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Sample records for newly hatched larvae

  1. River water with high iron concentration and low pH causes mortality of lamprey roe and newly hatched larvae.

    PubMed

    Myllynen, K; Ojutkangas, E; Nikinmaa, M

    1997-02-01

    The effects of prevailing water quality of Perhonjoki River in Western Finland on the hatchability of lamprey roe and survival of newly hatched larvae were investigated. The river flows through sulfide-rich soils, and is characterized by high average total iron (1.5-3 mg liter-1) and aluminum (0.45-0.6 mg liter-1) concentrations and relatively low pH commonly 5.5 to 6.0, with acidification peaks below pH 5. The hatchability of lamprey roe was markedly reduced under these conditions as compared with ground water with low iron (0.002 mg liter-1) and aluminum (0.11 mg liter-1) concentrations but at the same pH. Furthermore, the hatchability of roe and survival of newly hatched larvae was especially affected by an increase in total iron concentration to values that may be observed after heavy rains and during the snow-melt period (4-6 mg liter-1). The results suggest that increases in total iron concentration may play a role in the reproductive failures of lampreys observed in Finnish rivers. PMID:9056399

  2. [General Brain Structure of Newly Hatched Larva and Neuroblasts in Larval Mushroom Bodies in Pterostichus niger Deg. (Coleoptera: Carabidae)].

    PubMed

    Panov, A A

    2015-01-01

    It is revealed that the larval brain of Pterostichus niger, an active predator with well-developed long-distance sense organs (the set of antennal sensilla and lateral ocelli, or stemmata) at hatching already contains optic lobes, which include two groups of optic neuropils and complex antennal lobes of glomerular neuropil. It is shown that the central complex of the protocerebrum is represented by a bipartite protocerebral bridge and the upper part of the central body and the mushroom bodies include, numerous Kenyon cells, a well-developed calyx, a peduncular apparatus, and numerous neuroblasts. PMID:26638237

  3. Histopathological responses of newly hatched larvae of whitefish (Coregonus lavaretus s.l.) to UV-B induced toxicity of retene.

    PubMed

    Häkkinen, Jani; Vehniäinen, Eeva; Oikari, Aimo

    2003-04-10

    Positively phototactic fish larvae may be exposed to increased ultraviolet-B (UV-B) radiation alone or, potentially and in addition, to polycyclic aromatic hydrocarbons (PAHs) such as retene (7-isopropyl-1-methylphenanthrene) at the egg or larval stages. Suspended and sedimental particulate material near pulp and paper mills may act as sources of retene in chemically contaminated lake areas. In laboratory conditions whitefish larvae were pre-exposed to retene (10, 32 and 100 microg/l), with relevant controls, and irradiated in semi-static tests for 3 h once a day (2 consecutive days) with two UV-B doses (CIE-weighted 2.8 or 5.4 kJ per m(2) per day) or with visible light only. These UV-B doses correspond with slightly subambient and 80% increases relative to the natural maximum daily doses of the solar UV-B in Finland in early May. The UV-B radiation alone increased mortality only slightly (2.7 and 4.0%, respectively). Similarly, no mortality was observed due to retene alone. On the contrary, simultaneous UV-B and retene exposure caused very high mortality to whitefish and all larvae died in the highest retene concentration. The photoinduced acute LC(50) for retene was 13.3 microg/l. Retene treated fish exhibited signs of behavioral irritation and hypoxia during and after the exposure to UV light. Severe skin damages were detected in larvae exposed simultaneously to retene and UV-B. The structural signs of sunburn could also be seen in UV-B and solvent controls (DMSO) with UV-B. Even at the lowest retene concentration, the number of mucous cells increased significantly in simultaneous chemical and UV-B treatment. We consider the tissue reaction as protective response against UV induced retene toxicity. Further, regarding liver parenchyma, fish exposed to retene with UV-B had lesions, revealing hepatotoxicity. We suggest that synergism of the UV-B radiation and the photoactivating pollutants such as retene is a potential risk factor to be taken into consideration in

  4. Newly hatched chicks solve the visual binding problem.

    PubMed

    Wood, Justin N

    2014-07-01

    For an organism to perceive coherent and unified objects, its visual system must bind color and shape features into integrated color-shape representations in memory. However, the origins of this ability have not yet been established. To examine whether newborns can build an integrated representation of the first object they see, I raised newly hatched chicks (Gallus gallus) in controlled-rearing chambers that contained a single virtual object. This object rotated continuously, revealing a different color and shape combination on each of its two faces. Chicks were able to build an integrated representation of this object. For example, they reliably distinguished an object defined by a purple circle and yellow triangle from an object defined by a purple triangle and yellow circle. This result shows that newborns can begin binding color and shape features into integrated representations at the onset of their experience with visual objects. PMID:24840718

  5. Age, growth and hatch dates of ingressing larvae and surviving juveniles of Atlantic menhaden Brevoortia tyrannus.

    PubMed

    Lozano, C; Houde, E D; Wingate, R L; Secor, D H

    2012-10-01

    Ages, growth and hatch dates of ingressing Brevoortia tyrannus larvae were determined in a 3 year sampling survey at the mouth of the Chesapeake Bay, U.S.A. To determine if otolith-aged cohorts had variable relative survival, hatch dates of summer-caught young-of-the-year (YOY) juveniles collected throughout the Chesapeake Bay were compared with hatch dates of ingressing larvae. Modal total length of ingressing larvae was similar among years: 28 mm in 2005-2006 and 2007-2008, and 30 mm in 2006-2007. Ages of ingressing larvae ranged from 9 to 96 days post hatch (dph); mean ages were similar among years, but significantly older in 2006-2007 (50 dph) than in 2005-2006 (44 dph) and 2007-2008 (46 dph). Larval growth rates differed among years. Earliest growth, when larvae were offshore (0-20 dph), was faster in 2006-2007 (0·62 mm day(-1)), than in 2005-2006 and 2007-2008 (0·55 mm day(-1) in these years). Subsequently, from 30 to 80 dph, growth was slowest in 2006-2007. Hatch dates of ingressing larvae occurred from September to March and 90% (2007-2008) to 98% (2006-2007) had hatched prior to 31 December. In contrast, most surviving YOY juvenile B. tyrannus had hatched in January to February, suggesting selective mortality of early-hatched individuals, apparently during the overwinter, larval to juvenile transition period. PMID:23020567

  6. Tracking living decapod larvae: mass staining of eggs with neutral red prior to hatching.

    PubMed

    Øresland, V; Horobin, R W

    2012-04-01

    Mass staining of decapod females carrying eggs, with subsequent identification of hatched larvae in the environment, is a research tool with great potential for field ecologists wishing to track the movements of larvae. For this to be achieved, however, numerous requirements must be met. These include adequate dye solubility, short staining time, dye penetration through different tissues, dye retention within the organism, absence of toxic and behavioral effects, low visibility to predators of stained larvae, no loss of staining owing to preservatives and low cost. The dye, neutral red, appears to meet most of these requirements. This dye was used in aliquots of 0.7 g/770 ml seawater applied to the females of Norway lobster (Nephrops norvegicus) and European lobster (Homarus gammarus) for 10 min. This procedure stained lobster eggs and embryos so that hatched larvae could be distinguished easily by fluorescence microscopy from larvae that hatched from unstained eggs. Stained larvae that were preserved in 4% formaldehyde in seawater were still stained after 1 year. Larvae should not come in contact with ethanol, because it extracts the dye rapidly.

  7. Tracking living decapod larvae: mass staining of eggs with neutral red prior to hatching.

    PubMed

    Øresland, V; Horobin, R W

    2012-04-01

    Mass staining of decapod females carrying eggs, with subsequent identification of hatched larvae in the environment, is a research tool with great potential for field ecologists wishing to track the movements of larvae. For this to be achieved, however, numerous requirements must be met. These include adequate dye solubility, short staining time, dye penetration through different tissues, dye retention within the organism, absence of toxic and behavioral effects, low visibility to predators of stained larvae, no loss of staining owing to preservatives and low cost. The dye, neutral red, appears to meet most of these requirements. This dye was used in aliquots of 0.7 g/770 ml seawater applied to the females of Norway lobster (Nephrops norvegicus) and European lobster (Homarus gammarus) for 10 min. This procedure stained lobster eggs and embryos so that hatched larvae could be distinguished easily by fluorescence microscopy from larvae that hatched from unstained eggs. Stained larvae that were preserved in 4% formaldehyde in seawater were still stained after 1 year. Larvae should not come in contact with ethanol, because it extracts the dye rapidly. PMID:22149046

  8. Hatching rhythms and dispersion of decapod crustacean larvae in a brackish coastal lagoon in Argentina

    NASA Astrophysics Data System (ADS)

    Anger, K.; Spivak, E.; Bas, C.; Ismael, D.; Luppi, T.

    1994-12-01

    Mar Chiquita, a brackish coastal lagoon in central Argentina, is inhabited by dense populations of two intertidal grapsid crab species, Cyrtograpsus angulatus and Chasmagnathus granulata. During a preliminary one-year study and a subsequent intensive sampling programme (November December 1992), the physical properties and the occurrence of decapod crustacean larvae in the surface water of the lagoon were investigated. The lagoon is characterized by highly variable physical conditions, with oligohaline waters frequently predominating over extended periods. The adjacent coastal waters show a complex pattern of semidiurnal tides that often do not influence the lagoon, due to the existence of a sandbar across its entrance. Besides frequently occurring larvae (exclusively freshly hatched zoeae and a few megalopae) of the two dominating crab species, those of three other brachyurans ( Plathyxanthus crenulatus, Uca uruguayensis, Pinnixa patagonica) and of one anomuran (the porcellanid Pachycheles haigae) were also found occasionally. Caridean shrimp ( Palaemonetes argentinus) larvae occurred in a moderate number of samples, with a maximum density of 800·m-3. The highest larval abundance was recorded in C. angulatus, with almost 8000°m-3. Significantly more C. angulatus and C. granulata zoeae occurred at night than during daylight conditions, and more larvae (statistically significant only in the former species) during ebb (outflowing) than during flood (inflowing) tides. In consequence, most crab zoeae were observed during nocturnal ebb, the least with diurnal flood tides. Our data suggest that crab larvae do not develop in the lagoon, where the adult populations live, but exhibit an export strategy, probably based upon exogenously coordinated egg hatching rhythms. Zoeal development must take place in coastal marine waters, from where the megalopa eventually returns for settlement and metamorphosis in the lagoon. Significantly higher larval frequency of C. granulata in

  9. Latex constituents from Calotropis procera (R. Br.) display toxicity upon egg hatching and larvae of Aedes aegypti (Linn.).

    PubMed

    Ramos, Márcio Viana; Bandeira, Glaís de Paiva; de Freitas, Cléverson Diniz Teixeira; Nogueira, Nádia Accioly Pinto; Alencar, Nylane Maria Nunes; de Sousa, Petrônio Augusto Simão; Carvalho, Ana Fontenele Urano

    2006-08-01

    Calotropis procera R. Br. (Asclepiadaceae) is a well-known medicinal plant with leaves, roots, and bark being exploited by popular medicine to fight many human and animal diseases. This work deals with the fractionation of the crude latex produced by the green parts of the plant and aims to evaluate its toxic effects upon egg hatching and larval development of Aedes aegypti. The whole latex was shown to cause 100% mortality of 3rd instars within 5 min. It was fractionated into water-soluble dialyzable (DF) and non-dialyzable (NDF) rubber-free materials. Both fractions were partially effective to prevent egg hatching and most of individuals growing under experimental conditions died before reaching 2nd instars or stayed in 1st instars. Besides, the fractions were very toxic to 3rd instars causing 100% mortality within 24 h. When both fractions were submitted to heat-treatment the toxic effects were diminished considerably suggesting low thermostability of the toxic compounds. Polyacrylamide gel electrophoresis of both fractions and their newly fractionated peaks obtained through ion exchange chromatography or desalting attested the presence of proteins in both materials. When submitted to protease digestion prior to larvicidal assays NDF lost most of its toxicity but DF was still strongly active. It may be possible that the highly toxic effects of the whole latex from C. procera upon egg hatching and larvae development should be at least in part due to its protein content found in NDE However the toxicity seems also to involve non protein molecules present in DF. PMID:17072453

  10. Composition of Gut Microbiota Influences Resistance of Newly Hatched Chickens to Salmonella Enteritidis Infection.

    PubMed

    Varmuzova, Karolina; Kubasova, Tereza; Davidova-Gerzova, Lenka; Sisak, Frantisek; Havlickova, Hana; Sebkova, Alena; Faldynova, Marcela; Rychlik, Ivan

    2016-01-01

    Since poultry is a very common source of non-typhoid Salmonella for humans, different interventions aimed at decreasing the prevalence of Salmonella in chickens are understood as an effective measure for decreasing the incidence of human salmonellosis. One such intervention is the use of probiotic or competitive exclusion products. In this study we tested whether microbiota from donor hens of different age will equally protect chickens against Salmonella Enteritidis infection. Newly hatched chickens were therefore orally inoculated with cecal extracts from 1-, 3-, 16-, 28-, and 42-week-old donors and 7 days later, the chickens were infected with S. Enteritidis. The experiment was terminated 4 days later. In the second experiment, groups of newly hatched chickens were inoculated with cecal extracts of 35-week-old hens either on day 1 of life followed by S. Enteritidis infection on day 2 or were infected with S. Enteritidis infection on day 1 followed by therapeutic administration of the cecal extract on day 2 or were inoculated on day 1 of life with a mixture of the cecal extract and S. Enteritidis. This experiment was terminated when the chickens were 5 days old. Both Salmonella culture and chicken gene expression confirmed that inoculation of newly hatched chickens with microbiota from 3-week-old or older chickens protected them against S. Enteritidis challenge. On the other hand, microbiota from 1-week-old donors failed to protect chickens against S. Enteritidis challenge. Microbiota from 35-week-old hens protected chickens even 24 h after administration. However, simultaneous or therapeutic microbiota administration failed to protect chickens against S. Enteritidis infection. Gut microbiota can be used as a preventive measure against S. Enteritidis infection but its composition and early administration is critical for its efficacy. PMID:27379083

  11. Composition of Gut Microbiota Influences Resistance of Newly Hatched Chickens to Salmonella Enteritidis Infection

    PubMed Central

    Varmuzova, Karolina; Kubasova, Tereza; Davidova-Gerzova, Lenka; Sisak, Frantisek; Havlickova, Hana; Sebkova, Alena; Faldynova, Marcela; Rychlik, Ivan

    2016-01-01

    Since poultry is a very common source of non-typhoid Salmonella for humans, different interventions aimed at decreasing the prevalence of Salmonella in chickens are understood as an effective measure for decreasing the incidence of human salmonellosis. One such intervention is the use of probiotic or competitive exclusion products. In this study we tested whether microbiota from donor hens of different age will equally protect chickens against Salmonella Enteritidis infection. Newly hatched chickens were therefore orally inoculated with cecal extracts from 1-, 3-, 16-, 28-, and 42-week-old donors and 7 days later, the chickens were infected with S. Enteritidis. The experiment was terminated 4 days later. In the second experiment, groups of newly hatched chickens were inoculated with cecal extracts of 35-week-old hens either on day 1 of life followed by S. Enteritidis infection on day 2 or were infected with S. Enteritidis infection on day 1 followed by therapeutic administration of the cecal extract on day 2 or were inoculated on day 1 of life with a mixture of the cecal extract and S. Enteritidis. This experiment was terminated when the chickens were 5 days old. Both Salmonella culture and chicken gene expression confirmed that inoculation of newly hatched chickens with microbiota from 3-week-old or older chickens protected them against S. Enteritidis challenge. On the other hand, microbiota from 1-week-old donors failed to protect chickens against S. Enteritidis challenge. Microbiota from 35-week-old hens protected chickens even 24 h after administration. However, simultaneous or therapeutic microbiota administration failed to protect chickens against S. Enteritidis infection. Gut microbiota can be used as a preventive measure against S. Enteritidis infection but its composition and early administration is critical for its efficacy. PMID:27379083

  12. The Effect of Chlortetracycline Meditation on the Coliform Microflora of Newly Hatched Chicks.

    PubMed

    Chopra, S L; Blackwood, A C; Dale, D G

    1963-03-01

    Newly hatched chicks were medicated with chlortetracycline at levels of 0, 400, 800 and 1200 mg. per imperial gallon of drinking water, for the first 5 days in the brooders. Coliform microflora of the ceca were counted when the chicks were first removed from the incubator and at 2 and 5 days of age. The numbers of coliforms decreased with increasing levels of the antibiotic and with increasing age. Sixtyfour per cent of the coliforms were E. coli and of these a large proportion were resistant to chlortetracycline and oxytetracycline in vitro. There was a trend towards increasing incidence of isolation of other resistant gram negative rods with increasing levels of chlortetracycline medication.

  13. The development of the olfactory organs in newly hatched monotremes and neonate marsupials.

    PubMed

    Schneider, Nanette Yvette

    2011-08-01

    Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat, placing the neonate directly in the pouch. In monotremes they were the furthest developed as Bowman glands were found underlying the main olfactory epithelium. This may reflect the need to locate the milk field each time they drink as they cannot permanently attach to it, unlike therian mammals. While it still needs to be determined how an odour signal could be further processed in the brain, this study suggests that marsupials and monotremes possess well enough developed olfactory systems to be able to detect an odour cue from the mammary area at birth/hatching. It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the

  14. The development of the olfactory organs in newly hatched monotremes and neonate marsupials

    PubMed Central

    Schneider, Nanette Yvette

    2011-01-01

    Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat, placing the neonate directly in the pouch. In monotremes they were the furthest developed as Bowman glands were found underlying the main olfactory epithelium. This may reflect the need to locate the milk field each time they drink as they cannot permanently attach to it, unlike therian mammals. While it still needs to be determined how an odour signal could be further processed in the brain, this study suggests that marsupials and monotremes possess well enough developed olfactory systems to be able to detect an odour cue from the mammary area at birth/hatching. It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the

  15. The development of the olfactory organs in newly hatched monotremes and neonate marsupials.

    PubMed

    Schneider, Nanette Yvette

    2011-08-01

    Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat, placing the neonate directly in the pouch. In monotremes they were the furthest developed as Bowman glands were found underlying the main olfactory epithelium. This may reflect the need to locate the milk field each time they drink as they cannot permanently attach to it, unlike therian mammals. While it still needs to be determined how an odour signal could be further processed in the brain, this study suggests that marsupials and monotremes possess well enough developed olfactory systems to be able to detect an odour cue from the mammary area at birth/hatching. It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the

  16. Innate sensitivity for self-propelled causal agency in newly hatched chicks

    PubMed Central

    Mascalzoni, Elena; Regolin, Lucia; Vallortigara, Giorgio

    2010-01-01

    The idea that sensitivity to self-produced motion could lie at the foundations of the clear-cut divide that the brain operates between the two basic domains of inanimate and animate objects dates back to Aristotle. Sensitivity to self-propelled objects is apparent in human infants from around the fifth month of age, which leaves undetermined whether it is acquired by experience with animate objects or whether it is innately predisposed in the brain. Here, we report that newly hatched, visually naïve domestic chicks presented with objects exhibiting motion either self-produced or caused by physical contact prefer to associate with self-propelled objects. This finding supports the idea of an evolutionarily ancient, predisposed neural mechanism in the vertebrate brain for the detection of animacy. PMID:20160095

  17. Characterizing the information content of a newly hatched chick's first visual object representation.

    PubMed

    Wood, Justin N

    2015-03-01

    How does object recognition emerge in the newborn brain? To address this question, I examined the information content of the first visual object representation built by newly hatched chicks (Gallus gallus). In their first week of life, chicks were raised in controlled-rearing chambers that contained a single virtual object rotating around a single axis. In their second week of life, I tested whether subjects had encoded information about the identity and viewpoint of the virtual object. The results showed that chicks built object representations that contained both object identity information and view-specific information. However, there was a trade-off between these two types of information: subjects who were more sensitive to identity information were less sensitive to view-specific information, and vice versa. This pattern of results is predicted by iterative, hierarchically organized visual processing machinery, the machinery that supports object recognition in adult primates. More generally, this study shows that invariant object recognition is a core cognitive ability that can be operational at the onset of visual object experience.

  18. Face recognition in newly hatched chicks at the onset of vision.

    PubMed

    Wood, Samantha M W; Wood, Justin N

    2015-04-01

    How does face recognition emerge in the newborn brain? To address this question, we used an automated controlled-rearing method with a newborn animal model: the domestic chick (Gallus gallus). This automated method allowed us to examine chicks' face recognition abilities at the onset of both face experience and object experience. In the first week of life, newly hatched chicks were raised in controlled-rearing chambers that contained no objects other than a single virtual human face. In the second week of life, we used an automated forced-choice testing procedure to examine whether chicks could distinguish that familiar face from a variety of unfamiliar faces. Chicks successfully distinguished the familiar face from most of the unfamiliar faces-for example, chicks were sensitive to changes in the face's age, gender, and orientation (upright vs. inverted). Thus, chicks can build an accurate representation of the first face they see in their life. These results show that the initial state of face recognition is surprisingly powerful: Newborn visual systems can begin encoding and recognizing faces at the onset of vision.

  19. Effect of cadmium injected in ovo on hatching results and the activity of plasma hydrolytic enzymes in newly hatched chicks.

    PubMed

    Dżugan, Małgorzata; Lis, Marcin; Droba, Maria; Niedziółka, Jerzy W

    2011-09-01

    The aim of the study was to determine the toxicity of cadmium ions in chick embryos, using plasma hydrolytic enzyme as its biomarker. Hatching eggs (n = 300) from Ross 308 broilers were incubated under standard conditions. On day 4 of incubation, 50 μl of saline solution, containing Cd ions at a concentration from 0 (control group) to 24 μg, was injected in ovo into the egg albumen. The results indicate that the administration of cadmium at doses exceeding 1 μg/egg caused a gradual decrease in hatchability, with an LD50 of 3.9 μg/egg. The greatest differences between the groups in the enzymatic activities studied were found for N-acetyl-β-D-glucosaminidase (NAG), β-D-mannosidase (β-MAN) and arylsulphatase (ARYL). Compared to the control group, in the blood serum of chicks from the groups receiving 3, 6 and 12 μg Cd/egg the NAG activity increased by 79, 108 and 54% and β-MAN activity by 33, 119 and 108%, respectively. Exposure to cadmium at a dose of 1 to 6 μg per egg caused an about 60% increase in ARYL activity while a dose of 12 μg decreased the activity by about 35% below the level observed in the control group. These findings show that cadmium has a similar toxicity mechanism in mammals and birds, which opens the possibility of using NAG activity as a biomarker of the cytotoxic effect of cadmium in birds.

  20. Effects of glyphosate on egg incubation, larvae hatching, and ovarian rematuration in the estuarine crab Neohelice granulata.

    PubMed

    Avigliano, Luciana; Alvarez, Natalia; Loughlin, Camila Mac; Rodríguez, Enrique Marcelo

    2014-08-01

    Ovigerous females of the estuarine crab (Neohelice granulate) were exposed to both pure glyphosate (2.5 mg/L and 5 mg/L) and a glyphosate formulation (Roundup Ultramax, containing glyphosate at 2.5 mg/L acid equivalent). At the end of the egg incubation period, a significant reduction in the number of hatched larvae was seen as a result of Roundup exposure. Additionally, several larvae abnormalities were seen in both pure glyphosate (2.5 mg/L) and Roundup treatments, such as hydropsy and hypopigmented eyes, and atrophied eyes were observed in the Roundup treatment. To evaluate the effect of the herbicide on ovarian rematuration, females remained exposed for 32 d. Pure glyphosate at 2.5 mg/L stimulated ovarian maturation over control levels, mainly in terms of a higher gonadosomatic index and a higher percentage of vitellogenic oocytes. A plausible hypothesis to be tested in further experiments is that exposure to glyphosate disrupts the hormonal system controlling reproduction.

  1. Egg Hatch and Survival and Development of Beet Webworm (Lepidoptera: Crambidae) Larvae at Different Combinations of Temperature and Relative Humidity.

    PubMed

    Tang, Jihong; Cheng, Yunxia; Sappington, Thomas W; Jiang, Xingfu; Zhang, Lei; Luo, Lizhi

    2016-08-01

    To understand the role that temperature and humidity play in the population dynamics of the beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), egg hatch, survival of first-fifth instars, survival of the full larval stage, survival curves, and larval development rates were investigated at combinations of four temperatures (18, 22, 26, and 30°C) and five relative humidities (RH; 20%, 40%, 60%, 80%, and 100%). We found that greatest egg hatch rate, survival rates of the first and second instars, and survival rate of the complete larval stage occurred at 22°C and 60-80% RH; the lowest values for these parameters were observed at 30°C and 20% RH. Survival of first instars was significantly affected by the interaction of temperature and relative humidity. However, survival of third and fourth instars was neither affected by temperature nor relative humidity, and that of fifth instars was significantly affected only by relative humidity level. The survival curve for larvae was well described by a type III Weibull distribution. Duration of larval stage decreased as temperature increased, but was not affected by relative humidity. We therefore conclude that eggs and early instars are the most critical stages for survival to the pupal stage, and 22-26°C and 60-80% RH are the optimum conditions for their survival and development. These findings confirm that temperature and relative humidity are the critical environmental factors affecting the population growth of L. sticticalis, with temperature being more important. PMID:27329620

  2. Effects of copper exposure on the hatching status and antioxidant defense at different developmental stages of embryos and larvae of goldfish Carassius auratus.

    PubMed

    Kong, Xianghui; Jiang, Hongxia; Wang, Shuping; Wu, Xiangmin; Fei, Wei; Li, Li; Nie, Guoxing; Li, Xuejun

    2013-09-01

    This study aims to assess the effects of copper exposure on hatching status and antioxidant defense at different stages of embryos and larvae of goldfish Carassius auratus. In this study, day-old embryos were randomly grouped after fertilization and then exposed to copper concentrations of 0, 0.1, 0.4, 0.7, and 1.0mgL(-1). Copper-exposed fish embryos were sampled every 24h to determine superoxide dismutase (SOD), and catalase (CAT) activities, as well as malondialdehyde (MDA) content. In addition, cumulative mortality and larval deformity were also investigated. The findings showed that cumulative mortality and larval deformity rate increased gradually with copper concentration increase. SOD and CAT activities were inhibited at higher copper concentrations. At a lower concentration (0.1mgL(-1)), SOD activity increased in larvae, whereas CAT activity showed no significant change (p>0.05). MDA, as the lipid peroxidation product, gradually accumulated in embryos and larvae with increasing copper concentration and the extension of exposure time. At 0.4mgL(-1) and more, copper toxicity was shown in embryos and larvae. In conclusion, copper-exposed effects on hatching status and antioxidant defense in C. auratus embryos and larvae showed concentration- and time-dependent patterns. The biochemical parameters in this study can be used as effective indicators for evaluating the responses of copper-exposed fish embryos. In addition, this study demonstrates that 0.4mgL(-1) copper (corresponding to 1mgL(-1) copper sulfate), used to kill parasites in aquaculture, is not safe concentration, because it can result in toxicity to larvae. Therefore, the copper concentration to kill pathogen should be less than 0.4mgL(-1) for C. auratus.

  3. In Ovo Injection of Betaine Affects Hepatic Cholesterol Metabolism through Epigenetic Gene Regulation in Newly Hatched Chicks

    PubMed Central

    Hu, Yun; Sun, Qinwei; Li, Xiaoliang; Wang, Min; Cai, Demin; Li, Xi; Zhao, Ruqian

    2015-01-01

    Betaine is reported to regulate hepatic cholesterol metabolism in mammals. Chicken eggs contain considerable amount of betaine, yet it remains unknown whether and how betaine in the egg affects hepatic cholesterol metabolism in chicks. In this study, eggs were injected with betaine at 2.5 mg/egg and the hepatic cholesterol metabolism was investigated in newly hatched chicks. Betaine did not affect body weight or liver weight, but significantly increased the serum concentration (P < 0.05) and the hepatic content (P < 0.01) of cholesterol. Accordingly, the cholesterol biosynthetic enzyme HMGCR was up-regulated (P < 0.05 for both mRNA and protein), while CYP7A1 which converts cholesterol to bile acids was down-regulated (P < 0.05 for mRNA and P = 0.07 for protein). Moreover, hepatic protein content of the sterol-regulatory element binding protein 1 which regulates cholesterol and lipid biosynthesis, and the mRNA abundance of ATP binding cassette sub-family A member 1 (ABCA1) which mediates cholesterol counter transport were significantly (P < 0.05) increased in betaine-treated chicks. Meanwhile, hepatic protein contents of DNA methyltransferases 1 and adenosylhomocysteinase-like 1 were increased (P < 0.05), which was associated with global genomic DNA hypermethylation (P < 0.05) and diminished gene repression mark histone H3 lysine 27 trimethylation (P < 0.05). Furthermore, CpG methylation level on gene promoters was found to be increased (P < 0.05) for CYP7A1 yet decreased (P < 0.05) for ABCA1. These results indicate that in ovo betaine injection regulates hepatic cholesterol metabolism in chicks through epigenetic mechanisms including DNA and histone methylations. PMID:25860502

  4. In Ovo injection of betaine affects hepatic cholesterol metabolism through epigenetic gene regulation in newly hatched chicks.

    PubMed

    Hu, Yun; Sun, Qinwei; Li, Xiaoliang; Wang, Min; Cai, Demin; Li, Xi; Zhao, Ruqian

    2015-01-01

    Betaine is reported to regulate hepatic cholesterol metabolism in mammals. Chicken eggs contain considerable amount of betaine, yet it remains unknown whether and how betaine in the egg affects hepatic cholesterol metabolism in chicks. In this study, eggs were injected with betaine at 2.5 mg/egg and the hepatic cholesterol metabolism was investigated in newly hatched chicks. Betaine did not affect body weight or liver weight, but significantly increased the serum concentration (P < 0.05) and the hepatic content (P < 0.01) of cholesterol. Accordingly, the cholesterol biosynthetic enzyme HMGCR was up-regulated (P < 0.05 for both mRNA and protein), while CYP7A1 which converts cholesterol to bile acids was down-regulated (P < 0.05 for mRNA and P = 0.07 for protein). Moreover, hepatic protein content of the sterol-regulatory element binding protein 1 which regulates cholesterol and lipid biosynthesis, and the mRNA abundance of ATP binding cassette sub-family A member 1 (ABCA1) which mediates cholesterol counter transport were significantly (P < 0.05) increased in betaine-treated chicks. Meanwhile, hepatic protein contents of DNA methyltransferases 1 and adenosylhomocysteinase-like 1 were increased (P < 0.05), which was associated with global genomic DNA hypermethylation (P < 0.05) and diminished gene repression mark histone H3 lysine 27 trimethylation (P < 0.05). Furthermore, CpG methylation level on gene promoters was found to be increased (P < 0.05) for CYP7A1 yet decreased (P < 0.05) for ABCA1. These results indicate that in ovo betaine injection regulates hepatic cholesterol metabolism in chicks through epigenetic mechanisms including DNA and histone methylations.

  5. Development of an in vitro drug sensitivity assay based on newly excysted larvae of Echinostoma caproni

    PubMed Central

    2013-01-01

    Background Echinostomiasis is one of the major food-borne trematodiases and the species Echinostoma caproni serves as a useful model for trematocidal drug discovery. The current in vitro drug sensitivity assay uses adult E. caproni worms that are incubated with candidate drugs and scored microscopically for viability at 72 hrs. The aim of this study was to investigate the use of newly excysted larvae (NEL) of E. caproni for in vitro drug testing, which would be faster, more cost effective and more ethical compared to adult worm assays. Methods Larvae were obtained by collecting metacercariae from snails and triggering their excystation using the trypsin-bile salt excystation method. Studies concerning various parameters of this chemical transformation process as well as appropriate NEL culturing conditions were carried out and findings evaluated. NEL and adult worms were incubated with praziquantel, tribendimidine, albendazole and quinine and evaluated microscopically 72 hrs post-incubation. In addition, the colorimetric markers resazurin, CellTiter-Glo® and Vybrant® were tested as an alternative assay read-out method. Results The chemical excystation method successfully induced E. caproni metacercariae to excyst at a rate of about 20-60%. NEL remained viable in culture medium for 5–7 days. The results of an in vitro drug assay using NEL mirrored the results of an assay using adult worms incubated with the same drugs. None of the markers could reliably produce signals proportional to NEL viability or cytotoxicity without significant complications. Conclusion NEL are adequate for in vitro drug testing. Challenges remain in further improving the excystation yield and the practicability of the assay setup. Resolving these issues could also improve read-outs using colorimetric markers. Using NEL is in alignment with the 3 R rules of the ethical use of laboratory animals and can greatly increase the rate and affordability with which drugs are screened in vitro

  6. Effects of feeding deoxynivalenol (DON)-contaminated wheat to laying hens and roosters of different genetic background on the reproductive performance and health of the newly hatched chicks.

    PubMed

    Ebrahem, Mohammad; Kersten, Susanne; Valenta, Hana; Breves, Gerhard; Beineke, Andreas; Hermeyer, Kathrin; Dänicke, Sven

    2014-08-01

    A total of 216 23-week-old laying hens from two different genetic backgrounds (half of the birds were Lohmann brown [LB] and [LSL] hens, respectively) and 24 adult roosters were assigned to a feeding trial to study the effect of increasing concentrations of deoxynivalenol (DON) in the diet (0, 5, 10 mg/kg) on the reproductive performance of hens and roosters, and the health of the newly hatched chicks. Hatchability was adversely affected by the presence of DON in LB hens' diet, while the hatchability of the LSL chicks was significantly higher than LB chicks. An interaction effect between DON in the hens' diet and the breed was noticed on fertility, as the fertility was decreased in the eggs of LB hens receiving 10 mg/kg DON in their diet and increased in the eggs of LSL hens fed 10 mg/kg DON. Moreover, spleen relative weight was significantly decreased in the chicks hatched from eggs of hens fed contaminated diets, while gizzard relative weight was significantly decreased in LB chicks with 10 mg/kg DON in their diet compared with the control group. On the other hand, the chicks' haematology and organ histopathology were not affected by the dietary treatment. Additionally, the presence of DON in the roosters' diet had no effect on fertility (the percentage of fertile eggs of all laid eggs). Consequently, the current results indicate a negative impact of DON in LB hens' diet on fertility and hatchability, indicating that the breed of the hens seems to be an additional factor influencing the effect of DON on reproductive performance of the laying hens.

  7. Administration of a Salmonella Enteritidis ΔhilAssrAfliG strain by coarse spray to newly hatched broilers reduces colonization and shedding of a Salmonella Enteritidis challenge strain.

    PubMed

    De Cort, W; Haesebrouck, F; Ducatelle, R; van Immerseel, F

    2015-01-01

    Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans. Colonization inhibition (CI) occurs when a live Salmonella strain is administered to chickens and subsequently protects against challenge with another Salmonella strain belonging to the same serotype. A Salmonella Enteritidis hilAssrAfliG deletion mutant has previously been proven to reduce colonization and shedding of a wild-type Salmonella Enteritidis strain in newly hatched broilers after experimental infection. In this study, we compared two administration routes for this strain. Administering the Salmonella Enteritidis ΔhilAssrAfliG strain through drinking water on the first day of life resulted in decreased fecal shedding and cecal colonization of a wild-type Salmonella Enteritidis challenge strain administered 24 h later using a seeder-bird model. When administering the CI strain by coarse spray on newly hatched broiler chicks, an even more pronounced reduction of cecal colonization was observed, and fecal shedding of the Salmonella Enteritidis challenge strain ceased during the course of the experiment. These data suggest that administering a Salmonella Enteritidis ΔhilAssrAfliG strain to newly hatched chicks using a coarse spray is a useful and effective method that reduces colonization and shedding of a wild-type Salmonella Enteritidis strain after early challenge. PMID:25535402

  8. Station Crew Opens Dragon's Hatch

    NASA Video Gallery

    The hatch between the newly arrived SpaceX Dragon spacecraft and the Harmony module of the International Space Station was opened by NASA Astronaut Don Pettit at 5:53 am EDT as the station flew 253...

  9. Hatch Cover Slides Through Hatch

    NASA Technical Reports Server (NTRS)

    Alton, Charles; Okane, James H.

    1989-01-01

    Hatch cover for pressurized vessel provides tight seal but opened quickly from either side. In opening or closing, cover sweeps out relatively little volume within vessel, so it does not hinder movement of people or objects from vessel to outside or placement of people or objects near hatch. Cover uses internal pressure to create seal when closed. Design of cover eliminates leakage paths, and cover immune to hazards of sudden decompression or jamming when bolts and latches fail.

  10. Effects of photoinduced toxicity of fluoranthene on amphibian embryos and larvae

    SciTech Connect

    Hatch, A.C.; Burton, G.A. Jr.

    1998-09-01

    Embryos and newly hatched larvae of three amphibian species, the spotted salamander (Ambystoma maculatum), the northern leopard frog (Rana pipiens), and the African clawed frog (Xenopus laevis), were exposed to fluoranthene and ultraviolet (UV) light in two scenarios. Embryos were exposed in a laboratory setting from an early developmental stage through hatching under artificial UV light, and newly hatched larvae were exposed outdoors in varying sunlight intensity levels. Outdoor exposures indicated greater sensitivity in the toxic response than did laboratory exposures. In the laboratory, mortality and malformation of X. laevis were the most sensitive indicators of exposure. Xenopus laevis was also the most sensitive species tested to the effects of UV light alone. Hatching success of R. pipiens was monitored outdoors and was not a useful predictive endpoint in the determination of photoinduced toxicity; however, newly hatched larvae were sensitive to the effects of photoinduced toxicity. Amybstoma maculatum and X. laevis larvae were affected by low ({micro}g/L) concentrations of fluoranthene in sunlight. These findings suggest that low levels of polycyclic aromatic hydrocarbons could be acting synergistically with environmental factors such as UV light to place young amphibians at risk.

  11. Intermitochondrial bridge junctions in fat body cells of the pre-hatch larvae of the forest tent caterpillar Malacosoma disstria HBN.

    PubMed

    Harris, J D

    1979-06-01

    An electron microscopic feature of fat body cells of diapausing Malacosoma disstria pre-hatch caterpillars, experimentally held at certain controlled time-and-temperature conditions, is an elaborate bridge junction, between mitochondria, strikingly similar in appearance to the septate junction which has frequently been described as occurring between cells of many invertebrate species. It is suggested that the intermitochondrial unctions may well represent elaborate forms of interaction between organelles in order to enhance metabolic efficiency in times of stress.

  12. Abiotic factors influencing embryonic development, egg hatching, and larval orientation in the reindeer warble fly, Hypoderma tarandi.

    PubMed

    Karter, A J; Folstad, I; Anderson, J R

    1992-10-01

    Wild-caught, tethered females of the reindeer warble fly, Hypoderma tarandi (L.) (= Oedemagena tarandi (L.)), (Diptera, Oestridae) were stimulated to oviposit on hairs of a reindeer hide. Newly laid eggs incubated at constant temperatures and relative humidities hatched within 3 days to 2 weeks, depending on the experimental conditions. Over a range of 7-40 degrees C, hatching only occurred between 20 and 37 degrees C. Eggs held at 100% relative humidity had lower hatchability and longer time to hatch relative to eggs held at 77% relative humidity. The average number of degree-days for hatching was 50.35. Between 20 and 33 degrees C there was a temperature-dependent linear trend in developmental rate, and the proportion of eggs hatching was highest, and least variable, at the mid-temperature ranges. The temperature range found in the natural host micro-habitat where H. tarandi commonly affix their eggs (close to the skin at the base of a host hair) was consistent with the experimental temperature treatments that produced the highest hatching rate. Newly emerged larvae displayed positive thermotaxis, while showing no phototaxic or geotaxic behaviour. Results indicate that constraints of the host environment, coupled with temperature-dependent hatching success, may impose a selective pressure on oviposition behaviour. PMID:1463901

  13. Abiotic factors influencing embryonic development, egg hatching, and larval orientation in the reindeer warble fly, Hypoderma tarandi.

    PubMed

    Karter, A J; Folstad, I; Anderson, J R

    1992-10-01

    Wild-caught, tethered females of the reindeer warble fly, Hypoderma tarandi (L.) (= Oedemagena tarandi (L.)), (Diptera, Oestridae) were stimulated to oviposit on hairs of a reindeer hide. Newly laid eggs incubated at constant temperatures and relative humidities hatched within 3 days to 2 weeks, depending on the experimental conditions. Over a range of 7-40 degrees C, hatching only occurred between 20 and 37 degrees C. Eggs held at 100% relative humidity had lower hatchability and longer time to hatch relative to eggs held at 77% relative humidity. The average number of degree-days for hatching was 50.35. Between 20 and 33 degrees C there was a temperature-dependent linear trend in developmental rate, and the proportion of eggs hatching was highest, and least variable, at the mid-temperature ranges. The temperature range found in the natural host micro-habitat where H. tarandi commonly affix their eggs (close to the skin at the base of a host hair) was consistent with the experimental temperature treatments that produced the highest hatching rate. Newly emerged larvae displayed positive thermotaxis, while showing no phototaxic or geotaxic behaviour. Results indicate that constraints of the host environment, coupled with temperature-dependent hatching success, may impose a selective pressure on oviposition behaviour.

  14. Effects of hatching time for larval ambystomatid salamanders

    USGS Publications Warehouse

    Boone, M.D.; Scott, D.E.; Niewiarowski, P.H.

    2002-01-01

    In aquatic communities, the phenology of breeding may influence species interactions. In the early-breeding marbled salamander, Ambystoma opacum, timing of pond filling may determine whether interactions among larvae are competitive or predatory. The objectives of our studies were to determine how time of egg hatching affected size, larval period, and survival to metamorphosis in A. opacum, and if early-hatching in A. opacum influenced the competitive and predator-prey relationships with smaller larvae of the mole salamander, Ambystoma talpoideum. Salamander larvae were reared from hatching through metamorphosis in large, outdoor enclosures located in a natural temporary pond in Aiken County, South Carolina, in two experiments. In study 1, we reared early- and late-hatching A. opacum larvae separately from hatching through metamorphosis. In study 2, we examined how early- versus late-hatching A. opacum affected a syntopic species, A. talpoideum. In general, early-hatching A. opacum were larger and older at metamorphosis, had greater survival, and left the pond earlier than late-hatching larvae. Ambystoma talpoideum reared in the presence of early-hatching A. opacum had lower survival than in controls, suggesting that A. opacum may predate upon A. talpoideum when they gain a growth advantage over later-hatching larvae. Our studies demonstrate that time of pond filling and phenology of breeding may influence population dynamics and alter the nature of relationships that develop among species.

  15. Elm leaves 'warned' by insect egg deposition reduce survival of hatching larvae by a shift in their quantitative leaf metabolite pattern.

    PubMed

    Austel, Nadine; Eilers, Elisabeth J; Meiners, Torsten; Hilker, Monika

    2016-02-01

    Plants may take insect eggs on their leaves as a warning of future herbivory and intensify their defence against feeding larvae. Responsible agents are, however, largely unknown, and little knowledge is available on this phenomenon in perennial plants. We investigated how egg deposition affects the anti-herbivore defence of elm against the multivoltine elm leaf beetle. Prior egg deposition caused changes in the quality of feeding-damaged leaves that resulted in increased larval mortality and reduced reproductive capacity of the herbivore by harming especially female larvae. Chemical analyses of primary and secondary leaf metabolites in feeding-damaged, egg-free (F) and feeding-damaged, egg-deposited (EF)-leaves revealed only small differences in concentrations when comparing metabolites singly. However, a pattern-focused analysis showed clearly separable patterns of (F) and (EF)-leaves because of concentration differences in especially nitrogen and phenolics, of which robinin was consumed in greater amounts by larvae on (EF) than on (F)-leaves. Our study shows that insect egg deposition mediates a shift in the quantitative nutritional pattern of feeding-damaged leaves, and thus might limit the herbivore's population growth by reducing the number of especially female herbivores. This may be a strategy that pays off in a long run particularly in perennial plants against multivoltine herbivores.

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

    PubMed

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

    2014-02-01

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

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

    USGS Publications Warehouse

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

    1994-01-01

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

  18. Morphological Development of Larvae and Juveniles of Acanthopagrus schlegeli

    PubMed Central

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

    2014-01-01

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

  19. Hatching Behavior of Potato Cyst Nematodes from the Canary Islands

    PubMed Central

    Gonzalez, J. A.; Phillips, M. S.

    1996-01-01

    The present work investigated early hatching differences in naturally occuring field populations and newly reared populations of potato cyst nematodes from the Canary Islands. Hatching behavior of the two species appears to be distinct, with more juveniles hatched from G. pallida that hatch earlier and over a shorter time than G. rostochiensis. The hatching rate of 3-year-old PCN populations was more than double (mean 44.5% ñ 1) that shown by newly reared populations (mean 19.1% ñ 12.5), and those that could be classified as pathotype Pa 1 (Pa 1 and P 13) were found to hatch particularly poorly. Significant differences were also observed in the juveniles released in tap water between newly reared populations of both species, with mean hatch significantly higher for G. rostochiensis. The results are discussed in relation to the implication that these findings may have for competition between the two species of PCN in the field. PMID:19277163

  20. Seasonal variations in larval biomass and biochemical composition of brown shrimp, Crangon crangon (Decapoda, Caridea), at hatching

    NASA Astrophysics Data System (ADS)

    Urzúa, Ángel; Anger, Klaus

    2013-06-01

    The "brown shrimp", Crangon crangon (Linnaeus 1758), is a benthic key species in the North Sea ecosystem, supporting an intense commercial fishery. Its reproductive pattern is characterized by a continuous spawning season from mid-winter to early autumn. During this extended period, C. crangon shows significant seasonal variations in egg size and embryonic biomass, which may influence larval quality at hatching. In the present study, we quantified seasonal changes in dry weight (W) and chemical composition (CHN, protein and lipid) of newly hatched larvae of C. crangon. Our data revealed significant variations, with maximum biomass values at the beginning of the hatching season (February-March), a decrease throughout spring (April-May) and a minimum in summer (June-September). While all absolute values of biomass and biochemical constituents per larva showed highly significant differences between months ( P < 0.001), CHN, protein and lipid concentrations (expressed as percentage values of dry weight) showed only marginally significant differences ( P < 0.05). According to generalized additive models (GAM), key variables of embryonic development exerted significant effects on larval condition at hatching: The larval carbon content (C) was positively correlated with embryonic carbon content shortly after egg-laying ( r 2 = 0.60; P < 0.001) and negatively with the average incubation temperature during the period of embryonic development ( r 2 = 0.35; P < 0.001). Additionally, water temperature ( r 2 = 0.57; P < 0.001) and food availability (phytoplankton C; r 2 = 0.39; P < 0.001) at the time of hatching were negatively correlated with larval C content at hatching. In conclusion, "winter larvae" hatching from larger "winter eggs" showed higher initial values of biomass compared to "summer larvae" originating from smaller "summer eggs". This indicates carry-over effects persisting from the embryonic to the larval phase. Since "winter larvae" are more likely exposed to

  1. Degradation of extracellular matrix by larvae of Schistosoma mansoni. II. Degradation by newly transformed and developing schistosomula

    SciTech Connect

    Keene, W.E.; Jeong, K.H.; McKerrow, J.H.; Werb, Z.

    1983-01-01

    The ability of schistosomula of Schistosoma mansoni to degrade an extracellular connective tissue matrix synthesized by rat vascular smooth muscle cells in culture was investigated. Six to 12% of the total matrix was degraded by schistosomula from the time of transformation from cercariae to adult development in vitro. Most matrix degradation occurred during the first 24 hours of incubation and was dependent on the number of schistosomula and the type of medium in which they were incubated. The use of proteinase inhibitors indicated that schistosomula activity was distinctly different from that of cercariae. Newly transformed schistosomula expressed one activity that was similar in inhibition characteristics to that of cercarial preacetabular gland secretions and another activity that was unique to schistosomula. From 1 day after transformation to adulthood, the schistosomula-derived activity was the predominant activity detected. Schistosomula degraded a smaller percentage of the total matrix than did cercariae and showed a different substrate profile. Schistosomula degraded glycoprotein components of extracellular matrix but showed little or no activity against elastin or collagen. Matrix-degrading activity was also detected in schistosomula-conditioned medium. Sedimentation of the activity and lack of permeability through filter barriers suggest that the enzyme may be initially associated with membrane and then sloughed with membrane fragments. Since the schistosomula-derived activity initially overlaps with cercarial preacetabular gland proteolytic activity, the two activities may act in concert to facilitate skin penetration by newly transformed schistosomula. However, schistosomula activity probably serves some, as yet undetermined, function later in development.

  2. Unified hatch system

    NASA Technical Reports Server (NTRS)

    Hart, R. J.; Walkover, L. J.; Zosky, E. W.

    1971-01-01

    Special hatch sealing mechanism design increases safety, reliability, and convenience. Adaptations are possible for oceanographic and high-speed aircraft design, or for any system where quick-opening pressure hatch is required. In normal mode, hatching mechanism is manually operated from either side.

