delayed development of the larvae due to abnormal host reactions. Warble fly larvae, probably H. tarandi, are also reported from moose {Alces alces in northern Norway.

  1. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae.

    Directory of Open Access Journals (Sweden)

    Wendy Kloezen

    Full Text Available Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future.

  2. A Model of Drosophila Larva Chemotaxis.

    Science.gov (United States)

    Davies, Alex; Louis, Matthieu; Webb, Barbara

    2015-11-01

    Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays.

  3. A Model of Drosophila Larva Chemotaxis.

    Directory of Open Access Journals (Sweden)

    Alex Davies

    2015-11-01

    Full Text Available Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays.

  4. Metamorphosis of cinctoblastula larvae (Homoscleromorpha, porifera).

    Science.gov (United States)

    Ereskovsky, Alexander V; Tokina, Daria B; Bézac, Chantal; Boury-Esnault, Nicole

    2007-06-01

    The metamorphosis of the cinctoblastula of Homoscleromorpha is studied in five species belonging to three genera. The different steps of metamorphosis are similar in all species. The metamorphosis occurs by the invagination and involution of either the anterior epithelium or the posterior epithelium of the larva. During metamorphosis, morphogenetic polymorphism was observed, which has an individual character and does not depend on either external or species specific factors. In the rhagon, the development of the aquiferous system occurs only by epithelial morphogenesis and subsequent differentiation of cells. Mesohylar cells derive from flagellated cells after ingression. The formation of pinacoderm and choanoderm occurs by the differentiation of the larval flagellated epithelium. This is possibly due to the conservation of cell junctions in the external surface of the larval flagellated cells and of the basement membrane in their internal surface. The main difference in homoscleromorph metamorphosis compared with Demospongiae is the persistence of the flagellated epithelium throughout this process and even in the adult since exo- and endopinacoderm remain flagellated. The antero-posterior axis of the larva corresponds to the baso-apical axis of the adult in Homoscleromorpha.

  5. BACTERIAL FLORA OF RAINBOW TROUT LARVAE AND FRY (ONCORHYNCHUS MYKISS

    Directory of Open Access Journals (Sweden)

    Damir Kapetanović

    2003-09-01

    Full Text Available There are no information in available literature about the structure of bacterial flora in rainbow trout larvae and fry in the first days of their lives. The objective of our work has been to follow bacteroflora between the third and the eighth week of their lives. During 35 days of experiment bacteroflora of rainbow trout has been examined, along with following physico–chemical characteristics of water quality as well as it’s influence on health. Samples for bacteriological examination were taken from gill, heart and kidney areas and innoculated on the plates. Bacterial colonies were examined macroscopically, slides with Gram staining, and afterwords biochemical tests were performed. For identification, APILAB Plus programme (bio Mérieux, France was used. Bacterial population of rainbow trout larvae and fry changed in dependence with their age. Physico–chemical characteristics of water ranged within optimal values. Most of bacterial colonies originated from gill isolates (64,4 %, than from heart (21,8 % and kidney areas (13,8 %. The bacterial flora of larvae in incubator was composed mostly of Gram–positive bacteria (75,1 %, genera: Renibacterium (25 %, Lactobacillus (16,7 %, Staphilococcus (16,7 % and Corynebacterium (16,7 %. The transfer of larvae from incubator into the pools resulted in reducing bacterial flora (–66,7 % after 45 minute stay in the pool. Gram–negative bacteria, which have been represented in larvae in incubator with low percent (24, 9 %, after the transfer of larvae to the pools became dominant and represented more than 95 % of rainbow trout larvae and fry bacterial flora. Flavobacterium, Acinetobacter and Yersinia were the predominant Gram–negative genera in larvae in incubator, whereas Aeromonas, Pseudomonas, Flavobacterium and Pasteurella were the main isolates from rainbow trout larvae and fry until the end of experiment. Bacterial flora of larvae in incubator mostly consists of Gram–positive bacteria

  6. Cadmium and zinc reversibly arrest development of Artemia larvae

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, J.C.; Rafiee, P.; Matthews, C.O.; MacRae, T.H.

    1986-08-01

    Despite the widespread distribution of heavy metals such as cadmium and zinc in the environment and their well-known cytotoxicity and embryotoxicity in mammals, comparatively little is known about their effect on aquatic organisms, particularly invertebrates. Post-gastrula and early larval development of the brine shrimp, Artemia, present some useful advantages for studies of developmental aspects of environmental toxicology. Dormant encysted gastrulae, erroneously called brine shrimp eggs, can be obtained commercially and raised in the laboratory under completely defined conditions. Following a period of post-gastrula development within the cyst, pre-nauplius larvae emerge through a crack in the cyst shell. A few hours later, free-swimming nauplius larvae hatch. Cadmium is acutely toxic to both adults and nauplius larvae of Artemia, but the reported LC50s are as high as 10 mM, depending on larval age. In this paper the authors show that pre-nauplius larvae prior to hatching are much more sensitive to cadmium than are hatched nauplius larvae. At 0.1 ..mu..m, cadmium retards development and hatching of larvae; higher concentrations block hatching almost completely and thus are lethal. However, the larvae arrested at the emergence stage survive for 24 hours or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect is reversible if the larvae are placed in cadmium-free medium. The effects of zinc parallel those of cadmium, although zinc is somewhat less toxic than cadmium at equal concentrations.

  7. Activity of Bacillis thuringiensis toxins against cocoa pod borer larvae

    NARCIS (Netherlands)

    Santoso, D.; Chaidamsari, T.; Wiryadiputra, S.; Maagd, de R.A.

    2004-01-01

    Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of coco

  8. Prey capture of pike Esox lucius larvae in turbid water.

    Science.gov (United States)

    Salonen, M; Engström-Ost, J

    2010-06-01

    Pike Esox lucius larvae captured fewer calanoid and cyclopoid copepods in turbid than in clear water, whereas no differences were detected in feeding rates on Daphnia longispina. Decreased capture of copepods may lead to lower growth and survival of E. lucius larvae in turbid areas, in particular, if cladocerans are scarce.

  9. The effects of dissolved gas supersaturation on white sturgeon larvae

    Science.gov (United States)

    Counihan, T.D.; Miller, A.I.; Mesa, M.G.; Parsley, M.J.

    2000-01-01

    Spill at dams has caused supersaturation of atmospheric gas in waters of the Columbia and Snake rivers and raised concerns about the effects of dissolved gas supersaturation (DGS) on white sturgeons Acipenser transmontanus. The timing and location of white sturgeon spawning and the dispersal of white sturgeon larvae from incubation areas makes the larval stage potentially vulnerable to the effects of DGS. To assess the effects of DGS on white sturgeon larvae, we exposed larvae to mean total dissolved gas (TDG) levels of 118% and 131% saturation in laboratory bioassay tests. Gas bubble trauma (GBT) was manifested as a gas bubble in the buccal cavity, nares, or both and it first occurred at developmental stages characterized by the formation of the mouth and gills. Exposure times of 15 min were sufficient to elicit these signs in larvae in various stages of development. No mortality was observed in larvae exposed to 118% TDG for 10 d, but 50% mortality occurred after a 13-d exposure to 131% TDG. The signs of GBT we observed resulted in positive buoyancy and alterations in behavior that may affect the dispersal and predation vulnerability of white sturgeon larvae. The exact depth distribution of dispersing white sturgeon larvae in the Columbia River currently is unknown. Thus, our results may represent a worst-case scenario if white sturgeon larvae are dispersed at depths with insufficient hydrostatic pressure to compensate for high TDG levels.

  10. Active downward propulsion by oyster larvae in turbulence.

    Science.gov (United States)

    Fuchs, Heidi L; Hunter, Elias J; Schmitt, Erika L; Guazzo, Regina A

    2013-04-15

    Oyster larvae (Crassostrea virginica) could enhance their settlement success by moving toward the seafloor in the strong turbulence associated with coastal habitats. We characterized the behavior of individual oyster larvae in grid-generated turbulence by measuring larval velocities and flow velocities simultaneously using infrared particle image velocimetry. We estimated larval behavioral velocities and propulsive forces as functions of the kinetic energy dissipation rate ε, strain rate γ, vorticity ξ and acceleration α. In calm water most larvae had near-zero vertical velocities despite propelling themselves upward (swimming). In stronger turbulence all larvae used more propulsive force, but relative to the larval axis, larvae propelled themselves downward (diving) instead of upward more frequently and more forcefully. Vertical velocity magnitudes of both swimmers and divers increased with turbulence, but the swimming velocity leveled off as larvae were rotated away from their stable, velum-up orientation in strong turbulence. Diving speeds rose steadily with turbulence intensity to several times the terminal fall velocity in still water. Rapid dives may require a switch from ciliary swimming to another propulsive mode such as flapping the velum, which would become energetically efficient at the intermediate Reynolds numbers attained by larvae in strong turbulence. We expected larvae to respond to spatial or temporal velocity gradients, but although the diving frequency changed abruptly at a threshold acceleration, the variation in propulsive force and behavioral velocity was best explained by the dissipation rate. Downward propulsion could enhance oyster larval settlement by raising the probability of larval contact with oyster reef patches.

  11. Rapid bioassay to screen potential biopesticides in Tenebrio molitor larvae

    Science.gov (United States)

    A simplified assay was devised to evaluate the response of Tenebrio molitor larvae to potential insect control products. The assay incorporates punched disks of flattened whole-grain bread placed in 96-well plates, with treatments applied topically, and neonate larvae added to each well. To evalua...

  12. Cultivation of sponge larvae: settlement, survival, and growth of juveniles

    NARCIS (Netherlands)

    Caralt, de S.; Otjens, H.; Uriz, M.J.; Wijffels, R.H.

    2007-01-01

    The aim of this study was to culture sponge juveniles from larvae. Starting from larvae we expected to enhance the survival and growth, and to decrease the variation in these parameters during the sponge cultures. First, settlement success, morphological changes during metamorphosis, and survival of

  13. [Tungiasis and cutaneous larva migrans: unpleasant travel souvenirs].

    Science.gov (United States)

    Feldmeier, Hermann

    2009-12-01

    Tungiasis (sand flea disease) and cutaneous larva migrans (creeping eruption) are parasitic skin diseases in which the infectious agents only temporarily invade human skin. The parasites die in situ and eventually are eliminated by tissue repair mechanisms. Both diseases are zoonoses. Humans only accidentally become a host for animal hookworm larvae (resulting in cutaneous larva migrans), but get infected with Tunga penetrans as frequent as domestic animals. In travelers to tropical and subtropical regions tungiasis and cutaneous larva migrans are the most common imported skin diseases. The diagnosis is made clinically. In tungiasis the clinical manifestations depend on the stage of the disease. Intense local inflammation and bacterial superinfection are common. Cutaneous larva migrans is treated orally with ivermectin or albendazole. A repellent based on coconut oil effectively prevents penetration of sand fleas.

  14. Implantation of human bot fly larvae in host skin.

    Science.gov (United States)

    Leite, A C R; Nascimento, M F A; Serafim, L R

    2010-01-01

    Adult males of Mus musculus each infested with four first-instar (L1) larvae of Dermatobia hominis (Linneaus, Jr.) were used as donors of larvae to other mice (recipients). Larvae at four (L1), six (early L2), 12 (L2), or 20 (L3) days postinfestation (dpi), were implanted into the skin of each recipient. Only two of 38 mice (5.3%) were refractory to implants and three died after implantation. Developmental times (pre- plus postimplantation) of implanted larvae were of similar duration to those in larvae that completed their development in the original mice. The L3 that emerged from implanted hosts developed to pupae and fertile adult specimens, whose L1 descendants were used to maintain the D. hominis life cycle in our laboratory. The model described here has several potential applications, including studies of the host relationship with specific instars and the development of management and control measures to combat this Neotropical myiasis.

  15. Neuromechanics of crawling in D. melanogaster larvae

    Science.gov (United States)

    Pehlevan, Cengiz; Paoletti, Paolo; Mahadevan, L.

    2015-03-01

    Nervous system, body and environment interact in non-trivial ways to generate locomotion and thence behavior in an organism. Here we present a minimal integrative mathematical model to describe the simple behavior of forward crawling in Drosophila larvae. Our model couples the excitation-inhibition circuits in the nervous system to force production in the muscles and body movement in a frictional environment, which in turn leads to a proprioceptive signal that feeds back to the nervous system. Our results explain the basic observed phenomenology of crawling with or without proprioception, and elucidate the stabilizing role of proprioception in crawling with respect to external and internal perturbations. Our integrated approach allows us to make testable predictions on the effect of changing body-environment interactions on crawling, and serves as a substrate for the development of hierarchical models linking cellular processes to behavior.

  16. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua larvae

    Directory of Open Access Journals (Sweden)

    S Penglase

    2013-02-01

    Full Text Available Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I, at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua were fed rotifers enriched to intermediate (26 mg I kg-1 dry weight; MI group or copepod (129 mg I kg-1 DW; HI group I levels and compared to cod larvae fed control rotifers (0.6 mg I kg-1 DW. Larval I concentrations were increased by 3 (MI and 7 (HI fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg-1 DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg-1 DW.

  17. Nutritional condition and vertical distribution of Baltic cod larvae

    DEFF Research Database (Denmark)

    Grønkjær, P.; Clemmesen, C.; St. John, Michael

    1997-01-01

    Newly hatched Baltic cod Gadus morhua larvae are typically found at depths >60 m. This is a region of low light and prey availability, hence generating the hypothesis that larvae have to migrate from hatching depth to the surface layer to avoid starvation and improve their nutritional condition....... To lest this hypothesis, Baltic cod larvae were sampled during the spawning seasons of 1994 and 1995 with depth-resolving multiple opening/closing nets. Each larva was aged by otolith readings and its RNA/DNA ratio was determined as a measure of nutritional condition. The RNA/DNA ratios of these larvae...... aged 2-25 days (median 10 days) ranged from 0.4 to 6.2, corresponding to levels exhibited by starving and fast growing larvae in laboratory calibration studies (starvation, protein growth rate, G(pi)=-12.2% day(-1); fast-growing larvae, G(pi)=14.1% day(-1)) respectively. Seventy per cent of the field...

  18. Biodiversity of Insect Larvae in Streams at Jobolarangan Forest

    Directory of Open Access Journals (Sweden)

    MANAN EFENDI

    2001-07-01

    Full Text Available Insect larvae are macro-invertebrate that becomes the most perfect indicator of aquatic-environmental health. Natural streams usually determined by its insect-larvae community in a good condition, in which their taxonomic diversity and richness are high. The objective of the research was to know the taxonomic diversity and richness of insect-larvae family in streams at Jobolarangan forest. The larvae were sampled using net-surber (dip-net in three location of streams, i.e.: Parkiran (1773 m asl., Mrutu (1875 m asl., and Air Terjun (1600 m asl.. The screened insect-larvae were grouped its family and counted their individual number. The diversity was counted using Shanon-Weiner diversity indices. In this research was found 12 families of insect-larvae consisted of two families of Odonata order, 3 families of Coleopteran order, and a family of Lepidoptera. Nine families identified, while the three insect-larvae i.e. 2 of Coleoptera and 1 of Lepidoptera were not identified yet. The Parkiran station indicated the highest diversity index of 0.1436.

  19. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aladawi, M.A. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: Scientific@aec.org.sy; Albarodi, H. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Hammoudeh, A. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Shamma, M. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Sharabi, N. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2006-01-15

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  20. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    Science.gov (United States)

    Aladawi, M. A.; Albarodi, H.; Hammoudeh, A.; Shamma, M.; Sharabi, N.

    2006-01-01

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  1. MORPHOLOGICAL DEVELOPMENT OF Napoleon WRASSE, Cheilinus undulatus LARVAE

    Directory of Open Access Journals (Sweden)

    Jhon Harianto Hutapea

    2006-12-01

    Full Text Available To improve the survival rate, napoleon wrasse larval rearing trial was conducted at Research Institute for Mariculture, Gondol-Bali in 2003. The trial aims at assessing initial feed for larvae, food habit, and morphological development from early larval stage to juvenile. The results showed that chicken egg yolk could be applied as initial feed and followed by rotifer, Artemia and mysid (Mesophodopsis sp.. Three swimming behavior of larvae were observed, drifting, free swimming and hiding on the substrate as larvae develop. Digestive system development, simple tube like, transition stage and coiled where digestive system could be distinguished between stomach, intestine and rectum.

  2. What do barnacle larvae feed on ? Implications in biofouling ecology

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.; Anil, A.C.

    and diversity indicated that the percentage of defaecating larvae (an indicator of food consumed) was comparatively higher during the pre-monsoon season. Generally this season is characterized by lower chlorophyll-a concentration. However, the average number...

  3. Microbial interference with hatch and survival of European eel larvae

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Lauesen; Tomkiewicz, Jonna;

    Recent research has significantly improved our knowledge and capabilities in the field of in vitro production of yolk sac larvae from European eel (Anguilla anguilla). Female broodstock European eels are matured by weekly administration of pituitary extract and male eels with hCG (human chorionic...... gonadotropin), which afford gametes for in vitro fertilization studies. The maturing process may lead to mass hatchings of up to ½ million larvae of which some survive the entire yolk sac phase. However, the rearing of larvae suffers from high larval mortalities, and water quality might be a crucial factor...... for larval survival in rearing systems. By applying antibiotic treatment as a research tool, it was possible to determine the extent of microbial interference in the production of high numbers of good quality larvae. By controlling microbiota during egg and larval incubation, the egg hatching success...

  4. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai S; Apiwathnasorn C; Leemingsawat S; Wongwit W; Overgaard HJ

    2011-01-01

    Objective: To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods: Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results: Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 μg/g), than in the wastewaters surface (0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions: The Cx.quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques.

  5. Improved Software for Quantifying the Behavior of Drosophila Larvae

    Science.gov (United States)

    Bernat, Natalie; Gershow, Marc

    A key advantage of small crawling organisms like C elegans and the Drosophila larva is that their behaviors may be assayed automatically using computer vision software. Current state of the art software is capable of detecting the positions and postures of crawling larvae and automatically categorize their behaviors in parallel. However, these algorithms, which are based on frame-by-frame analysis of thresholded black and white images, fail to correctly describe the postures of larvae executing sharp bends and have difficulty separating multiple larvae that are physically touching. We present new tracking software that uses intensity information in grayscale images and applies temporal smoothness constraints to positions and postures. We implemented this software as an ImageJ plugin, extending its portability and applicability.

  6. [Community features of Sacrabaeoida larvae in Stipa grandis steppe].

    Science.gov (United States)

    Xinmin, Liu; Ning, Wu

    2004-09-01

    The study showed that in the Stipa grandis steppe of Inner Mongolia, there were 4 families and 9 species of Scarabaeoidea larvae, among which, the numbers of species and individuals of Melolonthidae were more than those of other families. The important value of the dominant species in Scarabaeoidea larvae community were Trematodes tenebrioides > Serica orientalis > Amphimallon solstitialis > Cyriopertha arcuata. Based on the features of their seasonal dynamics, they could be classified into three kinds. The first kind was that their density peak occurred in spring and autumn, such as Serica orientalis. Cyriopertha arcuata belonged to the second kind, and its density had no obvious fluctuation through all the year. Trematodes tenebrioides and Amphimallon solstitialis could be classified into the third kind, and their density peak all occurred in autumn. The biodiversity index of Scarabaeoidea larvae community was relatively higher in autumn than in spring and summer. Although the richness of Scarabaeoidea larvae populations was not lower in spring, their composition was very simple.

  7. Starvation threshold of Balanus amphitrite larvae in relation to temperature

    Digital Repository Service at National Institute of Oceanography (India)

    Anil, A.C.; Desai, D.V.

    Energy content in the non-feeding (lecithotrophic) cyprid larvae of B. amphitrite plays an important role in determining its metamorphic characteristics. In this context it is important to understand the energy transformed to this stage from...

  8. Symbiotic bacteria enable olive fly larvae to overcome host defences

    OpenAIRE

    Ben-Yosef, Michael; Pasternak, Zohar; Jurkevitch, Edouard; Yuval, Boaz

    2015-01-01

    Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies (Bactrocera oleae) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. ...

  9. Effects of Dimethoate on Tree Frog (Hyla arborea) Larvae

    OpenAIRE

    Ferah SAYIM; Kaya, Uğur

    2006-01-01

    Considering the global decline of amphibian populations, the present study aimed to investigate the sensitivity of tree frogs to a common pesticide, dimethoate. Our study reports the effects of dimethoate on 21st- and 25th-stage Hyla arborea larvae under standardized laboratory conditions in an acute toxicity test using the static system. Specimens used for testing were obtained from the eggs of mating pairs collected at a local natural pond. Each experimental group contained 10 healthy larva...

  10. Antimicrobial activity of essential oils against Paenibacillus larvae

    OpenAIRE

    Gende, L. B.; Pires, Sância; Fernandez, N.J.; Damiani, M.; Churio, M.S.; Fritz, R.; Eguaras, M. J.

    2012-01-01

    American foulbrood is a serious bacterial disease that affects Apis mellifera colonies; the causative agent is Paenibacillus larvae [1 ]. The aim of the study was to evaluate in vitro the antimicrobial activity of 32 essential oils against P. larvae. Oils from 21 botanical species were analyzed by gas chromatography (CG and CG/EM). All essential oils were classified according to the composition of their main components in two groups: benzene ring compounds (BRC) and terpene com...

  11. Characterization of secreted proteases of Paenibacillus larvae, potential virulence factors in honeybee larval infection

    Science.gov (United States)

    Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae se...

  12. Long-duration feedings and caste differentiation in Bombus terrestris larvae

    NARCIS (Netherlands)

    Ribeiro, M.F.

    2002-01-01

    The duration of feedings received by Bombus terrestris larvae was studied using video-recordings. In the last days of development all larvae received feedings mainly of long duration. Worker larvae of the third brood received significantly longer feedings than worker larvae reared in the other brood

  13. Larva migrans in squirrel monkeys experimentally infected with Baylisascaris potosis.

    Science.gov (United States)

    Tokiwa, Toshihiro; Tsugo, Kosuke; Nakamura, Shohei; Taira, Kensuke; Une, Yumi

    2015-10-01

    Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30 days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections.

  14. Quantification of vestibular-induced eye movements in zebrafish larvae

    Directory of Open Access Journals (Sweden)

    Mo Weike

    2010-09-01

    Full Text Available Abstract Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR, a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf, which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs.

  15. Biorheological action of Ascaris lumbricoides larvae on human erythrocytes.

    Science.gov (United States)

    de León, Patricia Ponce; Del Balzo, Gonzalo; Riquelme, Bibiana

    2013-03-01

    Previous studies have shown that A. lumbricoides extracts capture sialic acid (SA) from human red blood cells (RBC). The aim of this work was to study hemorheological alterations in vitro caused by parasite larvae. The biorheological action of three larva concentrates of first and second larval stage on group O erythrocytes was analyzed by incubating the erythrocyte packed together with an equal volume of larvae (treated RBC) and PBS (control RBC). Distribution and parameters of aggregation (digital image analysis), aggregation kinetics (erythroaggregameter), and viscoelasticity (erythrodeformeter) were measured. The digital image analysis showed that all the larvae diminished the isolated cells percentage and increased the size of the formed aggregates. The aggregate formation velocity was lower in the treated than in the control. The deformability index (ID) values of treated RBC did not present variations with respect to those of the control, but a decrease in the erythrocyte elastic modulus (μ(m)) and membrane surface viscosity (η(m)) values was observed, indicating that the larvae not only induced a diminution in the membrane surface viscosity of RBC but also altered the dynamic viscoelasticity of the membrane. Experiments carried out in vitro support the conclusion that the contact between larvae and RBC produces hemorheological alterations.

  16. Long-wavelength photosensitivity in coral planula larvae.

    Science.gov (United States)

    Mason, Benjamin M; Cohen, Jonathan H

    2012-04-01

    Light influences the swimming behavior and settlement of the planktonic planula larvae of coral, but little is known regarding the photosensory biology of coral at this or any life-history stage. Here we used changes in the electrical activity of coral planula tissue upon light flashes to investigate the photosensitivity of the larvae. Recordings were made from five species: two whose larvae are brooded and contain algal symbionts (Porites astreoides and Agaricia agaricites), and three whose larvae are spawned and lack algal symbionts (Acropora cervicornis, Acropora palmata,and Montastrea faveolata). Photosensitivity originated from the coral larva rather than from, or in addition to, its algal symbionts as species with and without symbionts displayed similar tissue-level electrical responses to light. All species exhibited as much (or more) sensitivity to red stimuli as to blue/green stimuli, which is consistent with a role for long-wavelength visible light in the preference for substrata observed during settlement and in facilitating vertical positioning of larvae in the water column.

  17. Optokinetic behavior is reversed in achiasmatic mutant zebrafish larvae.

    Science.gov (United States)

    Rick, J M; Horschke, I; Neuhauss, S C

    2000-05-18

    The vertebrate optokinetic nystagmus (OKN) is a compensatory oculomotor behavior that is evoked by movement of the visual environment. It functions to stabilize visual images on the retina. The OKN can be experimentally evoked by rotating a drum fitted with stripes around the animal and has been studied extensively in many vertebrate species, including teleosts. This simple behavior has earlier been used to screen for mutations affecting visual system development in the vertebrate model organism zebrafish. In such a screen, we have found a significant number of homozygous belladonna (bel) mutant larvae to be defective in the correct execution of the OKN [1]. We now show that about 40% of homozygous bel larvae display a curious reversal of the OKN upon visual stimulation. Monocular stimulation leads to primary activation of ipsilateral eye movements in larvae that behave like the wild type. In contrast, affected larvae display contralateral activation of eye movements upon monocular stimulation. Anatomical analysis of retinal ganglion cell axon projections reveal a morphological basis for the observed behavioral defect. All animals with OKN reversal are achiasmatic. Further behavioral examination of affected larvae show that OKN-reversed animals execute this behavior in a stimulus-velocity-independent manner. Our data support a parsimonious model of optokinetic reversal by the opening of a controlling feedback loop at the level of the optic chiasm that is solely responsible for the observed behavioral abnormality in mutant belladonna larvae.

  18. Using Real-time PCR for Identification of Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Vladimíra Kňazovická

    2011-05-01

    Full Text Available The aim of the study was identification of Paenibacillus larvae that causes American foulbrood disease (AFB in colony of bees (Apis mellifera. Bacterial isolates originated from honey samples, because presence of P. larvae in honey is treated as early diagnostic of AFB. Intense proteolytic activity and no catalase activity are typical for Gram positive rod-shaped bacteria P. larvae. We diluted honey (1:2, heated at 80 °C for 10 min and inoculated on semiselective medium MYPGP agar with nalidixic acid. Plates were cultivated at 37 °C for 48 – 72 h under the aerobic conditions. Selected colonies were transferred on MYT agar and cultivated 24 h. We analysed 30 honey samples and found 27 bacterial isolates. All isolates were Gram positive and mainly rod-shaped. No catalase activity was documented for 6 from 27 isolates. Identification was finished by real-time PCR to detect the 16S rRNA gene of Paenibacillus larvae with real-time cycler Rotor-Gene 6000. As DNA template we used genomic DNA isolated with commercial kit and DNA lysate obtaining by boiled cells. We used 2 strains of P. larvae from CCM (Czech Collection of Microorganisms as positive control. The reliable method of detection P. larvae has important rule for beekeeping.

  19. Description of larva and puparium of Oplodontha rubrithorax (Diptera: Stratiomyidae) from the Oriental Region.

    Science.gov (United States)

    Nerudová, Jana; Kovac, Damir; Tóthová, Andrea

    2015-05-01

    This is the first description of larva and puparium of Oplodontha rubrithorax (Macquart, 1838) from the Oriental Region. Larvae were found at a hot spring in North Thailand. The morphological features and cuticular structures of the larva are documented by drawings and SEM micrographs and the main characters are compared with the European O. viridula (Fabricius, 1775), the only described larva of this genus. Differences between larvae of both species were only found in pubescence. The characteristic, somewhat dilated and slightly clavate hairs on the dorsal surface of the body segments of O. viridula larva are apparently lacking in the larva of O. rubrithorax.

  20. Fish larvae at fronts: Horizontal and vertical distributions of gadoid fish larvae across a frontal zone at the Norwegian Trench

    DEFF Research Database (Denmark)

    Munk, Peter

    2014-01-01

    The reproduction and early life history of many fish species are linked to the physical and biological characteristics of fronts. In order to ascertain linkages between frontal physics and fish larvae, we investigated distributional differences among gadoid fish larvae comparing these to both....... Measurements demonstrated a distinct bottom front at the southern slope of the Trench with deepening isopycnals and high chlorphyll a concentrations. Abundances of both gadoid fish larvae and copepods peaked in vicinity of the front around mid-depth, and findings points to an inter-connection between...... the vertical and horizontal distributions of each species. However, the three-dimensional pattern of distribution differed significantly among species of larvae and species of copepods. The study underlines the complexity of bio-physical interrelationships in the frontal zone, and indicates that the zone...

  1. Acute toxicity of sodium metabisulphite in larvae and post-larvae of the land crab, Cardisoma guanhumi.

    Science.gov (United States)

    Galli, Orlando B S; Fujimoto, Rodrigo Y; Abrunhosa, Fernando A

    2012-08-01

    Sodium metabisulphite (SMB) is used in marine shrimp aquaculture to prevent the occurrence of black spot. The release SMB into the estuarine environment from shrimp farm pond effluents has been reported. This study evaluated the susceptibility of larvae and post-larvae of land crab, Cardisoma guanhumi to this salt. A decrease in dissolved oxygen and pH occurred with increasing concentration of SMB and exposure time. LC(50) values after 48 h of exposure were 34 ± 1.1 mg/L, 31.1 ± 1.9 mg/L, and 30.6 ± 0.5 mg/L for I zoea larvae, megalopa larvae and stage I juveniles, respectively.

  2. First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera

    Directory of Open Access Journals (Sweden)

    Susana Trivinho-Strixino

    2012-09-01

    Full Text Available First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera. This study constitutes the first record of Temnocephala Blanchard, an ectosymbiont on Corydalidae, as a possible predator of chironomid larvae. Twenty-eight Corydalidae larvae (Corydalus and Protochauliodes were examined under stereomicroscopic in search for Temnocephala and Chironomidae larvae, of which five megalopteran larvae had 24 Temnocephala sp. associated. Furthermore, eight of these Temnocephala worms had chironomid larvae in their gut contents, an interaction previously unknown. Gut content analyses revealed Corynoneura as the commonest chironomid, but larvae of Larsia, Rheotanytarsus and Tanytarsus were recorded as well. This study included Corydalus and Protochauliodes as hosts for Temnocephala, which might be important for this worm dispersion and population dynamics.

  3. Amostragem por larva-única na vigilância de Aedes aegypti Single-larva sampling for Aedes aegypti surveillance

    Directory of Open Access Journals (Sweden)

    José Eduardo Bracco

    1995-04-01

    Full Text Available Com a finalidade de testar a metodologia de amostragem por larva-única na vigilância entomológica do Aedes aegypti, foram pesquisados domicílios do Município de Araraquara, SP (Brasil. Nos criadouros que continham larvas de Aedes uma delas foi coletada. Como controle, após a coleta da larva-única, todas as larvas foram coletadas para identificação posterior. Esse processo foi repetido no laboratório. Dos 447 domicílios visitados, apenas 12 foram considerados positivos e 20 criadouros foram identificados; destes, 13 continham larvas de Aedes; 5, larvas de Aedes e Culex e 2, larvas de Culex. Os resultados mostram o reconhecimento correto, no campo, de todos os criadouros, evidenciando que o método poderia ser utilizado na vigilância entomológica de municípios sem infestação domiciliar ou infestados apenas com uma única espécie de Aedes.Buildings in Araraquara city, Southeastern Brazil, were searched during a year for the presence of Aedes larvae using single larva sampling in order to check the single-larva methodology. In those breeding places in wich Aedes larvae were found, one of them was collected. As a control, after the single larva had been collected, all the larvae from the breeding place were collected for later identification. This process was repeated in the laboratory. Of the 447 domiciles searched, 12 were considered positive and 20 breeding places were found. Of the breeding places, 13 contained Aedes larvae, 5 both Aedes and Culex larvae and 2 Culex larvae only. The results show that all the breeding places in the field were properly recognited showing the method may be used for Aedes surveillance in cities infested with one species only or without any domiciliary infestation.

  4. Descrição da larva de Diastatops obscura (Fabricius (Odonata, Libellulidae Description of the larva of Diastatops obscura (Fabricius (Odonata, Libellulidae

    Directory of Open Access Journals (Sweden)

    N.D. Santos

    1993-01-01

    Full Text Available The larva of Diastatops obscura (Fabricius, 1775 is described and figured based on exuviae of last instar of reared specimes collected on still waters in São João river, Silva Jardim (22º38' - 42º18', Rio de Janeiro, Brazil. The relationship among the larva of D. obscura and larvae of Celithemis are discussed.

  5. Activity of Thymus vulgaris essential oil against Anisakis larvae.

    Science.gov (United States)

    Giarratana, F; Muscolino, D; Beninati, C; Giuffrida, A; Panebianco, A

    2014-07-01

    Anisakiasis is an important food-borne disease especially in countries with high fish consumption. The increase of cases of human disease and the virtual absence of effective treatments have prompted the research on new active compounds against Anisakis larvae. As well known, the disease is related to the consumption of raw or almost raw seafood products, but also marinated and/or salted fishery products, if the processing is insufficient to destroy nematode larvae can represent a risks for the consumers. In the light of the biocidal efficacy against different pathogens demonstrated for various essential oils, the aim of this work is to evaluate the effect of Thymus vulgaris essential oil (TEO) against anisakidae larvae. The TEO at 10% and 5% concentration in oil sunflower seeds, caused in vitro the death of all larvae within 14 h, with cuticle and intestinal wall damages. The results obtained showing a significant activity against Anisakis larvae, suggest further investigation on TEO as a larvicidal agent and on its potential use in the industrial marinating process.

  6. Inactivation of Chironomid Larvae with Chlorine Dioxide and Chlorine

    Institute of Scientific and Technical Information of China (English)

    SUN Xin-bin; CUI Fu-yi

    2008-01-01

    Chironomid larvae propagate prolifically in eutrophic water body and they cannot be exterminated by conventional disinfection process.The inactivation effects of chlorine and chlorine dioxide on Chironomid larvae were investigated and some boundary values in practice were determined under conditions of various oxidant dosage,organic precursor concentration and pH value.In addition,removal effect of differmt pre-oxidation combined with coagulation process on Chironomid larvae in law water was evaluated.It was found that chlorine dioxide possessed better inactivation effect than chlorine.Complete inactivation of Chironomid larvae in raw water was resulted by 1.5mg/L of chlorine dioxide with 30min of contact time. Additionally,the ocgallic precursor concentration,pH value had little influence on the inactivation effect.The coagulation jar test showed that Chironomid larvae in the raw water could be completely ronxwed by chlorine dioxide pre-oxidation in combination with the omgulation process at chlorine dioxide dosage of 0.8 mg/L.

  7. Image enhancement for tracking the translucent larvae of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Sukant Khurana

    Full Text Available Drosophila melanogaster larvae are model systems for studies of development, synaptic transmission, sensory physiology, locomotion, drug discovery, and learning and memory. A detailed behavioral understanding of larvae can advance all these fields of neuroscience. Automated tracking can expand fine-grained behavioral analysis, yet its full potential remains to be implemented for the larvae. All published methods are unable to track the larvae near high contrast objects, including the petri-dish edges encountered in many behavioral paradigms. To alleviate these issues, we enhanced the larval contrast to obtain complete tracks. Our method employed a dual approach of optical-contrast boosting and post-hoc image processing for contrast enhancement. We reared larvae on black food media to enhance their optical contrast through darkening of their digestive tracts. For image processing we performed Frame Averaging followed by Subtraction then Thresholding (FAST. This algorithm can remove all static objects from the movie, including petri-dish edges prior to processing by the image-tracking module. This dual approach for contrast enhancement also succeeded in overcoming fluctuations in illumination caused by the alternating current power source. Our tracking method yields complete tracks, including at the edges of the behavioral arena and is computationally fast, hence suitable for high-throughput fine-grained behavioral measurements.

  8. Larvicidal activity of Brazilian plant essential oils against Coenagrionidae larvae.

    Science.gov (United States)

    Silva, D T; Silva, L L; Amaral, L P; Pinheiro, C G; Pires, M M; Schindler, B; Garlet, Q I; Benovit, S C; Baldisserotto, B; Longhi, S J; Kotzian, C B; Heinzmann, B M

    2014-08-01

    Odonate larvae can be serious pests that attack fish larvae, postlarvae, and fingerlings in fish culture tanks, causing significant loss in the supply and production of juveniles. This study reports a screen of the essential oils (EOs) of Nectandra megapotamica (Sprengel) Mez, Nectandra grandiflora Nees, Hesperozygis ringens (Bentham) Epling, Ocimum gratissimum L., Aloysia gratissima (Gillies & Hooker) Troncoso, and Lippia sidoides Chamisso against Coenagrionidae larvae. In addition, the most effective EO and its 50% lethal concentration (LC50) and chemical analysis are described. The larvae of Acanthagrion Selys, Homeoura Kennedy, Ischnura Charpentier, and Oxyagrion Selys were used to assess the EO effects. EO obtained from H. ringens, O. gratissimum, and L. sidoides showed the highest larvicidal effects at 19 h of treatment. The major constituents of the EO of H. ringens include pulegone and limonene, while eugenol and Z-beta-ocimene predominate in the EO of O. gratissimum, and carvacrol and rho-cymene were the major compounds of the EO of L. sidoides. Leaf EOs from H. ringens, O. gratissimum, and L. sidoides showed activity against Coenagrionidae larvae at similar concentrations with LC50s of 62.92, 75.05, and 51.65 microl liter(-1), respectively, and these were considered the most promising treatments.

