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Sample records for stage larvae l4

  1. Quantitative Profiling Identifies Potential Regulatory Proteins Involved in Development from Dauer Stage to L4 Stage in Caenorhabditis elegans.

    Science.gov (United States)

    Kim, Sunhee; Lee, Hyoung-Joo; Hahm, Jeong-Hoon; Jeong, Seul-Ki; Park, Don-Ha; Hancock, William S; Paik, Young-Ki

    2016-02-05

    When Caenorhabditis elegans encounters unfavorable growth conditions, it enters the dauer stage, an alternative L3 developmental period. A dauer larva resumes larval development to the normal L4 stage by uncharacterized postdauer reprogramming (PDR) when growth conditions become more favorable. During this transition period, certain heterochronic genes involved in controlling the proper sequence of developmental events are known to act, with their mutations suppressing the Muv (multivulva) phenotype in C. elegans. To identify the specific proteins in which the Muv phenotype is highly suppressed, quantitative proteomic analysis with iTRAQ labeling of samples obtained from worms at L1 + 30 h (for continuous development [CD]) and dauer recovery +3 h (for postdauer development [PD]) was carried out to detect changes in protein abundance in the CD and PD states of both N2 and lin-28(n719). Of the 1661 unique proteins identified with a proteomic approach identifies and quantitates the regulatory proteins potentially involved in PDR in C. elegans, which safeguards the overall lifecycle in response to environmental changes.

  2. Encysted cyathostomin larvae in foals - progression of stages and the effect of seasonality.

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    Nielsen, Martin K; Lyons, Eugene T

    2017-03-15

    Cyathostomins (small strongyles) are ubiquitous in grazing horses and are known pathogens as cause of larval cyathostominosis. As part of their life cycle, cyathostomin larvae invade the mucosal walls of the large intestines and undergo encystment. Newly ingested third stage larvae are known to undergo arrested development and this can lead to an accumulation of encysted burdens over the course of a grazing season. It is believed that the host immune system plays a significant role in triggering this arrestment. Little is known about the development and progression of larval stages in foals that are not expected to mount a pronounced immune response to ingested cyathostomin larvae. This study evaluated counts of encysted larvae measured in 37 foals. The foals were born in 2013, 2014, and 2015 into a parasitology research herd kept without anthelmintic intervention and were humanely euthanatized between 50 and 293days of age as part of an ongoing parasite transmission study. A mucosal digestion technique was performed to enumerate encysted early third stage (EL3) and late third stage/fourth stage (LL3/L4) larvae in the cecum, ventral colon and dorsal colon. Counts were analyzed statistically to evaluate the influence of foal age, sex, and seasonality on the counts. Total counts as well as LL3/L4 counts were significantly higher during the grazing season (March-November). Three defined age groups (>100, 100-200, >200days) did not have statistically different counts. Male foals had significantly higher total counts compared to females, and this has not been reported before. The study found that 41% of the recovered larvae were EL3s, but no indication of arrested development of these was observed. This indicates that cyathostomin infection in foals progresses in a manner substantially different from mature horses. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. [Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

    Science.gov (United States)

    Zhang, Chao-Wei; Zhou, Xiao-Nong; Lv, Shan; Zhang, Yi; Liu, He-Xiang

    2008-06-30

    To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata. P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics. The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva. Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.

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

    International Nuclear Information System (INIS)

    Aikens, L.M.; Schad, G.A.

    1989-01-01

    A technique is described for radiolabeling Strongyloides stercoralis larvae with [ 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 [ 75 Se]selenomethionine. When the 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. Infectivity and development of X-irradiated third-stage larvae of Angiostrongylus cantonensis in rats

    International Nuclear Information System (INIS)

    Fujiu, Yoshinori

    1989-01-01

    Angiostrongylus cantonensis third-stage larvae were exposed to less than 10Krad of X-radiation and then given orally to white rats to examine the effects of X-radiation on infectivity and development of the irradiated third-stage larvae and on fecundity of adults developing from the irradiated third-stage larvae. The deleterious effects of X-radiation were observed at relatively lower dosage in the above three parameters. A degree in susceptibility on X-radiation was shown to be radiation-dose-dependent. Comparing to the irradiation of larvae in vitro, the irradiation of larvae in snails caused less deleterious effects at the same dose of X-irradiation. Application of X-radiation to food hygiene was also discussed. (author)

  6. Differential utilization of ash phloem by emerald ash borer larvae: Ash species and larval stage effects

    Science.gov (United States)

    Yigen Chen; Michael D. Ulyshen; Therese M. Poland

    2012-01-01

    Two experiments were performed to determine the extent to which ash species (black, green and white) and larval developmental stage (second, third and fourth instar) affect the efficiency of phloem amino acid utilization by emerald ash borer (EAB) Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) larvae. EAB larvae generally utilized green ash...

  7. Effects of starvation on moult cycle and hepatopancreas of Stage I lobster (Homarus americanus) larvae

    Science.gov (United States)

    Anger, K.; Storch, V.; Anger, V.; Capuzzo, J. M.

    1985-06-01

    Effects of feeding and starvation on the moult cycle and on the ultrastructure of hepatopancreas cells were studied in Stage I lobster larvae ( Homarus americanus Milne-Edwards). The relative significance of yolk and first food was quite different in larvae originating from two females. This difference was evident also in the amounts of stored lipid in the R-cells of the larval hepatopancreas. Most larvae from one hatch were, in principle, able to develop exclusively with yolk reserves (without food) to the second instar. The larvae from the second hatch showed lecithotrophic development only to the transition between late intermoult and early premoult (Stages C/D0 of Drachs's moult cycle) of the first larval instar. When initial starvation in this group lasted for 3 days or more, the point of no return (PNR) was exceeded. After the PNR, consumption of food was still possible, but development ceased in the transition C/D0 or in late premoult (D3 4). It is suggested that these stages of the moult cycle are critical points were cessation of development and increased mortality are particularly likely in early larval lobsters under nutritional stress. Examination of hepatopancreas R-cells suggested that the PNR is caused by an irreversible loss of the ability to restore lipid reserves depleted during initial starvation. Initial periods of starvation ending before the PNR prolonged mainly Stage D0 of the same instar (I). During this delay, structural changes in the R-cells caused by the preceding period of starvation were reversed: reduced lipid inclusions, swollen mitochondria, an increased number of residual bodies indicating autolysis, and a reduction of the microvillous processes. Continually starved larvae which showed lecithotrophic development throughout the first instar and were then re-fed after moulting successfully, had later a prolonged intermoult (Stage C) period in the second instar. This shows that, despite occasional lecithotrophy, food is an important

  8. Presence of Hypoderma lineatum stage I larvae in the esophagus of cattle slaughtered in Chihuahua, Chih., Mexico.

    Science.gov (United States)

    Quintero-Martínez, M T; Otero Negrete, J; Benítez, R; Méndez, M A; Juárez Vega, G; Cruz-Vázquez, C

    2007-05-15

    In order to detect the presence of Hypoderma lineatum stage I larvae within the esophagus of cattle slaughtered in Chihuahua, Chihuahua, Mexico, a total of five samplings were carried out between July and November 2000. In each instance, a random sample was taken from 10% of the animals slaughtered in a single work shift in each of the two slaughterhouses included in this study. The esophagus were cut longitudinally in order to carry out visual inspection and detect the presence of H. lineatum stage I larvae in the submucosa. The larvae were separated and counted. We identified the presence of H. lineatum stage I larvae in the esophagus for all sampling dates, nevertheless, within the last sampling only one esophagus had them. For all sampling dates the prevalence ranged between 11 and 33%; the latter corresponded to the sampling in October. A total of 287 esophagus was inspected of which 54 were positive with one or more larvae (19%); 233 larvae were obtained from these cases. The number of larvae recovered per sampling ranged from 46 to 74 between July and October, the highest number was found in September's sampling. The largest amount of stage I larvae per esophagus was 22 in the months of July and August. Larvae were always located in the submucosa of the esophagus and all were oriented longitudinally.

  9. Some aspects in early life stage of climbing perch, Anabas testudineus larvae

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    Ponpanom Promkaew

    2005-02-01

    volume 10 liters containing 1,000 larvae aged 1 days post-hatching (just before the mouth opened. They were fed with rotifer at a density of 10 ind/ml. Twenty larvae were collected at random from the aquarium at 2-hourly intervals, preserved in 10% buffered formalin, and then dissected to determine the presence of rotifer in the digestive tract. The digestive tracts were fixed at 32 hr of hatching at water temperatures of 27.0-30.5ºC, and measured477.63±47.80 mm in mouth height. The average number of rotifer in the digestive tract at the start of feeding was 1.50 individual/larva. A starvation experiment was carried out using a 15-liter glass aquarium (water volume 10 liters with three replications. Two hundred newly hatched larvae were kept without feeding. Larvae started to die at 216 hr and totally died within 348 hr after hatching at water temperature ranging between 27.0 and 30.5ºC. The feeding scheme experiments were done in a 15-liter glass aquarium (water volume 10 liters containing 500 of two-day old larvae (stage at first feeding. It was found that larval climbing perch aged 3- 10 days (average total length 3.02-4.97 mm consumed rotifer. The larvae of age 8-15 days (average total length 3.94-12.60 mm consumed Moina. The larvae of age 8-10 days (average total length 3.94-4.97 mmconsumed both rotifer and Moina. The larvae of age 11-day (average total length 5.51 mm consumed only Moina. The larvae of age 14-15 days (average total length 7.34-12.60 mm consumed both Moina and artificial feed. Larvae aged more than 16 days consumed only artificial feed. Determining the daily food uptake by the larvae and juveniles was done in a 15-liter glass aquarium (water volume 10 liters containing 100 larvae. The larvae consumed the living food organism i.e. rotifer or Moina depending on larval stage, with density of rotifer 100 individual/ml or with density of Moina 10 individual/ml. The amount of food intake was calculated based on changes of food density in the

  10. Stage-dependent toxicity of bisphenol a on Rhinella arenarum (anura, bufonidae) embryos and larvae.

    Science.gov (United States)

    Wolkowicz, Ianina R Hutler; Herkovits, Jorge; Pérez Coll, Cristina S

    2014-02-01

    The acute and chronic toxicity of bisphenol A (BPA) was evaluated on the common South American toad Rhinella arenarum embryos and larvae by means of continuous and pulse exposure treatments. Embryos were treated continuously from early blastula (S.4) up to complete operculum (S.25), during early larval stages and by means of 24 h pulse exposures of BPA in concentrations ranging between 1.25 and 40 mg L(-1) , in order to evaluate the susceptibility to this compound in different developmental stages. For lethal effects, S.25 was the most sensitive and gastrula was the most resistant to BPA. The Teratogenic Index for neurula, the most sensitive embryonic stage for sublethal effects was 4.7. The main morphological alterations during early stages were: delayed or arrested development, reduced body size, persistent yolk plug, microcephaly, axial/tail flexures, edemas, blisters, waving fin, underdeveloped gills, mouth malformations, and cellular dissociation. BPA caused a remarkable narcotic effect from gill circulation stage (S.20) onwards in all the organisms exposed after 3 h of treatment with 10 mg L(-1) BPA. After recovering, the embryos exhibited scarce response to stimuli, erratic or circular swimming, and spasmodic contractions from 5 mg L(-1) onwards. Our results highlight the lethal and sublethal effectsof BPA on R. arenarum embryos and larvae, in the last case both at structural and functional levels. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  11. Microfluidic platform for electrophysiological recordings from host-stage hookworm and Ascaris suum larvae: A new tool for anthelmintic research.

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    Weeks, Janis C; Roberts, William M; Robinson, Kristin J; Keaney, Melissa; Vermeire, Jon J; Urban, Joseph F; Lockery, Shawn R; Hawdon, John M

    2016-12-01

    The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device ('chip') that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping) of the worm's pharynx. These electropharyngeograms (EPGs) are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels. Microfluidic technologies have transformed C. elegans research and the goal of the current study was to validate hookworm and Ascaris suum host-stage larvae in the microfluidic EPG platform. Ancylostoma ceylanicum and A. caninum infective L3s (iL3s) that had been activated in vitro generally produced erratic EPG activity under the conditions tested. In contrast, A. ceylanicum L4s recovered from hamsters exhibited robust, sustained EPG activity, consisting of three waveforms: (1) conventional pumps as seen in other nematodes; (2) rapid voltage deflections, associated with irregular contractions of the esophagus and openings of the esophogeal-intestinal valve (termed a 'flutter'); and (3) hybrid waveforms, which we classified as pumps. For data analysis, pumps and flutters were combined and termed EPG 'events.' EPG waveform identification and analysis were performed semi-automatically using custom-designed software. The neuromodulator serotonin (5-hydroxytryptamine; 5HT) increased EPG event frequency in A. ceylanicum L4s at an optimal concentration of 0.5 mM. The anthelmintic drug ivermectin (IVM) inhibited EPG activity in a concentration-dependent manner. EPGs from A. suum L3s recovered from pig lungs exhibited robust pharyngeal pumping in 1 mM 5HT, which was inhibited by IVM. These experiments validate the use of A. ceylanicum L4s and A

  12. Microfluidic platform for electrophysiological recordings from host-stage hookworm and Ascaris suum larvae: A new tool for anthelmintic research

    Directory of Open Access Journals (Sweden)

    Janis C. Weeks

    2016-12-01

    Full Text Available The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device (‘chip’ that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping of the worm's pharynx. These electropharyngeograms (EPGs are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels. Microfluidic technologies have transformed C. elegans research and the goal of the current study was to validate hookworm and Ascaris suum host-stage larvae in the microfluidic EPG platform. Ancylostoma ceylanicum and A. caninum infective L3s (iL3s that had been activated in vitro generally produced erratic EPG activity under the conditions tested. In contrast, A. ceylanicum L4s recovered from hamsters exhibited robust, sustained EPG activity, consisting of three waveforms: (1 conventional pumps as seen in other nematodes; (2 rapid voltage deflections, associated with irregular contractions of the esophagus and openings of the esophogeal-intestinal valve (termed a ‘flutter’; and (3 hybrid waveforms, which we classified as pumps. For data analysis, pumps and flutters were combined and termed EPG ‘events.’ EPG waveform identification and analysis were performed semi-automatically using custom-designed software. The neuromodulator serotonin (5-hydroxytryptamine; 5HT increased EPG event frequency in A. ceylanicum L4s at an optimal concentration of 0.5 mM. The anthelmintic drug ivermectin (IVM inhibited EPG activity in a concentration-dependent manner. EPGs from A. suum L3s recovered from pig lungs exhibited robust pharyngeal pumping in 1 mM 5HT, which was inhibited by IVM. These experiments validate the use of A

  13. Dynamics of gastropod infection by first-stage larvae of protostrongylid nematodes--a model.

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    Rezác, P; Kindlmann, P; Dostálková, I; Holasová, E

    1993-12-01

    For the description of the dynamics of snail infection by the 1st-stage larvae of protostrongylid nematodes, Skorping (1988) used the miracidia-snail model (Anderson, 1978). Here it is shown that, in contrast to miracidia, in protostrongylids the instantaneous rate of infection, alpha, is strongly dependent on the experimental design (factors like host size and size of the experimental arena). With respect to this, Anderson's model is modified by incorporation of the experimental design. The parameter alpha in its new sense as the rate of penetration (probability that the infective larva will penetrate into the host during a time unit) is shown to remain dependent, although much less so, on the experimental design. Only the inclusion of the assumed effect of mucus, which decreases the rate of penetration, yields a parameter alpha 0 (the initial rate of penetration), which is completely independent of the design of the experiment, is species-specific, and also gives the best fit to the empirical data. As the above-mentioned factors can strongly influence the value of the instantaneous rate of infection in the laboratory experiments, alpha 0 is more suitable as a measure of either the larval infectivity for the snail or snail susceptibility to infection by the protostrongylid larvae.

  14. Effect of Vaccination with Irradiated Third Stage Larvae of Haemonchus Contortus

    International Nuclear Information System (INIS)

    Beriajaya; Sukardji, P.

    2000-01-01

    The objective of this study was to determine the effect of vaccination with irradiated third stage larvae of Haemonchus contortus on immune responses in sheep. A number of 15 young male thin-tail sheep freed of worms were divided into 3 groups of 5. The first group was vaccinated with 50.000 irradiated third larvae of H. contortus . The second group was vaccinated as group 1 but without challenged. The third group was not vaccinated but challenged as group 1. Observations were carried out on egg counts, worn counts, total serum protein and antibody titer against H. contortus. The results showed there was no significant differences (P>0.05) on egg counts, worn counts and antibody titer, but a significant difference was seen on value of serum protein between vaccinated group and non vaccinated group. The results showed no protective immunity which is showed in worn counts of vaccinated and non vaccinated groups. Key word: Haemonchus contortus, irradiated larvae, sheep, vaccine

  15. Early stages of test formation in larva of Ascidia malaca (Tunicata, Ascidiacea): ultrastructural and cytochemical investigations.

    Science.gov (United States)

    Dolcemascolo, Giuseppe; Gianguzza, Mario

    2004-01-01

    The swimming larvae of ascidians are entirely covered by a hyalin coat called tunic, or test. This covering consists of two cuticular layers, C1 and C2, which surround an inner compartment composed of an amorphous hyalin matrix with numerous fibrils dispersed inside. Data from the literature agree on the key role played by the cells of the larval ectodermic layer in the synthesis and secretion of larval test components. In the present article are reported ultrastructural and cytochemical investigations made during test formation in the swimming larva of Ascidia malaca. Besides confirming the role played by ectodermic cells during the early stages of test formation, the investigations highlight the way in which the fibrillar component of the test is synthetized and secreted. At the ultrastructural level it has been evidenced that the C1 and C2 cuticular layers originate from the tight packing of fibrils. Based on the data reported in the present study, it is hypothesized that while a relevant part of the fibrils, once secreted, remains dispersed inside the matrix of the inner compartment of the test, quite likely in order to increase its consistency, packing of the remaining fibrils leads to the formation of the C1 and C2 cuticular layers. Packing of the fibrils in C1 and C2 could be favoured by their chemically adhesive nature. This hypothesis is strongly supported by the herewith reported results of the cytochemical investigations carried out on the test of the swimming larva of A. malaca. The cytochemical PA-TCH-SP reaction has in fact evidenced that both fibril types, i.e. those dispersed inside the inner compartment and those packed in the C1 and C2 cuticular layers, are constituted by glycoproteins and/or proteoglycans substances whose adhesive properties are well documented in the literature.

  16. New morphological data on the first-stage larvae of two Procamallanus species (Nematoda: Camallanidae) based on SEM studies.

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    Masová, Sárka; Barus, Vlastimil; Moravec, Frantisek

    2011-11-01

    First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy. Larvae of both species are characterised by the presence of a dorsal cephalic tooth, four submedian cephalic papillae and a pair of amphids, and by the elongate tail with several terminal digit-like processes. The latter formations probably serve for the attachment of larvae to the substrate in water when the larvae attract copepod intermediate hosts by their movements; these structures, especially their numbers, may be of taxonomic importance in camallanid nematodes.

  17. Diet and prey selection in late-stage larvae of five species of fish in a ...

    African Journals Online (AJOL)

    pelagic prey. All larvae selected P. hessei as a prey item. Myxus capensis and R. holubi also selected this copepod and showed the largest diversity in diet. Keywords: copepod eggs, insect larvae, larval fish assemblage, predation, seasonality

  18. ASSESSMENT OF IVERMECTIN THERAPEUTIC EFFICACY ON THIRD-STAGE LARVAE OF Lagochilascaris minor IN MICE EXPERIMENTALLY INFECTED

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    Carlos Augusto Lopes BARBOSA

    1998-05-01

    Full Text Available In this study we evaluated the potential action of ivermectin on third-stage larvae, both at migratory and encysted phases, in mouse tissues after experimental infection with Lagochilascaris minor. Study groups I and II consisted of 120 mice that were orally administered 1,000 parasite eggs. In order to assess ivermectin action upon migratory larvae, group I (60 mice was equally split in three subgroups, namely I-A, I-B, and I-C. On the 7th day after inoculation (DAI, each animal from the subgroup I-A was treated with 200 µg/Kg ivermectin while subgroup I-B was given 1,000 µg/Kg, both groups received a single subcutaneous dose. To assess the drug action on encysted larvae, group II was equally split in three subgroups, namely II-A, II-B, II-C. On the 45th DAI each animal was treated with ivermectin at 200 µg/Kg (subgroup II-A and 1,000 µg/Kg (group II-B with a single subcutaneous dose. Untreated animals of subgroups I-C and II-C were used as controls. On the 60th DAI all animals were submitted to larva search. At a dose of 1,000 µg/Kg the drug had 99.5% effectiveness on third-stage migratory larvae (subgroup I-B. Ivermectin efficacy was lower than 5% on third-stage encysted larvae for both doses as well as for migratory larvae treated with 200µg/Kg.Avaliação da eficácia terapêutica da Ivermectina sobre larvas de terceiro estádio de Lagochilascaris minor em camundongos infectados experimentalmente Avaliou-se a ação da ivermectina sobre larvas de 3o estádio, tanto em fase de migração, quanto larvas encistadas em tecidos de camundongos infectados experimentalmente com Lagochilascaris minor. Foram utilizados 120 camundongos (grupos I e II, sendo que cada animal foi inoculado, por via oral, com 1.000 ovos do parasito. Para verificar a ação da ivermectina sobre larvas em migração, o grupo I (60 animais foi dividido igualmente em três subgrupos: I-A, I-B e I-C. No 7o dia após a inoculação (DAI, cada animal foi tratado com

  19. Morphology and diagnosis of some fourth-stage larvae of cyathostomines (Nematoda: Strongyloidea) in donkeys Equus asinus L. from Ethiopia.

    Science.gov (United States)

    Kharchenko, Vitaliy; Kuzmina, Tetyana; Trawford, Andrew; Getachew, Mulugeta; Feseha, Gebreab

    2009-01-01

    Fourth-stage larvae of four species of the Cyathostominae Nicoll, 1927 parasitic in donkeys Equus asinus L. from Ethiopia were identified mainly using moulting specimens. They are Cylicocyclus asini Matthee, Krecek & Gibbons, 2001, C. auriculatus (Looss, 1900) Chaves, 1930, Cyathostomum tetracanthum (Mehlis, 1831) Molin, 1861 (sensu Looss, 1900) and Cylindropharynx brevicauda Leiper, 1911. The larva of Cylicocyclus asini is similar to those of C. nassatus (Looss, 1900) Chaves, 1930 and C. leptostomum Kotlán, 1920, but differs from the former by the shape of the dorsal tooth in the oesophageal funnel, which is notably smaller than in C. asini but similar to that of C. leptostomum. However, the larva of C. asini differs from that of C. leptostomum in the size of the buccal capsule, which is notably larger than in C. leptostomum but similar to that of C. nassatus. The larva of C. auriculatus is very similar to that of C. insigne (Boulenger, 1917) Chaves, 1930. The larva of Cyathostomum tetracanthum is similar to those of Cylicostephanus bidentatus (Ihle, 1925) Lichtenfels, 1975, C. goldi (Boulenger, 1917) Lichtenfels, 1975 and Cyathostomum catinatum Looss, 1900. The larva of Cylindropharynx brevicauda is similar to that of Petrovinema skrjabini (Ershov, 1930) Ershov, 1943 but smaller in size. Including the four cyathostomine species identified in the present study, 36 species belonging to 13 genera have so far been described and identified of a total of 64 recognised and confirmed species of equine strongyles.

  20. Small larvae in large rivers: observations on downstream movement of European grayling Thymallus thymallus during early life stages.

    Science.gov (United States)

    Van Leeuwen, C H A; Dokk, T; Haugen, T O; Kiffney, P M; Museth, J

    2017-06-01

    Behaviour of early life stages of the salmonid European grayling Thymallus thymallus was investigated by assessing the timing of larval downstream movement from spawning areas, the depth at which larvae moved and the distribution of juvenile fish during summer in two large connected river systems in Norway. Trapping of larvae moving downstream and electrofishing surveys revealed that T. thymallus larvae emerging from the spawning gravel moved downstream predominantly during the night, despite light levels sufficient for orientation in the high-latitude study area. Larvae moved in the water mostly at the bottom layer close to the substratum, while drifting debris was caught in all layers of the water column. Few young-of-the-year still resided close to the spawning areas in autumn, suggesting large-scale movement (several km). Together, these observations show that there may be a deliberate, active component to downstream movement of T. thymallus during early life stages. This research signifies the importance of longitudinal connectivity for T. thymallus in Nordic large river systems. Human alterations of flow regimes and the construction of reservoirs for hydropower may not only affect the movement of adult fish, but may already interfere with active movement behaviour of fish during early life stages. © 2017 The Fisheries Society of the British Isles.

  1. EVALUATION OF THE THERAPEUTIC EFFICACY OF LEVAMISOLE HYDROCHLORIDE ON THIRD-STAGE LARVAE OF Lagochilascaris minor IN EXPERIMENTALLY INFECTED MICE

    Directory of Open Access Journals (Sweden)

    Dulcinéa Maria Barbosa CAMPOS

    2016-01-01

    Full Text Available Lagochilascariosis, a disease caused by Lagochilascaris minor, affects the neck, sinuses, tonsils, lungs, the sacral region, dental alveoli, eyeballs and the central nervous system of humans. A cycle of autoinfection may occur in human host tissues characterized by the presence of eggs, larvae and adult worms. This peculiarity of the cycle hinders therapy, since there are no drugs that exhibit ovicidal, larvicidal and vermicidal activity. Given these facts, we studied the action of levamisole hydrochloride on third-stage larvae in the migration phase (G1 and on encysted larvae (G3 of L. minor. To this end, 87 inbred mice of the C57BL/6 strain were divided into test groups comprising 67 animals (G1-37; G3-30 and a control group (G2-10; G4-10 with 20 animals. Each animal was inoculated orally with 2,000 infective eggs of the parasite. The animals of the test groups were treated individually with a single oral dose of levamisole hydrochloride at a concentration of 0.075 mg. The drug was administered either 30 minutes prior to the parasite inoculation (G1 animals or 120 days after the inoculation (G3 animals. The mice in the control groups were not treated with the drug. After the time required for the migration and the encysting of L. minor larvae, all the animals were euthanized and their tissues examined. The data were analyzed using the Student's unpaired t-test and the Levene test. The groups showed no statistically significant difference. Levamisole hydrochloride was ineffective on third-stage larvae of L. minor. These findings explain the massive expulsion of live adult worms, as well as the use of long treatment schemes, owing to the persistence of larvae and eggs in human parasitic lesions.

  2. Age matters: Developmental stage of Danio rerio larvae influences photomotor response thresholds to diazinion or diphenhydramine

    Energy Technology Data Exchange (ETDEWEB)

    Kristofco, Lauren A. [Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX (United States); Cruz, Luis Colon [Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan (Puerto Rico); Haddad, Samuel P. [Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX (United States); Behra, Martine L. [Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan (Puerto Rico); Chambliss, C. Kevin [Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX (United States); Department of Chemistry, Baylor University, Waco, TX (United States); Brooks, Bryan W., E-mail: Bryan_Brooks@baylor.edu [Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX (United States)

    2016-01-15

    Highlights: • Fish behavior impairments by biological active contaminants are limited yet necessary. • Aquatic toxicology assays with 0–4 dpf larval zebrafish are increasingly important. • Larval zebrafish locomotion varied with age and daylight during typical workday hours. • Photomotor behavior to diazinion and diphenhydramine differed by larval zebrafish age. • Behavioral responses of 7–10 dpf zebrafish were markedly more sensitive than 0–4 dpf. - Abstract: Because basic toxicological data is unavailable for the majority of industrial compounds, High Throughput Screening (HTS) assays using the embryonic and larval zebrafish provide promising approaches to define bioactivity profiles and identify potential adverse outcome pathways for previously understudied chemicals. Unfortunately, standardized approaches, including HTS experimental designs, for examining fish behavioral responses to contaminants are rarely available. In the present study, we examined movement behavior of larval zebrafish over 7 days (4–10 days post fertilization or dpf) during typical daylight workday hours to determine whether intrinsic activity differed with age and time of day. We then employed an early life stage approach using the Fish Embryo Test (FET) at multiple developmental ages to evaluate whether photomotor response (PMR) behavior differed with zebrafish age following exposure to diazinon (DZN), a well-studied orthophosphate insecticide, and diphenhydramine (DPH), an antihistamine that also targets serotonin reuptake transporters and the acetylcholine receptor. 72 h studies were conducted at 1–4, 4–7 and 7–10 dpf, followed by behavioral observations using a ViewPoint system at 4, 7 and 10 dpf. Distance traveled and swimming speeds were quantified; nominal treatment levels were analytically verified by isotope-dilution LC–MSMS. Larval zebrafish locomotion displayed significantly different (p < 0.05) activity profiles over the course of typical daylight and

  3. Gregariousness does not vary with geography, developmental stage, or group relatedness in feeding redheaded pine sawfly larvae.

    Science.gov (United States)

    Terbot, John W; Gaynor, Ryan L; Linnen, Catherine R

    2017-06-01

    Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion , which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggregative tendency within a single widespread species, the redheaded pine sawfly ( N. lecontei ). To do so, we developed a quantitative assay in which we measured interindividual distances over a 90-min video. This assay revealed minimal behavioral differences: (1) between early-feeding and late-feeding larval instars, (2) among larvae derived from different latitudes, and (3) between groups composed of kin and those composed of nonkin. Together, these results suggest that, during the larval feeding period, the benefits individuals derive from aggregating outweigh the costs and that this cost-to-benefit ratio does not vary dramatically across space (geography) or ontogeny (developmental stage). In contrast to the feeding larvae, our assay revealed a striking reduction in gregariousness following the final larval molt in N. lecontei . We also found some intriguing interspecific variation: While N. lecontei and N. maurus feeding larvae exhibit significant aggregative tendencies, feeding N. compar larvae do not aggregate at all. These results set the stage for future work investigating the proximate and ultimate mechanisms underlying developmental and interspecific variation in larval gregariousness across Neodiprion .

  4. Variation in the diel vertical distributions of larvae and transforming stages of oceanic fishes across the tropical and equatorial Atlantic

    Science.gov (United States)

    Olivar, M. Pilar; Contreras, Tabit; Hulley, P. Alexander; Emelianov, Mikhail; López-Pérez, Cristina; Tuset, Víctor; Castellón, Arturo

    2018-01-01

    The vertical distributions of early developmental stages of oceanic fishes were investigated across the tropical and equatorial Atlantic, from oligotrophic waters close to the Brazilian coast to more productive waters close to the Mauritanian Upwelling Region. Stratification of the water column was observed throughout the study region. Fishes were caught with a MOCNESS-1 net with mouth area of 1 m2 at 11 stations. Each station was sampled both during the day and at night within a single 24-h period. The investigation covered both larvae and transforming stages from the surface to 800 m depth. Distribution patterns were analysed, and weighted mean depths for the larvae and transforming stages of each species were calculated for day and night conditions. Forty-seven different species were found. The highest number of species occurred in the three stations south of Cape Verde Islands, characterized by a mixture of South Atlantic Central Water (SACW) and Eastern North Atlantic Central Water (ENACW). There was a marked drop in species richness in the three stations closer to the African upwelling, dominated by ENACW. The highest abundances occurred in the families Myctophidae, Sternoptychidae, Gonostomatidae and Phosichthyidae. Day and night vertical distributions of larvae and transforming stages showed contrasting patterns, both in the depths of the main concentration layers in the water column, and in the diel migration patterns (where these were observed). Larvae generally showed a preference for the upper mixed layer (ca. 0-50 m) and upper thermocline (ca. 50-100 m), except for sternoptychids, which were also abundant in the lower thermocline layer (100-200 m) and even extended into the mesopelagic zone (down to 500 m). Transforming stages showed a more widespread distribution, with main concentrations in the mesopelagic zone (200-800 m). Larvae showed peak concentrations in the more illuminated and zooplankton-rich upper mixed layers during the day and a wider

  5. Changes in physicochemical properties of chitin at developmental stages (larvae, pupa and adult) of Vespa crabro (wasp).

    Science.gov (United States)

    Kaya, Murat; Sofi, Karwan; Sargin, Idris; Mujtaba, Muhammad

    2016-07-10

    It is already known that chitin in a single organism can exhibit huge differences depending on the functions it serves in different body parts, but the alterations in the characteristics of chitin in course of developmental stages of an organism still remain unknown. This study presents findings on how chitin matrix is changing physicochemically through discrete morphological stages - larva, pupa and adult - of an insect (Vespa crabro). Chitin content of the organisms were found to increase gradually as the organism grew; 2.1, 6.2 and 10.3%, with a dramatic increase in chitin deposition (nearly 3 folds) during the instar from larva to pupa. Enzymatic digestion test demonstrated that chitin isolates were close to pure. Chitin isolates were also subjected to thermal pyrolysis and no variations were observed in the thermal stability of the samples. However, it was observed that surface characteristics of chitin changed greatly as the insect grew. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. New morphological data on the first-stage larvae of two Procamallanus species (Nematoda: Camallanidae) based on SEM studies

    OpenAIRE

    Mašová Šárka; Baruš Vlastimil; Moravec František

    2011-01-01

    First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy V článku jsou popsána první stádia larev of kamlanidních hlístic Procamallanus (Procamallanus) laeviconchus (Wedl, 1...

  7. Influence of Ephestia kuehniella stage larvae on the potency of Bacillus thuringiensis Cry1Aa delta-endotoxin.

    Science.gov (United States)

    Abdelmalek, Nouha; Sellami, Sameh; Kallassy-Awad, Mireille; Tounsi, Molka Feki; Mebarkia, Abdelkrim; Tounsi, Slim; Rouis, Souad

    2017-04-01

    The economically important crop pest Ephestia kuehniella was tested at two stages of larval development for susceptibility to Bacillus thuringiensis Cry1Aa toxin. Bioassays showed that toxicity decreased during the development of larvae stage. In fact, Cry1Aa toxins from BNS3-Cry - (pHT-cry1Aa) showed low toxicity against the first-instar larvae (L1) with a LC 50 value of about 421.02μg/g of diet and was not toxic against the fifth-instar (L5), comparing to the BLB1 toxins used as positive control which represent a LC 50 value of about 56.96 and 84.21μg/g of diet against L1 and L5 instars larvae, respectively. Effects of Cry1Aa toxins were reflected in histopathological observations by the weak destruction of midgut epithelium, slight hypertrophy of epithelial cells, and minor alteration of brush border membrane (BBM) detected mainly in L1 larvae stage comparing to the more extensive damage caused by BLB1 toxins. Interestingly, in vitro proteolysis of Cry1Aa toxins was found to correlate with the difference of toxicity during larval stage development. In fact, the weak proteinase activity detected inside the L1 midgut has led to the persistence of the Cry1Aa active forms (65 and 58kDa) during prolonged incubations, causing the alterations described previously. Three subfamilies of aminopeptidase (APN) receptors were detected in both larvae instars with different intensities and molecular weights (150kDa and 55kDa for APN1, and 90kDa for APN2 and APN4). Remarkably, binding assay using Cry1Aa toxin seems to have no direct correlation with larval stages toxicity differences, since same putative receptors were detected. Understanding the reasons for the clear differences in the effectiveness of Cry1Aa toxins during larval development stages of E. kuehniella is very important for the design of future improvement insecticidal approaches and for the accomplishment of resistance prevention strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Prevalence and intensity of third stage Gnathostoma spinigerum larvae in swamp eels sold in three large markets in Bangkok, Thailand.

    Science.gov (United States)

    Saksirisampant, Wilai; Nuchprayoon, Surang; Wiwanitkit, Viroj; Kraivichian, Kanyarat; Suwansaksri, Jamsai

    2002-01-01

    Gnathostoma spinigerum is a common human tissue parasite in Thailand. The swamp eel is the major intermediate or paratenic host for this parasite. The high prevalence of the infective third stage larvae (L3) of this parasite in the rainy season has been noted in previous studies. During June 1999 (rainy season), we performed a cross-sectional survey of the prevalence and the intensity of G. spinigerum L3s in the livers of swamp eels that were obtained from three large Bangkok markets (Klong Toey, Pran Nok, and Tevej). Of a total of 785 livers, G. spinigerum L3s were found in 97: an infection rate of 12%. The prevalence rates in Klong Toey, Pran Nok, and Tevej markets were 13%, 10% and 14% respectively. There was no significant difference in the proportion of infected eels between the markets (p > 0.05). The intensity of L3 burden in the livers ranged from 1-17 larvae, with an average of 2.60 +/- 0.24 larvae (mean +/- SE). In this study a high prevalence of G. spinigerum L3s was found; there was no significant difference in the intensity of larvae in swamp eels between markets. These findings emphasize the importance of public health education: people need to be aware of the dangers of consuming raw or undercooked food.

  9. Effect of Thai 'koi-hoi' food flavoring on the viability and infectivity of the third-stage larvae of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae).

    Science.gov (United States)

    Eamsobhana, Praphathip; Yoolek, Adisak; Yong, Hoi-Sen

    2010-03-01

    The effect of the food flavoring of 'koi-hoi', a popular Thai snail dish, on the viability and infectivity of Angiostrongylus (=Parastrongylus) cantonensis third-stage larvae was assessed in a mouse model. Groups of 50 each of actively moving, non-motile coiled, and extended larvae were obtained from experimentally infected snail meat, after one-hour exposure to standard 'koi-hoi' flavoring. These larvae and groups of 50 unexposed moving larvae (control) were individually fed to each group of three experimental BALB/c mice. The effect on Angiostrongylus worm burden was measured after 3 weeks of infection. Infectivity of the motile larvae after exposure to 'koi-hoi' food flavoring was 38 + or - 5.29%. This was highly significantly lower than the infectivity (62 + or - 7.21%) of the control (unexposed) third-stage larvae (chi(2) = 17.28, P food flavoring, no adult worm was recovered from the extended larvae, indicating that they were no longer alive and unable to cause infection. A small proportion (3.33 + or - 2.31%) of the coiled larvae developed into young adult worms, indicating that mobility alone is not a definitive indicator of viability. The present study confirms that the food flavoring components of 'koi-hoi' dish adversely affect the viability and infectivity of A. cantonensis larvae. Exposure of the third-stage larvae to 'koi-hoi' food flavoring resulted in decreased viability and eventually death. Prolonged treatment with food flavoring to inactivate/immobilize and then kill the infective, third-stage larvae of A. cantonensis in snail meat prior to consumption may be one of the possible economical means of reducing human infection. Copyright 2009 Elsevier B.V. All rights reserved.

  10. Some aspects in early life stage of Siamese gourami, Trichogaster pectoralis (Regan Larvae

    Directory of Open Access Journals (Sweden)

    Ponpanom Promkaew

    2005-05-01

    Full Text Available The sexual maturity of female Siamese gourami, Trichogaster pectoralis was studied by determining fecundity and gonadosomatic index (GSI. It was found that the size at sexual maturity of female Siamese gourami was 18.07±1.10 cm (mean±SD in average total length and 94.20±13.39 g in average body weight. The fecundity was 26,261±5,215.81 ova/fish and gonadosomatic index (GSI was 10.9±2.1%.Newly hatched larvae of Siamese gourami were produced by induced spawning using chemical injection (Suprefact and Motilium. The sexually mature fishes were cultured in fiber-glass tank (water volume 300 liters with the ratio of male and female brooders 1:1. The fertilization rate, hatching out and hatching rate experiments were carried out using a 15-liter aquarium (water volume 10 liters containing 1,000 eggs. It was found that the eggs were floating and rounded. The fertilized eggs had a diameter of 908.25±39.13 μm. The average fertilization rate was 91.12%, hatching out was 22 hr 10 min and average hatching rate was 83.03% at a water temperature of 27.0-30.5ºC. Sampling of the newly-hatched larvae was done at 2-hour intervals, when 20 of them were randomly taken and preserved in 10% buffered formalin for later analysis to determine the time of final yolk absorption. Observation using a microscope revealed that newly hatched larvae were 2.73±0.02 mm in total length and had yolk sacs of 153.76±2.49 μm3 in volume. The yolk sacs were completely absorbed within 110 hr after hatching at a water temperature of 27.0-30.5ºC. Up until full mouth development (start of feeding, 2-hourly samplings of twenty newly hatched larvae were taken from an aquarium for observation of the size of mouth opening. All the larvae had open mouths about 60 hr after hatching (3.56±0.04 mm TL, with the mouths measuring 443.64±24.26 μm in height.The feeding experiments were carried out using a 15-liter glass aquarium (water volume 10 liters containing 1,000 larvae aged 1.5 days

  11. 1H NMR metabolic profiling of cod (Gadus morhua larvae: potential effects of temperature and diet composition during early developmental stages

    Directory of Open Access Journals (Sweden)

    Matilde Skogen Chauton

    2015-12-01

    Full Text Available Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development.

  12. 1H NMR metabolic profiling of cod (Gadus morhua) larvae: potential effects of temperature and diet composition during early developmental stages.

    Science.gov (United States)

    Chauton, Matilde Skogen; Galloway, Trina Falck; Kjørsvik, Elin; Størseth, Trond Røvik; Puvanendran, Velmurugu; van der Meeren, Terje; Karlsen, Ørjan; Rønnestad, Ivar; Hamre, Kristin

    2015-11-06

    Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development. © 2015. Published by The Company of Biologists Ltd.

  13. Population-specific genotype x genotype x environment interactions in bacterial disease of early life stages of Pacific oyster larvae.

    Science.gov (United States)

    Wendling, Carolin C; Fabritzek, Armin G; Wegner, K Mathias

    2017-04-01

    The consequences of emerging marine diseases on the evolutionary trajectories of affected host populations in the marine realm are largely unexplored. Evolution in response to natural selection depends on the genetic variation of the traits under selection and the interaction of these traits with the environment (GxE). However, in the case of diseases, pathogen genotypes add another dimension to this interaction. Therefore, the study of disease resistance needs to be extended to the interaction of host genotype, pathogen genotype and environment (GxGxE). In this study, we used a full-sib breeding design crossing two genetically differentiated populations of the Pacific oyster Crassostrea gigas (Thunberg, 1793), to determine the influence of host genotype, pathogen genotype and temperature on disease resistance. Based on a controlled infection experiment on two early life stages, that is, D-larvae and Pediveliger larvae at elevated and ambient water temperatures, we estimated disease resistance to allopatric and sympatric Vibrio sp . by measuring survival and growth within and between genetically differentiated oyster populations. In both populations, survival was higher upon infection with sympatric Vibrio sp ., indicating that disease resistance has a genetic basis and is dependent on host genotype. In addition, we observed a significant GxGxE effect in D-larvae, where contrary to expectations, disease resistance was higher at warm than at cold temperatures. Using thermal reaction norms, we could further show that disease resistance is an environment dependent trait with high plasticity, which indicates the potential for a fast acclimatization to changing environmental conditions. These population-specific reaction norms disappeared in hybrid crosses between both populations which demonstrates that admixture between genetically differentiated populations can influence GxGxE interactions on larger scales.

  14. Association of insect life stages using DNA sequences : the larvae of Philodytes umbrinus (Motschulsky) (Coleoptera : Dytiscidae)

    NARCIS (Netherlands)

    Miller, KB; Alarie, Y; Wolfe, GW; Whiting, MF

    2005-01-01

    Insect life stages are known imperfectly in many cases, and classifications are based often on only one or a few semaphoronts of a species. This is unfortunate as information in alternative life stages often is useful for scientific study. Although recent examples of DNA in taxonomy have emphasized

  15. Limnoperna fortunei Dunker, 1857 larvae in different environments of a Neotropical floodplain: relationships of abiotic variables and phytoplankton with different stages of development

    Directory of Open Access Journals (Sweden)

    J. Ernandes-Silva

    Full Text Available Abstract Limnoperna fortunei Dunker, 1857 is an Asian invasive freshwater bivalve. Although there need to contain their spread, studies about the biology of the larvae are scarce. We correlated the larval stages of L. fortunei with biotic factors such as phytoplankton and main abiotic variables in lotic environments of the Upper Paraná River floodplain. The four samples were taken quarterly during the year 2012. The Principal component analysis (PCA showed only spatial differences, as did a Canonical Correspondence Analysis (CCA. High densities of larvae were recorded in all samples the Paraná River and Baía River only in December, especially those in their initial stage. In the biovolume of Class of algae, Bacillarophyceae showed the highest value, but Chlorophycea who was strongly correlated with the density of D-stage larvae. The large variety of phytoplankton, especially microplankton Chlorophyceae, high values of PO4, NH4 and temperature were positively correlated with high densities of D-stage larvae. We conclude that high temperature, and food availability, indicated by phytoplankton community, favored the reproduction of L. fortunei and enhance the ability of specie dispersion due to the increase in the emission of propagules. Therefore, studies that address the biology of golden mussel larvae should be performed in order to prevent its spread.

  16. Lack of effects of quebracho and sainfoin hay on incoming third-stage larvae of Haemonchus contortus in goats.

    Science.gov (United States)

    Paolini, V; Prevot, F; Dorchies, Ph; Hoste, H

    2005-09-01

    The effects of tannins on adult populations of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. In contrast, the impact of tannins on T. colubriformis or T. circumcincta third-stage larvae (L3) is associated with a significant reduction in worm establishment. The objective of the present study was to examine the effects of quebracho extract tannins on H. contortus L3. The consequences of consumption of sainfoin hay were also examined. Twenty-one naïve kids were divided into three experimental groups. Group Q received quebracho extract and group S received sainfoin hay from days D3 to D5. Group C remained as an infected control group. All kids received 1500 L3 H. contortus on D0, D1 and D2. On D18, post-infection, the kids were slaughtered and the worm populations compared in the different groups. Compared to the control values, the worm counts decreased, respectively, by 33% and 38% in groups Q and S but the differences were not significant. No differences were found in pathophysiological measurements between the three groups. The results confirm differences in tannin effect according to nematode species but not parasitic stage.

  17. Effects of Temperature and Water Soluble Fraction of Palm Biodiesel and Diesel Fuel on Hatchability and Survival of First Stage Larvae of Macrobrachium rosenbergii

    Directory of Open Access Journals (Sweden)

    Puncharas Gorcharoenwat

    2015-01-01

    Full Text Available Effects of temperature and water soluble fraction (WSF of biodiesel and diesel on hatchability and survival of early stage Macrobrachium rosenbergii were investigated at the temperature of 25, 28, 31 and 34oC. The purpose of this study was to determine toxic effects of biodiesel and diesel on incubation period, hatchability, and survival of the first larval stage. The results showed a significant difference of incubation period among temperatures. The highest temperature (34°C resulted in the shortest incubation period (15 days while the lowest temperature (25°C gave the longest incubation period (19 days. One hundred percent of hatchability was found at temperature 28 and 31°C in the control group. The lowest hatchability occurred at 100% of WSF of palm biodiesel. The hatchability and survival of eggs through the first stage larvae in control and WSF of biodiesel decreased in higher temperature. However, in 50% WSF of diesel, the highest temperature (34°C increased the hatchability and survival whereas 100% WSF of diesel, no larval survival could be found. In comparison between WSF of biodiesel and diesel on newly hatched larvae, the diesel was more toxic to the larvae than that of the biodiesel. Regarding temperature and WSF of biodiesel and diesel effects on the first larval stage of M. rosenbergii, clearly diesel was more harmful to the larvae than biodiesel.

  18. Estimation of predation by the larvae of Toxorhynchites splendens on the aquatic stages of Aedes aegypti.

    Science.gov (United States)

    Dominic Amalraj, D; Das, P K

    1998-03-01

    Predation by instars of Toxorhynchites splendens on aquatic stages of Aedes aegypti was studied by estimating functional response parameters such as attack rate (a') and handling time (Th) in the laboratory. The predator displayed typical type-II functional response, similar to that of most insect predators when presented with increasing densities of any given size class of prey. Second instar predator attacked prey significantly at higher rate than the other instars. Small prey were attacked at higher rate than the predation on larger prey. Except second instar predator, other instars showed significant reduction in a' with increase in Th. Foraging surface area did not influence the predation rate. Predation was high at high water temperature and this was more prominent in the second instar predator. However, prey handling time was independent of the water temperature. Modeling of the predation of mixed age populations of prey and the predator through this short-term functional response experiment is discussed.

  19. Differential immune response of rainbow trout (Oncorhynchus mykiss) at early developmental stages (larvae and fry) against the bacterial pathogen Yersinia ruckeri

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Raida, Martin Kristian; Kania, Per Walter

    2012-01-01

    . We exposed 17 and 87 days post hatch larvae and fry (152 and 1118 degree days post hatch; avg. wt. 70 and 770 mg, respectively) to the bacterial pathogen, Yersinia ruckeri for 4 h by bath challenge. Samples were taken at 4, 24, 72 and 96 h post exposure for qPCR and immunohistochemical analyses......) and iNOS was found in infected fry when compared to the uninfected control. IgT molecules and mannose binding lectins in gills of both infected and uninfected fry were detected by immunohistochemistry. The study indicated that early life stages (yolk-sac larvae), merely up-regulate a few genes...... against broad range of pathogens. However, the increased susceptibility of older fry suggests that Y. ruckeri may utilize some of the immune elements to enter the naive fish. The up-regulation of iNOS and IL-22 in the infected larvae implicates an important role of these molecules in immune response...

  20. Larvae and a new species of Ancyronyx Erichson, 1847 (Insecta, Coleoptera, Elmidae from Palawan, Philippines, using DNA sequences for the assignment of the developmental stages

    Directory of Open Access Journals (Sweden)

    Hendrik Freitag

    2011-10-01

    Full Text Available Ancyronyx montanus sp. n. is described based on adults and larvae, matched using their cox1 DNA sequence data. Larvae of six additional species of Ancyronyx Erichson, 1847 were also described here for the first time, aided by cox1 or cob data: A. helgeschneideri Freitag & Jäch, 2007, A. minerva Freitag & Jäch, 2007, A. patrolus Freitag & Jäch, 2007, A. procerus Jäch, 1994, A. punkti Freitag & Jäch, 2007, A. pseudopatrolus Freitag & Jäch, 2007. Ancyronyx procerus is newly recorded from the Philippines by a larval specimen from Busuanga island. The new species and larval stages are described in detail and illustrated by digital and SEM images. A key to the Ancyronyx larvae of Palawan and an updated checklist of Philippine Ancyronyx is provided.

  1. Larvae and a new species of Ancyronyx Erichson, 1847 (Insecta, Coleoptera, Elmidae) from Palawan, Philippines, using DNA sequences for the assignment of the developmental stages.

    Science.gov (United States)

    Freitag, Hendrik; Balke, Michael

    2011-01-01

    Ancyronyx montanussp. n. is described based on adults and larvae, matched using their cox1 DNA sequence data. Larvae of six additional species of Ancyronyx Erichson, 1847 were also described here for the first time, aided by cox1 or cob data: Ancyronyx helgeschneideri Freitag & Jäch, 2007, Ancyronyx minerva Freitag & Jäch, 2007, Ancyronyx patrolus Freitag & Jäch, 2007, Ancyronyx procerus Jäch, 1994, Ancyronyx punkti Freitag & Jäch, 2007, Ancyronyx pseudopatrolus Freitag & Jäch, 2007. Ancyronyx procerus is newly recorded from the Philippines by a larval specimen from Busuanga island. The new species and larval stages are described in detail and illustrated by digital and SEM images. A key to the Ancyronyx larvae of Palawan and an updated checklist of Philippine Ancyronyx is provided.

  2. Identification of first-stage dorsal-spined lungworm larvae of Tunisian barbary red deer: First report of Varestrongylus sagittatus and Elaphostrongylus cervi in Africa.

    Science.gov (United States)

    Said, Yousra; Cabaret, Jacques; Harmache, Abdallah; Lahmar, Samia

    2018-03-23

    Barbary red deer (Cervus elaphus barbarus) is a protected rare subspecies of red deer. The study of its Protostrongylidae fauna based only on sporadic necropsy of naturally dead animals is difficult. Therefore diagnosis of lungworms rely mainly on the identification of the first stage larvae (L1). The L1 of the different species are not readily diagnosed on morphological basis since much variation is recorded within and among dorsal-spined larvae belonging to various species. The aim of this study was to identify the dorsal-spined lungworm larvae of the Barbary red deer. A discriminant function was established, using the measurements of L1 lungworms recorded from red deer in the literature, then applied to identify 220 dorsal-spined larvae extracted from 25 Tunisian Barbary red deer fresh fecal samples. Also the ITS2 region of rDNA of four pools of larvae (n = 25-60) were amplified, sequenced and analyzed. Using discriminant analysis of morphological traits, Elaphostrongylus cervi and Varestongylus sagittatus were identified. Molecular identification confirmed the presence of E. cervi which is the most prevalent species. This study represents the first identification of V. sagittatus and E. cervi in North Africa. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Acanthocheilonema viteae: Vaccination of jirds with irradiation-attenuated stage-3 larvae and with exported larval antigens

    International Nuclear Information System (INIS)

    Lucius, R.; Textor, G.; Kern, A.; Kirsten, C.

    1991-01-01

    Jirds (Meriones unguiculatus) were immunized with irradiated (35 krad) stage-3 larvae (L3) of Acanthocheilonema viteae. The induced resistance against homologous challenge infection and the antibody response of the animals were studied. Immunization with 3, 2, or 1 dose of 50 irradiated L3 induced approximately 90% resistance. Immunization with a single dose of only 5 irradiated L3 resulted in 60.8% protection while immunization with a single dose of 25 L3 induced 94.1% protection. The protection induced with 3 doses of 50 irradiated L3 did not decrease significantly during a period of 6 months. Sera of a proportion, but not all resistant jirds, contained antibodies against the surface of vector derived L3 as defined by IFAT. No surface antigens of microfilariae or adult worms were recognized by the sera. Vaccinated animals had antibody responses against antigens in the inner organs of L3 and in the cuticle and reproductive organs of adult worms as shown by IFAT. Immunoblotting with SDS-PAGE-separated L3 antigens and L3-CSN revealed that all sera contained antibodies against two exported antigens of 205 and 68 kDa, and against a nonexported antigen of 18 kDa. The 205-kDa antigen easily degraded into fragments of 165, 140, 125, and 105 kDa which were recognized by resistant jird sera. Various antigens of adult worms, but relatively few antigens of microfilariae, were also recognized. To test the relevance of exported antigens of L3 to resistance, jirds were immunized with L3-CSN together with a mild adjuvant. This immunization induced 67.7% resistance against challenge infection and sera of the immunized animals recognized the 205- and 68-kDa antigens of L3

  4. Genomic-bioinformatic analysis of transcripts enriched in the third-stage larva of the parasitic nematode Ascaris suum.

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    Cui-Qin Huang

    2008-06-01

    Full Text Available Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3 of A. suum was constructed by suppressive-subtractive hybridization (SSH, and a subset of cDNAs from 3075 clones subjected to microarray analysis using cDNA probes derived from RNA from different developmental stages of A. suum. The cDNAs (n = 498 shown by microarray analysis to be enriched in the L3 were sequenced and subjected to bioinformatic analyses using a semi-automated pipeline (ESTExplorer. Using gene ontology (GO, 235 of these molecules were assigned to 'biological process' (n = 68, 'cellular component' (n = 50, or 'molecular function' (n = 117. Of the 91 clusters assembled, 56 molecules (61.5% had homologues/orthologues in the free-living nematodes Caenorhabditis elegans and C. briggsae and/or other organisms, whereas 35 (38.5% had no significant similarity to any sequences available in current gene databases. Transcripts encoding protein kinases, protein phosphatases (and their precursors, and enolases were abundantly represented in the L3 of A. suum, as were molecules involved in cellular processes, such as ubiquitination and proteasome function, gene transcription, protein-protein interactions, and function. In silico analyses inferred the C. elegans orthologues/homologues (n = 50 to be involved in apoptosis and insulin signaling (2%, ATP synthesis (2%, carbon metabolism (6%, fatty acid biosynthesis (2%, gap junction (2%, glucose metabolism (6%, or porphyrin metabolism (2%, although 34 (68% of them could not be mapped to a specific metabolic pathway. Small numbers of these 50 molecules were predicted to be secreted (10%, anchored (2%, and/or transmembrane (12% proteins. Functionally, 17 (34% of them were predicted to be associated with (non-wild-type RNAi phenotypes in C. elegans, the majority being embryonic lethality (Emb (13 types; 58.8%, larval arrest

  5. Key to marine arthropod larvae

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    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.

  6. Activity of Ocimum basilicum, Ocimum canum, and Cymbopogon citratus essential oils against Plasmodium falciparum and mature-stage larvae of Anopheles funestus s.s.

    Science.gov (United States)

    Akono Ntonga, Patrick; Baldovini, Nicolas; Mouray, Elisabeth; Mambu, Lengo; Belong, Philippe; Grellier, Philippe

    2014-01-01

    The biological activities of essential oils from three plants grown in Cameroon: Ocimum basilicum, Ocimum canum, and Cymbopogon citratus were tested against Plasmodium falciparum and mature-stage larvae of Anopheles funestus. Gas chromatography and gas chromatography - mass spectrometry analyses showed that the main compounds are geranial, 1,8-cineole and linalool in C. citratus, O. canum and O. basilicum, respectively. Larvicidal tests carried out according to the protocol recommended by the World Health Organization showed that the essential oil of leaves of C. citratus is the most active against larvae of An. funestus (LC50 values = 35.5 ppm and 34.6 ppm, respectively, for larval stages III and IV after 6 h of exposure). Besides, the in vitro anti-plasmodial activity evaluated by the radioisotopic method showed that the C. citratus oil is the most active against P. falciparum, with an IC50 value of 4.2 ± 0.5 μg/mL compared with O. canum (20.6 ± 3.4 μg/mL) and O. basilicum (21 ± 4.6 μg/mL). These essential oils can be recommended for the development of natural biocides for fighting the larvae of malaria vectors and for the isolation of natural products with anti-malarial activity. © P. Akono Ntonga et al., published by EDP Sciences, 2014.

  7. Ancyronyx Erichson, 1847 (Coleoptera, Elmidae) from Mindoro, Philippines, with description of the larvae and two new species using DNA sequences for the assignment of the developmental stages.

    Science.gov (United States)

    Freitag, Hendrik

    2013-01-01

    Ancyronyx buhid sp. n. and Ancyronyx tamaraw sp. n. are described based on adults and larvae, matched using their cox1 or cob DNA sequence data. Additional records of Ancyronyx schillhammeri Jäch, 1994 and Ancyronyx minerva Freitag & Jäch, 2007 from Mindoro are listed. The previously unknown larva of Ancyronyx schillhammeri is also described here, aided by cox1 data. The new species and larval stages are described in detail and illustrated by SEM and stacked microscopic images. Keys to the adult and larval Ancyronyx species of Mindoro and an updated checklist of Philippine Ancyronyx species are provided. The usefulness as bioindicators, the phylogenetic relationships and biogeographic aspects affecting the distribution patterns are briefly discussed.

  8. Ancyronyx Erichson, 1847 (Coleoptera, Elmidae from Mindoro, Philippines, with description of the larvae and two new species using DNA sequences for the assignment of the developmental stages

    Directory of Open Access Journals (Sweden)

    Hendrik Freitag

    2013-08-01

    Full Text Available Ancyronyx buhid sp. n. and A. tamaraw sp. n. are described based on adults and larvae, matched using their cox1 or cob DNA sequence data. Additional records of A. schillhammeri Jäch, 1994 and A. minerva Freitag & Jäch, 2007 from Mindoro are listed. The previously unknown larva of A. schillhammeri is also described here, aided by cox1 data. The new species and larval stages are described in detail and illustrated by SEM and stacked microscopic images. Keys to the adult and larval Ancyronyx species of Mindoro and an up­dated checklist of Philippine Ancyronyx species are provided. The usefulness as bioindicators, the phylogenetic relationships and biogeographic aspects affecting the distribution patterns are briefly discussed.

  9. 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

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

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    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

  11. Proteinases in excretory-secretory products of Toxocara canis second-stage larvae: zymography and modeling insights.

    Science.gov (United States)

    González-Páez, Gonzalo Ernesto; Alba-Hurtado, Fernando; García-Tovar, Carlos Gerardo; Argüello-García, Raúl

    2014-01-01

    Components released in excretory-secretory products of Toxocara canis larvae (TES) include phosphatidylethanolamine-binding proteins (TES26), mucins (TES120, MUC2-5), and C-type lectins (TES32, TES70) and their biochemical, immunological, and diagnostic properties have been extensively studied albeit proteinase activities towards physiological substrates are almost unknown. Proteolytic activities in TES samples were first analyzed by gel electrophoresis with gelatin as substrate. Major activities of ~400, 120, and 32 kDa in TES were relatively similar over a broad pH range (5.5-9.0) and all these were of the serine-type as leupeptin abolished gelatinolysis. Further, the ~400 kDa component degraded all physiological substrates tested (laminin, fibronectin, albumin, and goat IgG) and the 120 kDa component degraded albumin and goat IgG while proteinases of lower MW (45, 32, and 26 kDa) only degraded laminin and fibronectin, preferentially at alkaline pH (9.0). By protein modeling approaches using the known sequences of TES components, only TES26 and MUC4 displayed folding patterns significantly related to reference serine proteinases. These data suggest that most of serine proteinase activities secreted in vitro by infective larvae of T. canis have intriguing nature but otherwise help the parasite to affect multiple components of somatic organs and bodily fluids within the infected host.

  12. In vitro effects of three woody plant and sainfoin extracts on 3rd-stage larvae and adult worms of three gastrointestinal nematodes.