  3. Perinatal broiler physiology between hatching and chick collection in 2 hatching systems.

    PubMed

    van de Ven, L J F; van Wagenberg, A V; Decuypere, E; Kemp, B; van den Brand, H

    2013-04-01

    Little is known about physiological responses of early- versus late-hatching chicks to early posthatch conditions in broiler practice. We investigated effects of hatching time on perinatal broiler physiology in 2 hatching systems, differing in conditions: a conventional hatcher, where chicks are deprived of feed and water between hatching and the moment of chick pulling (d E21.5), and a patio system, in which the hatching and brooding phase are combined, and chicks have immediate posthatch feed and water access. Climate conditions in patio also differ with about 3°C lower temperature and 20% lower RH compared with conventional hatchers. At E18, fertile eggs were transferred to either a hatcher or the patio until the end of incubation. From each system, 50 newly hatched chicks were collected at 3 hatching times: at 468 h (early), 483 h (midterm), and 498 h (late) of incubation, of which 25 chicks were decapitated for analyses of physiological parameters. The other 25 chicks were returned to the hatching system for analyses after 515 h of incubation (E21.5). At hatch, weights of the heart, lungs, stomach, and intestine increased with hatching time, concurrent with a decrease in residual yolk weight, regardless of hatching system, and indicating that later hatching chicks are more matured. Weights of the heart, liver, stomach, and intestines were lower in hatcher than in patio chicks. Between hatch and E21.5, residual yolk weight decreased, whereas organ weights increased in both fasted hatcher and fed patio chicks, but at a higher rate in the latter. At E21.5, plasma glucose and triiodothyronine had increased with time after hatch in patio chicks, whereas levels were similar among hatching times and lower in hatcher chicks. Early feed and water access seems to enable early hatching chicks to compensate for their apparent disadvantage in development at hatching, whereas chicks subjected to fasting show metabolic adaptations to preserve nutrients. Chick physiology at

  4. Responses of Takifugu obscurus fertilized eggs and larvae to increased ammonia exposure.

    PubMed

    Wang, Jun; Li, Jiajia; Xu, Nuo; Li, Jing; Li, Ziheng; Chen, Yafen; Yang, Zhou

    2015-10-01

    Ammonia is a common toxicant in aquatic systems; this substance has become a critical threat to fish, especially in early life stages. This study aimed to evaluate the effects of unionized ammonia (NH3-N: 0, 0.068, 0.138, 0.206, 0.275, 0.343, 0.412, and 0.481 mg L(-1)) on fertilized eggs and larvae of obscure puffer Takifugu obscurus, a fish species with potential economic value. Results showed that hatch time was significantly retarded and hatch rate was significantly decreased as NH3-N concentrations increased; newly hatched larvae exhibited high rate of abnormalities and low viability. The survival rate of larvae also decreased significantly as NH3-N concentrations increased; larvae could tolerate NH3-N to a less extent than embryos. NH3-N also caused a significant decrease in superoxide dismutase (SOD) and Na(+)/K(+) ATPase activities but not in malondialdehyde (MDA) levels of larvae. Two-way ANOVA indicated that there was a statistically significant interaction between NH3-N concentrations and exposure times on SOD activity but not on Na(+)/K(+) ATPase activity. Such responses indicated that an increase in ammonia concentration in surface water may negatively affect the early development of T. obscurus and thus likely impair population recruitment and persistence of this fish species.

  5. [Larva migrans].

    PubMed

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

    1995-01-01

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

  6. [Larva migrans].

    PubMed

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

    1995-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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).

  8. Capture of white sturgeon larvae downstream of The Dalles Dam, Columbia River, Oregon and Washington, 2012

    USGS Publications Warehouse

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    Wild-spawned white sturgeon (Acipenser transmontanus) larvae captured and reared in aquaculture facilities and subsequently released, are increasingly being used in sturgeon restoration programs in the Columbia River Basin. A reconnaissance study was conducted to determine where to deploy nets to capture white sturgeon larvae downstream of a known white sturgeon spawning area. As a result of the study, 103 white sturgeon larvae and 5 newly hatched free-swimming embryos were captured at 3 of 5 reconnaissance netting sites. The netting, conducted downstream of The Dalles Dam on the Columbia River during June 25–29, 2012, provided information for potentially implementing full-scale collection efforts of large numbers of larvae for rearing in aquaculture facilities and for subsequent release at a larger size in white sturgeon restoration programs.

  9. Expedition 30 Hatch Opening

    NASA Video Gallery

    Expedition 30 Flight Engineers Don Pettit, Oleg Kononenko and Andre Kuipers are welcomed aboard the International Space Station when the hatches between the station and the Soyuz TMA-03M spacecraft...

  10. Spread of hatch and delayed feed access affect post hatch performance of female broiler chicks up to day 5.

    PubMed

    Wang, Y; Li, Y; Willems, E; Willemsen, H; Franssens, L; Koppenol, A; Guo, X; Tona, K; Decuypere, E; Buyse, J; Everaert, N

    2014-04-01

    It is not rare that newly hatched chicks remain without feed for about 24 to 48 h before they are placed on farms due to a series of logistic operations. Furthermore, the spread in hatching time can also mount up to 30 to 48 h for late v. early hatchers. In other words, the practice is a complex combination of spread of hatch and delayed feed access. The present study was aimed to investigate the combined effects of hatching time with a delay in feed access of 48 h, starting from their hatch-time (biological age). When chicks had access to feed immediately after hatch, late hatchers had a higher feed intake and relative growth rate up to day 5 compared with their early hatched counterparts. Feed deprivation during the first 48 h resulted in retarded early growth rate, which was further aggravated by an impaired feed intake after refeeding. In addition, the differential effects of hatching time on relative growth rate and feed intake observed in immediately fed chicks were eliminated by the 48 h feed delay. The yolk utilization after hatch was faster for the late hatchers up to biological day 2 regardless of the feeding treatments. Hatching muscle glycogen content was higher in the late hatchers compared with that of their early counterparts at hatch and at biological day 2 independent of feeding treatment. Moreover, the liver glycogen content of the late hatchers was also higher at hatch. For the immediately fed chicks, the proportional breast muscle weight of the late hatchers was higher at biological day 2 and 5. For the starved chicks, on the other hand, this effect was only observed after they had access to feed (biological day 5). The different plasma T3 levels at hatch may have contributed to the different post hatch performance. It is concluded that the spread of hatch influenced post hatch performance, especially appetite and growth at least until day 5. Moreover, the delay in feed access interacted with the hatching time and caused adverse effects on the

  11. Culture, feeding, and growth of alewives hatched in the laboratory

    USGS Publications Warehouse

    Heinrich, John W.

    1981-01-01

    Alewives (Alosa pseudoharengus) were reared from the egg to the early juvenile life stage. The major obstacle to rearing alewives from the egg- providing an acceptable food that facilitates first feeding- was overcome by presenting a mixture of wild zooplankton to the larvae twice daily, beginning on the day of hatching. Initial feeding by larvae held at 20A?C was observed 2 days after hatching, when the yolk was nearly absorbed. Comparison of stomach contents and the wild zooplankton composition suggested that the diet of larvae during the first 15 days of life shifted with changes in the availability of food but remained within a fairly narrow range of food sizes. Larvae hatched at a mean total length of 3.8 mm and grew at an average rate of 0.62 mm per day, to a mean of 35.5 mm after 50 days. At 50 days most fish had transformed into juveniles. The daily instantaneous mortality coefficient was 0.018. About half of the mortality occurred during the first 13 days after hatching.

  12. Distribution and elimination of Norfloxacin in Fenneropenaeus chinensis larvae

    NASA Astrophysics Data System (ADS)

    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.

  13. Examination of an amphibian-based assay using the larvae of Xenopus laevis and Ambystoma mexicanum.

    PubMed

    Saka, Masahiro

    2003-05-01

    Semistatic acute toxicity tests of amphibian larvae (Xenopus laevis and Ambystoma mexicanum) were conducted at different developmental stages and by different methods to establish a simple amphibian-based assay. Test substance was pentachlorophenol sodium salt (PCP-Na). The endpoint was mortality and the 24-, 48-, 72-, and 96-h LC50 values were calculated by probit analysis. Interspecific differences in larval responses were not clear. Larval sensitivity tended to increase with larval age. Newly hatched larvae were most resistant to PCP-Na. During the tests of well-developed larvae, concentrations of dissolved oxygen and PCP-Na in the test solutions greatly dropped owing to uptake by the larvae. Therefore, middle-developed (2-week-old) larvae were most suitable for the test. Toxicity tests for volatile substances would be also possible using 2-week-old larvae in closed vessels. Test individuals should be kept individually to avoid the effects of poisonous skin secretions released from dead larvae. PMID:12706392

  14. Hatching Eggs in the Classroom.

    ERIC Educational Resources Information Center

    Smith, Robert W.

    1984-01-01

    This article provides detailed instructions on how to hatch chicken eggs. Sections include: (1) making the incubator; (2) making the brooder; (3) guidelines for hatching eggs; (4) from incubator to brooder; and (5) recommended readings. (JMK)

  15. Plasticity of hatching in amphibians: evolution, trade-offs, cues and mechanisms.

    PubMed

    Warkentin, Karen M

    2011-07-01

    Many species of frogs and salamanders, in at least 12 families, alter their timing of hatching in response to conditions affecting mortality of eggs or larvae. Some terrestrially laid or stranded embryos wait to hatch until they are submerged in water. Some embryos laid above water accelerate hatching if the eggs are dehydrating; others hatch early if flooded. Embryos can hatch early in response to predators and pathogens of eggs or delay hatching in response to predators of larvae; some species do both. The phylogenetic pattern of environmentally cued hatching suggests that similar responses have evolved convergently in multiple amphibian lineages. The use of similar cues, including hypoxia and physical disturbance, in multiple contexts suggests potential shared mechanisms underlying the capacity of embryos to respond to environmental conditions. Shifts in the timing of hatching often have clear benefits, but we know less about the trade-offs that favor plasticity, the mechanisms that enable it, and its evolutionary history. Some potentially important types of cued hatching, such as those involving embryo-parent interactions, are relatively unexplored. I discuss promising directions for research and the opportunities that the hatching of amphibians offers for integrative studies of the mechanisms, ecology and evolution of a critical transition between life-history stages.

  16. A novel report of hatching plasticity in the phylum Echinodermata.

    PubMed

    Armstrong, A Frances; Blackburn, Holly N; Allen, Jonathan D

    2013-02-01

    Hatching plasticity occurs in response to a wide range of stimuli across many animal taxa, including annelids, arthropods, mollusks, and chordates. Despite the prominence of echinoderms in developmental biology and more than 100 years of detailed examination of their development under a variety of conditions, environmentally cued hatching plasticity has never been reported in the phylum Echinodermata. Here we report plasticity in the timing and stage of hatching of embryos of the sand dollar Echinarachnius parma in response to reductions in salinity. Embryos of E. parma increased their time to hatching more than twofold in response to ecologically relevant salinity reductions, while maintaining an otherwise normal developmental schedule. Embryos that experienced the greatest delay in hatching time emerged from the fertilization envelope as four-arm pluteus larvae rather than hatching as blastulae or early gastrulae. Salinity manipulations across multiple male-female pairs indicated high variability in hatching time both within and among clutches, suggesting significant intraspecific variation in developmental responses to salinity.

  17. Metabolism during delayed hatching in terrestrial eggs of a marine fish, the grunion Leuresthes tenuis.

    PubMed

    Darken, R S; Martin, K L; Fisher, M C

    1998-01-01

    California grunion, Leuresthes tenuis (Osteichthyes: Atherinidae), leave the ocean to spawn in the sand following extreme high tides in summer. Eggs develop out of water and are able to hatch within 9-13 d, the primary hatching period. Eggs hatch on immersion and agitation by waves at the next extreme high-tide series. However, if the waves do not reach them and hatching is not induced, eggs remain viable in the sand for several weeks. During this period, grunion eggs will delay hatching, but will hatch at any time if immersed and agitated in seawater. Egg metabolism during embryonic development was measured by aerial respirometry. Metabolism increased linearly until the first date at which eggs were able to hatch. At that time, metabolic rate stabilized and remained constant for two additional weeks of embryonic incubation. Larvae induced to hatch after different durations of incubation within this period were not significantly different in length; however, the amount of oil contained in the yolk decreased linearly during the delayed hatching period. We suggest that the increase in grunion egg metabolism during the time to primary hatching capability, and the steady, high metabolic rate throughout the delayed hatching period, permit reproduction in the unique niche of these marine eggs. These semiterrestrial anamniotic eggs develop quickly and remain continuously ready to hatch over an extended period in response to an environmentally dependent and somewhat unpredictable embryonic timetable. PMID:9678500

  18. The activity of carbohydrate-degrading enzymes in the development of brood and newly emerged workers and drones of the Carniolan honeybee, Apis mellifera carnica.

    PubMed

    Żółtowska, Krystyna; Lipiński, Zbigniew; Łopieńska-Biernat, Elżbieta; Farjan, Marek; Dmitryjuk, Małgorzata

    2012-01-01

    The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degradation in all developmental stages. Developmental profiles of hydrolase activity were similar in both sexes of brood; high activity was found in unsealed larvae, the lowest in prepupae followed by an increase in enzymatic activity. Especially intensive increases in activity occurred in the last stage of pupae and newly emerged imago. Besides α-amylase, the activities of other enzymes were higher in drone than in worker broods. Among drones, activity of glucoamylase was particularly high, ranging from around three times higher in the youngest larvae to 13 times higher in the oldest pupae. This confirms earlier suggestions about higher rates of metabolism in drone broods than in worker broods.

  19. Adaptive plasticity in hatching age: a response to predation risk trade-offs.

    PubMed Central

    Warkentin, K M

    1995-01-01

    The life histories of many animals are characterized by niche shifts, the timing of which can strongly affect fitness. In the tree frog Agalychnis callidryas, which has arboreal eggs, there is a trade-off between predation risks before and after hatching. When eggs are attacked by snakes, tadpoles escape by hatching rapidly and falling into the water below. Eggs not attacked by snakes hatch later, when newly emerged tadpoles are less vulnerable to aquatic predators. Plasticity in hatching allows embryos to use immediate, local information on risk of mortality to make instantaneous behavioral decisions about hatching and the accompanying shift from arboreal to aquatic habitats. Images Fig. 3 PMID:11607529

  20. 29 CFR 1918.31 - Hatch coverings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 'tween-decks unless all hatch beams are in place under the hatch covers. (c) Missing, broken, or poorly... covers and hatch beams not of uniform size shall be placed only in the hatch, deck, and section in...

  1. 29 CFR 1918.31 - Hatch coverings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 'tween-decks unless all hatch beams are in place under the hatch covers. (c) Missing, broken, or poorly... covers and hatch beams not of uniform size shall be placed only in the hatch, deck, and section in...

  2. Temperature and water quality effects in simulated woodland pools on the infection of Culex mosquito larvae by Lagenidium giganteum (Oomycetes: Lagenidiales) in North Carolina

    SciTech Connect

    Guzman, D.R.; Axtell, R.C.

    1987-06-01

    Asexual stages of the California (CA) isolate of Lagenidium giganteum cultured on sunflower seed extract (SFE)-agar, were applied to outdoor pools containing Culex larvae near Raleigh, NC in August and September 1984. Infection rates among the larvae ranged from 19 to 74% at 2-4 days posttreatment and subsequent epizootics eliminated most of the newly hatched larvae for at least 10 days posttreatment. Substantial reductions in numbers of larvae and adult emergence were achieved from a single application of the fungus. Water quality and temperature data are presented. From laboratory assays of organically polluted water, the percent infection of Culex quinquefasciatus by the fungus was correlated with water quality and temperature. A logistic model of water quality (COD and NH/sub 3/-N) effects on infectivity rates by the CA isolate is described.

  3. Causes of hatching failure in endangered birds

    PubMed Central

    Hemmings, N.; West, M.; Birkhead, T. R.

    2012-01-01

    About 10 per cent of birds' eggs fail to hatch, but the incidence of failure can be much higher in endangered species. Most studies fail to distinguish between infertility (due to a lack of sperm) and embryo mortality as the cause of hatching failure, yet doing so is crucial in order to understand the underlying problem. Using newly validated techniques to visualize sperm and embryonic tissue, we assessed the fertility status of unhatched eggs of five endangered species, including both wild and captive birds. All eggs were classified as ‘infertile’ when collected, but most were actually fertile with numerous sperm on the ovum. Eggs of captive birds had fewer sperm and were more likely to be infertile than those of wild birds. Our findings raise important questions regarding the management of captive breeding programmes. PMID:22977070

  4. Environmentally cued hatching in reptiles.

    PubMed

    Doody, J S

    2011-07-01

    Evidence is accumulating for the widespread occurrence of environmentally cued hatching (ECH) in animals, but its diversity and distribution across taxa are unknown. Herein I review three types of ECH in reptiles: early hatching, delayed hatching, and synchronous hatching. ECH is currently known from 43 species, including turtles, crocodilians, lizards, snakes, tuatara, and possibly worm lizards. Early hatching caused by physical disturbance (e.g., vibrations) is the most commonly reported ECH across all groups; although it apparently serves an antipredator function in some species, its adaptive value is unknown in most. Delayed hatching, characterized by metabolic depression or embryonic aestivation, and sometimes followed by a hypoxic cue (flooding), occurs in some turtles and possibly in monitor lizards and crocodilians; in some of these species delayed hatching serves to defer hatching from the dry season until the more favorable conditions of the wet season. Synchronous hatching, whereby sibling eggs hatch synchronously despite vertical thermal gradients in the nest, occurs in some turtles and crocodilians. Although vibrations and vocalizations in hatching-competent embryos can stimulate synchronous hatching, cues promoting developmentally less advanced embryos to catch up with more advanced embryos have not been confirmed. Synchronous hatching may serve to dilute predation risk by promoting synchronous emergence or reduce the period in which smells associated with hatching can attract predators to unhatched eggs. Within species, advancing our understanding of ECH requires three types of studies: (1) experiments identifying hatching cues and the plastic hatching period, (2) experiments disentangling hypotheses about multiple hatching cues, and (3) investigations into the environmental context in which ECH might evolve in different species (major predators or abiotic influences on the egg, embryo, and hatchling). Among species and groups, surveys for ECH are

  5. Cadmium and zinc reversibly arrest development of Artemia larvae

    SciTech Connect

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

    1986-08-01

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

  6. Delayed egg hatching of Anopheles gambiae (Diptera: Culicidae) pending water agitation.

    PubMed

    Ebrahimi, Babak; Shakibi, Sanam; Foster, Woodbridge A

    2014-05-01

    Mosquito eggs laid on water surfaces typically hatch spontaneously soon after the embryos within them become fully formed first-instar larvae. However, we have found that Anopheles gambiae Giles, an important vector of malaria in Africa, exhibits delayed hatching until the water surface is agitated, a feature overlooked in most laboratory colonies. Agitation within 24 h postoviposition, before embryonation was complete, failed to stimulate delayed postembryonic hatching of isolated eggs on the following day (day 2), when < 1% had hatched spontaneously. However, 5 min of water agitation of these dormant pharate first-instar larvae on day 2 resulted in an almost immediate hatch of 63.3 versus 0% of nonagitated controls, plus another 3.9 versus 0.3%, respectively, during the following 24 h. With daily agitation, installment hatching occurred mainly during 2-6 d postoviposition. The mean cumulative hatch after 7 d of daily agitation was 83.1 versus 1.1% of nonagitated eggs. Experiments with eggs in groups demonstrated that egg density and activity of already-hatched larvae had no stimulatory effect. Eggs stored 1-4 wk at 25.5 or at 15.5 degrees C, and then agitated daily for 6 d at 25.5 degrees C, showed a gradual decline in viability. Viability was sustained longer at the lower temperature. Implications of agitation-induced egg hatching for rainy-season and dry-season ecology of An. gambiae are discussed. Suspended hatching and cool storage already are proving convenient for efficient mass rearing and accurate modeling of weather-based population dynamics.

  7. Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

    NASA Technical Reports Server (NTRS)

    Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

    1994-01-01

    Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by introduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spa ceflight, and show that extensive degrees of development can take place in this microgravity environment.

  8. Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

    NASA Astrophysics Data System (ADS)

    Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

    1994-08-01

    Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by intrduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spaceflight, and show that extensive degress of development can take place in this microgravity environment.

  9. Plasticity of hatching and the duration of planktonic development in marine invertebrates.

    PubMed

    Oyarzun, Fernanda X; Strathmann, Richard R

    2011-07-01

    Plasticity in hatching potentially adjusts risks of benthic and planktonic development for benthic marine invertebrates. The proportionate effect of hatching plasticity on duration of larval swimming is greatest for animals that can potentially brood or encapsulate offspring until hatching near metamorphic competence. As an example, early hatching of the nudibranch mollusk Phestilla sibogae is stimulated by scattering of encapsulated offspring, as by a predator feeding on the gelatinous egg ribbon. When egg ribbons are undisturbed, hatching is at or near metamorphic competence. Disturbance of an unguarded benthic egg mass can insert 4 or more days of obligate larval dispersal into the life history. As another example, the spionid annelid Boccardia proboscidea broods capsules, each with both cannibalistic and developmentally arrested planktivorous siblings plus nurse eggs. Early hatching produces mainly planktivorous larvae with a planktonic duration of 15 days. Late hatching produces mainly adelphophages who have eaten their planktivorous siblings and metamorphose with little or no period of swimming. Mothers actively hatch their offspring by tearing the capsules, and appeared to time hatching in response to their environment and not to the stage of development of their offspring. Higher temperature increased the variance of brooding time. Females appeared to hatch capsules at an earlier developmental stage at lower temperatures. Species that release gametes or zygotes directly into the plankton have less scope for plasticity in stage at hatching. Their embryos develop singly with little protection and hatch at early stages, often as blastulae or gastrulae. Time of hatching cannot be greatly advanced, and sensory capabilities of blastulae may be limited. PMID:21576120

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

    SciTech Connect

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

    1981-01-01

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

  11. Host cues induce egg hatching and pre-parasitic foraging behaviour in the mosquito parasitic nematode, Strelkovimermis spiculatus.

    PubMed

    Wang, Yi; Lutfi, Zainal; Dong, Limin; Suman, Devi S; Sanad, Manar; Gaugler, Randy

    2012-09-01

    The responses of eggs in diapause and the infective stage of the nematode, Strelkovimermis spiculatus, to larvae of its host, Culex pipiens pipiens, were investigated in the laboratory. The results indicated that the presence of the host induced the egg hatching. The hatching rate increased when larger numbers of host larvae were present. Second instar mosquito larvae induced significantly higher hatching rates than any other stages. These findings explain how S. spiculatus synchronizes its life cycle with its host life cycle and population dynamics to increase its fitness when the natural habitat is constantly covered by water. Direct exposure of the nematode eggs to host larvae resulted in consumption of as many as 20 eggs per host. The eggs consumed caused 0-70% host mortality depending on the number consumed, which indicated an infection path other than cuticle penetration although it may represent a rare situation in nature. The result of host cue assays showed that the combination of chemical cues and physical vibration induced the highest egg hatching, which may increase the chance of host availability after hatching. However, once hatched, the nematodes ignored vibrations and used only chemical cues for host location. These findings suggest that eggs hatch synchronously with the most susceptible mosquito stage and with peak mosquito larval density.

  12. Station Crew Opens Dragon Hatch

    NASA Video Gallery

    Expedition 33 Commander Suni Williams and Flight Engineer Aki Hoshide opened the hatch to the SpaceX Dragon cargo ship at 1:40 p.m. EDT Wednesday, Oct. 10, marking a milestone for the first commerc...

  13. NSA AERI Hatch Correction Data Set

    SciTech Connect

    Turner, David

    2012-03-23

    From 2000-2008, the NSA AERI hatch was determined to be indicated as open too frequently. Analysis suggests that the hatch was actually opening and closing properly but that its status was not being correctly reported by the hatch controller to the datastream. An algorithm was written to determine the hatch status from the observed

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

    USGS Publications Warehouse

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

    1998-01-01

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

  15. The Hatch-Smolensk exchange

    SciTech Connect

    Sproles, A.

    1993-03-01

    During summer 1992, the World Association of Nuclear Operators (WANO) sponsored an exchange visit between Georgia Power Company's Edwin I. Hatch nuclear plant, a two-unit boiling water reactor site, and the Smolensk atomic energy station, a three-unit RBMK (graphite-moderated and light-water-cooled) plant located 350 km west of Moscow, in Desnogorsk, Russia. The Plant Hatch team included Glenn Goode, manager of engineering support; Curtis Coggin, manager of training and emergency preparedness; Wayne Kirkley, manager of health physics and chemistry; John Lewis, manager of operations; Ray Baker, coordinator of nuclear fuels and contracts; and Bruce McLeod, manager of nuclear maintenance support. Also traveling with the team was Jerald Towgood, of WANO's Atlanta Centre. The Hatch team visited the Smolensk plant during the week of July 27, 1992.

  16. Determining trace element concentrations in marine larvae using electrothermal vaporization and laser ablation technology. Final report, 1 March 1997--28 February 1998

    SciTech Connect

    Levin, L.A.

    1998-09-29

    The objective of this DURIP award was the acquisition of an instrument to enhance analytical capabilities in support of grant no. N00014-96- 1-0025 (Bay Ocean Exchange Processes: Development and Application of a Meroplankton Tracer Technique). This research is concerned with (1) determining the uptake and retention of trace metals by invertebrate larvae and (2) elemental fingerprinting of naturally occurring larvae as a means to determine site of origin. The objective was to quantify composition of multiple trace elements for small samples (i.e., individual larvae). With DURIP funds an Inductively Coupled Plasma-Optical Emission Spectrometer was purchased for the Scripps Institution of Oceanography analytical facilities. The ICP-OES has been used to characterize the elemental composition of newly hatched crab larvae sampled from San Diego Bay, neighboring embayments and coastal habitats. Results have shown that elements can be quantified for individual larvae and are useful in distinguishing larvae originating from inner vs outer San Diego Bay and coastal habitats. Other applications of the Scripps ICP-OES since its purchase include trace element characterization of (a) contaminated sediments to develop remediation methods, (b) meteorites to model age of the early solar system, and (c) igneous rocks to track earth history.

  17. Chilling requirements for hatching of a New Zealand isolate of Nematodirus filicollis.

    PubMed

    Oliver, A-M B; Pomroy, W E; Ganesh, S; Leathwick, D M

    2016-08-15

    The eggs of some species of the parasitic nematode Nematodirus require a period of chilling before they can hatch; N. filicollis is one such species. This study investigated this requirement for chilling in a New Zealand strain of this species. Eggs of N. filicollis were extracted from lamb's faeces and incubated at 20°C to allow development to the third stage larvae within the egg. These eggs were then placed into tissue culture plates and incubated at: 2.7°C (±0.99), 3.6°C (±0.90), 4.7°C (±0.35), 6.4°C (±0.37), 8.0°C (±1.54) or 9.9°C (±0.14) for up to 224 days. At 14day intervals until day 84, then every 28 days, one plate was removed from each temperature and placed at 13.1°C (±0.44) for 14 days. Eggs were then assessed for hatching. From this data, chill units were calculated by subtracting the culture temperature from a constant threshold of 11°C and multiplying by the number of days for which the sample was cultured; then the Gompertz model fitted. Even though hatching overall was low, a greater proportion of eggs hatched with chill accumulation. Maximum hatching of eggs required 800-1000 chill units. Consequently in the field, more than one season of chilling would be required before hatching. As such a generation time could take more than one year to complete. This is different to the hatching dynamics of N. spathiger, the other main species found in New Zealand sheep, which does not display this requirement for chilling and hatches immediately once the third stage larvae are developed. PMID:27514876

  18. Chilling requirements for hatching of a New Zealand isolate of Nematodirus filicollis.

    PubMed

    Oliver, A-M B; Pomroy, W E; Ganesh, S; Leathwick, D M

    2016-08-15

    The eggs of some species of the parasitic nematode Nematodirus require a period of chilling before they can hatch; N. filicollis is one such species. This study investigated this requirement for chilling in a New Zealand strain of this species. Eggs of N. filicollis were extracted from lamb's faeces and incubated at 20°C to allow development to the third stage larvae within the egg. These eggs were then placed into tissue culture plates and incubated at: 2.7°C (±0.99), 3.6°C (±0.90), 4.7°C (±0.35), 6.4°C (±0.37), 8.0°C (±1.54) or 9.9°C (±0.14) for up to 224 days. At 14day intervals until day 84, then every 28 days, one plate was removed from each temperature and placed at 13.1°C (±0.44) for 14 days. Eggs were then assessed for hatching. From this data, chill units were calculated by subtracting the culture temperature from a constant threshold of 11°C and multiplying by the number of days for which the sample was cultured; then the Gompertz model fitted. Even though hatching overall was low, a greater proportion of eggs hatched with chill accumulation. Maximum hatching of eggs required 800-1000 chill units. Consequently in the field, more than one season of chilling would be required before hatching. As such a generation time could take more than one year to complete. This is different to the hatching dynamics of N. spathiger, the other main species found in New Zealand sheep, which does not display this requirement for chilling and hatches immediately once the third stage larvae are developed.

  19. Oxygenation of anoxic sediments triggers hatching of zooplankton eggs.

    PubMed

    Broman, Elias; Brüsin, Martin; Dopson, Mark; Hylander, Samuel

    2015-10-22

    Many coastal marine systems have extensive areas with anoxic sediments and it is not well known how these conditions affect the benthic-pelagic coupling. Zooplankton lay their eggs in the pelagic zone, and some sink and lie dormant in the sediment, before hatched zooplankton return to the water column. In this study, we investigated how oxygenation of long-term anoxic sediments affects the hatching frequency of dormant zooplankton eggs. Anoxic sediments from the brackish Baltic Sea were sampled and incubated for 26 days with constant aeration whereby, the sediment surface and the overlying water were turned oxic. Newly hatched rotifers and copepod nauplii (juveniles) were observed after 5 and 8 days, respectively. Approximately 1.5 × 10(5) nauplii m(-2) emerged from sediment turned oxic compared with 0.02 × 10(5) m(-2) from controls maintained anoxic. This study demonstrated that re-oxygenation of anoxic sediments activated a large pool of buried zooplankton eggs, strengthening the benthic-pelagic coupling of the system. Modelling of the studied anoxic zone suggested that a substantial part of the pelagic copepod population can derive from hatching of dormant eggs. We suggest that this process should be included in future studies to understand population dynamics and carbon flows in marine pelagic systems.

  20. Vertical distribution of first stage larvae of the blue crab, Callinectes sapidus, at the mouth of Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Provenzano, Anthony J.; McConaugha, John R.; Philips, Kathleen B.; Johnson, David F.; Clark, John

    1983-05-01

    The vertical distribution of stage I blue crab larvae, near the mouth of Chesapeake Bay, was examined over four diurnal cycles. Each of two stations was occupied for 30 hours twice during the summer of 1979. On each of the four cruises, peak larval abundance occurred after a night time high slack tide, suggesting a synchronized hatch of blue crab larvae. 90-99% of all larvae collected were taken in the neuston layer. The apparent timing of the hatches to coincide with the beginning of an ebb tide and the concentration of larvae in the neuston layer strongly suggests seaward transport of these early stage larvae and the probability of offshore development.

  1. 78 FR 6173 - Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-29

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF TRANSPORTATION Surface Transportation Board Diana Del Grosso, Ray Smith, Joseph Hatch, Cheryl Hatch, Kathleen... Smith, Joseph Hatch, Cheryl Hatch, Kathleen Kelley, Andrew Wilklund, and Richard Kosiba...

  2. The development of gypsy moth larvae raised on gray and yellow birch foliage grown in ambient and elevated CO[sub 2

    SciTech Connect

    Traw, M.B.B.; Bazzaz, F.A. )

    1993-06-01

    This study addresses insect-host plant interactions in an elevated CO[sub 2] atmosphere. Gypsy moth larvae (Lynmtria dispar) were raised on two of their natural host species of New England's temperate forest, yellow and gray birch (Betula alleganiensis and B. populifolia). Birch seedlings were germinated and grown at either ambient (350 ppm) or elevated (700 ppm) CO[sub 2] in light and temperature controlled chambers. After four months, we added newly hatched L dispar larvae. Twenty-four mesh cages, each containing one caterpillar and one plant, were set up for each treatment (2 host species x 2 CO[sub 2] levels). Over the next two months, we tracked larval weights and behavior. A sub sample of birch were harvested to measure characteristics that might affect herbivores. A separate group of second and third instar larvae were given the choice of two different, detached leaves in a petri dish. Two preference tests were performed; between species (Yb vs Gb), CO[sub 2] levels (350 vs 700). Our results show that larvae grew significantly larger and reach maturity more rapidly at 350 ppm CO[sub 2] and on gray birch. In preference tests, larvae preferred yellow birch over gray at 350 ppm, and in yellow birch, preferred 350 ppm foliage over 700 ppm foliage. These results suggest that the impact of a generatist insect herbivore on different host plant species may change in an elevated CO[sub 2] atmosphere.

  3. Glassfrog embryos hatch early after parental desertion

    PubMed Central

    Delia, Jesse R. J.; Ramírez-Bautista, Aurelio; Summers, Kyle

    2014-01-01

    Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations. PMID:24789892

  4. Spatial distribution and hatching of overwintered eggs of a fish ectoparasite, Argulus coregoni (Crustacea: Branchiura).

    PubMed

    Mikheev, V N; Pasternak, A F; Valtonen, E T; Lankinen, Y

    2001-09-12

    The habitat distribution of overwintered eggs, which were found to be the only source of spring recruitment of Argulus coregoni Thorell, was studied at a commercial fish farm in Central Finland. The frequency of occurrence of egg clutches in the deep parts of the canals and ponds was 50 to 80% and the percentage cover of the surface of stones with egg clutches was 1.7 to 6.4%, while in the shallow parts these values were 8 to 27% and 0.1 to 0.3%, respectively. A greater proportion of empty egg-shells was observed in shallow water in the mid-May, suggesting an earlier hatching there stimulated by the increased temperature and higher illumination. Under laboratory conditions, only elevated UV illumination, but not diurnally fluctuating temperature, significantly accelerated hatching. Normally overwintered eggs produced a pronounced peak of hatched larvae at the end of May and hatching continued at a much slower rate throughout the summer. Eggs that overwintered twice, first normally and then for a second time buried under sediments, were exposed to the same laboratory conditions simultaneously with normally overwintered eggs, but their hatching was delayed until August. The hatching rate was low, but markedly increased in December. PMID:11678227

  5. Worldwide Spacecraft Crew Hatch History

    NASA Technical Reports Server (NTRS)

    Johnson, Gary

    2009-01-01

    The JSC Flight Safety Office has developed this compilation of historical information on spacecraft crew hatches to assist the Safety Tech Authority in the evaluation and analysis of worldwide spacecraft crew hatch design and performance. The document is prepared by SAIC s Gary Johnson, former NASA JSC S&MA Associate Director for Technical. Mr. Johnson s previous experience brings expert knowledge to assess the relevancy of data presented. He has experience with six (6) of the NASA spacecraft programs that are covered in this document: Apollo; Skylab; Apollo Soyuz Test Project (ASTP), Space Shuttle, ISS and the Shuttle/Mir Program. Mr. Johnson is also intimately familiar with the JSC Design and Procedures Standard, JPR 8080.5, having been one of its original developers. The observations and findings are presented first by country and organized within each country section by program in chronological order of emergence. A host of reference sources used to augment the personal observations and comments of the author are named within the text and/or listed in the reference section of this document. Careful attention to the selection and inclusion of photos, drawings and diagrams is used to give visual association and clarity to the topic areas examined.

  6. Effects of cyclic temperature on larvae of marine invertebrates. Progress report, January 15, 1981-January 14, 1982

    SciTech Connect

    Costlow, J.D.

    1981-09-16

    The effects of constant and cyclic temperatures on the larval development of several crustaceans, molluscs and polychaetes have been studied. Survival, duration of development and the appearance of morphological abnormalities were investigated. The experimental temperatures were: constant temperatures at 15, 20, 25, 30 and 35/sup 0/C; cyclic temperatures of equal periodicity (COEP) at 15-20, 22-27, at 25-30 and 30-35/sup 0/C; and five cycles of unequal periodicity (COUP) at 15-20 and 30-35/sup 0/C. Experimental salinities ranged from 5 to 40/sup 0///sub 00/ depending on the species used. Growth studies indicated that growth is precisely regulated in crustacean larvae and that cyclic temperatures act as a perturbation on growth regulation. Newly hatched larvae were exposed to either a cyclic temperature, a constant temperature, or some combination of the two. In larvae exposed to cyclic temperatures, cumulative growth was significantly inhibited. Also, the specific growth rate (anti R) of larvae in the cyclic temperature regime was found to oscillate with decreasing amplitude around the anti R of the larvae exposed to constant temperatures. This oscillatory pattern has been observed in a wide variety of self-regulating systems. Evidence is presented to demonstrate that this regulatory mechanism also adapts to long-term exposure to cyclic temperatures. These findings increase our understanding of how larvae cope with and adapt to changing environmental temperatures. More significantly, the mechanism could provide a sensitive tool for estimating the effects of specific environmental disturbances on fitness. Progress is being made in understanding the biochemical processes underlying this growth regulating mechanism.

  7. Newly Diagnosed?

    MedlinePlus

    ... Suggestions Examine Your Skin Newly Diagnosed? Understanding Your Pathology Biopsy: The First Step Sentinel Node Biopsy Melanoma ... start this journey: Get a copy of your pathology report. We can help you understand the report ...

  8. Spawning Behavior, Egg Development, Larvae and Juvenile Morphology of Hyphessobrycon eques (Pisces: Characidae) Characidae Fishes

    PubMed Central

    Park, Jae-Min; Kim, Na-Ri; Han, Kyeong-Ho; Han, Ji-Hyeong; Son, Maeng-Hyun; Cho, Jae-Kwon

    2014-01-01

    Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2–3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at 28°C. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of 0.92 ± 0.01 mm. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged 2.90 ± 0.16 mm in total length (LT). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were 12.5 ± 1.60 mm LT and had reached the juvenile stage. PMID:25949194

  9. Spawning Behavior, Egg Development, Larvae and Juvenile Morphology of Hyphessobrycon eques (Pisces: Characidae) Characidae Fishes.

    PubMed

    Park, Jae-Min; Kim, Na-Ri; Han, Kyeong-Ho; Han, Ji-Hyeong; Son, Maeng-Hyun; Cho, Jae-Kwon

    2014-12-01

    Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2-3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at 28°C. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of 0.92 ± 0.01 mm. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged 2.90 ± 0.16 mm in total length (LT ). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were 12.5 ± 1.60 mm LT and had reached the juvenile stage. PMID:25949194

  10. Dietary lufenuron reduces egg hatch and influences protein expression in the fruit fly Bactrocera latifrons (Hendel)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newly emerged virgin adults were fed for 12 days with various concentrations of lufenuron incorporated agar diet until sexual maturation. After maturation, pairing tests were conducted. At 12 days old, eggs were collected and egg production and egg hatch were assessed. The results showed that lufenu...

  11. 29 CFR 1918.35 - Open hatches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Open hatches. 1918.35 Section 1918.35 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Working Surfaces § 1918.35 Open hatches. Open weather...

  12. Shuttle Crew Says Farewell, Closes Hatches

    NASA Video Gallery

    At 7:23 a.m. Sunday, hatches were closed between Endeavour and the station 12 days, 22 hours and 27 minutes into the mission. The hatches between the two spacecraft were opened at 7:38 a.m. on May ...

  13. Hatching asynchrony, survival, and the fitness of alternative adult morphs in Ambystoma talpoideum.

    PubMed

    Ryan, Travis J; Plague, Gordon R

    2004-06-01

    The mole salamander, Ambystoma talpoideum, exhibits both aquatic (gilled) and terrestrial (metamorphosed) adult morphologies. Previous studies have shown the existence of body-size advantages associated with the terrestrial morph in A. talpoideum and other polymorphic salamanders (e.g., A. tigrinum). However, aquatic adult A. talpoideum mature at a younger age and often breed earlier than terrestrial adults. We tested the hypothesis that early maturation and reproduction in aquatic adults increase fitness (irrespective of body size). We reared larval A. talpoideum in mesocosms and varied the timing of hatching, with early-hatching larvae representing the offspring from early-breeding aquatic adults, and late-hatching larvae representing the offspring of later-breeding terrestrial adults. Our results demonstrate significantly higher survival rates among early-hatchlings relative to late-hatching conspecifics, supporting the hypothesis that early reproduction may be an important mechanism mediating the polymorphism in A. talpoideum. We discuss our results within the context of size-based models of the fitness of alternative life-cycles. PMID:15127287

  14. The Activity of Carbohydrate-Degrading Enzymes in the Development of Brood and Newly Emerged workers and Drones of the Carniolan Honeybee, Apis mellifera carnica

    PubMed Central

    Żółtowska, Krystyna; Lipiński, Zbigniew; Łopieńska-Biernat, Elżbieta; Farjan, Marek; Dmitryjuk, Małgorzata

    2012-01-01

    The activity of glycogen Phosphorylase and carbohydrate hydrolyzing enzymes α-amylase, glucoamylase, trehalase, and sucrase was studied in the development of the Carniolan honey bee, Apis mellifera carnica Pollman (Hymenoptera: Apidae), from newly hatched larva to freshly emerged imago of worker and drone. Phosphorolytic degradation of glycogen was significantly stronger than hydrolytic degradation in all developmental stages. Developmental profiles of hydrolase activity were similar in both sexes of brood; high activity was found in unsealed larvae, the lowest in prepupae followed by an increase in enzymatic activity. Especially intensive increases in activity occurred in the last stage of pupae and newly emerged imago. Besides α-amylase, the activities of other enzymes were higher in drone than in worker broods. Among drones, activity of glucoamylase was particularly high, ranging from around three times higher in the youngest larvae to 13 times higher in the oldest pupae. This confirms earlier suggestions about higher rates of metabolism in drone broods than in worker broods. PMID:22943407

  15. The influence of water and humidity on the hatching of Nematodirus battus eggs.

    PubMed

    van Dijk, J; Morgan, E R

    2012-09-01

    This paper examines the influence of water on the ecology of the eggs of Nematodirus battus, with a view to estimating the importance of including rainfall in mathematical models of parasite abundance. The literature suggests that, under pasture conditions, the availability of moisture is unlikely to be limiting for egg development, while eggs and infective larvae are highly resistant to desiccation. In the presented experiment, eggs that had been kept in salt sludges at 95% and 70% RH and were subsequently put at 15°C produced only a mildly accelerated, but not a mass, hatch, in the first few days after return to water. Eggs kept at higher osmotic pressures died. Mass hatching of infective larvae, described at pasture when spells of rain follow periods of drought, is unlikely to occur as the result of a sudden water influx into eggs. Since water is not necessary for migration of infective larvae from the soil on to grass, such peaks in larval abundance are more likely to arise from the effects of temperature on hatching of eggs.

  16. The effects of temperature change on the hatching success and larval survival of largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu.

    PubMed

    Landsman, S J; Gingerich, A J; Philipp, D P; Suski, C D

    2011-04-01

    In this study, the effects of abrupt temperature change on the hatching success and larval survival of eggs, yolk-sac larvae (YSL) and larvae above nest (LAN), for both largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieu were quantified. Temperature had a significant effect on hatching success and time to 50% mortality, with large heat shocks causing accelerated mortality. The temperature changes shown to influence survival of all life stages, however, were beyond what is typically experienced in the wild. Micropterus salmoides had greater egg hatching success rates and increased survival rates at YSL and LAN stages, relative to M. dolomieu. Additionally, egg hatching success and survival of LAN varied across nests within the study. These findings suggest that temperature alone may not account for variations in year-class strength and may emphasize the need for protection of the nest-guarding male Micropterus spp. to ensure recruitment.

  17. Safety Considerations in Design of Spacecraft Hatches

    NASA Astrophysics Data System (ADS)

    Ciancone, Michael L.; Johnson, Gary W.

    2010-09-01

    Human spaceflight missions have grown longer and more complex as international spaceflight programs have evolved. This has presented additional safety considerations in the design of hatches for habitable spacecraft. One important decision in the design of spacecraft is whether to use pressure-sealing hatches that open inward(i.e., internal cabin pressure keeps the hatch sealed on orbit) or hatches that open outward(i.e., facilitates crew egress during pre-launch and post-landing events). This paper will explore safety considerations that influence that decision, as well as hazards associated with hatches. Safety considerations include mission duration, mission profile(relatively short sorties to ISS versus extended journeys to the Moon or planets), intended usage(e.g., flight and ground crew ingress/egress during ground phases, flight crew ingress/egress during EVA, or inter-spacecraft access during docked operations), reliability/complexity(usually involving mechanisms and/or pyrotechnics), and off-nominal ground ingress/egress(how many crew members must egress within a specified length of time under what circumstances). In addition, this paper will provide a historical survey of hatch designs for manned spacecraft, including a brief list of incidents involving hatches.

  18. Fatty Acids of Densely Packed Embryos of Carcinus maenas Reveal Homogeneous Maternal Provisioning and No Within-Brood Variation at Hatching.

    PubMed

    Rey, Felisa; Moreira, Ana S P; Ricardo, Fernando; Coimbra, Manuel A; Domingues, M Rosário M; Domingues, Pedro; Rosa, Rui; Queiroga, Henrique; Calado, Ricardo

    2016-04-01

    Embryonic development of decapod crustaceans relies on yolk reserves supplied to offspring through maternal provisioning. Unequal partitioning of nutritional reserves during oogenesis, as well as fluctuating environmental conditions during incubation, can be sources of within-brood variability. Ultimately, this potential variability may promote the occurrence of newly hatched larvae with differing yolk reserves and an unequal ability to endure starvation and/or suboptimal feeding during their early pelagic life. The present study evaluated maternal provisioning by analyzing fatty acid (FA) profiles in newly extruded embryos of Carcinus maenas Also assessed were the dynamics of such provisioning during embryogenesis, such as embryo location within the regions of the brooding chamber (left external, left internal, right external, and right internal). The FA profiles surveyed revealed a uniform transfer of maternal reserves from the female to the entire mass of embryos, and homogeneous embryonic development within the brooding chamber. Although C. maenas produces a densely packed mass of embryos that are unevenly distributed within its brooding chamber, this factor is not a source of within-brood variability during incubation. This finding contrasts with data already recorded for larger-sized brachyuran crabs, and suggests that the maternal behavior of C. maenas promotes homogeneous lipid catabolism during embryogenesis. PMID:27132134

  19. Hatches Open, Expedition 32 Expands to Six

    NASA Video Gallery

    The hatches between the Soyuz and the Rassvet module opened Tuesday at 3:23 a.m. when Flight Engineers Suni Williams, Yuri Malenchenko and Aki Hoshide entered the International Space Station. Exped...

  20. Effects of high pressure processing on hatching of eggs of the zoonotic rat tapeworm Hymenolepis diminuta.

    PubMed

    Merwad, A M A; Mitchell, S M; Zajac, A M; Flick, G J; Lindsay, D S

    2011-03-10

    High hydrostatic pressure processing (HPP) is an effective non-thermal treatment to remove pathogens from a variety of food and food products. It has been extensively examined using prokaryotic organisms but has had limited study on eukaryotic organisms. Treatment using HPP has been shown to be effective in inactivating nematode larvae in food and Ascaris suum eggs. Nothing is known on the efficacy of HPP on tapeworm cysts or eggs. Eggs of important zoonotic tapeworms including Echinococcus and Taenia spp. can potentially contaminate water and food intended for human consumption. The present study examined the efficacy of HPP on the viability of Hymenolepis diminuta eggs. Efficacy of HPP treatment was measured using an egg hatch assay in two experiments. One thousand unhatched H. diminuta eggs in Hanks balanced salt solution were packaged in sealable bags and exposed to 100-600megapascals (MPa; 1MPa=10atm=147psi) for 60s in a commercial HPP unit. Positive (no HPP) and negative (No HPP but frozen/thawed) controls were examined in each experiment. None of the HPP untreated and frozen eggs (negative controls) were able to hatch or exclude trypan blue when placed in the hatching solution in experiment 1 or 2. HPP untreated and nonfrozen eggs (positive controls) hatched and excluded trypan blue; 75% were positive in experiment 1 and 80% were positive in experiment 2. No hatched eggs were observed when they were exposed to 300-600MPa for 60s. Treatment at 400MPa and above caused rupturing of the oncosphere. Results from this study indicate that HPP is a possible method to inactivate tapeworm eggs and that the susceptibility of tapeworm eggs to HPP is similar to or greater than that of nematode eggs or tissue larvae.

  1. 29 CFR 1918.43 - Handling hatch beams and covers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... stable piles not closer to the hatch coaming than three feet (.91 m). Exception: On the working side of... side of the hatch. (2) On seagoing vessels, hatch boards or similar covers removed from the hatch beams... their sides, or stood on an edge close together and lashed. Exception: This paragraph (b) shall...

  2. 9 CFR 147.22 - Hatching egg sanitation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Procedures § 147.22 Hatching egg sanitation. Hatching eggs should be collected from the nests at frequent... collecting the nest eggs for hatching. Egg handlers should thoroughly wash their hands with soap and water... used for hatching purposes and should be collected in a separate container from the nest eggs....

  3. 9 CFR 147.22 - Hatching egg sanitation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Procedures § 147.22 Hatching egg sanitation. Hatching eggs should be collected from the nests at frequent... collecting the nest eggs for hatching. Egg handlers should thoroughly wash their hands with soap and water... used for hatching purposes and should be collected in a separate container from the nest eggs....

  4. 9 CFR 147.22 - Hatching egg sanitation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Procedures § 147.22 Hatching egg sanitation. Hatching eggs should be collected from the nests at frequent... collecting the nest eggs for hatching. Egg handlers should thoroughly wash their hands with soap and water... used for hatching purposes and should be collected in a separate container from the nest eggs....

  5. 9 CFR 147.22 - Hatching egg sanitation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Procedures § 147.22 Hatching egg sanitation. Hatching eggs should be collected from the nests at frequent... collecting the nest eggs for hatching. Egg handlers should thoroughly wash their hands with soap and water... used for hatching purposes and should be collected in a separate container from the nest eggs....

  6. 9 CFR 147.22 - Hatching egg sanitation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Procedures § 147.22 Hatching egg sanitation. Hatching eggs should be collected from the nests at frequent... collecting the nest eggs for hatching. Egg handlers should thoroughly wash their hands with soap and water... used for hatching purposes and should be collected in a separate container from the nest eggs....

  7. 29 CFR 1918.43 - Handling hatch beams and covers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... more of the height of the web; and (2) The flange rests flat on the deck when the hatch beam is stood... hatch beam or pontoon left in place next to an open hatch section being worked shall be locked or... adjacent sections, unless securely lashed. (f)(1) The roller hatch beam at the edge of the open section...

  8. 29 CFR 1918.43 - Handling hatch beams and covers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... more of the height of the web; and (2) The flange rests flat on the deck when the hatch beam is stood... hatch beam or pontoon left in place next to an open hatch section being worked shall be locked or... adjacent sections, unless securely lashed. (f)(1) The roller hatch beam at the edge of the open section...