  9. Ecdysteroids in the larvae of Opogona sacchari (Bojer), a invasive alien pest

    Institute of Scientific and Technical Information of China (English)

    WANG FangHai; ZHANG GuRen; WEN RuiZhen; HE GuoFeng

    2007-01-01

    In order to understand the composition and quantitative variation of ecdysteriods in the larvae of Opogona sacchari (Bojer), a invasive alien pest, we analyzed the larval ecdysteroid composition and titers in this pest. The main component of ecdysteriods in the larvae of O. Sacchari is 20-hydroxyecdysone, and also there is a little 26-hydroxyecdysone. The titer of ecdysteriods in the larvae from the 1st instar to the 7th instar was gotten higher gradually compared on ng ecdysteroid/larva, but no regularity could be found about the titer if compared on ng ecdysteroid/g avoirdupois. There was only one peak of ecdysteroids (0.5475 ng/larva) showed at day 2 during the developmental time of the 6th instar larvae. However, there were two peaks appearing during the developmental time of the 7th instar larvae , one peak (0.29415 ng/larva) at day 3, another (0.214 ng/larva) at day 5.

  10. Lipid and fatty acid analysis of uninfected and granulosis virus-infected Plodia interpunctella larvae

    Science.gov (United States)

    Shastri-Bhalla, K.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    A comparative study on the lipid and fatty acid composition of the uninfected and GV-infected Plodia interpunctella larvae was performed. Higher levels of free fatty acids were found in GV-infected larvae compared to those of the uninfected larvae, while the latter had more triacylglycerol compared to the former. The known identified phospholipids were fewer in the GV-infected larvae compared to those in the uninfected larvae. However, an unidentified phospholipid was found to be approximately two times higher in GV-infected larvae. The total lipid of both larvae had palmitic, oleic, and linoleic as the major fatty acids. The fatty acid composition of the GV-infected larval phospholipid differed considerably compared to that of the uninfected larvae, in that the ratio of unsaturated fatty acid to saturated fatty acid was 3.5 times less in the GV-infected larvae.

  11. Feeding rates of the jellyfish Aurelia aurita on fish larvae

    DEFF Research Database (Denmark)

    Titelman, J.; Hansson, L.J.

    2006-01-01

    We quantified feeding rates of field caught Aurelia aurita feeding on yolk sac cod (Gadus morhua) larvae in a series of incubation experiments. A short-time (similar to 1 h) functional response experiment with a wide range of prey concentrations (0.5-16 prey l(-1)supercript stop, initial concentr......We quantified feeding rates of field caught Aurelia aurita feeding on yolk sac cod (Gadus morhua) larvae in a series of incubation experiments. A short-time (similar to 1 h) functional response experiment with a wide range of prey concentrations (0.5-16 prey l(-1)supercript stop, initial...... to presence of fish larvae. There were no significant differences between A. aurita feeding rates in light and darkness for yolk sac prey ages 0-7 days (at 7.5 degrees C). Although prey vision and escape abilities of fish may develop rapidly during early larval ontogeny, these factors apparently have little...

  12. Effects of endosulfan on Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae.

    Science.gov (United States)

    Kalender, Yusuf; Uzunhisarcikli, Meltem; Ogutcu, Ayse; Suludere, Zekiye; Kalender, Suna

    2005-01-01

    Thaumetopoea pityocampa larvae are very harmful to pines and they also cause allergic reactions in men and animals. In this study, different concentrations of endosulfan were administered to T. pityocampa larvae via pine needles which were prepared by the dipping method. The data obtained were statistically evaluated using probit analysis and a LC(50/48 hrs) value for T. pityocampa larvae found to be 1.679 mg/l. Also, 12, 24, 36 and 48 hrs after 1.679 mg/1 endosulfan treatment, ultrastructural changes in the midgut epithelium of T. pityocampa were investigated. No pathological changes were observed after 12 hrs, swelling and vacuolization of mitochondria and dilation ofendoplasmic reticulum after 24 hrs, swelling ofmitochondria and breaking of mitochondrial cristae and dissolving of nucleoplasm after 36 hrs, finally large vacuoles in the midgut epithelium cells were observed after 48 hrs.

  13. An improved brine shrimp larvae lethality microwell test method.

    Science.gov (United States)

    Zhang, Yi; Mu, Jun; Han, Jinyuan; Gu, Xiaojie

    2012-01-01

    This article described an improved brine shrimp larvae lethality microwell test method. A simply designed connecting vessel with alternative photoperiod was used to culture and collect high yield of active Artemia parthenogenetica nauplii for brine shrimp larvae lethality microwell test. Using this method, pure A. parthenogenetica nauplii suspension was easily cultured and harvested with high density about 100-150 larvae per milliliter and the natural mortality was reduced to near zero by elimination of unnecessary artificial disturbance. And its sensitivity was validated by determination of LC(50)-24 h of different reference toxicants including five antitumor agents, two pesticides, three organic pollutants, and four heavy metals salts, most of which exhibited LC(50)-24 h between 0.07 and 58.43 mg/L except for bleomycin and mitomycin C with LC(50)-24 h over 300 mg/L.

  14. Aquaculture and feeding ecology: Feeding behaviour in turbot larvae

    DEFF Research Database (Denmark)

    Bruno, Eleonora

    challenging for larval rearing. After the start of exogenous feeding, another intense and likely critical period of change occurs in the early life stages of fish. This stage is the metamorphosis, during which the larvae transform organs and body morphology to become juveniles. Compared to other teleosts...... metamorphosis in flatfish species is often unsuccessful, resulting in different types of abnormal development. The objective of this thesis was to analyse the feeding behaviour of the flatfish species turbot (Psetta maxima L.) larvae during the two crucial life periods, 1) first feeding and 2) metamorphosis....... To analyse whether these two periods are critical for the correct development and survival of turbot, feeding behaviours of larvae during the period of first feeding and during the first stages of metamorphosis was studied using video recordings. This provided qualitative and quantitative descriptions...

  15. Fish larvae at fronts: Horizontal and vertical distributions of gadoid fish larvae across a frontal zone at the Norwegian Trench

    Science.gov (United States)

    Munk, Peter

    2014-09-01

    The reproduction and early life history of many fish species are linked to the physical and biological characteristics of fronts. In order to ascertain linkages between frontal physics and fish larvae, we investigated distributional differences among gadoid fish larvae comparing these to both horizontal and vertical variability in hydrography and abundances of potential copepod prey The investigation was carried out at a frontal zone along the Norwegian Trench in the northern North Sea, and was based on a series of cross-bathymetric sampling transects. Tows with a large ring net and an opening-closing net were used for describing fish larval horizontal and vertical distributions, while a submersible pump was used for describing vertical distributions of copepods. Hydrographic profiles and current velocity measurements were used to outline variability in temperature, salinity and current structure. Measurements demonstrated a distinct bottom front at the southern slope of the Trench with deepening isopycnals and high chlorphyll a concentrations. Abundances of both gadoid fish larvae and copepods peaked in vicinity of the front around mid-depth, and findings points to an inter-connection between the vertical and horizontal distributions of each species. However, the three-dimensional pattern of distribution differed significantly among species of larvae and species of copepods. The study underlines the complexity of bio-physical interrelationships in the frontal zone, and indicates that the zone encompasses specific ecological niches to which each species of fish larvae is adapted.

  16. Predation on crown-of-thorns starfish larvae by damselfishes

    Science.gov (United States)

    Cowan, Zara-Louise; Dworjanyn, Symon A.; Caballes, Ciemon F.; Pratchett, Morgan S.

    2016-12-01

    Examining the functional response of predators can provide insight into the role of predation in structuring prey populations and ecological communities. This study explored feeding behaviour and functional responses of planktivorous damselfishes when offered captive reared larvae of crown-of-thorns starfish, Acanthaster sp., with the aim of determining whether these predators could ever play a role in moderating outbreaks of Acanthaster sp. We examined predatory behaviour of 11 species of planktivorous damselfish, testing: (1) the relationship between predator size and predation rate, both within and among fish species; (2) consumption rates on larvae of Acanthaster sp. versus larvae of a common, co-occurring coral reef asteroid Linckia laevigata; (3) maximal feeding rates upon both Acanthaster sp. and L. laevigata; and (4) functional responses of planktivorous fishes to increasing densities of Acanthaster sp. Consumption rates of crown-of-thorns larvae by damselfishes were independent of predator size; however, there was a significant negative relationship between predator size and consumption rate of L. laevigata, when pooling across all predatory species. Some damselfishes, including Acanthochromis polyacanthus and Amblyglyphidodon curacao, consumed larval Acanthaster sp. at a greater rate than for L. laevigata. Most predatory species (all except A. curacao and Pomacentrus amboinensis) exhibited a Type II functional response whereby the increasing feeding rate decelerated with increasing prey density. In addition to revealing that a wide range of planktivorous fishes can prey upon larvae of Acanthaster sp., these data suggest that planktivorous damselfishes may have the capacity to buffer against population fluctuations of Acanthaster sp. Importantly, predators with Type II functional responses often contribute to stability of prey populations, though planktivorous fishes may be swamped by an abnormally high influx of larvae, potentially contributing to the

  17. CONTROLE DE LARVAS DE Diloboderus abderus COM INSETICIDAS EM TRIGO

    Directory of Open Access Journals (Sweden)

    Silva Mauro Tadeu Braga da

    2002-01-01

    Full Text Available A larva de Diloboderus abderus Sturm (Coleoptera: Melolonthidae é uma praga importante da cultura do trigo (Triticum aestivum L. em plantio direto na região Sul do Brasil. Este estudo teve como objetivo avaliar diferentes inseticidas aplicados nas sementes (fipronil e tiametoxam e via pulverização do solo (clorpirifós e lambdacialotrina para o controle dessa praga. A eficiência dos inseticidas foi determinada através do número de larvas vivas no solo aos 30, 60 e 90 dias após a emergência das plantas (DAE, da massa seca da parte aérea das plantas aos 90 DAE e da produção de grãos. Foram observadas correlações negativas significativas entre a dose dos inseticidas fipronil e tiametoxam e o número de larvas, e correlações positivas significativas entre estes inseticidas e a massa seca da parte aérea e a produtividade de grãos. Infestações de larvas nas testemunhas não tratadas reduziram a produtividade em relação às áreas tratadas com inseticidas. A produtividade incrementou à medida que aumentou a eficiência de controle do inseto pelos inseticidas. Concluiu-se que clorpirifós (960 e 1200g i.a./ha e lambdacialotrina a 25g i.a./ha (formulação CE, aplicados em pulverização do solo, são eficientes para reduzir a população de larvas de D. abderus, garantindo a produtividade de grãos. Sugerem-se novos testes com os inseticidas fipronil, tiametoxam e lambdacialotrina (formulação SC para determinar doses técnica e economicamente adequadas para o controle de larvas de D. abderus em trigo.

  18. Distribution and elimination of Norfloxacin in Fenneropenaeus chinensis larvae

    Science.gov (United States)

    Sun, Ming; Li, Jian; Zhao, Fazhen; Li, Jitao; Chang, Zhiqiang

    2013-09-01

    This study examined the distribution and elimination of Norfloxacin (NFLX) in Fenneropenaeus chinensis ovary and egg and newly hatched larvae. Mature parental shrimp were exposed to 4 or 10 mg L-1 NFLX for 2 or 5 d. Ovary and eggs of the shrimp were sampled after spawning in order to detect NFLX residue using high-performance liquid chromatography (HPLC). Results showed that NFLX residue accumulated in F. chinensis eggs after the parental exposure, with the highest residue detected in ovary. To examine the fate of NFLX residue in larvae, we further determined the concentration of NFLX residue in F. chinensis eggs and larvae at 4 different developmental stages after 24-h exposure. From the newly metamorphosed larvae (0 h post-metamorphosis, h.p.m), samples were taken at different time intervals to 72 h.p.m. HPLC assay showed that the concentrations of NFLX residue in zoea exposed to 4 and 10 mg L-1 NFLX were the highest at 1.5 h, i.e., 0.332 and 0.454 μg g-1, respectively. At the two NFLX exposure levels, the elimination time of half NFLX (half life) in nauplius was 45.36 and 49.85 h, respectively, followed by that in zoea (31.68 and 33.13 h), mysis larvae (42.24 and 47.28 h) and postlarvae (24.48 and 30.96 h). Both NFLX exposure levels had a germicidal effect. The distribution and elimination of NFLX residue in F. chinensis tissue, eggs and larvae correlated well with the drug exposure level. The disappearance of NFLX residue coincided with the larval growth, and the half-life of NFLX decreased with the larval development.

  19. Distribution and Elimination of Norfloxacin in Fenneropenaeus chinensis Larvae

    Institute of Scientific and Technical Information of China (English)

    SUN Ming; LI Jian; ZHAO Fazhen; LI Jitao; CHANG Zhiqiang

    2013-01-01

    This study examined the distribution and elimination of Norfloxacin (NFLX) in Fenneropenaeus chinensis ovary and egg and newly hatched larvae.Mature parental shrimp were exposed to 4 or 10mg L-1 NFLX for 2 or 5d.Ovary and eggs of the shrimp were sampled after spawning in order to detect NFLX residue using high-performance liquid chromatography (HPLC).Results showed that NFLX residue accumulated in F.chinensis eggs after the parental exposure,with the highest residue detected in ovary.To examine the fate of NFLX residue in larvae,we further determined the concentration of NFLX residue in F.chinensis eggs and larvae at 4 different developmental stages after 24-h exposure.From the newly metamorphosed larvae (0h post-metamorphosis,h.p.m),samples were taken at different time intervals to 72 h.p.m.HPLC assay showed that the concentrations of NFLX residue in zoea exposed to 4 and 10mgL-1 NFLX were the highest at 1.5h,i.e.,0.332 and 0.454μgg-1,respectively.At the two NFLX exposure levels,the elimination time of half NFLX (half life) in nauplius was 45.36 and 49.85 h,respectively,followed by that in zoea (31.68 and 33.13 h),mysis larvae (42.24 and 47.28 h) and postlarvae (24.48 and 30.96 h).Both NFLX exposure levels had a germicidal effect.The distribution and elimination of NFLX residue in F.chinensis tissue,eggs and larvae correlated well with the drug exposure level.The disappearance of NFLX residue coincided with the larval growth,and the half-life of NFLX decreased with the larval development.

  20. Ultrastructural observations of the larva of Tubiluchus corallicola (Priapulida)

    Science.gov (United States)

    Higgins, R. P.; Storch, V.

    1989-03-01

    Larvae of Tubiluchus corallicola van der Land 1968 were investigated by scanning and transmission electron microscopy. The scalids are sensory organs, each has a bipolar receptor cell with a single apical cilium similar to the scalid in the adult. Muscle cells of the larva are more differentiated than previously reported for other Priapulida; the larval arrangement of circular and longitudinal musculature differs from that of the adult, and a diaphragm is reported for the first time in Priapulida. The diaphragm may function in hydrostatic control of eversion and inversion of the introvert and mouth cone. The functional morphology of these two structures is discussed and contrasted with the Kinorhyncha.

  1. Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae).

    Science.gov (United States)

    Macedo, Lilian Cristina; Melo, Francisco Tiago de Vasconcelos; Ávila-Pires, Teresa Cristina Sauer; Giese, Elane Guerreiro; dos Santos, Jeannie Nascimento

    2016-01-01

    Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the "Osvaldo Rodrigues da Cunha" Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.

  2. The Early Cretaceous Hemeroscopid larva fossils from Beijing, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    More than 100 Hemeroscopid larva fossils were discovered from the Lower Cretaceous in Southwest Beijing,which effectively ends the discussion of morphology and makes it more complete. It is assigned within the LibelluIoidea, and shows close evolutionary correlations with modern Libellulidae. Although the wing characters of adult Hemeroscopus from the same formation indicates the close relationship to Aeschnoidea, we suggest that the larvae and the adults were the same species. Therefore, it probably shows the evolutionary ancestors of Libellulidae. Being the fundamental species discriminating Jehol Entomofauna and Lushangfen Entomofauna, Hemeroscopus bears great significance in the study of stratigraphy.``

  3. Development of a two photon microscope for tracking Drosophila larvae

    Science.gov (United States)

    Karagyozov, Doycho; Mihovilovic Skanata, Mirna; Gershow, Marc

    Current in vivo methods for measuring neural activity in Drosophila larva require immobilization of the animal. Although we can record neural signals while stimulating the sensory organs, we cannot read the behavioral output because we have prevented the animal from moving. Many research questions cannot be answered without observation of neural activity in behaving (freely-moving) animals. Our project aims to develop a tracking microscope that maintains the neurons of interest in the field of view and in focus during the rapid three dimensional motion of a free larva.

  4. Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae).

    Science.gov (United States)

    Macedo, Lilian Cristina; Melo, Francisco Tiago de Vasconcelos; Ávila-Pires, Teresa Cristina Sauer; Giese, Elane Guerreiro; Santos, Jeannie Nascimento Dos

    2016-03-11

    Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the "Osvaldo Rodrigues da Cunha" Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.

  5. A case report of cutaneous larva migrans in Argentina

    Institute of Scientific and Technical Information of China (English)

    Javier Bava; Lucia G Gonzalez; Celeste M Seley; Gisela P Lpez; Alcides Troncoso

    2011-01-01

    Cutaneous larva migrans (CLM) represents the most common tropically acquired dermatosis. CLM is caused by infection with hookworm larvae in tropical and sub-tropical areas, and people who have a history of foreign travel and of walking barefoot on sandy soil or beaches are at a high risk of getting infected with it. The diagnosis is usually made on the basis of the typical appearance of the lesion, intense itching and history of foreign travel. CLM is a common parasitic skin disease that can be easily prevented by wearing 'protective' footwear. A case of CLM is described in this article.

  6. A case report of cutaneous larva migrans in Argentina

    Institute of Scientific and Technical Information of China (English)

    Javier; Bava; Lucia; G; Gonzalez; Celeste; M; Seley; Gisela; P; Lopez; Alcides; Troncoso

    2011-01-01

    Cutaneous larva migrans(CLM) represents the most common tropically acquired dermatosis.CLM is caused by infection with hookworm larvae in tropical and sub-tropical areas,and people who have a history of foreign travel and of walking barefoot on sandy soil or beaches are at a high risk of getting infected with it.The diagnosis is usually made on the basis of the typical appearance of the lesion,intense itching and history of foreign travel.CLM is a common parasitic skin disease that can be easily prevented by wearing ’protective’ footwear.A case of CLM is described in this article.

  7. Culture of Eriocheir sinensis Larvae in Ponds in Greenhouse

    Institute of Scientific and Technical Information of China (English)

    Guoliang RUAN; Liangcheng HU; Hai ZHOU; Dawen MA; Yabin TANG

    2016-01-01

    A total of 15 pools were selected from a greenhouse, and they were randomly and evenly divided into three groups. In each group, one stocking density of Eriocheir sinensis was arranged. The results showed that after 45-d culture, the crab number per kilogram reached about 300 with survival rate of about 20%; the initial stocking density had significantly effect on the body size of E. sinensis on sel , instead on the survival rate of E. sinensis larvae. Therefore, it is feasible to conduct the culture of E. sinensis larvae in a pool in greenhouse.

  8. Dual RNA-seq of parasite and host reveals gene expression dynamics during filarial worm-mosquito interactions.

    Directory of Open Access Journals (Sweden)

    Young-Jun Choi

    2014-05-01

    Full Text Available BACKGROUND: Parasite biology, by its very nature, cannot be understood without integrating it with that of the host, nor can the host response be adequately explained without considering the activity of the parasite. However, due to experimental limitations, molecular studies of parasite-host systems have been predominantly one-sided investigations focusing on either of the partners involved. Here, we conducted a dual RNA-seq time course analysis of filarial worm parasite and host mosquito to better understand the parasite processes underlying development in and interaction with the host tissue, from the establishment of infection to the development of infective-stage larva. METHODOLOGY/PRINCIPAL FINDINGS: Using the Brugia malayi-Aedes aegypti system, we report parasite gene transcription dynamics, which exhibited a highly ordered developmental program consisting of a series of cyclical and state-transitioning temporal patterns. In addition, we contextualized these parasite data in relation to the concurrent dynamics of the host transcriptome. Comparative analyses using uninfected tissues and different host strains revealed the influence of parasite development on host gene transcription as well as the influence of the host environment on parasite gene transcription. We also critically evaluated the life-cycle transcriptome of B. malayi by comparing developmental stages in the mosquito relative to those in the mammalian host, providing insight into gene expression changes underpinning the mosquito-borne parasitic lifestyle of this heteroxenous parasite. CONCLUSIONS/SIGNIFICANCE: The data presented herein provide the research community with information to design wet lab experiments and select candidates for future study to more fully dissect the whole set of molecular interactions of both organisms in this mosquito-filarial worm symbiotic relationship. Furthermore, characterization of the transcriptional program over the complete life cycle of

  9. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: “The Worminator”

    Directory of Open Access Journals (Sweden)

    Bob Storey

    2014-12-01

    Full Text Available A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the “Worminator” system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application “WormAssay”, developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic parasites (e.g. Brugia malayi. We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3 of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the “Worminator” provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and

  10. In vitro and in vivo susceptibility of the honeybee bacterial pathogen Paenibacillus larvae subsp. larvae to the antibiotic tylosin.

    Science.gov (United States)

    Alippi, Adriana M; Albo, Graciela N; Reynaldi, Francisco J; De Giusti, Marisa R

    2005-08-10

    The minimal inhibitory concentrations (MICs) of tylosin were determined to 67 strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood (AFB) disease, from different geographical origins. MIC values obtained ranged from 0.0078 to 0.5 microg/ml. These very low values imply that no resistance to tylosin was found in any isolate of the Foulbrood pathogen. The measurement of diseased larvae with AFB-clinical symptoms in three different field studies demonstrated that tylosin treatment could be effective in vivo. No negative effects in colonies were noted at any dosage rates or forms of application. These studies demonstrate that tylosin, as tartrate, can be used to treat AFB in honeybee colonies.

  11. Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands

    Science.gov (United States)

    Wissinger, S.A.; Sparks, G.B.; Rouse, G.L.; Brown, W.S.; Steltzer, H.

    1996-01-01

    Comparative data from subalpine wetlands in Colorado indicate that larvae of the limnephilid caddisflies, Asynarchus nigriculus and Limnephilus externus, are reciprocally abundant among habitats - Limnephilus larvae dominate in permanent waters, whereas Asynarchus larvae dominate in temporary basins. The purpose of this paper is to report on field and laboratory experiments that link this pattern of abundance to biotic interactions among larvae. In the first field experiment, growth and survival were compared in single and mixed species treatments in littoral enclosures. Larvae, which eat mainly vascular plant detritus, grew at similar rates among treatments in both temporary and permanent habitats suggesting that exploitative competition is not important under natural food levels and caddisfly densities. However, the survival of Limnephilus larvae was reduced in the presence of Asynarchus larvae. Subsequent behavioral studies in laboratory arenas revealed that Asynarchus larvae are extremely aggressive predators on Limnephilus larvae. In a second field experiment we manipulated the relative sizes of larvae and found that Limnephilus larvae were preyed on only when Asynarchus larvae had the same size advantage observed in natural populations. Our data suggest that the dominance of Asynarchus larvae in temporary habitats is due to asymmetric intraguild predation (IGP) facilitated by a phenological head start in development. These data do not explain the dominance of Limnephilus larvae in permanent basins, which we show elsewhere to be an indirect effect of salamander predation. Behavioral observations also revealed that Asynarchus larvae are cannibalistic. In contrast to the IGP on Limnephilus larvae, Asynarchus cannibalism occurs among same-sized larvae and often involves the mobbing of one victim by several conspecifics. In a third field experiment, we found that Asynarchus cannibalism was not density-dependent and occurred even at low larval densities. We

  12. First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera Primeiro registro de larvas de Chironomidae como presas de Temnocephala sp. (Platyhelminthes, Temnocephalidae, um ectosimbionte de larvas de Corydalidae (Maegaloptera

    Directory of Open Access Journals (Sweden)

    Susana Trivinho-Strixino

    2012-09-01

    Full Text Available First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera. This study constitutes the first record of Temnocephala Blanchard, an ectosymbiont on Corydalidae, as a possible predator of chironomid larvae. Twenty-eight Corydalidae larvae (Corydalus and Protochauliodes were examined under stereomicroscopic in search for Temnocephala and Chironomidae larvae, of which five megalopteran larvae had 24 Temnocephala sp. associated. Furthermore, eight of these Temnocephala worms had chironomid larvae in their gut contents, an interaction previously unknown. Gut content analyses revealed Corynoneura as the commonest chironomid, but larvae of Larsia, Rheotanytarsus and Tanytarsus were recorded as well. This study included Corydalus and Protochauliodes as hosts for Temnocephala, which might be important for this worm dispersion and population dynamics.Primeiro registro de larvas de Chironomidae como presas de Temnocephala sp. (Platyhelminthes, Temnocephalidae, um ectosimbionte de larvas de Corydalidae (Maegaloptera. Este estudo constitui o primeiro registro de Temnocephala Blanchard (Platyhelminthes, Temnocephalidae, um ectosimbionte em larvas de Megaloptera, como um possível predador de larvas de Chironomidae. Vinte e oito larvas de Corydalidae (Corydalus e Protochauliodes foram examinadas sobre estereomicroscópio na busca por Temnocephala e larvas de Chironomidae, das quais cinco larvas de Megaloptera continham 24 Temnocephala sp. associadas. Além disso, oito Temnocephala possuíam em seu conteúdo estomacal larvas de Chironomidae, uma interação desconhecida anteriormente. A análise do conteúdo estomacal revelou Corynoneura como o quironomídeo mais abundante, e também algumas larvas de Larsia, Rheotanytarsus e Tanytarsus. Este estudo inclui Corydalus e Protochauliodes como hospedeiros de Temnocephala, os quais podem ser importantes

  13. The larvae of decapods and fishes of Amba estuary, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Devi, C.B.L.; Govindan, K.; Gajbhiye, S.N.; Nair, V.R.

    larvae to the total zooplankton population were 3.63 and 0.03 respectively. In the assessment of larval stocks environmental parameters and the presence of adult fish caught in the area were considered. The estuarine area supported fairly high fishery...

  14. Visceral larva migrans: migratory pattern of Toxocara canis in pigs

    DEFF Research Database (Denmark)

    Helwigh, Birgitte; Lind, Peter; Nansen, Peter

    1999-01-01

    recovered from the brain on days 14 and 21, with a maximum on day 14 p.i. No larvae were found in the eyes. Severe pathological changes were observed in the liver and lungs, especially on day 14 p.i.; also, development of granulomas was observed in the kidneys. Finally, a strong specific antibody response...

  15. Ingestion of microplastic has limited impact on a marine larva.

    Science.gov (United States)

    Kaposi, Katrina L; Mos, Benjamin; Kelaher, Brendan P; Dworjanyn, Symon A

    2014-01-01

    There is increasing concern about the impacts of microplastics (marine biota. Microplastics may be mistaken for food items and ingested by a wide variety of organisms. While the effects of ingesting microplastic have been explored for some adult organisms, there is poor understanding of the effects of microplastic ingestion on marine larvae. Here, we investigated the ingestion of polyethylene microspheres by larvae of the sea urchin, Tripneustes gratilla. Ingestion rates scaled with the concentration of microspheres. Ingestion rates were, however, reduced by biological fouling of microplastic and in the presence of phytoplankton food. T. gratilla larvae were able to egest microspheres from their stomach within hours of ingestion. A microsphere concentration far exceeding those recorded in the marine environment had a small nondose dependent effect on larval growth, but there was no significant effect on survival. In contrast, environmentally realistic concentrations appeared to have little effect. Overall, these results suggest that current levels of microplastic pollution in the oceans only pose a limited threat to T. gratilla and other marine invertebrate larvae, but further research is required on a broad range of species, trophic levels, and polymer types.

  16. Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.

    Science.gov (United States)

    Kim, Haein; Choi, Min Sung; Kang, KyeongJin; Kwon, Jae Young

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds.

  17. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai; S; Apiwathnasorn; C; Leemingsawat; S; Wongwit; W; Overgaard; HJ

    2011-01-01

    Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.

  18. Two alternating motor programs drive navigation in Drosophila larva.

    Science.gov (United States)

    Lahiri, Subhaneil; Shen, Konlin; Klein, Mason; Tang, Anji; Kane, Elizabeth; Gershow, Marc; Garrity, Paul; Samuel, Aravinthan D T

    2011-01-01

    When placed on a temperature gradient, a Drosophila larva navigates away from excessive cold or heat by regulating the size, frequency, and direction of reorientation maneuvers between successive periods of forward movement. Forward movement is driven by peristalsis waves that travel from tail to head. During each reorientation maneuver, the larva pauses and sweeps its head from side to side until it picks a new direction for forward movement. Here, we characterized the motor programs that underlie the initiation, execution, and completion of reorientation maneuvers by measuring body segment dynamics of freely moving larvae with fluorescent muscle fibers as they were exposed to temporal changes in temperature. We find that reorientation maneuvers are characterized by highly stereotyped spatiotemporal patterns of segment dynamics. Reorientation maneuvers are initiated with head sweeping movement driven by asymmetric contraction of a portion of anterior body segments. The larva attains a new direction for forward movement after head sweeping movement by using peristalsis waves that gradually push posterior body segments out of alignment with the tail (i.e., the previous direction of forward movement) into alignment with the head. Thus, reorientation maneuvers during thermotaxis are carried out by two alternating motor programs: (1) peristalsis for driving forward movement and (2) asymmetric contraction of anterior body segments for driving head sweeping movement.

  19. Electric shock-induced associative olfactory learning in Drosophila larvae.

    Science.gov (United States)

    Pauls, Dennis; Pfitzenmaier, Johanna E R; Krebs-Wheaton, Rebecca; Selcho, Mareike; Stocker, Reinhard F; Thum, Andreas S

    2010-05-01

    Associative plasticity is a basic essential attribute of nervous systems. As shown by numerous reports, Drosophila is able to establish simple forms of appetitive and aversive olfactory associations at both larval and adult stages. Whereas most adult studies on aversive learning employed electric shock as a negative reinforcer, larval paradigms essentially utilized gustatory stimuli to create negative associations, a discrepancy that limits the comparison of data. To overcome this drawback, we critically revisited larval odor-electric shock conditioning. First, we show that lithium chloride (LiCl), which was used in all previous larval electric shock paradigms, is not required per se in larval odor-electric shock learning. This is of considerable practical advantage because beside its peculiar effects LiCl is attractive to larvae at low concentration that renders comparative learning studies on genetically manipulated larvae complicated. Second, we confirm that in both a 2-odor reciprocal and a 1-odor nonreciprocal conditioning regimen, larvae are able to associate an odor with electric shock. In the latter experiments, initial learning scores reach an asymptote after 5 training trials, and aversive memory is still detectable after 60 min. Our experiments provide a comprehensive basis for future comparisons of larval olfactory conditioning reinforced by different modalities, for studies aimed at analyzing odor-electric shock learning in the larva and the adult, and for investigations of the cellular and molecular substrate of aversive olfactory learning in the simple Drosophila model.

  20. Cryopreservation of Greenshell™ mussel (Perna canaliculus) trochophore larvae.

    Science.gov (United States)

    Paredes, E; Adams, S L; Tervit, H R; Smith, J F; McGowan, L T; Gale, S L; Morrish, J R; Watts, E

    2012-12-01

    The Greenshell™ mussel (Perna canaliculus) is the main shellfish species farmed in New Zealand. The aim of this study was to evaluate the effects of cryoprotectant concentration, loading and unloading strategy as well as freezing and thawing method in order to develop a protocol for cryopreservation of trochophore larvae (16-20 h old). Toxicity tests showed that levels of 10-15% ethylene glycol (EG) were not toxic to larvae and could be loaded and unloaded in a single step. Through cryopreservation experiments, we designed a cryopreservation protocol that enabled 40-60% of trochophores to develop to D-larvae when normalized to controls. The protocol involved: holding at 0 °C for 5 min, then cooling at 1 °C min⁻¹ to -10 °C, holding for a further 5 min, then cooling at 0.5 °C min⁻¹ to -35 °C followed by a 5 min hold and then plunging into liquid nitrogen. A final larval rearing experiment of 18 days was conducted to assess the ability of these frozen larvae to develop further. Results showed that only 2.8% of the frozen trochophores were able to develop to competent pediveligers.

  1. Enantiomerization and enantioselective bioaccumulation of metalaxyl in Tenebrio molitor larvae.

    Science.gov (United States)

    Gao, Yongxin; Wang, Huili; Qin, Fang; Xu, Peng; Lv, Xiaotian; Li, Jianzhong; Guo, Baoyuan

    2014-02-01

    The enantiomerization and enantioselective bioaccumulation of metalaxyl by a single dose of exposure to Tenebrio molitor larvae under laboratory condition were studied by high-performance liquid chromatography tandem mass spectroscopy (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. Exposure of enantiopure R-metalaxyl and S-metalaxyl in Tenebrio molitor larvae exhibited significant enantiomerization, with formation of the R enantiomers from the S enantiomers, and vice versa, which might be attributed to the chiral pesticide catalyzed by a certain enzyme in Tenebrio molitor larvae. Enantiomerization was not observed in wheat bran during the period of 21 d. In addition, bioaccumulation of rac-metalaxyl in Tenebrio molitor larvae was enantioselective with a preferential accumulation of S-metalaxyl. These results showed that enantioselectivity was caused not only by actual degradation and metabolism but also by enantiomerization, which was an important process in the environmental fate and behavior of metalaxyl enantiomers.

  2. [Effect of wound to growth of larva of host to Ophiocordyceps sinensis during artificial breeding].

    Science.gov (United States)

    Liu, Fei; Zhang, De-li; Zeng, Wei; Li, Li; Luo, Qing-ming; Tu, Yong-qin; Chen, Shi-jiang; Yin, Ding-hua

    2015-01-01

    To clear the effect of the wound to the growth of the larva of the host to the Ophiocordyceps sinensis, the wounds of same severity at the same position were made artificially to the larva and which were artificial fed at the same environment and condition. The results indicated that, over the winter, the survival rate of the wounded of the infection larva was lower than that of the healthy larva, but the weight had no significant difference between the wounded and the healthy larva. The survival rate of the wounded of the no infection larva was lower than that of the healthy larva, but except with black skin, the wounded larva with offwhite and dusty red had no influence on the variety of the weight. In summery, wound had no advantage to the survival rate, but had no influence to the weight. The result had provided theoretical basis to the reforming of the system of the artificial culture O. sinensis.

  3. The method by which Cephenemyia trompe (Modeer larvae invade reindeer (Rangifer tarandus

    Directory of Open Access Journals (Sweden)

    John R. Anderson

    1990-09-01

    Full Text Available Laboratory electrostimulated C. trompe (Modeer females forcefully expelled (sprayed larvae for 5-20 cm. The watery spray consisted of about 20 tiny droplets containing two to several larvae. Crawling first-instar larvae exhibited negative geotactic and phototropic responses; they were subject to rapid desiccation and became immobile as the tiny droplets dried within a few seconds. When 5-50 larvae from dissectedfemales were dropped in physiological saline onto different areas of the muzzle of restrained reindeer, only larvae placed deep within the nostrils and on the lips crawled out-of-sight down the nostril passage or into the mouth. Drops of larvae placed elsewhere quickly desiccated and the larvae became immobile. Larvae deposited by wild females onto a COz-baited reindeer model with the muzzle, lips and nostrils coated with insect trapping adhesive all were stuck only along the dorsal lip below the philtrum. All experimental evidence supports a natural per os mode of invasion.

  4. Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

    NARCIS (Netherlands)

    Bukhari, S.T.; Takken, W.; Koenraadt, C.J.M.

    2011-01-01

    Background The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana have demonstrated effectiveness against anopheline larvae in the laboratory. However, utilising these fungi for the control of anopheline larvae under field conditions, relies on development of effective means of app

  5. Effects of gamma-irradiation on the infective larvae of Bunostomum trigonocephalum (Rud. , 1808) in lambs

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.K.; Singh, K.S. (Indian Veterinary Research Inst., Izatnagar. Div. of Parasitology)

    1985-03-01

    Infective larvae of Bunostomum trigonocephalum exposed to gamma-irradiation at 60 kr failed to develop in the lamb. At levels of 20 and 40 kr, the infectivity of the larvae was reduced and fewer worms developed with a predominating female population. The worms developing from the irradiated larvae were smaller and the sex organs were ill developed. The females developing from larvae irradiated at 40 kr were functionally sterile with atrophied uterus devoid of eggs.

  6. Larvicidal efficacy of monoterpenes against the larvae of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Eliningaya J.Kweka; Tamires Cardoso Lima; Chrian M.Marciale; Dami?o Pergentino de Sousa

    2016-01-01

    Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both laboratory and semi-field trials.Stock solution was prepared and serial dilutions were made in six concentrations for each compound.A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12,24,48 and 72 h.Larvae monitoring was done on basis of dead and live larvae in all intervals.Results:All assayed compounds were larvicides and presented varying degrees of larval toxicity,with LC50 values ranging from 1.28 to 1 938.92 mg/L depending on the treatment time(12,24,48 or 72 h).(-)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae,with LC50 values of 73.60,18.36,1.72 and1.28 mg/L after 12,24,48 and 72 h of exposure,respectively.The next strongest were(-)-isopulegol(LC50= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC50= 168.86,124.74,80.84 and 23.46 mg/L).After 12,24 and 48 h of treatment,hydroxydihydrocarvone was the least toxic compound,with LC50 values of 1 938.92,1 172.18 and 401.03 mg/L,respectively.Conclusions:The data obtained in this study suggest that all evaluated monoterpenes,especially(-)-perillyl alcohol,have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs.Further small-scale field trials should be conducted.