    Science.gov (United States)

    Paolini, V; Fouraste, I; Hoste, H

    2004-07-01

    Most studies on the effects of tanniferous plants on nematodes have examined forages but have neglected the woody plants. Therefore, in vitro effects of extracts from 3 woody plants (Rubus fructicosus, Quercus robur, Corylus avellana) have been tested on trichostrongyles and compared to sainfoin, a legume forage. Because some in vivo results indicated that the effects of tannins differed depending on the parasitic species and/or stages, the effects were measured on 3rd-stage larvae (L3) and adult worms of Teladorsagia circumcincta, Haemonchlus contortus and Trichostrongylus colubriformis. The effects of plant extracts varied according to the plant sources, the parasite species and stages. For the woody plants, significant inhibitory effects were obtained on both stages of abomasal species. Results for T. colubriformis were more variable. Effects of sainfoin extracts were significant on T. colubriformis and H. contortus L3, and on abomasal adult worms. In order to assess the implications of tannins, polyethylene glycol (PEG), an inhibitor of tannins, was added to hazel tree, oak and sainfoin extracts. Without PEG, significant inhibitory effects on L3 and adult worms were confirmed. After addition of PEG, the larval migration and motility of adult worms were restored in most cases. These results confirm variations in effects depending on factors related to plants or parasites and suggest that tannins are partly responsible for the effects.

  13. Fungi predatory activity on embryonated Toxocara canis eggs inoculated in domestic chickens (Gallus gallus domesticus) and destruction of second stage larvae.

    Science.gov (United States)

    Hiura, Emy; Del Carmen Garcia Lopes, Aline; da Paz, Jeanne Saraiva; Gava, Maylla Garschagen; Flecher, Mayra Cunha; Colares, Manuela; de Freitas Soares, Filippe Elias; da Fonseca, Leandro Abreu; Lacerda, Tracy; de Araújo, Jackson Victor; Braga, Fabio Ribeiro

    2015-09-01

    The objective of this study was to evaluate the infectivity of Toxocara canis eggs after interacting with isolated nematophagous fungi of the species Duddingtonia flagrans (AC001) and Pochonia chlamydosporia (VC4), and test the predatory activity of the isolated AC001 on T. canis second stage larvae after 7 days of interaction. In assay A, 5000 embryonated T. canis eggs previously in contact with the AC001 and VC4 isolated for 10 days were inoculated into domestic chickens (Gallus gallus domesticus), and then these animals were necropsied to collect material (digested liver, intestine, muscles and lungs) at 3-, 7-, 14-, and 21-day intervals after inoculation. In assay A, the results demonstrated that the prior interaction of the eggs with isolated AC001 and VC4 decreases the amount of larvae found in the collected organs. Difference (p canis eggs with the tested fungal isolates were efficient in reducing the development and migration of this parasite, in addition to the first report of proven predatory activity on L2.

  14. Ultrastructural changes in the third-stage, infective larvae of ruminant nematodes treated with sainfoin (Onobrychis viciifolia) extract.

    Science.gov (United States)

    Brunet, S; Fourquaux, I; Hoste, H

    2011-12-01

    Plants rich in condensed tannins are an alternative to chemical anthelmintics to control gastrointestinal nematodes (GINs) in ruminants. Previous functional studies have shown that sainfoin extracts affect the two forms of infective larvae (L3), ensheathed and exsheathed. However, the mechanisms of action remain unknown. The aim of this study was thus to compare ultrastructural changes in ensheathed and exsheathed L3 of two GIN species after in vitro contact with sainfoin extracts using transmission electron microscopy. The main changes identified were an alteration of the hypodermis, the presence of numerous vesicles in the cytoplasm and degeneration and/or death of muscular and intestinal cells. The changes suggested similar and nonspecies-specific lesions in the two nematode species. Comparison of the modifications found in the ensheathed vs. exsheathed L3s revealed different locations of the main cellular changes depending on the larval form. It is hypothesized that these spatial differences in lesions are mainly influenced by the presence of the sheath which favors contact between the active compounds and either the cuticle or the digestive tract. Overall, our observations suggest that the functional changes observed in the biology of GIN L3s after contact with sainfoin extracts are mediated through a direct mode of action, i.e. different interactions between the bioactive plant metabolites and the nematode structure depending on the route of contact. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. The impact of environmental heterogeneity and life stage on the hindgut microbiota of Holotrichia parallela larvae (Coleoptera: Scarabaeidae.

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    Shengwei Huang

    Full Text Available Gut microbiota has diverse ecological and evolutionary effects on its hosts. However, the ways in which it responds to environmental heterogeneity and host physiology remain poorly understood. To this end, we surveyed intestinal microbiota of Holotrichia parallela larvae at different instars and from different geographic regions. Bacterial 16S rRNA gene clone libraries were constructed and clones were subsequently screened by DGGE and sequenced. Firmicutes and Proteobacteria were the major phyla, and bacteria belonging to Ruminococcaceae, Lachnospiraceae, Enterobacteriaceae, Desulfovibrionaceae and Rhodocyclaceae families were commonly found in all natural populations. However, bacterial diversity (Chao1 and Shannon indices and community structure varied across host populations, and the observed variation can be explained by soil pH, organic carbon and total nitrogen, and the climate factors (e.g., mean annual temperature of the locations where the populations were sampled. Furthermore, increases in the species richness and diversity of gut microbiota were observed during larval growth. Bacteroidetes comprised the dominant group in the first instar; however, Firmicutes composed the majority of the hindgut microbiota during the second and third instars. Our results suggest that the gut's bacterial community changes in response to environmental heterogeneity and host's physiology, possibly to meet the host's ecological needs or physiological demands.

  16. A complete three-dimensional reconstruction of the myoanatomy of Loricifera: comparative morphology of an adult and a Higgins larva stage.

    Science.gov (United States)

    Neves, Ricardo C; Bailly, Xavier; Leasi, Francesca; Reichert, Heinrich; Sørensen, Martin V; Kristensen, Reinhardt M

    2013-04-15

    Loricifera is a group of small, marine animals, with undetermined phylogenetic relationships within Ecdysozoa (molting protostome animals). Despite their well-known external morphology, data on the internal anatomy of loriciferans are still incomplete. Aiming to increase the knowledge of this enigmatic phylum, we reconstruct for the first time the three-dimensional myoanatomy of loriciferans. Adult Nanaloricus sp. and the Higgins larva of Armorloricus elegans were investigated with cytochemical labeling techniques and CLSM. We discuss our findings with reference to other loriciferan species and recently established phylogenies. The somatic musculature of both adult and larval stages is very complex and includes several muscles arranged in three orientations: circular, transverse and longitudinal. In adult Nanaloricus sp., the introvert is characterized by a net-like muscular arrangement, which is composed of five thin circular fibers crossed by several (up to 30) thin longitudinal fibers with bifurcated anterior ends. Two sets of muscles surround the pre-pharyngeal armature: 6 buccal tube retractors arranged 3 × 2 in a conical shaped structure, and 8 mouth cone retractors. Additionally, a thick, circular muscle marks the neck region and a putative anal sphincter is the posteriormost myoanatomical feature. In the Higgins larva of A. elegans, two circular muscles are distinguished anteriorly in the introvert: a dorsal semicircular fiber and a thin ring muscle. The posteriormost region of the body is characterized by an anal sphincter and a triangular muscle. Based on the currently available knowledge, the myoanatomical bodyplan of adult loriciferans includes: (i) 8 mouth cone retractors, (ii) a pharynx bulb composed of transversal fibers arranged radially, (iii) circular muscles of the head and neck, (iv) internal muscles of the spinoscalids, (v) longitudinal muscles spanning all body regions, and (vi) transverse (circular) muscles in the abdomen. Concerning the

  17. Comparative Evaluation of the Gut Microbiota Associated with the Below- and Above-Ground Life Stages (Larvae and Beetles) of the Forest Cockchafer, Melolontha hippocastani

    Science.gov (United States)

    Arias-Cordero, Erika; Ping, Liyan; Reichwald, Kathrin; Delb, Horst; Platzer, Mathias; Boland, Wilhelm

    2012-01-01

    A comparison of the diversity of bacterial communities in the larval midgut and adult gut of the European forest cockchafer (Melolontha hippocastani) was carried out using approaches that were both dependent on and independent of cultivation. Clone libraries of the 16S rRNA gene revealed 150 operational taxonomic units (OTUs) that belong to 11 taxonomical classes and two other groups that could be classified only to the phylum level. The most abundant classes were β, δ and γ-proteobacteria, Clostridia, Bacilli, Erysipelotrichi and Sphingobacteria. Although the insect’s gut is emptied in the prepupal stage and the beetle undergoes a long diapause period, a subset of eight taxonomic classes from the aforementioned eleven were found to be common in the guts of diapausing adults and the larval midguts (L2, L3). Moreover, several bacterial phylotypes belonging to these common bacterial classes were found to be shared by the larval midgut and the adult gut. Despite this, the adult gut bacterial community represented a subset of that found in the larvae midgut. Consequently, the midgut of the larval instars contains a more diverse bacterial community compared to the adult gut. On the other hand, after the bacteria present in the larvae were cultivated, eight bacterial species were isolated. Moreover, we found evidence of the active role of some of the bacterial species isolated in food digestion, namely, the presence of amylase and xylanolytic properties. Finally, fluorescence in situ hybridization allowed us to confirm the presence of selected species in the insect gut and through this, their ecological niche as well as the metagenomic results. The results presented here elucidated the heterogeneity of aerobic and facultative bacteria in the gut of a holometabolous insect species having two different feeding habits. PMID:23251574

  18. Comparative evaluation of the gut microbiota associated with the below- and above-ground life stages (larvae and beetles of the forest cockchafer, Melolontha hippocastani.

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    Erika Arias-Cordero

    Full Text Available A comparison of the diversity of bacterial communities in the larval midgut and adult gut of the European forest cockchafer (Melolontha hippocastani was carried out using approaches that were both dependent on and independent of cultivation. Clone libraries of the 16S rRNA gene revealed 150 operational taxonomic units (OTUs that belong to 11 taxonomical classes and two other groups that could be classified only to the phylum level. The most abundant classes were β, δ and γ-proteobacteria, Clostridia, Bacilli, Erysipelotrichi and Sphingobacteria. Although the insect's gut is emptied in the prepupal stage and the beetle undergoes a long diapause period, a subset of eight taxonomic classes from the aforementioned eleven were found to be common in the guts of diapausing adults and the larval midguts (L2, L3. Moreover, several bacterial phylotypes belonging to these common bacterial classes were found to be shared by the larval midgut and the adult gut. Despite this, the adult gut bacterial community represented a subset of that found in the larvae midgut. Consequently, the midgut of the larval instars contains a more diverse bacterial community compared to the adult gut. On the other hand, after the bacteria present in the larvae were cultivated, eight bacterial species were isolated. Moreover, we found evidence of the active role of some of the bacterial species isolated in food digestion, namely, the presence of amylase and xylanolytic properties. Finally, fluorescence in situ hybridization allowed us to confirm the presence of selected species in the insect gut and through this, their ecological niche as well as the metagenomic results. The results presented here elucidated the heterogeneity of aerobic and facultative bacteria in the gut of a holometabolous insect species having two different feeding habits.

  19. Increase of the Bacillus thuringiensis secreted toxicity against lepidopteron larvae by homologous expression of the vip3LB gene during sporulation stage.

    Science.gov (United States)

    Sellami, Sameh; Jamoussi, Kaïs; Dabbeche, Emna; Jaoua, Samir

    2011-09-01

    The Vegetative insecticidal Vip3A proteins display a wide range of insecticidal spectrum against several agricultural insect pests. The fact that the expression of vip3 genes occurs only during the vegetative growth phase of Bacillus thuringiensis is a limiting factor in term of production level. Therefore, extending the synthesis of the Vip proteins to the sporulation phase is a good alternative to reach high levels of toxin synthesis. In this study, we have demonstrated that the maximal production of the secreted Vip3LB (also called Vip3Aa16) during the growth of the wild-type strain B. thuringiensis BUPM 95 is reached at the end of the vegetative growth phase, and that the protein remains relatively stable in the culture supernatant during the late sporulation stages. The vip3LB gene was cloned and expressed under the control of the sporulation dependant promoters BtI and BtII in B. thuringiensis BUPM 106 (Vip3(-)) and BUPM 95 (Vip3(+)) strains. The examination of the culture supernatants during the sporulation phase evidenced the synthesis of Vip3LB and its toxicity against the second-instars larvae of the Lepidopteron insect Spodoptera littoralis for the recombinant BUPM 106. Moreover, there was an increase of the Vip3LB synthesis level and an enhancement of the oral toxicity for the recombinant BUPM 95 resulting from the expression of the vip3LB gene during both the vegetative and sporulation phases and the relative stability of the Vip3LB protein.

  20. A note on the correlation between rainfall and the prevalence of Gnathostoma spp. infective stage larvae in swamp eels in Thailand

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    Wiwanitkit V.

    2004-12-01

    Full Text Available Gnathostoma spinigerum is the major causative agent of human gnathostomiasis, a parasitic zoonosis with a great variety of clinical manifestations. Generally, humans are infected by consumption of third-stage larvae (L3 of G. spinigerum in infected hosts in the form of partially cooked or uncooked food. Surveys of the contamination of Gnathostoma spp. L3 in swamp eels are useful for prevention and control of diseases and have been continuously performed in Thailand. The author performed a retrospective study on 33 previous cross-sectional surveys with geographical data and the prevalence of Gnathostoma spp. L3 that covered 12 provinces in Thailand. The relation between rainfall (derived from the geographical data and the prevalence of Gnathostoma spp. L3 in swamp eels (derived from the overall infection rate of Gnathostoma spp. L3 was investigated. The least- square equation plot rainfall (y versus prevalence (x is y = 9.68x + 1,035.1 2 (r = 0.83; p < 0.01. A significant correlation was discerned between rainfall and the prevalence of eel infection but not for the season of the survey. Similar to the previous study, the prevalence of eel infection may depend on rainfall rather than season. However, this study focused on only 33 cross-sectional surveys in Thailand; further similar study in other countries to assess the correlation between rainfall and the prevalence of infection is required to substantiate this conclusion.

  1. Thai koi-hoi snail dish and angiostrongyliasis due to Angiostrongylus cantonensis: Effects of food flavoring and alcoholic drink on the third-stage larvae in infected snail meat.

    Science.gov (United States)

    Eamsobhana, Praphathip; Yoolek, Adisak; Punthuprapasa, Paibulaya; Yong, Hoi-Sen

    2009-04-01

    Human infection with the rat lungworm Angiostrongylus cantonensis (Parastrongylus cantonensis) in Thailand, especially in the northeastern region, is associated with the habit of eating koi-hoi, which contains raw snail meat. Infection results from the snails being carriers of the larval parasite. The present study was conducted to assess the effect of food flavorings in koi-hoi, alcohol, and exposure time of the two variable on the infective larvae of A. cantonensis. Infected Biomphalaria glabrata snails were used for koi-hoi preparation. Raw snail meat was mixed with koi-hoi flavoring and left at room temperature for various time periods ranging from 5 to 60 minutes. At a predetermined time, two pieces of snail meat were removed at random and examined for viability (as determined by motility) of the parasitic third-stage larvae. At the same time, two random pieces of snail meat were removed and treated with 10 mL of a local 40% alcoholic drink for 30 minutes before examination of larval viability. Exposure of infected snail meat for 10 minutes or more to koi-hoi food flavoring resulted in significantly more nonmotile (dying or dead) larvae. Addition of the local alcoholic drink after exposure to the flavoring exerted an additional killing effect on the larvae. Despite long exposure time, both the koi-hoi flavoring and addition of alcoholic drink were not completely effective in killing the infective larvae in the snail meat. Thorough cooking of the food intended for human consumption should still be practiced.

  2. Elevated temperatures and long drought periods have a negative impact on survival and fitness of strongylid third stage larvae.

    Science.gov (United States)

    Knapp-Lawitzke, Friederike; von Samson-Himmelstjerna, Georg; Demeler, Janina

    2016-04-01

    In grazing cattle, infections with gastrointestinal nematodes pose some of the most important health threats and subclinical infections result in considerable production losses. While there is little doubt that climate change will affect grazing ruminants directly, mean temperature increases of ∼ 3°C and longer drought stress periods in summer may also influence the free-living stages of parasitic nematodes. Hostile climatic conditions reduce the number of L3s on pasture and therefore the refugium, which is expected to result in a higher selection pressure, accelerating development of resistance against anthelmintic drugs. The aim of the current experiments was to investigate the effects of drought stress and different temperature/humidity ranges over time on the survival and fitness of Cooperia oncophora L3s and their distribution in grass and soil under controlled conditions using a climate chamber. Grass containers inoculated with L3s were analysed after 1-6weeks using descriptive statistics as well as linear models. A large proportion of L3s was recovered from soil where fitness was also better preserved than on grass. Numbers and fitness of recovered L3s declined with duration in the climate chamber under both temperature profiles. However, the results of the linear models confirmed that higher temperatures (20-33°C versus 17-22.6°C) significantly impaired survival, distribution and fitness of L3s. Application of drought stress, known as another important factor, had a surprisingly smaller impact than its duration or higher temperatures. The climate chamber enabled exclusion of confounding factors and therefore accurate interpretation of the investigated climatic aspects. The obtained results highlight the relative importance of those factors, and will help to design better models for the population dynamics of L3s on pasture in the future. Additionally, the outcomes of these investigations may offer explanations regarding interdependencies of development

  3. Third-stage Gnathostoma spinigerum larva excretory secretory antigens modulate function of Fc gamma receptor I-mediated monocytes in peripheral blood mononuclear cell culture.

    Science.gov (United States)

    Benjathummarak, Surachet; Kumsiri, Ratchanok; Nuamtanong, Supaporn; Kalambaheti, Thareerat; Waikagul, Jitra; Viseshakul, Nareerat; Maneerat, Yaowapa

    2016-01-01

    Third (infective)-stage Gnathostoma spinigerum larvae (L3) mainly cause human gnathostomiasis. G. spinigerum L3 migrate throughout the subcutaneous tissues, vital organs, and central nervous system and can cause various pathogenesis including sudden death. Interestingly, G. spinigerum L3 can survive and evade host cellular immunity for months or years. The effects of G. spinigerum excretory-secretory (ES) products involved in larval migration and immune-evasive strategies are unknown. Monocytes are innate immune cells that act as phagocytic and antigen-presenting cells and also play roles against helminthic infections via a complex interplay between other immune cells. Fc gamma receptor I (FcγRI) is a high-affinity receptor that is particularly expressed on monocytes, macrophages, and dendritic cells. The cross-linking of FcγRI and antigen-antibody complex initiates signal transduction cascades in phagocytosis, cytokine production, and antibody-dependent cell-mediated cytotoxicity (ADCC). This study investigated whether ES antigen (ESA) from G. spinigerum L3 affects monocyte functions. Cultures of normal peripheral blood mononuclear cells (PBMC) separated from healthy buffy coats were used as a human immune cell model. ESA was prepared from G. spinigerum L3 culture. Using Real-Time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), the effect of ESA to down-regulate FcγRI mRNA expression in monocytes during 90 min of observation was not well delineated. Flow cytometry analysis revealed a significant phenotypic-decreased FcγRI expression on the monocyte surface at 12 hours (h) of cultivation with the ESA (p = 0.033). Significantly reduced monocyte-mediated phagocytosis capacity was consistently observed after 12 h of ESA pretreatment (p = 0.001). Our results suggest that G. spinigerum ESA modulates monocyte function via depletion of FcγRI expression. This study provides preliminary information for future in-depth studies to

  4. Effect of Moringa oleifera lectins on survival and enzyme activities of Aedes aegypti larvae susceptible and resistant to organophosphate.

    Science.gov (United States)

    Agra-Neto, Afonso Cordeiro; Napoleão, Thiago Henrique; Pontual, Emmanuel Viana; Santos, Nataly Diniz de Lima; Luz, Luciana de Andrade; de Oliveira, Cláudia Maria Fontes; de Melo-Santos, Maria Alice Varjal; Coelho, Luana Cassandra Breitenbach Barroso; Navarro, Daniela Maria do Amaral Ferraz; Paiva, Patrícia Maria Guedes

    2014-01-01

    The indiscriminate use of synthetic insecticides to control Aedes aegypti has led to emergence of resistant populations. Moringa oleifera seeds contain the lectins WSMoL and cMoL. WSMoL has larvicidal activity on fourth-stage of A. aegypti organophosphate-susceptible larvae (Rockefeller L4). This study reports on the effects of cMoL on the survival of Rockefeller L4 as well as of WSMoL and cMoL on L4 from an organophosphate-resistant population (Rec-R). The effects of lectins on digestive (amylase, trypsin, and protease) and detoxifying (superoxide dismutase (SOD), α- and β-esterases) enzymes from larvae were also determined. cMoL (0.1-0.8 mg/ml) did not kill Rockefeller L4 as well as WSMoL and cMoL (0.1-0.8 mg/ml) were not larvicidal for Rec-R L4. WSMoL stimulated protease, trypsin-like, and α-amylase from Rockefeller L4 while cMoL inhibited these enzymes. WSMoL had no effect on trypsin-like activity from Rec-R L4 but inhibited protease and α-amylase. Among digestive enzymes of Rec-R L4, cMoL inhibited only trypsin-like activity. cMoL inhibited SOD activities from Rockefeller and Rec-R L4 in a higher level than WSMoL while β-esterase from Rockefeller L4 was more inhibited by WSMoL. The lectins promoted low stimulation or inhibition of α-esterase activities from both populations. In conclusion, Rockefeller and Rec-R larvae were distinctly affected by M. oleifera lectins, and larvicidal mechanism of WSMoL on Rockefeller L4 may involve deregulation of digestive enzymes. cMoL interfered mainly on SOD activity and thus it can be investigated as a synergistic agent for controlling populations whose resistance is linked to an increased detoxifying process mediated by this enzyme.

  5. Age of Haemonchus contortus third stage infective larvae is a factor influencing the in vitro assessment of anthelmintic properties of tannin containing plant extracts.

    Science.gov (United States)

    Castañeda-Ramírez, G S; Mathieu, C; Vilarem, G; Hoste, H; Mendoza-de-Gives, P; González-Pech, P G; Torres-Acosta, J F J; Sandoval-Castro, C A

    2017-08-30

    The larval exsheathment inhibition assay (LEIA) of infective larvae (L 3 ) is an in vitro method used to evaluate the anthelmintic (AH) activity of tannin-containing plant extracts against different species of gastrointestinal nematodes, including Haemonchus contortus. Some conditions remain to be defined in order to standardize the LEIA, i.e. the optimal age of larvae produced from donor animals to use in the assays. Therefore, this study aimed at identifying the effect of age and age-related vitality of H. contortus infective larvae produced under tropical conditions, on the in vitro AH activity measured with the LEIA. The same acetone:water (70:30) extract from Acacia pennatula leaves was used to perform respective LEIA tests with H. contortus L 3 of different ages (1-7 weeks). Each week, the L 3 were tested against different concentrations of extract (1200, 600, 400, 200, 100, 40μg/mL of extract) plus a PBS control. Bioassays were performed with a benzimidazole (Bz) resistant H. contortus (Paraíso) strain. In order to identify changes in L 3 vitality on different weeks (1-7), two assays testing larval motility were included only with PBS: the larval migration assay (LMA) and the larval motility observation assay (LMOA). Mean effective concentrations causing 50% and 90% exsheathment inhibition (EC 50 , EC 90 ) were obtained for every week using respective Probit analyses. On the first week, the larvae had lowest EC 50 and EC 90 (39.4 and 65.6μg/mL) compared to older larvae (P0.05), while older larvae tended to show higher EC 50 and EC 90 (Page of larvae (r≥-0.83; P age. More stable efficacy results were found between two to five weeks of age. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Aspectos biológicos da fase adulta de Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae oriunda de larvas alimentadas com Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae Biological aspects of the adult stage of Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae originating from the larvae fed Planococcus citri (Risso, 1813 (Hemiptera: Pseudococcidae

    Directory of Open Access Journals (Sweden)

    Gerane Celly Dias Bezerra

    2006-08-01

    Full Text Available Objetivou-se estudar alguns aspectos biológicos da fase adulta de Chrysoperla externa (Hagen quando as larvas desse predador foram alimentadas com ninfas e fêmeas adultas de Planococcus citri (Risso. O experimento foi conduzido em câmara climatizada regulada a 25 ± 1 ºC, 70 ± 10% de UR e fotofase de 12 horas. Os adultos de C. externa cujas larvas foram alimentadas com ninfas nos três ínstares e fêmeas adultas da cochonilha, foram separados por sexo e 25 casais foram individualizados em gaiolas determinando-se a razão sexual, período de pré-oviposição, capacidade de oviposição diária e total durante 40 dias consecutivos, longevidade, período embrionário e viabilidade de ovos. Constatou-se que as ninfas nos três ínstares e fêmeas adultas fornecidas como alimento, não afetaram a razão sexual, período de pré-oviposição, período embrionário e longevidade dos adultos de C. externa. A produção diária e total de ovos por C. externa foi afetada pelo tipo de alimento fornecido ao predador durante a fase de larva, observando-se uma maior produção quando os casais foram alimentados na fase de larva com fêmeas adultas da cochonilha. Analisando-se a produção de ovos, observou-se uma maior concentração de oviposição nos primeiros dez dias do período reprodutivo, decrescendo nas avaliações seguintes. Foram obtidas porcentagens maiores de ovos viáveis e menores de inviáveis e inférteis, porém, não diferiram em função do alimento fornecido ao predador na fase de larva.It was aimed to study some biological aspects in the adult stage of Chrysoperla externa (Hagen when the larvae of predator were fed both nymphs and adult females of Planococcus citri (Risso. The experiment was conducted in climate chamber at 25 ± 1°C, 70 ± 10% of RH and 12-h photophase. The adults of C. externa whose larvae were fed nymphs at the three instars and adult females of mealybug were separated by sex and 25 couples were individualized

  7. Parasitism between Anisakis simplex (Nematoda: Anisakidae) third-stage larvae and the spotted mackerel Scomber australasicus with regard to the application of stock identification.

    Science.gov (United States)

    Chou, Yi-Ying; Wang, Chun-Shun; Chen, Hui-Guan; Chen, Hui-Yu; Chen, Shiu-Nan; Shih, Hsiu-Hui

    2011-05-11

    The nematode fauna of 369 spotted mackerel of the species Scomber australasicus, collected off the northeastern Taiwanese coast of the northwestern Pacific, was investigated monthly from April 2004 to March 2005. The following nematode species were recorded: Anisakis simplex complex, Hysterothylacium aduncum, Porrocaecum decipiens and Raphidascaris trichiuri. The seasonal variation in the infection with A. simplex third stage larva (L3) was studied throughout the 12 months. The prevalence of A. simplex L3 recorded for total fish samples was 93.6%, varying between 86.7 and 100%. There was an increase in the abundance of this nematode in spring, with the peak occurring in April. To reveal whether intrinsic factors of the spotted mackerel host contributed to infection with this nematode, fish were grouped according to their body weight, age and gonad development (reported as gonadoosomatic index, GSI), respectively, and infection parameters (i.e., prevalence, abundance and intensity) were analyzed. Results showed that abundance was significantly higher in both larger (>450 g) and older (>3 years old) fish. The gonad development of the host fish was not correlated with the intensity of the larval infection in both female and male fish. Two distinct Anisakis species were identified by PCR-RFLP, namely A. pegreffii and a recombinant genotype of A. pegreffii and A. simplex sensu stricto. These species occurred with frequencies of 97% and 3%, respectively. The usefulness of using parasites as biomarkers for spotted mackerel stock identification around Taiwanese waters was confirmed herein. A second group of 58 spotted mackerel were obtained from the coastal waters off southwestern Taiwan. In addition to the two species, A. pegreffii and the recombinant one, which were found with frequencies of 63% and 9%, respectively, an additional Anisakis species A. typica was identified with a frequency of 28% from these fish. Two spotted mackerel stocks could thus be identified based

  8. Predatory potential of Chrysoperla carnea and Cryptolaemus montrouzieri larvae on different stages of the mealybug, Phenacoccus solenopsis: a threat to cotton in South Asia.

    Science.gov (United States)

    Khan, Hafiz Azhar Ali; Sayyed, Ali H; Akram, Waseem; Raza, Sabtain; Ali, Muhammad

    2012-01-01

    The outbreaks of mealybug, Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae), have created problems to cotton crops in South Asia in the recent years. To control this menace, predatory potential of Chrysoperla carnea and Cryptolaemus montrouzieri larvae were investigated under laboratory conditions (27 ± 5° C and 65 ± 5% RH). The experiments were conducted in no choice (only first, second, or third instar larvae of mealybug were offered at a time) and choice (first, second, and third instar larvae were offered simultaneously) feeding tests. Both predators had high consumption rates, with C. montrouzeiri being the most voracious feeder. In the no choice feeding tests, third instar larvae of C. montrouzeiri devoured the highest mean number of first instar P. solenopsis (439.38) In the choice feeding tests, a similar number of first instar nymphs (410) were consumed. In both feeding tests, C. carnea devoured relatively fewer numbers of P. solenopsis than C. montrouzeiri. Manly's preference index suggested that the both predators preferred first instar nymphs of P. solenopsis over second or third instar nymphs. Furthermore, studies on developmental rate and fecundity revealed that first instar nymphs of P. solenopsis significantly reduced development time but increased the fecundity of both predators.

  9. Effect of Myracrodruon urundeuva leaf lectin on survival and digestive enzymes of Aedes aegypti larvae.

    Science.gov (United States)

    Napoleão, Thiago Henrique; Pontual, Emmanuel Viana; de Albuquerque Lima, Thâmarah; de Lima Santos, Nataly Diniz; Sá, Roberto Araújo; Coelho, Luana Cassandra Breitenbach Barroso; do Amaral Ferraz Navarro, Daniela Maria; Paiva, Patrícia Maria Guedes

    2012-02-01

    Aedes aegypti transmits the viruses that cause yellow and dengue fevers. Vector control is essential, since a vaccine for dengue has not as yet been made available. This work reports on the larvicidal activity of Myracrodruon urundeuva leaf lectin (MuLL) against A. aegypti fourth-stage larvae (L(4)). Also, the resistance of MuLL to digestion by L(4) gut proteases and the effects of MuLL on protease, trypsin-like and α-amylase activities from L(4) gut were evaluated to determine if lectin remains active in A. aegypti gut and if insect enzyme activities can be modulated by MuLL. MuLL promoted mortality of L(4) with LC(50) of 0.202 mg/ml. Haemagglutinating activity of MuLL was detected even after incubation for 96 h with L(4) gut preparation containing protease activity. MuLL affected the activity of gut enzymes, inhibiting protease and trypsin activities and stimulating α-amylase activity. The results suggest that MuLL may become a new biodegradable larvicidal agent for dengue control. Larvicidal activity of MuLL may be linked to its resistance to proteolysis by larval enzymes and interference in the activity of digestive larval enzymes.

  10. 1H NMR metabolic profiling of cod (Gadus morhua) larvae: potential effects of temperature and diet composition during early developmental stages

    OpenAIRE

    Chauton, Matilde Skogen; Galloway, Trina Falck; Kj?rsvik, Elin; St?rseth, Trond R?vik; Puvanendran, Velmurugu; van der Meeren, Terje; Karlsen, ?rjan; R?nnestad, Ivar; Hamre, Kristin

    2015-01-01

    Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as tempera...

  11. [Dynamics of nitrogen-containing compounds in the hemolymph of 2d- and 3d-stage larvae of the reindeer warblefly (Hypodermatidae)].

    Science.gov (United States)

    Borozdina, N I

    1979-01-01

    The content of the total protein, residual and amine nitrogen, urea and ammoniac depends on the physiological state of the warble fly larvae of the reindeer. Metabolism of nitrogen-containing compounds carries out most intensively in the growing organism and during the moulting period. The moulting period is characterized by the fall in the total protein, residual and amine nitrogen and increase of the ammonias and urea.

  12. Survival and swimming behavior of insecticide-exposed larvae and pupae of the yellow fever mosquito Aedes aegypti

    Science.gov (United States)

    2014-01-01

    Background The yellow fever mosquito Aedes aegypti is essentially a container-inhabiting species that is closely associated with urban areas. This species is a vector of human pathogens, including dengue and yellow fever viruses, and its control is of paramount importance for disease prevention. Insecticide use against mosquito juvenile stages (i.e. larvae and pupae) is growing in importance, particularly due to the ever-growing problems of resistance to adult-targeted insecticides and human safety concerns regarding such use in human dwellings. However, insecticide effects on insects in general and mosquitoes in particular primarily focus on their lethal effects. Thus, sublethal effects of such compounds in mosquito juveniles may have important effects on their environmental prevalence. In this study, we assessed the survival and swimming behavior of A. aegypti 4th instar larvae (L4) and pupae exposed to increasing concentrations of insecticides. We also assessed cell death in the neuromuscular system of juveniles. Methods Third instar larvae of A. aegypti were exposed to different concentrations of azadirachtin, deltamethrin, imidacloprid and spinosad. Insect survival was assessed for 10 days. The distance swam, the resting time and the time spent in slow swimming were assessed in 4th instar larvae (L4) and pupae. Muscular and nervous cells of L4 and pupae exposed to insecticides were marked with the TUNEL reaction. The results from the survival bioassays were subjected to survival analysis while the swimming behavioral data were subjected to analyses of covariance, complemented with a regression analysis. Results All insecticides exhibited concentration-dependent effects on survival of larvae and pupae of the yellow fever mosquito. The pyrethroid deltamethrin was the most toxic insecticide followed by spinosad, imidacloprid, and azadirachtin, which exhibited low potency against the juveniles. All insecticides except azadirachtin reduced L4 swimming speed and

  13. 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...

  14. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans

    Science.gov (United States)

    Masure, Dries; Wang, Tao; Nejsum, Peter; Hokke, Cornelis H.; Geldhof, Peter

    2016-01-01

    Background The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Methodology/Principal Findings Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively. Conclusions/Significance These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody

  15. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans.

    Science.gov (United States)

    Vlaminck, Johnny; Masure, Dries; Wang, Tao; Nejsum, Peter; Hokke, Cornelis H; Geldhof, Peter

    2016-12-01

    The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively. These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs.

  16. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans.

    Directory of Open Access Journals (Sweden)

    Johnny Vlaminck

    2016-12-01

    Full Text Available The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential.Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12 that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively and specificity (95.5% and 90.0% in pigs and humans, respectively.These findings show the presence of a highly stage specific, glycolipid-like component (As12 that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs.

  17. Image-based automatic recognition of larvae

    Science.gov (United States)

    Sang, Ru; Yu, Guiying; Fan, Weijun; Guo, Tiantai

    2010-08-01

    As the main objects, imagoes have been researched in quarantine pest recognition in these days. However, pests in their larval stage are latent, and the larvae spread abroad much easily with the circulation of agricultural and forest products. It is presented in this paper that, as the new research objects, larvae are recognized by means of machine vision, image processing and pattern recognition. More visional information is reserved and the recognition rate is improved as color image segmentation is applied to images of larvae. Along with the characteristics of affine invariance, perspective invariance and brightness invariance, scale invariant feature transform (SIFT) is adopted for the feature extraction. The neural network algorithm is utilized for pattern recognition, and the automatic identification of larvae images is successfully achieved with satisfactory results.

  18. Predatory activity of Rhantus sikkimensis and larvae of Toxorhynchites splendens on mosquito larvae in Darjeeling, India.

    Science.gov (United States)

    Aditya, Gautam; Ash, Anirban; Saha, Goutam K

    2006-06-01

    Predation potential of the dytiscid beetle, Rhantus sikkimensis Regimbart 1899 and the larvae of Toxorhynchites splendens Wiedemann 1819 occurring along with the larval stages of the mosquitoes in the annual lentic water bodies of Darjeeling was evaluated using the larvae of Culex quinquefasciatus Say 1823 as preys, in the laboratory under simulated natural conditions. Field collected R. sikkimensis and larvae of Tx. splendens were offered IV instar larvae of Cx. quinquefasciatus to observe the rate of predation, at varying prey and predator densities. Based on the data obtained on the predation for a period of three consecutive days, two indices of predation, predatory impact (PI) and clearance rate (CR) values were estimated, and compared between the predator species. The rate of predation of IV instar Cx. quinquefasciatus larvae by R. sikkimensis ranged between 21.56 and 86.89 larvae per day, depending on the prey and predator densities. The PI value remained between 18.67 and 35.33 larvae/day depending on prey densities, while the CR ranged between 2.21 and 2.23 larvae litres/day/predator. Compared to these, the Tx. splendens larvae consumed the prey larvae at the rate of 0.67 to 34.22 larvae per day, depending on the prey and predator densities. The PI value ranged between 7.67 and 11.33 larvae/day, and the CR value ranged between 1.41 and 1.76 larvae litres/day/predator. The rate of predation, CR values and PI values of R. sikkimensis and Tx. splendens varied significantly. Both the predators R. sikkimensis and larvae of Tx. splendens can consume a good number of mosquito larvae, though the rate of consumption between the two predators vary owing to the difference in the life history traits and features. It can be assumed that these predators play an important role in larval population regulation of mosquitoes and thereby impart an effect on species composition and interactions in the aquatic insect communities of Darjeeling Hills, India.

  19. 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.

  20. Soil Moisture Active Passive Mission L4_SM Data Product Assessment (Version 2 Validated Release)

    Science.gov (United States)

    Reichle, Rolf Helmut; De Lannoy, Gabrielle J. M.; Liu, Qing; Ardizzone, Joseph V.; Chen, Fan; Colliander, Andreas; Conaty, Austin; Crow, Wade; Jackson, Thomas; Kimball, John; hide

    2016-01-01

    During the post-launch SMAP calibration and validation (Cal/Val) phase there are two objectives for each science data product team: 1) calibrate, verify, and improve the performance of the science algorithm, and 2) validate the accuracy of the science data product as specified in the science requirements and according to the Cal/Val schedule. This report provides an assessment of the SMAP Level 4 Surface and Root Zone Soil Moisture Passive (L4_SM) product specifically for the product's public Version 2 validated release scheduled for 29 April 2016. The assessment of the Version 2 L4_SM data product includes comparisons of SMAP L4_SM soil moisture estimates with in situ soil moisture observations from core validation sites and sparse networks. The assessment further includes a global evaluation of the internal diagnostics from the ensemble-based data assimilation system that is used to generate the L4_SM product. This evaluation focuses on the statistics of the observation-minus-forecast (O-F) residuals and the analysis increments. Together, the core validation site comparisons and the statistics of the assimilation diagnostics are considered primary validation methodologies for the L4_SM product. Comparisons against in situ measurements from regional-scale sparse networks are considered a secondary validation methodology because such in situ measurements are subject to up-scaling errors from the point-scale to the grid cell scale of the data product. Based on the limited set of core validation sites, the wide geographic range of the sparse network sites, and the global assessment of the assimilation diagnostics, the assessment presented here meets the criteria established by the Committee on Earth Observing Satellites for Stage 2 validation and supports the validated release of the data. An analysis of the time average surface and root zone soil moisture shows that the global pattern of arid and humid regions are captured by the L4_SM estimates. Results from the

  1. 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

  2. Comparison of constitutive and thiabendazole-induced expression of five cytochrome P450 genes in fourth-stage larvae of Haemonchus contortus isolates with different drug susceptibility identifies one gene with high constitutive expression in a multi-resistant isolate.

    Science.gov (United States)

    Yilmaz, Esra; Ramünke, Sabrina; Demeler, Janina; Krücken, Jürgen

    2017-12-01

    Benzimidazoles (BZs) remain amongst the most widely used anthelmintic drug classes against gastro-intestinal nematode infections, although their efficacy is increasingly compromised by resistance. The primary underlying mechanisms for BZ resistance are single-nucleotide polymorphisms (SNPs) in the isotype 1 β-tubulin gene causing the substitutions F167Y, E198A or F200Y. However, resistance is believed to be multi-genic and previous studies have shown that isolates carrying 90-100% F200Y can vary considerably in their resistance level in the egg hatch assay (EHA). Cytochrome P450 monooxygenases (CYPs) are associated with drug resistance in mammals and arthropods and have been considered as mediators of anthelmintic resistance. In Caenorhabditis elegans, several members of the CYP34/35 and CYP31 families are BZ and/or xenobiotic inducible and thiabendazole (TBZ) is metabolised by CYP35D1. Here, expression of all 5 CYPs closely related to the C. elegans CYP34/35 and CYP31 families was investigated in fourth-stage larvae of two susceptible and three BZ-resistant Haemonchus contortus isolates following in vitro exposure to TBZ for 3 and 6 h using real-time RT-PCR. The resistance status of all isolates was determined using EHAs and quantification of resistance-associated β-tubulin SNPs using pyrosequencing. While none of the CYPs was TBZ inducible, constitutive expression of CYP34/35 family member HCOI100383400 was significantly 2.4-3.7-fold higher in the multi-drug resistant WR isolate with the strongest BZ resistance phenotype compared to susceptible and intermediate-level BZ-resistant isolates. Although this increase is only moderate, HCOI100383400 might still be involved in high-level BZ resistance by further decreasing susceptibility in isolates already carrying 100% of a β-tubulin SNP causing BZ resistance. Lower transcript levels were observed for all CYPs in the intermediately resistant IRE isolate in comparison to the susceptible HcH isolate, which, except

  3. 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.

  4. The influence of dietary concentrations of arachidonic acid and eicosapentaenoic acid at various stages of larval ontogeny on eye migration, pigmentation and prostaglandin content of common sole larvae ( Solea solea L.)

    DEFF Research Database (Denmark)

    Lund, Ivar; Steenfeldt, Svend Jørgen; Banta, G.

    2008-01-01

    metamorphosis. Initiation of metamorphosis (i.e. start of eye migration) was related to the size of larvae and not related to ARA or EPA content. Dietary EPA or DHA did not retard the advance of eye migration. More than 90 % of highly malpigmented juveniles, (i.e. "albinos") had a permanent aberrant eye...

  5. Abscisic acid enhances cold tolerance in honeybee larvae.

    Science.gov (United States)

    Ramirez, Leonor; Negri, Pedro; Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

    2017-04-12

    The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee ( Apis mellifera ). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro -reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin , and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. © 2017 The Author(s).

  6. Progress and achievements of the ITER L-4 blanket project

    International Nuclear Information System (INIS)

    Daenner, W.; Toschi, R.; Cardella, A.

    1999-01-01

    The L-4 Blanket Project embraces the R and D of the ITER Shielding Blanket, and its main objective is the fabrication of prototype components. This paper summarises the main conclusions from the materials R and D and the development of technologies which were required for the prototype specifications and manufacturing. The main results of the ongoing testing activities, and of the component manufacture are outlined.The main objectives of the project have been achieved including improvements of the material properties and of joining technologies, which resulted in good component quality and high performance in qualification tests. (author)

  7. Progress and achievements of the ITER L-4 blanket project

    International Nuclear Information System (INIS)

    Daenner, W.; Toschi, R.; Cardella, A.

    2001-01-01

    The L-4 Blanket Project embraces the R and D of the ITER Shielding Blanket, and its main objective is the fabrication of prototype components. This paper summarises the main conclusions from the materials R and D and the development of technologies which were required for the prototype specifications and manufacturing. The main results of the ongoing testing activities, and of the component manufacture are outlined. The main objectives of the project have been achieved including improvements of the material properties and of joining technologies, which resulted in good component quality and high performance in qualification tests. (author)

  8. Feeding behaviour of snake head fish, Channa striatus larvae

    Directory of Open Access Journals (Sweden)

    Thumronk Amornsakun1*

    2011-12-01

    Full Text Available Feeding scheme experiments were done in a 15-liter glass aquarium (water volume 10 liters containing 500 of two-dayold larvae (stage at first feeding. It was found that larval snake head fish aged 3-11 days (average total length 6.08-10.86 mmconsumed Moina. Larvae aged 12-15 days (average total length 10.79-14.61 mm consumed both Moina and commercialpellet (40 % crude protein. Larvae aged more than 16 days consumed only commercial pellet.Determining the daily food uptake by the larvae and juveniles was done in a 15-liter glass aquarium (water volume 10liters containing 1,000 larvae. The larvae consumed Moina ,provide of a density of Moina 10 individual/ml. The amount offood intake was calculated based on changes of food density in the aquarium with and without fish larvae at 2-hour intervals.It was found that larvae aged 3-15 days consumed Moina. The average uptake of Moina in digestive tract per day of larvaeage 3, 6, 9, 12 and 15 days old was 28.7, 115.70, 162.27, 195.30 and 227.30 individual/larva, respectively at water temperaturesranging between 25 and 28°C.A starvation experiment was carried out using a 15-liter glass aquarium (water volume 10 liters with three replications.Two hundred newly hatched larvae were kept without feeding. Larvae started to die at 216 hr and totally died within 326 hrafter hatching at water temperature ranging between 28.0 and 30.5°C.

  9. Análise da dieta das larvas de 4º estádio de Cricotopus sp. (Diptera: Chironomidae, em diferentes substratos artificiais e fases hídricas, no trecho superior do rio Paraná = Diet analysis of Cricotopus sp. larvae (Diptera: Chironomidae, fourth stage, in different artificial substrates and hydrological phases, in the upper Paraná river

    Directory of Open Access Journals (Sweden)

    Adriana Felix dos Anjos

    2009-10-01

    Full Text Available No Brasil, estudos sobre hábitos alimentares das larvas de Chironomidae ainda são escassos e estas informações são importantes para entender a estrutura trófica e a organização dos ecossistemas aquáticos. Neste estudo, teve-se como objetivo identificar osprincipais itens alimentares ingeridos por Cricotopus sp. e comparar as possíveis diferenças na dieta das larvas em diferentes substratos artificiais e fases hídricas. Foram utilizados quatro tipos de substratos artificiais: madeira em forma de X (MADX, placas de nitacetal em forma de X (NITX, PVC em forma de tubo (PVCT e metal galvanizado em forma de tubo (METT, cada um com três réplicas. As coletas foram realizadas quinzenalmente, entre os meses de agosto de 2004 e dezembro de 2005. A dieta de Cricotopus sp. foi constituída por detritos, algas e hifas de fungos. Detrito foi o principal item alimentar, com valores superiores a 50% do total consumido. Os resultados indicaram que Cricotopus sp. é uma espécie coletora e, independentemente do substrato, as larvas alimentam-se dos recursos disponíveis no ambiente. Entretanto, mudanças no regime hidrológico do rio Paraná podem influenciar a disponibilidade de alimento, principalmente algumas diatomaceas como Melosira sp., consumidas em maior quantidade apenas na fase de águas baixas.In Brazil, studies on the diet of Chironomidae larvae are still scarce and these data are important to understand the trophic structure and organization of aquatic ecosystems. In this study, we identified the main food items consumed by Cricotopus sp. and compared possible differences in the larval diet at different artificial substrates and hydrological phases. We used four types of artificial substrates: X-shaped wood (MADX; X-shaped nitacetal plates (NITX; tube-shaped PVC (PVCT and tube-shaped galvanizedmetal (METT, each with three replicates. Samplings were undertaken fortnightly, between August 2004 and December 2005. Cricotopus sp. diet was

  10. Protein Metabolism in Lecithotrophic Larvae (Gastropoda: Haliotis rufescens).

    Science.gov (United States)

    Vavra, J; Manahan, D T

    1999-04-01

    Rates of protein depletion, synthesis, and turnover were measured in larvae of the abalone Haliotis rufescens as an approach to understanding macromolecular metabolism during lecithotrophic development. Protein content decreased linearly during development to metamorphic competence, with 34% of the initial protein in eggs depleted during the 8-day larval life span. Fractional rates of protein synthesis (percentage of total body-protein synthesized per day) decreased during development, from 40% (1-day-old trochophore larva) to 14% (7-day-old veliger larva). Separation of proteins by one-dimensional gel electrophoresis showed that protein pools in larvae are dominated by two high-molecular-weight protein classes (88 and 121 kDa). When the proteins of 1- and 3-day-old larvae were labeled with a mixture of 35S-methionine and cysteine, the pattern on two-dimensional gels showed that the turnover process (protein synthesis and degradation) involved hundreds of different proteins. The energy gained from loss of protein could account for 20% of the protein turnover rates for trochophore larvae and 79% of the lower turnover costs for late-stage veligers. Lecithotrophic larvae of H. rufescens maintained high biosynthetic activities, with up to 40% of their whole-body protein being turned over each day. Such dynamic processes during development of nonfeeding larvae would contribute significantly to maintenance metabolism.

  11. Seasonality of larvae of Brachyura and Anomura (Crustacea Decapoda in the Beagle Channel, Argentina

    Directory of Open Access Journals (Sweden)

    Gustavo A. Lovrich

    1999-12-01

    Full Text Available This is the first study in the Beagle Channel that reports the larval seasonal distribution, abundance and duration of the larval stages of Anomura and Brachyura, on the basis of a fortnightly sampling programme. An identification key to the specific level of zoeal stages is included. Between September 1987 and March 1989, 304 plankton samples were taken by means of oblique hauls from the bottom to the sea-surface. Eighty-five percent of the samples were taken shallower than 60 m depth. Decapod larvae occurred only in spring and summer. All but two taxa showed a single cohort of larvae which emerge at the beginning of the spring. A second cohort of Munida spp. and Halicarcinus planatus also occurred during summer. The most abundant taxa were Munida spp. (312 larvae ? 10 m-3, Peltarion spinosulum (288 larvae ? 10 m-3,, H. planatus (143 larvae ? 10 m-3, and Pagurus spp. (79 larvae ? 10 m-3, which represented 97% of the total larvae collected. Larvae of Pinnotheridae, Eurypodius latreillii, Libidoclaea granaria, and Paralomis granulosa were about an order of magnitude less abundant. Relative abundances of larvae correspond to relative abundances of the respective benthic stages. The absence of certain larval stages or of certain species (Acanthocyclus albatrossis and Lithodes santolla probably indicates their differential distribution within the Beagle Channel. Particularly, lithodid larvae may have benthic or epibenthic habits.

  12. 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.

  13. 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.

  14. Efeito da composição iônica da água do mar artificial no desenvolvimento de larvas de Macrobrachium rosenbergii - DOI: 10.4025/actascibiolsci.v20i0.4484 Effect of artificial seawater ionic composition on the development of Macrobrachium rosenbergii (De Man, 1879 [Crustacea, Decapoda] at the larval stage II - DOI: 10.4025/actascibiolsci.v20i0.4484

    Directory of Open Access Journals (Sweden)

    Margarete Mallasen

    1998-07-01

    Full Text Available Avaliou-se a importância da presença na água dos íons Ca2+, K+, HCO3-, Br-, Sr2+, Mn2+, HPO42-, Li+, MoO42-, S2O32-, Al3+, Rb+, Zn2+, Co2+ e Cu2+ para o desenvolvimento do Macrobrachium rosenbergii no estágio larval II. Aplicou-se um teste de inanição, que consistiu na estocagem das larvas em béqueres contendo 15ml de água salobra (12‰, de diferentes composições iônicas. A cada 8 horas contou-se o número de larvas vivas e calculou-se o tempo médio de vida em todos os tratamentos. Os elementos Al3+, Rb+, Zn2+, Co2+, Cu2+, Sr2+, Mn2+, HPO42-, Li+, MoO42- e S2O32- não influenciaram o tempo de vida das larvas. O K+ e o Ca2+ foram os íons mais importantes para o desenvolvimento das larvas, seguidos pelo Br- e pelo HCO3-, respectivamente, a presença desses íons no meio é indispensável e as larvas devem apresentar mecanismos eficientes de absorção desses elementos.The importance of the ions Ca2+, K+, HCO3-, Br-, Sr2+, Mn2+, HPO42-, Li+, MoO42-, S2O32-, Al3+, Rb+, Zn2+, Co2+ and Cu2+ in water on the development of Macrobrachium rosenbergii at the larval stage II was evaluated. A starvation test was applied. It consisted in keeping larvae of M. rosenbergii in beakers containing 15ml of brackish water (12‰ with different ionic compositions. In order to estimate average life time, larvae which survived the treatment were counted every eight hours. Elements Al3+, Rb+, Zn2+, Co2+,Cu2+, Sr2+, Mn2+, HPO42-, Li+, MoO4M2- and S2O32 were not effective on the larvae life time, whereas K and Ca2+ were the most important ions for larvae development, followed by Br- and HCO3-, respectively. These ions are indispensable in water and larvae must have an efficient mechanism to absorb them.

  15. Rotational properties of L4 Trojan asteroids from K2

    Science.gov (United States)

    Ryan, Erin L.; Woodward, Charles E.; Sharkey, Benjamin N. L.

    2016-10-01

    Our understanding of solar system formation is undergoing a renaissance as new planetary systems are found, often unlike our own. Many questions now ask how the giant planets and their satellite systems accreted and if there is evidence that they migrated to new orbital positions. One of the keys to understanding these questions within our own solar system is the Jupiter Trojan population which is co-orbital with Jupiter. The two Trojan clouds at the stable L4 and L5 Lagrangian points are in orbits which are stable over the age of the Solar System, unlike many other present epoch small body populations. Planetary migration models suggest that the Trojan asteroids, and the dynamically hot (i.e. "scattered"), population of Kuiper Belt objects originate from the same region in the early solar system. While these objects would have started with the same compositions, establishing compositional linkages is challenging and complicated due to a paucity of distinct and easily identifiable mineralogical features in the optical, where these objects are the brightest. While the surface compositions and colors of the Trojans match objects in the inner solar system, as well as the Kuiper Belt, physical characterization of this large population of objects has been scarce. During Campaign 6 in late 2015, the 115 square degree K2 spacecraft field of view overlapped with the L4 Trojan cloud, allowing for long term monitoring. We report on the fitted rotational periods and lightcurve amplitudes from 56 Trojan asteroids that were observed for an average of 11 days by K2. We find ~20% of objects have rotational periods longer than 50 hours and ~40% of the objects have lightcurves with shapes characteristic of contact binary systems.

  16. 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.

  17. Lagrangian Observations and Modeling of Marine Larvae

    Science.gov (United States)

    Paris, Claire B.; Irisson, Jean-Olivier

    2017-04-01

    Just within the past two decades, studies on the early-life history stages of marine organisms have led to new paradigms in population dynamics. Unlike passive plant seeds that are transported by the wind or by animals, marine larvae have motor and sensory capabilities. As a result, marine larvae have a tremendous capacity to actively influence their dispersal. This is continuously revealed as we develop new techniques to observe larvae in their natural environment and begin to understand their ability to detect cues throughout ontogeny, process the information, and use it to ride ocean currents and navigate their way back home, or to a place like home. We present innovative in situ and numerical modeling approaches developed to understand the underlying mechanisms of larval transport in the ocean. We describe a novel concept of a Lagrangian platform, the Drifting In Situ Chamber (DISC), designed to observe and quantify complex larval behaviors and their interactions with the pelagic environment. We give a brief history of larval ecology research with the DISC, showing that swimming is directional in most species, guided by cues as diverse as the position of the sun or the underwater soundscape, and even that (unlike humans!) larvae orient better and swim faster when moving as a group. The observed Lagrangian behavior of individual larvae are directly implemented in the Connectivity Modeling System (CMS), an open source Lagrangian tracking application. Simulations help demonstrate the impact that larval behavior has compared to passive Lagrangian trajectories. These methodologies are already the base of exciting findings and are promising tools for documenting and simulating the behavior of other small pelagic organisms, forecasting their migration in a changing ocean.

  18. Tadpoles of three common anuran species from Thailand do not prey on mosquito larvae.

    Science.gov (United States)

    Weterings, Robbie

    2015-12-01

    Tadpoles are often considered to be predators of mosquito larvae and are therefore beneficial for the control of certain disease vectors. Nevertheless, only a few species have actually been recorded to prey on mosquito larvae. The mosquito larvae predation rates of tadpoles of three common Thai anuran species (Bufo melanostictus, Kaloula pulchra and Hylarana raniceps) were experimentally tested. Tadpoles in varying developmental stages were used to assess a size/age effect on the predation rate. In addition, different instars of Culex quinquefasciatus were used in order to assess a prey size effect on the predation rates. All three species failed to show any evidence of mosquito larvae predation. Neither small nor large tadpoles fed on mosquito larvae. Prey size also did not affect predation. Although tadpoles do not feed on mosquito larvae, there may be other direct or indirect inter-specific interactions that adversely impact the development of larvae in shared habitats with tadpoles. © 2015 The Society for Vector Ecology.

  19. Berbagai Cara Pengendalian Larva Nyamuk

    Directory of Open Access Journals (Sweden)

    Nungki Hapsari Suryaningtyas

    2017-02-01

    Full Text Available Tindakan pencegahan dengan memberantas sarang nyamuk dan membunuh larva serta nyamuk dewasa terus digalakkan. Stadium pradewasa atau larva dapat dikontrol secara biologi maupun kimiawi.1 Berikut adalah beberapa cara pengendalian larva nyamuk.Pengendalian secara biologi Beberapa organisme yang efektif untuk mengendalikan larva secara biologi diantaranya adalah Ikan (larvavivorous fish,Aplocheilus panchax (ikan kepala timah, Ctenops vittatus (ikan cupang,Oreochromis (Tilapia mossambicus (ikan nila dan Cyprinus carpio (ikan tombro, larva nyamuk dari genus Toxorhynchites, Capung (Dragonflies/Labellula . Kelompok Udang (Cyclopoid copepods Jenis Copepoda yang tersebar sebagai plankton dan bentos ini bersifat predator yang efektif untuk mengendalikan stadium pradewasa nyamuk instar satu dan instar dua. Pada suatu penelitian di Polynesia Perancis terbukti bahwa M. aspericornis pengaruhnya tidak konsisten terhadap larva Ae. aegypti yang ditemukan berada di tangki air, drum dan sumur yang tertutup. Keadaan tersebut tampaknya bergantung pada tersedianya mikrofauna di tempat perkembangbiakannya yang dibutuhkan untuk pertumbuhan Copepoda tersebut

  20. Caracterização dos tipos celulares presentes na hemolinfa de larvas e ninfas de Rhipicephalus sanguineus (Latreille (Ixodoidea, Ixodidae em diferentes estados nutricionais Characterization of the celular types present in the Haemolymph of larvae and nimphs of Rhipicephalus sanguineus (Latreille (Ixodoidea, Ixodidae in different nutritional stages

    Directory of Open Access Journals (Sweden)

    Maria Elisa Carneiro

    1996-01-01

    Full Text Available With the purpose of characterize morphologically the hemocytes of larvae and nymphs of Rhipicephalus sanguineus on different nutritional phases, it was obtained samples of haemolymph were obtained by sectioning the forelegs and collecting the drop there formed. After dried, the samples were fixed by methanol and stained by Giemsa. Microscopical observation resulted in the characterization of five basic cellular types: prohemocytes, plasmatocytes, granulocytes, spherulocytes and oenocytoids. Moreover, undefined cell types, whose morphological patterns didn't have correlation with the characteristics cited for hemocytes, were found in low frequency. The change in the relative composition of the haemolimph was characterized by decrease of the number of granulocytes and greater variabilily of the cell types present in the hemolymph as the tick evolved. This fact may be linked to the alterations that these cells suffer along the development of the tick.

  1. A Phosphorylcholine-Containing Glycolipid-like Antigen Present on the Surface of Infective Stage Larvae of Ascaris spp. Is a Major Antibody Target in Infected Pigs and Humans

    DEFF Research Database (Denmark)

    Vlaminck, Johnny; Masure, Dries; Wang, Tao

    2016-01-01

    Background The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating...... larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential. Methodology/Principal Findings Pigs were immunized...... by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies...

  2. Tracheopulmonary Myiasis Caused by a Mature Third-Instar Cuterebra Larva: Case Report and Review

    OpenAIRE

    Cornet, Muriel; Florent, Martine; Lefebvre, Aurélie; Wertheimer, Christophe; Perez-Eid, Claudine; Bangs, Michael J.; Bouvet, Anne

    2003-01-01

    Myiasis is the infestation of vertebrate tissues with fly larvae (Diptera). Most human cases in North America are subcutaneous forms due to Dermatobia hominis imported from Central and South America. Human cases of myiasis acquired in North America are rare and are primarily subdermal or ophthalmologic forms of infestation caused by early stages of Cuterebra larvae. We report an unusual case of tracheopulmonary myiasis, resulting from the in situ development of a mature cuterebrine larva asso...

  3. Immune response of rainbow trout (Oncorhynchus mykiss) larvae to Yersinia ruckeri

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Kania, Per Walter; Raida, Martin Kristian

    Innate immune factors play a crucial role in survival of young fish especially during early stages of life where adaptive immunity is not fully developed. In the present study, we investigated the immune response of rainbow trout larvae (Onchorhynchus mykiss) at an early stage of development. We...... of immune factors at the transcriptional level. It may be speculated that at this stage of life, larvae may combat invading pathogens by using armour consisting of different immune factors without regulating their expression....

  4. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.

  5. Temporal and spatial distribution patterns of echinoderm larvae in La Parguera, Puerto Rico.

    Science.gov (United States)

    Williams, Stacey M; Jorge, García-Sais

    2010-10-01

    This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64 microm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval abundances, oblique tows were taken with 64 and 202 microm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin) exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star) ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber) and Asteroidea larvae (sea star) accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old) of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (approximately 24 day old) D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64 microm mesh net was more efficient for collection of echinoderm larvae than the 202 microm mesh net.

  6. Overview: Pyraloidea larvae (Insecta: Lepidoptera)

    Science.gov (United States)

    The larvae of pyraloid or snout moths are pests to many crops and stored products and rank as among the most destructive pests to graminaceous crops such as corn, sugarcane, and rice. On the other hand, some larvae have been investigated and used for the biological control of noxious terrestrial a...

  7. Cutaneous larva migrans

    Directory of Open Access Journals (Sweden)

    Aleksandra Wieczorek

    2016-09-01

    Full Text Available Introduction . Cutaneous larva migrans (CLM is a tropical zoonosis, caused by parasites, usually Ancylostoma braziliense. Humans are an accidental host. Polish patients with CLM are usually tourists visiting tropical and subtropical countries. The first symptoms do not always appear as creeping eruptions, which complicates the diagnosis. Objective. To present the case of a man with CLM after returning from Thailand to Poland and associated diagnostic difficulties. Case report. We present a case of a 28-year-old man who returned to Poland from Thailand. The first symptoms appeared as disseminated pruritic papules. No improvement after treatment with corticosteroids and antihistamines was observed. The diagnosis was established after the appearance of serpentine erythemas and improvement after albendazole therapy. Conclusions. In the case of returnees from exotic countries suffering from raised, pruritic rashes, and no improvement after treatment with corticosteroids and antihistamines, parasitic etiology should be considered.

