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Sample records for desenvolvimento da larva

  1. Evaluating the potential of marine Bacteriovorax sp. DA5 as a biocontrol agent against vibriosis in Litopenaeus vannamei larvae.

    PubMed

    Wen, Chongqing; Xue, Ming; Liang, Huafang; Zhou, Shining

    2014-09-17

    The potential application of Bdellovibrio-and-like organisms (BALOs) for the biocontrol of bacterial diseases has been widely recognized. However, no marine BALOs have been reported for Vibrio-related infections in penaeid shrimp. In the present study, the bacteriolytic ability of the marine Bacteriovorax strain DA5 against Vibrio alginolyticus zouA was examined by cocultivation and electron microscopy, and optimal lysis was observed at 30-35°C and 20-30‰ salinity along with a high multiplicity of infection. Then, we showed that experimentally infected Litopenaeus vannamei larvae exhibited significantly higher survival with incremental DA5 levels. Finally, variation in the bacterial counts and the bacterial community in larval rearing water was investigated after prophylactic application of DA5. The elimination effect of DA5 on vibrios was visible at early time points, whereas only a few non-dominant bacteria, rather than the predominant populations, were affected through analysis of denaturing gradient gel electrophoresis of the 16S rDNA V3 region. Accordingly, the prophylactic and therapeutic efficacies of DA5 on vibriosis associated with L. vannamei could markedly enhance larval survivability, and these results will facilitate the application of marine Bacteriovorax to control vibriosis in shrimp larviculture. PMID:25139659

  2. [Larva migrans].

    PubMed

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

    1995-01-01

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

  3. Reclassification of Paenibacillus larvae subsp. pulvifaciens and Paenibacillus larvae subsp. larvae as Paenibacillus larvae without subspecies differentiation.

    PubMed

    Genersch, Elke; Forsgren, Eva; Pentikäinen, Jaana; Ashiralieva, Ainura; Rauch, Sandra; Kilwinski, Jochen; Fries, Ingemar

    2006-03-01

    A polyphasic taxonomic study of the two subspecies of Paenibacillus larvae, Paenibacillus larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens, supported the reclassification of the subspecies into one species, Paenibacillus larvae, without subspecies separation. Our conclusions are based on the analysis of six reference strains of P. larvae subsp. pulvifaciens and three reference strains and 44 field isolates of P. larvae. subsp. larvae. The latter originated from brood or honey of clinically diseased honey bee colonies or from honey of both clinically diseased and asymptomatic colonies from Sweden, Finland and Germany. Colony and spore morphology, as well as the metabolism of mannitol and salicin, did not allow a clear identification of the two subspecies and SDS-PAGE of whole-cell proteins did not support the subspecies differentiation. For genomic fingerprinting, repetitive element-PCR fingerprinting using ERIC primers and PFGE of bacterial DNA were performed. The latter method is a high-resolution DNA fingerprinting method proven to be superior to most other methods for biochemical and molecular typing and has not previously been used to characterize P. larvae. ERIC-PCR identified four different genotypes, while PFGE revealed two main clusters. One cluster included most of the P. larvae subsp. larvae field isolates, as well as all P. larvae subsp. pulvifaciens reference strains. The other cluster comprised the pigmented variants of P. larvae subsp. larvae. 16S rRNA gene sequences were determined for some strains. Finally, exposure bioassays demonstrated that reference strains of P. larvae subsp. pulvifaciens were pathogenic for honey bee larvae, producing symptoms similar to reference strains of P. larvae subsp. larvae. In comparison with the type strain for P. larvae subsp. larvae, ATCC 9545T, the P. larvae subsp. pulvifaciens strains tested were even more virulent, since they showed a shorter LT100. An emended description of the species is given

  4. [Larva migrans cutanea].

    PubMed

    Nevoralová, Z

    2006-01-01

    A case of rare skin disease in Czech Republic caused by nematode larva is presented. The disease is most frequently caused by Ankylostoma brasiliensis and was imported from Brazil. It was successfully treated by peroral therapy with albendazol. PMID:16639935

  5. Baylisascaris larva migrans.

    PubMed

    Kazacos, Kevin R; Jelicks, Linda A; Tanowitz, Herbert B

    2013-01-01

    Baylisascaris procyonis is a roundworm of the raccoon found primarily in North America but also known to occur in other parts of the world including South America, Europe, and Japan. Migration of the larvae of this parasite is recognized as a cause of clinical neural larva migrans (NLM) in humans, primarily children. It is manifested as meningoencephalitis associated with marked eosinophilia of the cerebrospinal fluid and peripheral blood. Diagnosis is made by recovering and identifying larvae in or from the tissues, epidemiological history, serology, and imaging of the central nervous system. Treatment is with albendazole and steroids, although the prognosis is generally poor. This parasite can also cause ocular larva migrans (OLM) which usually presents as diffuse unilateral subacute neuroretinitis (DUSN). The ocular diagnosis can be made by visualizing the larva in the eye and by serology. Intraocular larvae can be destroyed by photocoagulation although albendazole and steroids may also be used. However, once visual disturbance is established the prognosis for improved vision is poor. Related Baylisascaris species occur in skunks, badgers, and certain other carnivores, although most cases of NLM are caused by B. procyonis. Baylisascaris procyonis has also been found in kinkajous in the USA and South America and may also occur in related procyonids (coatis, olingos, etc.). PMID:23829916

  6. Baylisascaris larva migrans

    USGS Publications Warehouse

    Kazacos, Kevin R.

    2016-01-01

    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.

  7. Hepatic visceral larva migrans

    PubMed Central

    Rohilla, Seema; Jain, Nitin; Yadav, Rohtas; Dhaulakhandi, Dhara Ballabh

    2013-01-01

    Visceral larva migrans (VLM) is a systemic manifestation of migration of second stage larvae of nematodes through the tissue of human viscera. It is not uncommon but is underdiagnosed in developing countries. The liver is the most common organ to be involved due to its portal venous blood supply. The imaging findings are subtle and differentiation from hepatocellular carcinoma (HCC), metastases, cystic mesenchymal hamartoma and granulomatous diseases is difficult. This case report highlights the imaging features of hepatic lesions of VLM along with clinical and laboratory data which help in clinching the diagnosis. PMID:23853189

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

    PubMed

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

    2013-06-01

    The objective of the present study was to study the characteristics of lactate dehydrogenase (LDH) from Hypoderma sinense larva. H. sinense larvae were collected from yak (Bos grunniens) and identified by a PCR-RFLP method. Analysis of LDH activity showed that the total LDH activity in H. sinense larva was negatively correlated with the length of larva. Polyacrylamide gel electrophoresis of the extracts of H. sinense larvae revealed one band of LDH, which was then purified by affinity chromatography and gel filtration. This enzyme showed an approximately 36 kDa band on SDS-gel under both reducing and non-reducing conditions, in addition, size exclusion chromatography analysis showed that its molecular weight was smaller than bovine serum albumin (67 kDa), indicating that it contains only one subunit. Michaelis constants (Km) values assay revealed that LDH from H. sinense larva showed significantly lower Km for lactate than other animals. LDH of H. sinense larva was stable at 60 °C for 15 min, and also exhibited high catalytic efficiency in a wide range of pH. HgCl₂ at the concentration of 0.1mM significantly decreased the activity of LDH from H. sinense larva but not at the concentration of 0.01 mM. The results of the present study demonstrate that LDH from H. sinense larva is a thermal stable and pH insensitive enzyme suitable for catalyzing both forward and reverse reactions. PMID:23474203

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

    PubMed

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

    2016-01-01

    Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the "Osvaldo Rodrigues da Cunha" Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard. PMID:27027551

  10. [Visceral and cutaneous larva migrans].

    PubMed

    Petithory, Jean-Claude

    2007-11-30

    The syndrome of visceral larva migrans was described for the first time in 1952 by Beaver. He demonstrated that the presence of nematodes larvae, particularly in the liver, were those of Toxocara canis and T. cati. Baylisascaris procyonis, the common racoon ascarid in the U.S.A. can also cause serious diseases in human. Digestive and respiratory clinical symptoms are usually moderate, however severe disease resulting from invasion of the myocardium or the brain has been reported. A blood hypereosinophilia is usually present the first few years after infection. Diagnosis uses serological methods, among them the ELISA test. Ocular larva is also possible with in that case, immunological modifications of the aqueous. Cutaneous larva migrans characterized by a linear, progressing, serpigenous eruption and intense itching is easy to diagnose. Larva migrans is due to dogs, cats and horses helminths. Dogs and cats (referred here as pets) now receive antihelmintitic treatments and parasites are now in decrease. PMID:18326429

  11. Physicochemical comparison of chitin and chitosan obtained from larvae and adult Colorado potato beetle (Leptinotarsa decemlineata).

    PubMed

    Kaya, Murat; Baran, Talat; Erdoğan, Sevil; Menteş, Ayfer; Özüsağlam, Meltem Aşan; Çakmak, Yavuz Selim

    2014-12-01

    Chitins and chitosans obtained from larva and adult Colorado potato beetles (Leptinotarsa decemlineata) were physico-chemically characterized and differences between adults and larvae were identified. The dry weight chitin contents of the adult Colorado potato beetles and larvae were determined as 20% and 7%, respectively. The chitin produced chitosan yields of 72% from the adult Colorado potato beetles and 67% from the larvae. FTIR analysis showed that the isolated chitins were in the alpha form. Crystalline index values, determined by XRD, were 72% for larvae and 76% for adults. The degradation temperatures of the isolated chitin structures were measured by TGA, and this showed that the chitin from adult Colorado potato beetles had a more stable structure than that from the larvae. The surface morphologies of the isolated chitin and chitosan structures were analysed with SEM and it was revealed that these structures consisted of nanofibres. According to elemental analysis, the purity of chitin and chitosan from adults was greater than that from the larvae. The results of molecular analysis showed that the chitosans from adults (2.722 kDa) and larvae (2.676 kDa) of the Colorado potato beetle have low molecular weights. Antimicrobial and antioxidant activities of both adult and larval chitosans were determined. The adult potato beetle is more appropriate than the larvae as an alternative chitin source because of the fact that its dry weight chitin content, chitosan yield and purity of chitin are higher than those from the larvae, and its antimicrobial and antioxidant activities are also higher than those from the larvae. PMID:25491803

  12. Microgavage of zebrafish larvae.

    PubMed

    Cocchiaro, Jordan L; Rawls, John F

    2013-01-01

    The zebrafish has emerged as a powerful model organism for studying intestinal development(1-5), physiology(6-11), disease(12-16), and host-microbe interactions(17-25). Experimental approaches for studying intestinal biology often require the in vivo introduction of selected materials into the lumen of the intestine. In the larval zebrafish model, this is typically accomplished by immersing fish in a solution of the selected material, or by injection through the abdominal wall. Using the immersion method, it is difficult to accurately monitor or control the route or timing of material delivery to the intestine. For this reason, immersion exposure can cause unintended toxicity and other effects on extraintestinal tissues, limiting the potential range of material amounts that can be delivered into the intestine. Also, the amount of material ingested during immersion exposure can vary significantly between individual larvae(26). Although these problems are not encountered during direct injection through the abdominal wall, proper injection is difficult and causes tissue damage which could influence experimental results. We introduce a method for microgavage of zebrafish larvae. The goal of this method is to provide a safe, effective, and consistent way to deliver material directly to the lumen of the anterior intestine in larval zebrafish with controlled timing. Microgavage utilizes standard embryo microinjection and stereomicroscopy equipment common to most laboratories that perform zebrafish research. Once fish are properly positioned in methylcellulose, gavage can be performed quickly at a rate of approximately 7-10 fish/ min, and post-gavage survival approaches 100% depending on the gavaged material. We also show that microgavage can permit loading of the intestinal lumen with high concentrations of materials that are lethal to fish when exposed by immersion. To demonstrate the utility of this method, we present a fluorescent dextran microgavage assay that can be

  13. Culturing larvae of marine invertebrates.

    PubMed

    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. PMID:24567204

  14. Sediment bioassays with oyster larvae

    SciTech Connect

    Chapman, P.M.; Morgan, J.D.

    1983-10-01

    Tests with naturally-occurring sediments are rare and sediment testing methodology is not standardized. The authors present a simple methodology for undertaking sediment bioassays with oyster larvae, and present data from a recent study to prove the utility of this method.

  15. How the pilidium larva feeds

    PubMed Central

    2013-01-01

    Introduction The nemertean pilidium is a long-lived feeding larva unique to the life cycle of a single monophyletic group, the Pilidiophora, which is characterized by this innovation. That the pilidium feeds on small planktonic unicells seems clear; how it does so is unknown and not readily inferred, because it shares little morphological similarity with other planktotrophic larvae. Results Using high-speed video of trapped lab-reared pilidia of Micrura alaskensis, we documented a multi-stage feeding mechanism. First, the external ciliation of the pilidium creates a swimming and feeding current which carries suspended prey past the primary ciliated band spanning the posterior margins of the larval body. Next, the larva detects prey that pass within reach, then conducts rapid and coordinated deformations of the larval body to re-direct passing cells and surrounding water into a vestibular space between the lappets, isolated from external currents but not quite inside the larva. Once a prey cell is thus captured, internal ciliary bands arranged within this vestibule prevent prey escape. Finally, captured cells are transported by currents within a buccal funnel toward the stomach entrance. Remarkably, we observed that the prey of choice – various cultured cryptomonads – attempt to escape their fate. Conclusions The feeding mechanism deployed by the pilidium larva coordinates local control of cilia-driven water transport with sensorimotor behavior, in a manner clearly distinct from any other well-studied larval feeding mechanisms. We hypothesize that the pilidium’s feeding strategy may be adapted to counter escape responses such as those deployed by cryptomonads, and speculate that similar needs may underlie convergences among disparate planktotrophic larval forms. PMID:23927417

  16. Workbook on the Identification of Mosquito Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

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

  17. Calreticulin enriched as an early-stage encapsulation protein in wax moth Galleria mellonella larvae.

    PubMed

    Choi, J Y; Whitten, M M A; Cho, M Y; Lee, K Y; Kim, M S; Ratcliffe, N A; Lee, B L

    2002-05-01

    To investigate the molecular mechanism of the early-stage encapsulation reaction in insects, we purified a 47kDa protein from injected beads into Galleria mellonella larvae. When a cDNA clone was isolated, the 47kDa protein showed high homology with Drosophila and human calreticulin. Western blotting analysis showed that the 47kDa protein was present in the hemocytes, but not in the plasma. When the early-stage encapsulated beads were coated with 47kDa protein antibody and reinjected into G. mellonella larvae, any further encapsulation reaction was inhibited. These results suggest that calreticulin is involved in non-self recognition in invertebrate cellular defense reactions. PMID:11888648

  18. Treatment of cutaneous larva migrans.

    PubMed

    Caumes, E

    2000-05-01

    Cutaneous larva migrans caused by the larvae of animal hookworms is the most frequent skin disease among travelers returning from tropical countries. Complications (impetigo and allergic reactions), together with the intense pruritus and the significant duration of the disease, make treatment mandatory. Freezing the leading edge of the skin track rarely works. Topical treatment of the affected area with 10%-15% thiabendazole solution or ointment has limited value for multiple lesions and hookworm folliculitis, and requires applications 3 times a day for at least 15 days. Oral thiabendazole is poorly effective when given as a single dose (cure rate, 68%-84%) and is less well tolerated than either albendazole or ivermectin. Treatment with a single 400-mg oral dose of albendazole gives cure rates of 46%-100%; a single 12-mg oral dose of ivermectin gives cure rates of 81%-100%. PMID:10816151

  19. How the pilidium larva grows

    PubMed Central

    2014-01-01

    Background For animal cells, ciliation and mitosis appear to be mutually exclusive. While uniciliated cells can resorb their cilium to undergo mitosis, multiciliated cells apparently can never divide again. Nevertheless, many multiciliated epithelia in animals must grow or undergo renewal. The larval epidermis in a number of marine invertebrate larvae, such as those of annelids, mollusks and nemerteans, consists wholly or in part of multiciliated epithelial cells, generally organized into a swimming and feeding apparatus. Many of these larvae must grow substantially to reach metamorphosis. Do individual epithelial cells simply expand to accommodate an increase in body size, or are there dividing cells amongst them? If some cells divide, where are they located? Results We show that the nemertean pilidium larva, which is almost entirely composed of multiciliated cells, retains pockets of proliferative cells in certain regions of the body. Most of these are found near the larval ciliated band in the recesses between the larval lobes and lappets, which we refer to as axils. Cells in the axils contribute both to the growing larval body and to the imaginal discs that form the juvenile worm inside the pilidium. Conclusions Our findings not only explain how the almost-entirely multiciliated pilidium can grow, but also demonstrate direct coupling of larval and juvenile growth in a maximally-indirect life history. PMID:24690541

  20. Ecophysiology of dorsal versus ventral cuticle in flattened sawfly larvae

    NASA Astrophysics Data System (ADS)

    Boevé, Jean-Luc; Angeli, Sergio

    2010-06-01

    Platycampus larvae are highly cryptic leaf feeders characterised by a dorso-ventrally flattened body, the dorsal integument resembling a shield. Dorsal and ventral cuticles from Platycampus luridiventris were compared by histology and gel electrophoresis. By Azan-staining, a red and a blue layer were distinguished in the dorsal cuticle, while the ventral cuticle showed one, almost uniform blue layer, as in both cuticles of control species. The two cuticles from P. luridiventris had similar amounts and sodium dodecyl sulphate-polyacrylamide gel electrophoresis profiles of soluble proteins, but not insoluble proteins. One insoluble protein (MW ≈ 41 kDa) was visible as a large band in the ventral cuticle only. It is likely that this protein renders the cuticle elastic, and that the dorsal, red layer is the exocuticle, mainly composed of insoluble proteins. We discuss eco-physiological implications of the exocuticle in insects. Further, data from the literature indicate that the defence strategy in P. luridiventris larvae relies on being visually cryptic towards avian predators and tactically cryptic towards arthropod predators and parasitoids. Crypsis in both senses is favoured by the shield effect, itself based on an abnormally thick dorsal exocuticle. Although the larvae are external feeders, they may be considered as hidden from an ecological perspective.

  1. Biology of Paenibacillus larvae, a deadly pathogen of honey bee larvae.

    PubMed

    Ebeling, Julia; Knispel, Henriette; Hertlein, Gillian; Fünfhaus, Anne; Genersch, Elke

    2016-09-01

    The gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood of honey bees, a notifiable disease in many countries. Hence, P. larvae can be considered as an entomopathogen of considerable relevance in veterinary medicine. P. larvae is a highly specialized pathogen with only one established host, the honey bee larva. No other natural environment supporting germination and proliferation of P. larvae is known. Over the last decade, tremendous progress in the understanding of P. larvae and its interactions with honey bee larvae at a molecular level has been made. In this review, we will present the recent highlights and developments in P. larvae research and discuss the impact of some of the findings in a broader context to demonstrate what we can learn from studying "exotic" pathogens. PMID:27394713

  2. Differentiation of Larva Migrans Caused by Baylisascaris procyonis and Toxocara Species by Western Blotting▿

    PubMed Central

    Dangoudoubiyam, Sriveny; Kazacos, Kevin R.

    2009-01-01

    Baylisascaris procyonis and Toxocara species are two important causes of larva migrans in humans. Larva migrans caused by Toxocara spp. is well known and is diagnosed serologically by enzyme immunoassay. Over a dozen cases of larva migrans and associated eosinophilic encephalitis caused by B. procyonis have also been reported, and at least a dozen additional cases are known. An enzyme-linked immunosorbent assay (ELISA) using the excretory-secretory (ES) antigen of B. procyonis larvae is currently being used in our laboratory as an aid in the diagnosis of this infection in humans. Clinically affected individuals show very high reactivity (measured as the optical density) on this ELISA; however, a one-way cross-reactivity with Toxocara spp. has been observed. As an approach to differentiate these two infections based on serology, we performed Western blots, wherein the B. procyonis ES antigen was reacted with serum samples from individuals known to be positive for either Toxocara spp. or B. procyonis larva migrans. Western blot results showed that B. procyonis antigens of between 30 and 45 kDa were specifically identified only by the sera from individuals with Baylisascaris larva migrans, thus allowing for differentiation between the two infections. This included human patient serum samples submitted for serologic testing, as well as sera from rabbits experimentally infected with B. procyonis. When used in conjunction with the ELISA, Western blotting could be an efficient tool for diagnosis of this infection in humans. PMID:19741091

  3. Differentiation of larva migrans caused by Baylisascaris procyonis and Toxocara species by Western blotting.

    PubMed

    Dangoudoubiyam, Sriveny; Kazacos, Kevin R

    2009-11-01

    Baylisascaris procyonis and Toxocara species are two important causes of larva migrans in humans. Larva migrans caused by Toxocara spp. is well known and is diagnosed serologically by enzyme immunoassay. Over a dozen cases of larva migrans and associated eosinophilic encephalitis caused by B. procyonis have also been reported, and at least a dozen additional cases are known. An enzyme-linked immunosorbent assay (ELISA) using the excretory-secretory (ES) antigen of B. procyonis larvae is currently being used in our laboratory as an aid in the diagnosis of this infection in humans. Clinically affected individuals show very high reactivity (measured as the optical density) on this ELISA; however, a one-way cross-reactivity with Toxocara spp. has been observed. As an approach to differentiate these two infections based on serology, we performed Western blots, wherein the B. procyonis ES antigen was reacted with serum samples from individuals known to be positive for either Toxocara spp. or B. procyonis larva migrans. Western blot results showed that B. procyonis antigens of between 30 and 45 kDa were specifically identified only by the sera from individuals with Baylisascaris larva migrans, thus allowing for differentiation between the two infections. This included human patient serum samples submitted for serologic testing, as well as sera from rabbits experimentally infected with B. procyonis. When used in conjunction with the ELISA, Western blotting could be an efficient tool for diagnosis of this infection in humans. PMID:19741091

  4. Taste processing in Drosophila larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Rist, Anna; Thum, Andreas S.

    2015-01-01

    The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances. PMID:26528147

  5. Single stimulus learning in zebrafish larvae.

    PubMed

    O'Neale, Ashley; Ellis, Joseph; Creton, Robbert; Colwill, Ruth M

    2014-02-01

    Learning about a moving visual stimulus was examined in zebrafish larvae using an automated imaging system and a t1-t2 design. In three experiments, zebrafish larvae were exposed to one of two inputs at t1 (either a gray bouncing disk or an identical but stationary disk) followed by a common test at t2 (the gray bouncing disk). Using 7days post-fertilization (dpf) larvae and 12 stimulus exposures, Experiment 1 established that these different treatments produced differential responding to the moving disk during testing. Larvae familiar with the moving test stimulus were significantly less likely to be still in its presence than larvae that had been exposed to the identical but stationary stimulus. Experiment 2 confirmed this result in 7dpf larvae and extended the finding to 5 and 6dpf larvae. Experiment 3 found differential responding to the moving test stimulus with 4 or 8 stimulus exposures but not with just one exposure in 7dpf larvae. These results provide evidence for learning in very young zebrafish larvae. The merits and challenges of the t1-t2 framework to study learning are discussed. PMID:24012906

  6. Metalloprotease production by Paenibacillus larvae during the infection of honeybee larvae.

    PubMed

    Antúnez, Karina; Arredondo, Daniela; Anido, Matilde; Zunino, Pablo

    2011-05-01

    American foulbrood is a bacterial disease of worldwide distribution that affects larvae of the honeybee Apis mellifera. The causative agent is the Gram-positive, spore-forming bacterium Paenibacillus larvae. Several authors have proposed that P. larvae secretes metalloproteases that are involved in the larval degradation that occurs after infection. The aim of the present work was to evaluate the production of a metalloprotease by P. larvae during larval infection. First, the complete gene encoding a metalloprotease was identified in the P. larvae genome and its distribution was evaluated by PCR in a collection of P. larvae isolates from different geographical regions. Then, the complete gene was amplified, cloned and overexpressed, and the recombinant metalloprotease was purified and used to generate anti-metalloprotease antibodies. Metalloprotease production was evaluated by immunofluorescence and fluorescence in situ hybridization. The gene encoding a P. larvae metalloprotease was widely distributed in isolates from different geographical origins in Uruguay and Argentina. Metalloprotease was detected inside P. larvae vegetative cells, on the surface of P. larvae spores and secreted to the external growth medium. Its production was also confirmed in vivo, during the infection of honeybee larvae. This protein was able to hydrolyse milk proteins as described for P. larvae, suggesting that could be involved in larval degradation. This work contributes to the knowledge of the pathogenicity mechanisms of a bacterium of great economic significance and is one step in the characterization of potential P. larvae virulence factors. PMID:21330433

  7. Ganzfeld ERG in zebrafish larvae.

    PubMed

    Seeliger, Mathias W; Rilk, Albrecht; Neuhauss, Stephan C F

    2002-01-01

    In developmental biology, zebrafish are widely used to study the impact of mutations. The fast pace of development allows for a definitive morphological evaluation of the phenotype usually 5 days post fertilization (dpf). At that age, a functional analysis is already feasible using electroretinographic (ERG) methods. Corneal Ganzfeld ERGs were recorded with a glass microelectrode in anaesthetized, dark-adapted larvae aged 5 dpf, using a platinum wire beneath a moist paper towel as reference. ERG protocols included flash, flicker, and ON/OFF stimuli, both under scotopic and photopic conditions. Repetitive, isoluminant stimuli were used to assess the dynamic effect of pharmacological agents on the ERG. Single flash, flicker, and ON/OFF responses had adequately matured at this point to be informative. Typical signs of the cone dominance were the small scotopic a-wave and the large OFF responses. The analysis of consecutive single traces was possible because of the lack of EKG, breathing, and blink artefacts. After application of APB, which selectively blocks the ON channel via the mGluR6 receptor, the successive loss of the b-wave could be observed, which was quite different from the deterioration of the ERG after a circulatory arrest. The above techniques allowed to reliably obtain Ganzfeld ERGs in larvae aged 5 dpf. This underlines the important role of the zebrafish as a model for the functional analysis of mutations disrupting the visual system. PMID:11949809

  8. Workbook on Identification of Aedes Aegypti Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

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

  9. [Identification of serological antigens in excretory-secretory antigens of Trichinella spiralis muscle larvae].

    PubMed

    Huang, Xuegui; He, Lifang; Yuan, Shishan; Liu, Hui; Wang, Xin

    2016-05-01

    Objective To isolate and identify serological antigens in the excretory-secretory antigens of Trichinella spiralis muscle larvae by the combination of co-immunoprecipitation and mass spectrometric technology. Methods The serum IgG of New Zealand rabbits infected with Trichinella spiralis was isolated by ammonium sulfate precipitation. Muscle larvaes were isolated from the infected muscle, and then purified and cultured to collect excretory-secretory antigens. Serological antigens in excretory-secretory antigens were isolated by co-immunoprecipitation and SDS-PAGE, and analyzed by Western blotting. Moreover, the protein bands in New Zealand rabbit sera infected with Trichinella spiralis were identified by mass spectrometric technology. Results Indirect ELISA showed that the titer of serum antibody of New Zealand rabbits infected with Trichinella spiralis was 1:6400. The rabbit serum IgG was effectively isolated by ammonium sulfate precipitation. A total of four clear protein bands of the excretory-secretory antigens of Trichinella spiralis were obtained by electrophoresis. Among them, three clear protein bands with relative molecular mass (Mr) being 40 kDa, 50 kDa and 83 kDa were recognized by the rabbit sera infected with Trichinella spiralis but not recognized by the normal rabbit sera. The obtained four protein molecules were confirmed as serine protease, specific serine protease of muscle larvae, 43 kDa secreted glycoprotein and 53 kDa excretory-secretory antigen. Conclusion Four proteins were obtained from the excretory-secretory antigens of Trichinella spiralis muscle larvae by combination of co-immunoprecipitation and mass spectrometric technique analysis, which provided new sources and insights for the diagnosis and vaccine candidates of Trichinellosis. PMID:27126943

  10. Directional flow sensing by passively stable larvae.

    PubMed

    Fuchs, Heidi L; Christman, Adam J; Gerbi, Gregory P; Hunter, Elias J; Diez, F Javier

    2015-09-01

    Mollusk larvae have a stable, velum-up orientation that may influence how they sense and react to hydrodynamic signals applied in different directions. Directional sensing abilities and responses could affect how a larva interacts with anisotropic fluid motions, including those in feeding currents and in boundary layers encountered during settlement. Oyster larvae (Crassostrea virginica) were exposed to simple shear in a Couette device and to solid-body rotation in a single rotating cylinder. Both devices were operated in two different orientations, one with the axis of rotation parallel to the gravity vector, and one with the axis perpendicular. Larvae and flow were observed simultaneously with near-infrared particle-image velocimetry, and behavior was quantified as a response to strain rate, vorticity and centripetal acceleration. Only flows rotating about a horizontal axis elicited the diving response observed previously for oyster larvae in turbulence. The results provide strong evidence that the turbulence-sensing mechanism relies on gravity-detecting organs (statocysts) rather than mechanosensors (cilia). Flow sensing with statocysts sets oyster larvae apart from zooplankters such as copepods and protists that use external mechanosensors in sensing spatial velocity gradients generated by prey or predators. Sensing flow-induced changes in orientation, rather than flow deformation, would enable more efficient control of vertical movements. Statocysts provide larvae with a mechanism of maintaining their upward swimming when rotated by vortices and initiating dives toward the seabed in response to the strong turbulence associated with adult habitats. PMID:26333930

  11. Behavior of Settling Marine Larvae in Flow

    NASA Astrophysics Data System (ADS)

    Hernandez, J.; Koehl, M. A.

    2012-12-01

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

  12. Trypsin inhibitor from Moringa oleifera flowers interferes with survival and development of Aedes aegypti larvae and kills bacteria inhabitant of larvae midgut.

    PubMed

    Pontual, Emmanuel Viana; de Lima Santos, Nataly Diniz; de Moura, Maiara Celine; Coelho, Luana Cassandra Breitenbach Barroso; do Amaral Ferraz Navarro, Daniela Maria; Napoleão, Thiago Henrique; Paiva, Patrícia Maria Guedes

    2014-02-01

    Moringa oleifera flower extract, with trypsin inhibitor activity, is a larvicidal agent on Aedes aegypti. This work reports the isolation of trypsin inhibitor (M. oleifera flower trypsin inhibitor (MoFTI)) and its effect on A. aegypti egg hatching, viability of newly hatched larvae, survival of pupae, and growth of inhabitant bacteria from midgut of fourth-instar larvae (L4). MoFTI (K i, 2.4 μM), isolated by affinity chromatography on trypsin-agarose column, was an 18.2 kDa polypeptide on sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Flower extract (at concentrations of 8.5-17.0 mg/mL) reduced egg hatchability while MoFTI (0.05-0.5 mg/mL) did not affect the hatching rate. Mortality of newly hatched larvae ranged from 3.5 to 19.1 % in the presence of the extract (4.0-17.0 mg/mL) and was also promoted by MoFTI (LC50, 0.3 mg/mL). After 72 h, larvae incubated with extract at 13.0 and 17.0 mg/mL were at stages L2 and L1, respectively, while in control they reached L3 instar. In the presence of MoFTI, at all concentrations tested, the larvae did not pass the first instar. Flower extract and MoFTI did not interfere on pupae survival. The extract and MoFTI inhibited the growth of L4 gut bacteria (minimum inhibitory concentrations of 3.47 and 0.031 mg/mL, respectively) but only the inhibitor showed bactericide effect (minimum bactericidal concentration of 1.0 mg/mL). The findings reported herein indicate that MoFTI constitutes a larvicidal principle from M. oleifera flowers against A. aegypti newly hatched larvae and is an antibacterial agent active against the microbiota from L4 gut. PMID:24271154

  13. Cutaneous Larva Migrans in Early Infancy.

    PubMed

    Siddalingappa, Karjigi; Murthy, Sambasiviah Chidambara; Herakal, Kallappa; Kusuma, Marganahalli Ramachandra

    2015-01-01

    Cutaneous larva migrans or creeping eruptions is a cutaneous dermatosis caused by hookworm larvae, Ancylostoma braziliense. A 2-month-old female child presented with a progressive rash over the left buttock of 4 days duration. Cutaneous examination showed an urticarial papule progressing to erythematous, tortuous, thread-like tract extending a few centimeters from papule over the left gluteal region. A clinical diagnosis of cutaneous larva migrans was considered. Treatment with albendazole led to complete resolution, confirming the diagnosis. This is to the best of our knowledge, the youngest age at which this condition is being reported. PMID:26538729

  14. Cutaneous Larva Migrans in Early Infancy

    PubMed Central

    Siddalingappa, Karjigi; Murthy, Sambasiviah Chidambara; Herakal, Kallappa; Kusuma, Marganahalli Ramachandra

    2015-01-01

    Cutaneous larva migrans or creeping eruptions is a cutaneous dermatosis caused by hookworm larvae, Ancylostoma braziliense. A 2-month-old female child presented with a progressive rash over the left buttock of 4 days duration. Cutaneous examination showed an urticarial papule progressing to erythematous, tortuous, thread-like tract extending a few centimeters from papule over the left gluteal region. A clinical diagnosis of cutaneous larva migrans was considered. Treatment with albendazole led to complete resolution, confirming the diagnosis. This is to the best of our knowledge, the youngest age at which this condition is being reported. PMID:26538729

  15. Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera)

    PubMed Central

    Pineda-Castellanos, Mónica L.; Rodríguez-Segura, Zitlhally; Villalobos, Francisco J.; Hernández, Luciano; Lina, Laura; Nuñez-Valdez, M. Eugenia

    2015-01-01

    Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology. PMID:25984910

  16. Ultrastructural analysis of midgut cells from Culex quinquefasciatus (Diptera: Culicidae) larvae resistant to Bacillus sphaericus.

    PubMed

    de Melo, Janaina Viana; Vasconcelos, Romero Henrique Teixeira; Furtado, André Freire; Peixoto, Christina Alves; Silva-Filha, Maria Helena Neves Lobo

    2008-12-01

    The larvicidal action of the entomopathogen Bacillus sphaericus towards Culex quinquefasciatus is due to the binary (Bin) toxin present in crystals, which are produced during bacterial sporulation. The Bin toxin needs to recognize and bind specifically to a single class of receptors, named Cqm1, which are 60-kDa alpha-glucosidases attached to the apical membrane of midgut cells by a glycosylphosphatidylinositol anchor. C. quinquefasciatus resistance to B. sphaericus has been often associated with the absence of the alpha-glucosidase Cqm1 in larvae midgut microvilli. In this work, we aimed to investigate, at the ultrastructural level, the midgut cells from C. quinquefasciatus larvae whose resistance relies on the lack of the Cqm1 receptor. The morphological analysis showed that midgut columnar cells from the resistant larvae are characterized by a pronounced production of lipid inclusions, throughout the 4th instar. At the end of this stage, resistant larvae had an increased size and number of these inclusions in the midgut cells, while only a small number were observed in the cells from susceptible larvae. The morphological differences in the midgut cells of resistant larvae found in this work suggested that the lack of the Cqm1 receptor, which also has a physiological role as being an alpha-glucosidase, can be related to changes in the cell metabolism. The ultrastructural effects of Bin toxin on midgut epithelial cells from susceptible and resistant larvae were also investigated. The cytopathological alterations observed in susceptible larvae treated with a lethal concentration of toxin included breakdown of the endoplasmic reticulum, mitochondrial swelling, microvillar disruption and vacuolization. Some effects were observed in cells from resistant larvae, although those alterations did not lead to larval death, indicating that the receptor Cqm1 is essential to mediate the larvicidal action of the toxin. This is the first ultrastructural study to show differences

  17. TIME management by medicinal larvae.

    PubMed

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

    2016-08-01

    Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue. PMID:26179750

  18. Image-based automatic recognition of larvae

    NASA Astrophysics Data System (ADS)

    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.

  19. What's eating you? Cutaneous larva migrans.

    PubMed

    Prickett, Kyle A; Ferringer, Tammie C

    2015-03-01

    This article provides a focused update and clinical review on cutaneous larva migrans (CLM), including atypical clinical presentations and newer management recommendations. The results and recommendations are subject to modification based on future studies. PMID:25844779

  20. First evidence of fish larvae producing sounds

    PubMed Central

    Staaterman, Erica; Paris, Claire B.; Kough, Andrew S.

    2014-01-01

    The acoustic ecology of marine fishes has traditionally focused on adults, while overlooking the early life-history stages. Here, we document the first acoustic recordings of pre-settlement stage grey snapper larvae (Lutjanus griseus). Through a combination of in situ and unprovoked laboratory recordings, we found that L. griseus larvae are acoustically active during the night, producing ‘knock’ and ‘growl’ sounds that are spectrally and temporally similar to those of adults. While the exact function and physiological mechanisms of sound production in fish larvae are unknown, we suggest that these sounds may enable snapper larvae to maintain group cohesion at night when visual cues are reduced. PMID:25274018

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

    PubMed

    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. PMID:26675898

  2. Coral Larvae Move toward Reef Sounds

    PubMed Central

    Vermeij, Mark J. A.; Marhaver, Kristen L.; Huijbers, Chantal M.; Nagelkerken, Ivan; Simpson, Stephen 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 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. PMID:20498831

  3. Coral larvae move toward reef sounds.

    PubMed

    Vermeij, Mark J A; Marhaver, Kristen L; Huijbers, Chantal M; Nagelkerken, Ivan; Simpson, Stephen 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 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. PMID:20498831

  4. Automated analysis of behavior in zebrafish larvae.

    PubMed

    Creton, Robbert

    2009-10-12

    Zebrafish larvae have become a popular model system to examine genetic and environmental factors that affect behavior. However, studying complex behavior in large numbers of fish larvae can be challenging. The present study describes a novel high-resolution imaging system that is unique in its ability to automatically analyze the location and orientation of zebrafish larvae in multiwell plates. The system revealed behaviors in zebrafish larvae that would have been missed by more manual approaches, including a preference to face a threatening stimulus from a distance and a clockwise orientation in a two-fish assay. The clockwise orientation of the larvae correlates with a clockwise orientation of molecular structures during early development. Larvae with reversed embryonic asymmetries display a counter-clockwise orientation in the two-fish assay, suggesting that embryonic asymmetry and chiral behavior are regulated by the same developmental mechanisms. The developed imaging techniques may be used in large-scale screens to identify genes, pharmaceuticals, and environmental toxicants that influence complex behaviors. PMID:19409932

  5. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and...

  6. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

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

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly's power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer's disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  7. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

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

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  8. Sensorimotor structure of Drosophila larva phototaxis

    PubMed Central

    Kane, Elizabeth A.; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R.; de Bivort, Benjamin L.; Sprecher, Simon G.; Samuel, Aravinthan D. T.

    2013-01-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons. PMID:24043822

  9. Arthropod larvae misidentified as parasitic worm infection.

    PubMed

    Munisamy, Sreetharan; Kilner, Rachael

    2011-01-01

    A healthy, asymptomatic man living in London, presented with seeing 'worms' in his toilet for two successive summer seasons. Repeated microscopic examination and cultures of both his faeces and urine were normal. He was empirically treated with multiple courses of antihelminthics without resolution of this problem. A sample of the worms was obtained, and positively identified as arthropod larvae under microscopic examination. These larvae do not parasitically colonise humans. It was subsequently deduced that a flying arthropod (most likely Culex pipiens mosquito) had laid eggs in standing toilet water, and the hatched larvae had been mistaken for parasitic worms. The patient was declared free of parasites and remains healthy. This case illustrates the dangers of starting empirical treatment without positive confirmation of causative organisms, which can result in unnecessary and potentially harmful treatment. PMID:22675109

  10. Delayed effects of methylmercury on the mitochondria of dopaminergic neurons and developmental toxicity in zebrafish larvae (Danio rerio).

    PubMed

    Huang, Susie S Y; Noble, Sandra; Godoy, Rafael; Ekker, Marc; Chan, Hing Man

    2016-06-01

    Methylmercury (MeHg) is a known neurotoxicant affecting the central nervous system but effects on dopaminergic (DA) neurons are not well understood. Wild-type zebrafish (Danio rerio) and two transgenic lines: Tg(dat:eGFP) expressing enhanced green fluorescent protein (eGFP) in DA neuron clusters and Tg(dat:tom20 MLS-mCherry) expressing red fluorescence (mCherry) targeted to mitochondria of DA neurons were used to evaluate the effects of micromolar MeHg exposure on DA neuron and whole animal motor function during early development. Three-day-old larvae were exposed to micromolar concentrations of MeHg (0.03, 0.06, and 0.3μM) in system water. Exposure to 0.3μM MeHg caused mortality and significant morphological abnormalities including edema, curvature of the spine, and hemorrhages in zebrafish larvae after a 48h exposure period. At 0.06μM MeHg, the appearance of morphological abnormalities was delayed for 72h and far less severe, whereas 0.03μM MeHg did not cause any morphological defects or mortalities. A delayed but significant reduction in locomotor ability and mCherry fluorescence in specific brain regions in the 0.06μM MeHg exposed larvae suggests that DA neuron function rather than neuron numbers was compromised. Double immunolabeling with tyrosine hydroxylase and pan neural staining showed no effect of MeHg exposure. We have established Tg(dat:tom20 MLS-mCherry) zebrafish larvae as a model which can be used to assess MeHg neurotoxicity and that exposure to low dose MeHg (0.06μM) during development may predispose DA neurons to impairment caused by changes in mitochondrial dynamics. PMID:26994370

  11. [Stereotactic aspiration of Spirometra mansonides larvae].

    PubMed

    Caballero, Joel; Morales, Losmill; García, Diana; Alarcón, Idelmys; Torres, Anay; Sáez, Gladys

    2015-08-01

    Brain sparganosis is a non-common parasite infection by Diphyllobothrium or Spirometra mansonoides larvae. This last one is responsible for most of the infestations in humans. We report a 19 years male patient bearer of a brain sparganosis. The patient presented with headache and left hemiparesis. CT diagnosis of right thalamic lesions was made and aspiration biopsy was performed using stereotactic system, obtaining a whole and death larvae. Histopathology confirms a CNS parasitism and it was treated initially with albendazol. ELISA test confirmed Spirometra spp. infestation. The patient developed asymptomatic with total remission of the lesions. It constitutes the second report in Cuba of brain sparganosis. PMID:26436792

  12. Common European harmful algal blooms affect the viability and innate immune responses of Mytilus edulis larvae.

    PubMed

    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 < 0.001) and larval viability (p < 0.01) at concentrations as low as 37.8 μg l(-1). P. multiseries (1400 cells ml(-1)), 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. PMID:26348409

  13. EFFECTS OF THERMAL POLLUTION OF PELAGIC LARVAE OF CRUSTACEA

    EPA Science Inventory

    Larvae of six species, Cancer irroratus, C. borealis and Homarus americanus of coastal waters (high salinity), and Palaemonetes pugio, Pagurus longicarpus and Rhithropanopeus harrisii, from the estuarine region (variable salinity) were studied. Larvae were cultured at various com...

  14. Evolution of foraging behavior in Drosophilid larvae

    NASA Astrophysics Data System (ADS)

    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.

  15. Involvement of the processing step in the susceptibility/tolerance of two lepidopteran larvae to Bacillus thuringiensis Cry1Aa toxin.

    PubMed

    Dammak, Mariam; Khedher, Saoussen Ben; Boukedi, Hanen; Chaib, Ikbel; Laarif, Asma; Tounsi, Slim

    2016-02-01

    Bacillus thuringiensis (Bt) Cry1A toxins are known for their effectiveness against lepidopteran insects. In this study, the entomopathogenic activity of Cry1Aa was investigated against two lepidopteran larvae causing serious threat to various crops, Spodoptera littoralis and Tuta absoluta. Contrarily to S. littoralis, which showed low susceptibility to Cry1Aa (40% mortality with 1μg/cm(2)), T. absoluta was very sensitive to this delta-endotoxin (LC50 of 95.8ng/cm(2)). The different steps in the mode of action of this toxin on the two larvae were studied with the aim to understand the origin of their difference of susceptibility. Activation of the 130kDa Cry1Aa protein by T. absoluta larvae juice generated a 65kDa active toxin, whereas S. littoralis gut juice led to a complete degradation of the protoxin. The study of the interaction of the brush border membrane vesicles (BBMV) with purified biotinylated Cry1Aa toxin revealed six and seven toxin binding proteins in T. absoluta and S. littoralis BBMV, respectively. Midgut histopathology of Cry1Aa fed larvae demonstrated approximately similar damage caused by the toxin in the two larvae midguts. These results suggest that the activation step was strongly involved in the difference of susceptibility of the two larvae to Cry1Aa. PMID:26821657

  16. An Introduction to the Identification of Chironomid Larvae.

    ERIC Educational Resources Information Center

    Mason, William T., Jr.

    This publication is an introductory guide to the identification of Chironomid (Midge) larvae. The larvae of these small flies are an important link in the food chain between algae and microinvertebrates. As a family, the larvae exhibit a wide range of tolerance to environmental factors such as amounts and types of pollutants. Much of this…

  17. Workbook on the Identification of Anopheles Larvae. Preliminary Issue.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; Stojanovich, Chester J.

    This self-instructional booklet is designed to enable malarial control workers to identify the larvae of "Anopheles" species that are important malaria vectors. The morphological features of the larvae are illustrated in a programed booklet, which also contains an illustrated taxonomic key to 25 species of anopheline larvae. A glossary and a short…

  18. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City.

    PubMed

    Peréz de la Rosa, D; Pérez de la Rosa, J J; Cossio-Bayugar, R; Miranda-Miranda, E; Lozano, L; Bravo-Díaz, M A; Rocha-Martínez, M K; Sachman-Ruiz, B

    2015-01-01

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). PMID:26316636

  19. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City

    PubMed Central

    Peréz de la Rosa, D.; Pérez de la Rosa, J. J.; Cossio-Bayugar, R.; Miranda-Miranda, E.; Lozano, L.; Bravo-Díaz, M. A.; Rocha-Martínez, M. K.

    2015-01-01

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). PMID:26316636

  20. Molecular cloning and characterization of transgelin-like proteins mainly transcribed in newborn larvae of Trichinella spp.

    PubMed

    Nagano, Isao; Wu, Zhiliang; Asano, Kazunobu; Takahashi, Yuzo

    2011-05-31

    A cDNA library was constructed from Trichinella pseudospiralis muscle larvae. One cDNA clone, designated Tp4, contained a cDNA transcript of 783 bp in length, with a single open reading frame that encoded 153 amino acids (16,793 Da as the estimated molecular mass). The predicted amino acid sequence of Tp4 showed that the clone had a calponin homology domain and was approximately 50% identical to the transgelin-like proteins (calponin-family members) present in Bombyx mori or Tribolium castaneum. A homologue of the Tp4 clone was also present in cDNA from Trichinella spiralis, and this clone was designated Ts4. A comparison of the amino acid sequence of the transgelin-like proteins from T. spiralis (Ts4 protein) with the Tp4 protein indicated that the two proteins are very similar (about 94% homology). Real time quantitative polymerase chain reaction results showed that the transcription level of the Tp4 and Ts4 genes was highest in newborn larvae. On Western blot, the recombinant Tp4 and Ts4 proteins migrated at 20 kDa when reacted to an antibody against the recombinant Tp4 and Ts4 proteins, respectively. An antibody against the recombinant Tp4 and Ts4 proteins strongly stained two bands migrating at approximately 9 and 8 kDa in the crude extracts from adult worms and newborn larvae, but only weakly stained proteins in muscle larvae. However, an immunocytochemical study showed that the Tp4 protein was present within the muscle of the muscle larvae of T. pseudospiralis. The antibody level against the recombinant Tp4 antigens in infected mice began to increase from 8 days post-infection, was highest in 13 days post-infection, and then slowly decreased. PMID:21242032

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

    PubMed

    Neiss, Ulisses Gaspar; Hamada, Neusa

    2016-01-01

    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. PMID:27395963

  2. Toxicity of dissolved ozone to fish eggs and larvae

    SciTech Connect

    Asbury, C.; Coler, R.

    1980-07-01

    To find levels of dissolved residual ozone lethal to fish eggs and larvae during brief exposures, continuous-flow toxicity tests were performed with eggs and larvae of yellow perch (Perca flavescens), and fathead minnow (Pimephales promelas), eggs of white sucker (Catastomus commersoni), and larvae of bluegill sunfish (Lepomis macrochirus). The 50 and 99% lethal concentrations with confidence limits were calculated. Eggs of the species tested were more tolerant than larvae, which were destroyed by very brief exposures (less than 2 minutes) to residuals less than 0.1 mg/1. Because of the sensitivity of the larvae, residual ozone concentrations in natural waters should remain well below 50 ..mu..g/1.

  3. Characterization of a Cry1Ac-receptor alkaline phosphatase in susceptible and resistant Heliothis virescens larvae.

    PubMed

    Jurat-Fuentes, Juan L; Adang, Michael J

    2004-08-01

    We reported previously a direct correlation between reduced soybean agglutinin binding to 63- and 68-kDa midgut glycoproteins and resistance to Cry1Ac toxin from Bacillus thuringiensis in the tobacco budworm (Heliothis virescens). In the present work we describe the identification of the 68-kDa glycoprotein as a membrane-bound form of alkaline phosphatase we term HvALP. Lectin blot analysis of HvALP revealed the existence of N-linked oligosaccharides containing terminal N-acetylgalactosamine required for [125I]Cry1Ac binding in ligand blots. Based on immunoblotting and alkaline phosphatase activity detection, reduced soybean agglutinin binding to HvALP from Cry1Ac resistant larvae of the H. virescens YHD2 strain was attributable to reduced amounts of HvALP in resistant larvae. Quantification of specific alkaline phosphatase activity in brush border membrane proteins from susceptible (YDK and F1 generation from backcrosses) and YHD2 H. virescens larvae confirmed the observation of reduced HvALP levels. We propose HvALP as a Cry1Ac binding protein that is present at reduced levels in brush border membrane vesicles from YHD2 larvae. PMID:15265032

  4. In vitro culture of Parascaris equorum larvae and initial investigation of parasite excretory-secretory products.

    PubMed

    Burk, Steffanie V; Dangoudoubiyam, Sriveny; Brewster-Barnes, Tammy; Bryant, Uneeda K; Howe, Daniel K; Carter, Craig N; Vanzant, Eric S; Harmon, Robert J; Kazacos, Kevin R; Rossano, Mary G

    2014-11-01

    Currently, diagnosis of Parascaris equorum infection in equids is limited to patent infections. The goals of this study were to culture P. equorum larvae in vitro and identify excretory-secretory (ES) products for prepatent diagnostic testing. Parascaris equorum L2/L3 larvae were hatched and cultured for up to 3 weeks for ES product collection. Fifth stage (L5) P. equorum were also cultured for ES product collection. Examination of ES fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver stain revealed L2/L3 products ranging from 12-94 kDa and L5 products ranging from 12-189 kDa. Western blot analyses were conducted using polyclonal antibodies produced against P. equorum or Baylisascaris procyonis L2/L3 ES products, sera from rabbits inoculated with B. procyonis or Toxocara canis eggs, and sera from animals naturally infected with P. equorum or T. canis. Western blot results indicated parasite antigens migrating at 19 and 34 kDa may be useful for specifically detecting P. equorum infections. PMID:25209615

  5. Characterization of a novel negevirus isolated from Aedes larvae collected in a subarctic region of Japan.

    PubMed

    Kawakami, Kota; Kurnia, Yudistira Wahyu; Fujita, Ryosuke; Ito, Toshiaki; Isawa, Haruhiko; Asano, Shin-Ichiro; Binh, Ngo Dinh; Bando, Hisanori

    2016-04-01

    We isolated and characterized a novel positive-sense, single-stranded RNA virus from Aedes larvae collected on Okushiri Island, Hokkaido, Japan. This virus, designated Okushiri virus (OKV), replicated in the Aedes albopictus cell line C6/36 with severe cytopathic effects and produced a large number of spherical viral particles that were 50-70 nm in diameter and released into the cell culture medium. The OKV genome consisted of 9,704 nucleotides, excluding the poly(A) tail at the 3'-terminus, and contained three major open reading frames (ORF1, ORF2, and ORF3). ORF1 encoded a putative protein of approximately 268 kDa that included a methyltransferase domain, FtsJ-like methyltransferase domain, helicase domain, and RNA-dependent RNA polymerase domain. The genome organization and results of a phylogenetic analysis based on the amino acid sequence predicted from the nucleotide sequence indicated that OKV is a member of a new insect virus group of negeviruses with a possible evolutionary relationship to some plant viruses. ORF2 and ORF3 were suggested to encode hypothetical membrane-associated proteins of approximately 45 kDa and 22 kDa, respectively. This is the first study on a novel negevirus isolated from mosquito larvae in Japan. PMID:26687585

  6. A novel 95-kilodalton antigen of Wuchereria bancrofti infective larvae identified by species-specific monoclonal antibodies.

    PubMed Central

    Burkot, T R; Kwan-Lim, G E; Maizels, R M

    1996-01-01

    CBA and BALB/c mice produced polyspecific and monospecific polyclonal antibody responses, respectively, following immunization with Wuchereria bancrofti stage-3 larvae. Two monoclonal antibodies (MAbs) were produced from the immunized BALB/c mouse. These MAbs (both isotype M) recognized a previously undescribed highly expressed W. bancrofti antigen present in stage-3 larvae. The epitopes bound by the MAbs appear to be species specific for W. bancrofti since the MAbs did not bind to antigens of either nine other nematode species or two vector species in Western blots (immunoblots). Phosphorylcholine epitopes, responsible for immunological cross-reactivity among nematodes, were identified only on a 200-kDa antigen and not on the 95-kDa molecule. The targets of these immunoglobulin M MAbs are not carbohydrate epitopes. PMID:8550196

  7. Encysted parasitic larvae in the mouth.

    PubMed

    Hansen, L S; Allard, R H

    1984-04-01

    Oral appearances of intestinal parasitic disease are rare. One such appearance is the presence in oral tissues of encysted or encapsulated larvae of organisms from the classes Cestoidea and Nematoda. Cestode larvae form cyst-like lesions that are often clinically diagnosed as mucoceles. In these lesions, the cyst cavity is lined by fibrous tissue with inflammatory cells, and contains fluid and the larval stage of a parasite. The diagnosis of these parasitic cysts is more frequently made in younger persons. The cysts may be treated by simple excision, but care must be taken that the cyst does not rupture, as in some parasites this may result in new cyst formation. Nematode infection in the oral cavity, the most common of which appears to be trichinosis, is rarely reported. Patients with oral or maxillofacial (or both) parasitic disease must undergo a thorough medical investigation to exclude possible life-threatening involvement in other parts of the body. PMID:6586809

  8. Visceral larva migrans (toxocariasis) in Toronto.

    PubMed Central

    Fanning, M; Hill, A; Langer, H M; Keystone, J S

    1981-01-01

    A 7-year-old child was admitted to Toronto's Hospital for Sick Children in 1976 with symptoms and laboratory findings compatible with visceral larva migrans, a disease usually caused by Toxocara canis. This prompted a search for other cases seen at the hospital during the period 1952 through 1978. Only 18 cases were discovered that met at least three of six criteria and thus were considered possible or probably cases of the disease. Three possible cases of ocular toxocariasis during the same period were also uncovered. Fever was the commonest presenting symptom. Eosinophilia, leukocytosis and hyperglobulinemia were the most frequent laboratory findings. In view of the small number of cases found in 27 years at this large pediatric hospital with a broad referral base, it is concluded that visceral larva migrans poses little risk to the health of children in the Toronto area. PMID:7459767

  9. The early stress responses in fish larvae.

    PubMed

    Pederzoli, Aurora; Mola, Lucrezia

    2016-05-01

    During the life cycle of fish the larval stages are the most interesting and variable. Teleost larvae undergo a daily increase in adaptability and many organs differentiate and become active. These processes are concerted and require an early neuro-immune-endocrine integration. In larvae communication among the nervous, endocrine and immune systems utilizes several known signal molecule families which could be different from those of the adult fish. The immune-neuroendocrine system was studied in several fish species, among which in particular the sea bass (Dicentrarchus labrax), that is a species of great commercial interest, very important in aquaculture and thus highly studied. Indeed the immune system of this species is the best known among marine teleosts. In this review the data on main signal molecules of stress carried out on larvae of fish are considered and discussed. For sea bass active roles in the early immunological responses of some well-known molecules involved in the stress, such as ACTH, nitric oxide, CRF, HSP-70 and cortisol have been proposed. These molecules and/or their receptors are biologically active mainly in the gut before complete differentiation of gut-associated lymphoid tissue (GALT), probably acting in an autocrine/paracrine way. An intriguing idea emerges from all results of these researches; the molecules involved in stress responses, expressed in the adult cells of the hypothalamic-pituitary axis, during the larval life of fish are present in several other localizations, where they perform probably the same role. It may be hypothesized that the functions performed by hypothalamic-pituitary system are particularly important for the survival of the larva and therefore they comprises several other localizations of body. Indeed the larval stages of fish are very crucial phases that include many physiological changes and several possible stress both internal and environmental. PMID:26968620

  10. Caffeine Taste Signaling in Drosophila Larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C. Giovanni; Lüdke, Alja; Thum, Andreas S.

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  11. Caffeine Taste Signaling in Drosophila Larvae.

    PubMed

    Apostolopoulou, Anthi A; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C Giovanni; Lüdke, Alja; Thum, Andreas S

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  12. Molecular detection of marine invertebrate larvae.

    PubMed

    Goffredi, Shana K; Jones, William J; Scholin, Christopher A; Marin, Roman; Vrijenhoek, Robert C

    2006-01-01

    The ecological patterns of many invertebrate larvae remain an ongoing mystery, in large part owing to the difficult task of detecting them in the water column. The development of nucleic-acid-based technology has the potential to resolve this issue by direct identification and monitoring of embryonic and larval forms in situ. We report herein on the successful development and application of nucleic-acid-based sandwich hybridization assays that detect barnacles using rRNA-targeted probes with both group-(order Thoracica) and species-(Balanus glandula) specificity. Primary results include the determination of target 18S rRNA sequences and the construction of "capture" probes for detection of larvae using hybridization techniques. In addition, we modified existing protocols for whole cell hybridization of invertebrate larvae as confirmation of the sandwich hybridization results. We used both hybridization techniques successfully in the laboratory on a plankton time series collected over 3 months, as well as a week-long in situ deployment of the technique in Monterey Bay, CA. The adaptability of this technology promises to be further applicable to various organisms and could be used to enhance our understanding of larval presence in the world's oceans. PMID:16380809

  13. Biochemical characterization of different genotypes of Paenibacillus larvae subsp. larvae, a honey bee bacterial pathogen.