  7. Developmental Toxicity of Dextromethorphan in Zebrafish Embryos/Larvae

    Science.gov (United States)

    Xu, Zheng; Williams, Frederick E.; Liu, Ming-Cheh

    2012-01-01

    Dextromethorphan is widely used in over-the-counter cough and cold medications. Its efficacy and safety for infants and young children remains to be clarified. The present study was designed to use the zebrafish as a model to investigate the potential toxicity of dextromethorphan during the embryonic and larval development. Three sets of zebrafish embryos/larvae were exposed to dextromethorphan at 24 hours post fertilization (hpf), 48 hpf, and 72 hpf, respectively, during the embryonic/larval development. Compared with the 48 and 72 hpf exposure sets, the embryos/larvae in the 24 hpf exposure set showed much higher mortality rates which increased in a dose-dependent manner. Bradycardia and reduced blood flow were observed for the embryos/larvae treated with increasing concentrations of dextromethorphan. Morphological effects of dextromethorphan exposure, including yolk sac and cardiac edema, craniofacial malformation, lordosis, non-inflated swim bladder, and missing gill, were also more frequent and severe among zebrafish embryos/larvae exposed to dextromethorphan at 24 hpf. Whether the more frequent and severe developmental toxicity of dextromethorphan observed among the embryos/larvae in the 24 hpf exposure set, as compared with the 48 and 72 hpf exposure sets, is due to the developmental expression of the Phase I and Phase II enzymes involved in the metabolism of dextromethorphan remains to be clarified. A reverse transcription-polymerase chain reaction (RT-PCR) analysis, nevertheless, revealed developmental stage-dependent expression of mRNAs encoding SULT3 ST1 and SULT3 ST3, two enzymes previously shown to be capable of sulfating dextrorphan, an active metabolite of dextromethorphan. PMID:20737414

  8. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Science.gov (United States)

    Waldbusser, George G; Hales, Burke; Langdon, Chris J; Haley, Brian A; Schrader, Paul; Brunner, Elizabeth L; Gray, Matthew W; Miller, Cale A; Gimenez, Iria; Hutchinson, Greg

    2015-01-01

    Ocean acidification (OA) is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

  9. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Directory of Open Access Journals (Sweden)

    George G Waldbusser

    Full Text Available Ocean acidification (OA is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4 with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material

  10. Nutrition and related ontogenetic aspects in larvae of the African catfish Clarias gariepinus.

    NARCIS (Netherlands)

    Verreth, J.

    1994-01-01

    The absence of adequate techniques for rearing fish larvae constitutes a bottleneck for sustainable aquacultural growth. Important constraints are the tiny size of the larvae, the dependance on live food organisms and the developmental stage of the fish larvae. The development of dependable rearing

  11. Predaceous diving beetle, Dytiscus sharpi sharpi (Coleoptera: Dytiscidae) larvae avoid cannibalism by recognizing prey.

    Science.gov (United States)

    Inoda, Toshio

    2012-09-01

    Larvae of diving beetles such as the various Dytiscus species (Coleoptera: Dytiscidae) are carnivorous and usually prey on other aquatic animals. Cannibalism among larvae of Dytiscus sharpi sharpi (Wehncke) was observed to begin when they were starved for more than two days under artificial breeding conditions. However, the 2-day starved larvae did not show cannibalism in the presence of intact, motionless, frozen tadpoles, or frozen shrimps. The beetle larvae attacked and captured intact tadpoles faster (15 sec) than other motionless and frozen tadpoles (120 sec), indicating that prey movement was an important factor in stimulating feeding behavior in larvae. Prey density does not have an effect on larval cannibalism. In cases in which preys are present at lower densities than that of larvae, a group of beetle larvae frequently fed on single prey. This feeding behavior, therefore, provides direct evidence of self-other recognition at the species level. Using two traps in one aquarium that allows the larvae to detect only prey smell, one containing tadpoles and another empty, the beetle larvae were attracted to the trap with tadpoles at high frequency, but not to the empty trap. In another experiment, the beetle larvae were not attracted to the trap containing a beetle larva. These results suggest that the larvae of D. sharpi sharpi are capable of recognizing prey scent, which enables the promotion of foraging behavior and the prevention of cannibalism.

  12. In vitro and in vivo susceptibility of the honey bee bacterial pathogen Paenibacillus larvae subsp larvae to the antibiotic tylosin

    OpenAIRE

    2005-01-01

    The minimal inhibitory concentrations (MICs) of tylosin were determined to 67 strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood (AFB) disease, from different geographical origins. MIC values obtained ranged from 0.0078 to 0.5 microg/ml. These very low values imply that no resistance to tylosin was found in any isolate of the Foulbrood pathogen. The measurement of diseased larvae with AFB-clinical symptoms in three different field studies demonstrated that t...

  13. Evaluation of immune response elicited by inulin as an adjuvant with filarial antigens in mice model.

    Science.gov (United States)

    Mahalakshmi, N; Aparnaa, R; Kaliraj, P

    2014-10-01

    Filariasis caused by infectious parasitic nematodes has been identified as the second leading source of permanent and long-term disability in Sub-Saharan Africa, Asia and Latin America. Several vaccine candidates were identified from infective third-stage larvae (L3) which involves in the critical transition from arthropod to human. Hitherto studies of these antigens in combination with alum adjuvant have shown to elicit its characteristic Th2 responses. Inulin is a safe, non-toxic adjuvant that principally stimulates the innate immune response through the alternative complement pathway. In the present study, the immune response elicited by inulin and alum as adjuvants were compared with filarial antigens from different aetiological agents: secreted larval acidic protein 1 (SLAP1) from Onchocerca volvulus and venom allergen homologue (VAH) from Brugia malayi as single or as cocktail vaccines in mice model. The study revealed that inulin can induce better humoral response against these antigens than alum adjuvant. Antibody isotyping disclosed inulin's ability to elevate the levels of IgG2a and IgG3 antibodies which mediates in complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC), respectively, in mice. Splenocyte analysis showed that T cells prestimulated with inulin have higher stimulation index (P inulin formulation had induced higher cytotoxicity with filarial antigens (as single P inulin to deplete the levels of Treg and brought a balance in Th1/Th2 arms against filarial antigens in mice.

  14. [Scanning microscopical observations on the foregut structures o mosquitoes and their role for the ingestion of microfilariae (author's transl)].

    Science.gov (United States)

    Buse, E; Kuhlow, F

    1979-12-01

    Experiments on the transmission of Brugia malayi by various mosquitoes had shown that microfilariae ingested by some species were badly damaged when they reached the stomach, but were much less hurt in others. The structures of the foregut likely to cause these injuries, were investigated and documented by scanning microscope techniques. In Anopheles albimanus, A. arabiensis, A. stephensi and A. pharoensis which have well developed armatures the microfilariae showed a high rate of destruction. In A. stroparvus as well as in Aedes aegypti, Ae. togoi and Culex fatigans in which these structures are missing or poorly developed the larvae were much less affected. From the size, shape and position of the different papillae, spines, rods and cones observed it can be concluded and confirmed that the pharyngeal armature (buccopharyngeal bar) will be by far the most important structure responsible for the injuries of the microfilariae. However, it appears that the characteristics of different filaria species can play an important role in preventing such damages.

  15. MENGENAL PARASIT FILARIA

    Directory of Open Access Journals (Sweden)

    Tri Ramadhani

    2012-11-01

    Full Text Available Filariasis atau kaki gajah adalah penyakit menular yang disebabkan karena infeksi cacing filaria yang hidup disaluran dan kelenjar getah bening (limfe serta menyebabkan gejala akut, kronis. Filariasis mulai dikenal di Indonesia tahun 1889 sejak Haga dan Van Eecke menemukan kasus pembesaran scrotum di Jakarta. Penyakit tersebut dapat menular kepada orang lain dengan perantara gigitan nyamuk. Seluruh wilayah Indonesia berpotensi untuk terjangkitnya penyakit tersebut, hal ini mengingat cacing sebagai penyebabnya dan nyamuk penularnya tersebar luas. Keadaan ini didukung oleh kerusakan lingkungan, seperti banjir, penebangan hutan dan lainnya yang memperluas tempat berkembangbiaknya nyamuk. Meskipun filariasis tidak mematikan secara langsung, dengan adanya demam dan bisul-bisul (abses yang hilang timbul, dan gejala menahun berupa pembesaran/elefantiasis yang merupakan cacat menetap akan sangat mengganggu. Secara ekonomis keadaan tersebut sangat merugikan, karena mengurangi produktivitas masyarakat, serta diperlukan biaya pengobatan dan perawatan yang tidak mudah dan tidak murah.Di Indonesia filariasis limfatik di sebabkan oleh tiga spesies cacing filaria yaitu Brugia malayi,B.timori dan Wuchereria bancrofti, yang terbagi lagi menjadi 6 tipe secara epidemiologi.Tiap parasit mempunyai siklus hidup yang kompleks dan infeksi pada manusia tidak akan berhasil kecuali jika terjadi pemaparan larva infektif untuk waktu yang lama. Setelah terjadi pemaparan, dibutuhkan waktu bertahun-tahun sebelum timbulnya perubahan patologis yang nyata pada manusia. Periodisitas dalam sirkulasi setiap mikrofilaria akan berbeda, tergantung dari spesiesnya.

  16. Índices parasitarios en larvas, post larvas y alevinos de Piaractus brachypomus “paco” en relación a los factores ambientales

    OpenAIRE

    Narda Dinis-Vásquez; Manuel Soplín-Bosmediano; Emer Pizango-Paima; Fred Chu-Koo; Lorgio Verdi-Olivares

    2014-01-01

    La presente investigación tuvo como finalidad determinar la relación que existe entre los índices parasitarios en larvas, post larvas y alevinos de Piaractus brachypomus "paco" y las variaciones de los factores ambientales en el Centro de Investigaciones Fernando Alcántara del Instituto de Investigaciones de la Amazonía Peruana (Iquitos, Perú). Fueron analizados un total de 180 individuos, repartidos en 60 larvas y 60 post larvas colectados de tanques de concreto de 1,05 m2 con una profundida...

  17. Agathomerus (Agathomeroides flavomaculatus (Coleoptera, Megalopodidae, Megalopodinae: morfologia da larva e do adulto Agathomerus (Agathomeroides flavomaculatus (Coleoptera, Megalopodidae, Megalopodinae: larva and adult morphology

    Directory of Open Access Journals (Sweden)

    Elisa B. Carvalho

    Full Text Available A larva de Agathomerus (Agathomeroides flavomaculatus (Klug, 1824, coletada em Capsicum baccatum L. (Solanaceae, é descrita e ilustrada. A redescrição do adulto inclui caracteres das peças bucais, venação da asa, endosternitos e terminálias masculina e feminina. Pela primeira vez uma larva da subfamília Megalopodinae é descrita.The larva of Agathomerus (Agathomeroides flavomaculatus (Klug, 1824, collected in Capsicum baccatum L. (Solanaceae, is described and illustrated. The adult redescription includes characters of mouthparts, wing venation, endosternites and male and female terminalia. For the first time a larva of subfamily Megalopodinae is described.

  18. MOLECULAR IDENTIFICATION OF Pseudoterranova azarasi LARVAE IN COD (Gadus sp.) SOLD FOR HUMAN CONSUMPTION IN BRAZIL.

    Science.gov (United States)

    Marigo, Juliana; Taniwaki, Sueli Akemi; Pinto, Pedro Luiz Silva; Soares, Rodrigo Martins; Catão-Dias, José Luiz

    2015-12-01

    Anisakiasis and Pseudoterranovosis are human diseases caused by the ingestion of live Anisakidae larvae in raw, undercooked or lightly marinated fish. Larvae were collected from one salted cod sold for human consumption in a Sao Paulo market in 2013. One section of one brownish larva was used for molecular analyses. The partial COX2 gene sequence from the larva had a nucleotide identity of 99.8 % with Pseudoterranova azarasi, which belongs to the Pseudoterranova decipiens species complex. The risk of allergy when consuming dead larvae in salted fish is not well known and should be considered.

  19. Description of the larva of Gynacantha millardi Selys, 1891 (Odonata: Aeshnidae) from Chhattisgarh, India.

    Science.gov (United States)

    Dawn, Prosenjit; Chandra, Kailash

    2016-06-29

    The larva of Gynacantha millardi Selys is described here from female larvae and male and female exuviae collected from Chhattisgarh, India. Unlike other Gynacantha larvae known so far, G. millardi has 7 palpal setae almost equal in length; in other species, the palpal setae are of different lengths. The larvae lack a tooth on each side of the median cleft and have a distinct blunt tooth on the inner margin corner of each labial palp. The larvae were found in a semi-stagnant forest pool with enormous growth of aquatic vegetation.

  20. Infestation of a bird and two cats by larvae of Plodia interpunctella (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Pinckney, R D; Kanton, K; Foster, C N; Steinberg, H; Pellitteri, P

    2001-09-01

    The larvae of Plodia interpunctella (Hübner), commonly known as the Indian meal moth, often cause enormous losses in stored food supplies. We present three clinical case reports of accidental infestation by P. interpunctella larvae in two domestic cats and one parakeet. A larva gained entry into the avian host and subsequently migrated to the brain. It was alive, covered with "silk-like" fibers and confirmed to be a fourth instar. Plodia interpunctella larvae were excised with forceps from the subcutaneous tissues of the ear and neck of two cats in a different household. Previous reports of infestation by P. interpunctella larvae in vertebrates are unknown.

  1. Reduction of muscle larvae burden in rats experimentally infected with Trichinella spiralis

    Directory of Open Access Journals (Sweden)

    Machnicka-Rowinska B.

    2001-06-01

    Full Text Available In Wistar rats infected with 500 to 2,500 Trichinella spiralis larvae the muscle larvae intensity (larvae per gram-l.p.g. was measured from 20 to 180 day post infection (d.p.i. The l.p.g. increased to day 40-50 p.i. and decreased thereafter. The highest reduction took place between 6 0 and 120 d.p.i. with intermediate inoculum of T. spiralis larvae. The mechanism of the reduction of T. spiralis larvae in muscles is suggested to depend on pericapsular-intercapsular host cells infiltrations attracted by parasite antigens.

  2. ASPEK ZOONOTIK PARASIT NEMATODA PADA KERA DAN BINATANG MENGERAT DI BENGKULU, SUMATERA. INDONESIA

    Directory of Open Access Journals (Sweden)

    Untung S.

    2012-09-01

    Full Text Available Twentyfive monkeys and 481 rats were examined for parasitic nematodes in Bengkulu, nine species of nematode were found infecting these animals. Five of filarían nematodes, i.e. Brugia malayi, Brugia pahangi, Dirofilaria magnilarvatum and Edesonfilaria malayensis were infecting monkeys and one speciesTBreinlia booliati, was found infecting rats. Three species of gastrointestinal helminths, i.e. Trichuris trichiura, Enterobius vermicularis and Oestophagomomum spp were found in monkeys; a lung worm, Angiostrongylus cantonensis, was found in rats. The most important nematode species is B. malayi, which was found in Presbytis cristatus (36.8 % and in Macaca fascicularis (20.0 %. T. trichiura was found in R. cristatus (47.9 % and A. cantonensis in Rattus argentiventer (4.0 % and Rattus tiomanicus (2.9%.

  3. EFFICACY OF THAI NEEM OIL AGAINST AEDES AEGYPTI (L.) LARVAE.

    Science.gov (United States)

    Silapanuntakul, Suthep; Keanjoom, Romnalin; Pandii, Wongdyan; Boonchuen, Supawadee; Sombatsiri, Kwanchai

    2016-05-01

    Trees with larvicidal activity may be found in Thailand. We conducted this study to evaluate the efficacy and length of efficacy of Thai neem (Azadirachta siamensis) oil emulsion and an alginate bead of Thai neem oil formulation against early fourth stage Aedes aegypti larvae using a dipping test. The Thai neem oil emulsion had significantly greater larvicidal activity than the alginate bead formulation at 12 to 60 hours post-exposure (p neem oil formulation resulted in 100% mortality among the early fourth stage Aedes aegypti larvae at 48 hours, while the alginate bead formulation resulted in 98% larval mortality at 84 hours and 100% mortality at 96 hours. The mean larval mortality using the Thai neem oil emulsion dropped to < 25% by 12 days and with the alginate beads dropped to < 25% by 15 days of exposure.

  4. The larva of Athripsodes genei (Rambur 1842) (Trichoptera, Leptoceridae).

    Science.gov (United States)

    Waringer, Johann; Graf, Wolfram

    2014-09-29

    This paper describes the previously unknown larva of Athripsodes genei (Rambur 1842). Information on the morphology of the 5th larval instar is given and the most important diagnostic features are illustrated. In the context of existing identification keys the larva of A. genei keys together with A. albifrons (Linnaeus 1758), A. commutatus (Rostock 1874), A. leucophaeus (Rambur 1842) and Athripsodes tavaresi (Navás 1916). These species differ in the number of ventral edge setae at the 1st tibia and in the shape and colour of the submentum. With respect to zoogeography, Athripsodes genei is a (micro-)endemic of the collin and planar regions of Sardinia and Corsica (Graf et al. 2008). According to mandible morphology, A. genei is a collector-gatherer, shredder and, to a minor extent, also a predator.

  5. Extreme adaptations for aquatic ectoparasitism in a Jurassic fly larva.

    Science.gov (United States)

    Chen, Jun; Wang, Bo; Engel, Michael S; Wappler, Torsten; Jarzembowski, Edmund A; Zhang, Haichun; Wang, Xiaoli; Zheng, Xiaoting; Rust, Jes

    2014-06-24

    The reconstruction of ancient insect ectoparasitism is challenging, mostly because of the extreme scarcity of fossils with obvious ectoparasitic features such as sucking-piercing mouthparts and specialized attachment organs. Here we describe a bizarre fly larva (Diptera), Qiyia jurassica gen. et sp. nov., from the Jurassic of China, that represents a stem group of the tabanomorph family Athericidae. Q. jurassica exhibits adaptations to an aquatic habitat. More importantly, it preserves an unusual combination of features including a thoracic sucker with six radial ridges, unique in insects, piercing-sucking mouthparts for fluid feeding, and crocheted ventral prolegs with upward directed bristles for anchoring and movement while submerged. We demonstrate that Q. jurassica was an aquatic ectoparasitic insect, probably feeding on the blood of salamanders. The finding reveals an extreme morphological specialization of fly larvae, and broadens our understanding of the diversity of ectoparasitism in Mesozoic insects.DOI: http://dx.doi.org/10.7554/eLife.02844.001.

  6. EVALUASI PRODUKSI LARVA BEBERAPA VARIETAS INDUK IKAN NILA UNGGUL

    Directory of Open Access Journals (Sweden)

    Estu Nugroho

    2013-12-01

    Full Text Available Berbagai varietas induk ikan nila unggul telah dihasilkan oleh anggota Jejaring Pemuliaan Ikan di antaranya adalah Nirwana, BEST, Selfam (Selabintana, dan Central Pertiwi (CP. Kualitas dari benih yang dihasilkan telah menunjukkan tren yang positif dalam pertumbuhan. Peningkatan kualitas ini perlu diimbangi dengan jumlah larva yang dihasilkan sehingga perpaduan antara keduanya dapat menaikkan efisiensi produksi yang merupakan salah satu pilar dalam prinsip “blue economy” yang sekarang sedang dikembangkan oleh Kementerian Kelautan dan Perikanan. Evaluasi dilakukan untuk melengkapi informasi tentang ikan nila unggul yang telah dihasilkan. Pasangan NC (jantan Nirwana x betina CP dan NN (jantan Nirwana dan betina Nirwana menghasilkan jumlah larva yang paling banyak yaitu 132 ribu dan 104,467 ekor.

  7. VISCERAL LARVA MIGRANS AND TROPICAL PYOMYOSITIS: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Roberto LAMBERTUCCI

    1998-11-01

    Full Text Available We report a case of tropical pyomyositis in a boy who presented with a severe febrile illness associated with diffuse erythema, and swelling in many areas of the body which revealed on operation extensive necrotic areas of various muscles that required repeated débridement. The patient gave a history of contact with dogs, and an ELISA test for Toxocara canis was positive. He also presented eosinophilia and high serum IgE levels. Staphylococcus aureus was the sole bacteria isolated from the muscles affected. We suggest that tropical pyomyositis may be caused by the presence of migrating larvae of this or other parasites in the muscles. The immunologic and structural alterations caused by the larvae, in the presence of concomitant bacteremia, would favour seeding of the bacteria and the development of pyomyositis.

  8. Larva currens in a case of Organophosphorous poisoning

    Directory of Open Access Journals (Sweden)

    Rao D

    2006-01-01

    Full Text Available A 20-year-old healthy farmer consumed organophosphorous poison. On third day he developed diarrhoea and on fourth day linear serpiginous ulcers appeared on both buttocks. Clinically lesions were considered as decubitus ulcers. By stool examination and other laboratory investigations it was diagnosed as cutaneous larva currens due to S trongyloides stercoralis in a case of organophosphorus poisoning. Patient responded very well to a course of albendazole.

  9. Granulomatous colitis associated with small strongyle larvae in a horse.

    Science.gov (United States)

    Jasko, D J; Roth, L

    1984-09-01

    Horses presented with chronic weight loss are difficult to manage clinically. A diagnosis of granulomatous colitis due to mucosal stages of cyathostomes (small strongyles) should be considered in those cases exhibiting weight loss, intermittent diarrhea, hypoalbuminemia, increased serum globulins, and low fecal egg counts. Treatment can be attempted with larva-cidal doses of fenbendazole or ivermectin. Clinical and necropsy findings in one such case are presented.

  10. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Sukant Khurana; Mohammed Bin AbuBaker; Obaid Siddiqi

    2009-10-01

    Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of aversive conditioning and a procedure for decomposing learning retention curve that enables us to do a quantitative analysis of memory phases, short term (STM), middle term (MTM) and long term (LTM) as a function of training cycles. The same method of analysis when applied to learning mutants dunce, amnesiac, rutabaga and radish reveals memory deficits characteristic of the mutant strains.

  11. Homeotic gene function in the muscles of Drosophila larvae

    OpenAIRE

    Hooper, Joan E.

    1986-01-01

    The segmental musculature of Drosophila melanogaster larvae consists of 24-30 muscles per segment. Unique patterns of muscles are found in the three thoracic segments and the first and last abdominal segments; the remaining abdominal segments share the same pattern. Mutations in Ultrabithorax (Ubx) cause partial transformation of the muscle pattern of larval abdominal segments towards metathorax. The muscles of the thorax are not affected. In the first two abdominal segments the changes inclu...

  12. Morphological development of larvae and juveniles of Prochilodus argenteus

    Directory of Open Access Journals (Sweden)

    Irũ Menezes Guimarães

    Full Text Available ABSTRACT: Prochilodus argenteus is an endemic fish species from the São Francisco River basin that is of high economic and environmental importance. The present study aimed to contribute with information to the taxonomic identification of larvae and juveniles of this species. Larvae , obtained from induced spawning of wild animals, were reared in ponds. Individuals were collected daily and classified into larval stages or juvenile phase. Morphological descriptions and morphometric measurements were performed, together with a piece wise linear regression analysis of the body proportions throughout the development process. Individuals in the preflexion stage had a standard length (SL of 4.48 to 6.64mm, long to moderate body (BH/SL, small to moderate head (HL/SL, and a small to moderate eye (ED/HL. In the flexion stage, the SL varied from 6.60 to 11.00mm, long to moderate body, moderate head, and small to moderate eye. Larvae in the postflexion stage presented SL of 10.54-19.93mm, moderate body, moderate to big head and small eye. The juvenile phase included specimens with a SL of 18.27 to 42.21mm which presented a moderate to high body, big head and small to moderate eye. Regression analysis showed significant moments of change in rate of increase of the body proportions, presenting a change in the growth pattern from allometry to isometry during the early development.

  13. Candidate ionotropic taste receptors in the Drosophila larva.

    Science.gov (United States)

    Stewart, Shannon; Koh, Tong-Wey; Ghosh, Arpan C; Carlson, John R

    2015-04-07

    We examine in Drosophila a group of ∼35 ionotropic receptors (IRs), the IR20a clade, about which remarkably little is known. Of 28 genes analyzed, GAL4 drivers representing 11 showed expression in the larva. Eight drivers labeled neurons of the pharynx, a taste organ, and three labeled neurons of the body wall that may be chemosensory. Expression was not observed in neurons of one taste organ, the terminal organ, although these neurons express many drivers of the Gr (Gustatory receptor) family. For most drivers of the IR20a clade, we observed expression in a single pair of cells in the animal, with limited coexpression, and only a fraction of pharyngeal neurons are labeled. The organization of IR20a clade expression thus appears different from the organization of the Gr family or the Odor receptor (Or) family in the larva. A remarkable feature of the larval pharynx is that some of its organs are incorporated into the adult pharynx, and several drivers of this clade are expressed in the pharynx of both larvae and adults. Different IR drivers show different developmental dynamics across the larval stages, either increasing or decreasing. Among neurons expressing drivers in the pharynx, two projection patterns can be distinguished in the CNS. Neurons exhibiting these two kinds of projection patterns may activate different circuits, possibly signaling the presence of cues with different valence. Taken together, the simplest interpretation of our results is that the IR20a clade encodes a class of larval taste receptors.

  14. Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

    Science.gov (United States)

    Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

    2016-01-01

    Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

  15. Toxic dinoflagellates and Vibrio spp. act independently in bivalve larvae.

    Science.gov (United States)

    De Rijcke, M; Van Acker, E; Nevejan, N; De Schamphelaere, K A C; Janssen, C R

    2016-10-01

    Harmful algal blooms (HABs) and marine pathogens - like Vibrio spp. - are increasingly common due to climate change. These stressors affect the growth, viability and development of bivalve larvae. Little is known, however, about the potential for interactions between these two concurrent stressors. While some mixed exposures have been performed with adult bivalves, no such work has been done with larvae which are generally more sensitive. This study examines whether dinoflagellates and bacteria may interactively affect the viability and immunological resilience of blue mussel Mytilus edulis larvae. Embryos were exposed to environmentally relevant concentrations (100, 500, 2500 & 12,500 cells ml(-1)) of a dinoflagellate (Alexandrium minutum, Alexandrium ostenfeldii, Karenia mikimotoi, Protoceratium reticulatum, Prorocentrum cordatum, P. lima or P. micans), a known pathogen (Vibrio coralliilyticus/neptunius-like isolate or Vibrio splendidus; 10(5) CFU ml(-1)), or both. After five days of exposure, significant (p larval viability and larval development were found for all dinoflagellates (except P. cordatum) and V. splendidus. Yet, despite the individual effect of each stressor, no significant interactions were found between the pathogens and harmful algae. The larval viability and the phenoloxidase innate immune system responded independently to each stressor. This independence may be related to a differential timing of the effects of HABs and pathogens.

  16. Probiotic legacy effects on gut microbial assembly in tilapia larvae

    Science.gov (United States)

    Giatsis, Christos; Sipkema, Detmer; Ramiro-Garcia, Javier; Bacanu, Gianina M.; Abernathy, Jason; Verreth, Johan; Smidt, Hauke; Verdegem, Marc

    2016-01-01

    The exposure of fish to environmental free-living microbes and its effect on early colonization in the gut have been studied in recent years. However, little is known regarding how the host and environment interact to shape gut communities during early life. Here, we tested whether the early microbial exposure of tilapia larvae affects the gut microbiota at later life stages. The experimental period was divided into three stages: axenic, probiotic and active suspension. Axenic tilapia larvae were reared either under conventional conditions (active suspension systems) or exposed to a single strain probiotic (Bacillus subtilis) added to the water. Microbial characterization by Illumina HiSeq sequencing of 16S rRNA gene amplicons showed the presence of B. subtilis in the gut during the seven days of probiotic application. Although B. subtilis was no longer detected in the guts of fish exposed to the probiotic after day 7, gut microbiota of the exposed tilapia larvae remained significantly different from that of the control treatment. Compared with the control, fish gut microbiota under probiotic treatment was less affected by spatial differences resulting from tank replication, suggesting that the early probiotic contact contributed to the subsequent observation of low inter-individual variation. PMID:27670882

  17. DINAMIKA LARVA IKAN SEBAGAI DASAR OPSI PENGELOLAAN SUMBER DAYA IKAN DI LAGUNA PULAU PARI KEPULAUAN SERIBU

    Directory of Open Access Journals (Sweden)

    Reny Puspasari

    2013-05-01

    Full Text Available Proses rekruitmen populasi ikan sangat ditentukan oleh kelangsungan hidup larva ikan yang ada di daerah pemijahan/asuhan. Laguna Pulau Pari merupakan daerah pemjahan bagi banyak jenis larva ikan karang. Tujuan dari penelitian ini adalah untuk mengkaji dinamika kelimpahan dan komposisi dari larva ikan di laguna Pulau Pari. Hasil penelitian menunjukkan bahwa kelimpahan larva ikan yang ditemukan berkisar antara 1,0 x103 – 14,7 x 103 individu/m3. Puncak kelimpahan tertinggi terjadi pada bulan Juli dan Oktober. Larva ikan ditemukan tersebar di semua lokasi pengamatan. Larva pada fase perkembangan pre flexion ditemukan dalam presentase yang paling tinggi. Selama masa pengamatan ditemukan 79 famili larva ikan yang didominasi oleh Pomacentridae, Aulostomidae, Blenniidae, Engraulidae dan Pinguipedidae. Dinamika yang terjadi pada larva ikan dapat dijadikan dasar bagi pengelolaan perikanan di wilayah Laguna Pulau Pari dengan cara memperluas daerah perlindungan laut dan rehabilitasi ekosistem Laguna Pulau Pari, sehingga peran dan fungsinya sebagai pemasok rekrut bagi stok ikan di perairan sekitarnya terjaga.   Fish Recruitment is, in turn, thought to be directly related to the survival of the early life stages in the spawning/nursery ground. Pulau Pari Laguna is considered as a spawning ground for many reef fishes. The aims of the research were to investigate the dynamic of abundance and composition of fish larvae in Pulau Pari lagune. The Results show, fish larvae abundance range between 1,0 x 103 – 14,7 x 103 ind/m3. Highest larval abundance occurred on July and October, which predicted as the month of fish larvae production seasons. Fish larvae were distributed in all part of the lagune. Larvae in the pre flexion stage found in the highest precentation compare to other. Totally 79 families of reef fish larvae were found during June – November 2010 dominated by Pomacentridae, Aulostomidae, Blenniidae, Engraulidae and Pinguipedidae.

  18. Multi-year survival of sugarbeet root maggot (Tetanops myopaeformis) larvae in cold storage.

    Science.gov (United States)

    Chirumamilla, Anitha; Yocum, George D; Boetel, Mark A; Dregseth, Robert J

    2008-04-01

    To test the hypothesis that long-term survival of sugarbeet root maggot in storage is facilitated by larvae undergoing prolonged diapause, respiration and gene expression patterns of field-collected diapausing larvae were compared with those of 1-, 2-, and 5-year laboratory-stored larvae. Additional assessments were made on post-storage survival, emergence, and reproductive fitness of stored larvae. Respirometry, carried out at 5 and 20 degrees C revealed no differences among respiration rates of initially diapausing and long-term stored larvae. A 15 degrees increase in temperature elevated respiration in both diapausing and stored larvae, with levels of CO2 release ranging between 8- and 14-fold higher at 20 degrees C than at 5 degrees C. Similarly, 6-10-fold increases in O2 consumption levels were observed at the higher temperature. A transcript with sequence similarity to the fat body protein 2 (Fbp2) gene was highly expressed in diapausing larvae, and trace levels were expressed in some samples of 1-year stored larvae. However, no expression was detected in 2- and 5-year stored larvae. Survival and emergence studies of stored larvae revealed mixed populations of diapausing (i.e., the 5-17% of larvae that did not pupate) and post-diapausing (62-84% of larvae pupated) insects, with a high incidence of pupation (62%) and emergence (47%), even after 4 years in cold storage. Therefore, extended survival of Tetanops myopaeformis larvae in long-term cold storage is facilitated by two mechanisms, with a majority of larvae in post-diapause quiescence and a smaller fraction in a state of prolonged diapause.

  19. Mananoligossacarídeo em dietas para larvas de tilápia Mannanoligosaccharides in diets for tilapia larvae

    Directory of Open Access Journals (Sweden)

    Kátia Kalko Schwarz

    2011-12-01

    Full Text Available Este experimento foi realizado para avaliar níveis crescentes de mananoligossacarídeo (MOS na dieta de larvas de tilápias-do-nilo (linhagem Supreme® na fase de reversão sexual durante 30 dias. Larvas de tilápia-do-nilo (n=1500, P=0,01 g ± 0,001 g foram distribuídas aleatoriamente em 30 tanques de 100 litros. Os peixes foram distribuídos em delineamento inteiramente casualizado, composto por seis tratamentos e cinco repetições. A dieta controle (isenta de MOS foi elaborada para conter aproximadamente 35% de proteína bruta e 3.100 kcal de ED/kg. As demais foram suplementadas com 0; 0,15; 0,30; 0,45; 0,60 e 0,75% de MOS em substituição ao milho da dieta controle. Com o aumento nos níveis de MOS nas dietas, foi observado aumento linear sobre o comprimento do intestino, a altura das vilosidades intestinais e a densidade dos vilos. Não houve diferença na composição corporal, no ganho em peso, no peso final, no comprimento final, no fator de condição, na taxa de sobrevivência e no número de células caliciformes do intestino das larvas. Os níveis de MOS tiveram efeito quadrático sobre a conversão alimentar, cujos melhores resultados foram obtidos com 0,34% de MOS. A utilização de MOS no nível de 0,34% em dietas para larvas de tilápia-do-nilo melhora a conversão alimentar e promove aumento do comprimento do intestino, da altura das vilosidades e da densidade de vilos intestinal.This experiment was conducted to evaluate increasing levels of mannanoligosaccharides (MOS in the diet of Nile tilapia larvae (Supreme® at the sex reversal stage for 30 days. Nile tilapia larvae (n = 1500, p = 0.01 ± 0.001 g, were randomly distributed in 30 tanks of 100 liters each, for 30 days. The fish were distributed in a randomized design with six treatments and five replicates. The control diet (no MOS was elaborated to contain approximately 35% of crude protein and 3,100 kcal DE/kg. Mannanoligosaccharides were included in the other diets

  20. Morphological and behavioral development of the piracanjuba larvae Desenvolvimento morfológico e comportamental de larvas de piracanjuba

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Reis Raposo Maciel

    2010-05-01

    Full Text Available The objective of this work was to study the morphologic development and the swimming and feeding behaviors of piracanjuba larvae, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae, during the period from zero to 172 hours after hatching (standard length = 3.62 - 11.94 mm. The morphological analyses were accomplished by using a trinocular stereo microscope, while the behavioral analyses were performed through periodic observations. In 28 hours after hatching, the larvae (standard length = 6.25 ± 0.13 mm showed the following structural and behavioral characteristics that made them become active predators able to overcome a larval critical phase, the beginning of exogenous feeding: presence of pigmented eyes, terminal and wide mouth, developed oral dentition, developing digestive tube, yolk sac reduction, fins and swim bladder formation, horizontal swimming, cannibalism, and predation. Intense cannibalism among larvae was verified from 26 to 72 hours. At the end of the metamorphosis - 172 hours after hatching - the larvae measuring 11.94 + 0.80 mm in standard length presented a flexed notochord, caudal fin bifurcation, dorsal and anal fin formation, synchronized movements, and formation of shoals, characteristics that together allow enhanced perception and locomotio in exploration of the environment, determining the best moment for transfering to the fishponds. New studies can contribute to commercial fish farming by improving feeding management, performance, survival, and productivity of this species.Objetivou-se estudar o desenvolvimento morfológico e os comportamentos natatório e alimentar de larvas de piracanjuba, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae no período de 0 a 172 horas após a eclosão (comprimento-padrão = 3,62 - 11,94 mm. As análises morfológicas foram realizadas com auxílio de um microscópio estereoscópico trinocular e as comportamentais, por meio de

  1. 豆天蛾幼虫保藏研究%Study on Preservation of Clanis bilineata Walker Larva

    Institute of Scientific and Technical Information of China (English)

    吴胜军; 夏振强

    2008-01-01

    In order to solve the seasonal supply problem of Clanis bilineata Walker larvae, effects of larva instar, time and temperature on larvae preserva-tion were studied in this experiment. The results indicated that the 5th instal" mature larvae had the best preservation durability, and their optimum preserva-tion condition was 2 -4℃ with a upper time limit of 8 months.

  2. Comparison of nutritional status of field and laboratory reared Balanus amphitrite Darwin (Cirripedia: Thoracica) larvae and implication of starvation

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, D.V.; Anil, A.C.

    amphitrite. The larvae were also field-reared using micro-enclosures. Laboratory-reared larvae were larger in size than the field-reared larvae. An increase in size, DNA content and instar index of the starved II instar larvae was observed indicating...

  3. Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Bahlool, Qusay Z. M.; Skovgaard, Alf;

    2014-01-01

    A parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found...

  4. Radiolabeling of infective third-stage larvae of Strongyloides stercoralis by feeding ( sup 75 Se)selenomethionine-labeled Escherichia coli to first- and second-stage larvae

    Energy Technology Data Exchange (ETDEWEB)

    Aikens, L.M.; Schad, G.A. (Univ. of Pennsylvania, Philadelphia (USA))

    1989-10-01

    A technique is described for radiolabeling Strongyloides stercoralis larvae with ({sup 75}Se)selenomethionine. Cultures of an auxotrophic methionine-dependent stain of Escherichia coli were grown in a medium containing Dulbecco's modified Eagle's medium supplemented with 5% nutrient broth, amino acids, and ({sup 75}Se)selenomethionine. When the {sup 75}Se-labeled bacterial populations were in the stationary phase of growth, cultures were harvested and the bacteria dispersed on agar plates to serve as food for S. stercoralis larvae. Use of nondividing bacteria is important for successful labeling because the isotope is not diluted by cell division and death of larvae attributable to overgrowth by bacteria is prevented. First-stage S. stercoralis larvae were recovered from feces of infected dogs and reared in humid air at 30 C on agar plates seeded with bacteria. After 7 days, infective third-stage larvae were harvested. The mean specific activity of 6 different batches of larvae ranged from 75 to 330 counts per min/larva with 91.8 +/- 9.5% of the population labeled sufficiently to produce an autoradiographic focus during a practicable, 6-wk period of exposure. Labeled infective larvae penetrated the skin of 10-day-old puppies and migrated to the small intestine, where the developed to adulthood.

  5. Inclusion of protein hydrolysates in the diet of white seabream (Diplodus sargus) larvae: impacts on skeleton quality and larvae proteome expression

    OpenAIRE

    2010-01-01

    In order to investigate the effects of dietary protein hydrolysate on larval skeleton quality and larvae proteome expression, triplicate groups of white seabream (Diplodus sargus) larvae were co-fed from first-feeding onwards with live feed and three microencapsulated diets ir differing only on the molecular weight of their protein hydrolysate fraction.