  8. Immunity through early development of coral larvae.

    Science.gov (United States)

    Palmer, C V; Graham, E; Baird, A H

    2012-10-01

    As a determinant of survival, immunity is likely to be significant in enabling coral larvae to disperse and successfully recruit, however, whether reef-building coral larvae have immune defenses is unknown. We investigated the potential presence and variation in immunity in the lecithotrophic larvae of Acropora tenuis through larval development. Enzymes indicative of tyrosinase and laccase-type melanin-synthesis were quantified, and the concentration of three coral fluorescent proteins was measured over six developmental stages; egg, embryo, motile planula, planula post-exposure to crustose coralline algae (CCA; settlement cue), settled, settled post-exposure to Symbiodinium (endosymbiont). Both types of melanin-synthesis pathways and the three fluorescent proteins were present in A. tenuis throughout development. Laccase-type activity and red fluorescence increased following exposure of planula to CCA, whereas tyrosinase-type activity and cyan fluorescence increased following settlement. No change was detected in the measured parameters following exposure to Symbiodinium. This study is the first to document coral larval immune responses and suggests the melanin-synthesis pathways have disparate roles-the laccase-type potentially non-immunological and the tyrosinase-type in cytotoxic defense. Our results indicate that corals have the potential to resist infection from the earliest life history phase. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. 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...

  10. Description of the Larva of a New Species of the Genus Afronurus ...

    African Journals Online (AJOL)

    A new species of Afronurus, A. opa sp. n., (Ephemeroptera: Heptageniidae), from Opa River catchment basin, Nigeria is described from the larval stage. The diagnostic morphological characters of the larva are illustrated and discussed. Keywords: Afronurus opa sp. n. larva, Heptageniidae, Ephemeroptera, Nigeria. Tropical ...

  11. Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery ?

    OpenAIRE

    Nunes, Viviane Regina Hernandez; Jacob, Charbel; Cardoso, Igor Machado; Batista, Jos? Lucas; Brazolino, Marcus Alexandre Novo; Maia, Thiago Cardoso

    2016-01-01

    ABSTRACT OBJECTIVE: To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. METHODS: This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. RESULTS: Patients with lumbar disk herniation at L4-L5 level had a mean tilt of 8.06, mean slope of 36.93, an...

  12. Oviposition Behavior in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Response to the Presence of Heterospecific and Conspecific Larvae.

    Science.gov (United States)

    Gonzalez, Paula V; González Audino, Paola A; Masuh, Héctor M

    2016-03-01

    In mosquitoes, location of suitable sites for oviposition requires a set of visual, tactile, and olfactory cues that influences females before laying their eggs. The ability of gravid females to distinguish among potential oviposition sites that will or will not support the growth, development, and survival of their progeny is critical. Aedes aegypti (L.) and Aedes albopictus (Skuse) share ecological niches, being highly competitive in larval stage. We studied the oviposition behavior of both species in the presence of larvae of one or the other species (heterospecific or conspecific larvae). The number of eggs laid by gravid females on oviposition sites (water with different or the same species of Aedes larvae) were compared. The presence and density of heterospecific or conspecific larvae had a positive or negative effect on the ovipositional responses, measured as an oviposition activity index. For both species, the oviposition was not affected by heterospecific larvae with densities between 10 and 100 larvae in water, but a strong attractant behavior was observed for a density of 500 larvae in water. For Ae. albopictus in the presence of larvae of the same species (conspecific oviposition), we observed an attractant effect for larvae density of 10 but not for 100 or 500 larvae in water. Instead, for Ae. aegypti, we observed attraction only for 100 larvae, not for 10 or 500 larvae. Results presented here provide an additional insight about oviposition behavior responses of gravid females in the presence of conspecific and heterospecific larvae in breeding sites.

  13. 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.

  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. 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.

  16. Sensitivity of larvae, pupae, and adults of the driedfruit beetle (Coleoptera: Nitidulidae) to gamma radiation

    International Nuclear Information System (INIS)

    Johnson, J.A.

    1987-01-01

    Raisins infested with three different ages of larvae of dried fruit beetle, Carpophilus hemipterus (L.), were treated with gamma radiation doses of 130-798 Gy. Pupae and unmated adults were also treated at 338 and 486 Gy. All doses to larvae prevented adult development. Only the oldest treated larvae were able to develop to the wandering stage (late third instar) before dying. Complete larval mortality occurred sooner at higher doses. Most younger larvae died within the raisins. Mortality of irradiated pupae at both doses was 90%, and adults emerging from treated pupae died within 48 h. Irradiated adults produced no progeny and died within 1 wk after treatment

  17. Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery.

    Science.gov (United States)

    Nunes, Viviane Regina Hernandez; Jacob, Charbel; Cardoso, Igor Machado; Batista, José Lucas; Brazolino, Marcus Alexandre Novo; Maia, Thiago Cardoso

    2016-01-01

    To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. Patients with lumbar disk herniation at L4-L5 level had a mean tilt of 8.06, mean slope of 36.93, and mean PI of 45. In patients with degenerative spondylolisthesis at the L4-L5 level, a mean tilt of 22.1, mean slope of 38.3, and mean PI of 61.4 were observed. This article reinforces the finding that the high mean tilt and PI are related to the onset of degenerative spondylolisthesis, and also concluded that the same angles, when low, increase the risk for disk herniation.

  18. Multi-Satellite Air Quality Sulfur Dioxide (SO2) Database Long-Term L4 Global V1 (MSAQSO2L4) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — These data are a part of Multi-Decadal Sulfur Dioxide Climatology from Satellite Instrument (MEaSUREs-12-0022 project). The catalogue MSAQSO2L4 file contains the...

  19. Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery

    Directory of Open Access Journals (Sweden)

    Viviane Regina Hernandez Nunes

    Full Text Available ABSTRACT OBJECTIVE: To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. METHODS: This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. RESULTS: Patients with lumbar disk herniation at L4-L5 level had a mean tilt of 8.06, mean slope of 36.93, and mean PI of 45. In patients with degenerative spondylolisthesis at the L4-L5 level, a mean tilt of 22.1, mean slope of 38.3, and mean PI of 61.4 were observed. CONCLUSION: This article reinforces the finding that the high mean tilt and PI are related to the onset of degenerative spondylolisthesis, and also concluded that the same angles, when low, increase the risk for disk herniation.

  20. Defensive enrolment in mantis shrimp larvae (Malacostraca: Stomatopoda)

    NARCIS (Netherlands)

    Haug, C.; Haug, J.T.

    2014-01-01

    We describe a possible new defensive behaviour of larval stages of mantis shrimps (Stomatopoda). Mantis shrimp larvae are rarely observed in nature, thus the study is based on postures of museum material and functional morphological aspects. Specimens described here are tightly enrolled, their pleon

  1. Hydrodynamics of burst swimming fish larvae; a conceptual model approach

    NARCIS (Netherlands)

    Verhagen, J.H.G.

    2004-01-01

    Burst swimming of fish larvae is analysed from a hydrodynamic point of view. A picture of the expected flow pattern is presented based on information in literature on unsteady-flow patterns around obstacles in the intermediate Reynolds number region. It is shown that the acceleration stage of burst

  2. The structure of carbon nanotubes formed of graphene layers L4-8, L5-7, L3-12, L4-6-12

    Science.gov (United States)

    Shapovalova, K. E.; Belenkov, E. A.

    2017-11-01

    We geometrically calculate the optimized structure of nanotubes based on the graphene layers, using the method of molecular mechanics MM+. It was found that only the nanotubes, based on the graphene layers L4-8, L5-7, L3-12, L4-6-12, have a cylindrical form. Calculations of the sublimation energy, carried out using the semi-empirical quantum-mechanic method PM3, show that energy increases with the increase of nanotube diameters.

  3. Food web changes under ocean acidification promote herring larvae survival.

    Science.gov (United States)

    Sswat, Michael; Stiasny, Martina H; Taucher, Jan; Algueró-Muñiz, Maria; Bach, Lennart T; Jutfelt, Fredrik; Riebesell, Ulf; Clemmesen, Catriona

    2018-05-01

    Ocean acidification-the decrease in seawater pH due to rising CO 2 concentrations-has been shown to lower survival in early life stages of fish and, as a consequence, the recruitment of populations including commercially important species. To date, ocean-acidification studies with fish larvae have focused on the direct physiological impacts of elevated CO 2 , but largely ignored the potential effects of ocean acidification on food web interactions. In an in situ mesocosm study on Atlantic herring (Clupea harengus) larvae as top predators in a pelagic food web, we account for indirect CO 2 effects on larval survival mediated by changes in food availability. The community was exposed to projected end-of-the-century CO 2 conditions (~760 µatm pCO 2 ) over a period of 113 days. In contrast with laboratory studies that reported a decrease in fish survival, the survival of the herring larvae in situ was significantly enhanced by 19 ± 2%. Analysis of the plankton community dynamics suggested that the herring larvae benefitted from a CO 2 -stimulated increase in primary production. Such indirect effects may counteract the possible direct negative effects of ocean acidification on the survival of fish early life stages. These findings emphasize the need to assess the food web effects of ocean acidification on fish larvae before we can predict even the sign of change in fish recruitment in a high-CO 2 ocean.

  4. Amino Acid Absorption by Tiger Grouper Fish (Epinephelus fuscoguttatus Larvae. (Absorbsi Asam Amino oleh Larva Ikan Kerapu Macan (Epinephelus fuscoguttatus

    Directory of Open Access Journals (Sweden)

    Ambariyanto Ambariyanto

    2013-12-01

    cultivation i.e. high mortality rate at larva stage. Many different efforts have been done to overcome this problem mainly by using drugs and antibiotics, which have caused another problem i.e. bacteria resitance. One aspect that has not been widely investigated is by increasing its growth rate so that the larvae will have the ability to avoid mortality, such as by utilising dissolved organic matter (DOM which naturally occur in the environment. This research investigates the question whether Kerapu fish larvae have the ability to absorb DOM (in this case disolved free amino acids; DAA as well as the preference and the rate of absorbsion. There were 16 species of DAA used in this experiment which consist of three classes i.e. neutral, basic, and acidic. Two days old larvae were used in the experimant. The results showed that Kerapu larvae absorbed all classes of amino acids, although not all amino acids given being absorbed but only glutamine, histidine, lysin, serine, triptophan, metionine and iso leusine. While the most absorbed amino acids was lysine. One interesting results showed that the larvae secrete several amino acids i.e. glysine, alanine, tyrosine, valine, phenil alanine and leusine. The absorbsion and secretion of amino acids were possibly related to its metabolic processes within the larvae in relation to growth processes. Keywords: dissolved free amino acids, DAA, larvae, Kerapu, Epinephelus fuscoguttatus

  5. 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.

  6. Scanning electron microscope observations of brine shrimp larvae from space shuttle experiments

    Science.gov (United States)

    DeBell, L.; Paulsen, A.; Spooner, B.

    1992-01-01

    Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays. Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage in the sealed syringes. We studied the morphogenesis of the brine shrimp larvae and found the larvae from the space shuttle experiments similar in rate of growth and extent of development, to larvae grown in sealed syringes on the ground. Extensive differentiation and development of embryos and larvae can occur in a microgravity environment.

  7. Color variability and body size of larvae of two Epomis species (Coleoptera: Carabidae in Israel

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    2011-07-01

    Full Text Available Species identification using the characteristics of developmental stages is challenging. However, for insect taxonomy the coloration of larval stages can be an informative feature. The use of live specimens is recommended for this because the color fades in preserved specimens. In this study we examine the possibility of using variation in coloration and color pattern of larvae in order to distinguish between two ground beetles species Epomis dejeani Dejean, 1831 and E. circumscriptus Duftschmid, 1812. We present an atlas and describe the coloration and body size of the three larval stages of the above species based on live specimens. The first instar larvae of the two Epomis species can be easily distinguished based on their color. From the second instar on, the variability in coloration and color patterns increases, creating an overlap in these attributes between larvae of the two species. Except for minor differences in color of the antennae and the base of the mandibles, larvae of the two species are indistinguishable at the second and third larval stages. To the best of our knowledge this is the first attempt to use variation in coloration and color pattern in live larvae in order to identify coleopterans. The color atlas of the larvae enables simple separation of the two Epomis species without requiring sophisticated magnifying devices, although it is less straightforward at the second and third larval stages. We found similar body lengths between the two species for all developmental stages, except for third instar larvae prior to pupation. In the two species the difference in larval body length before pupation positively correlated with that of the adult beetles. More than 70% of the adults' length can be explained by the length of the late third-instar larva; i.e. the large larvae develop into large adults. The larger specimens are the females.

  8. Culturing larvae of marine invertebrates.

    Science.gov (United States)

    Strathmann, Richard R

    2014-01-01

    Larvae of marine invertebrates cultured in the laboratory experience conditions that they do not encounter in nature, but development and survival to metamorphic competence can be obtained in such cultures. This protocol emphasizes simple methods suitable for a wide variety of larvae. Culturing larvae requires seawater of adequate quality and temperature within the tolerated range. Beyond that, feeding larvae require appropriate food, but a few kinds of algae and animals are sufficient as food for diverse larvae. Nontoxic materials include glass, many plastics, hot-melt glue, and some solvents, once evaporated. Cleaners that do not leave toxic residues after rinsing include dilute hydrochloric or acetic acid, sodium hypochlorite (commercial bleach), and ethanol. Materials that can leave toxic residues, such as formaldehyde, glutaraldehyde, detergents, and hand lotions, should be avoided, especially with batch cultures that lack continuously renewed water. Reverse filtration can be used to change water gently at varying frequencies, depending on temperature and the kinds of food that are provided. Bacterial growth can be limited by antibiotics, but antibiotics are often unnecessary. Survival and growth are increased by low concentrations of larvae and stirring of large or dense cultures. One method of stirring large numbers of containers is a rack of motor-driven paddles. Most of the methods and materials are inexpensive and portable. If necessary, a room within a few hours of the sea could be temporarily equipped for larval culture.

  9. 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.

  10. Predatory efficiency of the sewage drain inhabiting larvae of Toxorhynchites splendens Wiedemann on Culex quinquefasciatus Say and Armigeres subalbatus (Coquillett) larvae.

    Science.gov (United States)

    Aditya, Gautam; Bhattacharyya, Sankar; Kundu, Niloy; Kar, Pradip Kumar; Saha, Goutam Kumar

    2007-09-01

    The rate of predation by stage IV instar Toxorhynchites splendens larvae on the equivalent instar stage larvae of Culex quinquefasciatus and Armigeres subalbatus, co-occurring in sewage drains, were noted for a period of three consecutive days in the laboratory using different prey densities and combinations. The rate of predation varied by age of the predator, density of prey, and prey type. The number of Ar. subalbatus larvae consumed by a single Tx. splendens larva ranged between 0.50 +/- 0.71 and 16.40 +/- 2.01; while for Cx. quinquefasciatus larvae, the number consumed ranged from 0.20 +/- 0.42 to 20.40 +/- 1.43 per day. The pupation rates of the prey species varied in respect to control, with a minimum of 0.20 +/- 0.42 pupa/day to a maximum of 12.20 +/- 2.30 pupa/day in the presence of Tx. splendens. The values for the controls were 1.00 +/- 0.87 and 14.44 +/- 2.83 pupa/day, respectively. Irrespective of prey densities and combinations, a single Tx. splendens fourth instar larvae was found to consume on average 10.07 larvae on the first day 16.57 larvae on the second day and 4.38 larvae on the third day, killing a total of 17.70 to 45.10 larvae, in three days. In the presence of Tx. splendens, the cumulative pupation, irrespective of prey, remained between 12.20 and 45.10, and differed significantly from control where the values were between 13.90 and 54.70. The results indicate that Tx. splendens can significantly reduce immature numbers and lower the rate of pupation of Cx. quinquefasciatus and Ar. subalbatus. Tx. splendens may be a potential biological resource in the control of mosquitoes inhabiting sewage drains.

  11. [The morphology and differential diagnosis of parasitic larvae of Triodontophorus (Nematoda, Strongylidae)].

    Science.gov (United States)

    Kharchenko, V A; Dvoĭnos, G M

    1989-01-01

    356 parasitic larvae of the genus Triodontophorus from Equidae (two Equus hemionus and one E. grevyi) have been investigated. They belong to three phenons, which differ from each other by the shape and dimensions of a stoma, the structure of teeth and other signs. That phenons belong to three different species: T. serratus, T. tenuicollis and T. brevicauda. The differential diagnosis of L4 of that species of Triodontophorus are given.

  12. Cold hardiness and supercooling capacity in the overwintering larvae of the codling moth, Cydia pomonella.

    Science.gov (United States)

    Khani, Abbas; Moharramipour, Saeid

    2010-01-01

    The codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), a worldwide apple pest, is classified as a freeze-intolerant organism and one of the most cold-tolerant pests. The objectives of this study were to examine the supercooling point of overwintering and non-diapausing larvae of C. pomonella as an index of its cold hardiness, and to assess larval mortality following 24 h exposure to extreme low temperatures ranging from -5 to -25 degrees C. The mean (+/-SE) supercooling point for feeding larvae (third through fifth instars) was -12.4 +/- 1.1 degrees C. The mean supercooling point for cocooned, non-diapausing larvae (i.e., non-feeding stages) decreased as the days that the arvae were cocooned increased and changed between -15.1 +/- 1.2 degrees C for one to two day cocooned arvae and -19.2 +/- 1.8 degrees C for less than five day cocooned larvae. The mean (+/-SE) supercooling point for other non-feeding stages containing pupae and overwintering larvae were -19.9 +/- 1.0 degrees C and -20.2 +/- 0.2 degrees C, respectively. Mean supercooling points of C. pomonella larvae were significantly lower during the winter months than the summer months, and sex had no effect on the supercooling point of C. pomonella larvae. The mortality of larvae increased significantly after individuals were exposed to temperatures below the mean supercooling point of the population. The supercooling point was a good predictor of cold hardiness.

  13. Dimethyl Sulfide is a Chemical Attractant for Reef Fish Larvae.

    Science.gov (United States)

    Foretich, Matthew A; Paris, Claire B; Grosell, Martin; Stieglitz, John D; Benetti, Daniel D

    2017-05-31

    Transport of coral reef fish larvae is driven by advection in ocean currents and larval swimming. However, for swimming to be advantageous, larvae must use external stimuli as guides. One potential stimulus is "odor" emanating from settlement sites (e.g., coral reefs), signaling the upstream location of desirable settlement habitat. However, specific chemicals used by fish larvae have not been identified. Dimethyl sulfide (DMS) is produced in large quantities at coral reefs and may be important in larval orientation. In this study, a choice-chamber (shuttle box) was used to assess preference of 28 pre-settlement stage larvae from reef fish species for seawater with DMS. Swimming behavior was examined by video-tracking of larval swimming patterns in control and DMS seawater. We found common responses to DMS across reef fish taxa - a preference for water with DMS and change in swimming behavior - reflecting a switch to "exploratory behavior". An open water species displayed no response to DMS. Affinity for and swimming response to DMS would allow a fish larva to locate its source and enhance its ability to find settlement habitat. Moreover, it may help them locate prey accumulating in fronts, eddies, and thin layers, where DMS is also produced.

  14. Microplastic ingestion in fish larvae in the western English Channel.

    Science.gov (United States)

    Steer, Madeleine; Cole, Matthew; Thompson, Richard C; Lindeque, Penelope K

    2017-07-01

    Microplastics have been documented in marine environments worldwide, where they pose a potential risk to biota. Environmental interactions between microplastics and lower trophic organisms are poorly understood. Coastal shelf seas are rich in productivity but also experience high levels of microplastic pollution. In these habitats, fish have an important ecological and economic role. In their early life stages, planktonic fish larvae are vulnerable to pollution, environmental stress and predation. Here we assess the occurrence of microplastic ingestion in wild fish larvae. Fish larvae and water samples were taken across three sites (10, 19 and 35 km from shore) in the western English Channel from April to June 2016. We identified 2.9% of fish larvae (n = 347) had ingested microplastics, of which 66% were blue fibres; ingested microfibers closely resembled those identified within water samples. With distance from the coast, larval fish density increased significantly (P microplastic concentrations (P microplastics and the incidence of ingestion in fish larvae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Desiccation resistance of Chironomid larvae

    Directory of Open Access Journals (Sweden)

    Jan Frouz

    2015-07-01

    Full Text Available Resistance to desiccation in larvae of eight species of aquatic, semiaquatic and terrestrial chironomids (Pseudodiamesa branickii, Macropelopia sp., Prodiamesa olivacea, Micropsectra sp., Chironomus riparius, Chironomus dorsalis, Metriocnemus martini and Camptocladius stercorarius was studied. The larvae were desiccated in exicator at constant conditions (15 °C, 80% RH and changes in moisture and body water content was recorded. The LD-50 for loss of body water was calculated. The lowest resistance to loss of body water was found in larvae from subfamilies Tanypodinae and Diamesinae Macropelopia sp. and P. branickii. They survived loss of 49.7 and 56.6% of original water content (presented values are LD-50. On the other hand the highest resistance to water loss was found in C. dorsalis. M. martini and C. stercorarius. The larvae of these species may survive loss of 67.4, 76.6 and 84.2% of original water content. Nevertheless the survival time under experimental conditions depends more closely on larval size than on lethal level of water loss. The smaller larvae desiccated faster and perished sooner than large ones despite they tolerate higher loss of body water.

  17. Hepatic arginase activity in intra- and extrauterine larvae of the ovoviviparous salamander. Salamandra salamandra (L.) (Amphibia, Urodela).

    Science.gov (United States)

    Schindelmeiser, J; Schindelmeiser, I; Greven, H

    1983-01-01

    The hepatic arginase activity of Salamandra salamandra was determined at three different stages of intra- and extrauterine larval development and at fully metamorphosed juveniles. The highest enzymatic activity was found in intrauterine larvae in November, the lowest in intrauterine larvae in June of the following year. These data can be correlated with the ureotelism of intrauterine larvae previously described and are discussed with respect to the metabolism of larval and juvenile fire salamanders.

  18. Reduction of Escherichia coli, Salmonella Enteritidis and Campylobacter jejuni in poultry manure by rearing of Musca domestica fly larvae

    DEFF Research Database (Denmark)

    Nordentoft, Steen; Fischer, C.; Bjerrum, L.

    2017-01-01

    A major barrier for using animal waste as substrate for production of insects for feed or food is the concern for safety of the end products. In this study we investigated how rearing of fly larvae of Musca domestica in poultry manure influenced the counts of three pathogenic test strains...... of the larvae stage. This study provides data for evaluation of feed safety of fly larvae reared on animal waste. Furthermore suggests a potential use for reduction of these pathogens in manure....

  19. Isospin breaking and radiative corrections in K{sub l4} decays; Brisure d'isospin et corrections radiatives au processus K{sub l4}

    Energy Technology Data Exchange (ETDEWEB)

    Cuplov, V

    2004-04-15

    This thesis is dedicated to the impact of electromagnetic corrections on the decays of K{sub l4}. 2 types of electromagnetic contributions have to be considered: first the exchange of virtual photons and secondly the non-perturbative part of meson-photon interactions. We have also considered the effects of isospin breaking. We have shown that the isospin breaking and the electromagnetic corrections affect K{sub l4} decays in the neutral and mixed channels (respectively by 8% and -2%), while the charged channel is unaffected. It also appears that the tree approximation for the computation of the decay rates, is not accurate enough to explain experimental data. In the second part of this work, we give the analytical expressions of the F and G form factors associated with the amplitude of the K{sub l4} process in the charged mode. Infra-red divergencies counterbalance each other in the decay rates calculation when we consider the process K{sub l4{gamma}} where 1 photon is emitted with an energy below the sensitivity of the detector. We have found that the calculation in one loop order represents 75% of the measured value. The impact of radiative corrections is about 0.9% while the isospin breaking effect is about 1.6 per cent.

  20. Aluminium chloride-induced toxicity in zebrafish larvae.

    Science.gov (United States)

    Monaco, A; Grimaldi, M C; Ferrandino, I

    2017-05-01

    Embryos at shield stage and larvae at protruding mouth stage were exposed to different concentrations of aluminium chloride (AlCl 3 ) for 72 h with the purpose to analyse their phenotype and lethality. After 24, 48 and 72 h of treatment, higher toxicity of the metal was observed on larvae with minimal lethal concentration of 0.25, 0.20 and 0.08 mm, respectively, while for embryos the corresponding values were 40, 25 and 16 mm. We observed pericardial oedema and alteration of heart rate in 50% of larvae after 48 h of exposure to 100 μm. In larvae exposed to the same concentration, there was also a neurological injury at the level of glial cells, with the number of glial fibrillary acidic protein-positive cells being significantly reduced. This study confirms the toxic nature of this metal and shows that aluminium could also interestingly represent a cardiotoxin in addition to its neurotoxic ability. © 2016 John Wiley & Sons Ltd.

  1. Resistance to OsHV-1 infection in Crassostrea gigas larvae

    Directory of Open Access Journals (Sweden)

    Lionel eDégremont

    2016-02-01

    Full Text Available The ostreid herpesvirus (OsHV-1 is one of the major diseases that affect the Pacific oyster Crassostrea gigas. Selective breeding programs were recently shown to improve resistance easily to OsHV-1 infections in spat, juvenile and adult oysters. Nevertheless, this resistance has never been investigated in larvae, whereas this developmental stage has crucial importance for the production of commercial hatcheries, as well as explaining the abundance of spatfall. A first trial tested several viral suspensions at several concentrations using contaminated water with OsHV-1 in four-day-old and ten-day-old larvae that were produced from an unselected broodstock. In follow up on the results, one viral suspension at a final concentration of 10+6 OsHV-1 DNA copies per L was used to assess resistance to OsHV-1 infection in C. gigas larvae that were produced from selected and unselected broodstock. A second trial evaluated OsHV-1 resistance in larvae from both broodstocks in trials 2a, 2b and 2c with 4, 10 and 16-day-old larvae for 7 days, which corresponded to post D larvae, umbo larvae and eyed larvae, respectively. The mortality of unchallenged larvae for both stocks were low (<15% at day 7 in trials 2a and 2b, whereas it ranged from 48 to 56% in trial 2c. More interestingly, selected larvae had significantly lower mortality than unselected larvae when exposed to OsHV-1 in all of the trials. Thus, the mortality was 11% and 49% for the selected larvae at day 7 post-exposure in trials 2a and 2c, respectively, in comparison with 84% and 97% for the unselected larvae. Although this difference in mortality was observed at day 5 in trial 2b, it was reduced at day 7, to 86% and 98% for the selected and unselected larvae, respectively. For the first time in the literature, the difference in mortality or the delayed onset of mortality between selected and unselected larvae have indicated a genetic resistance to OsHV-1 infection at the larval stage. Such finding

  2. Soil Moisture Active Passive (SMAP) Mission Level 4 Carbon (L4_C) Product Specification Document

    Science.gov (United States)

    Glassy, Joe; Kimball, John S.; Jones, Lucas; Reichle, Rolf H.; Ardizzone, Joseph V.; Kim, Gi-Kong; Lucchesi, Robert A.; Smith, Edmond B.; Weiss, Barry H.

    2015-01-01

    This is the Product Specification Document (PSD) for Level 4 Surface and Root Zone Soil Moisture (L4_SM) data for the Science Data System (SDS) of the Soil Moisture Active Passive (SMAP) project. The L4_SM data product provides estimates of land surface conditions based on the assimilation of SMAP observations into a customized version of the NASA Goddard Earth Observing System, Version 5 (GEOS-5) land data assimilation system (LDAS). This document applies to any standard L4_SM data product generated by the SMAP Project.

  3. Identification of immature stages of phlebotomine sand flies using MALDI-TOF MS and mapping of mass spectra during sand fly life cycle.

    Science.gov (United States)

    Halada, Petr; Hlavackova, Kristyna; Dvorak, Vit; Volf, Petr

    2018-02-01

    The aim of the study was to evaluate the potential of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) for the species identification of sand flies at different developmental stages and map changes in their protein profiles during the course of whole life cycle. Specimens of six different species from laboratory colonies at larval and pupal stages were examined using MALDI-TOF MS. The protein profiles of larvae were stable from the L2 to L4 developmental stages and clearly distinguishable at the species level. In a validation study, 123 larvae of the six species were queried against reference database resulting in 93% correct species identification (log score values higher than 2.0). The spectra generated from sand fly pupae allow species identification as well and surprisingly, in contrast to biting midges and mosquitoes, they did not change during this developmental stage. For adults, thorax was revealed as the optimal body part for sample preparation yielding reproducible spectra regardless age and diet. Only variations were uncovered for freshly engorged females profiles of which were affected by blood signals first two days post bloodmeal. The findings demonstrate that in addition to adult species differentiation MALDI-TOF MS may also serve as a rapid and effective tool for species identification of juvenile stages of phlebotomine sand flies. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Preliminary Results On the Efficacy of Macroalgal Extracts Against Larvae of Aedes albopictus.

    Science.gov (United States)

    Minicante, Simona Armeli; Carlin, Sara; Stocco, Marica; Sfriso, Adriano; Capelli, Gioia; Montarsi, Fabrizio

    2017-12-01

    Activity of ethanolic extracts of the algae Ulva rigida, Asparagopsis taxiformis, Dictyota dichotoma, and Cystoseira barbata, collected along Italian coasts, was tested against larvae of the Asian tiger mosquito ( Aedes albopictus), a vector of pathogens for animals and humans. Tests were carried out using 10 specimens of 3rd-stage larvae per test, following the World Health Organization standard protocol with minor modifications. Among algal extracts, only D. dichotoma was active against the larvae of Ae. albopictus. Ethanolic extracts of that species showed LC 90 (the concentration that kills 90% of larvae) and LC 50 (the concentration that kills 50% of larvae) values at 44.32 and 85.92 mg/liter, respectively. Based on the data obtained, D. dichotoma biometabolic extracts could be potential candidates as larvicide compounds to control Ae. albopictus, encouraging the use of macroalgae as natural resources in integrated vector management strategies.

  5. 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.

  6. EX1504L4 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  7. EX1504L4 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  8. EX1504L4 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  9. EX1504L4 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  10. EX1504L4 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  11. A Real-Time Programmer's Tour of General-Purpose L4 Microkernels

    Directory of Open Access Journals (Sweden)

    Ruocco Sergio

    2008-01-01

    Full Text Available Abstract L4-embedded is a microkernel successfully deployed in mobile devices with soft real-time requirements. It now faces the challenges of tightly integrated systems, in which user interface, multimedia, OS, wireless protocols, and even software-defined radios must run on a single CPU. In this paper we discuss the pros and cons of L4-embedded for real-time systems design, focusing on the issues caused by the extreme speed optimisations it inherited from its general-purpose ancestors. Since these issues can be addressed with a minimal performance loss, we conclude that, overall, the design of real-time systems based on L4-embedded is possible, and facilitated by a number of design features unique to microkernels and the L4 family.

  12. SMAP L4 Global Daily 9 km Carbon Net Ecosystem Exchange V003

    Data.gov (United States)

    National Aeronautics and Space Administration — The Level-4 (L4) carbon product (SPL4CMDL) provides global gridded daily estimates of net ecosystem carbon (CO2) exchange derived using a satellite data based...

  13. EX0909L4 Water Column Summary Report and Profile Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX0909L4: Mapping Field Trials -...

  14. EX1504L4 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  15. GHRSST_NCDC_GLOB_L4_AVHRR_AMSR_OI_SST:1

    Data.gov (United States)

    National Aeronautics and Space Administration — A GHRSST L4 sea surface temperature analysis produced daily at the NOAA National Climatic Data Center using optimal interpolation from AVHRR Pathfinder Version 5...

  16. Trojan asteroids - Populations, dynamical structure and origin of the L4 and L5 swarms

    International Nuclear Information System (INIS)

    Shoemaker, E.M.; Shoemaker, C.S.; Wolfe, R.F.

    1989-01-01

    The origin of Trojan asteroids, their populations, and dynamical structures are examined. Data available of Trojan asteroids reveal that the total population of Trojans of greater than 15-km diam is roughly half that estimated for the main-belt asteroids. Two-thirds of the known Trojans are in the L4 swarm. Bright Trojans are as numerous in the L5 swarm as in L4 swarm, but faint L5 Trojans are only half as numerous. Similarities of characteristic orbital parameters among certain Trojans indicate the presence of five and possibly as many as eight collisional groups in the L4 swarm. It is suggested that the magnitude distribution of L4 Trojans is probably a result of strong collisional evolution. It is suggested that the present Trojans are chiefly fragments of Jupiter planetesimals that were captured during an episode of heavy flux near Jupiter during the dispersal of the planetesimal swarm. 40 refs

  17. GHRSST_NCDC_GLOB_L4_AVHRR_OI_SST:1

    Data.gov (United States)

    National Aeronautics and Space Administration — A GHRSST L4 sea surface temperature analysis produced daily at the NOAA National Climatic Data Center using optimal interpolation from AVHRR Pathfinder Version 5...

  18. EX1504L4 Water Column Summary Report and Profile Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1504L4: Campaign to Address Pacific...

  19. EX1504L4 Dive01 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  20. EX1504L4 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  1. EX1504L4 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  2. EX1504L4 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  3. EX1504L4 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  4. EX1504L4 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  5. EX1504L4 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L4: Campaign to Address...

  6. [Biotechnological aspects in "loco" larvae].

    Science.gov (United States)

    Inestrosa, N C; Labarca, R; Perelman, A; Campos, E O; Araneda, R; González, M; Brandan, E; Sánchez, J P; González-Plaza, R

    1990-10-01

    The biology of planktotrophic larvae of Concholepas concholepas is the main bottleneck towards developing biotechnologies to rear this muricid. Data concerning planktonic larvae development, diets and environmental signals triggering larval settlement and recruitment is scarce. We have begun the study of the molecular and cell biology of embryos, larvae and recruits having as a final goal, the development of appropriate biotechnologies to rear this gastropod. First, an inverse ratio between BuChE and AChE enzyme activities was established. This ratio may be a precise developmental marker for this species. Second, for the first time a phosphoinositide related regulatory pathway is reported in a muricid, opening a new approach to the biotechnological management of larvae. Third, the relation between sulfate in sea water and larval motility was studied. Concentrations below 125 microM sulfate decreases larval motility. The sulfate is incorporated in proteoglycans which participate in different developmental phenomena. Lastly, a genomic Concholepas concholepas DNA sequence, similar to that of a human growth hormone probe was detected. This is very interesting since growth factors are key molecules during development, growth and are involved in food conversion rates in fish and also, in a variety of marine invertebrates.

  7. Reorientation and Swimming Stability in Sea Urchin Larvae

    Science.gov (United States)

    Wheeler, J.; Chan, K. Y. K.; Anderson, E.; Helfrich, K. R.; Mullineaux, L. S.; Sengupta, A.; Stocker, R.

    2016-02-01

    Many benthic marine invertebrates have two-phase life histories, relying on planktonic larval stages for dispersal and exchange of individuals between adult populations. The dispersal of planktonic larvae is determined by two factors: passive advection by the ambient flow and active motility. By modifying dispersal and ultimately settlement, larval motility influences where and when individuals recruit into benthic communities. Despite its ecological relevance, our understanding of larval motility and behavior in the plankton remains limited, especially regarding the interactions of larval motility and ambient turbulence. As most larvae are smaller than the Kolmogorov scale, they experience ocean turbulence in part as a time-changing viscous torque produced by local fluid shear. This torque causes larval reorientation, impacting swimming direction and potentially dispersal at the macroscale. It is therefore paramount to understand the mechanisms of larval reorientation and the stability of larvae against reorientation. Here we report on the larval reorientation behavior of the sea urchins Arbacia punctulata and Heliocidaris crassispina. Both species have life histories characterized by ontogenetic changes to internal density structure and morphology, which we hypothesized to impact stability. To test this hypothesis, we performed "flip chamber" experiments, in which larvae swim freely in a small chamber that is intermittently inverted, mimicking the overturning experienced by larvae in turbulence. We investigated the role of larval age, body size, species, morphology (number of arms), and motility (live versus dead) on the reorientation dynamics. Our work contributes to a more mechanistic understanding of the role of hydrodynamics in the motility and transport of planktonic larvae.

  8. The morphology of the immature stages of two rare Lixus species (Coleoptera, Curculionidae, Lixinae) and notes on their biology

    OpenAIRE

    Trnka,Filip; Stejskal,Robert; Skuhrovec,Jiří

    2016-01-01

    Abstract The mature larvae and pupae of Lixus (Ortholixus) bituberculatus Smreczy?ski, 1968 and Lixus (Dilixellus) neglectus Fremuth, 1983 ( Curculionidae : Lixinae : Lixini ) are described and compared with known larvae of 21 other Lixus and 2 Hypolixus taxa. The mature larva and pupa of Lixus bituberculatus are the first immature stages described representing the subgenus Ortholixus . The larva of Lixus neglectus , in the subgenus Dilixellus , is distinguished from the known larvae of four ...

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

    Directory of Open Access Journals (Sweden)

    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

  10. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

    International Nuclear Information System (INIS)

    Harvey, Jeffrey A.; Hamilton, James G.C.; Ward, Richard D.

    2010-01-01

    The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

  11. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae).

    Science.gov (United States)

    Harvey, Jeffrey A; Hamilton, James G C; Ward, Richard D

    2010-01-01

    The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies.

  12. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Jeffrey A. [Netherlands Institute of Ecology, Heteren (Netherlands). Dept. of Terrestrial Ecology; Hamilton, James G.C.; Ward, Richard D. [University of Keele, Staffordshire (United Kingdom). Centre for Applied Entomology and Parasitology. Dept. of Biological Sciences

    2010-01-15

    The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

  13. Snail Larvae From Turbulent Inlets and the Wavy Continental Shelf Use Different Physical Behavioral Cues

    Science.gov (United States)

    Fuchs, H. L.; Gerbi, G. P.

    2016-02-01

    Dispersing larvae experience hydrodynamic signals from turbulence and waves; these signals vary geographically in their intensity and may cue behaviors enhancing transport to suitable habitats. Turbulence dominates the production of spatial velocity gradients (strain or vorticity), whereas waves often dominate the production of accelerations. Spatial patterns in these two signal types create a potential mechanism for larvae to distinguish or navigate among habitats. We quantified flow-induced behaviors in late-stage larvae of congeneric snails from turbulent coastal inlets (Ilyanassa obsoleta) and from the wavy continental shelf (Ilyanassa trivittata). Larvae were exposed to turbulence and to simpler flows dominated by strain, vorticity, or wave-generated acceleration. Fluid flow and individual larvae were observed simultaneously using infrared, particle-image velocimetry. In turbulence, larvae of both species sank or swam downward more frequently at higher dissipation rates, but the average vertical velocities of I. obsoleta became more negative (downward) than those of I. trivittata. In simpler flows, larvae of I. obsoleta reacted more strongly to vorticity-induced rotation relative to gravity, whereas only I. trivittata exhibited a strong reaction to wave-generated accelerations. Both species reacted to vorticity or acceleration in the absence of large strain rates, indicating that larvae likely sense flow using the statocysts. Although statocysts can sense two signal types, these closely related species responded differently to those signals, suggesting that behavior is attuned to the physical signals that dominate their respective adult habitats.

  14. 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.

  15. A new mutant, White larva, of the mosquito Toxorhynchites splendens: genetics and cannibalism.

    Science.gov (United States)

    Horio, M; Tsukamoto, M; Miyagi, I

    1990-09-01

    A strain of a new body-color mutant, white larva (wl), was established from a field-collected wild-type strain of Toxorhynchites splendens. The mutant can be distinguished from the wild type in both the larval and pupal stages, but not in the adult. Crossing experiments confirmed its mode of inheritance to be a single recessive system. This is the first visible mutant found in Tx. splendens. Larvae of the wl phenotype seem to be recognized as prey by other individuals in mass larvae rearing.

  16. Egg Predation Risk Trigger Adult Hoverfly (Diptera: Syrphidae to Avoid Laying Eggs in Patches Attended by Ladybird Larvae (Coleoptera: Coccinellidae

    Directory of Open Access Journals (Sweden)

    Nugroho Susetya Putra

    2005-12-01

    Full Text Available Oviposition preference of a predatory hoverfly, Episyrphus balteatus on the presence of its potential predators, the ladybird larvae which are inflicted serious impacts on its eggs was examined in a non-choice test. Our results revealed that the biggest and the most aggressive species of ladybird, Harmonia axyridis caused the worst impact on hoverfly eggs by attacking and feeding on. The species and developmental stages of ladybird were attributed to the level of predation risk. We correlated the oviposition site selection by hoverfly females to the egg predation risk level inflicted by ladybird larvae. Hoverfly females laid the least number of eggs on the patches attended by the strongest competitor, the larva of H. axyridis, and tended to lay the highest number of eggs on colonies attended by the weakest competitor, the larva of Scymnus posticalis. In addition, the impact of the fourth instar larva of ladybirds was stronger than of the first instar larva.

  17. PREFERENSI PENEMPELAN, PERTUMBUHAN, DAN SINTASAN LARVA TERIPANG PASIR, Holothuria scabra PADA SUBSTRAT LAMUN YANG BERBEDA

    Directory of Open Access Journals (Sweden)

    Lisa Fajar Indriana

    2017-01-01

    Sandfish Holothuria scabra is marine commodities with a high economic value. Overfishing of natural stocks has compelled an interest to begin aquaculture practice. Settlement is a critical phase for the planktonic larvae as they will transform to benthic form in the presence of substrate. This study aims to evaluate the settlement preferences, growth, and survival rate of H. scabra larvae settled on different seagrass leaves. The research was conducted using the Completely randomized design with four different species of seagrass leaves and five replications. The treatments consist of Enhalus acoroides (L-1, Syringodium isoetifolium (L-2, Cymodocea serrulata (L-3, and Cymodocea rotundata (L-4. Initial number of larvae was 1,000 individuals and the substrate was set with same widthof 12 cm x 17 cm for each unit. Results of the experiment indicated that settlement preference and survival rate of H. scabra larvae was significantly affected by seagrass used as substrate while no significantly differences was observed for growth of larvae. E. acoroides showed the best result with 0.26 ind. cm-2 settelement preference and 10.66% survival rate, so that suitable to be used as settlement substrate in H. scabra hatchery.

  18. Immune response of rainbow trout (Oncorhynchus mykiss) larvae to Yersinia ruckeri

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Kania, Per Walter; Raida, Martin Kristian

    Innate immune factors play a crucial role in survival of young fish especially during early stages of life where adaptive immunity is not fully developed. In the present study, we investigated the immune response of rainbow trout larvae (Onchorhynchus mykiss) at an early stage of development. We...

  19. Effect of gamma radiation on the Mediterranean flour moth, Ephestia Kuehniella, mature larvae and acceptability of irradiated larvae by Bracon hebetor female

    International Nuclear Information System (INIS)

    Mansour, M.

    2012-01-01

    Mediterranean flour moth, Ephestia kuehniella, mature 5 t h instar larvae were exposed to gamma radiation dosages ranging from 50-350 Gy at 50 Gy increment and the effects of gamma radiation on pupation, adult emergence and sex ratio were investigated. In addition, effects of irradiation on the rate of development to pupae and adults and the acceptance of irradiated larvae by B. hebetor females were examined. Results showed that the radio-sensitivity of E. kuehniella larvae increased with increasing dose. Pupation was significantly affected at 100 Gy dose, and completely prevented at 350 Gy dose. Adult emergence was only slightly different from pupation; emergence was significantly affected at 100 Gy dose and completely prevented at 300 Gy dose. Irradiation also negatively affected the rate of development of larvae to pupae and adults. While more than 98% of control larvae pupated within 10 days of treatment, this ratio decreased to about 79% in larvae exposed to 50 Gy and less than 4% in larvae exposed to 100 Gy dose. The rate of development to the adult stage was also similarly affected. While 97% of control insects emerged as adults in the 1st 20 days of treatment, this ratio decreased to about 53, 2 and zero percent in larvae exposed to 50, 100 and 150 Gy dose respectively. In addition, irradiation significantly affected male: female ratio; sex ratio was skewed in favor of males, and at 250 Gy dose all emerged moths were males. Furthermore, irradiation had no adverse effect on the degree of acceptance of mature larvae to parasitization; irradiated insects were as acceptable to B. hebetor females as unirradiated ones. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Temperature responses in larvae of Macoma balthica from a northerly and southerly population of the European distribution range

    NARCIS (Netherlands)

    Drent, J

    2002-01-01

    Planktonic marine invertebrate embryos and larvae experience high mortality rates. Processes during these early vulnerable stages of development are an important determinant of the dynamics of marine invertebrate populations. In order to evaluate possible specific local adaptations of the bivalve

  2. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowiong behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva)(Diptera: Psychodidae)

    NARCIS (Netherlands)

    Harvey, J.A.; Hamilton, J.G.C.; Ward, R.D.

    2010-01-01

    The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to

  3. Delivery of marine larvae to shore requires multiple sequential transport mechanisms.

    Science.gov (United States)

    Pfaff, Maya C; Branch, George M; Fisher, Jennifer L; Hoffmann, Vera; Ellis, Allan G; Largier, John L

    2015-05-01

    Most sedentary marine animals disperse from their place of origin during their initial life stages as larvae. The delivery of planktonic larvae back to coastal adult habitats after weeks or months of offshore development is commonly thought to be stochastic, resulting in large recruitment fluctuations and making predictive understanding of population dynamics difficult. Time series of invertebrate settlement on intertidal shores have been used to infer how various oceanographic processes deliver planktonic larvae ashore. However, the possibility that successful settlement may involve a series of different transport mechanisms, which are sequentially utilized by late-stage larvae, has received little attention. To address this, we monitored both the delivery of mussel and barnacle larvae to inner-shelf moorings positioned 200-1400 m from the shore, and larval settlement in the intertidal adult habitat, at two contrasting sites: a headland forming an upwelling center and a downstream bay. Model selection was employed to determine the most likely scenario(s) of larval onshore transport from four a priori transport mechanisms individually and in combination: (1) upwelling or relaxation/downwelling, (2) tidal motions, (3) diurnal sea breezes, and (4) surface waves. Mussel larvae were delivered to the inner shelf during upwelling in the bay, but during downwelling at the headland, and were further transported to the shore by surface waves at both locales. In contrast, the delivery of barnacle larvae to the inner shelf occurred during relaxation/downwelling events at both sites, and intertidal settlement coincided with spring tides, suggesting a role for internal tides in their onshore transport. Thus, sequential mechanisms appear to be utilized by larvae to get to the shore, involving interactions of regional-scale upwelling/downwelling processes and local-scale tidal and surface-wave processes, which differ among taxa and among sites with different topography. A

  4. [Studies on susceptibility of Pomacea canaliculata of different developmental stages to infection with Angiostrongylus cantonensis].

    Science.gov (United States)

    Liu, He-xiang; Zhang, Yi; Zhou, Xiao-nong; Lv, Shan; Zhu, Dan; Lin, Jin-xiang; Li, Li-sha; Li, You-song; Yin, Wei-gang

    2005-10-30

    OBJECTIVE To study the susceptibility of Pomacea canaliculata of different developmental stages to Angiostrongylus cantonensis infection. P. canaliculata snails breeding at laboratory were divided into four rank (I-IV) according to the weight, and infected with the first stage larvae of A. cantonensis from Fujian Province. Their mortality, infection rate, worm burden, and the size, development and distribution of larvae in snails were examined. Snails at different developmental stages were readily infected with A. cantonensis. The infection rate was between 76% and 100%, with no significant difference among the groups (P>0.05). Snails at earlier developmental stage showed higher mortality. The heaviest worm burden and the largest number of snails harboring more than 100 larvae were found in snails of rank III. In general the larvae in snails showed a synchronous development in the groups. Sizes of the third stage larvae in snails of various ranks were homogeneous. The period before the third stage larva emergence and the time for a peak percentage of the larvae exhibited no significant difference among the four ranks. The larvae widely distributed in various parts of snails, with more in the lung and foot, and larvae from snails of different ranks could all infect rats successfully. P. canaliculata of the four ranks can all be infected by the first stage larvae of A. cantonensis. Rank III snails may be better for studying the relationship between P. canaliculata and A. cantonensis. The potential role of young snails in angiostrongyliasis transmission should be recognized.

  5. A Radiographic Measurement of the Anterior Epidural Space at L4-5 Disc Level.

    Science.gov (United States)

    Xu, Rui-Sheng; Wu, Jie-Shi; Lu, Hai-Dan; Zhu, Hao-Gang; Li, Xia; Dong, Jian; Yuan, Feng-Lai

    2017-05-01

    To observe the morphology character of the anterior epidural space at the L 4-5 disc level and to provide an anatomical basis for safely and accurately performing a percutaneous endoscopic lumbar discectomy (PELD). Fifty-five cases with L 5 S 1 lumbar disc herniation were included in this study, and cases with L 4-5 disease were excluded. When the puncture needle reached the epidural space at the L 5 S 1 level, iohexol was injected at the pressure of 50 cm H 2 O during the PELD, then C-Arm fluoroscopy was used to obtain standard lumbar frontal and lateral images. The widths of epidural space at the level of the L 4 lower endplate, the L 5 upper endplate, as well as the middle point of the L 4-5 disc were measured from the lumbar lateral X-ray film. Epidural space at the L 4-5 disc plane performs like a trapezium chart with a short side at the head end and a long side at the tail end in the lumbar lateral X-ray radiograph, while the average widths of epidural space were 10.2 ± 2.5, 12.3 ± 2.3, and 13.8 ± 2.6 mm at the upper, middle, and lower level of the L 4-5 disc. Understanding the morphological characteristics of epidural space will contribute to improving the safety of the tranforaminal percutaneous endoscopy technique. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

  6. 26 CFR 1.167(l)-4 - Public utility property; election to use asset depreciation range system.

    Science.gov (United States)

    2010-04-01

    ... depreciation range system. 1.167(l)-4 Section 1.167(l)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Individuals and Corporations § 1.167(l)-4 Public utility property; election to use asset depreciation range system. (a) Application of section 167(l) to certain property subject to asset depreciation range system...

  7. 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)

  8. Induced metamorphosis in crustacean y-larvae: towards a solution to a 100-year-old riddle

    DEFF Research Database (Denmark)

    Glenner, Henrik; Høeg, Jens T; Grygier, Mark J

    2008-01-01

    BACKGROUND: The y-larva, a crustacean larval type first identified more than 100 years ago, has been found in marine plankton samples collected in the arctic, temperate and tropical regions of all oceans. The great species diversity found among y-larvae (we have identified more than 40 species......-larvae into a novel, highly reduced juvenile stage by applying the crustacean molting hormone 20-HE. The new stage is slug-like, unsegmented and lacks both limbs and almost all other traits normally characterizing arthropods, but it is capable of vigorous peristaltic motions. CONCLUSION: From our observations on live...

  9. Feeding behavior and capture success of turbot Psetta maxima larvae during the transition from upright to tilted swimming position

    DEFF Research Database (Denmark)

    Bruno, Eleonora; Mahjoub, Mohamed Sofiane; Hansen, Benni Winding

    2017-01-01

    larvae. In order to ascertain changes in feeding during metamorphosis of flatfish, we here compared feeding behavior when larvae of turbot Psetta maxima were either swimming upright or tilted. Using video recordings, we compared the attack rate and prey capture success between flexion (12-13 days-post-hatch......, stage 4b-4c) swimming predominantly in upright position and post-flexion (16-17 days-post-hatch, stage 5a-5b) larvae in tilted swimming mode. Both larval groups were fed on copepod nauplii and copepodites. Our results showed a capture success of

  10. Trophic ecology of Atlantic bluefin tuna Thunnus thynnus larvae.

    Science.gov (United States)

    Catalán, I A; Tejedor, A; Alemany, F; Reglero, P

    2011-05-01

    Feeding intensity, diet composition, selectivity, energy ingestion and dietary niche breadth of larval Atlantic bluefin tuna Thunnus thynnus were studied on the eastern (Mediterranean) spawning grounds of the species. Larval T. thynnus were collected in the Balearic Archipelago (north-west Mediterranean Sea) during 2004 and 2005 using surveys specific for larval scombrids. Larvae between 2·6 and 8·7 mm standard length (L(S) ) are diurnal feeders, and 94% of the guts collected during daylight hours were full. The mean ±s.d. number of prey per gut was 7·1 ± 5·7, with mean ±s.d. ranging from 3·0 ± 1·6 in the smallest T. thynnus larvae to 11·1 ± 5·8 in 5·0-6·0 mm L(S) larvae. Up to 21 prey were found in a single larval gut (5·0-6·0 mm L(S) ) at the end of the day. Larvae progressively selected larger prey and exhibited increased carbon content concurrent with preflexion development of feeding and locomotory structures. Larvae of 5·0-6·0 mm L(S) exhibited positive selection of cladocerans over other prey (Chesson's index), whereas copepod nauplii dominated the diets of earlier stages. The dietary niche breadth measured increased initially but decreased at c. 5·5 mm L(S) . Appendicularians were found in the diet of larger larval sizes, but no piscivory was observed. Results are discussed in light of the sparse existing data for larval T. thynnus and other larval tuna species. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles. No claim to original US government works.

  11. 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

  12. 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

  13. Biallelic expression of Tssc4, Nap1l4, Phlda2 and Osbpl5 in adult ...

    Indian Academy of Sciences (India)

    , kidney, skeletal muscle and subcutaneous fat using polymorphism-based sequencing approach. It was found that all the four genes showed biallelic expression in tissues in which transcripts were detected. Nap1l4 and Tssc4 were detected in ...

  14. GE~L ~4J SIR HE~R Y TI~SO~ LUKI~

    African Journals Online (AJOL)

    GE~L ~4J SIR HE~R Y TI~SO~ LUKI~. Herkoms en Jeugjare. Fulham is 'n voorstad van Londen. Oit is daar waar Henry Timson Lukin op 24 Mei 1860 as die oudste en enigste seun van Robert Henry. Lukin gebore is. Alhoewel 'n gekwalifiseerde advokaat wat daarby talle oorsese ekspedisies onderneem het, het Robert ...

  15. Influence of laser power on the deposition Ti64l4V/W composite

    CSIR Research Space (South Africa)

    Ndou, N

    2016-10-01

    Full Text Available The influence of laser power on the deposited of Ti64l4V/W composites was investigated. The energy flow rates were varied while every single other parameter were kept at a steady. The evolving microstructure and the hardness of the composites were...

  16. Cytotoxicity of poly(96L/4D-lactide) : the influence of degradation and sterilization

    NARCIS (Netherlands)

    Cordewener, FW; Joziasse, CAP; Schmitz, JP; Bos, RRM; Rozema, FR; Pennings, AJ

    2000-01-01

    The cytotoxicity of poly(96L/4D-lactide) (PLA96), and of its accumulated degradation products, was investigated following different sterilization methods and pre-determined heat-accelerated degradation intervals. PLA96 samples sterilized by either steam, ethylene oxide, or gamma irradiation were

  17. Citrus Seed Oils Efficacy against Larvae of Aedes aegypti.

    Science.gov (United States)

    Bilal, Hazrat; Akram, Waseem; Hassan, Soaib Ali; Din, Sadrud

    2017-09-01

    Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti . Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae. Among the Citrus cultivar seed oil, rough lemon ( Citrus jambhiri ) had the lowest LC 50 value (200.79ppm), while musambi ( C. sinensis var musambi ) had the highest LC 50 value (457.30ppm) after 24 h of exposure. Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. aegypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine operational feasibility.

  18. Effects of Nanosilver Exposure on Cholinesterase Activities, CD41, and CDF/LIF-Like Expression in ZebraFish (Danio rerio Larvae

    Directory of Open Access Journals (Sweden)

    Marzhan Myrzakhanova

    2013-01-01

    Full Text Available Metal nanosolicoparticles are suspected to cause diseases in a number of organisms, including man. In this paper, we report the effects of nanosilver (Ag, 1–20 nm particles on the early development of the zebrafish, a well-established vertebrate model. Embryos at the midgastrula stage were exposed to concentrations ranging from 100 to 0.001 mg/L to verify the effects on different endpoints: lethality, morphology, expression of cholinergic molecules, and development of the immune system. (1 Relative risk of mortality was exponential in the range between 0.001 and 10 mg/L. Exposure to 100 mg/L caused 100% death of embryos before reaching the tail-bud stage. (2 Developmental anomalies were present in the 72 h larvae obtained from embryos exposed to nanosilver: whole body length, decreased eye dimension, and slow response to solicitation by gentle touch with a needle tip, with a significant threshold at 0.1 mg/L. (3 Dose-dependent inhibition of acetylcholinesterase activity was significant among the exposures, except between 1 mg/L and 10 mg/L. (4 The distribution of CD41+ cells and of CDF/LIF-like immunoreactivity was altered according to the Ag concentration. The possible effect of nanosilver in impairing immune system differentiation through the inhibition of molecules related to the cholinergic system is discussed.

  19. Soil Moisture Active Passive Mission L4_C Data Product Assessment (Version 2 Validated Release)

    Science.gov (United States)

    Kimball, John S.; Jones, Lucas A.; Glassy, Joseph; Stavros, E. Natasha; Madani, Nima; Reichle, Rolf H.; Jackson, Thomas; Colliander, Andreas

    2016-01-01

    The SMAP satellite was successfully launched January 31st 2015, and began acquiring Earth observation data following in-orbit sensor calibration. Global data products derived from the SMAP L-band microwave measurements include Level 1 calibrated and geolocated radiometric brightness temperatures, Level 23 surface soil moisture and freezethaw geophysical retrievals mapped to a fixed Earth grid, and model enhanced Level 4 data products for surface to root zone soil moisture and terrestrial carbon (CO2) fluxes. The post-launch SMAP mission CalVal Phase had two primary objectives for each science product team: 1) calibrate, verify, and improve the performance of the science algorithms, and 2) validate accuracies of the science data products as specified in the L1 science requirements. This report provides analysis and assessment of the SMAP Level 4 Carbon (L4_C) product pertaining to the validated release. The L4_C validated product release effectively replaces an earlier L4_C beta-product release (Kimball et al. 2015). The validated release described in this report incorporates a longer data record and benefits from algorithm and CalVal refinements acquired during the SMAP post-launch CalVal intensive period. The SMAP L4_C algorithms utilize a terrestrial carbon flux model informed by SMAP soil moisture inputs along with optical remote sensing (e.g. MODIS) vegetation indices and other ancillary biophysical data to estimate global daily net ecosystem CO2 exchange (NEE) and component carbon fluxes for vegetation gross primary production (GPP) and ecosystem respiration (Reco). Other L4_C product elements include surface (10 cm depth) soil organic carbon (SOC) stocks and associated environmental constraints to these processes, including soil moisture and landscape freeze/thaw (FT) controls on GPP and respiration (Kimball et al. 2012). The L4_C product encapsulates SMAP carbon cycle science objectives by: 1) providing a direct link between terrestrial carbon fluxes and

  20. Extreme morphologies of mantis shrimp larvae

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... 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....

  1. Brief Exposure to Turbulence Permanently Alters Development of Sand Dollar Larvae

    Science.gov (United States)

    Ferner, M. C.; Hodin, J.; Ng, G.; Lowe, C. J.; Gaylord, B.

    2016-02-01

    Fluid motion underlies interactions between animals and their environment through effects on locomotion, food capture, respiration, information transfer, and other processes. Recent studies of marine invertebrates indicate that metamorphosis and settlement can be altered when swimming larvae experience a change in turbulence intensity, possibly increasing the likelihood that larvae will settle in appropriate habitat. For example, brief exposure to levels of turbulence characteristic of wave-swept coasts causes echinoderm larvae to quickly transition from a non-responsive "pre-competent" stage into a "competent" stage, thereby allowing the larvae to respond to local cues and settle. However, responding to one's entry into the nearshore environment isn't enough, as many such species live as adults in a narrower range of highly specific benthic habitat that is even more rarely encountered. Here we provide an account for this apparent mismatch between larval responses to broadly distributed cues and their need for more specialized settlement locations: turbulence exposure seems to cause larval sand dollars (Dendraster excentricus) to permanently shift from pre-competence to competence. This observation suggests a scenario where turbulence can activate a temporally extensive search image in larvae over a broad habitat range, a seemingly adaptive feature for larvae entering dynamic coastal environments.

  2. LPJmL4 - a dynamic global vegetation model with managed land - Part 1: Model description

    Science.gov (United States)

    Schaphoff, Sibyll; von Bloh, Werner; Rammig, Anja; Thonicke, Kirsten; Biemans, Hester; Forkel, Matthias; Gerten, Dieter; Heinke, Jens; Jägermeyr, Jonas; Knauer, Jürgen; Langerwisch, Fanny; Lucht, Wolfgang; Müller, Christoph; Rolinski, Susanne; Waha, Katharina

    2018-04-01

    This paper provides a comprehensive description of the newest version of the Dynamic Global Vegetation Model with managed Land, LPJmL4. This model simulates - internally consistently - the growth and productivity of both natural and agricultural vegetation as coherently linked through their water, carbon, and energy fluxes. These features render LPJmL4 suitable for assessing a broad range of feedbacks within and impacts upon the terrestrial biosphere as increasingly shaped by human activities such as climate change and land use change. Here we describe the core model structure, including recently developed modules now unified in LPJmL4. Thereby, we also review LPJmL model developments and evaluations in the field of permafrost, human and ecological water demand, and improved representation of crop types. We summarize and discuss LPJmL model applications dealing with the impacts of historical and future environmental change on the terrestrial biosphere at regional and global scale and provide a comprehensive overview of LPJmL publications since the first model description in 2007. To demonstrate the main features of the LPJmL4 model, we display reference simulation results for key processes such as the current global distribution of natural and managed ecosystems, their productivities, and associated water fluxes. A thorough evaluation of the model is provided in a companion paper. By making the model source code freely available at https://gitlab.pik-potsdam.de/lpjml/LPJmL, we hope to stimulate the application and further development of LPJmL4 across scientific communities in support of major activities such as the IPCC and SDG process.

