Differences in transcription between free-living and CO2-activated third-stage larvae of Haemonchus contortus

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Zhong Weiwei

2010-04-01

Full Text Available Abstract Background The disease caused by Haemonchus contortus, a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3 of this gastric nematode is enclosed in a cuticle (sheath and, once ingested with herbage by the host, undergoes an exsheathment process that marks the transition from the free-living (L3 to the parasitic (xL3 stage. This study explored changes in gene transcription associated with this transition and predicted, based on comparative analysis, functional roles for key transcripts in the metabolic pathways linked to larval development. Results Totals of 101,305 (L3 and 105,553 (xL3 expressed sequence tags (ESTs were determined using 454 sequencing technology, and then assembled and annotated; the most abundant transcripts encoded transthyretin-like, calcium-binding EF-hand, NAD(P-binding and nucleotide-binding proteins as well as homologues of Ancylostoma-secreted proteins (ASPs. Using an in silico-subtractive analysis, 560 and 685 sequences were shown to be uniquely represented in the L3 and xL3 stages, respectively; the transcripts encoded ribosomal proteins, collagens and elongation factors (in L3, and mainly peptidases and other enzymes of amino acid catabolism (in xL3. Caenorhabditis elegans orthologues of transcripts that were uniquely transcribed in each L3 and xL3 were predicted to interact with a total of 535 other genes, all of which were involved in embryonic development. Conclusion The present study indicated that some key transcriptional alterations taking place during the transition from the L3 to the xL3 stage of H. contortus involve genes predicted to be linked to the development of neuronal tissue (L3 and xL3, formation of the cuticle (L3 and digestion of host haemoglobin (xL3. Future efforts using next-generation sequencing and bioinformatic technologies should provide the efficiency and depth of coverage required for the determination of the

Acute intestinal anisakiasis in Spain: a fourth-stage Anisakis simplex larva

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Mª José Rosales

1999-11-01

Full Text Available A case of acute intestinal anisakiasis has been reported; a nematode larva being found in the submucosa of the ileum of a woman in Jaén (Spain. The source of infection was the ingestion of raw Engraulis encrasicholus. On the basis of its morphology, the worm has been identified as a fourth-stage larva of Anisakis simplex. In Spain, this is the ninth report of human anisakiasis and also probably the first case of anisakiasis caused by a fourth-stage larva of A. simplex.

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

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Gil Wizen

2011-07-01

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

Protective immune responses with trickle infections of third-stage filarial larvae of Wuchereria bancrofti in mice.

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Rajasekariah, G R; Monteiro, Y M; Netto, A; Deshpande, L; Subrahmanyam, D

1989-01-01

Groups of inbred BALB/c mice were immunized with trickle doses of 20 live third-stage larvae (L3) of Wuchereria bancrofti each subcutaneously or with 150 microg of sonicated microfilarial antigens emulsified in Freund's adjuvant intramuscularly. An antibody response was distinctly seen after seven trickle doses of L3 and following with the sonicated microfilarial immunization. Due to the non-permissive nature of inbred mice to W. bancrofti infections, a novel immunization approach was adopted using appropriate age- and sex-matched controls. The anti-L3 response in terms of antibody-dependent cell-mediated adhesion and killing was assessed in the immunized animals by implanting live L3 in micropore chambers subcutaneously. About 75% L3 W. bancrofti were affected in animals sensitized with seven trickle doses of L3. When sensitizations were continued, as high as 92% of L3 were seen affected with ten trickle doses compared with 27% in age-matched controls. Immunization with sonicated microfilarial antigen affected about 70% of L3 as opposed to only 12% in controls. A positive correlation was observed in the antibody response with protectivity. This method of induction and assessment of the anti-L3 response involving a small set of animals has not only allowed quantification of affected L3 but has also enabled us to visualize larval conditions in immunologically activated animals. The micropore chamber system, would be useful in monitoring the induction of protective immune response against W. bancrofti in inbred mice. Experimentation on large numbers of animals is required to elucidate further the response of mice towards L3 and also to pinpoint the putative protective antigens. PMID:12412764

Heliconema anguillae Yamaguti, 1935, a physalopterid nematode found in Japanese eels: taxonomic resurrection with a note on the third-stage larva from intertidal crabs in western Japan.

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Katahira, Hirotaka; Nagasawa, Kazuya

2015-01-01

A parasitic nematode from the stomach of Japanese eel Anguilla japonica Temminck et Schlegel in western Japan, previously identified as Heliconema longissimum (Ortlepp, 1922), was morphologically re-examined and compared with the previous descriptions. In addition, the third-stage larva of this nematode is described, based on the specimens of encapsuled larvae found in musculature of two crabs, Hemigrapsus sp. and Perisesarma bidens (De Haan), caught from the upper-intertidal zone of the same locality. As a result of the morphological observation, seven pairs of postcloacal papillae in adult males are confirmed. This matches with the character of H. longissimum, but the shape of the fifth postcloacal papillae differs between the present material and H. longissimum; the former possesses pedunculate papillae in the fifth pair whereas the latter has sessile papillae. Since the pedunculate papillae can be found in the original description and the syntype specimens of H. anguillae Yamaguti, 1935 that has been synonymised with H. longissimum, we thus here resurrect H. anguillae as an accepted species. For the life-cycle of the present nematode, littoral crabs, including the two infected species, are likely to be the source of infections for Japanese eels, acting as intermediate hosts.

Observations of the third instar larva and puparium of Chrysomya bezziana (Diptera: Calliphoridae).

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Sukontason, K L; Piangjai, S; Boonsriwong, W; Bunchu, N; Ngern-klun, R; Vogtsberger, R C; Sukontason, K

2006-11-01

Observations on the ultrastructure of the third instar larva and puparium of the Old World screw-worm fly, Chrysomya bezziana, are presented utilizing both light microscopy (LM) and scanning electron microscopy (SEM). Results of this study indicate that the shape of the intersegmental spines between the pro- and mesothorax markedly differ from other blow fly species (Chrysomya megacephala, Chrysomya rufifacies, Chrysomya nigripes, Lucilia cuprina) in being broad-based with sharp recurved tips. Other characters such as the posterior spiracles, number of papillae on the anterior spiracles, oral grooves, and posterior spiracular hairs also differ. The strong and robust mouthhooks may explain the ability of larvae to penetrate deeply into human tissues. Perforated sieve plates covered with antler-like projections were observed within the anterior spiracles of the puparium of C. bezziana. The posterior spiracular discs each bear three spiracular slits with approximately 2-microm wide openings that were viewed either open or closed by a membrane underneath. This study expands our knowledge of the fine details of the external morphology of both the third instar larva and puparium of C. bezziana, which is an obligatory myiasis-producing species in many regions. A key to differentiate the third instar of C. bezziana from other blow flies in Thailand is given.

Sensory Neuroanatomy of Parastrongyloides trichosuri, a Nematode Parasite of Mammals: Amphidial Neurons of the First-Stage Larva

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Zhu, He; Li, Jian; Nolan, Thomas J.; Schad, Gerhard A.; Lok, James B.

2011-01-01

Owing to its ability to switch between free-living and parasitic modes of development, Parastrongyloides trichosuri represents a valuable model with which to study the evolution of parasitism among the nematodes, especially aspects pertaining to morphogenesis of infective third-stage larvae. In the free-living nematode Caenorhabditis elegans, developmental fates of third-stage larvae are determined in part by environmental cues received by chemosensory neurons in the amphidial sensillae. As a basis for comparative study, we have described the neuroanatomy of the amphidial sensillae of P. trichosuri. Using computational methods we incorporated serial electron micrographs into a three-dimensional reconstruction of the amphidial neurons of this parasite. Each amphid is innervated by 13 neurons, and the dendritic processes of 10 of these extend nearly to the amphidial pore. Dendritic processes of two specialized neurons leave the amphidial channel and terminate within invaginations of the sheath cell. One of these is similar to the finger cell of C. elegans, terminating in digitiform projections. The other projects a single cilium into the sheath cell. The dendritic process of a third specialized neuron terminates within the tight junction of the amphid. Each amphidial neuron was traced from the tip of its dendrite(s) to its cell body in the lateral ganglion. Positions of these cell bodies approximate those of morphologically similar amphidial neurons in Caenorhabditis elegans, so the standard nomenclature for amphidial neurons in C. elegans was adopted. A map of cell bodies within the lateral ganglion of P. trichosuri was prepared to facilitate functional study of these neurons. PMID:21456026

Experimental immunization of ponies with Strongylus vulgaris radiation-attenuated larvae or crude soluble somatic extracts from larval or adult stages.

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Monahan, C M; Taylor, H W; Chapman, M R; Klei, T R

1994-12-01

Protection from Strongylus vulgaris infection through immunization with radiation-attenuated third-stage larvae (L3) or crude soluble homogenates from larval or adult stages was examined. Yearling ponies raised parasite-free were divided into 3 immunization groups: radiation-attenuated L3; soluble adult somatic extracts; larval somatic extracts with excretory/secretory products (E/S) from in vitro culture; and 1 medium control group. Ponies were immunized twice; attenuated larvae were administered orally and somatic extracts or controls injected intramuscularly with adjuvant. Approximately 6 wk following the second immunization, all ponies were challenged. Necrospy examinations were performed 6 wk following challenge. Irradiated larvae recipients had the fewest postchallenge clinical signs and lesions and were 91% protected from infection determined by larval recoveries from arterial dissections. Soluble antigen recipients and controls had similar larval recoveries and thus equal susceptibility to challenge. Soluble antigen recipients had more severe clinical signs and lesions than controls, suggesting that parenteral immunization exacerbated postchallenge inflammatory responses. Protection by immunization with irradiated larvae was associated with an anamnestic eosinophilia and postimmunization antibody recognition of S. vulgaris L3 surface antigens. Histologic staining of eosinophils within tissues of this group suggested that this immunization induced a cytophilic antibody response that facilitated degranulation.

[Arterial repair after mechanical injury by migrating fourth-stage larvae of Strongylus vulgaris in the horse (a light and electron microscopic study) (author's transl)].

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Pauli, B; Althaus, S; Von Tscharner, C

1975-08-01

Migrating fourth-stage larvae of Strongylus vulgaris, a parasite of equines, damage the intima of the anterior mesenteric artery and its larger branches and induce thrombus formation on the injured sites. As the time of larval passage through each of these branches has been exactly determined in earlier experiments, the aim of the present studies is to contribute to a more complete understanding of repair mechanisms in the process of time after thrombotic vascular injuries. five foals were separated individually to specially cleaned stables and given anthelmintic treatment till the age of one year. One foal was infected per os with 350, the second with 500 and the remaining three with 1,000 third-stage larvae of Strongylus vulgaris...

Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

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Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

2017-07-01

Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

International Nuclear Information System (INIS)

Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

2017-01-01

Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

Gamma radiation tolerance in different life stages of the fruit fly Drosophila melanogaster.

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Paithankar, Jagdish Gopal; Deeksha, K; Patil, Rajashekhar K

2017-04-01

Insects are known to have higher levels of radiation tolerance than mammals. The fruit fly Drosophila provides opportunities for genetic analysis of radiation tolerance in insects. A knowledge of stage-specific sensitivity is required to understand the mechanisms and test the existing hypothesis of insect radiation tolerance. Drosophila melanogaster were irradiated using gamma rays at different life stages. Irradiation doses were chosen to start from 100-2200 Gy with increments of 100 Gy, with a dose rate of 12.5 and 25 Gy/min. The threshold of mortality, LD 50 and LD 100 1 h post-irradiation was recorded for larvae and adults and 24 h post-irradiation for eggs and after 2-3 days for early and late pupae. Total antioxidant capacity for all the life stages was measured using the phosphomolybdenum method. Twenty-four hours post-irradiation, 100% mortality was recorded for eggs at 1000 Gy. One hour post irradiation 100% mortality was recorded at 1300 Gy for first instar larvae, 1700 Gy for second instar larvae, 1900 Gy for feeding third instar larvae and 2200 Gy for non-feeding third instar larvae. Post-irradiation complete failure of emergence (100% mortality) was observed at 130 Gy for early pupae and 1500 Gy for late pupae; 100% mortality was observed at 1500 Gy for adults. The values of LD 50 were recorded as 452 Gy for eggs, 1049 Gy for first instar larvae, 1350 Gy for second instar larvae, 1265 Gy for feeding third instar larvae, 1590 Gy for non-feeding third instar larvae, 50 Gy for early pupae, 969 Gy for late pupae, 1228 Gy for adult males and 1250 Gy for adult females. Early pupae were found to be prone to radiation, whereas the non-feeding third instar larvae were most resistant among all stages. The chromosome number being constant and total antioxidant capacity being nearly constant in all stages, we suggest that high rate of cell division during early pupae makes this stage sensitive to radiation.

Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9

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YASIR HASAN SIDDIQUE

2017-07-01

Full Text Available Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05. The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05.

Bacterial communities associated with white shrimp (Litopenaeus vannamei larvae at early developmental stages

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ANTONIUS SUWANTO

2010-04-01

Full Text Available Bacterial communities associated with white shrimp (Litopenaeus vannamei larvae at early developmental stages. Biodiversitas 11 (2: 65-68.Terminal Restriction Fragment Length Polymorphism (T-RFLP was used to monitor the dynamics of the bacterial communities associated with early developmental stages of white shrimp (Litopenaeus vannamei larvae. Samples for analysis were egg, hatching nauplii, 24 hours old nauplii, and 48 hours old nauplii which were collected from one cycle of production at commercial hatchery. T-RFLP results indicated that the bacterial community associated with early stages of shrimp development might be transferred vertically from broodstock via egg. There was no significant difference between bacterial communities investigated, except the bacterial community of 48 hours old nauplii. Diversity analyses showed that the bacterial community of egg had the highest diversity and evenness, meanwhile the bacterial community of 48 hours old nauplii had the lowest diversity. Nine phylotypes were found at all stages with high abundance. Those TRFs were identified as γ- proteobacteria, α-proteobacteria, and bacteroidetes group.

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

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Michelle L Castelletto

2009-04-01

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

Effect of SKT-b Vibrio probiotic bacteria addition at different developmental stages on tiger shrimp Penaeus monodon larvae survival rate

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. Widanarni

2009-07-01

Full Text Available This experiment was conducted to study the effect of probiotic bacteria SKT-b Vibrio addition at different developmental stages on survival rates of tiger shrimp Penaeus monodon larva.  Main activity of this experiment consisted of tiger shrimp rearing started from nauplius stage until Pl10 and addition of 106 CFU/ml SKT-b Vibrio probiotic bacteria at various developmental stages namely at early nauplius stage, early zoea zoea stage, early mysis stage, early postlarva (Pl stage, every developmental stage changes, everyday, and control (without probiotic bacteria addition. Results showed that survival rates of shrimp larva ranged at 24,17%-35,83% with the higest value in the treatment of probiotic bacteria addition at every developmental stage changes namely 35,83%, whereas the lowest was found at control (without probiotic bacteria addition namely 24,17%.  No significantly different was found in term of shrimp growth rate among control and treatment. Growth rate in length of tiger shrimp larva ranged 18,64%-19,09% for SKT-b Vibrio addition and 18,47% for control. Key word: Probiotic bacteria, SKT-b Vibrio, Penaeus monodon, shrimp larvae stages   ABSTRAK Penelitian ini dilakukan untuk mempelajari pengaruh pemberian bakteri probiotik Vibrio SKT-b pada stadia yang berbeda terhadap kelangsungan hidup larva udang windu Penaeus monodon. Kegiatan utama dari penelitian ini adalah pemeliharaan udang windu yang dimulai dari stadia nauplius sampai Pl10 dan diberi bakteri probiotik Vibrio SKT-b dengan dosis 106 CFU/ml pada waktu yang berbeda yaitu pada awal stadia nauplius, awal stadia zoea, awal stadia mysis, awal stadia postlarva (Pl, setiap pergantian stadia, setiap hari, dan kontrol (tanpa pemberian bakteri probiotik. Hasil penelitian yang diperoleh menunjukkan bahwa tingkat kelangsungan hidup larva udang berkisar antara 24,17%-35,83% dengan nilai tertinggi terdapat pada perlakuan pemberian bakteri probiotik pada setiap pergantian stadia yaitu

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

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

1985-06-01

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

Visualisation of cerebrospinal fluid flow patterns in albino Xenopus larvae in vivo

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Mogi Kazue

2012-04-01

Full Text Available Abstract Background It has long been known that cerebrospinal fluid (CSF, its composition and flow, play an important part in normal brain development, and ependymal cell ciliary beating as a possible driver of CSF flow has previously been studied in mammalian fetuses in vitro. Lower vertebrate animals are potential models for analysis of CSF flow during development because they are oviparous. Albino Xenopus laevis larvae are nearly transparent and have a straight, translucent brain that facilitates the observation of fluid flow within the ventricles. The aim of these experiments was to study CSF flow and circulation in vivo in the developing brain of living embryos, larvae and tadpoles of Xenopus laevis using a microinjection technique. Methods The development of Xenopus larval brain ventricles and the patterns of CSF flow were visualised after injection of quantum dot nanocrystals and polystyrene beads (3.1 or 5.8 μm in diameter into the fourth cerebral ventricle at embryonic/larval stages 30-53. Results The fluorescent nanocrystals showed the normal development of the cerebral ventricles from embryonic/larval stages 38 to 53. The polystyrene beads injected into stage 47-49 larvae revealed three CSF flow patterns, left-handed, right-handed and non-biased, in movement of the beads into the third ventricle from the cerebral aqueduct (aqueduct of Sylvius. In the lateral ventricles, anterior to the third ventricle, CSF flow moved anteriorly along the outer wall of the ventricle to the inner wall and then posteriorly, creating a semicircle. In the cerebral aqueduct, connecting the third and fourth cerebral ventricles, CSF flow moved rostrally in the dorsal region and caudally in the ventral region. Also in the fourth ventricle, clear dorso-ventral differences in fluid flow pattern were observed. Conclusions This is the first visualisation of the orchestrated CSF flow pattern in developing vertebrates using a live animal imaging approach. CSF flow

Third Stage (S-IVB) At KSC

Science.gov (United States)

1960-01-01

A NASA technician is dwarfed by the gigantic Third Stage (S-IVB) as it rests on supports in a facility at KSC. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

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

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Nyindo Mramba

2011-07-01

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

Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua)

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Zuo, S.; Barlaup, L.; Mohammadkarami, A.

2017-01-01

Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization...

Bacterial Community Associated with Healthy and Diseased Pacific White Shrimp (Litopenaeus vannamei) Larvae and Rearing Water across Different Growth Stages.

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Zheng, Yanfen; Yu, Min; Liu, Jiwen; Qiao, Yanlu; Wang, Long; Li, Zhitao; Zhang, Xiao-Hua; Yu, Mingchao

2017-01-01

Bacterial communities are called another "organ" for aquatic animals and their important influence on the health of host has drawn increasing attention. Thus, it is important to study the relationships between aquatic animals and bacterial communities. Here, bacterial communities associated with Litopenaeus vannamei larvae at different healthy statuses (diseased and healthy) and growth stages (i.e., zoea, mysis, and early postlarvae periods) were examined using 454-pyrosequencing of the 16S rRNA gene. Bacterial communities with significant difference were observed between healthy and diseased rearing water, and several bacterial groups, such as genera Nautella and Kordiimonas could also distinguish healthy and diseased shrimp. Rhodobacteraceae was widely distributed in rearing water at all growth stages but there were several stage-specific groups, indicating that bacterial members in rearing water assembled into distinct communities throughout the larval development. However, Gammaproteobacteria , mainly family Enterobacteriaceae , was the most abundant group (accounting for more than 85%) in shrimp larvae at all growth stages. This study compared bacterial communities associated with healthy and diseased L . vannamei larvae and rearing water, and identified several health- and growth stage-specific bacterial groups, which might be provided as indicators for monitoring the healthy status of shrimp larvae in hatchery.

Bacterial Community Associated with Healthy and Diseased Pacific White Shrimp (Litopenaeus vannamei Larvae and Rearing Water across Different Growth Stages

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Yanfen Zheng

2017-07-01

Full Text Available Bacterial communities are called another “organ” for aquatic animals and their important influence on the health of host has drawn increasing attention. Thus, it is important to study the relationships between aquatic animals and bacterial communities. Here, bacterial communities associated with Litopenaeus vannamei larvae at different healthy statuses (diseased and healthy and growth stages (i.e., zoea, mysis, and early postlarvae periods were examined using 454-pyrosequencing of the 16S rRNA gene. Bacterial communities with significant difference were observed between healthy and diseased rearing water, and several bacterial groups, such as genera Nautella and Kordiimonas could also distinguish healthy and diseased shrimp. Rhodobacteraceae was widely distributed in rearing water at all growth stages but there were several stage-specific groups, indicating that bacterial members in rearing water assembled into distinct communities throughout the larval development. However, Gammaproteobacteria, mainly family Enterobacteriaceae, was the most abundant group (accounting for more than 85% in shrimp larvae at all growth stages. This study compared bacterial communities associated with healthy and diseased L. vannamei larvae and rearing water, and identified several health- and growth stage-specific bacterial groups, which might be provided as indicators for monitoring the healthy status of shrimp larvae in hatchery.

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

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

2017-06-01

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

A reverse transcriptase-PCR assay for detecting filarial infective larvae in mosquitoes.

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Sandra J Laney

2008-06-01

Full Text Available Existing molecular assays for filarial parasite DNA in mosquitoes cannot distinguish between infected mosquitoes that contain any stage of the parasite and infective mosquitoes that harbor third stage larvae (L3 capable of establishing new infections in humans. We now report development of a molecular L3-detection assay for Brugia malayi in vectors based on RT-PCR detection of an L3-activated gene transcript.Candidate genes identified by bioinformatics analysis of EST datasets across the B. malayi life cycle were initially screened by PCR using cDNA libraries as templates. Stage-specificity was confirmed using RNA isolated from infected mosquitoes. Mosquitoes were collected daily for 14 days after feeding on microfilaremic cat blood. RT-PCR was performed with primer sets that were specific for individual candidate genes. Many promising candidates with strong expression in the L3 stage were excluded because of low-level transcription in less mature larvae. One transcript (TC8100, which encodes a particular form of collagen was only detected in mosquitoes that contained L3 larvae. This assay detects a single L3 in a pool of 25 mosquitoes.This L3-activated gene transcript, combined with a control transcript (tph-1, accession # U80971 that is constitutively expressed by all vector-stage filarial larvae, can be used to detect filarial infectivity in pools of mosquito vectors. This general approach (detection of stage-specific gene transcripts from eukaryotic pathogens may also be useful for detecting infective stages of other vector-borne parasites.

Anisakis simplex (Nematoda: Anisakidae) third-stage larval infections of marine cage cultured cobia, Rachycentron canadum L., in Taiwan.

Science.gov (United States)

Shih, Hsiu-Hui; Ku, Chen-Chun; Wang, Chun-Shun

2010-08-04

The first confirmed case of Anisakis simplex infection of the marine cage cobia, Rachycentron canadum (L.), was recorded in Taiwan. The case investigation revealed the presence of third-stage larvae (L3) in either the stomach lumen or abdominal cavity of the cobia but never within the musculatures. Larvae were mainly encapsulated in the peritoneal mesentery on the outer surface of the stomach wall and occasionally on the liver surface. Part of the diet fed to the cobia includes chopped raw fish, and of these, seven species were found to harbor these larvae (as paratenic hosts), indicating that these particular fish might be the larval sources for this infection. To illustrate the course of infection and distribution of this parasite inside cobia, both juvenile and adult cobia were experimentally infected with live L3 by oral transmission. The prevalence of infection reached 100% at the end of all trials. The course of the infection was assessed after necropsy by histological and ultrastructural observations. A. simplex L3 recovered from various locations within juvenile cobia at different post-infection (p.i.) times were at the L3 stage and did not grow significantly. The L3 either adhered to or penetrated into the gastric mucosa of cobia by 2 h p.i. By 25 d p.i., many were trapped within the submucosa and encapsulated by fibroconnective tissue. This phenomenon was more apparent in adult cobia, such that 37.5-86.0% of the injected L3 were primarily found encapsulated within the gastric submucosa. Based upon a PCR-RFLP assay, the larvae encountered in this study were identified as having a recombinant genotype of A. simplex sensu stricto and A. pegreffii. Based upon the results of this study, strategies to ensure the safety of seafood manufactured from cobia and to prevent the potential risks of anisakiasis or allergies risk to consumers were suggested. Copyright 2010 Elsevier B.V. All rights reserved.

Infective larvae of Rhabdiasidae (Nematoda): comparative morphology of seven European species.

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Kuzmin, Yuriy; Junker, Kerstin; Bain, Odile

2014-03-01

The morphology of infective third-stage larvae of Rhabdias bufonis, R. rubrovenosa, R. sphaerocephala, R. fuscovenosa, R. elaphe, Entomelas entomelas and E. dujardini is described. The sheath structure in the studied larvae appeared to be similar to that described in other species of the family Rhabdiasidae, its chequered aspect being caused by a combination of outer longitudinal striations and inner longitudinal as well as transverse ridges. The larvae were similar in general morphology but differed in the presence/absence of anterior apical protuberances (pseudolabia), the shape and ornamentation of the tail tip, and the structure of lateral alae in the caudal region of the body. No relationship between the morphological characters of the larvae of the studied species and their taxonomic position or specificity of adult parasites to a particular host group was observed. Regardless, the larvae of each species can be identified by a combination of morphological peculiarities in the anterior and caudal regions of the body.

Forensic age estimation based on magnetic resonance imaging of third molars: converting 2D staging into 3D staging.

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De Tobel, Jannick; Hillewig, Elke; Verstraete, Koenraad

2017-03-01

Established methods to stage development of third molars for forensic age estimation are based on the evaluation of radiographs, which show a 2D projection. It has not been investigated whether these methods require any adjustments in order to apply them to stage third molars on magnetic resonance imaging (MRI), which shows 3D information. To prospectively study root stage assessment of third molars in age estimation using 3 Tesla MRI and to compare this with panoramic radiographs, in order to provide considerations for converting 2D staging into 3D staging and to determine the decisive root. All third molars were evaluated in 52 healthy participants aged 14-26 years using MRI in three planes. Three staging methods were investigated by two observers. In sixteen of the participants, MRI findings were compared with findings on panoramic radiographs. Decisive roots were palatal in upper third molars and distal in lower third molars. Fifty-seven per cent of upper third molars were not assessable on the radiograph, while 96.9% were on MRI. Upper third molars were more difficult to evaluate on radiographs than on MRI (p third molars were equally assessable on both imaging techniques (93.8% MRI, 98.4% radiograph), with no difference in level of difficulty (p = .375). Inter- and intra-observer agreement for evaluation was higher in MRI than in radiographs. In both imaging techniques lower third molars showed greater inter- and intra-observer agreement compared to upper third molars. MR images in the sagittal plane proved to be essential for staging. In age estimation, 3T MRI of third molars could be valuable. Some considerations are, however, necessary to transfer known staging methods to this 3D technique.

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

Science.gov (United States)

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

2018-01-01

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

Peculiarities of Embryonic and Post-Embryonic Development of Оesophagostomum dentatum (Nematoda, Strongylidae Larvae Cultured in Vitro

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Yevstafieva V. А.

2017-02-01

Full Text Available Morphometric peculiarities of the development of Оesophagostomum dentatum Rudolphi, 1803 from egg to infective larva were studied under laboratory conditions at various temperatures. The determined optimum temperature for embryonic and post-embryonic development of О. dentatum larvae from domestic pig (Sus scrofa domesticus Linnaeus, 1758 is 22 °С. At this temperature, 81 % of larvae develop to the third stage (L3 on the 10th day. Temperatures of 24 °С and 20 °С are less favorable for the development of the nematode, at those temperatures only 67 and 63 % of larvae, respectively, reached infective stage by the 10th day of cultivation. Embryonic development of О. dentatum eggs is characterized by their lengthening (by 8.87-9.50 %, р < 0.01 and widening (by 6.77-9.35 %, р < 0.05-0.01, and post-embryonic larval development is associated with lengthening (by 4.59-17.33 %, р < 0.01-0.001.

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

International Nuclear Information System (INIS)

Hernandez Paz, M.

1992-01-01

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

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

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J. Ernandes-Silva

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

First stage larva of the mud shrimp Nihonotrypaea makarovi Marin, 2013 (Decapoda: Axiidea: Callianassidae) obtained in the laboratory.

Science.gov (United States)

Korn, Olga M; Kornienko, Elena S; Golubinskaya, Darya D

2016-02-19

First stage larva of a new mud shrimp Nihonotrypaea makarovi Marin, 2013 (Decapoda: Axiidea: Callianassidae) obtained from the ovigerous female is described and illustrated for the first time. The first zoea of N. makarovi is well distinguished from the first larvae of N. japonica and N. petalura, sympatric callianassid species inhabiting Russian waters of the Sea of Japan, only by the greater size and by the presence of two terminal setae on the antennal endopod.

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

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Blondine Ch. P.

2012-09-01

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

Development sites, feeding modes and early stages of seven European Palloptera species (Diptera, Pallopteridae).

Science.gov (United States)

Rotheray, Graham E

2014-12-19

Two hundred and ninety-eight rearing records and 87 larvae and puparia were obtained of seven species of Palloptera Fallén (Diptera, Pallopteridae), mainly in Scotland during 2012-2013. The third stage larva and puparium of each species were assessed morphologically and development sites and feeding modes investigated by rearing, observation and feeding tests. Early stages appear to be distinguished by the swollen, apico-lateral margins of the prothorax which are coated in vestiture and a poorly developed anal lobe with few spicules. Individual pallopteran species are separated by features of the head skeleton, locomotory spicules and the posterior respiratory organs. Five species can be distinguished by unique character states. Observations and feeding tests suggest that the frequently cited attribute of zoophagy is accidental and that saprophagy is the primary larval feeding mode with autumn/winter as the main period of development. Food plants were confirmed for flowerhead and stem developing species and rain is important for maintaining biofilms on which larvae feed. Due to difficulties in capturing adults, especially males, the distribution and abundance of many pallopteran species is probably underestimated. Better informed estimates are possible if early stages are included in biodiversity assessments. To facilitate this for the species investigated, a key to the third stage larva and puparium along with details on finding them, is provided. 

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

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

2017-08-30

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

Dose titration of moxidectin oral gel against migrating Strongylus vulgaris and Parascaris equorum larvae in pony foals.

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Monahan, C M; Chapman, M R; Taylor, H W; French, D D; Klei, T R

1995-11-01

Moxidectin was tested for efficacy in ponies against experimental infections of 56 day Strongylus vulgaris larvae and 11 day Parascaris equorum larvae. Three dosages of moxidectin were tested: 300 micrograms per kg live body weight, 400 micrograms per kg, and 500 micrograms per kg, and the vehicle served as control. Ponies were first infected with 600 S. vulgaris third-stage larvae (L3) on Experiment Day 0 and then with 3000 embryonated P. equorum eggs on Day 45. Moxidectin treatments were administered on Day 56 and necropsy examinations were performed on Day 91. Strongylus vulgaris fourth-stage (L4) and fifth-stage (L5) larvae were recovered at necropsy from the control ponies, in dissections of the cranial mesenteric artery and its branches (L4 and L5), and recovered from nodules in the wall of the cecum and ventral colon (L5). Parascaris equorum larvae were recovered from the small intestine of control ponies. Moxidectin was highly efficacious against S. vulgaris L4 and L5 at all three doses tested (99.6-100%), and appeared to be equally efficacious against P. equorum larvae (100%); however, control ponies had low levels of P. equorum infections compared to previous experimental infections performed using identical methods. This suggests that the prior S. vulgaris infection on Day 0 may have influenced the subsequent experimental P. equorum infection on Day 45 and contributed to the lower recovery.

Potency of Bacillus thuringiensis isolates from bareng Tenes-Malang City as a biological control agent for suppressing third instar of Aedes aegypti larvae

Science.gov (United States)

Lutfiana, Nihayatul; Gama, Zulfaidah Penata

2017-11-01

Dengue is a mosquito-borne viral disease that is transmitted by the female Aedes species. The number of dengue fever cases has increased in many geographic regions including Indonesia and one of them occurred in Bareng Tenes, Malang City, East Java Province. The objective of this research was to identify the potency of B. thuringeinsis isolates from Bareng Tenes, Malang, as the biological agent to control third instar Ae. aegypti larvae and to identify the potential B. thuringiensis isolates based on 16S rDNA sequence. B. thuringiensis was isolated from water and soil from 12 sites in the Bareng Tenes area. Bacterial isolation was performed using B. thuringiensis selective media. Several isolates had similar phenotypic characters with B. thuringiensis used to toxicity test against third instar Ae. aegypti larvae. The LC50-96h value was determined using probit regression. The most effective isolate was identified based on the 16S rDNA sequence, then aligned to the reference isolate using the BLAST program. A phylogeny tree was constructed using the Maximum Likelihood method. This study showed that among 22 isolates of B. thuringiensis, only BA02b, BS04a, and BA03a isolates have similar phenotypic characters with B. thuringiensis. Based on the toxicity test of B. thuringiensis against the third instar of Ae. aegypti larvae, it was indicated that BA02b and BA03a isolates were the potential agents to control Ae. aegypti larvae. BA02b isolate was the most effective B. thuringiensis (LC50-96h = 2,75 x 107 cell/mL). Based on 16S rDNA sequence, BA02b was identified as Bacillus thuringiensis var. Israelensis BGSC4Q2 (99 % similarities).

Evaluating Penetration Ability of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) Larvae into Multilayer Polypropylene Packages.

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Scheff, Deanna S; Sehgal, Blossom; Subramanyam, Bhadriraju

2018-04-18

The larvae of the Indian meal moth, Plodia interpunctella (Hübner), can invade or penetrate packaging materials and infest food products. Energy bars with three polypropylene packaging types were challenged with eggs (first instars), third instars, and fifth instars of P. interpunctella to determine package resistance at 28 °C and 65% r.h. The packing types were also challenged with two male and two female pupae of P. interpunctella under similar conditions in order to determine which package provided the greatest protection against larval penetration. Samples infested with eggs, third instars, and pupae were evaluated after 21 days and 42 days to count the number of larvae, pupae, and adults found inside the packages. Packages challenged with fifth instars were observed after 21 days to count the number of larvae, pupae, and adults inside each package. The number and diameter of the holes were determined in each package, followed by the amount of damage sustained to the energy bar. Third and fifth instars showed a higher tendency to penetrate all of the packaging types. First instars showed a reduction in package penetration ability compared with third and fifth instars. The increase in exposure time resulted in an increase in the damage sustained to the energy bars. Among packaging types, the thickest package (Test A) was most resilient to penetration by all of the larval stages. In conclusion, energy bar manufacturers need to invest more effort into improving packaging designs, creating thicker gauge films, or advancing odor barrier technology, in order to prevent penetration and infestation by P. interpunctella larvae.

Evaluating Penetration Ability of Plodia interpunctella (Hübner (Lepidoptera: Pyralidae Larvae into Multilayer Polypropylene Packages

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Deanna S. Scheff

2018-04-01

Full Text Available The larvae of the Indian meal moth, Plodia interpunctella (Hübner, can invade or penetrate packaging materials and infest food products. Energy bars with three polypropylene packaging types were challenged with eggs (first instars, third instars, and fifth instars of P. interpunctella to determine package resistance at 28 °C and 65% r.h. The packing types were also challenged with two male and two female pupae of P. interpunctella under similar conditions in order to determine which package provided the greatest protection against larval penetration. Samples infested with eggs, third instars, and pupae were evaluated after 21 days and 42 days to count the number of larvae, pupae, and adults found inside the packages. Packages challenged with fifth instars were observed after 21 days to count the number of larvae, pupae, and adults inside each package. The number and diameter of the holes were determined in each package, followed by the amount of damage sustained to the energy bar. Third and fifth instars showed a higher tendency to penetrate all of the packaging types. First instars showed a reduction in package penetration ability compared with third and fifth instars. The increase in exposure time resulted in an increase in the damage sustained to the energy bars. Among packaging types, the thickest package (Test A was most resilient to penetration by all of the larval stages. In conclusion, energy bar manufacturers need to invest more effort into improving packaging designs, creating thicker gauge films, or advancing odor barrier technology, in order to prevent penetration and infestation by P. interpunctella larvae.

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

Czech Academy of Sciences Publication Activity Database

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

2016-01-01

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

Toxic Potential of Synthesized Graphene Zinc Oxide Nanocomposite in the Third Instar Larvae of Transgenic Drosophila melanogaster (hsp70-lacZBg9

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Yasir Hasan Siddique

2014-01-01

Full Text Available In the present study the graphene zinc oxide nanocomposite (GZNC was synthesized, characterized, and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZBg9. The synthesized GZNC was characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The GZNC in 0.1% dimethyl sulphoxide (DMSO was sonicated for 10 minutes and the final concentrations 0.033, 0.099, 0.199, and 3.996 μg/μL of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hr. The hsp70 expression was measured by o-nitrophenyl-β-D-galactopyranoside assay, tissue damage was measured by trypan blue exclusion test, and β-galactosidase activity was monitored by in situ histochemical β-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 μg/μL of GZNC was toxic for both 24 hr and 48 hr of exposure. The doses of 0.033 μg/μL and 0.099 of GZNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hr of duration.

Extreme morphologies of mantis shrimp larvae

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Carolin Haug

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

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

Science.gov (United States)

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

2015-11-01

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

Estados inmaduros de Ancognatha ustulata (Coleoptera: Melolonthidae: Dynastinae: Cyclocephalini Immature stages of Ancognatha ustulata (Coleoptera: Melolonthidae: Dynastinae: Cyclocephalini

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Jhon César Neita-Moreno

2008-12-01

Full Text Available Se describen y se ilustran por primera vez la larva de tercer estadio y la pupa de Ancognatha ustulata Burmeister, 1847 (Coleoptera: Melolonthidae: Dynastinae: Cyclocephalini. Se aportan datos sobre la biología de la especie y su distribución en Colombia. Se proporciona una clave para la identificación de las larvas de tercer estadio conocidas de las especies del género Ancognatha Erichson.The third instar larva and pupa of Ancognatha ustulata Burmeister, 1847 (Coleoptera: Melolonthidae: Dynastinae: Cyclocephalini are described and illustrated for the first time. New data on larval biology and distribution of the species in Colombia are included. A key to the known third stage larvae of Ancognatha Erichson is provided.

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

DEFF Research Database (Denmark)

Hassanpour, Mehdi; Mohaghegh, Jafar; Iranipour, Shahzad

2011-01-01

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

Preventing postpartum haemorrhage: active management of the third stage of labour.

Science.gov (United States)

de Castro Parreira, Maria V B; Gomes, Nádia C Ferreira

2013-12-01

To review scientific publications on health to identify the main practices used for the active management of the third stage of vaginal labour and to assess their effectiveness in preventing postpartum haemorrhage. According to the World Health Organization (WHO Recommendations for the Prevention of Postpartum Haemorrhage, 2007. WHO Document Production Services, Geneva), postpartum haemorrhage is considered to be the cause of a quarter of maternal morbidity and mortality rates worldwide. In an attempt to reduce the risk of haemorrhage, a group of interventions have been introduced into clinical practice that constitute active management conduct during the third stage of labour and are recommended by the international organisations. An integrative literature review of studies on the subject in question, indexed in databases of health between the years 2006-2012, was conducted. The analysis included 13 articles, six of which were original articles and seven of which were literature reviews. Based on our data analysis, we found that most studies supported the effectiveness of active management in reducing the risk of haemorrhage, in the immediate postpartum period. Despite the fact that active management practices for the third stage of labour differ in their specific elements, in the majority of the selected studies, the interventions followed those recommended by the international organisations. The results of this review of management practices supported active management of the third stage of labour to prevent postpartum haemorrhage, with five main forms of intervention: administration of oxytocin, delayed clamping of umbilical cord, draining of placental blood, controlled cord traction and uterine massage. There is a need to determine gaps in the clinical practices of midwives in regard to the active management of third stage of labour, to update knowledge and practices with the latest scientific evidence. © 2013 John Wiley & Sons Ltd.

Morphology of the advanced-stage larva of Eustrongylides wenrichi Canavan 1929, occurring encapsulated in the tissues of Amphiuma in Louisiana.

Science.gov (United States)

Panesar, T S; Beaver, P C

1979-02-01

Larval nematodes identified as Eustrongylides wenrichi Canavan 1929, from cysts in the tissues of Amphiuma means tridactylum Cuvier in Louisana were redescribed. The extent of differentiation of the sex organs was found to be greater than that of 3rd-stage Dioctophyma renale, or of the infective stage of Trichinella spiralis, and comparable with the late 4th-stage larva of secernentean (phasmid) nematodes.

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

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S. M. Andrade-Porto

Full Text Available Abstract 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.

Immature stages of giants: morphology and growth characteristics of Goliathus Lamarck, 1801 larvae indicate a predatory way of life (Coleoptera, Scarabaeidae, Cetoniinae

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Tomáš Vendl

2016-09-01

Full Text Available The third larval instar of Goliathus goliatus (Drury, 1770, G. orientalis Moser, 1909 and G. albosignatus Boheman, 1857 are described and illustrated for the first time and compared with the immature stages of other Cetoniinae. Larval development of G. goliatus is investigated under laboratory conditions, with particular emphasis on food requirements. These results support the obligatory requirement of proteins in the larval diet. The association between larval morphological traits (e. g., the shape of the mandibles and pretarsus, presence of well-developed stemmata and larval biology is discussed. Based on observations and the data from captive breeds it is concluded that a possible shift from pure saprophagy to an obligatory predaceous way of larval life occurred within the larvae of this genus, which may explain why these beetles achieve such an enormous size.

Key to marine arthropod larvae

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John A. Fornshell

2012-03-01

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

Aft View of Saturn V Third Stage (S-IVB)

Science.gov (United States)

1960-01-01

The powerful J-2 engine is prominent in this photograph of a Saturn V Third Stage (S-IVB) resting on a transporter in the Manufacturing Facility at Marshall Space Flight Center in Huntsville, Alabama. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Third-stage turbine bucket airfoil

Science.gov (United States)

Pirolla, Peter Paul; Siden, Gunnar Leif; Humanchuk, David John; Brassfield, Steven Robert; Wilson, Paul Stuart

2002-01-01

The third-stage buckets have airfoil profiles substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in inches in Table I wherein Z is a perpendicular distance from a plane normal to a radius of the turbine centerline and containing the X and Y values with the Z value commencing at zero in the X, Y plane at the radially innermost aerodynamic section of the airfoil and X and Y are coordinates defining the airfoil profile at each distance Z. The X, Y and Z values may be scaled as a function of the same constant or number to provide a scaled-up or scaled-down airfoil section for the bucket.