  6. Production of the Catechol Type Siderophore Bacillibactin by the Honey Bee Pathogen Paenibacillus larvae

    Science.gov (United States)

    Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D.; Genersch, Elke

    2014-01-01

    The Gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood. This bacterial infection of honey bee brood is a notifiable epizootic posing a serious threat to global honey bee health because not only individual larvae but also entire colonies succumb to the disease. In the recent past considerable progress has been made in elucidating molecular aspects of host pathogen interactions during pathogenesis of P. larvae infections. Especially the sequencing and annotation of the complete genome of P. larvae was a major step forward and revealed the existence of several giant gene clusters coding for non-ribosomal peptide synthetases which might act as putative virulence factors. We here present the detailed analysis of one of these clusters which we demonstrated to be responsible for the biosynthesis of bacillibactin, a P. larvae siderophore. We first established culture conditions allowing the growth of P. larvae under iron-limited conditions and triggering siderophore production by P. larvae. Using a gene disruption strategy we linked siderophore production to the expression of an uninterrupted bacillibactin gene cluster. In silico analysis predicted the structure of a trimeric trithreonyl lactone (DHB-Gly-Thr)3 similar to the structure of bacillibactin produced by several Bacillus species. Mass spectrometric analysis unambiguously confirmed that the siderophore produced by P. larvae is identical to bacillibactin. Exposure bioassays demonstrated that P. larvae bacillibactin is not required for full virulence of P. larvae in laboratory exposure bioassays. This observation is consistent with results obtained for bacillibactin in other pathogenic bacteria. PMID:25237888

  7. Transcriptome Sequencing Reveals Large-Scale Changes in Axenic Aedes aegypti Larvae.

    Science.gov (United States)

    Vogel, Kevin J; Valzania, Luca; Coon, Kerri L; Brown, Mark R; Strand, Michael R

    2017-01-01

    Mosquitoes host communities of microbes in their digestive tract that consist primarily of bacteria. We previously reported that Aedes aegypti larvae colonized by a native community of bacteria and gnotobiotic larvae colonized by only Escherichia coli develop very similarly into adults, whereas axenic larvae never molt and die as first instars. In this study, we extended these findings by first comparing the growth and abundance of bacteria in conventional, gnotobiotic, and axenic larvae during the first instar. Results showed that conventional and gnotobiotic larvae exhibited no differences in growth, timing of molting, or number of bacteria in their digestive tract. Axenic larvae in contrast grew minimally and never achieved the critical size associated with molting by conventional and gnotobiotic larvae. In the second part of the study we compared patterns of gene expression in conventional, gnotobiotic and axenic larvae by conducting an RNAseq analysis of gut and nongut tissues (carcass) at 22 h post-hatching. Approximately 12% of Ae. aegypti transcripts were differentially expressed in axenic versus conventional or gnotobiotic larvae. However, this profile consisted primarily of transcripts in seven categories that included the down-regulation of select peptidases in the gut and up-regulation of several genes in the gut and carcass with roles in amino acid transport, hormonal signaling, and metabolism. Overall, our results indicate that axenic larvae exhibit alterations in gene expression consistent with defects in acquisition and assimilation of nutrients required for growth.

  8. Biophysical processes leading to the ingress of temperate fish larvae into estuarine nursery areas: A review

    Science.gov (United States)

    Teodósio, Maria Alexandra; Paris, Claire B.; Wolanski, Eric; Morais, Pedro

    2016-12-01

    A series of complementary hypotheses have been proposed to explain the recruitment of marine and temperate pelagic fish larvae originated from pelagic eggs in coastal environments. In this review, we propose a new and complementary hypothesis describing the biophysical processes intervening in the recruitment of temperate fish larvae into estuaries. This new hypothesis, the Sense Acuity And Behavioral (SAAB) hypothesis, recognizes that recruitment is unlikely if the larvae drift passively with the water currents, and that successful recruitment requires the sense acuity of temperate fish larvae and their behavioral response to the estuarine cues present in coastal areas. We propose that temperate fish larvae use a hierarchy of sensory cues (odor, sound, visual and geomagnetic cues) to detect estuarine nursery areas and to aid during navigation towards these areas. The sensorial acuity increases along ontogeny, which coincides with increased swimming capabilities. The swimming strategies of post-flexion larvae differ from offshore areas to the tidal zone. In offshore areas, innate behavior might lead larvae towards the coast guided by a sun compass or by the earth's geomagnetic field. In areas under limited influence of estuarine plumes (either in energetic nearshore areas or offshore), post-flexion larvae display a searching swimming behavior for estuarine disconnected patches (infotaxis strategy). After finding an estuarine plume, larvae may swim along the increasing cue concentration to ingress into the estuary. Here, larvae exhibit a rheotaxis behavior and avoid displacement by longshore currents by keeping bearing during navigation. When larvae reach the vicinity of an estuary, merging diel rhythms with feeding and predator avoidance strategies with tidally induced movements is essential to increase their chances of estuarine ingress. A fish larva recruitment model developed for the Ria Formosa lagoon supports the general framework of the SAAB hypothesis. In

  9. A description of the Larva of Metapteron xanthomelas (Lucas, 1857) from the Restinga Forest of Southeastern Brazil (Coleoptera: Lycidae, Calopterini).

    Science.gov (United States)

    Ferreira, Vinicius De Souza; Costa, Cleide

    2015-02-03

    The last instar larva of Metapteron xanthomelas (Lucas, 1857) is described. This is the first description of a larva for the genus. Two live larvae collected in the Brazilian Atlantic coast Restinga Forest of Itanhaém, São Paulo, were reared, one to adult and one was fixed in the last instar. This larva differs from the known Calopterini larvae by the absence of urogomphi, the dorsal abdominal segments undivided and strongly alveolate ornamentation on the head. 

  10. Description of the larva of Tetragonoderus (Crossonychus) variegatus Dejean, 1829 (Coleoptera: Carabidae: Cyclosomini) with notes on biology.

    Science.gov (United States)

    Santos, Guilherme Ide Marques Dos

    2015-06-16

    A late instar of the Tetragonoderus (Crossonychus) variegatus Dejean, 1829 larva is described for the first time, and is compared with its first instar, with the larva of another Tetragonoderus species, and with the larva of one Cyclicus species. Habitus and important structures of the larva are illustrated, as well the adult's membranous wings. Some aspects of the natural history of the larva and adult are also noted.

  11. Natural hosts of the larvae of Nuttalliella sp. (N. namaqua?) (Acari: Nuttalliellidae).

    Science.gov (United States)

    Horak, Ivan G; Lutermann, Heike; Medger, Katarina; Apanaskevich, Dmitry A; Matthee, Conrad A

    2012-02-02

    The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua?) from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank.

  12. Natural hosts of the larvae of Nuttalliella sp. (N. namaqua? (Acari: Nuttalliellidae

    Directory of Open Access Journals (Sweden)

    Ivan G. Horak

    2012-02-01

    Full Text Available The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua? from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank.

  13. Gene expression in honey bee (Apis mellifera) larvae exposed to pesticides and Varroa mites (Varroa destructor).

    Science.gov (United States)

    Gregorc, Aleš; Evans, Jay D; Scharf, Mike; Ellis, James D

    2012-08-01

    Honey bee (Apis mellifera) larvae reared in vitro were exposed to one of nine pesticides and/or were challenged with the parasitic mite, Varroa destructor. Total RNA was extracted from individual larvae and first strand cDNAs were generated. Gene-expression changes in larvae were measured using quantitative PCR (qPCR) targeting transcripts for pathogens and genes involved in physiological processes, bee health, immunity, and/or xenobiotic detoxification. Transcript levels for Peptidoglycan Recognition Protein (PGRPSC), a pathogen recognition gene, increased in larvae exposed to Varroa mites (Ppesticide treated larvae. As expected, Varroa-parasitized brood had higher transcripts of Deformed Wing Virus than did control larvae (Ppesticides and Varroa parasitism on honey bee larval gene expression were demonstrated. Interactions between larval treatments and gene expression for the targeted genes are discussed.

  14. Nematode larvae infecting Priacanthus arenatus Cuvier, 1829 (Pisces: Teleostei in Brazil

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    BIANCA P. KURAIEM

    2016-06-01

    Full Text Available From July to December, 2013, thirty Priacanthus arenatus specimens commercialized in the cities of Niterói and Rio de Janeiro, State of Rio de Janeiro, were acquired. The fish were necropsied and filleted to investigate the presence of nematode larvae. Twenty fish (66.7% out of the total were parasitized by nematode larvae. A total of 2024 larvae were collected; among them, 30 third-instar larvae of Anisakis sp. showed prevalence (P = 20%, mean abundance (MA = 1, and the mean intensity (MI = 5, and infection sites (IS = caecum, stomach, liver, and mesentery; and 1,994 third-instar larvae (1,757 encysted and 237 free of Hysterothylacium deardorffoverstreetorum with P = 66.7%, MA = 66.5, and MI = 99.7, and IS = spleen, caecum, stomach, liver, mesentery, and abdominal muscle. This is the first study to report H. deardorffoverstreetorum and Anisakis sp. larvae parasitizing P. arenatus.

  15. Adult fruit fly attraction to larvae biases experience and mediates social learning.

    Science.gov (United States)

    Durisko, Zachary; Anderson, Blake; Dukas, Reuven

    2014-04-01

    We investigated whether adult fruit flies (Drosophila melanogaster) use cues of larvae as social information in their food patch choice decisions. Adult male and female fruit flies showed attraction to odours emanating from foraging larvae, and females preferred to lay eggs on food patches occupied by larvae over similar unoccupied patches. Females learned and subsequently preferred to lay eggs at patches with novel flavours previously associated with feeding larvae over patches with novel flavours previously associated with no larvae. However, when we controlled for the duration of exposure to each flavoured patch, females no longer preferred the flavour previously associated with feeding larvae. This suggests that social learning in this context is indirect, as a result of strong social attraction biasing experience.

  16. Cumulative mortality of Aedes aegypti larvae treated with compounds

    Science.gov (United States)

    Torres, Sandra Maria; da Cruz, Nadine Louise Nicolau; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; da Silva, Valdemiro Amaro

    2014-01-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. PMID:25119939

  17. Cumulative mortality of Aedes aegypti larvae treated with compounds.

    Science.gov (United States)

    Torres, Sandra Maria; Cruz, Nadine Louise Nicolau da; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; Silva Júnior, Valdemiro Amaro da

    2014-06-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs.

  18. Cumulative mortality of Aedes aegypti larvae treated with compounds

    Directory of Open Access Journals (Sweden)

    Sandra Maria Torres

    2014-06-01

    Full Text Available OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762 (Diptera: Culicidae. METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI in concentrations of 0.37 ppm (PC1 and 0.06 ppm (PC2; treated with compounds of essential oils and fermented extract, 50.0% concentration (G1; treated with compounds of essential oils and fermented extract, 25.0% concentration (G2; treated with compounds of essential oils and fermented extract, 12.5% concentration (G3; and negative control group using water (NC1 and using dimethyl (NC2. The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs.

  19. Lobesia botrana larvae develop faster in the presence of parasitoids.

    Science.gov (United States)

    Vogelweith, Fanny; Moret, Yannick; Thiery, Denis; Moreau, Jérôme

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics.

  20. Lobesia botrana larvae develop faster in the presence of parasitoids.

    Directory of Open Access Journals (Sweden)

    Fanny Vogelweith

    Full Text Available To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics.

  1. Immunization with irradiated larvae against Dictyocaulus filaria in young lambs

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, D.N.; Sharma, R.L. (Regional Centre, Indian Veterinary Research Institute, Rawalpora, Kashmir (India))

    1981-12-01

    In the lungworm-endemic areas of Kashmir, 6-10 week old lambs of Karnah and Kashmir Merino breeds were vaccinated with two doses of 50 kR gamma-irradiated larvae of Dictyocaulus filaria, given a month apart. Assessed on the basis of reduced prevalence and significantly lower faecal larval output over an eight-month observation period, vaccinated lambs showed a high degree of resistance to naturally acquired D. filaria infection. The results also show that vaccination against D. filaria provided some degree of protection against infection with other lungworm species.

  2. Identification of first-stage larvae of metastrongyles from dogs.

    Science.gov (United States)

    McGarry, J W; Morgan, E R

    2009-08-29

    By examining larvae from dogs in which the adult stages had been identified, the morphology of Angiostrongylus vasorum, Filaroides osleri, Filaroides hirthi and Crenosoma vulpis from samples of faeces or bronchoalveolar lavage was compared. The tail morphology of the four species was distinctive: A vasorum had a typical cuticular indentation and projection on the dorsal surface of the tail (referred to as the dorsal notch and dorsal spine, respectively) and a smaller indentation on the ventral surface. The tails of the other species are described. A vasorum was significantly longer (mean [sd] 358.4 microm [10.28], range 334 to 380 microm) than the other species (range 229 to 281 microm).

  3. Catching large herring larvae: Gear applicability and larval distribution

    DEFF Research Database (Denmark)

    Munk, Peter

    1988-01-01

    given to the influence of gear speed on catching effectiveness. An additional objective was to investigate larval distributional patterns of potential importance to sampling strategy. Gear speed had a pronounced influence on the efficiency of the IKMT. Catches per unit volume filtered decreased to one...... third when speed was increased by one knot. The efficiency of the MIK did not change in the speed range investigated, and this gear was in every case more efficient than the IKMT. Larvae were found to be patchily distributed at the scale of sampling, and the degree of patchiness did not increase when...

  4. A linear model for the dynamics of fish larvae

    Directory of Open Access Journals (Sweden)

    Noureddine Ghouali

    2004-11-01

    Full Text Available We consider a linear model for the growth and the dispersion of fish larvae of certain species. Dispersion is modeled as entailed by the combination of transport and vertical diffusion. We generalize the work of Boushaba, Arino and Boussouar [5,6] in the sense that horizontal velocities are uniform throughout the water column; but we deal with vertical component velocity and vertical diffusion depending on the space variables and on time, which was not the case in [5,6]. This new vision leads us to non-autonomous problems, the aim of this work is to show the existence, uniqueness, and positivity of solutions.

  5. Generation of aneurogenic larvae by parabiosis of salamander embryos.

    Science.gov (United States)

    Kumar, Anoop; Delgado, Jean Paul

    2015-01-01

    Limb regeneration of salamanders is nerve dependent, and the removal of the nerves in early stages of limb regeneration severely curtails the proliferation of the blastemal cells and growth of the regenerate. The removal of the neural tube from a developing salamander embryo results in an aneurogenic larva and the aneurogenic limb (ANL) develops independently without innervation. Paradoxically, the limb in an ANL is capable of regeneration in a nerve-independent manner. Here, we describe a detailed method for the generation of ANL in the spotted salamander, Ambystoma maculatum, for regeneration studies.

  6. Descrição da larva de Erythemis mithroides (Brauer e notas sobre outras larvas conhecidas do gênero (Odonata, Libellulidae Description of the larva of Erythemis mithroides (Brauer and notes on other known larvae of the genus (Odonata, Libellulidae

    Directory of Open Access Journals (Sweden)

    J.M. Costa

    1993-01-01

    Full Text Available The last instar larva of Erythemis mithroides (Brauer, 1900 is described and figured based on exuviae of reared specimens. A comparative analysis of this immature stage and the known larvae of the genus are furnished according to the data available in the literature and of specimens of E credula (Hagen, 1861 and E. vesiculosa (Fab., 1775 permiting a diagnose for the larvae of the genus Erylhemis Hagen, 1861.

  7. Gastrointestinal symptoms resembling ulcerative proctitis caused by larvae of the drone fly Eristalis tenax.

    Science.gov (United States)

    Desoubeaux, Guillaume; Gaillard, Julien; Borée-Moreau, Diane; Bailly, Éric; Andres, Christian R; Chandenier, Jacques

    2014-04-01

    We report a case of facultative intestinal myiasis due to larvae of the drone fly Eristalis tenax, also named the rat-tailed maggots. The development of larvae in the lower bowel was responsible for non-specific gastrointestinal symptoms that resembled ulcerative proctitis. The diagnosis was established upon the observation of four spontaneously excreted mobile larvae. The definite identification of the E. tenax species was made possible by scanning electron microscopy. The clinical outcome was satisfactory.

  8. Limit of detection of Toxocara canis larvae in experimentally contaminated bovine milk

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    Edlayne Larissa Gretter Machado Pereira

    2016-02-01

    Full Text Available This study aimed to evaluate the limit of detection of Toxocara canis larvae in experimentally contaminated commercial bovine milk samples, based on a centrifuge-sedimentation technique. Firstly, bovine milk (whole and skim samples were contaminated with 50 T. canis larvae in order to evaluate the interference of milk fat with the recovery of the larvae. Next, the effects of 10% formalin (100 ?L, ether (100 ?L, and a combination of both solutions on the recovery of the larvae was examined. Thereafter, the limit of detection of the larvae was determined using the solution (from step 2 considered optimal for degreasing the milk sample. Samples were contaminated with aliquots of 1, 5, 10, 25, and 50 larvae. For each milk sample (1.0 mL, 15 repetitions were analysed. The recovery of the larvae from the skim milk samples was higher (p = 0.0031 than that from the whole milk samples. No significant difference (p = 0.5681 was observed with regard to the percentage of recovered larvae when comparing the degreasing solutions. Nevertheless, the formalin-ether combination was more efficient for recovering the larvae (73.1% than ether (71.9%, formalin (67.6%, and pure whole milk (70.0%. Concerning the limit of detection (using formalin-ether, all the samples contaminated with 5, 10, 25, and 50 larvae tested positive (minimum: 62.7%. Of the samples contaminated with a single larva, 66.7% tested positive. These results suggest that the centrifugation-sedimentation technique may be useful for recovering larvae of Toxocara spp. in naturally or experimentally contaminated milk samples obtained from a wide range of animal species.

  9. Volatiles induced by the larvae of the Asian corn borer (Ostrinia furnacalis) in maize plants affect behavior of conspecific larvae and female adults

    Institute of Scientific and Technical Information of China (English)

    Cui-Hong Huang; Feng-Ming Yan; John A.Byers; Rong-Jiang Wang; Chong-Ren Xu

    2009-01-01

    Effects of maize (Zea mays L.) volatiles induced by larvae of the Asian corn borer, Ostrinia furnacalis (Guenee), on the orientation behaviors of Asian corn borer larvae and oviposition of the females were investigated. Nineteen volatile chemicals, with terpenes being the major components, were identified from maize plants attacked by third instar Asian corn borer larvae. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses revealed some electroantennographic differences between female and male Asian corn borer antennae in response to larvae-induced maize volatiles; female responded to (E)-2-hexenal, nonanal, (Z)-3-hexen-1-ol and three unknown compounds while the male only responded to (E)-2-hexenal, nonanal and one unknown compound. In laboratory orientation bioassays, Asian corn borer neonate larvae were attracted to extracts collected from Asian corn borer-damaged plants as well as to synthetic famesene, but were repelled by (Z)-3-hexen- 1-ol. In laboratory oviposition bioassays, gravid females laid fewer eggs on plants damaged by larvae than on mechanically damaged plants or undamaged plants. Adult Asian corn borer females deposited fewer eggs on wax paper treated with (E)-2-hexenal or (Z)-3-hexen-l-ol than on wax paper treated with hexane (control). The results suggest that Asian corn borer can affect the behaviors of conspecific larvae and adults by changing host plant volatiles.

  10. The use of morphological and histological features as nutritional condition indices of Pagrus pagrus larvae

    Directory of Open Access Journals (Sweden)

    Marina Vera Diaz

    Full Text Available Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata and rotifers (Brachionus plicatilis were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.

  11. Purification and properties of a monomeric lactate dehydrogenase from yak Hypoderma sinense larva.

    Science.gov (United States)

    Li, Pengfei; Jin, Suyu; Huang, Lin; Liu, Haohao; Huang, Zhihong; Lin, Yaqiu; Zheng, Yucai

    2013-06-01

    The objective of the present study was to study the characteristics of lactate dehydrogenase (LDH) from Hypoderma sinense larva. H. sinense larvae were collected from yak (Bos grunniens) and identified by a PCR-RFLP method. Analysis of LDH activity showed that the total LDH activity in H. sinense larva was negatively correlated with the length of larva. Polyacrylamide gel electrophoresis of the extracts of H. sinense larvae revealed one band of LDH, which was then purified by affinity chromatography and gel filtration. This enzyme showed an approximately 36 kDa band on SDS-gel under both reducing and non-reducing conditions, in addition, size exclusion chromatography analysis showed that its molecular weight was smaller than bovine serum albumin (67 kDa), indicating that it contains only one subunit. Michaelis constants (Km) values assay revealed that LDH from H. sinense larva showed significantly lower Km for lactate than other animals. LDH of H. sinense larva was stable at 60 °C for 15 min, and also exhibited high catalytic efficiency in a wide range of pH. HgCl₂ at the concentration of 0.1mM significantly decreased the activity of LDH from H. sinense larva but not at the concentration of 0.01 mM. The results of the present study demonstrate that LDH from H. sinense larva is a thermal stable and pH insensitive enzyme suitable for catalyzing both forward and reverse reactions.

  12. Cutaneous larva migrans in northern climates. A souvenir of your dream vacation.

    Science.gov (United States)

    Edelglass, J W; Douglass, M C; Stiefler, R; Tessler, M

    1982-09-01

    Three young women recently returned to the metropolitan Detroit area with cutaneous larva migrans. All three had vacationed at a popular club resort on the Caribbean island of Martinique. Cutaneous larva migrans is frequently seen in the southern United States, Central and South America, and other subtropical areas but rarely in northern climates. Several organisms can cause cutaneous larva migrans, or creeping eruption. The larvae of the nematode Ancylostoma braziliense are most often the causative organisms. Travel habits of Americans make it necessary for practitioners in northern climates to be familiar with diseases contracted primarily in warmer locations. The life cycle of causative organisms and current therapy are reviewed.

  13. Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae from Mexico

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    Miguel A. Morón

    2014-09-01

    Full Text Available Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae from Mexico. Larvae of four species of Cyclocephala are described for the first time based on specimens collected in Mexican localities: C. barrerai Martínez, 1969 from Puebla, C. sinaloae Howden & Endrödi, 1966 from Sinaloa, C. fasciolata Bates, 1888 from Veracruz, and C. jalapensis Casey, 1915 from Hidalgo. Larva of C. lunulata Burmeister, 1847, is redescribed based on specimens from the Mexican states of Morelos, Puebla, and Veracruz. Diagnostic structures are illustrated and the differences and similarities of each species with other previously described larvae of the genus are commented.

  14. Number of malpighian tubules in larvae and adults of stingless bees (Hymenoptera: Apidae) from Amazonia.

    Science.gov (United States)

    Barbosa-Costa, K; Kerr, W E; Carvalho-Zilse, G A

    2012-02-01

    The number of Malpighian tubules in larvae and adults of bees is variable. Larvae of Apis mellifera L. have four Malpighian tubules, while adults have 100 tubules. In stingless bees, this number varies from four to eight. The objectives of this study were to provide characteristics of the Malpighian tubules as well as to quantify their number in larvae and adults of six species of Meliponinae, Melipona seminigra merrillae Cockerell, Melipona compressipes manaosensis Schwarz, Melipona rufiventris Lepeletier, Scaptotrigona Moure, Frieseomelitta Ihering, and Trigona williana Friese. Malpighian tubules were dissected from larvae and adults, measured, quantified, and maintained in microtubes with Dietrich's solution. The numbers of Malpighian tubules were constant only for larvae of M. rufiventris (four and eight) and Scaptotrigona sp. (four). The most frequent number of tubules in the Melipona group was seven and eight in larvae, and 70 and 90 in adults. In the Trigona group were four and 20 to 40, for larvae and adults, respectively. The results showed differences in the number of Malpighian tubules among the species analyzed and also between the larvae and adults of the same species. Despite the variation observed, species of the group Melipona always have a larger number and longer Malpighian tubules in both larvae and adults as compared to the Trigona group, which may indicate an evolutionary trend of differentiation between these groups.

  15. Chronic Larva Currens Following Tourist Travel to the Gambia and Southeast Asia Over 20 Years Ago.

    Science.gov (United States)

    Bailey, Kristy E; Danylo, Alexis; Boggild, Andrea K

    2015-01-01

    Larva currens is the cutaneous manifestation of human infection with the geotropic helminth Strongyloides stercoralis. Strongyloidiasis is a lifelong infection unless treated. A high index of suspicion is needed to prevent chronic symptoms of strongyloidiasis (eg, larva currens, eosinophilia, abdominal discomfort) and to prevent fatal dissemination. We present a case of chronic larva currens following tourist travel to the Gambia and Southeast Asia>20 years ago. This case highlights several important features of larva currens and strongyloidiasis, including the chronicity of symptoms, the rapidity of the migratory serpiginous rash, and the absence of high-grade eosinophilia.

  16. The Effects of Shrimp Gut Probiotic Bacteria on the Shrimp Larvae (Penaeus Chinensis)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The survival rates of shrimp larvae in different stage are higher than those of control groups when probiotic bacteria strains X4B-1 and X1B-1 which are isolated from gut of adult shrimp are added into the little volume rearing sea water of shrimp larvae. The effects of probiotic bacteria are evaluated by challenge test (pathogenic bacteria Z3G2 isolated from disease shrimp larvae in the hatchery of Jimo town) and low salinity stress resistance tests on shrimp larvae, the survival rate and lengths of the shrimp larvae in the experiment are determined. Results indicate that 1. The survival rate, ability of resistant to low salinity, lengths of the delivered shrimp larvae are improved after the strains of probiotic bacteria, X4B-1 or X1B-1, are added into the rearing sea water of hatchery. 2. The addition of the probiotic bacteria could not influence the change of the bacteria number, NH3-N and COD value in the rearing sea water. 3. The probiotic bacteria used in the experiment have many enzymes such as Lipase, Amylase, Gelatinase and Lecithinase. These enzymes may help the probiotic bacteria to digest the food components fed to shrimp larvae and increase the digestive efficiency of post larvae. This may be one of the reasons why these probiotic bacteria are beneficial to the shrimp larvae.

  17. Length changes in white sturgeon larvae preserved in ethanol or formaldehyde

    Science.gov (United States)

    Bayer, J.M.; Counihan, T.D.

    2001-01-01

    We examined the effects of two preservatives on the notochord and total lengths of white sturgeon (Acipenser transmontanus) larvae. White sturgeon larvae that were one, seven, and 14 days old were measured live and then preserved in 95% ethanol or 10% formaldehyde. Length changes were then determined at 20 and 95 days after preservation. We found mean length changes ranging from 0.4% to 3.4% shrinkage. Length changes varied with preservative, age of larvae, and length of time preserved. Constant length correction factors are provided for 10% formaldehyde or 95% ethanol valid for larvae between 1 and 14 days old preserved for less than 100 days.

  18. Vertical migrations of herring, Clupea harengus, larvae in relation to light and prey distribution

    DEFF Research Database (Denmark)

    Munk, Peter; Kiørboe, Thomas; Christensen, Villy

    1989-01-01

    The influence of light and prey abundance on the vertical distribution of herring larvae was evaluated by three investigations made under calm weather conditions in the North Sea off the Scottish coast. The investigations took place at different time after hatching and the vertical distributions...... towards the surface at dawn larvae stayed in the upper water column during the day. The observations suggest that the daytime vertical distribution of larvae in calm weather is mainly determined by feeding conditions: the larvae move to depths were light is sufficient for feeding, and refinement within...... that zone is made according to a compromise between optimal light conditions for feeding and optimal prey densities....

  19. Diagnosis of brugian filariasis by loop-mediated isothermal amplification.

    Directory of Open Access Journals (Sweden)

    Catherine B Poole

    Full Text Available In this study we developed and evaluated a Brugia Hha I repeat loop-mediated isothermal amplification (LAMP assay for the rapid detection of Brugia genomic DNA. Amplification was detected using turbidity or fluorescence as readouts. Reactions generated a turbidity threshold value or a clear visual positive within 30 minutes using purified genomic DNA equivalent to one microfilaria. Similar results were obtained using DNA isolated from blood samples containing B. malayi microfilariae. Amplification was specific to B. malayi and B. timori, as no turbidity was observed using DNA from the related filarial parasites Wuchereria bancrofti, Onchocerca volvulus or Dirofilaria immitis, or from human or mosquito. Furthermore, the assay was most robust using a new strand-displacing DNA polymerase termed Bst 2.0 compared to wild-type Bst DNA polymerase, large fragment. The results indicate that the Brugia Hha I repeat LAMP assay is rapid, sensitive and Brugia-specific with the potential to be developed further as a field tool for diagnosis and mapping of brugian filariasis.

  20. Diagnosis of brugian filariasis by loop-mediated isothermal amplification.

    Science.gov (United States)

    Poole, Catherine B; Tanner, Nathan A; Zhang, Yinhua; Evans, Thomas C; Carlow, Clotilde K S

    2012-01-01

    In this study we developed and evaluated a Brugia Hha I repeat loop-mediated isothermal amplification (LAMP) assay for the rapid detection of Brugia genomic DNA. Amplification was detected using turbidity or fluorescence as readouts. Reactions generated a turbidity threshold value or a clear visual positive within 30 minutes using purified genomic DNA equivalent to one microfilaria. Similar results were obtained using DNA isolated from blood samples containing B. malayi microfilariae. Amplification was specific to B. malayi and B. timori, as no turbidity was observed using DNA from the related filarial parasites Wuchereria bancrofti, Onchocerca volvulus or Dirofilaria immitis, or from human or mosquito. Furthermore, the assay was most robust using a new strand-displacing DNA polymerase termed Bst 2.0 compared to wild-type Bst DNA polymerase, large fragment. The results indicate that the Brugia Hha I repeat LAMP assay is rapid, sensitive and Brugia-specific with the potential to be developed further as a field tool for diagnosis and mapping of brugian filariasis.

  1. Description of the final stadium larva of Heliocypha perforata perforata (Percheron), with discussion of the taxonomic characters of the larvae of the genus Heliocypha Fraser (Odonata: Zygoptera: Chlorocyphidae).

    Science.gov (United States)

    Xu, Qi-Han

    2015-03-04

    The final stadium larva of Heliocypha perforata perforata is described and illustrated for the first time. It is characterized by having a row of filiform setae present laterally on distal half of prementum, 6-7 setae on the outer side of palpal lobe, very long lateral gills and distinct abdominal color pattern. The taxonomic characters of the larvae of the genus Heliocypha Fraser are discussed and summarized. Heliocypha larvae share a high similarity with Rhinocypha in general appearance and cannot be clearly distinguished from the latter in structure.

  2. Otolith geochemistry does not reflect dispersal history of clownfish larvae

    KAUST Repository

    Berumen, Michael L.

    2010-07-01

    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: "self-recruiters" spawned by parents on Kimbe Island and "immigrants" that had dispersed from distant reefs (>10 km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags. © 2010 Springer-Verlag.

  3. The hemolymph proteome of fed and starved Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Björn Handke

    Full Text Available The co-operation of specialized organ systems in complex multicellular organisms depends on effective chemical communication. Thus, body fluids (like blood, lymph or intraspinal fluid contain myriads of signaling mediators apart from metabolites. Moreover, these fluids are also of crucial importance for immune and wound responses. Compositional analyses of human body fluids are therefore of paramount diagnostic importance. Further improving their comprehensiveness should increase our understanding of inter-organ communication. In arthropods, which have trachea for gas exchange and an open circulatory system, the single dominating interstitial fluid is the hemolymph. Accordingly, a detailed analysis of hemolymph composition should provide an especially comprehensive picture of chemical communication and defense in animals. Therefore we used an extensive protein fractionation workflow in combination with a discovery-driven proteomic approach to map out the detectable protein composition of hemolymph isolated from Drosophila larvae. Combined mass spectrometric analysis revealed more than 700 proteins extending far beyond the previously known Drosophila hemolymph proteome. Moreover, by comparing hemolymph isolated from either fed or starved larvae, we provide initial provisional insights concerning compositional changes in response to nutritional state. Storage proteins in particular were observed to be strongly reduced by starvation. Our hemolymph proteome catalog provides a rich basis for data mining, as exemplified by our identification of potential novel cytokines, as well as for future quantitative analyses by targeted proteomics.

  4. The colonization dynamics of the gut microbiota in tilapia larvae.

    Science.gov (United States)

    Giatsis, Christos; Sipkema, Detmer; Smidt, Hauke; Verreth, Johan; Verdegem, Marc

    2014-01-01

    The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated. Interactions between factors are difficult to separate and any response could be masked due to high inter-individual variation even for individuals that share a common environment. In this study we characterized and quantified the spatio-temporal variation in the gut microbiota of tilapia larvae, reared in recirculating aquaculture systems (RAS) or active suspension tanks (AS). Our results showed that variation in gut microbiota between replicate tanks was not significantly higher than within tank variation, suggesting that there is no tank effect on water and gut microbiota. However, when individuals were reared in replicate RAS, gut microbiota differed significantly. The highest variation was observed between individuals reared in different types of system (RAS vs. AS). Our data suggest that under experimental conditions in which the roles of deterministic and stochastic factors have not been precisely determined, compositional replication of the microbial communities of an ecosystem is not predictable.

  5. Decapod larvae dynamics on Berlengas Biosphere Reserve (UNESCO - Portugal

    Directory of Open Access Journals (Sweden)

    Lénia Da Fonseca Alexandre Rato

    2014-05-01

    Total decapoda abundance ranged from 0,06 ind.m-3 in May 2011 to 64,28ind.m-3 in August 2012, and significantly different between summer/winter and winter/spring months (P(perm≤0,05. The data obtained on this study revealed that Infraorders Brachyura, Anomura and Caridea are the most common. All three are significantly different between months (P(perm≤0,05 but not between sampling stations (P(perm>0,05. Brachyuran abundance was significantly affected by the Oceanograhic Conditions (P(perm≤0,05. Abundances were higher in spring and summer months, when Chlorophyl a values (mg.m-3, Temperature (ºC and Salinity (ppt were also higher. Decapoda community is directly affected by the surrounding environmental conditions in Berlengas Biosphere Reserve and abundance might also be related with specific larvae release throughout the year. Each sampling station was considered a replica from the study area. The ecological importance of Berlengas was also verified by the presence of non-frequent larvae of Achelata and Stomatopoda.

  6. Otolith geochemistry does not reflect dispersal history of clownfish larvae

    Science.gov (United States)

    Berumen, M. L.; Walsh, H. J.; Raventos, N.; Planes, S.; Jones, G. P.; Starczak, V.; Thorrold, S. R.

    2010-12-01

    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: “self-recruiters” spawned by parents on Kimbe Island and “immigrants” that had dispersed from distant reefs (>10 km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags.

  7. Cranial features of dendrobatid larvae (Amphibia: Anura: Dendrobatidae).

    Science.gov (United States)

    Haas, A

    1995-06-01

    The larval neurocranium and visceral arches of seven dendrobatid species representing four genera are described, based on cleared-and-stained and serially sectioned specimens. A variety of characters is shared by all seven species. Larval features do not substantiate the assumption of close ranoid affinities of the Dendrobatidae. Instead dendrobatid larvae share features such as the special quadripartite cartilago suprarostralis, the lack of the larval processus oticus, the presence of three foramina acustica, and the lack of a foramen perilymphaticum accessorius with many bufonoid larvae. The first of these characters is unique to bufonids, hylids, dendrobatids, and some New World leptodactylids; the other characters also occur in pelobatids and are presumably plesiomorphic for the Neobatrachia. The free proximal ends of Ceratobranchialia II and III are an autapomorphy of the Dendrobatidae supporting the monophyly of the family. Some features of the cranium are paedomorphic: low cartilago orbitalis, lack of connection between cartilage orbitalis and otic capsule (most species), and vestigal taeniae tecti. New anatomical terms are introduced.

  8. Seasonal variation in toxicity of citral against Fasciola larva

    Institute of Scientific and Technical Information of China (English)

    Kumari Sunita; Pradeep Kumar; Dinesh Kumar Singh

    2014-01-01

    Objective:To test whether the larvicidal activity of citral against Fasciola varies by season. Methods:Mortality of Fasciola larva in different month of year (2011-2012) in in vitro and in vivo condition were observed at 2 h, 4 h, 6 h and 8 h exposure of citral. Results:In vitro toxicity of citral against redia was highest in between the June to August (8 h LC50: 2.58-2.62 mg/L), whereas against cercaria 8 h LC50 was in between 3.44-2.62 mg/L. Highest in vivo toxicity against redia was noted in between June to August (8h LC50: 4.20-5.09 mg/L). The lowest toxicity was observed from November to April. The highest temperature, free carbon dioxide, and lowest pH, dissolved oxygen were observed from June to August. Conclusions:The present study conclusively shows that varying a biotic factor can significantly alter the in vitro and in vivo toxicity of citral against sporocyst redia and cercaria larva.

  9. Vibrio harveyi effect under survival of Litopenaeus vannamei larvae

    Directory of Open Access Journals (Sweden)

    Gabriel Aguirre-Guzmán

    2013-06-01

    Full Text Available The culture of aquatic organisms show a high relevance in the human feeding and the culture activities can create artificial conditions that increase the growth and selection of specific bacteria. Vibrio species are normal bacteria’s from microflora of penaeid shrimp, those are opportunistic pathogens that can take advantage of the ecological changes generated for the culture of aquatic organisms and which may cause diseases, low survival and economic losses in the shrimp production. The aim of this research was to determine the variation in the survival of different larval substages (nauplius, zoea I-III, mysis I-III and postlarvae 1, of Pacific white shrimp Litopenaeus vannamei exposed at three doses [103 , 105 , and 107 colony-forming unit (CFU ml-1 [ of V. harveyi, by immersion (30 min as infection method. This species generated a significant low survival in larvae (p < 0.05 only in high doses (105 and 107 CFU ml-1 , where higher doses show the lowest values of survival. Larval substages and postlarvae 1 of shrimp showed sensitivity associate to the increase of Vibrio doses and this sensitivity decreased with the growth of larval substages and postlarvae 1. This information has high significance for the fisheries and aquaculture industry, which help to generate strategies to reduce the effects of V. harveyi with positive effect in growth and survival of the shrimp larvae and postlarvae 1.

  10. Phthalate esters reduce predation efficiency of dragonfly larvae, Odonata; Aeshna

    Energy Technology Data Exchange (ETDEWEB)

    Woin, P.; Larsson, P.