  3. Evaluation of a rapid water-surface sweeping method to accurately estimate numbers of Aedes aegypti (Diptera: Culicidae) late larval stages in large water-storage containers: comparison with pupal estimates.

    Science.gov (United States)

    Romero, Claudia M E; Llinás, Humberto; Falconar, Andrew K I

    2010-01-01

    Since the methodologies used to calculate Stegomyia indices have been shown to be inadequate for assessing the risk of dengue virus transmission and targeting Aedes aegypti control strategies, new surveillance methods are needed. To evaluate the water-surface sweeping method in combination with calibration factors to estimate the total number of Ae. aegypti late larval stages (L3/L4) in large water-storage containers at different temperatures at which transmission of dengue virus occurs. Calibration factors were derived based on the proportion of L3/L4 recovered from a predetermined number of larvae using a net of specific dimensions and water-storage containers of different capacities and water levels in semi-field conditions and at four different altitudes (14, 358, 998 and 1,630 meters above sea level). The calibration factors obtained at 14 masl were then fully validated in a field study site at this altitude. Four calibration factors were derived at 14 masl (28-30°C) that were used to estimate the total L3/L4 numbers in large water storage containers greater than 20 L (n=478) at 1/3, 2/3 and full water-levels. This methodology was accurate and robust within and between the 10 pairs of field workers who applied it. Different calibration factors were, however, derived to accurately estimate the total L3/L4 numbers at each of the study sites located at 358, 998 and 1,630 masl, where average temperatures were 19°C, 24°C, and 26°C respectively. The accurate estimates of L3/L4 numbers calculated using the water surface sweeping method can be useful for evaluating intervention strategies directed against the larval stages.

  4. Development and functional morphology of the mouthparts and foregut in larvae and post-larvae of Macrobrachium jelskii (Decapoda: Palaemonidae).

    Science.gov (United States)

    Rocha, Cristina Pantoja; Souza, Adelson Silva de; Maciel, Murilo; Maciel, Cristiana R; Abrunhosa, Fernando Araújo

    2016-05-01

    The morphology of the mouthparts and foregut of the larvae and post-larvae of Macrobrachium jelskii was investigated to determine their functional roles in feeding, in order to understand the larval feeding behaviour and the changes that occur during its development. The mouthparts and foregut of the zoea I and II are morphologically similar, rudimentary and non-functional in feeding. Only in the final larval stage, zoea III, do the external mouthparts and foregut become structurally more complex and thus likely to play a potential role in feeding. Two behavioral trials (point of no return, point of reserve saturation) evaluated the resistance to starvation in zoea I, II, and III. The results indicate that they have sufficient nutritional reserves to permit them to complete metamorphosis without feeding. Overall, our results suggest that the zoea I and II of Macrobrachium jelskii engage in obligate lecithotrophy and zoea III in facultative lecithotrophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Ecotoxicity of Lake Druksiai waters assessed by biotesting with rainbow trout spawn and larvae

    International Nuclear Information System (INIS)

    Kazlauskiene, N.; Cepuliene, Z.

    1998-01-01

    The toxicity of Lake Druksiai was assessed by testing with spawn and larvae of rainbow trout (Oncorhynchus mykiss). We sampled Ignalina NPP waste waters of various biotopes of the lake. Larvae of trout were found to be more sensitive to wastewaters than spawn. The hatching stage was one of the most sensitive stages in ontogenesis. Our data showed that the wastewater of Ignalina NPP was the most toxic, however waters of some biotopes of the lake were also toxic. That suggested that toxicants discharged into cooling reservoirs with NPP wastewater might affect test-organisms, disturbing their development and growth. The observed effects were irreversible and caused death. (author)

  6. Caenorhabditis elegans battling starvation stress: low levels of ethanol prolong lifespan in L1 larvae.

    Directory of Open Access Journals (Sweden)

    Paola V Castro

    Full Text Available The nematode Caenorhabditis elegans arrests development at the first larval stage if food is not present upon hatching. Larvae in this stage provide an excellent model for studying stress responses during development. We found that supplementing starved larvae with ethanol markedly extends their lifespan within this L1 diapause. The effects of ethanol-induced lifespan extension can be observed when the ethanol is added to the medium at any time between 0 and 10 days after hatching. The lowest ethanol concentration that extended lifespan was 1 mM (0.005%; higher concentrations to 68 mM (0.4% did not result in increased survival. In spite of their extended survival, larvae did not progress to the L2 stage. Supplementing starved cultures with n-propanol and n-butanol also extended lifespan, but methanol and isopropanol had no measurable effect. Mass spectrometry analysis of nematode fatty acids and amino acids revealed that L1 larvae can incorporate atoms from ethanol into both types of molecules. Based on these data, we suggest that ethanol supplementation may extend the lifespan of L1 larvae by either serving as a carbon and energy source and/or by inducing a stress response.

  7. Experimental infection of Radix natalensis and Culiseta longiareolata larvae with Plagiorchiid xiphidiocercariae in Egypt.

    Science.gov (United States)

    Dar, Yasser Disoky; El-Husseny, Iman Mohamad

    2013-12-01

    To clarify the life cycle of a plagiorchiid species which uses Radix natalensis as a first intermediate host for its larval development in Egypt, this study was carried out to investigate subsequent invertebrates where xiphidiocercariae of this digenean might encyst. Laboratory-bred R. natalensis and Culiseta longiareolata larvae (mosquito) were experimentally exposed to xiphidiocercariae under laboratory conditions. At 24h post-exposure, 70% of exposed juvenile R. natalensis were found harboring encysted cercariae in their tissues. In addition, C. longiareolata larvae of each developmental stage were infected with these xiphidiocercariae. Compared to unexposed mosquito larvae, a significantly higher mortality rate in first- and second-stage (L1 & L2) larvae was noted. Prevalence of infection was also significantly higher in these L1 & L2 (90% & 88%, respectively) than in third- and fourth-stage larvae. Mosquitoes emerging from exposed L1 & L2 were significantly less numerous when compared to corresponding control groups. Significant disturbance in male and female sex ratio was noted in L1- & L2-developing mosquitoes; it was equal in L1-emerging adults and slightly male biased for those coming from L2.

  8. Aquatic respiration as a potential survival mechanism of Brephidium pseudofea (Lepidoptera: Lycaenidae) larvae to intertidal environments.

    Science.gov (United States)

    Warren, V; Daniels, J C; Hahn, D A

    2011-10-01

    The eastern pygmy blue, Brephidium pseudofea (Morrison) (Lepidoptera: Lycaenidae: Polyommatinae), inhabits intertidal environments that are periodically flooded. The immature stages are subject to salt or brackish water inundation during this time and therefore must endure many stressors, including respiratory limitation and salt exposure. Our goal was to investigate possible mechanisms used by the larval stages of B. pseudofea to endure periodic tidal inundation by using physiological and morphological analyses in comparison with several species of terrestrial lepidopteran larvae. A review of tidal charts showed that the immature stages of B. pseudofea would be prone to complete inundation two to five times per month during the summer months (May to August) and partial submersion for up to 20 d per month during the rest of the year. Larvae of several terrestrial lepidopteran species studied consumed oxygen under water for a limited period, but B. pseudofea demonstrated substantially higher oxygen consumption. Light microscopy of B. pseudofea larvae revealed small air pockets in and around the spiracles when submerged in tap water; these air pockets disappeared when exposed to detergent solution. The resulting air pockets may function as a diffusion layer for oxygen to be absorbed from the surrounding water or may act in conjunction with trans-cuticular gas exchange to meet the larva's respiratory needs. Morphological examination by scanning electron microscopy showed that B. psudofea larvae have distinctively small, clavate setae that appear insufficient to effectively support a functional plastron.

  9. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean

    Science.gov (United States)

    Pimentel, Marta S.; Faleiro, Filipa; Diniz, Mário; Machado, Jorge; Pousão-Ferreira, Pedro; Peck, Myron A.; Pörtner, Hans O.; Rosa, Rui

    2015-01-01

    Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm) significantly decreased metabolic rates (up to 27.4 %) of flatfish larvae, Solea senegalensis, at both present (18 °C) and warmer temperatures (+4 °C). Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT) and glutathione S-transferase (GST), mainly in post-metamorphic larvae (30 dph). The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph) seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase) and intestinal enzymes (up to 36.1 % for alkaline phosphatase) in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels) were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems. PMID:26221723

  10. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean.

    Directory of Open Access Journals (Sweden)

    Marta S Pimentel

    Full Text Available Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm significantly decreased metabolic rates (up to 27.4 % of flatfish larvae, Solea senegalensis, at both present (18 °C and warmer temperatures (+4 °C. Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT and glutathione S-transferase (GST, mainly in post-metamorphic larvae (30 dph. The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase and intestinal enzymes (up to 36.1 % for alkaline phosphatase in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems.

  11. Operationalizing the TANIC and NICA-L3/L4 Tools to Improve Informatics Competencies.

    Science.gov (United States)

    Sipes, Carolyn; McGonigle, Dee; Hunter, Kathy; Hebda, Toni; Hill, Taryn; Lamblin, Jean

    2016-01-01

    Two tools were developed for nurses to self-assess different levels of informatics competencies. The TANIC is used for all nurses to self-assess; the NICA-L3/L4 is a tool for the informatics nurse specialist (INS) to self-assess skill levels. There are 167 informatics items in the TANIC and 178 advanced informatics items in the NICA-L3/L4. These tools were piloted; the results presented here. Based on the evaluation, the tools have been integrated into informatics courses at the BSN and MSN programs at Chamberlain College of Nursing, and presented in two AACN webinars and other national conferences. Numerous requests have been honored to provide the tools for other schools of nursing to use in their courses, including DNP programs. Other requests include those from CNIOs and managers to include in their job descriptions for informatics nurses.

  12. 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

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

    Directory of Open Access Journals (Sweden)

    Young-Jun Choi

    2011-12-01

    Full Text Available 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.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.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 the identification of novel transcribed elements and splice variants.

  14. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.Este estudio describe patrones de abundancia temporal y espacial de larvas de

  15. Macroevolutionary interplay between planktic larvae and benthic predators

    Science.gov (United States)

    Peterson, Kevin J.

    2005-12-01

    Many marine invertebrates have a complex life cycle in which the egg develops into an intermediate planktic larval form rather than developing directly to the benthic juvenile stage. Because of the evolutionary and ecological complexity of pelagic-benthic life cycles, the reasons behind the origin of larvae and their subsequent maintenance over geological time are not well understood. Using both a molecular clock and the fossil record, I show that the initial exploitation of the predator-free pelagic realm by lecithotrophic larvae was achieved independently multiple times by the end of the Early Cambrian, and that the convergent evolution of planktotrophy from lecithotrophic ancestors evolved between the latest Cambrian and Middle Ordovician at least four, and possibly as many as eight, times. Both the exploitation of the pelagic realm by nonfeeding larvae and the acquisition of planktotrophy correlate in time with novel modes of benthic predation, including the dramatic rise in the number and type of epifaunal suspension feeders in the Early Ordovician.

  16. Identification of Ruffe larvae (Gymnocephalus cernuus) in the ...

    Science.gov (United States)

    Non-native Ruffe (Gymnocephalus cernua; family Percidae) were first detected in the Laurentian Great Lakes in 1986, and are not included in the Great Lakes larval fish key which was published several years prior to their discovery. In addition, subsequent scientific literature has inconsistently described Ruffe larvae. As a result, identification of larval Ruffe remains challenging. We used traditional morphology paired with DNA technology to develop diagnostics for Ruffe larvae collected in the lower St. Louis River, and compared them to similar species. Ruffe < 6 mm total length have myomere counts and a phenotype that more closely resemble centrarchids like Black Crappie, Bluegill and Pumpkinseed rather than percids. However, morphometrics and pigment patterns can be used to distinguish Ruffe from similar centrarchids at this size. As Ruffe larvae develop, they increasingly resemble other percids such as Yellow Perch, but can be distinguished using myomere counts and morphological features. The findings presented here clarify conflicting descriptions in the scientific literature, and provide additional data to support more confident morphological identification of larval Ruffe. The impact of invasive Ruffe (Gymnocephalus cernuus) on the ecology of Great Lakes systems is currently being studied. Reproduction and early life history data, however, may be hampered by a general lack of information regarding their early life stage morphological description.

  17. Nutritional Transition Period in Early Larvae Clarias Gariepinus

    International Nuclear Information System (INIS)

    Ing, N.S.; Chew, H.H.

    2015-01-01

    The nutritional transition period of Clarias gariepinus were described based on the early development from hatching to 120 hours after hatching (hAH) reared at 27.5 - 28.6 degree Celsius. Newly hatched larvae had a large greenish yolk sac volume (0.99 ± 0.31 mm 3 ) located below a straight undeveloped digestive tract, mouth not opened, eyes unpigmented and the larvae lie on the bottom of rearing tank. During endogenous feeding period, the larval feeding system has developed rapidly with development oesophagus. Yolk sac were not completely depleted at the onset of exogenous feeding (36 hAH, 0.19 ± 0.11 mm 3 ), and a period of mixed nutrition was observed up to 68 hAH when yolk was completely exhausted. Yolk sac volume was significantly different by time at hatching, 6, 12 and 18 to 36 hAH (ANOVA, P<0.05). At 36 hAH, the larvae commenced feeding once morphologically developed with opened anus, functional jaw and intestine, and demonstrated horizontally swimming. The rudimentary chemoreceptors like olfactory organs and taste buds that were found on the barbels and oral cavity assisted in food detection and commenced feeding without vision. Due to the cannibalistic behaviour at early stage, feed are suggested to be provided during 36 hAH and avoided delay feeding in the larval rearing. (author)

  18. Comparative morphometry of L4 vertebrae: comparison of large animal models for the human lumbar spine.

    Science.gov (United States)

    McLain, Robert F; Yerby, Scott A; Moseley, Timothy A

    2002-04-15

    Anatomic analysis of L4 vertebral morphometry comparing specimens harvested from humans and five common large animal species. To compare fundamental structural similarities and differences in the vertebral bodies of commonly used experimental animals relative to human vertebrae. Animal models are commonly used for assessment of spine fusion, instrumentation techniques, and vertebral bone biology. Among the animals used, the lumbar vertebrae exhibit considerable anatomic variability. The goal of this study was to determine which of the animals commonly used for spine research is best suited as an anatomic model for the human lumbar spine. Morphometric features of the L4 vertebrae of five common research animals were compared with those of the human L4 vertebrae. Mature canines, immature pigs, mature micropigs, mature dairy goats, and mature sheep were analyzed. These species were chosen because they are commonly selected research animals, and most research facilities do not need to be modified to use them. The samples included ten L4 vertebrae of each animal species and seven human L4 vertebrae. Each specimen was meticulously cleaned of all soft tissue. The measurements were grouped into vertebral body parameters, neural canal dimensions, and pedicle and facet morphometery. The mean of each anatomic measurement was compared using a single factor analysis of variance and a Scheffe's post hoc test, with 0.05 denoting significance. The human vertebral body was significantly wider and deeper in the anteroposterior plane than any of the animals studied. However, the mean vertebral body height of the sheep and goat significantly exceeded that of the human specimens. The mean pedicle angle of every animal species was significantly greater than that of the human. The mean pedicle width of the micropig and goat were significantly narrower than the human pedicles, and the dog specimens lacked a definable pedicle altogether. There was no significant difference in mean pedicle

  19. The Antigenic Structure Characterization of Oestrus Ovis Larvae

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    Daniela Moţ

    2012-05-01

    Full Text Available With the aim of proteic components definition from Oestrus ovis larvae, endowed with antigenic properties, able to induce immune responses in vivo and to react in vitro with induced molecular effectors were been performed: electrophoresis in poliacrilamid gel, western blot technique preceded by immunotransfer, immunoassay test. Total soluble larval antigens of O. ovis were been prepared through ultrasonic disintegration, from all three larval stages. Western blot technique allowed and emphasized the specific antigens with a superior sensitivity in comparison with SDS-PAGE electrophoresis. After antigenic characteristics demonstration of investigated larval antigens were been performed the immunoassay test to emphasized the antibodies dozes for O. ovis infestation diagnosis.

  20. Whole-body gene expression pattern registration in Platynereis larvae.

    Science.gov (United States)

    Asadulina, Albina; Panzera, Aurora; Verasztó, Csaba; Liebig, Christian; Jékely, Gáspár

    2012-12-03

    Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the comparison of gene expression patterns is a widely used approach, such standardized anatomical atlases would allow a more rigorous assessment of the conservation of and changes in gene expression patterns during micro- and macroevolutionary time scales. Due to its small size and invariant early development, the annelid Platynereis dumerilii is particularly well suited for such studies. Recently a reference template with registered gene expression patterns has been generated for the anterior part (episphere) of the Platynereis trochophore larva and used for the detailed study of neuronal development. Here we introduce and evaluate a method for whole-body gene expression pattern registration for Platynereis trochophore and nectochaete larvae based on whole-mount in situ hybridization, confocal microscopy, and image registration. We achieved high-resolution whole-body scanning using the mounting medium 2,2'-thiodiethanol (TDE), which allows the matching of the refractive index of the sample to that of glass and immersion oil thereby reducing spherical aberration and improving depth penetration. This approach allowed us to scan entire whole-mount larvae stained with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP) in situ hybridization and counterstained fluorescently with an acetylated-tubulin antibody and the nuclear stain 4'6-diamidino-2-phenylindole (DAPI). Due to the submicron isotropic voxel size whole-mount larvae could be scanned in any orientation. Based on the whole-body scans, we generated four different reference templates by the iterative registration and averaging of 40 individual image stacks using either the acetylated-tubulin or the nuclear-stain signal for each developmental stage. We then registered to these templates the

  1. Whole-body gene expression pattern registration in Platynereis larvae

    Directory of Open Access Journals (Sweden)

    Asadulina Albina

    2012-12-01

    stage. We then registered to these templates the expression patterns of cell-type specific genes. In order to evaluate the gene expression pattern registration, we analyzed the absolute deviation of cell-center positions. Both the acetylated-tubulin- and the nuclear-stain-based templates allowed near-cellular-resolution gene expression registration. Nuclear-stain-based templates often performed significantly better than acetylated-tubulin-based templates. We provide detailed guidelines and scripts for the use and further expansion of the Platynereis gene expression atlas. Conclusions We established whole-body reference templates for the generation of gene expression atlases for Platynereis trochophore and nectochaete larvae. We anticipate that nuclear-staining-based image registration will be applicable for whole-body alignment of the embryonic and larval stages of other organisms in a similar size range.

  2. Newly occurred L4 spondylolysis in the lumbar spine with pre-existence L5 spondylolysis among sports players: case reports and biomechanical analysis.

    Science.gov (United States)

    Sairyo, Koichi; Sakai, Toshinori; Yasui, Natsuo; Kiapour, Ali; Biyani, Ashok; Ebraheim, Nabil; Goel, Vijay K

    2009-10-01

    Case series and a biomechanical study using a finite element (FE) analysis. To report three cases with multi-level spondylolysis and to understand the mechanism biomechanically. Multi-level spondylolysis is a very rare condition. There have been few reports in the literature on multi-level spondylolysis among sports players. We reviewed three cases of the condition, clinically. These patients were very active young sports players and had newly developed fresh L4 spondylolysis and pre-existing L5 terminal stage spondylolysis. Thus, we assumed that L5 spondylolysis may have increased the pars stress at the cranial adjacent levels, leading to newly developed spondylolysis at these levels. Biomechanically, we investigated pars stress at L4 with or without spondylolysis at L5 using the finite element technique. L4 pars stress decreased in the presence of L5 spondylolysis, which does not support our first hypothesis. It seems that multi-level spondylolysis may occur due to genetic and not biomechanical reasons.

  3. Correlations of age and growth rate with microbiota composition in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Trinh, Ly T T; Bakke, Ingrid; Vadstein, Olav

    2017-08-17

    Little information is available on the link between host development (growth rate and ontogeny) and the composition of the microbiota in fish larvae. This study was carried out to examine potential correlations of microbiota composition with age and growth rate of Atlantic cod larvae. Small and large cod larvae of the same age, representing slow and fast growing individuals, were sampled 10 times during a period of 42 days post hatching (dph), and the composition of the larval microbiota was investigated using a PCR/DGGE (Denaturing Gradient Gel Electrophoresis) strategy. We found significant differences in the intestinal microbiota of small and large larvae of the same age for 4 of the 10 age stages studied. We further found that the variation in the composition of the larval microbiota was more strongly correlated to age than to growth rate for larvae up to 28 dph, whereas for the older larvae growth rate and age was equally correlated to the composition of the microbiota. These results indicate that larval development may structure the microbiota through a change in selection pressure due to host-microbe and microbe-microbe interactions, and that the composition of the microbiota may influence larval development through improved energy gain.

  4. On chip cryo-anesthesia of Drosophila larvae for high resolution in vivo imaging applications.

    Science.gov (United States)

    Chaudhury, Amrita Ray; Insolera, Ryan; Hwang, Ran-Der; Fridell, Yih-Woei; Collins, Catherine; Chronis, Nikos

    2017-06-27

    We present a microfluidic chip for immobilizing Drosophila melanogaster larvae for high resolution in vivo imaging. The chip creates a low-temperature micro-environment that anaesthetizes and immobilizes the larva in under 3 minutes. We characterized the temperature distribution within the chip and analyzed the resulting larval body movement using high resolution fluorescence imaging. Our results indicate that the proposed method minimizes submicron movements of internal organs and tissue without affecting the larva physiology. It can be used to continuously immobilize larvae for short periods of time (minutes) or for longer periods (several hours) if used intermittently. The same chip can be used to accommodate and immobilize arvae across all developmental stages (1st instar to late 3rd instar), and loading larvae onto the chip does not require any specialized skills. To demonstrate the usability of the chip, we observed mitochondrial trafficking in neurons from the cell bodies to the axon terminals along with mitochondrial fusion and neuro-synaptic growth through time in intact larvae. Besides studying sub-cellular processes and cellular development, we envision the use of on chip cryo-anesthesia in a wide variety of biological in vivo imaging applications, including observing organ development of the salivary glands, fat bodies and body-wall muscles.

  5. AKTIVITAS INSEKTISIDA BAGIAN TUMBUHAN CALOPHYLLUM SOULTTRI BURM.F. (CLU IACEAE TERHADAP LARVA LEPIDOPTERA

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    Edy Syahputra

    2014-08-01

    Full Text Available The objective of this test was evaluate the insecticidal activity of ectract of some parts of Calophyllum soulattri (Clusiaceae against larvae of three species of Lepidoptera, i. e Crocidolomia pavonana, Plutella xylostela, and Pieris sp.. Extraction of plant materials was done by infusion method using ethanol. The bioassays were conducted by leaf-feeding method. Second-instar larvae were fed extract-treated broccoli leaves of 48 hours, then they were presented with untreated leaves until the surviving larvae larvae reached the fourth-instar stage. The number of dead larvae was recorded daily an larval mortality date were analyzed by probit method. The result showed the gummy bark exudates and bark extract of old and young C. soulattri plants were highly active against C. pavonana. The abrk extact of old C. soulattri plant was also effective against P. xilostella and Pieris sp. The gummy exudates possessed strong insecticidal activity against C. pavonana larvae with LC50 of 0.04% and prolonged the developmental time from second to fourth instar of C. soulattri 2.03-7.25 days compared with control. The bark excudate gave positive respon to alkaloid flavonoid, and tannin test. Futher studies are needed to identify insecticidal compound in those active extracts.

  6. [Observations on the larvae of the tropical marine crab Petrolisthes armatus in the Gulf of Nicoya, Costa Rica].

    Science.gov (United States)

    Díaz-Ferguson, Edgardo; Arroyo, Daisy; Morales, Alvaro; Vargas, José A

    2008-09-01

    During October and November 1998 (rainy season), and December, February and March 1999 (dry season), larvae distribution of Petrolisthes armatus and associated decapods were sampled in three different sites at the Punta Morales peninsula, Gulf of Nicoya, Costa Rica. A total of 6014 decapod larvae were collected, and 73 belonged to the genus Petrolisthes spp. No significant total larval density differences were found between seasons (p > 0.05); but there was a greater density of P. armatus and other decapod larvae (p > 0.05) during the dry season. In addition, no significant variations on temperature and oxygen concentration were observed. P. armatus larval abundance was higher during low tide, in contrast with other decapod larvae. Significant differences among sites were found for other decapod larvae, but not for P. armatus. The only parameter that varied significantly between seasons was salinity and results demonstrate that this factor regulates temporal concentration of larvae. Moreover, flow-tide oscillations were the most important spatial factor in larval dynamics. We propose this mechanism: P. armatus liberates larvae during high tide; these larvae leave the coastal area during low tide and return to the rocky intertidal ecosystem during high tide, when they are ready to settle as megalopa (pre-juvenile stage). Parallel laboratory observations showed higher survival rates at lower salinities (15 ups against 35 ups) and that the duration of the period from zoea I to megalopa was, in average, 19 days.

  7. Transcriptome profiling of individual larvae of two different developmental modes in the poecilogonous polychaete Streblospio benedicti (Spionidae).

    Science.gov (United States)

    Marsh, Adam G; Fielman, Kevin T

    2005-05-15

    Understanding the range of biochemical and physiological phenotypes in a cohort of embryos or larvae is crucial to understanding the lifespan, dispersal potential, and recruitment success of the early life history stages of a species. In this study, a novel kinetic assay has been employed to profile the transcriptome pool complexity in individual larvae of both planktotrophic and lecithotrophic developmental modes in the poecilogonous polycheate Streblospio benedicti. Using a nano-scale synthesis strategy, the mRNA pool in a single embryo or larva can be amplified into cDNA for quantitative characterization in a high-throughput, kinetic reannealing assay in a 96-well, microtiterplate format. This assay generates transcript-pool complexity estimates at 1 degrees C temperature increments for each sample producing 3,360 quantitative measurements per 96-well plate. Measuring transcriptome complexity on 8 individual planktotrophic and 8 individual lecithotrophic larvae (with 4 duplicate assays for each individual) reveals a more complex gene expression profile in planktotrophic larvae and a lower level of interindividual variation in expression patterns in lecithotrophic larvae. Although differences in these gene expression patterns are more likely due to physiological differences between feeding and non-feeding larval types in these late-stage individuals, this is one of the first assessments of inter-individual variation in gene expression patterns in marine invertebrate larvae and indicates a large potential for developmental variability. Copyright 2005 Wiley-Liss, Inc

  8. Larvae of the pycnogonids Ammothea gigantea Gordon, 1932 and Achelia cuneatis Child, 1999 described from archived specimens

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    John A. Fornshell

    2012-12-01

    Full Text Available The larvae of two species of Pycnogonida are described from archived collections. Achelia cuneatis Child, 1999 is an example of a typical protonymphon larva in having three pairs of three segmented appendages, cheliphores, palps and ovigerous appendages. Ammothea gigantea Gordon, 1932 is an example of a lecithotrophic protonymphon larva, having the three pair of appendages plus buds of the first walking legs. Ammothea gigantea is the third species known to have this larval type. The Achelia cuneatis protonymphon larvae is oval, 150 um long and characterized by a relatively long spinneret spine arising at the distal end of the first segment of each cheliphore. Spines also arise from the distal end of the first segment of the second and third limbs. This typical protonymphon larva of Achelia cuneatis has few yolk granules. The lecithotrophic protonymphon of Ammothea gigantea lacks a spinneret spine on the cheliphore; the larva is oval in shape, but much larger than Achelia cuneatis with a length of 700 um. Its second limb is much larger than the third limb on the first post-embryonic stage, and the third limb is further reduced to a spine-like structure on the second post-embryonic stage. This lecithotrophic protonymphon larva has a large number of yolk granules.

  9. Clash of kingdoms or why Drosophila larvae positively respond to fungal competitors

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    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

  10. Dynamic morphology of fish larvae, structural implications of friction forces in swimming, feeding and ventilation

    NARCIS (Netherlands)

    Osse, J.W.M.; Boogaart, van den J.G.M.

    1999-01-01

    Dynamic morphology is the study of the ontogenetic transformations of functional systems in growing organisms. This paper describes these processes in fish larvae as they grow into the juvenile stage. Details of form changes and growth at the level of the organism and its organs are given. Some

  11. Acute toxicity of chlorpyrifos to embryo and larvae of banded gourami Trichogaster fasciata

    NARCIS (Netherlands)

    Sumon, Kizar Ahmed; Saha, Sampa; Brink, van den Paul J.; Peeters, Edwin T.H.M.; Bosma, Roel H.; Rashid, Harunur

    2017-01-01

    This study elucidated the acute toxicity of chlorpyrifos on the early life stages of banded gourami (Trichogaster fasciata). To determine the acute effects of chlorpyrifos on their survival and development, we exposedthe embryos and two-day-old larvae to six concentrations (0, 0.01, 0.10, 1.0, 10

  12. Immunomodulatory effects of excretory/secretory compounds from Contracaecum osculatum larvae in a zebrafish inflammation model

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Kania, Per Walter; Nazemi, Sasan

    2017-01-01

    Excretory/secretory (ES) compounds isolated from third-stage larvae of the anisakid nematode Contracaecum osculatum parasitizing liver of Baltic cod were investigated for effects on immune gene expression in a zebrafish LPS-induced inflammation model. ES products containing a series of proteins, ...

  13. A freak twin trilobite larva of the Indian horseshoe crab Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Mishra, J.K.; Chatterji, A.; Parulekar, A.H.

    Early embryonic stages of a horseshoe crab Tachypleus gigas were studied using micrographs of live embryo. A freak egg showing two trilobite larvae bridged with each other was noticed on 38th day after fertilization. Morphology of this egg has been...

  14. Aras kerusakan ekonomi (AKE larva Ostrinia furnacalis (Lepidoptera: Crambidae pada tiga fase pertumbuhan tanaman jagung

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    Subiadi Subiadi

    2015-09-01

    Full Text Available The Asian corn borer, Ostrinia furnacalis (Guenée is an important economic pest of corn and is widely distributed in the Asia-Pacific region, including Indonesia. The objective of this research is to investigate the effect of infestation levels of O. furnacalis larvae per plant on corn grain yield reductions, and to determine economic injury levels (EIL of O. furnacalis larvae at three growth stages (V10, R1, and R2 of corn. The experiment was designed in a split-plot randomized complete block with blocks replicated three times. Differences in grain weight between the uninfested and highest infestation levels (six larvae per plant V10, R1, and R2 were 59.81; 58.76; and 49.20 g/plant, respectively. For each additional infestation by one larvae per plant at V10, R1, dan R2, there is reduction in grain weight of 4.94%, 4.56% and 3.76% respectively. The calculation of EILs was based on the proportion of yield loss per larvae per plant on three corn growth stages with the assumption that pesticide control reduced 67% of O. furnacalis population. The lowest EIL was 0.31 larvae per plant at V10 when the cost of control reaching Rp.125,000 per ha and crop value of Rp.12,000,000 per ha. The highest EIL of 1.24 larvae per plant was found at R2 with the cost of control of Rp.250,000 per ha and crop value of Rp.8,000,000 per ha.

  15. Occurrence of entomopathogenic fungi and parasitic nematodes on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae collected in Central Chiapas, Mexico

    Science.gov (United States)

    Fall armyworm larvae (FAW), Spodoptera frugiperda (J. E. Smith) were collected from whorl-stage cornfields, between the V2 and V4 stages, in 22 localities of Central, Chiapas, México, called "La Frailesca" during late June 2009 to determine the occurrence of native entomopathogens and parasitic nema...

  16. Exfoliation of the epidermal cells and defecation by amphibian larvae in response to coelomic fluid and lysenin from the earthworm Eisenia foetida.

    Science.gov (United States)

    Kobayashi, Hideshi; Suzuki, Hirohumi; Ohta, Naoshi

    2006-08-01

    Coelomic fluid (CF) and lysenin from the earthworm Eisenia foetida induced heavy epidermal exfoliation in the larvae of Bufo japonicus formosus at developmental stages from hatching (stage 22) to operculum completion (stage 34). In experiments with Xenopus laevis, we observed that exfoliated cells were not stained by trypan blue. Thus, it appeared that these cells were still alive. It is likely, therefore, that both CF and lysenin might disrupt the adhesion between epidermal cells of larvae prior to stage 34. Since it is known that lysenin exerts its toxic effects through its specific binding to sphingomyelin (SM), SM might be involved in such adhesion. This hypothesis was supported by the observations that CF and lysenin which had been incubated with SM-liposomes lost their exfoliative activity. In larvae after stage 34, the mechanism of adhesion between epidermal cells seemed to change and the adhesion was no longer disrupted by CF and lysenin. In larvae at around stage 34, a collagen layer started to form beneath the basement membrane of the epidermis. Furthermore, larvae at around this stage started to eat solid food. The developing collagen layer and food intake might be related indirectly to the chemical change in epidermal adhesion. The induction of exfoliation by CF and lysenin was also observed in other amphibian species. In Bufo larvae, defecation was induced both by CF and by lysenin but this effect was independent of exfoliation.

  17. Advanced finite element analysis of L4-L5 implanted spine segment

    Science.gov (United States)

    Pawlikowski, Marek; Domański, Janusz; Suchocki, Cyprian

    2015-09-01

    In the paper finite element (FE) analysis of implanted lumbar spine segment is presented. The segment model consists of two lumbar vertebrae L4 and L5 and the prosthesis. The model of the intervertebral disc prosthesis consists of two metallic plates and a polyurethane core. Bone tissue is modelled as a linear viscoelastic material. The prosthesis core is made of a polyurethane nanocomposite. It is modelled as a non-linear viscoelastic material. The constitutive law of the core, derived in one of the previous papers, is implemented into the FE software Abaqus®. It was done by means of the User-supplied procedure UMAT. The metallic plates are elastic. The most important parts of the paper include: description of the prosthesis geometrical and numerical modelling, mathematical derivation of stiffness tensor and Kirchhoff stress and implementation of the constitutive model of the polyurethane core into Abaqus® software. Two load cases were considered, i.e. compression and stress relaxation under constant displacement. The goal of the paper is to numerically validate the constitutive law, which was previously formulated, and to perform advanced FE analyses of the implanted L4-L5 spine segment in which non-standard constitutive law for one of the model materials, i.e. the prosthesis core, is implemented.

  18. Multilevel Thoracolumbar Spondylolysis with Spondylolisthesis at L4 on L5.

    Science.gov (United States)

    Kim, Whoan Jeang; Song, Young Dong; Choy, Won Sik

    2015-09-01

    A 24-year-old male patient was initially evaluated for persistent back pain. The visual analogue scale (VAS) score was 7 points. Physical examination revealed a decreased range of lumbar spinal motion, which caused pain. Simple X-ray revealed Meyerding grade 1 spondylolisthesis at L4 on L5, with mild dome-shaped superior endplate and consecutive multilevel spondylolysis at T12-L5. Standing anteroposterior and lateral views of the entire spine revealed normal balance of sagittal and coronal alignment. A computed tomography scan revealed bilateral spondylolysis at T12-L4, left unilateral spondylolysis at L5, and spina bifida at L5 to sacral region. Magnetic resonance imaging revealed mild dural ectasia at the lumbar region. Due to the absence of any neurological symptoms, the patient was managed conservatively. He was rested a few weeks with corset brace and physiotherapy. After treatment, his back pain improved, VAS score changed from 7 to 2, and he was able to return to normal activity.

  19. [Experimental observation of toxic effect of Bacillus thuringiensis var. israelensis against Aedes, Culex and Anopheles larvae].

    Science.gov (United States)

    Li, Ju-Lin; Zhu, Guo-Ding; Zhou, Hua-Yun; Tang, Jian-Xia; Cao, Jun

    2014-02-01

    To evaluate the toxic effect of Bacillus thuringiensis var. israelensis (Bti) wettable powder against Aedes, Culex and Anopheles larvae. The biological assay was applied to test the lethal concentration of 50% (LC50) of Bti wettable powder against Aedes, Culex and Anopheles larvae. The LC50(s) of Bti wettable powder against Aedes albopictus, Culex pipiens pallens and Anopheles sinensis larvae were 0.104, 0.160 microg/ml and 0.324 microg/ml, respectively; its biological potencies against them were 0.125, 0.192 IU/ml and 0.389 IU/ml, respectively. The LC50(s) of continuous contact of Bti wettable powder with An. sinensis stage III larvae for 1, 2 d and 3 d were 0.324, 0.092 microg/ml and 0.032 microg/ml, respectively, and its biological potencies were 0.389, 0.110 IU/ml and 0.038 IU/ml, respectively. The LC50(s) of the bacteria against An. sinensis stage I , II, III, IV were 0.024, 0.137, 0.324 microg/ml and 0.450 microg/ml, respectively, and the biological potencies were 0.029, 0.164, 0.389 IU/ml and 0.540 IU/ml, respectively. Bti wettable powder has a good toxicity to Aedes, Culex and Anopheles larvae, especially for the latter two. It is better to apply the bacteria at the early stage of mosquito larvae.

  20. Predation efficiency of Anopheles gambiae larvae by aquatic predators in western Kenya highlands

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    Nyindo Mramba

    2011-07-01

    Full Text Available Abstract Background The current status of insecticide resistance in mosquitoes and the effects of insecticides on non-target insect species have raised the need for alternative control methods for malaria vectors. Predation has been suggested as one of the important regulation mechanisms for malaria vectors in long-lasting aquatic habitats, but the predation efficiency of the potential predators is largely unknown in the highlands of western Kenya. In the current study, we examined the predation efficiency of five predators on Anopheles gambiae s.s larvae in 24 hour and semi- field evaluations. Methods Predators were collected from natural habitats and starved for 12 hours prior to starting experiments. Preliminary experiments were conducted to ascertain the larval stage most predated by each predator species. When each larval instar was subjected to predation, third instar larvae were predated at the highest rate. Third instar larvae of An. gambiae were introduced into artificial habitats with and without refugia at various larval densities. The numbers of surviving larvae were counted after 24 hours in 24. In semi-field experiments, the larvae were counted daily until they were all either consumed or had developed to the pupal stage. Polymerase chain reaction was used to confirm the presence of An. gambiae DNA in predator guts. Results Experiments found that habitat type (P P P P An. gambiae DNA was found in at least three out of ten midguts for all predator species. Gambusia affins was the most efficient, being three times more efficient than tadpoles. Conclusion These experiments provide insight into the efficiency of specific natural predators against mosquito larvae. These naturally occurring predators may be useful in biocontrol strategies for aquatic stage An. gambiae mosquitoes. Further investigations should be done in complex natural habitats for these predators.

  1. The Macroevolutionary Interplay Between Planktic Larvae and Benthic Predators

    Science.gov (United States)

    Peterson, K. J.

    2004-12-01

    Many marine invertebrates have a complex life cycle whereby the egg, rather than developing directly to the juvenile stage, develops instead into a intermediate larval form which may spend weeks to months feeding in the plankton before it becomes competent to undergo metamorphosis into the benthic juvenile. Because the selective advantages provided to the animal by having a planktotrophic larval stage are largely unknown, the reasons behind their origin and subsequent maintenance over geological time are not well understood. Using both a molecular clock and the fossil record, I show that four primitively non-feeding larval forms evolved sometime between the late Ediacaran and Early Cambrian, and feeding larvae appear to have evolved from non-feeding ancestors sometime between the Late Cambrian and Middle Ordovician in at least five, if not eight, of eight different clades analyzed. Thus, the initial exploitation of the predator-free pelagos by larvae was achieved independently multiple times by the end of the Early Cambrian, most likely driven by benthic predation pressures upon developing eggs and embryos. Then, because the evolution of larval planktotrophy from lecithotrophic ancestors correlates with the dramatic rise in the generic number of benthic suspension feeders in the Early Ordovician, it seems likely that benthic suspension feeding selected for fecundity, and thus indirectly for planktotrophy, in multiple lineages of marine invertebrates by the end of the Middle Ordovician.

  2. Activity of R(+ limonene against Anisakis larvae

    Directory of Open Access Journals (Sweden)

    Filippo Giarratana

    2015-12-01

    Full Text Available The aim of this work is to evaluate the activity of R(+ limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showing a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+ limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status.

  3. Activity of R(+) Limonene Against Anisakis Larvae

    Science.gov (United States)

    Muscolino, Daniele; Panebianco, Felice; Patania, Andrea; Benianti, Chiara; Ziino, Graziella; Giuffrida, Alessandro

    2015-01-01

    The aim of this work is to evaluate the activity of R(+) limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showed a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+) limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status. PMID:27800423

  4. Activity of R(+) limonene against Anisakis larvae

    OpenAIRE

    Filippo Giarratana; Daniele Muscolino; Felice Panebianco; Andrea Patania; Chiara Benianti; Graziella Ziino; Alessandro Giuffrida

    2015-01-01

    The aim of this work is to evaluate the activity of R(+) limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showing a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+) limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status.

  5. 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

  6. Fluorescent Beads Are a Versatile Tool for Staging Caenorhabditis elegans in Different Life Histories

    Directory of Open Access Journals (Sweden)

    Liberta Nika

    2016-07-01

    Full Text Available Precise staging of Caenorhabditis elegans is essential for developmental studies in different environmental conditions. In favorable conditions, larvae develop continuously through four larval stages separated by molting periods. Distinguishing molting from intermolt larvae has been achieved using transgenes with molting reporters, therefore requiring strain constructions, or careful observation of individuals for pharyngeal pumping or behavioral quiescence. In unfavorable conditions, larvae can enter the stress-resistant and developmentally arrested dauer larva stage. Identifying dauer larvae has been based on their ability to withstand detergent selection, precluding identification of recovering animals or of mutants with defects in dauer morphogenesis. Here, we describe a simple method to distinguish molting larvae or dauer larvae from intermolt larvae that bypasses the limitations of current methods. Fluorescent latex beads are mixed with the bacterial food source and ingested by intermolt larvae and adults. Molting and dauer larvae do not feed, and therefore lack beads in their digestive tract. The presence of beads can be determined using a dissecting microscope at magnifications as low as 100 ×, or by using a wormsorter for high-throughput experiments. We find that continuously developing bead-lacking larvae display hallmarks of molting, including expression of the mlt-10::gfp molting marker and a lack of pharyngeal pumping. Furthermore, wild-type and mutant dauer larvae produced by any of three common methods are accurately identified by a lack of beads. Importantly, this method is effective in SDS-sensitive mutant backgrounds and can identify recovering dauer larvae, a stage for which there is no other method of positive selection.

  7. Estimation of food limitation of bivalve larvae in coastal waters of north-western Europe

    DEFF Research Database (Denmark)

    Bos, O.G.; Hendriks, I.E.; Strasser, M.

    2006-01-01

    Marine invertebrate recruitment may be affected by food limitation during the pelagic larval life stages. In the present study, field data on abundance of bivalve larvae along with their prey (small phytoplankton) were examined to see whether they were consistent with predictions made...... assimilation rate averaged 7-26% of the maximum assimilation rate. Under the assumptions made for the present study, it is suggested that growth of larvae in north-west European waters is often food-limited. (c) 2005 Elsevier B.V. All rights reserved...

  8. Distribution and abundance of Syacium ovale larvae (Pleuronectiformes: Paralichthyidae in the Gulf of California

    Directory of Open Access Journals (Sweden)

    Gerardo Aceves-Medina

    2003-06-01

    Full Text Available The spawning season of the tonguefish Syacium ovale (Günter 1864 was determined by an analysis of the distribution of preflexion stage larvae in the Gulf of California. The larvae were collected during eight oceanographic surveys between 1984 and 1987. The spawning of this species starts in early summer and ends at the beginning of fall, with the highest reproductive activity in mid summer. The central and southern regions of the Gulf are the most important reproductive area. Spawning is associated with high sea surface temperatures and low plankton biomass, both of which are characteristics of the tropical current that invades the study area during summer.

  9. Determination of methyl methanesulfonate pretreatment effect in Drosophila melanogaster larvaes upon repair mechanisms in somatic cells

    International Nuclear Information System (INIS)

    Hernandez Paz, M.

    1992-01-01

    To make evident the existence of SOS repair mecanism in somatic cells, larvaes of drosophila melanogaster with MWH markers for females and FLR markers for males were used. This larvaes received a pretreatment with MMS at concentrations of 0.0007% and 0.0014% during 24 hours and latter a treatment with gamma rays at different dosis. SMART program was used to make stastistical evaluations. Small spots were observed which can have two origins. First could be damage in the last part of third stage in which cells are in last divisions and second could be the damage to larvaes in early stages in shich pretreatment with MMS cause lesions which prevent the reproduction of the cells. Also big spots were observed which presence is due to recombination. It was detected than the bigger the concentration of MMS and radiation dose, the bigger the induced damage. In some groups such observation was impossible may be to technical problems as relative humidity, out of phase in the growth of larvaes giving place that treatment were given in three stages. For this reasons it was impossible to discriminate if drosophila melanogaster is wheter or not capable to induce a repair mechanism (Author)

  10. Chiropractic and rehabilitation management of a patient with extraforaminal entrapment of L4 nerve with balance problem.

    Science.gov (United States)

    Alagha, Babak

    2015-01-01

    Disc herniation is one of the most common causes of low back pain with radicular pain. Among various types of disc herniation, the extraforaminal disc herniation is a rare cause of lumbar radiculopathy. The aim of presenting this case study is to demonstrate the benefits of Chiropractic care including spine and extremity manipulation and rehabilitation in the treatment of a rare case of extraforaminal L4 nerve entrapment causing severe L4 radiculopathy and chronic mild low back pain (LBP). The aim of presenting this case study is to demonstrate the benefits of Chiropractic care including spine and extremity manipulation and rehabilitation in treatment of rare case of extraforaminal L4 nerve entrapment which caused severe L4 radiculopathy and chronic mild low back pain (LBP). A 45-year old female patient arrived at the clinic with chronic mild low back pain and right buttock pain, all of which had presented for two years' duration. During the preceding month, the radicular pain initiated in medium to high intensity, radiating to her right leg following the L4 dermatomal pattern with a periodic tingling sensation in her right foot. A neuro exam demonstrated a proprioception deficit in her right leg. A Romberg test was positive. The patient was treated by low amplitude high velocity spinal and extremity manipulation for 10 consecutive sessions (2 weeks), followed by rehabilitation and exercise therapy including advanced myofascial release therapy for an additional 12 sessions (4 weeks). After treatment, the patient reported a significant improvement in her low back pain and radiculopathy. In addition, she achieved some improvement in balance. It seems that Chiropractic care and rehabilitation therapy may be a safe and effective modality in treatment of an L4 radiculopathy in a patient with an extraforaminal L4 nerve entrapment. Although it is rare, an L4 extraforaminal disc herniation should be considered as a possible cause of symptoms in patients with chronic mild

  11. Size of isospin breaking in charged $K_{l4}$ decay

    CERN Document Server

    Nehme, A

    2005-01-01

    We evaluate the size of isospin breaking corrections to form factors f and g of the K/sub l4/ decay process K/sup +/ to pi /sup +/ pi /sup -/l/sup +/vl which is actually measured by the extended NA48 setup at CERN. We found that, keeping apart the effect of Coulomb interaction, isospin breaking does not affect the moduli. This is due to the cancellation between corrections of electromagnetic origin and those generated by the difference between up and down quark masses. On the other hand, electromagnetism affects considerably the phases if the infrared divergence is dropped out using a minimal subtraction scheme. Consequently, the greatest care must be taken in the extraction of pi pi phase shifts from experiment.

  12. Progress of and future plans for the L-4 Blanket Project

    International Nuclear Information System (INIS)

    Daenner, W.; Ioki, K.; Cardella, A.

    2001-01-01

    The ITER L-4 Blanket Project has achieved substantial progress over the last two years. The qualification of materials so far considered as reference for the shield module fabrication has been completed, as well as the developments for joining the triplex First Wall structure. Several Primary Wall, baffle, and limiter mock-ups have been manufactured and tested showing comfortable margins against the loads expected in ITER. Shield prototypes have been manufactured by conventional and advanced technology, which have finally demonstrated the manufacturing feasibility. More recently, activities for the qualification of the module attachment system have been started, and first results from materials and mock-up tests have become available. Several test campaigns are still to be finished to complete the data base for the design. In the meantime, further activities have been initiated to adapt the R and D programme to the ITER-FEAT design features, with the aim to further reduce the cost. (author)

  13. The SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) Product

    Science.gov (United States)

    Reichle, Rolf; Crow, Wade; Koster, Randal; Kimball, John

    2010-01-01

    The Soil Moisture Active and Passive (SMAP) mission is being developed by NASA for launch in 2013 as one of four first-tier missions recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space in 2007. The primary science objectives of SMAP are to enhance understanding of land surface controls on the water, energy and carbon cycles, and to determine their linkages. Moreover, the high resolution soil moisture mapping provided by SMAP has practical applications in weather and seasonal climate prediction, agriculture, human health, drought and flood decision support. In this paper we describe the assimilation of SMAP observations for the generation of the planned SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) product. The SMAP mission makes simultaneous active (radar) and passive (radiometer) measurements in the 1.26-1.43 GHz range (L-band) from a sun-synchronous low-earth orbit. Measurements will be obtained across a 1000 km wide swath using conical scanning at a constant incidence angle (40 deg). The radar resolution varies from 1-3 km over the outer 70% of the swath to about 30 km near the center of the swath. The radiometer resolution is 40 km across the entire swath. The radiometer measurements will allow high-accuracy but coarse resolution (40 km) measurements. The radar measurements will add significantly higher resolution information. The radar is however very sensitive to surface roughness and vegetation structure. The combination of the two measurements allows optimal blending of the advantages of each instrument. SMAP directly observes only surface soil moisture (in the top 5 cm of the soil column). Several of the key applications targeted by SMAP, however, require knowledge of root zone soil moisture (approximately top 1 m of the soil column), which is not directly measured by SMAP. The foremost objective of the SMAP L4_SM product is to fill this gap and provide estimates of root zone soil moisture

  14. Electron and VLF travel time differences for wave-particle interactions at L=4: Pt. 2

    International Nuclear Information System (INIS)

    Rash, J.P.S.; Scourfield, M.W.J.; Dougherty, M.K.

    1984-01-01

    The cyclotron resonance or gyroresonance interaction has been widely invoked as a generation mechanism for discrete VLF emissions and plasmaspheric hiss. This interaction involves electrons and VLF waves travelling in opposite directions along a geomagnetic field line. We examine, for an interaction region in the equatorial plane at L=4, the energy of the resonant electrons as a function of VLF wave frequency and ambient equatorial electron density. Then for two different spatial configurations of the interaction and two standard plasma distribution models we examine the difference in travel times to a ground-based observer in the Southern hemisphere for the electrons and waves taking part in the interaction. This difference in travel times is shown as a function of VLF wave frequency and equatorial electron density. The results, and their significance for observations of auroral electrons and VLF at Sanae, Antarctica, are discussed and compared with similar results for the Cerenkov interaction discussed in an earlier paper

  15. Survival, growth and reproduction of cryopreserved larvae from a marine invertebrate, the Pacific oyster (Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Marc Suquet

    Full Text Available This study is the first demonstration of successful post-thawing development to reproduction stage of diploid cryopreserved larvae in an aquatic invertebrate. Survival, growth and reproductive performances were studied in juvenile and adult Pacific oysters grown from cryopreserved embryos. Cryopreservation was performed at three early stages: trochophore (13±2 hours post fertilization: hpf, early D-larvae (24±2 hpf and late D-larvae (43±2 hpf. From the beginning (88 days at the end of the ongrowing phase (195 days, no mortality was recorded and mean body weights did not differ between the thawed oysters and the control. At the end of the growing-out phase (982 days, survival of the oysters cryopreserved at 13±2 hpf and at 43±2 hpf was significantly higher (P<0.001 than those of the control (non cryopreserved larvae. Only the batches cryopreserved at 24±2 hpf showed lower survival than the control. Reproductive integrity of the mature oysters, formely cryopreserved at 13±2 hpf and 24±2 hpf, was estimated by the sperm movement and the larval development of their offspring in 13 crosses gamete pools (five males and five females in each pool. In all but two crosses out of 13 tested (P<0.001, development rates of the offspring were not significantly different between frozen and unfrozen parents. In all, the growth and reproductive performances of oysters formerly cryopreserved at larval stages are close to those of controls. Furthermore, these performances did not differ between the three initial larval stages of cryopreservation. The utility of larvae cryopreservation is discussed and compared with the cryopreservation of gametes as a technique for selection programs and shellfish cryobanking.

  16. Responses of bay anchovy (Anchoa mitchilli) larvae under lethal and sublethal scenarios of crude oil exposure.

    Science.gov (United States)

    Duffy, Tara A; Childress, William; Portier, Ralph; Chesney, Edward J

    2016-12-01

    Bay anchovy (Anchoa mitchilli) is an ecologically important zooplanktivorous fish inhabiting estuaries of the Gulf of Mexico and eastern North America from Maine to Florida. Because they have a protracted spawning season (spring through fall) and are abundant at all life stages in coastal estuaries, their eggs and larvae likely encountered oil that reached the coast during the Deepwater Horizon oil spill. We compared responses to oil exposure at different life stages and at lethal and sublethal conditions using acute, 24h exposures. In a series of experiments, bay anchovy larvae were exposed to high energy water accommodated fractions (HEWAF) and chemically-enhanced WAF (CEWAF) at two stages of larval development (5 and 21 days post hatch, dph). HEWAF oil exposures induced significantly greater life stage dependent sensitivity at 5 dph than at 21 dph but chemically dispersed (CEWAF) exposure mortality was more variable and LC 50s were not significantly different between 5 and 21dph larvae. Acute exposure to two low-level concentrations of CEWAF did not result in significant mortality over 24h, but resulted in a 25-77% reduction in larval survival and a 12-34% reduction in weight specific growth after six days of post-exposure growth following the initial 24h exposure. These results show that younger (5 dph) bay anchovy larvae are more vulnerable to acute oil exposure than older (21 dph) larvae, and that acute responses do not accurately reflect potential population level mortality and impacts to growth and development. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Tracheopulmonary myiasis caused by a mature third-instar Cuterebra larva: case report and review.

    Science.gov (United States)

    Cornet, Muriel; Florent, Martine; Lefebvre, Aurélie; Wertheimer, Christophe; Perez-Eid, Claudine; Bangs, Michael J; Bouvet, Anne

    2003-12-01

    Myiasis is the infestation of vertebrate tissues with fly larvae (Diptera). Most human cases in North America are subcutaneous forms due to Dermatobia hominis imported from Central and South America. Human cases of myiasis acquired in North America are rare and are primarily subdermal or ophthalmologic forms of infestation caused by early stages of Cuterebra larvae. We report an unusual case of tracheopulmonary myiasis, resulting from the in situ development of a mature cuterebrine larva associated with high eosinophilia. Only two other cases of tracheopulmonary cuterebrid myiasis have been reported in humans, and they are reviewed herein. Cuterebra myiasis (cuterebrosis) remains a rare and aberrant cause of tracheopulmonary disease and is a newly described cause of eosinophilia in humans.

  18. [Light and electron microscopic studies of oropharyngeal epithelium in Salamandra salamandra (L.) (Urodela: Salamandridae) larvae].

    Science.gov (United States)

    Clemen, G

    1984-01-01

    The oropharyngeal-epithelium of intrauterine and free swimming larvae of Salamandra salamandra has been investigated by electron microscopy. With the exception of the toothed areas, where it is multi-layered, the epithelium of intrauterine larvae consists of two cell layers, pavement and basal cells. In older larvae, however, the entire epithelium is multi-layered. The outermost layer contains nonciliated pavement cells, goblet cells and sporadically mitochondria-rich cells. Both, goblet cells and pavement cells synthesize mainly acid mucosubstances, which are localized in big confluent secretory granules in the former and in small granules immediately beneath the apical plasmalemm in the latter. In the second layer different developmental stages of goblet cells and pavement cells can be identified.

  19. Tracheopulmonary Myiasis Caused by a Mature Third-Instar Cuterebra Larva: Case Report and Review

    Science.gov (United States)

    Cornet, Muriel; Florent, Martine; Lefebvre, Aurélie; Wertheimer, Christophe; Perez-Eid, Claudine; Bangs, Michael J.; Bouvet, Anne

    2003-01-01

    Myiasis is the infestation of vertebrate tissues with fly larvae (Diptera). Most human cases in North America are subcutaneous forms due to Dermatobia hominis imported from Central and South America. Human cases of myiasis acquired in North America are rare and are primarily subdermal or ophthalmologic forms of infestation caused by early stages of Cuterebra larvae. We report an unusual case of tracheopulmonary myiasis, resulting from the in situ development of a mature cuterebrine larva associated with high eosinophilia. Only two other cases of tracheopulmonary cuterebrid myiasis have been reported in humans, and they are reviewed herein. Cuterebra myiasis (cuterebrosis) remains a rare and aberrant cause of tracheopulmonary disease and is a newly described cause of eosinophilia in humans. PMID:14662989

  20. Prolonged pre-incubation increases the susceptibility of Galleria mellonella larvae to bacterial and fungal infection.

    Science.gov (United States)

    Browne, Niall; Surlis, Carla; Maher, Amie; Gallagher, Clair; Carolan, James C; Clynes, Martin; Kavanagh, Kevin

    2015-01-01

    Galleria mellonella larvae are widely used for assessing the virulence of microbial pathogens and for measuring the in vivo activity of antimicrobial agents and produce results comparable to those that can be obtained using mammals. The aim of the work described here was to ascertain the effect of pre-incubation at 15°C for 1, 3, 6 or 10 weeks on the susceptibility of larvae to infection with Candida albicans and Staphylococcus aureus. Larvae infected with C. albicans after 1 week pre-incubation at 15°C showed 73.3 ± 3.3% survival at 24 hours post-infection while those infected after 10 weeks pre-incubation showed 30 ± 3.3% survival (P system but the duration of the pre-incubation stage significantly affects their susceptibility to microbial pathogens possibly as a result of altered metabolism.

  1. The innate immune and systemic response in honey bees to a bacterial pathogen, Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Foster Leonard J

    2009-08-01

    Full Text Available Abstract Background There is a major paradox in our understanding of honey bee immunity: the high population density in a bee colony implies a high rate of disease transmission among individuals, yet bees are predicted to express only two-thirds as many immunity genes as solitary insects, e.g., mosquito or fruit fly. This suggests that the immune response in bees is subdued in favor of social immunity, yet some specific immune factors are up-regulated in response to infection. To explore the response to infection more broadly, we employ mass spectrometry-based proteomics in a quantitative analysis of honey bee larvae infected with the bacterium Paenibacillus larvae. Newly-eclosed bee larvae, in the second stage of their life cycle, are susceptible to this infection, but become progressively more resistant with age. We used this host-pathogen system to probe not only the role of the immune system in responding to a highly evolved infection, but also what other mechanisms might be employed in response to infection. Results Using quantitative proteomics, we compared the hemolymph (insect blood of five-day old healthy and infected honey bee larvae and found a strong up-regulation of some metabolic enzymes and chaperones, while royal jelly (food and energy storage proteins were down-regulated. We also observed increased levels of the immune factors prophenoloxidase (proPO, lysozyme and the antimicrobial peptide hymenoptaecin. Furthermore, mass spectrometry evidence suggests that healthy larvae have significant levels of catalytically inactive proPO in the hemolymph that is proteolytically activated upon infection. Phenoloxidase (PO enzyme activity was undetectable in one or two-day-old larvae and increased dramatically thereafter, paralleling very closely the age-related ability of larvae to resist infection. Conclusion We propose a model for the host response to infection where energy stores and metabolic enzymes are regulated in concert with direct

  2. Energy density of zooplankton and fish larvae in the southern Catalan Sea (NW Mediterranean)

    Science.gov (United States)

    Barroeta, Ziortza; Olivar, M. Pilar; Palomera, Isabel

    2017-06-01

    In marine communities, energy of small planktonic organisms is transferred to their predators through feeding. The energy accumulated as organic substances by the different plankton organisms (Energetic Density content, ED) has been analysed in high latitudes and tropical areas, but not in the Mediterranean Sea. In this study, we approach this type of investigation for Mediterranean plankton through measures of total calorimetric content using an oxygen bomb calorimeter. We examined the spatiotemporal variation in the ED of microplankton (50-200 μm) and mesozooplankton (200-2000 μm), and two plankton-consumers, sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) larvae. The study was carried out during the winter and summer of 2013 off the Ebro River Delta (NW Mediterranean Sea). Both plankton fractions showed a more coastal distribution and higher biomasses during winter, the period of sardine larvae occurrences, in front of a wider cross-shelf distribution and lower biomasses in summer, when anchovy appeared. ED values increased with the size of each plankton component, i.e., microzooplankton < mesozooplankton < fish larvae. A tendency for higher plankton ED in the winter period was observed, although being only significant for coastal zone, associated to the more productive waters there. Sardine and anchovy larvae showed an increasing trend in the amount of energy during development, with significantly lower ED between early larvae (6-10 mm standard length) and late postflexion stages (16-20 mm standard length). Small larvae of both species departed from a similarly low ED content, but in the next two size classes sardine larvae showed higher ED values than anchovy, being significantly higher in the 16-20 mm size class. Information on larval feeding patterns and larval growth rates for each species were used to discuss differences in energy allocation strategies.