Extreme morphologies of mantis shrimp larvae

OpenAIRE

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

2016-01-01

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

Effects of irradiation of Bombyx mori larvae on the evolution of ecdysteroid titer in haemolymph and ecdysone metabolism

International Nuclear Information System (INIS)

Coulon, Madeleine; Feyereisen, Rene

1977-01-01

Second and third instar larvae of B. mori show a peak of ecdysteroids in the haemolymph towards the end of each instar. Second instar larvae which are X-ray treated at 0 h die at the third ecdysis. In these larvae, titer and metabolism of ecdysone is disturbed. Larvae X-ray treated at 24h in the second instar mostly become permanent larvae of the third instar, having a very low level of circulating ecdysteroids, which hardly metabolize injected ecdysone [fr

Sun-Compass Orientation in Mediterranean Fish Larvae.

Science.gov (United States)

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.

Sun-Compass Orientation in Mediterranean Fish Larvae.

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Robin Faillettaz

Full Text Available 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.

Dental age estimation from the developmental stage of the third molars in western Chinese population.

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Li, Guo; Ren, Jiayin; Zhao, Shuping; Liu, Yuanyuan; Li, Na; Wu, Wanhong; Yuan, Shanshan; Wang, Hu

2012-06-10

The purpose of this study is to provide reference data about estimating dental age from third molars of the western Chinese population for comparing with other populations and being applied to the age estimation of western Chinese juveniles and adolescents. A total of 2078 digital panoramic radiographs of 989 male and 1089 female Chinese subjects aged between 5 and 23 years were examined. The mineralization status of the third molars was assessed using the formation stages described by Demirjian et al. with two modifications. The results showed that the development of third molars in the western Chinese population was likely to begin at age 5 in both males and females. The third molars 28 and 48 showed significantly higher frequency in females than in males. The third molars 18 in the stage 1, 38 in the stages 1, A and G, and 48 in the stage H showed significantly older average age in females than in males. The Demirjian's stages C and D could be used as a reference stage to determine dichotomously whether a western Chinese is more likely to be under or above age 14 or 16, respectively. This study provided reference data for the age estimation of western Chinese juveniles and adolescents by the mineralization stages of the third molar. Apart from forensic age determination in living subjects, the presented reference data can also be used for age estimations of unidentified corpses and skeletons. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Estimation of legal age using calcification stages of third molars in living individuals.

Science.gov (United States)

Streckbein, Philipp; Reichert, Isabelle; Verhoff, Marcel A; Bödeker, Rolf-Hasso; Kähling, Christopher; Wilbrand, Jan-Falco; Schaaf, Heidrun; Howaldt, Hans-Peter; May, Andreas

2014-12-01

The increased number of adolescents and young adults with unknown or inaccurately given date of birth is a current issue in justice and legal medicine. The objective of this study was to determine the extent to which third molar calcification stages assessed on panoramic X-rays could be useful as additional criteria for forensic age estimation in living individuals, focusing on the legally important ages 17 and 18. In a retrospective multi-center study, the developmental stage of each individual's third molar was analyzed using Demirjian's scale in 2360 cases. Additionally, sex, age and ancestry were assessed. Individuals with the lowest calcification stage of all present molars in stage H were ≥18 years with a likelihood of ≥99.05% in the female (n=388), and ≥99.24% in the male (n=482) population. The lowest calcification stage of all present third molars proved to be useful as an additional reliable criterion for the determination of an age ≥18 years. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

WITHDRAWN: Active versus expectant management in the third stage of labour.

LENUS (Irish Health Repository)

Prendiville, Walter J P

2012-02-01

BACKGROUND: Expectant management of the third stage of labour involves allowing the placenta to deliver spontaneously or aiding by gravity or nipple stimulation. Active management involves administration of a prophylactic oxytocic before delivery of the placenta, and usually early cord clamping and cutting, and controlled cord traction of the umbilical cord. OBJECTIVES: The objective of this review was to assess the effects of active versus expectant management on blood loss, post partum haemorrhage and other maternal and perinatal complications of the third stage of labour. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register. SELECTION CRITERIA: Randomised trials comparing active and expectant management of the third stage of labour in women who were expecting a vaginal delivery. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by the reviewers. MAIN RESULTS: Five studies were included. Four of the trials were of good quality. Compared to expectant management, active management (in the setting of a maternity hospital) was associated with the following reduced risks: maternal blood loss (weighted mean difference -79.33 millilitres, 95% confidence interval -94.29 to -64.37); post partum haemorrhage of more than 500 millilitres (relative risk 0.38, 95% confidence interval 0.32 to 0.46); prolonged third stage of labour (weighted mean difference -9.77 minutes, 95% confidence interval -10.00 to -9.53). Active management was associated with an increased risk of maternal nausea (relative risk 1.83, 95% confidence interval 1.51 to 2.23), vomiting and raised blood pressure (probably due to the use of ergometrine). No advantages or disadvantages were apparent for the baby. AUTHORS\\' CONCLUSIONS: Routine \\'active management\\' is superior to \\'expectant management\\' in terms of blood loss, post partum haemorrhage and other serious complications of the third stage of labour. Active

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

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J.M. Costa

1993-01-01

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

Sensibility of different larval stages of Schistosoma mansoni to the Larvae Disappearing Reaction (LDR in murine schistosomiasis

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Alan Lane de Melo

1986-12-01

Full Text Available The delay produced by drug, in the process of cercaria-schistosomulum transformation, was used to verify the sensibility of different larval stages to the host cell immune responses, in vivo. The peritoneal cavity of mice, a model used for in vivo observations, was choiced for the experiments. As well characterized schistosomules, cercariae and larvae in the process of transformation were coated and arrested by host cells, and could not be recovered by simple saline washings. After 10-²M EDTA saline washings, they were released alive, with good vitality and movements. Thus, different kind of larvae in the process of adaptation of the cercaria to the host are strongly coated by immune cells, but these fail to kill the invading organisms, at least during a few hours after invasion.

A COMPARATIVE STUDY OF OXYTOCIN/MISOPROSTOL/METHYLERGOMETRINE FOR ACTIVE MANAGEMENT OF THE THIRD STAGE OF LABOUR

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Mundlapaty Sabitha

2017-08-01

Full Text Available BACKGROUND The third stage of labour is indeed the unforgiving stage of the labour and in it lurks more unheralded treachery than in both the other stages of labour combined. Many lifesaving drugs have been discovered and used for the management of this stage of labour. According to the WHO multicentric randomised trial using oral misoprostol with oxytocic, they concluded that oral misoprostol was associated with significantly high incidence of side effects like shivering and rise in body temperature and hence oxytocin is preferred to 600 mg of oral misoprostol in management of 3rd stage of labour in hospital settings, but still misoprostol has been suggested for the management of third stage of labour in developing countries, because it has strong uterotonic effects, can be given orally, inexpensive and does not need refrigeration. The aim of the study is to compare oxytocin, misoprostol, methylergometrine for active management of the third stage of labour. MATERIALS AND METHODS A total of 300 women of 37 weeks to 42 weeks of gestation delivering vaginally in Konaseema Institute of Medical Sciences, Amalapuram, Andhra Pradesh. 300 women allocated into 3 groups of 100 each to receive 10 IU I.M. oxytocin, 600 mcg sublingual misoprostol or 200 mcg I.M. methylergometrine, respectively. Primary outcome measure was blood loss in the third stage of labor; secondary measures were duration of the third stage, side effects and complications. RESULTS Subjects who received 600 mcg of misoprostol had the least blood loss (113 mL, followed by oxytocin and methylergometrine. The shortest mean duration of the third stage was with misoprostol (4.34 mins.. Shivering and pyrexia were observed in misoprostol group and raised blood pressure in methylergometrine group. CONCLUSION Misoprostol is as effective as oxytocin and both are more effective than methylergometrine in active management of the third stage of labour. Misoprostol therefore can be used in places

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

Science.gov (United States)

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

2012-08-01

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

Estuarine retention of larvae of the crab Rhithropanopeus harrisii

Science.gov (United States)

Cronin, Thomas W.

1982-08-01

Larvae of estuarine organisms continually face possible export from the parent estuary. Retention of larvae of the estuarine crab Rhithropanopeus harrisii was investigated in the upper Newport River estuary, North Carolina. All of the developmental stages occurred in the same area of the estuary with similar horizontal distributions, and the concentrations of intermediate and late stages were not greatly reduced from those of the first larval stage. This was strong evidence for the continuous retention of larvae in the upper estuary. To determine mechanisms by which retention might be effected, field studies of the vertical distributions and migrations of these larvae were made. The four zoeal stages had similar but complex vertical migration patterns, which varied from study to study. These migrations centered on the depth of no net flow, reducing longitudinal transport during development. Cross-spectral analysis of the larval migrations and the environmental cycles of light, salinity and current speed revealed that each of these external cycles affected larval depth. Megalopae of R. harrisii also migrated vertically, but they were present in much lower concentrations than the zoeal stages, an indication of a change to benthic existence in this final larval form.

Forensic age estimation based on development of third molars: a staging technique for magnetic resonance imaging.

Science.gov (United States)

De Tobel, J; Phlypo, I; Fieuws, S; Politis, C; Verstraete, K L; Thevissen, P W

2017-12-01

The development of third molars can be evaluated with medical imaging to estimate age in subadults. The appearance of third molars on magnetic resonance imaging (MRI) differs greatly from that on radiographs. Therefore a specific staging technique is necessary to classify third molar development on MRI and to apply it for age estimation. To develop a specific staging technique to register third molar development on MRI and to evaluate its performance for age estimation in subadults. Using 3T MRI in three planes, all third molars were evaluated in 309 healthy Caucasian participants from 14 to 26 years old. According to the appearance of the developing third molars on MRI, descriptive criteria and schematic representations were established to define a specific staging technique. Two observers, with different levels of experience, staged all third molars independently with the developed technique. Intra- and inter-observer agreement were calculated. The data were imported in a Bayesian model for age estimation as described by Fieuws et al. (2016). This approach adequately handles correlation between age indicators and missing age indicators. It was used to calculate a point estimate and a prediction interval of the estimated age. Observed age minus predicted age was calculated, reflecting the error of the estimate. One-hundred and sixty-six third molars were agenetic. Five percent (51/1096) of upper third molars and 7% (70/1044) of lower third molars were not assessable. Kappa for inter-observer agreement ranged from 0.76 to 0.80. For intra-observer agreement kappa ranged from 0.80 to 0.89. However, two stage differences between observers or between staging sessions occurred in up to 2.2% (20/899) of assessments, probably due to a learning effect. Using the Bayesian model for age estimation, a mean absolute error of 2.0 years in females and 1.7 years in males was obtained. Root mean squared error equalled 2.38 years and 2.06 years respectively. The performance to

Evaluation of the toxic potential of calcium carbide in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9).

Science.gov (United States)

Danish, Mohd; Fatima, Ambreen; Khanam, Saba; Jyoti, Smita; Rahul; Ali, Fahad; Naz, Falaq; Siddique, Yasir Hasan

2015-11-01

In the present study the toxic potential of calcium carbide (CaC2) was studied on the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9). The third instar larvae were exposed to 2, 4, 8, 16 and 32×10(-3)g/ml of CaC2 in diet for 24h. The results reveal that the dose 2×10(-3)g/ml was not toxic but the remaining doses showed a dose dependent significant increase in the hsp70 expression, β-galactosidase activity, tissue damage, oxidative stress markers (lipid peroxidation and protein carbonyl content), glutathione-S-transferase activity, expression of Caspase 3 and 9, apoptotic index and DNA damage (midgut cells). A significant reduction as compared to control group in total protein, glutathione content and acetylcholinesterase activity was also observed. The Inductively Coupled Plasma Atomic Emission Spectroscopy analysis (ICPAES) reveals the presence of copper, iron, sodium, aluminium, manganese, calcium, nickel and mercury. The toxic effects of CaC2 in the present study may be attributed to the impurities present in it. Copyright © 2015 Elsevier Ltd. All rights reserved.

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method).

Science.gov (United States)

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant ( P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old ( P age were above 90% (all P Third molar development was positively affected by the chronological age ( P = 0.000) and being maxillary ( P = 0.000) but not sex ( P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations.

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

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Takaoka H.

2003-03-01

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

PREVENTION OF BLOOD LOSS IN THIRD STAGE OF LABOUR BY PLACENTAL BLOOD DRAINAGE- A CLINICAL STUDY

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B. K. Dutta

2017-12-01

Full Text Available BACKGROUND Placental cord drainage is a simple, safe and non-invasive method which reduces the duration and blood loss in the third stage of labour thereby preventing PPH. This method is of great use in day to day obstetric practices not requiring any extra effort, cost or equipment, so this type of practice is more relevant in rural areas. The objectives of the study were1. To evaluate the effectiveness of placental blood drainage via umbilical cord in reducing duration and blood loss in third stage of labour. 2. Reducing the incidence of postpartum haemorrhage. 3. Decreasing the complications in third stage of labour and reduce maternal mortality. MATERIALS AND METHODS This study was carried out in 100 full term pregnant women admitted in the labour room in Gauhati medical college and hospital in the department of obstetrics and gynaecology since 1st August 2007 to 30th August 2008. Cases were divided into two. Study group and control group. RESULTS In control group the average duration of third stage was 7.41 minutes and in study group 5.57 minutes and p value was <0.001 which is very highly significant. The blood loss in third stage of labour was more in case of control group, the mean blood loss in control was 169.48 ml and study group was 110.38 ml after delivery of placenta. The post-partum haemorrhage was present in 2% of cases in control group while in study group it was present in 0% case. CONCLUSION Placental blood drainage is one of the additional components in active management of third stage of labour, which is safe, simple and non-invasive method. It reduces the duration of third stage of labour, amount of blood loss and decreases the duration of placental separation time.

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

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Stacey M Williams

2010-10-01

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

Extreme morphologies of mantis shrimp larvae

DEFF Research Database (Denmark)

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

2016-01-01

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

Phylogenetics links monster larva to deep-sea shrimp.

Science.gov (United States)

Bracken-Grissom, Heather D; Felder, Darryl L; Vollmer, Nicole L; Martin, Joel W; Crandall, Keith A

2012-10-01

Mid-water plankton collections commonly include bizarre and mysterious developmental stages that differ conspicuously from their adult counterparts in morphology and habitat. Unaware of the existence of planktonic larval stages, early zoologists often misidentified these unique morphologies as independent adult lineages. Many such mistakes have since been corrected by collecting larvae, raising them in the lab, and identifying the adult forms. However, challenges arise when the larva is remarkably rare in nature and relatively inaccessible due to its changing habitats over the course of ontogeny. The mid-water marine species Cerataspis monstrosa (Gray 1828) is an armored crustacean larva whose adult identity has remained a mystery for over 180 years. Our phylogenetic analyses, based in part on recent collections from the Gulf of Mexico, provide definitive evidence that the rare, yet broadly distributed larva, C. monstrosa, is an early developmental stage of the globally distributed deepwater aristeid shrimp, Plesiopenaeus armatus. Divergence estimates and phylogenetic relationships across five genes confirm the larva and adult are the same species. Our work demonstrates the diagnostic power of molecular systematics in instances where larval rearing seldom succeeds and morphology and habitat are not indicative of identity. Larval-adult linkages not only aid in our understanding of biodiversity, they provide insights into the life history, distribution, and ecology of an organism.

Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater

Science.gov (United States)

Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

2016-03-01

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.

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

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Maryam DADAR

2016-10-01

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

siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

KAUST Repository

Zhang, G.

2015-06-25

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

siRNA transfection in larvae of the barnacle Amphibalanus amphitrite

KAUST Repository

Zhang, G.; He, L.-S.; Wong, Y. H.; Yu, L.; Qian, P.-Y.

2015-01-01

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

First description of the immature stages of Hemilucilia segmentaria (Diptera: Calliphoridae

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PATRICIA J THYSSEN

2007-01-01

Full Text Available The immature stages oí Hemilucilia segmentaria (Fabricius, 1805 (Diptera: Calliphoridae are described. Egg morphology and structures such as the cephalopharyngeal skeleton, anterior and posterior spiracles, and the dorsal spines between the prothorax and mesothorax from first, second and third instar larvae are characterized, using light and scanning electron microscopy. This species is abundant in Neotropical forests and, because of its necrophagous behavior, is of substantial medico-legal importance for estimating the postmortem interval in criminal investigations. Information presented herein may be useful to differentiate among eggs and larvae of closely related species and to supplement the database for blowfly identification

Image-based automatic recognition of larvae

Science.gov (United States)

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

2010-08-01

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

Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers

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Gomes Almério de Castro

1995-01-01

Full Text Available Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6,27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18degrees C to 22degrees C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05 than that of those emerging from the tire.

Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers

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Almério de Castro Gomes

1995-02-01

Full Text Available Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6,27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18° C to 22° C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05 than that of those emerging from the tire.

Effect of Cymbopogon citratus (lemongrass) and Syzygium aromaticum (clove) oils on the morphology and mortality of Aedes aegypti and Anopheles dirus larvae.

Science.gov (United States)

Soonwera, Mayura; Phasomkusolsil, Siriporn

2016-04-01

Cymbopogon citratus (lemongrass) and Syzygium aromaticum (clove) oils were evaluated to determine mortality rates, morphological aberrations, and persistence when used against third and fourth larval instars of Aedes aegypti and Anopheles dirus. The oils were evaluated at 1, 5, and 10 % concentrations in mixtures with soybean oil. Persistence of higher concentrations was measured over a period of 10 days. For Ae. aegypti, both plant oils caused various morphological aberrations to include deformed larvae, incomplete eclosion, white pupae, deformed pupae, dead normal pupae, and incomplete pupal eclosion. All of these aberrations led to larval mortality. In Ae. aegypti larvae, there were no significant differences in mortality at days 1, 5, and 10 or between third and fourth larval instar exposure. In An. dirus, morphological aberrations were rare and S. aromaticum oil was more effective in causing mortality among all larval stages. Both oils were equally effective at producing mortality on days 1, 5, and 10. Both oils had slightly increased LT50 rates from day 1 to day 10. In conclusion, both lemongrass and clove oils have significant effects on the immature stages of Ae. aegypti and An. dirus and could potentially be developed for use as larvicides.

Long-wavelength photosensitivity in coral planula larvae.

Science.gov (United States)

Mason, Benjamin M; Cohen, Jonathan H

2012-04-01

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

[Biotechnological aspects in "loco" larvae].

Science.gov (United States)

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

1990-10-01

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

An appraisal of certain larval behavioural activities as affected by gamma irradiation of Spodoptera larvae

International Nuclear Information System (INIS)

Seth, R.K.; Sehgal, S.S.

1987-01-01

Gamma irradiation of Spodoptera litura larvae induced an abatement in their locomotor activity. The food perception range and feeding behaviour of the larvae were also impaired. Of various dosages tested, 4 Krad (the sterilizing dose for larvae) caused a decline in locomotor speed. The first instar larvae, for instance showed decline in a speed of 3.74 cm/min to 2.96 cm/min. Similarly at this dose, the third instar larvae exhibited a reduction in speed to the extent of 38 to 45 per cent, the normal speed being 8.02 cm/min. The reactive distances of the first and third instar normal larvae were 5.30 cm and 7.36, respectively. This reactive distance was reduced by about 25 per cent after irradiation at 4 Krad, thus decreasing the food perception capacity significantly. The feeding behaviour too was significantly affected whereas the dose range less than 4 Krad did not induce such a marked impact. (author). 9 refs., 2 tables

An automated technique to stage lower third molar development on panoramic radiographs for age estimation: a pilot study.

Science.gov (United States)

De Tobel, J; Radesh, P; Vandermeulen, D; Thevissen, P W

2017-12-01

Automated methods to evaluate growth of hand and wrist bones on radiographs and magnetic resonance imaging have been developed. They can be applied to estimate age in children and subadults. Automated methods require the software to (1) recognise the region of interest in the image(s), (2) evaluate the degree of development and (3) correlate this to the age of the subject based on a reference population. For age estimation based on third molars an automated method for step (1) has been presented for 3D magnetic resonance imaging and is currently being optimised (Unterpirker et al. 2015). To develop an automated method for step (2) based on lower third molars on panoramic radiographs. A modified Demirjian staging technique including ten developmental stages was developed. Twenty panoramic radiographs per stage per gender were retrospectively selected for FDI element 38. Two observers decided in consensus about the stages. When necessary, a third observer acted as a referee to establish the reference stage for the considered third molar. This set of radiographs was used as training data for machine learning algorithms for automated staging. First, image contrast settings were optimised to evaluate the third molar of interest and a rectangular bounding box was placed around it in a standardised way using Adobe Photoshop CC 2017 software. This bounding box indicated the region of interest for the next step. Second, several machine learning algorithms available in MATLAB R2017a software were applied for automated stage recognition. Third, the classification performance was evaluated in a 5-fold cross-validation scenario, using different validation metrics (accuracy, Rank-N recognition rate, mean absolute difference, linear kappa coefficient). Transfer Learning as a type of Deep Learning Convolutional Neural Network approach outperformed all other tested approaches. Mean accuracy equalled 0.51, mean absolute difference was 0.6 stages and mean linearly weighted kappa was

Transcriptional changes in the hookworm, Ancylostoma caninum, during the transition from a free-living to a parasitic larva.

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Bennett J D Datu

Full Text Available BACKGROUND: Third-stage larvae (L3 of the canine hookworm, Ancylostoma caninum, undergo arrested development preceding transmission to a host. Many of the mRNAs up-regulated at this stage are likely to encode proteins that facilitate the transition from a free-living to a parasitic larva. The initial phase of mammalian host invasion by A. caninum L3 (herein termed "activation" can be mimicked in vitro by culturing L3 in serum-containing medium. METHODOLOGY/PRINCIPAL FINDINGS: The mRNAs differentially transcribed between activated and non-activated L3 were identified by suppression subtractive hybridisation (SSH. The analysis of these mRNAs on a custom oligonucleotide microarray printed with the SSH expressed sequence tags (ESTs and publicly available A. caninum ESTs (non-subtracted yielded 602 differentially expressed mRNAs, of which the most highly represented sequences encoded members of the pathogenesis-related protein (PRP superfamily and proteases. Comparison of these A. caninum mRNAs with those of Caenorhabditis elegans larvae exiting from developmental (dauer arrest demonstrated unexpectedly large differences in gene ontology profiles. C. elegans dauer exiting L3 up-regulated expression of mostly intracellular molecules involved in growth and development. Such mRNAs are virtually absent from activated hookworm larvae, and instead are over-represented by mRNAs encoding extracellular proteins with putative roles in host-parasite interactions. CONCLUSIONS/SIGNIFICANCE: Although this should not invalidate C. elegans dauer exit as a model for hookworm activation, it highlights the limitations of this free-living nematode as a model organism for the transition of nematode larvae from a free-living to a parasitic state.

Effectivity of Sugar-Apple (Annona squamosa Seed Extract with a Different Length of Storage against Culec quinquefasciatus Larvae

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Heni Prasetyowati

2012-06-01

Full Text Available Synthetic insecticide have been used to control Culex quinquefasciatus, but the prolonged usage of synthetic insecticide has a bad impact on the environment and may caused resistance. Sugar apple’s (Annona squamosa seeds which contain alkaloid can be used as an alternative insecticide that was safe for environment. This research aims is to know the effect of sugar apple’s seeds with different length of storage as C. quinquefasciatus larvacide. This research was an experimental study with a randomized controlled trial group design approach. The test material was an extract of sugar apple’s seeds which have been kept for 0, 1, 2, and 3 week with LC50 (0,47 ppm was used. Each treatment used 25 C. quinquefasciatus larvae from third instar larvae stage and replicated five times. After exposed for 24 hours, dead larvae counted. The result confirmed that the extract of sugar apple’s seeds which has been stored in 0, 1, 2, and 3 week did not showed any significant different on larvae mortality. Extract of sugar apple’s seeds which have been stored in 0, 1, 2, and 3 week have an equal activity as Culex quinquefasciatus larvicide.

Placental cord drainage in the third stage of labor: Randomized clinical trial.

Science.gov (United States)

Vasconcelos, Fernanda Barros; Katz, Leila; Coutinho, Isabela; Lins, Vanessa Laranjeiras; de Amorim, Melania Maria

2018-01-01

An open randomized clinical trial was developed at Instituto de Medicina Integral Prof. Fernando Figueira (IMIP) in Recife and at Petronila Campos Municipal Hospital in São Lourenço da Mata, both in Pernambuco, northeastern Brazil, including 226 low-risk pregnant women bearing a single, full-term, live fetus after delayed cord clamping, 113 randomized to placental cord drainage and 113 to a control group not submitted to this procedure. Women incapable of understanding the study objectives and those who went on to have an instrumental or cesarean delivery were excluded. Duration of the third stage of labor did not differ between the two groups (14.2±12.9 versus 13.7±12.1 minutes (mean ± SD), p = 0.66). Likewise, there was no significant difference in mean blood loss (248±254 versus 208±187ml, p = 0.39) or in postpartum hematocrit levels (32.3±4.06 versus 32.8±4.25mg/dl, p = 0.21). Furthermore, no differences were found between the groups for any of the secondary outcomes (postpartum hemorrhage >500 or >1000ml, therapeutic use of oxytocin, third stage >30 or 60 minutes, digital evacuation of the uterus or curettage, symptoms of postpartum anemia and maternal satisfaction). Placental cord drainage had no effect in reducing duration or blood loss during the third stage of labor. ClinicalTrials.gov: www.clinicaltrial.gov, NCT01655576.

Dental Age Estimation (DAE): Data management for tooth development stages including the third molar. Appropriate censoring of Stage H, the final stage of tooth development.

Science.gov (United States)

Roberts, Graham J; McDonald, Fraser; Andiappan, Manoharan; Lucas, Victoria S

2015-11-01

The final stage of dental development of third molars is usually helpful to indicate whether or not a subject is aged over 18 years. A complexity is that the final stage of development is unlimited in its upper border. Investigators usually select an inappropriate upper age limit or censor point for this tooth development stage. The literature was searched for appropriate data sets for dental age estimation and those that provided the count (n), the mean (x¯), and the standard deviation (sd) for each of the tooth development stages. The Demirjian G and Demirjian H were used for this study. Upper and lower limits of the Stage G and Stage H data were calculated limiting the data to plus or minus three standard deviations from the mean. The upper border of Stage H was limited by appropriate censoring at the maximum value for Stage G. The maximum age at attainment from published data, for Stage H, ranged from 22.60 years to 34.50 years. These data were explored to demonstrate how censoring provides an estimate for the correct maximum age for the final stage of Stage H as 21.64 years for UK Caucasians. This study shows that confining the data array of individual tooth developments stages to ± 3sd provides a reliable and logical way of censoring the data for tooth development stages with a Normal distribution of data. For Stage H this is inappropriate as it is unbounded in its upper limit. The use of a censored data array for Stage H using Percentile values is appropriate. This increases the reliability of using third molar Stage H alone to determine whether or not an individual is over 18 years old. For Stage H, individual ancestral groups should be censored using the same technique. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

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

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Akono Ntonga Patrick

2014-01-01

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

Morphology of immature stages of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) for use in forensic entomology applications.

Science.gov (United States)

Sukontason, Kabkaew L; Sribanditmongkol, Pongruk; Chaiwong, Tarinee; Vogtsberger, Roy C; Piangjai, Somsak; Sukontason, Kom

2008-09-01

In forensic investigations, all immature stages of flies (egg, larvae, and puparium) can serve as entomological evidence at death scenes. These insects are primarily used to estimate the post mortem interval (PMI), but can also be involved in the analysis of toxic substances, determining manner of death, and in indicating relocation of a corpse in homicide cases. In this study, we present the morphology of the egg, larvae, and puparium of Hemipyrellia ligurriens, a blow fly species of forensic importance in Thailand. Examination was conducted using scanning electron microscopy (SEM). The egg stage was found to display a relatively wide plastron region (or median hatch line area) that spans almost the entire length of the egg. The median hatch line is oriented in an upright position. External chorionic sculpture of the egg is present in a hexagonal pattern whose reticular boundaries are slightly elevated. In the larval stages, the most prominent morphological changes were detected upon comparison of the first to the second instar; whereas, the differences between second and third instar larvae were less obvious outside of the increase in number of posterior spiracular slits. Most of the major differences involve body size and structure of the anterior and posterior spiracles. Each anterior spiracle in both the second and third instars projects five to seven papillae apically. Each posterior spiracular disc of a third instar exhibits a complete peritreme, three spiracular slits, and a prominent button that is ventromedially located. The puparium is coarctate and features a clustered bubble membrane comprised of approximately 57 mammillate structures positioned dorsolaterally on each side of the first abdominal segment in young puparia. This feature is replaced by short, tubular respiratory horns in aged puparia. This study provides more detailed exposure of important morphological features that can be used for accurate identification of immature stages of H

Attempts at immunization against Malayan filariasis using X-irradiated infective larvae

International Nuclear Information System (INIS)

Ramachandran, C.P.

1975-01-01

Recent studies on immunity to helminthic infections have shown that some degree of protective immunity may be stimulated by inoculations of attenuated living worms or their metabolites. Although much on these lines has been done with several helminths, little if any has been done with filarial infections in general. Experiments were designed to observe the effects of attempted immunization in the rhesus monkey as well as the domestic cat by the use of attenuated infective larvae of Brugia malayi. The sub-periodic strain of Brugia malayi, the major filarial parasite of man in Malaysia, maintained in the laboratory on experimentally infected cats and rhesus monkeys were used for the preparation of X-irradiated vaccines as well as for challenge inoculations. Third-stage infective larvae of Brugia malayi were obtained from experimentally fed Aedes togoi mosquitoes. Infective larvae were irradiated by X-rays, using a Dermopan X-ray unit at exposures between 10 - 40 kR. Rhesus monkeys and cats were inoculated twice with 100 - 400 attenuated larvae per inoculation at 2 week intervals and challenged about a month later by inoculation of 100 normal larvae. Control animals for each vaccination dose as well as for challenge doses were maintained. In rhesus monkeys persistent immunity to challenge infections (expressed as failure to cause microfilaraemia) were obtained in animals vaccinated with 200 infective larvae attenuated by X-irradiation at 20000 R. Encouraged with the results obtained on rhesus monkeys, similar experiments on an enlarged scale using varying strengths of the vaccines were carried out on the domestic cat, which is a more receptive animal host for Brugia malayi. However, all cats vaccinated when challenged came down with patent infection indicating lack of any definite immunity. In all these experiments, results of vaccine control animals showed that inoculation of irradiated larvae was not followed by the infection of microfilaria in the blood, indicating

The Effect of the Timing of Intramuscular Oxytocin Injection on Maternal Bleeding during the Third Stage of Labour

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Sakine Mohamadian

2013-12-01

Full Text Available Background and aim: The third stage of labour is one of the most troublesome stages of child delivery. The basic principle of the third stage management is administrating prophylactic uterotonics. However, the time of its administration varies in different hospitals. This study aimed to determine the effect of intramuscular oxytocin injection after emergence of the fetal anterior shoulder or placental expulsion on bleeding in the third stage of labour. Methodology: This clinical trial was conducted on 100 pregnant women with gestational age of 38-42 weeks, and singleton pregnancies. Subjects were selected using convenience sampling and were then randomly assigned to intervention (injection of 10 IU intramuscular oxytocin after emergence of the fetal anterior shoulder and control (injection of 10 IU intramuscular oxytocin after placental expulsion groups. Blood was collected in containers and weighed with a weighing scale.  A checklist was used to record labor and delivery related data. Data were analyzed by SPSS version 11.5, using Chi-square and t-test. Findings: The mean amount of bleeding during the third stage of labour was 183.4 ± 145.8 and 202.2 ±208.8 ml in intervention and control group, respectively. No significant difference was found between two groups in terms of maternal bleeding. Conclusion: Injection of intramuscular oxytocin either after emergence of the fetal anterior shoulder or placental expulsion does not affect the amount of maternal bleeding during the third stage of labour.

Cochliomyia Homnivorax in an advanced stage in the oral cavity

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Layla Gomes

Full Text Available Myiasis is characterized by the invasion of body or cavity tissues of live animals by larva. It is most frequently observed in underdeveloped and tropical countries, but there are cases described worldwide. Conventional treatment consists of mechanical removal of the larvae, one by one, which is a painful, embarrassing and repugnant process, both for the professional and patient. Although it is not considered rare, it has been observed that the dental professional has little knowledge for the diagnosis and treatment of this pathology. For this reason, this study reports a case of oral myiasis at an advanced stage, which affected a nine-year-old patient, treated at a medical-dental clinic. Diagnosis was based on the visual presence of Cochliomyia homnivorax larvae, diptera of the Calliphoridae family, which were between the second and third stages of development. Predisposing factors, such as the lack of information, malnutrition, poor oral hygiene, preexistenceof oral lesions and severe halitosis have a decisive influence in the appearance and progression of oral myiasis. A brief literaturereview was also conducted, in which this pathology was discussed, including the importance of early clinical diagnosis, its etiology, possible associations with other pathologies, and different types of treatment.

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

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Mennatallah M Y Albarqi

2016-01-01

Full Text Available 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

Oral misoprostol versus oxytocin in the management of third stage of labour

International Nuclear Information System (INIS)

Aziz, S.; Kazi, S.; Haq, G.; Soomro, N.

2014-01-01

Objectives: To compare oral misoprostol versus intramuscular oxytocin in the management of third stage of labour. Methods: The quasi-experimental study was conducted at the Obstetrics and Gynaecology Unit II, Civil Hospital, Karachi, from June 20 to December 19, 2006. A total of 70 patients diagnosed in active phase of labour who fulfilled the inclusion criteria were selected by non-probability convenience sampling. These patients were divided into 2 groups of 35 patients each, for Oxytocin (Group 1) and misoprostol (Group 2). Main and secondary outcome measures were analysed. SPSS 10 was used for statistical analysis. Results: Average amount of blood loss(ml) was 267.14+-140.35 with Oxytocin versus 302.86+-160.4, with Misoprostol, this difference was statistically insignificant (p=0.236). Average drop in haemoglobin concentration (g/dl) with Oxytocin was 1.55+-0.38 vs 1.66+-0.61 with Misoprostol (p=0.684). Drop in haematocrit (%) was 4.18+-0.64 with Oxytocin vs. 4.50+-0.92 with Misoprostol (p=0.133). There was also insignificant difference in duration of third stage of labour, between oxytocin and Misoprostol groups (5.37+-2.20 vs. 5.23+-2.46, p=0.451) Shivering, in Misoprostol group occured in n=11 (31.4%) vs n=3 (8.6%) with Oxytocin (p=0.017) and pyrexia in n=6 (17.1%) with misoprostol vs n=0, with oxytocin (p=0.025) thus significantly higher in misoprostol group. Conclusion: There were no major differences in oral misoprostol and intramuscular oxytocin in the management of third stage of labour. (author)

Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus

DEFF Research Database (Denmark)

Derua, Yahya A.; Malongo, Bernard B.; Simonsen, Paul E.

2016-01-01

. Methods: A total of 1800 laboratory reared mosquito larvae of each species were used in the bioassays. Twelve replicates were performed, each testing 6 concentrations of ivermectin (0.0, 0.001, 0.01, 0.1, 1.0 and 10.0 parts per million (ppm)) against third instar larvae of An. gambiae and Cx...

Effects of the Liquids Used to Kill Larvae on the Length of Forensically Important Blow Fly Lucilia sericata Meigen (Diptera: Calliphoridae Larvae

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Halide Nihal Açıkgöz

2017-12-01

Full Text Available Forensic entomological practices rely upon accurate larval identification and measurement of larval length, for the estimation of post-mortem intervals. The methods used for killing larvae may affect the length of larvae. In the autopsy hall, corpses which are contain entomological remains have been washed with grape vinegar. Besides, while collecting and killing the larvae on corpses, crime scene teams use alcohol 70% because it is practical. The aim of this study was to determine which of hot water (90°C, cold vinegar and cold alcohol 96 % method, preserved the best the length of larvae. To achieve this aim, third instar larvae which are reared on 200 g of veal meat were killed using hot water, cold vinegar and cold alcohol. Before killing and after killing the maggots, their length was measured. To determine the difference between the groups to be compared ANOVA test, to reliability and validity analyses Kruskal-Wallis and whether there was any difference between the groups were made with Tukey’s Honestly Significant Difference (Tukey’s HSD Hot water was found to preserve the length of the larvae more accurately than cold vinegar and alcohol.

Bacterial Community Associated with Healthy and Diseased Pacific White Shrimp (Litopenaeus vannamei) Larvae and Rearing Water across Different Growth Stages

OpenAIRE

Zheng, Yanfen; Yu, Min; Liu, Jiwen; Qiao, Yanlu; Wang, Long; Li, Zhitao; Zhang, Xiao-Hua; Yu, Mingchao

2017-01-01

Bacterial communities are called another “organ” for aquatic animals and their important influence on the health of host has drawn increasing attention. Thus, it is important to study the relationships between aquatic animals and bacterial communities. Here, bacterial communities associated with Litopenaeus vannamei larvae at different healthy statuses (diseased and healthy) and growth stages (i.e., zoea, mysis, and early postlarvae periods) were examined using 454-pyrosequencing of the 16S r...

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

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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.

Sun-Compass Orientation in Mediterranean Fish Larvae

OpenAIRE

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

2015-01-01

International audience; 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...

Salinity tolerance of northern Brazilian mangrove crab larvae, Ucides cordatus (Ocypodidae): Necessity for larval export?

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Diele, Karen; Simith, Darlan J. B.

2006-07-01

The life cycle of the semiterrestrial mangrove crab Ucides cordatus includes pelagic larvae that are released into estuarine waters during the wet season and who may thus encounter potentially stressful low and variable salinity conditions. The effect of salinity on the survival of the zoea larvae, the number of zoeal stages and the duration of development from hatching to megalopa was experimentally studied by rearing larvae from the Caeté estuary, Northern Brazil, in seven salinity treatments (0, 5, 10, 15, 20, 25, and 30). For a better interpretation of the laboratory results, estuarine salinities were measured over five consecutive years during the species' reproductive season. The survival of the zoea larvae varied significantly with salinity, while the number of stages and the duration of their development remained constant. Development to megalopa took 20.77 ± 1.57 days and comprised five zoeal stages with ZI and ZII being euryhaline and later stages stenohaline. The newly hatched larvae stayed alive for up to 6 days in freshwater (average 4.32 ± 0.82 days), but did not moult to the second zoeal stage. ZII larvae first occurred from salinity 5 onwards and later zoeal stages at all tested salinities ≥10. However, the larvae only survived to megalopa at salinities ≥15, with highest numbers at salinity 30 (72%) and lowest at 15 (16%). Lethal salinities ≤10 occurred frequently in the estuary during the reproductive season. This suggests a need for larval export to offshore and thus more saline waters to allow for significant larval survival and maintenance of viable populations of this commercially important species. A regional rather than local approach for management is suggested due to the likelihood of long distance larval dispersal by offshore currents.

Care during the third stage of labour: A postal survey of UK midwives and obstetricians

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Tuffnell Derek

2010-05-01

Full Text Available Abstract Background There are two approaches to care during the third stage of labour: Active management includes three components: administration of a prophylactic uterotonic drug, cord clamping and controlled cord traction. For physiological care, intervention occurs only if there is clinical need. Evidence to guide care during the third stage is limited and there is variation in recommendations which may contribute to differences in practice. This paper describes current UK practice during the third stage of labour. Methods A postal survey of 2230 fellows and members of the Royal College of Obstetricians and Gynaecologists (RCOG and 2400 members of the Royal College of Midwives was undertaken. Respondents were asked about care during the third stage of labour, for vaginal and caesarean births and their views on the need for more evidence to guide care in the third stage. The data were analysed in Excel and presented as descriptive statistics. Results 1189 (53% fellows and members of the RCOG and 1702 (71% midwives responded, of whom 926 (78% and 1297 (76% respectively had conducted or supervised births in the last year. 93% (863/926 of obstetricians and 73% (942/1297 of midwives report 'always or usually' using active management. 66% (611/926 of obstetricians and 33% (430/1297 of midwives give the uterotonic drug with delivery of the anterior shoulder; this was intramuscular Syntometrine® for 79% (728/926 and 86% (1118/1293 respectively. For term births, 74% (682/926 of obstetricians and 41% (526/1297 of midwives clamp the cord within 20 seconds, as do 57% (523/926 and 55% (707/1297 for preterm births. Controlled cord traction was used by 94% of both obstetricians and midwives. For caesarean births, intravenous oxytocin was the uterotonic used by 90% (837/926 of obstetricians; 79% (726/926 clamp the cord within 20 seconds for term births as do 63% (576/926 for preterm births. Physiological management was used 'always or usually' by 2% (21

Warming and pCO2 effects on Florida stone crab larvae

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Gravinese, Philip M.; Enochs, Ian C.; Manzello, Derek P.; van Woesik, Robert

2018-05-01

Greenhouse gas emissions are increasing ocean temperatures and the partial pressure of CO2 (pCO2), resulting in more acidic waters. It is presently unknown how elevated temperature and pCO2 will influence the early life history stages of the majority of marine coastal species. We investigated the combined effect of elevated temperature (30 °C control and 32 °C treatment) and elevated pCO2 (450 μatm control and 1100 μatm treatment) on the (i) growth, (ii) survival, (iii) condition, and (iv) morphology of larvae of the commercially important Florida stone crab, Menippe mercenaria. At elevated temperature, larvae exhibited a significantly shorter molt stage, and elevated pCO2 caused stage-V larvae to delay metamorphosis to post-larvae. On average, elevated pCO2 resulted in a 37% decrease in survivorship relative to the control; however the effect of elevated temperature reduced larval survivorship by 71%. Exposure to both elevated temperature and pCO2 reduced larval survivorship by 80% relative to the control. Despite this, no significant differences were detected in the condition or morphology of stone crab larvae when subjected to elevated temperature and pCO2 treatments. Although elevated pCO2 could result in a reduction in larval supply, future increases in seawater temperatures are even more likely to threaten the future sustainability of the stone-crab fishery.