  9. 29 CFR 1918.43 - Handling hatch beams and covers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... more of the height of the web; and (2) The flange rests flat on the deck when the hatch beam is stood... hatch beam or pontoon left in place next to an open hatch section being worked shall be locked or... adjacent sections, unless securely lashed. (f)(1) The roller hatch beam at the edge of the open section...

  10. 29 CFR 1918.43 - Handling hatch beams and covers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... more of the height of the web; and (2) The flange rests flat on the deck when the hatch beam is stood... hatch beam or pontoon left in place next to an open hatch section being worked shall be locked or... adjacent sections, unless securely lashed. (f)(1) The roller hatch beam at the edge of the open section...

  11. A role for amontillado, the Drosophila homolog of the neuropeptide precursor processing protease PC2, in triggering hatching behavior.

    PubMed

    Siekhaus, D E; Fuller, R S

    1999-08-15

    Accurate proteolytic processing of neuropeptide and peptide hormone precursors by members of the kexin/furin family of proteases is key to determining both the identities and activities of signaling peptides. Here we identify amontillado (amon), the Drosophila melanogaster homolog of the mammalian neuropeptide processing protease PC2, and show that in contrast to vertebrate PC2, amontillado expression undergoes extensive regulation in the nervous system during development. In situ hybridization reveals that expression of amontillado is restricted to the final stages of embryogenesis when it is found in anterior sensory structures and in only 168 cells in the brain and ventral nerve cord. After larvae hatch from their egg shells, the sensory structures and most cells in the CNS turn off or substantially reduce amontillado expression, suggesting that amontillado plays a specific role late in embryogenesis. Larvae lacking the chromosomal region containing amontillado show no gross anatomical defects and respond to touch. However, such larvae show a greatly reduced frequency of a hatching behavior of wild-type Drosophila in which larvae swing their heads, scraping through the eggshell with their mouth hooks. Ubiquitous expression of amontillado can restore near wild-type levels of this behavior, whereas expression of amontillado with an alanine substitution for the catalytic histidine cannot. These results suggest that amontillado expression is regulated as part of a programmed modulation of neural signaling that controls hatching behavior by producing specific neuropeptides in particular neurons at an appropriate developmental time. PMID:10436051

  12. Cosmonaut Gidzenko Near Hatch Between Unity and Destiny

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Cosmonaut Yuri P. Gidzenko, Expedition One Soyuz commander, stands near the hatch leading from the Unity node into the newly-attached Destiny laboratory aboard the International Space Station (ISS). The Node 1, or Unity, serves as a cornecting passageway to Space Station modules. The U.S.-built Unity module was launched aboard the Orbiter Endeavour (STS-88 mission) on December 4, 1998, and connected to Zarya, the Russian-built Functional Cargo Block (FGB). The U.S. Laboratory (Destiny) module is the centerpiece of the ISS, where science experiments will be performed in the near-zero gravity in space. The Destiny Module was launched aboard the Space Shuttle Orbiter Atlantis (STS-98 mission) on February 7, 2001. The aluminum module is 8.5 meters (28 feet) long and 4.3 meters (14 feet) in diameter. The laboratory consists of three cylindrical sections and two endcones with hatches that will be mated to other station components. A 50.9-centimeter- (20-inch-) diameter window is located on one side of the center module segment. This pressurized module is designed to accommodate pressurized payloads. It has a capacity of 24 rack locations, and payload racks will occupy 13 locations especially designed to support experiments.

  13. Dietary lufenuron reduces egg hatch and influences protein expression in the fruit fly Bactrocera latifrons (Hendel).

    PubMed

    Chang, Chiou Ling; Geib, Scott; Cho, Il Kyu; Li, Qing X; Stanley, David

    2014-08-01

    Lufenuron (LFN), a chitin synthase inhibitor, impacts the fertility of Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons. We posed the hypothesis that LFN curtails egg hatch in the solanaceous fruit fly, B. latifrons. In this study, newly emerged virgin adults were sexed and fed for 12 days with varying concentrations of LFN-laced agar diets until sexual maturation. Eggs were collected from 12-d-old adults and the egg hatch was assessed. Egg hatch decreased in adults reared on LFN-treated diets. LFN-treated media did not influence fertility after one gender was reared on experimental and the other on control media before mating. Exposure to LFN-treated medium after mating led to reduced egg hatch. We infer that LFN is not a permanent sterilant, and reduced egg hatch depends on continuous exposure to dietary LFN after mating. Proteomic analysis identified two differentially expressed proteins, a pheromone binding protein and a chitin binding protein, between adults maintained on LFN-treated and control diets. Expression of two genes encoding chitin synthase 2, and chitin binding protein, was altered in adults exposed to dietary LFN. LFN treatments also led to increased expression of two odorant binding proteins one in females and one in males. We surmise these data support our hypothesis and provide insight into LFN actions. PMID:24753137

  14. Killifish Hatching and Orientation experiment MA-161

    NASA Technical Reports Server (NTRS)

    Scheld, H. W.; Boyd, J. F.; Bozarth, G. A.; Conner, J. A.; Eichler, V. B.; Fuller, P. M.; Hoffman, R. B.; Keefe, J. R.; Kuchnow, K. P.; Oppenheimer, J. M.

    1976-01-01

    The killifish Fundulus heteroclitus was used as a model system for study of embryonic development and vestibular adaptation in orbital flight. Juvenile fish in a zero gravity environment exhibited looping swimming activity similar to that observed during the Skylab 3 mission. Hatchings from a 336 hour egg stage were also observed to loop. At splashdown, both juveniles and hatchings exhibited a typical diving response suggesting relatively normal vestibular function. Juveniles exhibited swimming patterns suggestive of abnormal swim bladders. The embryos exhibited no abnormalities resulting from development in a zero gravity environment.

  15. Hatching success in salamanders and chorus frogs at two sites in Colorado, USA: Effects of acidic deposition and climate

    USGS Publications Warehouse

    Muths, E.; Campbell, D.H.; Corn, P.S.

    2003-01-01

    The snowpack in the vicinity of the Mount Zirkel Wilderness Area is among the most acidic in the western United States. We analyzed water chemistry and examined hatching success in tiger salamanders and chorus frogs at ponds there and at nearby Rabbit Ears Pass (Dumont) to determine whether acid deposition affects amphibians or their breeding habitats at these potentially sensitive locations. We found a wide range of acid neutralizing capacity among ponds within sites; the minimum pH recorded during the experiment was 5.4 at one of 12 ponds with all others at pH ??? 5.7. At Dumont, hatching success for chorus frogs was greater in ponds with low acid neutralizing capacity; however, lowest pHs were >5.8. At current levels of acid deposition, weather and pond characteristics are likely more important than acidity in influencing hatching success in amphibian larvae at these sites.

  16. Freshwater influences on embryos, hatching and larval survival of euryhaline Gulf killifish Fundulus grandis and potential constraints on habitat distribution.

    PubMed

    Ramee, S W; Allen, P J

    2016-08-01

    The influence of fresh water on potential habitat occupancy of early life-history stages of euryhaline Gulf killifish Fundulus grandis was determined by evaluating fertilization of freshwater-spawned eggs and subsequent survival of embryos and larvae in comparison with saline water (salinity 7). Overall per cent fertilization of eggs was low (mean ± s.e. = 20·21 ± 0·03%). Embryo survival was greater in saline water, but hatching rate (mean ± s.e. = 81·6 ± 0·1%) and post-hatch survival of larvae in fresh water (mean ± s.e. = 74·5 ± 0·1%) was relatively high. Therefore, the relative limitation of fresh water on habitat distribution of F. grandis changes with development, stimulating further questions on factors that may constrain habitat distribution of euryhaline fishes. PMID:27238386

  17. 9 CFR 91.29 - Hatches.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Hatches. 91.29 Section 91.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  18. 9 CFR 91.29 - Hatches.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Hatches. 91.29 Section 91.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  19. 9 CFR 91.29 - Hatches.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Hatches. 91.29 Section 91.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  20. Mechanical Hatching Egg Sanitization: A Fresh Look

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three to four decades ago, hatching egg sanitization was done by immersion of eggs in an egg-gathering basket (plastic-coated metal wire) into a small vat with a heating element and disinfectant solution. This procedure failed miserably for several reasons. First, the eggs were not subjected to the...

  1. 29 CFR 1918.31 - Hatch coverings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Working Surfaces § 1918.31 Hatch coverings. (a) No cargo... unless the working area available for such employees extends for a distance of 10 feet (3.05 m) or...

  2. 9 CFR 91.29 - Hatches.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Hatches. 91.29 Section 91.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  3. 9 CFR 91.29 - Hatches.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Hatches. 91.29 Section 91.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  4. 1. VIEW OF THE ENTRANCE TO THE HATCH ADIT (FEATURE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF THE ENTRANCE TO THE HATCH ADIT (FEATURE B-28), FACING WEST. (OCTOBER, 1995) - Nevada Lucky Tiger Mill & Mine, Hatch Adit, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  5. 46 CFR 174.220 - Hatches and coamings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.220 Hatches and... securing-devices; and (2) Be attached to the hatch frame or coaming by hinges, captive chains, or...

  6. 46 CFR 174.220 - Hatches and coamings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Offshore Supply Vessels § 174.220 Hatches and... securing-devices; and (2) Be attached to the hatch frame or coaming by hinges, captive chains, or...

  7. Prebreeding survival of Roseate Terns Sterna dougallii varies with sex, hatching order and hatching date

    USGS Publications Warehouse

    Nisbet, Ian C.T.; Monticelli, David; Spendelow, Jeffrey A.; Szczys, Patricia

    2016-01-01

    Unequal sex ratios can reduce the productivity of animal populations and are especially prevalent among endangered species. A cohort of 333 Roseate Tern Sterna dougallii chicks at a site where the adult sex ratio was skewed towards females was sexed at hatching and followed through fledging and return to the breeding area, and subsequently during adulthood. The entire regional metapopulation was sampled for returning birds. Prebreeding survival (from fledging to age 3 years) was lower in males than in females, but only among B-chicks (second in hatching order). Prebreeding survival also declined with hatching date. The proportion of females in this cohort increased from 54.6% at hatching to 56.2% at fledging and to an estimated 58.0% among survivors at age 3 years. This was more than sufficient to explain the degree of skew in the sex ratio of the adult population, but changes in this degree of skew during the study period make it difficult to identify the influence of a single cohort of recruits. Many studies of prebreeding survival in other bird species have identified effects of sex, hatching order or hatching date, but no previous study has tested for effects of all three factors simultaneously.

  8. Effects of Galanthus nivalis agglutinin (GNA) expressed in tomato leaves on larvae of the tomato moth Lacanobia oleracea (Lepidoptera: Noctuidae) and the effect of GNA on the development of the endoparasitoid Meteorus gyrator (Hymenoptera: Braconidae).

    PubMed

    Wakefield, M E; Bell, H A; Fitches, E C; Edwards, J P; Gatehouse, A M R

    2006-02-01

    The effect of ingestion of transgenic tomato leaves expressing the plant lectin Galanthus nivalis agglutinin (GNA) on development of larvae of Lacanobia oleracea (Linnaeus) was studied under laboratory conditions. When L. oleracea larvae were fed on tomato line 14.1H, expressing approximately 2.0% GNA, significant increases in the mean larval weight and in the amount of food consumed were found. This resulted in an overall reduction in the mean development time to the pupal stage of approximately 7 days. A significant increase in the percentage survival to the adult moth was also recorded when newly hatched larvae were reared on transgenic tomato leaves (72%) compared to larvae reared on untransformed leaves (40%). The effects of ingestion of GNA by L. oleracea larvae, via artificial diet or the leaves of transgenic tomato or potato plants, on the subsequent development of its solitary endoparasitoid Meteorus gyrator (Thunberg) was also studied. No significant effects on the life cycle parameters of M. gyrator developing in L. oleracea fed on GNA-containing diets were observed. Experiments with transgenic potato plants indicated that the stadium of the host larvae at parasitism had a greater influence on M. gyrator development than the presence of GNA. Potential GNA-binding glycoproteins were detected in the gut and body tissues of larval M. gyrator. Despite detection in host tissues, GNA could not be detected in adult M. gyrator and therefore it is likely that at the time of pupation M. gyrator are able to void the GNA in the meconial pellet.

  9. Spawning Characteristics and Artificial Hatching of Female Mottled Skate, Beringraja pulchra in the West Coast of Korea

    PubMed Central

    Kang, Hee-Woong; Jo, Yeong-Rok; Kang, Duk-Yong; Jeong, Gyeong-Suk; Jo, Hyun-Su

    2013-01-01

    The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 ㎝ in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at 8°C, 13°C, 18°C, water temperature (12.8 to 24.2°C), and the best hatching temperature was 18°C. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate. PMID:25949140

  10. Consequences of Hatch Phenology on Stages of Fish Recruitment

    PubMed Central

    Bogner, David M.; Wuellner, Melissa R.

    2016-01-01

    Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching) could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus) annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A.) Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch influenced recruitment dynamics for both species but important hatching metrics were not similar between species across life stages. A longer hatch duration resulted in greater larval yellow perch abundance but greater age-1 bluegill abundance. In contrast, bluegill larval and age-0 abundances were greater during years when hatching duration was shorter and commenced earlier, whereas age-0 yellow perch abundance was greater when hatching occurred earlier. As a result of hatch phenology, yellow perch recruitment variability was minimized sooner (age-0 life stage) than bluegill (age-1 life stage). Collectively, hatch phenology influenced recruitment dynamics across multiple life stages but was unique for each species. Understanding the complexities of when progeny enter an environment and how this influences eventual recruitment into a population will be critical in the face of ongoing climate change. PMID:27764216

  11. Section BB Hatch Coating; Framing Plan on Line C Lodging ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Section B-B Hatch Coating; Framing Plan on Line C Lodging Knees at Hatch; Elevation A-A Hull Framing; Section at Hatch Frame 36, Starboard Looking Aft; Midship Section Frame 37, Port Looking Aft - Steam Schooner WAPAMA, Kaiser Shipyard No. 3 (Shoal Point), Richmond, Contra Costa County, CA

  12. Hatching asynchrony in Burrowing Owls is influenced by clutch size and hatching success but not by food.

    PubMed

    Wellicome, Troy I

    2005-01-01

    In most animals, siblings from a given reproductive event emerge over a very short period of time. In contrast, many species of birds hatch their young asynchronously over a period of days or weeks, handicapping last-hatched chicks with an age and size disadvantage. Numerous studies have examined the adaptive significance of this atypical hatching pattern, but few have attempted to explain the considerable intrapopulation variation that exists in hatching asynchrony. I explored proximate determinants of hatching asynchrony by monitoring 112 Burrowing Owl (Athene cunicularia) nests in the grasslands of southern Saskatchewan, Canada, over 4 years. Age disparities between first- and last-hatched siblings (i.e., hatching spans) varied considerably, ranging between 1 and 7 days (mode = 4 days). These hatching spans increased with increased hatching success. Hatching spans also increased with larger clutches, but the increase was less than predicted given the increased time required to lay more eggs. Hatching span was unrelated to number of prey cached in the nest during egg laying (an index of food availability), and was unaltered by a year of super-abundant prey. Furthermore, pairs given extra food during laying had hatching spans equal to those of unsupplemented control pairs. These results were inconsistent with both the energy constraint and facultative manipulation hypotheses, which predict that hatching asynchrony should vary with the level of food during laying, when incubation onset is determined. Burrowing Owls were apparently free of food limitation early in breeding, yet may not have been able to optimize hatching spans because food conditions during laying were largely unrelated to food conditions during brooding. Thus, one of the premises for facultative manipulation of hatching asynchrony-that laying females are able to forecast post-hatch food conditions-may not have been met for this population of Burrowing Owls. PMID:15480800

  13. Hatching asynchrony in Burrowing Owls is influenced by clutch size and hatching success but not by food.

    PubMed

    Wellicome, Troy I

    2005-01-01

    In most animals, siblings from a given reproductive event emerge over a very short period of time. In contrast, many species of birds hatch their young asynchronously over a period of days or weeks, handicapping last-hatched chicks with an age and size disadvantage. Numerous studies have examined the adaptive significance of this atypical hatching pattern, but few have attempted to explain the considerable intrapopulation variation that exists in hatching asynchrony. I explored proximate determinants of hatching asynchrony by monitoring 112 Burrowing Owl (Athene cunicularia) nests in the grasslands of southern Saskatchewan, Canada, over 4 years. Age disparities between first- and last-hatched siblings (i.e., hatching spans) varied considerably, ranging between 1 and 7 days (mode = 4 days). These hatching spans increased with increased hatching success. Hatching spans also increased with larger clutches, but the increase was less than predicted given the increased time required to lay more eggs. Hatching span was unrelated to number of prey cached in the nest during egg laying (an index of food availability), and was unaltered by a year of super-abundant prey. Furthermore, pairs given extra food during laying had hatching spans equal to those of unsupplemented control pairs. These results were inconsistent with both the energy constraint and facultative manipulation hypotheses, which predict that hatching asynchrony should vary with the level of food during laying, when incubation onset is determined. Burrowing Owls were apparently free of food limitation early in breeding, yet may not have been able to optimize hatching spans because food conditions during laying were largely unrelated to food conditions during brooding. Thus, one of the premises for facultative manipulation of hatching asynchrony-that laying females are able to forecast post-hatch food conditions-may not have been met for this population of Burrowing Owls.

  14. STS-96 Astronauts Adjust Unity Hatch

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Aboard the International Space Station (ISS), astronauts Rick D. Husband and Tamara E. Jernigan adjust the hatch for the U.S. built Unity node. The task was part of an overall effort of seven crew members to prepare the existing portion of the International Space Station (ISS). Launched on May 27, 1999, aboard the Orbiter Discovery, the STS-96 mission was the second ISS assembly flight and the first shuttle mission to dock with the station.

  15. Armstrong and Scott with Hatches Open

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts Neil A. Armstrong and David R. Scott sit with their spacecraft hatches open while awaiting the arrival of the recovery ship, the USS Leonard F. Mason after the successful completion of their Gemini VIII mission. They are assisted by U.S. Navy divers. The overhead view shows the Gemini 8 spacecraft with the yellow flotation collar attached to stabilize the spacecraft in choppy seas. The green marker dye is highly visible from the air and is used as a locating aid.

  16. CONSUMPTIONS RATES OF SUMMER FLOUNDER LARVAE ON ROTIFER AND BRINE SHRIMP PREY DURING LARVAL REARING

    EPA Science Inventory

    Larval summer flounder Paralichthys dentatus were hatched and reared through metamorphosis in the laboratory. At several points in the rearing cycle, larvae were removed from their rearing chambers and placed in small bowls, where they were fed known quantities of the rotifer Bra...

  17. First observations of fertilized eggs and preleptocephalus larvae of Rhinomuraena quaesita in the Vienna Zoo.

    PubMed

    Preininger, D; Halbauer, R; Bartsch, V; Weissenbacher, A

    2015-01-01

    For the first time worldwide, fertilized eggs of ribbon eels (Rhinomuraena quaesita) hatched into feeding preleptocephali and could be kept alive for a period of seven days in the Vienna Zoo. The study reports on husbandry, behavioral observations and dimensions of eggs and preleptocephalus larvae. Furthermore, body color variations of ribbon eels in captivity do not reflect its sex or sexual maturity.

  18. Redd dewatering effects on hatching and larval survival of the robust redhorse

    USGS Publications Warehouse

    Fisk, J. M.; Kwak, Thomas J.; Heise, R. J.; Sessions, F. W.

    2013-01-01

    Riverine habitats have been altered and fragmented from hydroelectric dams and change spatially and temporally with hydropower flow releases. Hydropeaking flow regimes for electrical power production inundate areas that create temporary suitable habitat for fish that may be rapidly drained. Robust redhorse Moxostoma robustum, an imperiled, rare fish species, uses such temporary habitats to spawn, but when power generation ceases, these areas are dewatered until the next pulse of water is released. We experimentally simulated the effects of dewatering periods on the survival of robust redhorse eggs and larvae in the laboratory. Robust redhorse eggs were placed in gravel in eyeing-hatching jars (three jars per treatment) and subjected to one of four dewatering periods (6, 12, 24 and 48 h), followed by 12 h of inundation for each treatment, and a control treatment was never dewatered. Egg desiccation was observed in some eggs in the 24- and 48-h treatments after one dewatering period. For all treatments except the control, the subsequent dewatering period after eggs hatched was lethal. Larval emergence for the control treatment was observed on day 5 post-hatching and continued until the end of the experiment (day 21). Larval survival was significantly different between the control and all dewatering treatments for individuals in the gravel. These findings support the need for hydropower facilities to set minimum flows to maintain inundation of spawning areas for robust redhorse and other species to reduce dewatering mortality.

  19. Impact of Daily Thermocycles on Hatching Rhythms, Larval Performance and Sex Differentiation of Zebrafish

    PubMed Central

    Villamizar, Natalia; Ribas, Laia; Piferrer, Francesc; Vera, Luisa M.; Sánchez-Vázquez, Francisco Javier

    2012-01-01

    In the wild, water temperature cycles daily: it warms up after sunrise, and cools rapidly after sunset. Surprisingly, the impact of such daily thermocycles during the early development of fish remains neglected. We investigated the influence of constant vs daily thermocycles in zebrafish, from embryo development to sexual differentiation, by applying four temperature regimens: two constant (24°C and 28°C) and two daily thermocycles: 28:24°C, TC (thermophase coinciding with daytime, and cryophase coinciding with night-time) and 24:28°C, CT (opposite to TC) in a 12:12 h light:dark cycle (LD). Embryo development was temperature-dependent but enhanced at 28°C and TC. Hatching rhythms were diurnal (around 4 h after lights on), but temperature- and cycle-sensitive, since hatching occurred sooner at 28°C (48 hours post fertilization; hpf) while it was delayed at 24°C (96 hpf). Under TC, hatching occurred at 72 hpf, while under CT hatching displayed two peaks (at 70 hpf and 94 hpf). In constant light (LL) or darkness (DD), hatching rhythms persisted with tau close to 24 h, suggesting a clock-controlled “gating” mechanism. Under 28°C or TC, larvae showed the best performance (high growth and survival, and low malformations). The sex ratio was strongly influenced by temperature, as the proportion of females was higher in CT and TC (79 and 83% respectively), contrasting with 28°C and 24°C, which led to more males (83 and 76%). Ovarian aromatase (cyp19a) expression in females was highest in TC and CT (6.5 and 4.6 fold higher than at 28°C, respectively); while anti-müllerian hormone (amh) expression in males increased in testis at 24°C (3.6 fold higher compared to TC) and particularly at 28°C (14.3 fold increase). Taken together, these findings highlight the key role of environmental cycles during early development, which shaped the daily rhythms in fish embryo and larvae, and ultimately influenced sex differentiation. PMID:23284912

  20. Hepoxilins and trioxilins in barnacles: an analysis of their potential roles in egg hatching and larval settlement.

    PubMed

    Vogan, Claire L; Maskrey, Ben H; Taylor, Graham W; Henry, Sheelagh; Pace-Asciak, Cecil R; Clare, Anthony S; Rowley, Andrew F

    2003-09-01

    The barnacle life cycle has two key stages at which eicosanoids are believed to be involved in cellular communication pathways, namely the hatching of nauplii and the settlement of cypris larvae. Barnacle egg-hatching activity has previously been reported to reside in a variety of eicosanoids, including 8-hydroxyeicosapentaenoic acid and a number of tri-hydroxylated polyunsaturated fatty acid derivatives, the trioxilins. The production of the eicosapentaenoic acid metabolite trioxilin A4 (8,11,12-trihydroxy-5,9,14,17-eicosatetraenoic acid) by the barnacles Balanus amphitrite and Elminius modestus was confirmed using a combination of high-performance liquid chromatography and gas chromatography, both linked to mass spectrometry. In addition, both species also generated trioxilin A3 (8,11,12-trihydroxy-5,9,14-eicosatrienoic acid; an arachidonic acid-derived product), 8,11,12-trihydroxy-9,14,17-eicosatrienoic acid (a omega3 analogue of trioxilin A3; derived from omega3 arachidonic acid) and 10,13,14-trihydroxy-4,7,11,16,19-docosapentaenoic acid (a docosahexaenoic acid-derived product). In contrast to earlier reports, trioxilin A3 had no E. modestus egg-hatching activity at any of the concentrations tested (10(-9)-10(-6) mol l(-1)). The unstable epoxide precursor hepoxilin A3, however, caused significant levels of hatching at 10(-6) mol l(-1). Furthermore, the stable hepoxilin B3 analogue PBT-3 stimulated hatching at 10(-7) mol l(-1). Neither trioxilin A3, hepoxilin A3 or PBT-3 at 0.25-30 micromol l(-1) served as settlement cues for B. amphitrite cypris larvae.

  1. Ixodes pacificus ticks maintain embryogenesis and egg hatching after antibiotic treatment of Rickettsia endosymbiont.

    PubMed

    Kurlovs, Andre H; Li, Jinze; Cheng, Du; Zhong, Jianmin

    2014-01-01

    Rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. Although Rickettsia appears to be common in ticks, most Rickettsia-tick relationships remain generally uncharacterized. The most intimate of these associations is Rickettsia species phylotype G021, a maternally and transstadially transmitted endosymbiont that resides in 100% of I. pacificus in California. We investigated the effects of this Rickettsia phylotype on I. pacificus reproductive fitness using selective antibiotic treatment. Ciprofloxacin was 10-fold more effective than tetracycline in eliminating Rickettsia from I. pacificus, and quantitative PCR results showed that eggs from the ciprofloxacin-treated ticks contained an average of 0.02 Rickettsia per egg cell as opposed to the average of 0.2 in the tetracycline-treated ticks. Ampicillin did not significantly affect the number of Rickettsia per tick cell in adults or eggs compared to the water-injected control ticks. We found no relationship between tick embryogenesis and rickettsial density in engorged I. pacificus females. Tetracycline treatment significantly delayed oviposition of I. pacificus ticks, but the antibiotic's effect was unlikely related to Rickettsia. We also demonstrated that Rickettsia-free eggs could successfully develop into larvae without any significant decrease in hatching compared to eggs containing Rickettsia. No significant differences in the incubation period, egg hatching rate, and the number of larvae were found between any of the antibiotic-treated groups and the water-injected tick control. We concluded that Rickettsia species phylotype G021 does not have an apparent effect on embryogenesis, oviposition, and egg hatching of I. pacificus.

  2. Effects of water hardness on size and hatching success of silver carp eggs

    USGS Publications Warehouse

    Rach, Jeff J.; Sass, Greg G.; Luoma, James A.; Gaikowski, Mark P.

    2010-01-01

    Eggs of silver carp Hypophthalmichthys molitrix absorb water after release from the female, causing them to become turgid and to increase substantially in size. The volume of water that diffuses within an egg is most likely determined by (1) the difference in ionic concentration between the egg and the water that surrounds it and (2) the elasticity of the egg membrane. Prior observations suggest that silver carp eggs may swell and burst in soft waters. If water hardness affects silver carp reproductive success in nonnative ecosystems, this abiotic factor could limit silver carp distribution or abundance. In this study, we tested the effect of water hardness on silver carp egg enlargement and hatching success. Groups of newly fertilized silver carp eggs were placed in water at one of five nominal water hardness levels (50, 100, 150, 200, or 250 mg/L as CaCO3) for 1 h to harden (absorb water after fertilization). Egg groups were then placed in separate incubation vessels housed in two recirculation systems that were supplied with either soft (50 mg/L as CaCO3) or hard (250 mg/L as CaCO3) water to evaluate hatching success. Tests were terminated within 24 h after viable eggs had hatched. Eggs that were initially placed in 50-mg/L water to harden were larger (i.e., swelled more) and had a greater probability of hatch than eggs hardened in other water hardness levels. Unlike the effect of water hardness during egg hardening, the water hardness during incubation appeared to have no effect on egg hatching success. Our research suggests that water hardness may not be a limiting factor in the reproduction, recruitment, and range expansion of silver carp in North America.

  3. Continuous measurements of instantaneous heart rate and its fluctuations before and after hatching in chickens.

    PubMed

    Moriya, K; Pearson, J T; Burggren, W W; Ar, A; Tazawa, H

    2000-03-01

    There has been considerable interest in heart rate (fh) fluctuations in relation to cardiovascular control systems and foetal conditions during pregnancy in mammals. Prominent fluctuations in fh also occur in avian embryos, which are an important experimental model for studying developmental physiology. The present study determined the instantaneous fh of seven chick embryos continuously from the last stage of prenatal development (day 18), throughout the pipping (perinatal) period (days 19-21) until hatching and, subsequently, of newly hatched chicks (up to day 2). The distinctive patterns of instantaneous fh fluctuations took the form of specific changes within a broad mean fh baseline. Cyclic oscillations (ultradian rhythm) occurred until an early stage of the perinatal period, when the fh baseline started rising. Subsequently, the baseline dropped and respiratory arrhythmia began to appear concomitant with external pipping. During the final stage of external pipping, when the fh baseline rose again prior to hatching, three unique patterns of instantaneous fh fluctuations were evident: relatively long-lasting cyclic small accelerations, irregular intermittent large accelerations and short-term repeated large accelerations. Furthermore, repeated alternate occurrences of the latter two types of acceleration formed an additional oscillating pattern with a period of 10-15 min. During the early period after hatching, when the fh baseline reached its maximum, instantaneous fh changed relatively slowly accompanied by transient rapid decelerations, probably due to augmented vagal tone. Subsequently, the mean fh baseline dropped to its minimum, and a circadian rhythm and three types of previously reported fh fluctuations (types I-III) appeared. Developmental patterns of mean fh and the appearance of distinctive patterns of instantaneous fluctuations in fh and circadian rhythms were not influenced by an ultimate failure of hatching after a normal development. The

  4. Larvae and Nests of Six Aculeate Hymenoptera (Hymenoptera: Aculeata) Nesting in Reed Galls Induced by Lipara spp. (Diptera: Chloropidae) with a Review of Species Recorded

    PubMed Central

    Bogusch, Petr; Astapenková, Alena; Heneberg, Petr

    2015-01-01

    Wetland species of aculeate Hymenoptera are poorly known, even though many of them may serve as diagnostic or flagship species in nature conservation. Here we examined 6,018 galls induced ≥1 year prior their collection by the chloropid flies Lipara spp. The galls were collected at 34 sites in Central Europe. We examined 1,389 nests (4,513 individuals) of nine species, part of which were parasitized by one dipteran and two chrysidid parasitoid species. We describe the nests of seven dominant species and larvae of four species (Pemphredon fabricii, Trypoxylon deceptorium, Hoplitis leucomelana and Hylaeus pectoralis) and two parasitoids (Trichrysis cyanea and Thyridanthrax fenestratus, both in nests of Pemphredon fabricii and Trypoxylon deceptorium). All the species, but H. pectoralis, preferred robust galls at very thin stalks (induced typically by Lipara lucens) over the narrow galls on thick stalks. The larvae of P. fabricii and T. deceptorium resembled strongly their sibling species (Pemphredon lethifer and Trypoxylon attenuatum sensu lato, respectively). The larvae of T. fenestratus showed features different from those previously described. By hatching set of another 10,583 galls induced by Lipara spp. ≥1 year prior their collection, we obtained 4,469 individuals of 14 nesting hymenopteran species, two cleptoparasites, three chrysidid and one dipteran parasitoid. Of these species, four new nesting species have been recorded for the first time in galls induced by Lipara spp.: Chelostoma campanularum, Heriades rubicola, Pseudoanthidium lituratum and Hylaeus incongruus. We also provide first records of their nest cleptoparasites Stelis breviuscula and Stelis ornatula, and the parasitoid Holopyga fastuosa generosa. Thyridanthrax fenestratus formed strong populations in nests of Pemphredon fabricii and Trypoxylon deceptorium, which are both newly recorded hosts for T. fenestratus. The descriptions provided here allow for the first time to identify the larvae of

  5. Larvae and Nests of Six Aculeate Hymenoptera (Hymenoptera: Aculeata) Nesting in Reed Galls Induced by Lipara spp. (Diptera: Chloropidae) with a Review of Species Recorded.

    PubMed

    Bogusch, Petr; Astapenková, Alena; Heneberg, Petr

    2015-01-01

    Wetland species of aculeate Hymenoptera are poorly known, even though many of them may serve as diagnostic or flagship species in nature conservation. Here we examined 6,018 galls induced ≥1 year prior their collection by the chloropid flies Lipara spp. The galls were collected at 34 sites in Central Europe. We examined 1,389 nests (4,513 individuals) of nine species, part of which were parasitized by one dipteran and two chrysidid parasitoid species. We describe the nests of seven dominant species and larvae of four species (Pemphredon fabricii, Trypoxylon deceptorium, Hoplitis leucomelana and Hylaeus pectoralis) and two parasitoids (Trichrysis cyanea and Thyridanthrax fenestratus, both in nests of Pemphredon fabricii and Trypoxylon deceptorium). All the species, but H. pectoralis, preferred robust galls at very thin stalks (induced typically by Lipara lucens) over the narrow galls on thick stalks. The larvae of P. fabricii and T. deceptorium resembled strongly their sibling species (Pemphredon lethifer and Trypoxylon attenuatum sensu lato, respectively). The larvae of T. fenestratus showed features different from those previously described. By hatching set of another 10,583 galls induced by Lipara spp. ≥1 year prior their collection, we obtained 4,469 individuals of 14 nesting hymenopteran species, two cleptoparasites, three chrysidid and one dipteran parasitoid. Of these species, four new nesting species have been recorded for the first time in galls induced by Lipara spp.: Chelostoma campanularum, Heriades rubicola, Pseudoanthidium lituratum and Hylaeus incongruus. We also provide first records of their nest cleptoparasites Stelis breviuscula and Stelis ornatula, and the parasitoid Holopyga fastuosa generosa. Thyridanthrax fenestratus formed strong populations in nests of Pemphredon fabricii and Trypoxylon deceptorium, which are both newly recorded hosts for T. fenestratus. The descriptions provided here allow for the first time to identify the larvae of

  6. Neural circuits for peristaltic wave propagation in crawling Drosophila larvae: analysis and modeling

    PubMed Central

    Gjorgjieva, Julijana; Berni, Jimena; Evers, Jan Felix; Eglen, Stephen J.

    2013-01-01

    Drosophila larvae crawl by peristaltic waves of muscle contractions, which propagate along the animal body and involve the simultaneous contraction of the left and right side of each segment. Coordinated propagation of contraction does not require sensory input, suggesting that movement is generated by a central pattern generator (CPG). We characterized crawling behavior of newly hatched Drosophila larvae by quantifying timing and duration of segmental boundary contractions. We developed a CPG network model that recapitulates these patterns based on segmentally repeated units of excitatory and inhibitory (EI) neuronal populations coupled with immediate neighboring segments. A single network with symmetric coupling between neighboring segments succeeded in generating both forward and backward propagation of activity. The CPG network was robust to changes in amplitude and variability of connectivity strength. Introducing sensory feedback via “stretch-sensitive” neurons improved wave propagation properties such as speed of propagation and segmental contraction duration as observed experimentally. Sensory feedback also restored propagating activity patterns when an inappropriately tuned CPG network failed to generate waves. Finally, in a two-sided CPG model we demonstrated that two types of connectivity could synchronize the activity of two independent networks: connections from excitatory neurons on one side to excitatory contralateral neurons (E to E), and connections from inhibitory neurons on one side to excitatory contralateral neurons (I to E). To our knowledge, such I to E connectivity has not yet been found in any experimental system; however, it provides the most robust mechanism to synchronize activity between contralateral CPGs in our model. Our model provides a general framework for studying the conditions under which a single locally coupled network generates bilaterally synchronized and longitudinally propagating waves in either direction. PMID

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

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

    PubMed

    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.

  9. Antimicrobial susceptibility patterns of competitive exclusion bacteria applied to newly hatched chickens.

    PubMed

    Wagner, R Doug; Cerniglia, Carl E

    2005-07-25

    Competitive exclusion (CE) products are mixtures of obligate and facultative anaerobic bacteria applied to poultry hatchlings for prevention of Salmonella colonization. These mixtures have the potential to introduce bacteria with undesirable antimicrobial drug resistance traits into the human food supply. Antimicrobial drug susceptibilities of 27 obligate and facultative anaerobes isolated from a commercial CE product were evaluated with a microdilution minimal inhibitory concentration (MIC) assay. Bacteroides distasonis and Bacteroides fragilis isolates were resistant to tetracycline and other antimicrobial drugs. An Escherichia coli isolate was resistant to four antimicrobial drugs: erythromycin, penicillin, vancomycin, and tylosin. Erythromycin-resistant enterococci and vancomycin-resistant Lactococcus lactis isolates in the CE product were detected. These findings suggest that more work needs to be done to assess the potential effects of CE product use in poultry on the food supply. PMID:16014302

  10. Ratio abstraction over discrete magnitudes by newly hatched domestic chicks (Gallus gallus)

    PubMed Central

    Rugani, Rosa; McCrink, Koleen; de Hevia, Maria-Dolores; Vallortigara, Giorgio; Regolin, Lucia

    2016-01-01

    A large body of literature shows that non-human animals master a variety of numerical tasks, but studies involving proportional discrimination are sparse and primarily done with mature animals. Here we trained 4-day-old domestic chicks (Gallus gallus) to respond to stimuli depicting multiple examples of the proportion 4:1 when compared with the proportion 2:1. Stimuli were composed of green and red dot arrays; for the rewarded 4:1 proportion, 4 green dots for every red dot (e.g. ratios: 32:8, 12:3, and 44:11). The birds continued to discriminate when presented with new ratios at test (such as 20:5), characterized by new numbers of dots and new spatial configurations (Experiment 1). This indicates that chicks can extract the common proportional value shared by different ratios and apply it to new ones. In Experiment 2, chicks identified a specific proportion (2:1) from either a smaller (4:1) or a larger one (1:1), demonstrating an ability to represent the specific, and not relative, value of a particular proportion. Again, at test, chicks selectively responded to the previously reinforced proportion from new ratios. These findings provide strong evidence for very young animals’ ability to extract, identify, and productively use proportion information across a range of different amounts. PMID:27465742

  11. Technology transfer opportunities : new development : new protocol verifies sterility of newly hatched fish

    USGS Publications Warehouse

    Jenkins, J.A.

    1996-01-01

    U.S. Geological Survey's Biological Resources Disicipline scientists have developed a procedure that could save commercial producers of triploid grass carp between $2000 and $3000 per pond. Since 1983, triploid grass carp have been commercially available for managing aquatic weeds that can cause water quality problems, replace native plants, or impede recreational and commercial use of fisheries and waterways. The carp eat the nuisance vegetation, but because the fish do not reproduce, they do not disturb habitat.

  12. Ratio abstraction over discrete magnitudes by newly hatched domestic chicks (Gallus gallus).

    PubMed

    Rugani, Rosa; McCrink, Koleen; de Hevia, Maria-Dolores; Vallortigara, Giorgio; Regolin, Lucia

    2016-01-01

    A large body of literature shows that non-human animals master a variety of numerical tasks, but studies involving proportional discrimination are sparse and primarily done with mature animals. Here we trained 4-day-old domestic chicks (Gallus gallus) to respond to stimuli depicting multiple examples of the proportion 4:1 when compared with the proportion 2:1. Stimuli were composed of green and red dot arrays; for the rewarded 4:1 proportion, 4 green dots for every red dot (e.g. ratios: 32:8, 12:3, and 44:11). The birds continued to discriminate when presented with new ratios at test (such as 20:5), characterized by new numbers of dots and new spatial configurations (Experiment 1). This indicates that chicks can extract the common proportional value shared by different ratios and apply it to new ones. In Experiment 2, chicks identified a specific proportion (2:1) from either a smaller (4:1) or a larger one (1:1), demonstrating an ability to represent the specific, and not relative, value of a particular proportion. Again, at test, chicks selectively responded to the previously reinforced proportion from new ratios. These findings provide strong evidence for very young animals' ability to extract, identify, and productively use proportion information across a range of different amounts. PMID:27465742

  13. From facultative to obligatory parental care: Interspecific variation in offspring dependency on post-hatching care in burying beetles

    PubMed Central

    Capodeanu-Nägler, Alexandra; Keppner, Eva M.; Vogel, Heiko; Ayasse, Manfred; Eggert, Anne-Katrin; Sakaluk, Scott K.; Steiger, Sandra

    2016-01-01

    Studies on the evolution of parental care have focused primarily on the costs and benefits of parental care and the life-history attributes that favour it. However, once care evolves, offspring in some taxa appear to become increasingly dependent on their parents. Although offspring dependency is a central theme in family life, the evolutionary dynamics leading to it are not fully understood. Beetles of the genus Nicrophorus are well known for their elaborate biparental care, including provisioning of their young. By manipulating the occurrence of pre- or post-hatching care, we show that the offspring of three burying beetle species, N. orbicollis, N. pustulatus, and N. vespilloides, show striking variation in their reliance on parental care. Our results demonstrate that this variation within one genus arises through a differential dependency of larvae on parental feeding, but not on pre-hatching care. In N. pustulatus, larvae appear to be nutritionally independent of their parents, but in N. orbicollis, larvae do not survive in the absence of parental feeding. We consider evolutionary scenarios by which nutritional dependency may have evolved, highlighting the role of brood size regulation via infanticide in this genus. PMID:27378180

  14. From facultative to obligatory parental care: Interspecific variation in offspring dependency on post-hatching care in burying beetles.

    PubMed

    Capodeanu-Nägler, Alexandra; Keppner, Eva M; Vogel, Heiko; Ayasse, Manfred; Eggert, Anne-Katrin; Sakaluk, Scott K; Steiger, Sandra

    2016-01-01

    Studies on the evolution of parental care have focused primarily on the costs and benefits of parental care and the life-history attributes that favour it. However, once care evolves, offspring in some taxa appear to become increasingly dependent on their parents. Although offspring dependency is a central theme in family life, the evolutionary dynamics leading to it are not fully understood. Beetles of the genus Nicrophorus are well known for their elaborate biparental care, including provisioning of their young. By manipulating the occurrence of pre- or post-hatching care, we show that the offspring of three burying beetle species, N. orbicollis, N. pustulatus, and N. vespilloides, show striking variation in their reliance on parental care. Our results demonstrate that this variation within one genus arises through a differential dependency of larvae on parental feeding, but not on pre-hatching care. In N. pustulatus, larvae appear to be nutritionally independent of their parents, but in N. orbicollis, larvae do not survive in the absence of parental feeding. We consider evolutionary scenarios by which nutritional dependency may have evolved, highlighting the role of brood size regulation via infanticide in this genus. PMID:27378180

  15. Ovulation Order Mediates a Trade-Off between Pre-Hatching and Post-Hatching Viability in an Altricial Bird

    PubMed Central

    Sockman, Keith W.

    2008-01-01

    Simultaneously dependent siblings often compete for parentally provided resources. This competition may lead to mortality, the probability of which may be a function, in part, of the individual offspring's production order. In birds, serial ovulation followed by hatching asynchrony of simultaneous dependents leads to differences in post-hatching survival that largely depend on ovulation (laying) order. This has led to the widespread assumption that early-laid eggs are of greater value and therefore should possess different maternally manipulated characteristics than later-laid eggs. However, this perspective ignores the potential effect of laying order on pre-hatching viability, an effect which some studies suggest should offset the effect of laying order on post-hatching viability. I examined the relationship between laying order and hatching and fledging probability in wild, free-living Lincoln's sparrows (Melospiza lincolnii). In broods with complete hatching success, first-laid and therefore first-hatched offspring had the highest probability of fledging, and fledging probability declined with increasing laying order. However, first-laid eggs were less likely than later-laid eggs to hatch. This effect of laying order on pre-hatching viability seemed to offset that on post-hatching viability, and, consistently, maternal investment in egg size varied little if at all with respect to laying order. These results suggest that ovulation order mediates a trade-off between pre-hatching and post-hatching viability and should encourage a re-evaluation of the solitary role post-embryonic survival often plays when researchers make assumptions about the value of propagules based on the order in which they are produced. PMID:18335056

  16. Ontogeny of critical and prolonged swimming performance for the larvae of six Australian freshwater fish species.

    PubMed

    Kopf, S M; Humphries, P; Watts, R J

    2014-06-01

    Critical (<30 min) and prolonged (>60 min) swimming speeds in laboratory chambers were determined for larvae of six species of Australian freshwater fishes: trout cod Maccullochella macquariensis, Murray cod Maccullochella peelii, golden perch Macquaria ambigua, silver perch Bidyanus bidyanus, carp gudgeon Hypseleotris spp. and Murray River rainbowfish Melanotaenia fluviatilis. Developmental stage (preflexion, flexion, postflexion and metalarva) better explained swimming ability than did length, size or age (days after hatch). Critical speed increased with larval development, and metalarvae were the fastest swimmers for all species. Maccullochella macquariensis larvae had the highest critical [maximum absolute 46.4 cm s(-1) and 44.6 relative body lengths (L(B)) s(-1)] and prolonged (maximum 15.4 cm s(-1), 15.6 L(B) s(-1)) swimming speeds and B. bidyanus larvae the lowest critical (minimum 0.1 cm s(-1), 0.3 L(B) s(-1)) and prolonged swimming speeds (minimum 1.1 cm s(-1), 1.0 L(B) s(-1)). Prolonged swimming trials determined that the larvae of some species could not swim for 60 min at any speed, whereas the larvae of the best swimming species, M. macquariensis, could swim for 60 min at 44% of the critical speed. The swimming performance of species with precocial life-history strategies, with well-developed larvae at hatch, was comparatively better and potentially had greater ability to influence their dispersal by actively swimming than species with altricial life-history strategies, with poorly developed larvae at hatch.

  17. Common volatiles are major attractants for neonate larvae of the specialist flea beetle Altica koreana (Coleoptera: Chrysomelidae)

    NASA Astrophysics Data System (ADS)

    Xue, Huai-Jun; Yang, Xing-Ke

    2008-07-01

    Olfactory stimuli play an important role in the host searching of larval phytophagous insects. Previous studies indicate that larvae that have to find feeding sites after hatching are generally attracted to host volatiles. However, there are few studies on the olfactory responses of neonate larvae to host volatiles in cases when those larvae hatched on the host plant. In the present study, we determined the olfactory responses of neonate larvae of the specialist flea beetle, Altica koreana Ogloblin, to host and six non-host plants, using a static-air “arena.” Larvae responded significantly to the host plant Potentilla chinensis Ser. and five of six non-host plants, compared to the control. Larvae did not prefer the host plant over the non-host plants (except Artemisia sp.) when offered a choice. Additionally, odours of a non-host plant, which were unattractive to neonate larvae, may have masked the attractive odour of the host plant. These results indicate that common volatiles can play a major role in attracting larvae of this specialist to plants, but attraction to such odours may not be the major mechanism of host choice.

  18. Effects of pentachlorophenol on Galba pervia, Tubifex sinicus and Chironomus plumousus larvae.

    PubMed

    Song, Z H

    2007-09-01

    The 24-h median lethal concentrations of pentachlorophenol to Chironomus plumousus, Tubifex sinicus and Galba pervia were 0.302, 0.977 and 0.293 mg/L, respectively. Bioconcentration factors of C. plumousus, T. sinicus and G. pervia to pentachlorophenol were 108, 367 and 85 at 0.02 mg/L pentachlorophenol, respectively. As pentachlorophenol concentration increased, the G. pervia egg hatching rates became lower, and the total hatched time became longer. Pentachlorophenol teratogenesis was demonstrated by observing the deformation of C. plumousus larvae mentum. PMID:17713712

  19. 29 CFR 780.211 - Contract production of hatching eggs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Contract production of hatching eggs. 780.211 Section 780... eggs. It is common practice for hatcherymen to enter into arrangements with farmer poultry raisers for the production of hatching eggs which the hatchery agrees to buy. Ordinarily, the farmer furnishes...

  20. 29 CFR 780.211 - Contract production of hatching eggs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Contract production of hatching eggs. 780.211 Section 780... eggs. It is common practice for hatcherymen to enter into arrangements with farmer poultry raisers for the production of hatching eggs which the hatchery agrees to buy. Ordinarily, the farmer furnishes...

  1. 29 CFR 780.211 - Contract production of hatching eggs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Contract production of hatching eggs. 780.211 Section 780... eggs. It is common practice for hatcherymen to enter into arrangements with farmer poultry raisers for the production of hatching eggs which the hatchery agrees to buy. Ordinarily, the farmer furnishes...

  2. 14. VIEW OF NORTHSOUTH ROAD WHICH PARALLELS ROAD TO HATCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW OF NORTH-SOUTH ROAD WHICH PARALLELS ROAD TO HATCH ADIT (FEATURE B-28). NOTE MODERN 'LAY DOWN' FENCE ON ROAD. ROAD LIES TO THE WEST OF THE HATCH ADIT AND PHOTOGRAPH IS VIEW TO THE SOUTH. (OCTOBER, 1995) - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  3. 29 CFR 780.211 - Contract production of hatching eggs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Contract production of hatching eggs. 780.211 Section 780... eggs. It is common practice for hatcherymen to enter into arrangements with farmer poultry raisers for the production of hatching eggs which the hatchery agrees to buy. Ordinarily, the farmer furnishes...

  4. 46 CFR 131.893 - Watertight doors and watertight hatches.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.893 Watertight doors and watertight hatches. Each watertight door in a bulkhead that must be watertight in compliance with the requirements in... 46 Shipping 4 2010-10-01 2010-10-01 false Watertight doors and watertight hatches. 131.893...

  5. 46 CFR 131.893 - Watertight doors and watertight hatches.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.893 Watertight doors and watertight hatches. Each watertight door in a bulkhead that must be watertight in compliance with the requirements in... 46 Shipping 4 2012-10-01 2012-10-01 false Watertight doors and watertight hatches. 131.893...

  6. 46 CFR 131.893 - Watertight doors and watertight hatches.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.893 Watertight doors and watertight hatches. Each watertight door in a bulkhead that must be watertight in compliance with the requirements in... 46 Shipping 4 2013-10-01 2013-10-01 false Watertight doors and watertight hatches. 131.893...