  3. Proteomic and metabolomic analysis reveals rapid and extensive nicotine detoxification ability in honey bee larvae.

    Science.gov (United States)

    du Rand, Esther E; Human, Hannelie; Smit, Salome; Beukes, Mervyn; Apostolides, Zeno; Nicolson, Susan W; Pirk, Christian W W

    2017-03-01

    Despite potential links between pesticides and bee declines, toxicology information on honey bee larvae (Apis mellifera) is scarce and detoxification mechanisms in this development stage are virtually unknown. Larvae are exposed to natural and synthetic toxins present in pollen and nectar through consumption of brood food. Due to the characteristic intensive brood care displayed by honey bees, which includes progressive feeding throughout larval development, it is generally assumed that larvae rely on adults to detoxify for them and exhibit a diminished detoxification ability. We found the opposite. We examined the proteomic and metabolomic responses of in vitro reared larvae fed nicotine (an alkaloid found in nectar and pollen) to understand how larvae cope on a metabolic level with dietary toxins. Larvae were able to effectively detoxify nicotine through an inducible detoxification mechanism. A coordinated stress response complemented the detoxification processes, and we detected significant enrichment of proteins functioning in energy and carbohydrate metabolism, as well as in development pathways, suggesting that nicotine may promote larval growth. Further exploration of the metabolic fate of nicotine using targeted mass spectrometry analysis demonstrated that, as in adult bees, formation of 4-hydroxy-4-(3-pyridyl) butanoic acid, the result of 2'C-oxidation of nicotine, is quantitatively the most significant pathway of nicotine metabolism. We provide conclusive evidence that larvae are capable of effectively catabolising a dietary toxin, suggesting that increased larval sensitivity to specific toxins is not due to diminished detoxification abilities. These findings broaden the current understanding of detoxification biochemistry at different organizational levels in the colony, bringing us closer to understanding the capacity of the colony as a superorganism to tolerate and resist toxic compounds, including pesticides, in the environment. Copyright © 2017

  4. Toxicity of cypermethrin and deltamethrin insecticides on embryos and larvae of Physalaemus gracilis (Anura: Leptodactylidae).

    Science.gov (United States)

    Macagnan, Natani; Rutkoski, Camila F; Kolcenti, Cassiane; Vanzetto, Guilherme V; Macagnan, Luan P; Sturza, Paola F; Hartmann, Paulo A; Hartmann, Marilia T

    2017-09-01

    It is important to establish the toxicity pesticides against non-target species, especially those pesticides used in commercial formulations. Pyrethroid insecticides are widely used in agriculture despite their toxicity to aquatic animals. In this study, we determine the toxicity of commercial formulation of two pyrethroid insecticides, cypermethrin and deltamethrin, in two life stages of Physalaemus gracilis, a frog that breeds in agricultural ecosystems and has potential contact with pyrethroid pesticides. The acute toxicity test (96 h) was carried out with embryos of stage 17:18 and larvae of stages 24:25. Embryos were more resistant to both pesticides than larvae. In embryo mobility assays, we found that both pesticides caused spasmodic contractions, suggestive of neurological effects. In acute toxicity assays, we found that P. gracilis is more resistant to these insecticides than other studied species.

  5. Expression of immune-related genes in embryos and larvae of sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Yang, Aifu; Zhou, Zunchun; Dong, Ying; Jiang, Bei; Wang, Xiaoyu; Chen, Zhong; Guan, Xiaoyan; Wang, Bai; Sun, Dapeng

    2010-11-01

    The echinoderm immunity system has been extensively investigated in adults in several classes such as echinoid and holothuroidea. However, the defense mechanism in embryos and larvae remains largely unexplored. To profile the immune-related genes expression in embryos and larvae and to monitor the stimulation of the innate immune response by lipopolysaccharides (LPS) challenge, we investigated the expression patterns of nine immune-related genes in embryos and larvae of sea cucumber (Apostichopus japonicus) at eleven developmental stages using quantitative real-time PCR (qRT-PCR). The expression of six encoding proteins including heat shock protein70 (Hsp70), Hsp90, Hsp gp96, thymosin-beta, ferritin and DD104 protein was detected at all eleven development stages according to mRNA expression data. However, the expression of mannan-binding C-type lectin (MBCL) was detected at early auricularia to juvenile stages, while lysozyme and serine proteinase inhibitor (SPI) were detected only at juvenile stage. Out of these nine genes, three (MBCL, lysozyme and SPI) were found to be up-regulated in mRNA expression upon LPS challenge, whereas the other six showed no significant change. Our study presents a first preliminary view into the expression patterns of immune-related genes at different developmental stages of sea cucumber, which increases the available information on echinoderm immunity. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

    KAUST Repository

    Zhang, G.

    2015-06-25

    RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in ‘double transfections’, in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

  7. Response of pre-adult and adult stages of Trichuris muris to common anthelmintics in mice.

    Science.gov (United States)

    Rajasekariah, G R; Deb, B N; Jones, M P; Dhage, K R; Bose, S

    1991-10-01

    The common anthelmintics, oxantel, mebendazole, albendazole and pyrantel were assessed for their comparative activity against Trichuris muris in mice. Mice were infected with T. muris and the infection was maintained by a brief cortisone administration during the second week of infection. Mice carrying the infection with different life cycle stages, viz. fourth stage larvae (L4), pre-adult and adult stages were dosed with anthelminitics. The worm burdens in control infection groups varied although infection dose and other conditions were uniformly followed. With various dose regimens tested, oxantel was highly potent; it eliminated completely pre-adult and adult stages, respectively at 25 and 12.5 mg kg-1 dose levels with significant activity also against adult worms at a 1.56 mg kg-1 dose level and against pre-adults at a 6.25 mg kg-1 level. Pre-adults required twice the dose given to that of adults for complete (100%) activity. Mebendazole was the next most active; a dosage of 37.5 mg kg-1 was completely active against pre-adults whereas a dosage of 2 x 50 mg kg-1 was required for complete elimination of adult worms. In addition, about 90% of the worms were eliminated with a single dose of 150 mg kg-1. However, a significant activity was seen against adults at a 25 mg kg-1 level and pre-adults at 37.5 mg kg-1, the lowest level tested. In comparison, albendazole did not induce complete clearance of pre-adult and adult stages even when tested at dose levels as high as 150 and 2 x 75 mg kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Vestigial ophiopluteal structures in the lecithotrophic larvae of Ophionereis schayeri (Ophiuroidea).

    Science.gov (United States)

    Selvakumaraswamy, P; Byrne, M

    2000-06-01

    Evolution of echinoderm development from a feeding to a non-feeding mode can be examined by studying non-feeding larvae with structures that appear to be vestiges derived from a feeding ancestral state. The lecithotrophic larvae of the Australian brittle star Ophionereis schayeri possess such features, and the early development of this species was documented by light and scanning electron microscopy. The embryos undergo irregular cleavage, resulting in the formation of different sized blastomeres, with subsequent development through a wrinkled blastula stage. The lecithotrophic larva of O. schayeri possesses several vestigial ophiopluteal structures, including a continuous ciliated band, a larval gut, and a larval skeleton. The ciliated band is a reduced expression of the continuous ciliated band typical of ophioplutei. The larval gut is a transiently complete system, but an esophageal plug and rapid closure of the blastopore renders it nonfunctional. The larval skeleton, though reduced, consists of four rods corresponding to the body, posterolateral, anterolateral, and postoral rods characteristic of an ophiopluteus. Due to a heterochrony in larval skeletogenesis, the postoral rods develop early and simultaneously with the other rods. Compared with the larvae of other lecithotrophic ophiuroids, the larva of O. schayeri is one of the most reduced ophiopluteal forms reported to date.

  9. A magnetic compass that might help coral reef fish larvae return to their natal reef.

    Science.gov (United States)

    Bottesch, Michael; Gerlach, Gabriele; Halbach, Maurits; Bally, Andreas; Kingsford, Michael J; Mouritsen, Henrik

    2016-12-19

    Many coral reef fish larvae spend days to months in the open ocean before settlement on coral reefs [1]. Early in development, larvae have limited swimming capabilities and will therefore be greatly affected by currents. This can potentially result in dispersal distances of tens of kilometers [2]. Nevertheless, up to 60 % of surviving larvae have been shown to return to their natal reefs [2]. To home, the larvae must develop strong swimming capabilities and appropriate orientation mechanisms. Most late-stage larval reef fish can, after being passively drifted for days to weeks, swim strongly [3], and Ostorhinchus doederleini larvae have been shown to use chemotaxis to identify their natal reef once in its vicinity [2] and a sun compass for longer distance orientation [4] during the day. But how do they orient at night? Here, we show that newly settled fish caught at One Tree Island (OTI) at the Capricorn Bunker Reef Group (Great Barrier Reef) can use geomagnetic compass information to keep a south-east heading. This behavior might help them return to their natal reef in the absence of any celestial cues at night. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Distribution and abundance of fish larvae in the northern Ionian Sea (Eastern Mediterranean)

    Science.gov (United States)

    Granata, Antonia; Cubeta, Annaluce; Minutoli, Roberta; Bergamasco, Alessandro; Guglielmo, Letterio

    2011-09-01

    The purpose of this paper was to study the spatial distribution, abundance and composition of fish larvae in the northern Ionian Sea. Samples were collected to the 600 m depth with an electronic multinet BIONESS during the "INTERREG Italia-Grecia" oceanographic cruise carried out in March 2000 off the Apulian Italian coast. A total of 46 species of teleost early stages were collected, belonging to 38 genera and 22 families. Over 52% of the larvae identified were mesopelagic species, almost 27% were demersal and about 21% pelagic. A total of 307 myctophids, 69 clupeids and 61 gadid post-larvae dominated the community. Benthosema glaciale (mean 6.1 mm SL) was the most abundant species (21.6%), the most frequent in the samples (28.8%), and dominant in the whole study area (mean 1.4 ind/100 m3). Particular attention was given to the horizontal and vertical distribution and abundance of the three dominant post-larval species: Benthosema glaciale, Sprattus sprattus sprattus and Notoscopelus elongatus. The Pearson coefficient ( R = 0.734) showed a high correlation between total zooplankton and fish larval assemblages in terms of spatial distribution abundance values. Regarding the vertical distribution of fish larvae, Sorensen's index ( S = 0.69) showed that fish larvae and total zooplankton abundance peaks co-occurred along the water column.

  11. Stereoselectivity in bioaccumulation and excretion of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae.

    Science.gov (United States)

    Lv, Xiaotian; Liu, Chen; Li, Yaobin; Gao, Yongxin; Wang, Huili; Li, Jianzhong; Guo, Baoyuan

    2014-09-01

    Stereoselectivity in bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20mg/kg and 2mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20mg/kg dose. The stereoselectivity in bioaccumulation in the 2mg/kg dosage was not obvious compared to the 20mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by bioaccumulation factor (BAF). Copyright © 2014 Elsevier Inc. All rights reserved.

  12. INHIBITION OF FATTY ACID DESATURASES IN Drosophila melanogaster LARVAE BLOCKS FEEDING AND DEVELOPMENTAL PROGRESSION.

    Science.gov (United States)

    Wang, Yiwen; da Cruz, Tina Correia; Pulfemuller, Alicia; Grégoire, Stéphane; Ferveur, Jean-François; Moussian, Bernard

    2016-05-01

    Fatty acid desaturases are metabolic setscrews. To study their systemic impact on growth in Drosophila melanogaster, we inhibited fatty acid desaturases using the inhibitor CAY10566. As expected, the amount of desaturated lipids is reduced in larvae fed with CAY10566. These animals cease feeding soon after hatching, and their growth is strongly attenuated. A starvation program is not launched, but the expression of distinct metabolic genes is activated, possibly to mobilize storage material. Without attaining the normal size, inhibitor-fed larvae molt to the next stage indicating that the steroid hormone ecdysone triggers molting correctly. Nevertheless, after molting, expression of ecdysone-dependent regulators is not induced. While control larvae molt a second time, these larvae fail to do so and die after few days of straying. These effects are similar to those observed in experiments using larvae deficient for the fatty acid desaturase1 gene. Based on these data, we propose that the ratio of saturated to unsaturated fatty acids adjusts a sensor system that directs feeding behavior. We also hypothesize that loss of fatty acid desaturase activity leads to a block of the genetic program of development progression indirectly by switching on a metabolic compensation program. © 2016 Wiley Periodicals, Inc.

  13. Musculoskeletal anatomy and feeding performance of pre-feeding engyodontic larvae of the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Bouilliart, M.; Tomkiewicz, Jonna; Lauesen, P.

    2015-01-01

    Being part of the elopomorph group of fishes, Anguillidae species show a leptocephalus larval stage. However, due to largely unknown spawning locations and habitats of their earliest life stages, as well as their transparency, these Anguilla larvae are rarely encountered in nature. Therefore......, information regarding the early life history of these larvae, including their exogenous feeding strategy and feeding performance, is rather scarce. To better understand the structural basis and functional performance of larval feeding in captivity, the functional morphology of the cranial musculoskeletal...... system in pre- and first-feeding engyodontic leptocephali of the European eel (Anguilla anguilla) was studied. A 3D reconstruction of the feeding apparatus (head of the leptocephali

  14. Citrus Seed Oils Efficacy against Larvae of Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Hazrat Bilal

    2017-10-01

    Full Text Available Background: Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti.Methods: Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae.Result: Among the Citrus cultivar seed oil, rough lemon (Citrus jambhiri had the lowest LC50 value (200.79ppm, while musambi (C. sinensis var musambi had the highest LC50 value (457.30ppm after 24 h of exposure.Conclusion: Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. ae­gypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine opera­tional feasibility.

  15. Resistance of developing honeybee larvae during chronic exposure to dietary nicotine.

    Science.gov (United States)

    Human, H; Archer, C R; du Rand, E E; Pirk, C W W; Nicolson, S W

    2014-10-01

    The effects of pesticides on honeybee larvae are less understood than for adult bees, even though larvae are chronically exposed to pesticide residues that accumulate in comb and food stores in the hive. We investigated how exposure to a plant alkaloid, nicotine, affects survival, growth and body composition of honeybee larvae. Larvae of Apis mellifera scutellata were reared in vitro and fed throughout development on standard diets with nicotine included at concentrations from 0 to 1000μg/100g diet. Overall mortality across all nicotine treatments was low, averaging 9.8% at the prepupal stage and 18.1% at the white-eyed pupal stage, but survival was significantly reduced by nicotine. The mass of prepupae and white-eyed pupae was not affected by nicotine. In terms of body composition, nicotine affected water content but did not influence either protein or lipid stores of white-eyed pupae. We attribute the absence of consistent negative effects of dietary nicotine to detoxification mechanisms in developing honeybees, which enable them to resist both natural and synthetic xenobiotics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Experimental skin lesions from larvae of the bot fly Dermatobia hominis.

    Science.gov (United States)

    Pereira, M C; Leite, V H; Leite, A C

    2001-03-01

    Skin biopsies from larvae of Rattus norvegicus, experimentally infested with Dermatobia hominis (Linnaeus Jr) (Diptera: Cuterebridae), were processed for histopathological studies. Two days after infestation, the first-stage larvae (L1) were located deep in the dermis, surrounded by an inflamed area infiltrated predominantly by neutrophils. On the fourth day a thin necrotic layer could be seen close to the larvae, surrounded by large numbers of neutrophils, lymphocytes, macrophages with a few eosinophils and mast cells. A small warble was formed after the fourth day, increasing in size until the seventh day, when the L1 moulted to the second-stage larva (L2). The inflammatory process continued with increasing numbers of neutrophils, macrophages, lymphocytes, eosinophils and mast cells invading the area, as well as the proliferation of fibroblasts and endothelial cells and the appearance of a few localized haemorrhages. After 18-20 days, the L2 moulted to the third-stage larva (L3), when a few plasma cells could be seen in the inflamed area. At 25-30 days there was a reduction in the necrotic layer, as well as in the number of neutrophils and lymphocytes, although large amounts of eosinophils, plasma cells, and collagen fibres were seen. The L3 usually left the host after 30 days. Two days later, the larval cavity was reduced, mast cells infiltrated the region and collagen fibre production were increased. After 7 days, an intense infiltration of plasma cells and scattered necrotic areas could be seen. A scar formed after 10 days. This study showed the laboratory rat to be a suitable model for studies of D. hominis infestation.

  17. Marine Invertebrate Larvae Associated with Symbiodinium: A Mutualism from the Start?

    KAUST Repository

    Mies, Miguel

    2017-05-30

    Symbiodinium are dinoflagellate photosynthetic algae that associate with a diverse array of marine invertebrates, and these relationships are comprehensively documented for adult animal hosts. Conversely, comparatively little is known about the associations during larval development of animal hosts, although four different metazoan phyla (Porifera, Cnidaria, Acoelomorpha, and Mollusca) produce larvae associated with Symbiodinium. These phyla represent considerable diversities in larval forms, manner of symbiont acquisition, and requirements on the presence of symbionts for successful metamorphosis. Importantly, the different requirements are conveyed by specific symbiont types that are selected by the host animal larvae. Nevertheless, it remains to be determined whether these associations during larval stages already represent mutualistic interactions, as evident from the relationship of Symbiodinium with their adult animal hosts. For instance, molecular studies suggest that the host larval transcriptome is nearly unaltered after symbiont acquisition. Even so, a symbiosis-specific gene has been identified in Symbiodinium that is expressed in larval host stages, and similar genes are currently being described for host organisms. However, some reports suggest that the metabolic exchange between host larvae and Symbiodinium may not cover the energetic requirements of the host. Here, we review current studies to summarize what is known about the association between metazoan larvae and Symbiodinium. In particular, our aim was to gather in how far the mutualistic relationship present between adult animals hosts and Symbiodinium is already laid out at the time of symbiont acquisition by host larvae. We conclude that the mutualistic relationship between animal hosts and algal symbionts in many cases is not set up during larval development. Furthermore, symbiont identity may influence whether a mutualism can be established during host larval stages.

  18. Following the infection process of vibriosis in Manila clam (Ruditapes philippinarum) larvae through GFP-tagged pathogenic Vibrio species.

    Science.gov (United States)

    Dubert, Javier; Nelson, David R; Spinard, Edward J; Kessner, Linda; Gomez-Chiarri, Marta; da Costa, Fiz; Prado, Susana; Barja, Juan L

    2016-01-01

    Vibriosis represents the main bottleneck for the larval production process in shellfish aquaculture. While the signs of this disease in bivalve larvae are well known, the infection process by pathogenic Vibrio spp. during episodes of vibriosis has not been elucidated. To investigate the infection process in bivalves, the pathogens of larvae as V. tubiashii subsp. europaensis, V. neptunius and V. bivalvicida were tagged with green fluorescent protein (GFP). Larvae of Manila clam (Ruditapes philippinarum) were inoculated with the GFP-labeled pathogens in different infection assays and monitored by microscopy. Manila clam larvae infected by distinct GFP-tagged Vibrio spp. in different challenges showed the same progression in the infection process, defining three infection stages. GFP-tagged Vibrio spp. were filtered by the larvae through the vellum and entered in the digestive system through the esophagus and stomach and colonized the digestive gland and particularly the intestine, where they proliferated during the first 2h of contact (Stage I), suggesting a chemotactic response. Then, GFP-tagged Vibrio spp. expanded rapidly to the surrounding organs in the body cavity from the dorsal to ventral region (Stage II; 6-8h), colonizing the larvae completely at the peak of infection (Stage III) (14-24h). Results demonstrated for the first time that the vibriosis is asymptomatic in Manila clam larvae during the early infection stages. Thus, the early colonization and the rapid proliferation of Vibrio pathogens within the body cavity supported the sudden and fatal effect of the vibriosis, since the larvae exhibited the first signs of disease when the infection process is advanced. As a first step in the elucidation of the potential mechanisms of bacterial pathogenesis in bivalve larvae the enzymatic activities of the extracellular products released from the wild type V. neptunius, V. tubiashii subsp. europaensis and V. bivalvicida were determined and their cytotoxicity was

  19. First record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu Arapaima gigas (Osteichthyes: Arapaimidae) from South America.

    Science.gov (United States)

    Andrade-Porto, S M; Cárdenas, M Q; Martins, M L; Oliveira, J K Q; Pereira, J N; Araújo, C S O; Malta, J C O

    2015-11-01

    Third-stage larvae (L3) of Hysterothylacium sp. were collected by the first time in juveniles of pirarucu Arapaima gigas farmed in the Rio Preto da Eva, Amazonas state. Ninety-eight (98) out of 100 examined fish showed to be parasitized. Five hundred and ninety larvae of Hysterothylacium sp. were collected from the intestines, stomach and pyloric caeca. The mean intensity of parasite indexes was 6.02 (±5.75) ranging from 1 to 40 larvae per host and the mean abundance was 5.9 (±5.76). The A. gigas is the new host record for larvae of Hysterothylacium sp. in Brazil, and this is the first record of larvae of Hysterothylacium (Nematoda: Anisakidae) with zoonotic potential in the pirarucu from South America.

  20. Osmoregulation in larvae and juveniles of two recently separated Macrobrachium species: Expression patterns of ion transporter genes.

    Science.gov (United States)

    Boudour-Boucheker, Nesrine; Boulo, Viviane; Charmantier-Daures, Mireille; Anger, Klaus; Charmantier, Guy; Lorin-Nebel, Catherine

    2016-05-01

    In this comparative study, osmoregulatory mechanisms were analyzed in two closely related species of palaemonid shrimp from Brazil, Macrobrachium pantanalense and Macrobrachium amazonicum. A previous investigation showed that all postembryonic stages of M. pantanalense from inland waters of the Pantanal are able to hyper-osmoregulate in fresh water, while this species was not able to hypo-osmoregulate at high salinities. In M. amazonicum originating from the Amazon estuary, in contrast, all stages are able to hypo-osmoregulate, but only first-stage larvae, late juveniles and adults are able to hyper-osmoregulate in fresh water. The underlying molecular mechanisms of these physiological differences have not been known. We therefore investigated the expression patterns of three ion transporters (NKA α-subunit, VHA B-subunit and NHE3) following differential salinity acclimation in different ontogenetic stages (stage-V larvae, juveniles) of both species. Larval NKAα expression was at both salinities significantly higher in M. pantanalense than in M. amazonicum, whereas no difference was noted in juveniles. VHA was also more expressed in larvae of M. pantanalense than in those of M. amazonicum. When NHE3 expression is compared between the larvae of the two species, further salinity-related differences were observed, with generally higher expression in the inland species. Overall, a high expression of ion pumps in M. pantanalense suggests an evolutionary key role of these transporters in freshwater invasion. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Screening of the ‘Open Scaffolds’ collection from Compounds Australia identifies a new chemical entity with anthelmintic activities against different developmental stages of the barber's pole worm and other parasitic nematodes

    Directory of Open Access Journals (Sweden)

    Sarah Preston

    2017-12-01

    Full Text Available The discovery and development of novel anthelmintic classes is essential to sustain the control of socioeconomically important parasitic worms of humans and animals. With the aim of offering novel, lead-like scaffolds for drug discovery, Compounds Australia released the ‘Open Scaffolds’ collection containing 33,999 compounds, with extensive information available on the physicochemical properties of these chemicals. In the present study, we screened 14,464 prioritised compounds from the ‘Open Scaffolds’ collection against the exsheathed third-stage larvae (xL3s of Haemonchus contortus using recently developed whole-organism screening assays. We identified a hit compound, called SN00797439, which was shown to reproducibly reduce xL3 motility by ≥ 70%; this compound induced a characteristic, “coiled” xL3 phenotype (IC50 = 3.46–5.93 μM, inhibited motility of fourth-stage larvae (L4s; IC50 = 0.31–12.5 μM and caused considerable cuticular damage to L4s in vitro. When tested on other parasitic nematodes in vitro, SN00797439 was shown to inhibit (IC50 = 3–50 μM adults of Ancylostoma ceylanicum (hookworm and first-stage larvae of Trichuris muris (whipworm and eventually kill (>90% these stages. Furthermore, this compound completely inhibited the motility of female and male adults of Brugia malayi (50–100 μM as well as microfilariae of both B. malayi and Dirofilaria immitis (heartworm. Overall, these results show that SN00797439 acts against genetically (evolutionarily distant parasitic nematodes i.e. H. contortus and A. ceylanicum [strongyloids] vs. B. malayi and D. immitis [filarioids] vs. T. muris [enoplid], and, thus, might offer a novel, lead-like scaffold for the development of a relatively broad-spectrum anthelmintic. Our future work will focus on assessing the activity of SN00797439 against other pathogens that cause neglected

  2. Localization of neuropeptide gene expression in larvae of an echinoderm, the starfish Asterias rubens

    Directory of Open Access Journals (Sweden)

    Tatiana D Mayorova

    2016-12-01

    Full Text Available Neuropeptides are an ancient class of neuronal signaling molecules that regulate a variety of physiological and behavioral processes in animals. The life cycle of many animals includes a larval stage(s that precedes metamorphic transition to a reproductively active adult stage but, with the exception of Drosophila melanogaster and other insects, research on neuropeptide signaling has hitherto largely focused on adult animals. However, recent advances in genome/transcriptome sequencing have facilitated investigation of neuropeptide expression/function in the larvae of protostomian (e.g. the annelid Platynereis dumerilii and deuterostomian (e.g. the urochordate Ciona intestinalis invertebrates. Accordingly, here we report the first multi-gene investigation of larval neuropeptide precursor expression in a species belonging to the phylum Echinodermata - the starfish Asterias rubens. Whole-mount mRNA in situ hybridization was used to visualize in bipinnaria and brachiolaria stage larvae the expression of eight neuropeptide precursors: L-type SALMFamide (S1, F-type SALMFamide (S2, vasopressin/oxytocin-type, NGFFYamide, thyrotropin-releasing hormone-type, gonadotropin-releasing hormone-type, calcitonin-type and corticotropin-releasing hormone-type. Expression of only three of the precursors (S1, S2, NGFFYamide was observed in bipinnaria larvae but by the brachiolaria stage expression of all eight precursors was detected. An evolutionarily conserved feature of larval nervous systems is the apical organ and in starfish larvae this comprises the bilaterally symmetrical lateral ganglia, but only the S1 and S2 precursors were found to be expressed in these ganglia. A prominent feature of brachiolaria larvae is the attachment complex, comprising the brachia and adhesive disk, which mediates larval attachment to a substratum prior to metamorphosis. Interestingly, all of the neuropeptide precursors examined here are expressed in the attachment complex, with

  3. Localization of Neuropeptide Gene Expression in Larvae of an Echinoderm, the Starfish Asterias rubens.

    Science.gov (United States)

    Mayorova, Tatiana D; Tian, Shi; Cai, Weigang; Semmens, Dean C; Odekunle, Esther A; Zandawala, Meet; Badi, Yusef; Rowe, Matthew L; Egertová, Michaela; Elphick, Maurice R

    2016-01-01

    Neuropeptides are an ancient class of neuronal signaling molecules that regulate a variety of physiological and behavioral processes in animals. The life cycle of many animals includes a larval stage(s) that precedes metamorphic transition to a reproductively active adult stage but, with the exception of Drosophila melanogaster and other insects, research on neuropeptide signaling has hitherto largely focused on adult animals. However, recent advances in genome/transcriptome sequencing have facilitated investigation of neuropeptide expression/function in the larvae of protostomian (e.g., the annelid Platynereis dumerilii ) and deuterostomian (e.g., the urochordate Ciona intestinalis ) invertebrates. Accordingly, here we report the first multi-gene investigation of larval neuropeptide precursor expression in a species belonging to the phylum Echinodermata-the starfish Asterias rubens . Whole-mount mRNA in situ hybridization was used to visualize in bipinnaria and brachiolaria stage larvae the expression of eight neuropeptide precursors: L-type SALMFamide (S1), F-type SALMFamide (S2), vasopressin/oxytocin-type, NGFFYamide, thyrotropin-releasing hormone-type, gonadotropin-releasing hormone-type, calcitonin-type and corticotropin-releasing hormone-type. Expression of only three of the precursors (S1, S2, NGFFYamide) was observed in bipinnaria larvae but by the brachiolaria stage expression of all eight precursors was detected. An evolutionarily conserved feature of larval nervous systems is the apical organ and in starfish larvae this comprises the bilaterally symmetrical lateral ganglia, but only the S1 and S2 precursors were found to be expressed in these ganglia. A prominent feature of brachiolaria larvae is the attachment complex, comprising the brachia and adhesive disk, which mediates larval attachment to a substratum prior to metamorphosis. Interestingly, all of the neuropeptide precursors examined here are expressed in the attachment complex, with distinctive

  4. PEMELIHARAAN LARVA KEPITING BAKAU, Scylla olivacea DENGAN PENAMBAHAN BIOFLOK

    Directory of Open Access Journals (Sweden)

    Gunarto Gunarto

    2014-06-01

    Full Text Available Abstrak lengkap dapat dilihat pada Full PDF   Tujuan penelitian ini adalah untuk mengetahui efek penambahan bioflok pada pemeliharaan larva kepiting bakau Scylla olivacea terutaman pada sintasan dan perkembangan larva hingga mencapai stadia krablet.

  5. 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...... caught larvae had RNA/DNA ratios between the mean values found for starving and fed laboratory larvae. Only larvae aged 8-11 days had higher mean RNA/DNA ratios above 45 m than below (t-test, P...

  6. 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],...

  7. CalCOFI Larvae Counts, Scientific Names CP to DE

    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 OM to OX

    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 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],...

  10. Decapod larvae from the nearshore waters of Karwar

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Paulinose, V.T.

    Abundance of decapod larvae at three stations in Binge Bay, Karwar has been reported based on surface collections taken during the period October 1975 to September 1976. The larvae were very common in the Bay and the postmonsoon months sustained...

  11. 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],...

  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. Low salinity tolerance 0/ eggs and larvae.

    African Journals Online (AJOL)

    the larvae permitting C. krauss; to spread into areas where it is unable to breed successfully. ACKNOWLEDGEMENTS. The author acknowledges the financial assistance of the Department of Nature Conserva- tion of the Cape Province of South Africa, and the South African National Committee for. Oceanographic Research ...

  14. Three cases of L4-5 Baastrup's disease due to L5-S1 spondylolytic spondylolisthesis.

    Science.gov (United States)

    Seo, Jin-Suk; Lee, Sang-Ho; Keum, Han Joong; Eun, Sang Soo

    2017-05-01

    Baastrup's disease is characterized by degeneration of spinous processes and interspinous soft tissue, which may cause spinal stenosis. Purpose of this article is to report the possible new cause of Baastrup's disease and result of surgical treatments. Authors treated three cases of Baastrup's disease on L4-L5 with L5-S1 spondylolytic listhesis. Conservative treatment did not relieve the pain; therefore, surgical treatments were planned according to each specific disease condition. In one case, anterior lumbar interbody fusion of L5-S1 was performed, and after surgery, the size of epidural cyst on L4-L5 was decreased. L4-L5 bilateral laminectomy was performed to directly decompress posterior epidural cyst in a case with stable L5-S1 spondylolytic listhesis. In last case, facet joints and spinous process were removed by L5-S1 posterior lumbar interbody fusion (PLIF) surgery. After the surgery, patients' back and leg pain was improved and postoperative MRI revealed successful decompression of the spinal canal. Improvement in back and leg symptoms was noted at 12-month follow-up. Baastrup's disease at the L4-L5 level may have developed from the instability caused by L5-S1 spondylolytic spondylolisthesis. Viable treatment options include the fusion of L5-S1 or a laminectomy at the L4-L5 level.

  15. Recovery after fracture dislocation of L3/L4 ASIA B: Case report

    Directory of Open Access Journals (Sweden)

    Gustavo Caldera

    2016-02-01

    Full Text Available In fracture dislocations of the lumbar region, two anatomical facts can help preserve neurological damage in patients, when compared with trauma in the cervical or thoracic region. Firstly, the spinal cord in adults extends only to the lower edge of the first lumbar vertebra, and secondly, the large vertebral space in this region gives ample space for the roots of the cauda equine. As a result, the nerve injury may be minimal, because the nerve roots in this region are accommodated in a larger area, with less content and space. This study presents the case of a 48-year-old male, a construction worker, who suffered a fall from a height of approximately 15 meters, directly hitting the lumbar region against a beam, and presenting pain and inability to move the legs. The patient was brought to the emergency room 1 hour after the accident, clinically assessed, submitted to x-rays and a CT scan, and diagnosed as having an ASIA B L3-L4 fracture dislocation. Three hours after the accident, reduction was performed via posterior transpedicular fixation. One week later, an anterior approach was performed. The patient progressed to ASIA C 24 hours after the first surgery. Three months later, the patient was functional with ASIA D and good sphincter control. The author's purpose is to show the results obtained by an intervention in the initial hours of the trauma, which helped promote the evolution from a nonfunctional injury to a functional one, with near-total recovery. Keywords: Spine fracture, Recovery, Neurological deficit, Asia scale, Dislocation

  16. Performance of Anastrepha obliqua (Diptera, Tephritidae larvae fed on artificial diets Desempenho das larvas de Anastrepha obliqua (Diptera, Tephritidae alimentadas com dietas artificiais

    Directory of Open Access Journals (Sweden)

    Tânia M. L. Fontellas-Brandalha

    2010-06-01

    Full Text Available Moscas das frutas do gênero Anastrepha Schiner, 1868 são conhecidas por sua importância econômica devido aos danos que elas causam nos frutos comerciais. As exigências nutricionais dos estágios imaturo e adulto são diferentes e as larvas não se desenvolvem bem utilizando a mesma dieta do adulto. Embora as necessidades nutricionais básicas dos insetos sejam bem conhecidas, existe ainda o problema de elaborar dietas de criação adequadas para espécies com necessidades específicas. O objetivo deste trabalho foi verificar o efeito de diferentes tipos e quantidades de carboidratos na dieta sobre a performance larval de Anastrepha obliqua (Macquart, 1835. Larvas foram criadas individualmente em tubos de ensaio contendo uma das dietas artificiais a serem testadas onde elas foram mantidas até a pupação. A composição básica das dietas testadas incluia 2,5 g de agar, 3,25 g de levedo de cerveja e quantidades variadas de sacarose e farinha de trigo. A adequação do meio artificial para A. obliqua foi testada pela avaliação da sobrevivência larval e pupal (% e o tempo de desenvolvimento larval, pupal e de larva-adulto. A dieta contendo farinha de trigo (2 g e sacarose (2 g e a dieta somente com sacarose (5,5 g foram as que apresentaram melhor performance larval. Todas as dietas testadas apresentaram resultados similares ou superiores às dietas utilizadas em outros trabalhos. A importância da presença da farinha de trigo e seu valor nutricional para as larvas são discutidos.Fruit flies of the genus Anastrepha Schiner, 1868 are well-known for having economical importance since they damage commercially cultivated fruits. Nutritional demands during the immature and adult stages are different, so the larvae do not develop well using the same diet as the adults. Although the insect basic nutritional needs are well-known, there is also the challenge to elaborate rearing diets adequate to species with specific needs. The aim of this study

  17. 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.

  18. A comparison of honeybee (Apis mellifera) queen, worker and drone larvae by RNA-Seq.

    Science.gov (United States)

    He, Xu-Jiang; Jiang, Wu-Jun; Zhou, Mi; Barron, Andrew B; Zeng, Zhi-Jiang

    2017-11-06

    Honeybees (Apis mellifera) have haplodiploid sex determination: males develop from unfertilized eggs and females develop from fertilized ones. The differences in larval food also determine the development of females. Here we compared the total somatic gene expression profiles of 2-day and 4-day-old drone, queen and worker larvae by RNA-Seq. The results from a co-expression network analysis on all expressed genes showed that 2-day-old drone and worker larvae were closer in gene expression profiles than 2-day-old queen larvae. This indicated that for young larvae (2-day-old) environmental factors such as larval diet have a greater effect on gene expression profiles than ploidy or sex determination. Drones had the most distinct gene expression profiles at the 4-day larval stage, suggesting that haploidy, or sex dramatically affects the gene expression of honeybee larvae. Drone larvae showed fewer differences in gene expression profiles at the 2-day and 4-day time points than the worker and queen larval comparisons (598 against 1190 and 1181), suggesting a different pattern of gene expression regulation during the larval development of haploid males compared to diploid females. This study indicates that early in development the queen caste has the most distinct gene expression profile, perhaps reflecting the very rapid growth and morphological specialization of this caste compared to workers and drones. Later in development the haploid male drones have the most distinct gene expression profile, perhaps reflecting the influence of ploidy or sex determination on gene expression. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  19. Laboratory evolution of the entomopathogenic fungus Beauveria bassiana against Anopheles stephensi larvae (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Rahele Veys-Behbahani

    2014-09-01

    Full Text Available Objective: To examine Beauveria bassiana (B. bassiana fungus bioassay against the larval stages of Anopheles stephensi in Iran. Methods: The fungal suspension by the concentrations of 1伊1 09, 5伊1 08, 1 08, 5伊1 07 and 1伊 107 conidia per milliliter have been prepared in different volumes (2, 4 and 6 mL and each concentration were added to containers containing 25 Anopheles larva instars 1 and 2. The mortality of the dead larvae with abnormal symptoms was recorded as a result of the fungal infection after 24, 48 and 72 h. Results: Comparison between the mean mortality rate of Anopheles stephensi larva at different concentrations of B. bassiana strain Iran 429C at 2, 4 and 6 mL showed that there was no significant relation of the mean mortality rate of larvae at concentrations of 1伊109 and 5伊108, and after 48 h resulted in 100% mortality rate of the larvae populations. In addition, there is no significant differences in the amounts of lethal times (LT (LT50 and LT90 as LT90 values calculated at a concentration of 5伊108 and in volumes 2, 4 and 6 mL were 1.46, 1.36 and 1.08 d, respectively. Conclusions: B. bassiana strain Iran 429C in 2 mL of 5伊108 concentration or the concentration of a 1伊109 mL per 100 mL of water is recommended as the optimal concentration for the control of Anopheles larvae. The development of suitable formulations of entomopathogenic fungi may be a promising prospect in the mosquito control programs.

  20. Feeding frequency and caste differentiation in Bombus terrestris larvae

    NARCIS (Netherlands)

    Ribeiro, M.F.; Velthuis, H.H.W.; Duchateau, Marie José; Tweel, I. van der

    1998-01-01

    The frequency with which bumble bee larvae are fed during their development was studied using video-recordings. The behaviour of the workers while feeding worker, male and queen larvae of Bombus terrestris was recorded. At the beginning of development, female larvae of both castes were fed at a

  1. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Prakash

    with electric shock in normal and mutant larvae and Tully et al. reported the passage of olfactory ... Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of ..... Pairing odour with shock drives the larvae to the opposite zone. Preference learning index PLI.

  2. THE CORRELATION DEPENDENCE OF THE CLINICAL AND MORPHOLOGICAL MANIFESTATIONS AND BIOMECHANICAL PARAMETERS IN PATIENTS WITH DEGENERATIVE SPONDYLOLISTHESIS L4 VERTEBRA

    Directory of Open Access Journals (Sweden)

    A. V. Krut’Ko

    2011-01-01

    Full Text Available The study included 59 operated patients with spondylolisthesis L4 vertebra of I degree. All the patients were held clinical-anamnestic, neurological, radiological, radiopaque and biomechanical studies, MRI, CT, as well as puncture performed provocative tests. Revealed correlation of clinical manifestations of degenerative spondylolisthesis L4 and biomechanical parameters of the shape and orientation of the lumbar spine. The most pronounced clinical and morphological changes detected at the level of spondylolisthesis and adjacent segments in the group with hyperlordosis and excessive tilt angle of the chord forward, which is confirmed by MRI, CT, and carried out a disco-puncture provocative tests. A variety of pathological changes of the lumbar spine at L4 vertebra degenerative spondylolisthesis correlated with the biomechanical parameters violation of the shape and orientation of the spine in the sagittal plane.

  3. 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. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  4. Respon Imun Spesifik Larva Ikan Mas (Cyprinus carpio melalui Imunitas Maternal yang Diberi Vaksin Inaktif Whole Cell Aeromonas salmonicida

    Directory of Open Access Journals (Sweden)

    Syohibahttul Islamiyah BAHAR

    2017-02-01

    Full Text Available Aeromonas salmonicida are specific bacteria that can cause infections and death to the cultivation of carp (Cyprinus carpio during larval stage. Death in carp can be prevented by a vaccine, but the vaccine can only be given on the seed over the age of 3 weeks. Maternal vaccination needs to be done to improve the immune system of the larvae by means of inactivated whole cell vaccine A. salmonicida on broodstock ready to spawn. Aims to determine the effectiveness of vaccines on breeders carp to the parent antibody titer test and larvae, as well Survival Rate (SR and the Relative Percent Survival (RPS larvae. This research was conducted with a completely randomized design, 4 treatments A (control; B (0.3 ml/kg; C (0.4 ml/kg; D (0.5 ml/kg and 3 repetitions. The results show that the antibody titer of 0.3 ml dose capable of providing agglutination reaction to pitting 7th (64x dilution in broodstock, and vaccine doses 0,4ml on broodstock able to give agglutination reaction to the larvae until all 6 wells (32x dilution. A dose of 0.4 ml/kg resulted the highest SR and RPS with 96.11% and 81.25% respectively. Clinical symptoms of redness in control larvae was spread throughout the body whereas on the vaccine treatment was only in certain body parts. Keywords: A. salmonicida, vaccines, maternal immunity, larva, specific immune respon

  5. Lipid metabolism-related gene expression pattern of Atlantic bluefin tuna (Thunnus thynnus L.) larvae fed on live prey.

    Science.gov (United States)

    Betancor, Mónica B; Ortega, Aurelio; de la Gándara, Fernando; Tocher, Douglas R; Mourente, Gabriel

    2017-04-01

    The present study is the first to evaluate lipid metabolism in first-feeding Atlantic bluefin tuna (ABT; Thunnus thynnus L.) larvae fed different live prey including enriched rotifers Brachionus plicatilis and Acartia sp. copepod nauplii from 2 days after hatch. Understanding the molecular basis of lipid metabolism and regulation in ABT will provide insights to optimize diet formulations for this high-value species new to aquaculture. To this end, we investigated the effect of dietary lipid on whole larvae lipid class and fatty acid compositions and the expression of key genes involved in lipid metabolism in first feeding ABT larvae fed different live prey. Additionally, the expression of lipid metabolism genes in tissues of adult broodstock ABT was evaluated. Growth and survival data indicated that copepods were the best live prey for first feeding ABT and that differences in growth performance and lipid metabolism observed between larvae from different year classes could be a consequence of broodstock nutrition. In addition, expression patterns of lipid metabolic genes observed in ABT larvae in the trials could reflect differences in lipid class and fatty acid compositions of the live prey. The lipid nutritional requirements, including essential fatty acid requirements of larval ABT during the early feeding stages, are unknown, and the present study represents a first step in addressing these highly relevant issues. However, further studies are required to determine nutritional requirements and understand lipid metabolism during development of ABT larvae and to apply the knowledge to the commercial culture of this iconic species.

  6. Histopathology of experimental myiasis in mice as a result of infestation and experimental implantation of Dermatobia hominis larvae.

    Science.gov (United States)

    Leite, A C R; Nascimento, M F A; Leite, L H R; Leite, V H R

    2011-05-01

    A laboratory model of myiasis as a result of Dermatobia hominis (L.) larvae was developed using mice as hosts. Mice in three groups were each infested with one newly hatched larva and skin biopsies processed for histopathology at 4, 12, and 20 d postinfestation (dpi). Mice in three other groups were each subjected to implantation of one larva collected from an infested (donor) mouse at 4, 12, and 20 dpi. Skin lesions of these receptor mice were then assessed at 10, 14, and 6 d postimplantation (dpimp), respectively. The inflammatory process in infested mice at 4 dpi was discrete, consisting of a thin necrotic layer around the larva, edema, many neutrophils, few eosinophils, mast cells, and proliferation of fibroblasts. At 12 dpi, there was a thicker necrotic layer, edema, many neutrophils and eosinophils, few mast cells, neoformation of capillaries, proliferation of the endothelium and fibroblasts, and early stages of fibrosis. These histopathological characteristics together with fibrosis were observed over a large area of the lesion at 20 dpi. Mice submitted to larval implantations demonstrated similar skin histopathology to that seen in the infested rodents, 10 dpimp corresponding to 12 dpi and 6 or 14 dpimp to 20 dpi. In all mice, the progressive acute inflammatory process followed a sequence linked to factors such as size of larvae and presence of secretory-excretory products. Both infested mice and those implanted experimentally with D. hominis larvae were shown to be suitable models for the study of the parasite-host relationship in this important zoonotic myiasis.

  7. [A comparative study of three methods in detecting Angiostrongylus cantonensis larvae in lung tissue of Pomacea canaliculata].

    Science.gov (United States)

    Liu, He-Xiang; Zhang, Yi; Lv, Shan; Zhu, Dan; Ang, Xian-Hong; Hu, Ling; Zhou, Xiao-Nong

    2007-02-28

    To compare the efficiency of three methods, lung-microscopy, tissue homogenate and enzyme digestion in the detection of Angiostrongylus cantonensis larvae from the lungs of snails. 60 Pomacea canalicular infected by the first-stage larvae of A. cantonensis were divided into 2 groups and the lung of each snail from the two groups was separated from the soft body. All the lungs were examined under microscope and larval nodes were counted. Each lung from one group was ground and that from the other was artificially digested by enzyme, the number of larvae in each lung was recorded. The efficiency of three methods was compared. Enzyme digestion was also used to estimate number of larvae in lung and in other body parts. By using enzyme digestion as the standard method, the detection rate of lung-microscopy, tissue homogenate and enzyme digestion was 96.7%, 93.4% and 100% respectively (chi2=2.069, P>0.05), while the lung-microscopy was significantly faster (Z=4.782, P<0.01). The number of larvae in snail lung was positively correlated with that in other part (r=0.847, P<0.01). The lung-microscopy in larvae detection is similarly efficient to the other two methods but faster, which is therefore more suitable for snail screening in the field.

  8. Stage design

    International Nuclear Information System (INIS)

    Shacter, J.

    1975-01-01

    A method is described of cycling gases through a plurality of diffusion stages comprising the steps of admitting the diffused gases from a first diffusion stage into an axial compressor, simultaneously admitting the undiffused gases from a second diffusion stage into an intermediate pressure zone of said compressor corresponding in pressure to the pressure of said undiffused gases, and then admitting the resulting compressed mixture of diffused and undiffused gases into a third diffusion stage

  9. A systems biology approach to the characterization of stress response in Dermacentor reticulatus tick unfed larvae.

    Directory of Open Access Journals (Sweden)

    Margarita Villar

    Full Text Available BACKGROUND: Dermacentor reticulatus (Fabricius, 1794 is distributed in Europe and Asia where it infests and transmits disease-causing pathogens to humans, pets and other domestic and wild animals. However, despite its role as a vector of emerging or re-emerging diseases, very little information is available on the genome, transcriptome and proteome of D. reticulatus. Tick larvae are the first developmental stage to infest hosts, acquire infection and transmit pathogens that are transovarially transmitted and are exposed to extremely stressing conditions. In this study, we used a systems biology approach to get an insight into the mechanisms active in D. reticulatus unfed larvae, with special emphasis on stress response. PRINCIPAL FINDINGS: The results support the use of paired end RNA sequencing and proteomics informed by transcriptomics (PIT for the analysis of transcriptomics and proteomics data, particularly for organisms such as D. reticulatus with little sequence information available. The results showed that metabolic and cellular processes involved in protein synthesis were the most active in D. reticulatus unfed larvae, suggesting that ticks are very active during this life stage. The stress response was activated in D. reticulatus unfed larvae and a Rickettsia sp. similar to R. raoultii was identified in these ticks. SIGNIFICANCE: The activation of stress responses in D. reticulatus unfed larvae likely counteracts the negative effect of temperature and other stress conditions such as Rickettsia infection and favors tick adaptation to environmental conditions to increase tick survival. These results show mechanisms that have evolved in D. reticulatus ticks to survive under stress conditions and suggest that these mechanisms are conserved across hard tick species. Targeting some of these proteins by vaccination may increase tick susceptibility to natural stress conditions, which in turn reduce tick survival and reproduction, thus reducing

  10. Perkembangan dan Kandungan Nutrisi Larva Hermetia illucens (Linnaeus (Diptera: Stratiomyidae pada Bungkil Kelapa Sawit

    Directory of Open Access Journals (Sweden)

    RACHMAWATI RACHMAWATI

    2015-09-01

    Full Text Available Hermetia illucens, is used as a reducing agent of palm kernel meal (PKM, as well as one of alternative protein sources for aquaculture purposes. Information about biology of H. illucens is absolutely required in mass production. The objectives of these researches were to study the development of H. illucens including the effect of supplementary food to the adult, and nutrient content of the immature stage. The sample of 20 larvae from each 3 replicates were measured and weighed on 0-19th day (larva and 24th day (pupa from egg hatching. H. illucens adults were fed by water and honey 5% (v/v. Eggs were collected and counted. Nutrient content of immature stage: 5, 10, 15, 20 days old (larvae, and 25 days old (prepupae reared on PKM were analyzed proximately. Dry matter was determined by weight loss on drying at 105 oC during overnight. Crude protein was determined by Kjeldahl procedure (N x 6.25, crude fat by soxhlet (ether extract, crude ash by determining the residue after heating at 550 oC for 4–5 h. Data were analyzed descriptively by average from triplicate. The development of H. illucens was shorter than those in previous studies as the differences of abiotical factor. PKM was a suitable medium for development. It was better, however, to fed the adult with honey since it could enhance the fecundity. The young larva certainly contained the best quality of nutrition. To meet the quantity of mass production, however, the use of the elder larva (bigger was suggested.

  11. Black flies (Diptera : Simuliidae attracted to humans and water buffalos and natural infections with filarial larvae, probably Onchocerca sp., in northern Thailand

    Directory of Open Access Journals (Sweden)

    Takaoka H.

    2003-03-01

    Full Text Available Several Simulium species were investigated as to their biting habits and natural infections with filarial larvae at Ban Pan Fan, Chiang Mai Province, in northern Thailand. Female adults flies landing on or flighting around a human and a water buffalo were collected during the daytime from 06.00 to 19.00 hours on 22 June 2001. As a result, 217 S. nodosum, 86 S. asakoae and two S. nigrogilvum were obtained from a human attractant, and 416 S. nodosum, 25 S. nakhonense, 16 S. asakoae, four 5. fenestratum and two S. nigrogilvum, from a water buffalo. The blood-feeding was confirmed only for S. nodosum and S. nigrogilvum on humans, and for S. nodosum and S. nakhonense on water buffalos. Dissections of these simuliids showed that S. nodosum was naturally infected with developing filarial larvae. Two types of microfilariae were distinguished but only one type of infective larvae. These larvae resembled Onchocerca suzukii, a parasite from a wild Japanese bovid, suggesting that an unknown Onchocerca species from ruminants was transmitted in Thailand. Infection rates with all stages of larvae and third-stage larvae were 2.3 % (14/608 and 1 .0 % (6/608, respectively. This is the first report of natural infections of black flies with Onchocerca larvae in Southeast Asia, and the involved black fly species is shown to be not only anthropophilic but also zoophilic in this region.

  12. The lethal giant larvae Gene in Tribolium castaneum: Molecular Properties and Roles in Larval and Pupal Development as Revealed by RNA Interference

    Directory of Open Access Journals (Sweden)

    Da Xiao

    2014-04-01

    Full Text Available We identified and characterized the TcLgl gene putatively encoding lethal giant larvae (Lgl protein from the red flour beetle (Tribolium castaneum. Analyses of developmental stage and tissue-specific expression patterns revealed that TcLgl was constitutively expressed. To examine the role of TcLgl in insect development, RNA interference was performed in early (1-day larvae, late (20-day larvae, and early (1-day pupae. The early larvae injected with double-stranded RNA of TcLgl (dsTcLgl at 100, 200, and 400 ng/larva failed to pupate, and 100% mortality was achieved within 20 days after the injection or before the pupation. The late larvae injected with dsTcLgl at these doses reduced the pupation rates to only 50.3%, 36.0%, and 18.2%, respectively. The un-pupated larvae gradually died after one week, and visually unaffected pupae failed to emerge into adults and died during the pupal stage. Similarly, when early pupae were injected with dsTcLgl at these doses, the normal eclosion rates were reduced to only 22.5%, 18.0%, and 11.2%, respectively, on day 7 after the injection, and all the adults with abnormal eclosion died in two days after the eclosion. These results indicate that TcLgl plays an essential role in insect development, especially during their metamorphosis.

  13. The Effects of Temperature and Innate Immunity on Transmission of Campylobacter jejuni (Campylobacterales: Campylobacteraceae) Between Life Stages of Musca domestica (Diptera: Muscidae)

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Gill, C.; Lowenberger, C.

    2014-01-01

    jejuni (Jones) could be transferred between life stages of M. domestica (larvae-pupae-adults) and determined bacterial counts of C. jejuni at different time points after bacterial exposure. C. jejuni was transmitted from infected larvae to pupae, but not to the adult stage. Infected larvae maintained....../g), and these numbers dropped to 4.8 +/- 0.1 SE log(10) (CFU/g) 24 h after pupation. The decline in C. jejuni numbers during pupal development coincided with increased expression of antimicrobial peptides, including cecropin, diptericin, attacin, and defensin, in the larva-pupa transition stage and a later second peak...

  14. Análise da dieta das larvas de 4º estádio de Cricotopus sp. (Diptera: Chironomidae, em diferentes substratos artificiais e fases hídricas, no trecho superior do rio Paraná - DOI: 10.4025/actascibiolsci.v31i4.3522 Diet analysis of Cricotopus sp. larvae (Diptera: Chironomidae, fourth stage, in different artificial substrates and hydrological phases, in the upper Paraná river - DOI: 10.4025/actascibiolsci.v31i4.3522

    Directory of Open Access Journals (Sweden)

    Alice Michiyo Takeda

    2009-08-01

    Full Text Available No Brasil, estudos sobre hábitos alimentares das larvas de Chironomidae ainda são escassos e estas informações são importantes para entender a estrutura trófica e a organização dos ecossistemas aquáticos. Neste estudo, teve-se como objetivo identificar os principais itens alimentares ingeridos por Cricotopus sp. e comparar as possíveis diferenças na dieta das larvas em diferentes substratos artificiais e fases hídricas. Foram utilizados quatro tipos de substratos artificiais: madeira em forma de X (MADX, placas de nitacetal em forma de X (NITX, PVC em forma de tubo (PVCT e metal galvanizado em forma de tubo (METT, cada um com três réplicas. As coletas foram realizadas quinzenalmente, entre os meses de agosto de 2004 e dezembro de 2005. A dieta de Cricotopus sp. foi constituída por detritos, algas e hifas de fungos. Detrito foi o principal item alimentar, com valores superiores a 50% do total consumido. Os resultados indicaram que Cricotopus sp. é uma espécie coletora e, independentemente do substrato, as larvas alimentam-se dos recursos disponíveis no ambiente. Entretanto, mudanças no regime hidrológico do rio Paraná podem influenciar a disponibilidade de alimento, principalmente algumas diatomaceas como Melosira sp., consumidas em maior quantidade apenas na fase de águas baixasIn Brazil, studies on the diet of Chironomidae larvae are still scarce and these data are important to understand the trophic structure and organization of aquatic ecosystems. In this study, we identified the main food items consumed by Cricotopus sp. and compared possible differences in the larval diet at different artificial substrates and hydrological phases. We used four types of artificial substrates: X-shaped wood (MADX; X-shaped nitacetal plates (NITX; tube-shaped PVC (PVCT and tube-shaped galvanized metal (METT, each with three replicates. Samplings were undertaken fortnightly, between August 2004 and December 2005. Cricotopus sp. diet was

  15. Neuromuscular development in Novocrania anomala: evidence for the presence of serotonin and a spiralian-like apical organ in lecithotrophic brachiopod larvae

    DEFF Research Database (Denmark)

    Altenburger, Andreas; Wanninger, Andreas Wilhelm Georg

    2010-01-01

    in the craniiform (inarticulate) brachiopod Novocrania anomala. Larvae of this species are lecithotrophic and have a bilobed body with three pairs of dorsal setal bundles that emerge from the posterior lobe. Fully developed larvae exhibit a network of setae pouch muscles as well as medioventral longitudinal...... stages. In the juveniles, the nervous system stained by a-tubulin is characterized by two ventral neurite bundles with three commissures. Our data are the first direct proof for the presence of an immunoreactive neurotransmitter in lecithotrophic brachiopod larvae and demonstrate the existence of flask...

  16. Efficacy of acaricides against larvae of Rhipicephalus sanguineus (Latreille, 1806 (Acari: Ixodidae and Rhipicephalus (Boophilus microplus (Canestrini, 1887 (Acari: Ixodidae

    Directory of Open Access Journals (Sweden)

    Luciano Melo de Souza

    2017-02-01

    Full Text Available Parasitism by mites has always been of concern with regard to losses in animal production and to the transmission of etiologic agents of important diseases as well, and about 95% of the developing forms of ticks in the non-parasitic phase are in the environment. In view of the importance of controlling larval stages of ticks in the environment, this study evaluated the efficacy of acaricides in vitro against larvae of Rhipicephalus (B. microplus and R. sanguineus. Accordingly, we tested: 15% cypermethrin (T1; 25% deltamethrin (T2; combination of cypermethrin 5% + 45% dichlorvos + 25% piperonyl butoxide (T3; combination of 15% cypermethrin + 25% chlorpyrifos + 1% citronella (T4; and 12.5% amitraz (T5. In each treatment, there were nine replicates with 20 larvae each. The larvae were observed for motility at: 1, 5, 10, 20 and 30 minutes post-treatment (MPT; 1, 2, 6, 12 and 24 hours post-treatment (HPT; and 5 days post-treatment. Tests in R. (B. microplus and R. sanguineus larvae with 25% deltamethrin served as a positive control and demonstrated 100% loss of motility at 2 HPT for both tick species. R. (B. microplus larvae were most sensitive to treatments containing 15% cypermethrin or 5% cypermethrin combined with dichlorvos and piperonyl butoxide. Larvae of R. sanguineus were most sensitive to treatment with 12.5% amitraz. However, despite the differences in acaricidal effect during the observation time, 100% efficacy was obtained for all treatments against larvae of R. sanguineus and R. (B. microplus at 12 HPT, demonstrating that appropriate doses of commercial acaricides can be effective in environmental control strategies against tick larvae.

  17. Testing pollen of single and stacked insect-resistant Bt-maize on in vitro reared honey bee larvae.

    Directory of Open Access Journals (Sweden)

    Harmen P Hendriksma

    Full Text Available The ecologically and economic important honey bee (Apis mellifera is a key non-target arthropod species in environmental risk assessment (ERA of genetically modified (GM crops. Honey bee larvae are directly exposed to transgenic products by the consumption of GM pollen. But most ERA studies only consider responses of adult bees, although Bt-proteins primarily affect the larval phases of target organisms. We adopted an in vitro larvae rearing system, to assess lethal and sublethal effects of Bt-pollen consumption in a standardized eco-toxicological bioassay. The effects of pollen from two Bt-maize cultivars, one expressing a single and the other a total of three Bt-proteins, on the survival and prepupae weight of honey bee larvae were analyzed. The control treatments included pollen from three non-transgenic maize varieties and of Heliconia rostrata. Three days old larvae were fed the realistic exposure dose of 2 mg pollen within the semi-artificial diet. The larvae were monitored over 120 h, until the prepupal stage, where larvae terminate feeding and growing. Neither single nor stacked Bt-maize pollen showed an adverse effect on larval survival and the prepupal weight. In contrast, feeding of H. rostrata pollen caused significant toxic effects. The results of this study indicate that pollen of the tested Bt-varieties does not harm the development of in vitro reared A. mellifera larvae. To sustain the ecosystem service of pollination, Bt-impact on A. mellifera should always be a crucial part of regulatory biosafety assessments. We suggest that our approach of feeding GM pollen on in vitro reared honey bee larvae is well suited of becoming a standard bioassay in regulatory risk assessments schemes of GM crops.

  18. Testing pollen of single and stacked insect-resistant Bt-maize on in vitro reared honey bee larvae.

    Science.gov (United States)

    Hendriksma, Harmen P; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2011-01-01

    The ecologically and economic important honey bee (Apis mellifera) is a key non-target arthropod species in environmental risk assessment (ERA) of genetically modified (GM) crops. Honey bee larvae are directly exposed to transgenic products by the consumption of GM pollen. But most ERA studies only consider responses of adult bees, although Bt-proteins primarily affect the larval phases of target organisms. We adopted an in vitro larvae rearing system, to assess lethal and sublethal effects of Bt-pollen consumption in a standardized eco-toxicological bioassay. The effects of pollen from two Bt-maize cultivars, one expressing a single and the other a total of three Bt-proteins, on the survival and prepupae weight of honey bee larvae were analyzed. The control treatments included pollen from three non-transgenic maize varieties and of Heliconia rostrata. Three days old larvae were fed the realistic exposure dose of 2 mg pollen within the semi-artificial diet. The larvae were monitored over 120 h, until the prepupal stage, where larvae terminate feeding and growing. Neither single nor stacked Bt-maize pollen showed an adverse effect on larval survival and the prepupal weight. In contrast, feeding of H. rostrata pollen caused significant toxic effects. The results of this study indicate that pollen of the tested Bt-varieties does not harm the development of in vitro reared A. mellifera larvae. To sustain the ecosystem service of pollination, Bt-impact on A. mellifera should always be a crucial part of regulatory biosafety assessments. We suggest that our approach of feeding GM pollen on in vitro reared honey bee larvae is well suited of becoming a standard bioassay in regulatory risk assessments schemes of GM crops.

  19. Effects of warming rate, acclimation temperature and ontogeny on the critical thermal maximum of temperate marine fish larvae.