Intraumbilical venous injection oxytocinin the active management of third stage of labor

International Nuclear Information System (INIS)

Tehseen, F.; Anwar, A.; Arfat, Y.

2008-01-01

To determine the role of intraumbilical vein oxytocin reducing blood loss during and after one hour of delivery of placenta and its efficacy in reducing the frequency of retained placenta. Five hundred parturient women with low risk singleton term pregnancy were enrolled in the study. Two hundred and fifty women each were included in the study and control group after randomization. The patients and health care providers both were blinded to the intervention. Primary outcome measures were kept as duration and amount of blood loss in third stage of labour. Secondary outcome measures included incidence of retained placenta, abdominal need for additional utero-tonics, frequency of postpartum pain, nausea and vomiting, fever, need for blood transfusion, establishment of breast feeding and total duration of hospital stay. Women in study group who received intraumbilical vein syntocinon lost 234.03 ml of blood while the control group lost 276.51 ml (p=0.001). Mean duration of third stage was 2.59 minutes in the study group and 7.67 minutes in the control group (p<0.001). The frequency of retained placenta was 1.2%, which involved only the control group. Abdominal pain was experienced by study group but the difference was not found statistically significant. Nausea and vomiting was more in study group (p=0.001). No discernible difference was found in length of hospital stay, the need for blood transfusion, fever and establishment of breast-feeding in both groups. The addition of intraumbilical vein syntocinon 10 units resulted in marked reduction in amount of blood loss, duration of third stage and incidence of retained placenta in comparison to intravenous 5 IU oxytocin+0.5 mg ergometrine alone. (author)

Outcomes of physiological and active third stage labour care amongst women in New Zealand.

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Dixon, Lesley; Tracy, Sally K; Guilliland, Karen; Fletcher, Lynn; Hendry, Chris; Pairman, Sally

2013-01-01

during the third stage of labour there are two approaches for care provision - active management or physiological (expectant) care. The aim of this research was to describe, analyse and compare the midwifery care pathway and outcomes provided to a selected cohort of New Zealand women during the third stage of labour between the years 2004 and 2008. These women received continuity of care from a midwife Lead Maternity Carer and gave birth in a variety of birth settings (home, primary, secondary and tertiary maternity units). retrospective aggregated clinical information was extracted from the New Zealand College of Midwives research database. Factors such as type of third stage labour care provided; estimated blood loss; rate of treatment (separate to prophylaxis) with a uterotonic; and placental condition were compared amongst women who had a spontaneous onset of labour and no further assistance during the labour and birth. The results were adjusted for age, ethnicity, parity, place of birth, length of labour and weight of the baby. the rates of physiological third stage care (expectant) and active management within the cohort were similar (48.1% vs. 51.9%). Women who had active management had a higher risk of a blood loss of more than 500mL, the risk was 2.761 when a woman was actively managed (95% CI: 2.441-3.122) when compared to physiological management. Women giving birth at home and in a primary unit were more likely to have physiological management. A longer labour and higher parity increased the odds of having active management. Manual removal of the placenta was more likely with active management (0.7% active management - 0.2% physiological pwomen who were given a uterotonic drug as a treatment rather than prophylaxis a postpartum haemorrhage of more than 500mL was twice as likely in the actively managed group compared to the physiological managed group (6.9% vs. 3.7%, RR 0.54, CI: 0.5, 0.6). the use of physiological care during the third stage of labour

In vitro anthelmintic activity of Combretum molle (R. Br. ex G. Don) (Combretaceae) against Haemonchus contortus ova and larvae.

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Ademola, I O; Eloff, J N

2010-04-19

Parasitic nematodes, especially Haemonchus contortus (Rudolphi), are among the most common and economically important causes of disease in sheep and goats owned by pastoralists and small holder farmers in Africa. The control of these infections relies mainly on the use of anthelmintic drugs. However, herbal preparations are widely used by pastoralists and small holder farmers for the treatment of their livestock against helminth parasites. The anthelmintic effect of acetone leaf extract and fractions of Combretum molle was investigated to determine the relative efficacy of the components against gastrointestinal sheep nematodes. The fractions were obtained by solvent:solvent extraction from the acetone extract. These were evaluated for nematocidal activity by means of an egg hatch (EHA) and larval a development and viability assay (LDVA) in vitro. The effect of the test extracts on the hatchability of eggs and development of first to third stage larvae and the survival rate of the third stage larvae. H. contortus, were used to determine the relative bioactivities. Best-fit LC(50) values were computed using global model of nonlinear regression curve-fitting. The extracts inhibited egg hatching and development of the larvae of H. contortus in a concentration-dependent manner. Best-fit LC(50) values for the egg hatch test were 0.866, 0.333, 0.833, 0.747, and 0.065mg/mL for acetone extract, n-butanol, hexane, chloroform, and 35% water in methanol fractions, respectively. The best-fit LC(50) values for the LDVA were 0.604, 0.362, 1.077, 0.131 and 0.318mg/mL for the acetone extract, butanol, hexane, chloroform, and 35% water in methanol fractions, respectively. In the EHA the 35% water in methanol fraction was significantly more active than all the other fractions (pmolle leaf could find application in anthelmintic therapy in veterinary practice.

Digestion in sea urchin larvae impaired under ocean acidification

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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.

Active versus expectant management for women in the third stage of labour

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Begley, Cecily M; Gyte, Gillian ML; Devane, Declan; McGuire, William; Weeks, Andrew

2014-01-01

Background Active management of the third stage of labour involves giving a prophylactic uterotonic, early cord clamping and controlled cord traction to deliver the placenta. With expectant management, signs of placental separation are awaited and the placenta is delivered spontaneously. Active management was introduced to try to reduce haemorrhage, a major contributor to maternal mortality in low-income countries. Objectives To compare the effectiveness of active versus expectant management of the third stage of labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group Trials Register (15 February 2011). Selection criteria Randomised and quasi-randomised controlled trials comparing active versus expectant management of the third stage of labour. Data collection and analysis Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Main results We included seven studies (involving 8247 women), all undertaken in hospitals, six in high-income countries and one in a low-income country. Four studies compared active versus expectant management, and three compared active versus a mixture of managements. We used random-effects in the analyses because of clinical heterogeneity. There was an absence of high quality evidence for our primary outcomes. The evidence suggested that for women at mixed levels of risk of bleeding, active management showed a reduction in the average risk of maternal primary haemorrhage at time of birth (more than 1000 mL) (average risk ratio (RR) 0.34, 95% confidence interval (CI) 0.14 to 0.87, three studies, 4636 women) and of maternal haemoglobin (Hb) less than 9 g/dL following birth (average RR 0.50, 95% CI 0.30 to 0.83, two studies, 1572 women). We also found no difference in the incidence in admission of infants to neonatal units (average RR 0.81, 95% CI 0.60 to 1.11, two studies, 3207 women) nor in the incidence of infant jaundice requiring treatment (0

Helminths Parasite Larvae collected from Arabian Gulf Fish. 4. Description of four Larvae including two Metacercarae, one Didymozoid and one Acanthocephalan from Emirati Coasts

International Nuclear Information System (INIS)

Kardousha, M.M.

2005-01-01

Four helminth larvae from different fish hosts caught from Emirate coasts are described. Two are metacercariae related to genus Southampton's, type (I) and (II). Type (I) was found encysted in body cavities of the Indian halibut Psettodes erumei and the areolate grouper Epinephelus areolatusu and type (II) in the golden stripped goatfish Mulloides flavolineatus. The third larva is related to Acanthocephala and identified as Serrasentis sagittifer. It was collected from the body cavity of the spotted lizard fish Saurida undosquamius. The fourth larva belongs to the didymozoid trematodes, and was found infecting the kidneys of different hosts, such as Saurida undosquamis, the Jack pomfret Parastromateus niger and mackerel tuna Euthynnus affins. The larva related to Stephanostomum type (I) and type (II) and the dydimozoid type are described for the first time in the Arabian Gulf. (author)

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

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Stacey M Williams

2010-10-01

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

Immune-physiological aspects of synergy between avermectins and the entomopathogenic fungus Metarhizium robertsii in Colorado potato beetle larvae.

Science.gov (United States)

Tomilova, Oksana G; Kryukov, Vadim Yu; Duisembekov, Bahytzhan A; Yaroslavtseva, Olga N; Tyurin, Maksim V; Kryukova, Natalia A; Skorokhod, Valery; Dubovskiy, Ivan M; Glupov, Viktor V

2016-10-01

The interaction between the entomopathogenic fungus Metarhizium robertsii and natural avermectin metabolites of the actinomycete Streptomyces avermitilis were investigated on Colorado potato beetle larvae. A synergy in the mortality of larvae was detected after simultaneous treatment with half-lethal doses of avermectins (commercial name actarophit) 0.005% and fungus (5×10 5 conidia/ml). The treatment with avermectins led to rapid fungal colonization of the hemolymph. The defense strategies of insects infected by fungus and treated with avermectins and untreated insects were compared to investigate the mechanisms of this synergy. We have shown an increase in hemocytes, especially immunocompetent cells - plasmatocytes and granular cells in the initial stages of mycosis (third day post inoculation). In contrast, avermectins suppressed cellular immunity in hemolymph. Specifically, avermectins dramatically decreased the count of granular cells in larvae infected and uninfected with fungus. Apoptosis inducement and hemocyte necrosis under the influence of avermectins has been shown in vitro as one of the possible reasons for hemocyte mortality. In addition, avermectins enhanced the activity of phenoloxidases in integuments and hemolymph and increased the activity of glutathione-S-transferases activity in the fat body and hemolymph of infected and uninfected larvae, thereby intensifying the development of fungal infection by M. robertsii in Colorado potato beetle larvae. The combination of fungal infection and avermectins constitutes a new perspective for developing multicomponent bioinsecticides. Copyright © 2016 Elsevier Inc. All rights reserved.

Staging of third molar development in relation to chronological age of 5-16 year old Indian children.

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Hegde, Sapna; Patodia, Akash; Dixit, Uma

2016-12-01

The usefulness of the developmental status of the third molar has been studied in assessment of the chronological age of adolescents in whom the development of the other permanent teeth is nearly complete. However, little is known about the timing and pattern of third-molar development in the Indian population. This study aimed to stage the third molar development in relation to chronological age of 5-16year old Indian children. In this cross-sectional observational study, the status of third molar development in relation to chronological age of 1139 Indian children aged 5-16 years was evaluated radiographically, using Orhan's modification of Demirjian's method. The frequency of occurrence of the third molars varied from 47% to 70%. Crypt formation, crown completion and root completion occurred as early as 5.4, 8.7 and 15.0 years, respectively. No significant differences based on gender or side were observed in third-molar development (p>0.05). For most stages, maxillary third molars were slightly more advanced than their mandibular counterparts (p>0.05). Considering the high degree of variability observed in third molar genesis and development, the usefulness of this tooth in age determination studies may be very limited in the age group studied. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Methodical aspects of rearing decapod larvae, Pagurus bernhardus (Paguridae) and Carcinus maenas (Portunidae)

Science.gov (United States)

Dawirs, R. R.

1982-12-01

Improved methods for experimental rearing of Pagurus bernhardus and Carcinus maenas larvae are presented. Isolated maintenance was found essential for reliable statistical evaluation of results obtained from stages older than zoea-1. Only by isolated rearing is it possible to calculate mean values ±95% confidence intervals of stage duration. Mean values (without confidence intervals) can only be given for group-reared larvae if mortality is zero. Compared to group rearing, isolated rearing led to better survival, shorter periods of development and stimulated growth. Due to different swimming behavior P. bernhardus zoeae needed larger water volumes than Carcinus maenas larvae. P. bernhardus zoeae were reared with best results when isolated in Petri dishes (ca. 50 ml). They fed on newly hatched brine shrimp nauplii ( Artemia spp.). P. bernhardus megalopa did not require any gastropod shell or substratum; it developed best in glass vials without any food. C. maenas larvae could be reared most sucessfully in glass vials (ca 20 ml) under a simulated day-night regime (LD 16:8); constant darkness had a detrimental effect on development, leading to prolonged stage-duration times. C. maenas larvae were fed a mixture of newly hatched brine shrimp naupli and rotifers ( Brachionus plicatilis).

Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua).

Science.gov (United States)

Zuo, S; Barlaup, L; Mohammadkarami, A; Al-Jubury, A; Chen, D; Kania, P W; Buchmann, K

2017-10-01

Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast escape of more than 60% of the worm larvae within 20 min and gave full release within 65 min but the liver tissue became highly dispersed. HCl alone, in concentrations of 48 and 72 mM, triggered a corresponding release of worm larvae with minor effect on liver integrity. A lower HCl concentration of 24 mM resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation, with subsequent release of reaction products, may contribute to activation of C. osculatum larvae and induce escape reactions. Short-term pretreatment of infected cod liver and possibly other infected fish products, using low acid concentrations is suggested as part of a technological solution for worm clearance as low acid concentrations had limited macroscopic effect on liver integrity within 35 min.

Morphological development of Anchoviella vaillanti (Steindachner, 1908 (Clupeiformes: Engraulidae larvae and early juveniles

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Anailza Cristina G. da Silva

Full Text Available The considerable similarity in the early life stages of different fish species makes egg and larvae identification in fishery biology and ichthyoplankton surveys a difficult task. Knowledge on early larval development of morphologically similar taxa and species-rich orders, such as Clupeiformes, mainly in the Neotropical fresh waters is rather limited. The aim of the present study was to describe morphological and meristic aspects of the larvae and early juveniles of Anchoviella vaillanti, an endemic species of the São Francisco River basin in Brazil. The characterization was based on an ontogenetic series of 132 individuals (1.3-51.0 mm SL. In the larval period, body varies from elongated to very elongated and the head is small, which is typical of Clupeiformes. The finfold is present beginning in the yolk-sac stage, when larvae have a large yolk sac, until the flexion stage. Pectoral fin buds are the first to form during the preflexion stage, when dorsal- and anal-fin pterygiophores and hypural bones are first visible. The total vertebra count ranges from 36 to 39 and the myomere number ranges from 31 to 45. Complete fin formation obeys the following sequence: anal and dorsal fins during flexion stage; and pectoral, pelvic and caudal fins during postflexion stage. Despite being the only freshwater clupeiform representative in the São Francisco River, A. vaillanti may occur sympatrically with A. lepidentostole in the lower stretches of the river basin. Although early larvae characteristics of A. lepidentostole are not known, its late larvae and early juveniles may be distinguished from those of A. vaillanti, by the higher number of dorsal-fin rays (15 or 16 vs. 12 or 13 in A. vaillanti, higher total vertebra count (40 vs. 37 to 40 and shorter pre-pectoral length (14 to 16 vs. 22.8 to 28.9% SL.

The hatching larva of the priapulid worm Halicryptus spinulosus

OpenAIRE

Janssen, Ralf; Wennberg, Sofia A; Budd, Graham E

2009-01-01

Abstract Despite their increasing evolutionary importance, basic knowledge about the priapulid worms remains limited. In particular, priapulid development has only been partially documented. Following previous description of hatching and the earliest larval stages of Priapulus caudatus, we here describe the hatching larva of Halicryptus spinulosus. Comparison of the P. caudatus and the H. spinulosus hatching larvae allows us to attempt to reconstruct the ground pattern of priapulid developmen...

Obstetric care providers' knowledge, practice and associated factors towards active management of third stage of labor in Sidama Zone, South Ethiopia.

Science.gov (United States)

Tenaw, Zelalem; Yohannes, Zemenu; Amano, Abdela

2017-09-07

Active management of third stage of labor played a great role to prevent child birth related hemorrhage. However, maternal morbidity and mortality related to hemorrhage is high due to lack of knowledge and skill of obstetric care providers 'on active management of third stage of labor. Our study was aimed to assess knowledge, practice and associated factors of obstetric care providers (Midwives, Nurses and Health officers) on active management of third stage of labor in Sidama Zone, South Ethiopia. An institution based cross sectional study design was conducted from December 1-30 /2015 among midwives, nurses and health officers. Simple random sampling technique was used to get the total of 528 participants. Data entry was done using EPI Info 3.5.1 and exported to SPSS version 20.0 software package for analysis. The presence of association between independent and dependent variables was assessed using odds ratio with 97% confidence interval by applying logistic regression model. Of the 528 obstetric care providers 37.7% and 32.8% were knowledgeable and skilled to manage third stage of labor respectively. After controlling for possible confounding factors, the result showed that pre/in service training, being midwife and graduation year were found to be the major predictors of proper active management of third stage of labor. The knowledge and practice of obstetric care providers towards active management of third stage of labor can be improved with appropriate interventions like in-service trainings. This study also clearly showed that the level of knowledge and practice of obstetric care providers to wards active management of third stage of labor needs immediate attention of Universities and health science colleges better to revise their obstetrics course contents, health institutions and zonal health bureau should arrange trainings for their obstetrics care providers to enhance skill.

Dynamics of Social Behavior in Fruit Fly Larvae

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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

Effect of stocking density on growth, survival and development of asp Aspius aspius (L., ide Leuciscus idus (L. and chub Leuciscus cephalus (L. larvae during initial rearing under laboratory conditions

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Katarzyna Targońska

2011-07-01

Full Text Available This study was aimed at determining the effect of stocking density on growth, survival and development of asp Aspius aspius (L., ide Leuciscus idus (L. and chub Leuciscus cephalus (L. larvae, reared under laboratory conditions. Fish larvae were obtained during artificial reproduction. The larvae were fed ad libitum with freshly hatched Artemia sp. nauplii. Eight density variants from 50 to 400 individuals per 1 L (at the interval of 50 individuals L–1 were tested. The initial rearing was carried out for 21 days at 25°C in a recirculation system especially designed for that purpose consisting of 16 tanks with a capacity of 1 L each. The fastest growth rate for all three species, expressed as the greatest average total length, weight and most advanced ontogenetic stage at the end of the experiment was obtained at the lowest stocking density. Fish from other treatments, particularly at densities exceeding 150 individuals L–1, were characterized by similar body sizes and the same ontogenetic stage on the last day of rearing. The recorded differences in the length of larvae among treatments became visible during the first (asp or third (chub, ide week of rearing. No effects of stocking density on larval mortality were found during the experiment.

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

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Foster Leonard J

2009-08-01

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

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

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Gerane Celly Dias Bezerra

2006-08-01

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

Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae, inquiline into the gall of Leandra aurea (Melastomataceae

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Daniela de Cassia Bená

2013-12-01

Full Text Available Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae, inquiline into the gall of Leandra aurea (Melastomataceae. The third instar larva and the pupa of Anthonomus vis Clark, 1992 are described and illustrated, based upon specimens collected in the Serra de São José, Tiradentes, in Minas Gerais, southeastern Brazil. The species was previously known from the type series collected in the states of Amapá and Pará. Comparisons with the larva and pupa of A. grandis Boheman, 1843 and A. monostigma Champion, 1903 are included. The larvae of A. vis live as inquilines in the galls induced by a species of momphid moths (Lepidoptera, Momphidae in the stems of Leandra aurea (Cham. Cogn. (Melastomataceae.

[Influence of lecithotrofic feeding on growth and development of larvae of freshwater shrimp Macrobrachium rosenbergii].

Science.gov (United States)

Borisov, R R; Kriakhova, N V

2011-01-01

In the giant freshwater shrimp Macrobrachium rosenbergii (De Man), lecithotrofic feeding was discovered at the zoea I stage, and facultative lecithotrofic feeding was found at the zoea II stage. Cases of the completion of the first two stages without feeding were detected. However, a delay in feeding at the zoea II stage caused the inhibition of the growth and development of larvae. In this connection, we recommend to introduce food to the aquaculture of the giant freshwater shrimp on the end of the first day after hatching, when the first zoea II larvae emerge.

Analysis of metallotionein expression and antioxidant enzyme activities in Meretrix meretrix larvae under sublethal cadmium exposure

Energy Technology Data Exchange (ETDEWEB)

Wang Qing [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Wang Xiaomei [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Wang Xiaoyu [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Engineering Research Center of Seawater Utilization Technology, Ministry of Education, Hebei University of Technology, Tianjin 300130 (China); Yang Hongsheng, E-mail: hshyang@ms.qdio.ac.cn [Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7th Nanhai Road, Qingdao 266071 (China); Liu Baozhong, E-mail: bzliu@ms.qdio.ac.cn [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)

2010-11-15

To investigate the possible role of metallothioneins (MTs) and antioxidant enzymes in cadmium (Cd) tolerance in Meretrix meretrix larvae, a new MT (designated MmMT) gene was identified and cloned from M. meretrix. The full-length cDNA of MmMT consisted of an open reading frame (ORF) of 231 bp encoding a protein of 76 amino acids, with 21 cysteine residues and a conserved structural pattern Cys-x-Cys-x(3)-Cys-Tyr-Gly-x(3)-Cys-x-Cys-x(3)-Cys-x-Cys-Lys at the C-terminus. The deduced amino acid sequence of MmMT showed about 57-84% identity with previously published MT sequences of mussels and oysters. Real-time PCR was used to analyze the expression level of MmMT mRNA at different M. meretrix larval stages under Cd exposure (25 {mu}g L{sup -1}). Results showed that Cd could induce the expression of MmMT mRNA in the larvae, and the expression level increased 5.04-fold and 3.99-fold in D-shaped larvae and pediveligers, respectively. Immunolocalization of MmMT in the stressed larvae revealed that MmMT was synthesized in almost all of the soft parts at the trochophore and postlarva stages, whereas it was only synthesized in the velum and epidermis at the D-shaped larva and pediveliger stages. The activities of three antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), also were measured in larvae at different developmental stages. Increased enzymatic activities were detected mainly in D-shaped larvae and pediveligers under Cd stress, suggesting that these enzymes respond synchronously with MT. Our results indicate that MmMT and antioxidant enzymes played important roles in counteracting Cd stress in M. meretrix larvae.

Analysis of metallotionein expression and antioxidant enzyme activities in Meretrix meretrix larvae under sublethal cadmium exposure

International Nuclear Information System (INIS)

Wang Qing; Wang Xiaomei; Wang Xiaoyu; Yang Hongsheng; Liu Baozhong

2010-01-01

To investigate the possible role of metallothioneins (MTs) and antioxidant enzymes in cadmium (Cd) tolerance in Meretrix meretrix larvae, a new MT (designated MmMT) gene was identified and cloned from M. meretrix. The full-length cDNA of MmMT consisted of an open reading frame (ORF) of 231 bp encoding a protein of 76 amino acids, with 21 cysteine residues and a conserved structural pattern Cys-x-Cys-x(3)-Cys-Tyr-Gly-x(3)-Cys-x-Cys-x(3)-Cys-x-Cys-Lys at the C-terminus. The deduced amino acid sequence of MmMT showed about 57-84% identity with previously published MT sequences of mussels and oysters. Real-time PCR was used to analyze the expression level of MmMT mRNA at different M. meretrix larval stages under Cd exposure (25 μg L -1 ). Results showed that Cd could induce the expression of MmMT mRNA in the larvae, and the expression level increased 5.04-fold and 3.99-fold in D-shaped larvae and pediveligers, respectively. Immunolocalization of MmMT in the stressed larvae revealed that MmMT was synthesized in almost all of the soft parts at the trochophore and postlarva stages, whereas it was only synthesized in the velum and epidermis at the D-shaped larva and pediveliger stages. The activities of three antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), also were measured in larvae at different developmental stages. Increased enzymatic activities were detected mainly in D-shaped larvae and pediveligers under Cd stress, suggesting that these enzymes respond synchronously with MT. Our results indicate that MmMT and antioxidant enzymes played important roles in counteracting Cd stress in M. meretrix larvae.

Microarray-based analysis of differential gene expression between infective and noninfective larvae of Strongyloides stercoralis.

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Roshan Ramanathan

2011-05-01

Full Text Available Differences between noninfective first-stage (L1 and infective third-stage (L3i larvae of parasitic nematode Strongyloides stercoralis at the molecular level are relatively uncharacterized. DNA microarrays were developed and utilized for this purpose.Oligonucleotide hybridization probes for the array were designed to bind 3,571 putative mRNA transcripts predicted by analysis of 11,335 expressed sequence tags (ESTs obtained as part of the Nematode EST project. RNA obtained from S. stercoralis L3i and L1 was co-hybridized to each array after labeling the individual samples with different fluorescent tags. Bioinformatic predictions of gene function were developed using a novel cDNA Annotation System software. We identified 935 differentially expressed genes (469 L3i-biased; 466 L1-biased having two-fold expression differences or greater and microarray signals with a p value<0.01. Based on a functional analysis, L1 larvae have a larger number of genes putatively involved in transcription (p = 0.004, and L3i larvae have biased expression of putative heat shock proteins (such as hsp-90. Genes with products known to be immunoreactive in S. stercoralis-infected humans (such as SsIR and NIE had L3i biased expression. Abundantly expressed L3i contigs of interest included S. stercoralis orthologs of cytochrome oxidase ucr 2.1 and hsp-90, which may be potential chemotherapeutic targets. The S. stercoralis ortholog of fatty acid and retinol binding protein-1, successfully used in a vaccine against Ancylostoma ceylanicum, was identified among the 25 most highly expressed L3i genes. The sperm-containing glycoprotein domain, utilized in a vaccine against the nematode Cooperia punctata, was exclusively found in L3i biased genes and may be a valuable S. stercoralis target of interest.A new DNA microarray tool for the examination of S. stercoralis biology has been developed and provides new and valuable insights regarding differences between infective and

Irradiation of Eggs and Larvae of Bactrocera Carambolae (Drew and Hancock) Fruit Fly to Produce Irradiation Host for Its Parasitoids

International Nuclear Information System (INIS)

Achmad Nasroh Kuswadi; Murni lndarwatmi; Nasution, Indah Arastuti

2004-01-01

Bactrocera carambolae (Drew and Hancock) fruit fly, a major pests of commercial fruits in Indonesia, is attacked by several species of parasitoids in the field, such as by Biosteres sp. that attacks on early instar larvae and Opius sp. on late instar larvae. In order to produce irradiated host in mass rearing of both species, several dosage of gamma were tested on both eggs and larvae. Egg masses of 0.5 ml were irradiated with 0, 10, 20, 30, 40 and 50 Gy and then inoculated into artificial diet. Viability of the eggs, the larval period and the number of pupae produced were observed. About 200 third instar larvae irradiated with 0, 10, 30, 50,70 dan 90 Gy and the number and quality of the pupae developed were then observed. The results showed that the eggs irradiated with tested dosage did not reduce its viability however it reduced the survival of larvae emerged. Number of pupae produced from 0.5 ml irradiated eggs were reduced from 2740 pupae to 407, 167, 113, 53 and 44 pupae, besides the pupation delayed up to three days. Irradiation on third instars larvae did not reduce its pupation, since pupae were developed from > 85 % of irradiated larvae. However, irradiation did reduced the fly emergence from the pupae. Irradiated hosts for Biosteres sp and Opius sp can be produced by irradiating eggs however it should be evaluated since the survival rate of the larvae reduced. Irradiation of third instar larvae may produce irradiated host for Opius sp So, the use of irradiated eggs or irradiated larvae as host in the colonization of the parasitoids will insure no hosts emerged as adult. However it remain to be proved whether irradiated hosts are prefered and able to support the life of parasitoid. (author)

Hyperprolinemic larvae of the drosophilid fly, Chymomyza costata, survive cryopreservation in liquid nitrogen.

Science.gov (United States)

Kostál, Vladimír; Zahradnícková, Helena; Šimek, Petr

2011-08-09

The larva of the drosophilid fly, Chymomyza costata, is probably the most complex metazoan organism that can survive submergence in liquid nitrogen (-196 °C) in a fully hydrated state. We examined the associations between the physiological and biochemical parameters of differently acclimated larvae and their freeze tolerance. Entering diapause is an essential and sufficient prerequisite for attaining high levels of survival in liquid nitrogen (23% survival to adult stage), although cold acclimation further improves this capacity (62% survival). Profiling of 61 different metabolites identified proline as a prominent compound whose concentration increased from 20 to 147 mM during diapause transition and subsequent cold acclimation. This study provides direct evidence for the essential role of proline in high freeze tolerance. We increased the levels of proline in the larval tissues by feeding larvae proline-augmented diets and found that this simple treatment dramatically improved their freeze tolerance. Cell and tissue survival following exposure to liquid nitrogen was evident in proline-fed nondiapause larvae, and survival to adult stage increased from 0% to 36% in proline-fed diapause-destined larvae. A significant statistical correlation was found between the whole-body concentration of proline, either natural or artificial, and survival to the adult stage in liquid nitrogen for diapause larvae. Differential scanning calorimetry analysis suggested that high proline levels, in combination with a relatively low content of osmotically active water and freeze dehydration, increased the propensity of the remaining unfrozen water to undergo a glass-like transition (vitrification) and thus facilitated the prevention of cryoinjury.

Breastfeeding or nipple stimulation for reducing postpartum haemorrhage in the third stage of labour.

Science.gov (United States)

Abedi, Parvin; Jahanfar, Shayesteh; Namvar, Farideh; Lee, Jasmine

2016-01-27

Oxytocin and prostaglandin are hormones responsible for uterine contraction during the third stage of labour. Receptors in the uterine muscles are stimulated by exogenous or endogenous oxytocin leading to uterine contractions. Nipple stimulation or breastfeeding are stimuli that can lead to the secretion of oxytocin and consequent uterine contractions. Consequently, uterine contractions can reduce bleeding during the third stage of labour. To investigate the effects of breastfeeding or nipple stimulation on postpartum haemorrhage (PPH) during the third stage of labour. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 July 2015) and reference lists of retrieved studies. Randomised and quasi-randomised controlled trials comparing breast stimulation, breastfeeding or suckling for PPH in the third stage of labour were selected for this review. Two review authors independently assessed studies for inclusion in terms of risk of bias and independently extracted data. Disagreements were resolved by a third review author. We included four trials (4608 women), but only two studies contributed data to the review's analyses (n = 4472). The studies contributing data were assessed as of high risk of bias overall. One of these studies was cluster-randomised and conducted in a low-income country and the other study was carried out in a high-income country. All four included studies assessed blood loss in the third stage of labour. Birth attendants estimated blood loss in two trials. The third trial assessed the hematocrit level on the second day postpartum to determine the effect of the bleeding. The fourth study measured PPH ≥ 500 mL. Nipple stimulation versus no treatmentOne study (4385 women) compared the effect of suckling versus no treatment. Blood loss was not measured in 114 women (59 in control group and 55 in suckling group). After excluding twin pregnancies, stillbirths and neonatal deaths, the main analyses for this trial were performed on

Description of the third instar larva of Megadytes latus (Fabricius (Coleoptera, Dytiscidae, with an identification key for described larvae of the genus Descrição da larva de terceiro ínstar de Megadytes latus (Fabricius (Coleoptera, Dytiscidae

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Nelson Ferreira-Jr

2006-09-01

Full Text Available The last instar larva of M. latus (Fabricius, 1801 is described and figured, based on reared specimens from Serra dos Órgãos, Teresópolis, state of Rio de Janeiro, Brazil. Some notes on the biotope are provided.A larva de terceiro ínstar de M. latus (Fabricius, 1801 é descrita e ilustrada, baseado em espécimes criados da Serra dos Órgãos, Teresópolis, Rio de Janeiro, Brasil. Algumas notas acerca do biótopo onde as larvas foram coletadas são incluídas.

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

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Miguel Mies

2017-05-01

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

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

KAUST Repository

Mies, Miguel

2017-05-30

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

Food web changes under ocean acidification promote herring larvae survival.

Science.gov (United States)

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

2018-05-01

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

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

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Paola V Castro

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

Bacterial fatty acids enhance recovery from the dauer larva in Caenorhabditis elegans.

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Tiffany K Kaul

Full Text Available The dauer larva is a specialized dispersal stage in the nematode Caenorhabditis elegans that allows the animal to survive starvation for an extended period of time. The dauer does not feed, but uses chemosensation to identify new food sources and to determine whether to resume reproductive growth. Bacteria produce food signals that promote recovery of the dauer larva, but the chemical identities of these signals remain poorly defined. We find that bacterial fatty acids in the environment augment recovery from the dauer stage under permissive conditions. The effect of increased fatty acids on different dauer constitutive mutants indicates a role for insulin peptide secretion in coordinating recovery from the dauer stage in response to fatty acids. These data suggest that worms can sense the presence of fatty acids in the environment and that elevated levels can promote recovery from dauer arrest. This may be important in the natural environment where the dauer larva needs to determine whether the environment is appropriate to support reproductive growth following dauer exit.

Insecticidal activity of the petroleum ether extract of Ageratum Conyzoides L

International Nuclear Information System (INIS)

Calle, Jairo; Rivera, Augusto

1990-01-01

We have determined the insecticidal activity of the petroleum ether (bp 40-60o C) extract of Ageratum Conyzoides L. Towards mosca domestica (diptera) third stage larvae and cynthia Carye (Lepidoptera) third, fourth and fifth stage larvae, being this extract also active against Acanthoscelides obtectus (Coleoptera) adults. We have isolated the known chromene precocene II from this extract, which is highly toxic to M. domestica third stage larvae under sunlight exposure, while no larvicidal effect was shown under U.V. irradiation or in dark. We have also identified two flavonoids: Eupalestin and lucidin dimethyl ether, which insecticidal role in this extract has not been determinate

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

International Nuclear Information System (INIS)

Mansour, M.

2011-06-01

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

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

International Nuclear Information System (INIS)

Mansour, M.

2012-01-01

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

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

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

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

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

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Liberta Nika

2016-07-01

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

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

Science.gov (United States)

Nika, Liberta; Gibson, Taylor; Konkus, Rebecca; Karp, Xantha

2016-01-01

Precise staging of Caenorhabditis elegans is essential for developmental studies in different environmental conditions. In favorable conditions, larvae develop continuously through four larval stages separated by molting periods. Distinguishing molting from intermolt larvae has been achieved using transgenes with molting reporters, therefore requiring strain constructions, or careful observation of individuals for pharyngeal pumping or behavioral quiescence. In unfavorable conditions, larvae can enter the stress-resistant and developmentally arrested dauer larva stage. Identifying dauer larvae has been based on their ability to withstand detergent selection, precluding identification of recovering animals or of mutants with defects in dauer morphogenesis. Here, we describe a simple method to distinguish molting larvae or dauer larvae from intermolt larvae that bypasses the limitations of current methods. Fluorescent latex beads are mixed with the bacterial food source and ingested by intermolt larvae and adults. Molting and dauer larvae do not feed, and therefore lack beads in their digestive tract. The presence of beads can be determined using a dissecting microscope at magnifications as low as 100 ×, or by using a wormsorter for high-throughput experiments. We find that continuously developing bead-lacking larvae display hallmarks of molting, including expression of the mlt-10::gfp molting marker and a lack of pharyngeal pumping. Furthermore, wild-type and mutant dauer larvae produced by any of three common methods are accurately identified by a lack of beads. Importantly, this method is effective in SDS-sensitive mutant backgrounds and can identify recovering dauer larvae, a stage for which there is no other method of positive selection. PMID:27172224

Larvae of the Commercial Tropical Oyster Crassostrea belcheri (Sowerby) are induced to settle by Pheromones from the Adults

DEFF Research Database (Denmark)

Bussarawit, Somchai; Cedhagen, Tomas

2012-01-01

Pediveliger larvae of the commercial tropical oyster Crassostrea belcheri were allowed to settle under different conditions. Two types of seawater were used for the experiments: aged seawater (1 month) and aged seawater conditioned by the presence of adult oysters for 24 hours. Two groups of five...... other species within the same genus or from a different genus. Settling frequency was increased by the presence of living oysters together with soaked spatfall collectors in commercial aquaculture. The fact that larvae are induced to settle by pheromones released from the adults is an important...... mechanism that favours the gregariousness of the oysters in nature. Settling behaviour of oyster larvae was observed and the behaviour of the three main stages was described: free swimming searching stage, crawling stage and cementing stage....

Analysis of 1202 orthopantograms to evaluate the potential of forensic age determination based on third molar developmental stages.

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Willershausen, B; Löffler, N; Schulze, R

2001-09-28

A total of 1202 orthopantograms of young dental patients were analyzed to assess the correlation of third molar root development with chronological age. The investigated patients were treated at a university dental clinic on an outpatient basis, included a variety of demographic characteristics (600 males and 602 females, 28% of other than central European background), and were 15-24 years old when the radiographs were obtained. Radiographs in which more than one third molar were either missing due to agenesia or extraction, or not evaluable because of deep destruction or marked tilting, were not included in the analysis. Our findings show that the growth patterns of third molars, based on seven defined stages of root development, did correlate with chronological age; age estimation when applied to a specific individual would involve a margin of error of +/- 2-4 years. There were no significant differences between the left and right jaw segments, but the stage of root development was generally more advanced in the upper than in the lower third molars. Root development was also more advanced among boys than among girls of the same age. There were no apparent differences in growth patterns based on national/ethnic background. While only 2.5% of 18-year-olds revealed fully developed third molars in all four quadrants, this percentage leaped to 38.4% among the 21-year-olds. To summarize, while the developmental stage of third molars is not per se a highly useful indicator of chronological age in juveniles and young adults, it is nevertheless a valuable supplementary parameter given the scarcity of other available age indicators.

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

Science.gov (United States)

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.

Dental age assessment of adolescents and emerging adults in United Kingdom Caucasians using censored data for stage H of third molar roots.

Science.gov (United States)

Boonpitaksathit, Teelana; Hunt, Nigel; Roberts, Graham J; Petrie, Aviva; Lucas, Victoria S

2011-10-01

The root of the third permanent molar is the only dental structure that continues development after completion of growth of the second permanent molar. It is claimed that the lack of a clearly defined end point for completion of growth of the third permanent molar means that this tooth cannot be used for dental age assessment. The aim of this study was to estimate the mean age of attainment of the four stages (E, F, G, and H) of root development of the third molar. The way in which the end point of completion of stage H can be identified is described. A total of 1223 dental panoramic tomographs (DPTs) available in the archives of the Eastman Dental Hospital, London, were used for this study. The ages of the subjects ranged from 12.6 to 24.9 years with 63 per cent of the sample being female. Demirjan's tooth development stages (TDSs), for the first and second molars, were applied to the third molars by a single examiner. For each of stages E, F, and G and for stage H censored data, the mean ages of the males and females were compared, separately within each tooth morphology type using the two sample t-test (P ages of the upper and lower third molars on each side, separately for each gender. The mean age of attainment and the 99 per cent confidence interval (CI) for each TDS were calculated for each third molar. The final stage H data were appropriately censored to exclude data above the age of completion of root growth. The results showed that, for each gender, the age in years at which individuals attained each of the four TDSs was approximately normally distributed. The mean age for appropriately censored data was always lower than the corresponding mean age of the inappropriately censored data for stage H (male UR8 19.57, UL8 19.53, LL8 19.91, and LR8 20.02 and female UR8 20.08, UL8 20.13, LL8 20.78, and LR8 20.70). This inappropriately censored data overestimated the mean age for stage H. The appropriately censored data for the TDSs of the third molar may be

Defensive enrolment in mantis shrimp larvae (Malacostraca: Stomatopoda)

NARCIS (Netherlands)

Haug, C.; Haug, J.T.

2014-01-01

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

The hatching larva of the priapulid worm Halicryptus spinulosus.

Science.gov (United States)

Janssen, Ralf; Wennberg, Sofia A; Budd, Graham E

2009-05-26

Despite their increasing evolutionary importance, basic knowledge about the priapulid worms remains limited. In particular, priapulid development has only been partially documented. Following previous description of hatching and the earliest larval stages of Priapulus caudatus, we here describe the hatching larva of Halicryptus spinulosus. Comparison of the P. caudatus and the H. spinulosus hatching larvae allows us to attempt to reconstruct the ground pattern of priapulid development. These findings may further help unravelling the phylogenetic position of the Priapulida within the Scalidophora and hence contribute to the elucidation of the nature of the ecdysozoan ancestor.

[Description of Melolonthidae (Coleoptera) third instar larvae associated to Agave tequilana var. Azul and their population fluctuation in Jalisco, Mexico].

Science.gov (United States)

García, Gabriel L; Ortega-Arenas, Laura; Hernández, Héctor G; García, Agustín A; Nápoles, Jesús R; Cortés, Ramón R

2009-01-01

Third instars of white grubs of six species associated to agave tequilero in Jalisco, México were described from 1,145 specimens collected from soil samples from September 2006 to August 2007, in the municipalities of Ixtlahuacán del Río, Tepatitlán de Morelos and San Juan de Escobedo, Jalisco, México. Diagnostic characters were illustrated and a key was also included. Cyclocephala comata (Bates) was the most abundant species (63.2%), followed by Phyllophaga ravida (Blanchard) (21.9%), Phyllophaga polyphylla (Bates) (9.4%), Phyllophaga misteca (Bates) (4.1%), Strategus aloeus (L.) (1.1%) and Anomala hoepfneri (Bates) (0.3%). Phyllophaga ravida and A. hoepfneri are reported for the first time on the agave plant and the latter is a new record for the State of Jalisco. All Melolonthidae species showed a marked seasonality with lower number of larvae in June 2007 and high number in August 2007, which is associated with the region's rainy season and the agave plant age, respectively.

Concomitant changes in radiation resistance and trehalose levels during life stages of Drosophila melanogaster suggest radio-protective function of trehalose.