  7. 46 CFR 131.893 - Watertight doors and watertight hatches.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.893 Watertight doors and watertight hatches. Each watertight door in a bulkhead that must be watertight in compliance with the requirements in... 46 Shipping 4 2011-10-01 2011-10-01 false Watertight doors and watertight hatches. 131.893...

  8. 46 CFR 131.893 - Watertight doors and watertight hatches.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.893 Watertight doors and watertight hatches. Each watertight door in a bulkhead that must be watertight in compliance with the requirements in... 46 Shipping 4 2014-10-01 2014-10-01 false Watertight doors and watertight hatches. 131.893...

  9. Effect of storage environment on hatching of Globodera ellingtonae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Globodera spp. eggs go through a diapause stage in which development remains dormant until favorable hatching conditions are reached. Because of the regulatory concerns with Globodera spp., it is often only possible to rear eggs for research in the greenhouse. However, hatch is often lower for green...

  10. Effects of pulsed turbidity and vessel traffic on lake herring eggs and larvae

    USGS Publications Warehouse

    Savino, Jacqueline F.; Blouin, Marc A.; Davis, Bruce M.; Hudson, Patrick L.; Todd, Thomas N.; Fleischer, Guy W.

    1994-01-01

    Proposals to extend commercial shipping in the St. Marys River (connecting Lakes Superior and Huron) to include winter months have raised concerns regarding its effect on lake herring (Coregonus artedi). Because lake herring spawn in fall and their eggs overwinter in the river and hatch in spring, their hatching success could be impacted by early opening of the locks in spring. Our laboratory studies showed that under the range of turbidities expected in the river due to vessel traffic, lake herring eggs hatched and larvae fed adequately. Field incubation studies produced about 75% survival and 70% hatching success of lake herring eggs at two of three study sites. Collections in the river throughout the month following ice-out showed that sufficient plankton of appropriate size were available to ensure growth and survival of larval lake herring. We did not detect any negative impacts on the early life stages of lake herring as a result of sedimentation in the laboratory or field. However, detailing the spawning sites of lake herring and defining the normal survival-to-hatch in these areas are necessary before making accurate predictions of the effects of early season vessel traffic on lake herring hatching success.

  11. Hatch Timing Variations Among Reservoir Gizzard Shad Populations: Implications for Stocked Sander spp. Fingerlings

    USGS Publications Warehouse

    Zweifela, Richard D.; Bunnell, David B.; Bremiganc, Mary T.; Hale, R. Scott

    2009-01-01

    Growth and survival of stocked Sander spp. fingerlings can be influenced by timing of stocking in relation to the peak in density of larval gizzard shad Dorosoma cepedianum. However, coordinating stockings to coincide with peaks in gizzard shad density is difficult due to temporal variation in spawn timing among reservoirs. We used weekly estimates of larval gizzard shad density and length distributions to identify dates of peak hatching and peak total density in Ohio reservoirs and to explore the influence of spring water temperature regimes on timing of peak larval density. Gizzard shad density peaked over 21–32 d among reservoirs but generally varied by 12 d or less among years for any given population. Density peaks were driven by hatching, as larvae smaller than 10 mm accounted for a majority of the gizzard shad collected on the peak date. Peaks in gizzard shad density corresponded to water temperatures of 17–22°C and occurred most frequently when water temperatures had been stable or rising. Reservoirs in the southern portion of the state were 2–5°C warmer than northern reservoirs throughout the spring; thus, gizzard shad spawning and date of peak larval density were earliest in southern reservoirs and became progressively later for populations in more northerly reservoirs. Historical stocking dates for fingerling walleyes S. vitreus and saugeyes (sauger S. canadensis × walleye) in Ohio reservoirs indicated that southern reservoirs were often stocked after the expected peak in gizzard shad density and northern reservoirs were stocked before the peak. A statewide approach to stocking that incorporates latitudinal variations in gizzard shad hatch timing whereby southern reservoirs are stocked earliest would better align stockings with peak gizzard shad density, potentially improving survival of fingerling walleyes and saugeyes.

  12. Egg-hatching synchrony and larval cannibalism in the dock leaf beetle Gastrophysa viridula (Coleoptera: Chrysomelidae).

    PubMed

    Kutcherov, Dmitry

    2015-12-01

    Females of leaf beetles and many other herbivorous insects lay eggs in coherent batches. Hatchlings emerge more or less simultaneously and often prey on their late-hatching clutchmates. It is not certain, however, whether this synchrony of hatching is a mere by-product of cannibalism or whether an additional synchronizing factor exists. The following simple experiment was aimed at determining the causal relationship between cannibalism and simultaneous larval emergence. Egg clutches of the dock leaf beetle Gastrophysa viridula were split into two halves. These halves were either kept as coherent groups in two separate dishes or, alternatively, only one half remained whole, whereas the other one was divided into single eggs, each of which was incubated in a separate dish. Halving of a clutch into coherent groups only slightly disrupted the synchrony of emergence. The consequence of individual isolation was more dramatic. Half-clutches consisting of disconnected solitary eggs required almost twice as much time for complete emergence of all larvae, which was significantly more than cannibalism as a sole synchronizing factor might explain. Moreover, survival rates were the same in coherent half-clutches (in the presence of cannibalism) and among isolated individuals. This group effect and the small contribution of cannibalism suggest the existence of an additional synchronizing factor. Possible mechanisms underpinning this phenomenon are discussed. PMID:26482400

  13. Egg-hatching synchrony and larval cannibalism in the dock leaf beetle Gastrophysa viridula (Coleoptera: Chrysomelidae).

    PubMed

    Kutcherov, Dmitry

    2015-12-01

    Females of leaf beetles and many other herbivorous insects lay eggs in coherent batches. Hatchlings emerge more or less simultaneously and often prey on their late-hatching clutchmates. It is not certain, however, whether this synchrony of hatching is a mere by-product of cannibalism or whether an additional synchronizing factor exists. The following simple experiment was aimed at determining the causal relationship between cannibalism and simultaneous larval emergence. Egg clutches of the dock leaf beetle Gastrophysa viridula were split into two halves. These halves were either kept as coherent groups in two separate dishes or, alternatively, only one half remained whole, whereas the other one was divided into single eggs, each of which was incubated in a separate dish. Halving of a clutch into coherent groups only slightly disrupted the synchrony of emergence. The consequence of individual isolation was more dramatic. Half-clutches consisting of disconnected solitary eggs required almost twice as much time for complete emergence of all larvae, which was significantly more than cannibalism as a sole synchronizing factor might explain. Moreover, survival rates were the same in coherent half-clutches (in the presence of cannibalism) and among isolated individuals. This group effect and the small contribution of cannibalism suggest the existence of an additional synchronizing factor. Possible mechanisms underpinning this phenomenon are discussed.

  14. In vitro development of the fish parasite Hysterothylacium aduncum from the third larval stage recovered from a host to the third larval stage hatched from the egg.

    PubMed

    Adroher, F J; Malagón, D; Valero, A; Benítez, R

    2004-01-28

    Anisakids are parasitic nematodes of fish worldwide, producing economic and human health concerns. It is thus important to ascertain their in vitro life cycle in laboratory studies. Here we describe the in vitro development of third-stage larvae (L3) of Hysterothylacium aduncum isolated from blue whiting Micromesistius poutassou, to the hatching of L3 from eggs obtained from H. aduncum worms grown in GLIT medium (a modified mixture of Yaeger's LIT [Liver Infusion Tryptose] and Grace's media) at pH 4.0, 13 degrees C and with 5% CO2 in air. Under these conditions, L3 recovered from fish developed to mature adults (3.4 to 6.2 cm in length), with oviposition starting from Day 26 in culture. Fertilized eggs (mean size 64 x 52 microm) had a thick, rugose eggshell and were larger than unfertilized ones (mean size 49 x 42 microm), whose eggshells were thin and smooth. Eggs laid during the first and second week of oviposition, and maintained in 2.8% NaCl solution at 13 degrees C, developed to L3. Under these maintenance conditions, between 20.6 and 52.5% of the eggs laid during the first week developed into larvae. Motile larvae, enclosed in a sheath, hatched from between 2 and 11% of these eggs. The larvae started to hatch 23 d after deposition. These larvae were 144 to 215 microm in length, enclosed in a 237 to 305 microm-long sheath. This GLIT culture medium may help to study the biology of this and other anisakids. PMID:15038450

  15. Effect of purified condensed tannins from pine bark on larval motility, egg hatching and larval development of Teladorsagia circumcincta and Trichostrongylus colubriformis (Nematoda: Trichostrongylidae).

    PubMed

    Molan, Abdul-Lateef

    2014-08-01

    The effects of condensed tannins (CTs) extracted from pine bark on egg hatching, larval development and the viability of infective L3 larvae of Trichostrongylus colubriformis (Giles, 1892) and Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. Significant inhibitory effects of CTs were obtained on the viability of the infective larvae, egg hatching and larval development of both nematodes. In all bioassays, the larval stages of Te. circumcincta were significantly (P < 0.05) more susceptible to the inhibitory effects of CT than those of Tr. colubriformis. At 1 000 microg/ml, CTs from pine bark inhibited 48% and 69% of the infective larvae of Tr. colubriformis and Te. circumcincta, respectively, from passing through the sieve relative to the control incubations (no CT added; P < 0.0001). At the same concentration, CTs were able to inhibit 36% and 47% of the eggs of the two parasites, respectively, from hatching relative to the control incubations without CTs. Moreover, at 150 microg/ml, the CTs were able to inhibit 88% and 95% (P < 0.0001 relative to control incubation) of L1 larvae of the two nematodes, respectively, from attaining the full development to L3 larvae in comparison with the control incubations without CTs. At 200 microg/ml, CTs were able to inhibit completely the larval development in both nematodes. Addition of 2 microg polyethylene glycol (PEG; tannin inhibitor) per microg CT eliminated up to 87% of the CT activity (P < 0.0001) compared to incubations without PEG. In conclusion, this study shows that CTs are able to disrupt the life cycle of nematodes and their effects varied according to the parasite species and stage.

  16. Can-out hatch assembly and positioning system

    DOEpatents

    Basnar, Paul J.; Frank, Robert C.; Hoh, Joseph C.

    1986-01-01

    A can-out hatch assembly is adapted to engage in a sealed manner the upper end of a covered sealed container around an aperture in a sealed chamber and to remove the cover from the container permitting a contaminant to be transferred between the container and the chamber while isolating internal portions of the container and chamber from the surrounding environment. A swing bracket is coupled at a first end thereof to the inner, lower wall of the sealed container adjacent to the aperture therein. To a second end of the swing bracket is mounted a hatch cover which may be positioned in sealed engagement about the chamber's aperture by rotating the hatch cover in a first direction when the swing bracket is in the full down position. Rotation of the hatch cover in a second direction releases it from sealed engagement with the chamber's aperture. A lid support rod also coupled to the second end of the swing bracket and inserted through an aperture in the center of the hatch cover may be rotated for threadably engaging the container's cover whereupon the cover may be removed from the container and the hatch cover displaced from the aperture by pivoting displacement of the swing bracket. The contaminant may then be either removed from the container and placed within the sealed chamber, or vice versa, followed by positioning of the cover upon the container and the hatch cover over the aperture in a sealed manner.

  17. Can-out hatch assembly and positioning system

    DOEpatents

    Basnar, P.J.; Frank, R.C.; Hoh, J.C.

    1985-07-03

    A can-out hatch assembly is adapted to engage in a sealed manner the upper end of a covered sealed container around an aperture in a sealed chamber and to remove the cover from the container permitting a contaminant to be transferred between the container and the chamber while isolating internal portions of the container and chamber from the surrounding environment. A swing bracket is coupled at a first end thereof to the inner, lower wall of the sealed container adjacent to the aperture therein. To a second end of the swing bracket is mounted a hatch cover which may be positioned in sealed engagement about the chamber's aperture by rotating the hatch cover in a first direction when the swing bracket is in the full down position. Rotation of the hatch cover in a second direction release it from sealed engagement with the chamber's aperture. A lid support rod also coupled to the second end of the swing bracket and inserted through an aperture in the center of the hatch cover may be rotated for theadably engaging the container's cover whereupon the cover may be removed from the container and the hatch cover displaced from the aperture by pivoting displacement of the swing bracket. The contaminant may then be either removed from the container and placed within the sealed chamber, or vice versa, followed by positioning of the cover upon the container and the hatch cover over the aperture in a sealed manner.

  18. Can-out hatch assembly and positioning system

    DOEpatents

    Basnar, Paul J.; Frank, Robert C.; Hoh, Joseph C.

    1986-01-07

    A can-out hatch assembly is adapted to engage in a sealed manner the upper end of a covered sealed container around an aperture in a sealed chamber and to remove the cover from the container permitting a contaminant to be transferred between the container and the chamber while isolating internal portions of the container and chamber from the surrounding environment. A swing bracket is coupled at a first end thereof to the inner, lower wall of the sealed container adjacent to the aperture therein. To a second end of the swing bracket is mounted a hatch cover which may be positioned in sealed engagement about the chamber's aperture by rotating the hatch cover in a first direction when the swing bracket is in the full down position. Rotation of the hatch cover in a second direction releases it from sealed engagement with the chamber's aperture. A lid support rod also coupled to the second end of the swing bracket and inserted through an aperture in the center of the hatch cover may be rotated for threadably engaging the container's cover whereupon the cover may be removed from the container and the hatch cover displaced from the aperture by pivoting displacement of the swing bracket. The contaminant may then be either removed from the container and placed within the sealed chamber, or vice versa, followed by positioning of the cover upon the container and the hatch cover over the aperture in a sealed manner.

  19. Can-out hatch assembly with magnetic retention means

    DOEpatents

    Frank, Robert C.; Hoh, Joseph C.

    1986-01-07

    A can-out hatch assembly may be positioned in sealed engagement about an aperture within a chamber and is adapted to engage a cover on a container positioned over the aperture to allow the transfer of a contaminant from the chamber to the container while maintaining the contaminant as well as internal portions of the chamber and container isolated from the surrounding environment. With the container's cover engaged by the can-out hatch assembly, the hatch assembly as well as the cover may be pivotally displaced from the aperture with the cover maintaining the exterior portion of the hatch assembly isolated from the contaminant. After the contaminant is transferred from the chamber to the container, the hatch assembly and cover are again positioned in sealed engagement about the aperture. The hatch assembly then positions the cover upon the open end of the container in a sealed manner allowing the container to be removed while maintaining the chamber sealed relative to the surrounding environment. The can-out hatch assembly is particularly adapted for operation by remote control means within the sealed chamber.

  20. Can-out hatch assembly with magnetic retention means

    DOEpatents

    Frank, R.C.; Hoh, J.C.

    1985-07-03

    A can-out hatch assembly may be positioned in sealed engagement about aperture within a chamber and is adapted to engage a cover on a container positioned over the aperture to allow the transfer of a contaminant from the chamber to the container while maintaining the contaminant as well as internal portions of the chamber and container isolated from the surrounding environment. With the container's cover engaged by the can-out hatch assembly, the hatch assembly as well as the cover may be pivotally displaced from the aperture with the cover maintaining the exterior portion of the hatch assembly isolated from the contaminant. After the contaminant is transferred from the chamber to the container, the hatch assembly and cover are again positioned in sealed engagement about the aperture. The hatch assembly then positions the cover upon the open end of the container in a sealed manner allowing the container to be removed while maintaining the chamber sealed relative to the surrounding environment. The can-out hatch assembly is particularly adapted for operation by remote control means within the sealed chamber.

  1. Can-out hatch assembly with magnetic retention means

    DOEpatents

    Frank, Robert C.; Hoh, Joseph C.

    1986-01-01

    A can-out hatch assembly may be positioned in sealed engagement about an aperture within a chamber and is adapted to engage a cover on a container positioned over the aperture to allow the transfer of a contaminant from the chamber to the container while maintaining the contaminant as well as internal portions of the chamber and container isolated from the surrounding environment. With the container's cover engaged by the can-out hatch assembly, the hatch assembly as well as the cover may be pivotally displaced from the aperture with the cover maintaining the exterior portion of the hatch assembly isolated from the contaminant. After the contaminant is transferred from the chamber to the container, the hatch assembly and cover are again positioned in sealed engagement about the aperture. The hatch assembly then positions the cover upon the open end of the container in a sealed manner allowing the container to be removed while maintaining the chamber sealed relative to the surrounding environment. The can-out hatch assembly is particularly adapted for operation by remote control means within the sealed chamber.

  2. Baylisascaris larva migrans

    USGS Publications Warehouse

    Kazacos, Kevin R.

    2016-01-01

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

  3. Baylisascaris larva migrans

    USGS Publications Warehouse

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

    2016-05-26

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

  4. Transcriptome Profiling Analysis on Whole Bodies of Microbial Challenged Eriocheir sinensis Larvae for Immune Gene Identification and SNP Development

    PubMed Central

    Cui, Zhaoxia; Li, Xihong; Liu, Yuan; Song, Chengwen; Hui, Min; Shi, Guohui; Luo, Danli; Li, Yingdong

    2013-01-01

    To study crab immunogenetics of individuals, newly hatched Eriocheir sinensis larvae were stimulated with a mixture of three pathogen strains (Gram-positive bacteria Micrococcus luteus, Gram-negative bacteria Vibrio alginolyticus and fungi Pichia pastoris; 108 cfu·mL-1). A total of 44,767,566 Illumina clean reads corresponding to 4.52 Gb nucleotides were generated and assembled into 100,252 unigenes (average length: 1,042 bp; range: 201-19,357 bp). 17,097 (26.09%) of 65,535 non-redundant unigenes were annotated in NCBI non-redundant protein (Nr) database. Moreover, 23,188 (35.38%) unigenes were assigned to three Gene Ontology (GO) categories, 15,071 (23.00%) to twenty-six Clusters of orthologous Groups (COG) and 8,574 (13.08%) to six Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. Numerous genes were further identified to be associated with multiple immune pathways, including Toll, immune deficiency (IMD), janus kinase (JAK)-signal transducers and activators of transcription (STAT) and mitogen-activated protein kinase (MAPK) pathways. Some of them, such as tumor necrosis factor receptor associated factor 6 (TRAF6), fibroblast growth factor (FGF), protein-tyrosine phosphatase (PTP), JNK-interacting protein 1 (JIP1), were first identified in E. sinensis. TRAF6 was even first discovered in crabs. Additionally, 49,555 single nucleotide polymorphisms (SNPs) were developed from over 13,309 unigenes. This is the first transcriptome report of whole bodies of E. sinensis larvae after immune challenge. Data generated here not only provide detail information to identify novel genes in genome reference-free E. sinensis, but also facilitate our understanding on host immunity and defense mechanism of the crab at whole transcriptome level. PMID:24324760

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

    PubMed

    Podeniene, Virginija; Naseviciene, Nijole; Podenas, Sigitas

    2014-01-01

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

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

    PubMed

    Podeniene, Virginija; Naseviciene, Nijole; Podenas, Sigitas

    2014-02-10

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

  7. Segregation of herring larvae from inshore and offshore spawning grounds in the north-western North Sea — Implications for stock structure

    NASA Astrophysics Data System (ADS)

    Heath, M.

    Herring larvae hatching from spawning sites around the Scottish coast are dispersed by water currents during the weeks following hatching. Hydrographic data, observations on the distribution of caesium-137 and measurements of current velocities by moored meters and drifting buoys, suggest that larvae from offshore spawning sites around the north of Scotland should be more rapidly dispersed than those hatching in inshore areas. This has been confirmed by direct observations on the advection of herring larvae in different regions of the north western North Sea. The conclusion is that larvae hatching in inshore areas, especially in the Moray Firth, are most likely to contribute to nearby juvenile populations, whereas larvae from offshore spawning sites should be widely dispersed over the North Sea. Tagging and parasitology investigations have shown that adult herring spawning in the north-western North Sea have been widely dispersed in the North Sea and adjacent waters as juveniles (six months — one and a half years old). However, a high proportion of adult fish caught at inshore spawning sites and in the Moray Firth were found to have been recruited from more local areas. Taken together with the observations on larval drift, these observations suggest that the stock structure of herring in the northern North Sea may in part be a consequence of the physical oceanography of the area.

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

    SciTech Connect

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

    1995-05-01

    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 {ge}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.

  9. Critical swimming speeds of wild-caught sand-smelt Atherina presbyter larvae.

    PubMed

    Faria, A M; Borges, R; Gonçalves, E J

    2014-09-01

    Swimming abilities of wild-caught sand-smelt Atherina presbyter larvae were assessed as critical swimming speed (Ucrit ) throughout ontogeny. The mean Ucrit increased with size, ranging from 3·6 to 18·7 cm s(-1) , over the size range of 6·6-21·0 mm LT . This indicates that at hatching A. presbyter larvae, far from being passive floaters, are already capable of active behaviours, which may influence their dispersal patterns. PMID:25041317

  10. Hypoosmoregulation of larvae of the turbot, Scophthalamus maximus: drinking and gut function in relation to environmental salinity.

    PubMed

    Brown, J A; Tytler, P

    1993-04-01

    Measurement of blood osmolarity of pre-metamorphic turbot larvae demonstrated that hypoosmoregulation is well established in larvae 6 days post-hatch (121 degree-days) and older. Blood osmolarity of 121-420 degree-day larvae reared in 100% seawater was significantly greater than blood osmolarity of larvae reared in 50% seawater. Hypoosmoregulation involved drinking, but instantaneous drinking rates of 340 degree-day larvae reared in 100% seawater were only slightly more than those of similarly aged larvae reared in 50% seawater. Adaptation to environmental salinity involved changes in gut water absorption; 65-74% water absorption occurred in larvae reared in seawater compared to 30-35% water absorption in larvae reared in 50% seawater. Gastrointestinal water absorption occurred prior to the rectum. In seawater this occurred alongside a decrease in gut fluid osmolarity but desalting was apparently less significant than in adult fish. Absolute water absorption by the gut of 340 degree-day larvae reared in seawater was about 2-fold that of larvae held in 50% seawater, while the osmotic gradient between internal body fluids and environmental media differed by 4-fold, which implies changes the in water permeability of skin and/or developing gills. PMID:24214447

  11. 8. INTERIOR VIEW OF STATION PARLEY LOOKING THROUGH THE HATCH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. INTERIOR VIEW OF STATION PARLEY LOOKING THROUGH THE HATCH, SHOWING THE FLOOR AND THE INSTRUMENT PEDESTAL WITH HARDWARE. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

  12. 46 CFR 174.220 - Hatches and coamings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... be only weathertight: (1) Each hatch on a watertight trunk that extends at least 430 millimeters (17... coaming at least 380 millimeters (15 inches) high must be installed for each opening in a deckhouse...

  13. 46 CFR 174.220 - Hatches and coamings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... be only weathertight: (1) Each hatch on a watertight trunk that extends at least 430 millimeters (17... coaming at least 380 millimeters (15 inches) high must be installed for each opening in a deckhouse...

  14. Interior below decks in fish hold looking forward. Fish hatch ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior below decks in fish hold looking forward. Fish hatch opening is at upper left, ceiling planks and knees at center and right. - Purse Seiner SHENANDOAH, Gig Harbor Peninsula Historical Society and Museum, Gig Harbor, Pierce County, WA

  15. 9. Mispillion Lighthouse, Tower Lantern Floor Hatch Mispillion Lighthouse, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Mispillion Lighthouse, Tower Lantern Floor Hatch - Mispillion Lighthouse, South bank of Mispillion River at its confluence with Delaware River at northeast end of County Road 203, 7 miles east of Milford, Milford, Sussex County, DE

  16. 13. VIEW LOOKING EAST, REMAINS OF HATCH COVER AND CHUTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW LOOKING EAST, REMAINS OF HATCH COVER AND CHUTE TO SMALL HOPPER, GRAIN LEGS, AND CONVEYOR DRIVE SHAFT FROM TRACK DECK - West Shore Railroad, Pier 7 Grain Elevator, Hudson River & Pershing Road vicinity, West New York, Hudson County, NJ

  17. 10. VIEW OF SILO DOORS, AIR VENTS, AND ESCAPE HATCH, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF SILO DOORS, AIR VENTS, AND ESCAPE HATCH, LOOKING EAST. WHITE STRUCTURES BELONG TO CURRENT OCCUPANTS Everett Weinreb, photographer, April 1988 - Los Pinetos Nike Missile Site, Santa Clara Road, Los Angeles National Forest, Sylmar, Los Angeles County, CA

  18. 14. View inside Building 802, the "Escape Hatch" at the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. View inside Building 802, the "Escape Hatch" at the rear of the "Sleeping Quarters", facing south. - Naval Air Station Fallon, 100-man Fallout Shelter, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  19. BLDG 10, INTERIOR DETAIL OF WINDOW AND CEILING FEED HATCHES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLDG 10, INTERIOR DETAIL OF WINDOW AND CEILING FEED HATCHES - Naval Magazine Lualualei, Headquarters Branch, Storage Building, Kolekole Road near Sixty-first Street intersection, Pearl City, Honolulu County, HI

  20. 52. Patent steering gear, hatch and steering compass binnacle, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. Patent steering gear, hatch and steering compass binnacle, view from starboard looking aft. Photograph by Jet Lowe, April 1988. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  1. Edwin I. Hatch nuclear plant implementation of improved technical specifications

    SciTech Connect

    Mahler, S.R.; Pendry, D.

    1994-12-31

    Edwin I. Hatch nuclear plant consists of two General Electric boiling water reactor/4 units, with a common control room and a common refueling floor. In March 1993, Hatch began conversion of both units` technical specifications utilizing NUREG 1433. The technical specifications amendment request was submitted February 25, 1994. Issuance is scheduled for October 21, 1994, with implementation on March 15, 1994. The current unit-1 technical specifications are in the {open_quotes}custom{close_quotes} format, and the unit-2 technical specifications are in the old standard format. Hatch previously relocated the fire protection and radiological technical specifications requirements. The Hatch conversion will provide consistency between the two units, to the extent practicable.

  2. Astronaut Richard Gordon returns to hatch of spacecraft following EVA

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronaut Richard F. Gordon Jr., pilot for the Gemini 11 space flight, returns to the hatch of the spacecraft following extravehicular activity (EVA). This picture was taken over the Atlantic Ocean at approximately 160 nautical miles above the earth's surface.

  3. Morphological Development of Embryo, Larvae and Juvenile in Yellowtail Kingfish, Seriola lalandi

    PubMed Central

    Yang, Sang Geun; Hur, Sang Woo; Ji, Seung Cheol; Lim, Sang Gu; Kim, Bong Seok; Jeong, Minhwan; Lee, Chi Hoon; Lee, Young-Don

    2016-01-01

    This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of 1.35 ± 0.04 mm and an oil globule diameter of 0.32 ± 0.02 mm. The fertilized eggs hatched 67–75 h after fertilization in water at 20 ± 0.5°C. The total length (TL) of the hatched larvae was 3.62 ± 0.16 mm. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was 4.72 ± 0.07 mm. At 40 DAH, the juveniles had grown to 30.44 ± 4.07 mm in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3–4 vertical stripes appeared. At 45 DAH, the juveniles were 38.67 ± 5.65 mm in TL and 10.10 ± 0.94 mm in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin. PMID:27660828

  4. Morphological Development of Embryo, Larvae and Juvenile in Yellowtail Kingfish, Seriola lalandi.

    PubMed

    Yang, Sang Geun; Hur, Sang Woo; Ji, Seung Cheol; Lim, Sang Gu; Kim, Bong Seok; Jeong, Minhwan; Lee, Chi Hoon; Lee, Young-Don

    2016-06-01

    This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of 1.35 ± 0.04 mm and an oil globule diameter of 0.32 ± 0.02 mm. The fertilized eggs hatched 67-75 h after fertilization in water at 20 ± 0.5°C. The total length (TL) of the hatched larvae was 3.62 ± 0.16 mm. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was 4.72 ± 0.07 mm. At 40 DAH, the juveniles had grown to 30.44 ± 4.07 mm in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3-4 vertical stripes appeared. At 45 DAH, the juveniles were 38.67 ± 5.65 mm in TL and 10.10 ± 0.94 mm in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin. PMID:27660828

  5. Morphological Development of Embryo, Larvae and Juvenile in Yellowtail Kingfish, Seriola lalandi

    PubMed Central

    Yang, Sang Geun; Hur, Sang Woo; Ji, Seung Cheol; Lim, Sang Gu; Kim, Bong Seok; Jeong, Minhwan; Lee, Chi Hoon; Lee, Young-Don

    2016-01-01

    This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of 1.35 ± 0.04 mm and an oil globule diameter of 0.32 ± 0.02 mm. The fertilized eggs hatched 67–75 h after fertilization in water at 20 ± 0.5°C. The total length (TL) of the hatched larvae was 3.62 ± 0.16 mm. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was 4.72 ± 0.07 mm. At 40 DAH, the juveniles had grown to 30.44 ± 4.07 mm in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3–4 vertical stripes appeared. At 45 DAH, the juveniles were 38.67 ± 5.65 mm in TL and 10.10 ± 0.94 mm in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.

  6. DETAIL OF OPEN HATCH SHOWING INTERIOR OF MISSILE TUBE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF OPEN HATCH SHOWING INTERIOR OF MISSILE TUBE AND OPEN HATCH AND DOOR ON OPPOSITE SIDE OF TUBE (AT THIRD LEVEL OF MISSILE LAB). VIEW FACING WEST - U.S. Naval Base, Pearl Harbor, Ford Island Polaris Missile Lab & U.S. Fleet Ballistic Missile Submarine Training Center, Between Lexington Boulvevard and the sea plane ramps on the southwest side of Ford Island, Pearl City, Honolulu County, HI

  7. Convair-240 aircraft modified with shuttle hatch for CES testing

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Shuttle Crew Escape System (CES) hardware includes space shuttle side hatch incorporated into Convair-240 aircraft at Naval Weapons Center, China Lake, California. Closeup shows dummy positioned in the Convair-240 escape hatch. Beginning this month, tests will be conducted here to evaluate a tractor rocket system - one of two escape methods being studied by NASA to provide crew egress capability during Space Shuttle controlled gliding flight.

  8. In vitro detection of benzimidazole resistance in Haemonchus contortus: egg hatch test versus larval development test.

    PubMed

    Várady, M; Cudeková, P; Corba, J

    2007-10-21

    The present study was designed to compare the egg hatch test (EHT) and the larval development test (LDT) as in vitro tools for detection of benzimidazole (BZ) resistance in Haemonchus contortus, a nematode parasite of small ruminants. Comparisons were made during a course of infection and changes in both EHT and LDT were monitored to measure the correlation between resistance and susceptibility in different parasite stages (eggs and larvae). In addition, mixed doses of known numbers of susceptible and BZ-resistant H. contortus eggs were used to assess the sensitivity of LDT for the detection of low levels of resistance. The degree of resistance for each test was expressed as resistance factor (RF). The LDT showed a greater ability to distinguish between four susceptible and four resistant isolates of H. contortus with higher resistance factors compared to the EHT. For the EHT the RF by using ED(50) criterion ranged from 3.2 to 13.3 and from 7.4 to 25.2 by using LC(99). For LDT the resistant isolates were 4.3-63.1 times more tolerant than the susceptible isolates using the ED(50) criterion and 91.1-1411.0 times more tolerant using the LC(99) criterion. The LDT was also able to clearly indicate the presence of low level (4%) of resistant larvae amongst a susceptible background population.

  9. Hatching the Cleidoic Egg: The Role of Thyroid Hormones

    PubMed Central

    De Groef, Bert; Grommen, Sylvia V.H.; Darras, Veerle M.

    2013-01-01

    A major life stage transition in birds and other oviparous sauropsids is the hatching of the cleidoic egg. Not unlike amphibian metamorphosis, hatching in these species can be regarded as a transition from a relatively well-protected “aqueous” environment to a more hazardous and terrestrial life outside the egg, a transition in which thyroid hormones (THs) (often in concert with glucocorticoids) play an important role. In precocial birds such as the chicken, the perihatch period is characterized by peak values of THs. THs are implicated in the control of muscle development, lung maturation and the switch from chorioallantoic to pulmonary respiration, yolk sac retraction, gut development and induction of hepatic genes to accommodate the change in dietary energy source, initiation of thermoregulation, and the final stages of brain maturation as well as early post-hatch imprinting behavior. There is evidence that, at least for some of these processes, THs may have similar roles in non-avian sauropsids. In altricial birds such as passerines on the other hand, THs do not rise significantly until well after hatching and peak values coincide with the development of endothermy. It is not known how hatching-associated processes are regulated by hormones in these animals or how this developmental mode evolved from TH-dependent precocial hatching. PMID:23755041

  10. Consequences of induced hatching plasticity depend on predator community.

    PubMed

    Wojdak, Jeremy M; Touchon, Justin C; Hite, Jessica L; Meyer, Beth; Vonesh, James R

    2014-08-01

    Many prey species face trade-offs in the timing of life history switch points like hatching and metamorphosis. Costs associated with transitioning early depend on the biotic and abiotic conditions found in the subsequent life stage. The red-eyed treefrog, Agalychnis callidryas, faces risks from predators in multiple, successive life stages, and can hatch early in response to mortality threats at the egg stage. Here we tested how the consequences of life history plasticity, specifically early hatching in response to terrestrial egg predators, depend on the assemblage of aquatic larval predators. We predicted that diverse predator assemblages would impose lower total predation pressure than the most effective single predator species and might thereby reduce the costs of hatching early. We then conducted a mesocosm experiment where we crossed hatchling phenotype (early vs. normal hatching) with five larval-predator environments (no predators, either waterbugs, dragonflies, or mosquitofish singly, or all three predator species together). The consequences of hatching early varied across predator treatments, and tended to disappear through time in some predation treatments, notably the waterbug and diverse predator assemblages. We demonstrate that the fitness costs of life history plasticity in an early life stage depend critically on the predator community composition in the next stage.

  11. Assisted hatching in assisted reproduction: a state of the art.

    PubMed

    Hammadeh, Mohamad Eid; Fischer-Hammadeh, Constanze; Ali, Khaled Refaat

    2011-02-01

    The World Health Organization estimates that one in six couples experience some delay in conception and an increasing number require treatment by the assisted conception (AC) procedures of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).The implantation rate of embryos resulting from in vitro fertilization cycles is generally less than 20%. The exposure of oocytes and embryos to the artificial conditions of in vitro culture may have negative effects on the embryo's ability to undergo normal hatching, resulting in low rates of implantation following IVF and embryo transfer. Human embryos resulting from superovulation develop more slowly in vitro compared to embryos in vivo, manifest a relatively high degree of cytogenetic abnormalities and undergo cellular fragmentation. Artificially disrupting the zona pellucida is known as assisted hatching (AH) and there is some evidence that embryos that have undergone zona manipulation for assisted hatching tend to implant one day earlier than unhatched embryos. A variety of techniques have since been employed to assist embryo hatching, including partial mechanical zona dissection, zona drilling and zona thinning, making use of acid tyrodes, proteinases, piezon vibrator manipulators and lasers. This review will consider the impact of IVF conditions on zona pellucida physiology, zona hardening, different techniques of assisted hatching, who may benefit from assisted hatching and potential hazards.

  12. Organogenesis of exocrine pancreas in sharpsnout sea bream (Diplodus puntazzo) larvae: characterization of trypsin expression.

    PubMed

    Kamaci, H Okan; Suzer, Cüneyt; Coban, Deniz; Saka, Sahin; Firat, Kürşat

    2010-12-01

    The ontogeny and differentiation stages of digestive systems related with trypsin expression in larvae of sharpsnout sea bream, Diplodus puntazzo, were investigated from hatching to 40 DAH (days after hatching), and total lengths and weights of larvae were determined. Histologic and enzymatic techniques were used to explain the functional development of the pancreas including trypsin activity. The pancreas was identified as a compact structure located in the region slightly posterior to the liver. At 3 DAH, first anus and then mouth opened. Incipient pancreas secretion polyhedral cells could be first observed as zymogen granules. During larval metamorphosis, the pancreas became diffuse, spreading throughout the mesentery in proximity to the stomach, the anterior intestine and the pyloric caeca. The specific activity of trypsin (42.54±6.8 mU/mg protein(-1)) was found as early as after hatching at larvae size of 2.87±0.34 mm at 0 DAH. Activity further increased until 10 DAH, especially after exogenous feeding. The highest trypsin activity was detected at 25 DAH as 119.26±11.6 mU/mg protein(-1). It is concluded that exocrine pancreas organogenesis is the main critical step in the development of digestive system that results in zymogen granules accumulation and increased trypsin activity. PMID:20077135

  13. 9 CFR 82.9 - Interstate movement of hatching eggs from a quarantined area.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Interstate movement of hatching eggs... Interstate movement of hatching eggs from a quarantined area. Hatching eggs from birds or poultry not known...) The hatching eggs are accompanied by a permit obtained in accordance with § 82.11; (b) Copies of...

  14. 9 CFR 82.9 - Interstate movement of hatching eggs from a quarantined area.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Interstate movement of hatching eggs... Interstate movement of hatching eggs from a quarantined area. Hatching eggs from birds or poultry not known...) The hatching eggs are accompanied by a permit obtained in accordance with § 82.11; (b) Copies of...

  15. 9 CFR 82.9 - Interstate movement of hatching eggs from a quarantined area.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Interstate movement of hatching eggs... Interstate movement of hatching eggs from a quarantined area. Hatching eggs from birds or poultry not known...) The hatching eggs are accompanied by a permit obtained in accordance with § 82.11; (b) Copies of...

  16. 9 CFR 82.9 - Interstate movement of hatching eggs from a quarantined area.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Interstate movement of hatching eggs... Interstate movement of hatching eggs from a quarantined area. Hatching eggs from birds or poultry not known...) The hatching eggs are accompanied by a permit obtained in accordance with § 82.11; (b) Copies of...

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

    USGS Publications Warehouse

    Park, W.; Douglas, D.C.; Shirley, T.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.

  18. Effects of copper on the egg development and hatching of a freshwater pulmonate snail Lymnaea luteola L.

    PubMed

    Khangarot, B S; Das, Sangita

    2010-07-15

    A freshwater invertebrate egg development and hatching toxicity test with an Indian freshwater pulmonate snail, Lymnaea luteola, comprising the following developmental endpoints was described: mortality, development, formation of eyes and foot structure, heart rate, duration of different larval stages, and hatching time. Developmental stages were morula, and at third, fifth, and eighth days; the trochophore, veliger, and hippo larvae, respectively. At the age of about 9th to 11th days after egg laying; more than 95% young snail hatched in control laboratory conditions. To evaluate effects on embryonic development, the pulmonate snail eggs of 24-h old were exposed to a series of nominal copper concentrations. The percentage survival of embryos treated in 10-32 microg l(-1) of Cu after 240 h of exposure drops sharply at veliger and hippo stages. All embryos died at 100-320 microg l(-1) of Cu within 168 h of exposure at trochophore and early veliger stages. The detected abnormalities were malformation of foot, eyes, thinness and incomplete formation of shell, growth retardation, and slow rotation of embryo within the egg capsule as compared to control embryos. Lethal and sublethal effects in terms of mortality and significant delay in hatching could be found in the 3.2, 5.6 and 10 microg l(-1) of Cu concentrations. This species is widely distributed in the Indian subcontinent freshwater reservoirs and more sensitive to Cu than other tested aquatic test organisms; therefore, could be used as a test model of Cu and possibly other pollutants for rapid risk assessment of environmental pollutants. The snail egg embryo bioassay is simple, rapid, highly sensitive, cost-effective, and easy to test under standardized laboratory conditions.

  19. Colour preference and light sensitivity in trilobite larvae of mangrove horseshoe crab, Carcinoscopius rotundicauda (Latreille, 1802).

    PubMed

    Srijayat, T C; Pradeep, P J; Hassan, A; Chatterji, A; Shaharom, F; Jeffs, Andrew

    2014-03-01

    The trilobite larvae of C. rotundicauda were tested to determine their colour preference and light sensitivity until their first moulting (25 days post hatching) under laboratory conditions. Maximum congregation size of the trilobite larvae was found in the white zone respectively where (n = 12) followed by yellow (n = 8) and orange (n = 8), which showed the larval preference for lighter zones. Morisita's index calculation showed a clumped/aggregated distribution (yellow, blue, orange and white) and uniform/hyper dispersed distribution (green, red and black) for various colours tested. Trilobite larvae showed least preference for brighter regions while tested in the experiment [black; (n = 4) and red; (n = 5)]. Experiments done to determine the light sensitivity of trilobite larvae showed that the larvae had more preference towards ultraviolet lights. The maximum congregation size of 38.8 and 40.7% of the larvae was encountered under ultraviolet light, when the light sources were kept horizontal and vertical, respectively. Overall, results suggested that the trilobite larvae of C. rotundicauda, preferred light source of shorter wavelengths (UV light) and colours of lighter zone (white, yellow, orange), which might be due to their adaptation to their natural habitat for predator avoidance, prey selection and water quality. PMID:24669671

  20. Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae

    PubMed Central

    Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A.

    2015-01-01

    This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish. PMID:26035592

  1. Colour preference and light sensitivity in trilobite larvae of mangrove horseshoe crab, Carcinoscopius rotundicauda (Latreille, 1802).

    PubMed

    Srijayat, T C; Pradeep, P J; Hassan, A; Chatterji, A; Shaharom, F; Jeffs, Andrew

    2014-03-01

    The trilobite larvae of C. rotundicauda were tested to determine their colour preference and light sensitivity until their first moulting (25 days post hatching) under laboratory conditions. Maximum congregation size of the trilobite larvae was found in the white zone respectively where (n = 12) followed by yellow (n = 8) and orange (n = 8), which showed the larval preference for lighter zones. Morisita's index calculation showed a clumped/aggregated distribution (yellow, blue, orange and white) and uniform/hyper dispersed distribution (green, red and black) for various colours tested. Trilobite larvae showed least preference for brighter regions while tested in the experiment [black; (n = 4) and red; (n = 5)]. Experiments done to determine the light sensitivity of trilobite larvae showed that the larvae had more preference towards ultraviolet lights. The maximum congregation size of 38.8 and 40.7% of the larvae was encountered under ultraviolet light, when the light sources were kept horizontal and vertical, respectively. Overall, results suggested that the trilobite larvae of C. rotundicauda, preferred light source of shorter wavelengths (UV light) and colours of lighter zone (white, yellow, orange), which might be due to their adaptation to their natural habitat for predator avoidance, prey selection and water quality.

  2. Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae.

    PubMed

    Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A

    2015-01-01

    This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish.

  3. Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae.

    PubMed

    Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A

    2015-01-01

    This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish. PMID:26035592

  4. Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

    PubMed

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Yin, Xuebo; Dou, Shuozeng

    2010-06-01

    This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph). Results showed that increasing mercury concentration led to increased mercury bioaccumulation and reduced flounder growth. Of the antioxidants investigated, superoxide dismutase (SOD) and catalase (CAT) activities at the three developmental stages were sensitive to mercury exposure and increased with increasing mercury concentration. Glutathione (GSH) content was elevated in metamorphosing larvae, but decreased in juveniles as mercury concentration increased. Glutathione-S-transferase (GST) activity did not significantly vary with mercury concentration in either larvae or juveniles. Mercury exposure did not affect malondialdehyde (MDA) content of larvae, but significantly increased MDA content of juveniles. Results suggest that flounder larvae and juveniles have the potential to manipulate the levels of antioxidants such as SOD, CAT and GSH, which protect flounder from oxidative stress induced by mercury exposure. These antioxidants could serve as biomarkers of mercury contamination in the aquatic environment.

  5. Molecular endocrine changes of Gh/Igf1 axis in gilthead sea bream (Sparus aurata L.) exposed to different environmental salinities during larvae to post-larvae stages.

    PubMed

    Mohammed-Geba, Khaled; Yúfera, Manuel; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

    2016-08-01

    The influence of acclimation of the euryhaline gilthead sea bream (Sparus aurata) larvae/post-larvae to brackish water on growth, energetic contents, and mRNA levels of selected hormones and growth-regulating hypothalamic neurohormones was assessed. Specimens from 49 days post-hatching were acclimated during 28 days to two different environmental salinities: 38 and 20 psu (as brackish water). Both groups were then transferred to 38 psu and acclimated for an additional week. Early juveniles were sampled after 28 days of acclimation to both salinities and one week after transfer to 38 psu. Pituitary adenylate cyclase-activating peptide (adcyap1; pacap), somatostatin-I (sst1), growth hormone (gh1), insulin-like growth factor-I (igf1), and prolactin (prl) mRNA expression were all studied by QPCR. Post-larvae acclimated to 20 psu showed better growth performance and body energetic content than post-larvae maintained at 38 psu. prl, adcyap1, and igf1 mRNA expression levels increased in 20-psu-acclimated post-larvae but decreased upon transfer to 38 psu. GH1 expression did not show significant changes under both experimental conditions. Our results suggested an enhanced general performance for post-larvae in brackish water, supported by the actions of adcyap1, igf1, and prl.

  6. Defining the starvation potential and the influence on RNA/DNA ratios in horse mackerel ( Trachurus mediterraneus) larvae

    NASA Astrophysics Data System (ADS)

    Yandi, Ilhan; Altinok, Ilhan

    2015-03-01

    Larval survival potentially affects recruitment strongly. Variability in larval growth rates, primarily caused by variable nutritional situations, is one of the factors that can influence larval survival rates. RNA/DNA ratio as well as protein content was analyzed in wild-caught laboratory-grown and in wild-caught horse mackerel Trachurus mediterraneus in relation to feeding and starvation. For this purpose, field-caught genoblast eggs were incubated and the hatched larvae were reared under different feeding regimes: fed control, unfed control, starved either for 1, 2 or 3 days, on feeding restrictions. The whole-body RNA/DNA ratio and the daily protein growth rate were individually analyzed. In all larvae eye pigmentation, mouth opening and subsequently first feeding started on the third day after hatching. All larvae in the unfed group died on day 8. The survival rate during the first 3 days in delayed feeding groups was higher than that of the unfed group. Overall, growth curves from feeding-delayed larvae indicated that fish fed after up to 3 days starvation were capable of complete recovery with the critical RNA/DNA ratio of 1.05 ± 0.08. According to this value, approximately 10 % of the field-caught larvae were starving. Therefore, the RNA/DNA ratio is an easy tool to assess the nutritional status in horse mackerel larvae caught in the field with a high precision rate.

  7. Maternal Vibration: An Important Cue for Embryo Hatching in a Subsocial Shield Bug

    PubMed Central

    Mukai, Hiromi; Hironaka, Mantaro; Tojo, Sumio; Nomakuchi, Shintaro

    2014-01-01

    Hatching care has been reported for many taxonomic groups, from invertebrates to vertebrates. The sophisticated care that occurs around hatching time is expected to have an adaptive function supporting the feeble young. However, details of the characteristics of the adaptive function of hatching care remain unclear. This study investigated the hatching care of the subsocial shield bug, Parastrachia japonensis (Heteroptera: Parastrachiidae) to verify its function. Results show that the P. japonensis mothers vibrated the egg mass intermittently while maintaining an egg-guarding posture. Then embryos started to emerge from their shells synchronously. Unlike such behaviors of closely related species, this vibrating behavior was faint, but lasted more than 6 h. To investigate the effect of this behavior on hatching synchrony and hatching success, we observed the hatching pattern and the hatching rate in control, mother-removed, and two artificial vibration groups. Control broods experienced continuous guarding from the mother. Intermittent artificial vibration broods were exposed to vibrations that matched the temporal pattern of maternal vibration produced by a motor. They showed synchronous hatching patterns and high hatching rates. However, for mother-removed broods, which were isolated from the mother, and when we provided continuous artificial vibration that did not match the temporal pattern of the maternal vibration, embryo hatching was not only asynchronous: some embryos failed to emerge from their shells. These results lead us to infer that hatching care in P. japonensis has two functions: hatching regulation and hatching assistance. Nevertheless, several points of observational and circumstantial evidence clearly contraindicate hatching assistance. A reduction in the hatching rate might result from dependence on maternal hatching care as a strong cue in P. japonensis. We conclude that the hatching care of P. japonensis regulates the hatching pattern and serves

  8. Hatching asynchrony in American Goldfinches: an experimental study

    USGS Publications Warehouse

    Skagen, Susan Knight

    1987-01-01

    I examined Lack's (1954, 1968) hypothesis that asynchronous hatching is an adaptive response to food shortage during the breeding season by comparing growth and survival of nestlings in asynchronous and artificially created synchronous broods of American Goldfinches (Carduelis tristis). I also examined the effects of seasonal and environmental factors on nestling growth and survival and on hatching asynchrony. Nestlings in asynchronous broods were more likely to diverge in mass and did so at a faster rate than those in synchronous broods. The lightest nestlings of asynchronous broods grew more slowly than their heavier nestmates and than all nestlings in synchronous broods. Brood reduction occurred more frequently in asynchronous broods. Survival and growth rates decreased throughout the breeding season and during inclement weather. Hatching intervals increased during the season. When brood reduction or differential growth among nestmates occurred in asynchronous broods, suggesting that the energy available for growth was limiting, heavy nestlings in asynchronous broods grew nonsignificantly faster than heavy nestlings in concurrent synchronous broods. This trend implies that when insufficient food is delivered to nestlings, asynchronous hatching may provide a slight advantage for older nestlings. Growth rates of all nestlings, however, were greatest in highly synchronous broods. Explanations other than growth of young must be invoked to explain why extreme synchrony is not more common in goldfinches. I discuss constraints on the normal pattern of hatching asynchrony characteristic of this species. The proximate mechanism for differential feeding and brood reduction is discussed.

  9. Heartbeat, embryo communication and hatching synchrony in snake eggs.

    PubMed

    Aubret, Fabien; Blanvillain, Gaëlle; Bignon, Florent; Kok, Philippe J R

    2016-01-01

    Communication is central to life at all levels of complexity, from cells to organs, through to organisms and communities. Turtle eggs were recently shown to communicate with each other in order to synchronise their development and generate beneficial hatching synchrony. Yet the mechanism underlying embryo to embryo communication remains unknown. Here we show that within a clutch, developing snake embryos use heart beats emanating from neighbouring eggs as a clue for their metabolic level, in order to synchronise development and ultimately hatching. Eggs of the water snake Natrix maura increased heart rates and hatched earlier than control eggs in response to being incubated in physical contact with more advanced eggs. The former produced shorter and slower swimming young than their control siblings. Our results suggest potential fitness consequences of embryo to embryo communication and describe a novel driver for the evolution of egg-clustering behaviour in animals. PMID:26988725

  10. Heartbeat, embryo communication and hatching synchrony in snake eggs

    PubMed Central

    Aubret, Fabien; Blanvillain, Gaëlle; Bignon, Florent; Kok, Philippe J. R.