    PubMed

    Neuendorf, Sandra; Hedtke, Kati; Tangen, Gerhard; Genersch, Elke

    2004-07-01

    Paenibacillus larvae subsp. larvae (P. l. larvae) is the aetiological agent of American foulbrood (AFB), the most virulent bacterial disease of honey bee brood worldwide. In many countries AFB is a notifiable disease since it is highly contagious, in most cases incurable and able to kill affected colonies. Genotyping of field isolates of P. l. larvae revealed at least four genotypes (AB, Ab, ab and alpha B) present in Germany which are genotypically different from the reference strain DSM 7030. Therefore, based on these data, five different genotypes of P. l. larvae are now identified with genotype AB standing out with a characteristic brown-orange and circled two-coloured colony morphology. Analysing the metabolic profiles of three German genotypes (AB, Ab and ab) as well as of the reference strain using the Biolog system, a characteristic biochemical fingerprint could be obtained for each strain. Cluster analysis showed that while genotypes Ab, ab and the reference strain DSM 7030 are rather similar, genotype AB is clearly different from the others. Analysis of all isolates for plasmid DNA revealed two different plasmids present only in isolates belonging to genotype AB. Therefore, genotype AB is remarkable in all aspects analysed so far. Future analysis will show whether or not these differences will expand to differences in virulence. PMID:15256579

  14. Drosophila larvae: Thermal ecology in changing environments

    NASA Astrophysics Data System (ADS)

    Wang, George

    Temperature affects almost all aspects of life. Although much work has been done to assess the impact of temperature on organismal performance, relatively little is known about how organisms behaviorally regulate temperature, how these behaviors effect population fitness, or how changing climate may interact with these behaviors. I explore these questions with the model system Drosophila larvae. Larvae are small, with a low thermal mass and limited capacity for physiological thermoregulation. Mortality is generally high in larvae, with large potential impacts on population growth rate. Thus behavioral thermoregulation in larvae should be of critical selective importance. I present a review of the current knowledge of Drosophila thermal preference. I describe quantifiable thermoregulatory behaviors ( TMV and TW) unique to larvae. I show interspecific variation of these behaviors in Drosophila melanogaster and several close relatives, and intraspecific variation between populations collected from different environments. I also investigate these behaviors in two mutant lines, ssa and biz, to investigate the genetic basis of these behaviors. I show that larval thermoregulatory systems are independent of those of adults. Further these thermoregulatory behaviors differ between two sister species, D. yakuba and D. santomea. Although these two species readily hybridize in laboratory conditions, very few hybrids are observed in the field. The surprising result that hybrids of D. yakuba and D. santomea seem to inherit TMV from D. yakuba suggests a novel extrinsic isolation mechanism between the two species. I explore how fitness is the result of the interaction between genetics and the environment. I utilize Monte Carlo simulation to show how non-linear norms of reaction generate variation in populations even in the absence of behavior or epigenetic evolutionary mechanisms. Finally I investigate the global distribution of temperatures in which these organisms exist using

  15. Requirements for in vitro germination of Paenibacillus larvae spores.

    PubMed

    Alvarado, Israel; Phui, Andy; Elekonich, Michelle M; Abel-Santos, Ernesto

    2013-03-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a disease affecting honey bee larvae. First- and second-instar larvae become infected when they ingest food contaminated with P. larvae spores. The spores then germinate into vegetative cells that proliferate in the midgut of the honey bee. Although AFB affects honey bees only in the larval stage, P. larvae spores can be distributed throughout the hive. Because spore germination is critical for AFB establishment, we analyzed the requirements for P. larvae spore germination in vitro. We found that P. larvae spores germinated only in response to l-tyrosine plus uric acid under physiologic pH and temperature conditions. This suggests that the simultaneous presence of these signals is necessary for spore germination in vivo. Furthermore, the germination profiles of environmentally derived spores were identical to those of spores from a biochemically typed strain. Because l-tyrosine and uric acid are the only required germinants in vitro, we screened amino acid and purine analogs for their ability to act as antagonists of P. larvae spore germination. Indole and phenol, the side chains of tyrosine and tryptophan, strongly inhibited P. larvae spore germination. Methylation of the N-1 (but not the C-3) position of indole eliminated its ability to inhibit germination. Identification of the activators and inhibitors of P. larvae spore germination provides a basis for developing new tools to control AFB. PMID:23264573

  16. Interactions among Drosophila larvae before and during collision.

    PubMed

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM(2c)), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae. PMID:27511760

  17. Interactions among Drosophila larvae before and during collision

    PubMed Central

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM2c), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae. PMID:27511760

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

    PubMed

    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. PMID:25690972

  19. The Identification of Congeners and Aliens by Drosophila Larvae

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  1. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae.

    PubMed

    Cornman, Robert Scott; Lopez, Dawn; Evans, Jay D

    2013-01-01

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and a general immunity is achieved by larvae as they age, the basis of which has not been identified. To quickly identify a pool of candidate genes responsive to P. larvae infection, we sequenced transcripts from larvae inoculated with P. larvae at 12 hours post-emergence and incubated for 72 hours, and compared expression levels to a control cohort. We identified 75 genes with significantly higher expression and six genes with significantly lower expression. In addition to several antimicrobial peptides, two genes encoding peritrophic-matrix domains were also up-regulated. Extracellular matrix proteins, proteases/protease inhibitors, and members of the Osiris gene family were prevalent among differentially regulated genes. However, analysis of Drosophila homologs of differentially expressed genes revealed spatial and temporal patterns consistent with developmental asynchrony as a likely confounder of our results. We therefore used qPCR to measure the consistency of gene expression changes for a subset of differentially expressed genes. A replicate experiment sampled at both 48 and 72 hours post infection allowed further discrimination of genes likely to be involved in host response. The consistently responsive genes in our test set included a hymenopteran-specific protein tyrosine kinase, a hymenopteran specific serine endopeptidase, a cytochrome P450 (CYP9Q1), and a homolog of trynity, a zona pellucida domain protein. Of the known honey bee antimicrobial peptides, apidaecin was responsive at both time-points studied whereas hymenoptaecin was more consistent in its level of change between biological replicates and had the greatest increase in expression by RNA-seq analysis

  2. Equipment for transporting live black fly larvae (Diptera: Simuliiae)

    USGS Publications Warehouse

    Tarshis, I.B.; Adkins, T.R.

    1971-01-01

    In studies relating to the biology and ecology of black flies, live larvae of at least 70 species of Simuliidae have been collected from their natural breeding sites and transported in containers with nonagitated water for short distances to the laboratory. One of us (Tarshis 1966) found, however, that even small numbers of simuliid larvae cannot survive in containers with nonagitated water for more than 6 hr. Additionally, when massive numbers of larvae are introduced into transport containers in which the water is not agitated, the larvae perish because they become entangled within the masses of silken threads they emit whenever disturbed (Tarshis and Neil 1970). Therefore, when transporting larvae long distances or when transporting large numbers of larvae any distance, it is essential to agitate the water in the transport containers.

  3. Validation of daily increments in otoliths of northern squawfish larvae

    USGS Publications Warehouse

    Wertheimer, R.H.; Barfoot, C.A.

    1998-01-01

    Otoliths from laboratory-reared northern squawfish, Ptychocheilus oregonensis, larvae were examined to determine the periodicity of increment deposition. Increment deposition began in both sagittae and lapilli after hatching. Reader counts indicated that increment formation was daily in sagittae of 1-29-day-old larvae. However, increment counts from lapilli were significantly less than the known ages of northern squawfish larvae, possibly because some increments were not detectable. Otolith readability and age agreement among readers were greatest for young (<11 days) northern squawfish larvae. This was primarily because a transitional zone of low-contrast material began forming in otoliths of 8-11-day-old larvae and persisted until approximately 20 days after hatching. Formation of the transition zone appeared to coincide with the onset of exogenous feeding and continued through yolk sac absorption. Our results indicate that aging wild-caught northern squawfish larvae using daily otolith increment counts is possible.

  4. Fate of pharmaceuticals and pesticides in fly larvae composting.

    PubMed

    Lalander, C; Senecal, J; Gros Calvo, M; Ahrens, L; Josefsson, S; Wiberg, K; Vinnerås, B

    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. PMID:27177134

  5. Microsporidium Infecting Anopheles supepictus (Diptera: Culicidae) Larvae

    PubMed Central

    Omrani, Seyed-Mohammad; Moosavi, Seyedeh-Fatemeh; Manouchehri, Kourosh

    2016-01-01

    Background: Microsporidia are known to infect a wide variety of animals including mosquitoes (Diptera: Culicidae). In a recent study on the mosquito fauna of Chahar Mahal and Bakhtiari Province, at the central western part of Iran, a few larvae of Anopheles superpictus were infected with a microsporidium-resembled microorganism. Current investigation deals with the identification of the responsible microorganism at the genus level. Methods: Fresh infected larvae were collected from the field. After determining the species identity they were dissected to extract their infective contents. Wet preparations were checked for general appearance and the size of the pathogenic microorganism. Fixed preparations were stained with Geimsa and Ryan-Blue modified Trichrome techniques to visualize further morphological characters. The obtained light microscopy data were used in the identification process. Results: The infected larvae were bulged by a whitish material filling the involved segments corresponding to a microsporidium infection. Bottle-shaped semioval spores ranged 4.33±0.19×2.67±0.12 and 4.18±0.43×2.45±0.33 micron in wet and fixed preparations, respectively. They were mostly arranged in globular structures comprised of 8 spores. These data was in favor of a species from the genus Parathelohania in the family Ambliosporidae. Conclusion: This is the first report of a microsporidium infection in An. superpictus. The causative agent is diagnosed as a member of the genus Parathelohania. Further identification down to the species level needs to determine its ultrastructural characteristics and the comparative analysis of ss rRNA sequence data. It is also necessary to understand the detail of the components of the transmission cycle. PMID:27308299

  6. Learning and memory in zebrafish larvae

    PubMed Central

    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. Dichloromethane attracts diabroticite larvae in a laboratory behavioral bioassay.

    PubMed

    Jewett, D K; Bjostad, L B

    1996-07-01

    A two-choice laboratory behavioral bioassay was used to demonstrate that dichloromethane elicits the dose-dependent attraction of secondinstar western and southern corn rootworms. Preliminary data suggest that second-instar banded cucumber beetles are also attracted to dichloromethane. An eluotropic series of 10 materials, including distilled water, ethanol, methanol, acetone, ethyl dichloroacetate, dichloromethane, diethyl ether, benzene, hexadecane, and hexane, was tested for attraction of western corn rootworm larvae. Dichloromethane was the only one attractive at all doses tested, and orthogonal comparisons revealed a quadratic trend (convex) for responses of larvae to increasing dose. Benzene and hexadecane also attracted larvae, but significantly fewer than dichloromethane, and only at three doses and one dose, respectively. Orthogonal comparisons revealed no linear or quadratic trend for responses of larvae to increasing doses of either compound. Dichloromethane is the first organic compound demonstrated to attract western corn rootworm larvae in the absence of carbon dioxide. Carbon dioxide has previously been reported to attract western corn rootworm larvae either independently or when combined with other organic compounds, and the sensitivity of our bioassay was tested by demonstrating the dose-dependent attraction of western corn rootworm larvae to carbonated water as a carbon dioxide source. We have also demonstrated the attraction of southern corn rootworm larvae to carbon dioxide and propose that carbon dioxide and dichloromethane behave analogously when they interact with chemoreceptor sites on larvae. PMID:24226089

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

    PubMed

    Kloezen, Wendy; van Helvert-van Poppel, Marilyn; Fahal, Ahmed H; van de Sande, Wendy W J

    2015-01-01

    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. PMID:26173126

  9. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae

    PubMed Central

    Kloezen, Wendy; van Helvert-van Poppel, Marilyn; Fahal, Ahmed H.; van de Sande, Wendy W. J.

    2015-01-01

    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. PMID:26173126

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

    SciTech Connect

    Law, A.T.; Yeo, M.E.

    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.

  11. Isolation and characterization of EG2158, a new strain of Bacillus thuringiensis toxic to coleopteran larvae, and nucleotide sequence of the toxin gene.

    PubMed

    Donovan, W P; Gonzalez, J M; Gilbert, M P; Dankocsik, C

    1988-11-01

    A novel strain of Bacillus thuringiensis was isolated from soybean grain dust from Kansas and found to be toxic to larvae of Leptinotarsa decemlineata (Colorado potato beetle). The strain (EG2158) synthesized two parasporal crystals: a rhomboid crystal composed of a 73116 dalton protein of approximately 30 kDa. Plasmid transfer and gene cloning experiments demonstrated that the 73 kDa protein was encoded on an 88 MDa plasmid and that the protein was toxic to the larvae of Colorado potato beetle (CPB). The sequence of the 73 kDa protein, as deduced from the sequence of its gene (cryC), was found to have regions of similarity with several B. thuringiensis crystal proteins: the lepidopteran-toxic P1 proteins of var. kurstaki and berliner, the lepidopteran- and dipteran-toxic P2 (or CRYB1) protein of var. kurstaki, and the dipteran-toxic 130 kDa protein of var. israelensis. While B. megaterium cells harboring the cryC gene from EG2158 synthesized significant amounts of the 73 kDa CRYC protein, Escherichia coli cells did not. The cryC-containing B. megaterium cells produced rhomboid crystals that were toxic to CPB larvae. PMID:3146015

  12. Modulatory effects on Drosophila larva hearts: room temperature, acute and chronic cold stress.

    PubMed

    Zhu, Yue Chen; Yocom, Emily; Sifers, Jacob; Uradu, Henry; Cooper, Robin L

    2016-10-01

    Ectothermic animals are susceptible to temperature changes such as cold shock with seasons. To survive through a cold shock or season, ectotherms have developed unique strategies. Our interest is focusing on the modulation of physiological functions during cold shock and prolonged cold exposure in the fruit fly. We use Drosophila melanogaster as a model system to investigate cardiac function in response to modulators (5-HT-serotonin, Ach-acetylcholine, OA-octopamine, DA-dopamine and a cocktail of modulators) in acute cold shock and chronic cold shock conditions. Semi-intact larvae are used to provide direct access to the modulators of known concentration in a defined saline. The results show that 10 µM 5HT is the only modulator which maintains heart rate for larva raised at 21 °C and then exposed to acute cold shock (10 °C). The modulators 1 µM OA, 10 µM 5HT, 1 mM Ach, 10 µM Ach and a cocktail of modulators (at 10 µM) increased the heart rate significantly in larvae which were cold conditioned (10 °C for 10 days). HPLC analysis indicated both OA and 5-HT decreased in chronic cold conditioning. The larvae maintain heart function in the cold which may be contributed by low circulating levels of modulators. The larval heart responds better to 5-HT, OA, and Ach in conditioned cold than for acute cold, suggesting some acclimation to cold. PMID:27209390

  13. Methemoglobin reduction by NADH-cytochrome b(5) reductase in Propsilocerus akamusi larvae.

    PubMed

    Maeda, Shintaro; Kobori, Hiroki; Tanigawa, Minoru; Sato, Katsuya; Yubisui, Toshitsugu; Hori, Hiroshi; Nagata, Yoko

    2015-07-01

    For oxygen respiration, a methemoglobin (metHb) reduction system is needed in the cell because metHb cannot bind oxygen. We examined the insect Propsilocerus akamusi larvae to elucidate the metHb reduction system in an organism that inhabits an oxygen-deficient environment. NADH-dependent reduction of metHb in coelomic fluid suggested the coexistence of cytochrome b5 reductase (b5R) and cytochrome b5 with hemoglobin in the fluid and that these proteins were involved in physiological metHb reduction in the larvae. The presence of b5R was revealed by purifying b5R to homogeneity from the midge larvae. Using purified components, we showed that larval metHb was reduced via the NADH-b5R (FAD)-cytochrome b5-metHb pathway, a finding consistent with that in aerobic vertebrates, specifically humans and rabbits, and b5R function between mammal and insect was conserved. b5R was identified as a monomeric FAD-containing enzyme; it had a molecular mass of 33.2 kDa in gel-filtration chromatography and approximately 37 kDa in SDS-PAGE analysis. The enzyme's optimal pH and temperature were 6.4 and 25 °C, respectively. The apparent Km and Vmax values were 345 μM and 160 μmol min(-1) mg(-1), respectively, for ferricyanide and 328 μM and 500 μmol min(-1) mg(-1), respectively, for 2,6-dichlorophenolindophenol. The enzyme reaction was inhibited by benzoate, p-hydroxymercuribenzoate, iodoacetamide, and iodoacetate, and was not inhibited by metal ions or EDTA. PMID:25829149

  14. Sensitivity of Mytilus galloprovincialis larvae to ammonia

    SciTech Connect

    Gardiner, W.W.; Antrim, L.D.; Word, J.Q.

    1994-12-31

    Free ammonia is a constituent of some marine effluents and sediments. The authors evaluated the sensitivity of the larval stage of the marine bivalve, Mytilus galloprovincialis, to concentrations of ammonium sulfate, as well as to suspended-particulate-phase (SPP) preparations of marine sediments and petroleum-based marine effluents. Mytilus larvae are commonly used test organisms because of their sensitivity to toxicants and their use in evaluation of water-column impacts of dredged material disposal. Ammonia-only EC{sub 50} values were between 3 mg/L NH{sub 3} and 8 mg/L NH{sub 3}; LC{sub 50} values ranged from 66 mg/L NH{sub 3} to 100 mg/L NH{sub 3}. Abnormalities included exogastrulation and arrested development at early gastrulation. The EC{sub 50} values for ammonia in SPP and effluents were within similar ranges, which indicates that ammonia may contribute significantly to toxicity of these materials. Exposure of larvae during different developmental stages and time periods will also be discussed.

  15. A Model of Drosophila Larva Chemotaxis

    PubMed Central

    Davies, Alex; Louis, Matthieu; Webb, Barbara

    2015-01-01

    Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays. PMID:26600460

  16. [Development of multiplex PCR for fast detection of Paenibacillus larvae in putrid masses and in isolated bacterial colonies].

    PubMed

    ruseinova, N V; Parvanov, P; Stanilova, S

    2013-01-01

    The present study was performed to develop a fast and sensitive multiplex polymerase chain reaction protocol for routine diagnostics of American foulbrood. A new approach for detection of Paenibacillus larvae in putrid masses was described. Forty five samples of putrid masses obtained from bee combs suspicious for American foulbrood, a reference strain Paenibacillus larvae (NBIMCC 8478), clinical isolates and 4 strains of closely related bacterial species were included in experiments. Bacterial colonies' DNA was isolated by heat and centrifugation method (standard procedure) and with prepGem commercial kit. DNA from putrid masses was isolated by standard and modified procedure. Three pairs of primers specific for 16S rRNA and one pair specific for 35 kDa metalloproteinase genes of Paenibacillus larvae were tested as single pair and in different combinations as multiplex PCR. The sensitivity of the multiplex PCR protocol for putrid masses, developed in study was 100%, versus 45.2% for the standard protocol. The developed multiplex PCR protocol could be successfully used for rapid and specific detection of Paenibacillus larvae in both putrid masses and isolated bacterial colonies. PMID:23662456

  17. Complete Genome Sequences of Five Paenibacillus larvae Bacteriophages.

    PubMed

    Sheflo, Michael A; Gardner, Adam V; Merrill, Bryan D; Fisher, Joshua N B; Lunt, Bryce L; Breakwell, Donald P; Grose, Julianne H; Burnett, Sandra H

    2013-01-01

    Paenibacillus larvae is a pathogen of honeybees that causes American foulbrood (AFB). We isolated bacteriophages from soil containing bee debris collected near beehives in Utah. We announce five high-quality complete genome sequences, which represent the first completed genome sequences submitted to GenBank for any P. larvae bacteriophage. PMID:24233582

  18. Trail marking by larvae of the eastern tent caterpillar.

    PubMed

    Fitzgerald, T D

    1976-11-26

    Eastern tent caterpillars that are successful foragers deposit trails as they return to the tent that are more attractive than the exploratory trails of the unfed larvae. The trails of these fed returning larvae attract unfed tentmates to food finds anre chemical factors account for the attractiveness of these trails. PMID:982055

  19. Early detection of non-native fishes using fish larvae

    EPA Science Inventory

    Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy approaches to investigate potential efficiencies. Fish larvae present an interesting opportunity for non-native fish early detection. First,...

  20. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 ??g/L from 24-Road, 0.9 ??g/L from Horsethief, 5.5 ??g/L from Adobe Creek, and 10.7 ??g/L from the North Pond. Selenium in dietary items averaged 2.7 ??g/g in brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Selenium impacts on razorback sucker, Colorado: Colorado River III. Larvae.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-06-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items averaged 2.7 microg/g in brine shrimp, 5.6 microg/g in zooplankton from Horsethief east wetland, 20 microg/g in zooplankton from Adobe Creek, and 39 microg/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of 4.6 microg/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish. PMID:15883090

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

    USGS Publications Warehouse

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

    2000-01-01

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

  4. Loeffler's Syndrome Following Cutaneous Larva Migrans: An Uncommon Sequel

    PubMed Central

    Podder, Indrashis; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2016-01-01

    Cutaneous larva migrans (CLM) is characterized by the formation of distinctive, tortuous, and serpentine skin lesions occurring as a result of epidermal burrowing by certain helminthic larvae. Although this condition is usually uneventful, rarely it may result in patchy pulmonary infiltration with peripheral eosinophilia, also called Loeffler's syndrome. This association is fairly uncommon and is thus being reported. PMID:27057020

  5. Loeffler's Syndrome Following Cutaneous Larva Migrans: An Uncommon Sequel.

    PubMed

    Podder, Indrashis; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2016-01-01

    Cutaneous larva migrans (CLM) is characterized by the formation of distinctive, tortuous, and serpentine skin lesions occurring as a result of epidermal burrowing by certain helminthic larvae. Although this condition is usually uneventful, rarely it may result in patchy pulmonary infiltration with peripheral eosinophilia, also called Loeffler's syndrome. This association is fairly uncommon and is thus being reported. PMID:27057020

  6. Cadmium and zinc reversibly arrest development of Artemia larvae

    SciTech Connect

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

    1986-08-01

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

  7. External Ophthalmomyiasis Caused by a Rare Infesting Larva, Sarcophaga argyrostoma

    PubMed Central

    Graffi, Shmuel; Peretz, Avi; Wilamowski, Amos; Schnur, Heather; Akad, Fouad; Naftali, Modi

    2013-01-01

    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. PMID:24455366

  8. Bacteria Present in Comadia redtenbacheri Larvae (Lepidoptera: Cossidae).

    PubMed

    Hernández-Flores, L; Llanderal-Cázares, C; Guzmán-Franco, A W; Aranda-Ocampo, S

    2015-09-01

    The external and internal culturable bacterial community present in the larvae of Comadia redtenbacheri Hammerschmidt, an edible insect, was studied. Characterization of the isolates determined the existence of 18 morphotypes and phylogenetic analysis of the 16S rRNA gene revealed the existence of Paenibacillus sp., Bacillus safensis, Pseudomonas sp., Bacillus pseudomycoides, Corynebacterium variabile, Enterococcus sp., Gordonia sp., Acinetobacter calcoaceticus, Arthrobacter sp., Micrococcus sp., and Bacillus cereus. Greater diversity of bacteria was found in those larvae obtained from vendors than in those directly taken from Agave plants in nature. Many of the larvae obtained from vendors presented signs of potential disease, and after the analysis, results showed a greater bacterial community compared with the larvae with a healthy appearance. This indicates that bacterial flora can vary in accordance with how the larvae are handled during extraction, collection, and transport. PMID:26336239

  9. Neuromechanics of crawling in D. melanogaster larvae

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  10. How to kill the honey bee larva: genomic potential and virulence mechanisms of Paenibacillus larvae.

    PubMed

    Djukic, Marvin; Brzuszkiewicz, Elzbieta; Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity. PMID:24599066

  11. How to Kill the Honey Bee Larva: Genomic Potential and Virulence Mechanisms of Paenibacillus larvae

    PubMed Central

    Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity. PMID:24599066

  12. Comparative proteomic analysis of surface proteins of Trichinella spiralis muscle larvae and intestinal infective larvae.

    PubMed

    Liu, Ruo Dan; Cui, Jing; Liu, Xiao Lin; Jiang, Peng; Sun, Ge Ge; Zhang, Xi; Long, Shao Rong; Wang, Li; Wang, Zhong Quan

    2015-10-01

    The critical step for Trichinella spiralis infection is that muscle larvae (ML) are activated to intestinal infective larvae (IIL) and invade intestinal epithelium to further develop. The IIL is its first invasive stage, surface proteins are directly exposed to host environment and are crucial for larval invasion and development. In this study, shotgun LC-MS/MS was used to analyze surface protein profiles of ML and IIL. Totally, 41 proteins common to both larvae, and 85 ML biased and 113 IIL biased proteins. Some proteins (e.g., putative scavenger receptor cysteine-rich domain protein and putative onchocystatin) were involved in host-parasite interactions. Gene ontology analysis revealed that proteins involved in generation of precursor metabolites and energy; and nucleobase, nucleoside, nucleotide and nucleic acid metabolic process were enriched in IIL at level 4. Some IIL biased proteins might play important role in larval invasion and development. qPCR results confirmed the high expression of some genes in IIL. Our study provides new insights into larval invasion, host-Trichinella interaction and for screening vaccine candidate antigens. PMID:26184560

  13. Screening and characterization of early diagnostic antigens in excretory-secretory proteins from Trichinella spiralis intestinal infective larvae by immunoproteomics.

    PubMed

    Liu, Ruo Dan; Jiang, Peng; Wen, Hui; Duan, Jiang Yang; Wang, Li Ang; Li, Jie Feng; Liu, Chun Ying; Sun, Ge Ge; Wang, Zhong Quan; Cui, Jing

    2016-02-01

    The excretory-secretory (ES) antigens from Trichinella spiralis muscle larvae are the most commonly used diagnostic antigens for trichinellosis, but specific IgG antibodies were not detected in early stage of infection. The aim of this study was to identify early diagnostic antigens from ES proteins of intestinal infective larvae (IIL), the first invasive stage of T. spiralis. Six bands (92, 52, 45, 35, 32, and 29 kDa) of IIL ES proteins were recognized by infection sera in Western blotting as early as 10 days post infection. Total of 54 T. spiralis proteins in six bands were identified by shotgun LC-MS/MS, 30 proteins were annotated, and 27 had hydrolase activity. Several proteins (serine protease, putative trypsin, deoxyribonuclease II family protein, etc.) could be considered as the potential early diagnostic antigens for trichinellosis. Our study provides new insights for screening early diagnostic antigens from intestinal worms of T. spiralis. PMID:26468148

  14. Novel Bacillus thuringiensis insecticidal crystal protein with a silent activity against coleopteran larvae.

    PubMed Central

    Lambert, B; Höfte, H; Annys, K; Jansens, S; Soetaert, P; Peferoen, M

    1992-01-01

    A novel Bacillus thuringiensis crystal protein with a silent activity against the Colorado potato beetle is described. The crystal proteins are produced as bipyramidal crystals. These crystals contain a protein of 129 kDa with a trypsin-resistant core fragment of 72 kDa. Neither a spore-crystal mixture nor in vitro-solubilized crystals are toxic to any of several Lepidoptera and Coleoptera species tested. In contrast, a trypsin-treated solution containing the 72-kDa tryptic core fragment of the protoxin is highly toxic to Colorado potato beetle larvae. The crystal protein-encoding gene was cloned and sequenced. The inferred amino acid sequence of the putative toxic fragment has 37, 32, and 33% homology to the CryIIIA, CryIIIB, and CryIIID toxins, respectively. Interestingly, the 501 C-terminal amino acids show 41 to 48% amino acid identity with corresponding C-terminal amino acid sequences of other crystal proteins. Because of the toxicity of the fragment to the Colorado potato beetle and because of the distinct similarities of the toxic fragment with the other CryIII proteins, this gene was given a new subclass name (cryIIIC) within the CryIII class of coleopteran-active crystal proteins. CryIIIC represents the first example of a crystal protein with a silent activity towards coleopteran insect larvae. Natural CryIIIC crystals are not toxic. Toxicity is revealed only after an in vitro solubilization and activation step. Images PMID:1514800

  15. [Migration and transposition of Oesophagostomum quadrispinulatum larvae from feces].

    PubMed

    Barutzki, D; Gothe, R

    1998-05-01

    Investigations on the migration and translation of free-living stages of Oesophagostomum quadrispinulatum, using faeces containing eggs as starting material, revealed that mostly third stage larvae and very few second stage larvae migrated out of faeces, whereas first stage larvae remained in the faeces. The emigration rates depended on ambient relative humidity. Compared with the control, third stage larvae emigrated out of faeces at rates of 0.3%, 1.6% and 12.2% at 50%, 75% and 100% relative humidity, respectively. Offering helminth-free faeces, emigrated third stage larvae returned into faces at rates of 0.4-1.2%, 5.8-17.7%, 39.0-52.7%, and 45.2-60.7% after 1 h, 24 h, 5 days and 14 days, respectively. After a period of 1, 2, 3 or 4 weeks staying out of faeces, emigrated third stage larvae returned into faeces at rates of 23.3%, 8.8%, 22.1% and 6.0%, respectively. An examination of the horizontal translation revealed that most of the third stage larvae migrated distances up to 80 cm and a few even up to 150 cm returning into helminth-free faeces. PMID:9640103

  16. Nociceptive neurons protect Drosophila larvae from parasitoid wasps

    PubMed Central

    Xu, Yifan; Johnson, Trevor; Zhang, Feng; Deisseroth, Karl

    2008-01-01

    Summary Background Natural selection has resulted in a complex and fascinating repertoire of innate behaviors that are produced by insects. One puzzling example occurs in fruitfly larvae that have been subjected to a noxious mechanical or thermal sensory input. In response, the larvae “roll” using a motor pattern that is completely distinct from the style of locomotion that is used for foraging. Results We have precisely mapped the sensory neurons that are used by the Drosophila larvae to detect nociceptive stimuli. Using complementary optogenetic activation and targeted silencing of sensory neurons, we have demonstrated that a single class of neuron (Class IV multidendritic neuron) is sufficient and necessary for triggering the unusual rolling behavior. In addition, we find that larvae have an innately encoded directional preference in the directionality of rolling. Surprisingly, the initial direction of rolling locomotion is towards the side of the body that has been stimulated. We propose that directional rolling might provide a selective advantage in escape from parasitoid wasps that are ubiquitously present in the natural environment of Drosophila. Consistent with this hypothesis, we have documented that larvae can escape attack of Leptopilina boulardi parasitoid wasps by rolling, occasionally flipping the attacker onto its back. Conclusions The Class IV multidendritic neurons of Drosophila larvae are nociceptive. The nociception behavior of Drosophila melanagaster larvae includes an innately encoded directional preference. Nociception behavior is elicited by the ecologically relevant sensory stimulus of parasitoid wasp attack. PMID:18060782

  17. [Toxicity and influencing factors of liquid chlorine on chironomid larvae].

    PubMed

    Sun, Xing-Bin; Cui, Fu-Yi; Zhang, Jin-Song; Guo, Zhao-Hai; Xu, Feng; Liu, Li-Jun

    2005-09-01

    The excessive propagation of Chironomid larvae (red worm) in the sedimentation tanks is a difficult problem for the normal function of waterworks. The toxic effect of liquid chlorine on the different instar larvae of Chironomid was studied using distilled water as test sample. Furthermore, the effect of pH value, organic matter content, ammonia nitrogen, and algae content on toxicity of liquid chlorine was observed. The results show that the tolerance of Chironomid larvae to liquid chlorine is strengthened with the increase in instar. The 24h semi-lethal concentration (LC50) of liquid chlorine to the 4th instar larvae of Chironomid is 3.39 mg/L. Low pH value and high algae content are helpful to improve the toxic effect of liquid chlorine to Chironomid larvae. In neutral water body, the increase in organic matter content results in the decrease in the death rate of Chironomid larvae. The toxicity of liquid chlorine differs greatly in different concentrations of ammonia nitrogen. The death rate of the 4th instar larvae of Chironomid in raw water is higher by contrast with that in sedimentation tanks water for 24h disposal with various amount of liquid chlorine. PMID:16366477

  18. The phylogenetic significance of colour patterns in marine teleost larvae.

    PubMed

    Baldwin, Carole C

    2013-07-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

  19. The phylogenetic significance of colour patterns in marine teleost larvae

    PubMed Central

    Baldwin, Carole C

    2013-01-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

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

    NASA Astrophysics Data System (ADS)

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

    2006-01-01

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

  1. Regulation of Life Cycle Checkpoints and Developmental Activation of Infective Larvae in Strongyloides stercoralis by Dafachronic Acid

    PubMed Central

    Pilgrim, Adeiye A.; Nolan, Thomas J.; Wang, Zhu; Kliewer, Steven A.; Mangelsdorf, David J.; Lok, James B.

    2016-01-01

    The complex life cycle of the parasitic nematode Strongyloides stercoralis leads to either developmental arrest of infectious third-stage larvae (iL3) or growth to reproductive adults. In the free-living nematode Caenorhabditis elegans, analogous determination between dauer arrest and reproductive growth is governed by dafachronic acids (DAs), a class of steroid hormones that are ligands for the nuclear hormone receptor DAF-12. Biosynthesis of DAs requires the cytochrome P450 (CYP) DAF-9. We tested the hypothesis that DAs also regulate S. stercoralis development via DAF-12 signaling at three points. First, we found that 1 μM Δ7-DA stimulated 100% of post-parasitic first-stage larvae (L1s) to develop to free-living adults instead of iL3 at 37°C, while 69.4±12.0% (SD) of post-parasitic L1s developed to iL3 in controls. Second, we found that 1 μM Δ7-DA prevented post-free-living iL3 arrest and stimulated 85.2±16.9% of larvae to develop to free-living rhabditiform third- and fourth-stages, compared to 0% in the control. This induction required 24–48 hours of Δ7-DA exposure. Third, we found that the CYP inhibitor ketoconazole prevented iL3 feeding in host-like conditions, with only 5.6±2.9% of iL3 feeding in 40 μM ketoconazole, compared to 98.8±0.4% in the positive control. This inhibition was partially rescued by Δ7-DA, with 71.2±16.4% of iL3 feeding in 400 nM Δ7-DA and 35 μM ketoconazole, providing the first evidence of endogenous DA production in S. stercoralis. We then characterized the 26 CYP-encoding genes in S. stercoralis and identified a homolog with sequence and developmental regulation similar to DAF-9. Overall, these data demonstrate that DAF-12 signaling regulates S. stercoralis development, showing that in the post-parasitic generation, loss of DAF-12 signaling favors iL3 arrest, while increased DAF-12 signaling favors reproductive development; that in the post-free-living generation, absence of DAF-12 signaling is crucial for iL3 arrest

  2. Regulation of Life Cycle Checkpoints and Developmental Activation of Infective Larvae in Strongyloides stercoralis by Dafachronic Acid.

    PubMed

    Albarqi, Mennatallah M Y; Stoltzfus, Jonathan D; Pilgrim, Adeiye A; Nolan, Thomas J; Wang, Zhu; Kliewer, Steven A; Mangelsdorf, David J; Lok, James B

    2016-01-01

    The complex life cycle of the parasitic nematode Strongyloides stercoralis leads to either developmental arrest of infectious third-stage larvae (iL3) or growth to reproductive adults. In the free-living nematode Caenorhabditis elegans, analogous determination between dauer arrest and reproductive growth is governed by dafachronic acids (DAs), a class of steroid hormones that are ligands for the nuclear hormone receptor DAF-12. Biosynthesis of DAs requires the cytochrome P450 (CYP) DAF-9. We tested the hypothesis that DAs also regulate S. stercoralis development via DAF-12 signaling at three points. First, we found that 1 μM Δ7-DA stimulated 100% of post-parasitic first-stage larvae (L1s) to develop to free-living adults instead of iL3 at 37°C, while 69.4±12.0% (SD) of post-parasitic L1s developed to iL3 in controls. Second, we found that 1 μM Δ7-DA prevented post-free-living iL3 arrest and stimulated 85.2±16.9% of larvae to develop to free-living rhabditiform third- and fourth-stages, compared to 0% in the control. This induction required 24-48 hours of Δ7-DA exposure. Third, we found that the CYP inhibitor ketoconazole prevented iL3 feeding in host-like conditions, with only 5.6±2.9% of iL3 feeding in 40 μM ketoconazole, compared to 98.8±0.4% in the positive control. This inhibition was partially rescued by Δ7-DA, with 71.2±16.4% of iL3 feeding in 400 nM Δ7-DA and 35 μM ketoconazole, providing the first evidence of endogenous DA production in S. stercoralis. We then characterized the 26 CYP-encoding genes in S. stercoralis and identified a homolog with sequence and developmental regulation similar to DAF-9. Overall, these data demonstrate that DAF-12 signaling regulates S. stercoralis development, showing that in the post-parasitic generation, loss of DAF-12 signaling favors iL3 arrest, while increased DAF-12 signaling favors reproductive development; that in the post-free-living generation, absence of DAF-12 signaling is crucial for iL3 arrest

  3. Anguilliform larvae collected off North Carolina

    USGS Publications Warehouse

    Ross, S.W.; Casazza, T.L.; Quattrini, A.M.; Sulak, K.J.

    2007-01-01

    The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999-2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April 2000 to December 2001 by bongo and neuston nets, Methot frame trawl, and Tucker trawl. Overall, 584 tows were completed, and 224 of these yielded larval eels. The 1,295 eel leptocephali collected (combining all methods and areas) represented at least 63 species (nine families). Thirteen species were not known previously from the area. Dominant families for all areas were Congridae (44% of individuals, 11 species), Ophichthidae (30% of individuals, 27 species), and Muraenidae (22% of individuals, ten species). Nine taxa accounted for 70% of the overall leptocephalus catches (in order of decreasing abundance): Paraconger caudilimbatus (Poey), Gymnothorax ocellatus Agassiz complex, Ariosoma balearicum (Delaroche), Ophichthus gomesii (Castelnau), Callechelys muraena Jordan and Evermann, Letharchus aliculatus McCosker, Rhynchoconger flavus (Goode and Bean), Ophichthus cruentifer (Goode and Bean), Rhynchoconger gracilior (Ginsburg). The top three species represented 52% of the total eel larvae collected. Most leptocephali were collected at night (79%) and at depths > 45 m. Eighty percent of the eels collected in discrete depth Tucker trawls at night ranged from mean depths of 59-353 m. A substantial number (38% of discrete depth sample total) of larval eels were also collected at the surface (neuston net) at night. Daytime leptocephalus

  4. Methemoglobin reduction mediated by D-amino acid dehydrogenase in Propsilocerus akamusi (Tokunaga) larvae.

    PubMed

    Kobori, Hiroki; Tanigawa, Minoru; Maeda, Shintaro; Hori, Hiroshi; Yubisui, Toshitsugu; Nagata, Yoko

    2015-06-01

    A methemoglobin (metHb) reduction system is required for aerobic respiration. In humans, Fe(III)-heme-bearing metHb (the oxidized form of hemoglobin), which cannot bind oxygen, is converted to Fe(II)-heme-bearing oxyhemoglobin (oxyHb, the reduced form), which can bind oxygen, in a system comprising NADH, NADH-cytochrome b5 reductase, and cytochrome b5. However, the mechanism of metHb reduction in organisms that inhabit oxygen-deficient environments is unknown. In the coelomic fluid of the larvae of Propsilocerus akamusi, which inhabit a microaerobic environment, we found that metHb was reduced by D-alanine. We purified an FAD-containing enzyme, D-amino acid dehydrogenase (DAD), and component V hemoglobin from the larvae. Using the purified components and spectrophotometric analyses, we showed a novel function of DAD: DAD-mediation of P. akamusi component V metHb reduction with using D-alanine as an electron donor. P. akamusi larvae possess this D-alanine-DAD metHb reduction system in addition to a previously discovered NADH-NADH-cytochrome b5 reductase system. This is the first report of the presence of DAD in a multicellular organism. The molecular mass of DAD was estimated to be 45 kDa. The optimal pH and temperature of the enzyme were 7.4 and 20 °C, respectively, and the optimal substrate was D-alanine. The enzyme activity was inhibited by benzoate and sulfhydryl-binding reagents. PMID:25896287

  5. Streptococcus agalactiae infection in zebrafish larvae

    PubMed Central

    Kim, Brandon J; Hancock, Bryan M; Cid, Natasha Del; Bermudez, Andres; Traver, David; Doran, Kelly S

    2015-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β il1b and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis. PMID:25617657

  6. Cerebral Baylisascaris larva migrans in a cynomolgus macaque (Macaca fascicularis).

    PubMed

    Shoieb, Ahmed; Radi, Zaher A

    2014-08-01

    An incidental, asymptomatic, focal inflammatory lesion was detected in brain cerebrum of an approximately 6-year-old, female cynomolgus macaque from a chronic toxicology study. No gross lesions were noted at necropsy. Microscopically, the lesion contained a cross-section of larvae approximately 70-80 μm in diameter, a centrally located intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. Mixed inflammatory cells of eosinophils, macrophages, and lymphocytes admixed with abundant connective tissue stroma and necrosis surrounded the larvae. Histochemical stains for trichrome revealed significant amount of fibrous connective tissue. The morphology of the larvae was compatible with Baylisascaris spp. Based on the microscopic and histochemical examination, a diagnosis of neural Baylisascaris spp. larva migrans was made. PMID:24795276

  7. Culturing Embryos and Larvae of Marine Molluscs and Protochordates.

    ERIC Educational Resources Information Center

    Healey, R.; Turner, S. C.

    1979-01-01

    Presents a description for maintaining adult forms of molluscs and protochordates in order to obtain gametes for laboratory studies of animal development. The methods also include those for culturing embryonic larvae forms in vitro. (Author/SA)

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

    PubMed Central

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

    2011-01-01

    Objective To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 µg/g), than in the wastewaters surface (0.01-0.78 µg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques. PMID:23569727

  9. Improved Software for Quantifying the Behavior of Drosophila Larvae

    NASA Astrophysics Data System (ADS)

    Bernat, Natalie; Gershow, Marc

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

  10. Microbial modulation of behavior and stress responses in zebrafish larvae.

    PubMed

    Davis, Daniel J; Bryda, Elizabeth C; Gillespie, Catherine H; Ericsson, Aaron C

    2016-09-15

    The influence of the microbiota on behavior and stress responses is poorly understood. Zebrafish larvae have unique characteristics that are advantageous for neuroimmune research, however, they are currently underutilized for such studies. Here, we used germ-free zebrafish to determine the effects of the microbiota on behavior and stress testing. The absence of a microbiota dramatically altered locomotor and anxiety-related behavior. Additionally, characteristic responses to an acute stressor were also obliterated in larvae lacking exposure to microbes. Lastly, treatment with the probiotic Lactobacillus plantarum was sufficient to attenuate anxiety-related behavior in conventionally-raised zebrafish larvae. These results underscore the importance of the microbiota in communicating to the CNS via the microbiome-gut-brain axis and set a foundation for using zebrafish larvae for neuroimmune research. PMID:27217102

  11. Ophthalmomyiasis caused by the reindeer warble fly larva.

    PubMed Central

    Kearney, M S; Nilssen, A C; Lyslo, A; Syrdalen, P; Dannevig, L

    1991-01-01

    Two boys with ophthalmomyiasis caused by the first instar larva of the reindeer warble fly Hypoderma tarandi are reported. Both were 9 years old and came from the coast of northern Norway. One had ophthalmomyiasis interna posterior and one eye had been removed because of progressive pain and blindness. Histological examination showed the remains of a fly larva. The second boy had ophthalmomyiasis externa with a tumour in the upper eyelid, and histological examination showed a warble with a well preserved larva. Identification of the parasite in the histological material was based on the finding of cuticular spines and parts of the cephalopharyngeal skeleton identical with those of the first instar larva of H tarandi. Images PMID:2030144

  12. EFFECTS OF CHLORINATED SEAWATER ON DECAPOD CRUSTACEANS AND 'MULINIA' LARVAE

    EPA Science Inventory

    Eggs and larvae of decapod crustaceans and embryos of Mulinia lateralis were exposed to chlorinated seawater for varying periods in continuous flow systems. Mortality, developmental rate, and general behavior were recorded. Panopeus herbstii zoeae were more sensitive to chlorine-...

  13. [Toxic effects of plant extracts on mosquito larvae].

    PubMed

    Rageau, J; Delaveau, P

    1979-01-01

    Vegetable extracts prepared with 530 species belonging to 120 botanical families are biologically screened with fourth stage larvae of Aedes aegypti. About twenty species are selected. Eight species of Convolvulaceae are specially toxic. PMID:527161

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Fatty acids in anopheline mosquito larvae and their habitats.

    PubMed

    Komínková, Dana; Rejmánková, Eliška; Grieco, John; Achee, Nicole

    2012-12-01

    Larvae of the three important Central American malaria vectors, Anopheles albimanus, An. vestitipennis, and An. darlingi, are found in distinctly different habitats broadly defined by hydrology and aquatic vegetation, but little is known about the actual food quality and quantity of these habitats. Polyunsaturated fatty acids (PUFA) are of special interest, because mosquitoes require 20:5ω3 (EPA), 20:4ω6 (ARA), and 22:6ω3 (DHA) and without an adequate supply of these PUFAs they are not able to complete their life cycle. We collected samples of larvae and their corresponding habitats and analyzed their fatty acid (FA) composition to reveal if there are any species-specific and habitat-specific differences in FA composition, and if habitat FA differences can be linked to differences in the mosquito FA pattern and, ultimately, mosquito performance. We also assessed how FA of wild larvae compare to the laboratory-reared larvae. Habitats were generally low in essential PUFAs and there were no significant differences among the FA composition of habitat samples. There were significant differences in FA composition of larvae. An. darlingi contained significantly higher amounts of FA, specifically a higher content of ω-6 PUFA, represented mainly by the linoleic acid (18:2ω-6). Large differences were found between field-collected and laboratory-reared An. vestitipennis larvae, especially in the content of PUFAs. The laboratory-reared larvae contained significantly more of the total FA, ω3 PUFA, and MUFA. The laboratory-reared larvae contained three to five times more essential PUFAs, EPA, and DHA. However, there were no differences in the total dry weight of the 4(th) instar larvae between the wild vs laboratory-reared larvae. Total FA in both larvae and habitats of An. albimanus and An. darlingi were positively correlated with the concentration of particulate organic carbon and nitrogen (POC, PON) in their respective habitats, but no such correlation was found for An

  16. Rearing gymnolaemate bryozoan larvae for cellular and molecular analyses.

    PubMed

    Temkin, Michael H

    2014-01-01

    Gymnolaemates represent the largest group of extant bryozoans, having more than 3,000 described species. Gymnolaemates display a diverse array of reproductive and developmental patterns including planktotrophy, lecithotrophy, and matrotrophy. The larvae of gymnolaemates have been broadly grouped into three types, cyphonautes (shelled, feeding), pseudocyphonautes (shelled, nonfeeding), and coronate (unshelled, nonfeeding), although each group is heterogeneous and probably includes various morphologies that are largely undescribed. Here, methods for rearing bryozoan colonies and larvae are presented. PMID:24567208

  17. Parasites of fish larvae: do they follow metabolic energetic laws?

    PubMed

    Muñoz, Gabriela; Landaeta, Mauricio F; Palacios-Fuentes, Pamela; George-Nascimento, Mario

    2015-11-01

    Eumetazoan parasites in fish larvae normally exhibit large body sizes relative to their hosts. This observation raises a question about the potential effects that parasites might have on small fish. We indirectly evaluated this question using energetic metabolic laws based on body volume and the parasite densities. We compared the biovolume as well as the numeric and volumetric densities of parasites over the host body volume of larval and juvenile-adult fish and the average of these parasitological descriptors for castrator parasites and the parasites found in the fish studied here. We collected 5266 fish larvae using nearshore zooplankton sampling and 1556 juveniles and adult fish from intertidal rocky pools in central Chile. We considered only the parasitized hosts: 482 fish larvae and 629 juvenile-adult fish. We obtained 31 fish species; 14 species were in both plankton and intertidal zones. Fish larvae exhibited a significantly smaller biovolume but larger numeric and volumetric densities of parasites than juvenile-adult fish. Therefore, fish larvae showed a large proportion of parasite biovolume per unit of body host (cm(3)). However, the general scaling of parasitological descriptors and host body volume were similar between larvae and juvenile-adult fish. The ratio between the biovolume of parasites and the host body volume in fish larvae was similar to the proportion observed in castrator parasites. Furthermore, the ratios were different from those of juvenile-adult fish, which suggests that the presence of parasites implies a high energetic cost for fish larvae that would diminish the fitness of these small hosts. PMID:26193824

  18. The use of fly larvae for organic waste treatment.

    PubMed

    Čičková, Helena; Newton, G Larry; Lacy, R Curt; Kozánek, Milan

    2015-01-01

    The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and

  19. Differentiation of Paenibacillus larvae subsp. larvae, the Cause of American Foulbrood of Honeybees, by Using PCR and Restriction Fragment Analysis of Genes Encoding 16S rRNA

    PubMed Central

    Alippi, Adriana M.; López, Ana Claudia; Aguilar, O. Mario

    2002-01-01

    A rapid procedure for the identification of Paenibacillus larvae subsp. larvae, the causal agent of American foulbrood (AFB) disease of honeybees (Apis mellifera L.), based on PCR and restriction fragment analysis of the 16S rRNA genes (rDNA) is described. Eighty-six bacterial strains belonging to 39 species of the genera Paenibacillus, Bacillus, Brevibacillus, and Virgibacillus were characterized. Amplified rDNA was digested with seven restriction endonucleases. The combined data from restriction analysis enabled us to distinguish 35 profiles. Cluster analysis revealed that P. larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens formed a group with about 90% similarity; however, the P. larvae subsp. larvae restriction fragment length polymorphism pattern produced by endonuclease HaeIII was found to be unique and distinguishable among other closely related bacteria. This pattern was associated with DNA extracted directly from honeybee brood samples showing positive AFB clinical signs that yielded the restriction profile characteristic of P. larvae subsp. larvae, while no amplification product was obtained from healthy larvae. The method described here is particularly useful because of the short time required to carry it out and because it allows the differentiation of P. larvae subsp. larvae-infected larvae from all other species found in apiarian sources. PMID:12089057

  20. A Trypsin Inhibitor from Clitoria fairchildiana Cotyledons is Active Against Digestive Enzymes of Aedes aegypti Larvae.

    PubMed

    de Oliveira, Lucilene O; Fernandes, Kátia V S; Pádua, Dayanni de Souza; Carvalho, André de O; Lemos, Francisco J A; Gomes, Valdirene M; Oliveira, Antônia E A; Ferreira, André T da Silva; Perales, Jonas

    2015-01-01

    Aedes aegypti, the principal mosquito vector of yellow fever, dengue fever and chikungunya fever virus-transmitted diseases, is an insect closely associated with humans and their housing habitats. As there is no commercially available vaccine, prevention is the most suggested form of avoiding disease spreading and a number of studies are being developed in order to give support to vector control operations. The present study reports on the identification of a trypsin inhibitor isolated from cotyledons of the Clitoria fairchildiana amazonic tree seeds, which was able to reduce by 87.93 % the activity of digestive enzymes of fourth instar A. aegypti larva. A partial amino acid sequence showed strong similarity with sequences from several trypsin inhibitors already reported in the literature. The 13,000 Da isolated inhibitor was seen to be active solely against trypsin-like enzymes, neither acting on papain, α-amylase nor on other serine proteases, such as elastase, chymotrypsin or subtilisin. At least six from seven active digestive proteases from A. aegypti larvae, visualized by zymography, were severely affected soon after exposed to the inhibitor. The strong and specific action of the isolated inhibitor against trypsin digestive enzymes of this insect vector led us to believe that this protein may be a good candidate for a prospective alternative biocontrol method. PMID:26156641

  1. Expression of human endostatin in larvae of silkworm (Bombyx mori) and in vitro activity assays.

    PubMed

    Yongfeng, Jin; Yingfei, Wang; Zhenhong, Zhu; Yaozhou, Zhang

    2002-08-01

    Human endostatin is a novel antiangiogenic molecule, which can inhibit the proliferation and development of new blood vessels, and experimentally can cause nearly complete regression of established tumors. In this paper, the cDNA encoding human endostatin was cloned into a baculovirus shuttle vector pBacPAK8 and co-infected with linearized Bm-BacPAK6 DNA into and BmN cells. The recombinant virus was screened and identified by PCR, DNA and RNA dot hybridization, and ELISA assay. The recombinant endostatin was expressed in culture cells, and the larvae and pupa of silkworm by inoculation of recombinant virus. The biological activity assay showed that the expression product in larvae was over 150 microg/ml, about 50-fold higher than that expressed in cultured cells. SDS-PAGE and Western blotting analysis showed a pattern of molecular weight of about 20 kDa. The bio-activity of the protein product was determined by human umbilical vein endothelial cells (ECV304) proliferation test in vitro and the chick chorioallantoic membrane (CAM) vascular inhibition test. Endostatin showed significant inhibitory effect on endothelial cells in a dose-dependent manner. Silkworm-produced endostatin induced apoptosis of endothelial cells and also inhibited angiogenesis in the CAM assay. Combination regimen using angiostatin and endostatin showed more than additive effect in angiogenic inhibition and increasing apoptosis when compared with treatment with the individual antiangiogenic protein. PMID:12186748

  2. Acaloleptins A: inducible antibacterial peptides from larvae of the beetle, Acalolepta luxuriosa.

    PubMed

    Imamura, M; Wada, S; Koizumi, N; Kadotani, T; Yaoi, K; Sato, R; Iwahana, H

    1999-01-01

    We purified and characterized three structurally related antibacterial peptides with a molecular mass of 8 kDa (acaloleptins A1, A2, and A3) from the hemolymph of immunized larvae of the Udo longicorn beetle, Acalolepta luxuriosa. These peptides have the same 6 N-terminal amino acid residues and show potent antibacterial activity against some Gram-negative bacteria. The three peptides are thought to be isoforms. Reverse phase HPLC analysis of the hemolymph of immunized and naive larvae showed that acaloleptins A1, A2, and A3 were inducible and suggested that all three peptides were produced in a single insect. We determined the complete amino acid sequence of acaloleptin A1: Acaloleptin A1 consists of 71 amino acid residues and shares significant sequence similarity with coleoptericin and holotricin 2, which were isolated from other coleopteran insects. Furthermore, the 29 C-terminal residues of acaloleptin A1 had 40% identity with the 30 C-terminal residues of hymenoptaecin found in honeybees. Arch. Insect Biochem. PMID:10077828

  3. Sun-Compass Orientation in Mediterranean Fish Larvae

    PubMed Central

    Faillettaz, Robin; Blandin, Agathe; Paris, Claire B.; Koubbi, Philippe; Irisson, Jean-Olivier

    2015-01-01

    Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally. PMID:26308915

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

    PubMed Central

    2010-01-01

    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. PMID:20815905

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

    PubMed

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

    2015-10-01

    Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30 days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections. PMID:25796550

  6. Guppies as predators of common mosquito larvae in Malaysia.

    PubMed

    Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

    2014-03-01

    Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities. PMID:24968669

  7. Incorporation of bacterial extracellular polysaccharide by black fly larvae (Simuliidae)

    USGS Publications Warehouse

    Couch, C.A.; Meyer, J.L.; Hall, R.O., Jr.

    1996-01-01

    Black fly larvae (Simulium) assimilated, with high efficiency (80-90%), bacterial extracellular polysaccharide (EPS) extracted from laboratory cultures of a pseudomonad isolated from the Ogeechee River. Incorporation was traced using 13C-labelled EPS offered to larvae as a coating on a mixture of 1-??m latex beads and kaolin particles. These EPS-coated particles were used to simulate natural particles, both living and dead. Solubility, protein, and nitrogen content of the EPS suggested it was a slime rather than a capsular polysaccharide. Glycosyl composition of the EPS was glucose and galactose in ?? and ?? linkages, with pyruvate, succinate, and possibly malonate constituent groups. To evaluate the incorporation of C derived from protein associated with the EPS matrix, feeding experiments were conducted using EPS with and without proteins extracted. Black fly larvae incorporated 7.2 ??g EPS C larva-1 d-1 from EPS that did not have proteins extracted, and 19.5 ??g EPS C larva-1 d-1 from EPS with proteins extracted. Carbon in protein that is typically associated with EPS was not solely or selectively incorporated. EPS incorporation rates are similar to rates of cellular bacterial carbon incorporation previously estimated for Ogeechee River black fly larvae. If EPS is generally available as a food resource, the importance of bacteria in detrital food webs may be underestimated by studies that examine only the consumption of bacterial cells.

  8. On the escape of infective filarial larvae from the mosquitoes.

    PubMed

    Zielke, E

    1977-12-01

    Experimentally infected females of Culex pipiens fatigans carrying infective larvae of Wuchereria bancrofti were fed, on the 16th day p.i., on four different solutions, which were offered "cold" (24 degrees C) or "warm" (34 degrees C) in Petri dishes as open fluids. Thus the sucking mosquitoes did not have to bend their labia. Only the "warm" human serum stimulated any considerable number of infective larvae (24.8%) to leave the mouthparts of the mosquitoes. 1289 infective C. fatigens females lost only an estimated 6.4% of their infective larvae of W. bancrofti, when they were maintained on sugar-water until their natural death. Most of the more heavily infected mosquitoes died relatively soon after the filarial larvae had reached maturity (15-20 days p.i.). The main stimulus provoking the filarial larvae to migrate into the labium is believed to be the movement of the muscles of the pharyngeal pump. Mature larvae protrude their anterior ends from the tip of the labellum. There they seem able to distinguish between suitable and unsuitable external conditions and accordingly they will either leave the proboscis completely or retract into the labium. PMID:601855

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

    PubMed

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

    2012-08-01

    Sodium metabisulphite (SMB) is used in marine shrimp aquaculture to prevent the occurrence of black spot. The release SMB into the estuarine environment from shrimp farm pond effluents has been reported. This study evaluated the susceptibility of larvae and post-larvae of land crab, Cardisoma guanhumi to this salt. A decrease in dissolved oxygen and pH occurred with increasing concentration of SMB and exposure time. LC(50) values after 48 h of exposure were 34 ± 1.1 mg/L, 31.1 ± 1.9 mg/L, and 30.6 ± 0.5 mg/L for I zoea larvae, megalopa larvae and stage I juveniles, respectively. PMID:22644045

  10. Differential immunological responses induced by infection with female muscle larvae and newborn larvae of Trichinella pseudospiralis.