    1987-02-01

    Sublethal exposure to persistent organic chemicals cause effects different than levels resulting in acute toxicity. These effects may result in altered behavior, which may reduce the fitness of the organism. Behavior changes are difficult to study in vertebrates and in highly specialized invertebrates because of large natural variation in behavioral patterns. The behavior of insects, however, is strongly governed by genetic constraints (instincts). Phthalate esters are one of the most produced chemical groups in the world and are used mainly as plasticizers. Of the phthalates DEHP (di(2-ethylhexyl)phthalate) seems to exhibit properties typical of organic micropollutants. The compound reduces reproduction in Daphnia magna and bioaccumulation occurs in invertebrates. Since phthalate esters are lipophilic they tend to become attached to particles in the aquatic environments and consequently are found in high levels in the sediment of the lakes and rivers. Benthic organisms are, therefore, more exposed to this substance than those living in the water column. An aquatic laboratory system was constructed to study the behavior (predation efficiency) of dragonfly larvae (Aeshna) exposed to sediment-bound DEHP. Dragonfly larvae were chosen since the predation behavior of these animals is easily studied.

  11. TEKNOLOGI PEMELIHARAAN LARVA KERAPU SUNU (Plectropomus leopardus SECARA MASSAL

    Directory of Open Access Journals (Sweden)

    Titiek Aslianti

    2016-12-01

    Seed production technology of leopard coral trout, Plectropomus leopardus by improving hatchery management had been conducted in order to increase survival rate and to produce seed continuity. The initial feeding can successfully support in larval rearing. Feed organism as rotifer, trochophore gonad, egg yolk emulsion, and artificial feed emulsion, had been used as an initial feed. The twelve of concrete tanks with 6 m3 capacity were stocked with coral trout eggs at density 100,000—150,000 eggs/tank. Artemia nauplii, artificial feed, and mysid as feed, start on larvae D20 up to juvenile stage (D45. Growth rate and survival rate were observed and calculated when the experiment was terminated. The data was analyzed by descriptive. Nutrition value of food was analyzed by proximate and fatty acid composition. The others parameters such as deformity and water quality were observed. The result showed that artificial feed emulsion and egg yolk emulsion as an initial feeding can be improve the growth rate and increase survival rate of larvae. The range of total length, body weight and survival rate of the seed i.e. 1.95—2.85 cm; 0.64—0.73 g, and 0.25%— 3.97% with the daily growth rate 3,9%—4,22%, respectively. No back bone deformity in the seed, that is 21—23 segments with interspaces of segments 0.030—0.036 mm.

  12. Pathogenicity of Four Entomopathogenic Nematodes Species to G. mellonella Larvae

    Directory of Open Access Journals (Sweden)

    Pavel Hyrsl

    2011-06-01

    Full Text Available Entomopathogenic nematodes (EPNs of the genera Heterorhabditis and Steinernema are obligate and lethal insect parasites. In last decade they are widely used as biological control agents for pest insects of commercial crops, therefore research in this area is directly linked to agriculture. In this study, the pathogenicity of four nematode species (Heterorhabditis bacteriophora, Steinernema glaseri, Steinernema scarabaei and Steinernema feltiae was tested against Galleria mellonella larvae. Infective stage of EPNs together with their symbiotic bacteria kills insect host within 48 hours. The results show that mortality of insect host correlates with number of invaded infective juveniles (IJs. The invasion process is very fast, IJs enters insect host within a few hours. The importance of digestive tract as entering site was clearly demonstrated, larvae with empty gut are much more sensitive to nematode infection. Nemato-bacterial complex is very effective system overcoming insect immune defences. Encapsulation as the only one cellular reaction is activated, but in very low rate and was detected only during infection of H. bacteriophora.

  13. New province record of Rhinagrion for Thailand and description of the larva of R. mima (Odonata: Zygoptera: Philosinidae).

    Science.gov (United States)

    Novelo-Gutiérrez, Rodolfo; Sites, Robert W; Vitheepradit, Akekawat

    2014-08-19

    The Oriental damselfly genus Rhinagrion includes 10 known species, but the larva of only R. philippinum has been described in any detail, while the larva of R. viridatum has been well-illustrated and features summarized. The larvae of the other eight species were unknown. Here, the larva of Rhinagrion mima is described and illustrated by supposition, based upon an F0 larva collected in Phetchabun Province in Thailand. It is compared with the larvae of R. philippinum and R. viridatum. This represents the first record of the genus for Phetchabun Province. 

  14. Host gut microorganisms' cues mediate orientation behaviour in the larva of the parasitoid Mallophora ruficauda.

    Science.gov (United States)

    Groba, H F; Castelo, M K

    2016-02-01

    The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system.

  15. Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae.

    Directory of Open Access Journals (Sweden)

    Thamara Figueiredo Procópio

    Full Text Available In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4, as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3-1.35%, w/v for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae and 1.03% (fed larvae. Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae, 61.7% of individuals emerged as adults. The extract (1.0% promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates

  16. Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae

    Science.gov (United States)

    Procópio, Thamara Figueiredo; Fernandes, Kenner Morais; Pontual, Emmanuel Viana; Ximenes, Rafael Matos; de Oliveira, Aline Rafaella Cardoso; Souza, Carolina de Santana; Melo, Ana Maria Mendonça de Albuquerque; Navarro, Daniela Maria do Amaral Ferraz; Paiva, Patrícia Maria Guedes; Martins, Gustavo Ferreira; Napoleão, Thiago Henrique

    2015-01-01

    In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4), as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3–1.35%, w/v) for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae) and 1.03% (fed larvae). Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae), 61.7% of individuals emerged as adults. The extract (1.0%) promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates that caution

  17. An unprecedented role reversal: ground beetle larvae (Coleoptera: Carabidae lure amphibians and prey upon them.

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    Full Text Available Amphibians often feed on beetle larvae, including those of ground beetles (Carabidae. Preliminary reports have detailed an unusual trophic interaction in which, in contrast, larvae of the ground beetle Epomis prey upon juvenile and adult amphibians. While it is known that these larvae feed exclusively on amphibians, how the predator-prey encounter occurs to the advantage of the beetle larvae had been unknown to date. Using laboratory observations and controlled experiments, we recorded the feeding behavior of Epomis larvae, as well as the behavior of their amphibian prey. Here we reveal that larvae of two species of Epomis (E. circumscriptus and E. dejeani lure their potential predator, taking advantage of the amphibian's predation behavior. The Epomis larva combines a sit-and-wait strategy with unique movements of its antennae and mandibles to draw the attention of the amphibian to the presence of a potential prey. The intensity of this enticement increases with decreasing distance between the larva and the amphibian. When the amphibian attacks, the larva almost always manages to avoid the predator's protracted tongue, exploiting the opportunity to attach itself to the amphibian's body and initiate feeding. Our findings suggest that the trophic interaction between Epomis larvae and amphibians is one of the only natural cases of obligatory predator-prey role reversal. Moreover, this interaction involves a small insect larva that successfully lures and preys on a larger vertebrate. Such role reversal is exceptional in the animal world, extending our perspective of co-evolution in the arms race between predator and prey, and suggesting that counterattack defense behavior has evolved into predator-prey role reversal.

  18. Salmonella recovery from broilers and litter following gavage with Salmonella colonized darkling beetles and larvae.

    Science.gov (United States)

    Transmission of Salmonella to broiler chicks with Salmonella colonized darkling beetles or larvae was evaluated by sampling litter and ceca during growout. In two trials, 1 or 2 day-of-hatch broiler chicks (in a pen of 40) were gavaged with either 4 darkling beetles, 4 beetle larvae, or 0.1 mL pept...

  19. Description of the last stadium larva and female of Microgomphus thailandica Asahina, 1981 (Odonata: Gomphidae).

    Science.gov (United States)

    Boonsoong, Boonsatien; Chainthong, Damrong

    2014-06-03

    The last stadium larva of Microgomphus thailandica is described, illustrated and compared with the larvae of congeneric species based on reared specimens collected from the Phachi headwater stream, Ratchaburi province, Thailand. The female adult of this species is described for the first time from a reared specimen from the same locality.

  20. Radiolabeling and autoradiographic tracing of Toxocara canis larvae in male mice

    Energy Technology Data Exchange (ETDEWEB)

    Wade, S.E.; Georgi, J.R.

    1987-02-01

    Artificially hatched infective larvae of Toxocara canis were labeled with /sup 75/Se in Medium 199 (Gibco) containing /sup 75/Se-methionine. Male CD-1 mice were infected with radiolabeled larvae by intragastric intubation or by intraperitoneal injection. At intervals of 3-56 days mice were killed and the organs prepared for compressed organ autoradiography. Radioactivity of parasitic larvae showed an exponential decrease with time, reflecting catabolism of label with a biological half life of 26 days (effective half life of 21 days) making possible experiments lasting several months. Total body larva counts, estimated by total body autoradiography, displayed an overall downward trend, but the rate of reduction was probably not constant because no significant positive or negative trends were noted from day 14 onward in the numbers of larvae. The carcass accumulated the greatest number of larvae followed by the central nervous system, liver, and lung in that order. When the numbers of larvae were considered in relationship to the mass of tissue, there were 4 groupings: central nervous system, liver, lung, carcass, and kidney, and genito-urinary organ, pelt, and intestine. No significant difference between intragastric and intraperitoneal administration was observed in the larval distribution after the larvae had left the initial site of deposition.

  1. The larva of Tricholeon relictus Hölzel & Monserrat, 2002 a synanthropic antlion (Neuroptera, Myrmeleontidae).

    Science.gov (United States)

    Acevedo, Fernando; Badano, Davide; Monserrat, Víctor J

    2014-07-11

    The larva of Tricholeon relictus, a Spanish endemic antlion of Afrotropical affinities, is described and illustrated for the first time also providing a comparison with the only other European member of the tribe Dendroleontini, Dendroleon pantherinus. The larva of this species is synanthropic but probably originally lived in cave-like habitats.

  2. A new species of Luchoelmis Spangler & Staines (Coleoptera: Elmidae) from Argentina and its probable larva.

    Science.gov (United States)

    Archangelsky, Miguel; Brand, Cecilia

    2014-03-19

    A new species of riffle beetle from southwestern Argentina, Luchoelmis kapenkemkensis, is described. Its diagnostic characters are illustrated and the key for the identification the species of the genus is updated. A larva, very likely belonging to this species, is also described and compared to other related larvae.

  3. The larva of Rhyacophila balcanica Radovanovic 1953 (Trichoptera: Rhyacophilidae) with notes on ecology.

    Science.gov (United States)

    Karaouzas, Ioannis; Graf, Wolfram; Kučinić, Mladen; Vučković, Ivan; Waringer, Johann

    2015-12-11

    The previously unknown larva of Rhyacophila balcanica Radovanovic 1953 is described. The diagnostic features of the species are listed and illustrated and some information on its ecology and distribution is included. In addition, diagnostic characters for larvae of the known Greek Rhyacophila species are provided.

  4. A new eel larva, Leptocephalus pseudomicrocephalus, belonging to the subfamily Bathymyrinae (Anguilliformes, Congridae)

    NARCIS (Netherlands)

    Utrecht, van W.L.

    1988-01-01

    An eel larva, caught in the mid North Atlantic, represents a new species and is described as Leptocephalus pseudomicrocephalus. In most of its characters it resembles the larvae of the Ariosoma-Bathymyrus group, especially in the pigmentation and the presence of an outer intestine or exterilium. The

  5. First report of antennular attachment organs in a barnacle nauplius larva

    DEFF Research Database (Denmark)

    Watanabe, H.; Høeg, Jens Thorvald; Chan, B.K.K.;

    2008-01-01

    Larvae released from Newmaniverruca albatrossiana were cultured in the laboratory until the cypris stage. The brood size of individuals was low, about 60 larvae per brood. The exact number of instars was not determined. Early instars had the morphology normally seen in lecithotrophic nauplii of t...

  6. Alterations in the fat body and midgut of Culex quinquefasciatus larvae following exposure to different insecticides.

    Science.gov (United States)

    Alves, Stênio Nunes; Serrão, José Eduardo; Melo, Alan Lane

    2010-08-01

    This study describes morphological alterations in the fat body and midgut of Culex quinquefasciatus larvae following exposure to different insecticides. To this end, both third and fourth instars of C. quinquefasciatus larvae were exposed for 30 and 60 min to organophosphate (50 ppb), pyrethroids (20 and 30 ppb), and avermectin derivates (1.5 and 54 ppb). Following incubation, pH measurements of the larvae gut were recorded. The fat body and midgut were also analyzed by light and transmission electron microscopy. These studies demonstrate a decrease in the pH of the larvae anterior midgut following exposure to all of the tested insecticides. Histochemical tests revealed a strong reaction for neutral lipids in the control group and a marked decrease in the group exposed to cypermethrin. Furthermore, a weak reaction with acidic lipids in larvae exposed to deltamethrin, temephos, ivermectin and abamectin was also observed. Insecticide-exposed larvae also exhibited cytoplasm granule differences, relative to control larvae. Finally, we noted a small reduction in microvilli size in the apex of digestive cells, although vesicles were found to be present. The destructive changes in the larvae were very similar regardless of the type of insecticide analyzed. These data suggest that alterations in the fat body and midgut are a common response to cellular intoxication.

  7. Genes Expressed Differentially in Hessian Fly Larvae Feeding in Resistant and Susceptible Plants

    Directory of Open Access Journals (Sweden)

    Ming-Shun Chen

    2016-08-01

    Full Text Available The Hessian fly, Mayetiola destructor, is a destructive pest of wheat worldwide and mainly controlled by deploying resistant cultivars. In this study, we investigated the genes that were expressed differentially between larvae in resistant plants and those in susceptible plants through RNA sequencing on the Illumina platform. Informative genes were 11,832, 14,861, 15,708, and 15,071 for the comparisons between larvae in resistant versus susceptible plants for 0.5, 1, 3, and 5 days, respectively, after larvae had reached the feeding site. The transcript abundance corresponding to 5401, 6902, 8457, and 5202 of the informative genes exhibited significant differences (p ≤ 0.05 in the respective paired comparisons. Overall, genes involved in nutrient metabolism, RNA and protein synthesis exhibited lower transcript abundance in larvae from resistant plants, indicating that resistant plants inhibited nutrient metabolism and protein production in larvae. Interestingly, the numbers of cytochrome P450 genes with higher transcript abundance in larvae from resistant plants were comparable to, or higher than those with lower transcript abundance, indicating that toxic chemicals from resistant plants may have played important roles in Hessian fly larval death. Our study also identified several families of genes encoding secreted salivary gland proteins (SSGPs that were expressed at early stage of 1st instar larvae and with more genes with higher transcript abundance in larvae from resistant plants. Those SSGPs are candidate effectors with important roles in plant manipulation.

  8. Secreted and immunogenic proteins produced by the honey bee bacterial pathogen, Paenibacillus larvae

    Science.gov (United States)

    American Foulbrood is a severe disease affecting larvae of honeybee Apis mellifera, causing significant decrease in the honeybee population, beekeeping industries and agricultural production. In spite of its importance, little is known about the virulence factors secreted by Paenibacillus larvae dur...

  9. Agathomerus (Agathomeroides) flavomaculatus (Coleoptera, Megalopodidae, Megalopodinae): morfologia da larva e do adulto

    OpenAIRE

    Carvalho,Elisa B.; Monné,Marcela L.

    2006-01-01

    A larva de Agathomerus (Agathomeroides) flavomaculatus (Klug, 1824), coletada em Capsicum baccatum L. (Solanaceae), é descrita e ilustrada. A redescrição do adulto inclui caracteres das peças bucais, venação da asa, endosternitos e terminálias masculina e feminina. Pela primeira vez uma larva da subfamília Megalopodinae é descrita.

  10. Morphogenesis of Strongyloides stercoralis infective larvae requires the DAF-16 ortholog FKTF-1.

    Directory of Open Access Journals (Sweden)

    Michelle L Castelletto

    2009-04-01

    Full Text Available Based on metabolic and morphological similarities between infective third-stage larvae of parasitic nematodes and dauer larvae of Caenorhabditis elegans, it is hypothesized that similar genetic mechanisms control the development of these forms. In the parasite Strongyloides stercoralis, FKTF-1 is an ortholog of DAF-16, a forkhead transcription factor that regulates dauer larval development in C. elegans. Using transgenesis, we investigated the role of FKTF-1 in S. stercoralis' infective larval development. In first-stage larvae, GFP-tagged recombinant FKTF-1b localizes to the pharynx and hypodermis, tissues remodeled in infective larvae. Activating and inactivating mutations at predicted AKT phosphorylation sites on FKTF-1b give constitutive cytoplasmic and nuclear localization of the protein, respectively, indicating that its post-translational regulation is similar to other FOXO-class transcription factors. Mutant constructs designed to interfere with endogenous FKTF-1b function altered the intestinal and pharyngeal development of the larvae and resulted in some transgenic larvae failing to arrest in the infective stage. Our findings indicate that FKTF-1b is required for proper morphogenesis of S. stercoralis infective larvae and support the overall hypothesis of similar regulation of dauer development in C. elegans and the formation of infective larvae in parasitic nematodes.

  11. Blood feeding of Ornithodoros turicata larvae using an artificial membrane system

    Science.gov (United States)

    An artificial membrane system was adapted to feed Ornithodoros turicata larvae from a laboratory colony using defibrinated swine blood. Aspects related to larval feeding and molting to the 1st nymphal instar were evaluated. Fifty-five percent of all larvae exposed to the artificial membrane in two e...

  12. Chemical Composition and Food Potential of Pachymerus nucleorum Larvae Parasitizing Acrocomia aculeata Kernels.

    Directory of Open Access Journals (Sweden)

    Ariana Vieira Alves

    Full Text Available Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq. Lodd. Ex Mart., 1845, which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%, with percentage higher than the bocaiuva kernels (14.21%. The larval lipid content (37.87% was also high, very close to the kernels (44.96%. The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel.

  13. Virulence of metalloproteases produced by Vibrio species on Pacific oyster Crassostrea gigas larvae.

    Science.gov (United States)

    Hasegawa, Hiroaki; Gharaibeh, Dima N; Lind, Erin J; Häse, Claudia C

    2009-06-10

    Vibrio tubiashii, a pathogen of shellfish larvae and juveniles, produces several extracellular products. Here, we document that culture supernatants of several marine Vibrio species showed toxicity to oyster larvae. Treatment of these supernatants with EDTA not only severely diminished proteolytic activities, but also dramatically reduced toxicity to the larvae. Culture supernatants of metalloprotease-deficient mutants of V. tubiashii, V. cholerae, and V. splendidus were impaired in their ability to cause larval death compared to the wild type strains. Culture supernatants of Pseudomonas aeruginosa, known to contain several secreted proteases, showed virtually no toxicity to oyster larvae. Purified V. tubiashii protease A (VtpA), but not the prototype metalloprotease, thermolysin from Bacillus thermoproteolyticus, was highly toxic to the larvae. In addition, toxicity of purified VtpA was much greater for 6-d-old oyster larvae than for 16-d-old larvae. Together, these results indicated that culture supernatants of a variety of Vibrio species are highly toxic to oyster larvae and that the production of a metalloprotease is required for this effect. We propose that there are, as yet uncharacterized, specific substrates contained in larval tissue that are degraded by VtpA as well as certain homologous metalloproteases produced by other marine Vibrio species which, in turn, may contribute to vibriosis.

  14. PENGARUH PAKAN ALAMI Chaetoceros spp. TERHADAP PERKEMBANGAN DAN SINTASAN LARVA UDANG WINDU, Penaeus monodon

    Directory of Open Access Journals (Sweden)

    Samuel Lante

    2015-09-01

    Full Text Available Pakan alami berupa mikroalga merupakan salah satu faktor pendukung dalam keberhasilan usaha pembenihan udang windu, Penaeus monodon. Penelitian ini bertujuan untuk mengetahui jenis pakan alami, Chaetoceros spp., yang dapat meningkatkan pertumbuhan dan sintasan larva udang windu. Penelitian ini menggunakan 15 buah bak fiber berukuran 60 cm x 40 cm x 50 cm dengan volume 120 liter yang disi air sebanyak 100 liter. Kepadatan naupli adalah 90 ekor/liter atau 9.000 ekor/bak dan lima jenis pakan alami Chaetoceros spp. yang diuji yaitu: Chaetoceros simplex, Chaetoceros ceratosporum, Chaetoceros calcitrans, Chaetoceros amami, dan Chaetoceros gracilis. Hasil penelitian menunjukkan bahwa aplikasi kelima jenis pakan alami memberikan laju perkembangan larva yang relatif sama sampai stadia PL-1. Aplikasi Chaetoceros gracilis memberikan sintasan larva udang windu tertinggi yaitu 41,48% dan dengan Chaetoceros simplex memberikan sintasan larva terendah (28,02%. Hasil penelitian ini mengindikasikan bahwa aplikasi Chaetoceros spp. yang berbeda pada pemeliharaan larva berpengaruh terhadap sintasan larva udang windu, namun tidak berpengaruh terhadap laju metamorfosis larva. Aplikasi Chaetoceros gracilis sebagai pakan alami adalah terbaik untuk sintasan larva udang windu.

  15. Immune response of rainbow trout (Oncorhynchus mykiss) larvae to Yersinia ruckeri

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Kania, Per Walter; Raida, Martin Kristian

    of naive larvae were bath exposed for 1 h with different concentrations of ß-glucan from Euglena gracilis. Two days post infection, larvae showed typical signs of Yersinia infection with haemorrhages in mouth region and inflammation on the dorsal side of the body. However, no mortality was observed during...

  16. A rat model of intragastric infection with Anisakis spp. live larvae: histopathological study.

    Science.gov (United States)

    Zuloaga, Jaime; Rodríguez-Bobada, Cruz; Corcuera, María Teresa; Gómez-Aguado, Fernando; González, Pablo; Rodríguez-Perez, Rosa; Arias-Díaz, Javier; Caballero, María Luisa

    2013-06-01

    Anisakiasis is a fish-borne parasitic disease caused by consumption of raw or undercooked fish or cephalopods parasited by Anisakis spp. third stage larvae. The pathological effects of the infection are the combined result of the mechanical action of the larva during tissue invasion, the direct tissue effects of the excretory/secretory products released by the parasite, and the complex interaction between the host immune system and the Anisakis antigens. The aim of this study was to develop an experimental model of infection with Anisakis spp. live larvae in rats, useful to study the acute and chronic histopathological effects of the Anisakis infection. Sprague-Dawley rats were subjected to esophageal catheterization to place larvae directly into the stomach. Reinfections at different intervals after the first infection were preformed. Live larvae were found anchored to the mucosa and passing through the wall of the stomach and showed a strong resistance being able to stay alive at different sites and at the different pH. Migration of larvae from the stomach to other organs out of the gastrointestinal tract was also observed. The histopathological study showed the acute inflammatory reaction, with predominance of polymorphonuclear eosinophils and a mild fibrotic reaction. The model of infection described is valid to study the behavior of the larvae inside the host body, the histopathological changes at the invasion site, and the effects of the repeated infections by ingestion of live larvae.

  17. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    Directory of Open Access Journals (Sweden)

    São Thiago André Iwersen de

    2002-01-01

    Full Text Available Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  18. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    OpenAIRE

    São Thiago André Iwersen de; Kupek Emil; Ferreira Neto Joaquim Alves; São Thiago Paulo de Tarso

    2002-01-01

    Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  19. Structure and occurrence of cyphonautes larvae (Bryozoa, Ectoprocta)

    DEFF Research Database (Denmark)

    Nielsen, Claus; Worsaae, Katrine

    2010-01-01

    . membranacea larva. The velum carries two rows of ciliated cells, though the lower "row" consists of only one or two cells. Both rows of ciliated cells are innervated by nerves, which have not been detected in the M. membranacea larva. The ciliated ridge of H. malayensis lacks the frontal cilia...

  20. Young and old honey bee (Apis mellifera) larvae differentially prime the developmental maturation of their caregivers

    Science.gov (United States)

    In eusocial insects daughters rear the offspring of the queen to adulthood. In the honey bee, Apis mellifera, nurses differentially regulate larval nutrition. Among worker-destined larvae, younger instars receive an unrestricted diet paralleling that of queen larvae in protein composition but with r...

  1. Entomopathogenic fungi disturbed the larval growth and feeding performance of Ocinara varians (Lepidoptera: Bombycidae) larvae

    Institute of Scientific and Technical Information of China (English)

    Abid Hussain; Ming-Yi Tian; Yu-Rong He; Sohail Ahmed

    2009-01-01

    Feeding experiments using three strains of entomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea were conducted with newly moulted 3rd-5th instar Ocinara varians Walker larvae in the laboratory. The mortality of larvae immersed individually in spore suspension (1×10~7 spores/mL) of all the strains was > 80% except 5th instar larvae treated with M. anisopliae which transformed into pupae, but did not result in adult emergence. The growth (total body mass), consumption, relative consumption rate and relative growth rate, were reduced at all three larval stages, while developmental time was extended in infected larvae with concurrent significant increase in approximate digestibility in infected larvae. Conversion of digested food (ECD) and ingested food (ECI) values declined in infected larvae as compared to the healthy larvae (control). The 5th instar larvae treated with M. anisopliae showed higher ECD and ECI values than control. Based on mortality and growth inhibition it can be suggested that all the studied fungal strains have a high potential for biocontrol and could be developed into biocontrol agents against O. varians.

  2. Pemakaian Duddingtonia flagrans dan Saccharomyces cerevisiae dalam Mereduksi Larva Infektif Haemonchus contortus (THE STUDY OF DUDDINGTONIA FLAGRANS AND SACCHAROMYCES CEREVISIAE USE ON REDUCING OF INFECTIVE HAEMONCHUS CONTORTUS LARVAE

    Directory of Open Access Journals (Sweden)

    Riza Zainuddin Ahmad

    2014-04-01

    Full Text Available The use of Duddingtonia flagrans as the biological control of nomatode infections has been widelyreported. However, no report is available on the use of yeast Saccharomyces cerviciacae for such purpose.The aim of this study was to ivestigate the use of both fungi to reduce the number of Heamoncus contortusinfective larvae. Agar and fecal media containing the spore of the fungi was inoculated with infected H.contortus larvae (3rd stage. Fecal media containing the fungi was prepared by oral inoculation of sheepwith liquid containing 106, 107 spores of D. flagrans, and 106, 107 spores of D. flagrans, and 106, 1012 sporesof S. cerviciae. The number of larvae trapped in the fungi was counted. The result showed both fungi wereable to reduce the number of infective lave. However, for D. flagrans, beside it able to kill the larvae, it alsoable to trap the larva which did not occur in S. cerviceae. The combination of both fungi can be used to reduceof the number of invected H. contortus larvae.

  3. Comparative study of cultivation of feces in vermiculite or charcoal to obtain larvae of Strongyloides venezuelensis

    Directory of Open Access Journals (Sweden)

    Steveen Rios Ribeiro

    2014-10-01

    Full Text Available Introduction We compared feces culturing in charcoal or vermiculite to obtain Strongyloides venezuelensis larvae. Methods Feces (5g from infected rats was mixed with vermiculite (10g or coal (10g in plastic cups and incubated at 28°C for 48h. Larvae were recovered using Baermann-Moraes method. Results Significantly higher number of positive larval cultures were recovered from vermiculite than from charcoal (15/17 and 4/17, respectively; p < 0.001; 990.6 ± 307.5 and 215 ± 78.1 larvae, p = 0.027. Conclusions Vermiculite yields more larvae and provides cleaner pellets, improving larvae identification and facilitating their use for other purposes.

  4. Redescription of late-instar larva of Scydmoraphes sparshalli (Denny) Coleoptera: Staphylinidae, Scydmaeninae).

    Science.gov (United States)

    Jałoszyński, Paweł

    2015-10-20

    The larva of Scydmoraphes sparshalli is redescribed. This is the first complete description of an immature Scydmoraphes with special focus on the chaetotaxic characters. The larva is unique among Cyrtoscydmini in having three pairs of stemmata, a very long sensory appendage of the antennomere II, mandibles with mesal row of microserrations interrupted by smooth portion of mandibular margin; maxillary mala with asetose apex and a row of very long, modified setae on mesal margin, and extremely elongate maxillary palpomere III and labium. A comparative study of previous descriptions resulted in recognizing a misidentification of a Scydmoraphes larva (the "Typ 2-Larve" of Schmid) as a putative Neuraphes (Pararaphes). The serial homology of chaetotaxic structures in the larva of Scydmoraphes sparshalli is discussed, and comparative notes on the larvae of Scydmoraphes, Neuraphes and Stenichnus are given, with an identification key.

  5. [Geostatistical analysis on distribution pattern of the tobacco budworm larva in Enshi, Hubei, China].

    Science.gov (United States)

    Xia, Peng-Liang; Wang, Rui; Tan, Jun

    2014-03-01

    Tobacco budworm (Helicoverpa assulta) larvae feed on tobacco leaves (Nicotiana sp.), resulting in significant loss in tobacco production. Geostatistical method was used to analyze H. assulta spatial patterns and dynamics in this paper. The results showed that, H. assulta larvae appeared 40 days after the tobacco plants transplanting, and reached its peak at the early-mature period. The nested spherical and exponential model was the major model for tobacco budworm larva in the field, suggesting its aggregated distribution. The spatial variability C/(C0 + C) was larger than 0.75, which indicated H. assulta larva had wider structural variation and narrower random variation. There was a massive migration of tobacco budworm larva in the fast-growing stage of tobacco. Its quantity became stable after that, especially at the mature stage of tobacco.

  6. Excision of furuncular myiasis larvae using a punch: a simple, practical and aesthetic method*

    Science.gov (United States)

    Pascoal, Gianne; de Oliveira, Fernanda Queiroz; Siqueira, Rosana Rocon; Lopes, Maria Gabriela Araújo; Martins Neto, Marcelino Pereira; Gamonal, Aloísio Carlos Couri

    2016-01-01

    Myiasis refers to Diptera larvae infesting vertebrate animals. There are two forms of the disease: primary and secondary. In primary myiasis, fly larvae invade and develop in healthy tissue; in secondary myiasis, flies lay their eggs in skin ulcerations, and the larvae develop in tissue necrosis products. Furuncular myiasis is a type of primary myiasis. Treatment for it consists of techniques such as the production of localized hypoxia to force the emergence of the larvae, and mechanical or surgical removal of the maggots. These techniques, however, are painful and often unsuccessful. We propose a new technique for extraction of myiasis larvae, which might facilitate the surgical procedure and constitute a virtually painless and aesthetic option for the patient. PMID:27438206

  7. Cannibalism among Myrmeleon brasiliensis larvae (Návas, 1914 (Neuroptera, Myrmeleontidae

    Directory of Open Access Journals (Sweden)

    Tatiane do Nascimento Lima

    2016-12-01

    Full Text Available Cannibalism is influenced by various intrinsic and extrinsic factors of the population, such as density, population structure, prey availability, habitat structure and famine. These factors acting either independently or in synergy determine the frequency of cannibalism. The aims of the present study were to evaluate the effect of density and food availability on the occurrence of cannibalism among Myrmeleon brasiliensis larvae (Neuroptera, Myrmeleontidae. In the present study, the occurrence of cannibalism among M. brasiliensis larvae was greater in the treatments that simulated an absence of food in situations of both high and low density. The search for food makes a larva move about to forage, thereby increasing the risk of falling into the trap of a neighboring larva. Thus, the cannibalistic behavior of M. brasiliensis larvae may be associated with opportunity rather than a direct attempt to pray on the same species.

  8. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

    Directory of Open Access Journals (Sweden)

    Sacchi L.

    2001-06-01

    Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

  9. Sex-specific developmental profiles of juvenile hormone synthesis in honey bee larvae.

    Science.gov (United States)

    Hartfelder, Klaus; de Oliveira Tozetto, Sibele; Rachinsky, Anna

    1993-02-01

    Juvenile hormone synthesis in drone larvae of the honey bee was measured by an in vitro radiochemical assay. The developmental profile of corpora allata activity in male larvae showed considerable differences from queen larvae, the presumptive reproductive females, and was comparable to workers, the sterile female morph. Drone and worker larvae, however, differed drastically in the regulation of juvenile hormone biosynthesis, as revealed by the addition of farnesoic acid to the culture medium. This precursor stimulated juvenile hormone synthesis of drone glands nearly eightfold, whereas in worker larvae it is known to lead to an accumulation of methyl farnesoate. The sex-specific differences in endocrine activity indicate a role for juvenile hormone in the expression of genetically determined sexually dimorphic characters during metamorphosis, a role not currently accounted for in models describing endocrine regulation of insect development.

  10. Eggs containing larvae of Enterobius vermicularis in vaginal smear

    Directory of Open Access Journals (Sweden)

    Jyothi B Shetty

    2012-01-01

    Full Text Available Enterobius vermicularis also known commonly as pinworm is the most common intestinal parasite. It is a nematode that inhabits the human terminal ileum, colon and appendix. The fertilized female migrates to the perianal area where eggs are deposited but occasionally introduces itself into adjacent orifices, most commonly the female genitourinary tract. Thus the eggs can be seen in the vaginal smear as a result of contamination. We report a case wherein the patient presented with signs and symptoms of vulvovaginitis. In her vaginal smear there were eggs of Enterobius vermicularis which showed a coiled larva within it. In the background there were plenty of acute inflammatory cells. This patient responded favorably to antihelminthics. We report this case to highlight the morphology of the parasite and also to emphasize that such findings should not be neglected. Timely reporting and appropriate treatment of such cases will prevent further complications of this parasite including endometritis, salphingitis and peritonitis.

  11. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    Directory of Open Access Journals (Sweden)

    Yufan Cao

    2016-01-01

    Full Text Available Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials.

  12. X-ray inactivation of Caenorhabditis elegans embryos or larvae

    Energy Technology Data Exchange (ETDEWEB)

    Ishi, N.; Suzuki, K. (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

    1990-11-01

    The lethal effects of X-irradiation were examined in staged populations of Caenorhabditis elegans embryos or larvae. Radiation resistance decreased slightly throughout the first, proliferative phase of embryogenesis. This might be due to the increase in target size, since most cells in C. elegans are autonomously determined. Animals irradiated in the second half of embryogenesis were about 40-fold more resistant to the lethal effects of X-rays. This is probably due to the absence of cell divisions during this time. The radiation resistance increased still more with advancing larval stages. A radiation hypersensitive mutant, rad-1, irradiated in the first half of embryogenesis, is about 30-fold more sensitive than wild-type, but in the second half it is the same as wild-type. (author).

  13. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    Science.gov (United States)

    Cao, Yufan; Qiao, Hongbin; Shi, Yanli; Han, Yu; Liu, Jinming; Li, Hao; Lu, Ke; Lin, Jiaojiao

    2016-01-01

    Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl) has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj) eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials. PMID:27957496

  14. Effective de novo assembly of fish genome using haploid larvae.

    Science.gov (United States)

    Iwasaki, Yuki; Nishiki, Issei; Nakamura, Yoji; Yasuike, Motoshige; Kai, Wataru; Nomura, Kazuharu; Yoshida, Kazunori; Nomura, Yousuke; Fujiwara, Atushi; Kobayashi, Takanori; Ototake, Mitsuru

    2016-02-01

    Recent improvements in next-generation sequencing technology have made it possible to do whole genome sequencing, on even non-model eukaryote species with no available reference genomes. However, de novo assembly of diploid genomes is still a big challenge because of allelic variation. The aim of this study was to determine the feasibility of utilizing the genome of haploid fish larvae for de novo assembly of whole-genome sequences. We compared the efficiency of assembly using the haploid genome of yellowtail (Seriola quinqueradiata) with that using the diploid genome obtained from the dam. De novo assembly from the haploid and the diploid sequence reads (100 million reads per each datasets) generated by the Ion Proton sequencer (200 bp) was done under two different assembly algorithms, namely overlap-layout-consensus (OLC) and de Bruijn graph (DBG). This revealed that the assembly of the haploid genome significantly reduced (approximately 22% for OLC, 9% for DBG) the total number of contigs (with longer average and N50 contig lengths) when compared to the diploid genome assembly. The haploid assembly also improved the quality of the scaffolds by reducing the number of regions with unassigned nucleotides (Ns) (total length of Ns; 45,331,916 bp for haploids and 67,724,360 bp for diploids) in OLC-based assemblies. It appears clear that the haploid genome assembly is better because the allelic variation in the diploid genome disrupts the extension of contigs during the assembly process. Our results indicate that utilizing the genome of haploid larvae leads to a significant improvement in the de novo assembly process, thus providing a novel strategy for the construction of reference genomes from non-model diploid organisms such as fish.

  15. Composition of agarose substrate affects behavioral output of Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi Aristomenis Apostolopoulou

    2014-01-01

    Full Text Available In the last decade the Drosophila larva has evolved into a simple model organism offering the opportunity to integrate molecular genetics with systems neuroscience. This led to a detailed understanding of the functional neuronal networks for a number of sensory functions and behaviors including olfaction, vision, gustation and learning and memory. Typically, behavioral assays in use exploit simple Petri dish setups with either agarose or agar as a substrate. However, neither the quality nor the concentration of the substrate is generally standardized across these experiments and there is no data available on how larval behavior is affected by such different substrates. Here, we have investigated the effects of different agarose concentrations on several larval behaviors. We demonstrate that agarose concentration is an important parameter, which affects all behaviors tested: preference, feeding, learning and locomotion. Larvae can discriminate between different agarose concentrations, they feed differently on them, they can learn to associate an agarose concentration with an odor stimulus and crawl faster on a substrate of higher agarose concentration. Additionally, we have investigated the effect of agarose concentration on three quinine based behaviors: preference, feeding and learning. We show that in all cases examined the behavioral output changes in an agarose concentration-dependent manner. Our results suggest that comparisons between experiments performed on substrates differing in agarose concentration should be done with caution. It should be taken into consideration that the agarose concentration can affect the behavioral output and thereby the experimental outcomes per se potentially due to an increased escape response on more rigid substrates.

  16. Biochemistry and molecular biology of the Caenorhabditis elegans dauer larva

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, W.G.