    2016-01-01

    Communication is central to life at all levels of complexity, from cells to organs, through to organisms and communities. Turtle eggs were recently shown to communicate with each other in order to synchronise their development and generate beneficial hatching synchrony. Yet the mechanism underlying embryo to embryo communication remains unknown. Here we show that within a clutch, developing snake embryos use heart beats emanating from neighbouring eggs as a clue for their metabolic level, in order to synchronise development and ultimately hatching. Eggs of the water snake Natrix maura increased heart rates and hatched earlier than control eggs in response to being incubated in physical contact with more advanced eggs. The former produced shorter and slower swimming young than their control siblings. Our results suggest potential fitness consequences of embryo to embryo communication and describe a novel driver for the evolution of egg-clustering behaviour in animals. PMID:26988725

  11. Clinically approved iron chelators influence zebrafish mortality, hatching morphology and cardiac function.

    PubMed

    Hamilton, Jasmine L; Hatef, Azadeh; Imran ul-Haq, Muhammad; Nair, Neelima; Unniappan, Suraj; Kizhakkedathu, Jayachandran N

    2014-01-01

    Iron chelation therapy using iron (III) specific chelators such as desferrioxamine (DFO, Desferal), deferasirox (Exjade or ICL-670), and deferiprone (Ferriprox or L1) are the current standard of care for the treatment of iron overload. Although each chelator is capable of promoting some degree of iron excretion, these chelators are also associated with a wide range of well documented toxicities. However, there is currently very limited data available on their effects in developing embryos. In this study, we took advantage of the rapid development and transparency of the zebrafish embryo, Danio rerio to assess and compare the toxicity of iron chelators. All three iron chelators described above were delivered to zebrafish embryos by direct soaking and their effects on mortality, hatching and developmental morphology were monitored for 96 hpf. To determine whether toxicity was specific to embryos, we examined the effects of chelator exposure via intra peritoneal injection on the cardiac function and gene expression in adult zebrafish. Chelators varied significantly in their effects on embryo mortality, hatching and morphology. While none of the embryos or adults exposed to DFO were negatively affected, ICL -treated embryos and adults differed significantly from controls, and L1 exerted toxic effects in embryos alone. ICL-670 significantly increased the mortality of embryos treated with doses of 0.25 mM or higher and also affected embryo morphology, causing curvature of larvae treated with concentrations above 0.5 mM. ICL-670 exposure (10 µL of 0.1 mM injection) also significantly increased the heart rate and cardiac output of adult zebrafish. While L1 exposure did not cause toxicity in adults, it did cause morphological defects in embryos at 0.5 mM. This study provides first evidence on iron chelator toxicity in early development and will help to guide our approach on better understanding the mechanism of iron chelator toxicity.

  12. Zinc oxide nanoparticles alter hatching and larval locomotor activity in zebrafish (Danio rerio).

    PubMed

    Chen, Te-Hao; Lin, Chia-Chi; Meng, Pei-Jie

    2014-07-30

    Zinc oxide nanoparticles (ZnO NP) are extensively used in various consumer products such as sunscreens and cosmetics, with high potential of being released into aquatic environments. In this study, fertilized zebrafish (Danio rerio) eggs were exposed to various concentrations of ZnO NP suspensions (control, 0.1, 0.5, 1, 5, and 10mg/L) or their respective centrifuged supernatants (0.03, 0.01, 0.08, 0.17, 0.75, and 1.21mg/L dissolved Zn ions measured) until reaching free swimming stage. Exposure to ZnO NP suspensions and their respective centrifuged supernatants caused similar hatching delay, but did not cause larval mortality or malformation. Larval activity level, mean velocity, and maximum velocity were altered in the groups exposed to high concentrations of ZnO NP (5-10mg/L) but not in the larvae exposed to the supernatants. To evaluate possible mechanism of observed effects caused by ZnO NP, we also manipulated the antioxidant environment by co-exposure to an antioxidant compound (N-acetylcysteine, NAC) or an antioxidant molecule suppressor (buthionine sulfoximine, BSO) with 5mg/L ZnO NP. Co-exposure to NAC did not alter the effects of ZnO NP on hatchability, but co-exposure to BSO caused further hatching delay. For larval locomotor activity, co-exposure to NAC rescued the behavioral effect caused by ZnO NP, but co-exposure to BSO did not exacerbate the effect. Our data indicated that toxicity of ZnO NP cannot be solely explained by dissolved Zn ions, and oxidative stress may involve in ZnO NP toxicity. PMID:24424259

  13. Clinically Approved Iron Chelators Influence Zebrafish Mortality, Hatching Morphology and Cardiac Function

    PubMed Central

    Hamilton, Jasmine L.; Hatef, Azadeh; Imran ul-haq, Muhammad; Nair, Neelima; Unniappan, Suraj; Kizhakkedathu, Jayachandran N.

    2014-01-01

    Iron chelation therapy using iron (III) specific chelators such as desferrioxamine (DFO, Desferal), deferasirox (Exjade or ICL-670), and deferiprone (Ferriprox or L1) are the current standard of care for the treatment of iron overload. Although each chelator is capable of promoting some degree of iron excretion, these chelators are also associated with a wide range of well documented toxicities. However, there is currently very limited data available on their effects in developing embryos. In this study, we took advantage of the rapid development and transparency of the zebrafish embryo, Danio rerio to assess and compare the toxicity of iron chelators. All three iron chelators described above were delivered to zebrafish embryos by direct soaking and their effects on mortality, hatching and developmental morphology were monitored for 96 hpf. To determine whether toxicity was specific to embryos, we examined the effects of chelator exposure via intra peritoneal injection on the cardiac function and gene expression in adult zebrafish. Chelators varied significantly in their effects on embryo mortality, hatching and morphology. While none of the embryos or adults exposed to DFO were negatively affected, ICL -treated embryos and adults differed significantly from controls, and L1 exerted toxic effects in embryos alone. ICL-670 significantly increased the mortality of embryos treated with doses of 0.25 mM or higher and also affected embryo morphology, causing curvature of larvae treated with concentrations above 0.5 mM. ICL-670 exposure (10 µL of 0.1 mM injection) also significantly increased the heart rate and cardiac output of adult zebrafish. While L1 exposure did not cause toxicity in adults, it did cause morphological defects in embryos at 0.5 mM. This study provides first evidence on iron chelator toxicity in early development and will help to guide our approach on better understanding the mechanism of iron chelator toxicity. PMID:25329065

  14. Lamellocyte differentiation in Drosophila larvae parasitized by Leptopilina.

    PubMed

    Rizki, T M; Rizki, R M

    1992-01-01

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

  15. Effect of caffeine, norfloxacin and nimesulide on heartbeat and VEGF expression of zebrafish larvae.

    PubMed

    Chakraborty, Chiranjib; Hsu, C H; Wen, Z H; Lin, C S; Agoramoorthy, Govindasamy

    2011-03-01

    The use of pharmaceuticals during pregnancy may causes abnormalities to the embryo. Sometime the drug also effect to the new born if the drug transferred through lactation. We have used zebrafish model to see the effect of some pharmaceuticals on embryos and larvae. Three drugs, caffeine, norfloxacin and nimesulide, were used for this study to see the effect mainly the hatching rate of eggs, heart beat rate and the vascular endothelial growth factor (VEGF) expression of the larvae. VEGF is an important signaling protein that involved generating the new blood vessels during embryonic development. We have used 10, 20, 50, 100 microg ml(-1) concentrations of all the drugs to see the effect. No significant mortality or malformations were observed in zebrafish embryos. Hatching was stared from 60 hr. In control group, 91% hatching rate was observed. Lowest hatching rate was observed using highest concentration of norfloxacin (100 microg ml(-1)) and nimesulide (100 microg ml(-1)) i.e. 55 and 56% respectively. In control group, 110 to 115 heart beat rate was counted per minute. Significantly higher heart beat was observed in caffeine treated group which is 125 to 140 min(-1) Lower heart beat was noted in nimesulide treated group which is 100 min(-1). We have tried to observe the possible effect of VEGF of the larvae by these three drugs. Expression of VEGF was very low in caffeine treated group. Almost no VGF expression was observe in 100 microg ml(-1) caffeine treated group. These studies suggest that there is a possibility that high dosage of caffeine can harm the unborn baby or new born babies, if the mothers use caffeine.

  16. Effects of freshwater petroleum contamination on amphibian hatching and metamorphosis

    SciTech Connect

    Mahaney, P.A. . Dept. of Zoology)

    1994-02-01

    This study examined the effects of freshwater petroleum contamination on amphibian reproduction. The primary objectives were to assess the potential environmental and physiological impacts of runoff petroleum products on amphibians, using the green tree frog (Hyla cinerea) as a target species and engine crankcase oil as a contaminant. Egg hatching success, tadpole growth, and successful metamorphosis were measured in four concentrations of oil. The effects of oil on food source was also studied. Hatching success was not measurably influenced by the presence of oil. Tadpole and alga growth were negatively associated with the presence of oil. No tadpoles from the high concentration of oil treatments successfully metamorphosed.

  17. Evaluation of an electronic fry counter with striped bass embryos and larvae

    USGS Publications Warehouse

    Lemarie, D.P.; Weller, D.A.; Theisen, D.D.; Woods, L. Curry

    1997-01-01

    We evaluated an electronic fry counter (Jensorter, Inc., model FC-2) for accuracy. precision, and effects on embryo hatchability and larval survival of striped bass Morone saxatilis. Hatching success of embryos and 96-h survival of 5-d larvae passed through the counter did not differ significantly (P > 0.05) from controls. Mean electronic counts of embryos and larvae differed from hand counts by -5.2% and -9.7%, respectively. Precision was estimated by the coefficient of variation of repeated counts and ranged as high as 4.43% for embryos and 8.62% for larvae. Site- and species-specific factors may have increased variability that re suited in the reduced levels of accuracy and precision. The advantages of greatly increased speed of counting and ease of use, as well as potentially better performance under other conditions, warrant further evaluation of this counter with other species and water supplies.

  18. Production of sea lamprey larvae from nests in two Lake Superior streams

    USGS Publications Warehouse

    Manion, Patrick J.

    1968-01-01

    The life history of the landlocked sea lamprey, Petromyzon marinus, has been described by several authors, the two most recent of which are Applegate and Wigley. The only information on the production of larvae from nests of the sea lamprey was reported by Applegate, who counted the larvae from three nests in the Ocqueoc River, a tributary of Lake Huron. The present report presents data on the hatching success of sea lamprey larvae from 19 nests in two small tributaries of southern Lake Superior and indicates greater production per nest than that recorded by Applegate. Studies were conducted by personnel of the U.S. Bureau of Commercial Fisheries on the Little Garlic River, Marquette County, Michigan, and on the Traverse River, Keweenaw County, Michigan.

  19. A novel model of early development in the brine shrimp, Artemia franciscana, and its use in assessing the effects of environmental variables on development, emergence, and hatching.

    PubMed

    Neumeyer, Courtney H; Gerlach, Jamie L; Ruggiero, Kristin M; Covi, Joseph A

    2015-03-01

    The brine shrimp, Artemia (Crustacea, Anostraca), is a zooplankton that is commonly used in both basic and applied research. Unfortunately, Artemia embryos are often cultured under conditions that alter early development, and reports based on these cultures oversimplify or fail to describe morphological phenotypes. This is due in part to the lack of a comprehensive developmental model that is applicable to observations of live specimens. The objective of this study was to build and test a descriptive model of post-diapause development in Artemia franciscana using observations made with a standard dissecting microscope. The working model presented is the first to comprehensively place all known "abnormal" embryonic and naupliar phenotypes within the context of a classic hatching profile. Contrary to previous reports, embryos and nauplii with aberrant phenotypes often recover and develop normally. Oval prenauplii may emerge as normal prenauplii (E2 stage). A delay of this transition leads to incomplete hatching or direct hatching of first instar larvae with a curved thoracoabdomen. When hatching is incomplete, retained cuticular remnants are shed during the next molt, and a "normal" second instar larva is produced. By differentiating between molting events and gross embryonic patterning in live embryos, this new model facilitates fine time-scale analyses of chemical and environmental impacts on early development. A small increase in salinity within what is commonly believed to be a permissive range (20‰-35‰) produced aberrant morphology by delaying emergence without slowing development. A similar effect was observed by decreasing culture density within a range commonly applied in toxicological studies. These findings clearly demonstrate that morphological data from end-point studies are highly dependent on the time points chosen. An alternate assessment method is proposed, and the potential impact of heavy metals, hexachlorobenzene, Mirex, and cis

  20. Evaluation of the impact of polyethylene microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae.

    PubMed

    Mazurais, D; Ernande, B; Quazuguel, P; Severe, A; Huelvan, C; Madec, L; Mouchel, O; Soudant, P; Robbens, J; Huvet, A; Zambonino-Infante, J

    2015-12-01

    Microplastics are present in marine habitats worldwide and may be ingested by low trophic organisms such as fish larvae, with uncertain physiological consequences. The present study aims at assessing the impact of polyethylene (PE 10-45 μM) microbeads ingestion in European sea bass (Dicentrarchus labrax) larvae. Fish were fed an inert diet including 0, 10(4) and 10(5) fluorescent microbeads per gram from 7 until 43 days post-hatching (dph). Microbeads were detected in the gastrointestinal tract in all fish fed diet incorporating PE. Our data revealed an efficient elimination of PE beads from the gut since no fluorescent was observed in the larvae after 48 h depuration. While the mortality rate increased significantly with the amount of microbeads scored per larvae at 14 and 20 dph, only ingestion of the highest concentration slightly impacted mortality rates. Larval growth and inflammatory response through Interleukine-1-beta (IL-1β) gene expression were not found to be affected while cytochrome-P450-1A1 (cyp1a1) expression level was significantly positively correlated with the number of microbeads scored per larva at 20 dph. Overall, these results suggest that ingestion of PE microbeads had limited impact on sea bass larvae possibly due to their high potential of egestion. PMID:26412109

  1. The effect of food provisioning on persistent organic pollutant bioamplification in Chinook salmon larvae.

    PubMed

    Daley, Jennifer M; Leadley, Todd A; Pitcher, Trevor E; Drouillard, Ken G

    2013-06-01

    Fall spawning pacific salmon provision large amounts of yolk to their eggs to allow survival of larvae during under the ice winter conditions. This yolk provisioning leads to maternal offloading of persistent organic pollutants (POPs) to eggs and larvae. Previous research has shown that Chinook salmon larvae exhibit limited capacity to eliminate POPs during the cold water period resulting in bioamplification of POP residues. This study compared POPs bioamplification in Chinook salmon larvae under a high food provisioning treatment and a non-fed treatment to test whether or not food availability attenuates POPs bioamplification via growth dilution. Results demonstrate that larvae in the food provisioning treatment did not gain weight until after day 129. Between hatching and day 129, fed and non-fed treatments exhibited similar decreases in whole body lipid content, negligible POPs elimination and POPs bioamplification factors approaching 1.6. By day 184 of the study, POPs bioamplification factors in the non-fed treatment were as high as 5.3 across chemicals but ranged from non-detectable to approaching 1 in the fed group. This study demonstrates that POPs bioamplification occurs in Chinook salmon larvae even under ideal rearing conditions but peaks after day 129, following which growth dilution can attenuate bioamplification relative to starved individuals.

  2. Comparative study of pikeperch Sander lucioperca (Percidae; Linnaeus, 1758) eggs and larvae from wild females or from captive females fed chopped marine fish.

    PubMed

    Ben Khemis, I; Hamza, N; Ben Messaoud, N; Ben Rached, S; M'Hetli, M

    2014-04-01

    Morphometric characteristics, proximal composition and fatty acids profiles of eggs and larvae at hatching and mouth opening were studied as indicators for assessing the potential differences between spawns obtained from wild or captive females of pikeperch (Sander lucioperca). Captive females were acclimated to hatchery conditions and fed to satiation with chopped marine fish for more than a year, guaranteeing that captivity covered the full cycle of gonad maturation. The number of larvae obtained from the spawnings did not differ between captive and wild females, but both mean diameter and mean weight of the eggs collected from the captive females were significantly larger. Proximal compositions were similar in eggs and larvae from both groups, but fatty acids (FA) profiles showed striking differences: polyunsaturated FA consisted mainly of linoleic acid in eggs and larvae from wild females, while they consisted mainly of long chains of n-3 series in eggs and larvae from captive females. The diet of captive females largely modified the FA profiles of eggs and of hatching or mouth opening larvae, but did not affect the growth potential of early larvae, demonstrating that they were able to satisfy their early physiological needs regardless of the striking differences in their FA.

  3. DETAIL OF MISSILE TUBE HATCH WITH MILLED FITTINGS AT GROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF MISSILE TUBE HATCH WITH MILLED FITTINGS AT GROUND FLOOR LEVEL. VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island Polaris Missile Lab & U.S. Fleet Ballistic Missile Submarine Training Center, Between Lexington Boulvevard and the sea plane ramps on the southwest side of Ford Island, Pearl City, Honolulu County, HI

  4. 11. BUOY DECK, NEAR PILOT HOUSE SUPERSTRUCTURE, LOOKING TOWARDS HATCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. BUOY DECK, NEAR PILOT HOUSE SUPERSTRUCTURE, LOOKING TOWARDS HATCH DOOR INTO WINCH ROOM IN THE SUPERSTRUCTURE (LABELED AT PASSAGE & HYDRAULIC MACHINERY ON PLAN). - U.S. Coast Guard Cutter WHITE HEATH, USGS Integrated Support Command Boston, 427 Commercial Street, Boston, Suffolk County, MA

  5. 6. Detail of forward fuselage showing open cockpit hatch and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail of forward fuselage showing open cockpit hatch and ladder. View to southeast. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  6. 46 CFR 78.17-35 - Hatches and other openings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... voyage: (1) Watertight doors between cargo spaces prescribed in § 170.275 of this chapter. (2) Portable... spaces appropriated alternately to the carriage of cargo and passengers, when cargo is carried. Dead covers on such port lights shall also be secured. (c) The time of opening and closing of hatches...

  7. PLAN SECTIONS AND DETAILS OF CELL HATCHES MAIN PROCESSING BUILDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PLAN SECTIONS AND DETAILS OF CELL HATCHES MAIN PROCESSING BUILDING (CPP-601). INL DRAWING NUMBER 200-0601-00-291-103256. ALTERNATE ID NUMBER 542-11-F-302. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  8. 3. VIEW OF WATER TANKS FROM ACCESS ROAD TO HATCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF WATER TANKS FROM ACCESS ROAD TO HATCH ADIT. VIEW NORTH. LUCKY TIGER MILL OFFICE (FEATURE B-I) IN DISTANCE. (OCTOBER, 1995) - Nevada Lucky Tiger Mill & Mine, Water Tanks, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  9. HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  10. 11. BUOY DECK, NEAR PILOT HOUSE SUPERSTRUCTURE, LOOKING TOWARDS HATCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. BUOY DECK, NEAR PILOT HOUSE SUPERSTRUCTURE, LOOKING TOWARDS HATCH DOOR INTO WINCH ROOM IN THE SUPERSTRUCTURE (LABELED AS FASSAGE & HYDRAULIC MACHINERY ON PLAN), SHOWING UNDERSIDE OF GEARED WHEEL OF BOOM. - U.S. Coast Guard Cutter WHITE LUPINE, U.S. Coast Guard Station Rockland, east end of Tillson Avenue, Rockland, Knox County, ME

  11. 2. WEST REAR, WITH PORTHOLE ESCAPE HATCH ABOVE ENTRY DOOR. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. WEST REAR, WITH PORTHOLE ESCAPE HATCH ABOVE ENTRY DOOR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  12. Next-Generation MKIII Lightweight HUT/Hatch Assembly

    NASA Technical Reports Server (NTRS)

    McCarthy, Mike; Toscano, Ralph

    2013-01-01

    The MK III (H-1) carbon-graphite/ epoxy Hard Upper Torso (HUT)/Hatch assembly was designed, fabricated, and tested in the early 1990s. The spacesuit represented an 8.3 psi (˜58 kPa) technology demonstrator model of a zero prebreathe suit. The basic torso shell, brief, and hip areas of the suit were composed of a carbon-graphite/epoxy composite lay-up. In its current configuration, the suit weighs approximately 120 lb (˜54 kg). However, since future planetary suits will be designed to operate at 0.26 bar (˜26 kPa), it was felt that the suit's re-designed weight could be reduced to 79 lb (˜35 kg) with the incorporation of lightweight structural materials. Many robust, lightweight structures based on the technologies of advanced honeycomb materials, revolutionary new composite laminates, metal matrix composites, and recent breakthroughs in fullerene fillers and nanotechnology lend themselves well to applications requiring materials that are both light and strong. The major problem involves the reduction in weight of the HUT/ Hatch assembly for use in lunar and/or planetary applications, while at the same time maintaining a robust structural design. The technical objective is to research, design, and develop manufacturing methods that support fa b rica - tion of a lightweight HUT/Hatch assembly using advanced material and geometric redesign as necessary. Additionally, the lightweight HUT/Hatch assembly will interface directly with current MK III hardware. Using the new operating pressure and current MK III (H-1) interfaces as a starting block, it is planned to maximize HUT/Hatch assembly weight reduction through material selection and geometric redesign. A hard upper torso shell structure with rear-entry closure and corresponding hatch will be fabricated. The lightweight HUT/Hatch assembly will retrofit and interface with existing MK III (H-1) hardware elements, providing NASA with immediate "plug-andplay" capability. NASA crewmembers will have a lightweight

  13. Hatch: Moving towards seamless database protocols for ecological data

    NASA Astrophysics Data System (ADS)

    Fremier, A. K.; Blair, C.; Smith, S.; Weigel, D.; Newsom, M. A.

    2013-12-01

    Data collection and ecological processes do not occur at similar scales. Monitoring our environment, therefore, requires research approaches that integrate data across spatial and temporal scales. Despite the enormous amount of data being collected annually, many government agencies are only now beginning to build coordinated data management systems. With efficient data flows and coded analysis tools, researchers will be better prepared to quickly answer key ecological questions across datasets. In this project, we designed an online platform for seamless data management, called Hatch. Our aim is to improve database protocols and data access to allow timely analysis of existing data, across time and space. Hatch is being developed for ecological monitoring of stream ecosystems in the Methow River basin in Washington State; however, the platform is general enough for managing multiple forms of database types. Hatch currently applies both a schema and schema-less database structure to link data collection events. It applies data standards developed and accepted across the Columbia River Basin. Initial data capture is driven by data needs for a mechanism-based model of ecosystem processes (namely periphyton production). Input data files, both past and current flows, are validated and stored along with metadata. Data search tools are being designed in accordance with data sharing agreements with appropriate security. The goal of Hatch is to defragment the analysis workspace by integrating data capture, search and analysis. Hatch helps researchers capture, search and analyze data in an online, flexible platform while conforming to project a specific schema. With less fragmented database protocols, scientists will be better prepared to efficiently answer scientific questions at relevant ecological scales.

  14. How embryos escape from danger: the mechanism of rapid, plastic hatching in red-eyed treefrogs.

    PubMed

    Cohen, Kristina L; Seid, Marc A; Warkentin, Karen M

    2016-06-15

    Environmentally cued hatching allows embryos to escape dangers and exploit new opportunities. Such adaptive responses require a flexibly regulated hatching mechanism sufficiently fast to meet relevant challenges. Anurans show widespread, diverse cued hatching responses, but their described hatching mechanisms are slow, and regulation of timing is unknown. Arboreal embryos of red-eyed treefrogs, Agalychnis callidryas, escape from snake attacks and other threats by very rapid premature hatching. We used videography, manipulation of hatching embryos and electron microscopy to investigate their hatching mechanism. High-speed video revealed three stages of the hatching process: pre-rupture shaking and gaping, vitelline membrane rupture near the snout, and muscular thrashing to exit through the hole. Hatching took 6.5-49 s. We hypothesized membrane rupture to be enzymatic, with hatching enzyme released from the snout during shaking. To test this, we displaced hatching embryos to move their snout from its location during shaking. The membrane ruptured at the original snout position and embryos became trapped in collapsed capsules; they either moved repeatedly to relocate the hole or shook again and made a second hole to exit. Electron microscopy revealed that hatching glands are densely concentrated on the snout and absent elsewhere. They are full of vesicles in embryos and release most of their contents rapidly at hatching. Agalychnis callidryas' hatching mechanism contrasts with the slow process described in anurans to date and exemplifies one way in which embryos can achieve rapid, flexibly timed hatching to escape from acute threats. Other amphibians with cued hatching may also have novel hatching mechanisms. PMID:27307544

  15. Mosquitoes feeding on insect larvae.

    PubMed

    Harris, P; Riordan, D F; Cooke, D

    1969-04-11

    Caged Aedes aegypti and Culex tarsalis are attracted to insect larvae, engorge on their body fluids, and produce viable eggs. Attractiveness of the larvae is related to their size, shape, and color but not to their movement. The possibility that wild mosquitoes substitute insect hemolymph for vertebrate blood is discussed. PMID:5774191

  16. Chemical Structures of Plant Hydrolyzable Tannins Reveal Their in Vitro Activity against Egg Hatching and Motility of Haemonchus contortus Nematodes.

    PubMed

    Engström, M T; Karonen, M; Ahern, J R; Baert, N; Payré, B; Hoste, H; Salminen, J-P

    2016-02-01

    The use of synthetic drugs against gastrointestinal nematodes of ruminants has led to a situation where resistance to anthelmintics is widespread, and there is an urgent need for alternative solutions for parasite control. One promising approach is to use polyphenol-rich bioactive plants in animal feeds as natural anthelmintics. In the present work, the in vitro activity of a series of 33 hydrolyzable tannins (HTs) and their hydrolysis product, gallic acid, against egg hatching and motility of L1 and L2 stage Haemonchus contortus larvae was studied. The effect of the selected compounds on egg and larval structure was further studied by scanning electron microscopy. The results indicated clear relationships between HT structure and anthelmintic activity. While HT size, overall flexibility, the types and numbers of functional groups, together with the linkage types between monomeric HTs affected the activity differently, the optimal structure was found with pentagalloylglucose.

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

    PubMed Central

    2014-01-01

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

  18. Virulent Hessian fly larvae manipulate the free amino acid content of host wheat plants.

    PubMed

    Saltzmann, Kurt D; Giovanini, Marcelo P; Zheng, Cheng; Williams, Christie E

    2008-11-01

    Gall-forming insects induce host plants to form specialized structures (galls) that provide immature life stages of the insect access to host plant nutrients and protection from natural enemies. Feeding by larvae of the Hessian fly (Mayetiola destructor Say) causes susceptible host wheat plants to produce a gall-like nutritive tissue that supports larval growth and development. To determine if changes in host plant free amino acid levels are associated with virulent Biotype L Hessian fly larval feeding, we quantified free amino acid levels in crown tissues of susceptible Newton wheat plants 1, 4, and 7 days after Hessian fly egg hatch. Hessian fly-infested susceptible plants were more responsive than resistant plants or uninfested controls, showing higher concentrations of alanine, glutamic acid, glycine, phenylalanine, proline, and serine 4 days after egg hatch. This 4-day post-hatch time point corresponds to the maturation of nutritive tissue cells in susceptible plants and the onset of rapid larval growth. By 7 days after egg hatch, when virulent second instars are actively feeding on the contents of nutritive tissue cells, the aromatic amino acids phenylalanine and tyrosine were more abundant compared to uninfested controls, but the levels of other free amino acids were no longer elevated. Changes in free amino acid abundance described in this report were associated with increased levels of mRNA encoded by wheat genes involved in amino acid synthesis and transport.

  19. STS-38 Pilot Culbertson rolls through CCT side hatch during egress training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Pilot Frank L. Culbertson, wearing launch and entry suit (LES) and launch and entry helmet (LEH), rolls through the side hatch of the crew compartment trainer (CCT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Assisted by technicians, Culbertson practices emergency egress through the side hatch using the crew escape system (CES) pole which extends out the side hatch. The inflated safety cushion breaks Culbertson's fall as he rolls out of the side hatch.

  20. Toxic effects of silica nanoparticles on zebrafish embryos and larvae.

    PubMed

    Duan, Junchao; Yu, Yongbo; Shi, Huiqin; Tian, Linwei; Guo, Caixia; Huang, Peili; Zhou, Xianqing; Peng, Shuangqing; Sun, Zhiwei

    2013-01-01

    Silica nanoparticles (SiNPs) have been widely used in biomedical and biotechnological applications. Environmental exposure to nanomaterials is inevitable as they become part of our daily life. Therefore, it is necessary to investigate the possible toxic effects of SiNPs exposure. In this study, zebrafish embryos were treated with SiNPs (25, 50, 100, 200 µg/mL) during 4-96 hours post fertilization (hpf). Mortality, hatching rate, malformation and whole-embryo cellular death were detected. We also measured the larval behavior to analyze whether SiNPs had adverse effects on larvae locomotor activity. The results showed that as the exposure dosages increasing, the hatching rate of zebrafish embryos was decreased while the mortality and cell death were increased. Exposure to SiNPs caused embryonic malformations, including pericardial edema, yolk sac edema, tail and head malformation. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lower dose (25 and 50 µg/mL SiNPs) produced substantial hyperactivity while the higher doses (100 and 200 µg/mL SiNPs) elicited remarkably hypoactivity in dark periods. In summary, our data indicated that SiNPs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior. PMID:24058598

  1. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity.

    PubMed

    Eiri, Daren M; Suwannapong, Guntima; Endler, Matthew; Nieh, James C

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study.

  2. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity

    PubMed Central

    Eiri, Daren M.; Suwannapong, Guntima; Endler, Matthew; Nieh, James C.

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study. PMID:26018139

  3. 123. Pre1911. View forward from near mizzen hatch, starboard side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    123. Pre-1911. View forward from near mizzen hatch, starboard side showing crew standing on a load of lumber. Note main fife rail, small hatch with cover (possibly original 'lime juice hatch') just aft. Fred Heick Collection. - Ship BALCLUTHA, 2905 Hyde Street Pier, San Francisco, San Francisco County, CA

  4. 9 CFR 82.9 - Interstate movement of hatching eggs from a quarantined area.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Interstate movement of hatching eggs... hatching eggs from a quarantined area. Hatching eggs from birds or poultry not known to be infected with or... eggs are accompanied by a permit obtained in accordance with § 82.11; (b) Copies of the...

  5. Relative acute effects of low pH and high iron on the hatching and survival of the water mite (Arrenurus manubriator) and the aquatic insect (Chironomus riparius)

    SciTech Connect

    Rousch, J.M.; Simmons, T.W.; Kerans, B.L.; Smith, B.P.

    1997-10-01

    The authors investigated the relative effects of low pH and high iron on a water mite, Arrenurus manubriator and an aquatic insect, Chironomus riparius. Eggs and active stages were exposed in static renewal toxicity tests to pH 6, 5, 4, 3, and 2, made by adding sulfuric acid to reconstituted soft water, or to iron levels of 200, 400, 600, 800, and 1,000 mg/L, made by adding ferrous sulfate to soft water at pH 4. Experiments were conducted at 22 C with a 16:8-h photoperiod, and treatments were replicated three times with at least nine individuals per treatment. Data were analyzed with a logistic response function and one-way ANOVA for pH and iron tests, respectively. Egg hatching was reduced at pH 2 for midges and at pH 3 for mites. Iron had no effect on hatching for either species. Survival of midge larvae was partially reduced at pH 4, and survival of mite deutonymphs, larvae, female and male adults was reduced at pH 3. Survival of midge larvae, and mite deutonymphs and male adults was reduced at 400, 200, and 1,000 mg Fe/L, respectively. Mite female adults and larvae were unaffected by iron. Higher metabolic requirements of unfed immature stages, the gelatinous covering of mite and insect eggs, the longer incubation period of mite eggs, and the greater osmoregulatory potential of adult mites may have contributed to the differences observed.

  6. Understanding Prostate Cancer: Newly Diagnosed

    MedlinePlus

    ... Wellness PCF Spotlight Glossary African American Men Understanding Prostate Cancer Newly Diagnosed Newly Diagnosed Staging the Disease Issues ... you care about has recently been diagnosed with prostate cancer, this section will help guide you through the ...

  7. [Assisted hatching for improving embryo implantation. A bibliographical review].

    PubMed

    Hernández-Nieto, Carlos Alberto; Soto-Cossio, Luz Estefhany; Basurto-Díaz, David

    2015-04-01

    Embryo implantation represents the most critical step of the reproductive process in many species, to be successful requires a receptive endometrium, functional embryo at a stage of embryonic development and proper dialogue between embryonic and maternal tissues. Hatching is the process in which the blastocyst gets rid of the zona pellucida to be implemented. The failure in this factor can lead to reproductive problems, even under assisted reproduction techniques. Assisted hatching is a technique used in assisted reproduction laboratories to improve performance in the process of fecundation or in vitro fertilization. This technique is based on impairment or section of the zona pellucida using different techniques. In this review, the most common indications and techniques used to perform this procedure and improve success rates in assisted reproduction techniques are synthesized. PMID:26727756

  8. Hatching and fledging times from grassland passerine nests

    USGS Publications Warehouse

    Pietz, P.J.; Granfors, D.A.; Grant, T.A.; Ribic, C.A.; Thompson, F. R.; Pietz, P.J.

    2012-01-01

    Accurate estimates of fledging age are needed in field studies to avoid inducing premature fledging or missing the fledging event. Both may lead to misinterpretation of nest fate. Correctly assessing nest fate and length of the nestling period can be critical for accurate calculation of nest survival rates. For researchers who mark nestlings, knowing the age at which their activities may cause young to leave nests prematurely could prevent introducing bias to their studies. We obtained estimates of fledging age using data from grassland bird nests monitored from hatching through fledging with video-surveillance systems in North Dakota and Minnesota during 1996–2001. We compared these values to those obtained from traditional nest visits and from available literature. Mean and modal fledging ages for video-monitored nests were generally similar to those for visited nests, although Clay-colored Sparrows (Spizella pallida) typically fledged 1 day earlier from visited nests. Average fledging ages from both video and nest visits occurred within ranges reported in the literature, but expanded by 1–2 days the upper age limit for Clay-colored Sparrows and the lower age limit for Bobolinks (Dolichonyx oryzivorus). Video showed that eggs hatched throughout the day whereas most young fledged in the morning (06:30–12:30 CDT). Length of the hatching period for a clutch was usually >1 day and was positively correlated with clutch size. Length of the fledging period for a brood was usually <1 day, and in nearly half the nests, fledging was completed within <2 hr. Video surveillance has proven to be a useful tool for providing new information and for corroborating published statements related to hatching and fledging chronology. Comparison of data collected from video and nest visits showed that carefully conducted nest visits generally can provide reliable data for deriving estimates of survival.

  9. Thermal effects in laser-assisted embryo hatching

    NASA Astrophysics Data System (ADS)

    Douglas-Hamilton, Diarmaid H.; Conia, Jerome D.

    2000-08-01

    Diode lasers [(lambda) equals 1480 nm] are used with in-vitro fertilization [IVF] as a promoter of embryo hatching. A focused laser beam is applied in vitro to form a channel in the zona pellucida (shell) of the pre-embryo. After transfer into the uterus, the embryo hatches: it extrudes itself through the channel and implants into the uterine wall. Laser-assisted hatching can result in improving implantation and pregnancy success rates. We present examples of zone pellucida ablation using animal models. In using the laser it is vital not to damage pre-embryo cells, e.g. by overheating. In order to define safe regimes we have derived some thermal side-effects of zona pellucida removal. The temperature profile in the beam and vicinity is predicted as function of laser pulse duration and power. In a crossed-beam experiment a HeNe laser probe detects the temperature-induced change in refractive index. We find that the diode laser beam produces superheated water approaching 200 C on the beam axis. Thermal histories during and following the laser pulse are given for regions in the neighborhood of the beam. We conclude that an optimum regime exists with pulse duration

  10. Hatching failure increases with severity of population bottlenecks in birds

    PubMed Central

    Briskie, James V.; Mackintosh, Myles

    2004-01-01

    Severe bottlenecks can reduce genetic diversity and increase inbreeding as individuals are forced to mate with close relatives, but it is unknown at what minimum population size the negative fitness consequences of bottlenecks are expressed. The New Zealand avifauna contains a large number of species that have gone through bottlenecks of varying severity, providing an exceptional opportunity to test this question by using the comparative method. Using decreased hatchability as a measure of fitness costs, we found that hatching failure was significantly greater among both native and introduced species that had passed through bottlenecks of <150 individuals. Comparisons between pre- and postbottleneck populations of introduced species suggest that hatching problems arise even in populations founded by <600 individuals. Our study confirms that hatching failure is widespread and persistent among birds passing through severe bottlenecks and that the population sizes at which this fitness cost is expressed are several times greater than the number of individuals currently used to found most new populations of endangered species. We recommend that conservation managers revise the protocols they use for reintroductions or they may unwittingly reduce the long-term viability of the species they are trying to save. PMID:14699045

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

    PubMed

    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. PMID:27037621

  12. Proteomic analysis of skeletal deformity in diploid and triploid rainbow trout (Oncorhynchus mykiss) larvae.

    PubMed

    Babaheydari, Samad Bahrami; Keyvanshokooh, Saeed; Dorafshan, Salar; Johari, Seyed Ali

    2016-09-01

    A proteomic screening approach was employed to achieve a better understanding of the changes that occur in protein expression patterns associated with skeletal deformities in both diploid and triploid rainbow trout larvae. Triploidy was induced through the application of heat shock of 28°C for 10min to eggs 10-min post fertilization in an aquarium equipped with a heater. Percentage of skeletal deformity in heat-shocked larvae (2.88±0.30, mean±S.E.) was significantly (P<0.05) greater than that of the diploids (0.55±0.24). At five days after hatching, proteins of normal and deformed specimens of deyolked larvae were subjected to proteomic analysis using two-dimensional electrophoresis and mass spectrometry. Among the identified protein spots from diploids, creatine kinase was found to be increased in larvae with skeletal deformities, while apolipoprotein A-I-2, apolipoprotein A-II and calmodulin were found to be decreased in deformed fish. Among the five protein spots that were identified in heat-shocked fish, apolipoprotein A-I-2, apolipoprotein A-II, parvalbumin, myosin light chain 1-1 and nucleoside diphosphate kinase were found to be decreased in deformed larvae. The identification of nine protein spots showing altered expression in deformed fish allows us to reach a preliminary view of the molecular mechanisms that are involved in the development of skeletal malformations in diploid and triploid fish.

  13. Gene regulation of lipid and phospholipid metabolism in Atlantic cod (Gadus morhua) larvae.

    PubMed

    Li, Keshuai; Østensen, Mari-Ann; Attramadal, Kari; Winge, Per; Sparstad, Torfinn; Bones, Atle M; Vadstein, Olav; Kjørsvik, Elin; Olsen, Yngvar

    2015-12-01

    The mechanism of essentiality of dietary phospholipid (PL) for larval fish is not clear. The main objective of the present study was to determine if the PL requirement of Atlantic cod larvae was due to any genetic impairment caused by functional immaturity. Cod larvae were sampled at 1, 3, 8, 13, 17, 18, 30, 42 and 60 days post hatch (dph) for transcriptome analysis using a recently developed microarray. The fatty acid profile and gene expression levels of cod larvae at 17 dph were compared after feeding differently enriched rotifers, which contained different DHA levels in PL. No significant differences (p<0.05) were found for the two rotifer diets in the overall gene expression level of cod larvae, their growth and survival, and their DHA levels in total lipid and PL fraction. The fatty acid data suggested that dietary EPA was elongated to DPA by cod larvae, and a threshold DHA level in PL to maintain membrane fluidity and other functions may exist. There appeared to be no major effect of development on the expression of key genes of PL biosynthesis suggesting no genetic constrain in early developmental stages. Our overall data suggested that besides the possible limited de novo PC synthesis ability in the intestine, other metabolic constraints should also be considered, especially the possible low input of bile PC as a result of immature liver. Further studies are needed to elucidate the gene expression level and enzyme activity in the PL biosynthesis pathways for specific tissue or cells.

  14. Proteomic analysis of skeletal deformity in diploid and triploid rainbow trout (Oncorhynchus mykiss) larvae.

    PubMed

    Babaheydari, Samad Bahrami; Keyvanshokooh, Saeed; Dorafshan, Salar; Johari, Seyed Ali

    2016-09-01

    A proteomic screening approach was employed to achieve a better understanding of the changes that occur in protein expression patterns associated with skeletal deformities in both diploid and triploid rainbow trout larvae. Triploidy was induced through the application of heat shock of 28°C for 10min to eggs 10-min post fertilization in an aquarium equipped with a heater. Percentage of skeletal deformity in heat-shocked larvae (2.88±0.30, mean±S.E.) was significantly (P<0.05) greater than that of the diploids (0.55±0.24). At five days after hatching, proteins of normal and deformed specimens of deyolked larvae were subjected to proteomic analysis using two-dimensional electrophoresis and mass spectrometry. Among the identified protein spots from diploids, creatine kinase was found to be increased in larvae with skeletal deformities, while apolipoprotein A-I-2, apolipoprotein A-II and calmodulin were found to be decreased in deformed fish. Among the five protein spots that were identified in heat-shocked fish, apolipoprotein A-I-2, apolipoprotein A-II, parvalbumin, myosin light chain 1-1 and nucleoside diphosphate kinase were found to be decreased in deformed larvae. The identification of nine protein spots showing altered expression in deformed fish allows us to reach a preliminary view of the molecular mechanisms that are involved in the development of skeletal malformations in diploid and triploid fish. PMID:27219664

  15. Pre- and post-hatch trophic egg production in the subsocial burrower bug, Canthophorus niveimarginatus (Heteroptera: Cydnidae)

    NASA Astrophysics Data System (ADS)

    Filippi, Lisa; Baba, Narumi; Inadomi, Koichi; Yanagi, Takao; Hironaka, Mantaro; Nomakuchi, Shintaro

    2009-02-01

    In recent years, three terrestrial bugs, Adomerus triguttulus and Sehirus cinctus (Cydnidae) and the closely related Parastrachia japonensis (Parastrachiidae), have been the focus of several fascinating studies because of the remarkable, extensive parental care they were found to display. This care includes egg and nymph guarding, production of trophic eggs, unfertilized, low cost eggs that are used as food by newly hatched nymphs, and progressive provisioning of the host seed. In this study, we have investigated yet a third related Asian cydnid, Canthophorus niveimarginatus, with regard to the possible occurrence of some or all of these complex traits in order to assess how widespread these maternal investment patterns are in this group of insects and to better understand the implications of their manifestations from an evolutionary context. Manipulative experiments were carried out in the lab to determine whether females provision nests. Observational and egg removal studies were carried out to determine whether trophic eggs are produced, and, if they are, their possible impact on nymphal success. The findings revealed that C. niveimarginatus does, in fact, progressively provision young, and this species also displays all of the other behaviors associated with extended parental care in subsocial insects. Moreover, unlike the other two related species, which place trophic eggs on the surface of the original egg mass, C. niveimarginatus produces both pre- and post-hatch trophic eggs. Nymphs deprived of access to post-hatch trophic eggs had significantly lower body weight and survival rate than those that fed on them. To our knowledge, this is the first time the production of both pre- and post-hatch trophic eggs has been demonstrated in insects outside the Hymenoptera. In this paper, we qualitatively and quantitatively demonstrate the provisioning behavior and patterns of trophic egg production in C. niveimarginatus. When and how trophic eggs are produced and

  16. Inheritance and World Variation in Thermal Requirements for Egg Hatch in Lymantria dispar (Lepidoptera: Erebidae).

    PubMed

    Keena, M A

    2016-02-01

    Mode of inheritance of hatch traits in Lymantria dispar L. was determined by crossing populations nearly fixed for the phenotypic extremes. The nondiapausing phenotype was inherited via a single recessive gene and the phenotype with reduced low temperature exposure requirements before hatch was inherited via a single dominant gene. There was no evidence for sex-linkage or cytoplasmic effects with either gene. Eggs from 43 geographic populations were evaluated for hatch characteristics after being held for 60 d at 5°C followed by incubation at 25°C. There was considerable variation both within and among the populations in the proportion able to hatch, time to first hatch, and average time to hatch. Egg masses with reduced requirement for low temperatures before the eggs were ready to hatch were present in all subspecies of L. dispar and the phenotype was not fixed in most populations. The populations clustered into three distinct groups, and climatic variables were found to be rough predictors of those groups. Variation in hatch phenotypes between populations is likely an adaptation to local climate and within a population provides a bet-hedging strategy to ensure that at least some hatch synchronizes with host leaf-out. Continued vigilance to prevent movement of populations both within and between countries is warranted, because some of the alleles that confer nondiapause or reduced low temperature requirements before egg hatch are not present in all populations and their introduction would increase variation in egg hatch within a population. PMID:26510608

  17. Inheritance and World Variation in Thermal Requirements for Egg Hatch in Lymantria dispar (Lepidoptera: Erebidae).

    PubMed

    Keena, M A

    2016-02-01

    Mode of inheritance of hatch traits in Lymantria dispar L. was determined by crossing populations nearly fixed for the phenotypic extremes. The nondiapausing phenotype was inherited via a single recessive gene and the phenotype with reduced low temperature exposure requirements before hatch was inherited via a single dominant gene. There was no evidence for sex-linkage or cytoplasmic effects with either gene. Eggs from 43 geographic populations were evaluated for hatch characteristics after being held for 60 d at 5°C followed by incubation at 25°C. There was considerable variation both within and among the populations in the proportion able to hatch, time to first hatch, and average time to hatch. Egg masses with reduced requirement for low temperatures before the eggs were ready to hatch were present in all subspecies of L. dispar and the phenotype was not fixed in most populations. The populations clustered into three distinct groups, and climatic variables were found to be rough predictors of those groups. Variation in hatch phenotypes between populations is likely an adaptation to local climate and within a population provides a bet-hedging strategy to ensure that at least some hatch synchronizes with host leaf-out. Continued vigilance to prevent movement of populations both within and between countries is warranted, because some of the alleles that confer nondiapause or reduced low temperature requirements before egg hatch are not present in all populations and their introduction would increase variation in egg hatch within a population.

  18. Culturing larvae of marine invertebrates.

    PubMed

    Strathmann, Richard R

    2014-01-01

    Larvae of marine invertebrates cultured in the laboratory experience conditions that they do not encounter in nature, but development and survival to metamorphic competence can be obtained in such cultures. This protocol emphasizes simple methods suitable for a wide variety of larvae. Culturing larvae requires seawater of adequate quality and temperature within the tolerated range. Beyond that, feeding larvae require appropriate food, but a few kinds of algae and animals are sufficient as food for diverse larvae. Nontoxic materials include glass, many plastics, hot-melt glue, and some solvents, once evaporated. Cleaners that do not leave toxic residues after rinsing include dilute hydrochloric or acetic acid, sodium hypochlorite (commercial bleach), and ethanol. Materials that can leave toxic residues, such as formaldehyde, glutaraldehyde, detergents, and hand lotions, should be avoided, especially with batch cultures that lack continuously renewed water. Reverse filtration can be used to change water gently at varying frequencies, depending on temperature and the kinds of food that are provided. Bacterial growth can be limited by antibiotics, but antibiotics are often unnecessary. Survival and growth are increased by low concentrations of larvae and stirring of large or dense cultures. One method of stirring large numbers of containers is a rack of motor-driven paddles. Most of the methods and materials are inexpensive and portable. If necessary, a room within a few hours of the sea could be temporarily equipped for larval culture. PMID:24567204

  19. Effects of polychlorinated biphenyl 126 on green frog (Rana clamitans) and leopard frog (Rana pipiens) hatching success, development, and metamorphosis

    SciTech Connect

    Rosenshield, M.L.; Jofre, M.B.; Karasov, W.H.

    1999-11-01

    Although increasing evidence links plana chlorinated hydrocarbons, such as polychlorinated biphenyls (PCBs), to decreases in survival and reproduction of fish, mammals, and birds near Green Bay, Wisconsin, and the Great Lakes, USA, relatively little is known of their bioaccumulation or of their possible effects in amphibians. The authors exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (Rana pipiens), to PCB 126, a model coplanar PCB compound. Nominal concentrations ranged from 0.005 to 50 {micro}g/L, and exposure lasted through metamorphosis. Tissue concentrations of PCB 126 in tadpoles that did not metamorphose by the end of the experiment ranged from 1.2 to 9,600 ng/g wet mass. No significant mortality of embryos occurred before hatching; however, survival of larvae was significantly reduced at the highest concentration for both species. Few deformities were observed, but the incidence of edema was significantly higher in tadpoles exposed to 50 {micro}g/L. Swimming speed and growth of tadpoles was also significantly reduced in this treatment. The percent of tadpoles that reached metamorphosis was significantly lower in green frogs at the highest concentration, and no leopard frogs survived past day 47 of the experiment in this treatment. At high concentrations, PCB 126 affected both ranid species; however, sublethal effects were not apparent for the parameters the authors measured at concentrations that occur in water in the Green Bay ecosystem.

  20. The Impact of Egg Ozonation on Hatching Success, Larval Growth, and Survival of Atlantic Cod, Atlantic Salmon, and Rainbow Trout.