    PubMed

    Wu, Z; Nagano, I; Asano, K; Liu, M Y; Takahashi, Y

    2013-05-20

    Trichinella pseudospiralis infection can modulate the immunological response of autoimmune and allergic diseases leading to the amelioration of these diseases. The present study was undertaken to compare immunity induced by adult worms and muscle larvae. Higher eosinophilia was observed from newborn larva (NBL) infection than from adult females while higher levels of IgE were observed in adult female infections over those induced by NBL. The IgG1 response to ES antigen was more prominent in infections with adult females. The IgG2 responses to larval crude antigen were prominent against NBL. The Th2 cytokine, IL-4 cytokine was elevated in adult female infection following re-stimulation with adult crude antigen and ES. Both infections induced strong IFN-γ responses. The present study demonstrates that adult female worms induced stronger Th2 responses (IgG1, IgE and IL-4 responses) than NBL. Further examination of the mechanisms involved in immune modulation may be helpful for identifying Trichinella-derived molecules responsible for regulating autoimmune and allergic diseases. PMID:23433605

  11. O que bilíngues bimodais têm a nos dizer sobre desenvolvimento bilíngue?

    PubMed Central

    de Quadros, Ronice Müller; Lillo-Martin, Diane; Pichler, Deborah Chen

    2013-01-01

    O objetivo deste trabalho é apresentar o que as pesquisas que estamos desenvolvendo com crianças ouvintes, filhas de pais surdos, adquirindo Língua Brasileira de Sinais (Libras) e Português e Língua de Sinais Americana (ASL) e Inglês (Lillo-Martin et al. 2010) têm a nos dizer sobre desenvolvimento bilíngue. Os dados deste estudo fazem parte de um banco de dados de interações espontâneas coletadas longitudinalmente, alternando contextos de aquisição da Libras e do português como língua alvo, no Brasil e dados coletados longitudinalmente. nos mesmos contextos, de crianças adquirindo ASL e inglês1. Além disso, há também dados do estudo experimental com testes aplicados nos dois pares de línguas que se agregam ao presente estudo. Uma visão geral dos estudos desenvolvidos sobre a aquisição bilíngue bimodal por crianças ouvintes, filhas de pais surdos, será apresentada e, então, serão expostos alguns aspectos linguísticos deste tipo de aquisição, considerando as discussões sobre aquisição bilíngue a partir da pesquisa realizada. PMID:24431480

  12. The central nervous system of ascidian larvae.

    PubMed

    Hudson, Clare

    2016-09-01

    Ascidians are marine invertebrate chordates. Their tadpole larvae contain a dorsal tubular nervous system, resulting from the rolling up of a neural plate. Along the anterior-posterior (A-P) axis, the central nervous system (CNS) is organized into a sensory vesicle, neck, trunk ganglion, and tail nerve cord and consists of approximately only 330 cells, of which around 100 are thought to be neurons. The organization of distinct neuronal cell types and neurotransmitter gene expression within the CNS has been described. The unique developmental mode of ascidians, with a small number of cells and a fixed cell division pattern, allows individual cells to be traced throughout development. This feature has led to the complete documentation of the cell lineages of certain cell types in the CNS. Thus, a step-by-step understanding of nervous system development from the initial stages of neural induction to the neurogenesis of individual neurons is a feasible goal. The genetic control of neural fate induction and early neural plate patterning are now well understood. The molecular mechanisms specifying the cholinergic neurons of the trunk ganglion as well as the pigment cells of the sensory organs are also well elucidated. In addition, studies have begun on the morphogenetic processes of neurulation. Remaining challenges include building an embryonic atlas integrating gene expression patterns, cell lineage, and neuronal cell types as well as developing the gene regulatory networks of cell fate specification and integrating them with the genetic control of morphogenesis. WIREs Dev Biol 2016, 5:538-561. doi: 10.1002/wdev.239 For further resources related to this article, please visit the WIREs website. PMID:27328318

  13. Loss of surface coat by Strongyloides ratti infective larvae during skin penetration: evidence using larvae radiolabelled with /sup 67/gallium

    SciTech Connect

    Grove, D.I.; Northern, C.; Warwick, A.; Lovegrove, F.T.

    1984-10-01

    The optimal conditions for labelling infective larvae of Strongyloides ratti with /sup 67/Ga citrate were determined. Radiolabelled larvae were injected s.c. into normal and previously infected rats. The distribution of radioactivity in these animals was compared with that in rats infected subcutaneously with a similar dose of free /sup 67/Ga by using a gamma camera linked to a computer system. Whereas free /sup 67/Ga was distributed throughout the body and excreted via the hepatobiliary system, the bulk of radioactivity in rats injected with radiolabelled larvae remained at the injection sites. Direct microscopical examination of these sites, however, revealed only minimal numbers of worms. When rats were infected percutaneously with radiolabelled larvae, it was found that most radioactivity remained at the surface, despite penetration of worms. When infective larvae were exposed to CO/sub 2/ in vitro and examined carefully by light microscopy, loss of an outer coat was observed. It was concluded that infective larvae lose an outer coat on skin penetration.

  14. Downregulation of dTps1 in Drosophila melanogaster larvae confirms involvement of trehalose in redox regulation following desiccation.

    PubMed

    Thorat, Leena; Mani, Krishna-Priya; Thangaraj, Pradeep; Chatterjee, Suvro; Nath, Bimalendu B

    2016-03-01

    As a survival strategy to environmental water deficits, desiccation-tolerant organisms are commonly known for their ability to recruit stress-protective biomolecules such as trehalose. We have previously reported the pivotal role of trehalose in larval desiccation tolerance in Drosophila melanogaster. Trehalose has emerged as a versatile molecule, serving mainly as energy source in insects and also being a stress protectant. While several recent reports have revealed the unconventional role of trehalose in scavenging reactive oxygen species in yeast and plants, this aspect has not received much attention in animals. We examined the status of desiccation-induced generation of reactive oxygen species in D. melanogaster larvae and the possible involvement of trehalose in ameliorating the harmful consequences thereof. Insect trehalose synthesis is governed by the enzyme trehalose 6-phosphate synthase 1 (TPS1). Using the ubiquitous da-GAL4-driven expression of the dTps1-RNAi transgene, we generated dTps1-downregulated Drosophila larvae possessing depleted levels of dTps1 transcripts. This resulted in the inability of the larvae for trehalose synthesis, thereby allowing us to elucidate the significance of trehalose in the regulation of desiccation-responsive redox homeostasis. Furthermore, the results from molecular genetics studies, biochemical assays, electron spin resonance analyses and a simple, non-invasive method of whole larval live imaging suggested that trehalose in collaboration with superoxide dismutase (SOD) is involved in the maintenance of redox state in D. melanogaster. PMID:26577464

  15. Marine water quality assessment using transplanted oyster larvae.

    PubMed

    Quiniou, F; Damiens, G; Gnassia-Barelli, M; Geffard, A; Mouneyrac, C; Budzinski, H; Roméo, M

    2007-01-01

    Active bio-monitoring in terms of biomarkers was attempted using Crassostrea gigas larvae produced in the laboratory and transplanted using special containers to two sites at the entrance (A) and inner part (P) of the harbour of Arcachon (French Atlantic Coast). The larvae were kept in the medium for 48 h. Their physiological status and their biomarker levels : acetylcholinesterase AChE, catalase CAT and glutathione S-transferase GST activities were determined together with metallothionein MT and Thiobarbituric Acid Reactive Substances TBARS concentrations. Copper and PAH (polycyclic aromatic hydrocarbon) concentrations were determined in the exposed larvae and in the sediments collected under the containers. Cadmium, lead and zinc could be also analyzed in the sediments. Toxicity tests demonstrate that the larvae are in better physiological conditions in A compared to P. Larvae transplanted in the inner harbour (P) present relatively high GST activity (869.1+/-39.3 nmol min(-1)mg protein(-1)), TBARS (2.74+/-0.19 nmol mg protein(-1)), compared to those exposed at the harbour entrance (A). Copper measured in the sediments (65+/-1 mg kg(-1) d.w.) collected under the cages at P is higher than at A. Larvae placed in A present higher total PAH concentrations compared to the inner part. The data tend to reveal a lower copper and higher PAH contamination in A than in P. Therefore larvae, developing in the natural medium, show different responses according to their immersion sites. These responses, obtained within 48 h, may be related to the chemical contamination of the environment and may be used for seawater quality assessment in future studies. PMID:16859746

  16. Retention of crab larvae in a coastal null zone

    NASA Astrophysics Data System (ADS)

    Tilburg, Charles E.; Dittel, Ana I.; Epifanio, Charles E.

    2007-05-01

    Alongshelf transport in the southern Middle Atlantic Bight is forced by buoyancy-driven currents originating in three large estuaries along the bight. These currents are strongest in the coastal ocean near the southern terminus of each estuary, while the analogous region on the northern side is characterized by weak subtidal flow. We used a combination of field observations and numerical modeling to test the hypothesis that these regions of weak subtidal flow are coastal null zones that serve as retention areas for larvae. The field study consisted of a four-day, shipboard investigation of the distribution of blue crab larvae ( Callinectes sapidus) near the mouth of Delaware Bay (˜39°N, 75°W) in late summer, 2004. Hydrographic surveys of the study site were conducted with a hull-mounted, surface-measuring system. Results showed a sharp boundary between the null zone and the buoyancy-driven current to the south. Blue crab larvae were collected in surface plankton tows along a 30-km transect that encompassed these two areas. Stations with higher densities of larvae were clustered in the null zone during both ebb and flood tides. A numerical model was used to examine the physical mechanisms responsible for the observed distribution. Model results agreed with the field survey and showed that simulated larvae are aggregated in the null zone. The simulations also demonstrated that larvae spawned within the null zone have a much greater probability of settling in juvenile nursery habitat within the bay. The close agreement between field and model results provides consistent support for the hypothesis that coastal null zones associated with the buoyancy-driven circulation of large estuaries may allow retention of larvae in the vicinity of the natal spawning population.

  17. Susceptibility of some vertebrate hosts to infection with early third-stage larvae of Gnathostoma hispidum.

    PubMed

    Sohn, W M; Lee, S H

    1997-09-01

    Susceptibility of some vertebrates was examined to the early third-stage larvae (EL3) of Gnathostoma hispidum. The larvae collected from the Chinese loaches were infected to 4 silk carps, 3 snake heads, 3 bullfrogs, 5 mice and 9 albino rats. No worms were detected in fish, silk carps and snake heads. In 3 bullfrogs fed 30 larvae, a total of 9 EL3 was recovered in the gastrointestinal tract (8 larvae) and liver (one). In 5 mice infected with 50 larvae, a total of 37 (74.0%) advanced third-stage larvae (AdL3) was recovered from the muscle (31 larvae), liver (5 larvae) and kidney at 4 weeks after infection. In 9 albino rats infected with 115 larvae, a total of 40 (34.8%) AdL3 was found in the muscle. The mammalian hosts were found susceptible to the EL3 of G. hispidum from Chinese loaches. PMID:9335187

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  19. Comparative analysis of Paenibacillus larvae genotypes isolated in Connecticut.

    PubMed

    Dingman, Douglas W

    2015-08-01

    Ninety-six strains of Paenibacillus larvae, causative agent of American foulbrood in honey bee (Apis mellifera) larvae, collected from Connecticut, USA (CT), honey bees, and 12 P. larvae strains not from CT, were genotyped via ERIC-PCR and XbaI-RFLP analysis. All CT-isolates, five strains isolated in South America, three strains from North America (not CT), and one strain isolated in Australia grouped into the ERIC I genotype. Three P. larvae formerly subsp. pulvifaciens strains grouped into ERIC III and IV genotypes. XbaI-RFLP genotyping showed three genotypes within the CT-isolates, and two were identified as XbaI-RFLP Type I and III. The third XbaI-RFLP genotype (Type Ib) represented one of four new XbaI-RFLP genotypes identified. Comparison of genotype results for the P. larvae strains tested was used to develop a correlation between ERIC-PCR genotyping and XbaI-RFLP genotyping. Sixteen CT-isolates were tetracycline-resistant and demonstrated PCR amplification using oligonucleotide primers for tetL. All 16 isolates grouped within XbaI-RFLP Type Ib, suggesting limited introduction of a tetracycline-resistant strain into CT. PMID:25929327

  20. Visceral and Neural Larva Migrans in Rhesus Macaques

    PubMed Central

    Gozalo, Alfonso S; Maximova, Olga A; StClaire, Marisa C; Montali, Richard J; Ward, Jerrold M; Cheng, Lily I; Elkins, William R; Kazacos, Kevin R

    2008-01-01

    Large ascarid larvae within granulomas were noted histologically in the mesenteric and pancreatic lymph nodes of 13 of 21 rhesus macaques (Macaca mulatta) euthanized as part of an experimental viral pathogenesis study. In addition, 7 of the 13 monkeys had cerebral granulomas, which in 4 animals contained nematode larvae similar to those within the lymph nodes. Despite the lesions, the animals did not show clinical signs associated with the parasitic infections. Characteristics of the larvae included, on cross-section, a midbody diameter of approximately 60 to 80 µm, a centrally located and slightly compressed intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. The morphology of the larvae was compatible with Baylisascaris spp. Baylisascariasis is a well-described infection of animals and humans that is caused by migrating larvae of the raccoon roundworm, Baylisascaris procyonis. A similar species, B. columnaris, is found in skunks and can cause cerebrospinal nematodiasis, but most reported cases of baylisascariasis have been due to B. procyonis. Our macaques were born free-ranging on an island in the southeastern United States where raccoons, but not skunks, were found to be common inhabitants, indicating that B. procyonis was the most likely parasite involved. These cases are similar to the low-level or covert cases of Baylisascaris infection described to occur in humans and provide further evidence of the existence of this parasite in the southeastern United States. PMID:18702454

  1. High magnetic field induced otolith fusion in the zebrafish larvae.

    PubMed

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-01-01

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an "all-or-none" manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish. PMID:27063288

  2. [Hemocytes of Calliphora vicina larvae. I. Histological analysis].

    PubMed

    Tulin, D V; Chaga, O Iu

    2003-01-01

    The rational classification of blood cells of a blowfly Calliphora vicina larva has been worked out basing on the studies of hemocyte morphology and their dynamics while ageing. Eight morphological cell types can be found during the third age in larva's hemolymph. Hemocytes of type I (prohemocytes) are undifferentiated cells, and, probably, serve as cambial elements of hemocytes of other types. Hemocytes of types II (thrombocytoids), III (cell platelets), IV, and V (early- and late post-thrombocytoids) possibly correspond to consecutive stages of a certain differentiation pattern. Hemocytes of types VI (filopodocytes), VII (crystal cells), and VIII (histolysocytes) posses a number of specific features and represent three independent cell lines. The existence of four independent cell lines in C. vicina hemolymph supports the polygenetic conception of hematopoiesis in insects. We compared our classification with other existing classifications of C. vicina larva blood cells, and proposed a new nomenclature of these cells. The existence of cells with crystal inclusions (type VII hemocytes) in C. vicina larva hemolymph has been shown for the first time. Data on two generations of blood cells during larval development of C. vicina were obtained. Hemocytes of types II, VI and VII belong to the first generation. These cells disappear completely at the stage of empty-poropped larva, when hemocytes of the second generation i.e. those of types III and VIII, appear in the hemolymph. PMID:14989169

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

    PubMed

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

    2014-08-01

    Odonate larvae can be serious pests that attack fish larvae, postlarvae, and fingerlings in fish culture tanks, causing significant loss in the supply and production of juveniles. This study reports a screen of the essential oils (EOs) of Nectandra megapotamica (Sprengel) Mez, Nectandra grandiflora Nees, Hesperozygis ringens (Bentham) Epling, Ocimum gratissimum L., Aloysia gratissima (Gillies & Hooker) Troncoso, and Lippia sidoides Chamisso against Coenagrionidae larvae. In addition, the most effective EO and its 50% lethal concentration (LC50) and chemical analysis are described. The larvae of Acanthagrion Selys, Homeoura Kennedy, Ischnura Charpentier, and Oxyagrion Selys were used to assess the EO effects. EO obtained from H. ringens, O. gratissimum, and L. sidoides showed the highest larvicidal effects at 19 h of treatment. The major constituents of the EO of H. ringens include pulegone and limonene, while eugenol and Z-beta-ocimene predominate in the EO of O. gratissimum, and carvacrol and rho-cymene were the major compounds of the EO of L. sidoides. Leaf EOs from H. ringens, O. gratissimum, and L. sidoides showed activity against Coenagrionidae larvae at similar concentrations with LC50s of 62.92, 75.05, and 51.65 microl liter(-1), respectively, and these were considered the most promising treatments. PMID:25195467

  4. Larva migrans in India: veterinary and public health perspectives.

    PubMed

    Sharma, Rajnish; Singh, B B; Gill, J P S

    2015-12-01

    Despite an important public health problem in developing world like India, larva migrans remains a neglected zoonosis. Cutaneous larva migrans, Visceral larva migrans, and Ocular larva migrans are the important clinical manifestations seen in humans in India. Although many nematode parasites have the ability to cause the infection, the disease primarily occurs due to Ancylostoma caninum and Toxocara canis. Presence of the infection in dogs is an indirect indication of its incidence in humans in endemic regions. In India, sporadic cases of this neglected but important parasitic zoonosis are the main implications of lack of diagnostic methods and under-reporting of human cases. Tropical climate in addition to overcrowding, poor hygiene and sanitation problems, stray dogs, open defecation by dogs and improper faecal disposal are the important factors for persistence of this disease in the country. Sanitary and hygienic measures, improved diagnostic techniques and surveillance programme in dogs as well as humans should be adopted for its effective control. Comprehensive collaborative efforts by physicians and veterinarians are required to tackle this problem in order to attain optimal health for humans, animals and the environment. Moreover, recognition of larva migrans as an important public health problem is the most important step to combat this neglected disease in developing countries like India. PMID:26688621

  5. Visceral and neural larva migrans in rhesus macaques.

    PubMed

    Gozalo, Alfonso S; Maximova, Olga A; StClaire, Marisa C; Montali, Richard J; Ward, Jerrold M; Cheng, Lily I; Elkins, William R; Kazacos, Kevin R

    2008-07-01

    Large ascarid larvae within granulomas were noted histologically in the mesenteric and pancreatic lymph nodes of 13 of 21 rhesus macaques (Macaca mulatta) euthanized as part of an experimental viral pathogenesis study. In addition, 7 of the 13 monkeys had cerebral granulomas, which in 4 animals contained nematode larvae similar to those within the lymph nodes. Despite the lesions, the animals did not show clinical signs associated with the parasitic infections. Characteristics of the larvae included, on cross-section, a midbody diameter of approximately 60 to 80 mum, a centrally located and slightly compressed intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. The morphology of the larvae was compatible with Baylisascaris spp. Baylisascariasis is a well-described infection of animals and humans that is caused by migrating larvae of the raccoon roundworm, Baylisascaris procyonis. A similar species, B. columnaris, is found in skunks and can cause cerebrospinal nematodiasis, but most reported cases of baylisascariasis have been due to B. procyonis. Our macaques were born free-ranging on an island in the southeastern United States where raccoons, but not skunks, were found to be common inhabitants, indicating that B. procyonis was the most likely parasite involved. These cases are similar to the low-level or covert cases of Baylisascaris infection described to occur in humans and provide further evidence of the existence of this parasite in the southeastern United States. PMID:18702454

  6. Feeding ecology of lake whitefish larvae in eastern Lake Ontario

    USGS Publications Warehouse

    Johnson, James H.; McKenna, James E.; Chalupnicki, Marc A.; Wallbridge, Tim; Chiavelli, Rich

    2009-01-01

    We examined the feeding ecology of larval lake whitefish (Coregonus clupeaformis) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

  7. Effects of food deprivation on the larvae of two flatfishes

    USGS Publications Warehouse

    Gadomski, D.M.; Petersen, J.H.

    1988-01-01

    For greatest survival, first-feeding halibut Paralichthys californicus and diamond turbot Hypsopsetta guttulata required food by the day of total yolk absorption. Some halibut larvae survived if fed 1 or 2 d after yolk depletion, but their growth rate was significantly less than larvae fed earlier. Survival of 3-wk-old larvae was greater in treatments with shorter starvation periods. A small percentage of 3-wk-old halibut larvae recovered from a maximum starvation period of 4 d while 3-wk-old diamond turbot successfully resumed feeding any time during food deprivation intervals lasting up to 9 d. Longer periods of starvation resulted in significant morphological differences – diamond turbot starved longer were not only smaller, but also less developed. In the field, larvae may experience varying periods of food deprivation due to differing spatial and temporal prey patch distributions. Our results demonstrate that differences in starvation resistance, and possibly mortality under patchy feeding conditions, are ontogenetic and species-specific.

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

    PubMed

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

    2014-07-01

    Anisakiasis is an important food-borne disease especially in countries with high fish consumption. The increase of cases of human disease and the virtual absence of effective treatments have prompted the research on new active compounds against Anisakis larvae. As well known, the disease is related to the consumption of raw or almost raw seafood products, but also marinated and/or salted fishery products, if the processing is insufficient to destroy nematode larvae can represent a risks for the consumers. In the light of the biocidal efficacy against different pathogens demonstrated for various essential oils, the aim of this work is to evaluate the effect of Thymus vulgaris essential oil (TEO) against anisakidae larvae. The TEO at 10% and 5% concentration in oil sunflower seeds, caused in vitro the death of all larvae within 14 h, with cuticle and intestinal wall damages. The results obtained showing a significant activity against Anisakis larvae, suggest further investigation on TEO as a larvicidal agent and on its potential use in the industrial marinating process. PMID:24721259

  9. What do tiger-fly larvae (Diptera: Muscidae) eat?

    PubMed

    Santos, S; Martins, J; Marcelino, J; Mateus, C; Figueiredo, E

    2013-01-01

    Coenosia attenuata, usually known as tiger-fly, is a generalist predator of agricultural and forest pests in both larval and adult stages; it has potential to be an effective biocontrol agent in protected crops. To contribute for the knowledge of which prey this predator larvae potentially consumes, and of the occurrence and the conditions that promote cannibalism by tiger-fly larvae, intact alive specimens and portions of the earthworm Lumbricus terrestris were tested as prey and the cannibalism was evaluated in the presence or in absence of fungus gnat larvae. The tiger-fly larvae fed on the bisected earthworm portions but seem to have difficulty to penetrate in the cuticle of the alive and moving L. terrestris. However, the time to start feeding on the portions of L terrestris was shorter than on fungus gnats. Cannibalism by C. attenuato was not detected, but mortality occurred in several modalities. Nevertheless, escaping from the Petri dishes was the dominant behaviour of the larvae in the cannibalism evaluation assay. PMID:25145255

  10. High magnetic field induced otolith fusion in the zebrafish larvae

    PubMed Central

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-01-01

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an “all-or-none” manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish. PMID:27063288

  11. Dynamics of Social Behavior in Fruit Fly Larvae

    PubMed Central

    Durisko, Zachary; Kemp, Rebecca; Mubasher, Rameeshay; Dukas, Reuven

    2014-01-01

    We quantified the extent and dynamics of social interactions among fruit fly larvae over time. Both a wild-type laboratory population and a recently-caught strain of larvae spontaneously formed social foraging groups. Levels of aggregation initially increased during larval development and then declined with the wandering stage before pupation. We show that larvae aggregated more on hard than soft food, and more at sites where we had previously broken the surface of the food. Groups of larvae initiated burrowing sooner than solitary individuals, indicating that one potential benefit of larval aggregations is an improved ability to dig and burrow into the food substrate. We also show that two closely related species, D. melanogaster and D. simulans, differ in their tendency to aggregate, which may reflect different evolutionary histories. Our protocol for quantifying social behavior in larvae uncovered robust social aggregations in this simple model, which is highly amenable to neurogenetic analyses, and can serve for future research into the mechanisms and evolution of social behavior. PMID:24740198

  12. [Visceral larva migrans. A rare cause of eosinophilia in adults].

    PubMed

    Lund-Tønnesen, S

    1996-09-20

    Toxocariasis is a cosmopolitan infection of dogs and cats with a roundworm resembling Ascaris. Man becomes infected by ingesting eggs from the environment. The infection occurs mainly in children. There are two distinct syndromes: visceral larva migrans and ocular toxocariasis. The author describes the case of a 70 year old Norwegian female with visceral larva migrans. One month after a visit to Spain she developed fever, hepatomegaly and marked eosinophilia. Liver biopsy revealed subacute hepatitis with eosinophilic leucocyte infiltration. Toxocara ELISA was strongly positive. Treatment with albendazol 400 mg b.i.d. and prednisone 10 mg daily for three weeks was successful. A clinical relapse after three months was treated in the same way for one month. Prolonged treatment is recommended. To our knowledge, this is the first reported case of visceral larva migrans in an adult Norwegian. Epidemiology, diagnosis and treatment are discussed. PMID:8928142

  13. Lamellocyte differentiation in Drosophila larvae parasitized by Leptopilina.

    PubMed

    Rizki, T M; Rizki, R M

    1992-01-01

    The presence of Leptopilina heterotoma or Leptopilina boulardi eggs in the hemocoel of a Drosophila melanogaster larva induces the differentiation of lamellocytes, the blood cells that encapsulate foreign objects. L. boulardi eggs are encapsulated by the newly differentiated lamellocytes, but L. heterotoma eggs are not. The induced lamellocytes in host larvae with L. heterotoma eggs undergo the same destructive morphological changes as reported previously for lamellocytes present in melanotic tumor mutant larvae at the time of parasitization. Thus, the virus-like particles produced by the L. heterotoma female to protect its eggs from encapsulation do not block the differentiation of lamellocytes, but rather destroy lamellocytes whenever they are present in the hemocoel. PMID:1499832

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

    PubMed

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

    2005-01-01

    Thaumetopoea pityocampa larvae are very harmful to pines and they also cause allergic reactions in men and animals. In this study, different concentrations of endosulfan were administered to T. pityocampa larvae via pine needles which were prepared by the dipping method. The data obtained were statistically evaluated using probit analysis and a LC(50/48 hrs) value for T. pityocampa larvae found to be 1.679 mg/l. Also, 12, 24, 36 and 48 hrs after 1.679 mg/1 endosulfan treatment, ultrastructural changes in the midgut epithelium of T. pityocampa were investigated. No pathological changes were observed after 12 hrs, swelling and vacuolization of mitochondria and dilation ofendoplasmic reticulum after 24 hrs, swelling ofmitochondria and breaking of mitochondrial cristae and dissolving of nucleoplasm after 36 hrs, finally large vacuoles in the midgut epithelium cells were observed after 48 hrs. PMID:19058549

  15. Developmental arrest in Caenorhabditis elegans dauer larvae causes high expression of enzymes involved in thymidylate biosynthesis, similar to that found in Trichinella muscle larvae.

    PubMed

    Wińska, P; Gołos, B; Cieśla, J; Zieliński, Z; Fraczyk, T; Wałajtys-Rode, E; Rode, W

    2005-08-01

    Crude extract specific activities of thymidylate synthase, dUTPase, thymidine kinase and dihydrofolate reductase were high during the development of Caenorhabditis elegans, the dauer larva activities being similar to those previously determined in Trichinella spiralis and T. pseudospiralis muscle larvae (with the exception of thymidine kinase, not detected in Trichinella). High thymidylate synthase expression in developmentally arrested larvae, demonstrated also at the mRNA and protein levels, is in agreement with a global cell cycle arrest of dauer larvae and indicates this unusual cell cycle regulation pattern can be shared by developmentally arrested larvae of C. elegans and the two Trichnella species. Hence, the phenomenon may be characteristic for developmentally arrested larvae of different nematodes, rather than specific for the parasitic Trichinella muscle larvae. Endogenous C. elegans thymidylate synthase was purified and its molecular properties compared with those of the recombinant protein, expression of the latter in E. coli cells confirming the NCBI database sequence identity. PMID:16145941

  16. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae

    PubMed Central

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy. PMID:26048941

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

    NASA Astrophysics Data System (ADS)

    Munk, Peter

    2014-09-01

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

  18. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae.

    PubMed

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner; Steinert, Michael

    2015-08-15

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy. PMID:26048941

  19. Nutrient effects of broodstocks on the larvae in Patinopecten yessoensis

    NASA Astrophysics Data System (ADS)

    Bai, Yucen; Zhang, Tao; Qiu, Tianlong; Gao, Yan; Zhang, Xiaofang

    2015-07-01

    Patinopecten yessoensis is a commercial valuable species. This study deals with the effect of nutrient effects of the broodstock (mainly ovaries) on the larvae. Concentrations of total carbohydrate, total protein and total lipid in the gonads of P. yessoensis from three Hatcheries (Hatchery 1, Hatchery 2, and Hatchery 3) were determined before and after spawning. The relationship between the nutrient concentration in ovaries before spawning (BC) and that of larvae (LC) was assessed as well as the change in nutrient levels in ovaries after spawning (DC). Results indicate that the BC of total carbohydrate (7.66%) and total lipid (14.48%) in ovaries were significantly higher than in testes (5.20%, 5.20% respectively), whereas the BC of total protein in the ovaries was lower (61.76%) than in the testes (81.67%). The different gonadal composition suggests the different nutrient demands between male and female broodstocks in breeding season. Patinopecten yessoensis gonads contained a higher proportion of lipids, in comparison to other bivalves, which might be a response to the low ambient water temperatures. Further analysis of fatty acids showed that the concentrations of n-3PUFA, EPA and DHA in larvae (LC) were positively correlated with BC and DC, indicating the significant nutrient influence of broodstocks on the larvae. As these fatty acids are important in metabolism, and have been demonstrated to be influential to the viability of the larvae, larval growth and the settlement, spat growth, and juvenile survival in many bivalves, they could possibly be used as indexes to evaluate, and predict condition of broodstocks and larvae.

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

    NASA Astrophysics Data System (ADS)

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

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

  1. HISTOCHEMICAL EFFECTS OF SOME BIOLOGICAL AGENTS ON CULEX PIPIENS LARVAE.

    PubMed

    El Sobky, Mona M; Ismail, Howaida I H; Assar, Abada A

    2016-04-01

    The histochemical effects of the lethal concentration that kills 50% of larvae (LC50) of three biological agents, abamectin, Bacillus thuringiensis and spinosad on the carbohydrates (polysaccharides), proteins, nucleic acids and lipids content of the midgut and fat bodies of Culex pipiens 2nd instar larvae were studied. The results showed that the three tested compounds reduced the carbohydrates (polysaccharides), proteins, RNA synthesis and lipids content after 72 hours of treatment where abamectin was the most effective followed by Bacillus thuringiensis then spinosad. PMID:27363043

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

    NASA Astrophysics Data System (ADS)

    Higgins, R. P.; Storch, V.

    1989-03-01

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

  3. American Foulbrood in honeybees and its causative agent, Paenibacillus larvae.

    PubMed

    Genersch, Elke

    2010-01-01

    After more than a century of American Foulbrood (AFB) research, this fatal brood infection is still among the most deleterious bee diseases. Its etiological agent is the Gram-positive, spore-forming bacterium Paenibacillus larvae. Huge progress has been made, especially in the last 20 years, in the understanding of the disease and of the underlying host-pathogen interactions. This review will place these recent developments in the study of American Foulbrood and of P. larvae into the general context of AFB research. PMID:19909971

  4. Neural larva migrans caused by the raccoon roundworm Baylisascaris procyonis.

    PubMed

    Gavin, Patrick J; Kazacos, Kevin R; Tan, Tina Q; Brinkman, William B; Byrd, Sharon E; Davis, A Todd; Mets, Marilyn B; Shulman, Stanford T

    2002-10-01

    Baylisascaris procyonis, the common raccoon roundworm, is a rare cause of devastating or fatal neural larva migrans in infants and young children. We describe the clinical features of two children from suburban Chicago who developed severe, nonfatal B. procyonis neural larva migrans. Despite treatment with albendazole and high dose corticosteroids, both patients are neurologically devastated. In many regions of North America, large populations of raccoons with high rates of endemic B. procyonis infection live in proximity to humans, which suggests that the risk of human infection is probably substantial. In the absence of effective treatment, prevention of infection remains the most important public health strategy. PMID:12394823

  5. Cutaneous larva migrans: case report with current recommendations for treatment.

    PubMed

    O'Quinn, Jonathan C; Dushin, Robert

    2005-01-01

    Cutaneous larva migrans is a common skin pathology that occurs in people who have recently visited tropical or subtropical climates. Given the ubiquity of this condition, the podiatric physician may encounter cutaneous larva migrans during clinical practice and should be cognizant of the presenting signs and typical patient history given in these cases. We describe the case of a 62-year-old man who presented with a pruritic, erythematous, serpiginous lesion on the dorsum of his left foot after having vacationed in Florida for several weeks. The patient was treated successfully with oral thiabendazole, 500 mg after meals 4 times daily for 5 days. PMID:15901819

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

    USGS Publications Warehouse

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

    1996-01-01

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

  7. Integration of carbohydrate metabolism and redox state controls dauer larva formation in Caenorhabditis elegans.

    PubMed

    Penkov, Sider; Kaptan, Damla; Erkut, Cihan; Sarov, Mihail; Mende, Fanny; Kurzchalia, Teymuras V

    2015-01-01

    Under adverse conditions, Caenorhabditis elegans enters a diapause stage called the dauer larva. External cues signal the nuclear hormone receptor DAF-12, the activity of which is regulated by its ligands: dafachronic acids (DAs). DAs are synthesized from cholesterol, with the last synthesis step requiring NADPH, and their absence stimulates dauer formation. Here we show that NADPH levels determine dauer formation in a regulatory mechanism involving key carbohydrate and redox metabolic enzymes. Elevated trehalose biosynthesis diverts glucose-6-phosphate from the pentose phosphate pathway, which is the major source of cellular NADPH. This enhances dauer formation due to the decrease in the DA level. Moreover, DAF-12, in cooperation with DAF-16/FoxO, induces negative feedback of DA synthesis via activation of the trehalose-producing enzymes TPS-1/2 and inhibition of the NADPH-producing enzyme IDH-1. Thus, the dauer developmental decision is controlled by integration of the metabolic flux of carbohydrates and cellular redox potential. PMID:26290173

  8. Low-molecular-weight metabolites secreted by Paenibacillus larvae as potential virulence factors of American foulbrood.

    PubMed

    Schild, Hedwig-Annabell; Fuchs, Sebastian W; Bode, Helge B; Grünewald, Bernd

    2014-04-01

    The spore-forming bacterium Paenibacillus larvae causes a severe and highly infective bee disease, American foulbrood (AFB). Despite the large economic losses induced by AFB, the virulence factors produced by P. larvae are as yet unknown. To identify such virulence factors, we experimentally infected young, susceptible larvae of the honeybee, Apis mellifera carnica, with different P. larvae isolates. Honeybee larvae were reared in vitro in 24-well plates in the laboratory after isolation from the brood comb. We identified genotype-specific differences in the etiopathology of AFB between the tested isolates of P. larvae, which were revealed by differences in the median lethal times. Furthermore, we confirmed that extracts of P. larvae cultures contain low-molecular-weight compounds, which are toxic to honeybee larvae. Our data indicate that P. larvae secretes metabolites into the medium with a potent honeybee toxic activity pointing to a novel pathogenic factor(s) of P. larvae. Genome mining of P. larvae subsp. larvae BRL-230010 led to the identification of several biosynthesis gene clusters putatively involved in natural product biosynthesis, highlighting the potential of P. larvae to produce such compounds. PMID:24509920

  9. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease.

    PubMed

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G; Amy, Penny S

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed. PMID:26136497

  10. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease

    PubMed Central

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G.; Amy, Penny S.

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed. PMID:26136497

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

    PubMed

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

    2005-08-10

    The minimal inhibitory concentrations (MICs) of tylosin were determined to 67 strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood (AFB) disease, from different geographical origins. MIC values obtained ranged from 0.0078 to 0.5 microg/ml. These very low values imply that no resistance to tylosin was found in any isolate of the Foulbrood pathogen. The measurement of diseased larvae with AFB-clinical symptoms in three different field studies demonstrated that tylosin treatment could be effective in vivo. No negative effects in colonies were noted at any dosage rates or forms of application. These studies demonstrate that tylosin, as tartrate, can be used to treat AFB in honeybee colonies. PMID:15951140

  12. Fluctuation of diptera larvae in phytotelmata and relation with climate variation in West Sumatra Indonesia.

    PubMed

    Rosa, Emantis; Dahelmi; Salmah, Siti; Syamsuardi

    2014-07-01

    Research of fluctuations in Diptera's larvae in Phytotelmata had been conducted at three locations in West Sumatra, Indonesia; Padang, Bukittinggi and Payakumbuh; which aimed to determine the number and fluctuations Diptera larvae in Phytotelmata. The results obtained; the highest number of individual larvae Diptera in Phytotelmata was 7109 Aedes albopictus larvae (49.56%), followed by larvae of Culex tritaeniorhynchus with 2409 individuals (16.80%). Larvae fluctuated every month and tent to increase in November and December. There was no difference in the number of Diptera larvae individuals inhabiting pandan, taro, and pineapple, but there were significant differences between the three types of Phytotelmata (pandanus, taro and pineapple) with bamboo (p < 0.05). Number of individual larvae in Phytotelmata negatively correlated with temperature and rainfall, but positively correlated with humidity (r = 0.44: p < 0.05). PMID:26035947

  13. Susceptibility of Apple Clearwing Moth Larvae, Synanthedon myopaeformis (Lepidoptera: Sesiidae) to Beauveria basiana and Metarhizium brunneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple clearwing moth larvae, Synanthedon myopaeformis (Lepidoptera: Sessidae) collected from orchards in British Columbia, Canada, were naturally infected with the entomopathogenic fungus, Metarhizium brunneum (Petch). In laboratory bioassays, larvae were susceptible to infection and dose related mo...

  14. New insights for Drosophila GAGA factor in larvae

    PubMed Central

    Blanch, Marta; Piñeyro, David; Bernués, Jordi

    2015-01-01

    GAGA factor plays important roles during Drosophila embryogenesis and its maternal contribution is essential for early development. Here, the role of GAGA factor was studied in 3rd instar larvae using depletion and overexpression conditions in wing disc and transcriptome analysis. We found that genes changing expression were different to those previously described using GAGA mutants in embryos. No apparent phenotypes on GAGA depletion could usually be observed at larval stages in imaginal discs but a strong effect on salivary gland polytene chromosomes was observed. In the adult, GAGA depletion produced many defects like abnormal cell proliferation in the wing, impaired dorsal closure and resulted in homeotic transformation of abdominal segment A5. Unexpectedly, no effects on Ultrabithorax expression were observed. Short overexpression of GAGA factor in 3rd instar larvae also resulted in activation of a set of genes not previously described to be under GAGA regulation, and in lethality at pupa. Our results suggest a little contribution of GAGA factor on gene transcription in wing discs and a change of the genes regulated in comparison with embryo. GAGA factor activity thus correlates with the global changes in gene expression that take place at the embryo-to-larva and, later, at the larva-to-pupa transitions. PMID:26064623

  15. Genome Sequences of Six Paenibacillus larvae Siphoviridae Phages.

    PubMed

    Carson, Susan; Bruff, Emily; DeFoor, William; Dums, Jacob; Groth, Adam; Hatfield, Taylor; Iyer, Aruna; Joshi, Kalyani; McAdams, Sarah; Miles, Devon; Miller, Delanie; Oufkir, Abdoullah; Raynor, Brinkley; Riley, Sara; Roland, Shelby; Rozier, Horace; Talley, Sarah; Miller, Eric S

    2015-01-01

    Six sequenced and annotated genomes of Paenibacillus larvae phages isolated from the combs of American foulbrood-diseased beehives are 37 to 45 kbp and have approximately 42% G+C content and 60 to 74 protein-coding genes. Phage Lily is most divergent from Diva, Rani, Redbud, Shelly, and Sitara. PMID:26089405

  16. Predation of Chaoborus punctipennis on larvae of Dorosoma

    SciTech Connect

    Dailey, N.S.; Mattice, J.S.

    1982-05-01

    Laboratory and field studies were conducted to evaluate the significance of predation of Chaoborus punctipennis on Dorosoma larvae. Only third (III) and fourth (IV) instars of Chaoborus consumed shad larvae in the laboratory studies. Predation was directly related to shad density and chaoborus size, but was not related to age (or size) of yolk-sac Dorosoma or to temperature in the range of 20 to 25/sup 0/C prevalent during shad spawning. Analysis of evening plankton samples collected in Blue Springs Cove, Watts Bar Reservoir, Tennessee, during the shad spawning season suggested that interactions between the two species were reduced by spatial, temporal, and seasonal separation. Shad larvae were most abundant near the water surface, particularly near the shoreline and near dawn; III and IV instar Chaoborus were most abundant at 3 or 5 meter depths below the surface and highest concentrations were in deeper water areas between 2100 and 0300. In Blue Springs Cove in 1980, densities of shad and Chaoborus were too low to expect predation to occur based on the extrapolation of predation rates derived from the laboratory studies. This conclusion received further support from the fact that no signs of shad larvae were found in the crops of narcotized Chaoborus collected in Blue Springs Cove.

  17. Strongyloides stercoralis larvae excretion patterns before and after treatment.

    PubMed

    Schär, F; Hattendorf, J; Khieu, V; Muth, S; Char, M C; Marti, H P; Odermatt, P

    2014-06-01

    The variability of larval excretion impedes the parasitological diagnosis of Strongyloides stercoralis in infected individuals. We assessed the number of larvae excreted per gram (LPG) stool in 219 samples from 38 infected individuals over 7 consecutive days before and in 470 samples from 44 persons for 21 consecutive days after ivermectin treatment (200 μg kg-1 BW). The diagnostic sensitivity of a single stool sample was about 75% for individuals with low-intensity infections (⩽1 LPG) and increased to 95% for those with high-intensity infections (⩾10 LPG). Doubling the number of samples examined per person increased sensitivity to more than 95%, even for low-intensity infections. There was no indication of a cyclic excretion of larvae. After treatment, all individuals stopped excreting larvae within 3 days. Larvae were not detected during any of the following 18 days (total 388 Baermann and 388 Koga Agar tests). Two stool samples, collected on consecutive days, are recommended in settings where low or heterogeneous infection intensities are likely. In this way, taking into account the possible biological variability in excretion, the efficacy of ivermectin treatment can be assessed as soon as 4 days after treatment. PMID:24534076

  18. Nonlinear ecological processes driving the distribution of marine decapod larvae

    NASA Astrophysics Data System (ADS)

    Peña, M.; Carbonell, A.; Tor, A.; Alvarez-Berastegui, D.; Balbín, R.; dos Santos, A.; Alemany, F.

    2015-03-01

    The complexity of the natural processes lead to many nonlinear interacting factors that influence the distribution and survival of marine pelagic species, particularly in their larval phase. The management of these ecosystems requires techniques that unveil those interactions by studying the system globally, including all relevant variables and combining both community and environmental data in a single step. Specifically, we apply an unsupervised neural network, the Self-Organising Map (SOM), to a combined dataset of environmental and decapod larvae community data from the Balearic sea, obtained in two years with contrasting environmental scenarios, as an Exploratory Data Analysis (EDA) technique that provides a global and more detailed view of both the environmental processes and their influence on the distribution of such planktonic community. We examine the parental influence on the initial larval distribution by aggregating data by adult habitat, which also increments the signal to noise ratio (mean data patterns over noise due to outliers or measurement errors), and consider the distribution of larvae by development stage (as a proxy of age and hence of potential dispersion). The joined study of parental effect, drifting or concentration events determined by dynamical processes in the whole water column, and lifespan, draws the possible paths followed by larvae, and highlights the more influencing variables in their distribution. Investigation of the different aspects of dynamic height (absolute values, gradients or edges and correlations) clarified the effect of the oceanographic processes on decapods' larvae.

  19. Ingestion of Nanoplastics and Microplastics by Pacific Oyster Larvae.

    PubMed

    Cole, Matthew; Galloway, Tamara S

    2015-12-15

    Plastic debris is a prolific contaminant effecting freshwater and marine ecosystems across the globe. Of growing environmental concern are "microplastics"and "nanoplastics" encompassing tiny particles of plastic derived from manufacturing and macroplastic fragmentation. Pelagic zooplankton are susceptible to consuming microplastics, however the threat posed to larvae of commercially important bivalves is currently unknown. We exposed Pacific oyster (Crassostrea gigas) larvae (3-24 d.p.f.) to polystyrene particles spanning 70 nm-20 μm in size, including plastics with differing surface properties, and tested the impact of microplastics on larval feeding and growth. The frequency and magnitude of plastic ingestion over 24 h varied by larval age and size of polystyrene particle (ANOVA, P < 0.01), and surface properties of the plastic, with aminated particles ingested and retained more frequently (ANOVA, P < 0.01). A strong, significant correlation between propensity for plastic consumption and plastic load per organism was identified (Spearmans, r = 0.95, P < 0.01). Exposure to 1 and 10 μm PS for up to 8 days had no significant effect on C. gigas feeding or growth at <100 microplastics mL(-1). In conclusion, whil micro- and nanoplastics were readily ingested by oyster larvae, exposure to plastic concentrations exceeding those observed in the marine environment resulted in no measurable effects on the development or feeding capacity of the larvae over the duration of the study. PMID:26580574

  20. Skeletogenesis in sea urchin larvae under modified gravity conditions

    NASA Astrophysics Data System (ADS)

    Marthy, H.-J.; Gasset, G.; Tixador, R.; Eche, B.; Schatt, P.; Dessommes, A.; Marthy, U.; Bacchieri, R.

    From many points of view, skeletogenesis in sea urchins has been well described. Based on this scientific background and considering practical aspects of sea urchin development (i.e. availability of material, size of larvae, etc.), we wanted to know whether orderly skeletogenesis requires the presence of gravity. The objective has been approached by three experiments successfully performed under genuine microgravity conditions (in the STS-65 IML-2 mission of 1994; in the Photon-10 IBIS mission of 1995 and in the STS-76 S/MM-03 mission of 1996). Larvae of the sea urchin Sphaerechinus granularis were allowed to develop in microgravity conditions for several days from blastula stage onwards (onset of skeletogenesis). At the end of the missions, the recovered skeletal structures were studied with respect to their mineral composition, architecture and size. Live larvae were also recovered for post-flight culture. The results obtained clearly show that the process of mineralisation is independent of gravity: that is, the skeletogenic cells differentiate correctly in microgravity. However, abnormal skeleton architectures were encountered, particularly in the IML-2 mission, indicating that the process of positioning of the skeletogenic cells may be affected, directly or indirectly, by environmental factors, including gravity. Larvae exposed to microgravity from blastula to prism/early pluteus stage for about 2 weeks (IBIS mission), developed on the ground over the next 2 months into normal metamorphosing individuals.

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

    PubMed Central

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

    2015-01-01

    Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies (Bactrocera oleae) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. We examined the interaction between larvae, their associated bacteria, and fruit chemical defence, hypothesizing that bacterial contribution to larval development is contingent on the phenology of fruit defensive chemistry. We demonstrate that larvae require their natural complement of bacteria (Candidatus Erwinia dacicola: Enterobacteriaceae) in order to develop in unripe olives. Conversely, when feeding on ripe fruit, larval development proceeds independently of these bacteria. Our experiments suggest that bacteria counteract the inhibitory effect of oleuropein—the principal phenolic glycoside in unripe olives. In light of these results, we suggest that the unique symbiosis in olive flies, compared with other frugivorous tephritids, is understood by considering the relationship between the fly, bacteria and fruit chemistry. When applied in an evolutionary context, this approach may also point out the forces which shaped symbioses across the Tephritidae. PMID:26587275

  2. Assaying Blood Cell Populations of the Drosophila melanogaster Larva

    PubMed Central

    Petraki, Sophia; Alexander, Brandy; Brückner, Katja

    2015-01-01

    In vertebrates, hematopoiesis is regulated by inductive microenvironments (niches). Likewise, in the invertebrate model organism Drosophila melanogaster, inductive microenvironments known as larval Hematopoietic Pockets (HPs) have been identified as anatomical sites for the development and regulation of blood cells (hemocytes), in particular of the self-renewing macrophage lineage. HPs are segmentally repeated pockets between the epidermis and muscle layers of the larva, which also comprise sensory neurons of the peripheral nervous system. In the larva, resident (sessile) hemocytes are exposed to anti-apoptotic, adhesive and proliferative cues from these sensory neurons and potentially other components of the HPs, such as the lining muscle and epithelial layers. During normal development, gradual release of resident hemocytes from the HPs fuels the population of circulating hemocytes, which culminates in the release of most of the resident hemocytes at the beginning of metamorphosis. Immune assaults, physical injury or mechanical disturbance trigger the premature release of resident hemocytes into circulation. The switch of larval hemocytes between resident locations and circulation raises the need for a common standard/procedure to selectively isolate and quantify these two populations of blood cells from single Drosophila larvae. Accordingly, this protocol describes an automated method to release and quantify the resident and circulating hemocytes from single larvae. The method facilitates ex vivo approaches, and may be adapted to serve a variety of developmental stages of Drosophila and other invertebrate organisms. PMID:26650404

  3. Behavior of bollworm (Lepidoptera: Noctuidae) larvae on genetically engineered cotton.

    PubMed

    Gore, J; Leonard, B R; Church, G E; Cook, D R

    2002-08-01

    Reports of bollworm, Helicoverpa zea (Boddie), larvae feeding in white flowers of Bollgard cotton have been relatively common since the commercialization of this technology in 1996. Field studies were conducted in Louisiana to determine if differences in bollworm larval behavior occuron non-Bollgard (cultivar 'Deltapine 5415') and Bacillus thuringiensis (Bt), Bollgard ('NuCOTN 33B') cottons. Larvae were placed on the terminal foliage of either single cotton plants or on all plants within 1-m row micro-plots. On preflowering cotton plants, significantly more bollworms moved from the site of infestation (terminal) on Bollgard plants compared with that on non-Bollgard plants. On individual flowering plants, the number of nodes larvae moved from the terminal and the number of infested bolls was greater on Bollgard cotton plants. Similar differences between Bollgard and non-Bollgard plants in the percentage of infested terminals and squares were observed at 48-h after infestation when 1-m rows were infested. These data will be used to refine scouting protocols for bollworm larvae on Bollgard cotton. PMID:12216818

  4. Kinematics and hydrodynamics of swimming in the mayfly larva.

    PubMed

    Brackenbury, John

    2004-02-01

    The kinematics and hydrodynamics of free-swimming mayfly larvae (Chloeon dipterum) were investigated with the aid of a simple wake visualisation technique (tracer dyes) and drag measurements on dead insects. The basic swimming movement consists of a high-amplitude dorso-ventral undulation and, during continuous swimming, this produces a wake of ring vortices shed alternately to the dorsal and ventral sides of the body. The ring vortices propagate laterally away from the body at an angle of approximately 80 degrees relative to dead aft of the swimming line. Thus, mayfly larvae, like damsel-fly larvae, resemble eels in producing a wake consisting of separate vortices that propagate laterally rather than the reverse von Karman vortex street characteristic of most caudal fin swimming fish. The thrust estimated from the momentum in the wake of swimming mayfly larvae was comparable with the drag measured on dead specimens. Possible sources of error in these estimates are discussed, but the conclusion is reached that even though only 14% of the total force generated by vortex production is directed forwards, it is still sufficient to account for the thrust required for steady locomotion. PMID:14766950

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

    PubMed

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

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds. PMID:26512069

  6. Genome Sequences of Six Paenibacillus larvae Siphoviridae Phages

    PubMed Central

    Carson, Susan; Bruff, Emily; DeFoor, William; Dums, Jacob; Groth, Adam; Hatfield, Taylor; Iyer, Aruna; Joshi, Kalyani; McAdams, Sarah; Miles, Devon; Miller, Delanie; Oufkir, Abdoullah; Raynor, Brinkley; Riley, Sara; Roland, Shelby; Rozier, Horace; Talley, Sarah

    2015-01-01

    Six sequenced and annotated genomes of Paenibacillus larvae phages isolated from the combs of American foulbrood-diseased beehives are 37 to 45 kbp and have approximately 42% G+C content and 60 to 74 protein-coding genes. Phage Lily is most divergent from Diva, Rani, Redbud, Shelly, and Sitara. PMID:26089405

  7. Effects of gamma irradiation as a quarantine treatment on development of codling moth larvae

    SciTech Connect

    Burditt, A.K. Jr.; Moffitt, H.R.; Hungate, F.P.

    1985-03-01

    Codling moth, Cydia pomonella (L.), larvae were exposed to gamma radiation at doses upto 160 Gy. Following irradiation the larvae were permited further development, pupation and adult emergence. The number of adults emerging, mature larvae and pupae present were determined. Data from these studies will be used to predict doses of gamma irradiation required as a quarantine treatment to prevent emergence of codling moth adults from fruit infested by larvae. 5 refs., 1 tab.

  8. Stage-specific quercetin sulfation in the gut of Mythimna separata larvae (Lepidoptera: Noctuidae).

    PubMed

    Aboshi, Takako; Ishida, Masahiro; Matsushita, Kaori; Hirano, Yunosuke; Nishida, Ritsuo; Mori, Naoki

    2014-01-01

    The metabolism of quercetin was investigated in Mythimna separata larvae. Quercetin 4'-O-sulfate was mainly identified in the frass when 6th instar larvae were fed artificial diets containing 1% quercetin. In the case of the 3rd instar larvae, a larger amount of quercetin was detected in the frass. M. separata larvae had different metabolic strategies for quercetin at different developmental stages. PMID:25036481

  9. An assay of behavioral plasticity in Drosophila larvae

    PubMed Central

    Min, Virginia A.; Condron, Barry G.

    2010-01-01

    Stress, or threats to homeostasis, is a universal part of life. Organisms face changing and challenging situations everyday, and the ability to respond to such stress is essential for survival. When subjected to acute stress, the body responds molecularly and behaviorally in order to recover a steady state. We developed a simple and robust assay of behavioral plasticity for Drosophila larvae in which well-defined behavioral responses and recovery can be observed and quantified. After experiencing different control and bright light treatments, populations of photophobic fly larvae were placed a defined distance from a food source to which they crawled. Half-times (t½), or times at which half the total number of larvae reached the food, were used to compare different treatments and larval populations. Repeated control treatments with a main experimental strain gave tight, reproducible t½ ranges. Control treatments with the wild type strains Oregon R and Canton S, the “rover” and “sitter” alleles of the forager locus, and eyeless mutants gave comparable results to those of the experimental strain. Exposure to bright light for a defined time period resulted in a reproducible slowing of locomotion. However, given a defined recovery period, the larvae recover full, normal locomotion. In addition, bright light treatments with Canton S gave comparable results to those of the experimental strain. Eyeless mutants, which are partially blind, do not show a response to bright light treatment. Thus, our assay measures the behavioral responses to bright light in Drosophila larvae and therefore might be useful as a general assay for studying behavioral plasticity and, potentially, adaptation to a stressful stimulus. PMID:15922026

  10. Defense by volatiles in leaf-mining insect larvae.

    PubMed

    Boevé, Jean-Luc; Sonet, Gontran; Nagy, Zoltán Tamás; Symoens, Françoise; Altenhofer, Ewald; Häberlein, Christopher; Schulz, Stefan

    2009-05-01

    The defense strategy of an insect toward natural enemies can include a trait that appears at first sight to contradict its defensive function. We explored phylogeny, chemistry, and defense efficiency of a peculiar group of hymenopteran sawfly larvae where this contradiction is obvious. Pseudodineurini larvae live in leaf mines that protect them from some enemies. Disturbed larvae also emit a clearly perceptible lemon-like odor produced by ventral glands, although the mine hampers the evaporation of the secretion. The mine could also lead to autointoxication of a larva by its own emitted volatiles. Citral was the major component in all Pseudodineurini species, and it efficiently repels ants. We conclude that full-grown larvae that leave their mine to pupate in the soil benefit from citral by avoiding attacks from ground-dwelling arthropods such as ants. In some species, we also detected biosynthetically related compounds, two 8-oxocitral diastereomers (i.e., (2E,6E)- and (2E,6Z)-2,6-dimethylocta-2,6-dienedial). Synthetic 8-oxocitral proved to be a potent fungicide, but not an ant repellent. The discrete distribution of 8-oxocitral was unrelated to species grouping in the phylogenetic tree. In contrast, we discovered that its presence was associated with species from humid and cold zones but absent in species favoring warm and dry environments. The former should be protected by 8-oxocitral when faced with a fungal infestation while crawling into the soil. Our work shows the importance of integrating knowledge about behavior, morphology, and life history stages for understanding the complex evolution of insects and especially their defense strategies. PMID:19390895

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

    PubMed Central

    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. Monitoring tectal neuronal activities and motor behavior in zebrafish larvae.

    PubMed

    Sumbre, Germán; Poo, Mu-Ming

    2013-09-01

    To understand how visuomotor behaviors are controlled by the nervous system, it is necessary to monitor the activity of large populations of neurons with single-cell resolution over a large area of the brain in a relatively simple, behaving organism. The zebrafish larva, a small lower vertebrate with transparent skin, serves as an excellent model for this purpose. Immediately after the larva hatches, it needs to catch prey and avoid predators. This strong evolutionary pressure leads to the rapid development of functional sensory systems, particularly vision. By 5 d postfertilization (dpf), tectal cells show distinct visually evoked patterns of activation, and the larvae are able to perform a variety of visuomotor behaviors. During the early larval stage, zebrafish breathe mainly through the skin and can be restrained under the microscope using a drop of low-melting-point agarose, without the use of anesthetics. Moreover, the transparency of the skin, the small diameter of the neurons (4-5 µm), and the high-neuronal density enable the use of in vivo noninvasive imaging techniques to monitor neuronal activities of up to ∼500 cells within the central nervous system, still with single-cell resolution. This article describes a method for simultaneously monitoring spontaneous and visually evoked activities of large populations of neurons in the optic tectum of the zebrafish larva, using a synthetic calcium dye (Oregon Green BAPTA-1 AM) and a conventional confocal or two-photon scanning fluorescence microscope, together with a method for measuring the tail motor behavior of the head-immobilized zebrafish larva. PMID:24003199

  13. Nutritional Limitation on Growth and Development of Horn Fly (Diptera:Muscidae) Larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aging of bovine dung for 3-5 yr under refrigeration depleted nutrients required for growth and development of horn fly larvae. Growth of horn fly larvae in mixtures of nutrient-depleted dung and fresh dung resulted in production of larvae and pupae stunted in proportion to the relative amount of ag...