    1989-01-01

    Biochemical and molecular techniques have been used to study the formation and recovery of the developmentally arrested, non-feeding dauer stage of the nematode Caenorhabditis elegans. While investigating developmental transitions in energy metabolism, a major metabolite isolated from perchloric acid extracts has been identified as a modified uridine nucleotide. The compound was isolated by gel filtration and ion-exchange chromatography and its structure was determined by {sup 1}H NMR and {sup 13}C NMR spectroscopy. This compound is the most abundant metabolite detected in {sup 31}PMR spectra of perchloric acid extracts from growing larvae. In the absence of phosphoarginine or phosphocreatine, this modified nucleotide may have an important function in the nematode's energy metabolism, and it may also be found in several other invertebrates. During recovery from the dauer stage, metabolic activation is accompanied by a decrease in intracellular pH (pH{sub i}). Although metabolic activation has been associated with an alkaline pH{sub i} shift in other organisms, in vivo {sup 31}P NMR analysis of recovering dauer larvae shows a pH{sub i} decrease from {approximately}7.3 to {approximately}6.3 within 3 hr after the animals encounter food. This shift occurs before feeding begins, and coincides with, or soon follows, the development commitment to recover from the dauer stage, suggesting that control of pH{sub i} may be important in the regulation of larval development in nematodes. A library enriched for sequences expressed specifically during the L2d (predauer) stage was made by selecting plaques from a genomic lambda library that hybridized to subtracted L2d cDNA probes. Ultimately, three clones that were shown to hybridize only to L2d RNA were selected.

  17. Impact of ultraviolet-B radiation on planktonic fish larvae: Alteration of the osmoregulatory function

    Energy Technology Data Exchange (ETDEWEB)

    Sucre, Elliott, E-mail: elliott.sucre@univ-montp2.fr [AEO Team (Adaptation Ecophysiologique et Ontogenese), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc092, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Vidussi, Francesca [RESEAUX Team (Reseaux Planctoniques et Changement Environnemental), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc093, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Mostajir, Behzad [RESEAUX Team (Reseaux Planctoniques et Changement Environnemental), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc093, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Centre d' ecologie marine experimentale MEDIMEER (Mediterranean centre for Marine Ecosystem Experimental Research), Universite Montpellier 2-CNRS (UMS 3301), Station Mediterraneenne de l' Environnement Littoral, MEDIMEER, 2 Rue des Chantiers, 34200 Sete (France); Charmantier, Guy; Lorin-Nebel, Catherine [AEO Team (Adaptation Ecophysiologique et Ontogenese), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc092, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France)

    2012-03-15

    Coastal marine ecosystems are submitted to variations of several abiotic and biotic parameters, some of them related to global change. Among them the ultraviolet-B (UV-B) radiation (UVBR: 280-320 nm) may strongly impact planktonic fish larvae. The consequences of an increase of UVBR on the osmoregulatory function of Dicentrarchus labrax larvae have been investigated in this study. In young larvae of D. labrax, as in other teleosts, osmoregulation depends on tegumentary ion transporting cells, or ionocytes, mainly located on the skin of the trunk and of the yolk sac. As early D. labrax larvae passively drift in the top water column, ionocytes are exposed to solar radiation. The effect of UVBR on larval osmoregulation in seawater was evaluated through nanoosmometric measurements of the blood osmolality after exposure to different UV-B treatments. A loss of osmoregulatory capability occured in larvae after 2 days of low (50 {mu}W cm{sup -2}: 4 h L/20 h D) and medium (80 {mu}W cm{sup -2}: 4 h L/20 h D) UVBR exposure. Compared to control larvae kept in the darkness, a significant increase in blood osmolality, abnormal behavior and high mortalities were detected in larvae exposed to UVBR from 2 days on. At the cellular level, an important decrease in abundance of tegumentary ionocytes and mucous cells was observed after 2 days of exposure to UVBR. In the ionocytes, two major osmoeffectors were immunolocalized, the Na{sup +}/K{sup +}-ATPase and the Na{sup +}/K{sup +}/2Cl{sup -} cotransporter. Compared to controls, the fluorescent immunostaining was lower in UVBR-exposed larvae. We hypothesize that the impaired osmoregulation in UVBR-exposed larvae originates from the lower number of tegumentary ionocytes and mucous cells. This alteration of the osmoregulatory function could negatively impact the survival of young larvae at the surface water exposed to UVBR.

  18. Seasonal fluctuation in the distribution of eggs and larvae of flat fishes (Pleuronectiformes - Pisces) in the Cochin Backwater

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    Attempts have been made to correlate the abundance of eggs and larvae of flat fishes belonging to families Cynoglossidae and Soleidae with the hydrographical parameters of the environment, particularly the salinity. The eggs and larvae were found...

  19. External morphology of the two cypridiform ascothoracid-larva instars of Dendrogaster: The evolutionary significance of the two-step metamorphosis and comparison of lattice organs between larvae and adult males (Crustacea, Thecostraca, Ascothoracida)

    DEFF Research Database (Denmark)

    Kolbasov, G.A.; Grygier, M.J.; Høeg, Jens Thorvald;

    2008-01-01

    We describe the external morphology of the two cypridiform larval instars (first and second ascothoracid-larvae, or -a-cyprids") of the ascothoracidan genus Dendrogaster. Ascothoracid-larvae of five species were studied with light and scanning electron microscopy, including both ascothoracid-larv...... to be functional in the cypridiform larvae as well. (c) 2008 Elsevier GmbH. All rights reserved...

  20. Description of the final instar larva of Orthetrum borneense Kimmins, 1936 (Odonata, Libellulidae), using rearing and molecular methods.

    Science.gov (United States)

    Steinhoff, Philip O M; Butler, Stephen G; Dow, Rory A

    2016-02-18

    The final instar larva of Orthetrum borneense Kimmins, 1936, is described and figured for the first time based on exuviae from three male and six female larvae collected in Sarawak, Borneo (East Malaysia). It is compared with an early instar larva, which was matched to the adult O. borneense by DNA barcoding, and the known larvae of other species of this genus that occur in the region.

  1. Description of the mature larva of Pseudopyrochroa depressa (Pic) (Coleoptera: Pyrochroidae: Pyrochroinae), with comparison to other Taiwanese Pseudopyrochroa.

    Science.gov (United States)

    Young, Daniel K; Hsiao, Yun

    2016-10-12

    Field collections and rearing has established an association between the larva and adult of the Taiwanese Pseudopyrochroa depressa. Larvae were collected from beneath bark of the exposed portions of a dead, decaying log in a mesic montane forest and successfully reared to the adult stage. The mature larva is described and salient features are illustrated and compared to other known pyrochroid larvae from Taiwan. Notes on larval habitats and natural history are also provided.

  2. The larva of Aphylla protracta (Hagen, 1859), and a redescription of the larva of A. angustifolia Garrison, 1986 (Odonata: Gomphidae).

    Science.gov (United States)

    Novelo-Gutiérrez, Rodolfo

    2014-11-17

    The larva of Aphylla protracta is described and figured. It is characterized by 3rd antennomere subcylindrical, flattened on ventral surface, 4.2 times longer than its widest part. Abdomen with dorsal protuberances well developed on S2-4, reduced on S5, vestigial or absent on S6-9; lateral spines lacking entirely, tergites 5-8 with minute reddish setae, tergite 9 with abundant, small, reddish setae on most of its surface and the whole posterior margin; S10 cylindrical, very long, five times longer than its base, much longer than S6+7+8+9. Also, a redescription and figures of A. angustifolia are provided, and a comparison of both species is made. Mainly differences between both species were found in abdominal dorsal protuberances and the presence/absence of small setae on abdominal tergites.

  3. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Science.gov (United States)

    2010-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other...-mortem inspection from any calf carcass infested with the larvae of the “oxwarble” fly (Hypoderma...

  4. Laboratory investigation of daily food intake and gut evacuation in larvae of African catfish Clarias gariepinus under different feeding conditions

    NARCIS (Netherlands)

    García-Ortega, A.; Verreth, J.A.J.; Vermis, K.; Nelis, H.J.; Sorgeloos, P.; Verstegen, M.W.A.

    2010-01-01

    Abstract Temporary accumulation of ascorbic acid 2-sulfate (AAS) was measured to estimate food intake and gut evacuation in larvae of African catfish. Fish larvae were fed decapsulated cysts of Artemia containing AAS. In a first experiment it was found that no biosynthesis of AAS occurs in the larva

  5. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae

    Science.gov (United States)

    Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D.

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins’ anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver. PMID:27760211

  6. Dietary fatty acid composition affects food intake and gut-brain satiety signaling in Senegalese sole (Solea senegalensis, Kaup 1858) larvae and post-larvae.

    Science.gov (United States)

    Bonacic, Kruno; Campoverde, Cindy; Gómez-Arbonés, Javier; Gisbert, Enric; Estevez, Alicia; Morais, Sofia

    2016-03-01

    Little is known how dietary lipids affect food intake during larval development of fish, especially with regard to fatty acid (FA) composition. In fact, very little work has been done on appetite regulation and food intake in fish larvae in general, due to biological and technical difficulties associated with this type of studies. A new method using fluorescent microspheres as markers was developed in this study to evaluate food intake and prey selectivity of Senegalese sole larvae and post-larvae. Food intake was quantified in fish fed Artemia metanauplii enriched with oils differing in FA profile: cod liver oil (CLO), linseed oil (LSO), soybean oil (SBO) or olive oil (OO). The fish did not preferentially ingest a specific diet when presented with a choice. However, pre-metamorphic larvae from the CLO treatment ingested more metanauplii per g body weight, while differences in post-larvae were not significant. These findings were developed further by analyzing mRNA levels of a range of putative anorexigenic (pyya, pyyb, glp1, cckl, cart1a, cart1b, cart2a, cart4, pomca, pomcb, crf) and orexigenic (gal, npy, agrp2) genes, to identify those which are significantly affected by feeding and/or dietary FA composition. The variety of expression patterns observed highlighted the complexity of appetite regulatory mechanisms. In general, fish fed the CLO diet tended to show gene expression patterns most dissimilar to the remaining treatments. Expression in pre-metamorphic larvae was generally less in accordance with the putative function of the genes than in post-larvae, which could suggest a yet underdeveloped regulatory system.

  7. Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

    Science.gov (United States)

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Yin, Xuebo; Dou, Shuozeng

    2010-06-01

    This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph). Results showed that increasing mercury concentration led to increased mercury bioaccumulation and reduced flounder growth. Of the antioxidants investigated, superoxide dismutase (SOD) and catalase (CAT) activities at the three developmental stages were sensitive to mercury exposure and increased with increasing mercury concentration. Glutathione (GSH) content was elevated in metamorphosing larvae, but decreased in juveniles as mercury concentration increased. Glutathione-S-transferase (GST) activity did not significantly vary with mercury concentration in either larvae or juveniles. Mercury exposure did not affect malondialdehyde (MDA) content of larvae, but significantly increased MDA content of juveniles. Results suggest that flounder larvae and juveniles have the potential to manipulate the levels of antioxidants such as SOD, CAT and GSH, which protect flounder from oxidative stress induced by mercury exposure. These antioxidants could serve as biomarkers of mercury contamination in the aquatic environment.

  8. Behaviour of damselfly larvae (Enallagma cyathigerum) (Insecta, Odonata) after long-term exposure to PFOS

    Energy Technology Data Exchange (ETDEWEB)

    Gossum, Hans van [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: hans.vangossum@ua.ac.be; Bots, Jessica [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: jessica.bots@ua.ac.be; Snijkers, Tom [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: tom.snijkers@gmail.com; Meyer, Johan [Research group of Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: izak.meyer@ua.ac.be; Van Wassenbergh, Sam [Laboratory for Functional Morphology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)], E-mail: sam.vanwassenbergh@ua.ac.be; De Coen, Wim [Research group of Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: wim.decoen@ua.ac.be; De Bruyn, Luc [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Research Institute for Nature and Forest, Kliniekstraat 25, 1070 Brussels (Belgium)], E-mail: luc.debruyn@ua.ac.be

    2009-04-15

    Perfluorooctane sulfonic acid (PFOS) is a persistent and ubiquitous environmental contaminant that has been detected in organisms worldwide. Here, we evaluate whether long-term (1 and 4 months) exposure to PFOS contamination affects the behavioural performance of freshwater larvae of the damselfly Enallagma cyathigerum (Insecta: Odonata). Our results show reduced behavioural performance with increasing PFOS concentration. In 1 month exposed larvae, no observed effect concentrations (NOECs) were 100 {mu}g/L for general activity. In 4 months exposed larvae, NOECs were 10 {mu}g/L, for each behavioural trait, except swimming acceleration of male larvae where the NOEC was 100 {mu}g/L. When faced with PFOS concentrations above the NOEC, E. cyathigerum larvae were less active, less capable to escape a simulated predator attack and less efficient in foraging. Together, our results show that damselfly larvae suffer reduced survival-related behavioural performance. - Long-term laboratory exposure to perfluorooctane sulfonic acid decreases behavioural performance of damselfly larvae (Insecta: Odonata)

  9. Resistance Detection of Aedes aegypti Larvae to Cypermethrin from Endemic Area in Cimahi City West Java

    Directory of Open Access Journals (Sweden)

    Endang Puji Astuti

    2014-06-01

    Full Text Available Vector control programs using chemical insecticide e.g organochlorin, organophosphate, carbamate, and pyrethroid (cypermethrin. When those insecticides were applied continuously, it may lead to vector resistance. The aim of this research was to detect any resistance of Ae. aegypti to cypermethrin in endemic areas of Cimahi. This research is a laboratory study that used biochemical test which referred to Lee’s method. Larva samples were collected from 8 villages, which are endemic area. Samples of larvae were collected from 15 villages belonged to dengue endemic areas in town of Cimahi, however, villages that meet the availability of larvae were only 8 villages. To detect the activity of monooxygenase enzyme, a biochemical assay was used in this research by created a reaction between larvae homogenate and sodium acetate substrate. The results of reaction were read using ELISA reader with spectrophotometer wave length of 595 nm. Overall, the results showed that most of the larvae in eight villages of Cimahi is still susceptible to cypermethrin. However, larvae from Cibabat village were 4% resistant, 2% tolerant, and 94% susceptible. On the other hand, Cigugur village showed that 12.7% larvae were tolerant and 87.3% still susceptible. Other villages like Cimahi, Cibeureum, Melong, Baros, Cipageran, and Pasirkaliki still remains susceptible. Resistance detection using biochemical assay of cypermethrin insecticide for Ae.aegypti resulting data stated that in 6 villages were still susceptible but in 3 other villages were already tolerant and 1 village was already resistance.

  10. Reduced cannibalistic behavior of African catfish, Clarias gariepinus, larvae under dark and dim conditions.

    Science.gov (United States)

    Mukai, Yukinori; Sanudin, Noorsyarinah; Firdaus, Rian Freddie; Saad, Shahbudin

    2013-06-01

    In general, African catfish shows higher survival rates in the dark conditions than in the light conditions. In this study, larval behavior of African catfish was observed under 0, 0.01, 0.1, 1, 10, and 100 lx using a CCD camera to investigate the reason why African catfish larvae show higher survival rates in dark conditions. The larvae showed significantly higher swimming activity under 0, 0.01, and 0.1 lx than that under 10 and 100 lx. The larvae also showed significantly increased aggressive behavior under 10 and 100 lx; the swimming larvae attacked resting individuals more frequently under 10 and 100 lx than under 0, 0.01, and 0.1 lx. The aggressive behavior and sharp teeth of the attacking larvae appeared to induce skin surface lesions on injured larvae. Chemical substances were then generated from the injured skin surface, and these chemical stimuli triggered cannibalistic behavior in other fish near the injured fish. The results of this study demonstrate that the higher survival rates of African catfish larvae under dark conditions are a result of inactivity and subsequent increase in chemical releasing stimuli concentrations around inactive individuals that triggers feeding behavior in nearby active catfish. Therefore, we recommend larval rearing of African catfish in dark or dim conditions, as it improves catfish survival rates.

  11. GC-MS investigation of the chemical composition of honeybee drone and queen larvae homogenate

    Directory of Open Access Journals (Sweden)

    Isidorov Valery A.

    2016-06-01

    Full Text Available Honeybee larva homogenate appears to be underrated and insufficiently explored but this homogenate is an exceptionally valuable honeybee product. Drone larva homogenate is very nutritional due to its high content of proteins, free amino acids, lipids, and carbohydrates. Moreover, the biological characteristics of honeybee larvae indicate the presence of chemical substances that may be pharmacologically active. In spite of the above, the chemical composition of honeybee larva has not gained as much attention as that of other bee products. In this study, the chemical composition of honeybee brood homogenate has been investigated using gas chromatography/mass spectrometry. As a result, it was possible to isolate as many as 115 extractive organic compounds from 6 samples of crude queen and 9 samples of drone homogenate. The main groups of substances extracted from either type of homogenate were composed of free amino acids and carbohydrates. The relative content of amino acids in queen homogenate as well as the share of essential amino acids were found to be higher than in the drone homogenate. Disaccharide trehalose was the dominant sugar in the queen larvae, whilst glucose prevailed in the drone larvae. Comparative chemical analyses of honeybee queen and drone larva homogenates have allowed us to make a preliminary inference about a higher overall value of the former.

  12. Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo-Costa

    2015-09-01

    Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

  13. Differential toxicity to Cd, Pb, and Cu in dragonfly larvae (Insecta: Odonata).

    Science.gov (United States)

    Tollett, V D; Benvenutti, E L; Deer, L A; Rice, T M

    2009-01-01

    Odonate larvae are important organisms in aquatic ecosystems but have been rarely studied in laboratory toxicity tests. Only a few previous studies have been conducted on odonates and their responses to heavy metals. We exposed two species of libellulid larvae (Anisoptera: Libellulidae) to equimolar concentrations of cadmium, lead, or copper in 7-day survival tests. Larvae were tolerant of high concentrations of cadmium and lead, as no significant decrease in survival was observed at exposures as high as 0.893 and 2.232 mM, respectively. In contrast, larvae were more sensitive to copper exposure, demonstrating significantly decreased survival to exposures as low as 2.360 microM. In whole animal samples, larvae accumulated very high concentrations (>1000 microg/g dry weight) of all three metals in an exposure-related manner. Much of this accumulation could probably be attributed to adsorption or accumulation of metal within the exoskeleton, because odonate larvae are known to sequester metals into this material. Our results were generally consistent with previous observations indicating that odonates are tolerant to metal exposures, even in comparison with other aquatic invertebrates. However, there are few studies that have used odonates in toxicity tests and compared these organisms to other aquatic life. Based on their abundance and their simple requirements in the laboratory, we believe that odonate larvae can be useful toxicological model organisms.

  14. Tracking living decapod larvae: mass staining of eggs with neutral red prior to hatching.

    Science.gov (United States)

    Øresland, V; Horobin, R W

    2012-04-01

    Mass staining of decapod females carrying eggs, with subsequent identification of hatched larvae in the environment, is a research tool with great potential for field ecologists wishing to track the movements of larvae. For this to be achieved, however, numerous requirements must be met. These include adequate dye solubility, short staining time, dye penetration through different tissues, dye retention within the organism, absence of toxic and behavioral effects, low visibility to predators of stained larvae, no loss of staining owing to preservatives and low cost. The dye, neutral red, appears to meet most of these requirements. This dye was used in aliquots of 0.7 g/770 ml seawater applied to the females of Norway lobster (Nephrops norvegicus) and European lobster (Homarus gammarus) for 10 min. This procedure stained lobster eggs and embryos so that hatched larvae could be distinguished easily by fluorescence microscopy from larvae that hatched from unstained eggs. Stained larvae that were preserved in 4% formaldehyde in seawater were still stained after 1 year. Larvae should not come in contact with ethanol, because it extracts the dye rapidly.

  15. Orientation mechanisms and sensory organs involved in host location in a dipteran parasitoid larva.

    Science.gov (United States)

    Crespo, José E; Lazzari, Claudio R; Castelo, Marcela K

    2011-01-01

    The robber fly Mallophora ruficauda is one of the principal pests of apiculture in the Pampas region of Argentina. Larvae are solitary ectoparasitoids of third-instar scarab beetle larvae. Females of M. ruficauda do not lay eggs on or near the hosts, but on tall grasses. After hatching, larvae are dispersed by the wind and drop to the ground, where they dig and search for potential hosts. It is known that second-instar larvae of M. ruficauda exhibit active host-searching behaviour towards their preferred hosts, i.e., third-instar larvae of Cyclocephala signaticollis. Although host-location seems to be mediated by chemical cues, the mechanism of orientation and the sensory organs involved in host location remain unknown. We carried out behavioural experiments in the laboratory to address these questions. We also tested whether the orientation behaviour is exclusively based on the use of chemical cues. We found that larvae of M. ruficauda detect the chemicals with chemosensilla on the maxillary palps. Only one maxillary palp suffices for orientation, but their bilateral ablation abolishes orientation. Besides, an hexane extract of the host body was as attractive as a live host. Our results support that M. ruficauda larvae find their hosts underground by means of chemoklinotaxis.

  16. Fish larvae retention linked to abrupt bathymetry at Mejillones Bay (northern Chile during coastal upwelling events

    Directory of Open Access Journals (Sweden)

    Pablo M Rojas

    2014-11-01

    Full Text Available The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax, associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus, associated with the thermocline (12°C, and finally, larvae of the families Myctophidae (Diogenichthys atlanticus and Bathylagidae (Bathylagus nigrigenys, associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.

  17. Initial characterization of receptors for molecules that induce the settlement and metamorphosis of Haliotis rufescens larvae

    Energy Technology Data Exchange (ETDEWEB)

    Trapido-Rosenthal, H.G.

    1985-01-01

    Larvae of the marine gastropod mollusc Haliotis refescens are induced to undergo metamorphosis by ..gamma..-aminobutyric acid (GABA) and stereochemically related compounds. The most potent of these inducers is (-)-..beta..-(parachlorophenyl)-GABA (baclofen). The inductive response exhibits positive cooperatively, and is subject to both facilitation (up-regulation) and habituation (down-regulation). Facilitation is brought about by diamino acids such as L-diaminopropionic acid (L-DAPA), and is characterized by decreased Hill coefficients (n/sub H/) and concentration requirements (EC/sub 50/) for inducers. Facilitation does not require the simultaneous presence of facilitating and inducing compounds, and the facilitated state is persistent. Larvae are capable of being up-regulated 2 days before they are capable of undergoing settlement and metamorphosis. Habituation can be brought about by exposure of pre-competent larvae to GABA 4 days prior to the attainment of competence; it is then slowly reversible. Larvae specifically bind tritiated (-)-baclofen in a manner that is saturable with both increasing time of exposure of larvae to, and with increasing concentration of, this compound. Specific binding can be competed for by unlabeled GABA-mimetic inducing molecules; the order of effectiveness of these molecules as competitors for specific binding correlates well with their effectiveness as inducers of metamorphosis. Facilitation of larvae by exposure to diamino acids does not alter their specific binding of tritiated (-)-baclofen. It is concluded from these findings that Haliotis larvae possess receptors for GABA-mimetic compounds.

  18. Diet affects the redox system in developing Atlantic cod (Gadus morhua larvae

    Directory of Open Access Journals (Sweden)

    Samuel Penglase

    2015-08-01

    Full Text Available The growth and development of marine fish larvae fed copepods is superior to those fed rotifers, but the underlying molecular reasons for this are unclear. In the following study we compared the effects of such diets on redox regulation pathways during development of Atlantic cod (Gadus morhua larvae. Cod larvae were fed a control diet of copepods or the typical rotifer/Artemia diet commonly used in commercial marine fish hatcheries, from first feeding until after metamorphosis. The oxidised and reduced glutathione levels, the redox potential, and the mRNA expression of 100 genes in redox system pathways were then compared between treatments during larval development. We found that rotifer/Artemia-fed cod larvae had lower levels of oxidised glutathione, a more reduced redox potential, and altered expression of approximately half of the redox system genes when compared to copepod-fed larvae. This rotifer/Artemia diet-induced differential regulation of the redox system was greatest during periods of suboptimal growth. Upregulation of the oxidative stress response transcription factor, nrf2, and NRF2 target genes in rotifer/Artemia fed larvae suggest this diet induced an NRF2-mediated oxidative stress response. Overall, the data demonstrate that nutritional intake plays a role in regulating the redox system in developing fish larvae. This may be a factor in dietary-induced differences observed in larval growth.

  19. [Effects of fermented cattle dung on the growth and development of Tenebrio molitor larvae].

    Science.gov (United States)

    Zeng, Xiang-Wei; Wang, Xia; Guo, Li-Yue; Zhan, Li-Jie; Bo, Wen-Jing; Li, Zhan; Wu, Guang-Lei; Jiang, Gao-Ming

    2012-07-01

    In order to make use of and industrialize the animal dung from large cattle farms, this paper explored the feasibility of using Tenebrio molitor to digest and utilize cattle dung. Cattle dung was mixed with the conventional feed (65% wheat bran, 30% corn flour, and 5% bean pulp) of T. molitor in definite proportions, and fermented with effective microorganisms (EM). The fermented products containing 60% and 80% of cattle dung (FD1 and FD2, respectively) were selected to feed T. molitor larvae, and the effects of the fermented products on the growth curve, death rate, pupation rate, and antioxidant system of the larvae were compared. Compared with CK (conventional deed), the FD1 made the developmental duration of the larvae prolonged by 10 days and the larvae's death rate upraised somewhat, but made the single larva's total food intake, average body mass, crude fat content, and ratio of unsaturated to saturated fat acids increased by 49%, 28%, 26%, and 32%, respectively (P molitor larvae had weak adaptability to FD2. Our findings suggested that using FD1 to feed the 3rd instar of T. molitor larvae would have good practical prospects in industrializing cattle dung.

  20. DISTRIBUSI, KELIMPAHAN DAN VARIASI UKURAN LARVA IKAN DI ESTUARIA SUNGAI MUSI

    Directory of Open Access Journals (Sweden)

    Eko Prianto

    2016-03-01

    Full Text Available Penelitian tentang distribusi, kelimpahan dan ukuran larva ikan dilakukan pada bulan Maret, Mei, Juni dan Oktober 2011. Stasiun pengambilan contoh meliputi Muara Delta Upang (stasiun 1, Muara Sungai Musi (stasiun 2 dan Pulau Payung (stasiun 3. Pengambilan larva pada siang hari menggunakan Bongo net yang berukuran mata jaring 250 µm. Hasil identifikasi diperoleh 13 famili ditinjau menurut musim, pada bulan Mei dan Oktober masing-masing diperoleh 7 famili, dan pada bulan juni sebanyak 3 famili. Kelimpahan larva ikan berkisar antara 9-46 ind/m3 dengan jumlah yang tertinggi (46 ind/m3 pada bulan Mei dan terendah pada bulan Juni (9 ind/m3. Larva ikan dari famili Gobiidae memiliki sebaran yang cukup luas baik spasial maupun temporal. Variasi ukuran larva ikan menurut famili setiap bulannya memiliki variasi ukuran yang hampir sama.  Research about the distribution, abundance and size of fish larvae was conducted in March, May, June and October 2011. Sampling stations encompasses Delta Upang (station 1, Muara Sungai Musi (station 2 and Pulau Payung (station 3. Larvae taken during the daytime using a Bongo net with mesh size of 250 µm. Identification results obtained 13 families based on the season, in May and October respectively 7 families, and in June as many as 3 families. Abundance of fish larval around 9-46 ind/m3 with the highest number (46 ind/m3 in May and the lowest in June (9 ind/m3. Larvae of Gobiidae family have a large distribution on spatial and temporal. The variation in size of fish larvae by family on each month are the same.

  1. Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

    Science.gov (United States)

    Gaonkar, Chetan A.; Anil, Arga Chandrashekar

    2012-10-01

    Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in feeding studies of various organisms. In this study we standardised the gut fluorescence method using laboratory-reared barnacle larvae (Balanus amphitrite) fed with mono-algal diet Chaetoceros calcitrans, a unicellular diatom at a cell concentration of 2 × 105 cells ml-1. The gut fluorescence of IV-VI instar nauplii was found to be 370(±12) ng chlorophyll a larva-1 and in faecal pellets it was 224(±63) ng chlorophyll a larva-1. A phaeopigment concentration in larval gut was found to be 311(±13) ng larva-1 and in faecal pellets it was 172(±61) ng larva-1. The study also analysed larval samples collected from the field during different seasons from a tropical environment influenced by monsoons (Dona Paula bay, Goa, west coast of India), with characteristic temporal variations in phytoplankton abundance and diversity. Gut fluorescence of larvae obtained during the post-monsoon season was consistently higher when compared to the pre-monsoon season, suggesting the predominance of autotrophic forms in the larval gut during the post-monsoon season. Whereas, the low gut fluorescence obtained during the pre-monsoon season indicated the ingestion of food sources other than autotrophs. Such differences observed in the feeding behaviour of larvae could be due to differential availability of food for the larvae during different seasons and indicate the capability of larvae to feed on wide range of food sources. This study shows the value of the fluorescence method in feeding studies of planktotrophic organisms and in the evaluation of ecosystem dynamics.

  2. Feasibility study of biodiesel production using lipids of Hermetia illucens larva fed with organic waste.

    Science.gov (United States)

    Leong, Siew Yoong; Kutty, Shamsul Rahman Mohamed; Malakahmad, Amirhossein; Tan, Chew Khun

    2016-01-01

    Hermetia illucens larvae by nature are a decomposer which fed on organic wastes. This study explores the potential of producing biodiesel using lipids from H. illucens larvae. Three types of organic wastes (sewage sludge, fruit waste and palm decanter cake from oil palm mill) were selected based on considerable generation and disposal concern in the area of study as well as lack of investigations as feed for Hermetia illucens larvae in current literatures. Growth rate of the larvae was determined with studying the changes in the biomass per day. H. illucens larvae fed with fruit waste and palm decanter cake have shown growth rates of 0.52±0.02 and 0.23±0.09 g d(-1), respectively. No positive sign of growth were observed in the larvae fed with treated sewage sludge (-0.04±0.01 g d(-1)). Biodiesel as fatty acid methyl ester (FAME) was synthesized by transesterification of the larvae lipid using sulphuric acid as catalyst in methanol. FAME produced was ascertained using ATR-FTIR spectroscopy and GC-MS. The main compositions of fatty acid were found to be C12:0, C16:0 and C18:1n9c. Fatty acid composition of C12:0 fed with fruit waste, sewage sludge and palm decanter was found to be most abundant in the larvae lipid. The amount of C12:0 obtained was 76.13%, 58.31% and 48.06%, respectively. In addition, fatty acid of C16:0 was attained at 16.48% and 25.48% fed with sewage sludge and palm decanter, respectively. Based on the findings, FAME derived from larvae lipids is feasible to be used for biodiesel production.

  3. Variation in brain organization of coral reef fish larvae according to life history traits.

    Science.gov (United States)

    Lecchini, David; Lecellier, Gael; Lanyon, Rynae Greta; Holles, Sophie; Poucet, Bruno; Duran, Emilio

    2014-01-01

    In coral reefs, one of the great mysteries of teleost fish ecology is how larvae locate the relatively rare patches of habitat to which they recruit. The recruitment of fish larvae to a reef, after a pelagic phase lasting between 10 and 120 days, depends strongly on larval ability to swim and detect predators, prey and suitable habitat via sensory cues. However, no information is available about the relationship between brain organization in fish larvae and their sensory and swimming abilities at recruitment. For the first time, we explore the structural diversity of brain organization (comparative sizes of brain subdivisions: telencephalon, mesencephalon, cerebellum, vagal lobe and inferior lobe) among larvae of 25 coral reef fish species. We then investigate links between variation in brain organization and life history traits (swimming ability, pelagic larval duration, social behavior, diel activity and cue use relying on sensory perception). After accounting for phylogeny with independent contrasts, we found that brain organization covaried with some life history traits: (1) fish larvae with good swimming ability (>20 cm/s), a long pelagic duration (>30 days), diurnal activity and strong use of cues relying on sensory perception for detection of recruitment habitat had a larger cerebellum than other species. (2) Fish larvae with a short pelagic duration (fish larvae exhibiting solitary behavior during their oceanic phase had larger inferior and vagal lobes. Overall, we hypothesize that a well-developed cerebellum may allow fish larvae to improve their chances of successful recruitment after a long pelagic phase in the ocean. Our study is the first one to bring together quantitative information on brain organization and the relative development of major brain subdivisions across coral reef fish larvae, and more specifically to address the way in which this variation correlates with the recruitment process.

  4. Successful determination of larval dispersal distances and subsequent settlement for long-lived pelagic larvae.

    Directory of Open Access Journals (Sweden)

    Pelayo Salinas-de-León

    Full Text Available Despite its importance, we still have a poor understanding of the level of connectivity between marine populations in most geographical locations. Taking advantage of the natural features of the southeast coast of New Zealand's North Island, we deployed a series of settlement stations and conducted plankton tows to capture recent settlers and planktonic larvae of the common intertidal gastropod Austrolittorina cincta (6-8 week larval period. Satellite image analysis and ground truthing surveys revealed the absence of suitable intertidal rocky shore habitat for A. cincta over a 100 km stretch of coastline between Kapiti Island to the south and Wanganui to the north. Fifteen settlement stations (3 replicates × 5 sites, which were used to mimic intertidal habitat suitable for A. cincta, were deployed for two months around and north of Kapiti Island (at 0.5, 1, 5, 15, 50 km. In addition, we also conducted plankton tows at each settlement station when the stations were first deployed to collect A. cincta larvae in the water column. On collection, all newly settled gastropods and larvae in the plankton samples were individually isolated, and a species-specific microsatellite marker was used to positively identify A. cincta individuals. Most of the positively identified A. cincta settlers and larvae were collected at the first three sampling stations (<5 km. However, low numbers of A. cincta settlers and larvae were also recorded at the two more distant locations (15 and 50 km. Dispersal curves modeled from our data suggested that <1% of gastropod larvae would travel more than 100 km. While our data show that most larvae are retained close to their natal populations (<5 km, a small proportion of larvae are able to travel much larger geographic distances. Our estimates of larval dispersal and subsequent settlement are one of only a few for marine species with a long-lived larva.

  5. Advances in Studies of the Effects of Starvation on Growth and Development of Fish Larvae

    Institute of Scientific and Technical Information of China (English)

    SHAN Xiujuan; HUANG Wei; CAO Liang; WU Yunfei

    2008-01-01

    Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae, and plays an important role in the dynamics of fish population and fisheries recruitment, in this review, we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adap- tive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes, evaluating the nutrition condition and growth of larval fish, protecting fish resource and breeding fish larvae.

  6. Identification of entomopathogenic Bacillus isolated from Simulium (Diptera, Simuliidae larvae and adults

    Directory of Open Access Journals (Sweden)

    Cavados CFG

    2001-01-01

    Full Text Available Entomopathogenic bacteria isolated from Simulium larvae and adults from breeding sites in the states of São Paulo and Rio de Janeiro, Brazil, were identified as 18 strains of Bacillus thuringiensis and one of B. sphaericus. Most of these strains were serotyped according to their flagellar antigens. However, nine of the B. thuringiensis samples, could not be serotyped and were designated as "autoagglutinating"; they were also shown to be toxic in preliminary tests against Aedes aegypti larvae. Additionally, B. sphaericus was also shown to be toxic towards Culex quinquefasciatus larvae.

  7. Mature larva of Stenichnus collaris (Müller & Kunze) (Coleoptera: Staphylinidae: Scydmaeninae).

    Science.gov (United States)

    Jałoszyński, Paweł

    2013-12-03

    The mature larva of Stenichnus collaris is re-described on the basis of a shed larval skin. This is the first description of an immature Stenichnus identified by rearing to an adult beetle, and not only by collecting the larva in association with adults, as in previously published works. New data on the life history of St. collaris are provided, and possible serial homology of chaetotaxic structures across body segments is discussed. The structures of immature Nearctic St. turbatus, the only Stenichnus larva described with focus on the chaetotaxy, are compared with those of St. collaris and possible homologies are indicated.

  8. Growth and structure of the digestive system of pacu larvae fed microencapsulated diet produced experimentally

    OpenAIRE

    Olívia Cristina Camilo Menossi; Rodrigo Takata; María Isabel Sánchez-Amaya; Thiago Mendes de Freitas; Manuel Yúfera; Maria Célia Portella

    2012-01-01

    Foram comparados os efeitos de diferentes dietas e da transição alimentar sobre o desempenho zootécnico e a morfologia do trato digestório de larvas de pacu alimentadas com duas dietas comerciais e uma dieta experimental microencapsulada produzida por gelificação interna. Larvas com quatro dias de vida receberam os seguintes protocolos alimentares: somente náuplios de artêmia em quantidades crescentes (controle positivo); larvas mantidas em jejum (controle negativo); três tipos de alimento fo...

  9. A case report of cutaneous larva migrans in a Mexican population of high marginalization

    Institute of Scientific and Technical Information of China (English)

    Isaac; Aguirre; Maldonadoa; Silvia; Cruz; Duartea; Felipe; Gonzlez; Velzqueza; Alfonso; Alexander; Aguilerab

    2014-01-01

    The creeping verminous dermatitis or cutaneous larva migrans is a parasitosis caused by percutaneous penetration and migration of larval nematode parasites characterized by producing one or more serpiginous erythematous,indurated,raised and pruritic lesion.The most common cause of cutaneous larva migrans is the Ancytostoma braziliensc located in warm climate zones.In the present study,authors reported a case of cutaneous larva migrans with a characteristic clinical picture:erythematous-papnlar and vesicular lesion and serpiginous path,with progressive,and pruritic growth and it shown that a living area with immigration,tropical weather conditions and poverty may lead to this common infection.

  10. Protozoosis caused by Vairimorpha necatrix (Microsporia, Nosematidae in larvae of Spodoptera frugiperda (Lepidoptera, Noctuidae

    Directory of Open Access Journals (Sweden)

    Prafulbala N. Patel

    1988-01-01

    Full Text Available Vairimorpha necatrix was detected among laboratory cultured and field collected Spodoptera frugiperda larvae. Weak infections were not always fatal. In the case of fatal infections among diseased larvae, white patches were formed by agglomerations of adipose tissue beneath the transparent integument. The mid-gut of S. frugiperda larvae presented the first site of histological alterations caused by V. necatrix. The migration of the pathogen, probably occured in the form of agglomerations, from the epithelial cells to the body cavity. Adipose tissue appears to be the principal site for the pathogen development. The nerve ganglia, muscle fibres and epidermis also presented histological alterations due to the pathogen propagation.