    PubMed

    Fry, Jessica; Casanova, Pérez Juan; Hamoutene, Dounia; Lush, Lynn; Walsh, Andy; Couturier, Cyr

    2015-03-01

    The direct exposure of fish eggs to ozonated water has generated interest as a means of ensuring pathogen-free eggs without the use of harsh chemicals. However, there are numerous knowledge gaps, including safe contact times, exposure levels, and potential long-term effects on aquaculture species in both freshwater and seawater. The effect of different ozone (O3) doses (0.5-1.0, 1.5-2.0, and 2.5-3.0 mg of O3/L for 90 s) on recently fertilized eggs of Atlantic Cod Gadus morhua and eyed eggs of Atlantic Salmon Salmo salar and Rainbow Trout Oncorhynchus mykiss was evaluated in comparison with the effects of two commercial disinfectants: Perosan (0.004 mg/L) and Ovadine (100 mg/L). The impact of ozone application was evaluated based on hatching success, larval nucleic acid concentration, larval growth, and survival. Overall, results indicated that ozonation of Atlantic Cod eggs at a dose less than 3.0 mg/L for 90 s produced no negative effect on the larvae up to 30 d posthatch. Furthermore, ozonation of Atlantic Salmon and Rainbow Trout eggs generated no negative effect on the larvae, based on monitoring until 85% yolk sac re-absorption (16 d posthatch). PMID:26306334

  1. Dengue virus detection in Aedes aegypti larvae from southeastern Brazil.

    PubMed

    Cecílio, Samyra Giarola; Júnior, Willer Ferreira Silva; Tótola, Antônio Helvécio; de Brito Magalhães, Cíntia Lopes; Ferreira, Jaqueline Maria Siqueira; de Magalhães, José Carlos

    2015-06-01

    The transmission of dengue, the most important arthropod-borne viral disease in Brazil, has been intensified over the past decades, along with the accompanying expansion and adaptation of its Aedes vectors. In the present study, we mapped dengue vectors in Ouro Preto and Ouro Branco, Minas Gerais, by installing ovitraps in 32 public schools. The traps were examined monthly between September, 2011 through July, 2012 and November, 2012 to April, 2013. The larvae were reared until the fourth stadium and identified according to species. The presence of dengue virus was detected by real time PCR and agarose gel electrophoresis. A total of 1,945 eggs was collected during the 17 months of the study. The Ovitrap Positivity Index (OPI) ranged from 0 to 28.13% and the Eggs Density Index (EDI) ranged from 0 to 59.9. The predominant species was Aedes aegypti, with 84.9% of the hatched larvae. Although the collection was low when compared to other ovitraps studies, vertical transmission could be detected. Of the 54 pools, dengue virus was detected in four Ae. aegypti pools. PMID:26047186

  2. Development of eggs and larvae of Emmelichthys nitidus (Percoidei: Emmelichthyidae) in south-eastern Australia, including a temperature-dependent egg incubation model

    NASA Astrophysics Data System (ADS)

    Neira, Francisco J.; Keane, John P.; Lyle, Jeremy M.; Tracey, Sean R.

    2008-08-01

    Reared eggs and field-collected material were employed to describe the development of the pelagic eggs and larvae of Emmelichthys nitidus (Emmelichthyidae), a small (36 cm TL) mid-water schooling species common in shelf waters of temperate Australia. Hydrated oocytes from adults trawled from spawning grounds off eastern Tasmania were fertilized and reared to the yolk-sac larval stage, and the data employed to build a temperature-dependent egg incubation model. Embryogenesis lasted 96, 84 and 54 h at mean temperatures of 13.1, 14.4 and 16.5 °C respectively, and was divided into seven stages based on extent of epiboly until blastopore closure (stages I-III) and embryo growth (stages IV-VII). Eggs (1.00-1.05 mm diameter) are spherical with a smooth chorion, small perivitelline space and prominent, unsegmented yolk with a single, posteriorly-located oil globule (0.18-0.20 mm diameter) that becomes pigmented from stage III. Embryos have two distinct snout melanophores, and a paired melanophore row laterally along the trunk and tail. Morphological identification of eggs collected during surveys in October 2005 and 2006 was validated using quantitative PCR amplification of the mtDNA d-loop gene region unique to E. nitidus, producing an 80-100% agreement across all seven stages. Newly-emerged larvae (1.9-3.3 mm) possess a prominent yolk sac with the posteriorly-located, pigmented oil globule, mouth not yet functional and unpigmented eyes. Notochord flexion occurs between 5 and 8 mm while fins are formed by 12 mm. Larvae examined (3.3-17.4 mm) are lightly pigmented and possess percoid features such as an elongate to moderate body, coiled, triangular-shaped gut, preopercular spines and 24-25 myomeres; two prominent pigment patches opposite each other dorsally and ventrally along the tail are diagnostic. Variability of mean egg ages ( y) by temperature ( t) and stage ( i) was best described by the deterministic stage-to-age model y = 35.911exp[-(0.155 t + 0.262 i)] i2

  3. Taxonomic studies on the 0-group eel larvae ( Anguilla sp.) caught in the Sargasso Sea in 1979

    NASA Astrophysics Data System (ADS)

    Schoth, Monika

    1982-09-01

    More than 2000 0-group larvae (5.0-30.0 mm long) of both Atlantic Anguilla species were examined taxonomically. With regard to the total number of myomeres in A. rostrata and A. anguilla, an average difference between the two species of 6 to 8 myomeres was found in all size groups. 31 specimens (i.e. 1.76 %) exhibited 111 myomeres. The position of the last vertical blood vessel and the number of preanal myomeres turned out to be statistically different in both species; however, these differences cannot be used for species identification. The regression line for the position of the last vertical blood vessel according to the total number of myomeres indicates that individuals with a total of 111 myomeres may be A. anguilla. Measurements of total lengths revealed highly significant differences between the larvae of both eel species. It can be concluded that, on the average, A. rostrata (bar x = 15.70 mm) hatched about two weeks before A anguilla (bar x = 12.32 mm). On the other hand, results obtained from the biggest A. rostrata larvae (29.5 mm) and A. anguilla larvae (23.5 mm) make a spawning of A. rostrata likely two months before A. anguilla, when findings from hatching experiments with A. japonica are taken as a basis. There is no difference in the relative length of the intestine in either Anguilla species.

  4. The transfer of titanium dioxide nanoparticles from the host plant to butterfly larvae through a food chain

    PubMed Central

    Kubo-Irie, Miyoko; Yokoyama, Masaaki; Shinkai, Yusuke; Niki, Rikio; Takeda, Ken; Irie, Masaru

    2016-01-01

    This study aimed to examine the transfer of nanoparticles within a terrestrial food chain. Oviposited eggs of the swallowtail butterfly (Atrophaneura alcinous) were hatched on the leaves of the host plant (Aristolochia debilis), and the root stock and root hairs were submerged in a suspension of 10 μg/ml titanium dioxide nanoparticles (TiO2-NPs) in a 100 ml bottle. The presence of TiO2-NPs in the veins of the leaves was confirmed by X-ray analytical microscopy (X-ray AM). The hatched 1st instar larvae fed on the leaves to moult into 2nd instar larvae. Small agglomerates of TiO2-NPs less than 150 nm in diameter were identified in the vascular tissue of the exposed plant, the midgut and the excreta of the larvae by transmission electron microscopy. The image of Ti elemental mapping by X-ray AM was analysed with the quantitative spatial information mapping (QSIM) technique. The results demonstrated that TiO2-NPs were transferred from the plant to the larvae and they were disseminated throughout the environment via larval excreta. PMID:27030539

  5. The transfer of titanium dioxide nanoparticles from the host plant to butterfly larvae through a food chain

    NASA Astrophysics Data System (ADS)

    Kubo-Irie, Miyoko; Yokoyama, Masaaki; Shinkai, Yusuke; Niki, Rikio; Takeda, Ken; Irie, Masaru

    2016-03-01

    This study aimed to examine the transfer of nanoparticles within a terrestrial food chain. Oviposited eggs of the swallowtail butterfly (Atrophaneura alcinous) were hatched on the leaves of the host plant (Aristolochia debilis), and the root stock and root hairs were submerged in a suspension of 10 μg/ml titanium dioxide nanoparticles (TiO2-NPs) in a 100 ml bottle. The presence of TiO2-NPs in the veins of the leaves was confirmed by X-ray analytical microscopy (X-ray AM). The hatched 1st instar larvae fed on the leaves to moult into 2nd instar larvae. Small agglomerates of TiO2-NPs less than 150 nm in diameter were identified in the vascular tissue of the exposed plant, the midgut and the excreta of the larvae by transmission electron microscopy. The image of Ti elemental mapping by X-ray AM was analysed with the quantitative spatial information mapping (QSIM) technique. The results demonstrated that TiO2-NPs were transferred from the plant to the larvae and they were disseminated throughout the environment via larval excreta.

  6. Effects of rearing temperature and density on growth, survival and development of sea cucumber larvae, Apostichopus japonicus (Selenka)

    NASA Astrophysics Data System (ADS)

    Liu, Guangbin; Yang, Hongsheng; Liu, Shilin

    2010-07-01

    In laboratory conditions, effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively. Data series like larval length and density, metamorphic time, and survival rate of the larvae were recorded. Statistics showed that for A. japonicus, survival rate (from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature ( P<0.05). At different temperatures SGR was statistically significant as well ( P<0.05) from day 1, and maximal SGR was found on day 9 at 24°C (159.26±3.28). This study clearly indicated that at low temperature (<24°C), metamorphic rate was remarkably higher than at higher temperature (>26°C). Hatching rate was significantly different between 0.2-5 ind./ml groups and 20-50 ind./ml groups. Rearing larvae at the higher density had the smaller maximal-length, whereas needed longer time to complete metamorphosis. This study suggested that 21°C and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large -scale artificial breeding of A. japonicus’s larvae.

  7. Comparison of early life-stage strategies in temperate freshwater fish species: trade-offs are directed towards first feeding of larvae in spring and early summer.

    PubMed

    Teletchea, F; Fontaine, P

    2010-07-01

    Based on the analysis of 12 egg and larval variables and temperature of 65 temperate freshwater fish species, the possible relationships between oocyte diameter, larval size at hatch, time and temperature were reassessed and the main early life-stage strategies were described and compared. Time and degree-days required to reach hatching and mixed feeding were weakly related to oocyte diameter and strongly to temperature. These results are chiefly because oocyte diameter and yolk reserves are weakly related and temperature strongly increases tissue differentiation rate, activity of hatching glands and embryo motility. Strong positive relationships were found between larval size and oocyte diameter and degree-days for incubation. No relationship was found between larval size and degree-days from hatching to mixed feeding and between degree-days for incubation and degree-days from hatching to mixed feeding. These last two results are chiefly because the developmental stages at hatching and at the onset of exogenous feeding are not fixed in ontogeny and are not directly related to either larval size or degree-days for incubation, but more probably are species specific. Whatever the spawning season, which can occur almost all year long, the different trade-offs at the early life-stages ensure that most larvae are first feeding during spring, when food size and abundance are the most appropriate.

  8. Combination of competitive exclusion and immunisation with a live Salmonella vaccine in newly hatched chickens: Immunological and microbiological effects.

    PubMed

    Braukmann, M; Barrow, P A; Berndt, A; Methner, U

    2016-08-01

    In addition to evaluating the efficacy potential of a combined use of vaccination and competitive exclusion (CE) against Salmonella exposure in chicks at 3-days of age, a live Salmonella Enteritidis vaccine (SE-LV) and a CE culture were tested for their ability to induce parameters of the innate immunity. Whereas the invasive SE-LV induced an influx of granulocytes and macrophages as well as an increased transcription of several cytokines in the caecal mucosa, the CE culture did not demonstrate any differences in these parameters compared to controls. It is therefore highly probable that the effects observed with CE cultures are not due to the rapid stimulation of the immune system. The combined use of both preparations did not result in an additive intestinal exclusion effect of the challenge strain more pronounced than that after single administration of the CE culture. The combined use of the Salmonella live vaccine and the CE culture resulted in an additive protective effect and prevented completely the systemic dissemination of the Salmonella challenge strain. To exploit the potential of combined use of CE and vaccination further and most effectively, live Salmonella vaccines are needed that are despite their attenuation in virulence still capable to induce both intestinal colonisation- and invasion-inhibition effects against Salmonella exposure. PMID:27473972

  9. Effects of the timing of initial feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae.

    PubMed

    Zhang, L; Wang, Y J; Hu, M H; Fan, Q X; Chenung, S G; Shin, P K S; Li, H; Cao, L

    2009-10-01

    The effects of delayed first feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae were examined under controlled conditions. Morphometric characters [yolk-sac volume, oil globule volume, head depth (H(D)), body depth (B(D)), eye diameter (E(D)), musculature height (M(H)), mouth diameter (M(D)) and total length (L(T))], body mass (M), specific growth rate (S(GR)) and survival were evaluated under different first-feeding time (2, 3, 4 and 5 days after hatching). Larvae began to feed exogenously at 2 days after hatching (DAH) and the point of no return (P(NR)) occurred between 5 and 6 DAH at 23 degrees C, range +/-1.0 degrees C. The yolk volume of larvae first-fed at 2 days had a significant difference compared with that of larvae first-fed at 3, 4 and 5 days on 3 and 4 DAH. The larvae first-fed at 2 days achieved comparatively better growth performance than that of 3, 4 and 5 days. On 5 DAH, all morphometric characters had significant differences between 2 and 5 days and 2 and 4 days initial feeding, respectively. Total mortality was recorded on 9 DAH for the larvae first-fed at 5 days. On 12 DAH, significant differences were observed between 2 and 4 days and 3 and 4 days initial feeding for all morphometric characters. From 16 DAH to the end of experiment, all growth variables of the larvae first-fed at 2 days were significantly higher than those in other treatments. The S(GR) (2-9 DAH) first-fed at 2 and 3 days were significantly higher than 4 and 5 day treatments, and the S(GR) (9-16 DAH) first-fed at 2 days was significantly higher than 3 and 4 day treatments. There was no significant difference, however, of S(GR) (16-28 DAH) among treatments. Survival rate was significantly higher at 2 days initial feeding (27.42%) when compared with 3 (15.96%) and 4 days (7.92%) initial feeding at the end of experiment. The present study suggests that the first feeding of S. scherzeri larvae should be initiated at 2 days after hatching for

  10. Inoculating poultry manure with companion bacteria influences growth and development of black soldier fly (Diptera: Stratiomyidae) larvae.

    PubMed

    Yu, Guohui; Cheng, Ping; Chen, Yanhong; Li, Yongjian; Yang, Zihong; Chen, Yuanfeng; Tomberlin, Jeffery K

    2011-02-01

    The growth and development of black soldier fly, Hermetia illucens (L.), larvae fed chicken manure inoculated with bacteria isolated from black soldier fly larvae and associated larval feed was evaluated. Four strains of Bacillus subtilis were evaluated. B. subtilis strains S15, S16, S19, were isolated from the gut of black soldier fly larvae. B. natto strain D1 was isolated from the diet fed to black soldier fly larvae. These bacteria were added individually into nonsterile 200 g fresh hen manure at 10(6) cfu/g and homogenized. Treated manure was then inoculated with 4-d old black soldier fly larvae. Prepupal weight ranged from 0.0606 g in the control to 0.0946 g in manure treated with the S15 strain. Larval survivorship to the prepupal stage in all treatments ranged from 98.00 ± 2.65% to 99.33 ± 1.15%. Prepupal survivorship to the pupal stage ranged from 91.92 ± 1.87% to 97.95 ± 1.03%. Adult emergence from the pupal stage did not significantly (P < 0.05) differ across treatments and ranged from 98.95 ± 1.82% to 100.00 ± 0.00%. Adult body length resulting from the larvae in each of the treatments was significantly greater than those from the control. Longevity of adults did not differ significantly between treatments. Time from hatching to the development of the first pupa did not differ significantly across treatments; however, development time from hatching to 90% reaching the prepupual stage was significantly different between treatments and ranged from 29.00 ± 1.00 d to 34.33 ± 3.51 d. Development time from hatching to 90% reaching the adult stages was significantly different between treatments. Our results demonstrate that inoculating poultry manure with bacteria from black soldier fly larvae influences the growth and development of conspecific larvae feeding on the manure. PMID:22182608

  11. Inoculating poultry manure with companion bacteria influences growth and development of black soldier fly (Diptera: Stratiomyidae) larvae.

    PubMed

    Yu, Guohui; Cheng, Ping; Chen, Yanhong; Li, Yongjian; Yang, Zihong; Chen, Yuanfeng; Tomberlin, Jeffery K

    2011-02-01

    The growth and development of black soldier fly, Hermetia illucens (L.), larvae fed chicken manure inoculated with bacteria isolated from black soldier fly larvae and associated larval feed was evaluated. Four strains of Bacillus subtilis were evaluated. B. subtilis strains S15, S16, S19, were isolated from the gut of black soldier fly larvae. B. natto strain D1 was isolated from the diet fed to black soldier fly larvae. These bacteria were added individually into nonsterile 200 g fresh hen manure at 10(6) cfu/g and homogenized. Treated manure was then inoculated with 4-d old black soldier fly larvae. Prepupal weight ranged from 0.0606 g in the control to 0.0946 g in manure treated with the S15 strain. Larval survivorship to the prepupal stage in all treatments ranged from 98.00 ± 2.65% to 99.33 ± 1.15%. Prepupal survivorship to the pupal stage ranged from 91.92 ± 1.87% to 97.95 ± 1.03%. Adult emergence from the pupal stage did not significantly (P < 0.05) differ across treatments and ranged from 98.95 ± 1.82% to 100.00 ± 0.00%. Adult body length resulting from the larvae in each of the treatments was significantly greater than those from the control. Longevity of adults did not differ significantly between treatments. Time from hatching to the development of the first pupa did not differ significantly across treatments; however, development time from hatching to 90% reaching the prepupual stage was significantly different between treatments and ranged from 29.00 ± 1.00 d to 34.33 ± 3.51 d. Development time from hatching to 90% reaching the adult stages was significantly different between treatments. Our results demonstrate that inoculating poultry manure with bacteria from black soldier fly larvae influences the growth and development of conspecific larvae feeding on the manure.

  12. Egg hatch and survival and development of beet webworm (Lepidoptera: Crambidae) larvae at different combinations of temperature and relative humidity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the role that temperature and humidity play in the population dynamics of the beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), egg hatchability, survival of 1st - 5th instars, survival of the complete larval stage, survival curves, and larval development rates were inve...

  13. Artificial Spawning Behavior and Development of Eggs, Larvae and Juveniles of the Red Spotted Grouper, Epinephelus akaara in Korea

    PubMed Central

    Park, Jong Youn; Cho, Jae Kwon; Son, Maeng Hyun; Kim, Kyong Min; Han, Kyeong Ho; Park, Jae Min

    2016-01-01

    This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaaraand the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred μg/kg of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder (2×2×2 m). Eggs were colorless transparent free pelagic eggs, 0.71–0.77 mm large (mean 0.74±0.02 mm, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02–2.17 mm in total length (mean 2.10±0.11 mm), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88–4.07 mm in total length (mean 3.98±0.13 mm), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9–35.2 mm in total length (mean 33.6±2.33 mm), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish. PMID:27294209

  14. Artificial Spawning Behavior and Development of Eggs, Larvae and Juveniles of the Red Spotted Grouper, Epinephelus akaara in Korea.

    PubMed

    Park, Jong Youn; Cho, Jae Kwon; Son, Maeng Hyun; Kim, Kyong Min; Han, Kyeong Ho; Park, Jae Min

    2016-03-01

    This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaaraand the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred μg/kg of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder (2×2×2 m). Eggs were colorless transparent free pelagic eggs, 0.71-0.77 mm large (mean 0.74±0.02 mm, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02-2.17 mm in total length (mean 2.10±0.11 mm), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88-4.07 mm in total length (mean 3.98±0.13 mm), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9-35.2 mm in total length (mean 33.6±2.33 mm), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish.

  15. Newly Deployed Sojourner Rover

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This 8-image mosaic was acquired during the late afternoon (near 5pm LST, note the long shadows) on Sol 2 as part of the predeploy 'insurance panorama' and shows the newly deployed rover sitting on the Martian surface. This color image was generated from images acquired at 530,600, and 750 nm. The insurance panorama was designed as 'insurance' against camera failure upon deployment. Had the camera failed, the losslessly-compressed, multispectral insurance panorama would have been the main source of image data from the IMP.

    However, the camera deployment was successful, leaving the insurance panorama to be downlinked to Earth several weeks later. Ironically enough, the insurance panorama contains some of the best quality image data because of the lossless data compression and relatively dust-free state of the camera and associated lander/rover hardware on Sol 2.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal investigator.

  16. Need for higher fuel burnup at the Hatch Plant

    SciTech Connect

    Beckhman, J.T.

    1996-03-01

    Hatch is a BWR 4 and has been in operation for some time. The first unit became commercial about 1975. Obtaining higher burnups, or higher average discharge exposures, is nothing new at Hatch. Since we have started, the discharge exposure of the plant has increased. Now, of course, we are not approaching the numbers currently being discussed but, the average discharge exposure has increased from around 20,000 MWD/MTU in the early to mid-1980s to 34,000 MWD/MTU in 1994, I am talking about batch average values. There are also peak bundle and peak rod values. You will have to make the conversions if you think in one way or the other because I am talking in batch averages. During Hatch`s operating history we have had some problems with fuel failure. Higher burnup fuel raises a concern about how much fuel failure you are going to have. Fuel failure is, of course, an economic issue with us. Back in the early 1980s, we had a problem with crud-induced localized corrosion, known as CILC. We have gotten over that, but we had some times when it was up around 27 fuel failures a year. That is not a pleasant time to live through because it is not what you want from an economic viewpoint or any other. We have gotten that down. We have had some fuel failures recently, but they have not been related to fuel burnup or to corrosion. In fact, the number of failures has decreased from the early 1980s to the 90s even though burnup increased during that time. The fuel failures are more debris-related-type failures. In addition to increasing burnups, utilities are actively evaluating or have already incorporated power uprate and longer fuel cycles (e.g., 2-year cycles). The goal is to balance out the higher power density, longer cycles, higher burnup, and to have no leakers. Why do we as an industry want to have higher burnup fuel? That is what I want to tell you a little bit about.

  17. Astronaut Vance Brand practices operating Docking Module hatch for ASTP

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Astronaut Vance D. Brand, command module pilot of the American Apollo Soyuz Test Project (ASTP) prime crew, practices operating a Docking Module hatch during ASTP pre-flight training at JSC. The Docking Module is designed to link the Apollo and Soyuz spacecraft during their docking in Earth orbit mission. Gary L. Doerre of JSC's Crew Training and Procedures Division is working with Brand. Doerre is wearing a face mask to help prevent possible exposure to Brand of disease prior to the ASTP launch.

  18. Motor racing accidents at Brands Hatch, 1988/9.

    PubMed

    Chapman, M A; Oni, J

    1991-09-01

    Little is known about the incidence of injury to race track motor-cyclists and car drivers. In a 1-year study at Brands Hatch, 70 of 33,184 competitors required hospital treatment. We found this injury rate to be higher than on the public highway. However, the anatomical distribution of injury caused by motor-bike accidents is similar to that found on the public highway. Motor-cyclists are more likely than car drivers to sustain limb trauma requiring outpatient treatment only. The number of participants requiring admission to hospital is broadly similar for car and bike races, being less than 0.1%.

  19. Potential role for gut microbiota in cell wall digestion and glucoside detoxification in Tenebrio molitor larvae.

    PubMed

    Genta, Fernando A; Dillon, Rod J; Terra, Walter R; Ferreira, Clélia

    2006-06-01

    Tenebrio molitor larvae were successfully reared free of cultivatable gut lumen bacteria, yeasts and fungi using two approaches; aseptic rearing from surface sterilized eggs and by feeding larvae with antibiotic-containing food. Insects were reared on a rich-nutrient complete diet or a nutrient-poor refractory diet. A comparison of digestive enzyme activities in germ free and conventional insects containing a gut microbiota did not reveal gross differences in enzymes that degrade cell walls from bacteria (lysozyme), fungi (chitinase and laminarinase) and plants (cellulase and licheninase). This suggested that microbial-derived enzymes are not an essential component of the digestive process in this insect. However, more detailed analysis of T. molitor midgut proteins using an electrophoretic separation approach showed that some digestive enzymes were absent and others were newly expressed in microbiota-free larvae. Larvae reared in antibiotic-containing refractory wheat bran diet performed poorly in comparison with controls. The addition of saligenin, the aglycone of the plant glucoside salicin, has more deleterious effects on microbiota-free larvae than on the conventionally reared larvae, suggesting a detoxifying role of midgut microbiota. Analysis of the volatile organic compounds released from the faecal pellets of the larvae shows key differences in the profiles from conventionally reared and aseptically reared larvae. Pentadecene is a semiochemical commonly found in other beetle species. Here we demonstrate the absence of pentadecene from aseptically reared larvae in contrast to its presence in conventionally reared larvae. The results are discussed in the light of the hypothesis that microbial products play subtle roles in the life of the insect, they are involved in the digestion of refractory food, detoxification of secondary plant compounds and modify the volatile profiles of the insect host.

  20. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility make final preparations for closing the access hatch to the Unity connecting module, part of the International Space Station, before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  1. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility close the access hatch to the Unity connecting module, part of the International Space Station, before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  2. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility prepare the hatch of the Unity connecting module for closure before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  3. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility hold part of the equipment to close the hatch to the Unity connecting module, part of the International Space Station, before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  4. Pesticide contamination and hatching success of waterbirds in Mississippi

    USGS Publications Warehouse

    White, D.H.; Fleming, W.J.; Ensor, K.L.

    1988-01-01

    Waterfowl wintering on the Yazoo National Wildlife Refuge (NWR) were contaminated (ltoreq 4 ppm wet wt) with dichloro diphenyl trichloroethane (DDT) and 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethylene (DDE), but residues were below levels known to affect waterfowl. Eggs of some nesting waterbirds contained higher than expected levels of DDE, especially those of green-backed herons (Butorides striatus), ranging up to 43 ppm wet weight. Hatching success (P lt 0.05) and eggshell thickness (P lt 0.05) in green-backed herons and anhingas (Anhinga anhinga) were negatively correlated with DDE in the eggs, and shell thinning (P lt 0.05) was evident 12-13 years after DDT was banned in the United States. The threshold level of DDE determined necessary for reduced hatching success in green-backed heron eggs was 5.1-10 ppm wet weight. These results further increase our ability to interpret DDE concentrations in waterbirds and predict their potential effects on productivity.

  5. Asynchronous hatching and food limitation: a test of Lack's hypothesis

    USGS Publications Warehouse

    Skagen, Susan Knight

    1988-01-01

    Lack’s (1954, 1968) hypothesis that asynchronous hatching of altricial birds is an adaptive response to unpredictable food shortages during the breeding season was examined in the highly granivorous Zebra Finch (Poephila guttata). I compared growth and survival of nestlings in asynchronous and artificially created synchronous brood reared under food-limited and food-abundant conditions in an aviary. I also examined the role of parental experience on survival and growth of nestlings. There was no differential mortality of Zebra Finch nestlings due to either asynchrony or food abundance. Young in abundant food treatments grew more rapidly, however, than those in food restricted treatments. Heaviest Zebra Finch nestlings in a brood grew more quickly than their lightest siblings when food was limited, supporting Lack’s hypothesis. Further, differential survival of light and heavy siblings occurred when food was abundant, suggesting that asynchronous hatching can be maladaptive under some ecological conditions. Nestlings reared by inexperienced parents suffered greater mortality and slower growth when food was abundant than nestlings raised by experienced parents. Prefledging mass was correlated with size at adulthood.

  6. Hatching of Echinostoma trivolvis miracidia in response to snail host and non-host chemical cues.

    PubMed

    Belden, Lisa K; Widder, Pamela D; Fischer, Lauren R; Carter, Ashlee B; Wojdak, Jeremy M

    2009-09-01

    Environmental cues are used by many organisms to time life history transitions and can be important for trematode host location. However, while much is understood about how larval trematodes locate hosts, much less is known about the potential role of host cues in the timing of trematode egg development and hatching. We addressed the potential role of host chemical cues in mediating hatching of Echinostoma trivolvis miracidia by comparing hatching in response to cues from the first intermediate host (the snail Planorbella trivolvis), a non-host snail (the snail Goniobasis proxima), and a non-host invertebrate (earthworm, Lumbricus terrestris). We hypothesized that in the presence of cues from their first intermediate host, E. trivolvis would hatch sooner and would be more synchronized than when host cues were absent. However, we found that hatching was unaffected by our cue treatments. In all treatments, hatching uniformly began at 13 days and was nearly evenly spread over the next 3 weeks. PMID:19513751

  7. Plant-Induced Hatching of Eggs of the Soybean Cyst Nematode Heterodera glycines.

    PubMed

    Tefft, P M; Bone, L W

    1985-07-01

    Root diffusate from soybean plants caused greater hatching of Heterodera glycines eggs during vegetative growth of the host, but the activity declined with plant senescence. Chelation of the root diffusate with ethylenediamine tetraacetic acid (EDTA) significantly increased hatching activity for H. glycines eggs. Diffusate from leafless plants caused little hatching, whereas treatment of intact plants with the growth regulators gibberellin and kinetin had no effect on the hatching activity of root diffusate. Treating H. glycines eggs with zinc chloride and root diffusate reduced egg hatching from zinc chloride alone. Levels of zinc in the root diffusate were insufficient to induce egg hatch, based on analysis by atomic absorption spectrophotometry. The enzymatic activity of leucine aminopeptidase in H. glycines eggs was not altered by treatment with chelated or nonchelated root diffusate.

  8. Experimental bacteriophage treatment of honeybees (Apis mellifera) infected with Paenibacillus larvae, the causative agent of American Foulbrood Disease

    PubMed Central

    Yost, Diane G.; Tsourkas, Philippos; Amy, Penny S.

    2016-01-01

    ABSTRACT American Foulbrood Disease (AFB) is an infection of honeybees caused by the bacterium Paenibacillus larvae. One potential remedy involves using biocontrol, such as bacteriophages (phages) to lyse P. larvae. Therefore, bacteriophages specific for P. larvae were isolated to determine their efficacy in lysing P. larvae cells. Samples from soil, beehive materials, cosmetics, and lysogenized P. larvae strains were screened; of 157 total samples, 28 were positive for at least one P. larvae bacteriophage, with a total of 30. Newly isolated bacteriophages were tested for the ability to lyse each of 11 P. larvae strains. Electron microscopy demonstrated that the phage isolates were from the family Siphoviridae. Seven phages with the broadest host ranges were combined into a cocktail for use in experimental treatments of infected bee larvae; both prophylactic and post-infection treatments were conducted. Results indicated that although both pre- and post-treatments were effective, prophylactic administration of the phages increased the survival of larvae more than post-treatment experiments. These preliminary experiments demonstrate the likelihood that phage therapy could be an effective method to control AFB. PMID:27144085

  9. Effects of Hatching Time on Behavior and Weight Development of Chickens

    PubMed Central

    Løtvedt, Pia; Jensen, Per

    2014-01-01

    The length of the embryonic period varies both among and within species and can affect the individual phenotype in many ways, both physiologically and behaviorally. In chickens, the hatch window may last 24–48 hours (up to 10% of the incubation time), and studies have shown that incubation length may affect post-hatch growth and physiology. However, little is known about effects on behavior. We therefore investigated how behavior variation correlates with hatching time in the early life of chickens. We also measured egg weight and egg weight loss in relation to hatching time, as well as post-hatch growth. For females, there was a negative correlation between hatch time and body weight from day 4 and throughout the experiment. For males, such a correlation was only observed when testing all hatched males up until day 10. The birds were exposed to a number of behavioral tests, and a principal components analysis was performed on the variables, resulting in four components. For the largest component, termed “Passivity”, a tendency of a difference was found between early and middle male hatchers. Furthermore, a significant difference between early and middle male hatchers was found in the second component, termed “Response to novelty”. In a spatial learning test, late hatchers tended to learn slower. The behavior of females was not significantly affected by hatching time in any of these tests. This study is among the first to demonstrate a link between time of hatching and early behavior in a precocial species like the chicken, and may help shedding light on the evolutionary trade-offs between incubation length and post-hatch traits. The results may also be relevant from a perspective of stress coping and therefore also for animal welfare and productivity in the chicken industry. The mechanisms linking hatching time with post-hatch phenotype remain to be investigated. PMID:25058654

  10. Effects of hatching time on behavior and weight development of chickens.

    PubMed

    Løtvedt, Pia; Jensen, Per

    2014-01-01

    The length of the embryonic period varies both among and within species and can affect the individual phenotype in many ways, both physiologically and behaviorally. In chickens, the hatch window may last 24-48 hours (up to 10% of the incubation time), and studies have shown that incubation length may affect post-hatch growth and physiology. However, little is known about effects on behavior. We therefore investigated how behavior variation correlates with hatching time in the early life of chickens. We also measured egg weight and egg weight loss in relation to hatching time, as well as post-hatch growth. For females, there was a negative correlation between hatch time and body weight from day 4 and throughout the experiment. For males, such a correlation was only observed when testing all hatched males up until day 10. The birds were exposed to a number of behavioral tests, and a principal components analysis was performed on the variables, resulting in four components. For the largest component, termed "Passivity", a tendency of a difference was found between early and middle male hatchers. Furthermore, a significant difference between early and middle male hatchers was found in the second component, termed "Response to novelty". In a spatial learning test, late hatchers tended to learn slower. The behavior of females was not significantly affected by hatching time in any of these tests. This study is among the first to demonstrate a link between time of hatching and early behavior in a precocial species like the chicken, and may help shedding light on the evolutionary trade-offs between incubation length and post-hatch traits. The results may also be relevant from a perspective of stress coping and therefore also for animal welfare and productivity in the chicken industry. The mechanisms linking hatching time with post-hatch phenotype remain to be investigated.

  11. Hatching success of Caspian terns nesting in the lower Laguna Madre, Texas, USA

    USGS Publications Warehouse

    Mitchell, C.A.; Custer, T.W.

    1986-01-01

    The average clutch size of Caspian Terns nesting in a colony in the Lower Laguna Madre near Laguna Vista, Texas, USA in 1984 was 1.9 eggs per nest. Using the Mayfield method for calculating success, one egg hatched in 84.1% of the nests and 69.8% of the eggs laid hatched. These hatching estimates are as high or higher than estimates from colonies in other areas.

  12. STS-38 MS Springer climbs through CCT side hatch prior to egress training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Mission Specialist (MS) Robert C. Springer, wearing launch and entry suit (LES), climbs through the side hatch of the crew compartment trainer (CCT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Springer will practice emergency egress through the side hatch using the crew escape system (CES) pole (at Springer's left). The inflated safety cushion under Springer will break his fall as he rolls out of the side hatch.

  13. Egg Development of the Ussurian Bullhead Fish, Leiocassis ussuriensis (Pisces: Bagridae) and Morphological Development of Its Larvae and Juveniles.

    PubMed

    Park, Jae-Min; Yim, Hu-Sun; Lee, Yong-Sik; Kim, Heung-Yun; Han, Kyeong-Ho

    2015-12-01

    This study was examined the ovogenesis of Ussurian bullhead, Leiocassis ussuriensis and the morphological development of its larvae and juveniles and to use the results as basic information for the preservation of species and resource enhancement. For artificial egg collection, human chorionic gonadotropin (HCG) was injected at a rate of 10 IU per gram of fish weight. During breeding period, water temperature maintained at 24.5~26.5°C (mean 25.0±0.05°C). The process of ovogenesis reached the two-cell stage in 50 minutes after fertilization. In 73 hours of fertilization the movement of the embryoid body became active state and the larvae began to hatch from the tail through the oolemma. Length of prelarvae were 6.33~6.50 mm long (mean 6.40±0.06 mm) just after hatching having yolk with their mouth not opened. After thirty eight days of hatching, juveniles were 30.6∼32.5 mm long (mean 31.5±0.65 mm). The color was dark yellowish brown throughout the entire body, and the number of caudal fin rays developed to thirty six perfectly.

  14. Ontogeny of body density and the swimbladder in yellowtail kingfish Seriola lalandi larvae.

    PubMed

    Woolley, L D; Qin, J G

    2013-02-01

    The ontogeny of larval body density and the morphological and histological events during swimbladder development were investigated in two cohorts of yellowtail kingfish Seriola lalandi larvae to understand the relationship between larval morphology and body density. Larvae <3 days post hatch (dph) were positively buoyant with a mean ± s.d. body density of 1.023 ± 0.001 g cm(-3). Histological evidence demonstrated that S. lalandi larvae are initially transient physostomes with the primordial swimbladder derived from the evagination of the gut ventral to the notochord and seen at 2 dph. A pneumatic duct connected the swimbladder to the oesophagus, but degenerated after 5 dph. Initial swimbladder (SB) inflation occurred on 3 dph, and the inflation window was 3-5 dph when the pneumatic duct was still connected to the gut. The swimbladder volume increased with larval age and the epithelial lining on the swimbladder became flattened squamous cells after initial inflation. Seriola lalandi developed into a physoclist with the formation of the rete mirabile and the gas-secreting gland comprised low-columnar epithelial cells. Larvae with successfully inflated swimbladders remained positively buoyant, whereas larvae without SB inflation became negatively buoyant and their body density gradually reached 1.030 ± 0.001 g cm(-3) by 10 dph. Diel density changes were observed after 5 dph, owing to day time deflation and night-time inflation of the swimbladder. These results show that SB inflation has a direct effect on body density in larval S. lalandi and environmental factors should be further investigated to enhance the rate of SB inflation to prevent the sinking death syndrome in the early life stage of the fish larvae. PMID:23398074

  15. Ontogeny of body density and the swimbladder in yellowtail kingfish Seriola lalandi larvae.

    PubMed

    Woolley, L D; Qin, J G

    2013-02-01

    The ontogeny of larval body density and the morphological and histological events during swimbladder development were investigated in two cohorts of yellowtail kingfish Seriola lalandi larvae to understand the relationship between larval morphology and body density. Larvae <3 days post hatch (dph) were positively buoyant with a mean ± s.d. body density of 1.023 ± 0.001 g cm(-3). Histological evidence demonstrated that S. lalandi larvae are initially transient physostomes with the primordial swimbladder derived from the evagination of the gut ventral to the notochord and seen at 2 dph. A pneumatic duct connected the swimbladder to the oesophagus, but degenerated after 5 dph. Initial swimbladder (SB) inflation occurred on 3 dph, and the inflation window was 3-5 dph when the pneumatic duct was still connected to the gut. The swimbladder volume increased with larval age and the epithelial lining on the swimbladder became flattened squamous cells after initial inflation. Seriola lalandi developed into a physoclist with the formation of the rete mirabile and the gas-secreting gland comprised low-columnar epithelial cells. Larvae with successfully inflated swimbladders remained positively buoyant, whereas larvae without SB inflation became negatively buoyant and their body density gradually reached 1.030 ± 0.001 g cm(-3) by 10 dph. Diel density changes were observed after 5 dph, owing to day time deflation and night-time inflation of the swimbladder. These results show that SB inflation has a direct effect on body density in larval S. lalandi and environmental factors should be further investigated to enhance the rate of SB inflation to prevent the sinking death syndrome in the early life stage of the fish larvae.

  16. Development and growth of larvae of the volute, Cymbiola nobilis Lightfoot

    NASA Astrophysics Data System (ADS)

    Noor, Noorsakinah Md; Cob, Zaidi Che; Ghaffar, Mazlan Abd.

    2013-11-01

    The volutid, Cymbiola nobilis Lightfoot, 1786, is a gastropods molluscs that inhabit deep seas and traditionally harvested by locals for food and hence fetch a high market value. The objective is to study the development of volutid and larval production as an effort to restore depleted natural population of this species. Egg masses used in this study was collected while still underneath spawning females, and embryonic and post-hatching larval development was observed in the laboratory. The larvae were reared in 50 × 100 cm aquarium with 0.22 μm filtered seawater medium at a salinity of 30 ± 1 PSU. Fecundity was estimated at 29 eggs/egg mass (n=10). The juvenile hatching was exactly the same as the adult. Base on this study the morphological features of Cymbiola nobilis can be assigned to eight different development stages beginning from egg described in this paper. The metamorphosis stage were took place in the egg and it is about 7 days before become pre-hatching juvenile. They showed a short period of metamorphic competence and morphological changes also described.

  17. Sediment bioassays with oyster larvae

    SciTech Connect

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

    1983-10-01

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

  18. Development of digestive enzymes in larvae of Mayan cichlid Cichlasoma urophthalmus.

    PubMed

    López-Ramírez, G; Cuenca-Soria, C A; Alvarez-González, C A; Tovar-Ramírez, D; Ortiz-Galindo, J L; Perales-García, N; Márquez-Couturier, G; Arias-Rodríguez, L; Indy, J R; Contreras-Sánchez, W M; Gisbert, E; Moyano, F J

    2011-03-01

    The development of digestive enzymes during the early ontogeny of the Mayan cichlid (Cichlasoma urophthalmus) was studied using biochemical and electrophoretic techniques. From yolk absorption (6 days after hatching: dah), larvae were fed Artemia nauplii until 15 dah, afterward they were fed with commercial microparticulated trout food (45% protein and 16% lipids) from 16 to 60 dah. Several samples were collected including yolk-sac larvae (considered as day 1 after hatching) and specimens up to 60 dah. Most digestive enzymes were present from yolk absorption (5-6 dah), except for the specific acid proteases activity (pepsin-like), which increase rapidly from 8 dah up to 20 dah. Three alkaline proteases isoforms (24.0, 24.8, 84.5 kDa) were detected at 8 dah using SDS-PAGE zymogram, corresponding to trypsin, chymotrypsin and probably leucine aminopeptidase enzymes, and only one isoform was detected (relative electromobility, Rf = 0.54) for acid proteases (pepsin-like) from 3 dah onwards using PAGE zymogram. We concluded that C. urophthamus is a precocious fish with a great capacity to digest all kinds of food items, including artificial diets provided from 13 dah.

  19. Development of digestive enzyme activity in spotted rose snapper, Lutjanus guttatus (Steindachner, 1869) larvae.

    PubMed

    Moguel-Hernández, I; Peña, R; Nolasco-Soria, H; Dumas, S; Zavala-Leal, I

    2014-06-01

    We describe digestive enzyme activity during the larval development of spotted rose snapper, Lutjanus guttatus. Trypsin, chymotrypsin, leucine aminopeptidase, pepsin, amylase, lipase, and acid and alkaline phosphatase activities were evaluated using spectrophotometric techniques from hatching through 30 days. The spotted rose snapper larvae present the same pattern of digestive enzyme activity previously reported for other species in which pancreatic (i.e., trypsin, chymotrypsin, amylase, and lipase) and intestinal (i.e., acid and alkaline phosphatases and leucine aminopeptidase) enzymatic activities are present from hatching allowing the larvae to digest and absorb nutrients in the yolk-sac and live prey by the time of first feeding. The digestive and absorption capacity of the spotted rose snapper increases during the larval development. A significant increase in individual activity of all enzymes occurs at 20 DAH, and around 25 DAH, the juvenile-type of digestion is observed with the appearance of pepsin secreted by the stomach, suggesting that maturation of the digestive function occurs around 20-25 DAH. Our results are in agreement with a previous suggestion that early weaning may be possible from 20 DAH. However, the patterns of enzymatic activities reported in our study should be considered during the formulation of an artificial diet for early weaning of the spotted rose snapper.

  20. How the pilidium larva feeds

    PubMed Central

    2013-01-01

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

  1. A comparison of artificial incubation and natural incubation hatching success of gopher tortoise (Gopherus polyphemus) eggs in southern Mississippi

    USGS Publications Warehouse

    Noel, Krista M.; Qualls, Carl P.; Ennen, Joshua R.

    2012-01-01

    Recent studies have found that Gopher Tortoise, Gopherus polyphemus, populations in southern Mississippi exhibit low recruitment, due in part to very low hatching success of their eggs. We sought to determine if the cause(s) of this low hatching success was related to egg quality (intrinsic factors), unsuitability of the nest environment (extrinsic factors), or a combination of the two. In 2003, hatching success was monitored simultaneously for eggs from the same clutches that were incubated in the laboratory and left to incubate in nests. A subset of randomly chosen eggs from each clutch was incubated in the laboratory under physical conditions that were known to be conducive to successful hatching to estimate the proportion of eggs that were capable of hatching in a controlled setting. Hatching success in the laboratory was compared with that of eggs incubated in natural nests to estimate the proportion of eggs that failed to hatch presumably from extrinsic factors. Laboratory hatching success was 58.8%, suggesting that roughly 40% of the eggs were intrinsically incapable of hatching even when incubated under controlled conditions. Hatching success in natural nests, 16.7%, was significantly lower than hatching success in the laboratory, suggesting that approximately 42.1% of eggs were capable of hatching but failed to hatch due to some extrinsic aspect(s) of the nest environment. Thus, the low hatching success of Gopher Tortoise eggs in southern Mississippi appears to be attributable to a combination of intrinsic (egg quality) and extrinsic (nest environment) factors.

  2. Workbook on the Identification of Mosquito Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

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

  3. Successful Determination of Larval Dispersal Distances and Subsequent Settlement for Long-Lived Pelagic Larvae

    PubMed Central

    Salinas-de-León, Pelayo; Jones, Timothy; Bell, James J.

    2012-01-01

    Despite its importance, we still have a poor understanding of the level of connectivity between marine populations in most geographical locations. Taking advantage of the natural features of the southeast coast of New Zealand's North Island, we deployed a series of settlement stations and conducted plankton tows to capture recent settlers and planktonic larvae of the common intertidal gastropod Austrolittorina cincta (6–8 week larval period). Satellite image analysis and ground truthing surveys revealed the absence of suitable intertidal rocky shore habitat for A. cincta over a 100 km stretch of coastline between Kapiti Island to the south and Wanganui to the north. Fifteen settlement stations (3 replicates×5 sites), which were used to mimic intertidal habitat suitable for A. cincta, were deployed for two months around and north of Kapiti Island (at 0.5, 1, 5, 15, 50 km). In addition, we also conducted plankton tows at each settlement station when the stations were first deployed to collect A. cincta larvae in the water column. On collection, all newly settled gastropods and larvae in the plankton samples were individually isolated, and a species-specific microsatellite marker was used to positively identify A. cincta individuals. Most of the positively identified A. cincta settlers and larvae were collected at the first three sampling stations (<5 km). However, low numbers of A. cincta settlers and larvae were also recorded at the two more distant locations (15 and 50 km). Dispersal curves modeled from our data suggested that <1% of gastropod larvae would travel more than 100 km. While our data show that most larvae are retained close to their natal populations (<5 km), a small proportion of larvae are able to travel much larger geographic distances. Our estimates of larval dispersal and subsequent settlement are one of only a few for marine species with a long-lived larva. PMID:22427885

  4. STS-108 and Expedition 4 pose outside Endeavour's hatch

    NASA Technical Reports Server (NTRS)

    2001-01-01

    KENNEDY SPACE CENTER, Fla. -- The STS-108 and Expedition 4 crews pose outside the hatch to Endeavour. Standing left to right are Daniel W. Bursch, Mission Commander Dominic L. Gorie, Pilot Mark E. Kelly and Expedition 4 Commander Yuri Onufrienko. Gorie and Onufrienko hold the patch for the mission. Kneeling in front are Expedition 4 member Carl E. Walz and Mission Specialists Daniel M. Tani and Linda A. Godwin. Crew members are at KSC for Terminal Countdown Demonstration Test activities that include a simulated launch countdown, plus the emergency exit training from the orbiter and launch pad. STS-108 is a Utilization Flight that will carry the replacement Expedition 4 crew to the International Space Station, as well as the Multi-Purpose Logistics Module Raffaello, filled with supplies and equipment. The l1-day mission is scheduled for launch Nov. 29 on Space Shuttle Endeavour.

  5. Biosimilars: impact of differences with Hatch-Waxman.

    PubMed

    Kowalchyk, Katherine; Crowley-Weber, Cara

    2013-01-01

    A comparison of the Hatch-Waxman Act for approval of small-molecule pharmaceuticals with the Biological Price Competition and Innovation Act for approval of biosimilars provides insight into the market entry and patent litigation for biosimilars. Key differences between the two statutes include a longer period of statutory exclusivity for biosimilars, no 30-month stay for a reference product sponsor upon initiation of litigation, and no 180-day market exclusivity period for the first filer of an application for approval of a biosimilar in the absence of interchangeability. These differences will focus the incentive to settle any patent litigation on the risk of invalidity and/or noninfringement of the reference product sponsor's patents. A biosimilar applicant should develop the best case for invalidity and/or noninfringement of these patents, identify third-party patents and develop a freedom to operate strategy, and file for patents on production, formulation, or use of the biosimilar.

  6. The proteolytic digestive activity and growth during ontogeny of Parachromis dovii larvae (Pisces: Cichlidae) using two feeding protocols.

    PubMed

    Quirós Orlich, José R; Valverde Chavarría, Silvia; Ulloa Rojas, Juan B

    2014-08-01

    The proteolytic digestive activity and growth of Parachromis dovii larvae during the ontogeny were evaluated in a recirculation system using two feeding strategies during a 28-day period. Larvae were reared using two feeding protocols (three replicates each): (A) Artemia nauplii (at satiation), fed from exogenous feeding [8 days after hatching (DAH)] until 15 DAH followed by nauplii substitution by formulated feed (20% day(-1)) until 20 DAH and then formulated feed until 28 DAH; (B) formulated feed (100 % BW daily) from exogenous feeding until 28 DAH. Levels of acid (pepsin type) and alkaline digestive proteases as well as growth and survival of larvae were measured along the feeding period. Survival was high and similar between treatments: 98.9 ± 0.0 for Artemia, 97.3 ± 0.0% for formulated feed. The specific growth rate for length and weight was higher in larvae fed with Artemia nauplii than in larvae reared with formulated feed: 3.4 ± 0.1 versus 1.8 ± 0.1% day(-1) for body length (P = 0.009) and 12.2 ± 0.1 versus 6.5 ± 0.3% day(-1) for body weight (P = 0.002). The acid and alkaline proteolytic activity was detected, in both treatments, from the beginning of the experiment, at 8 DAH. The total enzymatic activity (U larva(-1)) for acid and alkaline proteases was higher in larvae reared with Artemia after 12 DAH, whereas the specific enzymatic activity was similar for both enzyme types in the two treatments. The results suggest that P. dovii larvae were capable to digest formulated diets from the beginning of exogenous feeding and that they could be reared with formulated feeds. However, the formulated feed used should be nutritionally improved because of the poor growth obtained in this research.