  14. First detection of Paenibacillus larvae the causative agent of American Foulbrood in a Ugandan honeybee colony.

    PubMed

    Chemurot, Moses; Brunain, Marleen; Akol, Anne M; Descamps, Tine; de Graaf, Dirk C

    2016-01-01

    Paenibacillus larvae is a highly contagious and often lethal widely distributed pathogen of honeybees, Apis mellifera but has not been reported in eastern Africa to date. We investigated the presence of P. larvae in the eastern and western highland agro-ecological zones of Uganda by collecting brood and honey samples from 67 honeybee colonies in two sampling occasions and cultivated them for P. larvae. Also, 8 honeys imported and locally retailed in Uganda were sampled and cultivated for P. larvae. Our aim was to establish the presence and distribution of P. larvae in honeybee populations in the two highland agro-ecological zones of Uganda and to determine if honeys that were locally retailed contained this lethal pathogen. One honeybee colony without clinical symptoms for P. larvae in an apiary located in a protected area of the western highlands of Uganda was found positive for P. larvae. The strain of this P. larvae was genotyped and found to be ERIC I. In order to compare its virulence with P. larvae reference strains, in vitro infection experiments were conducted with carniolan honeybee larvae from the research laboratory at Ghent University, Belgium. The results show that the virulence of the P. larvae strain found in Uganda was at least equally high. The epidemiological implication of the presence of P. larvae in a protected area is discussed. PMID:27468390

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

    PubMed

    Inoda, Toshio

    2012-09-01

    Larvae of diving beetles such as the various Dytiscus species (Coleoptera: Dytiscidae) are carnivorous and usually prey on other aquatic animals. Cannibalism among larvae of Dytiscus sharpi sharpi (Wehncke) was observed to begin when they were starved for more than two days under artificial breeding conditions. However, the 2-day starved larvae did not show cannibalism in the presence of intact, motionless, frozen tadpoles, or frozen shrimps. The beetle larvae attacked and captured intact tadpoles faster (15 sec) than other motionless and frozen tadpoles (120 sec), indicating that prey movement was an important factor in stimulating feeding behavior in larvae. Prey density does not have an effect on larval cannibalism. In cases in which preys are present at lower densities than that of larvae, a group of beetle larvae frequently fed on single prey. This feeding behavior, therefore, provides direct evidence of self-other recognition at the species level. Using two traps in one aquarium that allows the larvae to detect only prey smell, one containing tadpoles and another empty, the beetle larvae were attracted to the trap with tadpoles at high frequency, but not to the empty trap. In another experiment, the beetle larvae were not attracted to the trap containing a beetle larva. These results suggest that the larvae of D. sharpi sharpi are capable of recognizing prey scent, which enables the promotion of foraging behavior and the prevention of cannibalism. PMID:22943777

  16. Expression and purification of the trypsin inhibitor from tartary buckwheat in Pichia pastoris and its novel toxic effect on Mamestra brassicae larvae.

    PubMed

    Ruan, Jingjun; Yan, Jun; Hou, Shengqi; Chen, Hui; Wu, Qi; Han, Xueyi

    2015-01-01

    The gene of the trypsin inhibitor of tartary buckwheat (Fagopyrum tataricum) was successfully cloned, expressed in Pichia pastoris and tested for regulatory effects on insect growth. The three significant factors were optimized by single-factor experiments and central composite design in response surface methodology. Proteins were efficiently expressed at levels of 489.6-527.4 U/mg in shaken flasks. The trypsin inhibitor from tartary buckwheat (FtTI) was purified by affinity chromatography and centrifugal ultrafiltration. The purified FtTI efficiently inhibited trypsin protease activity by competitive inhibition with a Ki value 1.5 nM. The molecular mass of the purified protein was approximately 13.8 kDa. FtTI had a higher toxic killing effect on Mamestra brassicae larvae. The median lethal concentration for the larvae was 15 μg/mL. PMID:25258121

  17. Expression and purification of virus like particles (VLPs) of foot-and-mouth disease virus in Eri silkworm (Samia cynthia ricini) larvae.

    PubMed

    Kumar, Manoj; Saravanan, P; Jalali, S K

    2016-03-01

    Foot-and-mouth disease (FMD) is a highly contagious viral disease, which causes severe economic loss to livestock. Virus like particles (VLPs) produced by recombinant DNA technology are gaining importance because of their immunogenic properties and safety in developing a new vaccine for FMD. In the present study, a practical and economically feasible approach of expression, purification and characterization of VLPs of FMDV in Eri silkworm (Samia cynthia ricini) larvae was described. Although three lepidopteran insect larvae (Helicoverpa armigera, Spodoptera litura and Samia cynthia ricini) were tested for production of VLPs, expression was obtained only in Eri silkworm larvae. High titred recombinant baculovirus encoding the polyprotein P1-2A-3C of FMDV was prepared in Sf9 cells. Injection of recombinant baculovirus into hemocoel of Eri silkworm larvae resulted in increasing levels of expression of VLPs in the hemolymph from 3 to 7 days post infection (dpi) compared to low level expression by oral feeding. The VLPs reacted in Sandwich ELISA with serum raised against whole virus particles of FMDV type O/IND/R2/75 and protein banding pattern of 26, 37 and 47 kDa in Western blotting demonstrated their antigenic resemblance to native virus. Sucrose density gradient purified VLPs were used for immunization of rabbits and guinea pigs for assessing immunogenicity. Further, the reactivity of serum samples of rabbits and guinea pigs in Indirect-ELISA with titres (1.30-2.81 Log10) indicated that the VLPs were antigenic and immunogenic in nature. We demonstrate that Eri silkworm larvae could be used for production of VLPs of FMDV type O/IND/R2/75 for the first time. This approach could be useful for large scale production of recombinant VLPs for vaccine or diagnostic use in FMD control programme. PMID:26925448

  18. Integration of Insecticidal Protein Vip3Aa1 into Beauveria bassiana Enhances Fungal Virulence to Spodoptera litura Larvae by Cuticle and Per Os Infection▿

    PubMed Central

    Qin, Yi; Ying, Sheng-Hua; Chen, Ying; Shen, Zhi-Cheng; Feng, Ming-Guang

    2010-01-01

    The entomopathogenic fungus Beauveria bassiana acts slowly on insect pests through cuticle infection. Vegetative insecticidal proteins (Vip3A) of Bacillus thuringiensis kill lepidopteran pests rapidly, via per os infection, but their use for pest control is restricted to integration into transgenic plants. A transgenic B. bassiana strain (BbV28) expressing Vip3Aa1 (a Vip3A toxin) was thus created to infect the larvae of the oriental leafworm moth Spodoptera litura through conidial ingestion and cuticle adhesion. Vip3Aa1 (∼88 kDa) was highly expressed in the conidial cytoplasm of BbV28 and was detected as a digested form (∼62 kDa) in the larval midgut 18 and 36 h after conidial ingestion. The median lethal concentration (LC50) of BbV28 against the second-instar larvae feeding on cabbage leaves sprayed with conidial suspensions was 26.2-fold lower than that of the wild-type strain on day 3 and 1.1-fold lower on day 7. The same sprays applied to both larvae and leaves for their feeding reduced the LC50 of the transformant 17.2- and 1.3-fold on days 3 and 7, respectively. Median lethal times (LT50s) of BbV28 were shortened by 23 to 35%, declining with conidial concentrations. The larvae infected by ingestion of BbV28 conidia showed typical symptoms of Vip3A action, i.e., shrinkage and palsy. However, neither LC50 nor LT50 trends differed between BbV28 and its parental strain if the infection occurred through the cuticle only. Our findings indicate that fungal conidia can be used as vectors for spreading the highly insecticidal Vip3A protein for control of foliage feeders such as S. litura. PMID:20495052

  19. [Ingestion and digestion of seven species of microalgae by larvae of Strombus gigas (Mesogastropoda: Strombidae)].

    PubMed

    Patiño Súarez, V; Aldana Aranda, D

    2000-12-01

    The potential nutritional value of seven microalgal diets as measured by their ingestibility and digestibility to queen conch Strombus gigas larvae was tested with 30 day old larvae reared at 28 degrees C and fed at 1000 cells x ml(-1). The algae were Tetraselmis suecica, Tetraselmis chuii Isochrysis aff. galbana, Dunaliella tertiolecta, Chlamydomonas coccoides, Chaetoceros sp. and Thalassiosira fluviatilis. Ingestion and digestion were measured by the four nutritional stages studied with epifluorescence microscopy with live larvae. Temporal and absolute indices showed that larvae fed Chaetoceros sp. and T. fluviatilis had lower ingestion and digestion levels. The other algae are recommend to feed S. gigas larvae. PMID:15266796

  20. Validation and efficacy of transgenerational mass marking of otoliths in viviparous fish larvae.

    PubMed

    Kuroki, M; Buckley, R M; Leclair, L L; Hauser, L

    2010-07-01

    Transgenerational mass marking of viviparous fish larvae in vivo was validated by intra-muscular injection of elemental strontium chloride (SrCl(2)) in gestating females and detection of the Sr in the otoliths of developing larvae. All otoliths of brown rockfish Sebastes auriculatus larvae produced from SrCl(2)-injected females showed enriched Sr:Ca ratios near the otolith edges, and the signatures did not appear to be affected by the anterior, centre and posterior positions of larvae within the ovary. Results from the present study indicate that transgenerational marking is a highly reliable technique for marking large numbers of extremely small viviparous fish larvae. PMID:20646154

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

    PubMed

    Dawn, Prosenjit; Chandra, Kailash

    2016-01-01

    The larva of Gynacantha millardi Selys is described here from female larvae and male and female exuviae collected from Chhattisgarh, India. Unlike other Gynacantha larvae known so far, G. millardi has 7 palpal setae almost equal in length; in other species, the palpal setae are of different lengths. The larvae lack a tooth on each side of the median cleft and have a distinct blunt tooth on the inner margin corner of each labial palp. The larvae were found in a semi-stagnant forest pool with enormous growth of aquatic vegetation. PMID:27395672

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

    PubMed Central

    MARIGO, Juliana; TANIWAKI, Sueli Akemi; PINTO, Pedro Luiz Silva; SOARES, Rodrigo Martins; CATÃO-DIAS, José Luiz

    2015-01-01

    Anisakiasis and Pseudoterranovosis are human diseases caused by the ingestion of live Anisakidae larvae in raw, undercooked or lightly marinated fish. Larvae were collected from one salted cod sold for human consumption in a Sao Paulo market in 2013. One section of one brownish larva was used for molecular analyses. The partial COX2 gene sequence from the larva had a nucleotide identity of 99.8 % with Pseudoterranova azarasi, which belongs to the Pseudoterranova decipiens species complex. The risk of allergy when consuming dead larvae in salted fish is not well known and should be considered. PMID:27049712

  3. Starving honey bee (Apis mellifera) larvae signal pheromonally to worker bees.

    PubMed

    He, Xu Jiang; Zhang, Xue Chuan; Jiang, Wu Jun; Barron, Andrew B; Zhang, Jian Hui; Zeng, Zhi Jiang

    2016-01-01

    Cooperative brood care is diagnostic of animal societies. This is particularly true for the advanced social insects, and the honey bee is the best understood of the insect societies. A brood pheromone signaling the presence of larvae in a bee colony has been characterised and well studied, but here we explored whether honey bee larvae actively signal their food needs pheromonally to workers. We show that starving honey bee larvae signal to workers via increased production of the volatile pheromone E-β-ocimene. Analysis of volatile pheromones produced by food-deprived and fed larvae with gas chromatography-mass spectrometry showed that starving larvae produced more E-β-ocimene. Behavioural analyses showed that adding E-β-ocimene to empty cells increased the number of worker visits to those cells, and similarly adding E-β-ocimene to larvae increased worker visitation rate to the larvae. RNA-seq and qRT-PCR analysis identified 3 genes in the E-β-ocimene biosynthetic pathway that were upregulated in larvae following 30 minutes of starvation, and these genes also upregulated in 2-day old larvae compared to 4-day old larvae (2-day old larvae produce the most E-β-ocimene). This identifies a pheromonal mechanism by which brood can beg for food from workers to influence the allocation of resources within the colony. PMID:26924295

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

    NASA Astrophysics Data System (ADS)

    Bos, Oscar G.; Hendriks, Iris E.; Strasser, Matthias; Dolmer, Per; Kamermans, Pauline

    2006-04-01

    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 by an energetic model of larval requirements. Bivalve larvae were monitored during 2000 at ten different study sites in four different areas (Limfjorden, Sylt-Rømø bight, Western Wadden Sea and Delta area) along the coast of north-western Europe. Calculation of the energetic requirements of the larvae at 15 °C indicated maintenance costs of a 200-μm bivalve larva to be 1.9 × 10 - 5 J larva - 1 d - 1 , while the maximum assimilation rate, resulting in maximum growth, would amount to 6.2 × 10 - 3 J larva - 1 d - 1 . Calculation of potential assimilation rates of larvae in the field resulted in estimates between 10 - 5 and 10 - 3 J larva - 1 d - 1 . Maximum larval concentrations in the field occurred from May to September and ranged between 17 and 392 larvae dm - 3 . Most larvae were able to cover their maintenance costs, but not to attain maximum growth rates. Between April and September, the potential 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.

  5. Starving honey bee (Apis mellifera) larvae signal pheromonally to worker bees

    PubMed Central

    He, Xu Jiang; Zhang, Xue Chuan; Jiang, Wu Jun; Barron, Andrew B.; Zhang, Jian Hui; Zeng, Zhi Jiang

    2016-01-01

    Cooperative brood care is diagnostic of animal societies. This is particularly true for the advanced social insects, and the honey bee is the best understood of the insect societies. A brood pheromone signaling the presence of larvae in a bee colony has been characterised and well studied, but here we explored whether honey bee larvae actively signal their food needs pheromonally to workers. We show that starving honey bee larvae signal to workers via increased production of the volatile pheromone E-β-ocimene. Analysis of volatile pheromones produced by food-deprived and fed larvae with gas chromatography-mass spectrometry showed that starving larvae produced more E-β-ocimene. Behavioural analyses showed that adding E-β-ocimene to empty cells increased the number of worker visits to those cells, and similarly adding E-β-ocimene to larvae increased worker visitation rate to the larvae. RNA-seq and qRT-PCR analysis identified 3 genes in the E-β-ocimene biosynthetic pathway that were upregulated in larvae following 30 minutes of starvation, and these genes also upregulated in 2-day old larvae compared to 4-day old larvae (2-day old larvae produce the most E-β-ocimene). This identifies a pheromonal mechanism by which brood can beg for food from workers to influence the allocation of resources within the colony. PMID:26924295

  6. Enhanced ammonia content in compost leachate processed by black soldier fly larvae.

    PubMed

    Green, Terrence R; Popa, Radu

    2012-03-01

    Black soldier fly (BSF) larvae (Hermetia illucens), feeding on leachate from decaying vegetable and food scrap waste, increase ammonia (NH (4) (+) ) concentration five- to sixfold relative to leachate unprocessed by larvae. NH (4) (+) in larva-processed leachate reached levels as high as ∼100 mM. Most of this NH (4) (+) appears to have come from organic nitrogen within the frass produced by the larvae as they fed on leachate. In nitrate-enriched solutions, BSF larvae also facilitate dissimilatory nitrate reduction to ammonia. The markedly higher concentration of NH (4) (+) recovered in leachates processed with BSF larvae and concomitant diversion of nutrients into insect biomass (itself a valuable feedstock) indicate that the use of BSF larvae in processing leachate of decaying organic waste could be advantageous in offsetting capital and environmental costs incurred in composting. PMID:22238016

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

    PubMed

    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. PMID:26611955

  8. Accumulation of mercury in larvae and adults, Chironomus riparius (Meigen)

    SciTech Connect

    Not Available

    1986-09-01

    Among benthic aquatic insects there are taxa that grow abundant in sediments polluted with organic matter. Some of them also tolerate high levels of heavy metals. In this research short exposure and partial life cycle tests were carried out to evaluate the accumulation of mercury in Chironomus riparius Meigen larvae, pupal exuviae and adults from water enriched with HgCl/sub 2/. Their abundance in heavily polluted waters and the fact that it is easy to rear them suggested the use of this species for the toxicity tests considered in our present research. Short exposure tests were carried out to evaluate the LC/sub 50/ of HgCl/sub 2/ for the 4th instar larva of C. riparius Meigen.

  9. Eosinophilic abscesses: a new facet of hepatic visceral larva migrans.

    PubMed

    Mukund, Amar; Arora, Ankur; Patidar, Yashwant; Mangla, Vivek; Bihari, Chhagan; Rastogi, Archana; Sarin, Shiv K

    2013-08-01

    Hepatic visceral larva migrans (VLM) refers to a condition characterized by granulomatous liver lesions containing eosinophils and inflammatory cells associated with migration of second-stage larvae of certain nematodes such as toxocara canis. The typical imaging findings described in the literature include small, ill-defined, oval or elongated, low-attenuating nodules with fuzzy margins, non-spherical shape, and absent or insignificant rim enhancement on contrast-enhanced CT scan. The present series in contrast depicts a new imaging manifestation of hepatic VLM presenting as confluent and clustered complex cystic liver lesions. Pre-treatment imaging studies including contrast-enhanced CT/MRI of three patients are presented. One of the patients underwent liver resection while post-treatment follow-up scan at 6 months in the remaining two displayed regression of the lesions with antihelminthic treatment. PMID:22801750

  10. Digestion in sea urchin larvae impaired under ocean acidification

    NASA Astrophysics Data System (ADS)

    Stumpp, Meike; Hu, Marian; Casties, Isabel; Saborowski, Reinhard; Bleich, Markus; Melzner, Frank; Dupont, Sam

    2013-12-01

    Larval stages are considered as the weakest link when a species is exposed to challenging environmental changes. Reduced rates of growth and development in larval stages of calcifying invertebrates in response to ocean acidification might be caused by energetic limitations. So far no information exists on how ocean acidification affects digestive processes in marine larval stages. Here we reveal alkaline (~pH 9.5) conditions in the stomach of sea urchin larvae. Larvae exposed to decreased seawater pH suffer from a drop in gastric pH, which directly translates into decreased digestive efficiencies and triggers compensatory feeding. These results suggest that larval digestion represents a critical process in the context of ocean acidification, which has been overlooked so far.

  11. Hookworm-related cutaneous larva migrans acquired in the UK.

    PubMed

    Baple, Katy; Clayton, James

    2015-01-01

    Hookworm-related cutaneous larva migrans (HrCLM) is a skin disease caused by infection with the larvae of animal hookworms. With conditions for infection more favourable in tropical climates, HrCLM in the UK is classically diagnosed in the returning traveller. We present two cases of clinically diagnosed UK-acquired HrCLM from a district general hospital in the south of England. A 68-year-old woman presented with a pruritic serpiginous tract on the right hand. She was a keen gardener and had been handling compost. A 50-year-old man, a long distance runner, presented with a similar lesion on the dorsum of his foot. Both patients were treated with a single dose of albendazole. These cases may represent an emerging infection in the UK. In the absence of a suggestive travel history, early recognition followed by efficient access to therapy is vital for treating HrCLM transmitted in the UK. PMID:26567237

  12. Intravenous microinjections of zebrafish larvae to study acute kidney injury.

    PubMed

    Cianciolo Cosentino, Chiara; Roman, Beth L; Drummond, Iain A; Hukriede, Neil A

    2010-01-01

    In this video article we describe a zebrafish model of AKI using gentamicin as the nephrotoxicant. The technique consists of intravenous microinjections on 2 dpf zebrafish. This technique represents an efficient and rapid method to deliver soluble substances into the bloodstream of zebrafish larvae, allowing for the injection of 15-20 fish per hour. In addition to AKI studies, this microinjection technique can also be used for other types of experimental studies such as angiography. We provide a detailed protocol of the technique from equipment required to visual measures of decreased kidney function. In addition, we also demonstrate the process of fixation, whole mount immunohistochemistry with a kidney tubule marker, plastic embedding and sectioning of the larval zebrafish. We demonstrate that zebrafish larvae injected with gentamicin show morphological features consistent with AKI: edema, loss of cell polarity in proximal tubular epithelial cells, and morphological disruption of the tubule. PMID:20729805

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

    PubMed

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

    2016-05-01

    Trees with larvicidal activity may be found in Thailand. We conducted this study to evaluate the efficacy and length of efficacy of Thai neem (Azadirachta siamensis) oil emulsion and an alginate bead of Thai neem oil formulation against early fourth stage Aedes aegypti larvae using a dipping test. The Thai neem oil emulsion had significantly greater larvicidal activity than the alginate bead formulation at 12 to 60 hours post-exposure (p < 0.01). The Thai neem oil formulation resulted in 100% mortality among the early fourth stage Aedes aegypti larvae at 48 hours, while the alginate bead formulation resulted in 98% larval mortality at 84 hours and 100% mortality at 96 hours. The mean larval mortality using the Thai neem oil emulsion dropped to < 25% by 12 days and with the alginate beads dropped to < 25% by 15 days of exposure. PMID:27405123

  14. Identification of common excitatory motoneurons in Drosophila melanogaster larvae.

    PubMed

    Takizawa, Eiji; Komatsu, Akira; Tsujimura, Hidenobu

    2007-05-01

    In insects, four types of motoneurons have long been known, including fast motoneurons, slow motoneurons, common inhibitory motoneurons, and DUM neurons. They innervate the same muscle and control its contraction together. Recent studies in Drosophila have suggested the existence of another type of motoneuron, the common excitatory motoneuron. Here, we found that shakB-GAL4 produced by labels this type of motoneuron in Drosophila larvae. We found that Drosophila larvae have two common excitatory motoneurons in each abdominal segment, RP2 for dorsal muscles and MNSNb/d-Is for ventral muscles. They innervate most of the internal longitudinal or oblique muscles on the dorsal or ventral body wall with type-Is terminals and use glutamate as a transmitter. Electrophysiological recording indicated that stimulation of the RP2 axon evoked excitatory junctional potential in a dorsal muscle. PMID:17867850

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

    PubMed

    Waringer, Johann; Graf, Wolfram

    2014-01-01

    This paper describes the previously unknown larva of Athripsodes genei (Rambur 1842). Information on the morphology of the 5th larval instar is given and the most important diagnostic features are illustrated. In the context of existing identification keys the larva of A. genei keys together with A. albifrons (Linnaeus 1758), A. commutatus (Rostock 1874), A. leucophaeus (Rambur 1842) and Athripsodes tavaresi (Navás 1916). These species differ in the number of ventral edge setae at the 1st tibia and in the shape and colour of the submentum. With respect to zoogeography, Athripsodes genei is a (micro-)endemic of the collin and planar regions of Sardinia and Corsica (Graf et al. 2008). According to mandible morphology, A. genei is a collector-gatherer, shredder and, to a minor extent, also a predator. PMID:25283900

  16. [Spatial distribution pattern of Pontania dolichura larvae and sampling technique].

    PubMed

    Zhang, Feng; Chen, Zhijie; Zhang, Shulian; Zhao, Huiyan

    2006-03-01

    In this paper, the spatial distribution pattern of Pontania dolichura larvae was analyzed with Taylor's power law, Iwao's distribution function, and six aggregation indexes. The results showed that the spatial distribution pattern of P. dolichura larvae was of aggregated, and the basic component of the distribution was individual colony, with the aggregation intensity increased with density. On branches, the aggregation was caused by the adult behavior of laying eggs and the spatial position of leaves, while on leaves, the aggregation was caused by the spatial position of news leaves in spring when m < 2.37, and by the spatial position of news leaves in spring and the behavior of eclosion and laying eggs when m > 2.37. By using the parameters alpha and beta in Iwao's m * -m regression equation, the optimal and sequential sampling numbers were determined. PMID:16724746

  17. RNAi KNOCKDOWN OF BmRab3 LED TO LARVA AND PUPA LETHALITY IN SILKWORM Bombyx mori L.

    PubMed

    Singh, Chabungbam Orville; Xin, Hu-hu; Chen, Rui-ting; Wang, Mei-xian; Liang, Shuang; Lu, Yan; Cai, Zi-zheng; Zhang, Deng-pan; Miao, Yun-gen

    2015-06-01

    Rab3 GTPases are known to play key a role in vesicular trafficking, and express highest in brain and endocrine tissues. In mammals, Rab3 GTPases are paralogs unlike in insect. In this study, we cloned Rab3 from the silk gland tissue of silkworm Bombyx mori, and identified it as BmRab3. Our in silico analysis indicated that BmRab3 is an isoform with a theoretical isoelectric point and molecular weight of 5.52 and 24.3 kDa, respectively. Further, BmRab3 showed the C-terminal hypervariability for GGT2 site but having two other putative guanine nucleotide exchange factor/GDP dissociation inhibitor interaction sites. Multiple alignment sequence indicated high similarities of BmRab3 with Rab3 isoforms of other species. The phylogeny tree showed BmRab3 clustered between the species of Tribolium castaneum and Aedes aegypti. Meanwhile, the expression analysis of BmRab3 showed the highest expression in middle silk glands (MSGs) than all other tissues in the third day of fifth-instar larva. Simultaneously, we showed the differential expression of BmRab3 in the early instar larva development, followed by higher expression in male than female pupae. In vivo dsRNA interference of BmRab3 reduced the expression of BmRab3 by 75% compared to the control in the MSGs in the first day. But as the worm grew to the third day, the difference of BmRab3 between knockdown and control was only about 10%. The knockdown later witnessed underdevelopment of the larvae and pharate pupae lethality in the overall development of silkworm B. mori L. PMID:25735242

  18. Toxic Peptides Occur Frequently in Pergid and Argid Sawfly Larvae

    PubMed Central

    Boevé, Jean-Luc; Rozenberg, Raoul; Shinohara, Akihiko; Schmidt, Stefan

    2014-01-01

    Toxic peptides containing D-amino acids are reported from the larvae of sawfly species. The compounds are suspected to constitute environmental contaminants, as they have killed livestock grazing in areas with congregations of such larvae, and related larval extracts are deleterious to ants. Previously, two octapeptides (both called lophyrotomin) and three heptapeptides (pergidin, 4-valinepergidin and dephosphorylated pergidin) were identified from three species in the family Pergidae and one in Argidae. Here, the hypothesis of widespread occurrence of these peptides among sawflies was tested by LC-MS analyses of single larvae from eight pergid and 28 argid species, plus nine outgroup species. At least two of the five peptides were detected in most sawfly species, whereas none in any outgroup taxon. Wherever peptides were detected, they were present in each examined specimen of the respective species. Some species show high peptide concentrations, reaching up to 0.6% fresh weight of 4-valinepergidin (1.75 mg/larva) in the pergid Pterygophorus nr turneri. All analyzed pergids in the subfamily Pterygophorinae contained pergidin and 4-valinepergidin, all argids in Arginae contained pergidin and one of the two lophyrotomins, whereas none of the peptides was detected in any Perginae pergid or Sterictiphorinae argid (except in Schizocerella pilicornis, which contained pergidin). Three of the four sawfly species that were previously known to contain toxins were reanalyzed here, resulting in several, often strong, quantitative and qualitative differences in the chemical profiles. The most probable ecological role of the peptides is defense against natural enemies; the poisoning of livestock is an epiphenomenon. PMID:25121515

  19. Cutaneous Larva Migrans Masquerading as Tinea Corporis: A Case Report

    PubMed Central

    Dhanaraj, Manoharan; Ramalingam, Manoharan

    2013-01-01

    A 25–year–old male was seen with complaints of itchy skin lesions over left thigh. On examination multiple annular scaly plaques with wavy borders, peripheral papules and central clearing was seen. Closer examination revealed multiple forked tracts with excoriated papules. A diagnosis of cutaneous larva migrans was made and the patient treated using T.Albendazole 400 mg twice daily for 7 days which resulted in complete clinical cure. PMID:24298515

  20. The diversity, development and evolution of polyclad flatworm larvae

    PubMed Central

    2014-01-01

    Polyclad flatworms offer an excellent system with which to explore the evolution of larval structures and the ecological and developmental mechanisms driving flatworm and marine invertebrate life history evolution. Although the most common mode of development in polyclads might be direct development (where the embryo develops directly into a form resembling the young adult), there are many species that develop indirectly, through a planktonic phase with transient larval features, before settling to the sea floor. In this review, I introduce polyclad life history strategies, larval diversity and larval anatomical features (presenting previously unpublished micrographs of a diversity of polyclad larvae). I summarize what is known about polyclad larval development during the planktonic phase and the transition to the benthic juvenile. Finally, I discuss evolutionary and developmental scenarios on the origin of polyclad larval characters. The most prominent characters that are found exclusively in the larval stages are lobes that protrude from the body and a ciliary band, or ciliary tufts, at the peripheral margins of the lobes. Larvae with 4–8 and 10 lobes have been described, with most indirect developing species hatching with 8 lobes. A ventral sucker develops in late stage larvae, and I put forward the hypothesis that this is an organ for larval settlement for species belonging to the Cotylea. Historically, the biphasic life cycle of polyclads was thought to be a shared primitive feature of marine invertebrates, with similarities in larval features among phyla resulting from evolutionary conservation. However, our current understanding of animal phylogeny suggests that indirect development in polyclads has evolved independently of similar life cycles found in parasitic flatworms and some other spiralian taxa, and that morphological similarities between the larvae of polyclads and other spiralians are likely a result of convergent evolution. PMID:24602223

  1. Dermatitis due to larvae of a soil nematode, Pelodera strongyloides.

    PubMed

    Ginsburg, B; Beaver, P C; Wilson, E R; Whitley, R J

    1984-07-01

    A 6-month-old infant girl was seen because of failure to thrive and hyperpigmented papulonodules on the lower abdomen and thighs. Results of skin biopsy demonstrated dauer larvae of a soil nematode, Pelodera strongyloides, in the dermis. This is the second documented episode of human dermatitis due to this nematode, which more often invades the skin of dogs, cattle, horses, and sheep. PMID:6542207

  2. Recording Field Potentials From Zebrafish Larvae During Escape Responses

    PubMed Central

    Monesson-Olson, Bryan D.; Troconis, Eileen L.; Trapani, Josef G.

    2014-01-01

    Among vertebrates, startle responses are a ubiquitous method for alerting, and avoiding or escaping from alarming or dangerous stimuli. In zebrafish larvae, fast escape behavior is easily evoked through either acoustic or tactile stimuli. For example, a light touch to the head will excite trigeminal neurons that in turn excite a large reticulospinal neuron in the hindbrain called the Mauthner cell (M-cell). The M-cell action potential then travels down the contralateral trunk of the larva exciting motoneurons, which subsequently excite the entire axial musculature, producing a large amplitude body bend away from the source of the stimulus. This body conformation is known as the “C-bend” due to the shape of the larva during the behavior. As a result of the semi-synchronized activation of the M-cell, the population of motor neurons, and the axial trunk muscles, a large field potential is generated and can be recorded from free-swimming or fixed-position larvae. Undergraduate laboratories that record field potentials during escape responses in larval zebrafish are relatively simple to setup and allow students to observe and study the escape reflex circuit. Furthermore, by testing hypotheses, analyzing data and writing journal-style laboratory reports, students have multiple opportunities to learn about many neuroscience topics including vertebrate reflexes; sensory transduction; synaptic-, neuro-, and muscle-physiology; the M-cell mediated escape response; and the zebrafish as a model organism. Here, we detail the equipment, software, and recording setup necessary to observe field potentials in an undergraduate teaching lab. Additionally, we discuss potential advanced laboratory exercises and pedagogical outcomes. Finally, we note possible low-cost alternatives for recording field potentials. PMID:25565920

  3. Simple and rapid quantification of thrombocytes in zebrafish larvae.

    PubMed

    Huarng, Michael C; Shavit, Jordan A

    2015-06-01

    Platelets are a critical component of hemostasis, with disorders of number or function resulting in coagulation disturbances. Insights into these processes have primarily been realized through studies using mammalian models or tissues. Increasingly, zebrafish embryos and larvae have been used to study the protein and cellular components of hemostasis and thrombosis, including the thrombocyte, a nucleated platelet analog. However, investigations of thrombocytes have been somewhat limited due to lack of a robust and simple methodology for quantitation, an important component of platelet studies in mammals. Using video capture, we have devised an assay that produces a rapid, reproducible, and precise measurement of thrombocyte number in zebrafish larvae by counting fluorescently tagged cells. Averaging 1000 frames, we were able to subtract background fluorescence, thus limiting assessment to circulating thrombocytes. This method facilitated rapid assessment of relative thrombocyte counts in a population of 372 zebrafish larvae by a single operator in less than 3 days. This technique requires basic microscopy equipment and rudimentary programming, lends itself to high throughput analysis, and will enhance future studies of thrombopoiesis in the zebrafish. PMID:25790244

  4. An improved method for nematode infection assays in Drosophila larvae

    PubMed Central

    Dobes, Pavel; Wang, Zhi; Markus, Robert; Theopold, Ulrich; Hyrsl, Pavel

    2012-01-01

    The infective juveniles (IJs) of entomopathogenic nematodes (EPNs) seek out host insects and release their symbiotic bacteria into their body cavity causing septicaemia, which eventually leads to host death. The interaction between EPNs and their hosts are only partially understood, in particular the host immune responses appears to involve pathways other than phagocytosis and the canonical transcriptional induction pathways. These pathways are genetically tractable and include for example clotting factors and lipid mediators. The aim of this study was to optimize the nematode infections in Drosophila melanogaster larvae, a well-studied and genetically tractable model organism. Here we show that two nematode species namely Steinernema feltiae and Heterorhabditis bacteriophora display different infectivity toward Drosophila larvae with the latter being less pathogenic. The effects of supporting media and IJ dosage on the mortality of the hosts were assessed and optimized. Using optimum conditions, a faster and efficient setup for nematode infections was developed. This newly established infection model in Drosophila larvae will be applicable in large scale screens aimed at identifying novel genes/pathways involved in innate immune responses. PMID:22614785

  5. Using black soldier fly larvae for processing organic leachates.

    PubMed

    Popa, Radu; Green, Terrence R

    2012-04-01

    A large number of biodegradable byproducts including alcohols, soluble saccharides, volatile organic acids, and amines accumulate in the liquid fraction (leachate) produced as vegetal and food scrap waste decomposes. Untreated leachate, because it is rich in nutrients and organic byproducts, has a high chemical oxygen demand and is normally cleared of soluble organic byproducts by mineralization before its discharge into waterways. Mineralizing leachates using chemical and microbial biotechnologies is, however, a lengthy and costly process. We report here that the larvae of the black soldier fly Hermetia illucens (L.) (Diptera: Stratiomyidae), an insect rich in protein and lipids, and having significant commercial value, while feeding and growing off of compost leachate, lowers its chemical oxygen demand relative to that of leachate unexposed to larvae, neutralizes its acidity, and clears it of volatile organic acids, amines, and alcohols. These observations demonstrate that black soldier fly larvae could be used to help offset the cost and clean up of organic solutes in leachate waste streams while recycling carbon, nitrogen, and phosphate into usable and commercially valuable biomass. PMID:22606806

  6. Morphological Development of Larvae and Juveniles of Acanthopagrus schlegeli

    PubMed Central

    Kang, Chung-Bae; Lee, Sung-Hoon; Hwang, Jae-Ho; Han, Kyeong-Ho

    2014-01-01

    Newly hatched black porgy larvae (Acanthopagrus schlegeli) swam to the surface, with the mouth and anus still closed and were 1.90–2.11 mm (mean, 2.0 mm) in total length (TL). The larvae were 2.71–2.94 mm TL (mean, 2.82 mm) on day 2 after hatching. At this time, about two-thirds of the yolk was absorbed, the bladder and intestines had formed, and the mouth and anus were open. Total length was 4.32–4.66 mm (mean, 4.45 mm) at the post-larval stage on days 5–6 after hatching, and the yolk and oil globule were almost absorbed. The end of the notochord began to flex, and 6–8 caudal fin rays were visible. The larvae were 15.37–16.1 mm TL (mean, 15.83 mm) at the juvenile stage on days 30–32 after hatching, and the number of rays in all fins was completely revealed. PMID:25949202

  7. Chlorpyrifos-induced toxicity in Duttaphrynus melanostictus (Schneider 1799) larvae.

    PubMed

    Wijesinghe, M R; Bandara, M G D K; Ratnasooriya, W D; Lakraj, G P

    2011-05-01

    This study investigates the effects of continuous exposure to a widely used organophosphate pesticide, chlorpyrifos, on survival, growth, development, and activity of larvae of the Asian common toad, Duttaphrynus melanostictus Schneider 1799. Larvae were continuously exposed to six different concentrations (1-1,500 μg l(-1)) of commercial-grade chlorpyrifos for 14 days and monitored for 1 additional week. Chlorpyrifos at ≥1,000 μg l(-1) caused significantly high and dose-dependent mortality, and the weekly LC50(7 day-21 day) values ranged from 3,003 to 462 μg l(-1). Larvae surviving exposure to ≥500 μg l(-1) chlorpyrifos showed significant growth impairment, delays in metamorphosis, and decreased swimming activity. Tail abnormalities were the most common morphologic deformity at concentrations of 1,000 and 1,500 μg l(-1) chlorpyrifos. The findings of the present study highlight the need to recognize the potential risk that agrochemicals pose to amphibians inhabiting agricultural landscapes in Sri Lanka and other Asian countries. PMID:20669016

  8. PCR assays for detection of Baylisascaris procyonis eggs and larvae.

    PubMed

    Dangoudoubiyam, Sriveny; Vemulapalli, Ramesh; Kazacos, Kevin R

    2009-06-01

    The objective of this study was to develop polymerase chain reaction (PCR) assays for detection of Baylisascaris procyonis eggs and larvae in fecal, environmental, and tissue samples. We have optimized conventional and real-time PCR assays for B. procyonis using the mitochondrial cytochrome oxidase 2 gene as the target for amplification. The lower limit of detection of the parasite genomic DNA was 10 pg in the conventional PCR and 100 fg in the real-time PCR. In both PCR assays, specific amplification of a 146 bp product was achieved with DNA extracted from a single in vitro hatched B. procyonis larva and also from canine fecal samples spiked with as few as 20 unembryonated B. procyonis eggs per gram of feces. The PCR assays were successfully used for detection of B. procyonis eggs and larvae in fecal, environmental, and tissue samples. No DNA amplification was seen when the genomic DNA of related ascarids (including B. transfuga) and a hookworm was used as template in the PCR; however, amplification was seen with the very closely related B. columnaris. PMID:19090651

  9. Cutaneous larva migrans with optic disc edema: a case report

    PubMed Central

    2010-01-01

    Introduction A rare case of optic disc edema associated with cutaneous larva migrans is presented. To the best of our knowledge, this has not been previously reported in literature. Joint management by ophthalmology and tropical medicine teams proved most beneficial for our patient, facilitating correct diagnosis, appropriate investigations and instigation of suitable treatment. Case presentation A 45-year-old Caucasian man, a naturalist, from the UK developed cutaneous larva migrans while in Kenya and presented to us with visual disturbance secondary to unilateral optic disc edema. This resolved after receiving a single dose of ivermectin and visual acuity reverted to normal. Conclusion To the best of our knowledge, optic disc edema associated with cutaneous larva migrans has not been previously reported. This case highlights the importance of taking relevant history of recent travel to endemic areas affected by the nematodes in patients presenting with optic disc edema, and pertinent questioning regarding non-ocular symptoms, including skin lesions. In this case, a history of recent foreign travel and treatment for skin lesions was crucial. PMID:20609253

  10. The larva of Drusus vinconi Sipahiler, 1992 (Trichoptera, Limnephilidae, Drusinae)

    PubMed Central

    Waringer, Johann; Graf, Wolfram; Bálint, Miklós; Kučinić, Mladen; Pauls, Steffen U.; Previšić, Ana; Keresztes, Lujza; Vitecek, Simon

    2013-01-01

    Abstract This paper describes the previously unknown larva of Drusus vinconi Sipahiler, 1992. Information on the morphology of the 5th larval instar is given, and the most important diagnostic features are illustrated. In the context of existing identification keys the larva of Drusus vinconi keys together with Drusus annulatus (Stephens, 1837), Drusus biguttatus (Pictet, 1834), Drusus ingridae Sipahiler, 1993, Hadimina torosensis Sipahiler, 2002 and Leptodrusus budtzi (Ulmer, 1913). These species differ in the contours of the pronotum in lateral view, the presence/absence of the pronotal transverse groove, the shape of the median notch of the pronotum (in anterior view), pronotal sculpturing, presence/absence of the lateral carina of the head capsule, the number of proximo-dorsal setae on the mid-and hind femora, where the lateral fringe starts on the abdomen, and in geographic distribution. With respect to zoogeography, Drusus vinconi is a (micro-)endemic of the Western Pyrenees. The species prefers stony substratum in springs and springbrooks of the montane and subalpine region (Graf et al. 2008; Sipahiler 1992, 1993). As a grazer, the larvae of Drusus vinconi feed on biofilm and epilithic algae. PMID:23950671

  11. Monarch larvae sensitivity to Bacillus thuringiensis- purified proteins and pollen

    PubMed Central

    Hellmich, Richard L.; Siegfried, Blair D.; Sears, Mark K.; Stanley-Horn, Diane E.; Daniels, Michael J.; Mattila, Heather R.; Spencer, Terrence; Bidne, Keith G.; Lewis, Leslie C.

    2001-01-01

    Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older instars were 12 to 23 times less susceptible to Cry1Ab toxin compared with first instars. Pollen bioassays suggest that pollen contaminants, an artifact of pollen processing, can dramatically influence larval survival and weight gains and produce spurious results. The only transgenic corn pollen that consistently affected monarch larvae was from Cry1Ab event 176 hybrids, currently <2% corn planted and for which re-registration has not been applied. Results from the other types of Bt corn suggest that pollen from the Cry1Ab (events Bt11 and Mon810) and Cry1F, and experimental Cry9C hybrids, will have no acute effects on monarch butterfly larvae in field settings. PMID:11559841

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

    SciTech Connect

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

    1991-08-01

    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.

  13. Investigation of larvae digestive β-glucosidase and proteases of the tomato pest Tuta absoluta for inhibiting the insect development.

    PubMed

    Sellami, S; Jamoussi, K

    2016-06-01

    The tomato leaf miner Tuta absoluta is one of the most devastating pests for tomato crops. Digestive proteases and β-glucosidase enzymes were investigated using general and specific substrates and inhibitors. Maximal β-glucosidase and proteolytic activities occurred at temperature and pH optima of 30 and 40°C, 5 and 10-11 unit of pH, respectively. Zymogram analysis showed the presence of distinguished β-glucosidase exhibiting a specific activity of about 183 ± 15 µmol min-1 mg-1. In vitro inhibition experiments suggested that serine proteases were the primary gut proteases. Gel based protease inhibition assays demonstrated that the 28 and 73 kDa proteases might be trypsin-like and chymotrypsin-like enzymes, respectively. Overall gut trypsin-like and chymotrypsin-like activities were evaluated to be about 27.2 ± 0.84 and 1.68 ± 0.03 µmol min-1 mg-1, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed that T. absoluta gut serine proteases are responsible for Bacillus thuringiensis Cry insecticidal proteins proteolysis. Additionally, bioassays showed that T. absoluta larvae development was more affected by the β-glucosidases inhibitor (D-glucono-δ-lactone) than the serine proteases inhibitor (soybean trypsin inhibitor). These results are of basic interest since they present interesting data of β-glucosidases and gut serine proteases of T. absoluta larvae. PMID:26898349

  14. Knockdown of ApoL1 in Zebrafish Larvae Affects the Glomerular Filtration Barrier and the Expression of Nephrin.

    PubMed

    Kotb, Ahmed M; Simon, Ole; Blumenthal, Antje; Vogelgesang, Silke; Dombrowski, Frank; Amann, Kerstin; Zimmermann, Uwe; Endlich, Karlhans; Endlich, Nicole

    2016-01-01

    APOL1, a secreted high-density lipoprotein, is expressed in different human tissues. Genetic variants of APOL1 are described to be associated with the development of end stage renal diseases in African Americans. In human kidney, APOL1 is mainly expressed in podocytes that are responsible for proper blood filtration. Since mice do not express ApoL1, the zebrafish is an ideal model to study the role of ApoL1. Injection of morpholinos against zApoL1 into zebrafish eggs and larvae, respectively, induces severe edema indicating a leakage of the filtration barrier. This was demonstrated in zApoL1 knockdown larvae by intravascular injection of fluorescently-labeled 10- and 500-kDa dextrans and by clearance of the vitamin D-binding protein from the circulation. Immunohistochemistry and RT-PCR revealed the reduction of nephrin, a podocyte-specific protein essential for blood filtration. Coinjection of human nephrin mRNA rescued the zApoL1 knockdown induced phenotype. Reduced APOL1 and nephrin levels were also found in biopsies of patients suffering from end stage renal diseases. Our results demonstrate that zApoL1 is essential for proper blood filtration in the zebrafish glomerulus and that zApoL1 affects the expression of nephrin. PMID:27138898

  15. Knockdown of ApoL1 in Zebrafish Larvae Affects the Glomerular Filtration Barrier and the Expression of Nephrin

    PubMed Central

    Kotb, Ahmed M.; Simon, Ole; Blumenthal, Antje; Vogelgesang, Silke; Dombrowski, Frank; Amann, Kerstin; Zimmermann, Uwe; Endlich, Karlhans; Endlich, Nicole

    2016-01-01

    APOL1, a secreted high-density lipoprotein, is expressed in different human tissues. Genetic variants of APOL1 are described to be associated with the development of end stage renal diseases in African Americans. In human kidney, APOL1 is mainly expressed in podocytes that are responsible for proper blood filtration. Since mice do not express ApoL1, the zebrafish is an ideal model to study the role of ApoL1. Injection of morpholinos against zApoL1 into zebrafish eggs and larvae, respectively, induces severe edema indicating a leakage of the filtration barrier. This was demonstrated in zApoL1 knockdown larvae by intravascular injection of fluorescently-labeled 10- and 500-kDa dextrans and by clearance of the vitamin D-binding protein from the circulation. Immunohistochemistry and RT-PCR revealed the reduction of nephrin, a podocyte-specific protein essential for blood filtration. Coinjection of human nephrin mRNA rescued the zApoL1 knockdown induced phenotype. Reduced APOL1 and nephrin levels were also found in biopsies of patients suffering from end stage renal diseases. Our results demonstrate that zApoL1 is essential for proper blood filtration in the zebrafish glomerulus and that zApoL1 affects the expression of nephrin. PMID:27138898

  16. An abundantly expressed mucin-like protein from Toxocara canis infective larvae: the precursor of the larval surface coat glycoproteins.

    PubMed Central

    Gems, D; Maizels, R M

    1996-01-01

    Evasion of host immunity by Toxocara canis infective larvae is mediated by the nematode surface coat, which is shed in response to binding by host antibody molecules or effector cells. The major constituent of the coat is the TES-120 glycoprotein series. We have isolated a 730-bp cDNA from the gene encoding the apoprotein precursor of TES-120. The mRNA is absent from T. canis adults but hyperabundant in larvae, making up approximately 10% of total mRNA, and is trans-spliced with the nematode 5' leader sequence SL1. It encodes a 15.8-kDa protein (after signal peptide removal) containing a typical mucin domain: 86 amino acid residues, 72.1% of which are Ser or Thr, organized into an array of heptameric repeats, interspersed with proline residues. At the C-terminal end of the putative protein are two 36-amino acid repeats containing six Cys residues, in a motif that can also be identified in several genes in Caenorhabditis elegans. Although TES-120 displays size and charge heterogeneity, there is a single copy gene and a homogeneous size of mRNA. The association of overexpression of some membrane-associated mucins with immunosuppression and tumor metastasis suggests a possible model for the role of the surface coat in immune evasion by parasitic nematodes. Images Fig. 1 Fig. 4 PMID:8643687

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

    PubMed

    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. PMID:26899315

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Larvae of the Asian corn borer (ACB), Ostrinia furnacalis, (Guenée), feeding on maize (Zea mays L.) induced volatiles from the plants that affected orientation behaviors of ACB larvae and oviposition of ACB adult females. Nineteen volatile chemicals were identified from maize plants attacked by thir...

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

    SciTech Connect

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

    1989-10-01

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

  20. Desenvolvimento das câmeras de raios-X duros do satélite MIRAX

    NASA Astrophysics Data System (ADS)

    Braga, J.; Rothschild, R.; Staubert, R.; Heise, J.; Remillard, R.; D'Amico, F.; Jablonski, F.; Mejía, J.; Carvalho, H.; Heindl, B.; Matteson, J.; Kendziorra, E.; Wilms, J.; in't Zand, J.; Kuulkers, E.

    2003-08-01

    O MIRAX (Monitor e Imageador de RAios-X) é um projeto de desenvolvimento de um pequeno satélite astronômico de raios-X (~200 kg, ~240 W). A estratégia básica da missão será observar continuamente (~9 meses por ano) a região central (~1000 graus2) do plano Galáctico e realizar estudos espectroscópicos de banda larga (2-200 keV) e alta sensibilidade de um grande conjunto de fontes através de imagens com resolução de ~6'. Isso proporcionará uma cobertura inédita do "espaço de descobertas" através da detecção, localização, identificação e estudo detalhado de fenômenos imprevisíveis, tais como transientes fracos de raios-X, novas rápidas de raios-X e bursts de raios gama, assim como o estudo de fontes com emissão persistente. Neste trabalho apresentamos o projeto das duas câmeras de raios-X duros (CXDs) do MIRAX, que irão operar na faixa de 10 a 200 keV. Cada CXD consistirá de um plano de detectores CZT (Cd0,9Zn0,1Te) de 0,5 mm de resolução espacial e 370 cm2 de área total, e de uma máscara codificada com elementos quadrados de 1,3 mm de lado e 0,5 cm de espessura. A máscara terá dimensões de 315 cm ´ 275 cm e será montada a 700 cm de distância dos detectores. Com essa configuração as CXDs terão 6' de resolução angular e, quando colocadas a um ângulo de 29° entre si, as duas câmeras propiciam um campo totalmente codificado de 39° ´ 6°12' e um campo total de 76° ´ 44°. Serão apresentadas simulações de observações da região do plano Galáctico com o conjunto formado pelas duas CXDs.

  1. Purification and characterization of a thermal stable antimicrobial protein from housefly larvae, Musca domestica, induced by ultrasonic wave.

    PubMed

    Hao, Y J; Jing, Y J; Qu, H; Li, D S; Du, R Q

    2008-09-01

    This work describes the induction, purification and partial biochemical characterizations of an antimicrobial protein from the housefly larvae induced by ultrasonic wave. It has been purified to apparent homogeneity by ammonium sulfate precipitation followed by Sephadex G-75, Bio-gel P6 gel filtration, and CM-Sepharose Fast Flow cation exchange chromatography. The protein is a cationic protein with an apparent molecular weight of 16315 Da determined by no-denaturing electrophoresis and SDS-PAGE, respectively. Biochemical profile assays show that this protein has good thermal stability, and repeatedly frozen and defrosted durability. The optimum pH for antimicrobial activity is around pH5. The antimicrobial range of the protein includes Gram-positive, Gram-negative bacteria and some fungi. Results of the membrane permeability assays suggest that the probable mode of action of this protein is membrane-disrupting mechanism. PMID:18839696

  2. The larvae of West Palaearctic Eurylophella Tiensuu, 1935 (Ephemeroptera: Ephemerellidae), with description of a new species from Georgia.

    PubMed

    Martynov, Alexander V; Palatov, Dmitry M; Godunko, Roman J

    2015-01-01

    Eurylophella korneyevi sp. nov. (larva) is described from the Kintrishi River within the Caucasus region of Georgia, Autonomous Republic of Adzharia. In addition to morphological data, biological and distribution data are also presented. The new species can be differentiated from other Eurylophella species by the shape of submedian tubercles on abdominal tergites, the structure of the dorsal subdivisions of the lower lamella of gills IV, and the shape and relative development of occipital tubercles. Distinguishing features of E. korneyevi sp. nov., Eurylophella karelica Tiensuu, 1935 and Eurylophella iberica Keffermüller & Da Terra, 1978 are given. The possibility of using chaetotaxy in the taxonomy of the genus is analyzed in detail for the West Palaearctic species of Eurylophella.  PMID:25660776

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

    PubMed Central

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

    2014-01-01

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

  4. Production of the catechol type siderophore bacillibactin by the honey bee pathogen Paenibacillus larvae.

    PubMed

    Hertlein, Gillian; Müller, Sebastian; Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D; Genersch, Elke

    2014-01-01

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

  5. Adenosine triphosphate quantification as related to cryptobiosis, nematode eggs, and larvae.

    PubMed

    Spurr, H W

    1976-04-01

    Sonification was the most effective method used for disintegrating nematode eggs and larvae for adenosine triphosphate (ATP) determinations. Sensitivity of the assay was sufficient to measure ATP in one larva. Second-stage larvae of Anguina tritici averaged 1 x 10 femtograms (fg) ATP and Meloidogyne incognita eggs, 0.8 x 105 fg ATP. Larvae of Panagrellus redivivus, a saprobe, averaged 12.2 x 105 fg ATP, a measurement which was considerably higher than the ATP levels in plant parasites. Endophytic bacteria and fungi from wheat galls were detected as background organisms associated with A. tritiei activated by hydration. Also, bacteria in suspensions of eggs from M. incognita prepared with NaCIO were measured by the use of butanol extraction and ATP determination. Second-stage A. tritici larvae increased in ATP content within 40 min after being activated from cryptobiosis by hydration. In the cryptobiotic state, larvae had 50% less ATP than when active. ATP concentrations were similar in galls of different ages. Apparently, ATP concentrations do not change during cryptobiosis. Starvation results in a decline in ATP concentration/larva. Subjecting A. tritici larvae to the lethal temperature of 60 C resulted in a three-fold increase in the decay rate of ATP over that of larvae sonified, then heated at 60 C. These results suggest an association between ATP decay and the mechanism that causes death of larvae at elevated temperatures. PMID:19308214

  6. Exposure to lead induces hypoxia-like responses in bullfrog larvae (Rana catesbeiana)

    SciTech Connect

    Rice, T.M.; Blackstone, B.J.; Nixdorf, W.L.; Taylor, D.H.

    1999-10-01

    Amphibians collected around mining sites, areas with extensive automobile traffic, and shooting ranges have been documented to contain high levels of lead. Lead-exposed amphibians might respond as if in hypoxic conditions because exposure is known to decrease hemoglobin levels, damage erythrocytes, and alter respiratory surfaces. Therefore, the authors exposed bullfrog larvae to either 0 or 780 {micro}g/L Pb and either 3.50 or 7.85 mg/L oxygen for 7 d and monitored activity, trips to the surface, and buccal ventilation rates. Activity was significantly decreased in larvae exposed to low oxygen, Pb, or both compared to activity of larvae in high oxygen with no Pb. Larvae exposed to both Pb and low oxygen displayed higher buccal ventilation rates than larvae exposed to either treatment separately. Lead-exposed larvae surfaced significantly more often than unexposed larvae even under high-oxygen conditions. Lead-exposed larvae decreased in mass during the exposure period, whereas unexposed larvae increased in mass. Lead exposure could decrease survival of larvae in the field not only because of physiological problems due to decreased oxygen uptake but also because of greater predation pressure due to increased presence at the surface and reduced growth rates.

  7. Effect of tributyltin on veliger larvae of the Manila clam, Ruditapes philippinarum.

    PubMed

    Inoue, Suguru; Oshima, Yuji; Usuki, Hironori; Hamaguchi, Masami; Hanamura, Yukio; Kai, Norihisa; Shimasaki, Yohei; Honjo, Tsuneo

    2007-01-01

    We investigated the effects of waterborne and maternal exposure to tributyltin (TBT) on veliger larvae of the Manila clam, Ruditapes philippinarum. In a waterborne exposure test, veliger larvae (D-larvae stage: 24h after fertilization) were exposed to TBT at measured concentrations of <0.01 (control), 0.055, 0.130, 0.340, and 0.600microg/l for 13d. The percentage of normal veliger larvae (the ratio of normal veliger larvae to all larvae) decreased significantly in all TBT treatment groups compared with that in the control group. In a maternal exposure test, 100 clams were exposed to TBT at measured concentrations of <0.01 (control), 0.061, and 0.310microg/l at 20-22 degrees C for 3 weeks, and the percentage of normal veliger larvae assessed for 13d. No maternal effects on veliger larvae from TBT were observed in TBT treatment groups as compared with the control group. These results demonstrate that waterborne TBT affects Manila clam veliger larvae, and indicates that TBT may have reduced Manila clam populations by preventing the development and survival of veliger larvae. PMID:16890269

  8. Transmission of a Gammabaculovirus within Cohorts of Balsam Fir Sawfly (Neodiprion abietis) Larvae

    PubMed Central

    Graves, Roger; Quiring, Dan T.; Lucarotti, Christopher J.