Science.gov (United States)

Paithankar, Jagdish Gopal; Raghu, Shamprasad Varija; Patil, Rajashekhar K

2018-04-20

During development, various life stages of Drosophila melanogaster (D. melanogaster) show different levels of resistance to gamma irradiation, with the early pupal stage being the most radiation sensitive. This provides us an opportunity to explore the biochemical basis of such variations. The present study was carried out to understand the mechanisms underlying radiation resistance during life stages of D. melanogaster. Homogenates from all the life stages of D. melanogaster were prepared at stipulated age. These homogenates were used for the determination of (1) enzymatic antioxidants: superoxide dismutase (SOD), catalase, D. melanogaster glutathione peroxidase (DmGPx), and glutathione S-transferase (GST); (2) reducing non-enzymatic antioxidants: total antioxidant capacity (TAC), reduced glutathione (GSH) and non-reducing non-enzymatic antioxidant trehalose; and (3) levels of protein carbonyl (PC) content. Age-dependent changes in radiation resistance and associated biochemical changes were also studied in young (2 d) and old (20 and 30 d) flies. TAC and GSH were found high in the early pupal stage, whereas catalase and DmGPx were found to increase in the early pupal stage. The non-feeding third instar (NFTI) larvae were found to have high levels of SOD and GST, besides NFTI larvae showed high levels of trehalose. A remarkable decrease was observed in radiation resistance and trehalose levels during the early pupal stage. The PC level was the highest during early pupal stage and was the lowest in NFTI larvae. Older flies showed high level of PC compared with young flies. In vitro increments in trehalose concentration correspond to reduced formation of PCs, suggesting a protective role of trehalose against free radicals. A strong correlation between levels of trehalose and PC formation suggests amelioration of proteome damage due to ionizing radiation (IR). Stages with high trehalose levels showed protected proteome and high radiation resistance, suggesting a

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

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Tatiana D Mayorova

2016-12-01

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

Nuttalliella namaqua (Ixodoidea: Nuttalliellidae: first description of the male, immature stages and re-description of the female.

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Abdalla A Latif

Full Text Available Nuttalliella namaqua is the only species of the enigmatic third tick family. Females possess features of hard and soft ticks and have been designated as the "missing link" between the main tick families. Its position at the base of the tick tree suggests that some of the features unique to hard and soft ticks were present in the ancestral tick lineage. Larvae, nymphae and males have not been described to date and questions regarding their biological affinities to the main tick families remain unclear. The current study addressed these questions via the description of larvae, nymphae and males and resolved issues pertaining to female morphology. Field collected as well as laboratory-engorged females laid eggs and viable larvae subsequently hatched. The larvae possess morphological structures not present in subsequent stages: namely, a sclerotized scutum, pores on the dorsal surface of legs and a dentate anal plate. The last two characters are not present in ixodids and argasids. N. namaqua larvae and nymphae show a similar morphology to females: a unique hypostomal structure i.e., bluntly rounded apically in nymphae and females and ball-like in the larvae. A re-description of some structures in female N. namaqua has resolved differences in the original descriptions, namely that N. namaqua have 4 palpal segments as found in ixodids and argasids and posthypostomal setae. The male was discovered for the first time and described. Characteristic male features include: a pseudoscutum over most of the dorsum, an outgrowth on the chelicerae forming a unique rod-like structure similar to a spematodactyl in mites and medial extension of palpal segment 2 forming a large ventral crib for segment 4. All life stages possess some features found in hard and soft ticks and its status as the "missing link" between the tick families remains.

First record of Naushonia sp. (Decapoda: Laomediidae) larva from the Equatorial Atlantic.

Science.gov (United States)

De Albuquerque Lira, Simone Maria; De Santana, Claudeilton Severino; Schwamborn, Ralf

2018-02-26

The first zoeal-stage larva of a possibly new species of mud shrimp Naushonia (Decapoda: Gebiidea: Laomediidae) was described from plankton samples taken off the Fernando de Noronha Archipelago, being the first occurrence at the oceanic islands of the Equatorial Atlantic. Five zoea I larvae were obtained and dissected for observation of mouthparts. This zoea I of Naushonia sp. is well distinguished from the first larvae of N. portoricensis (Rathbun 1901) from the Caribbean and N. cangronoides (Kingsley 1897) from the Northwest Atlantic in terms of development and setation of appendages, and possibly belongs to a new, undescribed species. The present study widens the knowledge on tropical oceanic decapod larvae and provides detailed drawings and new photographic illustrations with extended depth of field of these organisms.

Radiation tolerance in the fruit fly, Drosophila Melanogaster - effects of laboratory culturing and stages in life cycle

International Nuclear Information System (INIS)

Vas, Iril Prima; Naik, Pramila; Kumar, Vineeth; Naik, Prathima; Patil, Rajashekar K.

2013-01-01

Radiation induced damages are due to direct effect of radiation energy or through free radical generation. Recent studies suggest Drosophila to be a good animal model to study radiation tolerance. The present study on female Drosophila melanogaster was conducted to observe 1. Variations in larval and adult radiation tolerance 2. Variations in laboratory culture and field populations of Drosophila. Third instar larvae were exposed to gamma radiation of 6, 10, 20, 30, 40 and 50 Gy in gamma chamber GC 5000 (BRT, India). Larvae of flies collected from the field were reared for two generations in the lab before irradiation. The laboratory cultured files were from stocks that were maintained for more than 1000 generations. The larvae of field populations had higher survival rate at 51% as compared to 43% in case of cultured flies and thus more resistant. The III instar larval stage (lab culture) had a LD50 of 26 Gy as compared to LD 50 of 928 Gy in case of adult flies have ∼ 160 times higher tolerance compared to humans. Prolonged rearing comparable to 'domestication' might have induced reduction in tolerance. Larval stages have a lower tolerance than adults possibly due to higher metabolic rate. Adults are post-mitotic in nature with very low rate of cell division. This may contribute to higher tolerance. This however is in contradiction to studies of midge (Chironomous) where larvae also have higher tolerance. (author)

Quantification of vestibular-induced eye movements in zebrafish larvae

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Mo Weike

2010-09-01

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

Feeding for larvae of catfish Pangasionodon sp. larvae in different ages

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Muhammad Agus Suprayudi

2015-05-01

Full Text Available ABSTRACT Sludge worm (Tubifex sp. as natural feed on catfish (Pangasionodon sp. larvae rearing is available in limited amount especially during rainy season. It becomes a constraint factor for larvae rearing sector. This research was conducted to evaluate the appropriate initial age of catfish larvae to get artificial feed as sludge worm replacement. Evaluation was conducted on the growth and survival of catfish larvae in 14 days of culture. There were four treatments of feeding in triplicates i.e. larvae were given natural feed without artificial feed, given artificial feed started from d3, d6, and d9 with three replications. The results showed that larvae fed on artificial feed on d3 had the lowest growth compared to the other treatments, whereas the survival was not significantly different (P>0.05 among the treatments. As a conclusion, artificial feed could be used to replace natural feed for catfish larvae started at the age of nine days. Keywords: sludge worm, catfish larvae, artificial feed  ABSTRAK Cacing sutra (Tubifex sp. tersedia dalam jumlah terbatas terutama pada musim penghujan sebagai pakan alami dalam usaha pembenihan ikan patin (Pangasionodon sp.. Ini menjadi kendala dalam usaha pembenihan. Penelitian ini dilakukan untuk mengevaluasi umur larva ikan patin yang tepat untuk mulai diberi pakan buatan menggantikan cacing sutra. Evaluasi dilakukan pada pertumbuhan dan kelangsungan hidup larva ikan patin umur 14 hari. Selama pemeliharaan, larva diberi pakan dengan empat perlakuan; pemberian pakan alami tanpa pakan buatan, pemberian pakan buatan mulai d3, d6, dan d9 dengan tiga ulangan untuk masing-masing perlakuan. Hasil penelitian menunjukkan bahwa perlakuan pemberian pakan buatan mulai d3 memiliki pertumbuhan panjang yang terkecil dibandingkan perlakuan lain, sedangkan tingkat kelangsungan hidup larva tidak berbeda nyata (P>0,05 antarperlakuan. Berdasarkan hasil penelitian, dapat disimpulkan bahwa pakan buatan dapat digunakan

Induced abortion and duration of third stage labour in a subsequent pregnancy

DEFF Research Database (Denmark)

Zhou, Wei Jin; Gao, E; Che, Y

1999-01-01

We set out to evaluate the impact of first trimester induced abortion on the duration of third stage labour and related complications in a subsequent pregnancy. The study was conducted in Shanghai city at 15 general hospitals (or maternity and infant health institutes) from November 1993 to March...... 1998. We identified all nulliparae who came for antenatal care within the first 63 days of pregnancy (2953); the women were divided into two cohorts according to their previous history of first trimester induced abortion. After enrollment, the women were interviewed five times from recruitment until 42...... days after delivery. We included in the study all 1363 women who had a singleton vaginal live birth. Of these women, 703 were primigravida (non-exposed), 534 had had one previous first trimester induced abortion, and 126 women had had two or more first trimester induced abortions. The duration of third...

Comparative Analyses of Proteome Complement Between Worker Bee Larvae of High Royal Jelly Producing Bees (A. m. ligustica) and Carniolian Bees (A. m. carnica)

Institute of Scientific and Technical Information of China (English)

CHEN Jian; LI Jian-ke

2009-01-01

This study is to compare the protein composition of the high royal jelly producing bee (A. m. ligustica) with that of Carniolian bee (A. m. carnica) during their worker larval developmental stage. The experiment was carried out by two-dimensional gel electrophoresis. The results showed that significant higher numbers of total proteins (283) were detected in larvae of high royal jelly producing bees (Jelly bee) than those of Camiolian bees (152) on 2-d-old larvae. Among them, 110 proteins were presented on both strains of bee larvae, whereas 173 proteins were specific to larvae of Jelly bees, and 42 proteins were exclusive to Carniolian larvae. However, on the 4th d, a significant higher number of total proteins (290) were detected in larvae of Jelly bees than those of Camiolian bees (240), 163 proteins resolved to both bee larvae, and 127 proteins were specific to Jelly bees and 77 proteins to Camiolian bees. Until the 6th d, also a significant higher number of total proteins (236) were detected in larvae of Jelly bees than those of Carniolian bees (180), 132 proteins were constantly expressed in two bee larvae, whereas 104 and 48 proteins are unique to Jelly bee and Camiolian bee larvae, respectively. We tentatively concluded that the metabolic rate and gene expression of Jelly bees larvae is higher than those of Carniolian bees based proteins detected as total proteins and proteins specific to each stage of two strains of bee larvae. Proteins constantly expressed on 3 stages of larval development with some significant differences between two bee strains, and proteins unique to each stage expressed differences in term of quality and quantity, indicating that larval development needed house keeping and specific proteins to regulate its growth at different development phage, but the expression mold is different between two strains of larval development.

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

Science.gov (United States)

Weterings, Robbie

2015-12-01

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

Starvation threshold of Balanus amphitrite larvae in relation to temperature

Digital Repository Service at National Institute of Oceanography (India)

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

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

The hatching larva of the priapulid worm Halicryptus spinulosus

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Budd Graham E

2009-05-01

Full Text Available Abstract Despite their increasing evolutionary importance, basic knowledge about the priapulid worms remains limited. In particular, priapulid development has only been partially documented. Following previous description of hatching and the earliest larval stages of Priapulus caudatus, we here describe the hatching larva of Halicryptus spinulosus. Comparison of the P. caudatus and the H. spinulosus hatching larvae allows us to attempt to reconstruct the ground pattern of priapulid development. These findings may further help unravelling the phylogenetic position of the Priapulida within the Scalidophora and hence contribute to the elucidation of the nature of the ecdysozoan ancestor.

Descriptions of the larvae of two species of Paranomala and one species of strigoderma (Coleoptera: Melolonthidae: Rutelinae) from Puebla, Mexico

International Nuclear Information System (INIS)

Cuate Mozo, Victor Alfonso; Aragon Garcia, Agustin; Perez Torres, Betzabeth Cecilia; Moron, Miguel Angel; Lopez Olguin, Jesus Francisco; Marco Mancebon, Vicente Santiago

2014-01-01

The third instar larvae of Paranomala flavilla (Bates), P. hoepfneri (Bates) and Strigoderma costulipennis Bates, collected in Puebla, Mexico, in soils cultivated with Amaranth are described. Illustrations of the diagnostic structures and comments on the differences with other larvae of the genera studied in Mexico are included.

Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis

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Karina Mastropasqua Rebello

2012-09-01

Full Text Available Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1 were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3 were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.

Microplastic ingestion in fish larvae in the western English Channel.

Science.gov (United States)

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

2017-07-01

Microplastics have been documented in marine environments worldwide, where they pose a potential risk to biota. Environmental interactions between microplastics and lower trophic organisms are poorly understood. Coastal shelf seas are rich in productivity but also experience high levels of microplastic pollution. In these habitats, fish have an important ecological and economic role. In their early life stages, planktonic fish larvae are vulnerable to pollution, environmental stress and predation. Here we assess the occurrence of microplastic ingestion in wild fish larvae. Fish larvae and water samples were taken across three sites (10, 19 and 35 km from shore) in the western English Channel from April to June 2016. We identified 2.9% of fish larvae (n = 347) had ingested microplastics, of which 66% were blue fibres; ingested microfibers closely resembled those identified within water samples. With distance from the coast, larval fish density increased significantly (P < 0.05), while waterborne microplastic concentrations (P < 0.01) and incidence of ingestion decreased. This study provides baseline ecological data illustrating the correlation between waterborne microplastics and the incidence of ingestion in fish larvae. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

2014-01-01

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

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

Science.gov (United States)

Tomé, Hudson Vv; Pascini, Tales V; Dângelo, Rômulo Ac; Guedes, Raul Nc; Martins, Gustavo F

2014-04-24

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

Prophylactic oxytocin for the third stage of labour to prevent postpartum haemorrhage.

Science.gov (United States)

Westhoff, Gina; Cotter, Amanda M; Tolosa, Jorge E

2013-10-30

Active management of the third stage of labour has been shown to reduce the risk of postpartum haemorrhage (PPH) greater than 1000 mL. One aspect of the active management protocol is the administration of prophylactic uterotonics, however, the type of uterotonic, dose, and route of administration vary across the globe and may have an impact on maternal outcomes. To determine the effectiveness of prophylactic oxytocin at any dose to prevent PPH and other adverse maternal outcomes related to the third stage of labour. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2013). Randomised or quasi-randomised controlled trials including pregnant women anticipating a vaginal delivery where prophylactic oxytocin was given during management of the third stage of labour. The primary outcomes were blood loss > 500 mL and the use of therapeutic uterotonics. Two review authors independently assessed trials for inclusion, assessed trial quality and extracted data. Data were checked for accuracy. This updated review included 20 trials (involving 10,806 women). Prophylactic oxytocin versus placebo Prophylactic oxytocin compared with placebo reduced the risk of PPH greater than 500 mL, (risk ratio (RR) 0.53; 95% confidence interval (CI) 0.38 to 0.74; six trials, 4203 women; T² = 0.11, I² = 78%) and the need for therapeutic uterotonics (RR 0.56; 95% CI 0.36 to 0.87, four trials, 3174 women; T² = 0.10, I² = 58%). The benefit of prophylactic oxytocin to prevent PPH greater than 500 mL was seen in all subgroups. Decreased use of therapeutic uterotonics was only seen in the following subgroups: randomised trials with low risk of bias (RR 0.58; 95% CI 0.36 to 0.92; three trials, 3122 women; T² = 0.11, I² = 69%); trials that performed active management of the third stage (RR 0.39; 95% CI 0.26 to 0.58; one trial, 1901 women; heterogeneity not applicable); trials that delivered oxytocin as an IV bolus (RR 0.57; 95% CI 0.39 to 0.82; one trial, 1000 women

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

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Hideki Katow

2013-12-01

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

Immunological studies on Metastrongylus apri infection, 3. Migratory behavior in the guinea pig of 5 x 10/sup 4/R X-irradiated M. apri larvae used as attenuated larval vaccine

Energy Technology Data Exchange (ETDEWEB)

Onishi, T [Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture

1975-02-01

The purpose of this study is to investigate the migratory behavior of Metastronglylus apri larvae artificially attenuated by X-ray irradiation. Guinea pigs were inoculated orally with 2,000 M. apri larvae irradiated with 5 x 10/sup 4/ R of X-rays and killed at various intervals after inoculation. Various tissues were collected from them and examined for larvae by the pepsin digestion method (group A) and additionally by the microscopical method (group B). All larvae recovered were examined for the number and developmental stage. Results obtained are summarized as follows. On the 1st to 3rd days after inoculation, a large number of 3rd- or 4th-stage larvae were recovered from various tissues, as well as from the same tissues of normal controls. From the lungs, a few female 5th-stage worms were recovered on the 5th to 12th days, but to worms on the 15th day or later. There were no larvae in the thoracic cavity, blood from the right heart, or small intestine on any given day. In the tissues, especially in the walls of the cecum and the anterior part of the colon, and on the omentum, many larvae grew to early 4th-stage ones, but few to advanced 4th-stage ones. All the worms recovered from the lungs grew to early 5th-stage ones, but failed to reach the mature state. On the basis of these findings, it is concluded that 5 x 10/sup 4/ R X-irradiated larvae could penetrate rapidly into the gut and migrated for about 1 to 3 days after inoculation like normal larvae, but that they could grow neither to advanced 4th-stage ones nor to early 5th-stage ones. In other words, it can be seen that 5 x 10/sup 4/ R X-irradiation affected M. apri larvae over, or at least immediately after, the period of transition from the 4th to 5th stage. The 4th stage, however, was sustained longer in the X-irradiated larvae than in normal ones. All the larvae that had invaded tissues may have been caught mainly in the gut, on the omentum, or at other sites to be killed and organized in these tissues.

Commercially important penaeid shrimp larvae in the estuaries of Goa

Digital Repository Service at National Institute of Oceanography (India)

Achuthankutty, C.T.

Larval stages of the penaeid shrimps, Metapenaeus dobsoni (Miers), M. affinis (Milne - Edwards) and Penaeus merguiensis De Man were mostly distributed at the lower reaches of Mandovi and Zuari estuaries. While larvae of M. dobsoni and M. affinis...

Liver histopathology in the cane toad, Rhinella marina (Amphibia: Bufonidae), induced by Ortleppascaris sp. larvae (Nematoda: Ascarididae).

Science.gov (United States)

Silva, Jefferson P E; da Silva, Djane C B; Melo, Francisco T V; Giese, Elane G; Furtado, Adriano P; Santos, Jeannie N

2013-04-01

Exposure to parasites is considered to be an important factor in the development of many diseases and histopathologies which are the result of the parasite-host interaction. The present study evaluated the impact of natural infection by larvae of Ortleppascaris sp. (Nematoda: Ascaridida) in the liver of the cane toad Rhinella marina (Linnaeus, 1758). Larvae were encysted in nodules delimited by collagenous fibers and fibroblasts or freely within the hepatic parenchyma, provoking a clear response from the host. The histological examination of the liver revealed viable larvae in a number of different developmental stages, as well as cysts filled with amorphous material and cell residues and surrounded by dense fibrotic tissue. The infection of the liver by these larvae induces a significant increase in the area occupied by melanomacrophages and a reduction or deficit in the vascularization of the liver, hypertrophy of the hepatocytes, vacuolar bodies, and cytoplasmatic granules. Focal concentrations of inflammatory infiltrates were observed enclosing the unencapsulated early-stage larvae. These results indicate that infection by Ortleppascaris sp. induces severe physiological problems and histopathological lesions in the liver of R. marina .

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

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Wisnu Satria A.K.

2013-03-01

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

Effect of sublethal doses of radiation and cystamine on the dynamics of Rana temporaria L. larvae development

International Nuclear Information System (INIS)

Popov, D.V.

1979-01-01

The longevity of Rana temporaria L. larvae in the 45th stage of development is studied after irradiation in sublethal doses (10.000-20.000 R) and irradiation with preliminary cystamine protection. It has been shown that the protective effect of cystamine is revealed in partial normalization of the larvae development rate but does not eliminate the typical anomalies of extremity development and does not prolong the time of animal survival. It has been found that LD 50/30 dose for R. temporaria tadpoles in the 45th stage of development is slightly higher than 10.000 R. The selective effect of X-radiation on the formative bonds at cornea induction in Anura larvae is concluded

[Current wound care in patients with elephantiasis--third-stage lymphedema].

Science.gov (United States)

Rucigaj, Tanja Planinsek; Slana, Ana; Leskovec, Nada Kecelj

2012-10-01

Lymphedema resulting from fluid accumulation due to impairment in the lymphatic system drainage leads to enlargement of the body part involved. If left untreated, in its third stage it results in elephantiasis. Elephantiasis is frequently accompanied by papillomatosis and lymphocutaneous fistulas with lymphorrhoea, erosions and ulcers, frequently with the loss of function in the respective part of the body. Unlike other chronic wounds, wound healing in lymphedema is highly dependent on the use of combined therapies because local treatment with modern supportive dressings and compression therapy with adhesive and non-adhesive short-stretch systems is only part of the complete treatment. This treatment also includes sub-bandage foamy materials, kinesitherapy with tapes (kinesiotaping), intermittent local application of high-pressure oxygen, breathing exercise, and manual lymph drainage and exercises.

PERKEMBANGAN ENZIM PENCERNAAN LARVA IKAN PATIN, Pangasius hypophthalmus sp.

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Irzal Effendi

2003-05-01

Full Text Available Development of digestive enzymes; protease, lipase and amylase were observed in patin catfish, Pangasius hypophthalmus, larvae.  The 1 day old larvae (day after hatching, with 3,37-3,97 mm length and 0,62-0,79 mg weight, were reared in aquarium 60x50x40 cm with stocking  density of 20 fish/l.  Larvae were fed  Artemia dan tubificid worms 2-8 dan 7-15 days after hatching (dAH,  respectively (schedule I;  2-6 and  5-15 dAH (schedule II; and 2-4 and 5-15 dAH (schedule III.  Chlorella was ready to eat by larvae at the entirely rearing.  For enzyme assay, larvae were sampled from each aquarium at stages of 1, 2, 3, 5, 7, 10 and 15 dAH.    Protease and lipase activity were detected in digestive tract of  1 dAH larvae.   Digestive enzymes development have a similar pattern in larvae for all feeding schedules.  Protease activity  decreased with the increasing of age until 3 dAH, then increased  until the larvae reached 7 dAH, and sharply decreased until 10 dAH and then slowly decreased thereafter. Lipase activity tended to increase slowly with age up to 3 dAH, and increased sharply until 5 dAH, and then decreased sharply until 7 dAH  before decreased again up to the end of rearing.  Amylase activity in larvae increased slowly with the increasing of age up to 5 dAH, then increased sharply until 7 dAH, and decreased thereafter.  In dimly lighted larvae, amylase activity decreased before increased up to 12 d AH, then decreased thereafter.  The amount of food organisms in larval gut, body weight and length, and survival rate of larvae were also measured and discussed.Key Words:  Digestive enzymes, development, larvae, patin catfish, Pangasius hypophthalmus ABSTRAKPenelitian ini bertujuan untuk mengetahui perkembangan enzim protease, lipase dan amilase saluran pencernaan larva ikan patin akibat perubahan skedul pemberian pakan.  Larva ikan patin (panjang 3,77–3,97 mm dan bobot 0,62-0,79 mg berumur 1 hari dipelihara di akuarium 60x

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

Science.gov (United States)

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

2016-05-01

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

North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada

Science.gov (United States)

Park, W.; Douglas, David C.; Shirley, Thomas C.

2007-01-01

We propose and evaluate the hypothesis that Dungeness crab (Cancer magister) larvae from the northwestern coast of the United States and Canada can be transported northward to southeastern Alaska. Larvae collected in southeastern Alaska during May and June 1997–2004 had abundances and stages that varied seasonally, interannually, and spatially. An unexpected presence of late-stage larvae in spring raises a question regarding their origin, and the most plausible explanation is that they hatched off the northern Washington and British Columbia coasts and were transported to southeastern Alaska. Buoy drift tracks support the hypothesis that larvae released off the northern Washington and British Columbia coasts during the peak hatching season can be physically transported to southeastern Alaska, arriving as late-stage larvae in May and June, when local larvae are only beginning to hatch. A northward spring progression of monthly mean 7°C SST isotherms and phytoplankton blooms provide further evidence that environmental conditions are conducive for larval growth and metabolism during the transport period. The proposed larval transport suggests possible unidirectional gene flow between southern and northern populations of Dungeness crabs in southeastern Alaska.

Artificial induction of third-stage dispersal juveniles of Bursaphelenchus xylophilus using newly established inbred lines.

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Suguru E Tanaka

Full Text Available The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. This nematode has two developmental forms in its life cycle; i.e., the propagative and dispersal forms. The former is the form that builds up its population inside the host pine. The latter is specialized for transport by the vector. This form is separated into two dispersal stages (third and fourth; the third-stage dispersal juvenile (JIII is specialized for survival under unfavorable conditions, whereas the fourth-stage juvenile (JIV, which is induced by a chemical signal from the carrier Monochamus beetle, is transported to new host pines and invades them. Because of its importance in the disease cycle, molecular and chemical aspects of the JIV have been investigated, while the mechanism of JIII induction has not been sufficiently investigated. In an effort to clarify the JIII induction process, we established inbred lines of B. xylophilus and compared their biological features. We found that the total number of nematodes (propagation proportion was negatively correlated with the JIII emergence proportion, likely because nematode development was arrested at JIII; i.e., they could not develop to adults via the reproductive stage. In addition, JIII induction seemed to be regulated by a small number of genes because the JIII induction proportion varied among inbred lines despite the high homozygosity of the parental line. We also demonstrated that JIII can be artificially induced by the nematode's secreted substances. This is the first report of artificial induction of JIII in B. xylophilus. The dauer (dispersal juvenile of the model organism Caenorhabditis elegans corresponds functionally to JIII of B. xylophilus, and this stage is known to be induced by a chemical signal referred to as daumone, derived from the nematodes' secretion. The artificial induction of JIII suggests the presence of daumone-like material in B. xylophilus.

Food consumption by Chilo partellus (Lepidoptera: Pyralidae) larvae infected with Beauveria bassiana and Metarhizium anisopliae and effects of feeding natural versus artificial diets on mortality and mycosis.

Science.gov (United States)

Tefera, Tadele; Pringle, K L

2003-11-01

Second and third instar Chilo partellus larvae were infected with Beauveria bassiana and Metarhizium anisopliae (both at 1x10(8)conidia/ml) and daily consumption of maize leaves was measured. Infection by the fungi was associated with reduced mean daily food consumption. Reduction in food consumption became evident 3-4 days after treatment with the fungi for second instar larvae and 4-5 days for third instar larvae. Four conidial concentrations, 1x10(5), 1x10(6), 1x10(7), and 1x10(8)conidia/ml, were tested against second instar larvae. Food consumption dropped by 70-85% when the second instar larvae were treated with the fungi at 1x10(8)conidia/ml. Reduction in food consumption by C. partellus larvae infected with B. bassiana and M. anisopliae may offset the slow speed of kill of the fungi. The effect of artificial versus natural diets on mortality and mycoses of second instar larvae treated with the fungi at 1x10(8)conidia/ml was determined. Larvae provided with artificial diet suffered little mortality and mycoses than larvae provided with maize leaves. The LT(50) was longer for larvae provided with artificial diet.

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

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

2011-10-01

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

Policies for care during the third stage of labour: a survey of maternity units in Syria

Science.gov (United States)

2010-01-01

Background Care for women during the third stage aims to reduce the risk of major haemorrhage, but is very variable. The current World Health Organisation (WHO) recommendation is that care should include administration of a uterotonic (oxytocin, if it is available) soon after birth of the baby, delayed cord clamping, and delivery of the placenta by controlled cord traction. Methods To ascertain care policies used during the third stage of labour in maternity units in Syria, we conducted a survey of 69 maternity units in obstetric and general public hospitals. A brief questionnaire was administered by face to face interview or telephone with senior obstetricians and midwives. Outcome measures were the use of prophylactic uterotonic drugs, timing of cord clamping, use of controlled cord traction, and treatment for postpartum haemorrhage. Obstetricians were asked about both vaginal and caesarean births, midwives only about vaginal births. Results Responses were obtained for 66 (96%) hospitals: a midwife and an obstetrician were interviewed in 40; an obstetrician only in 20; a midwife only in 6. Responses were similar, although midwives were more likely to report that the umbilical cord was clamped after 1-3 minutes or after cessation of pulsation (2/40 obstetricians and 9/40 midwives). Responses have therefore been combined. One hospital reported never using a prophylactic uterotonic drug. The uterotonic was Syntometrine® (oxytocin and ergometrine) in two thirds of hospitals; given after delivery of the placenta in 60 (91%) for vaginal births, and in 47 (78%) for caesarean births. Cord clamping was within 20 seconds at 42 hospitals 64%) for vaginal births and 45 (75%) for caesarean births. Controlled cord traction was never used in a quarter (17/66) of hospitals for vaginal births and a half (32/60) for caesarean births. 68% of respondents (45/66) thought there was a need for more randomised trials of interventions during the third stage of labour. Conclusion Most

Early Cretaceous trypanosomatids associated with fossil sand fly larvae in Burmese amber

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George Poinar Jr

2007-08-01

Full Text Available Early Cretaceous flagellates with characters typical of trypanosomatids were found in the gut of sand fly larvae, as well as in surrounding debris, in Burmese amber. This discovery supports a hypothesis in which free-living trypanosomatids could have been acquired by sand fly larvae in their feeding environment and then carried transtadially into the adult stage. At some point in time, specific genera were introduced into vertebrates, thus establishing a dixenous life cycle.

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

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Sergio Cházaro-Olvera

2018-03-01

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

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

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Marina Vera Diaz

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

Larvae for layers

DEFF Research Database (Denmark)

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

2013-01-01

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

Lagrangian Observations and Modeling of Marine Larvae

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Paris, Claire B.; Irisson, Jean-Olivier

2017-04-01

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

Activity of Selected Formulated Biorational and Synthetic Insecticides Against Larvae of Helicoverpa armigera (Lepidoptera: Noctuidae).

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Vivan, L M; Torres, J B; Fernandes, P L S

2017-02-01

This work studied 17 insecticides belonging to nucleopolyhedrovirus (NPV), Bacillus thuringiensis (Bt kurstaki and Bt aizawai), benzoylureas (insect growth regulators [IGRs]), carbamates, organophosphates, spinosyns, and diamides against larvae of Helicoverpa armigera (Hübner), invasive species in the South American continent. Larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. Mortality was recorded daily for 7 d, and surviving larvae were individually weighed on the seventh day. The NPV and Bt insecticides caused 100% mortality of first-instar larvae and first-instar and second-instar larvae, respectively. However, both NPV and Bt-based products caused low mortality of third-instar larvae and did not kill older larvae. The IGR lufenuron was highly effective against all three ages of larvae tested, whereas teflubenzuron and triflumuron produced maximum 60% mortality of second-instar larvae and lower than 50% to older larvae. Thiodicarb, chlorantraniliprole, indoxacarb, chlorpyrifos, and chlorfenapyr, irrespective of tested age, caused 100% mortality of larvae, with the last two insecticides reaching 100% mortality within 2 d of feeding on the treated diet. Flubendiamide caused lower mortality but significantly affected the weight of surviving larvae, whereas neither spinosad nor methomyl produced significant mortality or affected the weight of larvae. Based on the results, the age of H. armigera larvae plays an important role in the recommendation of NPV and Bt insecticides. Furthermore, there are potential options between biological and synthetic insecticides tested against H. armigera, and recording larval size during monitoring, in addition to the infestation level, should be considered when recommending biological-based insecticides to control this pest. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Increased Relative Calcification, Shell Dissolution and Maintained Larval Growth in Mussel (Mytilus edulis) Larvae Exposed to Acidified Under-Saturated Seawater

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Ventura, A.; Dupont, S. T.; Schulz, S.

2016-02-01

Ocean acidification (OA) is known to affect bivalve early life-stages. It is often assumed that aragonite saturation state (Ωa) is the main driver of the biological response. However saturation state of different CaCO3 forms is not the main driver of most physiological processes and pH/pCO2 are playing an overarching role (e.g. acid-base regulation). The aim of our study was to investigate the effects of a wide range of seawater pH on different physiological parameters (e. g. calcification; growth) of blue mussel (Mytilus edulis) developing larvae in order to identify a physiological tipping point beyond which they are no longer capable of carrying out those functions necessary to their survival and recruitment into the adult population. Our results confirmed that increasing seawater acidity and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. No larvae reared at pHT ≈ 7.1 were able to reach the D-shell veliger stage and their development appeared to be arrested at the trochophore stage. However - despite morphological shell abnormalities - larvae were capable of reaching the D-shell stage when reared at pHT ≈ 7.35 and normally D-shaped larvae were observed in all the remaining treatments (pH ≈ 7.6, 7.85 and 8.1) including in under-saturated seawater with Ωa as low as 0.75 ± 0.03 (mean ± SE). Growth rate of these 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 suggest a shift in energy allocation toward growth in larvae exposed to ocean acidification.

Development of Digestive Enzyme of Patin Pangasius hypohthalmus Larvae

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I. Effendi

2007-01-01

Full Text Available Culture of patin Pangasius hypophthalmus especially larval rearing  very depends on the supply of natural food as energy source.  Artemia is the main natural food for fish larvae as a starter food, but its price is high.  To reduce production cost, farmers tend to reduce the feeding frequency and shorten  the Artemia feeding period.  Altering feeding regime however may reduce fry quality. This relate to the availability of digestive enzymes.  The objective of this study was  to examine digestive enzymes activity in patin larvae fed with  different feeding regime.  By shorten feeding period with Artemia to 2-4 days and Tubifex,substitution, the enzymes activity of protease, lipase and amylase were revealed similar pattern   The enzymes activity tends to increase and reach the peak at day 7 , and decrease later on until day 15 after hatching.  Survival rate of fish were varied for each treatment, and the highest survival rate was obtained when larvae were fed by Artemia for 8 days.  Blood worm were not fully digested by patin larvae at early stage. Keywords: enzyme, digestion, patin, Pangasius hypophthalmus   ABSTRAK Proses budidaya ikan patin, Pangasius hypophthalmus terutama pembenihan sangat tergantung oleh ketersediaan pakan alami sebagai sumber energinya. Artemia merupakan pakan alami yang banyak diberikan pada saat larva ikan mulai makan, namun harganya relatif tinggi. Untuk menekan biaya produksi, petani ikan patin cenderung mengurangi frekuensi pemberian Artemia dan mempersingkat waktu pemberiannya. Penggeseran jadwal ini diduga mengakibatkan penurunan kualitas benih ikan patin yang dihasilkan yang berhubungan dengan kesiapan enzim pencernaannya. Penelitian ini dilakukan untuk mengetahui aktivitas enzim pada larva ikan patin dengan jadwal pemberian pakan yang berbeda. Dengan memotong waktu pemberian Artemia 2 - 4 hari dan disubstitusi dengan Tubifex, aktifitas enzim protease, lipase dan amilase pada larva ikan patin, memiliki

COMPARISON OF EARLY AND DELAYED UMBILICAL CORD CLAMPING IN THE THIRD STAGE OF LABOUR

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Tamara Serdinšek

2015-09-01

Full Text Available Background: Umbilical cord clamping in the third stage of labour is still controversial. Early cord clamping is defined as clamping at 10, 15, 30 or 60 seconds after delivery and delayed as clamping after 60 seconds or at 2-5 minutes after delivery, when the cord stops pulsating or when the placenta is visible within the birth canal. Early clamping is one of the three components of active management of the third stage of labour, which has been used widely in modern obstetrics during the last century. However, in some northern European countries, various parts of the USA and Canada and in developing countries physiological management is preferred.Conclusions: After publication of several trials describing advantages of delayed clamping, this has recently been progressively replacing early clamping. The most important advantages of delayed cord clamping are higher haemoglobin and ferritin levels, higher iron stores, lower incidence of iron deficiency anaemia, better cardiopulmonary adaptation, lower rate of respiratory distress syndrome, and longer duration of early breastfeeding in term neonates, while there is no increase in the incidence of postpartum haemorrhage. Delayed clamping seems to bring some advantages for preterm neonates as well. However, caution is still advised because of the potential adverse effects, especially polycythaemia with hyperviscosity, hyperbilirubinaemia and respiratory distress.

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

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Alexandre Bortoli Machado

2003-04-01

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

Demirjian's stages and Cameriere's third molar maturity index to estimate legal adult age in Peruvian population.

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Quispe Lizarbe, Roselhy Juliana; Solís Adrianzén, Christian; Quezada-Márquez, Milushka Miroslava; Galić, Ivan; Cameriere, Roberto

2017-03-01

To compare the accuracy of Demirjian's stages (DS) and Cameriere's third molar maturity index cut-off value (I 3M age of majority on panoramic radiographs (OPTs) from the dental clinic of the Scientific University of the South (UCSUR), Lima, Peru. An observational cross-sectional study was conducted on the sample of 208 digital panoramic radiographs of patients aged 14-22years examined during 2015 in UCSUR. The left lower third molars were analyzed using Adobe Photoshop® CS6. An effectiveness of specific DS and I 3M third molar maturity index (I 3M <0.08) showed to be more accurate in discriminating adults and minors in Peruvian sample when a test with high sensitivity and specificity is required. Copyright © 2017 Elsevier B.V. All rights reserved.

Improvement of survival and development of Pacific white shrimp Litopenaeus vannamei larvae by feeding taurine enriched rotifers

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Dedi Jusadi

2015-03-01

Full Text Available ABSTRACTThe objective of the present experiment was to study the most optimum taurine enrichment concentration of rotifers in improving Pacific white shrimp larva Litopenaeus vannamei survival and development. White shrimp larvae at sixth naupliar stage were reared in 12 units of 500 L fibre glass tanks with a stocking density of 125 ind/L. Starting from zoea two stage (Z-2, the larva was provided with rotifers with different taurine enrichment concentration according to the treatments, i.e. 0 mg/L enrichment medium (A, 25 mg/L (B, 50 mg/L(C, and 100 mg/L (D. The results show that different taurine concentration in the enrichment media increased taurine level in rotifers. Furthermore, the administration of taurine enriched rotifers up to 50 mg/L significantly improved larval survival and may accelerate larval development. The experimental results also concluded that a concentration of 50 mg/L is the most optimum taurine enrichment concentration of rotifers for the improvement of white shrimp larval survival and developmental stage.Keywords: taurine, rotifer, white shrimp, enrichmentABSTRAKPenelitian ini bertujuan untuk mengkaji konsentrasi optimum taurin melalui pengayaan pada rotifera terhadap tingkat kelangsungan hidup dan perkembangan stadia larva udang vaname Litopenaeus vannamei. Larva udang vaname stadia naupli-6 dipelihara dalam 12 tangki fiberglass volume 500 L dengan kepadatan 125 ind/L. Dimulai sejak stadia zoea 2 (Z-2 larva diberi rotifera yang diperkaya dengan taurin dengan konsentrasi yang berbeda sesuai dengan perlakuan, yaitu 0 mg/L media pengkaya (A, 25 mg/L (B, 50mg/L (C, dan 100mg/L (D. Hasil penelitian menunjukkan pengayaan taurin pada konsentrasi yang berbeda menyebabkan peningkatan kandungan taurin rotifera. Sementara pemberian rotifera yang diperkaya taurin hingga 50 mg/L meningkatkan kelangsungan hidup dan mempercepat perkembangan stadia larva udang. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa pemberian

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

Science.gov (United States)

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

2016-01-01

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

Influence of irradiation on development of Caribbean fruit fly (diptera: tephritidae) larvae

International Nuclear Information System (INIS)

Nation, J.L.; Milne, K.; Dykstra, T.M.

1995-01-01

Larvae of the Caribbean fruit fly, Anastrepha suspensa (Loew), were irradiated at hatching with 0, 5, 10, 20, 50, 75, 100 and 150 Gy doses from a Cesium-137 source and dissected for measurements of the supraesophageal ganglion (brain) and proventriculus (B/Prv) as mature third instars. Cross-sectional area of a plane through the brain and proventriculus, and simple dorsal width measurements of the two organs were evaluated as indicators of radiation exposure. Brain area, brain width, and brain/proventriculus (B/Prv) ratios were significantly different from controls in insects treated with a dose ≥20 Gy. Detailed dissections of hatching larvae exposed to 50 Gy revealed reductions in brain growth, small and misshapen compound eye and leg imaginal disks, and a ventral nerve cord that was elongated and sinuous. Larvae irradiated on the 1st d of each of the three instars had smaller brains, with the percentage of reduction in brain size being greater the younger the larvae were at the time of exposure. Brain and proventriculus measurements and calculated B/Prv values are indicative of irradiation in Caribbean fruit fly larvae, but the procedure may not be adaptable for routine use by quarantine inspectors. 14 refs., 4 figs., 2 tabs

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

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Marc Suquet

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

Nematode cysts and larvae found in Achatina fulica Bowdich, 1822.

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Franco-Acuña, D O; Pinheiro, J; Torres, E J L; Lanfredi, R M; Brandolini, S V P B

2009-02-01

This study describes the morphology of the nematode cysts and larvae found in Achatina fulica (giant African snail) in Brazil. Sixty snails were collected in Mesquita, Rio de Janeiro State. Fourteen of the snails were naturally infected. The cysts were spherical, pink colored and measured 0.97 to 1.57 mm in diameter. In the majority of cases they had a single larvae involved in amorphous material. A total of 222 encysted larvae were recovered. Of these, 30 were utilized in the morphological study. The length of the larvae varied from 2.57 to 5.8 mm and they were classified as small--up to 3.5 mm; medium--from 3.53 to 4.5 mm; and large--greater than 4.52 mm. The average length of the larvae in the three groups was 2.85, 3.87 and 5.23 mm, respectively. The larval cuticle was white, shiny and transversally striated until the posterior end of the body. At the anterior end there is a mouth with three lips, with amphids and papillae, followed by a muscular esophagus with average length of 0.61 mm, terminating in an esophageal bulb and having a nerve ring in the middle third of the esophagus, and an intestine with an opening near the posterior end. The tail begins from this opening and has two types of ends: short and abrupt or long and gradually tapering. The difference in the tail end can suggest sexual dimorphism, although no primordial reproductive structures were observed. These characteristics were not sufficient to identify the larvae, so there is a need for further study.

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

International Nuclear Information System (INIS)

Kazlauskiene, N.; Cepuliene, Z.

1998-01-01

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

Role of biogenic amines in the post-mortem migration of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) larvae into fish fillets.