  11. Contrasting feeding patterns among species of fish larvae from the tropical Andaman Sea

    DEFF Research Database (Denmark)

    Østergaard, P.; Munk, Peter; Janekarn, V.

    2005-01-01

    Feeding habits of tropical fish larvae were analysed in a comparative study of four species (Scorpaenodes sp., Carangoides sp., Acanthocepola sp. and Cynoglossus sp.) from the Andaman Sea. We investigated morphological characteristics and their potential influence on larval feeding, and looked...... for common patterns in larval prey preference. Gut contents of a total of 300 larvae were examined and compared with local zooplankton composition. The feeding habits of the investigated larvae shared a number of characteristics. During ontogeny both the preferred prey size and the number of prey in the gut...

  12. A case report of cutaneous larva migrans in a Mexican population of high marginalization

    Institute of Scientific and Technical Information of China (English)

    Isaac Aguirre Maldonadoa; Silvia Cruz Duartea; Felipe Gonzlez Velzqueza; Alfonso Alexander Aguilerab

    2014-01-01

    The creeping verminous dermatitis or cutaneous larva migrans is a parasitosis caused by percutaneous penetration and migration of larval nematode parasites characterized by producing one or more serpiginous erythematous, indurated, raised and pruritic lesion. The most common cause of cutaneous larva migrans is the Ancylostoma braziliense located in warm climate zones. In the present study, authors reported a case of cutaneous larva migrans with a characteristic clinical picture: erythematous-papular and vesicular lesion and serpiginous path, with progressive, and pruritic growth and it shown that a living area with immigration, tropical weather conditions and poverty may lead to this common infection.

  13. INDEKS ENTOMOLOGI DAN KERENTANAN LARVA Aedes aegypti TERHADAP TEMEFOS DI KELURAHAN KARSAMENAK KECAMATAN KAWALU KOTA TASIKMALAYA

    Directory of Open Access Journals (Sweden)

    Hubullah Fuadzy

    2015-10-01

    Full Text Available AbstrakSalah satu upaya pengendalian vektor nyamuk Aedes aegypti adalah menggunakan larvasida sintetis seperti temefos. Pemanfaatan temefos secara terus menerus dan berulang merupakan faktor risiko terjadinya resistensi. Tujuan penelitian ini adalah untuk menentukan indeks entomologi dan status kerentanan larva Ae. aegypti terhadap temefos di Kelurahan Karsamenak Kecamatan Kawalu Kota Tasikmalaya. Jenis penelitian adalah eksperimen dengan rancangan acak lengkap. Populasi adalah larva nyamuk Ae. aegypti yang diperoleh dari 289 rumah penduduk di Kelurahan Karsamenak, dan sampel adalah 700 larva Ae. aegypti strain Karsamenak. Bioassay menggunakan metode Elliot dan Polson dengan konsentrasi diagnostik WHO sebesar 0,02 ppm. Hasil penelitian menunjukkan bahwa House Index (HI 24,9; Container Index (CI 9,05; Breteau Index (BI 29,07; dan Density Figure (DF 4. Larva Ae. aegypti umumnya ditemukan di Bak Mandi penduduk. Kemudian untuk membunuh 95% larva Ae. aegypti dibutuhkan konsentrasi temefos sebesar (LC95 0,02416 ppm (0,01917 ­ 0,03330 ppm dan RR95 3,02. Kelurahan Karsamenak termasuk wilayah yang potensial untuk penularan penyakit Demam Berdarah Dengue, dan larva Ae. aegypti terindikasi telah resisten terhadap temefos.Kata Kunci : Resisten, Aedes aegypti, temefos, kerentananAbstractOne effort for controlling Aedes aegypti as dengue vector is using synthetic larvacide such as temephos. Utilization of temephos continuously and repeatedly a risk factor for resistance. The objective of this study were to determine the entomology index and susceptibility of Ae. aegypti larvae against temephos in endemic areas of dengue fever in the Karsamenak District Kawalu of Tasikmalaya. The research was a true experimental study with a complete randomized design. The population were the larvae of Ae. aegypti were derived from 289 houses of resident in the Village Karsamenak and the sample was 700 larvae of Ae. aegypti strains Karsamenak. The Bioassay used Elliot and

  14. Descrição da larva de último estádio de Micrathyria pseudeximia Westfall (Odonata, Libellulidae

    Directory of Open Access Journals (Sweden)

    Marina Schmidt Dalzochio

    2009-08-01

    Full Text Available A larva de último estádio de Micrathyria pseudeximia Westfall, 1992 é descrita e ilustrada a partir de material procedente de Cascavel, Paraná, Brasil. A caracterização do gênero com base nas larvas é ampliada.Description of the Ultimate Stadium Larva of Micrathyria pseudeximia Westfall(Odonata, Libellulidae.Abstract. The larva of ultimate stadium of Micrathyria pseudeximia Westfall, 1992 is described and illustrated based on material collected in Cascavel Municipality, Paraná State, Brazil. The generic concept based on the larvae is amplified.

  15. Synergistic activity of Bacillus thuringiensis toxins against Simulium spp. larvae.

    Science.gov (United States)

    Monnerat, Rose; Pereira, Eleny; Teles, Beatriz; Martins, Erica; Praça, Lilian; Queiroz, Paulo; Soberon, Mario; Bravo, Alejandra; Ramos, Felipe; Soares, Carlos Marcelo

    2014-09-01

    Species of Simulium spread diseases in humans and animals such as onchocerciasis and mansonelosis, causing health problems and economic loses. One alternative for controlling these insects is the use of Bacillus thuringiensis serovar israelensis (Bti). This bacterium produces different dipteran-active Cry and Cyt toxins and has been widely used in blackfly biological control programs worldwide. Studies on other insect targets have revealed the role of individual Cry and Cyt proteins in toxicity and demonstrated a synergistic effect among them. However, the insecticidal activity and interactions of these proteins against Simulium larvae have not been reported. In this study we demonstrate that Cry4Ba is the most effective toxin followed by Cry4Aa and Cry11Aa. Cry10Aa and Cyt1Aa were not toxic when administered alone but both were able to synergise the activity of Cry4B and Cry11Aa toxins. Cyt1Aa is also able to synergise with Cry4Aa. The mixture of all toxin-producing strains showed the greatest level of synergism, but still lower than the Bti parental strain.

  16. MRI findings of spinal visceral larva migrans of Toxocara canis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Ho, E-mail: leeinho1974@hanmail.ne [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Department of Radiology, Chungnam National University Hospital, 33 Munhwa-ro, Jung-gu, Daejeon 301-721 (Korea, Republic of); Kim, Sung Tae, E-mail: st7.kim@hotmail.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Oh, Dae Kun, E-mail: odk6464@nate.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Kim, Hyung-Jin, E-mail: hyungkim@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Kim, Keon Ha, E-mail: somatom@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Jeon, Pyoung, E-mail: drpjeon@gmail.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Byun, Hong Sik, E-mail: byun5474@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of)

    2010-08-15

    Purpose: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord. Materials and methods: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response. Results: Total 8 patients (M = 8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients. Conclusion: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis.

  17. Enzymatic properties of phenoloxidase from Pieris rapae (Lepidoptera) larvae

    Institute of Scientific and Technical Information of China (English)

    CHAO-BIN XUE; WAN-CHUN LUO; QING-XI CHEN; QIN WANG; LI-NA KE

    2006-01-01

    The kinetic parameters of partially purified phenoloxidase (PO, EC. 1.14.18.1) from the 5th instar larvae of Pieris rapae (Lepidoptera) were determined, using L-3, 4-dihydroxyphenylalanine (L-DOPA) as substrate. The optimal pH and temperature of the enzyme for the oxidation of L-DOPA were determined to be at pH 7.0 and at 42℃,respectively. The enzyme was stable between pH 6.5 and 7.4 and at temperatures lower than 37℃. At pH 6.8 and 37℃, the Michaelis constant (Km) and maximal velocity (Vm) of the enzyme for the oxidation of L-DOPA were determined to be 0.80 mmol/L and 1.84 μmol/ L/min, respectively. Tetra-hexylresorcinol and 4-dodecylresorcinol effectively inhibited activity of phenoloxidase and this inhibition was reversible and competitive, with the IC50 of 1.50 and 1.12μmol/L, respectively. The inhibition constants were estimated to be 0.50 and 0.47μmol/L, respectively.

  18. Chronic Wounds, Biofilms and Use of Medicinal Larvae

    Directory of Open Access Journals (Sweden)

    Linda J. Cowan

    2013-01-01

    Full Text Available Chronic wounds are a significant health problem in the United States, with annual associated costs exceeding $20 billion annually. Traditional wound care consists of surgical debridement, manual irrigation, moisture retentive dressings, and topical and/or systemic antimicrobial therapy. However, despite progress in the science of wound healing, the prevalence and incidence of chronic wounds and their complications are escalating. The presence & complexity of bacterial biofilms in chronic wounds has recently been recognized as a key aspect of non-healing wounds. Bacterial biofilms are sessile colonies of polymicrobial organisms (bacteria, fungus, etc. enclosed within a self-produced exopolymeric matrix that provides high levels of tolerance to host defenses, antibiotics and antiseptics. Thus, there is a need for alternative therapies to reduce biofilms in chronic wounds. In this report, we present initial findings from in vitro experiments which show that larval debridement therapy with disinfected blow fly larvae (Phaenicia sericata reduced total CFUs (6-logs of planktonic and mature biofilms of Pseudomonas aeruginosa or Staphylococcus aureus grown on dermal pig skin explants by 5-logs after 24 hours of exposure, and eliminated biofilms (no measurable CFUs after 48 hours of exposure.

  19. A transcriptomic survey of Migdolus fryanus (sugarcane rhizome borer) larvae.

    Science.gov (United States)

    Nakayama, Darlan Gonçalves; Santos Júnior, Célio Dias; Kishi, Luciano Takeshi; Pedezzi, Rafael; Santiago, Adelita Carolina; Soares-Costa, Andrea; Henrique-Silva, Flavio

    2017-01-01

    Sugarcane, a major crop grown in the tropical and subtropical areas of the world, is produced mainly for sucrose, which is used as a sweetener or for the production of bioethanol. Among the numerous pests that significantly affect the yield of sugarcane, the sugarcane rhizome borer (Migdolus fryanus, a cerambycidae beetle) is known to cause severe damage to the crops in Brazil. The absence of molecular information about this insect reinforces the need for studies and an effective method to control this pest. In this study, RNA-Seq technology was employed to study different parts of M. fryanus larvae. The generated data will help in further investigations about the taxonomy, development, and adaptation of this insect. RNA was extracted from six different parts (head, fat body, integument, hindgut, midgut, and foregut) using Trizol methodology. Using Illumina paired-end sequencing technology and the Trinity platform, trimming and de novo assembly was performed, resulting in 44,567 contigs longer than 200 nt for a reunion of data from all transcriptomes, with a mean length of 1,095.27 nt. Transcripts were annotated using BLAST against different protein databanks (Uniprot/Swissprot, PFAM, KEEG, SignalP 4.1, Gene Ontology, and CAZY) and were compared for similarity using a Venn diagram. Differential expression patterns were studied for select genes through qPCR and FPKM comprising important protein families (digestive peptidases, glucosyl hydrolases, serine protease inhibitors and otopetrin), which allowed a better understanding of the insect's digestion, immunity and gravity sensorial mechanisms.

  20. Digestive enzymes activity in larvae of Cameraria ohridella (Lepidoptera: Gracillariidae).

    Science.gov (United States)

    Stygar, Dominika; Dolezych, Bogdan; Nakonieczny, Mirosław; Migula, Pawel; Michalczyk, Katarzyna; Zaak, Maria

    2010-10-01

    This article presents the activity of carbohydratases and proteases in the midgut of Cameraria ohridella larvae--an oligophagous pest whose preferred feeding is horse chestnuts leaves. Optimal media pH of the assayed enzymes were similar to those of other Lepidopterans. Relatively high amylase activity, as well as maltase and sucrase activities, indicates that starch and sucrose are the main digested saccharides. Trehalase activity was similar to that described in other Lepidopterans. Activities of glycosidases were significantly lower than those of disaccharidases what suggests that neither cellulose nor glycosides are important for C. ohridella. Trypsin is the main endoprotease of this pest. Like in other leaf-eaters carboxypeptidase activity was higher than that of aminopeptidase. The activity of the majority of examined enzymes increased in the following successive pest generations, which could be explained by the decreased nutritional value of older leaves. Probably this phenomenon in hydrolases activity in Cameraria is a nonspecific mechanism present at this stage of co-evolution of the horse chestnut and its pest.

  1. Proteomic analysis of peach fruit moth larvae treated with phosphine.

    Science.gov (United States)

    Liu, Tao; Li, Li; Li, Baishu; Zhang, Fanhua; Wang, Yuejin

    2012-01-01

    Phosphine has been used worldwide for the control of stored-product insects for many years. However, the molecular mechanism of its toxicity is not clearly understood. In the current study, larvae of the peach fruit moth were fumigated with phosphine. Proteomic analysis was then performed to identify the regulated proteins. Our results confirmed the phosphine toxicity on the peach fruit moth. The median lethal time LT50 was 38.5 h at 330 ppm at 25 degrees C. During fumigation, the respiration of the peach fruit moth was extremely inhibited. Of the 26 regulated proteins, 16 were identified by MALDI-TOF mass spectrometry after a 24 h treatment. The proteins were classified as related to metabolism (25 %), anti-oxidation (6 %), signal transduction (38 %), or defense (19 %). The rest (13 %) were unclassified. Phosphine regulation of ATP and glutathione contents, as well as of ATP synthase and glutathione S-transferase 2 activities were confirmed by enzyme activity analysis. These results demonstrate that complex transcriptional regulations underlie phosphine fumigation. New theories on the mechanism of phosphine toxicity may also be established based on these results.

  2. A digestive prolyl carboxypeptidase in Tenebrio molitor larvae.

    Science.gov (United States)

    Goptar, Irina A; Shagin, Dmitry A; Shagina, Irina A; Mudrik, Elena S; Smirnova, Yulia A; Zhuzhikov, Dmitry P; Belozersky, Mikhail A; Dunaevsky, Yakov E; Oppert, Brenda; Filippova, Irina Yu; Elpidina, Elena N

    2013-06-01

    Prolyl carboxypeptidase (PRCP) is a lysosomal proline specific serine peptidase that also plays a vital role in the regulation of physiological processes in mammals. In this report, we isolate and characterize the first PRCP in an insect. PRCP was purified from the anterior midgut of larvae of a stored product pest, Tenebrio molitor, using a three-step chromatography strategy, and it was determined that the purified enzyme was a dimer. The cDNA of PRCP was cloned and sequenced, and the predicted protein was identical to the proteomic sequences of the purified enzyme. The substrate specificity and kinetic parameters of the enzyme were determined. The T. molitor PRCP participates in the hydrolysis of the insect's major dietary proteins, gliadins, and is the first PRCP to be ascribed a digestive function. Our collective data suggest that the evolutionary enrichment of the digestive peptidase complex in insects with an area of acidic to neutral pH in the midgut is a result of the incorporation of lysosomal peptidases, including PRCP.

  3. Transcriptional response of Musca domestica larvae to bacterial infection.

    Directory of Open Access Journals (Sweden)

    Ting Tang

    Full Text Available The house fly Musca domestica, a cosmopolitan dipteran insect, is a significant vector for human and animal bacterial pathogens, but little is known about its immune response to these pathogens. To address this issue, we inoculated the larvae with a mixture of Escherichia coli and Staphylococcus aureus and profiled the transcriptome 6, 24, and 48 h thereafter. Many genes known to controlling innate immunity in insects were induced following infection, including genes encoding pattern recognition proteins (PGRPs, various components of the Toll and IMD signaling pathways and of the proPO-activating and redox systems, and multiple antimicrobial peptides. Interestingly, we also uncovered a large set of novel immune response genes including two broad-spectrum antimicrobial peptides (muscin and domesticin, which might have evolved to adapt to house-fly's unique ecological environments. Finally, genes mediating oxidative phosphorylation were repressed at 48 h post-infection, suggesting disruption of energy homeostasis and mitochondrial function at the late stages of infection. Collectively, our data reveal dynamic changes in gene expression following bacterial infection in the house fly, paving the way for future in-depth analysis of M. domestica's immune system.

  4. Effectiveness of probiotic Phaeobacter bacteria grown in biofilters against Vibrio anguillarum infections in the rearing of Turbot (Psetta maxima) larvae.

    Science.gov (United States)

    Prol-García, María J; Pintado, José

    2013-12-01

    The rearing environment of first-feeding turbot larvae, usually with high larvae densities and organic matter concentrations, may promote the growth of opportunistic pathogenic Vibrionaceae bacteria, compromising the survival of the larvae. The aim of this study was to assess the effectiveness of the biofilm-forming probiotic Phaeobacter 27-4 strain grown on a ceramic biofilter (probiofilter) in preventing Vibrio anguillarum infections in turbot larvae. In seawater with added microalgae and maintained under turbot larvae rearing conditions, the probiofilter reduced the total Vibrionaceae count and the concentration of V. anguillarum, which was undetectable after 144 h by real-time PCR. The probiofilter also improved the survival of larvae challenged with V. anguillarum, showing an accumulated mortality similar to that of uninfected larvae (35-40 %) and significantly (p biofilters can constantly inoculate probiotics into rearing tanks and are therefore potentially useful for bacterial control in both open and recirculating industrial units.

  5. Unusual pseudomyiasis with Musca domestica (housefly larvae in a child with chronic otitis media

    Directory of Open Access Journals (Sweden)

    Zafar Iqbal

    2016-01-01

    Full Text Available Myiasis is a disease caused by fly larvae and aural myiasis is a rare clinic condition often occurring in children or mentally retarded people. We report the case of an unusual presentation of a unilateral aural myiasis in a 3-year-old female child patient belonging to a slum with unilateral chronic otitis media caused by Musca domestica (housefly larvae. Eight larvae were removed from the external auditory canal while five more larvae were located in the middle ear cavity and were removed through perforation of the tympanic membrane. Management of ear myiasis is based on removal of the maggots and cleansing of the ear with ethanol, chloroform, or physiological saline. Physiological saline is preferred in patients who have tympanic membrane perforation. Myiasis is related to personal hygiene. Therefore, to decrease the incidence of these infestations, care, and hygiene standards should be carried out for those at risk through information, education, and communication.

  6. Description of two final stadium Onychogomphus larvae from Thailand (Odonata: Gomphidae).

    Science.gov (United States)

    Chainthong, Damrong; Boonsoong, Boonsatien

    2016-01-19

    The final stadium larvae of Onychogomphus castor Lieftinck and O. duaricus Fraser are described and illustrated for the first time based on reared specimens from Thailand. The taxonomic characteristics of the larvae of the genus Onychogomphus are discussed and summarized. The larva of O. castor differs from other Southeast Asian species in having distinct mid-dorsal spines on S2-9, divergent wing pads reaching S5, and lateral spines on S6-9. The larva of O. duaricus has a weakly swollen third antennal segment, with short blunt mid-dorsal spines on S2-9, divergent wing sheaths reaching the middle of S4, and lateral spines present on S7-9.

  7. Description of the larva of Argia chelata Calvert, 1902 (Odonata: Coenagrionidae).

    Science.gov (United States)

    Novelo-Gutiérrez, Rodolfo

    2013-12-06

    The larva of Argia chelata is described and figured. It falls into the group of Argia larvae with a moderately prominent ligula and two palpal seta, but it differs from its closest relatives by having labial palp with 2 setae plus one basal setella; the length of the ligula is 30% of its maximum width; basal tergites (1-5) lacking long, fine setae, mainly on midline; S8-10 mostly dark brown; paraprocts with spiniform setae on basal 0.25 and 0.55 of dorsal and ventral borders, respectively. Larvae were found in 2nd to 4th order shallow streams in cloud forest, crawling among debris, fine sand and mud where the water flow is slow or still, close to the shoreline. The larva is compared with A. lacrimans (Hagen), A. pima Garrison, and A. tonto Calvert, species apparently closely related. 

  8. Description of the larva of Neuraeschna claviforcipata Martin, 1909 (Insecta: Odonata: Aeshnidae).

    Science.gov (United States)

    De Marmels, Jürg; Neiss, Ulisses Gaspar

    2013-01-01

    The ultimate stadium larva of Neuraeschna claviforcipata is described and illustrated based on an F-0 exuvia of a reared female from northern Amazonas State, Brazil. This larva differs from the other two known larvae of the genus in lacking the spiny lateral prominence of the mandible, and in having only a short spine each side of the median cleft of the prementum; labium is shorter and cercus longer. Noteworthy is the presence of a hair brush on each occipital lobe behind mesal angle of compound eye. The larva was found in a small blackwater pool with abundant leaf litter in an open, "campina"-type habitat, with sandy soil and low, bushy vegetation.

  9. Description of the final instar larva of Rhionaeschna vigintipunctata (Ris, 1918) (Odonata: Aeshnidae).

    Science.gov (United States)

    Rodríguez, José Sebastián; Molineri, Carlos

    2014-11-14

    The final instar larva of Rhionaeschna vigintipunctata (Ris) (Odonata, Aeshnidae) is described for the first time. The description is based on a series of mature female larvae collected in Tucumán (NW Argentina) and reared to imago. It shares the U-shaped distal excision of epiproct with other larvae of the Marmaraeschna group (only R. pallipes and R. brevicercia known from this stage); but the minute tubercle at each side of the cleft of ligula is absent. Other characters unique to R. vigintipunctata include: open ligula (vs. closed in other "Marmaraeschna"), and mandibular formula. A table to distinguish the larvae of the three species of "Marmaraeschna" and biological and distributional data of R. vigintipunctata are included.

  10. Toxicity of poison from spider Nephila sp. to Aëdes aegypti L. larvae

    Directory of Open Access Journals (Sweden)

    YAYAN SANJAYA

    2006-04-01

    Full Text Available A research about the toxicity of poison from spider Nephila sp. unto larvae of Aëdes aegypti L. had been done. The objectives of this research were to get the information about the toxicity of poison from spider Nephila sp. into larvae A. aegypti. The experiment method of this research was using Randomized Complete Block Design. This experiment used all of four instars of A. aegypti larvae. The experiment of each instar had been done with six treatments of the lethal concentration from spiders poison. Those six treatments were 1%, 10%, 25%, 50%, 75% and 100%. Each treatment had four replications. The result of this research showed that poison from spider Nephila sp. is toxic unto the larvae of A. aegypti. The average of lethal concentration for the first instar is 13.11%, for the second instar is 28.16%, for the third instar is 41.46% and for the fourth instar is 63.09%.

  11. Expanding the locomotion repertoire of the eigenfish: Study of wildtype zebrafish larva escape response

    Science.gov (United States)

    Benitez-Jones, Maria; Girdhar, Kiran; Chemla, Yann; Gruebele, Martin

    2014-03-01

    The zebrafish larva is a thoroughly studied and an extensively used model for behavioral and biomedical research. The Zebrafish Laboratory at the University of Illinois at Urbana-Champaign has applied a mathematical method to describe quantitatively the larva's swimming behavior. With this method, the 98% of the larva's free-swimming behavior is described by its simplifiedeigen-fish model, which is a linear combination of its three characteristic components, or three eigen-modes. This presentation focuses on the quantification of a different swimming behavior called escape response in wildtype (WT) zebrafish larvae. Although more data is required before assuming certainty in our results, the escape response of the WT was also described up to 98% by three eigen-modes. This REU program is supported by NSF Grant PHY-1062690.

  12. Ophthalmomyiasis caused by a Phormia sp. (Diptera: Calliphoridae) larva in an enucleated patient.

    Science.gov (United States)

    Kim, Jae-Soo; Kim, Jong-Wan; Lee, Hye-Jung; Lee, In-Yong; Oh, Sang-Ah; Seo, Min

    2011-06-01

    Ophthalmomyiasis rarely occurs worldwide, and has not been reported in Korea. We present here a case of ophthalmomyiasis caused by Phormia sp. fly larva in an enucleated eye of a patient. In June 2010, a 50-year-old man was admitted to Dankook University Hospital for surgical excision of a malignant melanoma located in the right auricular area. He had a clinical history of enucleation of his right eye due to squamous cell carcinoma 5 years ago. During hospitalization, foreign body sensation developed in his right eye, and close examination revealed a fly larva inside the eye, which was evacuated. The larva was proved to be Phormia sp. based on the morphology of the posterior spiracle. Subsequently, no larva was found, and the postoperative course was uneventful without any complaints of further myiasis. This is the first case of ophthalmomyiasis among the literature in Korea, and also the first myiasis case caused by Phormia sp. in Korea.

  13. Effects of prey density on the growth and survival of hybrid snakehead larvae

    Institute of Scientific and Technical Information of China (English)

    Wenkui LIU; Qixue FAN; Bangke ZHU; Haiming DU; Xigang FENG

    2008-01-01

    The effects of prey density (0.1, 0.3, 1, 3 and snakehead (Channa argus × C. maculate) larvae were investigated. The larvae were divided into three groups with different body lengths of 0.68 cm, 1.50 cm and 3.20 cm, respectively. The growth of the hybrid snake-head larvae in all three groups increased with prey growth rate (SGR) was the highest when the prey density early development stage) decreased, while no significant change was observed in those of Group Ⅱ and Group Ⅲ. The survival rates of hybrid snakehead larvae in all three groups were high (91.11%-100%) and not significantly affected by the prey densities except in Group Ⅰ with the significantly lower than the others. Body size was not sensitive to prey density. The optimum prey density was confirmed at 1 prey·mL-1 in all the treatments.

  14. Larvae of fouling organisms and macrofouling at New Mangalore Port, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, D.C.; Anil, A.C.; Venkat, K.

    throughout the year, their representation in the macrofouling community was not prominent and yielded a poor correlation with recruitment. Bryozoan and ascidian larvae were sparsely encountered but indicated as significant correlation with their recruitment...

  15. Drosophila melanogaster larvae control amylase secretion according to the hardness of food

    Directory of Open Access Journals (Sweden)

    Honami eSakaguchi

    2013-08-01

    Full Text Available Drosophila melanogaster larvae excrete amylase and perform external digestion of their food. In this study, to investigate whether their external digestion ability varies in response to changes in the external environment, we measured the relative amount of amylase excreted by larvae using a new method: the iodine starch agar method (ISAM. Analysis using this method revealed that the amount of amylase excreted by larvae increased in accordance with the increase in the agar concentration. In addition, we investigated the effect on the larval growth rate of adding amylase to the diet. Pupation occurred 24 h later in food containing 1% amylase than in food containing no amylase. These results suggest that the larvae adjust their amylase excretion in response to changes in the external environment, and that its level has a marked influence on the larval growth rate.

  16. Organochlorine chemical hazards for sturgeon larvae in the Middle Mississippi River National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We conducted an ecological risk assessment to characterize organochlorine chemical hazards for sturgeon larvae in the Middle Mississippi River National Wildlife...

  17. Morphological and molecular identification of nasopharyngeal bot fly larvae infesting red deer (Cervus elaphus) in Austria.

    Science.gov (United States)

    Leitner, Natascha; Schwarzmann, Laurin; Zittra, Carina; Palmieri, Nicola; Eigner, Barbara; Otranto, Domenico; Glawischnig, Walter; Fuehrer, Hans-Peter

    2016-11-01

    Nasopharyngeal myiases are caused by larvae of bot flies (Diptera: Oestridae), which have evolved a high specificity for their hosts. Bot flies (n = 916) were collected from 137 (57.6 %) out of 238 red deer (Cervus elaphus) hunted in Vorarlberg and Tyrol (Western Austria). After being stored in 75 % ethanol, larvae were identified to species level and developmental stage using morphological and morphometric keys. Larvae were also molecularly characterized by polymerase chain reaction (PCR) amplification and partial sequencing of the mitochondrial cytochrome oxidase subunit I gene. Morphological and molecular analysis allowed identification of larvae as Cephenemyia auribarbis and Pharyngomyia picta. Genetic variations were also examined within the specimens collected in both geographical locations.

  18. Identification of Nanopillars on the Cuticle of the Aquatic Larvae of the Drone Fly (Diptera: Syrphidae).

    Science.gov (United States)

    Hayes, Matthew J; Levine, Timothy P; Wilson, Roger H

    2016-01-01

    Here, we describe a nano-scale surface structure on the rat-tailed maggot, the aquatic larva of the Drone fly Eristalis tenax(L.). Larvae of this syrphid hover fly live in stagnant, anaerobic water-courses that are rich in organic matter. The larvae burrow into fetid slurry and feed on microorganisms which they filter out from the organic material. This environment is rich in bacteria, fungi and algae with the capacity to form biofilms that might develop on the larval surface and harm them. Using transmission and scanning electron microscopy we have identified an array of slender (typically < 100 nm in diameter) nanopillars that cover the surface of the larvae. The high density and dimensions of these spine-like projections appear to make it difficult for bacteria to colonize the surface of the animal. This may interfere with the formation of biofilms and potentially act as a defence against bacterial infection.

  19. Effects and mechanisms of Bacillus thuringiensis crystal toxins for mosquito larvae.

    Science.gov (United States)

    Zhang, Qi; Hua, Gang; Adang, Michael J

    2016-09-15

    Bacillus thuringiensis is a Gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. The virulence factor, known as parasporal crystals, is composed of Cry and Cyt toxins. Most Cry toxins display a common 3-domain topology. Cry toxins exert intoxication through toxin activation, receptor binding and pore formation in a suitable larval gut environment. The mosquitocidal toxins of Bt subsp. israelensis (Bti) were found to be highly active against mosquito larvae and are widely used for vector control. Bt subsp. jegathesan is another strain which possesses high potency against broad range of mosquito larvae. The present review summarizes characterized receptors for Cry toxins in mosquito larvae, and will also discuss the diversity and effects of 3-D mosquitocidal Cry toxin and the ongoing research for Cry toxin mechanisms generated from investigations of lepidopteran and dipteran larvae.

  20. Effect of Exogenous MJA Treatment of Tea Plants on the Growth of Geometrid Larvae

    Institute of Scientific and Technical Information of China (English)

    GUI Lian-you; CHEN Zong-mao; LIU Shu-sheng

    2005-01-01

    The effect of tea plant Camellia sinensis induced by exogenous methyl jasmonate (MJA) on lipoxygenase (LOX), polyphenol oxidase (PPO) and proteinase inhibitor (PI) activity in the leaves of tea plants, as well as the growth and midgut proteinase activity of the geometrid Ectropis obliqua larvae were studied. MJA significantly induced LOX, PPO and PI activity in leaves of tea plants. When geometrid larvae have fed on leaves of tea plants treated with MJA, the activities of the high alkaline trypsin-like enzyme and chymotrypsin-like enzyme in their midgut were significantly inhibited, but the activities of the low alkaline trypsin-like enzyme in their midgut were unaffected, leading to imbalance between different types of proteinase activity in the midgut of the larvae and in turn, the growth were inhibited. These chains of response may be an important mechanism of the direct resistance induced by MJA-treatment of tea plant on geometrid larvae.

  1. Infectivity of Trichinella spiralis larvae in pork buried in the ground

    Directory of Open Access Journals (Sweden)

    Jovic S.

    2001-06-01

    Full Text Available Time of survival and infectivity of Trichinella spiralis larvae in pig muscle tissue, buried at various depths in the ground were assessed. In the pork pieces the number of infective larvae was 250 ML/g. Meat originated from pig halves was divided in 39 equal pieces, 0.7 kg each, disposed in three groups of 1 3, and buried in depths of 30, 50, and 100 centimeters respectively. The pork was dug up at 13 intervals, approximately every week, until 91st day of the experiment. After each time interval, infectivity of larvae was assessed by bioassay on rats. The artificially infected rats were sacrificed on 42nd day after the infection and meat was examined by the following methods - artificial digestion and trichinoscopy. It was found that the larvae during all 90 days preserved infectivity in each depth.

  2. Crown-of-Thorns Starfish Larvae Can Feed on Organic Matter Released from Corals

    Directory of Open Access Journals (Sweden)

    Ryota Nakajima

    2016-10-01

    Full Text Available Previous studies have suggested that Crown-of-Thorns starfish (COTS larvae may be able to survive in the absence of abundant phytoplankton resources suggesting that they may be able to utilize alternative food sources. Here, we tested the hypothesis that COTS larvae are able to feed on coral-derived organic matter using labeled stable isotope tracers (13C and 15N. Our results show that coral-derived organic matter (coral mucus and associated microorganisms can be assimilated by COTS larvae and may be an important alternative or additional food resource for COTS larvae through periods of low phytoplankton biomass. This additional food resource could potentially facilitate COTS outbreaks by reducing resource limitation.

  3. Capture of white sturgeon larvae downstream of The Dalles Dam, Columbia River, Oregon and Washington, 2012

    Science.gov (United States)

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    Wild-spawned white sturgeon (Acipenser transmontanus) larvae captured and reared in aquaculture facilities and subsequently released, are increasingly being used in sturgeon restoration programs in the Columbia River Basin. A reconnaissance study was conducted to determine where to deploy nets to capture white sturgeon larvae downstream of a known white sturgeon spawning area. As a result of the study, 103 white sturgeon larvae and 5 newly hatched free-swimming embryos were captured at 3 of 5 reconnaissance netting sites. The netting, conducted downstream of The Dalles Dam on the Columbia River during June 25–29, 2012, provided information for potentially implementing full-scale collection efforts of large numbers of larvae for rearing in aquaculture facilities and for subsequent release at a larger size in white sturgeon restoration programs.

  4. Quantification of the energy required for the destruction of Balanus Amphitrite larva by ultrasonic treatment

    Digital Repository Service at National Institute of Oceanography (India)

    Seth, N.; Chakravarty, P.; Khandeparker, L.; Anil, A.C.; Pandit, A.B.

    Ultrasonic treatment, a relatively less explored technology in water disinfection, was used to quantify the energy required for the destruction of larvae of barnacle Balanus amphitrite, which is a major marine fouling and a potential invasive...

  5. "Epidermal Streaming" and associated phenomena displayed by Larvae of Chrysomyia marginalis (Wd. (Diptera: CALLIPHORIDAE at carcasses

    Directory of Open Access Journals (Sweden)

    L.E.O Braack

    1984-12-01

    Full Text Available Competition with vertebrate scavengers for carrion necessitates blow-fly larvae to make rapid and effective use of dead animals. Blow-fly eggs are deposited in shaded, concealed positions at a carcass, and the larvae need to enter the body to feed on muscle and other soft tissues as soon as possible after eclosion. They do so by digesting away the skin with enzymes, but this is often preceded by an exploratory phase in which larvae migrate over the carcass to find wounds by which they are able to gain more rapid entry into the body. Epidermal streaming is one method of performing this exploratory phase, and involves movement by small larvae below the superficial outermost layer of skin. Several possible benefits of this behaviour are discussed.

  6. Toxocara cati larvae in the eye of a child:a case report

    Institute of Scientific and Technical Information of China (English)

    Mohammad Zibaei; Seyed Mahmoud Sadjjadi

    2014-01-01

    Toxocariasis is a consequence of human infection by Toxocara larvae. There are symptomatic (visceral, ocular) and asymptomatic course of toxocariasis. The ocular form is very rare. We present a 6-year-old patient who developed an ocular form of toxocariasis caused by Toxocaracati. He demonstrated lesions in the peripheral retina of the right eye. White granuloma was present in the superior peripheral retina. A positive immunological assay for toxocariasis essentially completed the outcomes. On the basis of clinical manifestations and conducted examinations, a diagnosis of ocular form of toxocariasis was established. Albendazole and corticosteroids were applied in treatment. Current results clearly highlight the usefulness of excretory-secretory antigens derived from larvae of Toxocara cati for the fine diagnosis ocular larva migrans caused by Toxocara larvae.

  7. Toxocara cati larvae in the eye of a child: a case report

    Directory of Open Access Journals (Sweden)

    Mohammad Zibaei

    2014-05-01

    Full Text Available Toxocariasis is a consequence of human infection by Toxocara larvae. There are symptomatic (visceral, ocular and asymptomatic course of toxocariasis. The ocular form is very rare. We present a 6-year-old patient who developed an ocular form of toxocariasis caused by Toxocara cati. He demonstrated lesions in the peripheral retina of the right eye. White granuloma was present in the superior peripheral retina. A positive immunological assay for toxocariasis essentially completed the outcomes. On the basis of clinical manifestations and conducted examinations, a diagnosis of ocular form of toxocariasis was established. Albendazole and corticosteroids were applied in treatment. Current results clearly highlight the usefulness of excretory-secretory antigens derived from larvae of Toxocara cati for the fine diagnosis ocular larva migrans caused by Toxocara larvae.

  8. Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.A; Anil, A

    Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in feeding studies of various organisms. In this study we standardized the gut fluorescence method using laboratory-reared barnacle larvae (Balanus amphitrite...

  9. Vulnerability of the mosquito larvae to the guppies (Poecilia reticulata in the presence of alternative preys

    Directory of Open Access Journals (Sweden)

    Barnali Manna

    2008-08-01

    Full Text Available Background & objectives: The predatory potential of the larvivorous fishes can be affected by the presence of alternative preys. In the present study the predation pattern of the sewage dwelling Poecilia reticulata (Peters 1872 on the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae was evaluated in the presence of alternative preys. Methods: The predation of Cx. quinquefasciatus larvae by different size groups of P. reticulata fishes was evaluated. In addition to this, the niche breadth (N and diet breadth (B were measured following Manly’s selectivity index (Si as an indicator of variation of such predation pattern in the presence of alternative prey types, like chironomid larvae and tubificid worms.Results: The consumption of IV instar Cx. quinquefasciatus larvae by individual P. reticulata ranged between 65 and 84 in a 3 h feeding period and varied with the size of fish (F2, 33 = 34.91; p<0.001. The selectivity coefficient revealed a significantly low preference for the Cx. quinquefasciatus larvae (0.16, CL: 0.05 – 0.27; p< 0.05 compared to the chironomid larvae and tubificid worms, when all the three prey types were present. The niche breadth (N and diet breadth (B ranged from 0.77 to 0.92 and 0.69 to 0.93, respectively. The total consumption of all the prey types varied with the predator density, but the selectivity index for the mosquito larvae was significantly low in all the instances.Interpretation & conclusion: P. reticulata can consume a good number of mosquito larvae, with the consumption rate varying with the body size. P. reticulata fishes exhibit low preference for mosquito larvae as prey in the presence of alternative controphic preys like chironomid larvae and tubificid worms. Though establishment and sustenance of P. reticulata in new habitats will be favoured by the presence of alternative preys, but vulnerability of mosquito larvae may be reduced with availability of multiple preys in natural conditions.