    2012-01-01

    Nucleopolyhedroviruses (NPV: Gammabaculovirus: Baculoviridae) of diprionid sawflies (Diprionidae: Hymenoptera) are highly host specific and only infect the midgut epithelium. While still alive, infected sawfly larvae excrete NPV-laden diarrhea that contaminates food sources. The diarrhea can then be consumed by conspecific larvae, resulting in rapid horizontal transmission of the virus. To better understand the efficacy of Gammabaculovirus-based biological control products, the horizontal spread of such a virus (NeabNPV) within cohorts of balsam fir sawfly (Neodiprion abietis) larvae was studied by introducing NeabNPV-treated larvae into single-cohort groups at densities similar to those observed during the increasing (field study) and peak (laboratory study) phases of an outbreak. In field studies (~200 N. abietis larvae/m2 of balsam fir (Abies balsamea) foliage), NeabNPV-induced mortality increased positively in a density-dependent manner, from 23% (in control groups) to 51% with the addition of one first-instar NeabNPV-treated larva, to 84% with 10 first–instar-treated larvae. Mortality was 60% and 63% when one or 10 NeabNPV-treated third-instar larva(e), respectively, were introduced into groups. Slightly higher levels of NeabNPV-induced mortality occurring when NeabNPV-treated larvae were introduced into first- rather than third-instar cohorts suggests that early instars are more susceptible to the virus. In the laboratory (~1330 N. abietis larvae/ m2 of foliage), NeabNPV-caused mortality increased from 20% in control groups to over 80% with the introduction of one, five or 10 NeabNPV-treated larvae into treatment groups of first-instar larvae. PMID:26466722

  9. Purification and characterization of a novel antibacterial peptide from black soldier fly (Hermetia illucens) larvae.

    PubMed

    Park, Soon-Ik; Kim, Jong-Wan; Yoe, Sung Moon

    2015-09-01

    In this study, we induced and purified a novel antimicrobial peptide exhibiting activity against Gram-positive bacteria from the immunized hemolymph of Hermetia illucens larvae. The immunized hemolymph was extracted, and the novel defensin-like peptide 4 (DLP4) was purified using solid-phase extraction and reverse-phase chromatography. The purified DLP4 demonstrated a molecular weight of 4267 Da, as determined using the matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) method. From analysis of DLP4 by N-terminal amino acid sequencing using Edman degradation, combined with MALDI-TOF and rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR), the amino acid sequence of the mature peptide was determined to be ATCDLLSPFKVGHAACAAHCIARGKRGGWCDKRAVCNCRK. In NCBI BLAST, the amino acid sequence of DPL4 was found to be 75% identical to the Phlebotomus duboscqi defensin. Analysis of the minimal inhibitory concentration (MIC) revealed that DLP4 have antibacterial effects against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). The expression of DLP4 transcripts in several tissues after bacterial challenge was measured by quantitative real-time PCR. Expression of the DLP4 gene hardly occurred throughout the body before immunization, but was mostly evident in the fat body after immunization. PMID:25956195

  10. Proteomic analysis of surface proteins of Trichinella spiralis muscle larvae by two-dimensional gel electrophoresis and mass spectrometry

    PubMed Central

    2013-01-01

    Background Trichinella spiralis is a zoonotic tissue-dwelling parasitic nematode that infects humans and other mammals. Its surface proteins are recognized as antigenic in many infected hosts, being directly exposed to the host’s immune system and are the main target antigens that induce the immune responses. The larval surface proteins may also interact with intestinal epithelial cells and may play an important role in the invasion and development process of T. spiralis. The purpose of this study was to analyze and characterize the surface proteins of T. spiralis muscle larvae by two-dimensional gel electrophoresis (2-DE) and mass spectrometry. Methods The surface proteins of T. spiralis muscle larvae were stripped from the cuticle of live larvae by the cetyltrimethylammonium bromide (CTAB) and sodium deoxycholate. The surface protein stripping was examined by an immunofluorescent test (IFT). The surface proteins were analyzed by SDS-PAGE and Western blotting, and then identified by 2-DE and MALDI-TOF/TOF mass spectrometry analysis. Results The IFT results showed that the surface proteins-stripped larvae were not recognized by sera of mice immunized with surface antigens. Western blotting showed 7 of 12 protein bands of the surface proteins were recognized by mouse infection sera at 18 dpi and at 42 dpi. The 2-DE results showed that a total of approximately 33 proteins spots were detected with molecular weights varying from 10 to 66 kDa and isoelectric point (pI) from 4 to 7. Twenty-seven of 33 protein spots were identified and characterized to correlate with 15 different proteins. Out of the 14 proteins identified as T. spiralis proteins, 5 proteins (partial P49 antigen, deoxyribonuclease II family protein, two serine proteases, and serine proteinase) had catalytic and hydrolase activity. All of these 5 proteins were also associated with metabolic processes and 2 of the five proteins were associated with cellular processes. Conclusions In this study, T

  11. Viral encephalitis of tilapia larvae: primary characterization of a novel herpes-like virus.

    PubMed

    Shlapobersky, Mark; Sinyakov, Michael S; Katzenellenbogen, Mark; Sarid, Ronit; Don, Jeremy; Avtalion, Ramy R

    2010-04-10

    We report here an outbreak of an acute disease that caused high mortality rate in laboratory-reared tilapia larvae. The disease was initially observed in inbred gynogenetic line of blue tilapia larvae (Oreochromis aureus) and could be transmitted to larvae of other tilapia species. Based on the clinical manifestation (a whirling syndrome), we refer to the disease as viral encephalitis of tilapia larvae. The disease-associated DNA virus is described and accordingly designated tilapia larvae encephalitis virus (TLEV). A primary morphological, biophysical and molecular characterization of TLEV is presented. By virtue of these properties, the newly discovered virus is a herpes-like virus. Phylogenetic analysis, albeit limited, confirms this assumption and places TLEV within the family of Herpesviridae and distantly from the families Alloherpesviridae and Iridoviridae. By using PCR with virus-specific primers, diseased larvae and adult TLEV carriers were also identified in tilapia delivered from external hatcheries. PMID:20117816

  12. A behavioral method for separation of house fly (Diptera: Muscidae) larvae from processed pig manure.

    PubMed

    Cicková, Helena; Kozánek, Milan; Morávek, Ivan; Takác, Peter

    2012-02-01

    A behavioral method applicable in biodegradation facilities for separation of house fly (Musca domestica L.) larvae from processed pig manure is presented. The method is based on placing a cover over the larval rearing tray, while escaping larvae are collected in collection trays. Separation units must be placed in a dark room to avoid negative phototactic responses of the larvae. After 24 h of separation, over 70% of the larvae escaped from processed manure and were collected in collection trays. Most of the larvae pupated within 48 h after separation. Mean weight of pupae recovered from manure residue was not significantly different from mean weight of pupae of separated individuals. Eclosion rate of pupae recovered from manure residue was significantly lower than eclosion of separated individuals, and was strongly related to separation success. Factors responsible for escape behavior of larvae are discussed. PMID:22420256

  13. Parasitism of Western Corn Rootworm Larvae and Pupae by Steinernema carpocapsae.

    PubMed

    Jackson, J J; Brooks, M A

    1995-03-01

    Virulence and development of the insect-parasitic nematode, Steinernema carpocapsae (Weiser) (Mexican strain), were evaluated for the immature stages of the western corn rootworm, Diabrotica virgifera virgifera LeConte. Third instar rootworm larvae were five times more susceptible to nematode infection than second instar larvae and 75 times more susceptible than first instar larvae and pupae, based on laboratory bioassays. Rootworm eggs were not susceptible. Nematode development was observed in all susceptible rootworm stages, but a complete life cycle was observed only in second and third instar larvae and pupae. Nematode size was affected by rootworm stage; the smallest infective-stage nematodes were recovered from second instar rootworm larvae. Results of this study suggest that S. carpocapsae should be applied when second and third instar rootworm larvae are predominant in the field. PMID:19277256

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

    PubMed

    Kuraiem, Bianca P; Knoff, Marcelo; Felizardo, Nilza N; Gomes, Delir C; Clemente, Sérgio C São

    2016-05-31

    From July to December, 2013, thirty Priacanthus arenatus specimens commercialized in the cities of Niterói and Rio de Janeiro, State of Rio de Janeiro, were acquired. The fish were necropsied and filleted to investigate the presence of nematode larvae. Twenty fish (66.7%) out of the total were parasitized by nematode larvae. A total of 2024 larvae were collected; among them, 30 third-instar larvae of Anisakis sp. showed prevalence (P) = 20%, mean abundance (MA) = 1, and the mean intensity (MI) = 5, and infection sites (IS) = caecum, stomach, liver, and mesentery; and 1,994 third-instar larvae (1,757 encysted and 237 free) of Hysterothylacium deardorffoverstreetorum with P = 66.7%, MA = 66.5, and MI = 99.7, and IS = spleen, caecum, stomach, liver, mesentery, and abdominal muscle. This is the first study to report H. deardorffoverstreetorum and Anisakis sp. larvae parasitizing P. arenatus. PMID:27254444

  15. Temperature and salinity effects on development of striped bass eggs and larvae

    SciTech Connect

    Morgan, R.P. II; Rasin, V.J. Jr.; Copp, R.L.

    1981-01-01

    Responses of eggs and larvae of striped bass, Morone saxatilis, to a series of temperature-salinity combinations were measured as percent hatch, percent survival of larvae 24 hours after hatch, and larva length for the temperature range of 10 to 28 C and the salinity range of 0 to 10%. Optimal temperature was 18 C, and optimal salinity varied, for the majority of these variables.

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

    PubMed Central

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

    2014-01-01

    We report a case of facultative intestinal myiasis due to larvae of the drone fly Eristalis tenax, also named the rat-tailed maggots. The development of larvae in the lower bowel was responsible for non-specific gastrointestinal symptoms that resembled ulcerative proctitis. The diagnosis was established upon the observation of four spontaneously excreted mobile larvae. The definite identification of the E. tenax species was made possible by scanning electron microscopy. The clinical outcome was satisfactory. PMID:24766340

  17. The influence of developmental stages and protective additives on cryopreservation of surf clam (Spisula sachalinensis) larvae.

    PubMed

    Choi, Youn Hee; Lee, Jeong Yong; Chang, Young Jin

    2008-07-01

    This study was performed to find out the optimal larval stage and the most desirable protective additives for cryopreservation of surf clam, Spisula sachalinensis larvae. The survival rates of frozen-thawed larvae increased with post developmental stage. The highest value of 96.1 +/- 1.0% was achieved using umbo stage larva as developmental stage and 0.2 M sucrose as protective additive. PMID:19195381

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

    PubMed

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

    2014-04-01

    We report a case of facultative intestinal myiasis due to larvae of the drone fly Eristalis tenax, also named the rat-tailed maggots. The development of larvae in the lower bowel was responsible for non-specific gastrointestinal symptoms that resembled ulcerative proctitis. The diagnosis was established upon the observation of four spontaneously excreted mobile larvae. The definite identification of the E. tenax species was made possible by scanning electron microscopy. The clinical outcome was satisfactory. PMID:24766340

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

    PubMed

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

    2014-06-01

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

  20. Cumulative mortality of Aedes aegypti larvae treated with compounds

    PubMed Central

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

    2014-01-01

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

  1. Coral larvae settle at a higher frequency on red surfaces

    NASA Astrophysics Data System (ADS)

    Mason, B.; Beard, M.; Miller, M. W.

    2011-09-01

    Although chemical cues serve as the primary determinants of larval settlement and metamorphosis, light is also known to influence the behavior and the settlement of coral planulae. For example, Porites astreoides planulae settle preferentially on unconditioned red substrata. In order to test whether this behavior was a response to color and whether other species also demonstrate color preference, settlement choice experiments were conducted with P. astreoides and Acropora palmata. In these experiments, larvae were offered various types of plastic substrata representing three to seven different color choices. Both species consistently settled on red (or red and orange) substrata at a higher frequency than other colors. In one experiment, P. astreoides settled on 100% of red, plastic cable ties but failed to settle on green or white substrata. In a second experiment, 24% of larvae settled on red buttons, more than settled on six other colors combined. A. palmata settled on 80% of red and of orange cables ties but failed to settle on blue in one experiment and settled on a greater proportion of red acrylic squares than on four other colors or limestone controls in a second experiment. The consistency of the response across a variety of plastic materials suggests the response is related to long-wavelength photosensitivity. Fluorescence and reflectance spectra of experimental substrata demonstrated that the preferred substrata had spectra dominated by wavelengths greater than 550 nm with little or no reflection or emission of shorter wavelengths. These results suggest that some species of coral larvae may use spectral cues for fine-scale habitat selection during settlement. This behavior may be an adaptation to promote settlement in crustose coralline algae (CCA)-dominated habitats facilitating juvenile survival.

  2. Thyroid endocrine disruption of acetochlor on zebrafish (Danio rerio) larvae.

    PubMed

    Yang, Mei; Hu, Jingjin; Li, Shuying; Ma, Youning; Gui, Wenjun; Zhu, Guonian

    2016-06-01

    The herbicide acetochlor is widely used and detected in the environment and biota, and has been suspected to disrupt the thyroid endocrine system, but underlying mechanisms have not yet been clarified. In the present study, zebrafish larvae (7 days post-fertilization) were exposed to a series concentration of acetochlor (0, 1, 3, 10, 30, 100 and 300 µg l(-1) ) within a 14-day window until 21 days post-fertilization. Thyroid hormones and mRNA expression profiles of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis were analyzed. Exposure to the positive control, 3,5,3'-triiodothyronine (T3 ), altered the mRNA expression, suggesting that the HPT axis in the critical window of zebrafish responded to chemical exposure and could be used to evaluate the effects of chemicals on the thyroid endocrine system. The mRNA expressions of genes involved in thyroid hormone synthesis (tshβ, slc5a5 and tpo) were upregulated significantly with acetochlor treatment, which might be responsible for the increased thyroxine concentrations. The downregulation of genes related to thyroid hormone metabolism (dio1 and ugt1ab) and transport (ttr) in zebrafish larvae exposed to acetochlor might further explain the increased thyroxine levels and decreased T3 levels. The mRNA expression of the thyroid hormone receptor (trα) was also upregulated upon acetochlor exposure. Results suggested that acetochlor altered mRNA expression of the HPT axis-related genes and changed the whole body thyroid hormone levels in zebrafish larvae. It demonstrated that acetochlor could cause endocrine disruption of the thyroid system by simulating the biological activity of T3 . Copyright © 2015 John Wiley & Sons, Ltd. PMID:26397822

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

    PubMed

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

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics. PMID:24015260

  4. Drosophila melanogaster larvae make nutritional choices that minimize developmental time.

    PubMed

    Rodrigues, Marisa A; Martins, Nelson E; Balancé, Lara F; Broom, Lara N; Dias, António J S; Fernandes, Ana Sofia D; Rodrigues, Fábio; Sucena, Élio; Mirth, Christen K

    2015-10-01

    Organisms from slime moulds to humans carefully regulate their macronutrient intake to optimize a wide range of life history characters including survival, stress resistance, and reproductive success. However, life history characters often differ in their response to nutrition, forcing organisms to make foraging decisions while balancing the trade-offs between these effects. To date, we have a limited understanding of how the nutritional environment shapes the relationship between life history characters and foraging decisions. To gain insight into the problem, we used a geometric framework for nutrition to assess how the protein and carbohydrate content of the larval diet affected key life history traits in the fruit fly, Drosophila melanogaster. In no-choice assays, survival from egg to pupae, female and male body size, and ovariole number - a proxy for female fecundity - were maximized at the highest protein to carbohydrate (P:C) ratio (1.5:1). In contrast, development time was minimized at intermediate P:C ratios, around 1:2. Next, we subjected larvae to two-choice tests to determine how they regulated their protein and carbohydrate intake in relation to these life history traits. Our results show that larvae targeted their consumption to P:C ratios that minimized development time. Finally, we examined whether adult females also chose to lay their eggs in the P:C ratios that minimized developmental time. Using a three-choice assay, we found that adult females preferentially laid their eggs in food P:C ratios that were suboptimal for all larval life history traits. Our results demonstrate that D. melanogaster larvae make foraging decisions that trade-off developmental time with body size, ovariole number, and survival. In addition, adult females make oviposition decisions that do not appear to benefit the larvae. We propose that these decisions may reflect the living nature of the larval nutritional environment in rotting fruit. These studies illustrate the

  5. Toxicity of Different Diets Contaminated with Various Fungi to Rice Moth Larvae (Corcyra Cephalonica St.)

    PubMed Central

    Hegde, Umashashi C.; Chandra, T.; Shanmugasundaram, E. R. B.

    1967-01-01

    Growth studies of rice moth larvae (Corcyra cephalonica st) have been carried out in groundnut meal and wheat bran contaminated with A. flavus, A. oryzae, P. purpurogenus and P. rubrum. It was observed that the diets contaminated with A. flavus only are toxic to these larvae. Wheat bran contaminated with A. flavus is more toxic than contaminated groundnut meal. The higher toxicity of wheat bran contaminated diet has been discussed. Aflatoxins produced in different substrata are shown to differ when analysed chromatographically. Growth studies of rice moth larvae have also been carried out with aflatoxin and the susceptibility of these larvae has been established. PMID:4227044

  6. Secreted and immunogenic proteins produced by the honeybee bacterial pathogen, Paenibacillus larvae.

    PubMed

    Antúnez, Karina; Anido, Matilde; Evans, Jay D; Zunino, Pablo

    2010-03-24

    American Foulbrood is a severe disease affecting larvae of honeybee Apis mellifera, causing significant decrease in the honeybee population, beekeeping industries and agricultural production. In spite of its importance, little is known about the virulence factors secreted by Paenibacillus larvae during larval infection. The aim of the present work was to perform a first approach to the identification and characterization of P. larvae secretome. P. larvae secreted proteins were analyzed by SDS-PAGE and identified by MALDI-TOF. Protein toxicity was evaluated using an experimental model based on feeding of A. mellifera larvae and immunogenicity was evaluated by Western blot, using an antiserum raised against cells and spores of P. larvae. Ten different proteins were identified among P. larvae secreted proteins, including proteins involved in transcription, metabolism, translation, cell envelope, transport, protein folding, degradation of polysaccharides and motility. Although most of these proteins are cytosolic, many of them have been previously detected in the extracellular medium of different Bacillus spp. cultures and have been related to virulence. The secreted proteins resulted highly toxic and immunogenic when larvae were exposed using an experimental model. This is the first description of proteins secreted by the honeybee pathogen P. larvae. This information may be relevant for the elucidation of bacterial pathogenesis mechanisms. PMID:19781868

  7. [Ingestion of Culex quinquefasciatus larvae (Diptera: Culicidae) by Girardinus metallicus (Cyprinodontiformes: Poecilidae)].

    PubMed

    Contreras, Natividad Hernández; Pérez, Manuel Díaz; Martínez, Judith Mendiola; Báez Artelles, Juan A; Avila, Israel García

    2004-01-01

    Data on ingestion of Culex quinquefasciatus Say 1823 larvae by Girardinus metallicus, Poey 1854 under lab and field conditions were obtained and compared to those reported on the same species by other authors. It was observed that G. metallicus is not so aggressive as other species of larvivorus fish in capturing larvae. The consumption of larvae is higher in females since males prefer feeding on vegetation. Because of the bioecological characteristics of the species, resistance to management and survival in cultural conditions, G. metallicus is recommended to be used as bioregulator of mosquito larvae. PMID:15846915

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

    SciTech Connect

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

    1982-09-01

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

  9. Paenilarvins: Iturin family lipopeptides from the honey bee pathogen Paenibacillus larvae.

    PubMed

    Sood, Sakshi; Steinmetz, Heinrich; Beims, Hannes; Mohr, Kathrin I; Stadler, Marc; Djukic, Marvin; von der Ohe, Werner; Steinert, Michael; Daniel, Rolf; Müller, Rolf

    2014-09-01

    The bacterium Paenibacillus larvae has been extensively studied as it is an appalling honey bee pathogen. In the present work, we screened crude extracts derived from fermentations of P. larvae genotypes ERIC I and II for antimicrobial activity, following the detection of four putative secondary metabolite gene clusters that show high sequence homology to known biosynthetic gene clusters for the biosynthesis of antibiotics. Low molecular weight metabolites produced by P. larvae have recently been shown to have toxic effects on honey bee larvae. Moreover, a novel tripeptide, sevadicin, was recently characterized from laboratory cultures of P. larvae. In this study, paenilarvins, which are iturinic lipopeptides exhibiting strong antifungal activities, were obtained by bioassay-guided fractionation from cultures of P. larvae, genotype ERIC II. Their molecular structures were determined by extensive 2D NMR spectroscopy, high resolution mass spectrometry, and other methods. Paenilarvins are the first antifungal secondary metabolites to be identified from P. larvae. In preliminary experiments, these lipopeptides also affected honey bee larvae and might thus play a role in P. larvae survival and pathogenesis. However, further studies are needed to investigate their function. PMID:25069424

  10. Fishing for prawn larvae in Bangladesh: an important coastal livelihood causing negative effects on the environment.

    PubMed

    Ahmed, Nesar; Troell, Max

    2010-02-01

    Freshwater prawn (Macrobrachium rosenbergii) farming in Bangladesh has, to a large extent, been dependent on the supply of wild larvae. Although there are 81 freshwater prawn hatcheries in the country, a lack of technical knowledge, inadequate skilled manpower, and an insufficient supply of wild broods have limited hatchery production. Many thousands of coastal poor people, including women, are engaged in fishing for wild prawn larvae along the coastline during a few months each year. On average, 40% of the total yearly income for these people comes from prawn larvae fishing activity. However, indiscriminate fishing of wild larvae, with high levels of bycatch of juvenile fish and crustaceans, may impact negatively on production and biodiversity in coastal ecosystems. This concern has provoked the imposition of restrictions on larvae collection. The ban has, however, not been firmly enforced because of the limited availability of hatchery-raised larvae, the lack of an alternative livelihood for people involved in larvae fishing, and weak enforcement power. This article discusses the environmental and social consequences of prawn larvae fishing and concludes that, by increasing awareness among fry fishers, improving fishing techniques (reducing bycatch mortality), and improving the survival of fry in the market chain, a temporal ban may be a prudent measure when considering the potential negative impacts of bycatch. However, it also suggests that more research is needed to find out about the impact of larvae fishing on nontarget organisms and on the populations of targeted species. PMID:20496649

  11. House fly oviposition inhibition by larvae ofHermetia illucens, the black soldier fly.

    PubMed

    Bradley, S W; Sheppard, D C

    1984-06-01

    Wild populations of house flies were inhibited from ovipositing into poultry manure containing larvae of the black soldier fly,Hermetia illucens (L.). A laboratory strain of house fly responded differently, readily ovipositing into manure with lower densities of soldier fly larvae, but avoiding the higher densities tested. The amount of timeH. illucens larvae occupy the manure prior to an oviposition test influences ovipositional responses of house flies. Manure conditioned byH. illucens larvae for 4-5 days did not significantly inhibit house fly oviposition. We suggest that some type of interspecific chemical communication (allomone) is present. PMID:24318779

  12. Fused embryos and pre-metamorphic conjoined larvae in a broadcast spawning reef coral

    PubMed Central

    Jiang, Lei; Lei, Xin-Ming; Liu, Sheng; Huang, Hui

    2015-01-01

    Fusion of embryos or larvae prior to metamorphosis is rarely known to date in colonial marine organisms. Here, we document for the first time that the embryos of the broadcast spawning coral Platygyra daedalea could fuse during blastulation and further develop into conjoined larvae, and the settlement of conjoined larvae immediately resulted in inborn juvenile colonies. Fusion of embryos might be an adaptive strategy to form pre-metamorphic chimeric larvae and larger recruits, thereby promoting early survival. However, future studies are needed to explore whether and to what extent fusion of coral embryos occurs in the field, and fully evaluate its implications. PMID:25901279

  13. Biological Control of the Nematode Infective larvae of Trichostrongylidae Family With Filamentous Fungi

    PubMed Central

    Zarrin, Majid; Rahdar, Mahmoud; Gholamian, Abbas

    2015-01-01

    Background: Biological control of parasitic nematodes by microorganisms is a promising approach to control such parasites. Microorganisms such as fungi, viruses and bacteria are recognized as biocontrol agents of nematodes. Objectives: The current study mainly aimed to evaluate the in vitro Potential of various saprophyte soil-fungi in reducing the infective larvae stage of parasitic nematode Trichostrongylidae family. Materials and Methods: Sheep feces were employed to provide the required third stage larvae source for the experiments. The nematode infective larvae of Trichostrongylidae family including three species of Ostertagia circumcincta, Marshalgia marshali and Heamonchos contortus were collected by Berman apparatus. Fifteen isolates of filamentous fungi were tested in the current study. One milliliter suspension containing 200 third stage larvae of Trichostrongylidae family was separately added to the fungal cultures in 2% water-agar medium Petri-dishes. Every day the live larvae were counted with light microscope (10X) and the number of captured larvae was recorded on different days. Results: Significant differences were observed in the results of co-culture of nematodes larva and fungi after seven days. The most effective fungi against the nematodes larvae were Cladosporium sp., Trichoderma sp., Fusarium equisetti, after seven days of incubation. Conclusions: The studies on fungi could be applied as suitable tools in biocontrol of nematode infections. However, additional surveys are required to select efficient with the ability to reduce the nematode larvae in the environment. PMID:25893084

  14. Identification of a New cry1I-Type Gene as a Candidate for Gene Pyramiding in Corn To Control Ostrinia Species Larvae.

    PubMed

    Zhao, Can; Jurat-Fuentes, Juan Luis; Abdelgaffar, Heba M; Pan, Hongyu; Song, Fuping; Zhang, Jie

    2015-06-01

    Pyramiding of diverse cry toxin genes from Bacillus thuringiensis with different modes of action is a desirable strategy to delay the evolution of resistance in the European corn borer (Ostrinia nubilalis). Considering the dependency of susceptibility to Cry toxins on toxin binding to receptors in the midgut of target pests, a diverse mode of action is commonly defined as recognition of unique binding sites in the target insect. In this study, we present a novel cry1Ie toxin gene (cry1Ie2) as a candidate for pyramiding with Cry1Ab or Cry1Fa in corn to control Ostrinia species larvae. The new toxin gene encodes an 81-kDa protein that is processed to a protease-resistant core form of approximately 55 kDa by trypsin digestion. The purified protoxin displayed high toxicity to Ostrinia furnacalis and O. nubilalis larvae but low to no activity against Spodoptera or heliothine species or the coleopteran Tenebrio molitor. Results of binding assays with (125)I-labeled Cry1Ab toxin and brush border membrane vesicles from O. nubilalis larvae demonstrated that Cry1Ie2 does not recognize the Cry1Ab binding sites in that insect. Reciprocal competition binding assays with biotin-labeled Cry1Ie2 confirmed the lack of shared sites with Cry1Ab or Cry1Fa in O. nubilalis brush border membrane vesicles. These data support Cry1Ie2 as a good candidate for pyramiding with Cry1Ab or Cry1Fa in corn to increase the control of O. nubilalis and reduce the risk of resistance evolution. PMID:25795679

  15. Identification of a New cry1I-Type Gene as a Candidate for Gene Pyramiding in Corn To Control Ostrinia Species Larvae

    PubMed Central

    Zhao, Can; Abdelgaffar, Heba M.; Pan, Hongyu; Song, Fuping

    2015-01-01

    Pyramiding of diverse cry toxin genes from Bacillus thuringiensis with different modes of action is a desirable strategy to delay the evolution of resistance in the European corn borer (Ostrinia nubilalis). Considering the dependency of susceptibility to Cry toxins on toxin binding to receptors in the midgut of target pests, a diverse mode of action is commonly defined as recognition of unique binding sites in the target insect. In this study, we present a novel cry1Ie toxin gene (cry1Ie2) as a candidate for pyramiding with Cry1Ab or Cry1Fa in corn to control Ostrinia species larvae. The new toxin gene encodes an 81-kDa protein that is processed to a protease-resistant core form of approximately 55 kDa by trypsin digestion. The purified protoxin displayed high toxicity to Ostrinia furnacalis and O. nubilalis larvae but low to no activity against Spodoptera or heliothine species or the coleopteran Tenebrio molitor. Results of binding assays with 125I-labeled Cry1Ab toxin and brush border membrane vesicles from O. nubilalis larvae demonstrated that Cry1Ie2 does not recognize the Cry1Ab binding sites in that insect. Reciprocal competition binding assays with biotin-labeled Cry1Ie2 confirmed the lack of shared sites with Cry1Ab or Cry1Fa in O. nubilalis brush border membrane vesicles. These data support Cry1Ie2 as a good candidate for pyramiding with Cry1Ab or Cry1Fa in corn to increase the control of O. nubilalis and reduce the risk of resistance evolution. PMID:25795679

  16. Histomorphogenesis of cranial nerves in Huso huso larvae

    PubMed Central

    Tavighi, Sherma; Saadatfar, Zohreh; Shojaei, Bahador; Behnam Rassouli, Morteza

    2016-01-01

    In this study the cranial nerves development of H. huso are explained from 1 to 54-days-old (1, 3, 6, 15, 21 and 54 days). Despite all the researches on fish brain, there are no study on nerves evolution on H. huso during their larvae life. For this research 40 samples of larvae H. huso were obtained (from each age, about six samples were selected). The specimens were maintained in fiberglass tank, then histological samples were taken from tissues and stained with hematoxylin and eosin for general histological studies using light microscope. According to the results, on 1 and 3-days-old, no nerve was observed. The terminal nerve and their dendrites were observed around the nasal cavity and the axons projected to different areas in forebrain especially around olfactory bulb diffusely, on 6-day-old fish. Also, olfactory, optic, oculomotor, trochlear, trigeminal, lateral line and vagus nerves were detected on 6-day-old fish, however two parts of lateral line nerve were separated on 54-day-old. Three nerves, profundus, facial and octaval were observed on 54-day-old, however, up to this age, epiphysial nerve was not observed. PMID:27482355

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

    PubMed

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

    2014-01-01

    The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated. Interactions between factors are difficult to separate and any response could be masked due to high inter-individual variation even for individuals that share a common environment. In this study we characterized and quantified the spatio-temporal variation in the gut microbiota of tilapia larvae, reared in recirculating aquaculture systems (RAS) or active suspension tanks (AS). Our results showed that variation in gut microbiota between replicate tanks was not significantly higher than within tank variation, suggesting that there is no tank effect on water and gut microbiota. However, when individuals were reared in replicate RAS, gut microbiota differed significantly. The highest variation was observed between individuals reared in different types of system (RAS vs. AS). Our data suggest that under experimental conditions in which the roles of deterministic and stochastic factors have not been precisely determined, compositional replication of the microbial communities of an ecosystem is not predictable. PMID:25072852

  18. Iodine binding in the endostyle of larvae Branchiostoma lanceolatum (Cephalochordata)

    SciTech Connect

    Fredriksson, G.; Ericson, L.E.; Olsson, R.

    1984-11-01

    The asymmetrical endostyle of Branchiostoma larvae contains two different zones of mucus-producing cells which metamorphose to the paired zones 2 and 4 respectively in the endostyle of the adult. In both the larva and the adult these zones are parts of the food-trapping mechanism. An endostyle zone, which has a position corresponding to that of the paired iodinating zones in the endostyle of the adult, binds iodine selectively. The ultrastructure and labeling pattern indicate that the labeled cells in the larval endostyle belong to functionally different types. In one region of the iodinating zone iodine is mainly bound extracellularly at the apical cell surface. Also in the second region grains are located at the apical cell surface as well as over the cytoplasm and extracellularly at the basal plasma membrane. It is possible that iodination takes place in the lumen close to cells in the first region and that the labeled product is taken up and eventually released by cells of the second region. Our observations show that this primitive endostyle already has iodinating capacity and may synthesize and release thyroid hormones.

  19. Endogenous Dopamine Suppresses Initiation of Swimming in Prefeeding Zebrafish Larvae

    PubMed Central

    Thirumalai, Vatsala; Cline, Hollis T.

    2008-01-01

    Dopamine is a key neuromodulator of locomotory circuits, yet the role that dopamine plays during development of these circuits is less well understood. Here, we describe a suppressive effect of dopamine on swim circuits in larval zebrafish. Zebrafish larvae exhibit marked changes in swimming behavior between 3 days postfertilization (dpf) and 5dpf. We found that swim episodes were fewer and of longer durations at 3 than at 5dpf. At 3dpf, application of dopamine as well as bupropion, a dopamine reuptake blocker, abolished spontaneous fictive swim episodes. Blocking D2 receptors increased frequency of occurrence of episodes and activation of adenylyl cyclase, a downstream target inhibited by D2-receptor signaling, blocked the inhibitory effect of dopamine. Dopamine had no effect on motor neuron firing properties, input impedance, resting membrane potential, or the amplitude of spike afterhyperpolarization. Application of dopamine either to the isolated spinal cord or locally within the cord does not decrease episode frequency, whereas dopamine application to the brain silences episodes, suggesting a supraspinal locus of dopaminergic action. Treating larvae with 10 μM MPTP reduced catecholaminergic innervation in the brain and increased episode frequency. These data indicate that dopamine inhibits the initiation of fictive swimming episodes at 3dpf. We found that at 5dpf, exogenously applied dopamine inhibits swim episodes, yet the dopamine reuptake blocker or the D2-receptor antagonist have no effect on episode frequency. These results led us to propose that endogenous dopamine release transiently suppresses swim circuits in developing zebrafish. PMID:18562547

  20. Zebrafish larvae evade predators by sensing water flow.

    PubMed

    Stewart, William J; Cardenas, Gilberto S; McHenry, Matthew J

    2013-02-01

    The ability of fish to evade predators is central to the ecology and evolution of a diversity of species. However, it is largely unclear how prey fish detect predators in order to initiate their escape. We tested whether larval zebrafish (Danio rerio) sense the flow created by adult predators of the same species. When placed together in a cylindrical arena, we found that larvae were able to escape 70% of predator strikes (mean escape probability P(escape)=0.7, N=13). However, when we pharmacologically ablated the flow-sensitive lateral line system, larvae were rarely capable of escape (mean P(escape)=0.05, N=11). In order to explore the rapid events that facilitate a successful escape, we recorded freely swimming predators and prey using a custom-built camera dolly. This device permitted two-dimensional camera motion to manually track prey and record their escape response with high temporal and spatial resolution. These recordings demonstrated that prey were more than 3 times more likely to evade a suction-feeding predator if they responded before (P(escape)=0.53, N=43), rather than after (P(escape)=0.15, N=13), a predator's mouth opened, which is a highly significant difference. Therefore, flow sensing plays an essential role in predator evasion by facilitating a response prior to a predator's strike. PMID:23325859

  1. Genes expressed in Brugia malayi infective third stage larvae.

    PubMed

    Blaxter, M L; Raghavan, N; Ghosh, I; Guiliano, D; Lu, W; Williams, S A; Slatko, B; Scott, A L

    1996-04-01

    We have used a tag sequencing approach to survey genes expressed in the third stage infective larvae of the human filarial nematode parasite Brugia malayi. RNA was isolated from late vector-stage L3 larvae after days 9 or 10 of infection in mosquitos, and converted to cDNA by reverse transcriptase. Double-stranded cDNA was produced by either conventional methods (non-SL cDNA library) or by PCR using the nematode spliced leader (SLI) and oligo(dT) primers (SL cDNA library). Two clone libraries (one from SL and one from non-SL cDNAs) were constructed in lambda ZapII. A set of these full-length clones was selected and 596 inserts were sequenced from the 5' end. We have identified 364 B. malayi genes (the majority of which are new) that encode housekeeping proteins, structural proteins, proteins of immediate immunological or drug-discovery interest as well as a large class of novel sequences which may prove to have significant involvement in host invasion. Extensive, genome-wide approaches to the analysis of larval gene expression are now possible for B. malayi. We present several examples of this approach. PMID:8784774

  2. The Colonization Dynamics of the Gut Microbiota in Tilapia Larvae

    PubMed Central

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

    2014-01-01

    The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated. Interactions between factors are difficult to separate and any response could be masked due to high inter-individual variation even for individuals that share a common environment. In this study we characterized and quantified the spatio-temporal variation in the gut microbiota of tilapia larvae, reared in recirculating aquaculture systems (RAS) or active suspension tanks (AS). Our results showed that variation in gut microbiota between replicate tanks was not significantly higher than within tank variation, suggesting that there is no tank effect on water and gut microbiota. However, when individuals were reared in replicate RAS, gut microbiota differed significantly. The highest variation was observed between individuals reared in different types of system (RAS vs. AS). Our data suggest that under experimental conditions in which the roles of deterministic and stochastic factors have not been precisely determined, compositional replication of the microbial communities of an ecosystem is not predictable. PMID:25072852

  3. How did indirect development with planktotrophic larvae evolve?

    PubMed

    Nielsen, Claus

    2009-06-01

    The two main types of theories for the evolution of the biphasic life cycles in marine invertebrates are discussed. The "intercalation" theories propose that the larval stages (planktotrophic or lecithotrophic) have evolved as specializations from the ancestral, direct life cycle. The opposing "terminal addition" theories propose that the ancestor was holopelagic and that the adult stage was added to the life cycle with the pelagic stage retained as a planktotrophic larva. It is emphasized that theories based on hypothetical ancestors that were unable to feed must be rejected. This applies to planula theories based on a compact planula. Various arguments against the theories that consider the feeding larvae as ancestral in the major eumetazoan lineages and in particular against the trochaea theory are discussed and found untenable. It is suggested that the "Cambrian explosion" was actually a rapid Ediacaran radiation of the eubilaterians that was made possible by the evolution of a tubular gut with all the resulting possibilities for new body plans. PMID:19556589

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

    PubMed Central

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

    2014-01-01

    The reconstruction of ancient insect ectoparasitism is challenging, mostly because of the extreme scarcity of fossils with obvious ectoparasitic features such as sucking-piercing mouthparts and specialized attachment organs. Here we describe a bizarre fly larva (Diptera), Qiyia jurassica gen. et sp. nov., from the Jurassic of China, that represents a stem group of the tabanomorph family Athericidae. Q. jurassica exhibits adaptations to an aquatic habitat. More importantly, it preserves an unusual combination of features including a thoracic sucker with six radial ridges, unique in insects, piercing-sucking mouthparts for fluid feeding, and crocheted ventral prolegs with upward directed bristles for anchoring and movement while submerged. We demonstrate that Q. jurassica was an aquatic ectoparasitic insect, probably feeding on the blood of salamanders. The finding reveals an extreme morphological specialization of fly larvae, and broadens our understanding of the diversity of ectoparasitism in Mesozoic insects. DOI: http://dx.doi.org/10.7554/eLife.02844.001 PMID:24963142

  5. Toxic activity of Bacillus sphaericus SSII-1 for mosquito larvae.

    PubMed

    Myers, P; Yousten, A A

    1978-03-01

    Using larvae of the mosquito Culex pipiens var. quinquefasciatus as a bioassay system, we have verified an earlier proposal that pathogenicity of Bacillus sphaericus SSII-1 is a toxin-mediated rather than an infectious process. Chloroform or ultraviolet-light treatments that decreased the viable count of SSII-1 cells by 4 or 5 logs did not significantly alter the ability of the bacterial cells to kill larvae. Three lines of evidence indicated that toxic activity was not related to sporulation: (i) cells grown in either a complex or a defined medium were toxic at all ages; (ii) when supplemental Mn2+ was excluded from a complex medium, the culture yielded few spores but was of equal toxicity to a culture containing many spores; and (iii) several early blocked oligosporogenous mutants were isolated that had toxic activities comparable to that of the parent. The toxin was shown to be relatively unstable because activity was destroyed by heat and decreased by refrigeration, a freeze-thaw cycle, or two methods of cell breakage. Thin sections of SSII-1 cells did not reveal the presence of any inclusion body that might be related to toxicity. PMID:640722

  6. Pyrethroid resistance in Aedes aegypti larvae (Diptera: Culicidae) from Singapore.

    PubMed

    Koou, Sin-Ying; Chong, Chee-Seng; Vythilingam, Indra; Ng, Lee-Ching; Lee, Chow-Yang

    2014-01-01

    We report the first comprehensive insecticide susceptibility status ofAedes aegypti (L.) larvae from Singapore. The study indicated that Ae. aegypti is susceptible to temephos, although resistance (RR50 = 1.29-4.43-fold) couldbe developing. Of high concern is the detection of moderate to high resistance to permethrin (RR50 = 29-47-fold) and etofenprox (RR50 = 14-34-fold). Biolarvicide Bacillus thuringiensis israelensis (Bti) remains effective. The insecticide susceptibility profile of Ae. aegypti larvae was found to be homogenous among the different sites studied across the island city. The addition of synergists piperonyl butoxide, S,S,S,-tributyl phosphorotrithioate, and triphenyl phosphate generally failed to enhance the toxicity of the insecticides investigated, suggesting an insignificant role of metabolic-based resistance, and a possible involvement of target site resistance. Further biochemical investigation of specific metabolic enzyme activities suggested that detoxifying enzymes, mono-oxygenases, esterases, glutathione S-transferases, and altered acetylcholinesterases, generally did not contribute to the resistance observed. This study clearly demonstrated that pyrethroid resistance is widespread among Ae. aegypti population and lowered susceptibility to organophosphates is developing. PMID:24605467

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

    PubMed

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

    2014-01-01

    The reconstruction of ancient insect ectoparasitism is challenging, mostly because of the extreme scarcity of fossils with obvious ectoparasitic features such as sucking-piercing mouthparts and specialized attachment organs. Here we describe a bizarre fly larva (Diptera), Qiyia jurassica gen. et sp. nov., from the Jurassic of China, that represents a stem group of the tabanomorph family Athericidae. Q. jurassica exhibits adaptations to an aquatic habitat. More importantly, it preserves an unusual combination of features including a thoracic sucker with six radial ridges, unique in insects, piercing-sucking mouthparts for fluid feeding, and crocheted ventral prolegs with upward directed bristles for anchoring and movement while submerged. We demonstrate that Q. jurassica was an aquatic ectoparasitic insect, probably feeding on the blood of salamanders. The finding reveals an extreme morphological specialization of fly larvae, and broadens our understanding of the diversity of ectoparasitism in Mesozoic insects.DOI: http://dx.doi.org/10.7554/eLife.02844.001. PMID:24963142

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

    SciTech Connect

    Woin, P.; Larsson, P.

    1987-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  10. Phototoxicity of petroleum products to marine invertebrate larvae and niles

    SciTech Connect

    Pelletier, M.C.; Burgess, R.; Ho, K.; Kuhn, A; McKinney, R.; Ryba, S.

    1995-12-31

    Ultraviolet light can activate certain polycyclic aromatic hydrocarbons (PAHs), inducing the production of free radicals. In biological organisms these free radicals destroy tissues, causing up to a 4,000 fold increase in toxicity. This dramatic response is a potential marker for PAH contamination in environmental samples. Ultraviolet enhancement of toxicity has ecological relevance as well. An oil spill can release large amounts of PAHs into the marine environment. Oil spill assessments to date have not included observations of any phototoxic effect on pelagic larvae or juveniles of benthic or epibenthic invertebrates. In this study, larvae and juveniles of the bivalve, Mulinia lateralis and juveniles of the mysid shrimp, Mysidopsis bahia were exposed to individual PAHs, as well as the water accommodated fractions of several petroleum products to verify the ability of this method to detect PAHs in environmental samples, and to determine if phototoxicity is a concern during and after an oil spill. Significant phototoxicity was seen in both single chemical and petroleum product exposures. Swartz`s EPAH model was not applicable to the authors` results. They hoped to show causality but were not fully successful due to the need to further develop the model with their species and expand the number of PAH analyzed.

  11. Multifractal anisotropic swimming: the optimal foraging behaviour of grouper larvae.

    PubMed

    Mahjoub, M S; Dur, G; Souissi, S; Schmitt, F G; Hwang, J S

    2016-05-01

    It was hypothesized that the Malabar grouper Ephinephelus malabaricus larvae have developed search patterns adapted to the distribution of their prey to maximise their net energy intake per unit time. Analysis of the swimming behaviour of E. malabaricus larvae in both the presence and absence of Artemia sp. nauplii is presented to test this hypothesis. A method derived from turbulence studies (the moment function of the displacements) was used to characterize the behaviour. The results revealed that larval swimming pattern was multifractal (intermittent and long-range-correlated) and isotropic (i.e. uniform in all directions) in the presence of prey, but multifractal and anisotropic (i.e. more frequent long displacement on the vertical axis) in the absence of prey. It is suggested that the search behaviour observed in the absence of prey is an adaptive response to prey distribution pattern, which is often characterised by multifractality and anisotropy (i.e. larger patches on the horizontal axes). In the presence of prey, E. malabaricus shifted to intensive search behaviour. Other possible contributors to the observed patterns are discussed. It is concluded that multifractality and anisotropy of swimming patterns observed in the experiment are mainly explained in an optimal foraging theory framework. PMID:27021375

  12. Histomorphogenesis of cranial nerves in Huso huso larvae.

    PubMed

    Tavighi, Sherma; Saadatfar, Zohreh; Shojaei, Bahador; Behnam Rassouli, Morteza

    2016-01-01

    In this study the cranial nerves development of H. huso are explained from 1 to 54-days-old (1, 3, 6, 15, 21 and 54 days). Despite all the researches on fish brain, there are no study on nerves evolution on H. huso during their larvae life. For this research 40 samples of larvae H. huso were obtained (from each age, about six samples were selected). The specimens were maintained in fiberglass tank, then histological samples were taken from tissues and stained with hematoxylin and eosin for general histological studies using light microscope. According to the results, on 1 and 3-days-old, no nerve was observed. The terminal nerve and their dendrites were observed around the nasal cavity and the axons projected to different areas in forebrain especially around olfactory bulb diffusely, on 6-day-old fish. Also, olfactory, optic, oculomotor, trochlear, trigeminal, lateral line and vagus nerves were detected on 6-day-old fish, however two parts of lateral line nerve were separated on 54-day-old. Three nerves, profundus, facial and octaval were observed on 54-day-old, however, up to this age, epiphysial nerve was not observed. PMID:27482355

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

    PubMed

    Handke, Björn; Poernbacher, Ingrid; Goetze, Sandra; Ahrens, Christian H; Omasits, Ulrich; Marty, Florian; Simigdala, Nikiana; Meyer, Imke; Wollscheid, Bernd; Brunner, Erich; Hafen, Ernst; Lehner, Christian F

    2013-01-01

    The co-operation of specialized organ systems in complex multicellular organisms depends on effective chemical communication. Thus, body fluids (like blood, lymph or intraspinal fluid) contain myriads of signaling mediators apart from metabolites. Moreover, these fluids are also of crucial importance for immune and wound responses. Compositional analyses of human body fluids are therefore of paramount diagnostic importance. Further improving their comprehensiveness should increase our understanding of inter-organ communication. In arthropods, which have trachea for gas exchange and an open circulatory system, the single dominating interstitial fluid is the hemolymph. Accordingly, a detailed analysis of hemolymph composition should provide an especially comprehensive picture of chemical communication and defense in animals. Therefore we used an extensive protein fractionation workflow in combination with a discovery-driven proteomic approach to map out the detectable protein composition of hemolymph isolated from Drosophila larvae. Combined mass spectrometric analysis revealed more than 700 proteins extending far beyond the previously known Drosophila hemolymph proteome. Moreover, by comparing hemolymph isolated from either fed or starved larvae, we provide initial provisional insights concerning compositional changes in response to nutritional state. Storage proteins in particular were observed to be strongly reduced by starvation. Our hemolymph proteome catalog provides a rich basis for data mining, as exemplified by our identification of potential novel cytokines, as well as for future quantitative analyses by targeted proteomics. PMID:23840627

  14. An Unprecedented Role Reversal: Ground Beetle Larvae (Coleoptera: Carabidae) Lure Amphibians and Prey upon Them

    PubMed Central

    Wizen, Gil; Gasith, Avital

    2011-01-01

    Amphibians often feed on beetle larvae, including those of ground beetles (Carabidae). Preliminary reports have detailed an unusual trophic interaction in which, in contrast, larvae of the ground beetle Epomis prey upon juvenile and adult amphibians. While it is known that these larvae feed exclusively on amphibians, how the predator-prey encounter occurs to the advantage of the beetle larvae had been unknown to date. Using laboratory observations and controlled experiments, we recorded the feeding behavior of Epomis larvae, as well as the behavior of their amphibian prey. Here we reveal that larvae of two species of Epomis (E. circumscriptus and E. dejeani) lure their potential predator, taking advantage of the amphibian's predation behavior. The Epomis larva combines a sit-and-wait strategy with unique movements of its antennae and mandibles to draw the attention of the amphibian to the presence of a potential prey. The intensity of this enticement increases with decreasing distance between the larva and the amphibian. When the amphibian attacks, the larva almost always manages to avoid the predator's protracted tongue, exploiting the opportunity to attach itself to the amphibian's body and initiate feeding. Our findings suggest that the trophic interaction between Epomis larvae and amphibians is one of the only natural cases of obligatory predator-prey role reversal. Moreover, this interaction involves a small insect larva that successfully lures and preys on a larger vertebrate. Such role reversal is exceptional in the animal world, extending our perspective of co-evolution in the arms race between predator and prey, and suggesting that counterattack defense behavior has evolved into predator-prey role reversal. PMID:21957480

  15. Effects of copper sulfate on ion balance and growth in tilapia larvae (Oreochromis mossambicus).

    PubMed

    Wu, S M; Jong, K J; Kuo, S Y

    2003-10-01

    Newly hatched tilapia larvae were exposed to sublethal concentrations of Cu2+ (0, 30, 50, and 100 microg/L) and lethal concentrations of Cu2+ (200 and 400 microg/L) for 24-96 h. The interaction of the exposure dose and time was related to the Cu2+ accumulation rate, which showed a higher accumulation rate with sublethal concentrations of Cu2+ within 24 h compared to the other treatments. Furthermore, Cu2+ contents in the whole body of larvae significantly increased following Cu2+ exposure times up to 96 h. Cu2+ in the medium produced a dose-response effect on Na+ and K+ contents in larvae after 96 h of exposure time. Changes in Ca2+ contents statistically significantly decreased and were shown to be dose-responsive for larval exposure times exceeding 72 h. Changes of Ca2+ contents were more sensitive than those of Na+ and K+ with Cu2+ treatment of early larvae. Notably Na+ and K+ contents showed significant increases of 17-23% in larvae exposed to low concentrations of Cu2+ (30-50 microg/L) for 24-72 h as compared to control larvae. Cu2+ caused no significant effect on body Cl- content or osmolality except at 100 microg/L Cu2+ for 24 h in tilapia larvae as compared to the control. However, there was a restoration phenomenon in larvae exposed to 100 microg/L Cu2+ for longer than 72 h. The water content of larvae exposed to Cu2+ for 96 h significantly decreased. The yolk absorption rate of tilapia larvae was significantly suppressed when they were exposed to Cu2+ medium containing 30, 50, 100, 200, or 400 Cu2+ microg/L from 72 h post transfer. These results obviously show that larvae are sensitive to Cu2+ during early development. PMID:14674589

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

    PubMed Central

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

    2015-01-01

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

  17. Effects of salinity on striped bass eggs and larvae from the Savannah River, Georgia

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    1994-01-01

    Operation of a tide gate installed in the Savannah River by the U.S. Army Corps of Engineers to reduce dredging activities increased salinities upstream in important spawning habitat for striped bass Morone saxatilis. To assess the effects of salinity on survival and growth of striped bass at early life stages, newly fertilized eggs and 48-h-posthatch were exposed to serial dilutions of seawater, with salinities ranging from 0 to 33 permill (g/L) in increments of 3 permill in addition, older larvae (5-d posthatch) were exposed to salinities of 0, 6, 12, 18, and 24 permill. Eggs were exposed until 24 h posthatch, 48-h-posthatch larvae were exposed for 10 d, and 5-d-posthatch larvae were exposed for 6 d. Eggs died within 24 h in salinities greater than 18 permill. Both survival and total length of larvae hatched from eggs exposed to salinities of 15 permill or higher were reduced. Percent mortality and mean total lengths of newly hatched larvae followed the same pattern for each of three sets of salinity regimes (i.e., changes in salinities over time) that striped bass eggs might encounter during passage downstream in the Savannah River. Hardening eggs in freshwater did not increase survival or length of hatched larvae over that shown by eggs hardened in saline water. The 5-d-posthatch larvae were less sensitive to salinity than the 48-h-posthatch larvae. Survival of larvae was negatively con-elated with both salinity and exposure time. For 48-h-posthatch larvae, the 10-d LC50 (the salinity lethal to 50% of the test fish within 10 d) was 10 permill. Probabilities of survival for larval striped bass exposed to different salinities for different amounts of time can be estimated from curves generated from models of survival analysis. Salinities judged to be critical to Savannah River striped bass eggs and larvae are those greater than 9 permill.

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

    PubMed

    Groba, H F; Castelo, M K

    2016-02-01

    The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system. PMID:26521818

  19. Effect of bodily fluids from honey bee (Apis mellifera) larvae on growth and genome-wide transcriptional response of the causal agent of American Foulbrood disease (Paenibacillus larvae).

    PubMed

    De Smet, Lina; De Koker, Dieter; Hawley, Alyse K; Foster, Leonard J; De Vos, Paul; de Graaf, Dirk C

    2014-01-01

    Paenibacillus larvae, the causal agent of American Foulbrood disease (AFB), affects honey bee health worldwide. The present study investigates the effect of bodily fluids from honey bee larvae on growth velocity and transcription for this Gram-positive, endospore-forming bacterium. It was observed that larval fluids accelerate the growth and lead to higher bacterial densities during stationary phase. The genome-wide transcriptional response of in vitro cultures of P. larvae to larval fluids was studied by microarray technology. Early responses of P. larvae to larval fluids are characterized by a general down-regulation of oligopeptide and sugar transporter genes, as well as by amino acid and carbohydrate metabolic genes, among others. Late responses are dominated by general down-regulation of sporulation genes and up-regulation of phage-related genes. A theoretical mechanism of carbon catabolite repression is discussed. PMID:24586572

  20. Fluorescence in situ hybridization (FISH) analysis of the interactions between honeybee larvae and Paenibacillus larvae, the causative agent of American foulbrood of honeybees (Apis mellifera).

    PubMed

    Yue, Dominique; Nordhoff, Marcel; Wieler, Lothar H; Genersch, Elke

    2008-06-01

    American foulbrood (AFB) is a bacterial disease of honeybee larvae caused by the spore-forming bacterium Paenibacillus larvae. Although AFB and its aetiological agent are described now for more than a century, the general and molecular pathogenesis of this notifiable disease is poorly understood. We used fluorescence in situ hybridization (FISH) performed with P. larvae-specific, 16S rRNA-targeted oligonucleotide probes to analyse the early steps in the pathogenesis of American foulbrood. The following chain of events could be demonstrated: (i) the spores germinate in the midgut lumen, (ii) the vegetative bacteria massively proliferate within the midgut before, and (iii) they start to locally breach the epithelium and invade the haemocoel. The paracellular route was shown to be the main mechanism for invasion contrasting earlier hypotheses of phagocytosis of P. larvae. Invasion coincided with the death of the host implicating that the penetration of the midgut epithelium is a critical step determining the time of death. PMID:18331334

  1. Strain- and genotype-specific differences in virulence of Paenibacillus larvae subsp. larvae, a bacterial pathogen causing American foulbrood disease in honeybees.

    PubMed

    Genersch, Elke; Ashiralieva, Ainura; Fries, Ingemar

    2005-11-01

    Virulence variations of Paenibacillus larvae subsp. larvae, the causative agent of American foulbrood disease of honeybees, were investigated by analysis of 16 field isolates of this pathogen, belonging to three previously characterized genotypes, as well as the type strain (ATCC 9545) of P. larvae subsp. larvae, with exposure bioassays. We demonstrated that the strain-specific 50% lethal concentrations varied within an order of magnitude and that differences in amount of time for the pathogen to kill 100% of the infected hosts (LT100) correlated with genotype. One genotype killed rather quickly, with a mean LT100 of 7.8 +/- 1.7 days postinfection, while the other genotypes acted more slowly, with mean LT100s of 11.2 +/- 0.8 and 11.6 +/- 0.6 days postinfection. PMID:16269801

  2. Strain- and Genotype-Specific Differences in Virulence of Paenibacillus larvae subsp. larvae, a Bacterial Pathogen Causing American Foulbrood Disease in Honeybees

    PubMed Central

    Genersch, Elke; Ashiralieva, Ainura; Fries, Ingemar

    2005-01-01

    Virulence variations of Paenibacillus larvae subsp. larvae, the causative agent of American foulbrood disease of honeybees, were investigated by analysis of 16 field isolates of this pathogen, belonging to three previously characterized genotypes, as well as the type strain (ATCC 9545) of P. larvae subsp. larvae, with exposure bioassays. We demonstrated that the strain-specific 50% lethal concentrations varied within an order of magnitude and that differences in amount of time for the pathogen to kill 100% of the infected hosts (LT100) correlated with genotype. One genotype killed rather quickly, with a mean LT100 of 7.8 ± 1.7 days postinfection, while the other genotypes acted more slowly, with mean LT100s of 11.2 ± 0.8 and 11.6 ± 0.6 days postinfection. PMID:16269801

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

    PubMed

    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. PMID:26634825

  4. Behavior of codling moth (Lepidoptera: Tortricidae)neonate larvae on surfaces treated with microencapsulated pear ester

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Codling moth (CM), Cydia pomonella, larvae cause severe damage apples, pears and walnuts worldwide by internal feeding and the introduction of molds and spoilage micro-organisms. CM neonate larvae are attracted to and arrested by a pear-derived kairomone, ethyl (2E,4Z)-2,4-decadienoate, the “pear es...

  5. Microarray analysis reveals strategies of Tribolium castaneum larvae to compensate for cysteine and serine protease inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microarrays containing Tribolium castaneum whole-genome sequences were developed to study the transcriptome response of T. castaneum larvae to dietary protease inhibitors. In larvae fed diets containing 0.1% of the cysteine protease inhibitor E-64 alone or in combination with 5.0% of the serine pro...

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

    PubMed

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

    2014-01-01

    The larva of Tricholeon relictus, a Spanish endemic antlion of Afrotropical affinities, is described and illustrated for the first time also providing a comparison with the only other European member of the tribe Dendroleontini, Dendroleon pantherinus. The larva of this species is synanthropic but probably originally lived in cave-like habitats. PMID:25081458

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

    PubMed

    Chen, Ming-Shun; Liu, Sanzhen; Wang, Haiyan; Cheng, Xiaoyan; El Bouhssini, Mustapha; Whitworth, R Jeff

    2016-01-01

    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 1(st) 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. PMID:27529231

  8. Estimating reproductive success of Aethina tumida (Coleoptera: Nitidulidae) in honey bee colonies by trapping emigrating larvae.