    Science.gov (United States)

    Moyano, Marta; Candebat, Caroline; Ruhbaum, Yannick; Álvarez-Fernández, Santiago; Claireaux, Guy; Zambonino-Infante, José-Luis; Peck, Myron A

    2017-01-01

    Most of the thermal tolerance studies on fish have been performed on juveniles and adults, whereas limited information is available for larvae, a stage which may have a particularly narrow range in tolerable temperatures. Moreover, previous studies on thermal limits for marine and freshwater fish larvae (53 studies reviewed here) applied a wide range of methodologies (e.g. the static or dynamic method, different exposure times), making it challenging to compare across taxa. We measured the Critical Thermal Maximum (CTmax) of Atlantic herring (Clupea harengus) and European seabass (Dicentrarchus labrax) larvae using the dynamic method (ramping assay) and assessed the effect of warming rate (0.5 to 9°C h-1) and acclimation temperature. The larvae of herring had a lower CTmax (lowest and highest values among 222 individual larvae, 13.1-27.0°C) than seabass (lowest and highest values among 90 individual larvae, 24.2-34.3°C). At faster rates of warming, larval CTmax significantly increased in herring, whereas no effect was observed in seabass. Higher acclimation temperatures led to higher CTmax in herring larvae (2.7 ± 0.9°C increase) with increases more pronounced at lower warming rates. Pre-trials testing the effects of warming rate are recommended. Our results for these two temperate marine fishes suggest using a warming rate of 3-6°C h-1: CTmax is highest in trials of relatively short duration, as has been suggested for larger fish. Additionally, time-dependent thermal tolerance was observed in herring larvae, where a difference of up to 8°C was observed in the upper thermal limit between a 0.5- or 24-h exposure to temperatures >18°C. The present study constitutes a first step towards a standard protocol for measuring thermal tolerance in larval fish.

  20. Nutritional Value of Pupae Versus Larvae of Tenebrio molitor (Coleoptera: Tenebrionidae) as Food for Rearing Podisus maculiventris (Heteroptera: Pentatomidae).

    Science.gov (United States)

    Morales-Ramos, Juan A; Rojas, M Guadalupe; Shelby, Kent S; Coudron, Thomas A

    2016-04-01

    Life-table analysis yielded demographic parameter values that indicate that Tenebrio molitor (L.) pupae are potentially more suitable factitious prey to mass-produce the predator Podisus maculiventris (Say) and are more suitable prey than the larvae. P. maculiventris developed faster (23.2 vs. 25.5 d), weighed more (females 80.9 vs. 66.6 mg and males 64.7 vs. 53.7 mg), and had a higher survival rate (0.88 vs. 0.7), fecundity, and reproductive output (87.1 vs. 22.8 eggs/female) when reared on pupae compared with larvae of T. molitor. The total protein content and soluble protein content were significantly higher in pupae (60.2 and 23%, respectively) than larvae (53.1 and 14.4%, respectively). Lipid content was significantly lower in pupae (32.1%) than larvae (35.9%), and larvae had more polyunsaturated fatty acids (83.6 vs. 56.6 mg/g) and less oleic (0.1 mg/g) and steric (6.1 mg/g) acids than pupae (37.3 and 12.3 mg/g, respectively). The total sugar content was not significantly different between pupae and larvae. However, larvae had significantly more fructose than pupae, but pupae had more galactose, glucosamine, glucose, mannose, and trehalose than larvae. Differences in nutritional composition and its impact on predator demographic parameters are potential factors that make the pupal stage a better food source.

  1. Resistance test at early larval stage of blue swimming crab, Portunus pelagicus

    Directory of Open Access Journals (Sweden)

    Mhd Ikhwanuddin

    2016-02-01

    Full Text Available The early larval stage is the crucial phase in the larviculture of blue swimming crab, Portunus pelagicus. The combination of stress resistance tests have been done to determine the maximum period of starvation and dissolved oxygen, the preferable range of temperature, salinity, pH and ammonia for P. pelagicus larvae survival at early larval stages. Larvae were exposed to various treatments as mentioned above to examine larvae competency against the stressor. In starvation test, at 12 hours, more than 50 percent of larvae were observed dead. While in the dissolved oxygen test, no larvae survived more than 6 hours without aeration treatment. The optimum temperature for larvae was 30C due to high survival rate (43.18% was found in the end of experiment. There were no larvae survival at salinity level 0 ppt, 10 ppt and 50 ppt respectively. The highest larvae survival was found at 30 ppt treatment (60.51%. The suitable pH for larval rearing condition was ranged from 8.0-8.2 (survival rate were 48.60% and 70.47%, respectively owing to larval survival rate in others treatments were very low. In the last experiment, lower concentration of ammonia treatments (0.02, 0.2 ppm showed higher survival rate (58.54% and 23.90% whereas the larvae in 2 ppm and 20 ppm treatments died with 24 hours and 6 hours after spike.

  2. A key to larvae of species belonging to the genus Diamesa from Alps and Apennines (Italy

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    Bruno Rossaro

    2015-07-01

    Full Text Available A key to species belonging to the genus Diamesa Meigen, 1835 (Diptera, Chironomidae from the Alps and Apennines (Italy is presented using characters observable in the fourth-instar larva. The larvae are separated on the basis of qualitative and quantitative characters. At present fifteen species from the Italian Alps are described in all three life stages, but only twelve species groups can be separated as larvae. The separation is based on the length and thickness of anal setae, antennal ratio, head capsule color and few other characters of the labrum and mentum. The shape of mental and mandibular teeth is still a valid taxonomic character, but unfortunately these characters can be rarely used because teeth are often excessively worn in samples collected in the field. Quantitative characters show variability within each species, differing according to the duration of larval development and must be used with caution. The species groups which can be separated in the larval stage are: the dampfi group, which includes D. dampfi and D. permacra, the latitarsis group including D. modesta and D. latitarsis, the zernyi group including D. zernyi and D. vaillanti. The species within each of these groups at present cannot be separated. D. starmachi, D. steinboecki, D. goetghebueri, D. bertrami, D. aberrata, D. incallida, D. cinerella, D. tonsa and D. insignipes can be separated from all the other known species in larval stage.

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

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    Sergio Cházaro-Olvera

    2018-03-01

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

  4. Larvae of Contracaecum sp. (Nematoda: Anisakidae) in the threatened freshwater fish Sandelia capensis (Anabantidae) in South Africa

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; van Rensburg, C.J.; Van As, L. L.

    2016-01-01

    Roč. 120, č. 3 (2016), s. 251-254 ISSN 0177-5103 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : parasitic nematode * third-stage larva * paratenic host * endangered fish species * Africa Subject RIV: EG - Zoology Impact factor: 1.549, year: 2016

  5. Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Helicoverpa armigera (Lepidoptera: Noctuidae): effect of prey and predator stages

    DEFF Research Database (Denmark)

    Hassanpour, Mehdi; Mohaghegh, Jafar; Iranipour, Shahzad

    2011-01-01

    Understanding predator–prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea (Stephens), preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa...... armigera Hübner. The first and second instar larvae of C. carnea exhibited type II functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a type III functional response to the eggs....... For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate...

  6. 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.

  7. Ingestion of bacteria by cod (Gadus morhua L.) larvae. In: The propagation of cod Gadus morhua L.: an international symposium, Arendal, 14 - 17 June 1983

    OpenAIRE

    Olafsen, Jan A.

    1984-01-01

    The uptake of Rhodamine-labelled bacteria by cod larvae was demonstrated using a fluorescent microscopy technique, which allowed a quick estimate of bacterial uptake and gut clearance. Live or heat-killed bacteria, isolated from cod-eggs, were rapidly ingested by larvae at yolk-sac and older stages. A substantial uptake could be seen after 15 min exposure, and eventually the bacteria became densely packed in the digestive tract. Some morphological details in the develo...

  8. A study of the life history of brazilian sardine, Sardinella brasiliensis.: III. development of sardine larvae

    Directory of Open Access Journals (Sweden)

    Yasunobu Matsuura

    1975-01-01

    Full Text Available Larvae and juveniles of S. brasiliensis (Steindachner, 1879, ranging from 6.4 mm to 35.5 mm, were identified from plankton samples taken in waters off the southern Brazilian coast from 1969 through 1971. Changes in the pattern of pigmentation, body proportions and formation of fin rays are described. During transformation stage a considerable advancement of the dorsal and anal fins was observed. Changes in body proportions are pronounced at the size of 19 mm. Complete ossification of all fin rays is attained at the size of 20 mm, but ossification of the ventral scutes is delayed and completed only at the size of 30 mm. Ossification of the vertebral column was completed at the size of about 16 mm.O presente trabalho é parte do projeto SOL e tem por objetivo descrever a morfologia das larvas da sardinha verdadeira, Sardinella brasiliensis (=S. aurita, com o intuito de determinar um padrão que possibilite a identificação das mesmas. São feitas considerações sobre a morfologia das larvas de outros clupeídeos existentes na região e ressaltadas as diferenças com relação as larvas de S. brasiliensis. Os resultados, posteriormente, serão usados como base para o estudo quantitativo da abundância de larvas de sardinha. O material foi coletado na costa sul do Brasil de 1969 a 1971, com uma rede de plâncton do tipo cônico-cilíndrico. Durante o desenvolvimento das larvas, foi observado um considerável deslocamento das bases das nadadeiras dorsal e anal, para uma posição mais anterior. Com o tamanho de 19 mm (comprimento padrão, ocorre uma mudança geral, considerável, nas proporções corporais. A ossificação de todos os raios das nadadeiras completa-se quando a larva atinge 20 mm, mas a ossificação dos escudos ventrais só se completa quando ela atinge 30 mm de comprimento. A ossificação das vertebras completa-se a 16 mm de comprimento. O tamanho de 19 mm foi considerado como o fim do estagio larval, e, apos este comprimento

  9. Evolution and development of the adelphophagic, intracapsular Schmidt's larva of the nemertean Lineus ruber.

    Science.gov (United States)

    Martín-Durán, José M; Vellutini, Bruno C; Hejnol, Andreas

    2015-01-01

    The life cycle of many animals includes a larval stage, which has diversified into an astonishing variety of ecological strategies. The Nemertea is a group of spiralians that exhibits a broad diversity of larval forms, including the iconic pilidium. A pelagic planktotrophic pilidium is the ancestral form in the Pilidiophora, but several lineages exhibit deviations of this condition, mostly as a transition to pelagic lecithotrophy. The most extreme case occurs, however, in the Pilidiophoran Lineus ruber, which exhibits an adelphophagic intracapsular pilidium, the so-called Schmidt's larva. We combined confocal laser scanning microscopy and gene expression studies to characterize the development and metamorphosis of the Schmidt's larva of L. ruber. The larva forms after gastrulation, and comprises a thin epidermis, a proboscis rudiment and two pairs of imaginal discs from which the juvenile will develop. The cells internalized during gastrulation form a blind gut and the blastopore gives rise to the mouth of the larva and juvenile. The Schmidt's larva eats other siblings that occupy the same egg capsule, accumulating nutrients for the juvenile. A gradual metamorphosis involves the differentiation of the juvenile cell types from the imaginal discs and the shedding of the larval epidermis. The expression of evolutionarily conserved anterior (foxQ2, six3/6, gsc, otx), endomesodermal (foxA, GATA456-a, twi-a) and posterior (evx, cdx) markers demonstrate that the juvenile retains the molecular patterning of the Schmidt's larva. After metamorphosis, the juveniles stay over 20 days within the egg masses, until they are fully mature and hatch. The evolution of the intracapsular Schmidt's larva involved the loss of the typical feeding structures of the planktotrophic pilidium and a precocious formation of the imaginal discs, as also observed in other pelagic lecithotrophic forms. However, no special adaptations are observed related to adelphophagy. As in planktotrophic

  10. PENGARUH HORMON ECDYSON TERHADAP SINTASAN DAN PERIODE MOULTING PADA LARVA KEPITING BAKAU Scylla olivacea

    Directory of Open Access Journals (Sweden)

    Sutia Budi

    2018-01-01

    Full Text Available Kepiting Bakau Scylla olivacea merupakan salah satu komoditas perikanan yang memiliki nilai ekonomis yang sangat tinggi. Kendala yang dihadapi dalam kegiatan perbenihan kepiting bakau adalah masih tingginya tingkat mortalitas. Tujuan penelitan untuk mengevaluasi pengaruh hormon ecdyson terhadap sintasan dan periode moulting pada larva kepiting bakau Scylla olivacea. Penelitian dilakukan di Unit Stasiun Pembenihan Kepiting Maranak Balai Riset Perikanan Budidaya Air Payau dan Penyuluhan Perikanan (BRPBAP3 Maros, Provinsi Sulawesi Selatan. Hewan uji berupa larva kepiting bakau Scylla spp. stadia zoea. Pakan uji dalam penelitian berupa rotifer dan Artemia yang dilakukan pengkayaan dengan hormon ecdyson. Wadah penelitian berupa akuarium 110 L berjumlah 12 buah yang diisi dengan air sebanyak 100 L, air bersalinitas 28-30 ppt dengan kepadatan larva sebanyak 50 ekor/L. Perlakuan yang diuji adalah berbagai dosis hormon ecdyson dalam pakan, yakni A= 0 mg/L; B= 0,5 mg/L; C= 1 mg/L; dan D= 1,5 mg/L; dengan tiga kali ulangan. Parameter yang diukur adalah sintasan dan periode moulting. Hasil penelitian menunjukkan bahwa perlakuan dosis hormon ecdyson memberikan pengaruh yang baik terhadap sintasan dan periode moulting larva kepiting bakau. Mud crab, Scylla olivacea is one of highly valued and sought-after fishery commodities. Despite its high economic value, mud crab culture still faces a problem in producing high-quality seed which is high mortality rate post-spawning. The study aim was to evaluate the effect of the Ecdyson hormone on the survival rate and molting period of the mud crab larvae. The study was conducted at the Maranak Crab Seedling, BRPBAP3 Maros, South Sulawesi Province. The trial used mud crabs larvae that were in zoea stage. The trial feed was given in the form of Rotifer and Artemia enriched with the Ecdyson hormone. Twelve 110-liter aquaria were filled with 100 L of 28-30 ppt of seawater. The stocking density of mud crab seed was 50

  11. Status Kerentanan Larva Aedes aegypti terhadap Temefos (Organofosfat di Tiga Kabupaten/Kota Provinsi Aceh

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    Mara Ipa

    2017-12-01

    Full Text Available Abstract. Dengue haemorrhagic fever (DHF incidence rate in Aceh Province for the past three years 2012-2014 were fluctuated from 51‰, 29 ‰ and 45 ‰. The most widely used larvacide to control larvae Ae. aegypti is temefos, in Indonesia 1% temefos (abate 1SG started used in 1976, and since 1980 has been used for the eradication program of Ae. aegypti larvae. The intensive use of temefos will be not a problem until population were dominated by resistant individuals. The purpose of this study was to determine the status of susceptibility of Ae. aegypti larvae against temefos in three dengue fever endemic areas in Aceh. We conducted an observational study to examine the susceptibility of Ae. aegypti population in 3 districts of Aceh Province: Banda Aceh, Lhokseumawe and Aceh Besar. Entomological survey and larval collection was assigned. Larvae then reared in laboratory until third generation. Third and early fourth instars stage of Ae. aegypti larvae were used as test samples. Susceptibility test was undergo based on World Health Organization guidelines. Results shows that larva Ae. aegypti from Banda Aceh (100% and Lhokseumawe (99% districts was still susceptible, while Aceh Besar (97% indicates tolerance to temefos 0,02%. In conclusion, temefos still effective to be used as larvicide for vector control in those three endemic of dengue fever in Aceh Province. The priority vector control program that can be suggested is put mosquito breeding place eradication called PSN as a proactive movement in community.Keywords: Aedes aegypti, temefos, susceptibility, insecticide, AcehAbstrak. Angka insidensi demam berdarah dengue (DBD di Provinsi Aceh tahun 2012-2014 berturut turut 51‰ menurun 29 ‰ dan meningkat kembali 45 ‰. Penggunaan larvasida temefos 1% (abate ISG untuk mengendalikan larva Aedes aegypti sudah digunakan oleh program sejak 1976. Penggunaan larvasida tidak akan menjadi masalah sampai suatu populasi didominasi oleh individu

  12. Analysis of feeding behavior of Drosophila larvae on liquid food.

    Science.gov (United States)

    Shen, Ping

    2012-05-01

    The food responses of Drosophila larvae offer an excellent opportunity to study the genetic and neural regulation of feeding behavior. Compared with fed larvae, hungry larvae are more likely to display aggressive foraging, rapid food intake, compensatory feeding, and stress-resistant food procurement. Behavioral assays have been developed to quantitatively assess particular aspects of the hunger-driven food response. In combination, these assays help define the specific role of signaling molecules or neurons in the regulation of feeding behavior in foraging larvae. This protocol describes the analysis of larvae feeding on liquid food. The test is designed for quantitative assessment of the food ingestion rate of individual larvae under different energy states. It provides a simple and reliable way to measure the graded modification of the baseline feeding rate of larvae as food deprivation is prolonged. The test is applicable to routine functional testing and larger-scale screening of genetic mutations and biologics that might affect food consumption.

  13. Velcro-Like System Used to Fix a Protective Faecal Shield on Weevil Larvae

    Science.gov (United States)

    Stejskal, Robert; Trnka, Filip; di Giulio, Andrea

    2017-01-01

    The last instar larva and pupa of Eucoeliodes mirabilis (A. Villa & G. B. Villa, 1835) (Curculionidae: Ceutorhynchini) are described using drawings and SEM images and are compared and keyed with already described larvae of 58 other ceutorhynchinae taxa. The larval body has an effective combination of morphological adaptations that assist a unique biological defensive strategy. All larval stages of E. mirabilis feed ectophytically on leaves of Euonymus europaeus L. (Celastraceae), and the larval body is covered with a thick faecal shield. The fixation of this protective shield on the larval back is performed by a peculiar dorsal microsculpture composed of a dense carpet of microtrichia on the thorax and abdomen, which serves effectively as a velcro system. Because of this strategy, macrosetae on the larval and pupal body of E. mirabilis are completely reduced. Larvae of E. mirabilis also have distinct morphological adaptations for protecting the spiracles against intrusion of faeces and avoiding occlusion of the tracheal system: a) microtrichia around spiracles are slightly shorter, distinctly stronger and are arranged with high-density and in clusters and b) spiracles are protected by an external safety valve. This strategy of E. mirabilis larvae is unique, although somewhat similar to that of Criocerinae and Blepharida-group leave beetles (Galerucinae) (both Coleoptera: Chrysomelidae), but with distinctly different morphological adaptations. PMID:28125664

  14. Velcro-Like System Used to Fix a Protective Faecal Shield on Weevil Larvae.

    Directory of Open Access Journals (Sweden)

    Jiří Skuhrovec

    Full Text Available The last instar larva and pupa of Eucoeliodes mirabilis (A. Villa & G. B. Villa, 1835 (Curculionidae: Ceutorhynchini are described using drawings and SEM images and are compared and keyed with already described larvae of 58 other ceutorhynchinae taxa. The larval body has an effective combination of morphological adaptations that assist a unique biological defensive strategy. All larval stages of E. mirabilis feed ectophytically on leaves of Euonymus europaeus L. (Celastraceae, and the larval body is covered with a thick faecal shield. The fixation of this protective shield on the larval back is performed by a peculiar dorsal microsculpture composed of a dense carpet of microtrichia on the thorax and abdomen, which serves effectively as a velcro system. Because of this strategy, macrosetae on the larval and pupal body of E. mirabilis are completely reduced. Larvae of E. mirabilis also have distinct morphological adaptations for protecting the spiracles against intrusion of faeces and avoiding occlusion of the tracheal system: a microtrichia around spiracles are slightly shorter, distinctly stronger and are arranged with high-density and in clusters and b spiracles are protected by an external safety valve. This strategy of E. mirabilis larvae is unique, although somewhat similar to that of Criocerinae and Blepharida-group leave beetles (Galerucinae (both Coleoptera: Chrysomelidae, but with distinctly different morphological adaptations.

  15. In vitro effects of thiamethoxam on larvae of Africanized honey bee Apis mellifera (Hymenoptera: Apidae).

    Science.gov (United States)

    Tavares, Daiana Antonia; Roat, Thaisa Cristina; Carvalho, Stephan Malfitano; Silva-Zacarin, Elaine Cristina Mathias; Malaspina, Osmar

    2015-09-01

    Several investigations have revealed the toxic effects that neonicotinoids can have on Apis mellifera, while few studies have evaluated the impact of these insecticides can have on the larval stage of the honeybee. From the lethal concentration (LC50) of thiamethoxam for the larvae of the Africanized honeybee, we evaluated the sublethal effects of this insecticide on morphology of the brain. After determine the LC50 (14.34 ng/μL of diet) of thiamethoxam, larvae were exposed to a sublethal concentration of thiamethoxam equivalent to 1.43 ng/μL by acute and subchronic exposure. Morphological and immunocytochemistry analysis of the brains of the exposed bees, showed condensed cells and early cell death in the optic lobes. Additional dose-related effects were observed on larval development. Our results show that the sublethal concentrations of thiamethoxam tested are toxic to Africanized honeybees larvae and can modulate the development and consequently could affect the maintenance and survival of the colony. These results represent the first assessment of the effects of thiamethoxam in Africanized honeybee larvae and should contribute to studies on honey bee colony decline. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Exposure of fish larvae to hydrocarbon concentration fields generated by subsurface blowouts

    International Nuclear Information System (INIS)

    Rye, Henrik; Johansen, Oeistein; Reed, Mark; Ekrol, Narve; Xiong Deqi

    2000-01-01

    As the oil activity outside the Norwegian coast moves towards north, the potential for conflict with the fishing industry increases. Reasons for this are the presence of spawning areas for important fish stocks like herring and cod, and also the technical development of subsurface solutions for the oil exploration, in-creasing the risks for the occurrence of subsurface blowouts. The paper explains how this potential for conflict can be described by means of numerical modelling techniques. The Haltenbanken area outside the western coast of Norway is selected as a field case. The modelling work involves underwater plume modelling as well as 3D modelling of ocean currents. The results from these modelling works are then combined with the modelling of the far-field transport and dilution of the underwater plume, and also the modelling of the spreading and transport of larvae from spawning areas. By combining the calculation of the concentration fields with the spreading calculations of the larvae, the exposure of a total larvae population (one year stock) can be estimated. The paper concludes that under unfavourable conditions, the overlap between the hydrocarbon concentration fields and the geographical distribution of larvae at its most vulnerable stage may cause a significant impact on a population level. (Author)

  17. Occurrence and Intensity of Anisakid Nematode Larvae in Some Commercially Important Fish Species in Persian Gulf

    Directory of Open Access Journals (Sweden)

    Maryam DADAR

    2016-10-01

    Full Text Available Background: Anisakid nematodes are common parasites of fish, mammals, fish-eating birds, and reptiles with a worldwide distribution, causing diseases in human, fish and important economic losses.Methods: A preliminary epidemiological study was carried out on Anisakid nematodes larvae in some commercially important fish species to evaluate the anisakid nematode larvae from greater lizardfish, (Saurida tumbil, Japanese thread fin bream (Nemipterus japonicus, crocodile longtom (Tylosurus crocodilus crocodiles and longfin trevally (Carangoides armatus from the Persian Gulf of Iran.Result: The collected larvae were identified mainly as the third larval stage (L3 of Hysterothylacium larval type A, B and C, Anisakis sp., Raphidascaris sp., Pseudoterranova sp. and Philometra sp. (Nematoda: Philometridae. The prevalence of Anisakid larvae infection of examined fishes was 97.2% in N. japonicus, 90.3% in S. tumbil, 20.5% in crocodile longtom and 5.5% in longfin trevally. Anisakis type III for the first time was different from Anisakis type I and Anisakis type II.Discussion: Zoonotic anisakids by high prevalence in edible fish could be a health hazard for people. So health practices should be considered in these areas.

  18. Velcro-Like System Used to Fix a Protective Faecal Shield on Weevil Larvae.

    Science.gov (United States)

    Skuhrovec, Jiří; Stejskal, Robert; Trnka, Filip; di Giulio, Andrea

    2017-01-01

    The last instar larva and pupa of Eucoeliodes mirabilis (A. Villa & G. B. Villa, 1835) (Curculionidae: Ceutorhynchini) are described using drawings and SEM images and are compared and keyed with already described larvae of 58 other ceutorhynchinae taxa. The larval body has an effective combination of morphological adaptations that assist a unique biological defensive strategy. All larval stages of E. mirabilis feed ectophytically on leaves of Euonymus europaeus L. (Celastraceae), and the larval body is covered with a thick faecal shield. The fixation of this protective shield on the larval back is performed by a peculiar dorsal microsculpture composed of a dense carpet of microtrichia on the thorax and abdomen, which serves effectively as a velcro system. Because of this strategy, macrosetae on the larval and pupal body of E. mirabilis are completely reduced. Larvae of E. mirabilis also have distinct morphological adaptations for protecting the spiracles against intrusion of faeces and avoiding occlusion of the tracheal system: a) microtrichia around spiracles are slightly shorter, distinctly stronger and are arranged with high-density and in clusters and b) spiracles are protected by an external safety valve. This strategy of E. mirabilis larvae is unique, although somewhat similar to that of Criocerinae and Blepharida-group leave beetles (Galerucinae) (both Coleoptera: Chrysomelidae), but with distinctly different morphological adaptations.

  19. Determination of proteolytic activity using L-[4,5-3H]leucine-labelled globin as a substrate

    International Nuclear Information System (INIS)

    Maliopoulou, T.B.; Dionyssiou-Asteriou, A.; Loucopoulos, D.

    1980-01-01

    A simple and sensitive method for the assay of proteolytic enzyme activity is described. This is based on the digestion of L-[4,5- 3 H]leucine globin by proteolytic enzymes and radioactivity measurement of the trichloroacetic acid soluble cleavage products. (Auth.)

  20. The active evolutionary lives of echinoderm larvae.

    Science.gov (United States)

    Raff, R A; Byrne, M

    2006-09-01

    Echinoderms represent a researchable subset of a dynamic larval evolutionary cosmos. Evolution of echinoderm larvae has taken place over widely varying time scales from the origins of larvae of living classes in the early Palaeozoic, approximately 500 million years ago, to recent, rapid and large-scale changes that have occurred within living genera within a span of less than a million years to a few million years. It is these recent evolutionary events that offer a window into processes of larval evolution operating at a micro-evolutionary level of evolution of discrete developmental mechanisms. We review the evolution of the diverse larval forms of living echinoderms to outline the origins of echinoderm larval forms, their diversity among living echinoderms, molecular clocks and rates of larval evolution, and finally current studies on the roles of developmental regulatory mechanisms in the rapid and radical evolutionary changes observed between closely related congeneric species.

  1. Sporulation and Germination of Paenibacillus larvae Cells.

    Science.gov (United States)

    Mahdi, Osama S; Fisher, Nathan A

    2018-02-22

    Endospores are metabolically dormant cells formed by a variety of Gram-positive bacteria within the phylum Firmicutes in response to nutrient limiting or otherwise unfavorable growth conditions. American foulbrood disease (AFB) is a serious disease of honeybees that is caused by the introduction of Paenibacillus larvae endospores into a honeybee colony. Progression to fulminant disease and eventual collapse of the colony requires multiple rounds of endospore germination, vegetative replication, endospore formation, and subsequent spread within the colony. This unit includes protocols for the in vitro sporulation and germination of P. larvae to assist investigators in the study of these processes. © 2018 by John Wiley & Sons, Inc. Copyright © 2018 John Wiley & Sons, Inc.

  2. Long-term Outcome After Monosegmental L4/5 Stabilization for Degenerative Spondylolisthesis With the Dynesys Device.

    Science.gov (United States)

    Hoppe, Sven; Schwarzenbach, Othmar; Aghayev, Emin; Bonel, Harald; Berlemann, Ulrich

    2016-03-01

    Retrospective analysis of prospectively collected clinical data. To assess the long-term outcome of patients with monosegmental L4/5 degenerative spondylolisthesis treated with the dynamic Dynesys device. The Dynesys system has been used as a semirigid, lumbar dorsal pedicular stabilization device since 1994. Good short-term results have been reported, but little is known about the long-term outcome after treatment for degenerative spondylolisthesis at the L4/5 level. A total of 39 consecutive patients with symptomatic degenerative lumbar spondylolisthesis at the L4/5 level were treated with bilateral decompression and Dynesys instrumentation. At a mean follow-up of 7.2 years (range, 5.0-11.2 y), they underwent clinical and radiographic evaluation and quality of life assessment. At final follow-up, back pain improved in 89% and leg pain improved in 86% of patients compared with preoperative status. Eighty-three percent of patients reported global subjective improvement. Ninety-two percent would undergo the surgery again. Eight patients (21%) required further surgery because of symptomatic adjacent segment disease (6 cases), late-onset infection (1 case), and screw breakage (1 case). In 9 cases, radiologic progression of spondylolisthesis at the operated segment was found. Seventy-four percent of operated segments showed limited flexion-extension range of spondylolisthesis at L4/5 shows good long-term results. The rate of secondary surgeries is comparable to other dorsal instrumentation devices. Residual range of motion in the stabilized segment is reduced, and the rate of radiologic and symptomatic adjacent segment degeneration is low. Patient satisfaction is high. Dynesys stabilization of symptomatic L4/5 degenerative spondylolisthesis is a possible alternative to other stabilization devices.

  3. Trading stages

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2012-01-01

    because they are hard to use and interpret, and tools for age and stage structured populations are missing. We present easily interpretable expressions for the sensitivities and elasticities of life expectancy to vital rates in age-stage models, and illustrate their application with two biological......Interest in stage-and age structured models has recently increased because they can describe quantitative traits such as size that are left out of age-only demography. Available methods for the analysis of effects of vital rates on lifespan in stage-structured models have not been widely applied...... examples. Much of our approach relies on trading of time and mortality risk in one stage for time and risk in others. Our approach contributes to the new framework of the study of age- and stage-structured biodemography....

  4. Influence of water infusion of medicinal plants on larvae of Strongyloides papillosus (Nematoda, Strongyloididae

    Directory of Open Access Journals (Sweden)

    A. A. Boyko

    2016-08-01

    Full Text Available One of the most common nematodes of ruminants is Strongyloides papillosus (Wedl, 1856. Disease caused by these parasites brings economic losses to livestock operations. Therefore it is necessary to control their numbers. The eggs and three larval stages of S. papillosus live in the environment, while the fourth, fifth and mature individuals live in host organisms. Control of these parasites is necessary at all stages of development, including the free-living stage. An experiment on changes in the number strongiloids under the influence of environmental factors was carried out using aqueous extracts of medicinal plants. In the laboratory experiment we researched the effect on the survival of invasive and noninvasive types of S. papillosus larvae of 24 hours exposure at different doses to Artemisia absinthium Linnaeus, 1753, Artemisia annua Linnaeus, 1753, Echinacea purpurea (Linnaeus, 1753 Moench, 1794, Matricaria chamomilla Linnaeus, 1753, Tanacetum vulgare Linnaeus, 1753, Salvia sclarea Linnaeus, 1753, Levisticum officinale W.D.J. Koch, 1824, Petroselinum crispum (Miller, 1768 Nyman ex A.W. Hill, 1925. The death of 50% of S. papillosus invasive larvae was registered at 464 ± 192 mg/l concentration of aqueous extract of S. sclarea inflorescences. The greatest effect up-on the non-invasive larvae was caused by aqueous extracts of inflorescences of S. sclarea, M. chamomilla and seeds of P. crispum: at concentrations of 327 ± 186, 384 ± 155 and 935 ± 218 mg/l, respectively, 50% of non-invasive larvae died. According to the results of the research, we suggest further study of the nematocidal activity of combinations, contained in the aboveground parts, of clary sage (S. sclarea, camomile (M. chamomilla and seeds of parsley (P. crispum, and also experimental usage of these species in the fodder compound for cattle, sheep, goats and pigs on experimental farms.

  5. Description of immature stages of Platycoelia valida Burmeister, 1844 (Coleoptera: Melolonthidae: Rutelinae: Anoplognathini

    Directory of Open Access Journals (Sweden)

    Jhon César Neita-Moreno

    Full Text Available Abstract Description of immature stages of Platycoelia valida Burmeister, 1844 (Coleoptera: Melolonthidae: Rutelinae: Anoplognathini. Third instar larva and pupa of P. valida are described for the first time based on specimens collected in soils of yucca and coffee fields in Cundinamarca, Colombia. Illustrations of diagnostic structures and keys to the known third-stage larvae of Rutelinae tribes and Platycoelia species are included. Data on the biology and distribution of P. valida in Colombia are also commented.

  6. Influence of the toxicity of cryoprotective agents on the involvement of insulin-like growth factor-I receptor in surf clam (Spisula sachalinensis) larvae.

    Science.gov (United States)

    Choi, Youn Hee; Nam, Taek Jeong

    2014-01-01

    The signaling of insulin-like growth factor-I (IGF-I) is involved in the development, growth, reproduction and aging of vertebrates. However, few studies have investigated the involvement of IGF-I during states of extreme shock, such as those induced by potently toxic cryoprotective agents (CPAs) or low temperature conditions, in bivalves. We investigated the toxicity of CPAs and the potential relationship between larval viability and the IGF-I receptor (IGF-IR) after treatment with CPAs or freezing in surf clam (Spisula sachalinensis) larvae. The umbo larvae and different concentrations of CPAs (dimethyl sulfoxide, DMSO; ethylene glycol, EG) were used to investigate the toxicity of CPAs and the vitrification of surf clam larvae. The relationship between larval viability and the IGF-I receptor (IGF-IR) after treatment with CPAs or freezing was investigated using immunoblot analysis. An increase in concentration greater than 4M DMSO was fatal in larvae; however, 5M EG combined with a mixture of CPAs had no harmful effects. Moreover, live larvae immersed in a 5M EG solution remained intact and maintained their normal shape and organs. However, even though the larvae survived the CPA toxicity test, none of the vitrified larvae survived. After immersion into CPAs and vitrification, 97-kDa IGF-IR ß-subunits could be detected in all larvae; but tyrosine phosphorylation of the intracellular β-subunits was detected only in the control and live groups. IGF-IR was activated in the umbo larvae but not in dead surf clam larvae treated with CPA and frozen. Activation of IGF-IR has relevance to the umbo larval stage in live surf clams treated with CPAs.

  7. Morphological characterization of Eustrongylides sp. larvae (Nematoda, Dioctophymatoidea) parasite of Rhinella marina (Amphibia: Bufonidae) from Eastern Amazonia.

    Science.gov (United States)

    Melo, Francisco Tiago de Vasconcelos; Melo, Caroline do Socorro Barros; Nascimento, Luciana de Cássia Silva do; Giese, Elane Guerreiro; Furtado, Adriano Penha; Santos, Jeannie Nascimento Dos

    2016-06-07

    Absctract Eustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.

  8. Possible presence of common tyvelose-containing glycans in Trichinella L1 larvae and embryonated eggs of several nematodes

    Directory of Open Access Journals (Sweden)

    Dea-Ayuela M.A.

    2001-06-01

    Full Text Available A monoclonal antibody (mAb US4 recognising an epitope containing tyvelose within the T. spiralis L-1 muscle larvae (TSL-1 antigens was tested in western-blot against various antigenic preparations from different stages of the following nematodes: T. spiralis (L1,adult, T. muris (egg, L1, L3, adult, Ascaris suum (egg, adult, Toxocara canis (egg, adult, Anisakis simplex (L3 and Haemochus contortus (egg. Positive reaction was present in antigen preparations from L1 larvae of T. spiralis and T. muris and from embryonated eggs of T. muris, A. suum, T. canis and H. conlortus.

  9. Effects of copper on development and survival rate of Paphia malabarica Chemnitz larvae under low saline condition

    Digital Repository Service at National Institute of Oceanography (India)

    Gireesh, R.; Gopinathan, C.P.

    replicates were maintained for each treatment and for copper exposures; a nominal concentration of 2.5 µgCu2 + l −1 was used. The larvae were kept inside the laboratory under con- stant conditions (temperature 28 ◦ C and irradiance 150 µE/m 2 , 12 h light... been reported in reef waters (Peters et al. 1997). It is very likely that copper in higher con- centrations than investigated in this study may further increase the mortality in P. malabarica larvae. Larval stages such as the swimming veliger lar- vae...

  10. Technical Report Series on Global Modeling and Data Assimilation. Volume 40; Soil Moisture Active Passive (SMAP) Project Assessment Report for the Beta-Release L4_SM Data Product

    Science.gov (United States)

    Koster, Randal D.; Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Liu, Qing; Colliander, Andreas; Conaty, Austin; Jackson, Thomas; Kimball, John

    2015-01-01

    During the post-launch SMAP calibration and validation (Cal/Val) phase there are two objectives for each science data product team: 1) calibrate, verify, and improve the performance of the science algorithm, and 2) validate the accuracy of the science data product as specified in the science requirements and according to the Cal/Val schedule. This report provides an assessment of the SMAP Level 4 Surface and Root Zone Soil Moisture Passive (L4_SM) product specifically for the product's public beta release scheduled for 30 October 2015. The primary objective of the beta release is to allow users to familiarize themselves with the data product before the validated product becomes available. The beta release also allows users to conduct their own assessment of the data and to provide feedback to the L4_SM science data product team. The assessment of the L4_SM data product includes comparisons of SMAP L4_SM soil moisture estimates with in situ soil moisture observations from core validation sites and sparse networks. The assessment further includes a global evaluation of the internal diagnostics from the ensemble-based data assimilation system that is used to generate the L4_SM product. This evaluation focuses on the statistics of the observation-minus-forecast (O-F) residuals and the analysis increments. Together, the core validation site comparisons and the statistics of the assimilation diagnostics are considered primary validation methodologies for the L4_SM product. Comparisons against in situ measurements from regional-scale sparse networks are considered a secondary validation methodology because such in situ measurements are subject to upscaling errors from the point-scale to the grid cell scale of the data product. Based on the limited set of core validation sites, the assessment presented here meets the criteria established by the Committee on Earth Observing Satellites for Stage 1 validation and supports the beta release of the data. The validation against

  11. Growth, survival and bone alterations in Piaractus mesopotamicus larvae under different rearing protocols

    Directory of Open Access Journals (Sweden)

    David Roque Hernández

    2015-09-01

    Full Text Available The pacu (Piaractus mesopotamicus is a neotropical freshwater fish. It is one of the most important species farmed in areas of the Parana and Paraguay Rivers basins. The effects of different rearing protocols on growth, survival and incidence of skeletal malformations in pacu larvae were analyzed. A total of six experimental treatments were considered, consisting of: a semi-intensive larviculture (LS in ponds; intensive larviculture (LIn in laboratory (both LS and LIn until 60 days of life; and mixed larviculture, with 20 days of semi-intensive larviculture into cages in ponds after 14 (L1, 21 (L2, 33 (L3 or 40 (L4 days of laboratory larviculture. At the end of the experimental period, LSlarvae showed higher growth rate, with average weight values (2.28g and total length (TL-48.20mm statistically higher than the rest (P1 to L4 treatments showed intermediate growth values, without differences between them (P>0.05, while LIn presented the lowest growth (PS, that presented a significantly lower value (17.5%, PIn and L1 presented the lowest incidence. In no case, visible morphological alterations were found. This study shows that prolonging pacu rearing under laboratory conditions at high densities improves temporal availability and survival of juvenile without affecting growth or subsequent osteological development of fish.

  12. From trochophore to pilidium and back again - a larva's journey.

    Science.gov (United States)

    Maslakova, Svetlana A; Hiebert, Terra C

    2014-01-01

    Nemerteans, a phylum of marine lophotrochozoan worms, have a biphasic life history with benthic adults and planktonic larvae. Nemertean larval development is traditionally categorized into direct and indirect. Indirect development via a long-lived planktotrophic pilidium larva is thought to have evolved in one clade of nemerteans, the Pilidiophora, from an ancestor with a uniformly ciliated planuliform larva. Planuliform larvae in a member of a basal nemertean group, the Palaeonemertea, have been previously shown to possess a vestigial prototroch, homologous to the primary larval ciliated band in the trochophores of other spiralian phyla, such as annelids and mollusks. We review literature on nemertean larval development, and include our own unpublished observations. We highlight recent discoveries of numerous pilidiophoran species with lecithotrophic larvae. Some of these larvae superficially resemble uniformly ciliated planuliform larvae of other nemerteans. Others possess one or two transverse ciliary bands, which superficially resemble the prototroch and telotroch of some spiralian trochophores. We also summarize accumulating evidence for planktotrophic feeding by larvae of the order Hoplonemertea, which until now were considered to be lecithotrophic. We suggest that 1) non-feeding pilidiophoran larval forms are derived from a feeding pilidium; 2) such forms have likely evolved many times independently within the Pilidiophora; 3) any resemblance of such larvae to the trochophores of other spiralians is a result of convergence and that 4) the possibility of planktotrophy in hoplonemertean larvae may influence estimates of pelagic larval duration, dispersal, and population connectivity in this group.

  13. 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.

  14. The influence of different rotifer and Artemia enrichment diets on growth, survival and pigmentation in turbot (Scophthalmus maximus L.) larvae

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Attramadal, Y.

    1992-01-01

    An experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low-HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids-HUFA). Seven tanks were set up for each diet. After the rotifer stage, approxima......An experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low-HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids-HUFA). Seven tanks were set up for each diet. After the rotifer stage......, approximately seven days after hatching, the larvae were fed newly-hatched Artemia salina nauplii (AT-1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tansk was further subdivided and the larvae fed Artemia nauplii enriched with one of four enrichment...... diets: Dry Selco, Protein Selco, ICES low-HUFA or Super Selco. The rotifer enrichments had no significant effect on larval growth and survival. The nutritional value of the Artemia stage (day 13 to 26) was more important for the overall larval survival....

  15. Mesomere-derived glutamate decarboxylase-expressing blastocoelar mesenchyme cells of sea urchin larvae

    Directory of Open Access Journals (Sweden)

    Hideki Katow

    2013-12-01

    The ontogenetic origin of blastocoelar glutamate decarboxylase (GAD-expressing cells (GADCs in larvae of the sea urchin Hemicentrotus pulcherrimus was elucidated. Whole-mount in situ hybridisation (WISH detected transcription of the gene that encodes GAD in H. pulcherrimus (Hp-gad in unfertilised eggs and all blastomeres in morulae. However, at and after the swimming blastula stage, the transcript accumulation was particularly prominent in clumps of ectodermal cells throughout the embryonic surface. During the gastrula stage, the transcripts also accumulated in the endomesoderm and certain blastocoelar cells. Consistent with the increasing number of Hp-gad transcribing cells, immunoblot analysis indicated that the relative abundance of Hp-Gad increased considerably from the early gastrula stage until the prism stage. The expression pattern of GADCs determined by immunohistochemistry was identical to the pattern of Hp-gad transcript accumulation determined using WISH. In early gastrulae, GADCs formed blastocoelar cell aggregates around the blastopore with primary mesenchyme cells. The increase in the number of blastocoelar GADCs was inversely proportional to the number of ectodermal GADCs ranging from a few percent of total GADCs in early gastrulae to 80% in late prism larvae; this depended on ingression of ectodermal GADCs into the blastocoel. Some of the blastocoelar GADCs were fluorescein-positive in the larvae that developed from the 16-cell stage chimeric embryos; these comprised fluorescein-labeled mesomeres and unlabelled macromeres and micromeres. Our finding indicates that some of the blastocoelar GADCs are derived from the mesomeres and thus they are the new group of mesenchyme cells, the tertiary mesenchyme cells.

  16. Toxicity studies for indigenous Bacillus thuringiensis isolates from Malang City, East Java on Aedes aegypti larvae.

    Science.gov (United States)

    Gama, Zulfaidah Penata; Nakagoshi, Nobukazu; Suharjono; Setyowati, Faridah

    2013-02-01

    To investigate the toxicity of indigenous Bacillus thuringiensis (B. thuringiensis)isolates from Malang City for controlling Aedes aegypti (Ae. aegypti) larvae. Soil samples were taken from Purwantoro and Sawojajar sub-districts. Bacterial isolation was performed using B. thuringiensis selective media. Phenotypic characteristics of the isolates were obtained with the simple matching method. The growth and prevalence of spores were determined by the Total Plate Count method, and toxicity tests were also performed on the third instar larval stage of Ae. aegypti. The percentage of larval mortality was analysed using probit regression. The LC50 was analysed by ANOVA, and the Tukey HSD interval was 95%. Among the 33 selected bacterial isolates, six were obtained (PWR4-31, PWR4-32, SWJ4-2b, SWJ4-4b, SWJ-4k and SWJ5-1) that had a similar phenotype to reference B. thuringiensis. Based on the dendrogram, all of the bacterial isolates were 71% similar. Three isolates that had a higher prevalence of reference B. thuringiensis were PWR4-32, SWJ4-4b and SW5-1, of which the spore prevalence was 52.44%, 23.59%, 34.46%, respectively. These three indigenous isolates from Malang City successfully killed Ae. aegypti larvae. The PWR4-32 isolates were the most effective at killing the larvae. Six indigenous B. thuringiensis isolates among the 33 bacterial isolates found in the Sawojajar and Purwantoro sub-districts were toxic to the third instar larvae of Ae. aegypti. The PWR4-32 isolates were identical to the reference B. thuringiensis and had 88% phenotype similarity. The PWR4-32 isolates had the highest spore prevalence (52.44%), and the early stationary phase occurred at 36 h. The PWR4-32 isolates were the most effective at killing Ae. aegypti larvae (LC50-72 h=2.3×10(8) cells/mL).

  17. Characterization of antennal sensilla, larvae morphology and olfactory genes of Melipona scutellaris stingless bee.

    Directory of Open Access Journals (Sweden)

    Washington João de Carvalho

    Full Text Available There is growing evidence in the literature suggesting that caste differentiation in the stingless bee, Melipona scutellaris, and other bees in the genus Melipona, is triggered by environmental signals, particularly a primer pheromone. With the proper amount of food and a chemical stimulus, 25% of females emerge as queens, in agreement with a long-standing "two loci/two alleles model" proposed in the 1950s. We surmised that these larvae must be equipped with an olfactory system for reception of these chemical signals. Here we describe for the first time the diversity of antennal sensilla in adults and the morphology of larvae of M. scutellaris. Having found evidence for putative olfactory sensilla in larvae, we next asked whether olfactory proteins were expressed in larvae. Since the molecular basis of M. scutellaris is still unknown, we cloned olfactory genes encoding chemosensory proteins (CSP and odorant-binding proteins (OBPs using M. scutellaris cDNA template and primers designed on the basis CSPs and OBPs previously reported from the European honeybee, Apis mellifera. We cloned two CSP and two OBP genes and then attempted to express the proteins encoded by these genes. With a recombinant OBP, MscuOBP8, and a combinatorial single-chain variable fragment antibody library, we generated anti-MscuOBP8 monoclonal antibody. By immunohistochemistry we demonstrated that the anti-MscuOBP8 binds specifically to the MscuOBP8. Next, we found evidence that MscuOBP8 is expressed in M. scutellaris larvae and it is located in the mandibular region, thus further supporting the hypothesis of olfactory function in immature stages. Lastly, molecular modeling suggests that MscuOBP8 may function as a carrier of primer pheromones or other ligands.

  18. Behavioral Response of Aedes aegypti (Diptera: Culicidae) Larvae to Synthetic and Natural Attractants and Repellents.

    Science.gov (United States)

    Gonzalez, Paula V; González Audino, Paola A; Masuh, Héctor M

    2015-11-01

    Aedes aegypti (L.) (Diptera: Culicidae) is the key vector of three important arboviral diseases: dengue, yellow fever, and chikungunya. Immature stages of this species inhabit human-made containers placed in residential landscapes. In this study, we evaluated a few compounds in a sensitive behavioral assay with Ae. aegypti larvae. The orientation of larvae to different compounds was surveyed using a performance index (PI). The PI represents the response to each odorant, where a value of +1 is indicative of full attraction and -1 represents complete repulsion. The widely used insect repellent N, N-diethyl-m-toluamide elicited a significantly negative PI, as did acetophenone and indole. A yeast extract, a known food source, elicited a significantly positive PI, as did 2-methylphenol, 1-octen-3-ol, 3-methylphenol, and fish food. On the other hand, no response was observed for the essential oil of Eucalyptus grandis x Eucalyptus camaldulensis at the concentration evaluated. Pretreatment of larvae with N-ethylmaleimide and ablation of the antennae resulted in a suppression of behavioral responses. The overall mobility of ablated larvae was indistinguishable from unablated controls, and absence of any visible locomotor dysfunction was observed. This work is a contribution to the study of the chemical ecology of disease vectors with the aim of developing more efficient tools for surveillance and control.Natural and synthetic compounds attractive to Ae. aegypti larvae should be incorporated into integrated pest management programs through the use of baited traps or by improving the efficacy of larvicides commonly used in control campaigns. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. SEBARAN LARVA IKAN DAN KAITANNYA DENGAN KONDISI OSEANOGRAFI LAUT SULAWESI

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    Khairul Amri

    2015-06-01

    Full Text Available Laut Sulawesi diketahui sebagai daerah penangkapan ikan yang potensial sekaligus diduga sebagai lokasi pemijahan. Berbagai jenis larva ikan pelagis maupun demersal ditemukan di perairan ini. Kelimpahan dan sebaran larva ikan di suatu perairan sangat dipengaruhi oleh kondisi oseanografi seperti temperatur, salinitas dan sejumlah parameter lainnya termasuk ketersediaan pakan. Untuk mengetahui pengaruh parameter oseanografi terhadap kelimpahan dan sebaran spasial larva ikan di Laut Sulawesi, telah dilakukan penelitian menggunakan kapal riset KR Baruna Jaya VII pada Oktober 2012. Parameter oseanografi yaitu temperatur dan salinitas diukur menggunakan iCTD dan sampling larva menggunakan bonggo net pada 18 stasiun pengukuran. Analisa hubungan kondisi oseanografi dengan sebaran larva dilakukan secara deskriptif dan pemetaan sebarannya dilakukan secara spasial. Hasil menunjukan keterkaitan sejumlah parameter oseanografi dengan kelimpahan dan sebaran spasial larva ikan. Sebaran larva famili Scombroidae dominan berada pada perairan bersalinitas tinggi karena merupakan jenis ikan oseanik. Larva ikan demersal banyak ditemukan di perairan sekitar Kep.Sangihe Talaud. Kelimpahan larva tertinggi ditemukan di perairan bagian utara dan barat lokasi penelitian dimana kelimpahan plankton tinggi ditemukan.   Celebes Sea is known as a potential fishing and spawning grounds for several pelagic fish species. Abundance and distribution of fish larvae are allegedly linked to oceanographic conditions such as temperature, salinity and others oceanographic parameters including food availablity. To see the effect of oceanographic on the abundance and spatial distribution of fish larvae in the Celebes Sea, has conducted a research in October 2012using the research vessel KR Baruna Jaya VII. The measurement of oceanographic parameters including temperature and salinity and larval sampling were done respectively by using iCTD and Bonggo net at 18 measuring stations. The

  20. Biological aspects of Periga circumstans Walker, 1855 (Lepidoptera: Saturniidae: Hemileucinae with larvae reared on khaki and mate-plant leaves

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    A. Specht

    Full Text Available The goal of the present study was to investigate biological aspects of Periga circumstans Walker, 1855 (Lepidoptera: Saturniidae: Hemileucinae whose larvae were fed on leaves of khaki-plant (Diospyros khaki Linnaeus - Ebenaceae and Mate-plant (Ilex paraguariensis Saint Hilaire - Aquifoliaceae leaves. The biological parameters were obtained from specimens kept under controlled conditions: temperature of 25 ± 1 °C, relative humidity of 70 ± 10%, and photoperiod of 12 hours. For each developmental stage, morphological and ethological parameters are described. The larvae passed through six instars with a growth average rate of 1.4 for each instar. The host plants influenced significantly only the total duration of the larval phase, which was prolonged for larvae fed on khaki-plant leaves. Several aspects related to the morphology and the ethology of P. circumstans are similar to those described for Lonomia obliqua Walker, 1855.

  1. Effect of X-rays on oogenesis of Telapia mossambica Peters 2. Irradiation of 15 days old larvae

    International Nuclear Information System (INIS)

    Chmilevskij, D.A.

    1982-01-01

    Tilapia larvae of 15 days old after hatching were exposed to x-rays at a dose of 350 R and gonad state in fishes of up to 120 days old was studied. The largest part of sex cells was perished in fishes of 20-30 days old. At the age of 60 days the process of gonad recovery began in consequence of which the number of sex cells in experimetnal fishes tall the end of experiment (fishes of 120 days old after hatching) was the same as in control fishes of the same age. However, unlike the experiment with irradiation of larvae of 6 days old, during irradiation of larvae of 15 days old there was no complete recovery of gonads-oocutes of the irradiated fishes didn't reach the stage of oocyte development under control

  2. DAYA LARVASIDA EKSTRAK BIJI SRIKAYA (ANNONA SQUAMOSA DENGAN RENTANG WAKTU PENYIMPANAN YANG BERBEDA TERHADAP LARVA CULEX QUINQUEFASCIATUS

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    Wisnu Satria A.K.

    2013-03-01

    Full Text Available Abstract. Synthetic insecticide have been used to control Culex quinquefasciatus, but the prolonged usage of synthetic insecticide has a bad impact on the environment and may caused resistance. Sugar apple’s (Annona squamosa seeds which contain alkaloid can be used as an alternative insecticide that was safe for environment. This research aims is to know the effect of sugar apple’s seeds with different length of storage as C. quinquefasciatus larvacide. This research was an experimental study with a randomized controlled trial group design approach. The test material was an extract of sugar apple’s seeds which have been kept for 0, 1, 2, and 3 week with LC50 (0,47 ppm was used. Each treatment used 25 C. quinquefasciatus larvae from third instar larvae stage and replicated five times. After exposed for 24 hours, dead larvae counted. The result confirmed that the extract of sugar apple’s seeds which has been stored in 0, 1, 2, and 3 week did not showed any significant different on larvae mortality. Extract of sugar apple’s seeds which have been stored in 0, 1, 2, and 3 week have an equal activity as Culex quinquefasciatus larvicide. Key Word: Sugar apple (Annona squamosa, seeds, larvicide, Culex quinquefasciatus, length of storage Abstrak. Insektisida sintetik telah banyak digunakan untuk mengontrol Culex quinquefasciatus, tetapi penggunaan insektisida sintetik terus-menerus berdampak buruk terhadap lingkungan dan mengakibatkan resistensi. Fakta ini menjadi alasan biji srikaya (Annona squamosa yang mengandung alkaloid digunakan sebagai insektisida alternatif yang aman bagi lingkungan. Penelitian ini bertujuan untuk mengetahui pengaruh biji srikaya dengan perbedaan lama penyimpanan terhadap larva C. quinquefasciatus. Penelitian ini merupakan penelitian eksperimental dengan desain rancangan acak kelompok. Bahan uji adalah ekstrak biji srikaya yang telah disimpan selama 0, 1, 2, dan 3 minggu. Sampel penelitian ini adalah larva instar ketiga

  3. Avulsion of the L4 spinous process: an unusual injury in a professional rugby player: case report.

    Science.gov (United States)

    Jones, Alwyn; Andrews, John; Shoaib, Amer; Lyons, Kath; Ahuja, Sashin; Howes, John; Davies, Paul

    2005-06-01

    A case of L4 spinous process avulsion following a hyperflexion injury treated with surgical excision. To show that single photon emission computerized tomography is essential for the diagnosis and that excision can provide a successful outcome. The avulsion resulted from a forced hyperflexion injury at the L4/5 area, where the interspinous ligament provides a high resistance to flexion. A 29-year-old international rugby football player injured his low back during a match. Plain radiography and magnetic resonance imaging did not reveal the injury. Single photon emission computerized tomography and computerized tomography showed the lesion. Initial conservative therapy failed to control the symptoms, and, therefore, late excision was performed with pain-free return to contact sports at 3 months. Few cases of interspinous process avulsions have been described, and, to our knowledge, this is the first reported case of rugby football player who had a successful outcome with late surgical excision.

  4. Summary and evaluation: fuel dynamics loss-of-flow experiments (tests L2, L3, and L4)

    International Nuclear Information System (INIS)

    Barts, E.W.; Deitrich, L.W.; Eberhart, J.G.; Fischer, A.K.; Meek, C.C.

    1975-09-01

    Three similar experiments conducted to support the analyses of hypothetical LMFBR unprotected-loss-of-flow accidents are summarized and evaluated. The tests, designated L2, L3, and L4, provided experimental data against which accident-analysis codes could be compared, so as to guide further analysis and modeling of the initiating phases of the hypothetical accident. The tests were conducted using seven-pin bundles of mixed-oxide fuel pins in Mark-II flowing-sodium loops in the TREAT reactor. Test L2 used fresh fuel. Tests L3 and L4 used irradiated fuel pins having, respectively, ''intermediate-power'' (no central void) and ''high-power'' (fully developed central void) microstructure. 12 references

  5. Bacterial fauna associating with chironomid larvae from lakes of Bengaluru city, India - A 16s rRNA gene based identification

    Directory of Open Access Journals (Sweden)

    Ramprasad Kuncham

    2017-06-01

    Full Text Available Chironomid larvae that inhabit in aquatic sediments play an important role as vector for bacterial pathogens. Its life cycle consists of four stages i.e. eggs, larvae, pupae and adult. In the present study we identified bacterial species associated with whole larvae of chironomids from 11 lake sediments of Bangalore region using 16s rRNA gene Sanger sequencing. We found that larvae from all lake sediments associated with bacterial species which include key pathogens. Totally we identified 65 bacterial isolates and obtained GenBank accession numbers (KX980423 - KX980487. Phylogenetic tree constructed using MEGA 7 software and tree analysis highlight the predominant bacterial community associated with larvae which include Enterobacteriaceae (43.08%; 28 isolates and Aeromonas (24.62%; 16 isolates, Shewanella, Delftia, Bacillus (6.15%; 4 isolates each, Pseudomonas (4.62%; 3 isolates and Exiguobacterium (3.08%; 2 isolates. Current findings state that among bacterial population Aeromonas, Enterobacter and Escherichia with serotypes are commonly associated with larvae in maximum lake points. In other hand Vibrio, Pseudomonas, Klebsiella, Shigella, Bacillus, and other bacterial species were identified moderately in all lakes. Interestingly, we identified first time Shigella Gram negative, rod shaped pathogenic organism of Enterobacteriaceae and Rheinheimera Gram negative, rod shaped organism associating chironomid larvae.

  6. Trophic Ecology of Atlantic Bluefin Tuna (Thunnusthynnus) Larvae from the Gulf of Mexico and NW Mediterranean Spawning Grounds: A Comparative Stable Isotope Study

    Science.gov (United States)

    Malca, Estrella; Quintanilla, José María; Muhling, Barbara A.; Alemany, Francisco; Privoznik, Sarah L.; Shiroza, Akihiro; Lamkin, John T.; García, Alberto

    2015-01-01

    The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6–10 mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton—zooplankton—larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae. PMID:26225849

  7. Transport of marine fish larvae to Saroma-ko Lagoon (Hokkaido, Japan) in relation to the availability of zooplankton prey under the winter ice cover

    Science.gov (United States)

    Fortier, Martin; Fortier, Louis

    1997-02-01

    To assess the importance of ice-covered Saroma-ko Lagoon as a winter nursery area for young fish spawned offshore, we monitored the recruitment of marine fish larvae from the Sea of Okhotsk to the lagoon as well as the availability of larval fish prey under the ice cover from 24 February to 23 March 1992. Sand lance ( Ammodytes sp.) and walleye pollock ( Theragra chalcogramma) larvae recruited to the lagoon on flood tide whereas snake prickleback ( Lumpenus sagitta) larvae were exported to the Sea of Okhotsk on ebb. Before the ice breakup, ice microalgae made up the bulk of the microalgal biomass in the lagoon. The production and release of ice algae did not trigger the maturation of the late copepodite stages of copepods, and the proportion of adult females in the copepod assemblage remained low. The production of copepod nauplii (the main prey of fish larvae) under the ice was probably insufficient to insure suitable feeding and growth of fish larvae entering the lagoon in winter. Sand lance larvae, the most abundant species to colonize the lagoon in February-March, had to survive for nearly two months at low food abundance. Based on our results, the importance of Saroma-ko Lagoon as a winter nursery area for fish larvae appears negligible.

  8. Bacterial fauna associating with chironomid larvae from lakes of Bengaluru city, India - A 16s rRNA gene based identification.

    Science.gov (United States)

    Kuncham, Ramprasad; Sivaprakasam, Thiyagarajan; Puneeth Kumar, R; Sreenath, P; Nayak, Ravi; Thayumanavan, Tha; Subba Reddy, Gopireddy V

    2017-06-01

    Chironomid larvae that inhabit in aquatic sediments play an important role as vector for bacterial pathogens. Its life cycle consists of four stages i.e. eggs, larvae, pupae and adult. In the present study we identified bacterial species associated with whole larvae of chironomids from 11 lake sediments of Bangalore region using 16s rRNA gene Sanger sequencing. We found that larvae from all lake sediments associated with bacterial species which include key pathogens. Totally we identified 65 bacterial isolates and obtained GenBank accession numbers (KX980423 - KX980487). Phylogenetic tree constructed using MEGA 7 software and tree analysis highlight the predominant bacterial community associated with larvae which include Enterobacteriaceae (43.08%; 28 isolates) and Aeromonas (24.62%; 16 isolates), Shewanella , Delftia , Bacillus (6.15%; 4 isolates each), Pseudomonas (4.62%; 3 isolates) and Exiguobacterium (3.08%; 2 isolates). Current findings state that among bacterial population Aeromonas , Enterobacter and Escherichia with serotypes are commonly associated with larvae in maximum lake points. In other hand Vibrio , Pseudomonas , Klebsiella , Shigella , Bacillus , and other bacterial species were identified moderately in all lakes. Interestingly, we identified first time Shigella Gram negative, rod shaped pathogenic organism of Enterobacteriaceae and Rheinheimera Gram negative, rod shaped organism associating chironomid larvae.

  9. Trophic ecology of Atlantic Bluefin Tuna (Thunnus thynnus) [corrected] larvae from the Gulf of Mexico and NW Mediterranean spawning grounds: A Comparative Stable Isotope Study.

    Science.gov (United States)

    Laiz-Carrión, Raúl; Gerard, Trika; Uriarte, Amaya; Malca, Estrella; Quintanilla, José María; Muhling, Barbara A; Alemany, Francisco; Privoznik, Sarah L; Shiroza, Akihiro; Lamkin, John T; García, Alberto

    2015-01-01

    The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6-10 mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton-zooplankton-larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae.