Science.gov (United States)

Šimat, Vida; Miletić, Jelena; Bogdanović, Tanja; Poljak, Vedran; Mladineo, Ivona

2015-12-02

Infective third-stage larvae (L3) of nematode Anisakis spp. have been recognized as one of the major food-borne threats in lightly processed fish products in Europe, particularly in the Mediterranean region. Therefore, the effect of different storage temperatures of fish on larval post-mortem migration from visceral cavity into fillets is an important parameter to take into account when evaluating the risk for consumer safety. The European anchovy (Engraulis encrasicolus) were caught during fishing season, a subsample of fillets was checked for the presence of Anisakis larvae at capture (mean abundance=0.07), and the rest was stored at four different temperatures (-18, 0, 4 and 22°C) in order to count migrating larvae and measure the production of biogenic amines over a period of time. Larvae were identified by morphological features and molecular tools. Post-mortem migration was observed in fillets stored at 0 and 4°C after three and five days, respectively, but not at 22 and -18°C. In case of storage at 22°C for two days, at the onset of putrefaction of the visceral organs, larvae migrated out of the visceral cavity towards the fish surface. Measured pH and biogenic amine profile during storage indicated that certain biochemical conditions trigger larval migration into fillets. Likewise, migration was observed at pH ~6.4 when sensory degradation of the fish was markedly visible. Although larval migration was delayed for approximately four days at a temperature of fillet was high and statistically significant at both 0 (r=0.998, p<0.01) and 4°C (r=0.946, p<0.05). Out of eight biogenic amines measured, cadaverine and putrescine levels correlated the most with the post-mortem migration at 4°C, while tyramine levels were significant at both temperatures. Copyright © 2015 Elsevier B.V. All rights reserved.

Developmental Toxicity of Dextromethorphan in Zebrafish Embryos/Larvae

Science.gov (United States)

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

2012-01-01

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

Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

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Sacchi L.

2001-06-01

Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

PERKEMBANGAN AWAL LARVA KERAPU KERTANG (Epinephelus lanceolatus

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Philip Teguh Imanto

2016-11-01

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

The morphology of the foregut of larvae and postlarva of Sesarma curacaoense De Man, 1892: a species with facultative lecithotrophy during larval development A morfologia do estômago de larvas e pós-larvas de Sesarma curacaoense De Man, 1892: uma espécie com desenvolvimento larval lecitotrófico facultativo

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Marlon Aguiar Melo

2006-01-01

Full Text Available Previous study on the resistance of larvae of Sesarma curacaoense submitted to starvation has revealed a facultative lecithotrophy during zoeal stages, but megalopa and first juvenile stages are exclusively feeding stages. In the present study, the gross morphology and fine structure of the foregut of S. curacaoense were investigated during larval, megalopa and first juvenile stages. The foregut of the zoea I show specific setae and a filter press apparently functional. The foregut undergoes changes in the zoea II (last larval stage with increment of setae number, mainly on the cardiopyloric valve and complexity of the filter press. After metamorphosis to megalopa stage the foregut become rather complex, with a gastric mill supporting a medial and two lateral teeth well-developed. The foregut of the first juvenile is more specialized compared to the previous stage, showing similar characteristics of the decapod adults. These results provide further evidence of facultative lecithotrophic development in the larvae of S. curacaoense.Estudo prévio sobre o efeito da inanição em larvas de Sesarma curacaoense propôs que estas larvas apresentam comportamento lecitotrófico facultativo. No presente trabalho a morfologia do estômago de S. curacaoense foi estudada durante os estágios larvais, megalopa e juvenil I. A estrutura do estômago da zoea I possui cerdas específicas e com filtro pilórico aparentemente funcional. Especialização no estômago do zoea II (último estágio larval foi evidenciada pelo incremento do número de cerdas na válvula cárdio-pilórica e pela complexidade do filtro pilórico. Após a metamorfose para o estágio megalopa, o estômago ficou consideravelmente complexo, com o aparecimento de um moinho gástrico contendo um medial e dois laterais dentes bem desenvolvidos. O estômago do juvenil I mostrou-se ainda mais especializado que no estágio anterior, exibindo características morfológicas similares �

Distribution and elimination of Norfloxacin in Fenneropenaeus chinensis larvae

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

2013-09-01

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

Toxicity of Spathodea campanulata P Beauvois (Scrophulariales: Bignoniaceae aqueous extracts against immature stages of Anopheles albimanus (Diptera: Culicidae under laboratory conditions

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Jose Luis Torres-Estrada

2010-12-01

Full Text Available Jose Luis Torres-Estrada1, Julio Cesar Velazquez Gonzalez1, Silvany M Rios Delgado1, María Guadalupe Vazquez-Martinez1, R Patricia Penilla-Navarro1, Americo D Rodriguez11Centro Regional de Investigación en Salud Pública, Instituto Nacional de Salud Pública, Colonia Centro, Tapachula, Chiapas, MéxicoPurpose: To determine the effects of African tulip Spathodea campanulata aqueous extracts on every immature stage of Anopheles albimanus under laboratory conditions.Methods: The extract was obtained making an incision on the apical part of prefloral bulbs, and two sets of dilutions with distilled water were prepared. The first set was used at 50%, 20%, 10%, 5%, and 2.5% concentrations in bioassays to test its effect on egg-hatching inhibition. The second set was used at 10%, 5%, 1%, 0.1%, and 0.01% to test toxicity on larvae and pupae. Also, residual efficacy and lethal time (LT were estimated.Results: The highest inhibition (87.5% recorded for egg hatching was at a 50% concentration. Third and fourth instar larvae and pupae were the most susceptible to 10% and 5% of S. campanulata aqueous extracts, with 98.3%–100% mortality. The residual activity with 10% concentration persisted 7 days, with 100% mortality, and LT for 99% mortality (LT99 was 2.28 hours on third instar larvae, 1.7 hours on fourth instar larvae, and 2.25 hours on pupae.Conclusion: S. campanulata extracts are promising as biolarvicides. Further toxicological and chromatographic studies are encouraged and needed.Keywords: African tulip, botanical insecticides, malaria, mosquitoes

Management of Third Stage of Labour with Per Rectal Administration of 400 MCG of Tablet Misoprostol Before Delivery of Placenta - Protocol for 3rd Stage of Labour - A Pilot Study

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Pragati Tugnait

2015-01-01

Conclusion: The third stage of labour poses potentially life threatening risks and several severe complications to a mother who has just delivered. The patients in rural and peripheral setups are more vulnerable given their poor nutritional status, rare health care facilities, non availability of trained birth attendants and distance to a tertiary care centre. In larger centres also ,avoidance of post partum haemorrhage adds to maternal well being and saves on hospital resources in terms of man and material. The mean blood loss of 163.41 ml during third stage of labour is an encouraging result especially when no significant side effects were noted.

Combined toxicity of free chlorine, chloramine, and temperature to stage 1 larvae of the American lobster Homarus americanus

Energy Technology Data Exchange (ETDEWEB)

Capuzzo, J M; Lawrence, S A; Davidson, J A

1976-01-01

The differential effects of free chlorine and chloramine on stage I larvae of the American lobster Homarus americanus have been investigated in continuous flow bioassay units. Applied chloramine was more toxic than corresponding concentrations of applied free chlorine to lobster larvae with estimated LC/sub 50/ values at 25/sup 0/ of 16.30 mg/l applied free chlorine and 2.02 mg/l applied chloramine. The synergistic effect of temperature on the toxicity of both free chlorine and chloramine has also been demonstrated. Exposure to applied free chlorine at 20/sup 0/ resulted in no significant mortality of test organisms, whereas exposure at 30/sup 0/ resulted in an estimated LC/sub 50/ value of 2.50 mg/l. Applied chloramine was considerably more toxic with an estimated LC/sub 50/ value at 20/sup 0/ of 4.08 mg/l and at 30/sup 0/ of 0.56 mg/l. The action of each toxicant appeared to be an alteration of standard metabolic activity as revealed by changes in respiration rates during and after exposure to applied free chlorine and chloramine. Initial respiratory stress was detected during exposure to 0.05 mg/l applied chloramine and 5.00 mg/l applied free chlorine. Reductions in respiration rates 48 h after exposure were observed with exposure to all concentrations tested, similar results being obtained following exposure to 0.05 mg/l applied chloramine and 0.10 mg/l applied free chlorine. These results are indicative of the need for information in addition to that obtained in standard bioassays for an adequate assessment of chlorine toxicity.

Policies for care during the third stage of labour: a survey of maternity units in Syria

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Abdulsalam Asma

2010-06-01

Full Text Available Abstract Background Care for women during the third stage aims to reduce the risk of major haemorrhage, but is very variable. The current World Health Organisation (WHO recommendation is that care should include administration of a uterotonic (oxytocin, if it is available soon after birth of the baby, delayed cord clamping, and delivery of the placenta by controlled cord traction. Methods To ascertain care policies used during the third stage of labour in maternity units in Syria, we conducted a survey of 69 maternity units in obstetric and general public hospitals. A brief questionnaire was administered by face to face interview or telephone with senior obstetricians and midwives. Outcome measures were the use of prophylactic uterotonic drugs, timing of cord clamping, use of controlled cord traction, and treatment for postpartum haemorrhage. Obstetricians were asked about both vaginal and caesarean births, midwives only about vaginal births. Results Responses were obtained for 66 (96% hospitals: a midwife and an obstetrician were interviewed in 40; an obstetrician only in 20; a midwife only in 6. Responses were similar, although midwives were more likely to report that the umbilical cord was clamped after 1-3 minutes or after cessation of pulsation (2/40 obstetricians and 9/40 midwives. Responses have therefore been combined. One hospital reported never using a prophylactic uterotonic drug. The uterotonic was Syntometrine® (oxytocin and ergometrine in two thirds of hospitals; given after delivery of the placenta in 60 (91% for vaginal births, and in 47 (78% for caesarean births. Cord clamping was within 20 seconds at 42 hospitals 64% for vaginal births and 45 (75% for caesarean births. Controlled cord traction was never used in a quarter (17/66 of hospitals for vaginal births and a half (32/60 for caesarean births. 68% of respondents (45/66 thought there was a need for more randomised trials of interventions during the third stage of labour

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

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Lilian Cristina Macedo

2016-03-01

Full Text Available Abstract 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.

Growth and development of Colorado potato beetle larvae, Leptinotarsa decemlineata, on potato plants expressing the oryzacystatin II proteinase inhibitor.

Science.gov (United States)

Cingel, Aleksandar; Savić, Jelena; Vinterhalter, Branka; Vinterhalter, Dragan; Kostić, Miroslav; Jovanović, Darka Šešlija; Smigocki, Ann; Ninković, Slavica

2015-08-01

Plant proteinase inhibitors (PIs) are attractive tools for crop improvement and their heterologous expression can enhance insect resistance in transgenic plants. PI oryzacystatin II (OCII), isolated from rice, showed potential in controlling pests that utilize cysteine proteinases for protein digestion. To evaluate the applicability of the OCII gene in enhancing plant defence, OCII-transformed potatoes were bioassayed for resistance to Colorado potato beetle (Leptinotarsa decemlineata Say). Feeding on transformed leaves of potato cultivars Desiree and Jelica significantly affected larval growth and development, but did not change mortality rates. During the L2 and L3 developmental stages larvae consumed the OCII-transformed foliage faster as compared to the nontransformed control. Also these larvae reached the prepupal stage (end of L4 stage) 2 days earlier than those fed on control leaves. However, the total amounts of consumed OCII-transformed leaves were up to 23% lower than of control, and the maximal weights of prepupal larvae were reduced by up to 18% as compared to larvae fed on nontransformed leaves. The reduction in insect fitness reported in this study in combination with other control measures, could lead to improved CPB resistance management in potato.

Morphological and molecular identification of nasopharyngeal bot fly larvae infesting red deer (Cervus elaphus) in Austria.

Science.gov (United States)

Leitner, Natascha; Schwarzmann, Laurin; Zittra, Carina; Palmieri, Nicola; Eigner, Barbara; Otranto, Domenico; Glawischnig, Walter; Fuehrer, Hans-Peter

2016-11-01

Nasopharyngeal myiases are caused by larvae of bot flies (Diptera: Oestridae), which have evolved a high specificity for their hosts. Bot flies (n = 916) were collected from 137 (57.6 %) out of 238 red deer (Cervus elaphus) hunted in Vorarlberg and Tyrol (Western Austria). After being stored in 75 % ethanol, larvae were identified to species level and developmental stage using morphological and morphometric keys. Larvae were also molecularly characterized by polymerase chain reaction (PCR) amplification and partial sequencing of the mitochondrial cytochrome oxidase subunit I gene. Morphological and molecular analysis allowed identification of larvae as Cephenemyia auribarbis and Pharyngomyia picta. Genetic variations were also examined within the specimens collected in both geographical locations.

Muscidae (Diptera) of forensic importance-an identification key to third instar larvae of the western Palaearctic region and a catalogue of the muscid carrion community.

Science.gov (United States)

Grzywacz, Andrzej; Hall, Martin J R; Pape, Thomas; Szpila, Krzysztof

2017-05-01

The Muscidae is one of the main dipteran families recognized as important for medico-legal purposes. Although an association of adult flies with decomposing human and animal bodies is documented for about 200 taxa worldwide, cadavers and carrion represents a breeding habitat for considerably fewer species. Species that do colonize dead human bodies can do so under diverse environmental conditions and, under certain circumstances, Muscidae may be the only colonizers of a body. Because of difficulties in identification, many studies have identified immature and/or adult muscids only to the genus or family level. This lack of detailed species-level identifications hinders detailed investigation of their medico-legal usefulness in carrion succession-oriented experiments. Identification to species level of third instars of Muscidae of forensic importance and the utility of larval morphological characters for taxonomic purposes were subjected to an in-depth revision. A combination of characters allowing for the discrimination of third instar muscids from other forensically important dipterans is proposed. An identification key for third instar larvae, which covers the full set of cadaver-colonising species of Muscidae from the western Palaearctic (Europe, North Africa, Middle East), is provided. This key will facilitate more detailed and species-specific knowledge of the occurrence of Muscidae in forensic entomology experiments and real cases. The carrion-visiting Muscidae worldwide are catalogued, and those species breeding in animal carrion and dead human bodies are briefly discussed with regard to their forensic importance.

Efecto de la temperatura sobre la viabilidad de larvas de Trichinella spiralis Effect of temperature on the viability of Trichinella spiralis larvae

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Viviana R Randazzo

2011-12-01

freezing, larval mortality signifcantly increased as a function of time. Regardless of temperature, encysted larvae survived longer than the free ones. At -30 °C, -20 °C, and 20 °C there were no signifcant differences between the survival curves for each larval stage. At 4 °C, mortality was less severe for encysted larvae. All free and encysted larvae died at 61 days and 95 days (-30 °C, 160 days and 180 days (-20 °C, 280 days and 330 days (4 °C and 460 days and 590 days (20 °C, respectively. Cooking at 90 °C and 100 °C during 15 minutes killed 100 % of free and encysted larvae, respectively. Our results suggest that temperatures and exposure times traditionally used to treat meat products with a potential to transmit T. spiralis are not entirely effcient.

Hydrodynamics of burst swimming fish larvae; a conceptual model approach

NARCIS (Netherlands)

Verhagen, J.H.G.

2004-01-01

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

Morphological and molecular identification of Gnathostoma binucleatum (Nematoda: Gnathostomatidae) advanced third stage larvae (AdvL3) in the state of Colima, Mexico Determinación morfológica y molecular de larvas del tercer estadio larvario (L3A) de Gnathostoma binucleatum (Nematoda: Gnathostomatidae) del estado de Colima, México

OpenAIRE

Luis Jorge García-Márquez; Rafael Lamothe-Argumedo; David Osorio-Sarabia; Luis García-Prieto; Virginia León-Règagnon

2009-01-01

As a part of an ongoing project to understand the current distribution of Gnathostoma species in Mexico, 22 species of vertebrates were examined for this nematode in the state of Colima. The fish species Dormitator latifrons ("chococo") and Sciades guatemalensis ("cuatete") from Cuyutlán Lagoon and the reptile Crocodylus acutus from the Amela Lagoon were positive for infection. Morphometric characteristics of the larvae collected in Colima were similar to those of G. binucleatum larvae collec...

Simulating the impact of the entrainment of winter flounder larvae

International Nuclear Information System (INIS)

Hess, K.W.; Sissenwine, M.P.; Saila, S.B.

1975-01-01

The transport of winter flounder larvae around the Millstone Point, Conn. Area by the action of tidal currents and diffusion was simulated by computer to predict the numbers which could be entrained during the operation of a local nuclear power station. A tidal hydrodynamic model with variable depth was employed to simulate currents and water levels. These techniques provided input to a transport model which simulated the concentration of larvae. A larval source in a tributary river was simulated for twenty tidal cycles, with and without entrainment. The results indicated that the reduction in winter flounder larvae near Millstone Point at the end of the pelagic stage (period during which larvae are likely to be entrained) was less than 1 percent when it was assumed that larvae have little chance of returning once lost from Millstone bight. In order to assess the effect of a 1 percent reduction in recruitment of winter flounder larvae to the benthic phase of their life cycle, the local population was simulated by a model in which year-classes and the total egg production were represented by compartments. Each year-class grew, produced eggs, suffered natural and fishing mortality according to information derived from the literature. The effect of power plant entrainment was incorporated by reducing the number of recruits to year-class I that would normally result from a specific level of egg production. For a 1 percent reduction in recruitment due to power plant entrainment, a potential 6 percent decrease in total population size following 35 years of operation was indicated. (U.S.)

Active management of the third stage of labour without controlled cord traction: a randomized non-inferiority controlled trial

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Derman Richard

2009-01-01

Full Text Available Abstract Background The third stage of labour refers to the period between birth of the baby and complete expulsion of the placenta. Some degree of blood loss occurs after the birth of the baby due to separation of the placenta. This period is a risky period because uterus may not contract well after birth and heavy blood loss can endanger the life of the mother. Active management of the third stage of labour (AMTSL reduces the occurrence of severe postpartum haemorrhage by approximately 60–70%. Active management consists of several interventions packaged together and the relative contribution of each of the components is unknown. Controlled cord traction is one of those components that require training in manual skill for it to be performed appropriately. If it is possible to dispense with controlled cord traction without losing efficacy it would have major implications for effective management of the third stage of labour at peripheral levels of health care. Objective The primary objective is to determine whether the simplified package of oxytocin 10 IU IM/IV is not less effective than the full AMTSL package. Methods A hospital-based, multicentre, individually randomized controlled trial is proposed. The hypothesis tested will be a non-inferiority hypothesis. The aim will be to determine whether the simplified package without CCT, with the advantage of not requiring training to acquire the manual skill to perform this task, is not less effective than the full AMTSL package with regard to reducing blood loss in the third stage of labour. The simplified package will include uterotonic (oxytocin 10 IU IM injection after delivery of the baby and cord clamping and cutting at approximately 3 minutes after birth. The full package will include the uterotonic injection (oxytocin 10 IU IM, controlled cord traction following observation of uterine contraction and cord clamping and cutting at approximately 3 minutes after birth. The primary outcome

Nutrient intake in the third instar larvae of Anomala cuprea and Protaetia orientalis submarmorea (Coleoptera; Scarabaeidae) from a mixture of cow dung and wood chips: Results from stable isotope analyses of nitrogen and carbon

International Nuclear Information System (INIS)

Koyama, Masahito; Iwata, Ryutaro; Yamane, Akiomi; Katase, Takao; Ueda, Shingo

2003-01-01

The nutrient intake of the third instar larvae of Anomala cuprea (Ac) and Protaerita orientalis submarmorea (Pos) (Colepotera: Scarabaeidae) from a mixture of cow dung and wood chips of two wood species (Cryptomeria japonica and Quercus mongolica), was assayed by the stable isotope technique. The values of δ 15 N and δ 13 C (deviations of 15 N/ 14 N and 13 C/ 12 C from the standard materials) were measured in the following samples: (1) the integument plus the head of the 3rd instar larvae of both species reared in 1999 autumn fed with a mixture of cow dung and wood chips or with leaf mold, (2) cow dung, (3) wood ships, and (4) leaf mold as the larval food before onset of rearing. The δ values of bodies of larvae fed with leaf mold differed with the beetle species. The δ 15 N values of the larval bodies of both species fed with the mixture were close to those of cow dung, whereas the δ 13 C values were in between those of cow dung and wood chips. Therefore, both species were presumed to obtain almost all their nitrogen from cow dung, and their carbon from both dung and wood chips. (author)

Seasonal occurrence and abundance of caridean shrimp larvae at Helgoland, German Bight

Science.gov (United States)

Wehrtmann, Ingo S.

1989-03-01

Plankton samples were collected from January 1985 to January 1986 three times per week at Helgoland to study seasonal occurrence and abundance of caridean shrimp larvae. A total of eleven species were obtained. Ninety-one % of all larvae collected during the sample period belonged to Crangon crangon L. and Crangon allmanni Kinahan, 6% to Philocheras trispinosus Hailstone and 3% to the remaining eight species. Collections were generally dominated by C. crangon larvae. However, C. allmanni larvae were most abundant in June coinciding with hatching activities of the population near Helgoland. C. allmanni was observed to have the highest density of all species with approximately 8 larvae per m3. Larvae of Eualus occultus (Lebour), Eualus pusiolus (Kroyer), Hippolyte varians Leach and Athanas nitescens Leach were most likely released by populations inhabiting the rocky intertidal zone around Helgoland. The presence of Processa modica Williamson & Rochanaburanon and Processa nouveli holthuisi Al-Adhub & Williamson in the German Bight was verified by observations of a series of different developmental stages. Larvae of the rare species Caridion steveni Lebour were also recorded. The observed shrimp species were placed into three different groups with respect to their seasonal occurrence. Possible advantages of the timing of larval dispersal relative to predation and food availability are given. The results on seasonal occurrence and relative abundance are discussed in relation to environmental factors (temperature, salinity) as well as to the geographical distribution of the species.

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

DEFF Research Database (Denmark)

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

2017-01-01

A major barrier for using animal waste as substrate for production of insects for feed or food is the concern for safety of the end products. In this study we investigated how rearing of fly larvae of Musca domestica in poultry manure influenced the counts of three pathogenic test strains...... of the larvae stage. This study provides data for evaluation of feed safety of fly larvae reared on animal waste. Furthermore suggests a potential use for reduction of these pathogens in manure........ Enteritidis, and C. jejuni was faster in manure with rearing of fly larvae than in manure without larvae; an 8 log10 reduction of all three test bacteria was observed within four days in manure with larvae; compared to manure without larvae where a 1 to 2 log10 was observed. We found no sign of propagation...

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

In situ hybridization using a DmKAP specific cRNA probe has revealed a dynamic pattern of expression in the developing nervous system. The staining first appears in a subset of cells in the embryonic central nervous system at stage 13 and continues till the first instar larva stage. At the third instar larva stage the staining ...

MBV infection in various stages of black tiger shrimp (Penaeus monodon

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Supamattaya, K.

2005-02-01

Full Text Available MBV infection in various stages of Penaeus monodon were studied. In hatcheries, MBV infection was detected early in nauplii stage using PCR technique, whereas rates of infection of 11.15-49.50% were observed in PL1 using histological technique, rising up to 15.26-100% in PL 10. In earthen ponds, the infection in PL15 was initially in the range of 68.68-96.00%. The infection was decreased toward the end of the first, second and third month of rearing period ranging between 13.63-54.83%. The laboratory trial showed that types of feed might affect the rate of MBV infection of larvae. Postlarva fed with artemia showed lowest infection rate at 29.41±7.98%, whereas the infection rates of shrimp fed with minced cockle flesh and commercial feed were 39.09±12.08% and 52.81±11.91, respectively. In stress test trial, a significant MBV infection was detected in the group of larvae that were raised with 25ºC and 34ºC and the salinity at 6 ppt and 18 ppt for 12 hours then rearing in normal condition for 3 days. In the 24 hour-stress trial, and transferred to normal condition for 7 day, the groups that were exposed to stress conditions had significantly higher rates of infection than the control group (p<0.05. The 24 hour - transportationcondition resulted in highest MBV infection rate (73.61±1.25%. From the present study, it was concluded that MBV infection in larvae from hatcheries increases with period of rearing and stress exposure, but the infection tended to decreased with rearing period in earthen pond condition. Proper feeding management and prevention of stress conditions could reduce of MBV infection in black tiger shrimp.

Temporal variability of fish larvae assemblages: influence of natural and anthropogenic disturbances

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David A. Reynalte-Tataje

Full Text Available Natural and induced disturbances greatly influence the temporal distribution of ichthyoplankton abundance. This study assesses and compares the temporal variability of fish larvae assemblages in controlled and free environments to determine the influence of environment variables on the main taxa in these systems. The study was conducted at the Chapecó (without dam impact and Ligeiro (with dam impact river mouths, which are located in the upper Uruguay River. Samples were made between October 2001 and March 2004 during three reproductive periods. The larvae assemblages were composed of small and medium-sized Characiformes and Siluriformes. The variation in the distribution of larvae was mainly temporal (>85%. When the three reproductive periods were compared, it was observed in the second period, characterized by a larger water flow and a lower temperature, that there was a reduction in abundance, a lower number of taxa, an absence of stages in post-flexion and a high dissimilarity in larvae assemblage structure. In general, the environmental variables of water flow and temperature most influenced the distribution of egg and larvae abundance. In the studied area, a smaller temporal variability was observed in the structure of larvae assemblages at the sampling sites in the Chapecó River mouth than in in the Ligeiro River mouth under the influence of dams.

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

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Edy Syahputra

2014-08-01

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

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

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RACHMAWATI RACHMAWATI

2015-09-01

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

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

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Dulce Maria Tocchetto Schuch

2003-03-01

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

Larvae of commercial  and other oyster species in Thailand (Andaman Sea and Gulf of Thailand)

DEFF Research Database (Denmark)

Bussarawit, Somchai; Cedhagen, Tomas

2012-01-01

The development of larvae of some Thai commercial oyster species (Crassostrea belcheri (Sowerby, 1871), Crassostrea bilineata (Röding, 1798), Saccostrea forskali (Gmelin, 1791) and Dendrostrea folium (Linnaeus, 1758)) is described from newly hatched to the settlement stage with particular...... reference to changes in shell morphology. Planktonic oyster larvae were collected in the Andaman Sea and the Gulf of Thailand. Different species of oyster larvae were found in the genera Crassostrea, Saccostrea, Ostrea, Dendrostrea, Nanostrea, Planostrea, Lopha, and Hyotissa. Detailed morphological...... descriptions and measurements are provided. Diagnostic features of the larval shape, hinge teeth, and prodissoconch sizes were identified in order to allow separation of commercial oyster larvae from other oyster species in Thai waters. Brooding species (incubatory) of the subfamilies Ostreinae (Ostrea...

Effects of inorganic mercury on the respiration and the swimming activity of shrimp larvae, Pandalus borealis

International Nuclear Information System (INIS)

St-Amand, L.; Gagnon, R.; Packard, T.T.; Savenkoff, C.

1999-01-01

In order to test the sensitivity of respiration (physiological and potential) to mercury (Hg) contamination, larval shrimp Pandalus borealis were exposed to inorganic Hg (0-160 ppb) for 27 h in the laboratory. Oxygen consumption rates (RO 2 ), potential respiration (determined by respiratory electron transfer system activity, ETSA), protein content, and swimming activity for zoeae III and zoeae V stages were measured. For both zoeae stages, ETSA and protein content remained constant after 27 h exposure to 160 ppb Hg whereas RO 2 and swimming activity decreased. This study revealed the impact of different Hg levels and different exposure times on RO 2 of shrimp larvae. After 10 h exposure to 160 ppb Hg, the RO 2 decreased by 43 and 49% in zoeae III and zoeae V stages, respectively. Exposure time of 27 h to 80 ppb Hg and higher, induced paralysis in nearly 100% larvae. Surprisingly, the paralysed larvae displayed almost 50% of the control's RO 2 . The results showed that Hg disturbs a part of the respiration process without modifying the maximum activity of the enzymes involved in the ETSA assay. Therefore, the ETSA assay can not be used as a sublethal bioanalytic probe to detect Hg in short-term exposures. The decline of the RO 2 /ETSA ratios reported here, indicates an inability of contaminated larvae to adapt their metabolism to physiological stress caused by Hg. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Development of two related endoparasitoids in larvae of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

NARCIS (Netherlands)

Malčická, Mima; Harvey, Jeffrey A.

2015-01-01

We compare the growth and development of two related solitary endoparasitoids (Braconidae, Microgastinae) in different instars (second and third) of the diamondback moth Plutella xylostella. Cotesia vestalis is a well-studied parasitoid whose larvae feed primarily on host hemolymph and fat body

Efficacy of maslinic acid and fenbendazole on muscle larvae of Trichinella zimbabwensis in laboratory rats.

Science.gov (United States)

Mukaratirwa, S; Gcanga, L; Kamau, J

2016-01-01

Trichinellosis is a zoonotic disease caused by nematode species of the genus Trichinella. Anthelmintics targeting the intestinal adults and muscle-dwelling larvae of Trichinella spp. have been tested, with limited success. This study was aimed at determining the efficacy of maslinic acid and fenbendazole on muscle larvae of Trichinella zimbabwensis in laboratory rats. Forty-two Sprague-Dawley rats, with an average weight of 270 g and 180 g for males and females respectively, were infected with T. zimbabwensis larvae. Infected rats were randomly assigned to three groups which were subjected to single treatments with each of maslinic acid, fenbendazole and a combination of both on day 25 post-infection (pi), and three groups which were subjected to double treatments with each of these drugs and a combination on days 25 and 32 pi. The untreated control group received a placebo. In single-treatment groups, the efficacy of each treatment, measured by rate of reduction in muscle larvae, was significant (P0.05). We conclude that the efficacy of maslinic acid against larval stages of T. zimbabwensis in rats was comparable to that of fenbendazole, with no side-effects observed, making maslinic acid a promising anthelmintic against larval stages of Trichinella species.

Evaluation of the myoelectrical activity of the equine ileum infected with Strongylus vulgaris larvae.

Science.gov (United States)

Berry, C R; Merritt, A M; Burrows, C F; Campbell, M; Drudge, J H

1986-01-01

Five weanling ponies were subjected to an intensive 6-week deworming program after which 4 Ag-AgCl bipolar electrodes were implanted surgically on the distal ileum. For 3 hours each day for 5 consecutive days, ileal myoelectrical activity was recorded from fed ponies under 3 sequential conditions: preinoculation, after oral administration of 1,000 killed Strongylus vulgaris infective larvae (3 ponies), and after oral administration of 1,000 live S vulgaris infective larvae. Recordings were analyzed for slow wave frequency, percentage duration of phases I, II, and III of the migrating myoelectrical complex (MMC), and the frequency of distinct, rapidly migrating action-potential complexes within phase 2 of the MMC. After administration of live and killed infected 3rd-stage larvae, there was a marked increase in the number of disrupted phase III complexes, and a significant (P less than 0.001) increase in the number of migrating action-potential complexes. In addition, after inoculation of live 3rd-stage larvae, there was a significant increase (P less than 0.001) in the percentage of time that the MMC was occupied by prolonged periods devoid of spike activity (phase I). The results indicate that S vulgaris larval mucosal penetration and submucosal migration can cause changes in ileal myoelectrical activity that could cause colic, and that larval antigen alone within the lumen may disrupt ileal motility.

Insecticidal activity of two proteases against Spodoptera frugiperda larvae infected with recombinant baculoviruses

Science.gov (United States)

2010-01-01

Background Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricutural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL), and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat), were constructed. and their insecticidal properties analysed against Spodoptera frugiperda larvae. Results Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill. Conclusions Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs. PMID:20587066

Three-dimensionally preserved minute larva of a great-appendage arthropod from the early Cambrian Chengjiang biota

Science.gov (United States)

Liu, Yu; Melzer, Roland R.; Haug, Joachim T.; Haug, Carolin; Briggs, Derek E. G.; Hörnig, Marie K.; He, Yu-yang; Hou, Xian-guang

2016-05-01

A three-dimensionally preserved 2-mm-long larva of the arthropod Leanchoilia illecebrosa from the 520-million-year-old early Cambrian Chengjiang biota of China represents the first evidence, to our knowledge, of such an early developmental stage in a short-great-appendage (SGA) arthropod. The larva possesses a pair of three-fingered great appendages, a hypostome, and four pairs of well-developed biramous appendages. More posteriorly, a series of rudimentary limb Anlagen revealed by X-ray microcomputed tomography shows a gradient of decreasing differentiation toward the rear. This, and postembryonic segment addition at the putative growth zone, are features of late-stage metanauplii of eucrustaceans. L. illecebrosa and other SGA arthropods, however, are considered representative of early chelicerates or part of the stem lineage of all euarthropods. The larva of an early Cambrian SGA arthropod with a small number of anterior segments and their respective appendages suggests that posthatching segment addition occurred in the ancestor of Euarthropoda.

SEAWARD DRIFT OF THE PONTIC SHAD LARVAE (ALOSA PONTICA) AND THE INFLUENCE OF DANUBE RIVER HYDROLOGY ON THEIR TRAVEL PATH THROUGH THE DANUBE DELTA SYSTEM.

OpenAIRE

NAVODARU I.

2001-01-01

The Pontic shad lives in the northwestern part of the Black Sea. It migrates in the Danube River for spawning. The larvae drift passively towards the sea when they reach the life stage ranging from pre-larvae to post-larvae. During the larval stage the Pontic shad is floating, mainly in the 0-50 cm upper layer of river. Upstream of the Danube Delta, in the straight sector of the river, alosids are distributed mostly towards the middle of the river, where the water velocity is higher. In the c...

The Effect of Water Content of Medium Containing Oryctes rhinoceros Larvae on Metarhizium anisopliae Pathogenicity

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Dyah Rini Indriyanti

2017-08-01

Full Text Available The entomopathogenic fungus, Metarhizium anisopliae (Metschnikoff Sorokin (Ascomycota: Hypocrealeswould effectively infect the target host on the appropriate medium water content. The aim of this study was to analyze the influence of water content of medium on the effectiveness of M. anisopliae fungus infection on O. rhinoceros larvae in the laboratory. Fifty healthy third instar larvae of O. rhinoceros were  obtained from field. The M. anisopliae obtained from Estate Crop Protection Board in Salatiga. The conidia density and viability of M. anisopliae were examined before used. The medium for maintaining the larva was the sawdust that had been sterilized. A total of 50 plastic cups were prepared to place 50 larvae (1 larva/cup. Each cup was filled with 100 g medium  of sawdust plus 2 g of M. anisopliae which was then stirred until mixed, with different water content: P1 (20%, P2 (40%, P3 (60%, P4 (80% and P5 (98%. The result indicated that  the water content of the medium affected the effectiveness of M. anisopliae fungus infection on O. rhinoceros larvae. The water content influenced the duration of larval mortality at each treatment. An important finding in this study is that controlling O. rhineceros larvae  with M. anisopliae can be done by manipulating the water content of medium. The benefit of this study may be used for the recommendation of O. rhinoceros pest control using M. anisopliae  with an effective water media content.

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

Science.gov (United States)

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

2014-09-01

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

Evaluating penetration ability of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larvae into multilayer polypropylene packages

Science.gov (United States)

Larvae of the Indian meal moth, Plodia interpunctella (Hübner), can invade or penetrate packaging materials and infest food products. Energy bars with three polypropylene packaging types were challenged with eggs (first instars), third, and fifth instars of P. interpunctella to determine package res...

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

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Kátia Kalko Schwarz

2011-12-01

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

Inorganic nutrients in natural and artificial food of Dacus oleae larvae (Diptera: Tephritidae)

International Nuclear Information System (INIS)

Manoukas, A.G.; Grimanis, A.; Mazomenos, B.

1978-01-01

Certain inorganic nutrients contained in the natural and artificial food of Dacus oleae larvae were determined by neutron activation analysis and spectrophotometry. The content of sodium, potassium, calcium, magnesium, manganese, iron, zinc, copper and phosporus was reported for the olive fruit mesocarp at three stages of maturity, brewer's yeast, soybean hydrolysate and roasted peanuts. Several differences were found between the inorganic nutrient content of the natural food (olive fruit) and artificial diet of D. oleae larvae. The differences which may be important in the nutrition and metabolism of this insect were estimated and discussed

Atividade residual in vitro do pelo de cobertura de cães tratados com dinotefuran sobre larvas e adultos de Ctenocephalides felis felis (Bouché, 1835 (Siphonaptera: pulicidae Residual activity in vitro of treated dog's hair coat with dinotefuran on larvae and adults of Ctenocephalides felis felis (Bouché, 1835 (Siphonaptera: Pulicidae

Directory of Open Access Journals (Sweden)

Thaís R. Correia

2008-12-01

Full Text Available O objetivo deste trabalho foi avaliar a atividade in vitro do resíduo em pelo de cobertura de cães tratados com dinotefuran sobre larvas e adultos de Ctenocephalides felis felis. Foram utilizadas três cadelas da Raça Beagle: a nº 1 foi tratada com uma formulação spray de dinotefuran a 0,834%, a nº 2 com uma formulação "strip-on" de dinotefuran a 30% e a nº 3 foi mantida sem tratamento. Pequenas áreas foram tricotomizadas nos dias 2, 9, 16, 23, 30, 37 e 44 após o tratamento. Para avaliação adulticida e larvicida, foram utilizados pulgas de uma colônia mantida em laboratório. Seis repetições com cada uma contendo 10 exemplares de C. f. felis, acondicionados em tubos de ensaio, da etapa correspondente foram utilizados por dia de desafio. Em cada repetição foi adicionado 0,02 gramas de pelo de cada área tricotomizada e dieta na etapa de larvas. O material da etapa adulto foi avaliado num período de 24 horas, o da etapa larvas foi avaliado após 20 dias de cada desafio. O resíduo no pêlo de cães tratados com ambas as formulações de dinotefuran foi eficaz no controle de larvas por um período de 44 dias, e no controle de adultos as formulações spray e a "strip-on" foram eficazes por um período de 16 e 23 dias, respectivamente.The aim of this study was to evaluate the residual activity of treated dog's hair coat with dinotefuran on larvae and adults of Ctenocephalides felis felis. Three female Beagle dogs were used. One female dog was treated with 0.834% dinotefuran spray, the second was treated with 30% dinotefuran strip-on and the third was not treated. Some areas of dog's hair were clipped on days 2, 9, 16, 23, 30, 37 and 44 after treatment. For the evaluation of adulticidal and larvicidal activities, flea adults and larvae from the laboratory colony were used. Six repetitions were used with 10 samples of each flea stage per day, placed in assay tubes. In each repetition we added 0.02 g of treated or untreated dog

Sensory Flask Cells in Sponge Larvae Regulate Metamorphosis via Calcium Signaling.

Science.gov (United States)

Nakanishi, Nagayasu; Stoupin, Daniel; Degnan, Sandie M; Degnan, Bernard M

2015-12-01

The Porifera (sponges) is one of the earliest phyletic lineages to branch off the metazoan tree. Although the body-plan of sponges is among the simplest in the animal kingdom and sponges lack nervous systems that communicate environmental signals to other cells, their larvae have sensory systems that generate coordinated responses to environmental cues. In eumetazoans (Cnidaria and Bilateria), the nervous systems of larvae often regulate metamorphosis through Ca(2+)-dependent signal transduction. In sponges, neither the identity of the receptor system that detects an inductive environmental cue (hereafter "metamorphic cues") nor the signaling system that mediates settlement and metamorphosis are known. Using a combination of behavioral assays and surgical manipulations, we show here that specialized epithelial cells-referred to as flask cells-enriched in the anterior third of the Amphimedon queenslandica larva are most likely to be the sensory cells that detect the metamorphic cues. Surgical removal of the region enriched in flask cells in a larva inhibits the initiation of metamorphosis. The flask cell has an apical sensory apparatus with a cilium surrounded by an apical F-actin-rich protrusion, and numerous vesicles, hallmarks of eumetazoan sensory-neurosecretory cells. We demonstrate that these flask cells respond to metamorphic cues by elevating intracellular Ca(2+) levels, and that this elevation is necessary for the initiation of metamorphosis. Taken together, these analyses suggest that sponge larvae have sensory-secretory epithelial cells capable of converting exogenous cues into internal signals via Ca(2+)-mediated signaling, which is necessary for the initiation of metamorphosis. Similarities in the morphology, physiology, and function of the sensory flask cells in sponge larvae with the sensory/neurosecretory cells in eumetazoan larvae suggest this sensory system predates the divergence of Porifera and Eumetazoa. © The Author 2015. Published by Oxford

Third molar development: measurements versus scores as age predictor.