    PubMed

    Arbogast, Richard T; Torto, Baldwyn; Willms, Steve; Fombong, Ayuka T; Duehl, Adrian; Teal, Peter E A

    2012-02-01

    The small hive beetle (Aethina tumida Murray) is a scavenger and facultative predator in honey bee colonies, where it feeds on pollen, honey, and bee brood. Although a minor problem in its native Africa, it is an invasive pest of honey bees in the United States and Australia. Adult beetles enter bee hives to oviposit and feed. Larval development occurs within the hive, but mature larvae leave the hive to pupate in soil. The numbers leaving, which can be estimated by trapping, measure the reproductive success of adult beetles in the hive over any given period of time. We describe a trap designed to intercept mature larvae as they reach the end of the bottom board on their way to the ground. Trap efficiency was estimated by releasing groups of 100 larvae into empty brood boxes and counting the numbers trapped. Some larvae escaped, but mean efficiency ranged from 87.2 to 94.2%. We envision the trap as a research tool for study of beetle population dynamics, and we used it to track numbers of larvae leaving active hives for pupation in the soil. The traps detected large increases and then decreases in numbers of larvae leaving colonies that weakened and died. They also detected small numbers of larvae leaving strong European and African colonies, even when no larvae were observed in the hives. PMID:22525070

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

    SciTech Connect

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

    1987-02-01

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

  10. Comparison of in vitro methods for the production of Paenibacillus larvae endospores.

    PubMed

    Alvarado, Israel; Elekonich, Michelle M; Abel-Santos, Ernesto; Wing, Helen J

    2015-09-01

    Paenibacillus larvae endospores are the infectious particles of the honey bee brood disease, American Foulbrood. We demonstrate that our previously published protocol (Alvarado et al., 2013) consistently yields higher numbers and purer preparations of P. larvae endospores, than previously described protocols, regardless of the strain tested (B-3650, B-3554 or B-3685). PMID:26130193

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

    Alves, Ariana Vieira; Sanjinez Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq.) Lodd. Ex Mart., 1845), which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%), with percentage higher than the bocaiuva kernels (14.21%). The larval lipid content (37.87%) was also high, very close to the kernels (44.96%). The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel. PMID:27031500

  14. Bivalve and barnacle larvae distribution driven by water temperature in a Mediterranean lagoon.

    PubMed

    Ziadi, Boutheina; Dhib, Amel; Turki, Souad; Aleya, Lotfi

    2015-05-01

    The objective of this study was to explore the relationships between the distribution of some meroplanktonic species and water temperature. Meroplankton larvae abundance of bivalves, and barnacles and water temperature fluctuations were studied from February 2011 to January 2012 at five stations in Ghar El Melh lagoon (GML) Mediterranean Sea, northern Tunisia). According to redundancy analysis (RDA), a significant difference was found in the distribution of larvae among the seasons (F = 10.28, p < 0.001); summer and autumn appear to be the period of bivalve larvae development, whereas the arrival of barnacle larvae coincided with winter and spring. The generalized additive models (GAMs) show strong correlation of bivalve larvae with high temperature (F = 23.2; p < 0.001) and the affinity of barnacle larvae to low temperature values (F = 8.41; p = 0.004). This environmental parameter accounted for 26 % of the deviance in variability in larvae abundance. The development process of many generations of larvae may therefore have been predetermined by temperature. PMID:25483975

  15. The potential for cryopreserving larvae of the sea urchin, Evechinus chloroticus.

    PubMed

    Adams, Serean L; Hessian, Paul A; Mladenov, Philip V

    2006-02-01

    Larvae of the sea urchin, Evechinus chloroticus, at varying stages of development, were assessed for their potential to survive cryopreservation. Ethylene glycol (EG) and dimethyl sulphoxide (Me2SO), at concentrations of 1-2 M, were evaluated as cryoprotectants (CPAs) in freezing regimes initially based on methods established for freezing larvae of other sea urchin species. Subsequent work varied cooling rate, holding temperature, holding time, and plunge temperature. Ethylene glycol was less toxic to larvae than Me2SO. However, no larvae survived freezing and thawing in EG. Larvae frozen in Me2SO at the gastrula stage and 4-armed pluteus stage regained motility post-thawing. The most successful freezing regime cooled straws containing larvae in 1.5 M Me2SO from 0 to -35 degrees C at 2.5 degrees C min(-1), held at -35 degrees C for 5 min, then plunged straws into liquid nitrogen. Motility was high 2-4 h post-thawing using this regime but decreased markedly within 24 h. Some 4-armed pluteus larvae that survived beyond this time developed through to metamorphosis and settled. Different Me2SO concentrations and supplementary trehalose did not improve long-term survival. Large variation in post-thaw survival was observed among batches of larvae produced from different females. PMID:16321369

  16. Chemically mediated group formation in soil-dwelling larvae and pupae of the beetle Trypoxylus dichotomus

    NASA Astrophysics Data System (ADS)

    Kojima, Wataru; Ishikawa, Yukio; Takanashi, Takuma

    2014-09-01

    Many insects form groups through interactions among individuals, and these are often mediated by chemical, acoustic, or visual cues and signals. In spite of the diversity of soil-dwelling insects, their aggregation behaviour has not been examined as extensively as that of aboveground species. We investigated the aggregation mechanisms of larvae of the Japanese rhinoceros beetle Trypoxylus dichotomus, which live in groups in humus soil. In two-choice laboratory tests, 2nd- and 3rd-instar larvae gathered at conspecific larvae irrespective of the kinship. The ablation of maxillae, which bear chemosensilla, abolished aggregation behaviour. Intact larvae also exhibited aggregation behaviour towards a larval homogenate. These results suggest that larval aggregation is mediated by chemical cues. We also demonstrated that the mature larvae of T. dichotomus built their pupal cells close to a mesh bag containing a conspecific pupal cell, which indicated that larvae utilize chemical cues emanating from these cells to select the pupation site. Thus, the larvae of T. dichotomus may use chemical cues from the conspecifics in two different contexts, i.e. larval aggregation and pupation site selection. Using conspecific cues, larvae may be able to choose suitable locations for foraging or building pupal cells. The results of the present study highlight the importance of chemical information in belowground ecology.

  17. Notes on the first instar larvae of Ctenophora and Nephrotoma (Diptera, Tipulidae).

    PubMed

    Podeniene, Virginija; Naseviciene, Nijole; Podenas, Sigitas

    2014-01-01

    1830 egg-larvae of 7 species belonging to long palped crane flies (Tipulidae): Ctenophora guttata Meigen, Nephrotoma pratensis Linnaeus, N. dorsalis Fabricius, N. scurra Meigen, N. flavescens Linnaeus, N. submaculosa Edwards and N. crocata Linnaeus were obtained from 22 females captured in Lithuania in 2011-2012. It took from five days to more than three weeks for eggs to hatch. Crane flies have four instars of larvae. Second, third and the last instar larvae are very similar, when the first instar or egg-larvae differs radically. Descriptions and illustrations of external morphology, chaetotaxy of abdominal segments, characters of head capsules and last abdominal segments are given for the previously unknown first instar larvae of Ct. guttata, N. crocata, N. dorsalis, N. flavescens, N. pratensis, N. scurra and poorly known N. submaculosa. It was found out that difference of head capsule and last abdominal segment among the first instar larvae of above mentioned species of genus Nephrotoma are more obvious than in last instar. During this study it was found, that such characters as shape of apical teeth of mandible, shape of basal segment of antenna and number of sensillae, shape of hypostomium and arrangement of sensory structures on labrum, differ among egg-larvae of Nephrotoma. It was found, that pads on frontal part of prothorax and shape of lateral plates of egg-larvae labrum of Nephrotoma differ significantly from that of Ctenophora and could be used as genus separating characters.  PMID:24870629

  18. Proteome analysis of Paenibacillus larvae reveals the existence of a putative S-layer protein.

    PubMed

    Fünfhaus, Anne; Genersch, Elke

    2012-04-01

    Honey bee pathology has attracted much interest recently due to the problems with honey bee declines in many regions of the world. American Foulbrood (AFB) caused by Paenibacillus larvae is the most devastating bacterial brood disease of the Western honey bee (Apis mellifera) causing considerable economic losses to beekeepers worldwide. AFB outbreaks are mainly caused by two differentially virulent genotypes of P. larvae, P. larvae ERIC I and ERIC II. To better understand AFB pathogenesis and to complement already existing data from the genetic level we aimed at obtaining expression data from the protein level. We successfully developed a protocol for two-dimensional proteome analysis of P. larvae with subsequent mass-spectrometry based protein sequencing. Based on the obtained master protein maps of P. larvae genotypes ERIC I and II we identified the dominantly expressed cytosolic proteins of both genotypes, some of them presumably linked to pathogenesis and virulence. Comparing the master maps of both genotypes revealed differentially expressed proteins, i.e. a putative S-layer protein which is expressed by P. larvae ERIC II but absent from the proteome of P. larvae ERIC I. The implications of our findings for pathogenesis of AFB and virulence of P. larvae will be discussed. PMID:23757273

  19. AN EXAMINATION OF DIFFERENT STOCKING DENSITIES OF SUNSHINE BASS LARVAE REARED IN TANKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to be cost effective, conditions for tank culture must be optimized. This experiment attempted to determine the relationship among stocking density of sunshine bass larvae in tanks and growth and survival. Sunshine bass larvae, 4 days post hatch (dph), were stocked into blue, polyethylen...

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

    PubMed

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

    2012-08-01

    Honey bee (Apis mellifera) larvae reared in vitro were exposed to one of nine pesticides and/or were challenged with the parasitic mite, Varroa destructor. Total RNA was extracted from individual larvae and first strand cDNAs were generated. Gene-expression changes in larvae were measured using quantitative PCR (qPCR) targeting transcripts for pathogens and genes involved in physiological processes, bee health, immunity, and/or xenobiotic detoxification. Transcript levels for Peptidoglycan Recognition Protein (PGRPSC), a pathogen recognition gene, increased in larvae exposed to Varroa mites (P<0.001) and were not changed in pesticide treated larvae. As expected, Varroa-parasitized brood had higher transcripts of Deformed Wing Virus than did control larvae (P<0.001). Varroa parasitism, arguably coupled with virus infection, resulted in significantly higher transcript abundances for the antimicrobial peptides abaecin, hymenoptaecin, and defensin1. Transcript levels for Prophenoloxidase-activating enzyme (PPOact), an immune end product, were elevated in larvae treated with myclobutanil and chlorothalonil (both are fungicides) (P<0.001). Transcript levels for Hexameric storage protein (Hsp70) were significantly upregulated in imidacloprid, fluvalinate, coumaphos, myclobutanil, and amitraz treated larvae. Definitive impacts of pesticides and Varroa parasitism on honey bee larval gene expression were demonstrated. Interactions between larval treatments and gene expression for the targeted genes are discussed. PMID:22497859

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

    PubMed Central

    Chen, Ming-Shun; Liu, Sanzhen; Wang, Haiyan; Cheng, Xiaoyan; El Bouhssini, Mustapha; Whitworth, R. Jeff

    2016-01-01

    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. PMID:27529231

  2. Neuropathological observation of rabbits (Oryctolagus cuniculus) affected with raccoon roundworm (Baylisascaris procyonis) larva migrans in Japan.

    PubMed

    Furuoka, Hidefumi; Sato, Hiroshi; Kubo, Midori; Owaki, Shigeo; Kobayashi, Yoshiyasu; Matsui, Takane; Kamiya, Haruo

    2003-06-01

    Larvae of the raccoon roundworm, Baylisascaris procyonis (B. procyonis) are a known cause of cerebrospinal larva migrans in animals and humans. The present paper described details of the central nervous lesion in the rabbits (Oryctolagus cuniculus) affected with B. procyonis larva migrans in Japan. Clinically affected animals showed neurological signs including circling, torticollis, tremor of head, or ataxic gait. The most characteristic pathological alterations were large malacic lesions associated with an activated astroglial proliferation which was seen at the corpus medullare in the cerebellum including the cerebellar peduncle. Moreover, focal malacic lesions with perivascular cuffing and infiltration by lymphocytes and heterophiles were scattered everywhere throughout the brain. In these lesions or normal-appearing areas away from obvious lesions, ascarid larvae, about a maximum 65-75 micro m in diameter, were recognized. Other prominent features were minute lesions (we call them migration tract-like lesions) composed of lymphocytes, hemosiderin-laden macrophages and reactive astrocytes scattering throughout the cerebrum. In this study, we demonstrated ascarid larvae in only eight out of 23 animals diagnosed as B. procyonis larva migrans. Since it is not always possible to detect the larvae, the possibility of B. procyonis larva migrans must be given serious consideration to the characteristic lesions described above. PMID:12867729

  3. Larvae of North American Eukiefferiella and Tvetenia (Diptera: Chironomidae). Bulletin No. 452.

    ERIC Educational Resources Information Center

    Bode, Robert W.

    "Eukiefferiella" and "Tvetenia" are closely related genera belonging to the subfamily Orthocladiinae within the Chironomidae, a family of non-biting midges. All known larvae in these genera are aquatic, being found predominantly in running water. Most species prefer cold, swift-flowing, well-oxygenated streams. Although larvae and pupae of these…

  4. Effects of Cucurbitacin on the Activity of Nucleopolyhedroviruses against Pickleworm Larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cucurbitacin-containing feeding stimulant (Invite® EC) was attractive to second instar pickleworm larvae in the absence of a food source. Second instar pickleworm larvae also fed preferentially on cucumber fruits that were treated with a 1% (0.01X) solution of Invite EC. However, 1% Invite did...

  5. The intestinal bacterial community in the food waste-reducing larvae of Hermetia illucens.

    PubMed

    Jeon, Hyunbum; Park, Soyoung; Choi, Jiyoung; Jeong, Gilsang; Lee, Sang-Beom; Choi, Youngcheol; Lee, Sung-Jae

    2011-05-01

    As it is known that food waste can be reduced by the larvae of Hermetia illucens (Black soldier fly, BSF), the scientific and commercial value of BSF larvae has increased recently. We hypothesised that the ability of catabolic degradation by BSF larvae might be due to intestinal microorganisms. Herein, we analysed the bacterial communities in the gut of BSF larvae by pyrosequencing of extracting intestinal metagenomic DNA from larvae that had been fed three different diets. The 16S rRNA sequencing results produced 9737, 9723 and 5985 PCR products from larval samples fed food waste, cooked rice and calf forage, respectively. A BLAST search using the EzTaxon program showed that the bacterial community in the gut of larvae fed three different diets was mainly composed of the four phyla with dissimilar proportions. Although the composition of the bacterial communities depended on the different nutrient sources, the identified bacterial strains in the gut of BSF larvae represented unique bacterial species that were unlike the intestinal microflora of other insects. Thus, our study analysed the structure of the bacterial communities in the gut of BSF larvae after three different feedings and assessed the application of particular bacteria for the efficient degradation of organic compounds. PMID:21267722

  6. Black soldier fly (Diptera: Stratiomyidae) larvae reduce Escherichia coli in dairy manure.

    PubMed

    Liu, Qiaolin; Tomberlin, Jeffery K; Brady, Jeff A; Sanford, Michelle R; Yu, Ziniu

    2008-12-01

    Escherichia coli labeled with a green fluorescent protein was inoculated into sterile dairy manure at 7.0 log cfu/g. Approximately 125 black soldier fly larvae were placed in manure inoculated and homogenized with E. coli. Manure inoculated with E. coli but without black soldier fly larvae served as the control. For the first experiment, larvae were introduced into 50, 75, 100, or 125 g sterilized dairy manure inoculated and homogenized with E. coli and stored 72 h at 27 degrees C. Black soldier fly larvae significantly reduced E. coli counts in all treatments. However, varying the amount of manure provided the black soldier fly larvae significantly affected their weight gain and their ability to reduce E. coli populations present. For the second experiment, larvae were introduced into 50 g manure inoculated with E. coli and stored for 72 h at 23, 27, 31, or 35 degrees C. Minimal bacterial growth was recorded in the control held at 35 degrees C and was excluded from the analysis. Black soldier fly larvae significantly reduced E. coli counts in manure held at remaining temperatures. Accordingly, temperature significantly influenced the ability of black soldier fly larvae to develop and reduce E. coli counts with greatest suppression occurring at 27 degrees C. PMID:19161696

  7. Species Composition of Cutworm Larvae (Lepidoptera: Noctuidae) in South Central Washington Vineyards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major grape growing areas of Washington were surveyed during 2003-2007 to determine the cutworm species present as larvae in vineyards during spring. We sampled vineyard floors, vines at night, and vines during the day. A total of 1,003 larvae was collected and 650 were reared to adults and iden...

  8. PHOTOINDUCED TOXICITY OF FLUORANTHENE TO LARVAE OF THE LEOPARD FROG (RANA PIPENS)

    EPA Science Inventory

    Rana pipiens larvae (96-118 hr old) were exposed to in a flow-through diluter system to five concentrations of fluoranthene for 48 hr. Following the uptake period the exposed larvae were divided into three groups: one for tissue residue analysis, a second for residue analysis fo...

  9. Description of larvae of the Feather Blenny, Hypsoblennius hentz (Pisces: Blenniidae), from New York Waters.

    PubMed

    Schmidt, Robert E; Moccio, Paul A

    2013-01-01

    Hypsoblennius hentz (Lesueur) larvae are described from specimens recently collected in the vicinity of New York Harbor and Raritan Bay. Previous descriptions (Hildebrand and Cable 1938) were erroneous and additionally we provide the first yolk-sac larval descriptions for Western Atlantic Hypsoblennius. H. hentz larvae are distinguished from the other Atlantic species by the size and distribution of preopercular spines. PMID:26213782

  10. Larvae of two East-Asian species of Nemoura (Plecoptera: Nemouridae).

    PubMed

    Teslenko, Valentina A

    2016-01-01

    Associated larvae of the two East-Asian Nemoura species, N. papilla Okamoto and N. ussuriensis Zhiltzova are described and illustrated in detail for the first time. The main diagnostic features of late instar larvae of both species are color and pigment patterns, the chaetotaxy of the pronotum, legs, abdomen, and cercal segments. PMID:27615981

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet root maggots (Tetanops myopaeformis), as third-instar larvae have been successfully maintained in cold (6 ± 1ºC) storage for up to six years. To test the hypothesis that this long term survival in storage is facilitated by larvae undergoing prolonged diapause, comparative studies on respir...

  12. Internal Lipids of Sugarbeet Root Maggot (Tetanops myopaeformis) Larvae: Effects of Multi-year Cold Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet root maggots, Tetanops myopaeformis (Röder), survive more than five years of laboratory cold (6oC) storage as mature third-instar larvae. To quantify energy costs associated with prolonged storage, internal lipids of larvae stored for 1, 2, 3, and 5 years were compared and characterized wi...

  13. Virulent Hessian Fly Larvae Manipulate the Free Amino Acid Content Of Host Wheat Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virulent Hessian fly larvae induce their host wheat plants to provide a favorable environment for larval development by altering plant gene expression and promoting the formation of nutritive tissue at larval feeding sites. To determine whether Hessian fly larvae manipulate the nutrient content of t...

  14. CHARACTERIZATION OF LOCOMOTOR ACTIVITY OF ZEBRAFISH LARVAE: TEMPORAL VARIABILITY AND PHOTORESPONSE.

    EPA Science Inventory

    As part of EPA’s effort to develop a rapid, in vivo, vertebrate screen for toxic chemicals, we have begun research to characterize the locomotor activity of 6-day post-fertilization (dpf) zebrafish (Danio rerio) larvae. Larvae were individually housed and tested in 96-well micro...

  15. Contest-Behavior of Maize Weevil Larvae when Competing within Seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food limitation induces severe competition for obligate seed-feeding insect larvae that are unable to leave the seed selected by their mother. The number of eggs laid per seed and the number of larvae hatched from the eggs determine whether larval behavior within the seed will be of the scramble or ...

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

    PubMed

    Alves, Ariana Vieira; Sanjinez Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq.) Lodd. Ex Mart., 1845), which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%), with percentage higher than the bocaiuva kernels (14.21%). The larval lipid content (37.87%) was also high, very close to the kernels (44.96%). The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel. PMID:27031500

  17. GROWTH AND SURVIVAL OF SUNSHINE BASS LARVAE STOCKED IN TANKS AT DIFFERENT DENSITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to be cost effective, conditions for tank culture must be optimized. This experiment attempted to determine the relationship among stocking density of sunshine bass larvae in tanks and growth and survival. Sunshine bass larvae, 4 days post hatch (dph), were stocked into blue, polyethylen...

  18. Protocols to test the activity of antimicrobial peptides against the honey bee pathogen Paenibacillus larvae.

    PubMed

    Khilnani, Jasmin C; Wing, Helen J

    2015-10-01

    Paenibacillus larvae is the causal agent of the honey bee disease American Foulbrood. Two enhanced protocols that allow the activity of antimicrobial peptides to be tested against P. larvae are presented. Proof of principle experiments demonstrate that the honey bee antimicrobial peptide defensin 1 is active in both assays. PMID:26210039

  19. Molecular endocrine changes of Gh/Igf1 axis in gilthead sea bream (Sparus aurata L.) exposed to different environmental salinities during larvae to post-larvae stages.

    PubMed

    Mohammed-Geba, Khaled; Yúfera, Manuel; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-08-01

    The influence of acclimation of the euryhaline gilthead sea bream (Sparus aurata) larvae/post-larvae to brackish water on growth, energetic contents, and mRNA levels of selected hormones and growth-regulating hypothalamic neurohormones was assessed. Specimens from 49 days post-hatching were acclimated during 28 days to two different environmental salinities: 38 and 20 psu (as brackish water). Both groups were then transferred to 38 psu and acclimated for an additional week. Early juveniles were sampled after 28 days of acclimation to both salinities and one week after transfer to 38 psu. Pituitary adenylate cyclase-activating peptide (adcyap1; pacap), somatostatin-I (sst1), growth hormone (gh1), insulin-like growth factor-I (igf1), and prolactin (prl) mRNA expression were all studied by QPCR. Post-larvae acclimated to 20 psu showed better growth performance and body energetic content than post-larvae maintained at 38 psu. prl, adcyap1, and igf1 mRNA expression levels increased in 20-psu-acclimated post-larvae but decreased upon transfer to 38 psu. GH1 expression did not show significant changes under both experimental conditions. Our results suggested an enhanced general performance for post-larvae in brackish water, supported by the actions of adcyap1, igf1, and prl. PMID:26947706

  20. Larvae of gryporhynchid cestodes (Cyclophyllidea) from fish: a review.

    PubMed

    Scholz, Tomás; Bray, Rodney A; Kuchta, Roman; Repová, Radmila

    2004-06-01

    Larvae (metacestodes) of tapeworms of the cyclophyllidean family Gryporhynchidae (previously included in the Dilepididae) occur in different internal organs of fresh- and brackish water fish (110 fish species of 27 families in 12 orders reported), which serve as the second intermediate hosts. The species composition, spectrum of fish hosts, sites of infection, and geographical distribution of gryporhynchids recorded from fish are reviewed here on the basis of literary data and examination of extensive material from helminthological collections. Metacestodes of the following genera have been found in fish: Amirthalingamia Bray, 1974 (1 species), Ascodilepis Guildal, 1960 (1), Cyclustera Fuhrmann, 1901 (4), Dendrouterina Fuhrmann, 1912 (1), Glossocercus Chandler, 1935 (3), Neogryporhynchus Baer et Bona, 1960 (1), Paradilepis Hsü, 1935 (5), Parvitaenia Burt, 1940 (2), and Valipora Linton, 1927 (3). However, most published records concern only three species, namely Neogryporhynchus cheilancristrotus (Wedl, 1855) from the intestinal lumen, Paradilepis scolecina (Rudolphi, 1819) from the liver and mesenteries, and Valipora campylancristrota (Wedl, 1855) from the gall bladder of cyprinids and other fish in the Palaearctic Region. Data on other species as well as reports from other regions are very scarce and almost no information is available from Australia, tropical Asia and South America. A recent study of gryporhynchid metacestodes from Mexico (Scholz and Salgado-Maldonado 2001), which reported 13 species, suggested that they may be more common than indicated by records in the literature. Although only a few cases of pathogenic influence of larvae on fish hosts have been reported, the veterinary importance of gryporhynchids remains to be assessed on the basis of more detailed studies. The data available indicate a strict host and site specificity of some species whereas others occur in a wide spectrum of fish hosts and are not strictly site-specific. Evaluation of

  1. A Study of Krebs Citric Acid Cycle Enzymes in Rice Larvae (Corcyrace phalonica St) During Mycotoxicosis

    PubMed Central

    Hegde, Umashashi C.; Shanmugasundaram, E. R. B.

    1967-01-01

    Krebs citric acid cycle enzymes have been studied in rice moth larvae (Corcyra cephalonica St) reared in groundnut meal control and contaminated with A. flavus, wheat bran control and wheat bran contaminated with A. flavus and also wheat bran containing aflatoxin. It was observed that the activity of enzymes other than succinic oxidase, succinic dehydrogenase and isocitric dehydrogenase were reduced significantly in larvae reared in contaminated groundnut meal when compared with the control. In the case of larvae reared in contaminated wheat bran all the enzymes except succinic oxidase were inhibited when compared to the control larvae. It was also observed that the inhibition of these enzymes is greater in the case of larvae reared in contaminated wheat bran than in contaminated groundnut meal. The higher toxicity of wheat bran has been discussed. PMID:4229935

  2. Effects of pesticides on DNA and protein of shrimp larvae Litopenaeus stylirostris of the California Gulf.

    PubMed

    Galindo Reyes, J Guillermo; Leyva, Nancy R; Millan, Olivia A; Lazcano, Guadalupe A

    2002-10-01

    Recently, diverse pathologies and massive mortalities have been presented in shrimp hatcheries located along the California Gulf; therefore, toxic responses of shrimp larvae were used as biomarkers of pesticide pollution, because in this region intensive agriculture is practiced. Shrimp larvae were exposed to DDT, azinphosmethyl, permethrine, parathion, chlorpyrifos, malathion, endosulfan, and carbaryl, in order to determine LC50, DNA adducts and/or breaks, and total protein in larvae. The results indicate reductions in protein and DNA in larvae exposed to these pesticides, and in those exposed to DDT, breaks and/or adducts were registered. It is possible that pesticide pollution is a cause of these problems, because reduction in protein indicates a decrease in larvae growth rate and DNA breaks or adducts have been related to pathologies and carcinogenesis in many aquatic organisms. PMID:12568452

  3. Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults

    PubMed Central

    Ahmad, Muhammad; Chaudhary, Safee Ullah; Afzal, Ahmed Jawaad; Tariq, Muhammad

    2015-01-01

    Drosophila melanogaster larvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism in Drosophila larvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed, Drosophila melanogaster larvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, including Musca domestica, Apis mellifera, and Lycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressed Drosophila show distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous. PMID:26399327

  4. Excision of furuncular myiasis larvae using a punch: a simple, practical and aesthetic method*

    PubMed Central

    Pascoal, Gianne; de Oliveira, Fernanda Queiroz; Siqueira, Rosana Rocon; Lopes, Maria Gabriela Araújo; Martins Neto, Marcelino Pereira; Gamonal, Aloísio Carlos Couri

    2016-01-01

    Myiasis refers to Diptera larvae infesting vertebrate animals. There are two forms of the disease: primary and secondary. In primary myiasis, fly larvae invade and develop in healthy tissue; in secondary myiasis, flies lay their eggs in skin ulcerations, and the larvae develop in tissue necrosis products. Furuncular myiasis is a type of primary myiasis. Treatment for it consists of techniques such as the production of localized hypoxia to force the emergence of the larvae, and mechanical or surgical removal of the maggots. These techniques, however, are painful and often unsuccessful. We propose a new technique for extraction of myiasis larvae, which might facilitate the surgical procedure and constitute a virtually painless and aesthetic option for the patient.

  5. Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 2. Larvae.

    PubMed

    Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; Schmitter-Soto, J J; González-Solís, D

    1995-01-01

    This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts. PMID:8774773

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

    NASA Technical Reports Server (NTRS)

    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. Redescription of late-instar larva of Scydmoraphes sparshalli (Denny) Coleoptera: Staphylinidae, Scydmaeninae).

    PubMed

    Jałoszyński, Paweł

    2015-01-01

    The larva of Scydmoraphes sparshalli is redescribed. This is the first complete description of an immature Scydmoraphes with special focus on the chaetotaxic characters. The larva is unique among Cyrtoscydmini in having three pairs of stemmata, a very long sensory appendage of the antennomere II, mandibles with mesal row of microserrations interrupted by smooth portion of mandibular margin; maxillary mala with asetose apex and a row of very long, modified setae on mesal margin, and extremely elongate maxillary palpomere III and labium. A comparative study of previous descriptions resulted in recognizing a misidentification of a Scydmoraphes larva (the "Typ 2-Larve" of Schmid) as a putative Neuraphes (Pararaphes). The serial homology of chaetotaxic structures in the larva of Scydmoraphes sparshalli is discussed, and comparative notes on the larvae of Scydmoraphes, Neuraphes and Stenichnus are given, with an identification key. PMID:26624387

  8. Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults.

    PubMed

    Ahmad, Muhammad; Chaudhary, Safee Ullah; Afzal, Ahmed Jawaad; Tariq, Muhammad

    2015-01-01

    Drosophila melanogaster larvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism in Drosophila larvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed, Drosophila melanogaster larvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, including Musca domestica, Apis mellifera, and Lycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressed Drosophila show distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous. PMID:26399327

  9. Closed loop tracked Doppler optical coherence tomography based heart monitor for the Drosophila melanogaster larvae.

    PubMed

    Zurauskas, Mantas; Bradu, Adrian; Ferguson, Daniel R; Hammer, Daniel X; Podoleanu, Adrian

    2016-03-01

    This paper presents a novel instrument for biosciences, useful for studies of moving embryos. A dual sequential imaging/measurement channel is assembled via a closed-loop tracking architecture. The dual channel system can operate in two regimes: (i) single-point Doppler signal monitoring or (ii) fast 3-D swept source OCT imaging. The system is demonstrated for characterizing cardiac dynamics in Drosophila melanogaster larva. Closed loop tracking enables long term in vivo monitoring of the larvae heart without anesthetic or physical restraint. Such an instrument can be used to measure subtle variations in the cardiac behavior otherwise obscured by the larvae movements. A fruit fly larva (top) was continuously tracked for continuous remote monitoring. A heartbeat trace of freely moving larva (bottom) was obtained by a low coherence interferometry based doppler sensing technique. PMID:25924107

  10. Influence of Low Temperature on Rate of Development of Meloidogyne incognita and M. hapla Larvae

    PubMed Central

    Vrain, T. C.; Barker, K. R.; Holtzman, G. I.

    1978-01-01

    Development of Meloidogyne incognita and M. hapla larvae in clover roots was studied at 20, 16, 12, and 8 C in growth chambers and in the field from fall through spring, in North Carolina. Larvae of both species invaded roots and developed at 20, 16, and 12 C, but not at 8 C. The time necessary to complete the larval stages at each temperature was determined. The minimal temperature for development of M. incognita larvae was 10.08 C and 8.8 C for M. hapla larvae. In the field, soil temperature at 10 cm deep was favorable for development of larvae until the end of November, and again from February on. All stages of the nematodes survived freezing temperatures in the roots. Reproduction of both species was evident in March or Apri1 after inoculation and accumulation of 8,500 to 11,250 degree-hours. PMID:19305832

  11. Influence of low temperature on rate of development of Meloidogyne incognita and M. hapla larvae.

    PubMed

    Vrain, T C; Barker, K R; Holtzman, G I

    1978-04-01

    Development of Meloidogyne incognita and M. hapla larvae in clover roots was studied at 20, 16, 12, and 8 C in growth chambers and in the field from fall through spring, in North Carolina. Larvae of both species invaded roots and developed at 20, 16, and 12 C, but not at 8 C. The time necessary to complete the larval stages at each temperature was determined. The minimal temperature for development of M. incognita larvae was 10.08 C and 8.8 C for M. hapla larvae. In the field, soil temperature at 10 cm deep was favorable for development of larvae until the end of November, and again from February on. All stages of the nematodes survived freezing temperatures in the roots. Reproduction of both species was evident in March or Apri1 after inoculation and accumulation of 8,500 to 11,250 degree-hours. PMID:19305832

  12. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other... and Hypoderma bovis), or external parasites, or affected with other pathological skin conditions....

  13. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other... and Hypoderma bovis), or external parasites, or affected with other pathological skin conditions....

  14. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other... and Hypoderma bovis), or external parasites, or affected with other pathological skin conditions....

  15. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other... and Hypoderma bovis), or external parasites, or affected with other pathological skin conditions....

  16. 9 CFR 310.10 - Carcasses with skin or hide on; cleaning before evisceration; removal of larvae of Hypodermae...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other pathological... on; cleaning before evisceration; removal of larvae of Hypodermae, external parasites and other... and Hypoderma bovis), or external parasites, or affected with other pathological skin conditions....

  17. Can small rare prey be chemically defended? The case for marine larvae

    SciTech Connect

    Lindquist, N.; Hay, M.E.

    1995-06-01

    Marine larvae are consumed by a wide variety of generalist fishes and particle-feeding invertebrates, but larvae of any particular species probably constitute a small and variable portion of the diet for these consumers. Because virtually all consumers can ingest small quantities of noxious compounds with minimal detrimental effects, it is uncertain that toxic chemicals in larvae could be consumed in quantities sufficient to select for predator recognition and avoidance. Despite this, chemically defended larvae do occur. We show that, at low doses, secondary metabolites (the didemnins) from adults and larvae of the Caribbean tunicate Trididenmum solidum induced vomiting in fish, resulting in rapid learned aversion to the dedemnin-defended food. The particle-feeding anemone Aiptasia pallida did not learn to avoid the chemically defended food. When anemones ingested the chemical equivalent of 15 larvae/d, representing <2% of the mass of their total daily diet, the didemnins in the {open_quotes}larvae{close_quotes} significantly reduced: (1) growth of adults by 82%, (2) combined growth of adults and daughter clones by 76%, (3) production of daughter clones by 44%, and (4) average mass of individual daughter clones by 41%. At higher water temperatures, anemones cloned more rapidly. Significant differences in the number of daughter clones produced between treatment and control anemones occurred after only 4 d at seawater temperatures of 27{degrees}-29{degrees}C vs. 32 d at seawater temperatures of 18{degrees}-21{degrees}C. Consumption of even very small quantities of secondary metabolites can decrease consumer fitness substantially and select for predators that recognize and avoid chemically defended larvae, as do many consumers that co-occur with Trididemnum solidum larvae. This is the first rigorous demonstration that consumption of marine secondary metabolites can decrease consumer fitness when ingested at ecologically realistic doses. 59 refs., 5 figs., 3 tabs.

  18. Impact of ultraviolet-B radiation on planktonic fish larvae: alteration of the osmoregulatory function.

    PubMed

    Sucré, Elliott; Vidussi, Francesca; Mostajir, Behzad; Charmantier, Guy; Lorin-Nebel, Catherine

    2012-03-01

    Coastal marine ecosystems are submitted to variations of several abiotic and biotic parameters, some of them related to global change. Among them the ultraviolet-B (UV-B) radiation (UVBR: 280-320 nm) may strongly impact planktonic fish larvae. The consequences of an increase of UVBR on the osmoregulatory function of Dicentrarchus labrax larvae have been investigated in this study. In young larvae of D. labrax, as in other teleosts, osmoregulation depends on tegumentary ion transporting cells, or ionocytes, mainly located on the skin of the trunk and of the yolk sac. As early D. labrax larvae passively drift in the top water column, ionocytes are exposed to solar radiation. The effect of UVBR on larval osmoregulation in seawater was evaluated through nanoosmometric measurements of the blood osmolality after exposure to different UV-B treatments. A loss of osmoregulatory capability occured in larvae after 2 days of low (50 μWcm(-2): 4 h L/20 h D) and medium (80 μWcm(-2): 4 h L/20 h D) UVBR exposure. Compared to control larvae kept in the darkness, a significant increase in blood osmolality, abnormal behavior and high mortalities were detected in larvae exposed to UVBR from 2 days on. At the cellular level, an important decrease in abundance of tegumentary ionocytes and mucous cells was observed after 2 days of exposure to UVBR. In the ionocytes, two major osmoeffectors were immunolocalized, the Na+/K(+)-ATPase and the Na+/K+/2Cl- cotransporter. Compared to controls, the fluorescent immunostaining was lower in UVBR-exposed larvae. We hypothesize that the impaired osmoregulation in UVBR-exposed larvae originates from the lower number of tegumentary ionocytes and mucous cells. This alteration of the osmoregulatory function could negatively impact the survival of young larvae at the surface water exposed to UVBR. PMID:22018917

  19. A 520 million-year-old chelicerate larva.

    PubMed

    Liu, Yu; Haug, Joachim T; Haug, Carolin; Briggs, Derek E G; Hou, Xianguang

    2014-01-01

    An important survival strategy for animal species is the so-called niche differentiation between larva and adult. Different developmental stages of the same animal occupy different ecological niches to avoid competing for food or other essential resources. Here, we describe an exceptionally preserved larval stage of the short great appendage (SGA) arthropod (megacheiran) Leanchoilia illecebrosa from the early Cambrian Chengjiang biota of China. The larval specimen preserves fine details of the main feeding limb, the SGA, which are unknown in the adult of the same species. This discovery demonstrates that niche differentiation during ontogeny was developed in this species of megacheiran--a group of fossil arthropods that has been considered to be early representatives of Chelicerata, which includes horseshoe crabs and arachnids. Hence, this type of niche differentiation, which is common today, originated from the early Cambrian. PMID:25022702

  20. Behavioral analysis of zebrafish larvae swimming in three dimensions

    NASA Astrophysics Data System (ADS)

    Feng, Ruopei; Girdhar, Kiran; Chemla, Yann; Gruebele, Martin

    2015-03-01

    Behavioral biologists have a strong interest in studying the behavior of larval zebrafish because the limited number of locomotor neurons in larval zebrafish couples with the rich repertoire of movements as a vertebrate animal. Current research uses a priori-selected parameters to describe their movements. Most research also only considers the 2D movements of zebrafish, leaving out the vertical component of their locomotion. Our lab has developed a method to reduce the dimensionality of the locomotion of zebrafish and determine the behavioral space of 2D swimming. We are extending this work to capture 3D locomotion of zebrafish larvae. Here we present our preliminary analysis of the 3D locomotion of zebrafish.

  1. Integrative neuromechanics of crawling in D. melanogaster larvae

    PubMed Central

    Pehlevan, Cengiz; Paoletti, Paolo; Mahadevan, L

    2016-01-01

    Locomotion in an organism is a consequence of the coupled interaction between brain, body and environment. Motivated by qualitative observations and quantitative perturbations of crawling in Drosophila melanogaster larvae, we construct a minimal integrative mathematical model for its locomotion. Our model couples the excitation-inhibition circuits in the nervous system to force production in the muscles and body movement in a frictional environment, thence linking neural dynamics to body mechanics via sensory feedback in a heterogeneous environment. Our results explain the basic observed phenomenology of crawling with and without proprioception, and elucidate the stabilizing role that proprioception plays in producing a robust crawling phenotype in the presence of biological perturbations. More generally, our approach allows us to make testable predictions on the effect of changing body-environment interactions on crawling, and serves as a step in the development of hierarchical models linking cellular processes to behavior. DOI: http://dx.doi.org/10.7554/eLife.11031.001

  2. Tracking zebrafish larvae in group – Status and perspectives☆

    PubMed Central

    Martineau, Pierre R.; Mourrain, Philippe

    2013-01-01

    Video processing is increasingly becoming a standard procedure in zebrafish behavior investigations as it enables higher research throughput and new or better measures. This trend, fostered by the ever increasing performance-to-price ratio of the required recording and processing equipment, should be expected to continue in the foreseeable future, with video-processing based methods permeating more and more experiments and, as a result, expanding the very role of behavioral studies in zebrafish research. To assess whether the routine video tracking of zebrafish larvae directly in the Petri dish is a capability that can be expected in the near future, the key processing concepts are discussed and illustrated on published zebrafish studies when available or other animals when not. PMID:23707495

  3. Interactions between Shewanella colwelliana, Oyster Larvae, and Hydrophobic Organophosphate Pesticides

    PubMed Central

    Labare, Michael P.; Weiner, Ronald M.

    1990-01-01

    Shewanella colwelliana (strain D) is a periphytic estuarine bacterium that forms biofilms beneficial to oyster set. Our study examined whether these and other films concentrated two hydrophobic, organophosphate pesticides, Abate and malathion, that are detected in Chesapeake Bay oyster waters. Both biofilms and purified exopolysaccharide of S. colwelliana did not adsorb more of the Abate or malathion than could be accounted for by adsorption to control surfaces. Similar results were obtained by using Deleya marina, Hyphomonas MHS3, and autochthonous biofilms. Conversely, decapsulated S. colwelliana D cells, prepared in the laboratory, bioconcentrated Abate. Significantly, the S. colwelliana D biofilms exposed to Abate did not inhibit the settlement and metamorphosis of Crassostrea gigas larvae. PMID:16348382

  4. Biochemistry and molecular biology of the Caenorhabditis elegans dauer larva

    SciTech Connect

    Wadsworth, W.G.

    1989-01-01

    Biochemical and molecular techniques have been used to study the formation and recovery of the developmentally arrested, non-feeding dauer stage of the nematode Caenorhabditis elegans. While investigating developmental transitions in energy metabolism, a major metabolite isolated from perchloric acid extracts has been identified as a modified uridine nucleotide. The compound was isolated by gel filtration and ion-exchange chromatography and its structure was determined by {sup 1}H NMR and {sup 13}C NMR spectroscopy. This compound is the most abundant metabolite detected in {sup 31}PMR spectra of perchloric acid extracts from growing larvae. In the absence of phosphoarginine or phosphocreatine, this modified nucleotide may have an important function in the nematode's energy metabolism, and it may also be found in several other invertebrates. During recovery from the dauer stage, metabolic activation is accompanied by a decrease in intracellular pH (pH{sub i}). Although metabolic activation has been associated with an alkaline pH{sub i} shift in other organisms, in vivo {sup 31}P NMR analysis of recovering dauer larvae shows a pH{sub i} decrease from {approximately}7.3 to {approximately}6.3 within 3 hr after the animals encounter food. This shift occurs before feeding begins, and coincides with, or soon follows, the development commitment to recover from the dauer stage, suggesting that control of pH{sub i} may be important in the regulation of larval development in nematodes. A library enriched for sequences expressed specifically during the L2d (predauer) stage was made by selecting plaques from a genomic lambda library that hybridized to subtracted L2d cDNA probes. Ultimately, three clones that were shown to hybridize only to L2d RNA were selected.

  5. Effective de novo assembly of fish genome using haploid larvae.

    PubMed

    Iwasaki, Yuki; Nishiki, Issei; Nakamura, Yoji; Yasuike, Motoshige; Kai, Wataru; Nomura, Kazuharu; Yoshida, Kazunori; Nomura, Yousuke; Fujiwara, Atushi; Kobayashi, Takanori; Ototake, Mitsuru

    2016-02-01

    Recent improvements in next-generation sequencing technology have made it possible to do whole genome sequencing, on even non-model eukaryote species with no available reference genomes. However, de novo assembly of diploid genomes is still a big challenge because of allelic variation. The aim of this study was to determine the feasibility of utilizing the genome of haploid fish larvae for de novo assembly of whole-genome sequences. We compared the efficiency of assembly using the haploid genome of yellowtail (Seriola quinqueradiata) with that using the diploid genome obtained from the dam. De novo assembly from the haploid and the diploid sequence reads (100 million reads per each datasets) generated by the Ion Proton sequencer (200 bp) was done under two different assembly algorithms, namely overlap-layout-consensus (OLC) and de Bruijn graph (DBG). This revealed that the assembly of the haploid genome significantly reduced (approximately 22% for OLC, 9% for DBG) the total number of contigs (with longer average and N50 contig lengths) when compared to the diploid genome assembly. The haploid assembly also improved the quality of the scaffolds by reducing the number of regions with unassigned nucleotides (Ns) (total length of Ns; 45,331,916 bp for haploids and 67,724,360 bp for diploids) in OLC-based assemblies. It appears clear that the haploid genome assembly is better because the allelic variation in the diploid genome disrupts the extension of contigs during the assembly process. Our results indicate that utilizing the genome of haploid larvae leads to a significant improvement in the de novo assembly process, thus providing a novel strategy for the construction of reference genomes from non-model diploid organisms such as fish. PMID:26478467

  6. Autonomous Circuitry for Substrate Exploration in Freely Moving Drosophila Larvae

    PubMed Central

    Berni, Jimena; Pulver, Stefan R.; Griffith, Leslie C.; Bate, Michael

    2014-01-01

    Summary Background Many organisms, from bacteria to human hunter-gatherers, use specialized random walk strategies to explore their environment. Such behaviors are an efficient stratagem for sampling the environment and usually consist of an alternation between straight runs and turns that redirect these runs. Drosophila larvae execute an exploratory routine of this kind that consists of sequences of straight crawls, pauses, turns, and redirected crawls. Central pattern generating networks underlying rhythmic movements are distributed along the anteroposterior axis of the nervous system. The way in which the operation of these networks is incorporated into extended behavioral routines such as substrate exploration has not yet been explored. In particular, the part played by the brain in dictating the sequence of movements required is unknown. Results We report the use of a genetic method to block synaptic activity acutely in the brain and subesophageal ganglia (SOG) of larvae during active exploratory behavior. We show that the brain and SOG are not required for the normal performance of an exploratory routine. Alternation between crawls and turns is an intrinsic property of the abdominal and/or thoracic networks. The brain modifies this autonomous routine during goal-directed movements such as those of chemotaxis. Nonetheless, light avoidance behavior can be mediated in the absence of brain activity solely by the sensorimotor system of the abdomen and thorax. Conclusions The sequence of movements for substrate exploration is an autonomous capacity of the thoracic and abdominal nervous system. The brain modulates this exploratory routine in response to environmental cues. PMID:22940472

  7. Description of the final instar larva of Orthetrum borneense Kimmins, 1936 (Odonata, Libellulidae), using rearing and molecular methods.

    PubMed

    Steinhoff, Philip O M; Butler, Stephen G; Dow, Rory A

    2016-01-01

    The final instar larva of Orthetrum borneense Kimmins, 1936, is described and figured for the first time based on exuviae from three male and six female larvae collected in Sarawak, Borneo (East Malaysia). It is compared with an early instar larva, which was matched to the adult O. borneense by DNA barcoding, and the known larvae of other species of this genus that occur in the region. PMID:27394221

  8. Response to host plant odors and aggregation pheromone by larvae of the Colorado potato beetle on a servosphere

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using a servosphere (locomotion compensator), locomotory behaviour of Colorado potato beetle larvae was measured in detail in response to pulsed and non-pulsed odors of hostplant and conspecific pheromone. Second instar larvae showed decreased Straightness of movement, and all larvae showed decrease...

  9. Setting tools for the early assessment of the quality of thawed Pacific oyster (Crassostrea gigas) D-larvae.

    PubMed

    Suquet, M; Le Mercier, A; Rimond, F; Mingant, C; Haffray, P; Labbe, C

    2012-07-15

    Parameters used to assess the survival of larvae after cryopreservation generally misestimate the damages that prevent larval development. The objectives of the present study were to 1) define the reliability of the survival rate, assessed at 2 and 7 days post fertilization, to estimate Pacific oyster larval quality after thawing, and 2) select complementary tools allowing an early and reliable estimation of their quality. Oyster larvae were reared for 25 h after fertilization at 19 °C and cryopreserved at early D-stage. Then, thawed larvae were incubated in 2-L beakers. At 2 days post fertilization, the survival rate of thawed Pacific oyster larvae was lower than that of fresh larvae for only one experiment (Experiment 3) among the four identical experiments carried out in this work (Experiments 1-4). By contrast, the survival of thawed larvae, as assessed 7 days after fertilization, was lower than that of fresh larvae for the four experiments. These results confirm that the quality of thawed larvae is lower than that of fresh larvae and that the survival rate, estimated 2 days post fertilization, is not adapted to a reliable estimation of the subsequent development ability of thawed larvae. Then, complementary parameters were tested at 2 days: the movement characteristics (Experiments 1 and 2) and the morphologic features (Experiments 3 and 4) of thawed larvae. Compared to values observed on fresh larvae, the percentage of thawed motile larvae was different for only one experiment (Experiment 2) of the two. Compared to control, a reduced Average Path Velocity (VAP) of larvae (determined at the D-larval stage using a CASA-Computer Assisted Sperm Analysis-system) was observed after thawing for both experiments (Experiments 1 and 2), suggesting the ability of larval movement velocity to assess the decrease of the quality of thawed oyster larvae. Using an ASMA (Automated Sperm Morphology Analysis) device, a lower area of thawed larvae was observed, compared to

  10. Dietary fatty acid composition affects food intake and gut-brain satiety signaling in Senegalese sole (Solea senegalensis, Kaup 1858) larvae and post-larvae.

    PubMed

    Bonacic, Kruno; Campoverde, Cindy; Gómez-Arbonés, Javier; Gisbert, Enric; Estevez, Alicia; Morais, Sofia

    2016-03-01

    Little is known how dietary lipids affect food intake during larval development of fish, especially with regard to fatty acid (FA) composition. In fact, very little work has been done on appetite regulation and food intake in fish larvae in general, due to biological and technical difficulties associated with this type of studies. A new method using fluorescent microspheres as markers was developed in this study to evaluate food intake and prey selectivity of Senegalese sole larvae and post-larvae. Food intake was quantified in fish fed Artemia metanauplii enriched with oils differing in FA profile: cod liver oil (CLO), linseed oil (LSO), soybean oil (SBO) or olive oil (OO). The fish did not preferentially ingest a specific diet when presented with a choice. However, pre-metamorphic larvae from the CLO treatment ingested more metanauplii per g body weight, while differences in post-larvae were not significant. These findings were developed further by analyzing mRNA levels of a range of putative anorexigenic (pyya, pyyb, glp1, cckl, cart1a, cart1b, cart2a, cart4, pomca, pomcb, crf) and orexigenic (gal, npy, agrp2) genes, to identify those which are significantly affected by feeding and/or dietary FA composition. The variety of expression patterns observed highlighted the complexity of appetite regulatory mechanisms. In general, fish fed the CLO diet tended to show gene expression patterns most dissimilar to the remaining treatments. Expression in pre-metamorphic larvae was generally less in accordance with the putative function of the genes than in post-larvae, which could suggest a yet underdeveloped regulatory system. PMID:26851305

  11. Diet affects the redox system in developing Atlantic cod (Gadus morhua) larvae

    PubMed Central

    Penglase, Samuel; Edvardsen, Rolf B.; Furmanek, Tomasz; Rønnestad, Ivar; Karlsen, Ørjan; van der Meeren, Terje; Hamre, Kristin

    2015-01-01

    The growth and development of marine fish larvae fed copepods is superior to those fed rotifers, but the underlying molecular reasons for this are unclear. In the following study we compared the effects of such diets on redox regulation pathways during development of Atlantic cod (Gadus morhua) larvae. Cod larvae were fed a control diet of copepods or the typical rotifer/Artemia diet commonly used in commercial marine fish hatcheries, from first feeding until after metamorphosis. The oxidised and reduced glutathione levels, the redox potential, and the mRNA expression of 100 genes in redox system pathways were then compared between treatments during larval development. We found that rotifer/Artemia-fed cod larvae had lower levels of oxidised glutathione, a more reduced redox potential, and altered expression of approximately half of the redox system genes when compared to copepod-fed larvae. This rotifer/Artemia diet-induced differential regulation of the redox system was greatest during periods of suboptimal growth. Upregulation of the oxidative stress response transcription factor, nrf2, and NRF2 target genes in rotifer/Artemia fed larvae suggest this diet induced an NRF2-mediated oxidative stress response. Overall, the data demonstrate that nutritional intake plays a role in regulating the redox system in developing fish larvae. This may be a factor in dietary-induced differences observed in larval growth. PMID:26099546

  12. Effects of Toxocara larvae on brain cell survival by in vitro model assessment.

    PubMed

    Heuer, Lea; Haendel, Sabine; Beineke, Andreas; Strube, Christina

    2015-09-01

    Neuroinvasive larvae of the common dog and cat roundworms, Toxocara canis and Toxocara cati, may cause severe neurological and neuropsychological disturbances in humans. Despite their pathogenic potential and high prevalence worldwide, little is known about their cell-specific influences and cerebral host-pathogen interactions in neurotoxocarosis. To address this discrepancy, a co-culture system of viable larvae with murine neuronal (CAD), oligodendrocytal (BO-1) and microglial (BV-2) cell lines has been established. Additionally, murine adult brain slices have been co-cultured with Toxocara larvae to consider complex organotypic cell-cell interplay. Cytotoxicity of larval presence was measured enzymatically and microscopically. Microscopic evaluation using trypan blue exclusion assay revealed to be less reliable and sensitive than the lactate dehydrogenase activity assay. Ultimately, even low numbers of both T. canis and T. cati larvae have impaired survival of differentiated CAD cells, which morphologically resemble primary neurons. In contrast, viability of oligodendrocytal and microglial cells as well as brain slices was not impaired by larval presence. Therefore, immune-mediated mechanisms or trauma by migrating larvae presumably induce the in vivo pathology rather than acute cytotoxic effects. Conclusively, the helminthic larvae co-culture system presented here is a valuable in vitro tool to study cell-specific effects of parasitic larvae and their products. PMID:26080924

  13. Initial characterization of receptors for molecules that induce the settlement and metamorphosis of Haliotis rufescens larvae

    SciTech Connect

    Trapido-Rosenthal, H.G.

    1985-01-01

    Larvae of the marine gastropod mollusc Haliotis refescens are induced to undergo metamorphosis by ..gamma..-aminobutyric acid (GABA) and stereochemically related compounds. The most potent of these inducers is (-)-..beta..-(parachlorophenyl)-GABA (baclofen). The inductive response exhibits positive cooperatively, and is subject to both facilitation (up-regulation) and habituation (down-regulation). Facilitation is brought about by diamino acids such as L-diaminopropionic acid (L-DAPA), and is characterized by decreased Hill coefficients (n/sub H/) and concentration requirements (EC/sub 50/) for inducers. Facilitation does not require the simultaneous presence of facilitating and inducing compounds, and the facilitated state is persistent. Larvae are capable of being up-regulated 2 days before they are capable of undergoing settlement and metamorphosis. Habituation can be brought about by exposure of pre-competent larvae to GABA 4 days prior to the attainment of competence; it is then slowly reversible. Larvae specifically bind tritiated (-)-baclofen in a manner that is saturable with both increasing time of exposure of larvae to, and with increasing concentration of, this compound. Specific binding can be competed for by unlabeled GABA-mimetic inducing molecules; the order of effectiveness of these molecules as competitors for specific binding correlates well with their effectiveness as inducers of metamorphosis. Facilitation of larvae by exposure to diamino acids does not alter their specific binding of tritiated (-)-baclofen. It is concluded from these findings that Haliotis larvae possess receptors for GABA-mimetic compounds.

  14. Effects of nutrition (herbivore vs carnivore) on energy charge and nucleotide composition in Hyas araneus larvae

    NASA Astrophysics Data System (ADS)

    Harms, J.

    1992-03-01

    Growth rate expressed as dry weight, elemetnal composition (C, N, H), protein content and nucleotide composition (ATP, ADP, AMP, CTP, GTP and UTP) as well as adenosine were measured in laboratory cultured Hyas araneus larvae fed two different diets. One group was fed freshly hatched Artemia sp. nauplii, the other the diatom Odontella (Biddulphia) sinensis. Growth rate was reduced in the O. sinensis-fed group, reaching 20 to 50% of the growth rate of Artemia-fed larvae. In all cases, some further development to the next instar occurred when larvae were fed O. sinensis, although at reduced levels compared to Artemia-fed larvae. The adenylic energy charge was quite similar for the two nutritional conditions tested and therefore does not reflect the reduced growth rate in O. sinensis-fed larvae. The individual nucleotide content was clearly reduced in O. sinensis-fed larvae, reflecting the nutritional conditions already during early developmental periods. These reduced amount of nucleotides in O. sinensis-fed larvae were most obvious when adenylic nucleotide contents were pooled. Pooled adenylic nucleotides were found to be correlated with the individual content of carbon and protein, showing significant differences at both nutritional conditions tested.

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

    PubMed

    Antúnez, Karina; Anido, Matilde; Schlapp, Geraldine; Evans, Jay D; Zunino, Pablo

    2009-10-01

    Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae secretes proteases that could be involved in the pathogenicity. In the present article, we present the secretion of different proteases by P. larvae. Inhibition assays confirmed the presence of metalloproteases. Two different proteases patterns (PP1 and PP2) were identified in a collection of P. larvae isolates from different geographic origin. Forty nine percent of P. larvae isolates showed pattern PP1 while 51% exhibited pattern PP2. Most isolates belonging to genotype ERIC I - BOX A presented PP2, most isolates belonging to ERIC I - BOX C presented PP1 although relations were not significant. Isolates belonging to genotypes ERIC II and ERIC III presented PP2. No correlation was observed between the secreted proteases patterns and geographic distribution, since both patterns are widely distributed in Uruguay. According to exposure bioassays, isolates showing PP2 are more virulent than those showing PP1, suggesting that difference in pathogenicity could be related to the secretion of proteases. PMID:19638278

  16. Caddisfly larvae as biological indicators of Pb pollution in an Austrian river

    SciTech Connect

    Koeck, G.; Pesendorfer, C.; Hofer, R.

    1995-12-31

    Caddisfly larvae (Trichoptera, Limnephilidae) were used as biomonitors of Pb pollution in an Austrian river. Pb-contaminated industrial effluents from a glass-manufacturing firm led to very high Pb concentrations in the sediment (up to 1,400 {micro}g.g{sup {minus}1} Pb, dry weight, in the clay fraction). Pb concentration in pooled samples of insect larvae from different sites were investigated during three consecutive years (1990--1992) to study time trends of Pb contamination after installation of a water purification plant (end of 1990). In 1990 Pb concentration of larvae from a sampling site downstream close to the pollution source were magnitudes higher (276 {micro}g.g{sup {minus}1} Pb, dry weight) than at an upstream reference site (6 {micro}g g{sup {minus}1} Pb, dry weight). However, after installation of the water purification plant, Pb concentration in caddisfly larvae decreased continuously by a constant rate of 64% per year. In 1992 Pb burden of the larvae amounted to only 13% of the Pb concentration in 1990. Pb burden of caddisfly larvae reflected the Pb contamination of the river even in 60 km distance from the pollution source. The study indicates caddisfly larvae to be valuable biomonitoring organisms of metal contamination in freshwater ecosystems.

  17. Predator response to releases of American shad larvae in the Susquehanna River basin

    USGS Publications Warehouse

    Johnson, James H.; Ringler, N.H.

    1998-01-01

    Predation on American shad (Alosa sapidissima) larvae within the first two hours of release was examined from 1989 to 1992 on 31 occasions at stocking sites in the Susquehanna River basin. Twenty-two fish species consumed shad larvae; the dominant predators were spotfin shiner (Cyprinella spiloptera), mimic shiner (Notropis volucellus) and juvenile smallmouth bass (Micropterus dolomieu). The number of shad larvae found in predator stomachs ranged from 0 to 900. Mortality of shad larvae at the stocking site was usually less than 2%. The greatest mortality (9.6%) occurred at the highest stocking level (1.5 million larvae). Highly variable predation rates and release levels of shad insufficient to achieve predator satiation hindered the ability to determine a specific type of functional response of predators. Predator numbers increased with stocking density, indicating short-term aggregation at the release site. Because of practical problems associated with releasing the large numbers of larvae that would be required to satiate predators, routine stocking at these levels is probably unreasonable. Releases of 400,000 to 700,000 larvae may reduce predation by offsetting depensatory mechanisms that operate on small releases and the effects of increased predation due to predator aggregation on large releases. Night stocking may reduce predation on larval shad at the release site.