  10. Trophic ecology of Atlantic Bluefin Tuna (Thunnus thynnus [corrected] larvae from the Gulf of Mexico and NW Mediterranean spawning grounds: A Comparative Stable Isotope Study.

    Directory of Open Access Journals (Sweden)

    Raúl Laiz-Carrión

    Full Text Available The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C as trophic indicators for Atlantic bluefin tuna larvae (BFT (6-10 mm standard length in the highly contrasting environmental conditions of the Gulf of Mexico (GOM and the Balearic Sea (MED. These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton-zooplankton-larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae.

  11. Identification of larvae: The zebra mussel (Dreissena polymorpha), quagga mussel (Dreissena rosteriformis bugensis), and Asian clam (Corbicula fluminea)

    Science.gov (United States)

    Nichols, S. Jerrine; Black, M.G.

    1994-01-01

    There are presently four freshwater bivalves in the United States that produce larvae or veligers commonly found in the water column: two forms of Asian clams and two species of dreissenids. Portions of the geographic range of three of these bivalves, one species of Asian clam (Corbicula fluminea), zebra mussels (Dreissena polymorpha), and quagga mussels (Dreissena rosteriformis bugensis), overlap, causing problems with larval identification. To determine which characteristics can be used to separate larval forms, adult Asian clams, quaggas, and zebra mussels were brought into the laboratory and induced to spawn, and the resulting larvae were reared. Hybrids between quaggas and zebra mussels were also produced, but not reared to maturity. Characteristics allowing for the most rapid and accurate separation of larvae were hinge length, shell length/height, shell shape, shell size, and the presence or absence of a foot and velum. These characteristics were observed in laboratory-reared larvae of known parentage and field-caught larvae of unknown parentage. In most cases, larvae of the Asian clam can be readily separated from those produced by either type of dreissenid on the basis of shell size and presence of a foot. Separating the gametes and embryos of the two types of dreissenids is not possible, but after shell formation, most of the larval stages can be distinguished. Hinge length, shell length/height, and the similarity in size of the shell valves can be used to separate straight-hinged, umbonal, pediveliger, and plantigrade larvae. Quagga × zebra mussel hybrids show characteristics of both parents and are difficult to identify.

  12. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23 with High Potential to Control American Foulbrood.

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    Ana Oliveira

    Full Text Available Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23 encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0, showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  13. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23) with High Potential to Control American Foulbrood.

    Science.gov (United States)

    Oliveira, Ana; Leite, Marta; Kluskens, Leon D; Santos, Sílvio B; Melo, Luís D R; Azeredo, Joana

    2015-01-01

    Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  14. Effect of Linear Alkylbenzene Sulfonate on Mortality, Hatching Rate of Eggs and Abnormality of Catfish (Pangasius hypophthalmus Sauvage Larvae

    Directory of Open Access Journals (Sweden)

    E. Supriyono

    2007-01-01

    Full Text Available Linear alkylbenzene sulfonate (LAS surfactant in the water can affecting fish in all developmental stages.  This study was aimed to observe the effect of LAS on mortality, hatching rate of eggs, and abnormality of patin catfish (Pangasius hypophthalmus Sauvage larvae.   Fertilized eggs were incubated in water containing LAS at the dosages of 0.0, 0.5, 1.5, 3.0, 9.0, and 18.0 mg/L.  Eggs mortality was observed every 6 hours until larvae hatched (24 hours.  The results of study showed that the exposure of 18.0 mg LAS per liter water could put to death all the fertilized eggs and larvae be abnormal.  The exposure of LAS at concentration of 9.0 mg/L could kill 98% of eggs and hatching rate was only 2%.  The abnormality in larvae was bending in the body and tails. Keywords: patin catfish, Pangasius, Linear Alkylbenzene Sulfonate, LAS, abnormality   ABSTRAK Surfaktan Linear Alkylbenzene Sulfonate (LAS yang masuk ke dalam perairan sangat berpengaruh terhadap ikan dari stadia awal hidup ikan sampai dewasa. Penelitian ini bertujuan untuk mengetahui pengaruh LAS terhadap mortalitas, daya tetas telur dan abnormalitas larva ikan patin (Pangasius hypophthalmus Sauvage.  Telur ikan patin yang telah dibuahi di rendam dalam air yang mengandung LAS dengan konsentrasi 0,0; 0,5; 1,5; 3,0; 9,0 dan 18,0 mg/L.  Mortalitas telur dicatat setiap 6 jam sampai menetas (24 jam.  Hasil penelitian menunjukkan bahwa konsentrasi LAS sebesar 18,0 mg/L dapat mengakibatkan mortalitas telur dan abnormalitas pada larva secara total.  Konsentrasi LAS sebesar 9,0 mg/L dapat mematikan telur hingga 98% dan hanya menghasilkan daya tetas sebanyak 2%. Abnormalitas pada larva berupa pembengkokan pada tubuh dan ekor. Kata kunci: ikan patin, Pangasius, Linear Alkylbenzene Sulfonate, LAS dan abnormalitas

  15. 2La chromosomal inversion enhances thermal tolerance of Anopheles gambiae larvae

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    Costantini Carlo

    2009-07-01

    Full Text Available Abstract Background The mosquito Anopheles gambiae is broadly distributed throughout sub-Saharan Africa and this contributes to making it the most efficient vector of malaria on the continent. The pervasiveness of this species is hypothesized to originate in local adaptations facilitated by inversion polymorphisms. One inversion, named 2La, is strongly associated with aridity clines in West and Central Africa: while 2La is fixed in arid savannas, the 2L+a arrangement is predominantly found in the rainforest. Ability to survive high temperature exposure is an essential component of aridity tolerance, particularly in immature stages that are restricted to shallow puddles. Toward deciphering the role of the 2La inversion in local adaptation, the present investigation focused on variation in larval and pupal thermo-tolerance in two populations dissimilar solely in 2La arrangement. Methods A laboratory colony of A. gambiae that is polymorphic for 2La but standard for all other known inversions was used to create 2 homokaryotypic populations (2L+a and 2La. The survival of 4th instar larvae and pupae from both populations was then tested following exposure to thermal stress with and without prior heat hardening. Results Larvae responded identically to a 40°C heat stress, with about 50% of larvae dying after 1.5–2 h and few larvae surviving a 3 h stress. When heat hardened prior to the thermal stress, thermo-tolerance of both larval populations increased, with 2La 24 h survival significantly exceeding that of 2L+a. Pupae were generally more thermo-tolerant than larvae, although 2La pupae were less so than 2L+a. Heat hardening had no positive effect on pupal thermo-tolerance. Conclusion The increased thermo-tolerance observed in 2La larvae following heat hardening suggests higher responsiveness (i.e., thermal sensitivity of the inverted karyotype. By responding more drastically to the heat shock, 2La larvae are better equipped to resist the

  16. Biolarvacidal activity of methanol extract of Kipahit leaves (Tithonia diversifolia against larvae of Chrysomya bezziana fly

    Directory of Open Access Journals (Sweden)

    Wardhana AH

    2014-03-01

    Full Text Available Myiasis or “belatungan” is the infestation of live human and vertebrate animal tissue with dipterous larvae, Chrysomya bezziana. In general, synthetic insecticides were applied to control the disease. However, it causes negative impact on animal product, so that it is required to find an alternative treatment using herbal medicine. The aim of this study was to access activity of methanol extract of Kipahit leaves (Tithonia diversifolia against various stages of C. bezziana larvae (L1, L2 and L3. Five treatments were applied with five replications, i.e. control/water (P0, 0,5%, 1%, 2% of the extract for PI, PII and PIII, respectively. Another treatment was 0,05% Asuntol for positive control (PIV. Each treatment was added with1% DMSO and twenty larvae were examined for each replication. Bioassay of L1 and L2 was addressed to investigate effect of intestinal toxicity by mixing the extract with Meat-Blood Mixture (MBM and Larval Rearing Media (LRM for L1 and L2, respectively. Bioassay of L3 was to investigate effect of contact toxicity through soaking the larvae into the extract solution for 10 seconds followed by incubating in vermiculite at 36oC. All living larvae after being treated by various concentration of the extract were reared to pupae and allowed to emerge as imago. Number of living larvae and pupae, pupae weight and number of imago were observed. All data were analysed using ANOVA followed by Dunnett test at 95% confidential limit. For L2, larval mortality were counted and probit analysed using POLO-PC software, therefore the lethal concentration (LC50 and LC95 and lethal time (LT50 and LT95 were defined. Results demonstrated that 1% of the extract was the most effective concentration which was able to kill the larvae and decrease the pupae weight. It also caused to fail pupation and imago emergence. The further study might be pursued to investigate in vivo assay of the extract in infested livestock.

  17. A methodology for quantifying trace elements in the exoskeletons of Florida stone crab (Menippe mercenaria) larvae using inductively coupled plasma optical emission spectrometry (ICP–OES)

    Science.gov (United States)

    Gravinese, Philip M.; Flannery, Jennifer A.; Toth, Lauren T.

    2016-11-23

    The larvae of the Florida stone crab, Menippe mercenaria, migrate through a variety of habitats as they develop and, therefore, experience a broad range of environmental conditions through ontogeny. Environmental variability experienced by the larvae may result in distinct elemental signatures within the exoskeletons, which could provide a tool for tracking the environmental history of larval stone crab populations. A method was developed to examine trace-element ratios, specifically magnesium-to-calcium (Mg/Ca) and strontium-to-calcium (Sr/Ca) ratios, in the exoskeletons of M. mercenaria larvae. Two developmental stages of stone crab larvae were analyzed—stage III and stage V. Specimens were reared in a laboratory environment under stable conditions to quantify the average ratios of Mg/Ca and Sr/Ca of larval stone crab exoskeletons and to determine if the ratios differed through ontogeny. The elemental compositions (Ca, Mg, and Sr) in samples of stage III larvae (n = 50 per sample) from 11 different broods (mean Sr/Ca = 5.916 ± 0.161 millimole per mole [mmol mol−1]; mean Mg/Ca = 218.275 ± 59.957 mmol mol−1) and stage V larvae (n = 10 per sample) from 12 different broods (mean Sr/Ca = 6.110 ± 0.300 mmol mol−1; mean Mg/Ca = 267.081 ± 67.211 mmol mol–1) were measured using inductively coupled plasma optical emission spectrometry (ICP–OES). The ratio of Sr/Ca significantly increased from stage III to stage V larvae, suggesting an ontogenic shift in Sr/Ca ratios between larval stages. The ratio of Mg/Ca did not change significantly between larval stages, but variability among broods was high. The method used to examine the trace-element ratios provided robust, highly reproducible estimates of Sr/Ca and Mg/Ca ratios in the larvae of M. mercenaria, demonstrating that ICP–OES can be used to determine the trace-element composition of chitinous organisms like the Florida stone crab.

  18. Analysis of feeding behavior of Drosophila larvae on solid food.

    Science.gov (United States)

    Shen, Ping

    2012-05-01

    The food responses of Drosophila larvae offer an excellent opportunity to study the genetic and neural regulation of feeding behavior. Compared with fed larvae, hungry larvae are more likely to display aggressive foraging, rapid food intake, compensatory feeding, and stress-resistant food procurement. Behavioral assays have been developed to quantitatively assess particular aspects of the hunger-driven food response. In combination, these assays help define the specific role of signaling molecules or neurons in the regulation of feeding behavior in foraging larvae. This protocol is designed for quantitative assessment of the willingness of individual larvae to procure solid food under different energy states. It provides a simple and reliable way to measure the graded modification of the baseline feeding rate of larvae as the period of food deprivation is increased. The test is applicable to routine functional testing and larger-scale screening of genetic mutations and biologics that might affect food consumption.

  19. Sensitivity of magnetic resonance imaging in the diagnosis of mobile and nonmobile L4-L5 degenerative spondylolisthesis.

    Science.gov (United States)

    Kuhns, Benjamin D; Kouk, Shalen; Buchanan, Colin; Lubelski, Daniel; Alvin, Matthew D; Benzel, Edward C; Mroz, Thomas E; Tozzi, James

    2015-09-01

    Lumbar degenerative spondylolisthesis (LDS) is often diagnosed by conventional supine magnetic resonance imaging (MRI). Numerous studies have shown, however, that the degree of spondylolisthesis can be reduced or disappears when the patient is supine as compared with standing lateral and flexion-extension (SLFE) radiographs. To compare the sensitivity of supine MRI with SLFE radiographs in patients with L4-L5 LDS. A retrospective imaging study. Included patients diagnosed with L4-L5 LDS with both SLFE films and supine MRI. Lumbar degenerative spondylolisthesis was defined radiographically as a slip greater than 4.5 mm. Mobile LDS was defined as a difference of greater than 3% in slip percentage between lateral radiographs and sagittal MRIs. Additional measurements included L4-L5 facet effusion diameter on axial MRIs. Measurements were performed by two independent examiners. The kappa coefficient was used to assess the interobserver agreement. Of 103 patients assessed, 68% were women and the average age was 66 years. Lumbar degenerative spondylolisthesis was seen on 101 (98%) lateral films and 80 (78%) MRIs. Average slip was 10.0 mm for lateral standing radiographs and 6.6 mm on MRI (p<.0001). Fifty (48%) patients were identified with mobile LDS. The positive predictive value of facet joint effusion for mobile LDS increased from 52% for effusions greater than 1 mm to 100% for effusions greater than 3.5 mm. This study found that MRI had a sensitivity of 78% for detecting L4-L5 LDS compared with 98% for lateral standing films. We also identified facet effusion size as a marker to predict mobile LDS. These findings suggest that, particularly in the setting of facet effusions, the complete workup of patients in whom LDS is possible should include standing radiographs. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. DETECTION OF PAENIBACILLUS LARVAE SPORES IN HONEY SAMPLES FROM BEEKEEPERS OF THE CENTRAL REGION OF ALGERIA

    Directory of Open Access Journals (Sweden)

    Adjlane Noureddine

    2013-08-01

    Full Text Available The American foulbrood in one of the most serious diseases that may affect brood of larvae and pupae stages, which cause economic losses and biological hazards in a large beekeeping sector in several countries across the world in general and Algeria in particular. The causative agent of this disease is a bacterium called Paenibacillus larvae that target bees Apis mellifera the latter are often present in honey.The aim of this project is studying the spread of this disease in the northern region of Algeria through the analysis of honey obtained from these areas. Microbiological, microscopic and biochemical methods were used in this study. The results obtained have shown that the prevalence rate varies from region to region, several factors may explain this variation in the prevalence of the disease. The average infection rate for all regions is 32%. To prevent the spread of this disease in Algeria must be taken is mandatory and means of prevention into account.

  1. With a Little Help from My Friends: Group Orientation by Larvae of a Coral Reef Fish.

    Science.gov (United States)

    Irisson, Jean-Olivier; Paris, Claire B; Leis, Jeffrey M; Yerman, Michelle N

    2015-01-01

    Theory and some empirical evidence suggest that groups of animals orient better than isolated individuals. We present the first test of this hypothesis for pelagic marine larvae, at the stage of settlement, when orientation is critical to find a habitat. We compare the in situ behaviour of individuals and groups of 10-12 Chromis atripectoralis (reef fish of the family Pomacentridae), off Lizard Island, Great Barrier Reef. Larvae are observed by divers or with a drifting image recording device. With both methods, groups orient cardinally while isolated individuals do not display significant orientation. Groups also swim on a 15% straighter course (i.e. are better at keeping a bearing) and 7% faster than individuals. A body of observations collected in this study suggest that enhanced group orientation emerges from simple group dynamics rather than from the presence of more skilful leaders.

  2. Biological activity of saponins from alfalfa tops and roots against Colorado potato beetle larvae

    Directory of Open Access Journals (Sweden)

    Maryla Szczepaniak

    2013-12-01

    Full Text Available The total saponins of alfalfa, Medicago sativa L., included in the diet of Colorado potato beetle larvae reduced their feeding, growth rate and survival. The biological activity of those compounds coming both from the roots and from the aerial parts is closely correlated with the dose. Larvae reared on leaves treated with a 0,5% dose virtually did not feed at all and died after 4-6 days. Lower saponin doses (0,01 and 0,001 % reduced the insects' feeding to a lesser degree. However, they inhibited their growth, caused an extension of the larval stage and mortality at a level of 76,7- 100%. No major differences have been found in saponin activity depending on its localization in the plant.

  3. Modification of polyethylene glycol onto solid lipid nanoparticles encapsulating a novel chemotherapeutic agent (PK-L4) to enhance solubility for injection delivery.

    Science.gov (United States)

    Fang, Yi-Ping; Wu, Pao-Chu; Huang, Yaw-Bin; Tzeng, Cherng-Chyi; Chen, Yeh-Long; Hung, Yu-Han; Tsai, Ming-Jun; Tsai, Yi-Hung

    2012-01-01

    The synthetic potential chemotherapeutic agent 3-Chloro-4-[(4-methoxyphenyl) amino]furo[2,3-b]quinoline (PK-L4) is an analog of amsacrine. The half-life of PK-L4 is longer than that of amsacrine; however, PK-L4 is difficult to dissolve in aqueous media, which is problematic for administration by intravenous injection. To utilize solid lipid nanoparticles (SLNs) modified with polyethylene glycol (PEG) to improve the delivery of PK-L4 and investigate its biodistribution behavior after intravenous administration. The particle size of the PK-L4-loaded SLNs was 47.3 nm and the size of the PEGylated form was smaller, at 28 nm. The entrapment efficiency (EE%) of PK-L4 in SLNs with and without PEG showed a high capacity of approximately 100% encapsulation. Results also showed that the amount of PK-L4 released over a prolonged period from SLNs both with and without PEG was comparable to the non-formulated group, with 16.48% and 30.04%, respectively, of the drug being released, which fit a zero-order equation. The half-maximal inhibitory concentration values of PK-L4-loaded SLNs with and those without PEG were significantly reduced by 45%-64% in the human lung carcinoma cell line (A549), 99% in the human breast adenocarcinoma cell line with estrogen receptor (MCF7), and 95% in the human breast adenocarcinoma cell line (MDA-MB-231). The amount of PK-L4 released by SLNs with PEG was significantly higher than that from the PK-L4 solution (P < 0.05). After intravenous bolus of the PK-L4-loaded SLNs with PEG, there was a marked significant difference in half-life alpha (0.136 ± 0.046 hours) when compared with the PK-L4 solution (0.078 ± 0.023 hours); also the area under the curve from zero to infinity did not change in plasma when compared to the PK-L4 solution. This demonstrated that PK-L4-loaded SLNs were rapidly distributed from central areas to tissues and exhibited higher accumulation in specific organs. The highest deposition of PK-L4-loaded SLNs with PEG was found in the

  4. 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.

  5. Improvement of survival and development of Pacific white shrimp Litopenaeus vannamei larvae by feeding taurine enriched rotifers

    Directory of Open Access Journals (Sweden)

    Dedi Jusadi

    2015-03-01

    Full Text Available ABSTRACTThe objective of the present experiment was to study the most optimum taurine enrichment concentration of rotifers in improving Pacific white shrimp larva Litopenaeus vannamei survival and development. White shrimp larvae at sixth naupliar stage were reared in 12 units of 500 L fibre glass tanks with a stocking density of 125 ind/L. Starting from zoea two stage (Z-2, the larva was provided with rotifers with different taurine enrichment concentration according to the treatments, i.e. 0 mg/L enrichment medium (A, 25 mg/L (B, 50 mg/L(C, and 100 mg/L (D. The results show that different taurine concentration in the enrichment media increased taurine level in rotifers. Furthermore, the administration of taurine enriched rotifers up to 50 mg/L significantly improved larval survival and may accelerate larval development. The experimental results also concluded that a concentration of 50 mg/L is the most optimum taurine enrichment concentration of rotifers for the improvement of white shrimp larval survival and developmental stage.Keywords: taurine, rotifer, white shrimp, enrichmentABSTRAKPenelitian ini bertujuan untuk mengkaji konsentrasi optimum taurin melalui pengayaan pada rotifera terhadap tingkat kelangsungan hidup dan perkembangan stadia larva udang vaname Litopenaeus vannamei. Larva udang vaname stadia naupli-6 dipelihara dalam 12 tangki fiberglass volume 500 L dengan kepadatan 125 ind/L. Dimulai sejak stadia zoea 2 (Z-2 larva diberi rotifera yang diperkaya dengan taurin dengan konsentrasi yang berbeda sesuai dengan perlakuan, yaitu 0 mg/L media pengkaya (A, 25 mg/L (B, 50mg/L (C, dan 100mg/L (D. Hasil penelitian menunjukkan pengayaan taurin pada konsentrasi yang berbeda menyebabkan peningkatan kandungan taurin rotifera. Sementara pemberian rotifera yang diperkaya taurin hingga 50 mg/L meningkatkan kelangsungan hidup dan mempercepat perkembangan stadia larva udang. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa pemberian

  6. 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. PMID:23935566

  7. Observaciones sobre la larva del cangrejo marino tropical (Decapoda: Porcellanidae Petrolisthes armatus en el Golfo de Nicoya, Costa Rica

    Directory of Open Access Journals (Sweden)

    Edgardo Díaz-Ferguson

    2008-09-01

    Full Text Available Durante octubre y noviembre de 1998 (estación lluviosa y diciembre, febrero y marzo de 1999 (estación seca se muestreó la distribución de la larva de Petrolisthes spp, así como la densidad del total de las larvas de decápodos en superficie y a 3 metros de profundidad. Los muestreos se realizaron en tres sitios de la zona de Punta Morales, Golfo de Nicoya, Costa Rica, por medio de arrastres con una red de plancton de 280 µm. Se recolectaron un total de 6014 larvas de decápodos de las cuales 73 (1.21% pertenecían al género Petrolisthes spp. No se encontraron diferencias significativas entre estaciones (p > 0.05, sin embargo fue posible observar una mayor densidad tanto de P. armatus como de larvas de decápodos en estación seca. Temporalmente el único parámetro físico-químico que varió significativamente fue la salinidad. En cuanto a la variación espacial no se encontraron diferencias significativas por profundidad, ni para Petrolisthes spp. ni para larvas de decápodos asociados (p > 0.05, a pesar de que la variación de algunos parámetros como la temperatura y el oxígeno si lo fue. Entre mareas se encontraron diferencias significativas para las larvas de Petrolisthes spp., no así para larvas de decápodos. Para la especie estudiada se observó un mayor número de larvas en marea baja. Entre los sitios hubo diferencias significativas para las larvas de decápodos, pero no para Petrolisthes spp.; físico-químicamente estos sitios son muy parecidos y solo difieren en penetración de luz, lo que parece no afectar a la larva de Petrolisthes. spp. Los resultados demuestran que el principal factor que regula la concentración temporal de las larvas es la salinidad, mientras que espacialmente las oscilaciones en el flujo mareal son de mayor importancia. Debido a las diferencias observadas marealmente para la concentración de larvas se propone el siguiente mecanismo: P. armatus libera sus larvas en el máximo de marea, éstas salen

  8. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  9. Contact toxicity of the crude extract of Chinese star anise fruits to house fly larvae and their development

    Directory of Open Access Journals (Sweden)

    Guntharee Sripongpun

    2008-08-01

    Full Text Available Contact toxicity of the ethanol crude extract of Chinese star anise fruits, Illicium verum Hook. F. (Illiciaceae to house fly larvae, Musca domestica L. (Diptera: Muscidae and their development were determined by a dipping method. Younger larvae were more susceptible than older. The median lethal concentration (LC50 values of the crude extract to the 2nd instar larvae at 24, 48 and 72 hours were 7.4x104, 4.1x104 and 3.2x104 mg/l, respectively. Furthermore, treated extractsaffected house fly development in pupal and adult stages. The number of test larvae developed to pupae and adults was lessthan that of control group. The crude extract at concentration 8.5x104 mg/l completely inhibited development from larvae to pupae. In addition, small pupae were found at every concentration between 2.5x103 -105x103 mg/l. Small treated pupae were observed more at higher concentrations. Some of them could continually develop to adults but their developmental percentageswere less than those of normal sized pupae in treatments and in control group. The crude extract of Chinese star anise fruits can be applied as an optional point source control of house fly.

  10. Perbandingan Efek Larvasida Minyak Atsiri Daun Cengkeh (Syzygium aromaticum L. Varietas Zanzibar dengan Temephos terhadap Larva Nyamuk Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Ridzmullah Wishnu Pamungkas

    2016-12-01

    Full Text Available The use of temephos as larvicides in disease prevention Dengue Hemorrhagic Fever (DHF in Indonesia has been going on for 40 years. Larviciding very long led the resistance to temephos. Cloves, one of native Indonesia plant contains eugenol that are toxic to the insect’s body. The aimed of this study to examine the effectiveness of Zanzibar clove leaf essential oil compared to temephos in killing the larvae of Aedes aegypti. This study used experimental laboratory research design. The samples are larvae of Aedes aegypti stage III. The mosquito larvae were classified into six groups, each given a clove leaf essential oil with different concentrations. Next will be observed the number of larvae that die after 24 hours. Based on statistical test p-value p <0.05 it indicates there are differences in the average mortality in the test group, and post hoc analysis showed the test group with 100 ppm of essential oil is not a significant difference with temephos. This study suggests the essential oil of clove leaf varieties of Zanzibar has the same effectiveness with temephos in killing the larvae of Aedes aegypti.

  11. Are Aristolochic Acids Responsible for the Chemical Defence of Aposematic Larvae of Battus polydamas (L.) (Lepidoptera: Papilionidae)?

    Science.gov (United States)

    Morais, A B B; Brown, K S; Stanton, M A; Massuda, K F; Trigo, J R

    2013-12-01

    Aristolochic acids (AAs) are thought to be responsible for the chemical protection of the aposematic larvae Battus polydamas (L.) (Papilionidae: Troidini) against predators. These compounds are sequestered by larvae from their Aristolochia (Aristolochiaceae) host plants. Studying the role of the chemical protection of the second and fifth instars of B. polydamas against potential predators, we found that the consumption of larvae by the carpenter ant Camponotus crassus Mayr and young chicks Gallus gallus domesticus was dependent on larval developmental stage. Second instars were more preyed upon than fifth instars; however, the assassin bug Montina confusa Stål was not deterred by chemical defences of the fifth instar B. polydamas. Laboratory bioassays with carpenter ants and young chicks using palatable baits topically treated with a pure commercial mixture of AAs I and AAs II in concentrations up to 100 times those previously found in B. polydamas larvae showed no activity. Similar results were found in field bioassays, where palatable baits treated as above were exposed to the guild of predators that attack B. polydamas larvae and were also consumed irrespective of the commercial AA concentration used. These results suggest that the mixture of AAs I and AAs II have no defensive role against predators, at least against those investigated in the present work. Other compounds present in Aristolochia host plants such as O-glycosylated AAs; benzylisoquinoline alkaloids; and mono-, sesqui-, di-, and triterpenes, which can be sequestered by Troidini, could act as deterrents against predators.

  12. The description of Austroglossus pectoralis (Teleostei: Soleidae larvae from the South-east coast of South Africa

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    Aidan D. Wood

    2000-12-01

    Full Text Available Preflexion and flexion larval stages of the East coast sole Austroglossus pectoralis are described. Larval morphology was consistent with that of other soleids. The yolk-sac was evident in larvae up to 2.9 mm BL. Flexion is evident in some 3.5 mm BL larvae and in all larvae > 3.8 mm BL. Larvae have 50 to 58 (8-10 + 40-49 myomeres and a large protruding gut. The head profile is rounded initially and becomes convex after flexion. Teeth are present at 4.0 mm BL and are initially robust, becoming elongate and incisor-shaped after flexion. Pectoral fins are present but no rays have developed in the largest specimen. The sequence of fin anlagen development is caudal, dorsal and anal. Eye migration is not evident in the largest (8.8 mm BL specimen examined. Pigment is evident over the fore- and mid-brain, snout and lower jaw, and along the ventral and dorsal midline of the trunk and tail. The ventral and lateral walls of the gut also bear melanophores. The larvae of A. pectoralis are compared with previously described soleid species which are found in southern African waters, including its congeneric A. microlepis.

  13. Direct effects of snowdrop lectin (GNA) on larvae of three aphid predators and fate of GNA after ingestion.

    Science.gov (United States)

    Hogervorst, Petra A M; Ferry, Natalie; Gatehouse, Angharad M R; Wäckers, Felix L; Romeis, Jörg

    2006-06-01

    Plants genetically modified to express Galanthus nivalis agglutinin (GNA) have been found to confer partial resistance to homopteran pests. Laboratory experiments were conducted to investigate direct effects of GNA on larvae of three species of aphid predators that differ in their feeding and digestive physiology, i.e. Chrysoperla carnea, Adalia bipunctata and Coccinella septempunctata. Longevity of all three predator species was directly affected by GNA, when they were fed a sucrose solution containing 1% GNA. However, a difference in sensitivity towards GNA was observed when comparing the first and last larval stage of the three species. In vitro studies revealed that gut enzymes from none of the three species were able to break down GNA. In vivo feed-chase studies demonstrated accumulation of GNA in the larvae. After the larvae had been transferred to a diet devoid of GNA, the protein stayed present in the body of C. carnea, but decreased over time in both ladybirds. Binding studies showed that GNA binds to glycoproteins that can be found in the guts of larvae of all three predator species. Immunoassay by Western blotting of haemolymph samples only occasionally showed the presence of GNA. Fluorescence microscopy confirmed GNA accumulation in the midgut of C. carnea larvae. Implications of these findings for non-target risk assessment of GNA-transgenic crops are discussed.

  14. Morphometrics and allometry of the larvae of five Characiformes species in the Paraíba do Sul River Basin.

    Science.gov (United States)

    Souza, Guilherme; Caramaschi, Erica P; Monteiro, Leandro R

    2017-08-01

    The aim of this study was to analyse the morphology and allometry of larvae belonging to five potamodromous species. Five breeding species belonging to the order Characiformes [Salminus brasiliensis (Cuvier, 1816), Leporinus steindachneri, Eigenmann, 1907, Prochilodus lineatus (Valenciennes, 1837), Prochilodus vimboides (Kner,1859) and Brycon insignis, Steindachner, 1877] were used to obtain larvae samples during the pre-flexing, post-flexing, and juvenile developmental stages. When we observed the degree-hour (DH) amplitude time values, we found three developmental groups based on allometry and morphometrics within the period between the pre-flexing and post-flexing phases. Group 1 consists of the species S. brasiliensis and B. insignis, Group 2 consists of P. lineatus and P. vimboides, and Group 3 consists of L. steindachneri. Group 1 requires less development time and has more slender larvae. Group 2 has a moderate development time and larvae with a more rounded shape. Group 3 presents a greater development time and an intermediate larval morphology. It was possible to classify the larvae through cross-validated discriminant analyses based on seven morphometric variables with 90% accuracy in B. insignis, 83% in L. steindachneri, 91% in P. lineatus, 80% in P. vimboides, and 96% in S. brasiliensis. These results indicate larval characteristics that can be used for the taxonomic identification of the icthyoplankton.

  15. Zoeal stages of Labidochirus anomalus (Balss, 1913) (Decapoda: Anomura: Paguridae) obtained under laboratory conditions.

    Science.gov (United States)

    Kornienko, Elena S; Korn, Olga M

    2015-10-08

    Zoeal stages of the hermit crab Labidochirus anomalus (Balss, 1913) (Decapoda: Anomura: Paguridae) are described and illustrated from the larvae reared in the laboratory. The development included four zoeal stages following the typical pattern in the Paguridae. Morphological features of the larvae of L. anomalus are compared with those described for the related species L. splendescens (Owen, 1839). The larvae of both species share numerous zoeal characters and are similar as the species of one genus. At the same time, zoeae of L. anomalus have no dorsal carina on the carapace and long posterolateral carapace spines-key features of the larvae of L. splendescens. These zoeal characters considered as generic are not characteristic of only the genus Labidochirus but sporadically occur among Pagurus species. Main characters of zoeal stages allow assignment of both Labidochirus species to the Group A of Pagurus (the typical representative P. bernhardus).

  16. Biofilms and Marine Invertebrate Larvae: What Bacteria Produce That Larvae Use to Choose Settlement Sites

    Science.gov (United States)

    Hadfield, Michael G.

    2011-01-01

    Communities of microorganisms form thin coats across solid surfaces in the sea. Larvae of many marine invertebrates use biofilm components as cues to appropriate settlement sites. Research on the tube-dwelling polychaete worm Hydroides elegans, a globally common member of biofouling communities, is described to exemplify approaches to understanding biofilm bacteria as a source of settlement cues and larvae as bearers of receptors for bacterial cues. The association of species of the bacterial genus Pseudoalteromonas with larval settlement in many phyla is described, and the question of whether cues are soluble or surface-bound is reviewed, concluding that most evidence points to surface-bound cues. Seemingly contradictory data for stimulation of barnacle settlement are discussed; possibly both explanations are true. Paleontological evidence reveals a relationship between metazoans and biofilms very early in metazoan evolution, and thus the receptors for bacterial cues of invertebrate larvae are very old and possibly unique. Finally, despite more than 60 years of intense investigation, we still know very little about either the bacterial ligands that stimulate larval settlement or the cellular basis of their detection by larvae.

  17. Effect of gut bacterial isolates from Apis mellifera jemenitica on Paenibacillus larvae infected bee larvae

    Directory of Open Access Journals (Sweden)

    Ahmad Al-Ghamdi

    2018-02-01

    Full Text Available The probiotic effects of seven newly isolated gut bacteria, from the indegenous honey bees of Saudi Arabia were investigated. In vivo bioassays were used to investigate the effects of each gut bacterium namely, Fructobacillus fructosus (T1, Proteus mirabilis (T2, Bacillus licheniformis (T3, Lactobacillus kunkeei (T4, Bacillus subtilis (T5, Enterobacter kobei (T6, and Morganella morganii (T7 on mortality percentage of honey bee larvae infected with P. larvae spores along with negative control (normal diet and positive control (normal diet spiked with P. larvae spores. Addition of gut bacteria to the normal diet significantly reduced the mortality percentage of the treated groups. Mortality percentage in all treated groups ranged from 56.67% up to 86.67%. T6 treated group exhibited the highest mortality (86.67%, whereas T4 group showed the lowest mortality (56.67%. Among the seven gut bacterial treatments, T4 and T3 decreased the mortality 56.67% and 66.67%, respectively, whereas, for T2, T6, and T7 the mortality percentage was equal to that of the positive control (86.67%. Mortality percentages in infected larval groups treated with T1, and T5 were 78.33% and 73.33% respectively. Most of the mortality occurred in the treated larvae during days 2 and 3. Treatments T3 and T4 treatments showed positive effects and reduced mortality.

  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. 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.

  20. 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.

  1. Fate of pharmaceuticals and pesticides in fly larvae composting

    International Nuclear Information System (INIS)

    Lalander, C.; Senecal, J.; Gros Calvo, M.; Ahrens, L.; Josefsson, S.; Wiberg, K.; Vinnerås, B.

    2016-01-01

    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.

  2. 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...... 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...

  3. Temperature and water quality effects in simulated woodland pools on the infection of Culex mosquito larvae by Lagenidium giganteum (Oomycetes: Lagenidiales) in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, D.R.; Axtell, R.C.

    1987-06-01

    Asexual stages of the California (CA) isolate of Lagenidium giganteum cultured on sunflower seed extract (SFE)-agar, were applied to outdoor pools containing Culex larvae near Raleigh, NC in August and September 1984. Infection rates among the larvae ranged from 19 to 74% at 2-4 days posttreatment and subsequent epizootics eliminated most of the newly hatched larvae for at least 10 days posttreatment. Substantial reductions in numbers of larvae and adult emergence were achieved from a single application of the fungus. Water quality and temperature data are presented. From laboratory assays of organically polluted water, the percent infection of Culex quinquefasciatus by the fungus was correlated with water quality and temperature. A logistic model of water quality (COD and NH/sub 3/-N) effects on infectivity rates by the CA isolate is described.

  4. First zoeal stage of the hermit crab Enallopaguropsis guatemoci (Glassell, 1937) (Crustacea: Anomura: Paguroidea: Paguridea) obtained in the laboratory.

    Science.gov (United States)

    Ayón-Parente, Manuel; Hendrickx, Michel E

    2017-02-03

    The first larval stage of Enallopaguropsis guatemoci is described in detail and illustrated. The larva is compared with larvae known for other genera of Paguridae except Pagurus. A synthesis of all characters provided herein indicates that first larvae of E. guatemoci can be separated from all known pagurid larvae (except Pagurus) by the combination of the following characters: carapace with long dorsal carina, posterolateral spines absent; abdominal somites 3-5 with pair of moderately long spines; telson narrowly triangular, not forked; spine at antennal protopod as long as endopod.

  5. Lagrange L4/L5 points and the origin of our Moon and Saturn's moons and rings.

    Science.gov (United States)

    Gott, J Richard

    2005-12-01

    The current standard theory of the origin of the Moon is that the Earth was hit by a giant impactor the size of Mars causing ejection of debris from its mantle that coalesced to form the moon; but where did this Mars-sized impactor come from? Isotopic evidence suggests that it came from 1 AU radius in the solar nebula, and computer simulations are consistent with its approaching Earth on a zero-energy parabolic trajectory. How could such a large object form at 1 AU in a quiescent disk of planetesimals without having already collided with the Earth at an earlier epoch before having the chance to grow large? Belbruno and Gott propose that the giant impactor could have formed in a stable orbit from debris at the Earth's Lagrange point L(5) (or L(4)). It would grow quietly by accretion at L(5) (or L(4)), but eventually gravitational perturbations by other growing planetesimals would kick it out into a horseshoe orbit and finally into a chaotic creeping orbit, which Belbruno and Gott show would, with high probability, hit the Earth on a near zero-energy parabolic trajectory. We can see other examples of this phenomenon occurring in the solar system. Asteroid 2002AA29 is in a horseshoe orbit relative to the Earth that looks exactly like the horseshoe orbits that Belbruno and Gott found for objects that had been perturbed from L(4)/L(5). The regular moons of Saturn are made of ice and have the same albedo as the ring particles (ice chunks, plus some dust). We (J. R. Gott, R. Vanderbei, and E. Belbruno) propose that the regular icy moons of Saturn (out to the orbit of Titan), which are all in nearly circular orbits, formed out of a thin disk of planetesimals (ice chunks) rather like the rings of Saturn today only larger in extent. In such a situation formation of objects at L(4)/L(5) might be expected. Indeed, Saturn's moon Dione is accompanied by moons (Helene and Polydeuces) at both L(4) and L(5) Lagrange points, and Saturn's moon Tethys is also accompanied by moons

  6. Fish larvae from the Gulf of California

    Directory of Open Access Journals (Sweden)

    Gerardo Aceves-Medina

    2003-03-01

    Full Text Available Taxonomic composition of fish larvae was analysed from 464 plankton samples obtained during 10 oceanographic surveys in the Gulf of California between 1984 and 1988. We identified 283 taxa: 173 species, 57 genera, and 53 families. Tropical and subtropical species predominated except during the winter, when temperate-subarctic species were dominant. The most abundant species were the mesopelagic Benthosema panamense, Triphoturus mexicanus and Vinciguerria lucetia, but the coastal pelagic species Engraulis mordax, Opisthonema spp., Sardinops caeruleus and Scomber japonicus were also prominent. The taxonomic composition of the ichthyoplankton shows the seasonality of the Gulf as well as environmental changes that occurred between the 1984-1987 warm period and the 1956-1957 cool period previously reported. The presence of E. mordax larvae as one of the most abundant species in the Gulf provides evidence of the reproduction of this species two years before the development of the northern anchovy fishery and the decline of the sardine fishery in the Gulf of California.

  7. 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.

  8. Morfologia do trato digestório e dieta de larvas de Bryconamericus aff. iheringii (Boulenger, 1887 (Osteichthyes, Characidae = Morphology of Digestive tract and diet of Bryconamericus aff. iheringii larvae (Boulenger, 1887 (Osteichthyes, Characidae

    Directory of Open Access Journals (Sweden)

    Renato Ziliani Borges

    2006-01-01

    Full Text Available Este trabalho teve como objetivo analisar alguns aspectos da alimentação de larvas de Bryconamericus aff. iheringii, capturadas nos meses de julho e novembro de 2001, nas regiões limnética e litorânea do reservatório de Santa Maria, rio Piquiri, Estado do Paraná. As larvas apresentaram boca subterminal durante todo o seu desenvolvimento. O tubo digestório se diferenciou em estômago e intestino apenas no estágio de pós-flexão. As larvas consumiram, principalmente, algas e microcrustáceos, o que permitiu caracterizá-las como planctófagas. A intensa modificação morfológica no trato digestório nos indivíduos em pósflexão coincidiu com o aumento na abundância de algas em relação aos itens de origemanimal; porém, de forma geral, a ocorrência aumentou para todos os itens. A análise do grau de digestão dos itens alimentares sugeriu que indivíduos em pré-flexão alimentaram-se, possivelmente, durante o dia, e os mais desenvolvidos, durante o entardecer e no períodonoturno.The aim of this study was to analyze some feeding treats of Bryconamericus aff. iheringii larvae, sampled in both the limnetic and littoral regions of the Piquiri River, in Santa Maria reservoir, between July and November 2001. The larvae presented sub-terminal mouth in larval period. The digestive tract differentiated in terms of stomach and intestine only in the postflexion larvae. The larvae fed mainly on algae and microcrustacea allowing to characterize them as planktivorous. The intense morphologic shift in the digestive tract in the postflexion larvae coincided with an increase in the abundance of algae in relation to animals items; however, in general, all the items had their occurrence increased. Analysis of the digestion stage suggested that preflexion larvae, possibly, fed themselves during the day, and those more developed, at dusk and night.

  9. Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae).

    Science.gov (United States)

    Abrunhosa, Fernando A; Simith, Darlan J B; Palmeira, Carlos A M; Arruda, Danielle C B

    2008-12-01

    Food supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development). In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period. High survival rate was observed in both experiments, in which only 2 megalopae and 1 zoea III died. These results strongly suggest that larvae of L. siriboia are lecithotrophic as they have sufficiently large yolk reserve to complete their larval development, while the megalopa stage shows facultative lecithotrophy. The larval periods of each stage of the treatments were quite similar and, despite some significant differences in some larval periods, these can be related probably to larval rearing conditions, abiotic factors or, individual variability of larval health, as well as stress caused to the ovigerous females during embryogenesis.

  10. Isotopic discrimination factors and nitrogen turnover rates in reared Atlantic bluefin tuna larvae (Thunnus thynnus: effects of maternal transmission

    Directory of Open Access Journals (Sweden)

    Amaya Uriarte

    2016-11-01

    Full Text Available The use of stable isotope analysis to study animal diets requires estimates of isotopic turnover rates (half time, t50 and discrimination factors (Δ for an accurate interpretation of trophic patterns. The stable isotopes of carbon and nitrogen were analysed for eggs and reared larvae of Thunnus thynnus, as well as for the different diets supplied during the experiment. The results showed high values of δ15N in eggs and larvae (n=646 until 4 DAH. After this time lapse, the stable isotope values declined progressively until 12 DAH, when notochord flexion began. The δ13C showed an inverse trend, suggesting that maternal inheritance of the stable isotopes is evident until pre-flexion stages. This study proposes a model for estimating maternal isotopic signatures of bluefin broodstock. After notochord flexion, larvae were fed with aquaculture-bred gilthead seabream, which resulted in a rapid increase of bluefin larvae δ15N values together with a rapid decrease in δ13C values. The estimated nitrogen half-time to reach the steady state from the diet was 2.5±0.3 days and the discrimination factor was 0.4±0.3(‰. These results represent the first data set that has allowed isotopic nitrogen turnover rates and discrimination factors of the larval stages of bluefin tuna to be estimated.

  11. Morphological Development of Eggs, Larvae and Juveniles of the Far Eastern Catfish, Silurus asotus in Korea (Pisces: Siluridae).

    Science.gov (United States)

    Mun, Seong Jun; Yim, Hu Sun; Han, Kyeong Ho; Park, Jae Min

    2017-12-01

    This study was conducted to investigate egg development and larvae morphological development of catfish and to provide basic data to clarify the genetic relationship with Siluriformes fish. The mother fish that was used in this study was caught in the stream of Nakdong River in Uiseong-gun, Gyeongbuk. The temperature range of the breeding was 23.0-25.0℃ (mean 24.0±1.0℃) and egg size was 1.62-1.70 mm (mean 1.66±0.05, n=30). Eggs of catfish began hatching at 54 hours and 40 minutes after fertilization. Immediately after hatching, the total length of larvae was 3.60-3.65 mm (mean 3.62±0.03, n=5) and had an egg yolk without swimming ability. On the third day after hatching, the larvae at the medium stage was 8.00-8.65 mm (mean 8.32±0.45) in total length, and two pairs of whiskers formed around the mouth were elongated. On the 12th day after hatching, the larvae at the juvenile stage was 16.5-17.0 mm (mean 16.7±0.35) in total length, and the stem of each fin was in the range, and the juvenile at this period was morphologically similar to the mother fish.

  12. Peculiarities of Embryonic and Post-Embryonic Development of Оesophagostomum dentatum (Nematoda, Strongylidae Larvae Cultured in Vitro

    Directory of Open Access Journals (Sweden)

    Yevstafieva V. А.

    2017-02-01

    Full Text Available Morphometric peculiarities of the development of Оesophagostomum dentatum Rudolphi, 1803 from egg to infective larva were studied under laboratory conditions at various temperatures. The determined optimum temperature for embryonic and post-embryonic development of О. dentatum larvae from domestic pig (Sus scrofa domesticus Linnaeus, 1758 is 22 °С. At this temperature, 81 % of larvae develop to the third stage (L3 on the 10th day. Temperatures of 24 °С and 20 °С are less favorable for the development of the nematode, at those temperatures only 67 and 63 % of larvae, respectively, reached infective stage by the 10th day of cultivation. Embryonic development of О. dentatum eggs is characterized by their lengthening (by 8.87-9.50 %, р < 0.01 and widening (by 6.77-9.35 %, р < 0.05-0.01, and post-embryonic larval development is associated with lengthening (by 4.59-17.33 %, р < 0.01-0.001.

  13. Musculoskeletal anatomy and feeding performance of pre-feeding engyodontic larvae of the European eel (Anguilla anguilla)

    Science.gov (United States)

    Bouilliart, Mathias; Tomkiewicz, Jonna; Lauesen, Peter; De Kegel, Barbara; Adriaens, Dominique

    2015-01-01

    Being part of the elopomorph group of fishes, Anguillidae species show a leptocephalus larval stage. However, due to largely unknown spawning locations and habitats of their earliest life stages, as well as their transparency, these Anguilla larvae are rarely encountered in nature. Therefore, information regarding the early life history of these larvae, including their exogenous feeding strategy and feeding performance, is rather scarce. To better understand the structural basis and functional performance of larval feeding in captivity, the functional morphology of the cranial musculoskeletal system in pre- and first-feeding engyodontic leptocephali of the European eel (Anguilla anguilla) was studied. A 3D reconstruction of the feeding apparatus (head of the leptocephali < 1 mm) was used to visualize and describe the musculoskeletal changes throughout these stages. To analyze the ontogenetic changes in the functionality of the feeding apparatus towards the active feeding phase, 3D data of joints, levers and muscles derived from the reconstructions were used to estimate bite and joint reaction forces (JRFs). Observing a maximum estimated bite force of about 65 μN (and corresponding JRFs of 260 μN), it can be hypothesized that leptocephalus larvae are functionally constrained to feed only on soft food particles. Additionally, potential prey items are size delimited, based on the theoretically estimated average gape of these larvae of about 100 μm. This hypothesis appears to be in line with recent observations of a diet consisting of small and/or gelatinous prey items (Hydrozoa, Thaliacea, Ctenophora, Polycystenia) found in the guts of euryodontic leptocephalus larvae. PMID:26278932

  14. Musculoskeletal anatomy and feeding performance of pre-feeding engyodontic larvae of the European eel (Anguilla anguilla).

    Science.gov (United States)

    Bouilliart, Mathias; Tomkiewicz, Jonna; Lauesen, Peter; De Kegel, Barbara; Adriaens, Dominique

    2015-09-01

    Being part of the elopomorph group of fishes, Anguillidae species show a leptocephalus larval stage. However, due to largely unknown spawning locations and habitats of their earliest life stages, as well as their transparency, these Anguilla larvae are rarely encountered in nature. Therefore, information regarding the early life history of these larvae, including their exogenous feeding strategy and feeding performance, is rather scarce. To better understand the structural basis and functional performance of larval feeding in captivity, the functional morphology of the cranial musculoskeletal system in pre- and first-feeding engyodontic leptocephali of the European eel (Anguilla anguilla) was studied. A 3D reconstruction of the feeding apparatus (head of the leptocephali < 1 mm) was used to visualize and describe the musculoskeletal changes throughout these stages. To analyze the ontogenetic changes in the functionality of the feeding apparatus towards the active feeding phase, 3D data of joints, levers and muscles derived from the reconstructions were used to estimate bite and joint reaction forces (JRFs). Observing a maximum estimated bite force of about 65 μN (and corresponding JRFs of 260 μN), it can be hypothesized that leptocephalus larvae are functionally constrained to feed only on soft food particles. Additionally, potential prey items are size delimited, based on the theoretically estimated average gape of these larvae of about 100 μm. This hypothesis appears to be in line with recent observations of a diet consisting of small and/or gelatinous prey items (Hydrozoa, Thaliacea, Ctenophora, Polycystenia) found in the guts of euryodontic leptocephalus larvae. © 2015 Anatomical Society.

  15. Distributions and seasonal abundances of krill eggs and larvae in the sub-Arctic Godthåbsfjord, SW Greenland

    DEFF Research Database (Denmark)

    Teglhus, Frederik Wolff; Agersted, Mette Dalgaard; Akther, Hasna

    2015-01-01

    and furcilia stages lasted 22 and 63 d, respectively. The growth rate from metanauplius to calyptopis was 0.12 d−1, while the growth rate across all developmental stages was 0.05 d−1. Mortality rates were calculated as 25% from eggs to nauplii, 48% from eggs to calyptopes and 83% from eggs to furcilia. During...... development, the larvae were dispersed from the shallow, warmer hatching area in the inner part of the fjord to the main fjord by tidal currents and runoff from land. The study showed that developmental stages of krill are a key group in Greenland coastal waters, one which should be considered in future...

  16. Toxicity and sublethal effects of six insecticides to last instar larvae and adults of the biocontrol agents Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Garzón, A; Medina, P; Amor, F; Viñuela, E; Budia, F

    2015-08-01

    To further develop Integrated Pest Management (IPM) strategies against crop pests, it is important to evaluate the effects of insecticides on biological control agents. Therefore, we tested the toxicity and sublethal effects (fecundity and fertility) of flonicamid, flubendiamide, metaflumizone, spirotetramat, sulfoxaflor and deltamethrin on the natural enemies Chrysoperla carnea and Adalia bipunctata. The side effects of the active ingredients of the insecticides were evaluated with residual contact tests for the larvae and adults of these predators in the laboratory. Flonicamid, flubendiamide, metaflumizone and spirotetramat were innocuous to last instar larvae and adults of C. carnea and A. bipunctata. Sulfoxaflor was slightly toxic to adults of C. carnea and was highly toxic to the L4 larvae of A. bipunctata. For A. bipunctata, sulfoxaflor and deltamethrin were the most damaging compounds with a cumulative larval mortality of 100%. Deltamethrin was also the most toxic compound to larvae and adults of C. carnea. In accordance with the results obtained, the compounds flonicamid, flubendiamide, metaflumizone and spirotetramat might be incorporated into IPM programs in combination with these natural enemies for the control of particular greenhouse pests. Nevertheless, the use of sulfoxaflor and deltamethrin in IPM strategies should be taken into consideration when releasing either of these biological control agents, due to the toxic behavior observed under laboratory conditions. The need for developing sustainable approaches to combine the use of these insecticides and natural enemies within an IPM framework is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae

    Directory of Open Access Journals (Sweden)

    Fernando A. Abrunhosa

    2008-12-01

    Full Text Available Food supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development. In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period. High survival rate was observed in both experiments, in which only 2 megalopae and 1 zoea III died. These results strongly suggest that larvae of L. siriboia are lecithotrophic as they have sufficiently large yolk reserve to complete their larval development, while the megalopa stage shows facultative lecithotrophy. The larval periods of each stage of the treatments were quite similar and, despite some significant differences in some larval periods, these can be related probably to larval rearing conditions, abiotic factors or, individual variability of larval health, as well as stress caused to the ovigerous females during embryogenesis.A alimentação é considerada crítica em cultivo de larvas de decápodes. No entanto, algumas espécies podem apresentar reservas nutritivas suficientes para completar o desenvolvimento larval sem a necessidade de alimentação externa (conhecido como desenvolvimento larval lecitotrófico. No presente estudo, dois experimentos foram realizados para verificar se o callianassídeo Lepidophthalmus siriboia tem comportamento lecitotrófico ou se precisa de alimento externo para completar o desenvolvimento larval: Experimento 1, larvas submetidas a um período inicial de alimentação e, Experimento 2, larvas submetidas a um período inicial de inanição. Em ambos os experimentos, observou-se altas taxas de sobrevivência, com

  18. Comparative assessment of the bacterial communities associated with Aedes aegypti larvae and water from domestic water storage containers.

    Science.gov (United States)

    Dada, Nsa; Jumas-Bilak, Estelle; Manguin, Sylvie; Seidu, Razak; Stenström, Thor-Axel; Overgaard, Hans J

    2014-08-24

    identified in fourth-instar Ae. aegypti larvae, suggesting that established larval bacteria, most likely acquired at earlier stages of development, control the larval microbiota. Further studies at all larval stages are needed to fully understand the dynamics involved. Isolation of enteric bacteria from water samples supports earlier outcomes of E. coli contamination in Ae. aegypti infested domestic containers, suggesting the need to further explore the role of enteric bacteria in Ae. aegypti infestation.

  19. Soil Moisture Active Passive (SMAP) Mission Level 4 Surface and Root Zone Soil Moisture (L4_SM) Product Specification Document

    Science.gov (United States)

    Reichle, Rolf H.; Ardizzone, Joseph V.; Kim, Gi-Kong; Lucchesi, Robert A.; Smith, Edmond B.; Weiss, Barry H.

    2015-01-01

    This is the Product Specification Document (PSD) for Level 4 Surface and Root Zone Soil Moisture (L4_SM) data for the Science Data System (SDS) of the Soil Moisture Active Passive (SMAP) project. The L4_SM data product provides estimates of land surface conditions based on the assimilation of SMAP observations into a customized version of the NASA Goddard Earth Observing System, Version 5 (GEOS-5) land data assimilation system (LDAS). This document applies to any standard L4_SM data product generated by the SMAP Project. The Soil Moisture Active Passive (SMAP) mission will enhance the accuracy and the resolution of space-based measurements of terrestrial soil moisture and freeze-thaw state. SMAP data products will have a noteworthy impact on multiple relevant and current Earth Science endeavors. These include: Understanding of the processes that link the terrestrial water, the energy and the carbon cycles, Estimations of global water and energy fluxes over the land surfaces, Quantification of the net carbon flux in boreal landscapes Forecast skill of both weather and climate, Predictions and monitoring of natural disasters including floods, landslides and droughts, and Predictions of agricultural productivity. To provide these data, the SMAP mission will deploy a satellite observatory in a near polar, sun synchronous orbit. The observatory will house an L-band radiometer that operates at 1.40 GHz and an L-band radar that operates at 1.26 GHz. The instruments will share a rotating reflector antenna with a 6 meter aperture that scans over a 1000 km swath.

  20. 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.

  1. Preliminary screening of plant essential oils against larvae of Culex ...

    African Journals Online (AJOL)

    Preliminary screenings of 22 plant essential oils were tested for mortality of the mosquito larvae Culex quinquefasciatus under laboratory conditions. Percent (%) mortality of the mosquito larvae were obtained for each essential oil. At different exposure periods, viz. 1, 3, 6, 12 and 24 h among the 22 plant oils tested, eight ...

  2. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... Biological control of mosquito larvae by using fish has shown many advantages over ... number of malaria cases in India that has been reduced from 75 million to 150,000 and deaths from 750,000 to ... aquatic weeds and G. affinis on the mosquito larvae. In addition to that G. affinis has some adverse effects ...

  3. Temporal dynamics of Chaoborus larvae (Diptera : Chaoboridae) in ...

    African Journals Online (AJOL)

    Chaoborus larvae are voracious predators of zooplankton able to change their specific composition and size structure. Thus they appear as competitors of fish. They also represent food for planktophage fish. The temporal dynamics of Chaoborus larvae was studied (from january to october 1997) in the fishery of Bakro ...

  4. 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

  5. Structure and occurrence of cyphonautes larvae (Bryozoa, Ectoprocta)

    DEFF Research Database (Denmark)

    Nielsen, Claus; Worsaae, Katrine

    2010-01-01

    We have studied larvae of the freshwater ctenostome Hislopia malayensis with scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and LM of serial sections. Some additional observations on larvae of M. membranacea using SEM and CLSM are also reported. The overall configu...

  6. Composition, Abundance and Distribution of Brachyuran Larvae in ...

    African Journals Online (AJOL)

    ... Ocypodidae, Grapsidae and Xanthidae. Abundance of brachyuran larvae was significantly positively correlated with total zooplankton abundance (r2 = 0.8) and salinity (r2 = 0.71). Keywords: Brachyuran larvae, abundance, composition, Mida creek, Kenya West Indian Ocean Journal of Marine Science Vol. 3 (2) 2004: pp.

  7. Occurrence of digenean larvae in freshwater snails in the Ruvu ...

    African Journals Online (AJOL)

    Occurrence of digenean larvae in freshwater snails in the Ruvu basin, Tanzania. G Nkwengulila, ESP Kigadye. Abstract. A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for ...

  8. The occurrence of digenean larvae in freshwater snails at Mbezi ...

    African Journals Online (AJOL)

    The occurrence of digenean larvae in freshwater snails at Mbezi-Temboni pond, Dar es Salaam. ESP Kigadye, G Nkwengulila. Abstract. The abundance of digenean larvae in snails at a pond in Mbezi-Temboni, Dar es Salaam, was investigated from July 1996 to June 1997. A total of 2,112 snails belonging to three species, ...

  9. Larvicidal effects of lemon peels on mosquito larvae | ANYANWU ...

    African Journals Online (AJOL)

    Methanol extract of the dry peels of the common edible plant, Citrus limon (family, Rutaceae), was obtained using a Soxhlet extractor and its larviciding effect evaluated against the larvae of two household mosquitoes: Aedes aegypti and Culex quinquefasciatus. Each batch of larvae (20-30) were treated with 3.90, 15.63, ...

  10. Shrinkage Rates In Newly Hatched Larvae Of Macrobrachium ...

    African Journals Online (AJOL)

    The effect of formalin/sea-water solution (2% and 4% formalin conc. buffered with borax) on the total lengths of preserved samples of newly hatched Macrobrachium vollenhovenii larvae was investigated. The influence of an aesthesia on larvae in 2% and 4% formal in was also studied to determine the combine influence of ...

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

    DEFF Research Database (Denmark)

    Helwigh, Birgitte; Lind, Peter; Nansen, Peter

    1999-01-01

    of uninfected pigs was used as negative controls for blood parameters and weight gain. Toxocara canis migrated well in the pig, although the relative numbers of larvae recovered decreased significantly during the experiment. On day 7 p.i., high numbers of larvae were recovered from the lymph nodes around...

  13. Nutritional condition of fish larvae in South African estuaries: an ...

    African Journals Online (AJOL)

    It is concluded that the individual RNA/DNA ratio can provide a reliable, sensitive and cost-effective method to assess the immediate effects of environmental changes on the nutritional condition of estuarine fish larvae. Keywords: estuarine ecology, Gilchristella aestuaria larvae, lipid content, protein content, RNA/DNA ratio, ...

  14. Observations on the seasonal dynamics of Caddisfly larvae ...

    African Journals Online (AJOL)

    The Trichoptera fauna in the water body consisted of two genera, Cheumatopsyche and Amphipsyche, which closely associated with the moss, Fontinalis (Bryophyta). The density of larvae increased with the occurrence and bloom of moss. The changes in density of larvae are discussed with reference to the resources ...

  15. Preliminary notes on the decapod larvae of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, M.K.; Menon, P.G.; Paulinose, V.T.

    fairly good numbers were captured are described and illustrated with suitable charts The possible effect of the time of haul and the season on the number of larvae caught is explained The probable parentage of the more commonly encountered types of larvae...

  16. Grid expansion: a rhombiclike [L4Fe2(Ag2)2] complex containing Ag2 dumbbells at two vertices.

    Science.gov (United States)

    Schneider, Benjamin; Demeshko, Serhiy; Dechert, Sebastian; Meyer, Franc

    2012-05-07

    The pyrazolate-based ditopic ligand HL forms a strongly hydrogen-bonded corner complex dimer [Fe(II)(HL)(2)](2)(BF(4))(4) (1) with a [2 × 2] gridlike arrangement of four ligand strands. The two empty vertices can then be filled with {Ag(2)}(2+) dumbbells, yielding the unprecedented diferric complex [L(4)Fe(III)(2)(Ag(I)(2))(2)](BF(4))(6) (2) that features a rhombiclike structure with an almost planar hexagon of metal ions.

  17. Description of the immature stages and life history of Euselasia (Lepidoptera: Riodinidae) on Miconia (Melastomataceae) in Costa Rica

    Science.gov (United States)

    K. Nishida

    2010-01-01

    The immature stages and life histories of Euselasia chrysippe (Bates, 1866) and E. bettina (Hewitson, 1869) are described, providing the first detailed morphological characters for the subfamily Euselasiinae. The larvae of Euselasia chrysippe and E. bettina ...