Science.gov (United States)

Thevissen, P W; Fieuws, S; Willems, G

2011-10-01

Human third molar development is widely used to predict chronological age of sub adult individuals with unknown or doubted age. For these predictions, classically, the radiologically observed third molar growth and maturation is registered using a staging and related scoring technique. Measures of lengths and widths of the developing wisdom tooth and its adjacent second molar can be considered as an alternative registration. The aim of this study was to verify relations between mandibular third molar developmental stages or measurements of mandibular second molar and third molars and age. Age related performance of stages and measurements were compared to assess if measurements added information to age predictions from third molar formation stage. The sample was 340 orthopantomograms (170 females, 170 males) of individuals homogenously distributed in age between 7 and 24 years. Mandibular lower right, third and second molars, were staged following Gleiser and Hunt, length and width measurements were registered, and various ratios of these measurements were calculated. Univariable regression models with age as response and third molar stage, measurements and ratios of second and third molars as predictors, were considered. Multivariable regression models assessed if measurements or ratios added information to age prediction from third molar stage. Coefficients of determination (R(2)) and root mean squared errors (RMSE) obtained from all regression models were compared. The univariable regression model using stages as predictor yielded most accurate age predictions (males: R(2) 0.85, RMSE between 0.85 and 1.22 year; females: R(2) 0.77, RMSE between 1.19 and 2.11 year) compared to all models including measurements and ratios. The multivariable regression models indicated that measurements and ratios added no clinical relevant information to the age prediction from third molar stage. Ratios and measurements of second and third molars are less accurate age predictors

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

Directory of Open Access Journals (Sweden)

Rohlfs Marko

2005-01-01

Full Text Available Abstract Background Competition with filamentous fungi has been demonstrated to be an important cause of mortality for the vast group of insects that depend on ephemeral resources (e.g. fruit, dung, carrion. Recent data suggest that the well-known aggregation of Drosophila larvae across decaying fruit yields a competitive advantage over mould, by which the larvae achieve a higher survival probability in larger groups compared with smaller ones. Feeding and locomotor behaviour of larger larval groups is assumed to cause disruption of fungal hyphae, leading to suppression of fungal growth, which in turn improves the chances of larval survival to the adult stage. Given the relationship between larval density, mould suppression and larval survival, the present study has tested whether fungal-infected food patches elicit communal foraging behaviour on mould-infected sites by which larvae might hamper mould growth more efficiently. Results Based on laboratory experiments in which Drosophila larvae were offered the choice between fungal-infected and uninfected food patches, larvae significantly aggregated on patches containing young fungal colonies. Grouping behaviour was also visible when larvae were offered only fungal-infected or only uninfected patches; however, larval aggregation was less strong under these conditions than in a heterogeneous environment (infected and uninfected patches. Conclusion Because filamentous fungi can be deadly competitors for insect larvae on ephemeral resources, social attraction of Drosophila larvae to fungal-infected sites leading to suppression of mould growth may reflect an adaptive behavioural response that increases insect larval fitness and can thus be discussed as an anti-competitor behaviour. These observations support the hypothesis that adverse environmental conditions operate in favour of social behaviour. In a search for the underlying mechanisms of communal behaviour in Drosophila, this study highlights

Dinámica de las larvas infestantes de estrongílidos gastrointestinales en ovinos en pastoreo Dynamics of gastrointestinal strongyle infesting larvae in grazing sheep

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J Arece

2010-03-01

Full Text Available Se desarrolló un estudio durante dos años, con el objetivo de caracterizar la dinámica de las poblaciones larvarias en «refugio» de nemátodos gastrointestinales, así como su interrelación con las variables meteorológicas, en tres unidades de producción ovina de la provincia de Matanzas (Dos Mercedes, LABIOFAM y la EEPF «Indio Hatuey». Con una frecuencia mensual se recolectaron e identificaron las larvas de estrongílidos gastrointestinales, mediante una técnica de lavado del pasto proveniente de cuartones centinelas previamente seleccionados. La dinámica de las poblaciones larvarias de tercer estadio tuvo un comportamiento similar en las unidades en estudio; sin embargo, hubo diferencias en las cantidades de L3 por kg de MS de pasto. Se registró un efecto de los meses y la época del año en la disponibilidad de larvas. En el período lluvioso (PLL se recolectó una mayor cantidad de L3 como producto de los efectos favorables de las precipitaciones y la temperatura. En el pasto se encontró un predominio de L3 de Haemonchus spp. y, en menor cuantía, Trichostrongylus colubriformis y Oesophagostomum columbianum. Las poblaciones larvarias aparecieron en mayor cuantía durante el PLL y su dinámica se relacionó con las variables ambientales y con los factores vinculados al sistema de producción en cada unidad.A study was conducted for two years, with the objective of characterizing the dynamics of the larval populations in «refuge» of gastrointestinal nematodes, as well as its interrelation with the meteorological variables in three sheep production farms in Matanzas province, Cuba (Dos Mercedes, LABIOFAM and the EEPF «Indio Hatuey». Larvae of gastrointestinal strongyles were monthly collected from pasture and identified by means of a pasture washing technique from previously selected sentinel paddocks. The third stage larval population's dynamics in pasture showed a similar trend in the three farms; however, there were

A scanning electron microscopy study of early development in vitro of Contracaecum multipapillatum s.l. (Nematoda: Anisakidae) from a brown pelican (Pelecanus occidentalis) from the Gulf of California, Mexico.

Science.gov (United States)

Molina-Fernández, Dolores; Valles-Vega, Isabel; Hernández-Trujillo, Sergio; Adroher, Francisco Javier; Benítez, Rocío

2017-10-01

Eggs obtained from the uteri of female nematodes, genetically identified as Contracaecum multipapillatum s.l., found in a brown pelican (Pelecanus occidentalis) from Bahía de La Paz, Gulf of California, Mexico, were used to study the early developmental stages of this anisakid by scanning electron microscopy (SEM). Egg dimensions were approximately 54 × 45 μm measured by SEM. Observation of the eggs revealed an outer surface of fibrous appearance. The newly hatched larvae were ensheathed and highly motile. Observation with SEM showed that the sheaths of the larvae were striated and revealed an excretory pore and a cleft near the anterior end of the sheath, presumably to facilitate the opening of the sheath for the emergence of the larva. The hatched larvae were placed in nutritive culture medium, where they grew within their sheath, some exsheathing completely 2 weeks later. The surface patterns of the sheath and the cuticle of the exsheathed larvae were clearly different. Although they did not moult during culture, SEM revealed a morphology typical of third-stage larvae of Contracaecum from fish, as previously observed by optical microscopy. Thus, we suggest that newly hatched larvae from eggs of C. multipapillatum are third larval stage but with sheath of the second larval stage, as occuring in other anisakids.

Human dental age estimation using third molar developmental stages: does a Bayesian approach outperform regression models to discriminate between juveniles and adults?

Science.gov (United States)

Thevissen, P W; Fieuws, S; Willems, G

2010-01-01

Dental age estimation methods based on the radiologically detected third molar developmental stages are implemented in forensic age assessments to discriminate between juveniles and adults considering the judgment of young unaccompanied asylum seekers. Accurate and unbiased age estimates combined with appropriate quantified uncertainties are the required properties for accurate forensic reporting. In this study, a subset of 910 individuals uniformly distributed in age between 16 and 22 years was selected from an existing dataset collected by Gunst et al. containing 2,513 panoramic radiographs with known third molar developmental stages of Belgian Caucasian men and women. This subset was randomly split in a training set to develop a classical regression analysis and a Bayesian model for the multivariate distribution of the third molar developmental stages conditional on age and in a test set to assess the performance of both models. The aim of this study was to verify if the Bayesian approach differentiates the age of maturity more precisely and removes the bias, which disadvantages the systematically overestimated young individuals. The Bayesian model offers the discrimination of subjects being older than 18 years more appropriate and produces more meaningful prediction intervals but does not strongly outperform the classical approaches.

Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae).

Science.gov (United States)

Abrunhosa, Fernando A; Simith, Darlan J B; Palmeira, Carlos A M; Arruda, Danielle C B

2008-12-01

Food supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development). In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period. High survival rate was observed in both experiments, in which only 2 megalopae and 1 zoea III died. These results strongly suggest that larvae of L. siriboia are lecithotrophic as they have sufficiently large yolk reserve to complete their larval development, while the megalopa stage shows facultative lecithotrophy. The larval periods of each stage of the treatments were quite similar and, despite some significant differences in some larval periods, these can be related probably to larval rearing conditions, abiotic factors or, individual variability of larval health, as well as stress caused to the ovigerous females during embryogenesis.

Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

Science.gov (United States)

2013-01-01

Background Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. Methods A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. Results A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes

Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina.

Science.gov (United States)

Hernández-Orts, Jesús S; Aznar, Francisco J; Blasco-Costa, Isabel; García, Néstor A; Víllora-Montero, María; Crespo, Enrique A; Raga, Juan A; Montero, Francisco E

2013-08-29

Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes. Most of the sealworms were

Antibody responses in pregnancy-induced transmammary transmission of Ancylostoma caninum hookworm larvae.

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Arasu, P; Heller, A

1999-09-20

Third stage larvae of the Ancylostoma caninum hookworm nematode have the capacity to infect a dog, abort the normal maturation pathway to become blood-feeding intestinal worms, and instead distribute throughout the body in a developmentally arrested state that is relatively resilient to most chemotherapeutic agents. During pregnancy, a percentage of the arrested larvae reactivate and transmit via the mammary glands to infect the nursing puppies with resulting iron-deficiency anemia and potential mortality. To determine if the suppression of parasite-specific antibody responses during pregnancy facilitates the reactivation and transmammary transfer of hookworm larvae, a murine model of A. caninum infection was used to compare the infected versus uninfected animals that were either bred or not bred. Initial comparisons of genetically divergent BALB/c versus C57BL/6 mice showed that both the strains mounted strong Th2 biased IgG1 and IgE antibody responses to A. caninum infection. Using the BALB/c strain for the breeding analyses, it was confirmed that larval transfer to the mouse pups only occurred during the post-partum lactational period. In the dams, levels of total and antigen-specific IgG1 and total IgE were highly correlated with parasite burden. During most phases of pregnancy and lactation, infected dams had lower total IgG1, IgG2a and IgE levels as compared to unbred mice at comparable times post-infection; this downward modulation of antibody responses supports the established dogma of a generalized immunosuppression associated with pregnancy. However, at parturition and post-partum lactation, antigen-specific IgG1 levels measured at 1:5000 serum dilutions were comparable between bred and unbred mice, and antigen-specific IgG2a levels at 1:100 serum dilutions were also not significantly different except for a marginal reduction in the bred mice at the lactational timepoint. The comparable anti-A. caninum IgG1 levels between bred and unbred mice, and low

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

DEFF Research Database (Denmark)

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

2006-01-01

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

In vitro development of Strongylus edentatus to the fourth larval stage with notes on Strongylus vulgaris and Strongylus equinus.

Science.gov (United States)

Farrar, R G; Klei, T R

1985-08-01

Strongylus edentatus was successfully cultured in vitro to the fourth larval stage (L4). Some growth continued for periods of 40-50 days at which time reductions in viability were observed in some of the culture systems tested. Various combinations of media, sera, buffers and organ explant cultures were tested. All cultures were incubated at 37 C in an atmosphere of 95% air and 5% CO2. Larvae underwent growth and differentiation to the L4 in all medium-serum combinations with and without organ explant cultures. Development and growth did occur but viability was reduced to insignificant levels in media without serum or cells. Optimal growth, differentiation, and longevity were observed in bicarbonate buffered RPMI-1640 containing 10% fetal calf serum and gerbil (Meriones unguiculatus) cecum explant cultures. Observations indicated that Strongylus vulgaris and Strongylus equinus also developed to the L4 stage using similar techniques. However, viability of S. vulgaris L4 was markedly limited. Specific morphological changes marked phases of development of S. edentatus, categorized as early, middle and late third stage, third molt and early fourth stage. Strongylus equinus appeared to follow the same developmental pattern in vitro as S. edentatus. Distinct differences in morphological features during differentiation were observed between S. edentatus and S. vulgaris.

Effects of inorganic mercury on the respiration and the swimming activity of shrimp larvae, Pandalus borealis

Energy Technology Data Exchange (ETDEWEB)

St-Amand, L.; Gagnon, R.; Packard, T.T.; Savenkoff, C. [Department of Fisheries and Oceans, Maurice Lamontagne Institute, Division of Ocean Sciences, 850 Rte de la Mer, P.O. Box 1000, Mont-Joli, Quebec G5H 3Z4 (Canada)

1999-01-01

In order to test the sensitivity of respiration (physiological and potential) to mercury (Hg) contamination, larval shrimp Pandalus borealis were exposed to inorganic Hg (0-160 ppb) for 27 h in the laboratory. Oxygen consumption rates (RO{sub 2}), potential respiration (determined by respiratory electron transfer system activity, ETSA), protein content, and swimming activity for zoeae III and zoeae V stages were measured. For both zoeae stages, ETSA and protein content remained constant after 27 h exposure to 160 ppb Hg whereas RO{sub 2} and swimming activity decreased. This study revealed the impact of different Hg levels and different exposure times on RO{sub 2} of shrimp larvae. After 10 h exposure to 160 ppb Hg, the RO{sub 2} decreased by 43 and 49% in zoeae III and zoeae V stages, respectively. Exposure time of 27 h to 80 ppb Hg and higher, induced paralysis in nearly 100% larvae. Surprisingly, the paralysed larvae displayed almost 50% of the control's RO{sub 2}. The results showed that Hg disturbs a part of the respiration process without modifying the maximum activity of the enzymes involved in the ETSA assay. Therefore, the ETSA assay can not be used as a sublethal bioanalytic probe to detect Hg in short-term exposures. The decline of the RO{sub 2}/ETSA ratios reported here, indicates an inability of contaminated larvae to adapt their metabolism to physiological stress caused by Hg. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

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

Science.gov (United States)

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

2010-10-01

We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

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

Digital Repository Service at National Institute of Oceanography (India)

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

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

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

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A. A. Boyko

2016-08-01

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

Effects of anisakid nematodes Anisakis simplex (s.l.), Pseudoterranova decipiens (s.l.) and Contracaecum osculatum (s.l.) on fish and consumer Health

DEFF Research Database (Denmark)

Buchmann, Kurt; Mehrdana, Foojan

2016-01-01

– including euphausiids, copepods and amphipods – feed on these larvae, become infected and serve as intermediate hosts. A range of fish species may serve as transport hosts following ingestion of infected invertebrates and the final stage develops after two additional moults in the stomach of marine mammals......The anisakid nematodes Anisakis simplex (Rudolphi, 1809), Pseudoterranova decipiens (Krabbe, 1878) and Contracaecum osculatum (Rudolphi, 1802) occur as third-stage larvae in marine fish products and may infect consumers ingesting raw or under-cooked fish products. Clinical symptoms associated...... with the infection, termed anisakidosis, vary from irritation of the oesophagus and stomach, via nausea, vomiting and diarrhoea to severe epigastric and abdominal pain. Third-stage larvae of A. simplex are found in the body cavity, musculature and various organs, P. decipiens occur mainly in the fish musculature...

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

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Da Xiao

2014-04-01

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

Evaluation of ivermectin against later fourth-stage Strongylus vulgaris in ponies at two and five weeks after treatment.

Science.gov (United States)

Slocombe, J O; McCraw, B M

1984-10-01

The efficacy of ivermectin against later fourth-stage Strongylus vulgaris larvae was studied in pony foals at 14 and 35 days after treatment. These foals had been reared parasite-free, inoculated with 500 infective larvae and 56 days later given either ivermectin at 200 micrograms/kg or a placebo intramuscularly. At necropsy, foals were examined for lesions and larvae grossly and histologically. Ivermectin was found to be highly effective (98.6%) against later fourth-stage larvae in five foals which were examined at 35 days after treatment, but not in five others examined at 14 days (72.5%). In some foals larvae were found in the tunica media of the ileocolic arteries. The conformation of these larvae appeared normal, but there were degenerative changes which suggested that they were dying or dead. Questions as to how the larvae attained that site and the consequences of their presence there were raised.

Toxicity of cadmium and lead on tropical midge larvae, Chironomus kiiensis Tokunaga and Chironomus javanus Kieffer (Diptera: Chironomidae)

Science.gov (United States)

Ebau, Warrin; Rawi, Che Salmah Md; Din, Zubir; Al-Shami, Salman Abdo

2012-01-01

Objective To investigate the acute toxicity of cadmium and lead on larvae of two tropical Chironomid species, Chironomus kiiensis (C. kiiensis) Tokunaga and Chironomus javanus (C. javanus) Kieffer. Methods Different larval instars (first-fourth) were exposed using a static non-replacement testing procedures to various concentrations of cadmium and lead. Results In general, younger larvae (first and second instars) of both species were more sensitive to both metals than older larvae (third and forth instars). The toxic effects of the metals on C. kiiensis and C. javanus were influenced by the age of the larvae (first to fourth instars), types of metals (cadmium or lead) and duration of larval exposure (24, 48, 72 and 96 h) to the metals. Conclusions Cadmium was more toxic to the chironomids than lead and C. javanus was significantly more sensitive to both metals than C. kiiensis (P<0.05). PMID:23569984

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

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José Eduardo Bracco

1995-04-01

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

Impaired Olfactory Associative Behavior of Honeybee Workers Due to Contamination of Imidacloprid in the Larval Stage

Science.gov (United States)

Yang, En-Cheng; Chang, Hui-Chun; Wu, Wen-Yen; Chen, Yu-Wen

2012-01-01

The residue of imidacloprid in the nectar and pollens of the plants is toxic not only to adult honeybees but also the larvae. Our understanding of the risk of imidacloprid to larvae of the honeybees is still in a very early stage. In this study, the capped-brood, pupation and eclosion rates of the honeybee larvae were recorded after treating them directly in the hive with different dosages of imidacloprid. The brood-capped rates of the larvae decreased significantly when the dosages increased from 24 to 8000 ng/larva. However, there were no significant effects of DMSO or 0.4 ng of imidacloprid per larva on the brood-capped, pupation and eclosion rates. Although the sublethal dosage of imidacloprid had no effect on the eclosion rate, we found that the olfactory associative behavior of the adult bees was impaired if they had been treated with 0.04 ng/larva imidacloprid in the larval stage. These results demonstrate that a sublethal dosage of imidacloprid given to the larvae affects the subsequent associative ability of the adult honeybee workers. Thus, a low dose of imidacloprid may affect the survival condition of the entire colony, even though the larvae survive to adulthood. PMID:23166680

Rate of sediment intake by midge larvae (Chironomus plumosus: diptera) using a 134Cs tracer

International Nuclear Information System (INIS)

Gerking, S.D.; Berg, A.; Gerard, P.

1976-01-01

The food intake and assimilation of midge larvae (Chironomus plumosus) were determined by a 134 Cs technique which utilized the principle that the rate of excretion can be substituted for the rate of absorption when the larvae are in 134 Cs equilibrium with their environment. The larvae were introduced into contaminated sediments until they reached 134 Cs equilibrium. The time of reaching equilibrium and levels of radioactivity were the same at 10 and at 15 0 C (70 hr at a level of 1367 dpm/mg of larva) and were both significantly different from that at 20 0 C (40 hr at 1062 dpm/mg of larva). Cesium-134 elimination was followed on equilibrated larvae for as long as 330 hr. One egestion compartment (fast) and two excretion (medium and slow) compartments could be recognized at the three experimental temperatures. The loss rates from the second and third compartments at 10 0 C were slower and stretched out over longer time periods compared with those at 15 0 C, while the loss rate from the first compartment was much more comparable at the two temperatures. The first and second compartments merged at 20 0 C, while the slow compartment rose to almost three times that at 15 0 C. The food intake was nearly the same at the three temperatures (0.0986, 0.0893 and 0.0876 mg dry sediment/mg of larva/day). Thus, the larvae relied on an increase in assimilation to meet increased metabolic requirements at higher temperatures rather than depending upon a higher food intake. The gross growth efficiencies varied with temperature from 9.9 percent at 10 0 C to 15.1 percent at 15 0 C

Painted Goby Larvae under High-CO2 Fail to Recognize Reef Sounds.

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Joana M Castro

Full Text Available Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus were exposed to control pCO2 (532 μatm, pH 8.06 and high pCO2 (1503 μatm, pH 7.66 conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.

Morphological and molecular identification of Gnathostoma binucleatum (Nematoda: Gnathostomatidae advanced third stage larvae (AdvL3 in the state of Colima, Mexico Determinación morfológica y molecular de larvas del tercer estadio larvario (L3A de Gnathostoma binucleatum (Nematoda: Gnathostomatidae del estado de Colima, México

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Luis Jorge García-Márquez

2009-12-01

Full Text Available As a part of an ongoing project to understand the current distribution of Gnathostoma species in Mexico, 22 species of vertebrates were examined for this nematode in the state of Colima. The fish species Dormitator latifrons ("chococo" and Sciades guatemalensis ("cuatete" from Cuyutlán Lagoon and the reptile Crocodylus acutus from the Amela Lagoon were positive for infection. Morphometric characteristics of the larvae collected in Colima were similar to those of G. binucleatum larvae collected from other regions and host species in Mexico. The low divergence of the ITS sequence obtained in this study from that of G. binucleatum (0.19% indicates that our material belongs to this species. This is the first record of the AdvL3 of G. binucleatum in Colima, the tenth state in Mexico in which this species has been recorded in wild vertebrates.Como parte de un proyecto para definir la distribución actual de las especies de Gnathostoma en México, examinamos 22 especies de vertebrados en el estado de Colima en busca de este nematodo. Las especies de peces Dormitator latifrons ("chococo" y Sciades guatemalensis ("cuatete" de la laguna de Cuyutlán y el reptil Crocodylus acutus de la laguna de Amela resultaron positivos a la infección. Las características morfométricas de las larvas encontradas en Colima son similares a las de las larvas de G. binucleatum recolectadas en otras regiones y especies de hospederos en México. La escasa divergencia entre las secuencias del ITS obtenidas en este estudio con aquella de G. binucleatum (0.19% indica que nuestro material pertenece a esta especie. Este es el primer registro de la L3A de G. binucleatum en Colima, siendo éste el décimo estado en México en donde se ha registrado a esta especie en vertebrados silvestres.

Effects of age and liquid holding on the UV-radiation sensitivities of wild-type and mutant Caenorhabditis elegans dauer larvae

Energy Technology Data Exchange (ETDEWEB)

Hartman, P S

1984-01-01

The dauer larva is a facultative developmental stage in the life cycle of the nematode Caenorhabditis elegans. Dauer larvae, which can survive under starvation for over 60 days, resume normal development when feeding is resumed. Wild-type (N2) and 4 radiation-sensitive (rad) mutant dauer larvae were tested for their abilities to develop into adults after UV-irradiation. The rad-3 mutant was over 30 times as sensitive as N2; rad-1, rad-2 and rad-7 mutants were not hypersensitive. Irradiation also delayed development in survivors. Wild-type dauer larvae did not differ in radiation sensitivity from 0 through 50 days of age. There was no liquid holding recovery (LHR); that is, survival did not increase when wild-type dauer larvae were held in buffer after irradiation. (orig.). 28 refs.; 4 figs.

Influence of Dietary Experience on the Induction of Preference of Adult Moths and Larvae for a New Olfactory Cue

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Petit, Christophe; Le Ru, Bruno; Dupas, Stéphane; Frérot, Brigitte; Ahuya, Peter; Kaiser-Arnauld, Laure; Harry, Myriam; Calatayud, Paul-André

2015-01-01

In Lepidoptera, host plant selection is first conditioned by oviposition site preference of adult females followed by feeding site preference of larvae. Dietary experience to plant volatile cues can induce larval and adult host plant preference. We investigated how the parent’s and self-experience induce host preference in adult females and larvae of three lepidopteran stem borer species with different host plant ranges, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and the monophagous Busseola nairobica, and whether this induction can be linked to a neurophysiological phenotypic plasticity. The three species were conditioned to artificial diet enriched with vanillin from the neonate larvae to the adult stage during two generations. Thereafter, two-choice tests on both larvae and adults using a Y-tube olfactometer and electrophysiological (electroantennography [EAG] recordings) experiments on adults were carried out. In the polyphagous species, the induction of preference for a new olfactory cue (vanillin) by females and 3rd instar larvae was determined by parents’ and self-experiences, without any modification of the sensitivity of the females antennae. No preference induction was found in the oligophagous and monophagous species. Our results suggest that lepidopteran stem borers may acquire preferences for new olfactory cues from the larval to the adult stage as described by Hopkins’ host selection principle (HHSP), neo-Hopkins’ principle, and the concept of ‘chemical legacy.’ PMID:26288070

Equine Cyathostominae can develop to infective third-stage larvae on straw bedding

DEFF Research Database (Denmark)

Love, Sandy; Burden, Faith A.; McGirr, Eoghan C.

2016-01-01

BACKGROUND: Domesticated grazing animals including horses and donkeys are frequently housed using deep litter bedding systems, where it is commonly presumed that there is no risk of infection from the nematodes that are associated with grazing at pasture. We use two different approaches to test w...

Nutritional Transition Period in Early Larvae Clarias Gariepinus

International Nuclear Information System (INIS)

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

2015-01-01

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

Baylisascaris Larva Migrans

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

2016-05-26

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

Ontogeny and growth of early life stages of captive-bred European eel

DEFF Research Database (Denmark)

Sørensen, Sune Riis; Tomkiewicz, Jonna; Munk, Peter

2016-01-01

of viable eggs and larvae of European eel, providing the basis for studies on early life stages of this species in captivity. In this study, we describe and illustrate morphological characteristics of eggs, embryos, and larvae from fertilization to termination of the yolk sac stage and provide a comparison...... forms a large perivitelline space, reaching an egg diameter of 1.45 ± 0.12 mm at 3.0 to 3.5 h post fertilization. Embryonic development from fertilization to larval hatch lasted ~46–48 h at 20 °C with the larvae emerging in a relatively undeveloped stage with a protuberant yolk sac. During the period......-sustained aquaculture of this high-value and critically endangered species. Statement of relevance: European eel is a high-value species in aquaculture, however, production is presently hampered by reliance on wild caught fry. Captive production of glass eels will reopen markets in Europe and Asia, benefiting European...

Polarized light sensitivity and orientation in coral reef fish post-larvae.

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Igal Berenshtein

Full Text Available Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity-the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun's position can take the form of polarized-light related cues (i.e., e-vector orientation and percent polarization and/or non-polarized-light related cues (i.e., the direct image of the sun, and the brightness and spectral gradients. We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly polarized light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC, which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light polarization. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh's test p<0.05, R = 0.74±0.23, but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze, which explained 38% of the observed variation. Moreover, post-larvae swimming under fully polarized light exhibited a distinct behavior of tracking the polarization axis, as it rotated along with the DISC. This behavior was not observed under partially-polarized illumination. We view these findings as an indication for the use of sun-related cues, and polarized light signal in specific, by orienting coral-reef fish larvae.

Polarized light sensitivity and orientation in coral reef fish post-larvae.

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Berenshtein, Igal; Kiflawi, Moshe; Shashar, Nadav; Wieler, Uri; Agiv, Haim; Paris, Claire B

2014-01-01

Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity-the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun's position can take the form of polarized-light related cues (i.e., e-vector orientation and percent polarization) and/or non-polarized-light related cues (i.e., the direct image of the sun, and the brightness and spectral gradients). We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly polarized light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC), which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light polarization. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh's test p<0.05, R = 0.74±0.23), but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze), which explained 38% of the observed variation. Moreover, post-larvae swimming under fully polarized light exhibited a distinct behavior of tracking the polarization axis, as it rotated along with the DISC. This behavior was not observed under partially-polarized illumination. We view these findings as an indication for the use of sun-related cues, and polarized light signal in specific, by orienting coral-reef fish larvae.

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

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

2013-04-15

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

Susceptibility of Ceraeochrysa cubana larvae and adults to six insect growth-regulator insecticides.

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Ono, Éric Kodi; Zanardi, Odimar Zanuzo; Aguiar Santos, Kenia Fernanda; Yamamoto, Pedro Takao

2017-02-01

The impacts of six insect growth-regulators were assessed on the predator Ceraeochrysa cubana (Hagen) larvae and adults. Our results showed that diflubenzuron, lufenuron and pyriproxyfen caused 100% larva mortality, whereas buprofezin, methoxyfenozide and tebufenozide were similar to control treatment. In comparison to the control, buprofezin prolonged the duration of larval stage, while methoxyfenozide and tebufenozide reduced the predator larva development time. Buprofezin, methoxyfenozide and tebufenozide did not affect the C. cubana duration and survival of pupal stage, fecundity and fertility. However, methoxyfenozide and tebufenozide reduced predator female and male longevities. Based on a reduction coefficient, diflubenzuron, lufenuron and pyriproxyfen were highly harmful to first instar larvae, while buprofezin, methoxyfenozide and tebufenozide were considered slightly harmful to the predator. Estimating the life table parameters, our results showed that buprofezin, methoxyfenozide and tebufenozide reduced the C. cubana R o , r and λ. In comparison to the control, buprofezin prolonged the T and methoxyfenozide and tebufenozide shortened the predator T. In adults, our results showed that the insecticides did not cause significant mortality, but diflubenzuron, lufenuron and pyriproxyfen reduced the C. cubana fecundity and longevity. Diflubenzuron and lufenuron also reduced the C. cubana fertility. Based on a reduction coefficient, diflubenzuron and lufenuron were highly harmful to C. cubana adults, while pyriproxyfen was slightly harmful and buprofezin, methoxyfenozide and tebufenozide were considered harmless to the predator. Therefore, insect growth-regulators affect the C. cubana biological or populational parameters, and they can harm the integrated pest management programs that aim the predator conservation and/or augmentation in agroecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative transcriptome analysis on the alteration of gene expression in ayu (Plecoglossus altivelis larvae associated with salinity change

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Xin-Jiang LU

2016-05-01

Full Text Available Ayu (Plecoglossus altivelis fish, which are an amphidromous species distributed in East Asia, live in brackish water (BW during their larval stage and in fresh water (FW during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendocrinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase (ID, pro-opiomelanocortin (POMC, betaine-homocysteine S-methyltransferase 1(BHMT, fructose-bisphosphate aldolase B (aldolase B, tyrosine aminotransferase (TAT, and Na+-K+ ATPase (NKA were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriuretic peptide (BNP and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.

Comparative transcriptome analysis on the alteration of gene expression in ayu (Plecoglossus altivelis) larvae associated with salinity change.

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Lu, Xin-Jiang; Zhang, Hao; Yang, Guan-Jun; Li, Ming-Yun; Chen, Jiong

2016-05-18

Ayu (Plecoglossus altivelis) fish, which are an amphidromous species distributed in East Asia, live in brackish water (BW) during their larval stage and in fresh water (FW) during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendocrinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase (ID), pro-opiomelanocortin (POMC), betaine-homocysteine S-methyltransferase 1(BHMT), fructose-bisphosphate aldolase B (aldolase B), tyrosine aminotransferase (TAT), and Na(+)-K(+) ATPase (NKA) were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriuretic peptide (BNP) and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.

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

DEFF Research Database (Denmark)

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

2012-01-01

. We exposed 17 and 87 days post hatch larvae and fry (152 and 1118 degree days post hatch; avg. wt. 70 and 770 mg, respectively) to the bacterial pathogen, Yersinia ruckeri for 4 h by bath challenge. Samples were taken at 4, 24, 72 and 96 h post exposure for qPCR and immunohistochemical analyses...... to elucidate the immune response mounted by these young fish. Larvae showed no mortality although infected larvae at 48 h post exposure showed hyperaemia in the mouth region and inflammation on the dorsal side of the body. Gene expression studies showed an up-regulation of iNOS and IL-22 in infected larvae 24...... h post exposure but most of the investigated genes did not show any difference between infected and uninfected larvae. Immunohistochemical studies demonstrated a high expression of IgT molecules in gills and CD8 positive cells in thymus of both infected and uninfected larvae. Infection of rainbow...

Contribuição ao conhecimento das larvas dos Sarcophagidae com especial referência ao esqueleto cefálico (Diptera

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H. de Souza Lopes

1943-01-01

Full Text Available The author publishes a comparative study of eleven species of Sarcophagid flies and gives a redescription of the larval stages of Musca domestica L. as a model. The work was made upon material obtained from Sarcophagidae reared in the Laboratory. Some of them were parasitic flies from Insects and other invertebrates. Protodexia was reared using the domestic cockroach (Periplaneta americana instead of the Orthroptera or Mantodea its true hosts. The larvae obtained by dissection of female abdomen was reared in flesh or agarhorse serum. The last proceeding is very good since the skins of all larval stages can be conserved for study and it is possible to observe the ecdyses. Some of the larvae prefer dead snails (Bulimulus and Fruticicola and is able to destroy larvae of other species found in the same molluscs. The first stage maggot can be obtained by dissections of dried female specimens and furnishes very good characters to determine the species and establish the philogenetical relationship of the genera in the family. Th pseudocephalon presents very curious ornaments or grooves in some species (Oxysarcodexia. Sometimes there is a pigmented capsule covering a great part of the pseudocephalon (Titanogrypa. The cephaloskeletal sclerietes have a peculiar shape and constitution for every species, mainly in the first stage maggot.

Visceral larva migrans: case report

OpenAIRE

Machado, Alexandre Bortoli; El Achkar, Marice Emanuela

2003-01-01

Larva migrans visceral é doença infecciosa, adquirida por ingestão de ovos provenientes dos vermes Toxocara canis e/ou Toxocara cati que infestam cães e gatos; as larvas penetram a parede intestinal e migram através dos tecidos levando a alterações diversas, conseqüentes a uma resposta inflamatória imune.¹ Os autores descrevem um caso clínico de larva migrans visceral com apresentação clínica atípica.Visceral larva migrans is an infectious human disease that occurs following ingestion of eggs...

Food restriction alters energy allocation strategy during growth in tobacco hornworms (Manduca sexta larvae).

Science.gov (United States)

Jiao, Lihong; Amunugama, Kaushalya; Hayes, Matthew B; Jennings, Michael; Domingo, Azriel; Hou, Chen

2015-08-01

Growing animals must alter their energy budget in the face of environmental changes and prioritize the energy allocation to metabolism for life-sustaining requirements and energy deposition in new biomass growth. We hypothesize that when food availability is low, larvae of holometabolic insects with a short development stage (relative to the low food availability period) prioritize biomass growth at the expense of metabolism. Driven by this hypothesis, we develop a simple theoretical model, based on conservation of energy and allometric scaling laws, for understanding the dynamic energy budget of growing larvae under food restriction. We test the hypothesis by manipulative experiments on fifth instar hornworms at three temperatures. At each temperature, food restriction increases the scaling power of growth rate but decreases that of metabolic rate, as predicted by the hypothesis. During the fifth instar, the energy budgets of larvae change dynamically. The free-feeding larvae slightly decrease the energy allocated to growth as body mass increases and increase the energy allocated to life sustaining. The opposite trends were observed in food restricted larvae, indicating the predicted prioritization in the energy budget under food restriction. We compare the energy budgets of a few endothermic and ectothermic species and discuss how different life histories lead to the differences in the energy budgets under food restriction.

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

Science.gov (United States)

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

2016-05-01

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

Whole-body gene expression pattern registration in Platynereis larvae.

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

2012-12-03

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

Whole-body gene expression pattern registration in Platynereis larvae

Directory of Open Access Journals (Sweden)

Asadulina Albina

2012-12-01

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

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

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Nugroho Susetya Putra

2005-12-01

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

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

Science.gov (United States)

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

Identification and characterization of two novel toxins expressed by the lethal honey bee pathogen Paenibacillus larvae, the causative agent of American foulbrood.

Science.gov (United States)

Fünfhaus, Anne; Poppinga, Lena; Genersch, Elke

2013-11-01

Paenibacillus larvae is a Gram-positive bacterial pathogen causing the epizootic American foulbrood in honey bee larvae. Four so-called enterobacterial repetitive intergenic consensus (ERIC) genotypes of P. larvae exist with P. larvae genotypes ERIC I and ERIC II being responsible for disease outbreaks all over the world. Very few molecular data on the pathogen, on pathogenesis or on virulence factors exist. We now identified two genomic loci in P. larvae ERIC I coding for two binary AB toxins, Plx1 and Plx2. In silico analyses revealed that Plx1 is the third member of an enigmatic family of AB toxins so far only comprising MTX1 of Lysinibacillus sphaericus and pierisin-like toxins expressed by several butterflies. Plx2 is also remarkable because the A-domain is highly similar to C3 exoenzymes, which normally are single domain proteins, while the B-domain is homologous to B-domains of C2-toxins. We constructed P. larvae mutants lacking expression of Plx1, Plx2 or both toxins and demonstrated that these toxins are important virulence factors for P. larvae ERIC I. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

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

International Nuclear Information System (INIS)

Kristofco, Lauren A.; Cruz, Luis Colon; Haddad, Samuel P.; Behra, Martine L.; Chambliss, C. Kevin; Brooks, Bryan W.

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-15

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

Scanning electron microscopy of third-instar sarcophagid (Diptera: Sarcophagidae recovered from a mummified human corpse in Thailand

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Sukontason Kom

2003-01-01

Full Text Available The third-instar of an unidentified sarcophagid, recovered from a mummified body of a 32-yr-old Thai male was examined using scanning electron microscopy (SEM. Although the morphological features of this larva are similar to the other sarcophagid larvae, some features could be helpful for species identification, which is a basic requirement for estimation of postmortem interval in forensic investigation. These features included number and arrangement of papillae on the anterior spiracle, structure of spines, size of circumspiracular tubercles at caudal segment and branching peculiarity of the posterior spiracular hairs. This information could benefit future identification of the sarcophagid larvae that exist in Thailand.

Natural variation in gene expression in the early development of dauer larvae of Caenorhabditis elegans

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Barker Gary LA

2009-07-01

Full Text Available Abstract Background The free-living nematode Caenorhabditis elegans makes a developmental decision based on environmental conditions: larvae either arrest as dauer larva, or continue development into reproductive adults. There is natural variation among C. elegans lines in the sensitivity of this decision to environmental conditions; that is, there is variation in the phenotypic plasticity of dauer larva development. We hypothesised that these differences may be transcriptionally controlled in early stage larvae. We investigated this by microarray analysis of different C. elegans lines under different environmental conditions, specifically the presence and absence of dauer larva-inducing pheromone. Results There were substantial transcriptional differences between four C. elegans lines under the same environmental conditions. The expression of approximately 2,000 genes differed between genetically different lines, with each line showing a largely line-specific transcriptional profile. The expression of genes that are markers of larval moulting suggested that the lines may be developing at different rates. The expression of a total of 89 genes was putatively affected by dauer larva or non-dauer larva-inducing conditions. Among the upstream regions of these genes there was an over-representation of DAF-16-binding motifs. Conclusion Under the same environmental conditions genetically different lines of C. elegans had substantial transcriptional differences. This variation may be due to differences in the developmental rates of the lines. Different environmental conditions had a rather smaller effect on transcription. The preponderance of DAF-16-binding motifs upstream of these genes was consistent with these genes playing a key role in the decision between development into dauer or into non-dauer larvae. There was little overlap between the genes whose expression was affected by environmental conditions and previously identified loci involved in

Localization of Ascaridia galli larvae in the jejunum of chickens 3 days post infection

DEFF Research Database (Denmark)

Luna Olivares, Luz Adilia; Ferdushy, Tania; Kyvsgaard, Niels Christian

2012-01-01

The normal habitat of the parasitic stages of Ascaridia galli is in the small intestine of poultry but the exact localization is poorly understood. Therefore, a histological study was conducted in order to localize the larvae during the early phase of infection. Six layer pullets seven-week old...... were infected orally with 20,000 embryonated A. galli eggs each, whereas four chickens were left as un-infected controls. At necropsy 3 days after infection the first half of jejunum/ileum was divided into two equally sized sections (J1 and J2). After taking samples for histology from the middle of J1...... and J2 and the junction between these determined JX, the two sections were subjected to parasitological examination. A higher number of A. galli larvae were recovered from section J2 than J1 and the majority of larvae were recovered from the most profound layers. Based on histology 144 larvae were...

Early larvae ontogeny of the Neotropical fishes: Prochilodus costatus and P. argenteus (Characiformes: Prochilodontidae).

Science.gov (United States)

dos Santos, José Enemir; Sales, Naiara Guimarães; dos Santos, Marcella Lourenço; Arantes, Fábio Pereira; Godinho, Hugo Pereira

2016-06-01

Early development of fish larvae is a highly dynamic process and its study may provide important information about ontogenetic development, bioenergetic growth, behaviour, taxonomic characteristics for identification in natural environments, identification of spawning areas, and population monitoring. With the aim to provide knowledge about their growth and behaviour, to support larval rearing, and also taxonomic purposes, we studied the life history of the Prochilodus argenteus and P. costatus from hatching until the complete absorption of the yolk. Larvae were obtained through artificial reproduction at the Hydrobiology and Aquaculture Station of Três Marias, Minas Gerais, Brazil. Immediately after hatching, 100 larvae of each species were put in two plastic incubators for conditioning. On a daily basis, larvae behavior was recorded and 14 larvae of each species were collected to analyse body morphology. On the first day after hatching, larvae of P. costatus and P. argenteus showed an elongated and transparent body; the yolk sac was filled with individualized yolk globules. In both species, the embryonic fin rounded the caudal region of the body, the retina was non-pigmented and the gut was obliterated. At the second day post-hatching, larvae of both species dendritic chromatophores had emerged, the mouth was obliterated and the pectoral fin was observed. The larvae showed 38-43 myomeres in P. costatus and 42-43 in P. argenteus. For both species, the gas bladder was inflated and the lumen of the gut was already open. On the third day post-hatching, the mouth of P. costatus and P. argenteus was already open in a sub-terminal position; the retina was pigmented; the gill arches had lamellar protrusions and were partially covered by the operculum. On the fourth day post-hatching, the pigmentation pattern was maintained with greater intensity; the mouth occupied a terminal position, the yolk sac was almost completely reabsorbed, and the pectoral and caudal fins

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

OpenAIRE

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

2016-01-01

Abstract 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” Herpetolog...

The early phyllosoma stages of spiny lobster Panulirus echinatus Smith, 1869 (Decapoda: Palinuridae reared in the laboratory

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FA. Abrunhosa

Full Text Available The early stages of the Panulirus echinatus were hatched and reared in the laboratory. Ovigerous females were captured in their habitat and carefully transported to the laboratory. Larvae were transferred in a recirculation water tank at a density of 10 larvae.L-1. The larvae were fed on Artemia and gonads of mussel Brachydonts sp. Microalgae Dunaliella viridis was added at a concentration of 150 x 10(4 cell.mL-1. Larvae and exuviae of each zoeal stage were preserved in an alcohol 70% + glycerin (1:1 solution. The phyllosomas moulted eight times; the intermoulting period of each instar averaged about 7 to 10 days. The main morphological changes of each appendage were described in detail, illustrated and compared with previous reports.

Survival dynamics of scleractinian coral larvae and implications for dispersal

Science.gov (United States)

Graham, E. M.; Baird, A. H.; Connolly, S. R.

2008-09-01

Survival of pelagic marine larvae is an important determinant of dispersal potential. Despite this, few estimates of larval survival are available. For scleractinian corals, few studies of larval survival are long enough to provide accurate estimates of longevity. Moreover, changes in mortality rates during larval life, expected on theoretical grounds, have implications for the degree of connectivity among reefs and have not been quantified for any coral species. This study quantified the survival of larvae from five broadcast-spawning scleractinian corals ( Acropora latistella, Favia pallida, Pectinia paeonia, Goniastrea aspera, and Montastraea magnistellata) to estimate larval longevity, and to test for changes in mortality rates as larvae age. Maximum lifespans ranged from 195 to 244 d. These longevities substantially exceed those documented previously for coral larvae that lack zooxanthellae, and they exceed predictions based on metabolic rates prevailing early in larval life. In addition, larval mortality rates exhibited strong patterns of variation throughout the larval stage. Three periods were identified in four species: high initial rates of mortality; followed by a low, approximately constant rate of mortality; and finally, progressively increasing mortality after approximately 100 d. The lifetimes observed in this study suggest that the potential for long-distance dispersal may be substantially greater than previously thought. Indeed, detection of increasing mortality rates late in life suggests that energy reserves do not reach critically low levels until approximately 100 d after spawning. Conversely, increased mortality rates early in life decrease the likelihood that larvae transported away from their natal reef will survive to reach nearby reefs, and thus decrease connectivity at regional scales. These results show how variation in larval survivorship with age may help to explain the seeming paradox of high genetic structure at metapopulation scales

SEAWARD DRIFT OF THE PONTIC SHAD LARVAE (ALOSA PONTICA AND THE INFLUENCE OF DANUBE RIVER HYDROLOGY ON THEIR TRAVEL PATH THROUGH THE DANUBE DELTA SYSTEM.