  7. Combined Effects of UVR and Temperature on the Survival of Crab Larvae (Zoea I) from Patagonia: The Role of UV-Absorbing Compounds

    PubMed Central

    Hernández Moresino, Rodrigo D.; Helbling, E. Walter

    2010-01-01

    The aim of our study was to assess the combined impact of UVR (280–400 nm) and temperature on the first larval stage (Zoea I) of three crab species from the Patagonian coast: Cyrtograpsus altimanus, C. angulatus, and Leucippa pentagona. We determined the survival response of newly hatched Zoea I after being exposed for 8–10 h under a solar simulator (Hönle SOL 1200) at 15 and 20 °C. There was no mortality due to Photosynthetic Active Radiation (PAR, 400–700 nm) or ultraviolet-A radiation (UV-A, 315–400 nm), and all the observed mortality was due to ultraviolet-B radiation (UV-B, 280–315 nm). The data of larval mortality relative to exposure time was best fit using a sigmoid curve. Based on this curve, a threshold (Th) and the lethal dose for 50% mortality (LD50) were determined for each species. Based on the Th and LD50, C. altimanus was found to be the most resistant species, while L. pentagona was found to be the most sensitive to UV-B. For both species of Cyrtograpsus, mortality was significantly lower at 20 °C than at 15 °C; however, no significant differences between the two temperature treatments were found in L. pentagona. Bioaccumulation of UV-absorbing compounds in the gonads and larvae of C. altimanus, and to a lesser extent in C. angulatus, might have contributed for counteracting the impact of UV-B. However, most of the resilience to UV-B observed with the increase in temperature might be due to an increase in metabolic activity caused by a repair mechanism mediated by enzymes. PMID:20559492

  8. The immunological capacity in the larvae of Pacific oyster Crassostrea gigas.

    PubMed

    Song, Xiaorui; Wang, Hao; Xin, Lusheng; Xu, Jiachao; Jia, Zhihao; Wang, Lingling; Song, Linsheng

    2016-02-01

    As the immune system has not fully developed during early developmental stages, bivalve larvae are more susceptible for pathogens, which frequently leads to the significant mortality in hatcheries. In the present study, the development of immune system and its response against bacteria challenge were investigated in order to characterize the repertoire of immunological capacity of Pacific oyster Crassostrea gigas during the ontogenesis. The phagocytosis was firstly observed in the early D-veliger larvae (17 hpf), especially in their velum site, which indicated the appearance of functional hemocytes during early D-veliger larvae stage. The whole-mount immunofluorescence assay of three pattern recognition receptors (integrin β-1, caspase-3 and C-type lectin 3) and one immune effector gene (IL17-5) was performed in blastula, early D-veliger and umbo larvae, suggested that velum and digestive gland were the potential sites of immune system in the larvae. The lowest activities of antioxidant enzymes (superoxide dismutase and catalase) and hydrolytic enzyme (lysozyme), as well as descended expression levels of 12 immune genes at the transition between embryogenesis and planktonic, indicated that the larvae at hatching (9 hpf) were in hypo-immunity. While the ascending activities of enzymes and expression levels of seven immune genes during the trochophore stage (15 hpf) suggested the initiation of immune system. The steadily increasing trend of all the 12 candidate genes at the early umbo larvae (120 h) hinted that the immune system was well developed at this stage. After bacterial challenge, some immune recognition (TLR4) and immune effector (IL17-5 and defh2) genes were activated in blastula stage (4 hpf), and other immune genes were up regulated in D-veliger larvae, indicating that the zygotic immune system could respond earlier against the bacterial challenge during its development. These results indicated that the cellular and humoral immune components

  9. Compensatory Growth Induced in Zebrafish Larvae after Pre-Exposure to a Microcystis aeruginosa Natural Bloom Extract Containing Microcystins

    PubMed Central

    Ghazali, Issam El; Saqrane, Sanaa; Carvalho, Antonio Paulo; Ouahid, Youness; Oudra, Brahim; Del Campo, Francisca Fernandez; Vasconcelos, Vitor

    2009-01-01

    Early life stage tests with zebrafish (Danio rerio) were used to detect toxic effects of compounds from a Microcystis aeruginosa natural bloom extract on their embryolarval development. We carried out the exposure of developing stages of fish to complex cyanobacterial blooms containing hepatotoxic molecules - microcystins. Fish embryo tests performed with the bloom extract containing 3 mg·L−1 Eq microcystin-LR showed that after 24 h of exposure all fish embryos died. The same tests performed with other diluted extracts (containing 0.3, 0.1 and 0.03 mg·L−1 Eq microcystin-LR) were shown to have an influence on zebrafish development and a large number of embryos showed malformation signs (edema, bent and curving tail). After hatching the larvae were transferred to a medium without toxins to follow the larval development under the new conditions. The specific growth of the pre-exposed larvae was significantly more important than that of the control larvae. This may represent a compensatory growth used to reduce the difference in size with the control fish noted after hatching. PMID:19333438

  10. Abundance of specific mRNA transcripts impacts hatching success in European eel, Anguilla anguilla L.

    PubMed

    Rozenfeld, Christoffer; Butts, Ian A E; Tomkiewicz, Jonna; Zambonino-Infante, Jose-Luis; Mazurais, David

    2016-01-01

    Maternal mRNA governs early embryonic development in fish and variation in abundance of maternal transcripts may contribute to variation in embryonic survival and hatch success in European eel, Anguilla anguilla. Previous studies have shown that quantities of the maternal gene products β-tubulin, insulin-like growth factor 2 (igf2), nucleoplasmin (npm2), prohibitin 2 (phb2), phosphatidylinositol glycan biosynthesis class F protein 5 (pigf5), and carnitine O-palmitoyltransferase liver isoform-like 1 (cpt1) are associated with embryonic developmental competence in other teleosts. Here, the relations between relative mRNA abundance of these genes in eggs and/or embryos and egg quality, was studied and analyzed. We compared egg quality of the two groups: i) batches with hatching and ii) batches with no hatching. Results showed no significant differences in relative mRNA abundance between the hatch and no hatching groups for any of the selected genes at 0, 2.5, and 5HPF. However, at 30HPF the hatch group showed significantly higher abundance of cpt1a, cpt1b, β-tubulin, phb2, and pigf5 transcripts than the no hatch group. Therefore, these results indicate that up-regulation of the transcription of these genes in European eel after the mid-blastula transition, may be needed to sustain embryonic development and hatching success.

  11. 2. VIEW OF THE HATCH ADIT (FEATURE B28), FACING NORTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF THE HATCH ADIT (FEATURE B-28), FACING NORTH. ADIT ROAD IS VISIBLE IN THE FOREGROUND AND OFFICE (FEATURE B-1) IN THE BACKGROUND. - Nevada Lucky Tiger Mill & Mine, Hatch Adit, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  12. Asynchronous hatching in the burying beetle, Nicrophorus quadripunctatus, maxmizes parental fitness.

    PubMed

    Takata, M; Hayashi, S; Thomas, C E; Koyama, S; Satoh, T; Fugo, H

    2014-09-01

    Life history theory predicts that natural selection favours parents who balance investment across offspring to maximize fitness. Theoretical studies have shown that the optimal level of parental investment from the offspring's perspective exceeds that of its parents, and the disparity between the two generates evolutionary conflict for the allocation of parental investment. In various species, the offspring hatch asynchronously. The age hierarchy of the offspring usually establishes competitive asymmetries within the brood and determines the allocation of parental investment among offspring. However, it is not clear whether the allocation of parental investment determined by hatching pattern is optimal for parent or offspring. Here, we manipulated the hatching pattern of the burying beetle Nicrophorus quadripunctatus to demonstrate the influence of hatching pattern on the allocation of parental investment. We found that the total weight of a brood was largest in the group that mimicked the natural hatching pattern, with the offspring skewed towards early hatchers. This increases parental fitness. However, hatching patterns with more later hatchers had heavier individual offspring weights, which increases offspring fitness, but this hatching pattern is not observed in the wild. Thus, our study suggests that the natural hatching pattern optimizes parental fitness, rather than offspring fitness.

  13. Hatching timing, oxygen availability, and external gill regression in the tree frog, Agalychnis callidryas.

    PubMed

    Warkentin, Karen M

    2002-01-01

    The physiological role of the embryonic external gills in anurans is equivocal. In some species, diffusion alone is clearly sufficient to supply oxygen throughout the embryonic period. In others, morphological elaboration and environmental regulation of the external gills suggest functional importance. Since oxygen stress is a common trigger of hatching, I examined the relationships among hatching timing, oxygen stress, and external gill loss. I worked with the red-eyed tree frog, Agalychnis callidryas, a species with arboreal eggs and aquatic tadpoles in which gill regression is associated with hatching, and hatching timing affects posthatching survival with aquatic predators. Both exposure to a hypoxic gas mixture and submergence in water, a natural context in which hypoxic stress can occur, induced early hatching. Exposure to hyperoxic gas mixtures induced regression of external gills, and subsequent exposure to air induced early hatching. Prostaglandin-induced external gill regression also induced hatching, and this effect was partially ameliorated by exposure to hyperoxic gas. Together, these results suggest that external gills enhance the oxygen uptake of embryos and are necessary to extend embryonic development past the onset of hatching competence. PMID:12024291

  14. Suspension of Egg Hatching Caused by High Humidity and Submergence in Spider Mites.

    PubMed

    Ubara, Masashi; Osakabe, Masahiro

    2015-08-01

    We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when high humidity or submergence treatments were implemented: either immediately after oviposition or immediately before hatching was due. Normal eyespot formation was observed in most eggs in the high humidity and submergence treatments, which indicates that spider mite embryos develop even when eggs are underwater. Therefore, delays in hatching are not caused by delayed embryonic development. A delay in hatching was always observed in Panonychus citri (McGregor) but was more variable in Tetranychus urticae Koch and Tetranychus kanzawai Kishida. The high humidity and submergence treatments affected but did not suppress larval development in these species. In contrast, many Oligonychus eggs died following the high humidity treatments. In Tetranychus and Panonychus spider mites, suspension of egg hatching may mitigate the adverse effects of rainfall.

  15. Cyst Distribution and Hatching Pattern of Chirocephalus ruffoi (Crustacea, Anostraca) in an Experimental Undisturbed Pool

    NASA Astrophysics Data System (ADS)

    Mura, Graziella

    2005-06-01

    The pattern of cyst distribution in the absence of turbation and their hatching behaviour were studied in an outdoor artificial pool, where just differentiated adults of the anostracan Chirocephalus ruffoi (sex ratio 1:3) lived until it dried up. The horizontal and vertical distributions of cysts in the pool bed were determined. The comparison between cyst bank estimate (Mura, 2004) and the actual number of cysts counted in the pool bed revealed an estimate error of 20.9%. Resting eggs occurred only in the upper 2.5 cm thick soil sections and decreased within this section as depth increased. Peripheral areas of the pool contained significantly larger numbers of cysts than the central area. Multiway analysis on the results recorded in hatching success (nested ANOVA) revealed that the differences were significantly affected by initial soil conditions, treatment and vertical distribution of cysts. Among these factors, vertical distribution (sections nested in cores) was the most influential. Hatching success was significantly inversely related to depth. Differences in the timing of hatching depending on the above considered factors were also noted. A nearly synchronous hatching pattern was observed only for cysts from initially dry sediment of the uppermost layers. In all successively deeper layers, hatching showed multiple peaks and was increasingly delayed and erratic (already mentioned). ANCOVA within each of the experimental conditions revealed significant differences in hatching frequencies (time as covariate) depending on sediment depth. Within any given layer, ANCOVA revealed a significant influence of initial sediment conditions and treatment on the timing of hatching.

  16. Hatching system and time effects on broiler physiology and posthatch growth.

    PubMed

    van de Ven, L J F; van Wagenberg, A V; Debonne, M; Decuypere, E; Kemp, B; van den Brand, H

    2011-06-01

    A multilevel housing system for broilers was developed, named Patio (Vencomatic BV, Eersel, the Netherlands), in which the hatching and brooding phase are combined. In a Patio system, climate conditions differ from those provided in the hatchers currently in use. We compared the physiology of broilers hatched in a hatcher or in a Patio system, and included the effects of hatching time. Eggs from 1 breeder flock were incubated until embryonic d 18 in a setter and subsequently placed in a hatcher or the Patio until the end of incubation. From each hatching system, 154 chicks were collected per hatching time, at 465 h (early), 480 h (midterm), and 493 h (late) of incubation, from which 24 chicks/group were decapitated for analyses of blood plasma and organ weights. The remaining 130 chicks in each group from both systems were individually labeled and placed together in the Patio system. All chicks were given access to feed and water directly after hatch and were housed up to d 45 to monitor growth. From embryonic d 18 until the end of incubation, average ambient temperature and RH were 38.1°C and 50.8% in the hatcher and 35.2°C and 29.7% in the Patio system. Glucose and corticosterone were slightly higher in hatcher chicks, whereas organ weights were not affected by the hatching system. Although hatchling weights were lower in hatchery chicks, growth from d 0 to 45 was not affected by the hatching system. In both systems, glucose increased with hatching time, whereas lactate and triiodothyronine levels decreased. Yolk weights decreased with hatching time, whereas absolute and relative weights of the yolk-free body, intestines, stomach, lungs, and heart increased, indicating more advanced maturation of organs. Growth up to d 21 was depressed in chicks in the late group, which was possibly related to lower thyroid hormone levels at hatching. We conclude that the hatching system had minor effects on hatchling physiology and that posthatch growth and livability were not

  17. Host Status of Different Potato (Solanum tuberosum) Varieties and Hatching in Root Diffusates of Globodera ellingtonae.

    PubMed

    Zasada, Inga A; Peetz, Amy; Wade, Nadine; Navarre, Roy A; Ingham, Russ E

    2013-09-01

    Globodera ellingtonae was detected in Oregon in 2008. In order to make decisions regarding the regulation of this nematode, knowledge of its biology is required. We determined the host status of a diversity of potato (Solanum tuberosum) varieties in soil-based experiments and identified hatching stimulants in in vitro hatching assays. 'Russet Burbank,' 'Desiree,' 'Modac,' 'Norland,' 'Umatilla,' and 'Yukon Gold' were good hosts (RF > 14) for G. ellingtonae. Potato varieties 'Maris Piper,' 'Atlantic,' and 'Satina,' all which contain the Ro1 gene that confers resistance to G. rostochiensis, were not hosts for G. ellingtonae. In in vitro hatching assays, G. ellingtonae hatched readily in the presence of diffusates from potato (PRD) and tomato (Solanum lycopersicum; TRD). Egg hatch occurred in an average of between 87% and 90% of exposed cysts, with an average of between 144 and 164 juveniles emerging per cyst, from PRD- and TRD-treated cysts, respectively. This nematode hatched rapidly in the presence of PRD and TRD, with at least 66% of total hatch occurring by day 3 of exposure. There was no dose-response of egg hatch to concentrations of PRD or TRD ranging from 1:5 to 1:100 diffusate to water. When G. ellingtonae was exposed to root diffusates from 21 different plants, hatch occurred in 0% to 70% of exposed cysts, with an average of between 0 to 27 juveniles emerging per cyst. When root diffusate-exposed cysts were subsequently transferred to PRD to test viability, root diffusates from arugula (Eruca sativa), sudangrass (Sorghum bicolor subsp. drummondii), and common vetch (Vicia sativa) continued to inhibit egg hatch compared with the other root diffusates or water in which hatch occurred readily (60 to 182 juveniles emerging per cyst). Previously known hatching stimulants of G. rostochiensis and G. pallida, sodium metavanadate, sodium orthovanadate, and sodium thiocyanate, stimulated some egg hatch. Although, Globodera ellingtonae hatched readily in PRD and TRD

  18. Efficacy of Bacillus thuringiensis (var. kurstaki) Against Diamondback Moth (Plutella xylostella L.) Eggs and Larvae on Cabbage Under Semi-Controlled Greenhouse Conditions

    PubMed Central

    Legwaila, Mitch M.; Munthali, David C.; Kwerepe, Baone C.; Obopile, Motshwari

    2015-01-01

    The efficacy of Bacillus thuringiensis (var. kurstaki) (Btk) against the diamondback moth (DBM) on cabbage was studied at Botswana College of Agriculture, Gaborone, Botswana. Using five concentrations of Btk: 2, 4, 6, 8, and 10 g/L, bioassays were conducted against DBM eggs and second instar larvae at 30°C ± 5°C. Each treatment was replicated three times. Probit analysis was used to determine the LD50 and LD90 values for the treatments against eggs and larvae. When the treatments were assessed at 72, 96, 120, and 144 hours, LD90 values against larvae were 11.02, 10.22, 5.92, and 4.01 g/L, whereas they were 7.71, 6.94, and 6.24 g/L against eggs when assessed 48, 72, and 96 hours after the expected time of hatching. This indicated that Btk was effective against both eggs and larvae when exposed for long periods. The slopes of the probit lines for larvae assessed at 24, 48, 72, 96, 120, and 144 hours after application were 0.250, 1.064, 0.910, 0.383, 0.453, and 0.414, while those against eggs were 1.153, 1.246, and 0.933 when assessed 48, 72, and 96 hours after the expected time of hatching. This indicates a smaller change in mortality with increase in pesticide dosage for both eggs and larvae. Btk treatments achieved 85.7%–94.6% reduction in DBM damage on cabbage. Therefore, Btk can be used to achieve effective control of DBM eggs and larvae and reduce damage on cabbage under greenhouse conditions. PMID:26816488

  19. Hatching rates of resting eggs of 'Cladocera' (Crustacea; Branchiopoda) at a tropical bay, Brazil.

    PubMed

    Mugrabe, G; Barros, S; Marazzo, A; Valentin, J L

    2007-08-01

    The aim of this study was to determine the development time of embryos and to estimate the hatching rates of resting eggs of cladocerans found in the sediment of Guanabara Bay, Rio de Janeiro, Brazil, under experimental conditions. Eggs were sorted by species (Penilia avirostris--Sididae; Pleopis polyphemoides and Pseudevadne tergestina--Podonidae) and incubated at a temperature of 25 degrees C, salinity 35 and photoperiod 12 hours light/ 12 hours dark. Hatching rates were about 38% for Pseudevadne tergestina and 28% for Pleopis polyphemoides. Embryos of resting eggs of Penilia avirostris developed comparatively slowly (hatching after 86 days of incubation), with a hatching rate of only 5%. It was observed that development and hatching of resting eggs of marine cladocerans suggest that pulses of recruitment may exist, thus contributing to the rapid appearance and maintenance of planktonic populations of these crustaceans in Guanabara Bay.

  20. How the pilidium larva grows

    PubMed Central

    2014-01-01

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

  1. Toxic effects of zinc on the development, growth, and survival of red sea bream Pagrus major embryos and larvae.

    PubMed

    Huang, Wei; Cao, Liang; Shan, Xiujuan; Xiao, Zhizhong; Wang, Qiyao; Dou, Shuozeng

    2010-01-01

    This study investigated the zinc toxicity to red sea bream Pagrus major embryos and larvae at 18 +/- 1 degrees C (33 +/- 1 per thousand in salinity) under laboratory conditions. The acute toxicity tests indicated that zinc 48-h LC50 to embryos and 96-h LC50 to larvae were 4.3 (3.3-6.3; 95% confidence limits) and 10.1 (9.0-11.4) mg l(-1), respectively, suggesting that embryos were more sensitive than larvae to zinc exposure. The subchronic toxicity test, in which embryos and larvae were continuously exposed to 0, 0.1, 0.3, 0.5, 0.7, 1.0, 1.5, 2.0, and 2.5 mg Zn2+ l(-1) solutions for 10 days, demonstrated that waterborne zinc had distinctly toxic effects on the development, growth, and survival of red sea bream embryos and larvae. Zinc exposure at concentrations > or = 0.5 mg l(-1) would lead to a low hatching rate (19-78%, vs. 98% in controls), high mortality (29-91%, vs. 10% in controls), and morphological abnormality (12-77%, vs. 0.3% in controls) in embryos and larvae, while it caused delay in time-to-hatch in embryos at concentrations > or = 1.0 mg l(-1). These four biological parameters were zinc concentration dependent and could be effective bioindicators for evaluating the toxicity of zinc to the early life stage of this fish. Heartbeats of embryos (9-13 beats 10 s(-1)) were relatively low and were not significantly influenced by zinc concentration, although they rose remarkably with elevated zinc concentration in larvae at the end of the test, particularly when it was > or = 1.0 mg l(-1) (36-38, vs. 31 beats 10 s(-1) in controls). The total length (LT) of the larvae at the end of the test was reduced by 12.2% and 15.6% in the 1.0 and 2.0 mg l(-1) solutions but did not vary significantly in other solutions in comparison with the controls. Heartbeat and LT were less sensitive to zinc exposure and might not be good biological parameters for determining the toxicity of zinc to the early life stage of red sea bream. PMID:19504147

  2. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae - can we identify the underlying factors?

    PubMed

    Karlsen, Ørjan; van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks.

  3. Effect of temperature and tree species on damage progression caused by whitespotted sawyer (Coleoptera: Cerambycidae) larvae in recently burned logs.

    PubMed

    Bélanger, Sébastien; Bauce, Eric; Berthiaume, Richard; Long, Bernard; Labrie, Jacques; Daigle, Louis-Frédéric; Hébert, Christian

    2013-06-01

    The whitespotted sawyer, Monochamus scutellatus scutellatus (Say) (Coleoptera: Ce-rambycidae), is one of the most damaging wood-boring insects in recently burned boreal forests of North America. In Canada, salvage logging after wildfire contributes to maintaining the timber volume required by the forest industry, but larvae of this insect cause significant damage that reduces the economic value of lumber products. This study aimed to estimate damage progression as a function of temperature in recently burned black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg) and jack pine (Pinus banksiana Lambert) trees. Using axial tomographic technology, we modeled subcortical development and gallery depth progression rates as functions of temperature for both tree species. Generally, these rates were slightly faster in black spruce than in jack pine logs. Eggs laid on logs kept at 12 degrees C did not hatch or larvae were unable to establish themselves under the bark because no larval development was observed. At 16 degrees C, larvae stayed under the bark for > 200 d before penetrating into the sapwood. At 20 degrees C, half of the larvae entered the sapwood after 30-50 d, but gallery depth progression stopped for approximately 70 d, suggesting that larvae went into diapause. The other half of the larvae entered the sapwood only after 100-200 d. At 24 and 28 degrees C, larvae entered the sapwood after 26-27 and 21 d, respectively. At 28 degrees C, gallery depth progressed at a rate of 1.44 mm/d. Temperature threshold for subcortical development was slightly lower in black spruce (12.9 degrees C) than in jack pine (14.6 degrees C) and it was 1 degrees C warmer for gallery depth progression for both tree species. These results indicate that significant damage may occur within a few months after fire during warm summers, particularly in black spruce, which highlights the importance of beginning postfire salvage logging as soon as possible to reduce economic

  4. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae - can we identify the underlying factors?

    PubMed

    Karlsen, Ørjan; van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks. PMID:26038712

  5. Rearing Larvae of the Avian Nest Parasite, Philornis downsi (Diptera: Muscidae), on Chicken Blood-Based Diets.

    PubMed

    Lahuatte, Paola F; Lincango, M P; Heimpel, G E; Causton, C E

    2016-01-01

    Captive rearing of insect pests is necessary to understand their biology and to develop control methods. The avian nest fly, Philornis downsi Dodge and Aitken, is a blood-sucking parasite during its larval stage and a serious threat to endemic birds in the Galapagos Islands where it is considered invasive. In order to procure large numbers of flies for biological studies, rearing media and diets were trialed for rearing the larval stage of P. downsi under controlled conditions in the absence of its avian host. P. downsi eggs were obtained from field-caught female flies, and once eggs hatched they were reared on chicken blood for the first 3 d. Following this, three diets were tested on second- and third-instar larvae: 1) chicken blood only; 2) chicken blood, hydrolyzed protein and dried milk powder; and 3) chicken blood, hydrolyzed protein and brewer's yeast. Out of 385 P. downsi larvae tested, we were able to rear 50 larvae to the adult stage. The highest level of mortality was found in the first-instar larvae. Survivorship of second- and third-instar larvae was similar irrespective of diet and diet did not significantly influence larval or pupal development times; though larvae fed the diet with brewer's yeast developed marginally faster. Pupal weights were similar to those of larvae that had developed on bird hosts in the field. To our knowledge, this is the first effective protocol for rearing a hematophagous parasitic avian fly from egg to adult in the absence of a living host. PMID:27493240

  6. Rearing Larvae of the Avian Nest Parasite, Philornis downsi (Diptera: Muscidae), on Chicken Blood-Based Diets

    PubMed Central

    Lahuatte, Paola F.; Lincango, M. P.; Heimpel, G. E.; Causton, C. E.

    2016-01-01

    Captive rearing of insect pests is necessary to understand their biology and to develop control methods. The avian nest fly, Philornis downsi Dodge and Aitken, is a blood-sucking parasite during its larval stage and a serious threat to endemic birds in the Galapagos Islands where it is considered invasive. In order to procure large numbers of flies for biological studies, rearing media and diets were trialed for rearing the larval stage of P. downsi under controlled conditions in the absence of its avian host. P. downsi eggs were obtained from field-caught female flies, and once eggs hatched they were reared on chicken blood for the first 3 d. Following this, three diets were tested on second- and third-instar larvae: 1) chicken blood only; 2) chicken blood, hydrolyzed protein and dried milk powder; and 3) chicken blood, hydrolyzed protein and brewer’s yeast. Out of 385 P. downsi larvae tested, we were able to rear 50 larvae to the adult stage. The highest level of mortality was found in the first-instar larvae. Survivorship of second- and third-instar larvae was similar irrespective of diet and diet did not significantly influence larval or pupal development times; though larvae fed the diet with brewer’s yeast developed marginally faster. Pupal weights were similar to those of larvae that had developed on bird hosts in the field. To our knowledge, this is the first effective protocol for rearing a hematophagous parasitic avian fly from egg to adult in the absence of a living host. PMID:27493240

  7. Rearing Larvae of the Avian Nest Parasite, Philornis downsi (Diptera: Muscidae), on Chicken Blood-Based Diets.

    PubMed

    Lahuatte, Paola F; Lincango, M P; Heimpel, G E; Causton, C E

    2016-01-01

    Captive rearing of insect pests is necessary to understand their biology and to develop control methods. The avian nest fly, Philornis downsi Dodge and Aitken, is a blood-sucking parasite during its larval stage and a serious threat to endemic birds in the Galapagos Islands where it is considered invasive. In order to procure large numbers of flies for biological studies, rearing media and diets were trialed for rearing the larval stage of P. downsi under controlled conditions in the absence of its avian host. P. downsi eggs were obtained from field-caught female flies, and once eggs hatched they were reared on chicken blood for the first 3 d. Following this, three diets were tested on second- and third-instar larvae: 1) chicken blood only; 2) chicken blood, hydrolyzed protein and dried milk powder; and 3) chicken blood, hydrolyzed protein and brewer's yeast. Out of 385 P. downsi larvae tested, we were able to rear 50 larvae to the adult stage. The highest level of mortality was found in the first-instar larvae. Survivorship of second- and third-instar larvae was similar irrespective of diet and diet did not significantly influence larval or pupal development times; though larvae fed the diet with brewer's yeast developed marginally faster. Pupal weights were similar to those of larvae that had developed on bird hosts in the field. To our knowledge, this is the first effective protocol for rearing a hematophagous parasitic avian fly from egg to adult in the absence of a living host.

  8. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility prepare the Unity connecting module for closure before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  9. Unity hatch closed in preparation for launch on STS-88

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Space Station Processing Facility work in the doorway of the Unity connecting module preparing it for closure before its launch aboard Space Shuttle Endeavour on STS-88 in December. Unity will now undergo a series of leak checks before a final purge of clean, dry air inside the module to ready it for initial operations in space. Other testing includes the common berthing mechanism to which other space station elements will dock and the Pad Demonstration Test to verify the compatibility of the module with the Space Shuttle as well as the ability of the astronauts to send and receive commands to Unity from the flight deck of the orbiter. The next time the hatch will be opened it will be by astronauts on orbit. Unity is expected to be ready for installation into the payload canister on Oct. 25, and transported to Launch Pad 39-A on Oct. 27. The Unity will be mated to the Russian-built Zarya control module which should already be in orbit at that time.

  10. Effects of Eight Herbicides on In Vitro Hatching of Heterodera glycines

    PubMed Central

    Wong, A. T. S.; Tylka, G. L.; Hartzler, R. G.

    1993-01-01

    Laboratory studies were conducted to evaluate effects of selected herbicides on hatching of free eggs of the soybean cyst nematode, Heterodera glycines. The herbicides used were Atrazine (atrazine), Basagran (bentazon), Bladex (cyanazine), Blazer (acifluorfen), Command (clomazone), Lasso (alachlor), Sonalan (ethalfluralin), and Treflan (trifluralin). Treatments comprised two concentrations of commercial herbicide formulations and deionized water and 3.14 mM zinc sulfate as negative and positive controls, respectively. Eggs were extracted from females and cysts, surface disinfested, and incubated in herbicide or control solutions at 25 ± 2 C in darkness. Hatched second-stage juveniles were counted every other day for 24 days. Hatching of H. glycines eggs in 50 and 500 μg/ml Blazer was 42 to 67% less than that in deionized water and 6l to 78% less than that in zinc sulfate solution. Zinc sulfate significantly increased hatching activity in 50 μg/ml but not 500 μg/ml Blazer. The other herbicides tested at various concentrations had no significant effect on egg hatching. The specific component of Blazer inhibiting egg hatching is unknown. Suppression of hatching by Blazer indicates that this postemergence soybean herbicide may have a potential role in managing H. glycines. PMID:19279812

  11. Effects of Eight Herbicides on In Vitro Hatching of Heterodera glycines.

    PubMed

    Wong, A T; Tylka, G L; Hartzler, R G

    1993-12-01

    Laboratory studies were conducted to evaluate effects of selected herbicides on hatching of free eggs of the soybean cyst nematode, Heterodera glycines. The herbicides used were Atrazine (atrazine), Basagran (bentazon), Bladex (cyanazine), Blazer (acifluorfen), Command (clomazone), Lasso (alachlor), Sonalan (ethalfluralin), and Treflan (trifluralin). Treatments comprised two concentrations of commercial herbicide formulations and deionized water and 3.14 mM zinc sulfate as negative and positive controls, respectively. Eggs were extracted from females and cysts, surface disinfested, and incubated in herbicide or control solutions at 25 +/- 2 C in darkness. Hatched second-stage juveniles were counted every other day for 24 days. Hatching of H. glycines eggs in 50 and 500 mug/ml Blazer was 42 to 67% less than that in deionized water and 6l to 78% less than that in zinc sulfate solution. Zinc sulfate significantly increased hatching activity in 50 mug/ml but not 500 mug/ml Blazer. The other herbicides tested at various concentrations had no significant effect on egg hatching. The specific component of Blazer inhibiting egg hatching is unknown. Suppression of hatching by Blazer indicates that this postemergence soybean herbicide may have a potential role in managing H. glycines.

  12. Hatching asynchrony aggravates inbreeding depression in a songbird (Serinus canaria): an inbreeding-environment interaction.

    PubMed

    de Boer, Raïssa A; Eens, Marcel; Fransen, Erik; Müller, Wendt

    2015-04-01

    Understanding how the intensity of inbreeding depression is influenced by stressful environmental conditions is an important area of enquiry in various fields of biology. In birds, environmental stress during early development is often related to hatching asynchrony; differences in age, and thus size, impose a gradient in conditions ranging from benign (first hatched chick) to harsh (last hatched chick). Here, we compared the effect of hatching order on growth rate in inbred (parents are full siblings) and outbred (parents are unrelated) canary chicks (Serinus canaria). We found that inbreeding depression was more severe under more stressful conditions, being most evident in later hatched chicks. Thus, consideration of inbreeding-environment interactions is of vital importance for our understanding of the biological significance of inbreeding depression and hatching asynchrony. The latter is particularly relevant given that hatching asynchrony is a widespread phenomenon, occurring in many bird species. The exact causes of the observed inbreeding-environment interaction are as yet unknown, but may be related to a decrease in maternal investment in egg contents with laying position (i.e. prehatching environment), or to performance of the chicks during sibling competition and/or their resilience to food shortage (i.e. posthatching environment). PMID:25689753

  13. Hatching asynchrony aggravates inbreeding depression in a songbird (Serinus canaria): an inbreeding-environment interaction.

    PubMed

    de Boer, Raïssa A; Eens, Marcel; Fransen, Erik; Müller, Wendt

    2015-04-01

    Understanding how the intensity of inbreeding depression is influenced by stressful environmental conditions is an important area of enquiry in various fields of biology. In birds, environmental stress during early development is often related to hatching asynchrony; differences in age, and thus size, impose a gradient in conditions ranging from benign (first hatched chick) to harsh (last hatched chick). Here, we compared the effect of hatching order on growth rate in inbred (parents are full siblings) and outbred (parents are unrelated) canary chicks (Serinus canaria). We found that inbreeding depression was more severe under more stressful conditions, being most evident in later hatched chicks. Thus, consideration of inbreeding-environment interactions is of vital importance for our understanding of the biological significance of inbreeding depression and hatching asynchrony. The latter is particularly relevant given that hatching asynchrony is a widespread phenomenon, occurring in many bird species. The exact causes of the observed inbreeding-environment interaction are as yet unknown, but may be related to a decrease in maternal investment in egg contents with laying position (i.e. prehatching environment), or to performance of the chicks during sibling competition and/or their resilience to food shortage (i.e. posthatching environment).

  14. Biochemical and histological effects of gibberellic acid on Locusta migratoria migratoria fifth instar larvae.

    PubMed

    Abdellaoui, Khemais; Ben Halima-Kamel, Monia; Acheuk, Fatma; Soltani, Noureddine; Aribi, Nadia; Hamouda, Mohamed HabibBen

    2013-09-01

    Experiments were conducted to assess the effect of gibberellic acid (GA3), a plant growth regulator, on Locusta migratoria migratoria fifth instar larvae. Newly emerged larvae were exposed to various concentrations of GA3 administered by topical application or by forced ingestion. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. GA3 toxicity was also demonstrated by perturbation of the moult processes. In fact, we noted that treated insects present exuviations difficulties due to the impossibility to reject the old integuments causing mortality in the 5th instar larvae. Histological study of proventriculus revealed alterations in the epithelial cells and absence of apolysis phenomenon. Data also showed that GA3 induced significant quantitative variation of haemolymph metabolites. These changes result in a significant decrease in the total concentration of proteins and carbohydrates and an increase in the total concentration of haemolymph lipids. PMID:25149232

  15. The effect of various assisted hatching techniques on the mouse early embryo development

    PubMed Central

    Park, Sung Baek; Kim, Hye Jin; Choi, Young Bae; Ahn, Kwang Hwa; Lee, Kee Hwan; Yang, Jung Bo; Yu, Chang Seok

    2014-01-01

    Objective In search of an ideal method of assisted hatching (AH), we compared the effects of conventional micropipette-AH and laser-AH on the blastocyst formation rate (BFR) and blastocyst cell numbers. Methods Four- to five-week-old ICR female mice were paired with male mice after superovulation using Pregnant mare's serum gonadotropin (PMSG) and hCG. The two-cell embryos were flushed from the oviducts of female mice. The retrieved two-cell embryos underwent one of five AH procedures: single mechanical assisted hatching (sMAH); cross mechanical assisted hatching (cMAH); single laser assisted hatching (sLAH); quarter laser assisted hatching (qLAH); and quarter laser zona thinning assisted hatching (qLZT-AH). After 72 hours incubation, double immunofluorescence staining was performed. Results Following a 72 hours incubation, a higher hatching BFR was observed in the control, sMAH, cMAH, and sLAH groups, compared to those in the qLAH and qLZT-AH groups (p<0.05). The hatched BFR was significantly higher in the qLAH and qLZT-AH groups than in the others (p<0.05 for each group). The inner cell mass (ICM) was higher in the control and sMAH group (p<0.05). The trophectoderm cell number was higher in the cMAH and qLAH groups (p<0.05). Conclusion Our results showed that the hatched BFR was higher in groups exposed the the qLAH and qLZT-AH methods compared to groups exposed to other AH methods. In the qLAH group, although the total cell number was significantly higher than in controls, the ICM ratio was significantly lower in than controls. PMID:25045630

  16. Factors affecting hatch success of hawksbill sea turtles on Long Island, Antigua, West Indies.

    PubMed

    Ditmer, Mark Allan; Stapleton, Seth Patrick

    2012-01-01

    Current understanding of the factors influencing hawksbill sea turtle (Eretmochelys imbricata) hatch success is disparate and based on relatively short-term studies or limited sample sizes. Because global populations of hawksbills are heavily depleted, evaluating the parameters that impact hatch success is important to their conservation and recovery. Here, we use data collected by the Jumby Bay Hawksbill Project (JBHP) to investigate hatch success. The JBHP implements saturation tagging protocols to study a hawksbill rookery in Antigua, West Indies. Habitat data, which reflect the varied nesting beaches, are collected at egg deposition, and nest contents are exhumed and categorized post-emergence. We analyzed hatch success using mixed-model analyses with explanatory and predictive datasets. We incorporated a random effect for turtle identity and evaluated environmental, temporal and individual-based reproductive variables. Hatch success averaged 78.6% (SD: 21.2%) during the study period. Highly supported models included multiple covariates, including distance to vegetation, deposition date, individual intra-seasonal nest number, clutch size, organic content, and sand grain size. Nests located in open sand were predicted to produce 10.4 more viable hatchlings per clutch than nests located >1.5 m into vegetation. For an individual first nesting in early July, the fourth nest of the season yielded 13.2 more viable hatchlings than the initial clutch. Generalized beach section and inter-annual variation were also supported in our explanatory dataset, suggesting that gaps remain in our understanding of hatch success. Our findings illustrate that evaluating hatch success is a complex process, involving multiple environmental and individual variables. Although distance to vegetation and hatch success were inversely related, vegetation is an important component of hawksbill nesting habitat, and a more complete assessment of the impacts of specific vegetation types on hatch

  17. Factors Affecting Hatch Success of Hawksbill Sea Turtles on Long Island, Antigua, West Indies

    PubMed Central

    Ditmer, Mark Allan; Stapleton, Seth Patrick

    2012-01-01

    Current understanding of the factors influencing hawksbill sea turtle (Eretmochelys imbricata) hatch success is disparate and based on relatively short-term studies or limited sample sizes. Because global populations of hawksbills are heavily depleted, evaluating the parameters that impact hatch success is important to their conservation and recovery. Here, we use data collected by the Jumby Bay Hawksbill Project (JBHP) to investigate hatch success. The JBHP implements saturation tagging protocols to study a hawksbill rookery in Antigua, West Indies. Habitat data, which reflect the varied nesting beaches, are collected at egg deposition, and nest contents are exhumed and categorized post-emergence. We analyzed hatch success using mixed-model analyses with explanatory and predictive datasets. We incorporated a random effect for turtle identity and evaluated environmental, temporal and individual-based reproductive variables. Hatch success averaged 78.6% (SD: 21.2%) during the study period. Highly supported models included multiple covariates, including distance to vegetation, deposition date, individual intra-seasonal nest number, clutch size, organic content, and sand grain size. Nests located in open sand were predicted to produce 10.4 more viable hatchlings per clutch than nests located >1.5 m into vegetation. For an individual first nesting in early July, the fourth nest of the season yielded 13.2 more viable hatchlings than the initial clutch. Generalized beach section and inter-annual variation were also supported in our explanatory dataset, suggesting that gaps remain in our understanding of hatch success. Our findings illustrate that evaluating hatch success is a complex process, involving multiple environmental and individual variables. Although distance to vegetation and hatch success were inversely related, vegetation is an important component of hawksbill nesting habitat, and a more complete assessment of the impacts of specific vegetation types on hatch

  18. Effect of Storage Environment on Hatching of the Cyst Nematode Globodera ellingtonae

    PubMed Central

    Ingham, Russell E.; Kroese, Duncan; Zasada, Inga A.

    2015-01-01

    Globodera spp. eggs go through a diapause, which remains dormant until favorable hatching conditions are reached. Because of the regulatory concerns with cyst nematodes, it is often only possible to rear eggs for research in the greenhouse. However, hatch is often lower for greenhouse-produced eggs than for eggs obtained from the field. The goal of this research was to determine storage conditions for Globodera ellingtonae eggs produced in the greenhouse that would increase percentage hatch. Over 3 yr, G. ellingtonae greenhouse-produced eggs were stored in different environments (−20°C, 4°C, room temperature, and the field) in either dry or moist soil. Percentage hatch after exposure to the different environments was determined in potato root diffusate. Across two experiments, field-produced eggs had higher hatch rates (65.2%) than greenhouse-produced eggs (10.4%). Temperature did not have an appreciable influence on hatch of eggs stored dry in two experiments (2.8% to 8.4% and 3.8% to 8.6%), but hatch of eggs stored in moist soil was significantly higher than in dry soil at all temperatures except −20°C (26.8% and 28.7%). However, the ability of G. ellingtonae greenhouse-, microplot-, and field-produced eggs to reproduce on potato in field microplots was not different. Although it may not be possible to produce G. ellingtonae eggs in the greenhouse that have the magnitude of hatch as those produced in the field, hatching can be greatly increased by storing eggs in moist soil at either 4°C or room temperature. PMID:25861115

  19. Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

    NASA Astrophysics Data System (ADS)

    Yang, Zhihui; Zhang, Xiangjing; Cai, Zhonghua

    2009-05-01

    As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP, DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

  20. Effect of rearing temperature on growth and thermal tolerance of Schizothorax (Racoma) kozlovi larvae and juveniles.

    PubMed

    He, Yongfeng; Wu, Xingbing; Zhu, Yongjiu; Li, Haocheng; Li, Xuemei; Yang, Deguo

    2014-12-01

    Effect of rearing temperature on growth and thermal tolerance of Schizothorax (Racoma) kozlovi Nikolsky larvae and juveniles was investigated. The fish (start at 12d post hatch) were reared for nearly 6 months at five constant temperatures of 10, 14, 18, 22 and 26°C. Then juvenile fish being acclimated at three temperatures of 14, 18 and 22°C were chosen to determine their critical thermal maximum (CTMax) and lethal thermal maximum (LTMax) by using the dynamic method. Growth rate of S. kozlovi larvae and juveniles was significantly influenced by temperature and fish size, exhibiting an increase with increased rearing temperature, but a decline with increased fish size. A significant ontogenetic variation in the optimal temperatures for maximum growth were estimated to be 24.7°C and 20.6°C for larvae and juveniles of S. kozlovi, respectively. The results also demonstrated that acclimation temperature had marked effects on their CTMax and LTMax, which ranged from 32.86°C to 34.54°C and from 33.79°C to 34.80°C, respectively. It is suggested that rearing temperature must never rise above 32°C for its successful aquaculture. Significant temperature effects on the growth rate and thermal tolerance both exhibit a plasticity pattern. Determination of critical heat tolerance and optima temperature for maximum growth of S. kozlovi is of ecological significance in the conservation and aquaculture of this species.

  1. Taste processing in Drosophila larvae

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-09-01

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

  3. Vitamin A and arachidonic acid altered the skeletal mineralization in Atlantic cod (Gadus morhua) larvae without any interactions on the transcriptional level.

    PubMed

    Lie, Kai Kristoffer; Kvalheim, Karen; Rasinger, Josef Daniel; Harboe, Torstein; Nordgreen, Andreas; Moren, Mari

    2016-01-01

    The main object of this study was to evaluate the impact of different levels of vitamin A (VA) and arachidonic acid (ARA) in relation to eicosapentaenoic acid (EPA) on mineralization and gene expression in Atlantic cod larvae (Gadus morhua). First-feeding larvae were fed enriched rotifers from start-feeding until 29 days post hatch (dph). Larvae in four tanks were fed one of the following diets: control (EPA/ARA ratio: 15.8, 0.9μg VA g(-1)), control+VA (EPA/ARA ratio: 15.8, 7.8μg VA g(-1)), High ARA (EPA/ARA ratio: 0.9, 1.5μg VA g(-1)) or High ARA+VA (EPA/ARA ratio: 0.9, 12.0μg VA g(-1)). Larvae fed High ARA+VA were shorter at 29dph compared to the other groups and had significantly less mineralized bones when comparing larvae of similar size, showing interaction effects between VA and ARA. Although transcriptomic analysis did not reveal any interaction effects, a higher number of genes were differentially expressed in the high ARA fed larvae compared to control+VA fed larvae. Furthermore, bglap1, bglap2 and col10a1 were all down-regulated in larvae fed High ARA-diets and to a greater extent than larvae fed VA supplemented diet, indicating an additive effect on mineralization. In conclusion, this study showed that the dietary increase in ARA and VA altered the skeletal metabolism during larval development, most likely through signaling pathways specific for each nutrient rather than an interaction. The present study also demonstrates that VA could affect the larval response to ARA, even within the accepted non-toxic/non-deficient range.

  4. Embryonic Development and Rates of Metabolic Activity in Early and Late Hatching Eggs of the Major Malaria Vector Anopheles gambiae

    PubMed Central

    Kaiser, Maria L.; Duncan, Frances D.; Brooke, Basil D.

    2014-01-01

    Anopheles gambiae eggs generally hatch at the completion of embryo development; two-three days post oviposition. However, staggered or delayed hatching has been observed whereby a single batch of eggs shows marked variation in time-to-hatch, with some eggs hatching 18 days post oviposition or later. The mechanism enabling delayed hatch has not been clearly elucidated but is likely mediated by environmental and genetic factors that either induce diapause or slow embryo development. This study aimed to compare metabolic activity and embryonic development between eggs collected from sub-colonies of the baseline Anopheles gambiae GAH colony previously selected for early or late time-to-hatch. Egg batches from early and late hatch sub-colonies as well as from the baseline colony were monitored for hatching. For both time-to-hatch selected sub-colonies and the baseline colony the majority of eggs hatched on day two post oviposition. Nevertheless, eggs produced by the late hatch sub-colony showed a significantly longer mean time to hatch than those produced by the early hatch sub-colony. The overall proportions that hatched were similar for all egg batches. CO2 output between eggs from early and late hatch sub-colonies showed significant differences only at 3 and 7 days post oviposition where eggs from the early hatch and the late hatch sub-colony were more metabolically active, respectively. No qualitative differences were observed in embryo development between the sub-colonies. It is concluded that all viable embryos develop to maturity at the same rate and that a small proportion then enter a state of diapause enabling them to hatch later. As it has previously been shown that it is possible to at least partially select for late hatch, this characteristic is likely to involve genetic as well as environmental factors. Delayed hatching in An. gambiae is likely an adaptation to maximise reproductive output despite the increased risk of desiccation in an unstable aquatic

  5. Reproduction, hatching success, and early naupliar survival in Centropages typicus

    NASA Astrophysics Data System (ADS)

    Ianora, A.; Miralto, A.; Halsband-Lenk, C.

    2007-02-01

    The broadcast spawner, Centropages typicus, is a very successful copepod species in many coastal areas of the Mediterranean Sea and North Atlantic Ocean. This review assembles the large amount of information on the reproduction and early life history of C. typicus that has emerged since the 1970s and has made this species one of the best-studied copepods, similar in that regard to species of Acartia and Calanus. Observations on mating behavior and the female gametogenic and oogenic cycles are presented, together with information on seasonal cycles of egg production rates in Mediterranean and Atlantic populations from various regions. These studies indicate a strong latitudinal gradient, with continuous reproduction and the main spawning season occurring earlier (late winter/spring) in warmer waters such as the Mediterranean Sea, compared to northern areas such as the North Sea and in the Kattegat, where C. typicus actively reproduces mainly in late summer and fall with reproduction ceasing altogether in winter in the German Bight. These observations strongly suggest that temperature is the controlling factor for reproductive activity in this species. Egg development times are also temperature dependent but do not vary with latitude, and there is as yet no conclusive evidence that diapause egg production occurs in C. typicus. Laboratory experiments have shown that food quantity and quality both affect fecundity and offspring fitness, but most of these studies have focused on diatom and dinoflagellate diets and non-algal prey have been strongly underrepresented, despite their importance for this omnivorous copepod. Large fluctuations in hatching success and naupliar survival have been reported in field surveys and have subsequently been related to maternal feeding history and food quality or toxicity in laboratory experiments. We identify future lines of research that will help to explain the interannual variability in breeding intensity and recruitment of C. typicus

  6. Post-hatching development of Alligator mississippiensis ovary and testis

    PubMed Central

    Moore, Brandon C.; Hamlin, Heather J.; Botteri, Nicole L.; Lawler, Ashley N.; Mathavan, Ketan K.; Guillette, Louis J.