  18. Large-scale expression of recombinant cardiac sodium-calcium exchange in insect larvae.

    PubMed

    Hale, C C; Zimmerschied, J A; Bliler, S; Price, E M

    1999-02-01

    Recombinant bovine cardiac sodium-calcium exchange (NCX1) in a baculovirus construct was used to infect cabbage looper larvae (Trichoplusia ni). Infected larvae were homogenized and larvae membrane vesicles were purified. Western blot analysis indicated the presence of recombinant NCX1 protein in vesicles from infected larvae but not in controls. Vesicles from infected larvae expressed high levels of NCX1 activity (1.7 nmol Ca2+/mg protein/s) while vesicles from control larvae had no activity. NCX1 in larvae vesicles was bidirectional. Kinetic analysis yielded a Vmax of 3.6 nmol Ca2+/mg protein/s and a Km for Ca of 4.2 microM. NCX1 activity was inhibited by the exchange inhibitory peptide with an IC50 of 4 microM. These data demonstrate a novel and efficient method for the expression of large amounts of active recombinant NCX1 protein that has general application for expression and analysis of recombinant membrane proteins. PMID:10024479

  19. Distribution of Lepidopteran Larvae on Norway Spruce: Effects of Slope and Crown Aspect.

    PubMed

    Kulfan, Ján; Dvořáčková, Katarína; Zach, Peter; Parák, Michal; Svitok, Marek

    2016-04-01

    Lepidoptera associated with Norway spruce, Picea abies (L.) Karsten, play important roles in ecosystem processes, acting as plant pests, prey for predators, and hosts for parasites and parasitoids. Their distribution patterns in spruce crowns and forests are only poorly understood. We examined how slope and crown aspect affect the occurrence and abundance of moth larvae on solitary spruce trees in a montane region in Central Europe. Moth larvae were collected from southern and northern crowns of trees growing on south- and north-facing slopes (four treatments) using emergence boxes at the end of winter and by the beating method during the growing season. Species responses to slope and crown aspect were not uniform. Treatment effects on moth larvae were stronger in the winter than during the growing season. In winter, the abundance of bud-boring larvae was significantly higher in northern than in southern crowns regardless of the slope aspect, while both slope and aspect had marginally significant effects on abundance of miners. During the growing season, the occurrence of free-living larvae was similar among treatments. Emergence boxes and beating spruce branches are complementary techniques providing valuable insights into the assemblage structure of moth larvae on Norway spruce. Due to the uneven distribution of larvae detected in this study, we recommend adoption of a protocol that explicitly includes sampling of trees from contrasting slopes and branches from contrasting crown aspect in all seasons. PMID:26795212

  20. Cannibalism and predation behaviour of the blowfly, Chrysomyia albiceps (Wiedemann) larvae (Diptera: Calliphoridae).

    PubMed

    Omar, A H

    1995-12-01

    Chrysomyia albiceps is considered as a carrion inhabitant and is essentially scavenger. It is among the first species to arrive at carrion and lays its eggs on it almost immediately under favourable conditions. Field studies in Giza area showed that although other flies arrive at the carrion shortly following Chrysomyia, as decomposition progresses, its larvae are the major component predominate, and the common fly emerging from carrion is its adults. First instar larvae is entirely necrophagous, but the 2nd and early 3rd instar larvae may be facultatively predaceous on other dipteran larvae (Muscina and Parasarcophaga) as an alternative food source under crowded or starved conditions. Cannibalism, second and early 3rd instars preying on the 1st instar larvae and on themselves has also been found. Considering the predation behaviour, C. albiceps may be considered as beneficial biological control agent to help in reducing populations of carrion flies which are of medical and veterinary importance owing to their significant role in causing the different kind of myiasis of man and animals. The second instar is less inclined than the early 3rd instar to serve as a predator. The numerous heavily sclerotized spines and fleshy processes of the robust and powerful preyer early 3rd instar larvae help in subduing the prey while their strong mouthhooks are used to penetrate the bodies of the other larvae for fluid extraction. PMID:8586867

  1. Effects of 2,3,7,8-TCDD on the larvae of fathead minnows (Pimephales promelas)

    SciTech Connect

    Olivieri, C.E.; Cooper, K.R.

    1994-12-31

    This study evaluated the sensitivity of the fathead minnow larvae to 2,3,7,8-TCDD. There are no reported studies that have examined 2,3,7,8-TCDD toxic effects on fathead minnow larvae (0.0017--0.0094 g). One month old fathead minnow larvae were exposed to varying concentrations of [H{sup 3}]2,3,7,8-TCDD for 24h, and then were transferred into clean water. The no-treatment, acetone-control and 2,3,7,8-TCDD exposed larvae were observed for at least 32 days after exposure. Mortality, growth and appearance of a wasting-type syndrome were noted. The tissue dose were based on larvae wet weight. One hundred percent mortality was observed at a tissue dose of 163 ng/g at 32 days. The wasting-type syndrome appeared at day 7 after the 2,3,7,8-TCDD exposure. Statistically significant differences in growth (total length and weight) were observed at tissue doses as low as 20 ng/g. The wasting-type syndrome was observed in all fish by day 20. The 2,3,7,8-TCDD tissue level showing this effect was 44 ng/g. These results suggested that the fathead minnow larvae are more sensitive than the Japanese medaka larvae, and not as sensitive as the lake trout.

  2. Antifungal agents against Aspergillus niger for rearing rice leaffolder larvae (Lepidoptera: Pyralidae) on artificial diet.

    PubMed

    Su, Jianya; Wang, Ye-Cheng; Zhang, Shu-Kun; Ren, Xiu-Bei

    2014-06-01

    Mold contamination is an important issue in insect mass rearing. Frequently used antifungal agents such as sorbic acid and methylparaben have negative impact on many lepidopteran larvae, which might be one of the reasons for the difficulty in rearing rice leaffolder, Cnaphalocrocis medinalis (Güenée). In this study, 19 antifungal agents, including 7 food preservatives, 6 antifungal drugs, and 6 agricultural fungicides, were screened for their inhibitory activities on Aspergillus niger in diets. The results demonstrated that most of the tested chemicals are unsuitable as mold inhibitors in the diets of the rice leaffolder, and the rice leaffolder neonate is sensitive to sorbic acid and methylparaben. These two mold inhibitors at commonly used concentrations were shown to impact the survival of rice leaffolder larvae fed on artificial diets. Among the tested mold inhibitors, natamycin was the safest for the rice leaffolder larvae. Much higher larva survival was observed for the larvae fed on diets containing natamycin as an antifungal agent (59 and 72% at 200 and 400 ppm, respectively). Two agricultural fungicides, tebuconazole and azoxystrobin, are also potent as mold inhibitors when used in insect diets. The mixed use of natamycin and sorbic acid, or methylparaben, and the mixed use of sorbic acid and azoxystrobin resulted in significantly higher larva survival than sorbic acid + methylparaben. Natamycin + azoxystrobin and sorbic acid + tebuconazole resulted in larva survival similar to that of sorbic acid + methylparaben. The ternary combination of natamycin, sorbic acid, and methylparaben was the best combination for the rearing of rice leaffolder. PMID:25026669

  3. Colour preference and light sensitivity in trilobite larvae of mangrove horseshoe crab, Carcinoscopius rotundicauda (Latreille, 1802).

    PubMed

    Srijayat, T C; Pradeep, P J; Hassan, A; Chatterji, A; Shaharom, F; Jeffs, Andrew

    2014-03-01

    The trilobite larvae of C. rotundicauda were tested to determine their colour preference and light sensitivity until their first moulting (25 days post hatching) under laboratory conditions. Maximum congregation size of the trilobite larvae was found in the white zone respectively where (n = 12) followed by yellow (n = 8) and orange (n = 8), which showed the larval preference for lighter zones. Morisita's index calculation showed a clumped/aggregated distribution (yellow, blue, orange and white) and uniform/hyper dispersed distribution (green, red and black) for various colours tested. Trilobite larvae showed least preference for brighter regions while tested in the experiment [black; (n = 4) and red; (n = 5)]. Experiments done to determine the light sensitivity of trilobite larvae showed that the larvae had more preference towards ultraviolet lights. The maximum congregation size of 38.8 and 40.7% of the larvae was encountered under ultraviolet light, when the light sources were kept horizontal and vertical, respectively. Overall, results suggested that the trilobite larvae of C. rotundicauda, preferred light source of shorter wavelengths (UV light) and colours of lighter zone (white, yellow, orange), which might be due to their adaptation to their natural habitat for predator avoidance, prey selection and water quality. PMID:24669671

  4. Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae

    PubMed Central

    Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A.

    2015-01-01

    This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish. PMID:26035592

  5. Force Measurement During Contraction to Assess Muscle Function in Zebrafish Larvae

    PubMed Central

    Sloboda, Darcée D.; Claflin, Dennis R.; Dowling, James J.; Brooks, Susan V.

    2013-01-01

    Zebrafish larvae provide models of muscle development, muscle disease and muscle-related chemical toxicity, but related studies often lack functional measures of muscle health. In this video article, we demonstrate a method to measure force generation during contraction of zebrafish larval trunk muscle. Force measurements are accomplished by placing an anesthetized larva into a chamber filled with a salt solution. The anterior end of the larva is tied to a force transducer and the posterior end of the larva is tied to a length controller. An isometric twitch contraction is elicited by electric field stimulation and the force response is recorded for analysis. Force generation during contraction provides a measure of overall muscle health and specifically provides a measure of muscle function. Although we describe this technique for use with wild-type larvae, this method can be used with genetically modified larvae or with larvae treated with drugs or toxicants, to characterize muscle disease models and evaluate treatments, or to study muscle development, injury, or chemical toxicity. PMID:23912162

  6. Effects of predator hunger and food abundance on prey selection by Chaoborus larvae

    SciTech Connect

    Pastorok, R.A.

    1980-09-01

    Laboratory experiments on prey selection by Chaoborus larvae show that predator choice as well as differential encounter rates with prey determine the composition of the diet. As the larvae crop and midgut become filled with food during a feeding bout, the predator avoids eating some available Daphnia and specializes on Diaptomus. After 3 days of starvation at 15/sup 0/C, the gut system is empty and Chaoborus attacks prey indiscriminately. Then, daphnids are overrepresented in the diet because the predator encounters them more frequently than copepods of equal size. Daphnia swims about twice as fast as Diaptomus and encounters a stationary electric eye at twice the rate measured for copepods. The strike efficiency of larvae for encountered prey is the same for both species. Since feeding selectivity is inversely proportional to larval hunger state, prey selection varies with the abundance of prey and season. In general, larvae collected during autumn have lower feeding rates and are more selective than larvae collected during summer. When food increases, previously opportunistic larvae may become selective within a few hours; but satiated larvae take several days to relax their preferences under a lowered food regime.

  7. Examination of an amphibian-based assay using the larvae of Xenopus laevis and Ambystoma mexicanum.

    PubMed

    Saka, Masahiro

    2003-05-01

    Semistatic acute toxicity tests of amphibian larvae (Xenopus laevis and Ambystoma mexicanum) were conducted at different developmental stages and by different methods to establish a simple amphibian-based assay. Test substance was pentachlorophenol sodium salt (PCP-Na). The endpoint was mortality and the 24-, 48-, 72-, and 96-h LC50 values were calculated by probit analysis. Interspecific differences in larval responses were not clear. Larval sensitivity tended to increase with larval age. Newly hatched larvae were most resistant to PCP-Na. During the tests of well-developed larvae, concentrations of dissolved oxygen and PCP-Na in the test solutions greatly dropped owing to uptake by the larvae. Therefore, middle-developed (2-week-old) larvae were most suitable for the test. Toxicity tests for volatile substances would be also possible using 2-week-old larvae in closed vessels. Test individuals should be kept individually to avoid the effects of poisonous skin secretions released from dead larvae. PMID:12706392

  8. Pathology of Yersinia entomophaga MH96 towards Costelytra zealandica (Coleoptera; Scarabaeidae) larvae.

    PubMed

    Hurst, Mark Robin Holmes; van Koten, Chikako; Jackson, Trevor Anthony

    2014-01-01

    The bacterium Yersinia entomophaga was isolated from larvae of the New Zealand grass grub, Costelytra zealandica (Coleoptera: Scarabaeidae), found in soil. Following ingestion of a lethal dose of bacteria, larvae of C. zealandica reduced feeding activity and movement. After approximately 4h infected larvae convulsed and regurgitated dark digestive fluid and expelled frass pellets leaving the midgut empty and the larva amber in appearance. In the initial stages of infection, ingested bacteria were mostly contained within the peritrophic membrane and expelled with the gut fluid or transferred into the hind gut. While few Y. entomophaga were associated with the midgut epithelial cells, by 24h cells were swelling and bursting with vesicles being expelled into the midgut lumen. By 48h, bacteria had entered the haemocoel and the midgut cells had further deteriorated. After 72h, the cellular remnants were totally detached from the basal membrane the infected insects were filled with bacteria and moribund or dead with septicaemia. Mortality was directly proportional to dose and time after infection. By applying a range of doses, the LD50 was determined as 2.9×10(4)Y. entomophaga per C. zealandica larva, with an LT50 of 2.94days for doses of>1×10(5) per larva. Ingestion of low doses of bacteria did not inhibit feeding activity but led more slowly to death. By time of death, Y. entomophaga had multiplied, approximately 500 fold, in the cadavers of the infected larvae. PMID:24291403

  9. DNA hybridization assay for detection of nucleopolyhedrovirus in whitemarked tussock moth (Orgyia leucostigma) larvae.

    PubMed

    Ebling, P M; Smith, P A; van Frankenhuyzen, K

    2001-01-01

    DNA dot-blot hybridization assays utilizing a horseradish peroxidase-labelled whole genomic DNA probe and enhanced chemiluminescence were conducted to quantify detection thresholds of nucleopolyhedrovirus (NPV) in whitemarked tussock moth (Orgyia leucostigma) larvae. The minimum detection thresholds for an aqueous suspension of occlusion bodies (OBs), OBs added to macerates of non-infected larvae and OBs in macerates of diseased larvae were 7.8 x 10(3), 7.8 x 10(3), and 1.5 x 10(3) OBs, respectively. Purified viral DNA was detected at a concentration of 1.6 x 10(-1) ng in a 20 microliters volume. The presence of pre-occluded viral nucleocapsids and DNA, inherent to infected larvae, improved the detection threshold five-fold compared with OBs alone. Larval tissues did not block the detection system utilized, nor did they bind non-specifically to the probe. Detection thresholds, upon sequential hybridization of the same membrane, on average deteriorated two-fold between the first and second hybridization and an additional six-fold between the second and third hybridization. NPV infection was detected two days post-inoculation (pi) in about one-third of the larvae examined and in almost all larvae three days pi. Microscopic analysis of stained larval smears missed NPV infection in almost all larvae two days pi and about two-thirds of the larvae three days pi. Results from the two methods of analysis were not comparable until four days pi. The detection system utilized is a reliable, efficient and simple method for the early detection of NPV infection in large numbers of larvae and may be used for further studies quantifying the role of this baculovirus in the ecology of whitemarked tussock moth populations. PMID:11455634

  10. Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

    NASA Astrophysics Data System (ADS)

    Gaonkar, Chetan A.; Anil, Arga Chandrashekar

    2012-10-01

    Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in feeding studies of various organisms. In this study we standardised the gut fluorescence method using laboratory-reared barnacle larvae (Balanus amphitrite) fed with mono-algal diet Chaetoceros calcitrans, a unicellular diatom at a cell concentration of 2 × 105 cells ml-1. The gut fluorescence of IV-VI instar nauplii was found to be 370(±12) ng chlorophyll a larva-1 and in faecal pellets it was 224(±63) ng chlorophyll a larva-1. A phaeopigment concentration in larval gut was found to be 311(±13) ng larva-1 and in faecal pellets it was 172(±61) ng larva-1. The study also analysed larval samples collected from the field during different seasons from a tropical environment influenced by monsoons (Dona Paula bay, Goa, west coast of India), with characteristic temporal variations in phytoplankton abundance and diversity. Gut fluorescence of larvae obtained during the post-monsoon season was consistently higher when compared to the pre-monsoon season, suggesting the predominance of autotrophic forms in the larval gut during the post-monsoon season. Whereas, the low gut fluorescence obtained during the pre-monsoon season indicated the ingestion of food sources other than autotrophs. Such differences observed in the feeding behaviour of larvae could be due to differential availability of food for the larvae during different seasons and indicate the capability of larvae to feed on wide range of food sources. This study shows the value of the fluorescence method in feeding studies of planktotrophic organisms and in the evaluation of ecosystem dynamics.

  11. Streambed Mobility and Displacement of Aquatic Insect Larvae: Results from a Laboratory Study.

    NASA Astrophysics Data System (ADS)

    Kenworthy, S. T.; Wilcock, P. R.

    2001-05-01

    Four series of flume experiments were conducted to quantify relationships between entrainment of surface layer gravels and displacement of benthic insect larvae. Two series (H, A) utilized a sediment mixture with a median size 6.9 mm, maximum size 45 mm, and 10% < 2mm. Two other series (B, C) examined the effects of locally coarsening the bed surface and increasing the < 2mm fraction to 20%. Aquatic insect larvae were collected in the field and placed in an upstream segment of the flume bed. Flow rate, flume slope, and sediment transport rate were varied systematically among experiments. Displaced larvae were collected in a net at the end of the flume. The distribution of larvae remaining in the bed was obtained by sorting larvae from the sediment in 25 channel segments. Flow rate and mean boundary shear stress varied among runs by factors of 1.2 and 2.4 respectively. Proportional entrainment of >11mm surface grains ranged from <0.05 to >0.90. Displacement of insect larvae increased in a regular and consistent manner with increasing flow strength and surface sediment entrainment. Significant displacement occurred for some types of larvae (Ephemerellid mayflies) over a relatively low range of shear stress and bed surface entrainment. Other larvae (Atherix sp.) were displaced only at the highest levels of bed surface entrainment. Displacement was lower from coarsened bed surfaces in series B, and higher from sandier sediments in series C experiments. The differential effects of bed surface entrainment upon various types of larvae are consistent with anatomical and behavioral differences that influence exposure to near-bed flow and bedload transport. These results suggest that a detailed characterization of sediment transport dynamics is an essential for understanding the dispersal and disturbance dynamics of streambed communities.

  12. Streambed Mobility and Dispersal of Aquatic Insect Larvae: Results from a Laboratory Study.

    NASA Astrophysics Data System (ADS)

    Kenworthy, S. T.

    2002-12-01

    Three series of flume experiments were conducted to quantify relationships between entrainment of surface layer gravels and displacement of benthic insect larvae. One series (B) utilized a sediment mixture with a median size 6.9 mm, maximum size 45 mm, and 10% < 2mm. Two other series examined the effects of locally coarsening the bed surface (Bc) and increasing the < 2mm fraction to 20% (S). Aquatic insect larvae were collected in the field and placed in an upstream segment of the flume bed. Flow rate, flume slope, and sediment transport rate were varied systematically among experiments. Displaced larvae were collected in a net at the end of the flume. The distribution of larvae remaining in the bed was obtained by sorting larvae from the sediment in 25 channel segments. Flow rate and mean boundary shear stress varied among runs by factors of 1.2 and 2.4 respectively. Proportional entrainment of >11mm surface grains ranged from <0.05 to >0.90. Displacement of insect larvae increased in a regular and consistent manner with increasing flow strength and surface sediment entrainment. Significant displacement occurred for some types of larvae (Ephemerellid mayflies) over a relatively low range of shear stress and bed surface entrainment. Other larvae (Atherix sp.) were displaced only at the highest levels of bed surface entrainment. Displacement was lower from coarsened bed surfaces in series Bc, and higher from sandier sediments in series S experiments. The differential effects of bed surface entrainment upon various types of larvae are consistent with anatomical and behavioral differences that influence exposure to near-bed flow and bedload transport. These results suggest that spatial patterns of sediment mobilization are important for understanding patterns of dispersal and disturbance of streambed communities.

  13. Responses of the Metabolism of the Larvae of Pocillopora damicornis to Ocean Acidification and Warming

    PubMed Central

    Rivest, Emily B.; Hofmann, Gretchen E.

    2014-01-01

    Ocean acidification and warming are expected to threaten the persistence of tropical coral reef ecosystems. As coral reefs face multiple stressors, the distribution and abundance of corals will depend on the successful dispersal and settlement of coral larvae under changing environmental conditions. To explore this scenario, we used metabolic rate, at holobiont and molecular levels, as an index for assessing the physiological plasticity of Pocillopora damicornis larvae from this site to conditions of ocean acidity and warming. Larvae were incubated for 6 hours in seawater containing combinations of CO2 concentration (450 and 950 µatm) and temperature (28 and 30°C). Rates of larval oxygen consumption were higher at elevated temperatures. In contrast, high CO2 levels elicited depressed metabolic rates, especially for larvae released later in the spawning period. Rates of citrate synthase, a rate-limiting enzyme in aerobic metabolism, suggested a biochemical limit for increasing oxidative capacity in coral larvae in a warming, acidifying ocean. Biological responses were also compared between larvae released from adult colonies on the same day (cohorts). The metabolic physiology of Pocillopora damicornis larvae varied significantly by day of release. Additionally, we used environmental data collected on a reef in Moorea, French Polynesia to provide information about what adult corals and larvae may currently experience in the field. An autonomous pH sensor provided a continuous time series of pH on the natal fringing reef. In February/March, 2011, pH values averaged 8.075±0.023. Our results suggest that without adaptation or acclimatization, only a portion of naïve Pocillopora damicornis larvae may have suitable metabolic phenotypes for maintaining function and fitness in an end-of-the century ocean. PMID:24769774

  14. Variation in brain organization of coral reef fish larvae according to life history traits.

    PubMed

    Lecchini, David; Lecellier, Gael; Lanyon, Rynae Greta; Holles, Sophie; Poucet, Bruno; Duran, Emilio

    2014-01-01

    In coral reefs, one of the great mysteries of teleost fish ecology is how larvae locate the relatively rare patches of habitat to which they recruit. The recruitment of fish larvae to a reef, after a pelagic phase lasting between 10 and 120 days, depends strongly on larval ability to swim and detect predators, prey and suitable habitat via sensory cues. However, no information is available about the relationship between brain organization in fish larvae and their sensory and swimming abilities at recruitment. For the first time, we explore the structural diversity of brain organization (comparative sizes of brain subdivisions: telencephalon, mesencephalon, cerebellum, vagal lobe and inferior lobe) among larvae of 25 coral reef fish species. We then investigate links between variation in brain organization and life history traits (swimming ability, pelagic larval duration, social behavior, diel activity and cue use relying on sensory perception). After accounting for phylogeny with independent contrasts, we found that brain organization covaried with some life history traits: (1) fish larvae with good swimming ability (>20 cm/s), a long pelagic duration (>30 days), diurnal activity and strong use of cues relying on sensory perception for detection of recruitment habitat had a larger cerebellum than other species. (2) Fish larvae with a short pelagic duration (<30 days) and nocturnal activity had a larger mesencephalon and telencephalon. Lastly, (3) fish larvae exhibiting solitary behavior during their oceanic phase had larger inferior and vagal lobes. Overall, we hypothesize that a well-developed cerebellum may allow fish larvae to improve their chances of successful recruitment after a long pelagic phase in the ocean. Our study is the first one to bring together quantitative information on brain organization and the relative development of major brain subdivisions across coral reef fish larvae, and more specifically to address the way in which this variation

  15. Feasibility study of biodiesel production using lipids of Hermetia illucens larva fed with organic waste.

    PubMed

    Leong, Siew Yoong; Kutty, Shamsul Rahman Mohamed; Malakahmad, Amirhossein; Tan, Chew Khun

    2016-01-01

    Hermetia illucens larvae by nature are a decomposer which fed on organic wastes. This study explores the potential of producing biodiesel using lipids from H. illucens larvae. Three types of organic wastes (sewage sludge, fruit waste and palm decanter cake from oil palm mill) were selected based on considerable generation and disposal concern in the area of study as well as lack of investigations as feed for Hermetia illucens larvae in current literatures. Growth rate of the larvae was determined with studying the changes in the biomass per day. H. illucens larvae fed with fruit waste and palm decanter cake have shown growth rates of 0.52±0.02 and 0.23±0.09 g d(-1), respectively. No positive sign of growth were observed in the larvae fed with treated sewage sludge (-0.04±0.01 g d(-1)). Biodiesel as fatty acid methyl ester (FAME) was synthesized by transesterification of the larvae lipid using sulphuric acid as catalyst in methanol. FAME produced was ascertained using ATR-FTIR spectroscopy and GC-MS. The main compositions of fatty acid were found to be C12:0, C16:0 and C18:1n9c. Fatty acid composition of C12:0 fed with fruit waste, sewage sludge and palm decanter was found to be most abundant in the larvae lipid. The amount of C12:0 obtained was 76.13%, 58.31% and 48.06%, respectively. In addition, fatty acid of C16:0 was attained at 16.48% and 25.48% fed with sewage sludge and palm decanter, respectively. Based on the findings, FAME derived from larvae lipids is feasible to be used for biodiesel production. PMID:25872864

  16. Vertical distribution of first stage larvae of the blue crab, Callinectes sapidus, at the mouth of Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Provenzano, Anthony J.; McConaugha, John R.; Philips, Kathleen B.; Johnson, David F.; Clark, John

    1983-05-01

    The vertical distribution of stage I blue crab larvae, near the mouth of Chesapeake Bay, was examined over four diurnal cycles. Each of two stations was occupied for 30 hours twice during the summer of 1979. On each of the four cruises, peak larval abundance occurred after a night time high slack tide, suggesting a synchronized hatch of blue crab larvae. 90-99% of all larvae collected were taken in the neuston layer. The apparent timing of the hatches to coincide with the beginning of an ebb tide and the concentration of larvae in the neuston layer strongly suggests seaward transport of these early stage larvae and the probability of offshore development.

  17. Susceptibility of Aedes aegypti and Culex quinquefasciatus Larvae to gedunin-related limonoids.

    PubMed

    Gurulingappa, Hallur; Tare, Vrushali; Pawar, Pushpa; Tungikar, Vijay; Jorapur, Yogesh R; Madhavi, Sriram; Bhat, Sujata V

    2009-06-01

    The major non-azadirachtin limonoids such as gedunin (1), epoxyazadiradione (3), nimbocinol (4), and nimolicinol (5) from Azadirachta indica A. Juss ('neem') and their derivatives were evaluated for their toxic action against fourth instar larvae of Aedes aegypti L. and Culex quinquefasciatus Say. Gedunin exhibited 100% toxic action against both the mosquito larvae at 50 and 10 ppm. Epoxyazadiradione and epoxynimolicinol also showed significant toxicities (> or =50%) against larvae of both mosquito species at 50 ppm. These neem limonoids can have benefits in mosquito-control programs. PMID:19551731

  18. Disseminated granulomas associated with nematode larvae in a shortfin mako shark.

    PubMed

    Borucinska, J D; Heger, K

    1999-01-01

    A shortfin mako shark (Isurus oxyrinchus) caught in 1996 by sportfishermen in Long Island (New York, USA) had many granulomas containing larval nematodes. Granulomas were present in the myocardium, spleen, pancreas, stomach, spiral intestine, hematopoietic tissue within the anterior kidney, and in the branchial septum and primary lamellae of the gills. Epicardial hyperplasia and granulomatous myocarditis were associated with the larvae. Although identification of the larvae was impossible due to lack of distinct morphological features, they resembled dracunculoid larvae previously reported from sharks. PMID:10073355

  19. Isolation of corn semiochemicals attractive and repellent to western corn rootworm larvae.

    PubMed

    Hibbard, B E; Bjostad, L B

    1990-12-01

    Dichloromethane extracts of germinating corn are significantly attractive to western corn rootworm larvae in choice tests with equal levels of carbon dioxide present on both sides of the choice. Two fractions that are significantly attractive and two fractions that are significantly repellent to larvae were isolated from these extracts of germinating corn by gas chromatography and silica gel chromatography. In a separate set of experiments, Porapak N was used to collect headspace volatiles from germinating corn; significantly more larvae were attracted to aliquots of these extracts in singlechoice tests without added carbon dioxide present than to solvent controls. PMID:24263439

  20. [Studies on the histochemistry of Culex tritaeniorhynchus larvae infected with Coelomomyces indica].

    PubMed

    Sun, J H; Wang, Z Y; Lian, W N; Liu, S L

    1993-01-01

    A sectional survey with histochemical technique was carried out on Culex tritaeniorhynchus larvae infected with Coelomomyces indica in comparison to the noninfected larvae. Studies were pursued by using micrograph and imaging analysis. The results showed that the glycogen, protein and nucleic acid (RNA and DNA) reaction in the infected group were less than those of the control group. The gray level assessment in tissue imaging showed marked difference between the two groups. It is suggested that C. indica has significant effect on the above biochemical elements of the mosquito larvae, which might be considered an important mechanism in the pathogenicity of the fungus. PMID:8168236

  1. Timing of hatching and release of larvae by brachyuran crabs: patterns, adaptive significance and control.

    PubMed

    Christy, John H

    2011-07-01

    Most semiterrestrial, intertidal and shallow subtidal brachyuran crabs that live in tropical and warm temperate estuaries, bays and protected coasts world-wide release their planktonic larvae near the times of nocturnal high tides on the larger amplitude tides in the biweekly or monthly cycles of tidal amplitude. Crab larvae usually emigrate quickly to the sea where they develop to return as postlarvae to settle in habitats suitable for their survival. Predators of larvae are more abundant where larvae are released than where they develop, suggesting that this migration from estuaries to the sea reduces predation on larvae. Crabs with larvae that are relatively well-protected by spines and cryptic colors do not emigrate and often lack strong reproductive cycles, lending support to this explanation. Adults control the timing of the release of larvae with respect to the biweekly and monthly cycles of tidal amplitude by controlling when they court and mate and females control when development begins by controlling when they ovulate and allow their eggs to be fertilized by stored sperm. By changing the time they breed, fiddler crabs (Uca terpsichores) compensate for the effects of spatial and temporal variation in incubation temperature on development rates so that embryos are ready to hatch at the appropriate time. Control of the diel and tidal timing of hatching and of release of larvae varies with where adults live. Females of the more terrestrial species often move from protected incubation sites, sometimes far from water, and they largely control the precise time, both, of hatching and of release of larvae. Females of intertidal species also may influence when embryos begin to hatch. Upon hatching, a chemical cue is released that stimulates the female to pump her abdomen, causing rapid hatching and release of all larvae in her clutch. Embryos, rather than females, largely control hatching in subtidal species, perhaps because females incubate their eggs where they

  2. Trombiculidae larvae (Neotrombicula autumnalis) infestation in a Little Bittern (Ixobrychus minutus) in Turkey.

    PubMed

    Cakiroglu, Duygu; Pekmezci, Didem; Meral, Yücel; Gokalp, Güvenç; Acici, Mustafa

    2008-04-01

    With this case report, we describe Trombiculidae larvae (Neotrombicula autumnalis) infestation in a Little Bittern (Ixobrychus minutus) which was brought to our clinics by the Directorship of Environmental and Forestry authorities of Samsun, Turkey in April, 2007. The male Little Bittern (I. minutus), with a black back and crown, and black wings with a large white patch on each wing, had thick Trombiculidae larvae infestation both on its legs. There were neither dermatological nor general conditional changes observed, except its superficial larval attachments to the skin. To our knowledge, this is the first report of Trombiculidae larvae (N. autumnalis) infestation in a Little Bittern (I. minutus) in Turkey. PMID:18266010

  3. Metabolomic Analysis of Diapausing and Noni-diapausing Larvae of the European Corn Borer Ostrinia nubilalis (Hbn.) (Lepidoptera: Crambidae).

    PubMed

    Purać, Jelena; Kojić, Danijela; Popović, Željko D; Vukašinović, Elvira; Tiziani, Stefano; Günther, Ulrich L; Grubor-Lajšić, Gordana

    2015-01-01

    In this study, an (1)H-NMR -based metabolomic approach was used to investigate the biochemical mechanisms of diapause and cold hardiness in diapausing larvae of the European corn borer Ostrinia nubilalis. Metabolomic patterns in polar hemolymph extracts from non-diapausing and diapausing larvae of O. nubilalis were compared. Analysis indicated 13 metabolites: 7 amino acids, glycerol, acetate, citrate, succinate, lactate and putrescine. Results show that diapausing larvae display different metabolomic patterns compared to active non-diapausing larvae, with predominant metabolites identified as glycerol, proline and alanine. In specific diapausing larvae initially kept at 5 °C then gradually chilled to –3 °C and –16 °C, alanine , glycerol and acetate were predominant metabolites. (1)H-NMR spectroscopy provides new insight into the metabolomic patterns associated with cold resistance and diapause in O. nubilalis larvae, suggesting distinct metabolomes function in actively developing and diapausing larvae. PMID:26680702

  4. Novel Isolate of Bacillus thuringiensis subsp. thuringiensis That Produces a Quasicuboidal Crystal of Cry1Ab21 Toxic to Larvae of Trichoplusia ni▿

    PubMed Central

    Swiecicka, Izabela; Bideshi, Dennis K.; Federici, Brian A.

    2008-01-01

    A new isolate (IS5056) of Bacillus thuringiensis subsp. thuringiensis that produces a novel variant of Cry1Ab, Cry1Ab21, was isolated from soil collected in northeastern Poland. Cry1Ab21 was composed of 1,155 amino acids and had a molecular mass of 130.5 kDa, and a single copy of the gene coding for this endotoxin was located on a ∼75-kbp plasmid. When synthesized by the wild-type strain, Cry1Ab21 produced a unique, irregular, bipyramidal crystal whose long and short axes were both approximately 1 μm long, which gave it a cuboidal appearance in wet mount preparations. In diet incorporation bioassays, the 50% lethal concentrations of the crystal-spore complex were 16.9 and 29.7 μg ml−1 for second- and fourth-instar larvae of the cabbage looper, Trichoplusia ni, respectively, but the isolate was essentially nontoxic to larvae of the beet armyworm, Spodoptera exigua. A bioassay of autoclaved spore-crystal preparations showed no evidence of β-exotoxin activity, indicating that toxicity was due primarily to Cry1Ab21. Studies of the pathogenesis of isolate IS5056 in second-instar larvae of T. ni showed that after larval death the bacterium colonized and subsequently sporulated extensively throughout the cadaver, suggesting that other bacteria inhabiting the midgut lumen played little if any role in mortality. As T. ni is among the most destructive pests of vegetable crops in North America and has developed resistance to B. thuringiensis, this new isolate may have applied value. PMID:18083867

  5. The Distribution of Dragonfly Larvae in a South Carolina Stream: Relationships With Sediment Type, Body Size, and the Presence of Other Larvae

    PubMed Central

    Worthen, Wade B.; Horacek, Henry Joseph

    2015-01-01

    Dragonfly larvae were sampled in Little Creek, Greenville, SC. The distributions of five common species were described relative to sediment type, body size, and the presence of other larvae. In total, 337 quadrats (1 m by 0.5 m) were sampled by kick seine. For each quadrat, the substrate was classified as sand, sand-cobble mix, cobble, coarse, or rock, and water depth and distance from bank were measured. Larvae were identified to species, and the lengths of the body, head, and metafemur were measured. Species were distributed differently across sediment types: sanddragons, Progomphus obscurus (Rambur) (Odonata: Gomphidae), were common in sand; twin-spotted spiketails, Cordulegaster maculata Selys (Odonata: Cordulegastridae), preferred a sand-cobble mix; Maine snaketails, Ophiogomphus mainensis Packard (Odonata: Gomphidae), preferred cobble and coarse sediments; fawn darners, Boyeria vinosa (Say) (Odonata: Aeshnidae), preferred coarse sediments; and Eastern least clubtails, Stylogomphus albistylus (Hagen) (Odonata: Gomphidae), preferred coarse and rock sediments. P. obscurus and C. maculata co-occurred more frequently than expected by chance, as did O. mainensis, B. vinosa, and S. albistylus. Mean size varied among species, and species preferences contributed to differences in mean size across sediment types. There were significant negative associations among larval size classes: small larvae (<12 mm) occurred less frequently with large larvae (>15 mm) than expected by chance, and large larvae were alone in quadrats more frequently than other size classes. Species may select habitats at a large scale based on sediment type and their functional morphology, but small scale distributions are consistent with competitive displacement or intraguild predation. PMID:25843584

  6. The distribution of dragonfly larvae in a South Carolina stream: relationships with sediment type, body size, and the presence of other larvae.

    PubMed

    Worthen, Wade B; Horacek, Henry Joseph

    2015-01-01

    Dragonfly larvae were sampled in Little Creek, Greenville, SC. The distributions of five common species were described relative to sediment type, body size, and the presence of other larvae. In total, 337 quadrats (1 m by 0.5 m) were sampled by kick seine. For each quadrat, the substrate was classified as sand, sand-cobble mix, cobble, coarse, or rock, and water depth and distance from bank were measured. Larvae were identified to species, and the lengths of the body, head, and metafemur were measured. Species were distributed differently across sediment types: sanddragons, Progomphus obscurus (Rambur) (Odonata: Gomphidae), were common in sand; twin-spotted spiketails, Cordulegaster maculata Selys (Odonata: Cordulegastridae), preferred a sand-cobble mix; Maine snaketails, Ophiogomphus mainensis Packard (Odonata: Gomphidae), preferred cobble and coarse sediments; fawn darners, Boyeria vinosa (Say) (Odonata: Aeshnidae), preferred coarse sediments; and Eastern least clubtails, Stylogomphus albistylus (Hagen) (Odonata: Gomphidae), preferred coarse and rock sediments. P. obscurus and C. maculata co-occurred more frequently than expected by chance, as did O. mainensis, B. vinosa, and S. albistylus. Mean size varied among species, and species preferences contributed to differences in mean size across sediment types. There were significant negative associations among larval size classes: small larvae (<12 mm) occurred less frequently with large larvae (>15 mm) than expected by chance, and large larvae were alone in quadrats more frequently than other size classes. Species may select habitats at a large scale based on sediment type and their functional morphology, but small scale distributions are consistent with competitive displacement or intraguild predation. PMID:25843584

  7. Gag grouper larvae pathways on the West Florida Shelf

    NASA Astrophysics Data System (ADS)

    Weisberg, Robert H.; Zheng, Lianyuan; Peebles, Ernst

    2014-10-01

    A numerical circulation model, quantitatively assessed against in situ observations, is used to describe the circulation on the West Florida Continental Shelf during spring 2007 when pre-settlement gag (Mycteroperca microlepis) were present in the surf zone near Tampa Bay, Florida. The pre-settlement fish were found to be isotopically distinct from settled juveniles in the area, which is consistent with recent arrival at near shore nursery habitats from offshore spawning grounds. Simulated particle trajectories are employed to test hypotheses relating to either a surface or a near-bottom route of across-shelf transport. The surface-route hypothesis is rejected, whereas the bottom-route hypothesis is found to be consistent with the location of pre-settlement fish and their co-occurrence with macroalgae of offshore, hard-bottom origin. We conclude that gag larvae are transported to the near shore via the bottom Ekman layer and that such transport is facilitated by remote forcing associated with Gulf of Mexico Loop Current interactions with the shelf slope near the Dry Tortugas. Being that such remote forcing occurs inter-annually and not always in phase with the preferred spawning months (late winter through early spring), gag recruitment success should similarly vary with year and location.

  8. Negative gravitactic behavior of Caenorhabditis japonica dauer larvae.

    PubMed

    Okumura, Etsuko; Tanaka, Ryusei; Yoshiga, Toyoshi

    2013-04-15

    Gravity on Earth is a constant stimulus and many organisms are able to perceive and respond to it. However, there is no clear evidence that nematodes respond to gravity. In this study, we demonstrated negative gravitaxis in a nematode using dauer larvae (DL) of Caenorhabditis japonica, which form an association with their carrier insect Parastrachia japonensis. Caenorhabditis japonica DL demonstrating nictation, a typical host-finding behavior, had a negative gravitactic behavior, whereas non-nictating C. japonica and C. elegans DL did not. The negative gravitactic index of nictating DL collected from younger nematode cultures was higher than that from older cultures. After a 24 h incubation in M9 buffer, nictating DL did not alter their negative gravitactic behavior, but a longer incubation resulted in less pronounced negative gravitaxis. These results are indicative of negative gravitaxis in nictating C. japonica DL, which is maintained once initiated, seems to be affected by the age of DL and does not appear to be a simple passive mechanism. PMID:23307800

  9. Transcriptional Response of Musca domestica Larvae to Bacterial Infection

    PubMed Central

    Tang, Ting; Li, Xiang; Yang, Xue; Yu, Xue; Wang, Jianhui; Liu, Fengsong; Huang, Dawei

    2014-01-01

    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. PMID:25137050

  10. In Vivo Cardiotoxicity Induced by Sodium Aescinate in Zebrafish Larvae.

    PubMed

    Liang, Jinfeng; Jin, Wangdong; Li, Hongwen; Liu, Hongcui; Huang, Yanfeng; Shan, Xiaowen; Li, Chunqi; Shan, Letian; Efferth, Thomas

    2016-01-01

    Sodium aescinate (SA) is a widely-applied triterpene saponin product derived from horse chestnut seeds, possessing vasoactive and organ-protective activities with oral or injection administration in the clinic. To date, no toxicity or adverse events in SA have been reported, by using routine models (in vivo or in vitro), which are insufficient to predict all aspects of its pharmacological and toxicological actions. In this study, taking advantage of transparent zebrafish larvae (Danio rerio), we evaluated cardiovascular toxicity of SA at doses of 1/10 MNLC, 1/3 MNLC, MNLC and LC10 by yolk sac microinjection. The qualitative and quantitative cardiotoxicity in zebrafish was assessed at 48 h post-SA treatment, using specific phenotypic endpoints: heart rate, heart rhythm, heart malformation, pericardial edema, circulation abnormalities, thrombosis and hemorrhage. The results showed that SA at 1/10 MNLC and above doses could induce obvious cardiac and pericardial malformations, whilst 1/3 MNLC and above doses could induce significant cardiac malfunctions (heart rate and circulation decrease/absence), as compared to untreated or vehicle-treated control groups. Such cardiotoxic manifestations occurred in more than 50% to 100% of all zebrafish treated with SA at MNLC and LC10. Our findings have uncovered the potential cardiotoxicity of SA for the first time, suggesting more attention to the risk of its clinical application. Such a time- and cost-saving zebrafish cardiotoxicity assay is very valid and reliable for rapid prediction of compound toxicity during drug research and development. PMID:26907249

  11. Transcriptional response of Musca domestica larvae to bacterial infection.

    PubMed

    Tang, Ting; Li, Xiang; Yang, Xue; Yu, Xue; Wang, Jianhui; Liu, Fengsong; Huang, Dawei

    2014-01-01

    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. PMID:25137050

  12. Innate Immune Response to Streptococcus iniae Infection in Zebrafish Larvae

    PubMed Central

    Harvie, Elizabeth A.; Green, Julie M.; Neely, Melody N.

    2013-01-01

    Streptococcus iniae causes systemic infection characterized by meningitis and sepsis. Here, we report a larval zebrafish model of S. iniae infection. Injection of wild-type S. iniae into the otic vesicle induced a lethal infection by 24 h postinfection. In contrast, an S. iniae mutant deficient in polysaccharide capsule (cpsA mutant) was not lethal, with greater than 90% survival at 24 h postinfection. Live imaging demonstrated that both neutrophils and macrophages were recruited to localized otic infection with mutant and wild-type S. iniae and were able to phagocytose bacteria. Depletion of neutrophils and macrophages impaired host survival following infection with wild-type S. iniae and the cpsA mutant, suggesting that leukocytes are critical for host survival in the presence of both the wild-type and mutant bacteria. However, zebrafish larvae with impaired neutrophil function but normal macrophage function had increased susceptibility to wild-type bacteria but not the cpsA mutant. Taking these findings together, we have developed a larval zebrafish model of S. iniae infection and have found that although neutrophils are important for controlling infection with wild-type S. iniae, neutrophils are not necessary for host defense against the cpsA mutant. PMID:23090960

  13. Osteological development of the garfish (Belone belone) larvae.

    PubMed

    Kuzir, S; Kozarić, Z; Gjurcević, E; Bazdarić, B; Petrinec, Z

    2009-10-01

    Garfish, Belone belone (Linnaeus, 1761) is an elongate, slander fish inhabiting the Eastern Atlantic and Mediterranean Sea. These fish from the Belonidae (Actinopterygii) family have important commercial value for Croatian fisheries. Samples for research were collected from experimental hatching in the Novigrad Sea. Preparation techniques included fixation in buffered formalin, trypsin clearing and staining with alcian blue and alizarin red. As little is known of garfish osteology and bone morphology, the main goal of this study was to describe ossification process in garfish fry. At hatching, no skeletal structure is present. Newly-hatched larvae also had no osteological elements. Ossification started at 7 day post-hatching (DPH) [total length (TL) 18 mm] with head bones and vertebral neural arch. Head skeleton continued to develop mostly over the period from 7 to 10 DPH. At 21 DPH (TL 49 mm), ossification process seemed to be finished, but it was not possible to distinguish borders of all bones. The primary interest of our research was to understand the growth dynamics as well as transformation of supporting body elements from cartilage to bone. At the end, developmental characteristics and functional aspects of this formation in different fish species are discussed. PMID:19681833

  14. Proteomic analysis of peach fruit moth larvae treated with phosphine.

    PubMed

    Liu, Tao; Li, Li; Li, Baishu; Zhang, Fanhua; Wang, Yuejin

    2012-01-01

    Phosphine has been used worldwide for the control of stored-product insects for many years. However, the molecular mechanism of its toxicity is not clearly understood. In the current study, larvae of the peach fruit moth were fumigated with phosphine. Proteomic analysis was then performed to identify the regulated proteins. Our results confirmed the phosphine toxicity on the peach fruit moth. The median lethal time LT50 was 38.5 h at 330 ppm at 25 degrees C. During fumigation, the respiration of the peach fruit moth was extremely inhibited. Of the 26 regulated proteins, 16 were identified by MALDI-TOF mass spectrometry after a 24 h treatment. The proteins were classified as related to metabolism (25 %), anti-oxidation (6 %), signal transduction (38 %), or defense (19 %). The rest (13 %) were unclassified. Phosphine regulation of ATP and glutathione contents, as well as of ATP synthase and glutathione S-transferase 2 activities were confirmed by enzyme activity analysis. These results demonstrate that complex transcriptional regulations underlie phosphine fumigation. New theories on the mechanism of phosphine toxicity may also be established based on these results. PMID:22201993

  15. Potency of Transgenic Effectors for Neurogenetic Manipulation in Drosophila Larvae

    PubMed Central

    Pauls, Dennis; von Essen, Alina; Lyutova, Radostina; van Giesen, Lena; Rosner, Ronny; Wegener, Christian; Sprecher, Simon G.

    2015-01-01

    Genetic manipulations of neuronal activity are a cornerstone of studies aimed to identify the functional impact of defined neurons for animal behavior. With its small nervous system, rapid life cycle, and genetic amenability, the fruit fly Drosophila melanogaster provides an attractive model system to study neuronal circuit function. In the past two decades, a large repertoire of elegant genetic tools has been developed to manipulate and study neural circuits in the fruit fly. Current techniques allow genetic ablation, constitutive silencing, or hyperactivation of neuronal activity and also include conditional thermogenetic or optogenetic activation or inhibition. As for all genetic techniques, the choice of the proper transgenic tool is essential for behavioral studies. Potency and impact of effectors may vary in distinct neuron types or distinct types of behavior. We here systematically test genetic effectors for their potency to alter the behavior of Drosophila larvae, using two distinct behavioral paradigms: general locomotor activity and directed, visually guided navigation. Our results show largely similar but not equal effects with different effector lines in both assays. Interestingly, differences in the magnitude of induced behavioral alterations between different effector lines remain largely consistent between the two behavioral assays. The observed potencies of the effector lines in aminergic and cholinergic neurons assessed here may help researchers to choose the best-suited genetic tools to dissect neuronal networks underlying the behavior of larval fruit flies. PMID:25359929

  16. Parasitic infection protects wasp larvae against a bacterial challenge.

    PubMed

    Manfredini, Fabio; Beani, Laura; Taormina, Mauro; Vannini, Laura

    2010-09-01

    Host antibacterial defense after Strepsiptera parasitization is a complex and rather unexplored topic. The way how these parasites interact with bacteria invading into the host insect during an infection is completely unknown. In the present study we demonstrate that larvae of the paper wasp Polistes dominulus are more efficient at eliminating bacteria when they are parasitized by the strepsipteran insect Xenos vesparum. We looked at the expression levels of the antimicrobial peptide defensin and we screened for the activity of other hemolymph components by using a zone of inhibition assay. Transcription of defensin is triggered by parasitization, but also by mechanical injury (aseptic injection). Inhibitory activity in vitro against the Gram positive bacterium Staphylococcus aureus is not influenced by the presence of the parasite in the wasp or by a previous immune challenge, suggesting a constitutive power of killing this bacterium by wasp hemolymph. Our results suggest either direct involvement of the parasite or that defensin and further immune components not investigated in this paper, for example other antimicrobial peptides, could play a role in fighting off bacterial infections in Polistes. PMID:20546915

  17. Xenobiotics Produce Distinct Metabolomic Responses in Zebrafish Larvae (Danio rerio).

    PubMed

    Huang, Susie S Y; Benskin, Jonathan P; Chandramouli, Bharat; Butler, Heather; Helbing, Caren C; Cosgrove, John R

    2016-06-21

    Sensitive and quantitative protocols for characterizing low-dose effects are needed to meet the demands of 21st century chemical hazard assessment. To test the hypothesis that xenobiotic exposure at environmentally relevant concentrations produces specific biochemical fingerprints in organisms, metabolomic perturbations in zebrafish (Danio rerio) embryo/larvae were measured following 24 h exposures to 13 individual chemicals covering a wide range of contaminant classes. Measured metabolites (208 in total) included amino acids, biogenic amines, fatty acids, bile acids, sugars, and lipids. The 96-120 h post-fertilization developmental stage was the most appropriate model for detecting xenobiotic-induced metabolomic perturbations. Metabolomic fingerprints were largely chemical- and dose-specific and were reproducible in multiple exposures over a 16-month period. Furthermore, chemical-specific responses were detected in the presence of an effluent matrix; importantly, in the absence of morphological response. In addition to improving sensitivity for detecting biological responses to low-level xenobiotic exposures, these data can aid the classification of novel contaminants based on the similarity of metabolomic responses to well-characterized "model" compounds. This approach is clearly of use for rapid, sensitive, and specific analyses of chemical effect on organisms, and can supplement existing methods, such as the Zebrafish Embryo Toxicity assay (OECD TG236), with molecular-level information. PMID:27232715

  18. Unique toxic peptides isolated from sawfly larvae in three continents.

    PubMed

    Oelrichs, P B; MacLeod, J K; Seawright, A A; Moore, M R; Ng, J C; Dutra, F; Riet-Corŕea, F; Mendez, M C; Thamsborg, S M

    1999-03-01

    D-Amino acid containing peptides have been found to be responsible for sawfly larvae poisoning in many parts of the world. These compounds, unique in the animal kingdom, were isolated from three different species of sawfly indigenous to Australia, Denmark and South America. The octapeptide, lophyrotomin, is the major toxin in the Australian and Danish species and is present in small amounts in the South American sawfly. Pergidin, the main toxin in the South American sawfly, is a heptapeptide containing a phosphoseryl residue. This, as far as we are aware, is the first example of such a peptide to be isolated from an animal source. Small amounts of pergidin have been found in the other two species. All available evidence suggests that both peptides are biosynthesised 'de novo' possibly as a protective device, however it cannot be excluded that microorganisms may be responsible. These compounds are stable to enzymatic breakdown because of their configuration and their strong chemical bonding and lipophilic character provide a potential for residues to remain in the host animal and cause significant changes. PMID:10080356

  19. Gnathostoma larva migrans among guests of a New Year party.

    PubMed

    Migasena, S; Pitisuttithum, P; Desakorn, V

    1991-12-01

    An outbreak of Gnathostoma larva migrans occurred among guests of a New Year's party in Chachoengsao, Thailand. Nine people who consumed a raw fish dish called 'Hu-sae' contracted the disease. Five of them developed gastro-intestinal symptoms consisting of nausea, vomiting, abdominal cramps and diarrhea as early as within the first 24 hours, while in the other four, symptoms started on the following day. After the initial symptoms pertaining to the gut, malaise, chest discomfort, cough, myalgia, weakness, itching and migratory swellings were experienced. Eosinophilia was demonstrated in every patient with a mean (+/- SE) count of 5,516 +/- 1,010 cells/cu mm. Detection of antibody against aqueous extracts of G. spinigerum adult antigen using an enzyme-linked immunosorbent assay showed a titer of 1:1,600 or greater in every patients except one who had a titer of 1:400 (positive greater than or equal to 1:400). This outbreak illustrates the high attack rate when heavily infected fish are consumed. PMID:1822891

  20. Analysis of somatic and salivary gland antigens of third stage larvae of Rhinoestrus spp. (Diptera, Oestridae).

    PubMed

    Milillo, Piermarino; Traversa, Donato; Elia, Gabriella; Otranto, Domenico

    2010-04-01

    Larvae of Rhinoestrus spp. (Diptera, Oestridae) infect nasal and sinus cavities of horses, causing a nasal myiasis characterized by severe respiratory distress. Presently, the diagnosis of horse nasal botfly relies on the observation of clinical signs, on the post mortem retrieval of larvae or on molecular assays performed using pharyngeal swabs. The present study was carried out to characterize larval somatic proteins and salivary glands of Rhinoestrus spp. in a preliminary assessment towards the immunodiagnosis of equine rhinoestrosis. Out of the 212 necropsied horses 13 were positive for the presence of Rhinoestrus spp. larvae. The analysis of the sera from the infected animals by Western blotting assay showed the presence of a specific host humoral immune response against Rhinoestrus spp. larvae and proved that the salivary glands are the major immunogens in horse nasal botflies. PMID:19948170

  1. [A duplicate staining method for permanent specimen of Trichinella spiralis encapsulated larvae].

    PubMed

    Li, Dan; Yang, Ding; Pi, Ben-Wei; Niu, Li-Na; Zhang, Ying; Wang, Guo-Ying

    2012-04-30

    With single staining method, Trichinella spiralis encapsulated larvae specimens were fixed with formaldehyde alcohol acetic acid fixative solution, and stained with alcohol borax-carmine staining solution (4% borax solution 100 ml, carmine 1 g, and 70% alcohol 100 ml). With duplicate staining, the encapsulated larvae specimens were fixed with formaldehyde alcohol acetic acid fixative solution, and double stained with alcohol borax carmine staining solution and fast green staining solution (fast green 0.1 g, 95% alcohol 100 ml). The results showed that with single staining, it was not clear-cut between the cyst and muscle cells although the larva was differentiable, while with duplicate staining, the larva, cyst and muscle cells were distinguished more clearly. PMID:22908823

  2. Mortality through ontogeny of soft-bottom marine invertebrates with planktonic larvae

    NASA Astrophysics Data System (ADS)

    Pedersen, Troels Møller; Hansen, Jørgen L. S.; Josefson, Alf B.; Hansen, Benni W.

    2008-09-01

    The present survey covers one spawning season of marine benthic invertebrates in a large geographical area, the inner Danish waters, and includes a wide range of habitats with steep salinity and nutrient load gradients. The loss ratios of soft-bottom marine invertebrates from one development stage to the next is calculated based on average abundances of pelagic larvae, benthic post-larvae and adults of Bivalvia, Gastropoda, Polychaeta and Echinodermata, with planktonic development. This gives a rough estimate of the larval and post-larval mortality. Loss ratios between post-larvae stage and adult stage (post-larval mortality) varies from 3:1 to 7:1 (71.2-84.9%) and loss ratios between larvae and post-larvae (larval mortality) and between larvae and adult, ranging from 7:1 to 42:1 (85.2-97.6%) and from 45:1 to 210:1 (97.8-99.5%), respectively. The results show a remarkable unity in loss ratios (mortality) between the mollusc taxa (Bivalvia and Gastropoda) at the phylum/class level. This similarity in loss ratios among the mollusc taxa exhibiting the same developmental pathways suggests that the mortality is governed by the same biotic and abiotic factors. Larval mortality is estimated to range from 0.10 d - 1 to 0.32 d - 1 for Bivalvia and ranging from 0.09 d - 1 to 0.23 d - 1 for Polychaeta. The species loss ratios combined with specific knowledge of the reproduction cycles give estimated loss ratios (mortality) between the post-larvae and the adult stage of 25:1 and 14:1 for the bivalves Abra spp. and Mysella bidentata. For the polychaete Pygospio elegans the loss ratio (larval mortality) between the larvae and the post-larval stage is 154:1 and between the post-larvae and the adult stage 41:1. For Pholoe inornata the loss ratio between post-larvae and adults is 7:1. The present results confirm that the larval stage, metamorphosis and settlement are the critical phase in terms of mortality in the life cycle for Bivalvia. Assuming steady state based on actual

  3. Capture of white sturgeon larvae downstream of The Dalles Dam, Columbia River, Oregon and Washington, 2012

    USGS Publications Warehouse

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    Wild-spawned white sturgeon (Acipenser transmontanus) larvae captured and reared in aquaculture facilities and subsequently released, are increasingly being used in sturgeon restoration programs in the Columbia River Basin. A reconnaissance study was conducted to determine where to deploy nets to capture white sturgeon larvae downstream of a known white sturgeon spawning area. As a result of the study, 103 white sturgeon larvae and 5 newly hatched free-swimming embryos were captured at 3 of 5 reconnaissance netting sites. The netting, conducted downstream of The Dalles Dam on the Columbia River during June 25–29, 2012, provided information for potentially implementing full-scale collection efforts of large numbers of larvae for rearing in aquaculture facilities and for subsequent release at a larger size in white sturgeon restoration programs.

  4. Description of the larva of Neuraeschna claviforcipata Martin, 1909 (Insecta: Odonata: Aeshnidae).

    PubMed

    De Marmels, Jürg; Neiss, Ulisses Gaspar

    2013-01-01

    The ultimate stadium larva of Neuraeschna claviforcipata is described and illustrated based on an F-0 exuvia of a reared female from northern Amazonas State, Brazil. This larva differs from the other two known larvae of the genus in lacking the spiny lateral prominence of the mandible, and in having only a short spine each side of the median cleft of the prementum; labium is shorter and cercus longer. Noteworthy is the presence of a hair brush on each occipital lobe behind mesal angle of compound eye. The larva was found in a small blackwater pool with abundant leaf litter in an open, "campina"-type habitat, with sandy soil and low, bushy vegetation. PMID:26120663

  5. Expanding the locomotion repertoire of the eigenfish: Study of wildtype zebrafish larva escape response

    NASA Astrophysics Data System (ADS)

    Benitez-Jones, Maria; Girdhar, Kiran; Chemla, Yann; Gruebele, Martin

    2014-03-01

    The zebrafish larva is a thoroughly studied and an extensively used model for behavioral and biomedical research. The Zebrafish Laboratory at the University of Illinois at Urbana-Champaign has applied a mathematical method to describe quantitatively the larva's swimming behavior. With this method, the 98% of the larva's free-swimming behavior is described by its simplifiedeigen-fish model, which is a linear combination of its three characteristic components, or three eigen-modes. This presentation focuses on the quantification of a different swimming behavior called escape response in wildtype (WT) zebrafish larvae. Although more data is required before assuming certainty in our results, the escape response of the WT was also described up to 98% by three eigen-modes. This REU program is supported by NSF Grant PHY-1062690.