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NAVODARU I.

2001-07-01

Full Text Available The Pontic shad lives in the northwestern part of the Black Sea. It migrates in the Danube River for spawning. The larvae drift passively towards the sea when they reach the life stage ranging from pre-larvae to post-larvae. During the larval stage the Pontic shad is floating, mainly in the 0-50 cm upper layer of river. Upstream of the Danube Delta, in the straight sector of the river, alosids are distributed mostly towards the middle of the river, where the water velocity is higher. In the curved section of the river, upstream of the location of the Danube River splitting in the delta’s branches, the water current is outwardly pushing the shad larvae to the right shore, the Romanian, respectively. Therefore, Tulcea branch (Romanian takes over 60-80 % from the total of Danubian larvae, even its water flow is smaller (40 % than Chilia branch (the border of Romania and Ukraine. The distribution of larvae at the splitting point influences the repartition of adult migratory catch, at return for spawning, between Saint George branch (Romania and Chilia branch. Consequently, the topography and hydrology of the river at the splitting point of the branceh which form the delta decide on the distribution of larvae, and later, when the shads are homing on the same way for spawning the sharing catch between Romania and Ukraine.

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

NARCIS (Netherlands)

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

2017-01-01

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

Effect of increased pCO2 level on early shell development in great scallop (Pecten maximus Lamarck larvae

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S. Andersen

2013-10-01

Full Text Available As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA. Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck, at pCO2 levels of 469 (ambient, 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the

Pre-pupation behaviour of the aphid parasitoid Aphidius ervi (Haliday) and its consequences for pre-imaginal learning

Science.gov (United States)

Gutiérrez-Ibáñez, Cristián; Villagra, Cristian A.; Niemeyer, Hermann M.

2007-07-01

Olfactory learning may occur at different stages of insect ontogeny. In parasitoid wasps, it has been mostly shown at adult emergence, whilst it remains controversial at pre-imaginal stages. We followed larval growth of the parasitoid wasp, Aphidius ervi Haliday, inside the host aphid, Acyrthosiphom pisum Harris, and characterised in detail the behaviour of third instar larvae. We found that just before cocoon spinning begins, the third instar larva bites a hole through the ventral side of the mummified aphid exoskeleton. We then evaluated whether this period of exposure to the external environment represented a sensitive stage for olfactory learning. In our first experiment, the third instar larvae were allowed to spin their cocoon on the host plant ( Vicia faba L.) surface or on a plastic plate covering the portion of the host plant exposed to the ventral opening. Recently emerged adults of the first group showed a preference for plant volatiles in a glass Y-olfactometer, whereas no preference was found in adults of the second group. In a second experiment, during the period in which the aphid carcass remains open or is being sealed by cocoon spinning, third instar larvae were exposed for 24 h to either vanilla odours or water vapours as control. In this experiment, half of the parasitoid larvae were later excised from the mummy to avoid further exposure to vanilla. Adult parasitoids exposed to vanilla during the larval ventral opening of the mummy showed a significant preference for vanilla odours in the olfactometer, regardless of excision from the mummy. The larval behaviour described and the results of the manipulations performed are discussed as evidences for the acquisition of olfactory memory during the larval stage and its persistence through metamorphosis.

General odorant-binding proteins and sex pheromone guide larvae of Plutella xylostella to better food.

Science.gov (United States)

Zhu, Jiao; Ban, Liping; Song, Li-Mei; Liu, Yang; Pelosi, Paolo; Wang, Guirong

2016-05-01

Olfaction of Lepidopteran larvae has received little attention, compared to the damage to crops done by insects at this stage. We report that larvae of the diamondback moth Plutella xylostella are attracted to their natural sex pheromone and to their major component (Z)-11-hexadecenal, but only in a food context. For such task they use two general odorant-binding proteins (GOBPs), abundantly expressed in the three major sensilla basiconica of the larval antenna, as shown by whole-mount immunostaining and immunocytochemistry experiments. None of the three genes encoding pheromone-binding proteins (PBPs) are expressed at this stage. Both recombinant GOBPs bind (Z)-11-hexadecenal and the corresponding alcohol, but not the acetate. Binding experiments performed with five mutants of GOBP2, where aromatic residues in the binding pocket were replaced with leucine showed that only one or two amino acid substitutions can completely abolish binding to the pheromone shifting the affinity to plant-derived compounds. We hypothesise that detection of their species-specific pheromone may direct larvae to the sites of foraging chosen by their mother when laying eggs, to find better food, as well as to reduce competition with individuals of the same or other species sharing the same host plant. We also provide evidence that GOBP2 is a narrowly tuned binding protein, whose affinity can be easily switched from linear pheromones to branched plants terpenoids, representing a tool better suited for the simple olfactory system of larvae, as compared to the more sophisticated organ of adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effectiveness of oxfendazole against early and later 4th-stage Strongylus vulgaris in ponies.

Science.gov (United States)

Slocombe, J O; McCraw, B M; Pennock, P; Ducharme, N G; Baird, J D

1986-03-01

Twenty pony foals (reared worm free), 6.5 to 10 weeks of age, were inoculated with Strongylus vulgaris and allocated to 5 groups, each with 4 foals. One week after inoculation, 1 group of 4 foals was given oxfendazole (OFZ) at a dosage rate of 10 mg/kg of body weight, another group was given 2 such treatments 48 hours apart, and a 3rd group was given a placebo. All treatments were administered by stomach tube. Three weeks later, foals were euthanatized and necropsied in a test for efficacy against early 4th-stage larvae. Oxfendazole was 80% and 94.9% effective against early 4th-stage S vulgaris with 1 and 2 doses, respectively. A 4th group of 4 foals was given 2 treatments of OFZ, 48 hours apart, about 8 weeks after inoculation, and a 5th group was given a placebo. These foals were euthanatized and necropsied 5 weeks after treatment in a test for efficacy against later 4th-stage larvae. Two doses of OFZ were 96.6% effective against later 4th-stage larvae.

Morfologia do trato digestório e dieta de larvas de Bryconamericus aff. iheringii (Boulenger, 1887 (Osteichthyes, Characidae = Morphology of Digestive tract and diet of Bryconamericus aff. iheringii larvae (Boulenger, 1887 (Osteichthyes, Characidae

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Renato Ziliani Borges

2006-01-01

Full Text Available Este trabalho teve como objetivo analisar alguns aspectos da alimentação de larvas de Bryconamericus aff. iheringii, capturadas nos meses de julho e novembro de 2001, nas regiões limnética e litorânea do reservatório de Santa Maria, rio Piquiri, Estado do Paraná. As larvas apresentaram boca subterminal durante todo o seu desenvolvimento. O tubo digestório se diferenciou em estômago e intestino apenas no estágio de pós-flexão. As larvas consumiram, principalmente, algas e microcrustáceos, o que permitiu caracterizá-las como planctófagas. A intensa modificação morfológica no trato digestório nos indivíduos em pósflexão coincidiu com o aumento na abundância de algas em relação aos itens de origemanimal; porém, de forma geral, a ocorrência aumentou para todos os itens. A análise do grau de digestão dos itens alimentares sugeriu que indivíduos em pré-flexão alimentaram-se, possivelmente, durante o dia, e os mais desenvolvidos, durante o entardecer e no períodonoturno.The aim of this study was to analyze some feeding treats of Bryconamericus aff. iheringii larvae, sampled in both the limnetic and littoral regions of the Piquiri River, in Santa Maria reservoir, between July and November 2001. The larvae presented sub-terminal mouth in larval period. The digestive tract differentiated in terms of stomach and intestine only in the postflexion larvae. The larvae fed mainly on algae and microcrustacea allowing to characterize them as planktivorous. The intense morphologic shift in the digestive tract in the postflexion larvae coincided with an increase in the abundance of algae in relation to animals items; however, in general, all the items had their occurrence increased. Analysis of the digestion stage suggested that preflexion larvae, possibly, fed themselves during the day, and those more developed, at dusk and night.

Biochemistry and physiology of overwintering in the mature larva of the pine needle gall midge, Thecodiplosis japonensis (Diptera: cecidomyiidae) in Korea.

Science.gov (United States)

Li, Y; Gong, H; Park, H

2000-01-01

The pine needle gall midge, Thecodiplosis japonensis, overwinters in the soil as a third instar mature larva. The metabolic and physiological compensations and adjustments during its overwintering and acclimation were studied. Field-sampled larvae in 1997/98 winter showed a significant increase in whole-body trehalose by January (5.71 +/- 0.09 vs. 9.41 +/- 0.42 mg/g wet weight) along with a more significant decrease in whole-body glycogen (16.25 +/- 0.18 vs. 5.65 +/- 0.45 mg/g wet weight). Afterwards, there was a partial reconversion of trehalose to glycogen. Moreover, trace amounts of glycerol and steady content of glucose as potential cryoprotectants were found during the overwintering period. Temperature acclimation of field-sampled larvae affects interconversion between trehalose and glycogen. Trehalose accumulation does not affect the larval supercooling capacity. The mean supercooling point of the larvae remained nearly constant at about -20 degree he winter and was unchanged after temperature acclimation. Low temperature survival experiment suggested that the larvae adopt a freeze-avoiding strategy for overwintering.

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

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Bruno Rossaro

2015-07-01

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

Laboratory Evaluation of the Toxicity of Systemic Insecticides to Emerald Ash Borer Larvae.

Science.gov (United States)

Poland, Therese M; Ciaramitaro, Tina M; McCullough, Deborah G

2016-04-01

Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding insect native to Asia, threatens at least 16 North American ash (Fraxinus) species and has killed hundreds of millions of ash trees in landscapes and forests. We conducted laboratory bioassays to assess the relative efficacy of systemic insecticides to control emerald ash borer larvae in winter 2009 and 2010. Second- and third-instar larvae were reared on artificial diet treated with varying doses of emamectin benzoate (TREE-äge, Arborjet, Inc., Woburn, MA), imidacloprid (Imicide, J. J Mauget Co., Arcadia, CA), dinotefuran (Safari, Valent Professional Products, Walnut Creek, CA), and azadirachtin (TreeAzin, BioForest Technologies, Inc., Sault Ste. Marie, Ontario, and Azasol, Arborjet, Inc., Woburn, MA). All of the insecticides were toxic to emerald ash borer larvae, but lethal concentrations needed to kill 50% of the larvae (LC50), standardized by larval weight, varied with insecticide and time. On the earliest date with a significant fit of the probit model, LC50 values were 0.024 ppm/g at day 29 for TREE-äge, 0.015 ppm/g at day 63 for Imicide, 0.030 ppm/g at day 46 for Safari, 0.025 ppm/g at day 24 for TreeAzin, and 0.027 ppm/g at day 27 for Azasol. The median lethal time to kill 50% (LT50) of the tested larvae also varied with insecticide product and dose, and was longer for Imicide and Safari than for TREE-äge or the azadirachtin products. Insecticide efficacy in the field will depend on adult and larval mortality as well as leaf and phloem insecticide residues.

Self mixing of fly larvae during feeding

Science.gov (United States)

Shishkov, Olga; Johnson, Christopher; Hu, David

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

Syntactic transfer in the initial stages of adult third language and fourth language acquisition

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Mahbube Tavakol

2016-01-01

Full Text Available This paper elucidates the articulated proposals for the initial stages of adult third language (L3 syntactic transfer, addressing their application for L3 and the subsequent fourth language (L4 acquisition. The study was set to demonstrate empirical evidence in line with or against the tenets of the models and to indicate if and how syntactic transfer might obtain differently depending on the language being acquired– L3 vs. L4. The models to be tested were Full Transfer/Full Access (FT/FA, L2 Status Factor Hypothesis (LSFH, Cumulative Enhancement Model (CEM and Typological Primacy Model (TPM. Following a principles and parameters framework, six parameters were selected to generate several language pairings and an adult female’s L3 Italian and L4 German’s early spontaneous productions of the selected features were audio-recorded. The accuracy levels with which the features were produced in tandem with the results of error analyses violated the positions of FT/FA as considered for L3/s acquisition and CEM and consistently identified Typological proximity and L2 status as affecting syntactic transfer during the early stages multilingual acquisition.

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

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Gerardo Aceves-Medina

2003-06-01

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

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

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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

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

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Thamara Figueiredo Procópio

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

Effects of gamma irradiation on the grape vine moth, Lobesia botrana, mature larvae

International Nuclear Information System (INIS)

Mansour, M.; Al-Attar, J.

2014-01-01

Mature 5th instars of the grape vine moth, Lobesia botrana (Denis and Schiffermuller) were exposed to gamma radiation dosages ranging from 50 to 250 Gy. The effects of gamma radiation on pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth larvae increased with increasing radiation dose. The severity of the effect, however, depends on the criterion used for measuring effectiveness; adult emergence was more severely affected than pupation. Pupation was significantly affected at 150 Gy and decreased by about 25% at 250 Gy. Adult emergence, on the other hand, was significantly affected at 100 Gy and completely prevented at 200 Gy. Probit analysis of dose mortality data for pupation and adult emergence show that the LD 99 for preventing subsequent development to pupae and adults was 2668 and 195 Gy, respectively. In addition, the rate of development of mature larvae to the adult stage was negatively affected and sex ratio was skewed in favor of males. - Highlights: • Effects of gamma irradiation on Lobesia botrana mature larvae are examined. • Results showed that a dose of 200 Gy was sufficient to prevent adult emergence from mature larvae. • This dose (200 Gy) is less than the suggested generic phytosanitary irradiation dose of 250 Gy for Lepidopteran larvae. • The dose is also much lower than the maximum allowed dose for irradiation of fresh fruits and vegetables

Chemical defense of early life stages of benthic marine invertebrates.

Science.gov (United States)

Lindquist, Niels

2002-10-01

Accurate knowledge of factors affecting the survival of early life stages of marine invertebrates is critically important for understanding their population dynamics and the evolution of their diverse reproductive and life-history characteristics. Chemical defense is an important determinant of survival for adult stages of many sessile benthic invertebrates, yet relatively little consideration has been given to chemical defenses at the early life stages. This review examines the taxonomic breadth of early life-stage chemical defense in relation to various life-history and reproductive characteristics, as well as possible constraints on the expression of chemical defense at certain life stages. Data on the localization of defensive secondary metabolites in larvae and the fitness-related consequences of consuming even a small amount of toxic secondary metabolites underpin proposals regarding the potential for Müllerian and Batesian mimicry to occur among marine larvae. The involvement of microbial symbionts in the chemical defense of early life stages illustrates its complexity for some species. As our knowledge of chemical defenses in early life stages grows, we will be able to more rigorously examine connections among phylogeny, chemical defenses, and the evolution of reproductive and life-history characteristics among marine invertebrates.

Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females.

Science.gov (United States)

Kryukov, Vadim Yu; Kryukova, Natalia A; Tyurin, Maksim V; Yaroslavtseva, Olga N; Glupov, Viktor V

2017-03-15

Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly (1.5-13 fold) increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with fungal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate (2 fold) was registered in the n-hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase (PO) activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Genetic support for the morphological identification of larvae of Myctophidae, Gonostomatidae, Sternoptychidae and Phosichthyidae (Pisces from the western Mediterranean

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Ainhoa Bernal

2014-12-01

Full Text Available Mesopelagic fishes experience an extreme body transformation from larvae to adults. The identification of the larval stages of fishes from the two orders Myctophiformes and Stomiiformes is currently based on the comparison of morphological, pigmentary and meristic characteristics of different developmental stages. However, no molecular evidence to confirm the identity of the larvae of these mesopelagic species is available so far. Since DNA barcoding emerged as an accurate procedure for species discrimination and larval identification, we have used the cytochrome c oxidase 1 or the mitochondrial 12S ribosomal DNA regions to identify larvae and adults of the most frequent and abundant species of myctophiforms (family Myctophidae and stomiiforms (families Gonostomatidae, Sternoptychidae and Phosichthyidae from the Mediterranean Sea. The comparisons of sequences from larval and adult stages corroborated the value of the morphological characters that were used for taxonomic classification. The combination of the sequences obtained in this study and those of related species from GenBank was used to discuss the consistency of monophyletic clades for different genera. Pairwise nucleotide distances were notably higher inter- than intraspecifically, and were useful to discern between congeners such as Cyclothone braueri and C. pygmaea, Hygophum benoiti and H. hygomii, Lampanyctus crocodilus and L. pusillus, and Notoscopelus bolini and N. elongatus.

Stage-specific appearance of cytoplasmic microtubules around the surviving nuclei during the third prezygotic division of Paramecium.

Science.gov (United States)

Wang, Yi-Wen; Yuan, Jin-Qiang; Gao, Xin; Yang, Xian-Yu

2012-12-01

There are six micronuclear divisions during conjugation of Paramecium caudatum: three prezygotic and three postzygotic divisions. Four haploid nuclei are formed during the first two meiotic prezygotic divisions. Usually only one meiotic product is located in the paroral cone (PC) region at the completion of meiosis, which survives and divides mitotically to complete the third prezygotic division to yield a stationary and a migratory pronucleus. The remaining three located outside of the PC degenerate. The migratory pronuclei are then exchanged between two conjugants and fuse with the stationary pronuclei to form synkarya, which undergo three successive divisions (postzygotic divisions). However, little is known about the surviving mechanism of the PC nuclei. In the current study, stage-specific appearance of cytoplasmic microtubules (cMTs) was indicated during the third prezygotic division by immunofluorescence labeling with anti-alpha tubulin antibodies surrounding the surviving nuclei, including the PC nuclei and the two types of prospective pronuclei. This suggested that cMTs were involved in the formation of a physical barrier, whose function may relate to sequestering and protecting the surviving nuclei from the major cytoplasm, where degeneration of extra-meiotic products occurs, another important nuclear event during the third prezygotic division.

Comparative assessment of the bacterial communities associated with Aedes aegypti larvae and water from domestic water storage containers.

Science.gov (United States)

Dada, Nsa; Jumas-Bilak, Estelle; Manguin, Sylvie; Seidu, Razak; Stenström, Thor-Axel; Overgaard, Hans J

2014-08-24

identified in fourth-instar Ae. aegypti larvae, suggesting that established larval bacteria, most likely acquired at earlier stages of development, control the larval microbiota. Further studies at all larval stages are needed to fully understand the dynamics involved. Isolation of enteric bacteria from water samples supports earlier outcomes of E. coli contamination in Ae. aegypti infested domestic containers, suggesting the need to further explore the role of enteric bacteria in Ae. aegypti infestation.

The influence of synthetic food additives and surfactants on the body weight of larvae of Tenebrio molitor (Coleoptera, Tenebrionidae

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V. O. Martynov

2017-08-01

Full Text Available The broad spectrum of negative effects of food additives and surfactants on living organisms and the environment in general indicate a necessity of a detailed study on this issue. The aim of this article is to evaluate the impact of food additives and surfactants in a concentration of 350 mg/kg of fodder on the body weight of third age Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae larvae. A significant change in the body weight of T. molitor larvae was observed when they consumed a diet containing 350 mg/kg of sodium glutamate, sodium cyclamate and sodium benzoate. We observed a tendency towards increase in body weight after addition of the food colouring Allura Red, saccharin, benzoic acid, betaine, emulsifying wax, AOS and SLES, and also we observed a decrease in body weight after addition of Tartrazine and Indigo Carmine in the same concentration. Out of the 18 tested food additives, 3 significantly stimulated an increase in the body weight of third age T. molitor larvae, and 3 manifested the same effect at the level of tendency (stimulated an increase in mass on average by 43–58% over the 14-day experiment, and 2 caused decrease in the body weight of larvae. Also, the 4 studied surfactants manifested a tendency towards increase in the body weight of T. molitor. This study on the impact of food additives and surfactants on organisms of insects is of great significance for protecting rare species of insects.

Effect of fruit and leaves of Meliaceae plants (Azadirachta indica and Melia azedarach) on the development of Lutzomyia longipalpis larvae (Diptera: Psychodidae: Phlebotominae) under experimental conditions.

Science.gov (United States)

Andrade-Coelho, Cláudia A; Souza, Nataly A; Gouveia, Cheryl; Silva, Vanderlei C; Gonzalez, Marcelo S; Rangel, Elizabeth F

2009-09-01

This no-choice, laboratory study focuses on the feeding of dried, ground, homogeneous powdered, unprocessed fruit and leaves of Azadirachta indica and Melia azedarach to Lutzomyia longipalpis larvae to determine the effects on their mortality and metamorphosis. A. indica and M. azedarach fruit and leaves significantly increased larval mortality in comparison to larvae fed the untreated, standard diet. A. indica fruit and leaves blocked the molting of the larvae to the fourth instar, resulting in them remaining as third instars until the end of the experiment. M. azedarach fruit also blocked the molting of larvae, which remained permanently in the fourth instar. Feeding M. azedarach leaves resulted in greater molt inhibition. All insects in this group stopped their development as second-instar larvae. No antifeedant effect was detected for any experimental treatment. The results indicate that nontoxic, unprocessed materials obtained from A. indica and M. azedarach are potent development inhibitors of L. longipalpis larvae.

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

Science.gov (United States)

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

2017-11-06

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

Complex vertical migration of larvae of the ghost shrimp, Nihonotrypaea harmandi, in inner shelf waters of western Kyushu, Japan

Science.gov (United States)

Tamaki, Akio; Mandal, Sumit; Agata, Yoshihiro; Aoki, Ikumi; Suzuki, Toshikazu; Kanehara, Hisao; Aoshima, Takashi; Fukuda, Yasushi; Tsukamoto, Hideshi; Yanagi, Tetsuo

2010-01-01

The position of meroplanktonic larvae in the water column with depth-dependent current velocities determines horizontal transport trajectories. For those larvae occurring in inner shelf waters, little is known about how combined diel and tidally-synchronized vertical migration patterns shift ontogenetically. The vertical migration of larvae of Nihonotrypaea harmandi (Decapoda: Thalassinidea: Callianassidae) was investigated in mesotidal, inner shelf waters of western Kyushu, Japan in July-August 2006. The larval sampling at seven depth layers down to 60 m was conducted every 3 h for 36 h in a 68.5-m deep area 10 km off a major coastal adult habitat. Within a 61-65-m deep area 5-7.5 km off the adult habitat, water temperature, salinity, chlorophyll a concentration, and photon flux density were measured, and water currents there were characterized from harmonic analysis of current meter data collected in 2008. The water column was stratified, with pycnocline, chlorophyll a concentration maximum, and 2% of photon flux density at 2 m, recorded at around 22-24 m. The stratified residual currents were detected in their north component, directed offshore and onshore in the upper and lower mixed layers, respectively. More than 87% of larvae occurred between 20 m and 60 m, producing a net onshore transport of approximately 1.3 km d -1. At the sunset flooding tide, all zoeal-stage larvae ascended, which could further promote retention (1.4-km potential onshore transport in 3 h). The actual onshore transport of larvae was detected by observing their occurrence pattern in a shallow embayment area with the adult habitat for 24 h in October 1994. However, ontogenetic differences in the vertical migration pattern in inner shelf waters were also apparent, with the maximum mean positions of zoeae deepening with increasing stages. Zoeae I and II performed a reverse diel migration, with their minimum and maximum depths being reached around noon and midnight, respectively. Zoeae IV

X-ray inactivation of Caenorhabditis elegans embryos or larvae

Energy Technology Data Exchange (ETDEWEB)

Ishi, N; Suzuki, K [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine

1990-11-01

The lethal effects of X-irradiation were examined in staged populations of Caenorhabditis elegans embryos or larvae. Radiation resistance decreased slightly throughout the first, proliferative phase of embryogenesis. This might be due to the increase in target size, since most cells in C. elegans are autonomously determined. Animals irradiated in the second half of embryogenesis were about 40-fold more resistant to the lethal effects of X-rays. This is probably due to the absence of cell divisions during this time. The radiation resistance increased still more with advancing larval stages. A radiation hypersensitive mutant, rad-1, irradiated in the first half of embryogenesis, is about 30-fold more sensitive than wild-type, but in the second half it is the same as wild-type. (author).

Life Cycle and Fecundity Analysis of Lutzomyia shannoni (Dyar (Diptera: Psychodidae

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Cristina Ferro

1998-03-01

Full Text Available The life cycle of Lutzomyia shannoni (Dyar, was described for laboratory conditions with maximum daily temperatures of 27-30°C, minimum daily temperatures of 22-27°C and relative humidity between 87-99 %. Life cycle in each stage was as follows: egg 6-12 days (ave. 8.5 days; first stage larva 5-13 days (ave. 9.6 days; second stage larva 4-13 days (ave. 9.2 days ; third stage larva 5-19 days (ave. 11.8 days; fourth stage larva 7-37 days (ave. 19.9 days; pupa 7-32 days (ave. 15.2 days. The life expectancy of adults ranged from 4 to 15 days (ave. 8.6 days. The entire egg to adult period ranged from 36 to 74 days (ave. 54.6 days. On average, each female oviposited 22.7 eggs; the average egg retention per female was 24.3 eggs.

Impacts of weathered tire debris on the development of Rana sylvatica larvae.

Science.gov (United States)

Camponelli, Kimberly M; Casey, Ryan E; Snodgrass, Joel W; Lev, Steven M; Landa, Edward R

2009-02-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg(-1)) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics.

Impacts of weathered tire debris on the development of Rana sylvatica larvae

Science.gov (United States)

Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

2009-01-01

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

Biochemistry and molecular biology of the Caenorhabditis elegans dauer larva

International Nuclear Information System (INIS)

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 1 H NMR and 13 C NMR spectroscopy. This compound is the most abundant metabolite detected in 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 i ). Although metabolic activation has been associated with an alkaline pH i shift in other organisms, in vivo 31 P NMR analysis of recovering dauer larvae shows a pH i decrease from ∼7.3 to ∼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 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

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

Science.gov (United States)

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

2017-06-01

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

Randomised controlled trial of oxytocin alone versus oxytocin and ergometrine in active management of third stage of labour.

OpenAIRE

McDonald, S J; Prendiville, W J; Blair, E

1993-01-01

OBJECTIVE--To compare intramuscular oxytocin alone and intramuscular oxytocin with ergometrine (Syntometrine) for their effect in reducing the risk of postpartum haemorrhage when both are used as part of the active management of the third stage of labour. DESIGN--Double blind, randomised controlled trial. SETTING--Two metropolitan teaching hospitals in Perth, Western Australia. SUBJECTS--All women who expected a vaginal birth during the period of the trial. Informed consent was obtained. MAIN...

Effect of the diet traditional and non-traditional on the respiration and excretion in larvae of white shrimp Litopenaeus vannamei

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María Alejandra Medina-Jasso

2015-11-01

Full Text Available Objetive. It was studied the respiration and ammoniacal excretion of zoeas and mysis of Litopenaeus vannamei fed with the diet used traditionally (of microalgae and nauplios of artemia and another alternative (not traditional of microalgae with rotifers. Materials and methods. After four hours the oxygen consumption and ammonia excretion in BOD bottles with 60 larvae (closed respirometers was estimated. The concentrations of O2 and NH4 + were measured with an electrode polarográfico in the first case and with the indophenol blue technique for the second. Results. In zoea, oxygen consumption increased with development and showed statistical differences (p=0.023. In mysis, the oxygen consumption were significance in the traditional diet, whereas no differences were alternative (p=0.003. In both stages for the ammoniacal excretion increased development stage and there were detected statistical difference (p<0.001, although to the diets were not noticed significant differences. Conclusions. A higher energy absorption for zoea (I, II y III what mysis (I, II y III larvae was obtained, this is likely an interaction between rates of respiration and excretion caused by variations in the efficiency of absorption by the larvae. The weights obtained in both larvae were not supplied with differences between diets.

Lethal effects of ichthyotoxic raphidophytes, Chattonella marina, C. antiqua, and Heterosigma akashiwo, on post-embryonic stages of the Japanese pearl oyster, Pinctada fucata martensii.

Science.gov (United States)

Basti, Leila; Nagai, Kiyohito; Go, Jiyoji; Okano, Sho; Oda, Tatsuya; Tanaka, Yuji; Nagai, Satoshi

2016-11-01

The inimical effects of the ichthyotoxic harmful algal bloom (HAB)-forming raphidophytes Heterosigma akashiwo, Chattonella marina, and Chattonella antiqua on the early-life stages of the Japanese pearl oyster Pinctada fucata martensii were studied. Fertilized eggs and developing embryos were not affected following exposure to the harmful raphidophytes; however, all three algal species severely affected trochophores and D-larvae, early-stage D-larvae, and late-stage pre-settling larvae. Exposure to C. marina (5×10 2 cellsml -1 ), C. antiqua (10 3 cellsml -1 ), and H. akashiwo (5×10 3 cellsml -1 ) resulted in decreased success of metamorphosis to the trochophore stage. A complete inhibition of trochophore metamorphosis was observed following exposure to C. antiqua at 5×10 3 cellsml -1 and C. marina at 8×10 3 cellsml -1 . In all experiments, more than 80% of newly formed trochophores were anomalous, and in the case of exposure to H. akashiwo at 10 5 cellsml -1 more than 70% of D-larvae were anomalous. The activity rates of D-larvae (1-day-old) were significantly reduced following exposure to C. antiqua (8×10 3 cellsml -1 , 24h), C. marina (8×10 3 cellsml -1 , 24h), and H. akashiwo (10 4 cellsml -1 , 24h). The activity rates of pre-settling larvae (21-day-old) were also significantly reduced following exposure to C. antiqua (10 3 cellsml -1 , 24h),C. marina (8×10 3 cellsml -1 , 24h), and H. akashiwo (5×10 4 cellsml -1 , 24h). Significant mortalities of both larval stages were induced by all three raphidophytes, with higher mortality rates registered for pre-settling larvae than D-larvae, especially following exposure to C. marina (5×10 2 -8×10 3 cellsml -1 , 48-86h) and C. antiqua (10 3 -8×10 3 cellsml -1 , 72-86h). Contact between raphidophyte cells and newly metamorphosed trochophores and D-larvae, 1-day-old D-larvae, and 21-day-old larvae resulted in microscopic changes in the raphidophytes, and then, in the motile early-life stages of pearl oysters. Upon

Desarrollo embrionario y larva del sapo Incilius aucoinae (Bufonidae en Golfito, Costa Rica

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Susy Segura-Solís

2009-11-01

Full Text Available Se describe la larva y los estadios del desarrollo del huevo y larva de Incilius aucoinae utilizando especímenes del río Cañaza, Golfito, Costa Rica, recolectados en enero de 1997 y enero-febrero de 1998. La muestra fue de 696 individuos, 317 huevos en estadios 1-12, 176 huevos con embriones en estadios 15-16, y 204 renacuajos en estadios 21-43. El promedio del número de huevos por nidada fue de 8 940 (n = 4, los cuales fueron colocados en una hilera, sujetos al sustrato del río. Los huevos en estadios 1-12 tienen un promedio de diámetro de 1.75 (s = 0.38 mm y los huevos con embriones en estadios 15-16 miden 1.33 (0.34 de ancho y 3.06 (1.46 mm de largo. La descripción del renacuajo basada en el espécimen UCR 19982, es como sigue: el dorso, el vientre y la cola son de color café y punteado de café oscuro; la cola mide 9.43 mm y el cuerpo 6.18, para un tamaño total de 15.62; las aletas son pequeñas café claro translúcidas, la dorsal con puntos dispersos y la ventral sin ningún tipo de pigmento oscuro. También es el único renacuajo ovoide con una tendencia a ser aplastado dorso-ventralmente, y con la boca antero-ventral. Dentro de la variación observada, algunos individuos son de color negro (3.4 % y pocos son uniformes (0.5- 1.5 %.Embryonic development and larva of the toad Incilius aucoinae (Bufonidae in Golfito, Costa Rica. The larva and developmental stages of Incilius aucoinae are described using specimens from Río Cañaza, Golfito, Costa Rica. We collected the individuals in January 1997, and January and February 1998. The total sample was 696 individuals, 317 eggs in 1-12 stages, 176 eggs with embryos in stages 15-16, and 204 tadpoles in stages 21-43. The average number of eggs per nest was 8 940 (n = 4. These eggs were laid in strings, attached to the river strata. Eggs in stages 1-12 had an average diameter of 1.75 (s = 0.38 mm and eggs with embryos in stages 15 -16 measured 1.33 (0.34 mm wide and 3.06 (1.46 mm long. The

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

Science.gov (United States)

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.

Realized habitats of early-stage North Sea herring: looking for signals of environmental change

DEFF Research Database (Denmark)

Röckmann, C.; Dickey-Collas, M.; Payne, Mark

2011-01-01

Realized habitats of North Sea herring for two larval and two juvenile stages were estimated over the past 30 years, using abundances from surveys tied to modelled estimates of temperature and salinity. Newly hatched larvae (NHL) were found mainly in water masses of 9–11°C, pre-metamorphosis larvae...

Radiographic evaluation of third molar development in 6 to 24 year olds

International Nuclear Information System (INIS)

Jung, Yun Hwa; Cho, Bong Hae

2014-01-01

This study investigated the developmental stages of third molars in relation to chronological age and compared third molar development according to location and gender. A retrospective analysis of panoramic radiographs of 2490 patients aged between 6 and 24 years was conducted, and the developmental stages of the third molars were evaluated using the modified Demirjian's classification. The mean age, standard deviation, minimal and maximal age, and percentile distributions were recorded for each stage of development. A Mann-Whitney U test was performed to test the developmental differences in the third molars between the maxillary and mandibular arches and between genders. A linear regression analysis was used for assessing the correlation between the third molar development and chronological age. The developmental stages of the third molars were more advanced in the maxillary arch than the mandibular arch. Males reached the developmental stages earlier than females. The average age of the initial mineralization of the third molars was 8.57 years, and the average age at apex closure was 21.96 years. The mean age of crown completion was 14.52 and 15.04 years for the maxillary and the mandibular third molars, respectively. The developmental stages of the third molars clearly showed a strong correlation with age. The third molars developed earlier in the upper arch than the lower arch; further, they developed earlier in males than in females.

Occurrence of larvae of Pseudorhombus elevatus Ogilby (Heterosomata-Pisces) along the south-west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Devi, C.B.L.

at less than 10 mm standard length The most notable character of middle and late stage larvae is the pronounced elongation of the nine anteriormost dorsal fin rays Adults of P elevatus with mature gonads were subsequently collected from the same region...

Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.

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Tu A. Vo

2016-11-01

Full Text Available Dynamics between hypertrophy (increase in cell size and hyperplasia (increase in cell numbers of white and red muscle in relation to body size [standard length (SL], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua. Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph, Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph, and a positive long term effect on muscle hypertrophy (60 dph. The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm, where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance.

UJI EFIKASI LARVASIDA BERBAHAN AKTIF DICHLORVOS TERHADAP LARVA LALAT RUMAH Musca domestica DI LABORATORIUM

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Hadi Suwasono

2012-10-01

Full Text Available The house fly, Musca domestica have been implicated in the mechanical transmission of pathogens causing diseases. Important diseases that may be transmitted under certain conditions include infection of virus, bacterial, protozoan, fungal and helminthic. Therefore control measures should be carried out only when the presence of the house fly is intolerable to humans due to their being a health hazard or nuisance. The larvicide with active ingredient of dichlorvos 250 g/l was applied to the house fly larvae which conducted in the laboratory. There were jive concentrations of larvicides to be tested i.e. 6; 12; 24; 48 and 96 ml by product/ 3 l of water/m2. A dried powder of chicken dung was utilized as larvae medium. The medium was inoculated with the third instar larvae then it sprayed with the larvicide suspension. All larvicidal assays were carried out at 26 - 30°C temperature and 60-80% RH in the laboratory. The results revealed that all of the five tested concentrations yielded between 0 and 5.2 percent larval mortalities.   Keywords: house fly, Musca domestica, larvicide, dichlorvos

Isotopic discrimination factors and nitrogen turnover rates in reared Atlantic bluefin tuna larvae (Thunnus thynnus: effects of maternal transmission

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Amaya Uriarte

2016-11-01

Full Text Available The use of stable isotope analysis to study animal diets requires estimates of isotopic turnover rates (half time, t50 and discrimination factors (Δ for an accurate interpretation of trophic patterns. The stable isotopes of carbon and nitrogen were analysed for eggs and reared larvae of Thunnus thynnus, as well as for the different diets supplied during the experiment. The results showed high values of δ15N in eggs and larvae (n=646 until 4 DAH. After this time lapse, the stable isotope values declined progressively until 12 DAH, when notochord flexion began. The δ13C showed an inverse trend, suggesting that maternal inheritance of the stable isotopes is evident until pre-flexion stages. This study proposes a model for estimating maternal isotopic signatures of bluefin broodstock. After notochord flexion, larvae were fed with aquaculture-bred gilthead seabream, which resulted in a rapid increase of bluefin larvae δ15N values together with a rapid decrease in δ13C values. The estimated nitrogen half-time to reach the steady state from the diet was 2.5±0.3 days and the discrimination factor was 0.4±0.3(‰. These results represent the first data set that has allowed isotopic nitrogen turnover rates and discrimination factors of the larval stages of bluefin tuna to be estimated.

The effect of starvation on the larval behavior of two forensically important species of blow flies (Diptera: Calliphoridae).

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Singh, Devinder; Bala, Madhu

2009-12-15

The postfeeding larval stage in blow flies is generally an irreversible condition when the fully grown third instar larvae stop feeding and give no response towards food. The larvae of most species then disperse away from their feeding medium and pupariate. There are several cases reported about the use of postfeeding larvae as forensic evidence. It is a matter of common observation that the postfeeding stage can be reached earlier than the expected time if food becomes unavailable. However, no information is available on whether postfeeding stage induced by scarcity of food is also irreversible. Similarly, the minimum period of development required by the larvae of different blow flies species to enable their survival as postfeeding larvae and pupariation in the absence of food is unknown. It was observed during the present studies that the larvae of two Chrysomya species must feed for at least 35 h at 28 degrees C in order to be capable of reaching the postfeeding stage and subsequent pupariation. Duration of the starvation period required to induce postfeeding behavior decreases with increasing age of larvae. In the case of Chrysomya megacephala, 35, 45, 55 and 65 h old larvae attained irreversible postfeeding stage after 30, 20, 12 and 2 h of starvation, respectively. Similarly, larvae of Chrysomya rufifacies that were 35, 45, 55 and 60 h old attained irreversible postfeeding stage after 25, 16, 6 and 2 h of starvation, respectively.

DNA barcoding facilitates associations and diagnoses for Trichoptera larvae of the Churchill (Manitoba, Canada) area.

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Ruiter, David E; Boyle, Elizabeth E; Zhou, Xin

2013-02-20

The North American Trichoptera larvae are poorly known at the species level, despite their importance in the understanding of freshwater fauna and critical use in biomonitoring. This study focused on morphological diagnoses for larvae occurring in the Churchill, Manitoba area, representing the largest larval association effort for the caddisflies at any given locality thus far. The current DNA barcode reference library of Trichoptera (available on the Barcode of Life Data Systems) was utilized to provide larval-adult associations. The present study collected an additional 23 new species records for the Churchill area, increasing the total Trichoptera richness to 91 species. We were able to associate 62 larval taxa, comprising 68.1% of the Churchill area Trichoptera taxa. This endeavor to identify immature life stage for the caddisflies enabled the development of morphological diagnoses, production of photographs and an appropriate taxonomic key to facilitate larval species analyses in the area. The use of DNA for associations of unknown larvae with known adults proved rapid and successful. This method should accelerate the state-of-knowledge for North American Trichoptera larvae as well as other taxonomic lineages. The morphological analysis should be useful for determination of material from the Churchill area.

Counterbalancing effects of maternal mercury exposure during different stages of early ontogeny in American toads.

Science.gov (United States)

Bergeron, Christine M; Hopkins, William A; Bodinof, Catherine M; Budischak, Sarah A; Wada, Haruka; Unrine, Jason M

2011-10-15

Maternal transfer of environmental contaminants is a disadvantageous parental effect which can have long-lasting implications for offspring fitness. We investigated the effects of mercury (Hg) on the reproductive success of female amphibians and the subsequent effects of maternal transfer on the development of their offspring. American toads (Bufo americanus) maternally transferred Hg to their eggs, and there was a negative relationship between Hg concentrations and the percentage of viable hatchlings produced in clutches. However, when we continued to monitor larvae that successfully hatched, we found 21% greater metamorphic success in larvae from Hg-exposed mothers compared to reference larvae. The negative effect in the embryonic stage and positive effect in the larval stage counterbalanced one another, ultimately resulting in no difference in predicted terrestrial recruitment, regardless of maternal Hg exposure. Our findings demonstrate that maternal effects on survival manifesting at different stages in ontogeny have the potential to produce complicated outcomes. Copyright © 2011 Elsevier B.V. All rights reserved.

The Marine Fungi Rhodotorula sp. (Strain CNYC4007) as a Potential Feed Source for Fish Larvae Nutrition

Science.gov (United States)

Barra, M.; Llanos-Rivera, A.; Cruzat, F.; Pino-Maureira, N.; González-Saldía, R. R.

2017-01-01

Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA). The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA) of total fatty acids), as feed for fish larvae. The total length and ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae). Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1). At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA). Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii) than in control group (C1). These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids. PMID:29194350

The effect of guided imagery on the third stage of labor: a pilot study.

Science.gov (United States)

Schorn, Mavis N

2009-08-01

The purpose of this pilot study was to test the effects of guided imagery on blood loss during the third stage of labor. This was a three-group randomized controlled trial. Recruitment was conducted from a university nurse-midwifery practice. Sixty (60) women between pregnancy weeks 36 and 38 participated. The women were randomized into experimental, placebo, and control groups. Intrauterine pressure catheters were used to measure uterine contraction frequency and intensity. Blood loss was measured. Analysis of variance was used to compare the three groups on continuous variables. Complete data were collected on 41 subjects. No significant differences were found among the groups on demographic or potentially confounding variables. Blood loss was nominally lower in the experimental group, but conclusions cannot be drawn due to the sample size.