  18. Freshly squeezed: anaphylaxis caused by drone larvae juice.

    Science.gov (United States)

    Stoevesandt, J; Trautmann, A

    2017-11-30

    Drone larvae are mostly considered a by-product of beekeeping, but have recently been advo-cated as a high-protein source of food. There are as yet no data concerning their allergenic po-tential. We report on a 29-year old bee keeper who experienced an anaphylactic reaction following the consumption of a freshly prepared beverage from raw drone larvae. Larvae-specific sensitization was confirmed by prick-to-prick and basophil activation testing. Bee stings and classical bee products including honey and royal jelly were tolerated. This is the hitherto first report on IgE-mediated allergy to drone larvae. We suggest that a certain awareness towards the allergenicity of bee larvae is required.

  19. External Ophthalmomyiasis Caused by a Rare Infesting Larva, Sarcophaga argyrostoma

    Directory of Open Access Journals (Sweden)

    Shmuel Graffi

    2013-01-01

    Full Text Available Purpose. External ophthalmomyiasis (EO is caused by infesting larvae belonging to various species of flies. Most documented cases result from sheep (Oestrus ovis and Russian (Rhinoestrus purpureus botfly larvae, but we recently discovered a rare case of EO caused by flesh fly (Sarcophaga argyrostoma larvae. Here, we report the case of a patient with EO who had been hospitalized and sedated for 1 week because of unrelated pneumonia. Methods. Case report. Results. A total of 32 larvae were removed from the adnexae of both eyes. Larvae identification was confirmed through DNA analysis. Treatment with topical tobramycin resulted in complete resolution of EO. Conclusion. EO can be caused by S. argyrostoma, and the elderly and debilitated may require extra ocular protection against flies during sedation.

  20. Sulfolipid in mulberry leaves and faeces of silkworm larvae

    International Nuclear Information System (INIS)

    Yamashita, Tadaaki

    1975-01-01

    Sulfoquinovosyl diglyceride (sulfolipid) were separated by chromatography on a ECTEOLA cellulose column from the extracts of mulberry leaves and faeces of silkworm larvae. Lipid from the leaves which had been labeled with 35 S-sulfuric acid for 24 hours separated to five 35 S containing fractions on column chromatography. Most of the 35 S in the lipid fraction was recovered as sulfolipid. No appreciable amounts of 35 S, however, were recognized as sulfolipid in the extract of the faeces of silkworm larvae which were fed 35 S-containing mulberry leaves. These results suggest that silkworm larvae actively dissimilate sulfolipid, which is the most abundant among the sulfur containing lipids in mulberry leaves. When 35 S labeled sulfolipid which was recovered from the extract of mulberry leaves was fed to the larvae, 35 S was not incorporated into the cell constituent of the larvae and 35 S of sulfolipid was entirely excreted. (auth.)

  1. Fixation of Ilyanassa snail embryos and larvae.

    Science.gov (United States)

    Gharbiah, Maey; Cooley, James; Leise, Esther M; Nakamoto, Ayaki; Rabinowitz, Jeremy S; Lambert, J David; Nagy, Lisa M

    2009-04-01

    The marine gastropod Ilyanassa obsoleta is a long-standing and very useful model for studies of embryonic development. It is an especially important model for spiralian development, and for studies of asymmetric cell division. The embryos are amenable to classic embryological manipulation techniques, as well as a growing number of molecular approaches. Ilyanassa is also an important model for studies of metamorphosis, the ecology of parasitism, the effects of environmental contaminants on morphology and sexual function, and comparative neurobiology. Ilyanassa embryos are particularly well suited for RNA and protein localization studies because of the relatively large cells and favorable properties for imaging. This protocol describes how to fix and store Ilyanassa embryos and larvae for use in whole-mount in situ hybridization and immunohistochemical studies.

  2. Morphology and Ecological Notes on the Larvae and Pupae of Simulium (Simulium from Korea

    Directory of Open Access Journals (Sweden)

    Sam-Kyu Kim

    2015-10-01

    Full Text Available Morphological features of larvae and pupae of twelve species of Simulium (Simulium from Korea are investigated and redescribed. Detailed descriptions of immature stages of each species are provided with photographs. For the Korean members of subgenus Simulium, combinations of the following characteristics can be used to separate them from other Korean subgenera: larval abdomen without a pair of conical-shaped ventral tubercles; postgenal cleft variously shaped, viz., miter shaped, spearhead, bullet shaped or triangular; rectal papillae 3 simple lobe or compound lobes; pupal gill of 6-16 filaments; cocoon shoe, boot or slipper shaped; and head trichomes 3 pairs (1 facial+2 frontal. Habitat information and other ecological aspects of each species are provided. Updated keys to larvae and pupae of the Korean species of the subgenus Simulium are also provided to facilitate species identification. Taxonomic treatment based on external morphologies of larvae and pupae of Korean species of the subgenus Simulium are focused and included in this study. To understand their interspecific relationships, phylogenetic analyses using multiple data from molecule, morphology, and ecology are warranted in future research. Also continued exploration for new character systems is needed to establish more stable boundaries for subgenus and species delimitations.

  3. Vitellin- and hemoglobin-digesting enzymes in Rhipicephalus (Boophilus) microplus larvae and females.

    Science.gov (United States)

    Estrela, Andréia Bergamo; Seixas, Adriana; Teixeira, Vivian de Oliveira Nunes; Pinto, Antônio Frederico Michel; Termignoni, Carlos

    2010-12-01

    The aim of the present study was to address the involvement of Rhipicephalus microplus larval cysteine endopeptidase (RmLCE) in protein digestion in R. microplus larvae and adult females. In this work, an improved purification protocol for native RmLCE was developed. Partial amino acid sequence of the purified enzyme indicates that it is the same enzyme as Boophilus microplus cathepsin-L1 (BmCL1). When vitellin (Vt) degradation by egg and larval enzymes was analyzed, stage-specific differences for RmLCE activity in comparison to vitellin-degrading cysteine endopeptidase (VTDCE) were observed. RmLCE is also able to degrade host hemoglobin (Hb). In agreement, an acidic cysteine endopeptidase activity was detected in larval gut. It was shown that cysteine and aspartic endopeptidases are involved in Vt and Hb digestion in R. microplus larvae and females. Interestingly, we observed that the aspartic endopeptidase Boophilus yolk cathepsin (BYC) is associated with a cysteine endopeptidase activity, in larvae. Synergic hemoglobin digestion by BYC and RmLCE was observed and indicates the presence of an Hb-degrading enzymatic cascade involving these enzymes. Our results suggest that RmLCE/BmCL1 has a continued role in vitellin and hemoglobin digestion during tick development. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Larvicidal Activity of Nerium oleander against Larvae West Nile Vector Mosquito Culex pipiens (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Fouad El-Akhal

    2015-01-01

    Full Text Available Background. Outbreaks of the West Nile virus infection were reported in Morocco in 1996, 2003, and 2010. Culex pipiens was strongly suspected as the vector responsible for transmission. In the North center of Morocco, this species has developed resistance to synthetic insecticides. There is an urgent need to find alternatives to the insecticides as natural biocides. Objective. In this work, the insecticidal activity of the extract of the local plant Nerium oleander, which has never been tested before in the North center of Morocco, was studied on larval stages 3 and 4 of Culex pipiens. Methods. Biological tests were realized according to a methodology inspired from standard World Health Organization protocol. The mortality values were determined after 24 h of exposure and LC50 and LC90 values were calculated. Results. The extract had toxic effects on the larvae of culicid mosquitoes. The ethanolic extract of Nerium oleander applied against the larvae of Culex pipiens has given the lethal concentrations LC50 and LC90 in the order of 57.57 mg/mL and 166.35 mg/mL, respectively. Conclusion. This investigation indicates that N. oleander could serve as a potential larvicidal, effective natural biocide against mosquito larvae, particularly Culex pipiens.

  5. Common European harmful algal blooms affect the viability and innate immune responses of Mytilus edulis larvae.

    Science.gov (United States)

    De Rijcke, M; Vandegehuchte, M B; Vanden Bussche, J; Nevejan, N; Vanhaecke, L; De Schamphelaere, K A C; Janssen, C R

    2015-11-01

    Like marine diseases, harmful algal blooms (HABs) are globally increasing in frequency, severity and geographical scale. As a result, bivalves will have to face the combined threat of toxic algae and marine pathogens more frequently in the (near) future. These stressors combined may further affect the recruitment of ecologically and economically important bivalve species as HABs can affect the growth, viability and development of their larvae. To date, little is known on the specific effects of HABs on the innate immune system of bivalve larvae. This study therefore investigates whether two common harmful algae can influence the larval viability, development and immunological resilience of the blue mussel Mytilus edulis. Embryos of this model organism were exposed (48 h) to five densities of Pseudo-nitzschia multiseries or Prorocentrum lima cells. In addition, the effect of six concentrations of their respective toxins: domoic acid (DA) and okadaic acid (OA) were assessed. OA was found to significantly reduce larval protein phosphatase activity (p lima (150 cells ml(-1)) and DA (dosed five times higher than typical environmental conditions i.e. 623.2 μg l(-1)) increased the phenoloxidase (PO) innate immune activity of the mussel larvae. These results suggest that the innate immune response of even the earliest life stages of bivalves is susceptible to the presence of HABs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Operational and structural measures to reduce hydro-peaking impact on fish larvae

    International Nuclear Information System (INIS)

    Kopecki, Ianina; Schneider, Matthias

    2016-01-01

    Eco-hydraulic investigations studying the effects of hydro-peaking on river biota are gaining in importance. Negative effects of rapid flow fluctuations due to hydro power production are well documented by many studies, with the larvae and juvenile fish identified among the mostly affected life stages. Therefore, elaboration of efficient hydro-peaking mitigation strategies is an important issue for energy companies as well as for water body administrations responsible for the fulfilment of WFD requirements. The present case study strives for practical solutions allowing to minimize or compensate the negative effects of hydro-peaking on the fish fauna of the 7 km long river reach on the river Lech (southern Germany). Model based investigations allow to access the impact from currently authorized discharge regime, suggest operational and structural measures within the reach in terms of reducing the risk of stranding for fish larvae and select the measures most easy to implement and with the largest ecological benefit. The paper describes the approach for accessing the effects of hydro-peaking based on 2D hydrodynamic modelling, fuzzy logic based habitat modelling and information on cutting-edge biological investigations on fish larvae from Lunz experimental facility (Austria). (authors)

  7. Bioamplification and the selective depletion of persistent organic pollutants in Chinook salmon larvae.

    Science.gov (United States)

    Daley, Jennifer M; Leadley, Todd A; Pitcher, Trevor E; Drouillard, Ken G

    2012-02-21

    The maternal provisioning of yolk to eggs transfers significant quantities of persistent organic pollutants (POPs). As yolk utilization progresses via metabolic activity, there is a potential to realize further increases in POP concentrations if yolk lipids are depleted at a faster rate than POPs, a condition referred to as bioamplification. This study investigated the bioamplification of POPs in Chinook salmon ( Oncorhynchus tshawytscha ) eggs and larvae. Chinook eggs were sampled from the Credit River, ON, Canada, and brought to an aquaculture facility where they were fertilized, incubated, and maintained posthatch until maternally derived lipid reserves became depleted (approximately 168 days). The loss of chemicals having an octanol-water partition coefficient (log K(OW)) greater than 5.8 was slow to negligible from days 0-135. However, during the increase in water temperatures in early spring, K(OW)-dependent elimination of POPs was observed. Bioamplification was maximized for the highest log K(OW) POPs, with an approximate 5-fold increase in lipid equivalents concentrations in 168 day old larvae as compared to newly fertilized eggs. This study demonstrates that later yolk-sac Chinook larvae (before exogenous feeding) are exposed to higher lipid equivalents POP concentrations than predicted by maternal deposition, which could lead to underestimates in the toxicity of critical life stages.

  8. Behavioural responses of Frankliniella occidentalis Pergande larvae to methyl jasmonate and cis-jasmone.

    Science.gov (United States)

    Egger, Barbara; Koschier, Elisabeth H

    2014-01-01

    The larval stages of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) cause more direct feeding damage to plants than the adults. We, therefore, investigated the behaviour-modifying effects on second instar larvae of two jasmonic acid derivatives. The artificial application of methyl jasmonate and cis -jasmone, both at 1 % concentration, deterred the larvae from settling in a dual choice bean leaf disc assay. We observed a dose-dependent feeding deterrence of both jasmonates and calculated the concentration required to reduce the feeding damage by 50 % relative to the control treatment (FDC 50 ) for each jasmonate. The feeding damage was reduced by the application of cis -jasmone at 1 % concentration, but not by the jasmonates at the respective FDC 50 in no-choice leaf disc bioassays. However, significantly more larvae left jasmonate-treated whole potted bean plants by migrating to the soil compared with control plants. Our results may be exploited extending behavioural manipulation by using plant compounds in thrips control programmes to the full lifecycle of the pest. Plant compounds could be used in integrated and biological pest management strategies against F. occidentalis in combination with the application of various above and below ground control measures.

  9. The other gastropod larvae: larval morphogenesis in a marine neritimorph.

    Science.gov (United States)

    Page, Louise R; Ferguson, Samuel J

    2013-04-01

    Two of the three major gastropod clades with feeding larvae are sister groups and larval morphogenesis for members of these clades, the Caenogastropoda and Heterobranchia, has been well studied. The third clade, the Neritimorpha, has an unstable phylogenetic position and little is known about development of their planktotrophic larvae. Information about larval morphology of neritimorphs and resolution of their controversial phylogenetic placement is critically important for understanding evolution of larval feeding within the Gastropoda. We describe larval morphogenesis to metamorphic competence for laboratory-reared larvae of Nerita melanotragus (Smith, 1884) (Neritimorpha: Neritidae). Preliminary observations suggest that prehatch larvae are capable of delayed hatching, possibly by entering a diapause state. Our description of larval morphogenesis, as based on tissue sections for light and transmission electron microscopy, scanning electron microscopy, three-dimensional-reconstructions of sectioned tissue, and labeling of muscles with fluorphore-tagged phalloidin, revealed four features that are unprecedented among both feeding and nonfeeding gastropod larvae. Larvae of N. melanotragus have muscles on the left and right side that both meet current criteria of a larval retractor muscle; shell-anchored muscles with oblique striations that project inside the visceral nerve loop to insert mainly on the velar lobes. They also have left and right digestive glands of similar size and a left and right hypobranchial gland. A larval "heart" is absent, but water circulation through the mantle cavity may be facilitated by large circular orifices, lined by patches of motile cilia, leading in and out of the mantle cavity. Comparison of larval traits among all three groups of gastropods with feeding larvae indicates that larvae of N. melanotragus have many unique characteristics, but they show more similarities to caenogastropod than to heterobranch larvae. These results are a

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Comparative proteome analysis between C . briggsae embryos and larvae reveals a role of chromatin modification proteins in embryonic cell division

    KAUST Repository

    An, Xiaomeng

    2017-06-21

    Caenorhabditis briggsae has emerged as a model for comparative biology against model organism C. elegans. Most of its cell fate specifications are completed during embryogenesis whereas its cell growth is achieved mainly in larval stages. The molecular mechanism underlying the drastic developmental changes is poorly understood. To gain insights into the molecular changes between the two stages, we compared the proteomes between the two stages using iTRAQ. We identified a total of 2,791 proteins in the C. briggsae embryos and larvae, 247 of which undergo up- or down-regulation between the two stages. The proteins that are upregulated in the larval stages are enriched in the Gene Ontology categories of energy production, protein translation, and cytoskeleton; whereas those upregulated in the embryonic stage are enriched in the categories of chromatin dynamics and posttranslational modification, suggesting a more active chromatin modification in the embryos than in the larva. Perturbation of a subset of chromatin modifiers followed by cell lineage analysis suggests their roles in controlling cell division pace. Taken together, we demonstrate a general molecular switch from chromatin modification to metabolism during the transition from C. briggsae embryonic to its larval stages using iTRAQ approach. The switch might be conserved across metazoans.

  12. Partitioning of the L4-L5 dynamic moment into disc, ligamentous, and muscular components during lifting.

    Science.gov (United States)

    McGill, S M; Norman, R W

    1986-09-01

    This work describes a dynamic model of the low back that incorporates extensive anatomical detail of a three-dimensional musculo-ligamentous-skeletal system. The reactive moment about L4-L5, determined from sagittal plane lifts, was partitioned into restorative components provided by the disc in bending, ligament strain, and active muscle contraction. Skeletal kinematics were obtained from cine analysis of markers on the rib cage and pelvis. The musculature was driven from surface EMG collected from six sites. When compared with past models, features of this model included improved anatomical modeling, improved monitoring of vertebral motion unit kinematics, improved estimation of neural activation of the musculature, and consideration of the effects of muscle length, velocity, cross-sectional area and passive elasticity in force estimation. Estimations of L4-L5 disc compression and shear were, on average, 16.2% and 42.5% lower, respectively, than those calculated from a simple 5 cm erector tissue moment arm length. There was no need to invoke intra-abdominal pressure or other contentious compression-reducing mechanisms. Muscle activity, particularly that of the sacrospinalis, dominated the generation of the restorative moment. Ligaments played a very minor role in the lifts studied. High muscle loads are consistent with the common clinical observation of muscle strain often produced by load handling.

  13. Proteomic analysis of Apis cerana and Apis mellifera larvae fed with heterospecific royal jelly and by CSBV challenge.

    Science.gov (United States)

    Zhang, Yi; Zhang, Guozhi; Huang, Xiu; Han, Richou

    2014-01-01

    Chinese honeybee Apis cerana (Ac) is one of the major Asian honeybee species for local apiculture. However, Ac is frequently damaged by Chinese sacbrood virus (CSBV), whereas Apis mellifera (Am) is usually resistant to it. Heterospecific royal jelly (RJ) breeding in two honeybee species may result in morphological and genetic modification. Nevertheless, knowledge on the resistant mechanism of Am to this deadly disease is still unknown. In the present study, heterospecific RJ breeding was conducted to determine the effects of food change on the larval mortality after CSBV infection at early larval stage. 2-DE and MALDI-TOF/TOF MS proteomic technology was employed to unravel the molecular event of the bees under heterospecific RJ breeding and CSBV challenge. The change of Ac larval food from RJC to RJM could enhance the bee resistance to CSBV. The mortality rate of Ac larvae after CSBV infection was much higher when the larvae were fed with RJC compared with the larvae fed with RJM. There were 101 proteins with altered expressions after heterospecific RJ breeding and viral infection. In Ac larvae, 6 differential expression proteins were identified from heterospecific RJ breeding only, 21 differential expression proteins from CSBV challenge only and 7 differential expression proteins from heterospecific RJ breeding plus CSBV challenge. In Am larvae, 17 differential expression proteins were identified from heterospecific RJ breeding only, 26 differential expression proteins from CSBV challenge only and 24 differential expression proteins from heterospecific RJ breeding plus CSBV challenge. The RJM may protect Ac larvae from CSBV infection, probably by activating the genes in energy metabolism pathways, antioxidation and ubiquitin-proteasome system. The present results, for the first time, comprehensively descript the molecular events of the viral infection of Ac and Am after heterospecific RJ breeding and are potentially useful for establishing CSBV resistant

  14. Proteomic analysis of Apis cerana and Apis mellifera larvae fed with heterospecific royal jelly and by CSBV challenge.

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    Full Text Available Chinese honeybee Apis cerana (Ac is one of the major Asian honeybee species for local apiculture. However, Ac is frequently damaged by Chinese sacbrood virus (CSBV, whereas Apis mellifera (Am is usually resistant to it. Heterospecific royal jelly (RJ breeding in two honeybee species may result in morphological and genetic modification. Nevertheless, knowledge on the resistant mechanism of Am to this deadly disease is still unknown. In the present study, heterospecific RJ breeding was conducted to determine the effects of food change on the larval mortality after CSBV infection at early larval stage. 2-DE and MALDI-TOF/TOF MS proteomic technology was employed to unravel the molecular event of the bees under heterospecific RJ breeding and CSBV challenge. The change of Ac larval food from RJC to RJM could enhance the bee resistance to CSBV. The mortality rate of Ac larvae after CSBV infection was much higher when the larvae were fed with RJC compared with the larvae fed with RJM. There were 101 proteins with altered expressions after heterospecific RJ breeding and viral infection. In Ac larvae, 6 differential expression proteins were identified from heterospecific RJ breeding only, 21 differential expression proteins from CSBV challenge only and 7 differential expression proteins from heterospecific RJ breeding plus CSBV challenge. In Am larvae, 17 differential expression proteins were identified from heterospecific RJ breeding only, 26 differential expression proteins from CSBV challenge only and 24 differential expression proteins from heterospecific RJ breeding plus CSBV challenge. The RJM may protect Ac larvae from CSBV infection, probably by activating the genes in energy metabolism pathways, antioxidation and ubiquitin-proteasome system. The present results, for the first time, comprehensively descript the molecular events of the viral infection of Ac and Am after heterospecific RJ breeding and are potentially useful for establishing CSBV

  15. Ascaris suum: partial fractionation of metabolic antigens from "in vitro" cultured larvae

    Directory of Open Access Journals (Sweden)

    Jorge Guerrero

    1973-10-01

    Full Text Available Ascaris suum metabolic antigens were obtained frorn second and early third stage larvae cultured in vitro in supplemented Eagle's minimum essential medium. Metabolic antigens harvested after 12 and 16 days from in vitro cultures were eluted through Bio-Gel Al.5. Three main elution peaks were identified, dialysed, lyophilized and injected into mice with 4% sodium alginate. Peak 11 from elution of two preparations of metabolic antigens protected mice against a chállenge infection of 10,000 A. suum embryonated eggs.

  16. Studies on Procamallanus (Spirocamallanus) pereirai Annereaux, 1946 (Nematoda: Camallanidae), with new host records and new morphological data on the larval stages

    OpenAIRE

    Santos,Cláudia Portes; Cárdenas,Melissa Querido; Lent,Herman

    1999-01-01

    Larval stages and adults of Procamallanus (Spirocamallanus) pereirai Annereaux, 1946 are described from naturally infected Paralonchurus brasiliensis (Steindachner) (Sciaenidae) from the coast of the State of Rio de Janeiro, Brazil. The translucent first-stage larvae have a denticulate process at the anterior end, no buccal capsule or esophagus undifferentiated into anterior muscular and posterior glandular parts and an elongate tail; third-stage larvae have a tail with three terminal project...

  17. Larvae and adults of Hysterothylacium aduncum (Rudolphi, 1802) (Nematoda: Anisakidae) in fishes and crustaceans in the south west Atlantic.

    Science.gov (United States)

    Navone, G T; Sardella, N H; Timi, J T

    1998-06-01

    Hysterothylacium aduncum (Rudolphi, 1802) is reported from five fishes and one invertebrate species. Third-stage larvae were found in the crustacean Themisto gaudichaudii and in mesenteries of the fishes Engraulis anchoita and Merluccius hubbsi; fourth-stage larvae were recovered from the digestive tract of M. hubbsi and Scomber japonicus and adult specimens were obtained from the stomach and intestine of M. hubbsi, S. japonicus, Genypterus blacodes and Genypterus brasiliensis. Nematodes are described, measured and illustrated. Parasitic prevalence, mean intensity and range were calculated in relation to different geographic zones, from the Argentinean-Uruguayan Common Fishing Zone to Patagonic areas. An increase of parasitism from the northern areas southwards was observed. The life-cycle of H. aduncum, involving the host species considered, is also postulated.

  18. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    International Nuclear Information System (INIS)

    Silva, Cátia S.E.; Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana; Oliveira, Ana P.; Gonçalves, Emanuel J.; Faria, Ana M.

    2016-01-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO 2 . However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO 2 , highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO 2 on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO 2 levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U crit ), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO 2 leads to higher energetic costs and morphometric changes, with larger larvae in high pCO 2 treatment and smaller larvae in medium pCO 2 treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO 2 treatment may indicate that at higher pCO 2 levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO 2 levels on organisms. - Highlights: • Exposure to high pCO 2

  19. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cátia S.E. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana [MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Oliveira, Ana P. [IPMA — Instituto Português do Mar e da Atmosfera, Algés (Portugal); Gonçalves, Emanuel J. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); Faria, Ana M., E-mail: afaria@ispa.pt [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal)

    2016-09-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO{sub 2}. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO{sub 2}, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO{sub 2} on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO{sub 2} levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U{sub crit}), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO{sub 2} leads to higher energetic costs and morphometric changes, with larger larvae in high pCO{sub 2} treatment and smaller larvae in medium pCO{sub 2} treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO{sub 2} treatment may indicate that at higher pCO{sub 2} levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO{sub 2} levels on

  20. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    In recent years, the social sciences have taken a “mobilities turn.” There has been a developing realisation that mobilities do not “just happen.” Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed and li......, the book asks: what are the physical, social, technical, and cultural conditions to the staging of contemporary urban mobilities?...... that mobility is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments...

  1. Mucous Secretion and Cilia Beating Defend Developing Coral Larvae from Suspended Sediments.

    Directory of Open Access Journals (Sweden)

    Gerard F Ricardo

    Full Text Available Suspended sediments produced from dredging activities, or added to the sediment budget via river runoff, are a concern for marine resource managers. Understanding the impact of suspended sediments on critical life history stages of keystone species like corals is fundamental to effective management of coastlines and reefs. Coral embryos (Acropora tenuis and A. millepora and larvae (A. tenuis, A. millepora and Pocillopora acuta were subjected to a range of suspended sediment concentrations of different sediment types (siliciclastic and carbonate to assess concentration-response relationships on ecologically relevant endpoints, including survivorship and ability to metamorphose. Embryos were subjected to short (12 h suspended sediment exposures from ages of 3-12 hours old or a long (30 h exposure at 6 hours old. Neither the survivorship nor metamorphosis function of embryos were significantly affected by realistic sediment exposures to ~1000 mg L-1. However, some embryos exhibited a previously undescribed response to dynamically suspended sediments, which saw 10% of the embryos form negatively buoyant cocoons at siliciclastic suspended sediment concentrations ≥35 mg L-1. Scanning electron and optical microscopy confirmed the presence of a coating on these embryos, possibly mucus with incorporated sediment particles. Cocoon formation was common in embryos but not in larvae, and occurred more often after exposure to siliciclastic rather than carbonate sediments. Once transferred into sediment-free seawater, functional ~36-h-old embryos began emerging from the cocoons, coinciding with cilia development. Ciliated (> 36-h-old larvae exposed to suspended sediments for 60 h were also observed to secrete mucus and were similarly unaffected by suspended sediment concentrations to ~800 mg L-1. This study provides evidence that mucous secretion and cilia beating effectively protect coral embryos and larvae from suspended sediment and that these mechanisms

  2. D1 dopamine receptor is involved in shell formation in larvae of Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Liu, Zhaoqun; Wang, Lingling; Yan, Yunchen; Zheng, Yan; Ge, Wenjing; Li, Meijia; Wang, Weilin; Song, Xiaorui; Song, Linsheng

    2018-07-01

    Dopamine (DA), a significant member of catecholamines, is reported to induce biomineralization of calcium carbonate vaterite microspheres via dopamine receptor (DR) in bivalves, implying the modulation of dopaminergic system on shell formation during larval development. In this research, a homologue of D1 type DR (CgD1DR-1) was identified from oyster Crassostrea gigas, whose full length cDNA was 1197 bp. It was widely expressed in various tissues of C. gigas, with the significantly higher levels in hepatopancreas, mantle, muscle and gill. During developmental stages, the mRNA transcripts of CgD1DR-1 in D-shape larvae were obviously higher (p < 0.05) than those in trochophore and umbo larvae, and CO 2 exposure could inhibit the synthesis of DA and mRNA expression of CgD1DR-1. After cell transfection and DA treatment, intracellular cAMP in cells with the expression of CgD1DR-1 increased significantly (p < 0.05). Furthermore, the incubation with SCH 23390 for the blockage of CgD1DR-1 significantly restrained the expressions of six shell formation-related genes including CgTyrosinase-1, CgTyrosinase-3, CgChitinaseLP, CgAMC, CgBMP and CgBMPR in trochophore and D-shape larvae. These results jointly suggested that DA together with its receptor CgD1DR-1 might be involved in shell formation during oyster larval development from trochophore to D-shape larvae, and CO 2 -induced ocean acidification (OA) might influence marine bivalves by inhibiting the DA-D1DR pathway to prohibit their shell formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Can carotenoids mediate the potentially harmful effects of ultraviolet light in Silurana (Xenopus) tropicalis larvae?

    Science.gov (United States)

    Ogilvy, V; Preziosi, R F

    2012-08-01

    Amphibians have recently experienced unprecedented declines in the wild, the causes of which are often difficult to mitigate. This has increased the importance of ex situ conservation; however, long-term maintenance and breeding of amphibians in captivity often has limited success. In vertebrates, vitamin D is required for calcium homeostasis and is produced endogenously in skin exposed to ultraviolet (UV) light; however, UV light can be harmful to amphibians in some instances. Carotenoids are dietary pigments that may provide protection from UV light. The aim of this study was to assess the protective capability of carotenoids against the potentially harmful effects of UV light in Silurana (=Xenopus) tropicalis larvae raised in an enhanced or limited UV environment. Tadpole survival and the size and developmental stage reached by the end of the study period were measured. Carotenoids had a significantly positive effect on developmental rate in both UV-limited and UV-enhanced environments. Larvae in an enhanced UV environment were significantly larger than those raised under a limited UV environment, irrespective of diet. Carotenoid-fed larvae tended to have increased survival in relation to those raised without carotenoids, but only in a limited UV environment. Carotenoids appear to provide little protection against UV light in this case. The role of carotenoids in amphibian health has not previously been studied. We show that carotenoid availability significantly influences development and may increase survival in S. (X.) tropicalis larvae. This finding may have important implications for recommendations made on the nutrition of amphibians in captivity. © 2011 Blackwell Verlag GmbH.

  4. Anthelmintic efficacy of hydro-methanolic extracts of Larrea tridentata against larvae of Haemonchus contortus.

    Science.gov (United States)

    García, José E; Gómez, Leónides; Mendoza-de-Gives, Pedro; Rivera-Corona, José L; Millán-Orozco, Jair; Ascacio, Juan A; Medina, Miguel A; Mellado, Miguel

    2018-02-09

    An in vitro study was conducted to determine the anthelminthic activity of hydro-methanolic extracts of Larrea tridentata on sheathed and exsheathed larvae of Haemonchus contortus. Larvae of the parasite were incubated at 20-25 °C in hydro-methanolic extracts at concentrations of 12.5, 25, 50, 100, and 200 mg/mL for 24, 48, or 72 h. Ivermectin and water were the positive and negative controls, respectively. Total phenolic compounds of leaves of L. tridentata were 97.88 ± 10.45 mg/g of dry matter. Other compounds detected in this shrub by HPLC-mass spectrometry were sesamin, galocatechin, peonidin 3-O rutinoside, methyl galangin, epigallocatechin 7-O-glucuronide, and epigalocatechin. Mortality rate of sheathed and exsheathed H. contortus was low (16-34%) with doses ≤ 100 mg/mL of the extracts. At 200 mg/ml, the hydro-methanolic extracts of L. tridentata killed 32.1 and 68.4% of sheathed and exsheathed larvae, respectively, regardless of incubation time. The effective concentration of the L. tridentata extract for 50% larvae mortality (EC 50 ) after 24 h of incubation was 36 mg/mL (CI = 6-94). Microscopic observations revealed damage to the cuticle of this parasite exposed to extracts of L. tridentata. These in vitro results provided evidence that L. tridentata extracts possess anti-Haemonchus contortus properties, particularly during the exsheathed stage of this nematode. It would be necessary to assess the safety of this shrub in vivo and also to carry out in vivo efficacy studies.

  5. Effects of various diets on the calcium and phosphorus composition of mealworms (Tenebrio molitor larvae) and superworms (Zophobas morio larvae).

    Science.gov (United States)

    Latney, La'Toya V; Toddes, Barbara D; Wyre, Nicole R; Brown, Dorothy C; Michel, Kathryn E; Briscoe, Johanna A

    2017-02-01

    OBJECTIVE To evaluate whether the nutritive quality of Tenebrio molitor larvae and Zophobas morio larvae, which are commonly cultured as live food sources, is influenced by 4 commercially available diets used as nutritional substrates; identify which diet best improved calcium content of larvae; and identify the feeding time interval that assured the highest calcium intake by larvae. ANIMALS 2,000 Zophobas morio larvae (ie, superworms) and 7,500 Tenebrio molitor larvae (ie, mealworms). PROCEDURES Larvae were placed in control and diet treatment groups for 2-, 7-, and 10-day intervals. Treatment diets were as follows: wheat millings, avian hand feeding formula, organic avian mash diet, and a high-calcium cricket feed. Control groups received water only. After treatment, larvae were flash-frozen live with liquid nitrogen in preparation for complete proximate and mineral analyses. Analyses for the 2-day treatment group were performed in triplicate. RESULTS The nutrient composition of the high-calcium cricket feed groups had significant changes in calcium content, phosphorus content, and metabolizable energy at the 2-day interval, compared with other treatment groups, for both mealworms and superworms. Calcium content and calcium-to-phosphorus ratios for larvae in the high-calcium cricket feed group were the highest among the diet treatments for all treatment intervals and for both larval species. CONCLUSIONS AND CLINICAL RELEVANCE A 2-day interval with the high-calcium cricket feed achieved a larval nutrient composition sufficient to meet National Research Council dietary calcium recommendations for nonlactating rats. Mealworm calcium composition reached 2,420 g/1,000 kcal at 48 hours, and superworm calcium composition reached 2,070g/1,000 kcal at 48 hours. These findings may enable pet owners, veterinarians, insect breeders, and zoo curators to optimize nutritive content of larvae fed to insectivorous animals.

  6. Neuromuscular development in Novocrania anomala: evidence for the presence of serotonin and a spiralian-like apical organ in lecithotrophic brachiopod larvae.

    Science.gov (United States)

    Altenburger, Andreas; Wanninger, Andreas

    2010-01-01

    The phylogenetic position of Brachiopoda remains unsettled, and only few recent data on brachiopod organogenesis are currently available. In order to contribute data to questions concerning brachiopod ontogeny and evolution we investigated nervous and muscle system development in the craniiform (inarticulate) brachiopod Novocrania anomala. Larvae of this species are lecithotrophic and have a bilobed body with three pairs of dorsal setal bundles that emerge from the posterior lobe. Fully developed larvae exhibit a network of setae pouch muscles as well as medioventral longitudinal and transversal muscles. After settlement, the anterior and posterior adductor muscles and delicate mantle retractor muscles begin to form. Comparison of the larval muscular system of Novocrania anomala with that of rhynchonelliform (articulate) brachiopod larvae shows that the former has a much simpler muscular organization. The first signal of serotonin-like immunoreactivity appears in fully developed Novocrania anomala larvae, which have an apical organ that consists of four flask-shaped cells and two ventral neurites. These ventral neurites do not stain positively for the axonal marker alpha-tubulin in the larval stages. In the juveniles, the nervous system stained by alpha-tubulin is characterized by two ventral neurite bundles with three commissures. Our data are the first direct proof for the presence of an immunoreactive neurotransmitter in lecithotrophic brachiopod larvae and demonstrate the existence of flask-shaped serotonergic cells in the brachiopod larval apical organ, thus significantly increasing the probability that this cell type was part of the bauplan of the larvae of the last common lophotrochozoan ancestor.

  7. Immuno-suppressive effects of aqueous extract of soapnut Sapindus emarginatus on the larvae and pupae of vector mosquito, Aedes aegypti.

    Science.gov (United States)

    Koodalingam, Arunagirinathan; Mullainadhan, Periasamy; Arumugam, Munusamy

    2013-06-01

    We recently reported the presence of potent anti-mosquito activity in aqueous kernel extract of the soapnut, Sapindus emarginatus, and demonstrated its impact on marker enzymes in larvae and pupae of the vector mosquito, Aedes aegypti. As a sequel to these findings, the present study elucidates immunotoxicity of this extract with respect to hemocyte-mediated cellular immune responses in fourth instar larvae and pupae as well as cuticular melanization reaction in the larvae of A. aegypti. The exposure of these two developmental stages of the mosquito to the soapnut extract at a lethal threshold concentration neither affected hemocyte viability tested up to 3h in vitro nor did it influence the hemocyte count. By contrast, exposure of the mosquito larvae and pupae to this extract significantly reduced the ability of their hemocytes to bind yeast cells, an important early event in the process of non-self recognition by immune cells. Consequently, the phagocytic activity of these hemocytes against yeast cells was also found to be adversely affected upon exposure of larvae and pupae to the extract. Besides, a perceptible initial delay in melanization reaction at the injured site of the cuticle in the extract-exposed larvae was observed. All these findings demonstrate, for the first time, the immuno-suppressive potential of a botanical biocide in the vector mosquito. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 4- Thermal biology of embryos and larvae

    OpenAIRE

    Baras, Etienne; Ginanjar, R.; Ahmad, M.; Permana, A.; Priyadi, A.; Legendre, Marc; Pouyaud, Laurent; Slembrouck, Jacques

    2012-01-01

    International audience; The knowledge of how fish survive and grow at different temperatures, and how these traits vary between life stages, is essential to evaluate the effects of climate change on wild fish and implement effective strategies in aquaculture. These issues are addressed in this study through a series of experiments that evaluate the effect of temperature (23-34 degrees C) on the embryos and larvae of clown loach, Chromobotia macracanthus. This species is endemic to the rivers ...

  9. Scanning electron microscopic (Sem studies on fourth instar larva and pupa of Anopheles (Cellia stephensi Liston (Anophelinae: Culicidae

    Directory of Open Access Journals (Sweden)

    Jagbir Singh Kirti

    2014-12-01

    Full Text Available Anopheles (Cellia stephensi Liston is a major vector species of malaria in Indian subcontinent. Taxonomists have worked on its various morphological aspects and immature stages to explore additional and new taxonomic attributes. Scanning electron microscopic (SEM studies have been conducted on the fourth instar larva and pupa of An. stephensi to find additional taxonomic features for the first time from Punjab state.

  10. Age dependent sensitivity of oil on fish larvae, used in assessment of potential oil pollution damages on fish resources

    OpenAIRE

    Føyn, Lars; Serigstad, Bjørn

    1987-01-01

    Oil exploration in Norwegian waters will probably be extended further north into the Barents Sea. The Barents Sea is the nursery ground for important fish stocks spawning outside the norwegian coast, north of 62°N. Fish eggs and larvae are transported with the current systems northwards ending up as 0-group fish no longer dependent of the transportation provided by the currents. Some place between the egg/larval stage and mature fish, the fish is not longer vulnerable ...

  11. Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.

    Directory of Open Access Journals (Sweden)

    Tu A. Vo

    2016-11-01

    Full Text Available Dynamics between hypertrophy (increase in cell size and hyperplasia (increase in cell numbers of white and red muscle in relation to body size [standard length (SL], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua. Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph, Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph, and a positive long term effect on muscle hypertrophy (60 dph. The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm, where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance.

  12. Transcriptional changes in the hookworm, Ancylostoma caninum, during the transition from a free-living to a parasitic larva.

    Directory of Open Access Journals (Sweden)

    Bennett J D Datu

    Full Text Available BACKGROUND: Third-stage larvae (L3 of the canine hookworm, Ancylostoma caninum, undergo arrested development preceding transmission to a host. Many of the mRNAs up-regulated at this stage are likely to encode proteins that facilitate the transition from a free-living to a parasitic larva. The initial phase of mammalian host invasion by A. caninum L3 (herein termed "activation" can be mimicked in vitro by culturing L3 in serum-containing medium. METHODOLOGY/PRINCIPAL FINDINGS: The mRNAs differentially transcribed between activated and non-activated L3 were identified by suppression subtractive hybridisation (SSH. The analysis of these mRNAs on a custom oligonucleotide microarray printed with the SSH expressed sequence tags (ESTs and publicly available A. caninum ESTs (non-subtracted yielded 602 differentially expressed mRNAs, of which the most highly represented sequences encoded members of the pathogenesis-related protein (PRP superfamily and proteases. Comparison of these A. caninum mRNAs with those of Caenorhabditis elegans larvae exiting from developmental (dauer arrest demonstrated unexpectedly large differences in gene ontology profiles. C. elegans dauer exiting L3 up-regulated expression of mostly intracellular molecules involved in growth and development. Such mRNAs are virtually absent from activated hookworm larvae, and instead are over-represented by mRNAs encoding extracellular proteins with putative roles in host-parasite interactions. CONCLUSIONS/SIGNIFICANCE: Although this should not invalidate C. elegans dauer exit as a model for hookworm activation, it highlights the limitations of this free-living nematode as a model organism for the transition of nematode larvae from a free-living to a parasitic state.

  13. Differentiated stable isotopes signatures between pre- and post-flexion larvae of Atlantic bluefin tuna (Thunnus thynnus) and of its associated tuna species of the Balearic Sea (NW Mediterranean)

    Science.gov (United States)

    García, Alberto; Laiz-Carrión, Raúl; Uriarte, Amaya; Quintanilla, José M.; Morote, Elvira; Rodríguez, José M.; Alemany, Francisco

    2017-06-01

    The trophic ecology of bluefin tuna larvae (Thunnus thynnus) from the Balearic Sea, together with its co-existing tuna species such as albacore (T. alalunga), bullet (Auxis rochei) and little tunny (Euthynnus alletteratus) were examined by nitrogen and carbon stable isotope analyses. A total of 286 larvae were analyzed for this study, of which 72 larvae corresponded to bluefin, 57 to albacore, 81 to bullet tuna and 76 to little tunny. Tuna larvae were separated into the pre-flexion and post-flexion developmental stages. Within the size 3-9 mm standard length (SL), the stable isotope of nitrogen (δ15N) showed significant differences between species where bluefin tuna larvae ranked highest. Pre-flexion bluefin tuna and little tunny larvae showed significantly higher δ15N signatures than the post-flexion larvae. This effect is attributed to a biochemical trace of maternal δ15N signatures. However, neither albacore nor bullet tuna larvae showed this pattern in δ15N signatures, possibly owing to a compensation effect between lower maternal δ15N values transmitted to pre-flexion larvae and the early increase of δ15N values in post-flexion stages. One way ANOVA showed significant differences between species in the stable isotope ratio of carbon (δ13C) values, which suggests specific differences of carbon sources. Furthermore, a similar significant ontogenic effect between δ13C signatures of pre-flexion and post-flexion larvae is also evidenced in all four species. At pre-flexion stages, all species except bullet tuna larvae showed significant negative relationships between δ15N and larval standard length. At post-flexion stages, a significant linear relationship with larval size was only observed in albacore and bullet tuna larvae indicating a possible trophic shift towards early piscivory. With respect to δ13C values with larval size, all four species showed significant linear decreases. It may be explained by the metabolism of growth of somatic mass subject to

  14. Larvas migrans ganglionar: Presentación de un caso

    Directory of Open Access Journals (Sweden)

    María del Carmen Luis Álvarez

    2003-04-01

    Full Text Available Las larvas migrans visceral cuya causa radica en la infestación con larvas de toxocara canis o cati, ocurre más frecuentemente en niños menores de 10 años. Se presenta el caso de un niño de 8 años de edad en el cual se diagnosticó larvas migrans ganglionar. Se comentan aspectos etioepidemiológicos de la enfermedad, su cuadro clínico y evolución. Se hace énfasis en las medidas higiénicas sanitarias de control y manipulación de excretas de animales domésticos, en este caso de perros y gatos.Visceral larvae migrans caused by the infestation with larvae of toxocara canis or cati are more frequent among children under 10. The case of an 8-year-old boy who was diagnosed ganglionar larva migrans is presented. Comments are made on some etioepidemiological aspects of the disease, as well as on his clinical picture and evolution. Emphasis is made on the hygienic and sanitary measures of control and manipulation of stools from pegs as dogs and cats. Las larvas migrans visceral cuya causa radica en la infestación con larvas de toxocara canis o cati, ocurre más frecuentemente en niños menores de 10 años. Se presenta el caso de un niño de 8 años de edad en el cual se diagnosticó larvas migrans ganglionar. Se comentan aspectos etioepidemiológicos de la enfermedad, su cuadro clínico y evolución. se hace énfasis en las medidas higiénicas sanitarias de control y manipulación de excretas de animales domésticos, en este caso de perros y gatos.

  15. Tools for automating the imaging of zebrafish larvae.

    Science.gov (United States)

    Pulak, Rock

    2016-03-01

    The VAST BioImager system is a set of tools developed for zebrafish researchers who require the collection of images from a large number of 2-7 dpf zebrafish larvae. The VAST BioImager automates larval handling, positioning and orientation tasks. Color images at about 10 μm resolution are collected from the on-board camera of the system. If images of greater resolution and detail are required, this system is mounted on an upright microscope, such as a confocal or fluorescence microscope, to utilize their capabilities. The system loads a larvae, positions it in view of the camera, determines orientation using pattern recognition analysis, and then more precisely positions to user-defined orientation for optimal imaging of any desired tissue or organ system. Multiple images of the same larva can be collected. The specific part of each larva and the desired orientation and position is identified by the researcher and an experiment defining the settings and a series of steps can be saved and repeated for imaging of subsequent larvae. The system captures images, then ejects and loads another larva from either a bulk reservoir, a well of a 96 well plate using the LP Sampler, or individually targeted larvae from a Petri dish or other container using the VAST Pipettor. Alternative manual protocols for handling larvae for image collection are tedious and time consuming. The VAST BioImager automates these steps to allow for greater throughput of assays and screens requiring high-content image collection of zebrafish larvae such as might be used in drug discovery and toxicology studies. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  16. Use of Probiotic Bacillus spp. in Rotifer (Brachionus plicatilis) and Artemia (Artemia urmiana) Enrichment: Effects on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei, Larvae.

    Science.gov (United States)

    Jamali, Hadi; Imani, Ahmad; Abdollahi, Daruosh; Roozbehfar, Reza; Isari, Amin

    2015-06-01

    This study was to evaluate the effect of a preparation of Bacillus probiotic (Bacillus licheniformis and B. subtilis, 1:1) on growth and survival rate of Pacific white shrimp, Litopenaeus vannamei larvae. The larvae were fed on Artemia urmiana nauplii and Brachionus plicatilis enriched with the probiotic preparation at 1 × 10(6) CFU mL(-1) rate. The experimental setup was completely randomized design comprised of six treatments, namely solo Artemia nauplii (A) or rotifer (R), Artemia nauplii and rotifer without any enrichment (A + R), Artemia nauplii enrichment with probiotic bacilli (Bacillus licheniformis and B. subtilis) (A + B), rotifer enrichment with probiotic bacilli (R + B) and enriched Artemia nauplii and rotifer (A + R + B). All treatments were performed in triplicate. Chemical parameters of rearing water viz. pH, salinity and temperature were 7.5-8, 30-31 ppt and 31-32 °C, respectively. Photoperiod was 16L:8D. Shrimp larvae were fed Artemia nauplii and rotifers at 5-20 and 10-40 individuals per shrimp larvae four times a day, respectively. Growth and survival rate of larvae were determined at MII, MIII, PL1, PL4, PL7 and PL10 stages. Larvae in A + R + B treatment showed the highest total length (10.89 ± 0.51 mm), weight (674 ± 73 μg) and survival rate (65% ± 3.5). Lowest total length, weight and survival rate (7.96 ± 0.63 mm, 493 ± 52 μg and 24.5 ± 2.4%, respectively) were recorded in treatment B larvae. We concluded that Bacillus probiotic can improve growth and survival rate of Pacific white shrimp larvae without conceivably undesirable effects.

  17. Tenebrio molitor L. (Coleoptera: Tenebrionidae) larva ve pupasının yağ asidi bileşimi

    OpenAIRE

    TAŞKIN, Deniz; AKSOYLAR, M. Yaşar

    2010-01-01

    Fatty acid compositions of last instar larvae and pupae of Tenebrio molitor were analysed by gas chromatographic methods. It was determined that total fatty acid compositions of both stages were contituted C12:0-C18:2 fatty acids. Oleic acid was found as the major fatty acid. Palmitic and linoleic acids also were high pencentage fatty acids.

  18. Vaccination of lambs with irradiated larvae of Bunostomum trigonocephalum

    International Nuclear Information System (INIS)

    Srivastava, V.K.; Singh, K.S.; Subramanian, G.

    1987-01-01

    Vaccination with a single dose of 2,000 infective larvae of Bunostomum trigonocephalum, irradiated at 40 kR, caused 80 per cent reduction in worm establishment and such lambs withstood a challenge infection which was otherwise fatal to non-vaccinated lambs. The female worms, which developed from irradiated larvae, were irregular in shape, had cuticular thickening at the genital opening and in many male worms the copulatory bursa was rudimentary. The sex ratio was adversely affected in worms developing from irradiated larvae. The population had preponderant sterile females and a very few male worms. (author)

  19. 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...

  20. The effects of stocking density and ration on survival and growth of winged pearl oyster (Pteria penguin larvae fed commercially available micro-algae concentrates

    Directory of Open Access Journals (Sweden)

    Matthew Wassnig

    2016-11-01

    Full Text Available Commercially available micro-algae concentrates have been successfully used as an alternative to live micro-algae as a food source during routine larval culture of the winged pearl oyster, Pteria penguin. This supports the development of simplified hatchery facilities and larval rearing protocols that are more appropriate to Pacific island nations. An optimal feeding regime based on these products that also accounts for larval stocking density is yet to be developed. Two experiments were conducted at a commercial pearl oyster hatchery facility in the Kingdom of Tonga to examine the combined effects of stocking density and ration on survival and growth of both D-stage (from 1 to 8 days post-fertilsation and umbo-stage (from 8 to 17 days P. penguin larvae. Both experiments used a factorial design combining three larval stocking densities (D-stage: 2, 6 & 10 larvae mL−1; umbo-stage: 1, 3 & 5 larvae mL−1 and three rations (D-stage: 5, 10 & 15 cells mL−1; umbo-stage: 10, 15 & 20 cells mL−1. Survival during D-stage was significantly improved in aquaria stocked below 10 larvae mL−1, whereby a density of 6 mL−1 maximised larval production. An intermediate ration of 10 × 103 cells mL−1 maximised both survival and growth during D-stage. Increasing the initial stocking density of umbo-stage larvae from 1 to 3 mL−1 resulted in significant reductions in both survival and growth. Growth of umbo-stage larvae stocked at a density of 1 mL−1 increased significantly when ration remained below 20 × 103 cells mL−1. The results of this study provide a basis for optimised hatchery culture protocols for P. penguin that are more appropriate to Pacific island nations.

  1. Nuclear inelastic scattering cross sections for the transitions to L = 4 and L = 5 states in nuclei

    International Nuclear Information System (INIS)

    Nasmin Rahman, S.; Haque, Sangita; Rahman, A.Md.

    2004-07-01

    The generalized scattering amplitudes of the adiabatic distorted waves theory have been developed by Austem and Blair, connecting the inelastic scattering amplitudes in terms of the elastic scattering amplitudes. Potgieter and Frahn obtained simple, closed and explicit expressions for the inelastic scattering amplitudes, again in the adiabatic approximation, under strong absorption condition. These are analogous to the strong absorption model formulae for elastic scattering. In a previous communication, inelastic scattering cross section leading to the population of L = 2 and L = 3 states in nuclei are derived by us, using the general formulations due to Potgieter and Fahn. We derive here closed expressions for the cross sections for the inelastic scattering, transiting to L = 4 and L = 5 states in nuclei in the same line as before and satisfactory and simultaneous fits to the elastic as well as inelastic angular distributions are obtained. (author)

  2. [Value of computerized tomography in the diagnosis of discopathy in the L4-L5-S1 segment].

    Science.gov (United States)

    Twarkowski, P; Lachowski, M; Podgórski, J K; Delimat, L

    1992-01-01

    The aim of this analysis was demonstration of the usefulness of CT in the diagnosis of lumbar discopathy. In 110 patients with backache, CT of the L4-L5-S1 part of the spine was done. The observed abnormalities were analysed, including presence of nucleus pulposus herniation, pathological changes of osseous structures of the spine, width of the vertebral canal and lateral recesses, and presence of other lesions there. Comparing the results of (CT) and myelography with intraoperative observations it was possible to confirm the high usefulness and value of CT in such cases. CT may be an important diagnostic method preoperatively in patients with iodine hypersensitivity and those with vertebral canal stenosis.

  3. Modification of polyethylene glycol onto solid lipid nanoparticles encapsulating a novel chemotherapeutic agent (PK-L4 to enhance solubility for injection delivery

    Directory of Open Access Journals (Sweden)

    Fang YP

    2012-09-01

    Full Text Available Yi-Ping Fang,1 Pao-Chu Wu,2 Yaw-Bin Huang,3 Cherng-Chyi Tzeng,4 Yeh-Long Chen,4 Yu-Han Hung,2 Ming-Jun Tsai,5,6 Yi-Hung Tsai31Department of Biotechnology, Yuanpei University, Hsinchu, Taiwan; 2School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Graduate Institute of Clinical Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan; 4School of Medicinal and Applied Chemistry, College of Life Science, Kaohsiung Medical University, Kaohsiung, Taiwan; 5Department of Neurology, China Medical University Hospital, Taichung, Taiwan; 6School of Medicine, Medical College, China Medical University, Taichung, TaiwanBackground: The synthetic potential chemotherapeutic agent 3-Chloro-4-[(4-methoxyphenylamino]furo[2,3-b]quinoline (PK-L4 is an analog of amsacrine. The half-life of PK-L4 is longer than that of amsacrine; however, PK-L4 is difficult to dissolve in aqueous media, which is problematic for administration by intravenous injection.Aims: To utilize solid lipid nanoparticles (SLNs modified with polyethylene glycol (PEG to improve the delivery of PK-L4 and investigate its biodistribution behavior after intravenous administration.Results: The particle size of the PK-L4-loaded SLNs was 47.3 nm and the size of the PEGylated form was smaller, at 28 nm. The entrapment efficiency (EE% of PK-L4 in SLNs with and without PEG showed a high capacity of approximately 100% encapsulation. Results also showed that the amount of PK-L4 released over a prolonged period from SLNs both with and without PEG was comparable to the non-formulated group, with 16.48% and 30.04%, respectively, of the drug being released, which fit a zero-order equation. The half-maximal inhibitory concentration values of PK-L4-loaded SLNs with and those without PEG were significantly reduced by 45%–64% in the human lung carcinoma cell line (A549, 99% in the human breast adenocarcinoma cell line with estrogen receptor (MCF7, and 95% in

  4. Growth performance and survival rate of Macrobrachium rosenbergii (De Man, 1979) larvae using different doses of probiotics.

    Science.gov (United States)

    Habib, Ahasan; Das, Nani Gopal; Hossain, M Belal

    2014-07-01

    The efficiency of probiotics (Ecomarine) in rearing of Macrobrachium rosenbergii larvae was evaluated in a commercial prawn hatchery for five weeks. Stage-1 (zero age) larvae (of length: 2 mm; weight: 0.12 mg) were stocked at the rate of 100 L(-1). The experiment determined the growth rate, survival rate of the larvae for the both treatment and control groups. Final average weight were found 8.39 ± 3.28E-04 and 8.18 ± 2.86E-04 mg and length were found 9.08 ± 0.649 and 9.02 ± 0.081 mm for treatment and control group respectively. Comparatively higher growth performance was observed in treatment than control. Post Larvae (PL) was first observed 20th days of culture in treatment tanks whereas PL in control tanks was found 24th days of culture. Survival rate was found 58 and 46% in treatment and control group respectively. There was significant (p < 0.05) survival rate between two experiment groups. This study revealed that probiotics could be better in quality seed production of M. rosenbergii while significant changes were not noticed in the physic-chemical parameters i.e., water temperature, salinity, DO, pH, nitrate-NO2, hardness and alkalinity observed in both the treatments.

  5. [Larvae culture of ovine gastrintestinal nematodes in sawdust substrates of Pinus taeda, P. elliottii and Araucaria angustifolia].

    Science.gov (United States)

    Bellato, Valdomiro; de Souza, Antonio P; Sartor, Amélia A; da Silva, Ana Valéria D B; Henschel, Gustavo Dos S

    2006-01-01

    The aim of this study was to verify the influence of sawdust substrates obtained from wood treated with sodium tribromophenate and not treated of Pinus elliotti, P. taeda, and Araucaria angustifolia in larval cultures of ovine gastrintestinal helminths. Feces samples were collected between 8 to 12am, from a lamb naturally infected with gastrintestinal nematodes and analysed by the modified Mc Master technique for worm egg counting (epg). Six groups of 20g of feces were prepared. Each group received 5g of one of the sawdust substrates and 5ml of distilled water. The material has been processed, identified and taken to a climatized chamber with a temperature of 27 +/- 1 degrees C, relative humidity above 70%, and in escotophase for seven days. The third stage larvae were recovered by the Baermann technique after four hours of sedimentation for the counting and identification of one hundred larvae per treatment. For each treatment were realized 10 repetitions. The average of EPG of Strongylida Order was 630. The average of the larvae number obtained in 20 grams of feces and the percentage of recovery in the different substrates based on the EPG was: P. taeda treated, 2719 (22.66%) and not treated, 2353 (20.08%); P. elliotti treated, 3069 (22.48%) and not treated, 3181 (24.54%); A. angustifolia treated, 2370 (18.73%) and not treated, 3361 (26.75%). There was no statistic difference in 5% level of significance between the averages and the number of larvae in the different substrates.

  6. Effectivity of Sugar-Apple (Annona squamosa Seed Extract with a Different Length of Storage against Culec quinquefasciatus Larvae

    Directory of Open Access Journals (Sweden)

    Heni Prasetyowati

    2012-06-01

    Full Text Available Synthetic insecticide have been used to control Culex quinquefasciatus, but the prolonged usage of synthetic insecticide has a bad impact on the environment and may caused resistance. Sugar apple’s (Annona squamosa seeds which contain alkaloid can be used as an alternative insecticide that was safe for environment. This research aims is to know the effect of sugar apple’s seeds with different length of storage as C. quinquefasciatus larvacide. This research was an experimental study with a randomized controlled trial group design approach. The test material was an extract of sugar apple’s seeds which have been kept for 0, 1, 2, and 3 week with LC50 (0,47 ppm was used. Each treatment used 25 C. quinquefasciatus larvae from third instar larvae stage and replicated five times. After exposed for 24 hours, dead larvae counted. The result confirmed that the extract of sugar apple’s seeds which has been stored in 0, 1, 2, and 3 week did not showed any significant different on larvae mortality. Extract of sugar apple’s seeds which have been stored in 0, 1, 2, and 3 week have an equal activity as Culex quinquefasciatus larvicide.

  7. Virulence Differences among Melissococcus plutonius Strains with Different Genetic Backgrounds in Apis mellifera Larvae under an Improved Experimental Condition.

    Science.gov (United States)

    Nakamura, Keiko; Yamazaki, Yuko; Shiraishi, Akiyo; Kobayashi, Sota; Harada, Mariko; Yoshiyama, Mikio; Osaki, Makoto; Okura, Masatoshi; Takamatsu, Daisuke

    2016-09-14

    European foulbrood (EFB) caused by Melissococcus plutonius is an important bacterial disease of honeybee larvae. M. plutonius strains can be grouped into three genetically distinct groups (CC3, CC12 and CC13). Because EFB could not be reproduced in artificially reared honeybee larvae by fastidious strains of CC3 and CC13 previously, we investigated a method to improve experimental conditions using a CC3 strain and found that infection with a potassium-rich diet enhanced proliferation of the fastidious strain in larvae at the early stage of infection, leading to the appearance of clear clinical symptoms. Further comparison of M. plutonius virulence under the conditions revealed that the representative strain of CC12 was extremely virulent and killed all tested bees before pupation, whereas the CC3 strain was less virulent than the CC12 strain, and a part of the infected larvae pupated. In contrast, the tested CC13 strain was avirulent, and as with the non-infected control group, most of the infected brood became adult bees, suggesting differences in the insect-level virulence among M. plutonius strains with different genetic backgrounds. These strains and the improved experimental infection method to evaluate their virulence will be useful tools for further elucidation of the pathogenic mechanisms of EFB.

  8. Dual impact of temperature on growth and mortality of marine fish larvae in a shallow estuarine habitat

    Science.gov (United States)

    Arula, Timo; Laur, Kerli; Simm, Mart; Ojaveer, Henn

    2015-12-01

    High individual growth and mortality rates of herring Clupea harengus membras and goby Pomatoschistus spp. larvae were observed in the estuarine habitat of the Gulf of Riga, Baltic Sea. Both instantaneous mortality (0.76-1.05) as well as growth rate (0.41-0.82 mm day-1) of larval herring were amongst highest observed elsewhere previously. Mortality rates of goby larvae were also high (0.57-1.05), while first ever data on growth rates were provided in this study (0.23-0.35 mm day-1). Our study also evidenced that higher growth rate of marine fish larvae did not result in lower mortalities. We suggest that high growth and mortality rates primarily resulted from a rapidly increasing and high (>18 °C) water temperature that masked potential food-web effects. The explanation for observed patterns lies in the interactive manner temperature contributed: i) facilitating prey production, which supported high growth rate and decreased mortalities; ii) exceeding physiological thermal optimum of larvae, which resulted in decreased growth rate and generally high mortalities. Our investigation suggests that the projected climate warming may have significant effect on early life history stages of the dominating marine fish species inhabiting shallow estuaries.

  9. Toxicity of Beauveria bassiana-28 Mycelial Extracts on Larvae of Culex quinquefasciatus Mosquito (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Perumal Vivekanandhan

    2018-03-01

    Full Text Available Microbial-based pest control is an attractive alternative to chemical insecticides. The present study sought to evaluate the toxicity of the entomopathogenic fungus Beauveria bassiana-28 ethyl acetate extracts on different larval stages and pupae of Culex quinquefasciatus mosquitoes. B. bassiana-28 ethyl acetate mycelial extracts produced mosquitocidal activity against larvae and pupae which was comparable to that of the commercial insecticide B. bassiana-22 extract. The LC50 (lethal concentration that kills 50% of the exposed larvae values of B. bassiana-28 ex