  6. Evaluation of Metarhizium brunneum F52 (Hypocreales: Clavicipitaceae) for control of Japanese beetle larvae in turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experimental and commercial preparations of Metarhizium brunneum strain F52 were evaluated for control of Japanese beetle Popillia japonica Newman (Coleoptera: Scarbaeidae) larvae (white grubs) in the laboratory and under field conditions. Experimental preparations consisted of granule and liquid f...

  7. Vertical and horizontal transmission of tilapia larvae encephalitis virus: the bad and the ugly.

    PubMed

    Sinyakov, Michael S; Belotsky, Sandro; Shlapobersky, Mark; Avtalion, Ramy R

    2011-02-01

    Impairment of innate immunity in tilapia larvae after vertical and horizontal infection with the newly characterized tilapia larvae encephalitis virus (TLEV) was accessed by evaluation of cell-mediated reactive oxygen species (ROS) production in affected fish with the use of horseradish peroxidase-amplified luminol-dependent chemiluminescence assay. The priming in-vivo infection with TLEV resulted in downregulation of ROS response in both vertically- and horizontally-infected fish; this suppression was further exacerbated by specific in-vitro booster infection with the same virus. Application of Ca ionophore and phorbol myristate acetate as alternative nonspecific boosters enabled restoration of ROS release in vertically-infected but not in horizontally-infected larvae. The results indicate severe TLEV-imposed phagocyte dysfunction in affected larvae. The difference in restoration potential of ROS production after vertical and horizontal virus transmission is interpreted in the frame of principal distinctions between the two modes. PMID:21131016

  8. A Laboratory Practical on the House Building Behaviour of Caddis Larvae

    ERIC Educational Resources Information Center

    Hansell, M. H.

    1973-01-01

    Describes a laboratory practical on animal behavior suitable for senior secondary school or university biology classes. Several separate exercises relating to the house building behavior of caddis fly larvae are detailed, together with the time required for preparation. (JR)

  9. Drosophila melanogaster larvae control amylase secretion according to the hardness of food.

    PubMed

    Sakaguchi, Honami; Suzuki, Masataka G

    2013-01-01

    Drosophila melanogaster larvae excrete amylase and perform external digestion of their food. In this study, to investigate whether their external digestion ability varies in response to changes in the external environment, we measured the relative amount of amylase excreted by larvae using a new method: the iodine starch agar method (ISAM). Analysis using this method revealed that the amount of amylase excreted by larvae increased in accordance with the increase in the agar concentration. In addition, we investigated the effect on the larval growth rate of adding amylase to the diet. Pupation occurred 24 h later in food containing 1% amylase than in food containing no amylase. These results suggest that the larvae adjust their amylase excretion in response to changes in the external environment, and that its level has a marked influence on the larval growth rate. PMID:23964241

  10. Viviparity of larvae, a new type of development in phoronids (Lophophorata: Phoronida).

    PubMed

    Temereva, E N; Malakhov, V V

    2016-03-01

    A new type of phoronid development, viviparity of larvae, has been discovered in a new phoronid species that lives as a commensal of digging sand shrimps in Vostok Bay, the Sea of Japan. The embryos develop in the mother's trunk coelom up to the young larva stage. During development, embryos increase in size twice and probably obtain nutriment from the mother's coelomic fluid. Spawning occurs by young larvae, which are released through nephridiopores. The new type of development is described in a phoronid that has a small body size but a high fertility, producing large amounts of extremely small eggs. The combination of viviparity and large number of eggs increases the number of competent larvae that can undergo metamorphosis in the burrows of shrimps. PMID:27193880

  11. Consequences of physical disturbance by tadpoles and snails on chironomid larvae.

    PubMed

    Pal, Gargi; Aditya, Gautam; Hazra, Niladri

    2014-01-01

    Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck), and Red-rimmed melania, Melanoides tuberculata (Müller), and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider), on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introduction of selected above mentioned organisms. The direct effects of non-predator organisms on the midge larvae are due to physical disturbance that destroys their tubes. This may result in vulnerability of midge larvae to predators in the wild. So the community structure may be altered by indirect effects, where one or more species, through their direct disturbance, indirectly change the abundance of other species. PMID:24672384

  12. Consequences of Physical Disturbance by Tadpoles and Snails on Chironomid Larvae

    PubMed Central

    Pal, Gargi; Aditya, Gautam; Hazra, Niladri

    2014-01-01

    Indirect interactions among community members impact on organisms. The effects of two snails, banded pond snail, Bellamya bengalensis (Lamarck), and Red-rimmed melania, Melanoides tuberculata (Müller), and tadpoles of Asian common toad, Duttaphrynus melanostictus (Schneider), on nonbiting midge larvae, Chironomus striatipennis Kieffer, were observed in experimental microcosm. Decrease in tube number and tube length of midge larvae was observed compared to control condition due to introduction of selected above mentioned organisms. The direct effects of non-predator organisms on the midge larvae are due to physical disturbance that destroys their tubes. This may result in vulnerability of midge larvae to predators in the wild. So the community structure may be altered by indirect effects, where one or more species, through their direct disturbance, indirectly change the abundance of other species. PMID:24672384

  13. Identification of Nanopillars on the Cuticle of the Aquatic Larvae of the Drone Fly (Diptera: Syrphidae).

    PubMed

    Hayes, Matthew J; Levine, Timothy P; Wilson, Roger H

    2016-01-01

    Here, we describe a nano-scale surface structure on the rat-tailed maggot, the aquatic larva of the Drone fly Eristalis tenax(L.). Larvae of this syrphid hover fly live in stagnant, anaerobic water-courses that are rich in organic matter. The larvae burrow into fetid slurry and feed on microorganisms which they filter out from the organic material. This environment is rich in bacteria, fungi and algae with the capacity to form biofilms that might develop on the larval surface and harm them. Using transmission and scanning electron microscopy we have identified an array of slender (typically < 100 nm in diameter) nanopillars that cover the surface of the larvae. The high density and dimensions of these spine-like projections appear to make it difficult for bacteria to colonize the surface of the animal. This may interfere with the formation of biofilms and potentially act as a defence against bacterial infection. PMID:27030395

  14. Identification of Nanopillars on the Cuticle of the Aquatic Larvae of the Drone Fly (Diptera: Syrphidae)

    PubMed Central

    Hayes, Matthew J.; Levine, Timothy P.; Wilson, Roger H.

    2016-01-01

    Here, we describe a nano-scale surface structure on the rat-tailed maggot, the aquatic larva of the Drone fly Eristalis tenax (L.). Larvae of this syrphid hover fly live in stagnant, anaerobic water-courses that are rich in organic matter. The larvae burrow into fetid slurry and feed on microorganisms which they filter out from the organic material. This environment is rich in bacteria, fungi and algae with the capacity to form biofilms that might develop on the larval surface and harm them. Using transmission and scanning electron microscopy we have identified an array of slender (typically < 100 nm in diameter) nanopillars that cover the surface of the larvae. The high density and dimensions of these spine-like projections appear to make it difficult for bacteria to colonize the surface of the animal. This may interfere with the formation of biofilms and potentially act as a defence against bacterial infection. PMID:27030395

  15. Description of two final stadium Onychogomphus larvae from Thailand (Odonata: Gomphidae).

    PubMed

    Chainthong, Damrong; Boonsoong, Boonsatien

    2016-01-01

    The final stadium larvae of Onychogomphus castor Lieftinck and O. duaricus Fraser are described and illustrated for the first time based on reared specimens from Thailand. The taxonomic characteristics of the larvae of the genus Onychogomphus are discussed and summarized. The larva of O. castor differs from other Southeast Asian species in having distinct mid-dorsal spines on S2-9, divergent wing pads reaching S5, and lateral spines on S6-9. The larva of O. duaricus has a weakly swollen third antennal segment, with short blunt mid-dorsal spines on S2-9, divergent wing sheaths reaching the middle of S4, and lateral spines present on S7-9. PMID:27395854

  16. [Description of the last instar larva and pupa of Cryptophlebia cortesi Clarke (Lepidoptera: Tortricidae)].

    PubMed

    Vargas, Héctor A

    2006-01-01

    A description of the last instar larva and pupa of Cryptophlebia cortesi Clarke, based on specimens collected on yaro, Acacia macracantha Bonpl & Humb ex Willd. (Fabaceae), in the Chaca valley, Primera Región, Chile, is presented. PMID:18575693

  17. [Last instar larva and pupa of Melipotis cellaris (Guenée) (Lepidoptera: Noctuidae)].

    PubMed

    Vargas, Héctor A

    2010-01-01

    The last instar larva and pupa of Melipotis cellaris (Guenée) are described and illustrated, based on specimens collected in northern Chile, associated with Acacia macracantha (Fabaceae). PMID:21120382

  18. Draft Genome Sequence of the New Pathogen for Bivalve Larvae Vibrio bivalvicida

    PubMed Central

    Dubert, Javier; Spinard, Edward J.; Gomez-Chiarri, Marta

    2016-01-01

    Vibrio bivalvicida is a novel pathogen of bivalve larvae responsible for recent vibriosis outbreaks affecting shellfish hatcheries. Here, we announce the draft genome sequence of V. bivalvicida 605T and describe potential virulence factors. PMID:27056224

  19. Description of the larva of Argia chelata Calvert, 1902 (Odonata: Coenagrionidae).

    PubMed

    Novelo-Gutiérrez, Rodolfo

    2013-01-01

    The larva of Argia chelata is described and figured. It falls into the group of Argia larvae with a moderately prominent ligula and two palpal seta, but it differs from its closest relatives by having labial palp with 2 setae plus one basal setella; the length of the ligula is 30% of its maximum width; basal tergites (1-5) lacking long, fine setae, mainly on midline; S8-10 mostly dark brown; paraprocts with spiniform setae on basal 0.25 and 0.55 of dorsal and ventral borders, respectively. Larvae were found in 2nd to 4th order shallow streams in cloud forest, crawling among debris, fine sand and mud where the water flow is slow or still, close to the shoreline. The larva is compared with A. lacrimans (Hagen), A. pima Garrison, and A. tonto Calvert, species apparently closely related.  PMID:25113363

  20. 16S rRNA amplicon sequencing dataset for conventionalized and conventionally raised zebrafish larvae.

    PubMed

    Davis, Daniel J; Bryda, Elizabeth C; Gillespie, Catherine H; Ericsson, Aaron C

    2016-09-01

    Data presented here contains metagenomic analysis regarding the sequential conventionalization of germ-free zebrafish embryos. Zebrafish embryos that underwent a germ-free sterilization process immediately after fertilization were promptly exposed to and raised to larval stage in conventional fish water. At 6 days postfertilization (dpf), these "conventionalized" larvae were compared to zebrafish larvae that were raised in conventional fish water never undergoing the initial sterilization process. Bacterial 16S rRNA amplicon sequencing was performed on DNA isolated from homogenates of the larvae revealing distinct microbiota variations between the two groups. The dataset described here is also related to the research article entitled "Microbial modulation of behavior and stress responses in zebrafish larvae" (Davis et al., 2016) [1]. PMID:27508247

  1. The Larva, ecology and distribution of Tinodes braueri McLachlan, 1878 (Trichoptera: Psychomyiidae)

    PubMed Central

    GRAF, WOLFRAM; KUČINIĆ, MLADEN; PREVIŠIĆ, ANA; VUČKOVIĆ, IVAN; WARINGER, JOHANN

    2016-01-01

    The hitherto unknown larva of Tinodes braueri McLachlan, 1878, is described and discussed in the context of contemporary Psychomyiidae keys. In addition, zoogeographical and ecological notes are included. PMID:26973366

  2. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity

    PubMed Central

    Eiri, Daren M.; Suwannapong, Guntima; Endler, Matthew; Nieh, James C.

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study. PMID:26018139

  3. Transport patterns of Pacific sardine Sardinops sagax eggs and larvae in the California Current System

    NASA Astrophysics Data System (ADS)

    Weber, Edward D.; Chao, Yi; Chai, Fei; McClatchie, Sam

    2015-06-01

    We simulated transport of Pacific sardine eggs captured offshore of California in spring of 2001-2012 using a regional ocean circulation model. Eggs were assumed to have developed into larvae within a few days and were modeled using five behavioral patterns: passive transport, diel vertical migration, diel vertical migration combined with swimming against the current, diel migration combined with migration toward shore, and diel migration combined with migration toward the best habitat. Simulated larvae with no swimming behavior were advected far offshore to poor habitat where they were unlikely to survive. Diel vertical migration resulted in less offshore transport because larvae were less affected by surface currents during the day. However, in half the years simulated nearly all juveniles were also located in poor habitat by late summer in this scenario. Swimming against the current combined with diel vertical migration resulted in similar transport patterns to the diel-vertical-migration scenario because currents dominated the transport of eggs and small larvae during the spring and early summer. Migration toward shore resulted in a large fraction of juveniles being located in appropriate habitat during late summer in all years. Migration toward the best habitat was the best strategy modeled. This strategy resulted in a slightly greater proportion of larvae being located in appropriate habitat at the end of summer than the swimming-toward-shore scenario, despite the fact that most larvae were located farther offshore. These results suggest that larval sardine might use directed horizontal swimming behavior to remain in suitable habitat conditions. A large fraction of larvae were transported south into Mexican waters by late summer in all five scenarios. Surveying juvenile sardines in fall near the border of the U.S. and Mexico may be an efficient means of estimating recruitment because the advection pattern of eggs and larvae to the south is opposite the adult

  4. Nematode larvae in fossilized animal coprolites from lower and middle Pleistocene sites, central Italy.

    PubMed

    Ferreira, L F; Araújo, A; Duarte, A N

    1993-06-01

    Nematode larvae were found in mineralized animal coprolites collected in lower and middle Pleistocene sites, central Italy. Coprolites collected in 4 paleontological sites dated from 1.5 million years to 30,000 years ago were identified as of Hyaenidae (Mammalia, Carnivora). Checklists available for present-day Hyaenidae did not permit identification of the larvae found. This is one of the most ancient parasite findings in coprolites. PMID:8501604

  5. Detection of Sindbis and Inkoo Virus RNA in Genetically Typed Mosquito Larvae Sampled in Northern Sweden

    PubMed Central

    Tingström, Olov; Wesula Lwande, Olivia; Näslund, Jonas; Spyckerelle, Iris; Engdahl, Cecilia; Von Schoenberg, Pontus; Ahlm, Clas; Evander, Magnus

    2016-01-01

    Abstract Introduction: Mosquito-borne viruses have a widespread distribution across the globe and are known to pose serious threats to human and animal health. The maintenance and dissemination of these viruses in nature are driven through horizontal and vertical transmission. In the temperate climate of northern Sweden, there is a dearth of knowledge on whether mosquito-borne viruses that occur are transmitted transovarially. To gain a better understanding of mosquito-borne virus circulation and maintenance, mosquito larvae were sampled in northern Sweden during the first and second year after a large outbreak of Ockelbo disease in 2013 caused by Sindbis virus (SINV). Materials and Methods: A total of 3123 larvae were sampled during the summers of 2014 and 2015 at multiple sites in northern Sweden. The larvae were homogenized and screened for viruses using RT-PCR and sequencing. Species identification of selected larvae was performed by genetic barcoding targeting the cytochrome C oxidase subunit I gene. Results and Discussion: SINV RNA was detected in mosquito larvae of three different species, Ochlerotatus (Oc.) communis, Oc. punctor, and Oc. diantaeus. Inkoo virus (INKV) RNA was detected in Oc. communis larvae. This finding suggested that these mosquitoes could support transovarial transmission of SINV and INKV. Detection of virus in mosquito larva may serve as an early warning for emerging arboviral diseases and add information to epidemiological investigations before, during, and after outbreaks. Furthermore, our results demonstrated the relevance of genetic barcoding as an attractive and effective method for mosquito larva typing. However, further mosquito transmission studies are needed to ascertain the possible role of different mosquito species and developmental stages in the transmission cycle of arboviruses. PMID:27159120

  6. A case of cutaneous larva migrans presenting in a pregnant patient.

    PubMed

    Kudrewicz, Kasie; Crittenden, Kylee N; Himes, Alison

    2014-01-01

    Cutaneous larva migrans (CLM) is a pruritic dermatitis caused by migration of the animal hookworm larvae into the epidermis. We present a case of CLM in a 31-year-old pregnant woman. The treatment of CLM relies on antihelminthic agents, such as thiabendazole, albendazole, and ivermectin. This case was interesting in that the standard treatment options previously mentioned were contraindicated owing to the patient's pregnancy. Cryotherapy with liquid nitrogen resulted in complete resolution of her lesion and symptoms. PMID:25526012

  7. A case of cutaneous larva migrans presenting in a pregnant patient.

    PubMed

    Kudrewicz, Kasie; Crittenden, Kylee N; Himes, Alison

    2015-01-01

    Cutaneous larva migrans (CLM) is a pruritic dermatitis caused by migration of animal hookworm larvae into the skin. We present a case of CLM in a 31-year-old pregnant woman. The treatment of CLM relies on antihelminthic agents, such as thiabendazole, albendazole, and ivermectin. This case was interesting in that the standard treatment options previously mentioned were contraindicated owing to the patient's pregnancy. Cryotherapy with liquid nitrogen resulted in complete resolution of her lesion and symptoms. PMID:25612130

  8. Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions

    PubMed Central

    Ross, Perran A.; Endersby, Nancy M.; Hoffmann, Ary A.

    2016-01-01

    The mosquito Aedes aegypti, the principal vector of dengue virus, has recently been infected experimentally with Wolbachia: intracellular bacteria that possess potential as dengue biological control agents. Wolbachia depend on their hosts for nutrients they are unable to synthesize themselves. Consequently, competition between Wolbachia and their host for resources could reduce host fitness under the competitive conditions commonly experienced by larvae of Ae. aegypti in the field, hampering the invasion of Wolbachia into natural mosquito populations. We assess the survival and development of Ae. aegypti larvae under starvation conditions when infected with each of three experimentally-generated Wolbachia strains: wMel, wMelPop and wAlbB, and compare their fitness to wild-type uninfected larvae. We find that all three Wolbachia infections reduce the survival of larvae relative to those that are uninfected, and the severity of the effect is concordant with previously characterized fitness costs to other life stages. We also investigate the ability of larvae to recover from extended food deprivation and find no effect of Wolbachia on this trait. Aedes aegypti larvae of all infection types were able to resume their development after one month of no food, pupate rapidly, emerge at a large size, and exhibit complete cytoplasmic incompatibility and maternal transmission. A lowered ability of Wolbachia-infected larvae to survive under starvation conditions will increase the threshold infection frequency required for Wolbachia to establish in highly competitive natural Ae. aegypti populations and will also reduce the speed of invasion. This study also provides insights into survival strategies of larvae when developing in stressful environments. PMID:26745630

  9. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity.

    PubMed

    Eiri, Daren M; Suwannapong, Guntima; Endler, Matthew; Nieh, James C

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study. PMID:26018139

  10. Feeding strategy of Downs herring larvae (Clupea harengus L.) in the English Channel and North Sea

    NASA Astrophysics Data System (ADS)

    Denis, Jeremy; Vallet, Carole; Courcot, Lucie; Lefebvre, Valérie; Caboche, Josselin; Antajan, Elvire; Marchal, Paul; Loots, Christophe

    2016-09-01

    This study aims to characterize the larval feeding strategy of the Downs sub-population of North Sea herring (Clupea harengus L.). Diet composition, vacuity rate and prey selectivity of larvae from 8 to 15 mm collected during the International Bottom Trawl Survey (IBTS) - MIK sampling from 2008 to 2013 were assessed by direct observation of their gut contents using Scanning Electron Microscopy (SEM). The high contribution of protists and small zooplanktonic prey observed in the gut contents proved the relevance of SEM to study the diet of first feeding larvae. The relatively low vacuity rate of 45% suggests that food may not be a limiting factor for Downs herring larvae in winter. These larvae appeared to be omnivorous and there was a clear shift in term of prey composition at a size of 13 mm. Smaller larvae (8-12 mm) fed on a higher diversity of small prey, mainly small copepods (Oncaea spp. and Euterpina acutifrons), invertebrate eggs, diatoms (Psammodicthyon panduriforme and Coscinodiscus spp.) and dinoflagellates (Dinophysis acuminate and Prorocentrum micans) whereas bigger larvae (13-15 mm) fed on a lower diversity of larger prey, mainly copepods (Temora longicornis and Paracalanus parvus) and dinoflagellates (Gonyaulax spp.). Downs herring larvae had clear prey preferences as some dinoflagellates (Pyrophacus spp., Gonyaulax spp., P. micans and Porocentrum lima), invertebrate eggs, copepods (Oncaea spp. and nauplii) and diatoms (Thalassiosira curviseriata) were positively selected and other diatoms (Nitzschia spp., Thalassiosira tenera, Thalassiosira spp. and Chaetoceros spp.) and copepods (Pseudocalanus elongatus, T. longicornis and Unidentified calanoid) were negatively selected. We argue that this shift in term of prey preferences occurring at a size of 13 mm constitutes the critical period for Downs herring larvae.

  11. Metal (Ag, Cd, Cu, Ni, Tl, and Zn) Binding to Cytosolic Biomolecules in Field-Collected Larvae of the Insect Chaoborus.

    PubMed

    Rosabal, Maikel; Mounicou, Sandra; Hare, Landis; Campbell, Peter G C

    2016-03-15

    We characterized the biomolecules involved in handling cytosolic metals in larvae of the phantom midge (Chaoborus) collected from five mining-impacted lakes by determining the distribution of Ag, Cd, Cu, Ni, Tl, and Zn among pools of various molecular weights (HMW: high molecular weight, >670-40 kDa; MMW: medium molecular weight, 40-<1.3 kDa; LMW: low molecular weight, <1.3 kDa). Appreciable concentrations of nonessential metals were found in the potentially metal-sensitive HMW (Ag and Ni) and LMW (Tl) pools, whereas the MMW pool, which includes metallothioneins (MTs) and metallothionein-like proteins and peptides (MTLPs), appears to be involved in Ag and Cd detoxification. Higher-resolution fractionation of the heat-stable protein (HSP) fraction revealed further differences in the partitioning of nonessential metals (i.e., Ag = Cd ≠ Ni ≠ Tl). These results provide unprecedented details about the metal-handling strategies employed by a metal-tolerant, freshwater animal in a field situation. PMID:26886407

  12. [The gene expression of the protein SLAWD, mediating the toxic effect of destruxin A on Spodoptera litura larvae, in procaryotic cells: purification and characterization].

    PubMed

    Meng, X; Li, L M; Gao, G; Jin, F L; Ren, S X

    2014-01-01

    Spodoptera litura is one of the most destructive phytophagous pest infesting cotton, vegetable, oilseed and ber crops around the world. Dextruxin A (DA), is a one of a kind microbial insecticide, which has potent toxins with bioactivity against S. litura larvae. An abnormal wing disc (AWD) protein was identified as a DA toxic effect protein in S. litura SL-1 cells. To better understand the role of the AWD gene of S. litura (SLAWD) it was purified and characterized. The entire coding region of the SLAWD gene was cloned into a pET-32a(+) expression vector and transformed into competent Escherichia coli BL21 (DE3) cells. SDS-PAGE and western blotting analysis and western blotting showed that the best induction conditions were 1 mmol mL(-1) isopropyl-β-D-thiogalactopyranoside (IPTG) for 6 h at 37°C; the molecular weight of the fusion protein was 35.0 kDa. The production of polyclonal antibodies and an enzyme-linked immunosorbent assay (ELISA) showed that the titer of antiserum was 1:25,600; western blotting analysis showed that the recombinant SLAWD was recognized by the anti-SLAWD polyclonal antibody. AWD is a key protein involved in wing development in insects. These tools will assist in the further characterization of SLAWD and studies on the mechanism of action of destruxin A. PMID:25845231

  13. Seasonal variation in growth and survival of Strombus canarium (Linnaeus, 1758) larvae.

    PubMed

    Cob, Z C; Arshad, A; Bujang, J S; Ghaffar, M A

    2009-05-01

    This study was conducted to analyze variation in Strombus canarium larvae development, growth and survivals when cultured during wet (main reproductive period) and dry seasons. Larvae were reared at 200 larvae L(-1) in filtered seawater (0.22 microm) and fed with Isochrysis galbana at 1000 cells mL(-1) ad libitum. The culture environment was maintained at 29 +/- 1 degrees C, salinity of 30 +/- 1 PSU and photoperiod of 12:12 light dark cycle. Growth of the larvae was described on a length-at-age basis using the modified Gompertz regression. There was high correlation in shell length-at-age relationship for both wet season (R2 = 0.99) and dry season (R2 = 0.98) culture experiments. The maximal growth rate (M) and survival rate (S) were higher for larvae cultured during wet season (M = 62.44 microm day(-1), S = 14.36-2.31%), compared with dry season (M = 43.05 microm day(-1), S = 5 +/- 1.15%). The maximal attainable larval size (a) was however lower during wet season (950.19 +/- 66.93 microm shell length) compared with dry season (1343.05 +/- 586.51 microm shell length), which might be due to significantly low larvae density in the latter. Further studies are needed to investigate variation in bio-chemical composition of the egg mass, which was suggested as the main reason for the differences. PMID:19634470

  14. Phage Therapy as an Approach to Prevent Vibrio anguillarum Infections in Fish Larvae Production

    PubMed Central

    Silva, Yolanda J.; Costa, Liliana; Pereira, Carla; Mateus, Cristiana; Cunha, Ângela; Calado, Ricardo; Gomes, Newton C. M.; Pardo, Miguel A.; Hernandez, Igor; Almeida, Adelaide

    2014-01-01

    Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL−1) and one was later treated with a phage lysate (∼108 PFU mL−1). A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control). Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture. PMID:25464504

  15. Genetic and Biochemical Diversity of Paenibacillus larvae Isolated from Tunisian Infected Honey Bee Broods

    PubMed Central

    Hamdi, Chadlia; Essanaa, Jihène; Sansonno, Luigi; Crotti, Elena; Abdi, Khaoula; Barbouche, Naima; Balloi, Annalisa; Gonella, Elena; Alma, Alberto; Daffonchio, Daniele; Boudabous, Abdellatif; Cherif, Ameur

    2013-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a virulent disease of honeybee (Apis mellifera) larvae. In Tunisia, AFB has been detected in many beekeeping areas, where it causes important economic losses, but nothing is known about the diversity of the causing agent. Seventy-five isolates of P. larvae, identified by biochemical tests and 16S rRNA gene sequencing, were obtained from fifteen contaminated broods showing typical AFB symptoms, collected in different locations in the northern part of the country. Using BOX-PCR, a distinct profile of P. larvae with respect to related Paenibacillus species was detected which may be useful for its identification. Some P. larvae-specific bands represented novel potential molecular markers for the species. BOX-PCR fingerprints indicated a relatively high intraspecific diversity among the isolates not described previously with several molecular polymorphisms identifying six genotypes on polyacrylamide gel. Polymorphisms were also detected in several biochemical characters (indol production, nitrate reduction, and methyl red and oxidase tests). Contrary to the relatively high intraspecies molecular and phenotypic diversity, the in vivo virulence of three selected P. larvae genotypes did not differ significantly, suggesting that the genotypic/phenotypic differences are neutral or related to ecological aspects other than virulence. PMID:24073406

  16. Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee ( Apis mellifera)

    NASA Astrophysics Data System (ADS)

    Shi, Yuan Yuan; Yan, Wei Yu; Huang, Zachary Y.; Wang, Zi Long; Wu, Xiao Bo; Zeng, Zhi Jiang

    2013-02-01

    The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.

  17. Genetic and biochemical diversity of Paenibacillus larvae isolated from Tunisian infected honey bee broods.

    PubMed

    Hamdi, Chadlia; Essanaa, Jihène; Sansonno, Luigi; Crotti, Elena; Abdi, Khaoula; Barbouche, Naima; Balloi, Annalisa; Gonella, Elena; Alma, Alberto; Daffonchio, Daniele; Boudabous, Abdellatif; Cherif, Ameur

    2013-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a virulent disease of honeybee (Apis mellifera) larvae. In Tunisia, AFB has been detected in many beekeeping areas, where it causes important economic losses, but nothing is known about the diversity of the causing agent. Seventy-five isolates of P. larvae, identified by biochemical tests and 16S rRNA gene sequencing, were obtained from fifteen contaminated broods showing typical AFB symptoms, collected in different locations in the northern part of the country. Using BOX-PCR, a distinct profile of P. larvae with respect to related Paenibacillus species was detected which may be useful for its identification. Some P. larvae-specific bands represented novel potential molecular markers for the species. BOX-PCR fingerprints indicated a relatively high intraspecific diversity among the isolates not described previously with several molecular polymorphisms identifying six genotypes on polyacrylamide gel. Polymorphisms were also detected in several biochemical characters (indol production, nitrate reduction, and methyl red and oxidase tests). Contrary to the relatively high intraspecies molecular and phenotypic diversity, the in vivo virulence of three selected P. larvae genotypes did not differ significantly, suggesting that the genotypic/phenotypic differences are neutral or related to ecological aspects other than virulence. PMID:24073406

  18. Effects of the ant Formica fusca on the transmission of microsporidia infecting gypsy moth larvae.

    PubMed

    Goertz, Dörte; Hoch, Gernot

    2013-06-01

    Transmission plays an integral part in the intimate relationship between a host insect and its pathogen that can be altered by abiotic or biotic factors. The latter include other pathogens, parasitoids, or predators. Ants are important species in food webs that act on various levels in a community structure. Their social behavior allows them to prey on and transport larger prey, or they can dismember the prey where it was found. Thereby they can also influence the horizontal transmission of a pathogen in its host's population. We tested the hypothesis that an ant species like Formica fusca L. (Hymenoptera: Formicidae) can affect the horizontal transmission of two microsporidian pathogens, Nosema lymantriae Weiser (Microsporidia: Nosematidae) and Vairimorpha disparis (Timofejeva) (Microsporidia: Burenellidae), infecting the gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae: Lymantriinae). Observational studies showed that uninfected and infected L. dispar larvae are potential prey items for F. fusca. Laboratory choice experiments led to the conclusion that F. fusca did not prefer L. dispar larvae infected with N. lymantriae and avoided L. dispar larvae infected with V. disparis over uninfected larvae when given the choice. Experiments carried out on small potted oak, Quercus petraea (Mattuschka) Liebl. (Fagaceae), saplings showed that predation of F. fusca on infected larvae did not significantly change the transmission of either microsporidian species to L. dispar test larvae. Microscopic examination indicated that F. fusca workers never became infected with N. lymantriae or V. disparis after feeding on infected prey. PMID:23926361

  19. Apical organs in echinoderm larvae: insights into larval evolution in the Ambulacraria.

    PubMed

    Byrne, Maria; Nakajima, Yoko; Chee, Francis C; Burke, Robert D

    2007-01-01

    The anatomy and cellular organization of serotonergic neurons in the echinoderm apical organ exhibits class-specific features in dipleurula-type (auricularia, bipinnaria) and pluteus-type (ophiopluteus, echinopluteus) larvae. The apical organ forms in association with anterior ciliary structures. Apical organs in dipleurula-type larvae are more similar to each other than to those in either of the pluteus forms. In asteroid bipinnaria and holothuroid auricularia the apical organ spans ciliary band sectors that traverse the anterior-most end of the larvae. The asteroid apical organ also has prominent bilateral ganglia that connect with an apical network of neurites. The simple apical organ of the auricularia is similar to that in the hemichordate tornaria larva. Apical organs in pluteus forms differ markedly. The echinopluteus apical organ is a single structure on the oral hood between the larval arms comprised of two groups of cells joined by a commissure and its cell bodies do not reside in the ciliary band. Ophioplutei have a pair of lateral ganglia associated with the ciliary band of larval arms that may be the ophiuroid apical organ. Comparative anatomy of the serotonergic nervous systems in the dipleurula-type larvae of the Ambulacraria (Echinodermata+Hemichordata) suggests that the apical organ of this deuterostome clade originated as a simple bilaterally symmetric nerve plexus spanning ciliary band sectors at the anterior end of the larva. From this structure, the apical organ has been independently modified in association with the evolution of class-specific larval forms. PMID:17845515

  20. Mosquito larvae change their feeding behavior in response to kairomones from some predators.

    PubMed

    Roberts, Derek

    2014-03-01

    The efficacy of using predators for the biological control of mosquito disease vectors will be reduced if mosquito larvae respond to predator presence. The larvae of two mosquito species were investigated to study whether they responded to predator kairomones by increasing surface filter-feeding, which is a less active and thus less risky feeding strategy than bottom feeding. Culex quinquefasciatus Say is normally found in highly polluted water, where it will have little contact with predators. Except for some third instars, its larvae showed no response to four different types of predators. Culiseta longiareolata Macquart, living in rain-filled rock pools, is frequently attacked by a range of predators. All instars tested (second, third, and fourth instars) strongly responded to chemicals from dragonfly nymphs (Crocothemis erythraea Brullé), damselfly nymphs (Ischnura evansi Morton), and the fish Aphanius dispar Ruppel. However, they did not respond to final-instar water scorpions (Nepa cinerea L.), which would not feed on the mosquito larvae. Second- and third-instar Cs. longiareolata produced the same response to chopped up mosquito larvae as they did to dragonfly nymphs, but fourth instars produced a significantly stronger response to dragonfly nymphs-both those unfed and those fed in situ. Thus, Cs. longiareolata not only identified different predators and responded accordingly, but also responded to conspecific alarm pheromones. Cx quinquefasciatus showed little response to predators or to alarm pheromones from damaged conspecific larvae. PMID:24724285

  1. The effects of maternal Cd on the metallothionein expression in tilapia (Oreochromis mossambicus) embryos and larvae.

    PubMed

    Wu, S M; Lin, H C; Yang, W L

    2008-05-30

    The purpose of this study was to identify the factor(s) which would enhance the Cd resistance as assessed by the metallothionein (MT) expression in tilapia larvae. Larvae were collected from parents that were pretreated respectively with Cd or saline. At the end of the 12-week experiment, the hepatic MT and Cd contents in the breeding female fish were recorded. Our results indicated that a significant relationship between Cd and MT contents can be found in the offspring from the parent fish treated with Cd. However, the higher Cd resistance, Cd contents, and MT expression were limited to those larvae from parent fish bred within 4 weeks of the injection. By week 12, the Cd-treated fish still contained high levels of MT in their hepatic tissues. However, the MT and Cd contents in the larvae from these adult fish were not significantly different from those from the controls. In summary, we suggest that the higher Cd resistance of larvae from the egg stage was a result of the Cd contamination of the parent female, as evidenced by an increase in MT expression induced in tilapia embryos and larvae. PMID:18406477

  2. Comparative studies of Metarhizium anisopliae and Tolypocladium cylindrosporum as pathogens of mosquito larvae.

    PubMed

    Riba, G; Keita, A; Soares, G G; Ferron, P

    1986-12-01

    Mosquito fungal pathogens, Metarhizium anisopliae and Tolypocladium cylindrosporum, were compared with regard to virulence against the larvae of Aedes aegypti, Anopheles stephensi and Culex pipiens. Culex pipiens larvae were much more susceptible to M. anisopliae conidia than An. stephensi or Ae. aegypti. But Ae. aegypti and Cx. pipiens larvae were equally susceptible to T. cylindrosporum propagules which weakly attack An. stephensi. Using a high concentration conidial suspension (10(7) sp/ml) of M. anisopliae no. 139, Ae. aegypti larvae were killed immediately within 1.1 days, before intrahemocoelian invasion; but at lower concentrations (10(6) and 10(5) sp/ml), typical mycosis occurred. However, T. cylindrosporum no. 3 blastospores were much more pathogenic to Ae. aegypti larvae than conidia. Conidial suspension of 10(7) spores/ml killed 68% fourth-instar larvae, relative to the 96% invaded by blastospores under the same conditions. Presoaked conidia virulence appeared still intermediate between conidia and blastospores. At low temperatures, 15 degrees C, virulence of M. anisopliae highly decreased, while at the same temperature, T. cylindrosporum blastospores were still virulent. PMID:2906985

  3. Cold hardiness of Asian longhorned beetle (Coleoptera: Cerambycidae) larvae in different populations.

    PubMed

    Feng, Yuqian; Xu, Lili; Tian, Bing; Tao, Jing; Wang, Jinlin; Zong, Shixiang

    2014-10-01

    The Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is distributed widely in China, where it causes severe damage to forests, and is a quarantine pest in Europe, the United States, and Canada. A. glabripennis overwinters as dormant larvae to avoid adverse environmental conditions. To elucidate the cold hardiness of A. glabripennis larvae, the supercooling point (SCP), freezing point (FP), and cold hardiness-related compounds were examined in overwintering larva from five populations in China (Yili, Yanchi, Wulateqianqi, Beijing, and Dezhou). The results showed that the SCP and FP differed significantly among populations, where the SCP of larvae in the Wulateqianqi population was the lowest and highest in the Beijing population. The water, fat, and glycogen contents also differed significantly among the five populations. The SCPs of larvae from all five populations were proportional to glycogen contents, but had no association with water contents and fat contents. The total contents of seven low-molecular weight compounds (glycerol, galactose, glucose, mannose, sorbitol, inositol, and trehalose) differed significantly among populations. Thus, A. glabripennis larvae from different geographical populations contained different sugars or sugar alcohols (especially glycerol, glucose, sorbitol, and trehalose), which helped them to resist cold temperatures. This study provides basic information about that may facilitate the prediction of distribution range expansions and ensure proper implementation of the integrated management of A. glabripennis populations. PMID:25202887

  4. Vibrio lentus protects gnotobiotic sea bass (Dicentrarchus labrax L.) larvae against challenge with Vibrio harveyi.

    PubMed

    Schaeck, M; Duchateau, L; Van den Broeck, W; Van Trappen, S; De Vos, P; Coulombet, C; Boon, N; Haesebrouck, F; Decostere, A

    2016-03-15

    Due to the mounting awareness of the risks associated with the use of antibiotics in aquaculture, treatment with probiotics has recently emerged as the preferred environmental-friendly prophylactic approach in marine larviculture. However, the presence of unknown and variable microbiota in fish larvae makes it impossible to disentangle the efficacy of treatment with probiotics. In this respect, the recent development of a germ-free culture model for European sea bass (Dicentrarchus labrax L.) larvae opened the door for more controlled studies on the use of probiotics. In the present study, 206 bacterial isolates, retrieved from sea bass larvae and adults, were screened in vitro for haemolytic activity, bile tolerance and antagonistic activity against six sea bass pathogens. Subsequently, the harmlessness and the protective effect of the putative probiotic candidates against the sea bass pathogen Vibrio harveyi were evaluated in vivo adopting the previously developed germ-free sea bass larval model. An equivalence trial clearly showed that no harmful effect on larval survival was elicited by all three selected probiotic candidates: Bacillus sp. LT3, Vibrio lentus and Vibrio proteolyticus. Survival of Vibrio harveyi challenged larvae treated with V. lentus was superior in comparison with the untreated challenged group, whereas this was not the case for the larvae supplemented with Bacillus sp. LT3 and V. proteolyticus. In this respect, our results unmistakably revealed the protective effect of V. lentus against vibriosis caused by V. harveyi in gnotobiotic sea bass larvae, rendering this study the first in its kind. PMID:26931390

  5. Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater

    PubMed Central

    Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

    2016-01-01

    Ocean acidification (OA) is known to affect bivalve early life-stages. We tested responses of blue mussel larvae to a wide range of pH in order to identify their tolerance threshold. Our results confirmed that decreasing seawater pH and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. Virtually no larvae reared at average pHT 7.16 were able to feed or reach the D-shell stage and their development appeared to be arrested at the trochophore stage. However larvae were capable of reaching the D-shell stage under milder acidification (pHT ≈ 7.35, 7.6, 7.85) including in under-saturated seawater with Ωa as low as 0.54 ± 0.01 (mean ± s. e. m.), with a tipping point for normal development identified at pHT 7.765. Additionally growth rate of normally developing larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results on OA impacts on mussel larvae suggest an average pHT of 7.16 is beyond their physiological tolerance threshold and indicate a shift in energy allocation towards growth in some individuals revealing potential OA resilience. PMID:27020613

  6. Can insect egg deposition ‘warn’ a plant of future feeding damage by herbivorous larvae?

    PubMed Central

    Beyaert, Ivo; Köpke, Diana; Stiller, Josefin; Hammerbacher, Almuth; Yoneya, Kinuyo; Schmidt, Axel; Gershenzon, Jonathan; Hilker, Monika

    2012-01-01

    Plant anti-herbivore defence is inducible by both insect feeding and egg deposition. However, little is known about the ability of insect eggs to induce defences directed not against the eggs themselves, but against larvae that subsequently hatch from the eggs. We studied how oviposition (OP) by the sawfly Diprion pini on Pinus sylvestris foliage affects the plant's defensive potential against sawfly larvae. Larvae that initiated their development on P. sylvestris twigs on which they hatched from eggs gained less weight and suffered higher mortality than those fed on egg-free twigs. The poor performance of these larvae also affected the next herbivore generation since fecundity of resulting females was lower than that of females which spent their larval development on egg-free pine. Transcript levels of P. sylvestris sesquiterpene synthases (PsTPS1, PsTPS2) were increased by D. pini OP, reached their highest levels just before larval hatching, and decreased when larvae started to feed. However, concentrations of terpenoid and phenolic metabolites presumed to act as feeding deterrents or toxins for herbivores did not change significantly after OP and feeding. Nevertheless, our performance data suggest that insect egg deposition may act to ‘warn’ a plant of upcoming feeding damage by larvae. PMID:21561977

  7. Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater.

    PubMed

    Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

    2016-01-01

    Ocean acidification (OA) is known to affect bivalve early life-stages. We tested responses of blue mussel larvae to a wide range of pH in order to identify their tolerance threshold. Our results confirmed that decreasing seawater pH and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. Virtually no larvae reared at average pHT 7.16 were able to feed or reach the D-shell stage and their development appeared to be arrested at the trochophore stage. However larvae were capable of reaching the D-shell stage under milder acidification (pHT ≈ 7.35, 7.6, 7.85) including in under-saturated seawater with Ωa as low as 0.54 ± 0.01 (mean ± s. e. m.), with a tipping point for normal development identified at pHT 7.765. Additionally growth rate of normally developing larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results on OA impacts on mussel larvae suggest an average pHT of 7.16 is beyond their physiological tolerance threshold and indicate a shift in energy allocation towards growth in some individuals revealing potential OA resilience. PMID:27020613

  8. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    NASA Astrophysics Data System (ADS)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  9. Efficacy of photodynamic therapy against larvae of Aedes aegypti: confocal microscopy and fluorescence-lifetime imaging

    NASA Astrophysics Data System (ADS)

    de Souza, L. M.; Pratavieira, S.; Inada, N. M.; Kurachi, C.; Corbi, J.; Guimarães, F. E. G.; Bagnato, V. S.

    2014-03-01

    Recently a few demonstration on the use of Photodynamic Reaction as possibility to eliminate larvae that transmit diseases for men has been successfully demonstrated. This promising tool cannot be vastly used due to many problems, including the lake of investigation concerning the mechanisms of larvae killing as well as security concerning the use of photosensitizers in open environment. In this study, we investigate some of the mechanisms in which porphyrin (Photogem) is incorporated on the Aedes aegypti larvae previously to illumination and killing. Larvae at second instar were exposed to the photosensitizer and after 30 minutes imaged by a confocal fluorescence microscope. It was observed the presence of photosensitizer in the gut and at the digestive tract of the larva. Fluorescence-Lifetime Imaging showed greater photosensitizer concentration in the intestinal wall of the samples, which produces a strong decrease of the Photogem fluorescence lifetime. For Photodynamic Therapy exposition to different light doses and concentrations of porphyrin were employed. Three different light sources (LED, Fluorescent lamp, Sun light) also were tested. Sun light and fluorescent lamp shows close to 100% of mortality after 24 hrs. of illumination. These results indicate the potential use of photodynamic effect against the LARVAE of Aedes aegypti.

  10. Mesoscale high-frequency variability in the Alboran Sea and its influence on fish larvae distributions

    NASA Astrophysics Data System (ADS)

    Vargas-Yáñez, Manuel; Sabatés, Ana

    2007-12-01

    This work analyses a multidisciplinary data set including hydrological and meteorological data, satellite images, and fish larvae abundance from a high-frequency experiment conducted along a north-south transect across the Western Alboran Sea anticyclonic gyre. Four consecutive occupations of the transect, crossing the frontal area, evidenced the high-frequency variability of hydrological structures and its influence on the latitudinal and vertical distribution of fish larvae in a period of a few days. The influence of dynamical processes on fish larvae depends on the location of the spawning as well as on the larval fish position in the water column. Wind induced upwelling and/or the southward drift of the Atlantic current transport larvae of neritic species, such as Sardina pilchardus and Engraulis encrasicolus to open sea areas. At the same time, these events bring about alterations in the latitudinal and vertical distributions of mesopelagic fish larvae. The species with a relatively surface distribution, as Ceratoscopelus maderensis, were transported and accumulated to the south of the Atlantic Jet (AJ), while those with a deeper distribution in the water column, as Maurolicus muelleri or Benthosema glaciale, would be upwelled and concentrated to the north. This study shows that it is difficult to extract conclusions about the mean or preferential distributions of fish larvae when one single/synoptic survey is considered and that time evolution of hydrological structures has to be considered in order to conclude.

  11. Larva migrans by Baylisascaris transfuga: fatal neurological diseases in Mongolian jirds, but not in mice.

    PubMed

    Sato, Hiroshi; Matsuo, Kayoko; Osanai, Arihiro; Kamiya, Haruo; Akao, Nobuaki; Owaki, Shigeo; Furuoka, Hidefumi

    2004-08-01

    Raccoon roundworms (Baylisascaris procyonis) and other Baylisascaris species cause patent or latent larva migrans (LM) in a variety of mammals and birds, including humans. It is not clear whether LM by Baylisascaris transfuga, roundworms of bears, is associated with clinical neurological disorders. To clarify this issue, ICR and BALB/c mice as well as Mongolian jirds (Meriones unguiculatus) were orally inoculated with 2,000-5,000 embryonated eggs of B. transfuga. In mice, the ascarid caused symptomatic LM of limited extent and duration, whereas the infection was fatal in jirds; i.e., they exhibited general signs such as severe depression and emaciation on days 8-11 postinfection (PI) and died, or they developed progressive and fatal neurological disorders after day 14 PI. Histological examination showed B. transfuga larvae in the brain of all mice and jirds examined, and the larvae collected from them developed to a size comparable with that of B. procyonis. There existed, however, critical differences in host reactions against larvae localized in the brain of mice and jirds; B. transfuga larvae found in mice were surrounded by granulomatous reactions and immobilized, whereas larvae found in jirds were free from any host reaction and mobile, causing extensive malacia. PMID:15357068

  12. The invention of the pilidium larva in an otherwise perfectly good spiralian phylum Nemertea.

    PubMed

    Maslakova, Svetlana A

    2010-11-01

    One of the most remarkable larval types among spiralians, and invertebrates in general, is the planktotrophic pilidium. The pilidium is found in a single clade of nemerteans, called the Pilidiophora, and appears to be an innovation of this group. All other nemerteans have either planktotrophic or lecithotrophic juvenile-like planuliform larvae or have direct development. The invention of the pilidium larva is associated with the formation of an extensive blastocoel that supports the delicate larval frame and elaborate ciliary band. Perhaps the most striking characteristic of the pilidium is the way the juvenile worm develops inside the larva from a series of isolated rudiments, called the imaginal discs. The paired cephalic discs, cerebral organ discs, and trunk discs originate as invaginations of larval epidermis and subsequently grow and fuse around the larval gut to form the juvenile. The fully formed juvenile ruptures the larval body and, more often than not, devours the larva during catastrophic metamorphosis. This review is an attempt to examine the pilidium in the context of recent data on development of non-pilidiophoran nemerteans, and speculate about the evolution of pilidial larval development. The author emphasizes the difference between the planuliform larvae of Palaeonemerteans and Hoplonemerteans, and suggest a new name for the hoplonemertean larvae--the decidula. PMID:21558236

  13. A Determination of Metallothionein in Larvae of Freshwater Midges (Chironomus riparius) Using Brdicka Reaction

    PubMed Central

    Fabrik, Ivo; Ruferova, Zuzana; Hilscherova, Klara; Adam, Vojtech; Trnkova, Libuse; Kizek, Rene

    2008-01-01

    Among wide spectrum of biomolecules induced by various stress factors low molecular mass protein called metallothionein (MT) is suitable for assessment of the heavy metal environmental pollution. The aim of this work was to determine the metallothionein and total thiols content in larvae of freshwater midges (Chironomus riparius) sampled from laboratory exposure to cadmium(II) ions and from field studies using differential pulse voltammetry Brdicka reaction. Unique electrochemical instrument, stationary electrochemical analyser Autolab coupled with autosampler, was utilized for the analysis of the samples. The detection limit for MT was evaluated as 5 nM. The larvae exposed to two doses (50 ng/g or 50 μg/g) of cadmium(II) ions for fifteen days under laboratory controlled conditions were at the end of the exposure killed, homogenized and analysed. MT content in control samples was 1.2 μM, in larvae exposed to 50 ng Cd/g it was 2.0 μM and in larvae exposed to 50 μg Cd/g 2.9 μM. Moreover at field study chironomid larvae as well as sediment samples have been collected from eight field sites with different levels of pollution by heavy. The metals content (chromium, nickel, copper, zinc, arsenic, molybdenum, cadmium, tin and lead) in the sediment and or MT content in the chironomid larvae were determined by inductively coupled plasma mass spectrometry or Brdicka reaction, respectively.

  14. Development of black soldier fly (Diptera: Stratiomyidae) larvae fed dairy manure.

    PubMed

    Myers, Heidi M; Tomberlin, Jeffery K; Lambert, Barry D; Kattes, David

    2008-02-01

    Black soldier flies, Hermetia illucens L., are a common colonizer of animal wastes. However, all published development data for this species are from studies using artificial diets. This study represents the first examining black soldier fly development on animal wastes. Additionally, this study examined the ability of black soldier fly larvae to reduce dry matter and associated nutrients in manure. Black soldier fly larvae were fed four rates of dairy manure to determine their effects on larval and adult life history traits. Feed rate affected larval and adult development. Those fed less ration daily weighed less than those fed a greater ration. Additionally, larvae provided the least amount of dairy manure took longer to develop to the prepupal stage; however, they needed less time to reach the adult stage. Adults resulting from larvae provided 27 g dairy manure/d lived 3-4 d less than those fed 70 g dairy manure. Percentage survivorship to the prepupal or adult stages did not differ across treatments. Larvae fed 27 g dairy manure daily reduced manure dry matter mass by 58%, whereas those fed 70 g daily reduced dry matter 33%. Black soldier fly larvae were able to reduce available P by 61-70% and N by 30-50% across treatments. Based on results from this study, the black soldier fly could be used to reduce wastes and associated nutrients in confined bovine facilities. PMID:18348791

  15. Cannibalism Affects Core Metabolic Processes in Helicoverpa armigera Larvae-A 2D NMR Metabolomics Study.

    PubMed

    Vergara, Fredd; Shino, Amiu; Kikuchi, Jun

    2016-01-01

    Cannibalism is known in many insect species, yet its impact on insect metabolism has not been investigated in detail. This study assessed the effects of cannibalism on the metabolism of fourth-instar larvae of the non-predatory insect Helicoverpa armigera (Lepidotera: Noctuidea). Two groups of larvae were analyzed: one group fed with fourth-instar larvae of H. armigera (cannibal), the other group fed with an artificial plant diet. Water-soluble small organic compounds present in the larvae were analyzed using two-dimensional nuclear magnetic resonance (NMR) and principal component analysis (PCA). Cannibalism negatively affected larval growth. PCA of NMR spectra showed that the metabolic profiles of cannibal and herbivore larvae were statistically different with monomeric sugars, fatty acid- and amino acid-related metabolites as the most variable compounds. Quantitation of ¹H-(13)C HSQC (Heteronuclear Single Quantum Coherence) signals revealed that the concentrations of glucose, glucono-1,5-lactone, glycerol phosphate, glutamine, glycine, leucine, isoleucine, lysine, ornithine, proline, threonine and valine were higher in the herbivore larvae. PMID:27598144

  16. Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee (Apis mellifera).

    PubMed

    Shi, Yuan Yuan; Yan, Wei Yu; Huang, Zachary Y; Wang, Zi Long; Wu, Xiao Bo; Zeng, Zhi Jiang

    2013-02-01

    The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation. PMID:23238637

  17. LARVA: an integrative framework for large-scale analysis of recurrent variants in noncoding annotations

    PubMed Central

    Lochovsky, Lucas; Zhang, Jing; Fu, Yao; Khurana, Ekta; Gerstein, Mark

    2015-01-01

    In cancer research, background models for mutation rates have been extensively calibrated in coding regions, leading to the identification of many driver genes, recurrently mutated more than expected. Noncoding regions are also associated with disease; however, background models for them have not been investigated in as much detail. This is partially due to limited noncoding functional annotation. Also, great mutation heterogeneity and potential correlations between neighboring sites give rise to substantial overdispersion in mutation count, resulting in problematic background rate estimation. Here, we address these issues with a new computational framework called LARVA. It integrates variants with a comprehensive set of noncoding functional elements, modeling the mutation counts of the elements with a β-binomial distribution to handle overdispersion. LARVA, moreover, uses regional genomic features such as replication timing to better estimate local mutation rates and mutational hotspots. We demonstrate LARVA's effectiveness on 760 whole-genome tumor sequences, showing that it identifies well-known noncoding drivers, such as mutations in the TERT promoter. Furthermore, LARVA highlights several novel highly mutated regulatory sites that could potentially be noncoding drivers. We make LARVA available as a software tool and release our highly mutated annotations as an online resource (larva.gersteinlab.org). PMID:26304545

  18. Notes on facultative predation in Prosimulium larvae (Diptera: Simuliidae) in alpine and subalpine streams in Colorado.

    PubMed

    Al-Shaer, Layla; Pierce, Allison K; Larson, David; Hancock, Robert

    2015-03-01

    Although it is widely accepted that black fly larvae employ filter feeding as their primary mode of nutrient intake, other forms of food acquisition, such as predation, may be more prevalent than previously realized. It has been suggested that environments where particulate matter is low, such as high-elevation seasonal streams, may drive predatory behavior in black fly larvae. Relatively little is known about the frequency at which larvae prey on other organisms or if predation may be obligate in some species. In order to supplement the idea that larval black fly predation may be a common method of feeding under certain conditions, a preliminary survey of predation by Prosimulium larvae was conducted in order to assess predation frequency at high-elevation sites (> 3,200 m) in the Colorado Rocky Mountains. Larvae were sampled from alpine and subalpine locations, and their gut content analysis revealed evidence of facultative predation and possible cannibalism. Evidence of predation was observed in all but 1 Prosimulium species collected. Predation frequency was highest in the North Fork Snake River headwater location, a small tributary stream of the Snake River in central Colorado. This survey suggests that further inquiry into predatory behavior of black fly larvae should be conducted to determine the mechanisms, behavior, and ecological impact of this understudied feeding strategy. PMID:25843187

  19. Evaluation of the impact of polyethylene microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae.

    PubMed

    Mazurais, D; Ernande, B; Quazuguel, P; Severe, A; Huelvan, C; Madec, L; Mouchel, O; Soudant, P; Robbens, J; Huvet, A; Zambonino-Infante, J

    2015-12-01

    Microplastics are present in marine habitats worldwide and may be ingested by low trophic organisms such as fish larvae, with uncertain physiological consequences. The present study aims at assessing the impact of polyethylene (PE 10-45 μM) microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae. Fish were fed an inert diet including 0, 10(4) and 10(5) fluorescent microbeads per gram from 7 until 43 days post-hatching (dph). Microbeads were detected in the gastrointestinal tract in all fish fed diet incorporating PE. Our data revealed an efficient elimination of PE beads from the gut since no fluorescent was observed in the larvae after 48 h depuration. While the mortality rate increased significantly with the amount of microbeads scored per larvae at 14 and 20 dph, only ingestion of the highest concentration slightly impacted mortality rates. Larval growth and inflammatory response through Interleukine-1-beta (IL-1β) gene expression were not found to be affected while cytochrome-P450-1A1 (cyp1a1) expression level was significantly positively correlated with the number of microbeads scored per larva at 20 dph. Overall, these results suggest that ingestion of PE microbeads had limited impact on sea bass larvae possibly due to their high potential of egestion. PMID:26412109

  20. Acute ecotoxicology of natural oil and gas condensate to coral reef larvae

    PubMed Central

    Negri, Andrew P.; Brinkman, Diane L.; Flores, Florita; Botté, Emmanuelle S.; Jones, Ross J.; Webster, Nicole S.

    2016-01-01

    Risks posed by oil spills to coral reefs are difficult to evaluate, partially due to the absence of studies that adequately assess toxicity to relevant coral reef species. Here we experimentally tested the acute toxicity of condensate, representing a fraction of light crude oil, to coral (Acropora tenuis) and sponge (Rhopaloeides odorabile) larvae. The metamorphosis of coral larvae was inhibited at total petroleum aromatic hydrocarbon (TPAH) concentrations of water accommodated fractions (WAF) as low as 103 μg l−1, similar to concentrations detected in seawater following large spills. The sensitivity of coral larvae increased by 40% when co-exposed to UV light that they might encounter in shallow reefal systems. Condensate WAF was more toxic to coral larvae than predicted by summing the toxicity of its main components (benzene, toluene, p-xylene and napthalene). In contrast, the sensitivity of sponge larvae to condensate WAF (>10,000 μg l−1 TPAH) was far less than coral in the presence and absence of UV, but similar to that of other marine invertebrates. While these results highlight the relative sensitivity of coral larvae to oil, further research is needed to better understand and predict the impacts and risks posed by hydrocarbons to tropical reef systems. PMID:26892387