Contenido de los nutrientes básicos en Catolaccus grandis Burks criados sobre larvas del picudo del algodon Basic nutrients content of Catolaccus grandis Burks reared in cotton boll weevil larvae

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LÚCIA HELENA AVELINO ARAUJO

2000-09-01

Full Text Available El objetivo del trabajo fue determinar los niveles de carbohidratos, proteínas solubles y aminoácidos libres de larvas, pupas hembras y adultos hembras de Catolaccus grandis (Burks (Hymenoptera: Pteromalidae criados sobre larvas del picudo del algodón envenenadas por hembras del parasitoide y por larvas de primer instar del parasitoide. Esto estudio fue conducido en la Unidade de Investigación de Control Biologico de Plagas del Departamento de Agricultura de los Estados Unidos de la América, en Weslaco, Texas. Las 20 muestras de cada uno de los tres estados de desarrollo: tercer instar larval, pupas hembra y adultos hembra del parasitoide C. grandis, fueron separadas y pesadas individualmente y se cuantió el contenido de carbohidratos totales, proteínas solubles totales y aminoácidos libres criados en diferentes sustratos. Los resultados obtenidos confirman la existencia de patrones metabólicos significativamente distintos de estos nutrientes básicos.The aim of this work was to determine the levels of carbohydrate, soluble proteins and free amino acids of larvae, pupae and adult females Catolaccus grandis Burks (Hymenoptera: Pteromalidae which were reared in cotton (Gossypium hirsutum L. r. latifolium Hutch boll weevil (Anthonomus grandis larvae venomized by ectoparasitoid of female and 1st instar ectoparasitoid larvae. This study was carried out at the Biological Control of Pests Research Unit, Weslaco, Texas. The twenty samples of each one of three stages of development: 3rd instar larval, female pupae and female adult of parasitoid C. grandis were separated and individually weighted, and levels of carbohydrates, proteins and amino acids were quantified when reared in different substrates. The results confirmed the existence of metabolic patterns significantly distinct from the basic nutrient model.

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

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Rahele Veys-Behbahani

2014-09-01

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

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

Science.gov (United States)

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

2016-04-01

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

Uterine Tonus Assessment by Midwives versus Patient self-assessment in the active management of the third stage of labor (UTAMP) : study protocol for a randomized controlled trial

NARCIS (Netherlands)

Browne, Joyce L; Damale, Nelson K R; Raams, Tessa M; Van der Linden, Eva L; Maya, Ernest T; Doe, Roseline; Rijken, Marcus J; Adanu, Richard; Grobbee, Diederick E; Franx, Arie; Klipstein-Grobusch, Kerstin

2015-01-01

BACKGROUND: Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide and accounts for one third of maternal deaths in low-income and middle-income countries. PPH can be prevented by active management of the third stage of labor (AMTSL), a series of steps recommended by the

Helicoverpa armigera (Lepidoptera: Noctuidae) larvae that survive sublethal doses of nucleopolyhedrovirus exhibit high metabolic rates.

Science.gov (United States)

Bouwer, Gustav; Nardini, Luisa; Duncan, Frances D

2009-04-01

To determine the effect of sublethal doses of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearSNPV) on the metabolic rate of H. armigera, the respiration rates of third instar H. armigera larvae inoculated with sublethal doses of HearSNPV were evaluated. Respiration rates, measured as the rate of CO(2) production (VCO(2)), were recorded daily using closed-system respirometry. By 4 days post-inoculation (dpi), the metabolic rates of LD(25) or LD(75) survivors were significantly higher than that of uninoculated controls. When dose data were pooled, the VCO(2) values of larvae that survived inoculation (0.0288mlh(-1)), the uninoculated controls (0.0250mlh(-1)), and the larvae that did not survive inoculation (0.0199mlh(-1)) differed significantly from one another. At 4dpi, the VCO(2) of the uninoculated controls were significantly lower than the VCO(2) of inoculation survivors, but significantly higher than the VCO(2) of inoculation non-survivors. Inoculation survivors may have had high metabolic rates due to a combination of viral replication, organ damage, and an energy-intensive induced cellular immune response. The high 4dpi metabolic rate of inoculation survivors may reflect an effective immune response and may be seen as the metabolic signature of larvae that are in the process of surviving inoculation with HearSNPV.

Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

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George G Waldbusser

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

Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

Science.gov (United States)

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

2015-01-01

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

Operational and structural measures to reduce hydro-peaking impact on fish larvae

International Nuclear Information System (INIS)

Kopecki, Ianina; Schneider, Matthias

2016-01-01

Eco-hydraulic investigations studying the effects of hydro-peaking on river biota are gaining in importance. Negative effects of rapid flow fluctuations due to hydro power production are well documented by many studies, with the larvae and juvenile fish identified among the mostly affected life stages. Therefore, elaboration of efficient hydro-peaking mitigation strategies is an important issue for energy companies as well as for water body administrations responsible for the fulfilment of WFD requirements. The present case study strives for practical solutions allowing to minimize or compensate the negative effects of hydro-peaking on the fish fauna of the 7 km long river reach on the river Lech (southern Germany). Model based investigations allow to access the impact from currently authorized discharge regime, suggest operational and structural measures within the reach in terms of reducing the risk of stranding for fish larvae and select the measures most easy to implement and with the largest ecological benefit. The paper describes the approach for accessing the effects of hydro-peaking based on 2D hydrodynamic modelling, fuzzy logic based habitat modelling and information on cutting-edge biological investigations on fish larvae from Lunz experimental facility (Austria). (authors)

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

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Susana Trivinho-Strixino

2012-09-01

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

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

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

2011-01-01

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

Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East.

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Duan, Jian J; Yurchenko, Galina; Fuester, Roger

2012-04-01

Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.

Larval recovery of Toxocara cati in experimentally infected Rattus norvegicus and analysis of the rat as potential reservoir for this ascarid

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Sérgio V Santos

2009-09-01

Full Text Available Toxocara cati is a common feline parasite transmitted by the ingestion of embryonated eggs, by the transmammary route or by predation of paratenic hosts harbouring third-stage larvae in their bodies. In the present study, the larval distribution of T. cati in tissues and organs of Rattus norvegicus experimentally infected with 300 embryonated eggs was analysed. Third-stage larvae were recovered from livers, lungs, kidneys, eyes, brains and carcasses of infected rats, following tissue digestion with HCl 0.5% for 24 h at 37°C. Some differences from the known larval distribution of Toxocara canisin the same rodent species were found.

Treatment post harvest of Citrus sinensis infested with Ceratitis capitata (Wied., 1824) (Diptera: Tephritidae) using gamma radiation

International Nuclear Information System (INIS)

Albergaria, Nuno M.M. Soares de; Bortoli, Sergio A. de; Doria, Hayda O.S.; Arthur, Valter

2009-01-01

This work was carried out to evaluate the effect of irradiation on fruit fly (Ceratitis capitata) eggs and larvae (first, second, third instars), in 'Valencia' oranges; and evaluate the effect of the irradiation on the chemical composition of the fruits. Fruits were artificially infested with the immature stages of the fruit fly and treated with 0, 10, 20, 30, 40, 50, 100, 150 and 200 Gy Cobalt-60 doses. By the results obtained it is possible to conclude that: third instar larvae are more tolerant to irradiation treatments; the dose of 50 Gy causes sterility to the adults emerged from all immature stages irradiated. (author)

Comparative proteome analysis between C . briggsae embryos and larvae reveals a role of chromatin modification proteins in embryonic cell division

KAUST Repository

An, Xiaomeng

2017-06-21

Caenorhabditis briggsae has emerged as a model for comparative biology against model organism C. elegans. Most of its cell fate specifications are completed during embryogenesis whereas its cell growth is achieved mainly in larval stages. The molecular mechanism underlying the drastic developmental changes is poorly understood. To gain insights into the molecular changes between the two stages, we compared the proteomes between the two stages using iTRAQ. We identified a total of 2,791 proteins in the C. briggsae embryos and larvae, 247 of which undergo up- or down-regulation between the two stages. The proteins that are upregulated in the larval stages are enriched in the Gene Ontology categories of energy production, protein translation, and cytoskeleton; whereas those upregulated in the embryonic stage are enriched in the categories of chromatin dynamics and posttranslational modification, suggesting a more active chromatin modification in the embryos than in the larva. Perturbation of a subset of chromatin modifiers followed by cell lineage analysis suggests their roles in controlling cell division pace. Taken together, we demonstrate a general molecular switch from chromatin modification to metabolism during the transition from C. briggsae embryonic to its larval stages using iTRAQ approach. The switch might be conserved across metazoans.

Radiographic evaluation of third molar development in 6- to 24-year-olds

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Jung, Yun-Hoa

2014-01-01

Purpose This study investigated the developmental stages of third molars in relation to chronological age and compared third molar development according to location and gender. Materials and Methods A retrospective analysis of panoramic radiographs of 2490 patients aged between 6 and 24 years was conducted, and the developmental stages of the third molars were evaluated using the modified Demirjian's classification. The mean age, standard deviation, minimal and maximal age, and percentile distributions were recorded for each stage of development. A Mann-Whitney U test was performed to test the developmental differences in the third molars between the maxillary and mandibular arches and between genders. A linear regression analysis was used for assessing the correlation between the third molar development and chronological age. Results The developmental stages of the third molars were more advanced in the maxillary arch than the mandibular arch. Males reached the developmental stages earlier than females. The average age of the initial mineralization of the third molars was 8.57 years, and the average age at apex closure was 21.96 years. The mean age of crown completion was 14.52 and 15.04 years for the maxillary and the mandibular third molars, respectively. Conclusion The developmental stages of the third molars clearly showed a strong correlation with age. The third molars developed earlier in the upper arch than the lower arch; further, they developed earlier in males than in females. PMID:25279338

Strongyloides stercoralis-infected dogs as a model for human disseminated strongyloidiasis

International Nuclear Information System (INIS)

Aikens, L.M.

1989-01-01

The route of migration of Strongyloides stercoralis third-stage infective larvae was explored in primary and autogenous infections in the dog. Larvae was radiolabeled by one of two means: (1) by culture of the free-living L3 stage in a nutrient medium, deficient in methionine, supplemented with [ 75 Se]Selenomethionine, and (2) by feeding of [ 75 Se]Selenomethionine-labeled bacteria to microbiverous L1 and L2 stages. Third-stage labeled larvae were then injected into 10-day-old pups either subcutaneously, to study primary migration, or into the distal ileum, to study autogenous migration. At intervals after infection pups were killed and whole body compressed organ autoradiography done on individual tissues to determine organ-specific larval transit sites. Autoradiographic recoveries were analyzed in the context of a series of mathematical models designed to test migratory route hypotheses. Postulated routes of migration for primary infections included (1) the Null Hypothesis or Scramble Route in which larvae migrate to the intestines by any available route, (2) the Classical Pulmonary Route in which larvae migrate sequentially from skin, to blood, to lungs, to the trachea, esophagus and intestines, and (3) the Head Migration Route in which larvae move from caudal to cranial sites within the skin and muscle before entering the intestines. Postulated routes for autoinfective migration reiterated 1 and 2 above. Least squares comparisons, of calculated models to observed autoradiographic distributions, led us to conclude that there was no reason to reject the simplest assumption that larvae move by any available route to the definitive site in both forms of migration. Sampling through tracheostomy sites in 14 pups for larval migrants confirmed this conclusion

Biological control of infective larvae of Ancylostoma spp. in beach sand.

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De Mello, Ingrid Ney Kramer; Braga, Fabio R; Monteiro, Thalita S Avelar; Freitas, Leandro G; Araujo, Juliana M; Soares, Filippe E Freitas; Araújo, Jackson V

2014-01-01

Geohelminths are parasites that stand out for their prevalence and wide distribution, depending on the soil for their transmission. The aim of this work was to evaluate the predatory capacity of the fungal isolate of the genus Duddingtonia (CG768) on third stage larvae (L3) of Ancylostoma spp. in beach sand under laboratory conditions. In the assay A five treatment groups and 1 control group were formed. The treatment groups contained 5000, 10,000, 15,000, 20,000 or 25,000 chlamydospores of the fungal isolate and 1000 Ancylostoma spp. L3 in pots containing 30g of sand. The control group (without fungus) contained only 1000 Ancylostoma spp. L3 and distilled water in pots with 30g of sand. Evidence of predatory activity was observed at the end of 15 days, where we observed the following percentages of reduction of L3: Group 1 (4.5%); Group 2 (24.5%); Group 3 (59.2%); Group 4 (58.8%); Group 5 (63%). However, difference was noted (p<0.01) only at concentrations 15,000, 20,000 and 25,000 in relation to control group. In the assay B two groups were formed in Petri dishes of 9cm in diameter containing agar water 2% medium. In the treated group, each Petri dish contained 500 Ancylostoma spp. L3 and 5g of sand containing the isolate CG 768 at a concentration of 25,000 chlamydospores/g of sand, and the control group (without fungus) contained only 500 L3. At the end of 7 days the non-predation L3 of Petri dishes using the method of Baermann were recovered. Difference (p<0.01) between groups on reducing the average number of Ancylostoma spp. L3 (percent reduction of 84%) was observed. The results of this study confirm earlier work on the efficiency of the Duddingtonia genus in the control of Ancylostoma spp. infective larvae. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Citrus Seed Oils Efficacy against Larvae of Aedes aegypti

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Hazrat Bilal

2017-10-01

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

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

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

2014-01-01

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

Larvicidal Activity of A Mixture of Cashew Nut Shell Liquid and Water-Soluble Extract of Soap Nut Fruit (Sapindus rarak DC. Against 3rd Instar Larvae of Aedes aegypti

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Glory Resia Raraswati

2015-10-01

Full Text Available Cashew Nut Shell Liquid (CNSL which has been known as a waste of processing cashew fruits which is contain phenolic compounds have activity as larvicides. Cashew nut shell liquid is not soluble in the water where the larvae grow. Cashew nut shell liquid mixed with water-soluble extract of soapnut fruit which serves as a natural surfactant that can emulsify oil in water. The test subjects were larvae of Aedes aegypti third instar. Test subjects were divided into treatment group and control group. In the treatment group, test subjects were  the mixture of CNSL and Ethylacetat Soluble Extract (ESE in tap water. The Larvae mortality observations were done 24 hours after the treatment. LC50 and LC90 as final test data were analyzed using probit analysis. Extract constituents   of CNSL and Water Soluble Extract of SoapNut fruit (WSEoSN were  investigated using Thin Layer Chromatography (TLC method. The effect of CNSL as larvicides against third instar larvae of Ae. aegypti with were LC50 of 14,12 ppm, while the LC90 of 24,85 ppm.

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

Science.gov (United States)

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

2017-01-01

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

Transgenic C. elegans dauer larvae expressing hookworm phospho null DAF-16/FoxO exit dauer.

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Verena Gelmedin

Full Text Available Parasitic hookworms and the free-living model nematode Caenorhabtidis elegans share a developmental arrested stage, called the dauer stage in C. elegans and the infective third-stage larva (L3 in hookworms. One of the key transcription factors that regulate entrance to and exit from developmental arrest is the forkhead transcription factor DAF-16/FoxO. During the dauer stage, DAF-16 is activated and localized in the nucleus. DAF-16 is negatively regulated by phosphorylation by the upstream kinase AKT, which causes DAF-16 to localize out of the nucleus and the worm to exit from dauer. DAF-16 is conserved in hookworms, and hypothesized to control recovery from L3 arrest during infection. Lacking reverse genetic techniques for use in hookworms, we used C. elegans complementation assays to investigate the function of Ancylostoma caninum DAF-16 during entrance and exit from L3 developmental arrest. We performed dauer switching assays and observed the restoration of the dauer phenotype when Ac-DAF-16 was expressed in temperature-sensitive dauer defective C. elegans daf-2(e1370;daf-16(mu86 mutants. AKT phosphorylation site mutants of Ac-DAF-16 were also able to restore the dauer phenotype, but surprisingly allowed dauer exit when temperatures were lowered. We used fluorescence microscopy to localize DAF-16 during dauer and exit from dauer in C. elegans DAF-16 mutant worms expressing Ac-DAF-16, and found that Ac-DAF-16 exited the nucleus during dauer exit. Surprisingly, Ac-DAF-16 with mutated AKT phosphorylation sites also exited the nucleus during dauer exit. Our results suggest that another mechanism may be involved in the regulation DAF-16 nuclear localization during recovery from developmental arrest.

The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23) with High Potential to Control American Foulbrood.

Science.gov (United States)

Oliveira, Ana; Leite, Marta; Kluskens, Leon D; Santos, Sílvio B; Melo, Luís D R; Azeredo, Joana

2015-01-01

Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

Angiostrongilose abdominal: profilaxia pela destruição das larvas infectantes em alimentos tratados com sal, vinagre ou hipoclorito de sódio

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Graziela Maria Zaniní

1995-12-01

Full Text Available A infecção acidental humana pelo Angiostrongylus costaricensis ocorre com elevada prevalência em certas áreas do Brasil meridional, eventualmente se manifestando como doença abdominal severa. Profilaxia é importante, pois não hã tratamento medicamentoso. Um dos modos de transmissão é a ingestão de frutas e vegetais contaminados com a mucosidade de moluscos infectados, os hospedeiros intermediários deste parasita. Larvas de terceiro estágio obtidas do ciclo mantido em laboratório foram incubadas a 5°C por 12 horas, em vinagre, solução saturada de cloreto de sódio e hipocloríto de sódio a 1,5%. A viabilidade das lamas tratadas foi testada através da inoculação em camundongos albinos. Os percentuais de larvas que estabeleceram infecção foram: 0% com hipocloríto de sódio, 1,8% com salmora e 2,4% com vinagre. Em conclusão, todas as substâncias - de baixo custo e disponíveis nas áreas endêmicas - reduziram à população de lamas viáveis e podem ser úteis na descontaminação de alimentos para profilaxia da angiostrongilose abdominal.There is a high prevalence of accidental human infection with Angiostrongylus costaricensis in some areas in southern Brazil and sometimes it presents as severe intestinal disease. Prophylaxis is important since there is no medical treatment for the disease. The ingestion of fruits and vegetables contaminated with the mucous secretion of infected molluscs (the intermediate hosts is one of the proposed modes of transmission. Third stage lamae were incubated at 5°C for 12 hours, in solutions of saturated sodium chloride, vinegar and sodium hypochlorite 1.5%. The larvae had their viability tested through inoculation into albino mice. The percentage of larvae that established infection were 0% in the group treated with sodium hypochloride, 1.8% with NaCl and 2.4% with vinegar. In conclusion, all substances tested reduced the population of viable larvae and may be useful in food

Fluorescence Imaging of Posterior Spiracles from Second and Third Instars of Forensically-important Chrysomya rufifacies (Diptera: Calliphoridae)*

OpenAIRE

Flores, Danielle; Miller, Amy L.; Showman, Angelique; Tobita, Caitlyn; Shimoda, Lori M.N.; Sung, Carl; Stokes, Alexander J.; Tomberlin, Jeffrey K.; Carter, David O.; Turner, Helen

2016-01-01

Entomological protocols for aging blow fly (Diptera: Calliphoridae) larvae to estimate the time of colonization (TOC) are commonly used to assist in death investigations. While the methodologies for analysing fly larvae differ, most rely on light microscopy, genetic analysis or, more rarely, electron microscopy. This pilot study sought to improve resolution of larval stage in the forensically-important blow fly Chrysomya rufifacies using high-content fluorescence microscopy and biochemical me...

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

Energy Technology Data Exchange (ETDEWEB)

Chmilevskij, D.A. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

1982-07-01

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

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

International Nuclear Information System (INIS)

Chmilevskij, D.A.

1982-01-01

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

Effects of gamma irradiation used to inhibit potato sprouting on potato tuber moth eggs, larvae and pupae Phthorimaea Operculella zeller (Lep., Gelechiidae)

International Nuclear Information System (INIS)

Saour, G.; Makee, H.

2002-12-01

Different age groups of potato tuber moth, Phthorimaea Operculella zeller, eggs were exposed to gamma irradiation at incremental doses up to 150 Gy (the upper dose limit allowed for potato sprout inhibition). Young eggs were more sensitive to gamma irradiation than older eggs and the sensitivity level declined with eggs age. The exposure of 3 - 3.5 d-old eggs to 150 Gy resulted in an 26% increase in egg incubation period compared with unirradiated eggs. The minimum dose required to 75 Gy, 9.7% of larvae survived to the adult stage but emerged as deformed moths. At 100 and 125 Gy, 10.2 and 9.6% of larvae pupated, respectively; however no adult eclosion was recorded. Whereas at 150 Gy, the larvae remained in mid-instar stage and eventually died. Young larvae and pupae were more susceptible to irradiation injuries than older ones. When larvae and of different ages were exposed to doses equal or higher than 100 Gy, only 13 to 35% pupated, but no adult emergence was obtained . The exposure of 1 - 1.5 or 3 - 3.5 day old pupae to 150 Gy induced high level of sterility and remarkable reduction in female mating ability and fecundity whereas, the reduction was less noticeable for 5 - 5.5 day-old pupae. Gamma irradiation doses applied to inhibit potato sprouting could used as an efficient control approach against potato tuber moth eggs, larval and pupal infestations (authors)

Effects of gamma irradiation used to inhibit potato sprouting on potato tuber moth eggs, larvae and pupae Phthorimaea Operculella zeller (Lep., Gelechiidae)

International Nuclear Information System (INIS)

Saour, G.; Makee, H.

2003-01-01

Different age groups of potato tuber moth, Phthorimaea Operculella zeller, eggs were exposed to gamma irradiation at incremental doses up to 150 Gy (the upper dose limit allowed for potato sprout inhibition). Young eggs were more sensitive to gamma irradiation than older eggs and the sensitivity level declined with eggs age. The exposure of 3 - 3.5 d-old eggs to 150 Gy resulted in an 26% increase in egg incubation period compared with unirradiated eggs. The minimum dose required to 75 Gy, 9.7% of larvae survived to the adult stage but emerged as deformed moths. At 100 and 125 Gy, 10.2 and 9.6% of larvae pupated, respectively. However no adult eclosion was recorded. Whereas at 150 Gy, the larvae remained in mid-in star stage and eventually died. Young larvae and pupae were more susceptible to irradiation injuries than older ones. When larvae and of different ages were exposed to doses equal or higher than 100 Gy, only 13 to 35% pupated, but no adult emergence was obtained . The exposure of 1 - 1.5 or 3 - 3.5 day old pupae to 150 Gy induced high level of sterility and remarkable reduction in female mating ability and fecundity whereas, the reduction was less noticeable for 5 - 5.5 day-old pupae. Gamma irradiation doses applied to inhibit potato sprouting could used as an efficient control approach against potato tuber moth eggs, larval and pupal infestations (authors)

Environmental exposure of Atlantic horseshoe crab (Limulus polyphemus) early life stages to essential trace elements.

Science.gov (United States)

Bakker, Aaron K; Dutton, Jessica; Sclafani, Matthew; Santangelo, Nicholas

2016-12-01

This study investigated the accumulation Co, Cu, Fe, Mn, Ni, Se, and Zn in Atlantic horseshoe crab (Limulus polyphemus) early life stages (egg, embryo and larvae) and compared the concentrations to the concentration of each element in sediment, pore water and overlying water for 5 sites across Long Island, NY. For the majority of the sites, all essential trace elements accumulated in the embryos and larvae. However, many of the embryos and larvae at specific sites presented different concentration patterns which had no apparent relationship with the local habitat sediment and water values. Generally, Cu, Fe, and Se sequentially increased from egg stage through larval stages for the majority of sites, while Co, Mn, and Ni only did for a few sites. Zinc also showed an increase across sites from embryo to larval stage, however was the only one to show a decrease in concentration from egg to embryo stage at all sites. Interestingly, Mn at Manhasset Bay presented embryo and larval stages to be 50 fold greater than all other sites while the egg stage showed similar values to other sites; this high degree of uptake could be due to a high concentration in the overlying water. All essential trace elements can be accumulated from the environment but greater concentrations may be influenced by abiotic factors and the predominant uptake route (aqueous versus diet) at each life stage. Future laboratory experiments are required to investigate factors that influence essential trace element accumulation and loss in horseshoe crab early life stages. Copyright © 2016 Elsevier B.V. All rights reserved.

Intraear Compensation of Field Corn, Zea mays, from Simulated and Naturally Occurring Injury by Ear-Feeding Larvae.

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Steckel, S; Stewart, S D

2015-06-01

Ear-feeding larvae, such as corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), can be important insect pests of field corn, Zea mays L., by feeding on kernels. Recently introduced, stacked Bacillus thuringiensis (Bt) traits provide improved protection from ear-feeding larvae. Thus, our objective was to evaluate how injury to kernels in the ear tip might affect yield when this injury was inflicted at the blister and milk stages. In 2010, simulated corn earworm injury reduced total kernel weight (i.e., yield) at both the blister and milk stage. In 2011, injury to ear tips at the milk stage affected total kernel weight. No differences in total kernel weight were found in 2013, regardless of when or how much injury was inflicted. Our data suggested that kernels within the same ear could compensate for injury to ear tips by increasing in size, but this increase was not always statistically significant or sufficient to overcome high levels of kernel injury. For naturally occurring injury observed on multiple corn hybrids during 2011 and 2012, our analyses showed either no or a minimal relationship between number of kernels injured by ear-feeding larvae and the total number of kernels per ear, total kernel weight, or the size of individual kernels. The results indicate that intraear compensation for kernel injury to ear tips can occur under at least some conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biological activity of saponins from alfalfa tops and roots against Colorado potato beetle larvae

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Maryla Szczepaniak

2013-12-01

Full Text Available The total saponins of alfalfa, Medicago sativa L., included in the diet of Colorado potato beetle larvae reduced their feeding, growth rate and survival. The biological activity of those compounds coming both from the roots and from the aerial parts is closely correlated with the dose. Larvae reared on leaves treated with a 0,5% dose virtually did not feed at all and died after 4-6 days. Lower saponin doses (0,01 and 0,001 % reduced the insects' feeding to a lesser degree. However, they inhibited their growth, caused an extension of the larval stage and mortality at a level of 76,7- 100%. No major differences have been found in saponin activity depending on its localization in the plant.

Case Report of Human Urinary Myiasis Caused by Clogmia albipunctata (Diptera: Psychodidae with Morphological Description of Larva and Pupa

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Nadia Ali El-Dib

2017-12-01

Full Text Available Background: Urinary myiasis is a form of myiasis caused mainly by larvae of Fannia scalaris, Musca, Sarcophaga, Lucilia, Wohlfahrtia, Calliphora, and rarely by Eristalis and Clogmia albipunctata.Methods: This report presents a case of female patient complaining of dysuria and frequency of micturition associ­ated with intermittent passage of small, motile, dark-colored worm-like organisms in urine. She was a married housewife aged 24 years old referred from the Tropical Outpatient Clinic of Beni-Suef University Hospital, Egypt. The patient was subjected to a full questionnaire sheet and investigations such as CBC, stool and urine analysis and uri­nary ul­traso­nography. Collected larvae and pupae from urine samples were examined macroscopically and micro­scopically.Results: The examined larvae and pupae belonged to C. albipunctata. Ivermectin was prescribed to the patient with complaint withdrawal and complete disappearance of the larvae from urine.Conclusion: This study reports the first case of urinary myiasis caused by C. albipunctata in Beni-Suef Governorate, the second in Egypt and third case worldwide. The study throws some light on the medical importance and manage­ment of urinary myiasis.

Seletividade de inseticidas utilizados em cultura cafeeira para larvas de Cryptolaemus montrouzieri Mulsant Selectivity of insecticides used in the coffee crop to larvae of Cryptolaemus montrouzieri Mulsant

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Luiz Carlos Dias Rocha

2011-06-01

association of selective compounds and natural enemies, composes an important tool for the integrated pest management (IPM. The objective of this study was to evaluate the selectivity of some pesticides used in coffee crops on larvae of Cryptolaemus montrouzieri Mulsant, 1853 (Coleoptera: Coccinellidae under controlled laboratory conditions (climatic chamber at 25±2°C, RH of 70±10% with a 12 h-photophase. The randomized experimental design was used, with six treatments and ten repetitions, being each composed for two larvae. For the comparisons of the averages of treatments, a factorial scheme was used with the products x number of instars for the different instars subsequent the application. The pesticides and doses in g of a.i. L-1 were: thiamethoxan (0.5, imidacloprid (0.7, mineral oil (13.3, endosulfan (2.63 and dimethoate (0.48. Distilled water was used as control. The sprayings of the pesticides were accomplished using a Potter's tower. The parameters evaluated were: specimens survival after the application of the compounds, and the compounds effects over the reproductive parameters of the predator. Thiamethoxan (0.5, imidacloprid (0.7 and endosulfan (2.63 were the most harmful to the treated individuals and for the first two compounds it was observed 100% of larvae mortality of the first and second instars soon at 1 day after the application and reduction in the survival of the larvae of third and fourth instars. Dimethoate (0.48 was harmful for the larvae of the first instar and slightly harmful for larvae of fourth instar. As a function of the selectivity presented by mineral oil (13.3, it can be recommended aiming its compatibilization with the C. montrouzieri natural enemy in programs of IPM in coffee crop.

The Marine Fungi Rhodotorula sp. (Strain CNYC4007 as a Potential Feed Source for Fish Larvae Nutrition

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M. Barra

2017-12-01

Full Text Available Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA. The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA of total fatty acids, as feed for fish larvae. The total length and ribonucleic acid (RNA/deoxyribonucleic acid (DNA ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae. Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1. At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA. Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii than in control group (C1. These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids.

Testing Pollen of Single and Stacked Insect-Resistant Bt-Maize on In vitro Reared Honey Bee Larvae

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

2011-01-01

The ecologically and economic important honey bee (Apis mellifera) is a key non-target arthropod species in environmental risk assessment (ERA) of genetically modified (GM) crops. Honey bee larvae are directly exposed to transgenic products by the consumption of GM pollen. But most ERA studies only consider responses of adult bees, although Bt-proteins primarily affect the larval phases of target organisms. We adopted an in vitro larvae rearing system, to assess lethal and sublethal effects of Bt-pollen consumption in a standardized eco-toxicological bioassay. The effects of pollen from two Bt-maize cultivars, one expressing a single and the other a total of three Bt-proteins, on the survival and prepupae weight of honey bee larvae were analyzed. The control treatments included pollen from three non-transgenic maize varieties and of Heliconia rostrata. Three days old larvae were fed the realistic exposure dose of 2 mg pollen within the semi-artificial diet. The larvae were monitored over 120 h, until the prepupal stage, where larvae terminate feeding and growing. Neither single nor stacked Bt-maize pollen showed an adverse effect on larval survival and the prepupal weight. In contrast, feeding of H. rostrata pollen caused significant toxic effects. The results of this study indicate that pollen of the tested Bt-varieties does not harm the development of in vitro reared A. mellifera larvae. To sustain the ecosystem service of pollination, Bt-impact on A. mellifera should always be a crucial part of regulatory biosafety assessments. We suggest that our approach of feeding GM pollen on in vitro reared honey bee larvae is well suited of becoming a standard bioassay in regulatory risk assessments schemes of GM crops. PMID:22194811

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

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Harmen P Hendriksma

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

Overwintering biology and limits of cold tolerance in larvae of pistachio twig borer, Kermania pistaciella.

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Mollaei, M; Izadi, H; Šimek, P; Koštál, V

2016-08-01

Pistachio twig borer, Kermania pistaciella is an important pest of pistachio trees. It has an univoltine life-cycle and its larvae tunnel and feed inside pistachio twigs for almost 10 months each year. The last larval instars overwinter inside the twigs. Survival/mortality associated with low temperatures during overwintering stage is currently unknown. We found that overwintering larvae of the Rafsanjan (Iran) population of K. pistaciella rely on maintaining a stably high supercooling capacity throughout the cold season. Their supercooling points (SCPs) ranged between -19.4 and -22.7°C from October to February. Larvae were able to survive 24 h exposures to -15°C anytime during the cold season. During December and January, larvae were undergoing quiescence type of dormancy caused probably by low ambient temperatures and/or changes in host tree physiology (tree dormancy). Larvae attain highest cold tolerance (high survival at -20°C) during dormancy, which offers them sufficient protection against geographically and ecologically relevant cold spells. High cold tolerance during dormancy was not associated with accumulation of any low-molecular mass cryoprotective substances. The SCP sets the limit of cold tolerance in pistachio twig borer, meaning that high mortality of overwintering populations can be expected only in the regions or years where or when the temperatures fall below the average larval SCP (i.e., below -20°C). Partial mortality can be expected also when temperatures repeatedly drop close to the SCP on a diurnal basis.

Effectivity of Musa paradisiaca extract to control Saprolegnia sp. infection on giant gourami larvae

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Sri Nuryati

2015-10-01

Full Text Available ABSTRACT Larval stage of giant gourami is a critical period due to fungal infection, such as Saprolegnia sp. infection. There are some plants which have antiseptic compound like banana Musa paradisiaca. This research was aimed to examine the effectiveness of the banana stem extract M. paradisiaca to control Saprolegnia sp. infection on giant gurami larvae through immersion. Eight-day old gorami larvae (at the initial of 0.5±0.03 cm was reared in an aquarium sized 25×25×25 cm3 at the density of 8 fry/L. Culture media were added banana stem extract at the dose of 0; 0.08; 0.12; and 0.16 g/L during 21 days of rearing period. Challenge test was performed for 14 days by giving Saprolegnia sp. spores at the density of 104 cells/mL and banana stem extract. The treatment dose of 0.16 g/L has showen survival 100% than positive control  after the challenge test. Keywords: giant gourami, Musa paradisiaca, Saprolegnia sp., fry  ABSTRAK Fase larva ikan gurami merupakan masa kritis terhadap infeksi cendawan, seperti jenis Saprolegnia sp. Beberapa tanaman memiliki daya antiseptik seperti tanaman pisang ambon Musa paradisiaca. Penelitian ini bertujuan untuk menguji efektivitas ekstrak batang pisang ambon M. paradisiaca dalam mengurangi infeksi Saprolegnia sp. pada larva ikan gurami melalui media pemeliharaan. Larva gurami umur delapan hari (panjang larva 0,5+0,03 cm dipelihara pada akuarium berukuran 25×25×25 cm3 dengan padat tebar 8 ekor/L. Media pemeliharaan diberi ekstrak batang pisang ambon dosis 0; 0,08; 0,12; dan 0,16 g/L selama 21 hari. Uji tantang dilakukan selama 14 hari dengan pemberian spora Saprolegnia sp. kepadatan 104 sel/mL dan ekstrak batang pisang ambon. Perlakuan dosis 0,16 g/L memberikan kelangsungan hidup sebesar 100% yang lebih tinggi dibandingkan perlakuan kontrol positif setelah uji tantang. Kata kunci: giant gourami, Musa paradisiaca, Saprolegnia sp., larva

Larvicidal Activity of Cassia occidentalis (Linn. against the Larvae of Bancroftian Filariasis Vector Mosquito Culex quinquefasciatus

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Deepak Kumar

2014-01-01

Full Text Available Background & Objectives. The plan of this work was to study the larvicidal activity of Cassia occidentalis (Linn. against the larvae of Culex quinquefasciatus. These larvae are the most significant vectors. They transmit the parasites and pathogens which cause a deadly disease like filariasis, dengue, yellow fever, malaria, Japanese encephalitis, chikungunya, and so forth, which are considered harmful towards the population in tropic and subtropical regions. Methods. The preliminary laboratory trail was undertaken to determine the efficacy of petroleum ether and N-butanol extract of dried whole plant of Cassia occidentalis (Linn. belonging to the family Caesalpiniaceae at various concentrations against the late third instar larvae of Culex quinquefasciatus by following the WHO guidelines. Results. The results suggest that 100% mortality effect of petroleum ether and N-butanol extract of Cassia occidentalis (Linn. was observed at 200 and 300 ppm (parts per million. The results obviously showed use of plants in insect control as an alternative method for minimizing the noxious effect of some pesticide compounds on the environment. Thus the extract of Cassia occidentalis (Linn. is claimed as more selective and biodegradable agent. Conclusion. This study justified that plant Cassia occidentalis (Linn. has a realistic mortality result for larvae of filarial vector. This is safe to individual and communities against mosquitoes. It is a natural weapon for mosquito control.

Larvicidal Activity of Cassia occidentalis (Linn.) against the Larvae of Bancroftian Filariasis Vector Mosquito Culex quinquefasciatus.

Science.gov (United States)

Kumar, Deepak; Chawla, Rakesh; Dhamodaram, P; Balakrishnan, N

2014-01-01

Background & Objectives. The plan of this work was to study the larvicidal activity of Cassia occidentalis (Linn.) against the larvae of Culex quinquefasciatus. These larvae are the most significant vectors. They transmit the parasites and pathogens which cause a deadly disease like filariasis, dengue, yellow fever, malaria, Japanese encephalitis, chikungunya, and so forth, which are considered harmful towards the population in tropic and subtropical regions. Methods. The preliminary laboratory trail was undertaken to determine the efficacy of petroleum ether and N-butanol extract of dried whole plant of Cassia occidentalis (Linn.) belonging to the family Caesalpiniaceae at various concentrations against the late third instar larvae of Culex quinquefasciatus by following the WHO guidelines. Results. The results suggest that 100% mortality effect of petroleum ether and N-butanol extract of Cassia occidentalis (Linn.) was observed at 200 and 300 ppm (parts per million). The results obviously showed use of plants in insect control as an alternative method for minimizing the noxious effect of some pesticide compounds on the environment. Thus the extract of Cassia occidentalis (Linn.) is claimed as more selective and biodegradable agent. Conclusion. This study justified that plant Cassia occidentalis (Linn.) has a realistic mortality result for larvae of filarial vector. This is safe to individual and communities against mosquitoes. It is a natural weapon for mosquito control.

Fate of pharmaceuticals and pesticides in fly larvae composting

Energy Technology Data Exchange (ETDEWEB)

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

2016-09-15

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

Fate of pharmaceuticals and pesticides in fly larvae composting

International Nuclear Information System (INIS)

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

2016-01-01

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

Effects of various diets on the calcium and phosphorus composition of mealworms (Tenebrio molitor larvae) and superworms (Zophobas morio larvae).

Science.gov (United States)

Latney, La'Toya V; Toddes, Barbara D; Wyre, Nicole R; Brown, Dorothy C; Michel, Kathryn E; Briscoe, Johanna A

2017-02-01

OBJECTIVE To evaluate whether the nutritive quality of Tenebrio molitor larvae and Zophobas morio larvae, which are commonly cultured as live food sources, is influenced by 4 commercially available diets used as nutritional substrates; identify which diet best improved calcium content of larvae; and identify the feeding time interval that assured the highest calcium intake by larvae. ANIMALS 2,000 Zophobas morio larvae (ie, superworms) and 7,500 Tenebrio molitor larvae (ie, mealworms). PROCEDURES Larvae were placed in control and diet treatment groups for 2-, 7-, and 10-day intervals. Treatment diets were as follows: wheat millings, avian hand feeding formula, organic avian mash diet, and a high-calcium cricket feed. Control groups received water only. After treatment, larvae were flash-frozen live with liquid nitrogen in preparation for complete proximate and mineral analyses. Analyses for the 2-day treatment group were performed in triplicate. RESULTS The nutrient composition of the high-calcium cricket feed groups had significant changes in calcium content, phosphorus content, and metabolizable energy at the 2-day interval, compared with other treatment groups, for both mealworms and superworms. Calcium content and calcium-to-phosphorus ratios for larvae in the high-calcium cricket feed group were the highest among the diet treatments for all treatment intervals and for both larval species. CONCLUSIONS AND CLINICAL RELEVANCE A 2-day interval with the high-calcium cricket feed achieved a larval nutrient composition sufficient to meet National Research Council dietary calcium recommendations for nonlactating rats. Mealworm calcium composition reached 2,420 g/1,000 kcal at 48 hours, and superworm calcium composition reached 2,070g/1,000 kcal at 48 hours. These findings may enable pet owners, veterinarians, insect breeders, and zoo curators to optimize nutritive content of larvae fed to insectivorous animals.

Studies on drosophila radiosensitive strains. 6. Influence of UV-rays and methyl methansulfonate on the survival and the frequency of chromosome aberrations in somatic cells of the larvae of mutant mus(2)201sup(G1)

International Nuclear Information System (INIS)

Levina, V.V.; Sharygin, V.I.

1984-01-01

Larvae of mutagen-sensitive mutant of mus (2) 201sup(G1) drosophila of different ages are subjected to the effect of UV-rays and methyl methan-sulfonate. After this mortality of individuals at the larva and chrysalis development stages is accounted, as well as chromosome aberrations in somatic cells of larvae of the 3-rd age. It is shown that mutation studied determines high mortality of flies at both larva and chrysalis stages and increased number of both spontaneous and induced aberrations. The conclusion is made that chromosome aberrations are not the only reason for the death of mutant individuals after treatment with mutagens and that functions of the gene studied are important for both dividing and nondividing cells

Feeding behavior of giant gourami, Osphronemus gouramy (Lacepede larvae

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Thumronk Amornsakun

2014-06-01

Full Text Available Feeding experiments were carried out in 15-liter glass aquaria with 10 liters of water containing 1000 larvae aged 1.5 days post-hatching (before mouth opening in three replicates. It was found that the feeding scheme of larval giant gourami aged 5-17 days (TL 8.36-13.40 mm consumed Moina. The larvae aged 14-17 days (TL 12.40-13.40 mm consumed both Moina and artificial pellet. Larvae aged more than 18-days (TL 13.60 mm consumed only artificial pellet. Daily food uptake by the larvae and juvenile were determined in a 15-liter aquaria (water volume 10 liters containing 500 larvae. The larvae were fed with Moina at density of 10 ind/ml. Aquaria without larvae were also set for a control of natural fluctuation in food density. The amount of food intake was calculated based on changes of food density in the aquarium with and without fish larvae. It was found the average uptake of Moina in digestive tract per day of larvae aged 5, 8, 11, 14 and 17 days old were 38, 52, 182, 205 and 266 individual/larva, respectively at density of 1.27, 1.73, 6.07, 6.83, and 8.87 individual/ml, respectively.

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

Science.gov (United States)

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

1994-01-01

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

The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23 with High Potential to Control American Foulbrood.

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Ana Oliveira

Full Text Available Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23 encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0, showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.