  10. Appearance of a reservoir of hookworm-related cutaneous larva migrans in Brittany?

    Science.gov (United States)

    Veraldi, S; Persico, M C; Francia, C; La Vela, V

    2012-12-01

    We describe two cases of hookworm-related cutaneous larva migrans acquired in Brittany (North-Western France). The patients were a 23-year-old woman and a 28-year-old man. In both patients the feet were involved. In the second patient, a superinfection due to Staphylococcus aureus was recorded. The appearance in Brittany of a reservoir of nematodes capable of causing hookworm-related cutaneous larva migrans is hypothesized.

  11. Clash of kingdoms or why Drosophila larvae positively respond to fungal competitors.

    Science.gov (United States)

    Rohlfs, Marko

    2005-01-27

    BACKGROUND: Competition with filamentous fungi has been demonstrated to be an important cause of mortality for the vast group of insects that depend on ephemeral resources (e.g. fruit, dung, carrion). Recent data suggest that the well-known aggregation of Drosophila larvae across decaying fruit yields a competitive advantage over mould, by which the larvae achieve a higher survival probability in larger groups compared with smaller ones. Feeding and locomotor behaviour of larger larval groups is assumed to cause disruption of fungal hyphae, leading to suppression of fungal growth, which in turn improves the chances of larval survival to the adult stage. Given the relationship between larval density, mould suppression and larval survival, the present study has tested whether fungal-infected food patches elicit communal foraging behaviour on mould-infected sites by which larvae might hamper mould growth more efficiently. RESULTS: Based on laboratory experiments in which Drosophila larvae were offered the choice between fungal-infected and uninfected food patches, larvae significantly aggregated on patches containing young fungal colonies. Grouping behaviour was also visible when larvae were offered only fungal-infected or only uninfected patches; however, larval aggregation was less strong under these conditions than in a heterogeneous environment (infected and uninfected patches). CONCLUSION: Because filamentous fungi can be deadly competitors for insect larvae on ephemeral resources, social attraction of Drosophila larvae to fungal-infected sites leading to suppression of mould growth may reflect an adaptive behavioural response that increases insect larval fitness and can thus be discussed as an anti-competitor behaviour. These observations support the hypothesis that adverse environmental conditions operate in favour of social behaviour. In a search for the underlying mechanisms of communal behaviour in Drosophila, this study highlights the necessity of

  12. Status of carbohydrate, protein and lipid profile in the mosquito larvae treated with certain phytoextracts

    Institute of Scientific and Technical Information of China (English)

    Preeti Sharma; Lalit Mohan; Kamal Kumar Dua; Chand Narayan Srivastava

    2011-01-01

    Objective:To investigate the impact of the most potent petroleum ether extract ofArtemisia annua (A. annua) andAzadirachta indica (Az. indica) on total carbohydrate, lipid and protein level ofAnopheles stephensi andCulex quinquefasciatuslarvae.Methods: Mosquito larvae were exposed to the extracts selected as per standardWHO procedure. Carbohydrate (glucose), total lipid and protein were estimated by the methods as Nelson, Bragdon and Lowry described, respectively.Results: The glucose levels were increased to27.87% and46.8%, respectively in anopheline larval tissues after treatment with petroleum ether extract ofA. annua and methanolic extract ofAz. indica. In culicine larvae, glucose levels were reduced to58.96% and24.65%, respectively. After treatment withA. annua extract, lipid contents in anopheline and culicine larvae decreased by28.57% and25.0%, respectively and increased by14.29% and50.00% in theAnopheles andCulex larvae, respectively after treatment with methanolic extract ofAz. indica. Total protein levels were reduced to63.13% and92.62% in anopheline and to32.39% and 48.12% in culicine larvae after treatment withA. annua andAz. Indica extracts, respectively. Conclusions: Two extracts produce significant alterations in the biochemical profiles of anopheline and culicine larvae. Further, the impacting factors of extracts on carbohydrate, lipid and protein contents of larvae are species and specific extraction. It indicates the disturbed metabolic activity of the larvae.

  13. Morphological description of the fourth instar larva: Culicoides cataneii and Culicoides sahariensis (Diptera: Ceratopogonidae).

    Science.gov (United States)

    Slama, Darine; Khedher, Asma; Bdira, Sassi; Khayech, Fethi; Delecolle, Jean-claude; Mezhoud, Habib; Babba, Hamouda; Emna, Chaker

    2013-01-01

    This study was carried out of the region of Monastir in Central Tunisia, between July and August 2010. Larvae were collected using a floatation technique with magnesium sulfate in mud samples. The fourth instar larva of Culicoides cataneii Clastrier, 1957 and Culicoides sahariensis Callot, Kremer, Bailly-Choumara, 1970 are described, illustrated and drawn. Measurements of instars IV are also presented. This is the first record of Culicoides cataneii and Culicoides sahariensis (Diptera: Ceratopogonidae) to Tunisia.

  14. POLA AKTIVITAS ENZIM PENCERNAAN LARVA IKAN KERAPU MACAN (Epinephelus fuscogutattus Forsskal, 1775)

    OpenAIRE

    Regina Melianawati; Rarastoeti Pratiwi

    2011-01-01

    Masalah utama yang masih dihadapi dalam usaha budidaya ikan kerapu macan adalah tingkat mortalitas yang tinggi pada stadia larva. Perkembangan struktur sistem pencernaan dan fungsi enzimatik yang masih sederhana dan belum sempurna diyakini merupakan salah satu penyebab terjadinya hal tersebut. Penelitian ini bertujuan untuk (1) mendeteksi waktu awal aktivitas enzim pencernaan dan (2) mengetahui pola aktivitas enzim pencernaan pada larva umur 1 hingga 20 hari. Enzim yang dianalisis meliputi pr...

  15. Amino acid requirements of white seabream (Diplodus sargus) larvae: effects on growth and performance

    OpenAIRE

    2008-01-01

    Tese dout., Aquacultura, Universidade do Algarve, 2008 Diplodus sargus is a potential species for aquaculture. Constraints to its production are a high incidence of skeletal deformities and stagnation of the growth rate in juvenile stage, possibly caused by dietary imbalances. This thesis is focused on the amino acid (AA) requirements of Diplodus sargus larvae, on the formulation of diets with AA supplementation and also identifies larvae skeletal deformities patterns (Chapter ...

  16. ANTHELMINTIC ACTIVITY OF LAPACHOL, β-LAPACHONE AND ITS DERIVATIVES AGAINST Toxocara canis LARVAE

    OpenAIRE

    MATA-SANTOS, Taís; PINTO, Nitza França; Hilton Antônio MATA-SANTOS; DE MOURA, Kelly Gallan; Carneiro, Paula Fernandes; CARVALHO, Tatiane dos Santos; DEL RIO, Karina Pena; PINTO, Maria do Carmo Freire Ribeiro; MARTINS, Lourdes Rodrigues; Juliana Montelli FENALTI; da Silva, Pedro Eduardo Almeida; Scaini, Carlos James

    2015-01-01

    Anthelmintics used for intestinal helminthiasis treatment are generally effective; however, their effectiveness in tissue parasitosis (i.e. visceral toxocariasis) is moderate. The aim of this study was to evaluate the in vitro activity of lapachol, β-lapachone and phenazines in relation to the viability of Toxocara canis larvae. A concentration of 2 mg/mL (in duplicate) of the compounds was tested using microculture plates containing Toxocara canis larvae in an RPMI-1640 environment, incubate...

  17. Validation studies of the latex agglutination test for the detection of Trichinella larvae in meat products.

    Science.gov (United States)

    Gayda, Jennifer; Reckinger, Sabine; Thaben, Nora; Nöckler, Karsten; Mayer-Scholl, Anne

    2016-11-15

    Human trichinellosis is a foodborne disease caused by ingestion of meat infected with Trichinella muscle larvae. To control Trichinella spp. infection in the European Union, all slaughtered pigs from holdings that are not officially recognized as applying controlled housing conditions and other animals susceptible to Trichinella infection and intended for human consumption should be examined by one of the approved digestion methods described in Regulation (EU) No. 2015/1375. In the past, Trichinella outbreaks due to the consumption of cured wild boar or pork products have been described in several European countries, making the identification of the larvae from these products relevant for Trichinella control. Therefore, this study aimed to validate the newly approved latex agglutination test (Trichin-L) for routine testing of cured meat products. The test was validated based on the OIE Guidelines using pork products spiked with Trichinella larvae. The sensitivity of the method varied greatly depending on the investigated meat product and was usually lower than for the gold standard, the magnetic stirrer method. The detection rate reached 80% for three larvae and 60% for one larva in cured pork sausages. A detection rate of 100% for three larvae and 50% for one larva was found in bacon. For frozen samples (-20°C) the Trichin-L kit is similarly sensitive as for cured samples. Further, to determine the performance of the test under field conditions, pork products from regions with known high Trichinella prevalences confiscated by customs authorities at two German international airports were analyzed. Problems associated with the Trichin-L test were incomplete digestion due to fatty ingredients, spices and very dry meat products, resulting in data which could not be evaluated. Therefore, the test is currently not suitable for the detection of Trichinella larvae in cured meat products and needs further adaptation steps to increase both usability and sensitivity.

  18. PENGARUH INTENSITAS CAHAYA TERHADAP PEMANGSAAN LARVA IKAN CLOWN (Amphiprion ocellaris PADA AWAL PEMELIHARAAN

    Directory of Open Access Journals (Sweden)

    Ketut Maha Setiawati

    2016-11-01

    Full Text Available Penelitian pemangsaan larva ikan clown (Amphiprion ocellaris pada awal pemeliharaan dan umur sepuluh hari dilakukan menggunakan tangki serat kaca (fiberglass volume 200 L. Pakan zooplankton rotifera disediakan sejak telur menetas dengan kepadatan 5 ind./mL. Mulai D-8 zooplankton nauplii Artemia ditambahkan dengan kepadatan 1.700 ind./tangki. Pengambilan sampel dilakukan pada umur 1 hari dan sepuluh hari, masing-masing 10 ekor larva/sampling dengan interval waktu 3 jam. Larva diukur kemudian dibedah dan dianalisis jumlah pemangsaaannya dengan bantuan stereoscopic microscope. Hasil analisis menunjukkan peranan intensitas cahaya dalam aktivitas pemangsaannya sebesar 5 individu rotifera dengan intensitas cahaya 70 lux pada pagi hari, sedang pemangsaan tertinggi terjadi pada pukul 13.00—16.00 dengan pemangsaan 57 individu rotifera pada saat intensitas cahaya menurun. Spektrum warna cahaya diduga lebih berperanan pada kemampuan maksimal memangsa dari larva ikan laut. Observation on feeding activity of clown fish (A. ocellaris larvae have been conducted in 200 L. fiberglass tanks. Zooplankton rotifers were used as initial feed at a rate of 5 ind./mL. After eight days culture, nauplii Artemia were added at rate of 1,700 ind./ tank. Sampling was done on D-1 and D-10 at 10 individuals even sampling at three hours interval. The larvae were measured under a stereoscopic microscope, examining the digestion apparatus to count number of rotifers and nauplii Artemia as well. The result showed that the role of light intensity in feeding: 5 individual rotifer at 70 lux in early morning for D-1 larvae. The highest feeding occurred at 13.00-16.00 in the after noon at 57 individual rotifer when light intensity decreased. Color spectrum of light were predicted having more roles related to the maximum feeding rate  of clown fish larvae.

  19. Oceanographic and behavioural assumptions in models of the fate of coral and coral reef fish larvae.

    Science.gov (United States)

    Wolanski, Eric; Kingsford, Michael J

    2014-09-06

    A predictive model of the fate of coral reef fish larvae in a reef system is proposed that combines the oceanographic processes of advection and turbulent diffusion with the biological process of horizontal swimming controlled by olfactory and auditory cues within the timescales of larval development. In the model, auditory cues resulted in swimming towards the reefs when within hearing distance of the reef, whereas olfactory cues resulted in the larvae swimming towards the natal reef in open waters by swimming against the concentration gradients in the smell plume emanating from the natal reef. The model suggested that the self-seeding rate may be quite large, at least 20% for the larvae of rapidly developing reef fish species, which contrasted with a self-seeding rate less than 2% for non-swimming coral larvae. The predicted self-recruitment rate of reefs was sensitive to a number of parameters, such as the time at which the fish larvae reach post-flexion, the pelagic larval duration of the larvae, the horizontal turbulent diffusion coefficient in reefal waters and the horizontal swimming behaviour of the fish larvae in response to auditory and olfactory cues, for which better field data are needed. Thus, the model suggested that high self-seeding rates for reef fish are possible, even in areas where the 'sticky water' effect is minimal and in the absence of long-term trapping in oceanic fronts and/or large-scale oceanic eddies or filaments that are often argued to facilitate the return of the larvae after long periods of drifting at sea.

  20. Larval structure of Passalus gravelyi and sexual dimorphism in Passalid larvae.

    Science.gov (United States)

    Mattos, Ingrid; Mermudes, José Ricardo Miras; Reyes-Castillo, Pedro

    2015-09-01

    The adults and larvae of Passalidae are subsocial insects commonly found in tropical forests, living in decaying wood gallery systems constructed by adults. Currently, few repots on the larvae of Neotropical Passalidae have been published and information is scarce. In this study, the Passalus (Pertinax) gravelyi Moreira, 1922 larvae is described for the first time, based on ten larval specimens 1 (1° instar), 4 (2° instar), and 5 (3° instar) associated with three adults collected from a single colony at the Parque Nacional do Itatiaia (Itatiaia, Rio de Janeiro, Brazil). The description was carried out based on electronic and digital photographs of diagnostic structures, with some details on the systematic of the species. The larvae of Passalus gravelyi has the general setal 'Pertinax' pattern and differed from others by 16 to 18 setae on the anal ring, the other larvae data from Brazilian species show the anal ring with 10 to 12 setae. A discussion on the presence of sexual dimorphism in 62 species of two and three instars of Passalidae larvae is provided for the first time. Besides, a description of the terminal ampulla present as a cuticular structure found in the medial-ventral area of the 9th abdominal sternite in males is also given. The terminal ampulla was only observed in the Passalidae male larvae and was not visible in female larvae. The terminal ampulla are acknowledged now in males of 64 passalid species, that are taxonomically distributed in world tropical forests, at the Oriental and Australian subfamily Aulacocyclinae (Aulacocyclini & Ceracupini) and the cosmotropical subfamily Passalinae (Solenocyclini, Macrolinini, Passalini, & Proculini).

  1. Vibrios Associated with Litopenaeus vannamei Larvae, Postlarvae, Broodstock, and Hatchery Probionts

    OpenAIRE

    Vandenberghe, Johan; Verdonck, Linda; Robles-Arozarena, Rocio; Rivera, Gabriel; Bolland, Annick; Balladares, Marcos; Gomez-Gil, Bruno; Calderon, Jorge; Sorgeloos, Patrick; Swings, Jean

    1999-01-01

    Several bacteriological surveys were performed from 1994 to 1996 at different Litopenaeus vannamei hatcheries (in Ecuador) and shrimp farms (in Mexico). Samples were taken from routine productions of healthy and diseased L. vannamei larvae, postlarvae, and their culture environment and from healthy and diseased juveniles and broodstock. In Ecuador, the dominant bacterial flora associated with shrimp larvae showing symptoms of zoea 2 syndrome, mysis mold syndrome, and bolitas syndrome has been...

  2. Laboratory evaluation of entomopathogenic fungi against larvae and adults of onion maggot (Diptera: Anthomyiidae).

    Science.gov (United States)

    Davidson, G; Chandler, D

    2005-12-01

    Laboratory experiments were done to measure the susceptibility of larvae and adults of the onion maggot, Delia antiqua (Meigen) (Diptera: Muscidae: Anthomyiidae) to 27 isolates of entomopathogenic fungi from four genera [Beauveria Vuillemin, Lecanicillium (Petch) Zare & W. Gams, Metarhizium Sorokin, and Paecilomyces Bainier]. A novel bioassay was developed for D. antiqua larvae by using a diet based on mixed vegetable powder. When evaluated in a virulence screen, the fungal isolates caused less mortality of D. antiqua larvae than adults. Only three isolates caused > 50% mortality of larvae, whereas 12 isolates caused > 50% mortality of adults. Fungal species was a statistically significant factor affecting the mortality of larvae but not of adults. The fungal isolates causing the most mortality of larvae tended to belong to Metarhizium anisopliae (Metschnikoff) Sorokin. Two M. anisopliae isolates (389.93 and 392.93) were evaluated in dose-response bioassays. The median lethal concentrations of the isolates against larvae were 6.1 x 10(7) conidia ml(-1) for isolate 389.93 and 7.6 x 10(7) conidia ml(-1) for isolate 392.93. The emergence of adult flies from pupae was reduced at high concentrations of conidia (3.0 x 10(8) and 1.0 x 10(8) conidia ml(-1)). The median lethal concentrations of the isolates against adults were 1.7 x 10(7) and 4.0 x 10(7) conidia ml(-1), respectively. Some of the fungal isolates examined may have potential as biological control agents of larvae of D. antiqua and related species.

  3. Molecular identification of nematode larvae different from those of the Trichinella genus detected by muscle digestion.

    Science.gov (United States)

    Marucci, Gianluca; Interisano, Maria; La Rosa, Giuseppe; Pozio, Edoardo

    2013-05-20

    Although larvae of the genus Trichinella are the most common parasite species detected in vertebrate muscles using artificial digestion, nematode larvae belonging to other genera are sometimes detected and incorrectly identified as Trichinella. However, it is often very difficult to identify these larvae at the species, genus or family level using microscopy because of the absence of specific morphological characters or cuticle damage, and the only means of identification is PCR and sequencing of specific molecular markers (12S mtDNA; COI; 18S rDNA; and ITS1). From 2008 to 2011, 18 nematode isolates not belonging to the genus Trichinella were collected from different host species. Eleven of these isolates were successfully identified at the species, genus or superfamily level: larvae from two common kestrels, three hooded crows, a hen harrier and a domestic pig were identified as Toxocara cati; larvae from a badger were identified as Toxocara canis; larvae from a domestic pig were identified as a free-living nematode of the genus Panagrolaimus; larvae from a wild boar were identified as belonging to the Metastrongylus genus; and larvae from a rough-legged buzzard were identified as belonging to the superfamily Filarioidea. The recovery of nematodes belonging to genera other than Trichinella during routine meat inspection suggests that the persons performing the analyses need to be informed of the possibility of false positives and that a molecular-based identification system that allows for a rapid and reliable response must be adopted (i.e., a DNA barcoding-like system).

  4. Clash of kingdoms or why Drosophila larvae positively respond to fungal competitors

    Directory of Open Access Journals (Sweden)

    Rohlfs Marko

    2005-01-01

    Full Text Available Abstract Background Competition with filamentous fungi has been demonstrated to be an important cause of mortality for the vast group of insects that depend on ephemeral resources (e.g. fruit, dung, carrion. Recent data suggest that the well-known aggregation of Drosophila larvae across decaying fruit yields a competitive advantage over mould, by which the larvae achieve a higher survival probability in larger groups compared with smaller ones. Feeding and locomotor behaviour of larger larval groups is assumed to cause disruption of fungal hyphae, leading to suppression of fungal growth, which in turn improves the chances of larval survival to the adult stage. Given the relationship between larval density, mould suppression and larval survival, the present study has tested whether fungal-infected food patches elicit communal foraging behaviour on mould-infected sites by which larvae might hamper mould growth more efficiently. Results Based on laboratory experiments in which Drosophila larvae were offered the choice between fungal-infected and uninfected food patches, larvae significantly aggregated on patches containing young fungal colonies. Grouping behaviour was also visible when larvae were offered only fungal-infected or only uninfected patches; however, larval aggregation was less strong under these conditions than in a heterogeneous environment (infected and uninfected patches. Conclusion Because filamentous fungi can be deadly competitors for insect larvae on ephemeral resources, social attraction of Drosophila larvae to fungal-infected sites leading to suppression of mould growth may reflect an adaptive behavioural response that increases insect larval fitness and can thus be discussed as an anti-competitor behaviour. These observations support the hypothesis that adverse environmental conditions operate in favour of social behaviour. In a search for the underlying mechanisms of communal behaviour in Drosophila, this study highlights

  5. Lethality and developmental delay in Drosophila melanogaster larvae after ingestion of selected Pseudomonas fluorescens strains.

    Directory of Open Access Journals (Sweden)

    Marika H Olcott

    Full Text Available BACKGROUND: The fruit fly, Drosophila melanogaster, is a well-established model organism for probing the molecular and cellular basis of physiological and immune system responses of adults or late stage larvae to bacterial challenge. However, very little is known about the consequences of bacterial infections that occur in earlier stages of development. We have infected mid-second instar larvae with strains of Pseudomonas fluorescens to determine how infection alters the ability of larvae to survive and complete development. METHODOLOGY/PRINCIPAL FINDINGS: We mimicked natural routes of infection using a non-invasive feeding procedure to study the toxicity of the three sequenced P. fluorescens strains (Pf0-1, SBW25, and Pf-5 to Drosophila melanogaster. Larvae fed with the three strains of P. fluorescens showed distinct differences in developmental trajectory and survival. Treatment with SBW25 caused a subset of insects to die concomitant with a systemic melanization reaction at larval, pupal or adult stages. Larvae fed with Pf-5 died in a dose-dependent manner with adult survivors showing eye and wing morphological defects. In addition, larvae in the Pf-5 treatment groups showed a dose-dependent delay in the onset of metamorphosis relative to control-, Pf0-1-, and SBW25-treated larvae. A functional gacA gene is required for the toxic properties of wild-type Pf-5 bacteria. CONCLUSIONS/SIGNIFICANCE: These experiments are the first to demonstrate that ingestion of P. fluorescens bacteria by D. melanogaster larvae causes both lethal and non-lethal phenotypes, including delay in the onset of metamorphosis and morphological defects in surviving adult flies, which can be decoupled.

  6. BIOENSAYO DE IVERMECTINA CONTRA LARVAS DE AEDES AEGYPTI, ALTERNATIVA PARA CONTROL DEL DENGUE EN ECUADOR

    OpenAIRE

    Silva Bustillos, Ricardo José

    2014-01-01

    The purpose of this research is to propose the use of ivermectin against the larvae of Aedes aegypti for dengue control in drinking water and as a vector control mechanism against the resistance of larvicides used today. In this study, various bioassays were conducted with ivermectin until 50% lethal dose (LD 50%) and it was demonstrated that with the use of antiparasitic human and veterinary use at very low concentrations, it is able to prevent the development of Aedes aegypti larvae. Result...

  7. Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions.

    Science.gov (United States)

    Ross, Perran A; Endersby, Nancy M; Hoffmann, Ary A

    2016-01-01

    The mosquito Aedes aegypti, the principal vector of dengue virus, has recently been infected experimentally with Wolbachia: intracellular bacteria that possess potential as dengue biological control agents. Wolbachia depend on their hosts for nutrients they are unable to synthesize themselves. Consequently, competition between Wolbachia and their host for resources could reduce host fitness under the competitive conditions commonly experienced by larvae of Ae. aegypti in the field, hampering the invasion of Wolbachia into natural mosquito populations. We assess the survival and development of Ae. aegypti larvae under starvation conditions when infected with each of three experimentally-generated Wolbachia strains: wMel, wMelPop and wAlbB, and compare their fitness to wild-type uninfected larvae. We find that all three Wolbachia infections reduce the survival of larvae relative to those that are uninfected, and the severity of the effect is concordant with previously characterized fitness costs to other life stages. We also investigate the ability of larvae to recover from extended food deprivation and find no effect of Wolbachia on this trait. Aedes aegypti larvae of all infection types were able to resume their development after one month of no food, pupate rapidly, emerge at a large size, and exhibit complete cytoplasmic incompatibility and maternal transmission. A lowered ability of Wolbachia-infected larvae to survive under starvation conditions will increase the threshold infection frequency required for Wolbachia to establish in highly competitive natural Ae. aegypti populations and will also reduce the speed of invasion. This study also provides insights into survival strategies of larvae when developing in stressful environments.

  8. Development of Steinernema feltiae (Rhabditida: Steinernematidae in larvae of Chaetonyx robustus (Coleoptera: Orphnidae

    Directory of Open Access Journals (Sweden)

    Denis Gradinarov

    2012-12-01

    Full Text Available Steinernema feltiae (Filipjev, 1934 infects and reproduces in larvae of Chaetonyx robustus Schaum, 1862 (Coleoptera: Orphnidae, isolated from soil of the same habitat. Insects of the family Orphnidae are reported for the first time as hosts of entomopathogenic nematodes. Lack of establishment of natural infected larvae may be due to the lower susceptibility of C. robustus to nematode invasion and random factors related to the spatial distribution of infective juveniles in soil.

  9. Analysis of metallotionein expression and antioxidant enzyme activities in Meretrix meretrix larvae under sublethal cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qing [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Wang Xiaomei [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Wang Xiaoyu [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Engineering Research Center of Seawater Utilization Technology, Ministry of Education, Hebei University of Technology, Tianjin 300130 (China); Yang Hongsheng, E-mail: hshyang@ms.qdio.ac.cn [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Liu Baozhong, E-mail: bzliu@ms.qdio.ac.cn [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)

    2010-11-15

    To investigate the possible role of metallothioneins (MTs) and antioxidant enzymes in cadmium (Cd) tolerance in Meretrix meretrix larvae, a new MT (designated MmMT) gene was identified and cloned from M. meretrix. The full-length cDNA of MmMT consisted of an open reading frame (ORF) of 231 bp encoding a protein of 76 amino acids, with 21 cysteine residues and a conserved structural pattern Cys-x-Cys-x(3)-Cys-Tyr-Gly-x(3)-Cys-x-Cys-x(3)-Cys-x-Cys-Lys at the C-terminus. The deduced amino acid sequence of MmMT showed about 57-84% identity with previously published MT sequences of mussels and oysters. Real-time PCR was used to analyze the expression level of MmMT mRNA at different M. meretrix larval stages under Cd exposure (25 {mu}g L{sup -1}). Results showed that Cd could induce the expression of MmMT mRNA in the larvae, and the expression level increased 5.04-fold and 3.99-fold in D-shaped larvae and pediveligers, respectively. Immunolocalization of MmMT in the stressed larvae revealed that MmMT was synthesized in almost all of the soft parts at the trochophore and postlarva stages, whereas it was only synthesized in the velum and epidermis at the D-shaped larva and pediveliger stages. The activities of three antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), also were measured in larvae at different developmental stages. Increased enzymatic activities were detected mainly in D-shaped larvae and pediveligers under Cd stress, suggesting that these enzymes respond synchronously with MT. Our results indicate that MmMT and antioxidant enzymes played important roles in counteracting Cd stress in M. meretrix larvae.

  10. Ontogeny and physiology of the digestive system of marine fish larvae

    OpenAIRE

    Zambonino, Jose-luis; Gisbert, E; C. Sarasquete; Navarro, I.; Gutiérrez, J.; Cahu, Chantal

    2008-01-01

    The ontogeny of the digestive tract of marine fish larvae has been the subject of many studies these last twenty years. Beyond the scientific interest for such animal species, particularly for developmental aspects, most of these studies aimed to come up with the expectations of commercial hatcheries by reducing the bottlenecks in larvae culture and weaning processes (switch from live preys to compound diet feeding sequence). Consequently, the profile and dietary adaptation of digestive enzym...

  11. Feeding strategy of Downs herring larvae (Clupea harengus L.) in the English Channel and North Sea

    Science.gov (United States)

    Denis, Jeremy; Vallet, Carole; Courcot, Lucie; Lefebvre, Valérie; Caboche, Josselin; Antajan, Elvire; Marchal, Paul; Loots, Christophe

    2016-09-01

    This study aims to characterize the larval feeding strategy of the Downs sub-population of North Sea herring (Clupea harengus L.). Diet composition, vacuity rate and prey selectivity of larvae from 8 to 15 mm collected during the International Bottom Trawl Survey (IBTS) - MIK sampling from 2008 to 2013 were assessed by direct observation of their gut contents using Scanning Electron Microscopy (SEM). The high contribution of protists and small zooplanktonic prey observed in the gut contents proved the relevance of SEM to study the diet of first feeding larvae. The relatively low vacuity rate of 45% suggests that food may not be a limiting factor for Downs herring larvae in winter. These larvae appeared to be omnivorous and there was a clear shift in term of prey composition at a size of 13 mm. Smaller larvae (8-12 mm) fed on a higher diversity of small prey, mainly small copepods (Oncaea spp. and Euterpina acutifrons), invertebrate eggs, diatoms (Psammodicthyon panduriforme and Coscinodiscus spp.) and dinoflagellates (Dinophysis acuminate and Prorocentrum micans) whereas bigger larvae (13-15 mm) fed on a lower diversity of larger prey, mainly copepods (Temora longicornis and Paracalanus parvus) and dinoflagellates (Gonyaulax spp.). Downs herring larvae had clear prey preferences as some dinoflagellates (Pyrophacus spp., Gonyaulax spp., P. micans and Porocentrum lima), invertebrate eggs, copepods (Oncaea spp. and nauplii) and diatoms (Thalassiosira curviseriata) were positively selected and other diatoms (Nitzschia spp., Thalassiosira tenera, Thalassiosira spp. and Chaetoceros spp.) and copepods (Pseudocalanus elongatus, T. longicornis and Unidentified calanoid) were negatively selected. We argue that this shift in term of prey preferences occurring at a size of 13 mm constitutes the critical period for Downs herring larvae.

  12. Immune response of Phyllophaga polyphylla larvae is not an effective barrier against Metarhizium pingshaense

    Directory of Open Access Journals (Sweden)

    JN Enríquez-Vara

    2014-09-01

    Full Text Available Previous research has uncovered that the cuticle of P. polyphylla larvae acts as a good non-immunological barrier against M. pingshaense. In the present study we investigated whether P. polyphylla larvae also show a similarly robust immunological response against M. pingshaense. Firstly, we estimated a median lethal dose (LD50 of blastospores to be injected into the hemocoel. Secondly, we injected the estimated LD50 of blastospores into the hemocoel of larvae to quantify phenoloxidase (PO, nitric oxide (NO and antimicrobial activity as a response against fungal invasion. In contrast to a previous report that showed that M. pingshaense is unable to kill P. polyphylla after topical applications, here we demonstrate that: (a 100 % of P. polyphylla larvae died when blastospores were injected into the hemocoel and (b when injecting the LD50 into the hemocoel of the larvae, immune response did not differ with control. Our results imply that immunological responses do not protect P. polyphylla larvae against M. pingshaense infections. Thus, the cuticle seems a better defense mechanism compared to PO, NO and antimicrobial activity. One proximate explanation for our results is that blastospores are not detected by the host’s immune machinery. An ultimate explanation is that there may be a resource-based tradeoff between non-immunological and immunological barriers, in which white grubs may be investing more in cuticle at the cost of PO, NO and antimicrobial activity.

  13. Influence of nutrient substrates on the expression of cellulases in Cerambyx cerdo L. (Coleoptera: Cerambycidae larvae

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    Pavlović R.

    2012-01-01

    Full Text Available The expression and distribution of digestive cellulases along the midgut of Cerambyx cerdo larvae were analyzed for the first time and are presented in this article. Four groups of larvae were examined: larvae developed in the wild; larvae taken from the wild and successively reared on an artificial diet based on polenta; and larvae hatched in the laboratory and reared on two different artificial diets. Seven endocellulase and seven β-D-glucosidase isoforms were detected in all midgut extracts of C. cerdo with a zymogram after native PAGE. We observed that C. cerdo larvae are capable of producing cellulase isoforms with different PAGE mobilities depending on the nutrient substrate. From our findings it can be assumed that, depending on the distribution of endocellulase and β-D-glucosidase, cellulose molecules are first fragmented in the anterior and middle midgut by endo-β-1,4-glucanase; subsequently, the obtained fragments are broken down by β-D-glucosidase mostly in middle midgut.

  14. Effect of zinc on the growth and development of larvae of bay scallop Argopecten Irradians

    Science.gov (United States)

    Lü, Yantian

    1989-12-01

    The 48-h straight-hinge larvae of Argopecten irradians were exposed for 9 days to various concentrations of zinc in seawater. The growth rate of larvae in the 50 ppb Zn mediums was 77% that of the controls, and nearly zero in the 200 ppb Zn mediums. A progressive decrease in growth and increase in larval deformity and mortality was observed with increasing zinc concentrations from 50 to 200 ppb. 50 and 100 ppb Zn resulted in delayed development of eye spot and metamorphosis and reduced numbers of larvae at both stages. All larvae subjected to higher zinc concentrations died before attaining the eye-spot stage. The zinc concentrations which caused 50% reduction in growth (G C50) and 50% mortality (LC50) were 109 and 120 ppb respectively. Growing in the medium with 100 ppb Zn, the larvae fed with Isochrysis galbana cultured in a medium with 100 ppb Zn showed more suppressed growth and development than those fed with normal food. It is suggested that zinc contaminated food has strong influence on the bay scallop larvae.

  15. A 2D virtual reality system for visual goal-driven navigation in zebrafish larvae

    Science.gov (United States)

    Jouary, Adrien; Haudrechy, Mathieu; Candelier, Raphaël; Sumbre, German

    2016-01-01

    Animals continuously rely on sensory feedback to adjust motor commands. In order to study the role of visual feedback in goal-driven navigation, we developed a 2D visual virtual reality system for zebrafish larvae. The visual feedback can be set to be similar to what the animal experiences in natural conditions. Alternatively, modification of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, we first generated a library of free-swimming behaviors from which we learned the relationship between the trajectory of the larva and the shape of its tail. Then, we used this technique to infer the intended displacements of head-fixed larvae, and updated the visual environment accordingly. Under these conditions, larvae were capable of aligning and swimming in the direction of a whole-field moving stimulus and produced the fine changes in orientation and position required to capture virtual prey. We demonstrate the sensitivity of larvae to visual feedback by updating the visual world in real-time or only at the end of the discrete swimming episodes. This visual feedback perturbation caused impaired performance of prey-capture behavior, suggesting that larvae rely on continuous visual feedback during swimming. PMID:27659496

  16. Acute ecotoxicology of natural oil and gas condensate to coral reef larvae

    Science.gov (United States)

    Negri, Andrew P.; Brinkman, Diane L.; Flores, Florita; Botté, Emmanuelle S.; Jones, Ross J.; Webster, Nicole S.

    2016-02-01

    Risks posed by oil spills to coral reefs are difficult to evaluate, partially due to the absence of studies that adequately assess toxicity to relevant coral reef species. Here we experimentally tested the acute toxicity of condensate, representing a fraction of light crude oil, to coral (Acropora tenuis) and sponge (Rhopaloeides odorabile) larvae. The metamorphosis of coral larvae was inhibited at total petroleum aromatic hydrocarbon (TPAH) concentrations of water accommodated fractions (WAF) as low as 103 μg l‑1, similar to concentrations detected in seawater following large spills. The sensitivity of coral larvae increased by 40% when co-exposed to UV light that they might encounter in shallow reefal systems. Condensate WAF was more toxic to coral larvae than predicted by summing the toxicity of its main components (benzene, toluene, p-xylene and napthalene). In contrast, the sensitivity of sponge larvae to condensate WAF (>10,000 μg l‑1 TPAH) was far less than coral in the presence and absence of UV, but similar to that of other marine invertebrates. While these results highlight the relative sensitivity of coral larvae to oil, further research is needed to better understand and predict the impacts and risks posed by hydrocarbons to tropical reef systems.

  17. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    Science.gov (United States)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  18. Effect of damaged pine needles on growth and development of pine caterpillar larvae

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lili; LI Zhenyu; LI Hailin; HAN Ruidong; ZHAO Yongli

    2006-01-01

    Chinese pine caterpillar (Dendrolimus tabulaeformis)larvae were fed with pine needles of different degrees of damage to evaluate the effects of pine needles on the growth and development of larvae.The results showed that the nutritional index of the larvae declines after feeding on the damaged pine needlings.The lowest amount of food ingested and voided feces,the lowest nutritional index,slowest development,lightest pupae and most mortality were found in those pine caterpillar larvae fed with pine needles which were 50% damaged.The damaged pine needles significantly affected the population dynamics of Chinese pine caterpillars.The nutritional indices of larvae fed with 25% and 75% damaged pine needles were similar.The nutritional index of the dark morphs was higher than that of the tinted morphs,however,their mortality was lower than that of the tinted morphs.This phenomenon was reversed at the later stage of development when the larvae were fed on 50% damaged pine needles.

  19. mRNA differential display on gene expression in settlement metamorphosis process of Ruditapes philippinarum larvae

    Institute of Scientific and Technical Information of China (English)

    Lu Sumin; Bao Zhenmin; Hu Jingjie; Hu Xiaoli; Mu Chunhua; Fang Jianguang

    2008-01-01

    The mRNA differential display (DDRT-PCR) technique was adopted to find out the genes related to settlement metamorphosis development process of Ruditapes philippinarum larvae.In this study, we have obtained three hundred and forty-six amplification bands in total from pedivehger larvae, veliger larvae,eye spot larvae and post-larvae.Sixty-five out of three hundred and forty-six bands are distinctly differential display from band pattern, which can be put into four groups, standing for different expression characters.Sixteen differential display bands were cloned, sequenced and analyzed and nine different sequences are obtained in the study.Three sequences have higher similarity to the eDNAs deposited in database and three are very similar to the rDNA of other species, considered as the rDNA of Ruditapes philippinarum.The rest three sequences are found to be novel sequences after analyzed.Their accession numbers are AY916799, AY916798, and AY916797 respectively.We thought the novel sequences are possibly relevant to the early embryo development of Ruditapes philippinarum larvae and can provide some fundamental understandings that are helpful for the improvement of scallop seed raising industry.

  20. Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee ( Apis mellifera)

    Science.gov (United States)

    Shi, Yuan Yuan; Yan, Wei Yu; Huang, Zachary Y.; Wang, Zi Long; Wu, Xiao Bo; Zeng, Zhi Jiang

    2013-02-01

    The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.