    2009-01-01

    We investigated ovary and testis development of Alligator mississippiensis during the first five months post-hatch. To better describe follicle assembly and seminiferous cord development, we employed histochemical techniques to detect carbohydrate-rich extracellular matrix components in one-week, one-month, three-month, and five-month-old gonads. We found profound morphological changes in both ovary and testis. During this time, oogenesis progressed up to diplotene arrest and meiotic germ cells increasingly interacted with follicular cells. Concomitant with follicles becoming invested with full complements of granulosa cells, a periodic acid Schiff’s (PAS)-positive basement membrane formed. As follicles enlarged and thecal layers were observed, basement membranes and thecal compartments gained periodic acid-methionine silver (PAMS)-reactive fibers. The ovarian medulla increased first PAS- and then PAMS-reactivity as it fragmented into wide lacunae lined with low cuboidal to squamous epithelia. During this same period, testicular germ cells found along the tubule margins were observed progressing from spermatogonia to round spermatids located within the center of tubules. Accompanying this meiotic development, interstitial Leydig cell clusters become more visible and testicular capsules thickened. During the observed testis development, the thickening tunica albuginea and widening interstitial tissues showed increasing PAS- and PAMS-reactivity. We observed putative inter-sex structures in both ovary and testis. On the coelomic aspect of testes were cell clusters with germ cell morphology and at the posterior end of ovaries, we observed “medullary rests” resembling immature testis cords. We hypothesize laboratory conditions accelerated gonad maturation due to optimum conditions, including nutrients and temperature. Laboratory alligators grew more rapidly and with increased body conditions compared to previous measured, field-caught animals. Additionally, we

  7. Ganzfeld ERG in zebrafish larvae.

    PubMed

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

    2002-01-01

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

  8. Molecular Characterization of Ancylostoma braziliense Larvae in a Patient with Hookworm-Related Cutaneous Larva Migrans

    PubMed Central

    Joncour, Alexandre Le; Lacour, Sandrine A.; Lecso, Gabriel; Regnier, Stéphanie; Guillot, Jacques; Caumes, Eric

    2012-01-01

    We report a case of hookworm-related cutaneous larva migrans diagnosed microscopically. Viable hookworm larvae were found by microscopic examination of a skin scraping from follicular lesions. Amplification and sequencing of the internal transcribed spacer 2 allowed the specific identification of the larvae as Ancylostoma braziliense. PMID:22556085

  9. The relationship between hatching rate and number of embryos of the brood pouch in Littorina saxatilis

    NASA Astrophysics Data System (ADS)

    Conde-Padín, P.; Carballo, M.; Caballero, A.; Rolán-Alvarez, E.

    2008-10-01

    Littorina saxatilis is an ovoviviparous organism in which shelled embryos can be directly observed in nearly all mature females captured in the wild. This characteristic has been used a number of times as an indirect estimate for fecundity of natural populations. However, there is no experimental corroboration that the number of embryos within a female brood pouch is actually related to the rate of hatching per unit of time, a more realistic estimate of female fecundity. In order to make this corroboration we estimated the correlation between the number of embryos in the brood pouch and the hatching rate of isolated females grown in the laboratory. We also compared the hatching rates of females from two sympatric ecotypes (RB and SU) of this species, which differ significantly in the number of embryos. We found a high agreement between hatching rate and number of embryos, concluding that the latter is a good proxy for fecundity.

  10. Astronaut Virgil Grissom shown through window of open hatch on Gemini craft

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Virgil I. Grissom, the command pilot of the Gemini-Titan 3 three orbit mission, is shown through the window of the open hatch on Gemini spacecraft in the white room on the mornining of the launch.

  11. Generation of Collapsed Cross Sections for Hatch 1 Cycles 1-3

    SciTech Connect

    Ade, Brian J

    2012-11-01

    Under NRC JCN V6361, Oak Ridge National Laboratory (ORNL) was tasked to develop and run SCALE/TRITON models for generation of collapsed few-group cross sections and to convert the cross sections to PMAXS format using the GENPMAXS conversion utility for use in PARCS/PATHS simulations of Hatch Unit 1, cycles 1-3. This letter report documents the final models used to produce the Hatch collapsed cross sections.

  12. Comparative hatching success of lake trout eggs in Lake Michigan water and well water

    USGS Publications Warehouse

    Edsall, Carol C.; Mac, Michael J.

    1982-01-01

    A study was undertaken to examine the influence of water from southern Lake Michigan on the survival of lake trout (Salvelinus namaycush) eggs by comparing the hatching success of eggs from the same source incubated in water from Lake Michigan, or from the laboratory well. It is concluded that the observed differences in hatching are probably attributable to chemical constituents of water from the lake (eg, chlorinated hydrocarbons, metals and other industrial and agricultural chemicals).

  13. External gills and adaptive embryo behavior facilitate synchronous development and hatching plasticity under respiratory constraint.

    PubMed

    Rogge, Jessica R; Warkentin, Karen M

    2008-11-01

    Plasticity in hatching timing allows embryos to balance egg- and larval-stage risks, and depends on the ability of hatching-competent embryos to continue developing in the egg. Hypoxia can slow development, kill embryos and induce premature hatching. For terrestrial eggs of red-eyed treefrogs, the embryonic period can extend approximately 50% longer than development to hatching competence, and development is synchronous across perivitelline oxygen levels (PO2) ranging from 0.5-16.5 kPa. Embryos maintain large external gills until hatching, then gills regress rapidly. We assessed the respiratory value of external gills using gill manipulations and closed-system respirometry. Embryos without external gills were oxygen limited in air and hatched at an external PO2 of 17 kPa, whereas embryos with gills regulated their metabolism and remained in the egg at substantially lower PO2. By contrast, tadpoles gained no respiratory benefit from external gills. We videotaped behavior and manipulated embryos to test if they position gills near the air-exposed portion of the egg surface, where PO2 is highest. Active embryos remained stationary for minutes in gills-at-surface positions. After manipulations and spontaneous movements that positioned gills in the O2-poor region of the egg, however, they returned their gills to the air-exposed surface within seconds. Even neural tube stage embryos, capable only of ciliary rotation, positioned their developing head in the region of highest PO2. Such behavior may be critical both to delay hatching after hatching competence and to obtain sufficient oxygen for normal, synchronous development at earlier stages.

  14. Warming affects hatching time and early season survival of eastern tent caterpillars.

    PubMed

    Abarca, Mariana; Lill, John T

    2015-11-01

    Climate change is disrupting species interactions by altering the timing of phenological events such as budburst for plants and hatching for insects. We combined field observations with laboratory manipulations to investigate the consequences of climate warming on the phenology and performance of the eastern tent caterpillar (Malacosoma americanum). We evaluated the effects of warmer winter and spring regimes on caterpillar hatching patterns and starvation endurance, traits likely to be under selection in populations experiencing phenological asynchrony, using individuals from two different populations (Washington, DC, and Roswell, GA). We also quantified the proximate and extended fitness effects of early food deprivation and recorded spring phenology of local caterpillars and their host plants. In addition, we conducted laboratory assays to determine if caterpillars are using plant chemical cues to fine-tune their hatching times. Warmer winter temperatures induced earlier hatching and caterpillars from GA survived starvation for periods that were 30% longer than caterpillars from DC. Warmer spring regimes reduced the starvation endurance of caterpillars overwintering in the wild but not in the laboratory. Early starvation dramatically reduced hatchling survival; however, surviving caterpillars did not show detrimental effects on pupal mass or development time. In the field, hatching preceded budburst in both 2013 and 2014 and the period of optimal foliage quality was 2 weeks shorter in 2013. Hatching time was unaffected by exposure to plant volatiles. Overall, we found that warmer temperatures can trigger late-season asynchrony by accelerating plant phenology and caterpillars from different populations exhibit differential abilities to cope with environmental unreliability.

  15. Using a Neural Network to Determine the Hatch Status of the AERI at the ARM North Slope of Alaska Site

    SciTech Connect

    Zwink, AB; Turner, DD

    2012-03-19

    The fore-optics of the Atmospheric Emitted Radiance Interferometer (AERI) are protected by an automated hatch to prevent precipitation from fouling the instrument's scene mirror (Knuteson et al. 2004). Limit switches connected with the hatch controller provide a signal of the hatch state: open, closed, undetermined (typically associated with the hatch being between fully open or fully closed during the instrument's sky view period), or an error condition. The instrument then records the state of the hatch with the radiance data so that samples taken when the hatch is not open can be removed from any subsequent analysis. However, the hatch controller suffered a multi-year failure for the AERI located at the ARM North Slope of Alaska (NSA) Central Facility in Barrow, Alaska, from July 2006-February 2008. The failure resulted in misreporting the state of the hatch in the 'hatchOpen' field within the AERI data files. With this error there is no simple solution to translate what was reported back to the correct hatch status, thereby making it difficult for an analysis to determine when the AERI was actually viewing the sky. As only the data collected when the hatch is fully open are scientifically useful, an algorithm was developed to determine whether the hatch was open or closed based on spectral radiance data from the AERI. Determining if the hatch is open or closed in a scene with low clouds is non-trivial, as low opaque clouds may look very similar spectrally as the closed hatch. This algorithm used a backpropagation neural network; these types of neural networks have been used with increasing frequency in atmospheric science applications.

  16. Workbook on Identification of Aedes Aegypti Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

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

  17. Impact of MON863 transgenic roots is equivalent on western corn rootworm larvae for a wide range of maize phenologies.

    PubMed

    Hibbard, Bruce E; El Khishen, Ahmed A; Vaughn, Ty T

    2009-08-01

    The effects of maize, Zea mays L., phenology on establishment, damage, and adult emergence of the western corn rootworm, Diabrotica virgifera virgifera LeConte, on MON863 transgenic maize expressing the Cry3Bb1 protein and its isoline was evaluated in field trials in 2002 and 2003. As expected, plant damage, western corn rootworm larval recovery, and adult emergence were significantly lower on MON863 than isoline maize. The average weight of larvae and adults recovered from MON863 and isoline maize was generally not significantly different. If western corn rootworm larvae were able to establish on transgenic rootworm-resistant plants, larval growth was relatively normal. Plant damage, the number of western corn rootworm larvae recovered, and adult emergence from MON863 did not significantly differ between egg hatch times from widely varying phenologies in either year of the study. Although the extractable level of Cry3Bb1 decreased significantly from vegetative (V)4 to V9 maize in previous studies, in the current study, the amount of Cry3Bb1 did not vary from V3 to R3 in a way that affected neonate survival by western corn rootworm larvae in the field.

  18. Exposure to DEHP and MEHP from hatching to adulthood causes reproductive dysfunction and endocrine disruption in marine medaka (Oryzias melastigma).

    PubMed

    Ye, Ting; Kang, Mei; Huang, Qiansheng; Fang, Chao; Chen, Yajie; Shen, Heqing; Dong, Sijun

    2014-01-01

    Concern has increased regarding the adverse effects of di-(2-ethylhexyl)-phthalate (DEHP) on reproduction. However, limited information is available on the effects of DEHP in marine organisms. The aim of the present study was to examine whether long-term exposure to DEHP and its active metabolite mono-(2-ethylhexyl)-phthalate (MEHP) disrupts endocrine function in marine medaka (Oryzias melastigma). Marine medaka larvae were exposed to either DEHP (0.1 and 0.5mg/L) or MEHP (0.1 and 0.5mg/L) for 6 months, and the effects on reproduction, sex steroid hormones, liver vitellogenin (VTG), gonad histology and the expression of genes involved in the hypothalamic-pituitary-gonad (HPG) axis were investigated. Exposure to DEHP, but not MEHP, from hatching to adulthood accelerated the start of spawning and decreased the egg production of exposed females. Moreover, exposure to both DEHP and MEHP resulted in a reduction in the fertilization rate of oocytes spawned by untreated females paired with treated males. A significant increase in plasma 17β-estradiol (E2) along with a significant decrease in testosterone (T)/E2 ratios was observed in males, which was accompanied by the upregulation of ldlr, star, cyp17a1, 17βhsd, and cyp19a transcription in the testis. Increased concentrations of T and E2 were observed in females, which was consistent with the upregulation of ldlr. The expression of brain gnrhr2, fshβ, cyp19b and steroid hormone receptor genes also corresponded well with hormonal and reproductive changes. The liver VTG level was significantly increased after DEHP and MEHP exposure in males. DEHP induced histological changes in the testes and ovaries: the testes displayed a reduced number of spermatozoa, and the ovaries displayed an increased number of atretic follicles. In addition, the tissue concentrations of MEHP, MEHHP and MEOHP in DEHP-exposed groups were much higher than those in MEHP-exposed groups, and there were no dose- or sex-specific effects. Thus, DEHP

  19. Characterization of developmental Na(+) uptake in rainbow trout larvae supports a significant role for Nhe3b.

    PubMed

    Boyle, David; Blair, Salvatore D; Chamot, Danuta; Goss, Greg G

    2016-11-01

    Developing freshwater fish must compensate for the loss of ions, including sodium (Na(+)), to the environment. In this study, we used a radiotracer flux approach and pharmacological inhibitors to investigate the role of sodium/hydrogen exchange proteins (Nhe) in Na(+) uptake in rainbow trout (Oncorhynchus mykiss) reared from fertilization in soft water (0.1mM Na(+)). For comparison, a second group of embryos/larvae reared in hard water (2.2mM Na(+), higher pH and [Ca(2+)]) were also included in the experiment but were fluxed in soft water, only. Unidirectional rates of Na(+) uptake increased throughout development and were significantly higher in embryos/larvae reared in soft water. However, the mechanisms of Na(+) uptake in both groups of larvae were not significantly different, either in larvae immediately post-hatch or later in development: the broad spectrum Na(+) channel blocker amiloride inhibited 85-90% of uptake and the Nhe-inhibitor EIPA also caused near maximal inhibitions of Na(+) uptake. These data indicated Na(+) uptake was Nhe-mediated in soft water. A role of Nhe3b (but not Nhe2 or Nhe3a) in Na(+) uptake in soft water was also supported through gene expression analyses: expression of nhe3b increased throughout development in whole embryos/larvae in both groups and was significantly higher in those reared in soft water. This pattern of expression correlated well with measurements of Na(+) uptake. Together these data indicate that in part, rainbow trout embryos/larvae reared in low Na(+) soft water maintained Na(+) homeostasis by an EIPA sensitive component of Na(+) uptake, and support a primary role for Nhe3b.

  20. Partial characterization and ontogenetic development of pancreatic digestive enzymes in Japanese eel Anguilla japonica larvae.

    PubMed

    Murashita, Koji; Furuita, Hirofumi; Matsunari, Hiroyuki; Yamamoto, Takeshi; Awaji, Masahiko; Nomura, Kazuharu; Nagao, Jiro; Tanaka, Hideki

    2013-08-01

    The pancreatic digestive enzymes, trypsin, chymotrypsin, lipase and amylase were partially characterized, and changes in their activities were examined during the initial ontogeny of Japanese eel Anguilla japonica larvae from 5 to 34 days post-hatching (dph). The pH optima of the eel larval enzymes were narrower than those other fish species; trypsin activity was highest at pH 9, chymotrypsin and amylase activities were highest at pH 7 and 8, and lipase activity was highest at pH 8 and 9. In an analysis of thermal profiles, the larval pancreatic enzymes had a high optimal temperature and high thermal stability, which are typical of fish from the tropics. At 12 and 13 dph, lipase activity and gene expression levels of trypsin (-a and -b), lipase and amylase decreased markedly, suggesting a marked change in larval metabolism at that time. These data could be useful in the development of artificial larval diets in Japanese eel.

  1. Feeding broodstocks different starfish diets affect growth and survival of larvae of trumpet shell ( Charonia lampas sauliae Reeve 1844)

    NASA Astrophysics Data System (ADS)

    Kang, Kyoungho; Kim, Malhee; Hong, Hyeran; Cha, Guyong; Sui, Zhenghong

    2016-10-01

    Trumpet shell ( Charonia lampas sauliae) (Mollusca, Heterogastropoda, Cymatidae) has extensive economic value. Studies on the artificial larval development of C. lampas sauliae for aquaculture utilization have become especially important due to the finite natural resources. In the present study, the growth and survival rate of the larvae of C. lampas sauliae broodstocks fed three types of starfish diets, Asterina pectinifera Müller & Troschel 1842, A. amurensis Lütken 1871 and their mixture were compared. The larval size increased gradually between day 10 and day 20 after hatching at 15°C and 20°C. No difference was found in body size and specific growth rate (SGR) (two-way ANOVA; P > 0.05). However, during transition from trochophore to veliger stage 20 days after hatching, significant increases in larval survival and growth rates were observed. The maximum survival rate was observed on day 10. The mean survival rate was 0.463, 0.730 and 0.515 at 15°C, and 0.369, 0.713 and 0.444 at 20°C when A. pectinifera, A. amurensis and their mixture were fed, respectively. The SGR and survival rate of the larvae were definitely influenced by the diets ( P < 0.05), and the effect of A. amurensis alone was higher than that of A. pectinifera alone and their mixture.

  2. 49 CFR 231.28 - Box and other house cars with roof hatches built or placed in service after October 1, 1966.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Box and other house cars with roof hatches built... RAILROAD SAFETY APPLIANCE STANDARDS § 231.28 Box and other house cars with roof hatches built or placed in... other house cars with roof hatches. Box and other house cars with roof hatches built on or before...

  3. 49 CFR 231.28 - Box and other house cars with roof hatches built or placed in service after October 1, 1966.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Box and other house cars with roof hatches built... RAILROAD SAFETY APPLIANCE STANDARDS § 231.28 Box and other house cars with roof hatches built or placed in... other house cars with roof hatches. Box and other house cars with roof hatches built on or before...

  4. Effects of air humidity during incubation and age after hatch on heat tolerance of neonatal male and female chicks.

    PubMed

    Hamdy, A M; Van der Hel, W; Henken, A M; Galal, A G; Abd-Elmoty, A K

    1991-07-01

    Effects of incubation 45 versus 55% relative humidity (RH) and early versus late hatching time on heat tolerance of neonatal male and female chicks were studied. Chicks were exposed for 48 h to temperatures of 35 (Experiment 1), 37 (Experiment 2), or 39 C (Experiment 3). Chicks that hatched from eggs incubated at 45% RH were lighter at hatch than chicks that hatched from eggs incubated at 55% RH. Chicks that hatched from eggs incubated at 55% RH lost more body weight and water during heat exposure than those that hatched from eggs incubated at 45% RH. Body weight and water loss during heat exposure of chicks that hatched early and late was similar. However, chicks that hatched late maintained their initial heat production and respiratory quotient better during heat exposure than chicks that hatched early. Body weight and water loss of male and female chicks was similar. At 37 and 39 C, heat production of chicks fell to lower values during the 2nd day of exposure compared with the 1st day. It was concluded that chicks that hatched late, i.e., with a short holding period in the hatcher, and coming from eggs incubated at 45% RH had increased heat tolerance in comparison with the other chicks.

  5. Eight-Shaped Hatching Increases the Risk of Inner Cell Mass Splitting in Extended Mouse Embryo Culture.

    PubMed

    Yan, Zheng; Liang, Hongxing; Deng, Li; Long, Hui; Chen, Hong; Chai, Weiran; Suo, Lun; Xu, Chen; Kuang, Yanping; Wu, Lingqian; Lu, Shengsheng; Lyu, Qifeng

    2015-01-01

    Increased risk of monozygotic twinning (MZT) has been shown to be associated with assisted reproduction techniques, particularly blastocyst culture. Interestingly, inner cell mass (ICM) splitting in human '8'-shaped hatching blastocysts that resulted in MZT was reported. However, the underlying cause of MZT is not known. In this study, we investigated in a mouse model whether in vitro culture leads to ICM splitting and its association with hatching types. Blastocyst hatching was observed in: (i) in vivo developed blastocysts and (ii-iii) in vitro cultured blastocysts following in vivo or in vitro fertilization. We found that '8'-shaped hatching occurred with significantly higher frequency in the two groups of in vitro cultured blastocysts than in the group of in vivo developed blastocysts (24.4% and 20.4% versus 0.8%, respectively; n = 805, P < 0.01). Moreover, Oct4 immunofluorescence staining was performed to identify the ICM in the hatching and hatched blastocysts. Scattered and split distribution of ICM cells was observed around the small zona opening of '8'-shaped hatching blastocysts. This occurred at a high frequency in the in vitro cultured groups. Furthermore, we found more double OCT4-positive masses, suggestive of increased ICM splitting in '8'-shaped hatching and hatched blastocysts than in 'U'-shaped hatching and hatched blastocysts (12.5% versus 1.9%, respectively; n = 838, P < 0.01). Therefore, our results demonstrate that extended in vitro culture can cause high frequencies of '8'-shaped hatching, and '8'-shaped hatching that may disturb ICM herniation leading to increased risk of ICM splitting in mouse blastocysts. These results may provide insights into the increased risk of human MZT after in vitro fertilization and blastocyst transfer.

  6. Aspects of hatching success and chick survival in Gull-billed Terns in coastal Virginia

    USGS Publications Warehouse

    Eyler, T.B.; Erwin, R.M.; Stotts, D.B.; Hatfield, J.S.

    1999-01-01

    Because of a long-term population decline in Gull-billed Terns (Sterna nilotica) nesting along the coast of Virginia, we began a three year study in 1994 to monitor hatching success and survival of Gull-billed Tern chicks at several Virginia colony sites. Colonies were located on either small, storm-deposited shellpiles along marsh fringes or large, sandshell overwash fans of barrier islands. Nests were monitored one to three times a week for hatching success, and enclosures were installed around selected nests to monitor chick survival from hatching to about two weeks of age. Hatching success was lower in marsh colonies than island colonies, and was lower in 1995 than in 1994 and 1996, primarily because of flooding. The average brood size of nests where at least one chick hatched was 1.99 chicks. Survival rates of chicks to 14 days depended on hatch order and year but not brood size (one vs. two or more) or time of season. A-chicks had higher survival rates than B-chicks and third-hatched C-chicks (0.661 compared to 0.442 and 0.357, respectively). The year effect was significant only for A-chicks, with lower survival in 1994 (0.50) than in 1995 (0.765) or 1996 (0.758). Overall, productivity was low (0.53 chick per nest) compared to estimates for colonies in Denmark, and was attributable to nest flooding by spring and storm-driven high tides and chick predation, presumably mostly by Great Horned Owls (Bubo virginianus).

  7. Influence of hatch time and access to feed on intramuscular adipose tissue deposition in broilers.

    PubMed

    Powell, D J; Velleman, S G; Cowieson, A J; Singh, M; Muir, W I

    2016-06-01

    The effect of hatch time and subsequent access to feed on intramuscular adipose tissue deposition was studied in the pectoralis major muscle of male Ross 308 broiler chickens. Based on their hatch time chicks were classified as early (EH), midterm (MH), or late (LH) hatchers, with an average incubation duration of 497.7 h for EH, 508.8 h for MH, and 514.5 h for LH birds. Chicks were provided access to feed either immediately at hatch, or 24 h after the conclusion of the hatch window. Expression of the adipogenic regulatory genes peroxisome proliferator-activated receptor gamma (PPARγ), and stearoyl-CoA desaturase (SCD), were measured at the time of hatch, and zero, one, 4, 7, 28, and 40 d. Intramuscular adipocyte cell width and visualization of adipose tissue deposition was observed at 28 and 40 d. Expression of PPARγ was increased in the pectoralis major of LH birds at the time of hatch, zero, and one d. The expression of PPARγ at one and 7 d, and SCD at 7 d were increased in all birds that received delayed access to feed. At 28 d, adipocyte cell width was increased in LH birds with delayed access to feed, compared to EH and MH birds with delayed access to feed and LH birds with immediate access to feed. At 40 d, adipocyte cell width was increased in all birds that received delayed access to feed. Also at 40 d, there was a trend (P = 0.078) for more extensive intramuscular adipose tissue deposition in LH than EH birds, and in birds with delayed access to feed (P = 0.075). These data indicate delayed access to feed increases intramuscular adipose tissue deposition in the pectoralis major muscle, and suggest that hatch time influences this regulation. PMID:26976909

  8. Influence of chick hatch time and access to feed on broiler muscle development.

    PubMed

    Powell, D J; Velleman, S G; Cowieson, A J; Singh, M; Muir, W I

    2016-06-01

    The effect of hatch time and the timing of access to feed on growth rate and breast muscle development was assessed in Ross 308 broiler chickens. Chicks were removed from the incubator upon hatching, and classified as early (EH), midterm (MH), or late (LH) hatchers, based on the duration of their incubation. Feed and water were available either immediately at hatch, or 24 h after the conclusion of the hatch period. Hatchling body weight was uniform regardless of hatch time. Subsequently, bodyweight was increased in EH compared to LH birds following immediate access to feed, until 7 d in female, and 14 d in male birds. Relative breast weight was increased until 28 d in birds with immediate access to feed, and also EH and MH birds regardless of access to feed. Pectoralis major muscle morphology and expression of the myogenic regulatory factors myogenic determination factor 1 (MYOD1) and myogenin, and the proteoglycans syndecan-4, glypican-1, and decorin were measured. Myogenin and glypican-1 stimulate satellite cell (SC) differentiation. Glypican-1 expression was unaffected by treatment. A late increase in myogenin expression was observed in MH birds with delayed access to feed, and all LH birds. Syndecan-4 and MYOD1, expressed in proliferating SC, and decorin, which stimulates satellite cell proliferation and differentiation, were variably upregulated in the first wk posthatch in the same birds. These data suggest SC were activated and proliferating, but had reduced differentiation in later hatching and feed deprived birds. Conversely, EH birds with immediate access to feed had maximal myofiber width at 7 d, while fiber width was increased in birds with immediate access to feed compared to those with delayed access to feed through 40 d of age. These results demonstrate that delaying chick access to feed for 24 h upon removal from the incubator will impair muscle growth. Additionally, hatch time influences muscle development, with accelerated muscle growth in EH and

  9. Development by injection in Simulium damnosum s.l. of two Onchocerca species from the wart hog to infective larvae resembling type D larvae (Duke, 1967).

    PubMed

    Wahl, G; Bain, O

    1995-03-01

    Four wart hogs (Phacochoerus aethiopicus) examined in the Sudan savanna of North-Cameroon were all found infected with two types of skin microfilariae. One was O. ramachandrini Bain, Wahl and Renz, 1993, the adult worms of which live in the subcutaneous tissues of the feet. The other, smaller type belongs to a new Onchocerca species, the adult worms of which were not yet found. O. ramachandrini-microfilariae were evenly distributed across the whole body surface, those of Onchocerca sp. were concentrated on the back. The two species of microfilariae were isolated from an infected hide separated under the dissecting microscope and injected into the thorax of pupae-hatched S. squamosum and S. damnosum s.slr. females. Both filariae developed in both flies at high rates (33-47% of injected microfilariae) and without pathological forms to infective larvae L3). Both L3-species had a caudal tip, were long, slender and very motile and had a conspicuous glandular oesophagus. L3 from O. ramachandrini-microfilariae had a long glandular oesophagus (55% of total L3 length), a round head and measured an average of 955 microns long and 19.2 microns wide. L3 from the other microfilaria-species were shorter (845 microns, P < 0.001) and thinner (16.7 microns, P < 0.001) and had a shorter glandular oesophagus (36%, P < 0.001), a shorter tail (P < 0.01) and a conical head. Both L3-species, by their caudal tip, their long and slender silhouette, their great motility and their conspicuous glandular oesophagus resemble non-O. volvulus filarial L3 known, since many years, to occur in "wild" S. damnosum s.l. in Cameroon (Type D larvae, Duke, 1967) and in Liberia (Agamofilaria Type VI, Voelker and Garms, 1972). During our study, L3 such larvae were found in 12 wild S. damnosum s.l. from two geographically different areas of North Cameroon and all identified as O. ramachandrini. The excellent development of the two Onchocerca species from the wart hog in S. damnosum s.l. after artificial

  10. Behavior of Settling Marine Larvae in Flow

    NASA Astrophysics Data System (ADS)

    Hernandez, J.; Koehl, M. A.

    2012-12-01

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

  11. Directional flow sensing by passively stable larvae.

    PubMed

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

    2015-09-01

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

  12. Directional flow sensing by passively stable larvae.

    PubMed

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

    2015-09-01

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

  13. Ability of Platygaster demades (Hymenoptera: Platygastridae) to Parasitize Both Eggs and Larvae Makes it an Effective Natural Enemy of Dasineura mali (Diptera: Cecidomyiidae).

    PubMed

    He, Xiao Zhao; Wang, Qiao

    2015-08-01

    Dasineura mali Kieffer (Diptera: Cecidomyiidae) is an important pest of young apple trees in New Zealand and a serious quarantine pest in Asia, Australia, and western United States. Platygaster demades Walker (Hymenoptera: Platygastridae) is a parasitoid of D. mali. The developmental period of the parasitoid is longer than that of D. mail, suggesting a possible asynchrony between the two species in the field. Prior to the present study, this parasitoid was considered laying eggs only in the host eggs. Here we carried out experiments in the laboratory and field to determine whether P. demades also parasitized other stages of the host and explain the recently observed high parasitism rate and parasitoid-host synchronization in the field. We demonstrated for the first time that P. demades explored and accepted both eggs and first-instar larvae of D. mali as hosts. This feature widens the phenological window for parasitization, allowing the parasitoid to continue laying eggs after D. mali eggs hatch, and contributes to the high within- and between-generation parasitism rate and synchronization of the two species. Therefore, the difference in developmental period between the pest and its parasitoid cannot simply be considered evidence of asynchrony between the two. The consistent superparasitism rate and progeny sex ratio regardless of host stage at parasitization detected in the present study may be attributed to the fact that P. demades eggs do not hatch until the host larvae reach the third instar (mature) and thus all parasitoid larvae feed on the third-instar larvae with similar quantity and quality of nutrition. The higher parasitism rate in eggs than in larvae may be due to higher larval defense ability against attack by and lower attractiveness to the parasitoid. PMID:26470331

  14. Variability in transport processes of Pacific saury Cololabis saira larvae leading to their broad dispersal: Implications for their ecological role in the western North Pacific

    NASA Astrophysics Data System (ADS)

    Oozeki, Yoshioki; Okunishi, Takeshi; Takasuka, Akinori; Ambe, Daisuke

    2015-11-01

    Transport of Pacific saury Cololabis saira larvae from spawning to nursery grounds was examined based on datasets from larval distribution surveys during winter seasons 1990-2011. In the surveys, a neuston net was towed for 10 min over broad areas off the southern Pacific coast of Japan. Transport trajectories of saury larvae and temperature they experienced were analyzed based on a numerical particle-tracking model from 1993 to 2011 using satellite-based sea surface current and temperature data. Larval growth during the transport was estimated from the relationship of larval growth to environmental factors obtained in a previous study. Results of the particle tracking experiments indicated that a large amount of saury juveniles (knob length, KnL, 40 mm) were transported to an area south of the Kuroshio axis. Only a relatively small amount (14.6%) of the 40 mm KnL stage juveniles were transported in and around the Kuroshio extension, although it has previously been considered important that the juveniles are transported to the area north of the Kuroshio extension. Abundance of juveniles transported to the area north of the Kuroshio extension indicated a positive relationship to the abundance of medium size class saury in the autumn fishing season. Even though a very small part (3.9%) of hatched larvae were transported to this area, recruitment of the saury population depends on this amount of transported hatched larvae. On the other hand, the high juvenile transport rate to the areas south of the Kuroshio axis may suggest a broad dispersal mechanism to ensure that some larvae find a suitable habitat. Subsequently, the importance of saury in the marine ecosystem as a food item for predatory species in the sub-tropical region is discussed.

  15. Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch).

    PubMed

    Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M Aminur; Subramaniam, Sreeramanan

    2013-01-01

    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish. PMID:24098390

  16. Cutaneous Larva Migrans in Early Infancy

    PubMed Central

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

    2015-01-01

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

  17. Zona hardening, zona drilling and assisted hatching: new achievements in assisted reproduction.

    PubMed

    De Vos, A; Van Steirteghem, A

    2000-01-01

    Prior to fertilization, the zona pellucida surrounding the mammalian oocyte acts as a species-specific sperm barrier and is involved in sperm binding. After fertilization, the zona plays a role in blocking polyspermic fertilization, it protects the integrity of the preimplantation embryo during early embryonic development, and also helps its oviductal transport. Zona hardening occurs naturally after fertilization in order to ensure this threefold function. A combination of lysins produced by the cleaving embryo or the uterus and physical expansion then reduces the zona thickness in preparation for hatching. Zona hardening, although not readily quantifiable, may also be induced by in vitro culture and by in vivo aging. Indeed, prolonged exposure of human oocytes and embryos to artificial culture conditions seems to impair their ability to implant. Implantation rates are also inversely correlated with advanced female age. Recently, failure of the embryonic zona pellucida to rupture following blastocyst expansion has been put forward as a possible contributing factor in implantation failure. In order to help embryos escape from their zonae during blastocyst expansion, different types of assisted hatching have been developed. Zona drilling involves the creation of an opening in the zona with acidified medium, whereas zona slitting is carried out in the same manner as partial zona dissection. In zona thinning, the zona is just made thinner over a certain area without a hole or a slit being created. More recently, laser-assisted hatching has been introduced. In vitro studies with both mouse and human embryos have indicated that an artificial gap in the zona pellucida significantly improves the hatching ability of blastocysts grown in vitro as compared to non-micromanipulated embryos. However, the clinical relevance of assisted hatching within an assisted reproduction program remains controversial and elusive. Very few randomized studies are available. Most reports are of

  18. Early and late maternal effects on hatching phenology of Heterocypris incongruens (Crustacea: Ostracoda).

    PubMed

    Rossi, Valeria; Albini, Dania; Pellegri, Valerio; Menozzi, Paolo

    2015-07-01

    In ephemeral ponds, the hatching asynchrony of resting eggs may be adaptive and the result of a maternal bet-hedging strategy. A mother can influence the progeny phenology through conditions experienced during life cycle even in early development stages. We investigated the consequences of a hatching delay for offspring and compared early and late maternal effects in a clonal lineage of Heterocypris incongruens. We used females from genetically identical, 40 months old, resting eggs that hatched, asynchronically, after a first (FI) or a second (SI) inundation event. Maternal origin (FI or SI) was considered an early effect involving the maternal response to hatching stimuli during the embryological dormant stage. Maternal age at deposition and egg size were considered late effects that account for maternal conditions during active stage. We compared size and development time of eggs produced by FI and SI females under laboratory condition (24°C 12:12 L:D photoperiod). Maternal origin affected development time to adulthood which was later in FI than in SI females, and fecundity that was higher in FI than in SI females. SI eggs were smaller than FI eggs: size was affected by maternal age at deposition and was directly related to the egg development time. Development time varied from 1 to 117 days and was shorter in SI eggs than in FI eggs. Our results showed that maternal response during embryological stage affects the performance in successive active stages and suggested that hatching asynchrony may be considered a risk spread strategy.

  19. Coots use hatch order to learn to recognize and reject conspecific brood parasitic chicks.

    PubMed

    Shizuka, Daizaburo; Lyon, Bruce E

    2010-01-14

    Avian brood parasites and their hosts provide model systems for investigating links between recognition, learning, and their fitness consequences. One major evolutionary puzzle has continued to capture the attention of naturalists for centuries: why do hosts of brood parasites generally fail to recognize parasitic offspring after they have hatched from the egg, even when the host and parasitic chicks differ to almost comic degrees? One prominent theory to explain this pattern proposes that the costs of mistakenly learning to recognize the wrong offspring make recognition maladaptive. Here we show that American coots, Fulica americana, can recognize and reject parasitic chicks in their brood by using learned cues, despite the fact that the hosts and the brood parasites are of the same species. A series of chick cross-fostering experiments confirm that coots use first-hatched chicks in a brood as referents to learn to recognize their own chicks and then discriminate against later-hatched parasitic chicks in the same brood. When experimentally provided with the wrong reference chicks, coots can be induced to discriminate against their own offspring, confirming that the learning errors proposed by theory can exist. However, learning based on hatching order is reliable in naturally parasitized coot nests because host eggs hatch predictably ahead of parasite eggs. Conversely, a lack of reliable information may help to explain why the evolution of chick recognition is not more common in hosts of most interspecific brood parasites. PMID:20016486

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

    PubMed

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

    2010-10-01

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

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

    PubMed

    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. PMID:20545737

  2. TIME management by medicinal larvae.

    PubMed

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

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

    Andersen, S.; Grefsrud, E. S.; Harboe, T.

    2013-02-01

    As a result of high anthropogenic emission of CO2, partial pressure of carbon dioxide (pCO2) in the oceans has increased causing a drop in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and that the early life stages are the most sensitive to OA. We studied the effects on embryo and larvae of great scallop (Pecten maximus L.), using mean pCO2-levels of 477 (ambient), 821, 1184, and 1627 ppm. OA affected both survival and shell growth negatively after seven days. Growth was reduced with 5-10% when pCO2 increased from ambient 477 ppm to 1627 ppm, and survival based on egg number was reduced from 40.4% in the ambient group to 10.7% in the highest pCO2-group. Larvae/embryos stained with calcein one day after fertilization, showed fluorescence in the newly formed shell area indicating calcification of the shell already at the trochophore stage. Shell hinge deformities were observed at elevated pCO2-levels in trochophore larvae after two days. After seven days, deformities in both shell hinge and shell edge were observed in veliger larvae at elevated pCO2-levels. Although the growth showed a moderate reduction, survival rate and increased amount of deformed larvae indicates that P. Maximus larvae are affected by elevated pCO2 levels within the range of what is projected for the next century.

  4. Larvae of the genus Eleodes (Coleoptera, Tenebrionidae): matrix-based descriptions, cladistic analysis, and key to late instars.

    PubMed

    Smith, Aaron D; Dornburg, Rebecca; Wheeler, Quentin D

    2014-01-01

    Darkling beetle larvae (Coleoptera, Tenebrionidae) are collectively referred to as false wireworms. Larvae from several species in the genus Eleodes are considered to be agricultural pests, though relatively little work has been done to associate larvae with adults of the same species and only a handful of species have been characterized in their larval state. Morphological characters from late instar larvae were examined and coded to produce a matrix in the server-based content management system mx. The resulting morphology matrix was used to produce larval species descriptions, reconstruct a phylogeny, and build a key to the species included in the matrix. Larvae are described for the first time for the following 12 species: Eleodes anthracinus Blaisdell, Eleodes carbonarius (Say), Eleodes caudiferus LeConte, Eleodes extricatus (Say), Eleodes goryi Solier, Eleodes hispilabris (Say), Eleodes nigropilosus LeConte, Eleodes pilosus Horn, Eleodes subnitens LeConte, Eleodes tenuipes Casey, Eleodes tribulus Thomas, and Eleodes wheeleri Aalbu, Smith & Triplehorn. The larval stage of Eleodes armatus LeConte is redescribed with additional characters to differentiate it from the newly described congeneric larvae.

  5. Larvae of the genus Eleodes (Coleoptera, Tenebrionidae): matrix-based descriptions, cladistic analysis, and key to late instars

    PubMed Central

    Smith, Aaron D.; Dornburg, Rebecca; Wheeler, Quentin D.

    2014-01-01

    Abstract Darkling beetle larvae (Coleoptera, Tenebrionidae) are collectively referred to as false wireworms. Larvae from several species in the genus Eleodes are considered to be agricultural pests, though relatively little work has been done to associate larvae with adults of the same species and only a handful of species have been characterized in their larval state. Morphological characters from late instar larvae were examined and coded to produce a matrix in the server-based content management system mx. The resulting morphology matrix was used to produce larval species descriptions, reconstruct a phylogeny, and build a key to the species included in the matrix. Larvae are described for the first time for the following 12 species: Eleodes anthracinus Blaisdell, Eleodes carbonarius (Say), Eleodes caudiferus LeConte, Eleodes extricatus (Say), Eleodes goryi Solier, Eleodes hispilabris (Say), Eleodes nigropilosus LeConte, Eleodes pilosus Horn, Eleodes subnitens LeConte, Eleodes tenuipes Casey, Eleodes tribulus Thomas, and Eleodes wheeleri Aalbu, Smith & Triplehorn. The larval stage of Eleodes armatus LeConte is redescribed with additional characters to differentiate it from the newly described congeneric larvae. PMID:25009429

  6. First evidence of fish larvae producing sounds

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Prickett, Kyle A; Ferringer, Tammie C

    2015-03-01

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

  8. Comparison of hatching mode in pelagic and demersal eggs of two closely related species in the order pleuronectiformes.

    PubMed

    Kawaguchi, Mari; Sano, Kaori; Yoshizaki, Norio; Shimizu, Daisuke; Fujinami, Yuichiro; Noda, Tsutomu; Yasumasu, Shigeki

    2014-11-01

    We compared several characteristics of the pelagic eggs of Verasper variegatus with those of demersal eggs of Pseudopleuronectes yokohamae, both in the order Pleuronectiformes (halibuts or flatfishes). V. variegatus eggs had about twice the diameter of P. yokohamae eggs. However, the total egg protein weight of P. yokohamae was similar to that of V. variegatus. The specific gravity of P. yokohamae eggs was calculated to be 7-fold that of V. variegatus. The difference in size is the main feature distinguishing the two types of egg. The thickness of the egg envelope of P. yokohamae- more than twice that of V. variegatus-must affect the manner of hatching. The amount of hatching enzyme synthesized in pre-hatching embryo was estimated to be larger in P. yokohamae than V. variegatus. The distribution of hatching gland cells differed between the species. In V. variegates embryos, these were located on the yolk sac as a narrow ring-shaped belt, resulting in cleavage of the egg envelope into two parts by digesting a limited region of the egg envelope, called "rim-hatching". The hatching gland cells of P. yokohamae embryos were distributed all over the surface of the yolk sac, forming a hole through which the embryo could escape. Thus, the location of the hatching gland cells in pre-hatching embryos varied during the evolution of the Pleuronectiformes, depending on the egg type and manner of hatching.

  9. Resuscitation of the newly born.

    PubMed

    Johannson, A B; Biarent, D

    2002-01-01

    International guidelines developed recommendations in the resuscitation of the new-born: at least one person trained in resuscitation of the newly born should attend every delivery. A minority of the new-borns require active resuscitation to achieve regular respiration, heart rhythm above 100/min, pink colour and adequate tone. Establishment of adequate ventilation should be of primary concern. Most new-borns who require positive-pressure ventilation can be adequately ventilated with a bag and mask. All healthcare providers, who may be asked to deal with an emergency delivery, should master such technique. In case of meconium-stained amniotic fluid, thorough oropharyngeal suctioning should be perform before the delivery of the chest. Tracheal aspiration of mecomium should be perform only in depressed child. Very few infants require chest compressions and much less administration of drugs. Umbilical access remains the most widely recommended access in new-born. Adequate transfer to Neonatal Unit improves outcome. PMID:12503356

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

    PubMed Central

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

    2015-01-01

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

  11. Hatch Integration Testing of a NASA TransHab Derivative Woven Inflatable Module

    NASA Technical Reports Server (NTRS)

    Edgecombe, John; Valle, Gerald

    2009-01-01

    Current options for Lunar habitat architecture include inflatable habitats and airlocks. Inflatable structures can have mass and volume advantages over conventional structures. However, inflatable structures are also perceived to carry additional risk because they are at a lower Technical Readiness Level (TRL) than more conventional metallic structures. The use of inflatable structures for habitation will require large penetrations in the inflatable structure to accommodate hatches and/or windows The Hatch Integration Test is designed to study the structural integrity of an expandable structure with an integrated hatch, and to verify mathematical models of the structure. The TransHab project developed an experimental inflatable module at Johnson Space Center in the 1990's. The TransHab design was originally envisioned for use in Mars Transits but was also studied as a potential habitat for the International Space Station (ISS).

  12. Coral Larvae Move toward Reef Sounds

    PubMed Central

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

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency. PMID:20498831

  13. Coral larvae move toward reef sounds.

    PubMed

    Vermeij, Mark J A; Marhaver, Kristen L; Huijbers, Chantal M; Nagelkerken, Ivan; Simpson, Stephen D

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency. PMID:20498831

  14. Warming affects hatching time and early season survival of eastern tent caterpillars.

    PubMed

    Abarca, Mariana; Lill, John T

    2015-11-01

    Climate change is disrupting species interactions by altering the timing of phenological events such as budburst for plants and hatching for insects. We combined field observations with laboratory manipulations to investigate the consequences of climate warming on the phenology and performance of the eastern tent caterpillar (Malacosoma americanum). We evaluated the effects of warmer winter and spring regimes on caterpillar hatching patterns and starvation endurance, traits likely to be under selection in populations experiencing phenological asynchrony, using individuals from two different populations (Washington, DC, and Roswell, GA). We also quantified the proximate and extended fitness effects of early food deprivation and recorded spring phenology of local caterpillars and their host plants. In addition, we conducted laboratory assays to determine if caterpillars are using plant chemical cues to fine-tune their hatching times. Warmer winter temperatures induced earlier hatching and caterpillars from GA survived starvation for periods that were 30% longer than caterpillars from DC. Warmer spring regimes reduced the starvation endurance of caterpillars overwintering in the wild but not in the laboratory. Early starvation dramatically reduced hatchling survival; however, surviving caterpillars did not show detrimental effects on pupal mass or development time. In the field, hatching preceded budburst in both 2013 and 2014 and the period of optimal foliage quality was 2 weeks shorter in 2013. Hatching time was unaffected by exposure to plant volatiles. Overall, we found that warmer temperatures can trigger late-season asynchrony by accelerating plant phenology and caterpillars from different populations exhibit differential abilities to cope with environmental unreliability. PMID:26093630

  15. Environmental concentration of carbamazepine accelerates fish embryonic development and disturbs larvae behavior.

    PubMed

    Qiang, Liyuan; Cheng, Jinping; Yi, Jun; Rotchell, Jeanette M; Zhu, Xiaotong; Zhou, Junliang

    2016-09-01

    Environmental pollution caused by pharmaceuticals has been recognized as a major threat to the aquatic ecosystems. Carbamazepine, as the widely prescribed antiepileptic drug, has been frequently detected in the aquatic environment and has created concerns about its potential impacts in the aquatic organisms. The effects of carbamazepine on zebrafish embryos were studied by examining their phenotype, behavior and molecular responses. The results showed that carbamazepine disturbed the normal growth and development of exposed zebrafish embryos and larvae. Upon exposure to carbamazepine at 1 μg/L, the hatching rate, body length, swim bladder appearance and yolk sac absorption rate were significantly increased. Embryos in treatment groups were more sensitive to touch and light stimulation. At molecular level, exposure to an environmentally relevant concentration (1 μg/L) of carbamazepine disturbed the expression pattern of neural-related genes of zebrafish embryos and larvae. This study suggests that the exposure of fish embryo to antiepileptic drugs, at environmentally relevant concentrations, affects their early development and impairs their behavior. Such impacts may have future repercussions by affecting fish population structure. PMID:27386877

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

    PubMed

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

    2014-11-01

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

  17. Distribution Characteristics of Eggs and Neonate Larvae of Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae)

    PubMed Central

    Wearing, Christopher H.

    2016-01-01

    Literature is reviewed on the spatial distribution of the eggs and neonate larvae of codling moth on apple trees in relation to research conducted in Nelson, New Zealand. At Nelson, oviposition increased with height and was greater in the north and east of the trees and in those with greater fruit load in some seasons, which matches published reports. All publications and the research recorded high percentages of eggs laid singly within 10–15 cm of the fruit, with most eggs on leaves even within fruit clusters; oviposition on fruit clusters of different sizes was nonrandom because more eggs were laid on those with more fruit, but the aggregation of both per cluster and within clusters was even greater than that caused by the fruit number alone. Oviposition at random with respect to the fruit occurred only at very low population density. The choice of oviposition site between fruit and the adaxial leaf surface and abaxial leaf surface (AbLS) was variable and cultivar related. Cultivars on which eggs predominated on the AbLS were less frequent and characterized by low trichome density. In the literature, neonate larvae from eggs on the AbLS suffered greater mortality, as did those in Nelson that hatched more distant from the fruit. This review discusses the interaction between these distribution characteristics and species-specific host–plant volatiles, egg adhesion to plant surfaces, oviposition deterrents, predation, and their relevance to pest management. PMID:27429560

  18. Distribution Characteristics of Eggs and Neonate Larvae of Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae).

    PubMed

    Wearing, Christopher H

    2016-01-01

    Literature is reviewed on the spatial distribution of the eggs and neonate larvae of codling moth on apple trees in relation to research conducted in Nelson, New Zealand. At Nelson, oviposition increased with height and was greater in the north and east of the trees and in those with greater fruit load in some seasons, which matches published reports. All publications and the research recorded high percentages of eggs laid singly within 10-15 cm of the fruit, with most eggs on leaves even within fruit clusters; oviposition on fruit clusters of different sizes was nonrandom because more eggs were laid on those with more fruit, but the aggregation of both per cluster and within clusters was even greater than that caused by the fruit number alone. Oviposition at random with respect to the fruit occurred only at very low population density. The choice of oviposition site between fruit and the adaxial leaf surface and abaxial leaf surface (AbLS) was variable and cultivar related. Cultivars on which eggs predominated on the AbLS were less frequent and characterized by low trichome density. In the literature, neonate larvae from eggs on the AbLS suffered greater mortality, as did those in Nelson that hatched more distant from the fruit. This review discusses the interaction between these distribution characteristics and species-specific host-plant volatiles, egg adhesion to plant surfaces, oviposition deterrents, predation, and their relevance to pest management. PMID:27429560

  19. A cysteine endopeptidase from tick (Rhipicephalus (Boophilus) microplus) larvae with vitellin digestion activity.

    PubMed

    Estrela, Andréia; Seixas, Adriana; Termignoni, Carlos

    2007-12-01

    The hard tick Rhipicephalus (Boophilus) microplus is a blood-sucking ectoparasite. R. microplus free-living stage comprises egg development, hatching, and subsequent larval development until encountering a host. In order to complete the embryological development, this tick relies on yolk reserve substances, mainly vitellin (Vt), which is still present in the larval stage. The present study demonstrates presence and digestion of Vt in unfed R. microplus larvae. An increasing proteolytic activity is observed in larval development, as well as a decrease in total protein and in Vt content. Partial purification and characterization of a R. microplus larval cysteine endopeptidase (RmLCE) with Vt-degrading activity is also described. RmLCE has optimal activity at 37 degrees C at pH 5.0, being unstable at pH > or =7.5. This enzyme is active upon fluorogenic peptide substrates and is able to degrade Vt, its putative natural substrate. These results indicate that RmLCE has a role in supporting the nutritional needs of unfed R. microplus larva through Vt proteolysis, allowing survival until the first blood meal.

  20. A novel agent (Endozoicomonas elysicola) responsible for epitheliocystis in cobia Rachycentrum canadum larvae.

    PubMed

    Mendoza, Mabel; Güiza, Linda; Martinez, Ximena; Caraballo, Xenia; Rojas, Jaime; Aranguren, Luis Fernando; Salazar, Marcela

    2013-09-24

    Aquaculture of cobia has gained popularity in the last decade, and this species is now farmed in several countries in Latin America and Asia. Despite recent improvement in production techniques that allowed the expansion of the industry, little is known about the diseases that affect cobia during the larviculture stage. In this article we investigated the cause of mass mortalities occurring 13-20 d post-hatching in 3 cycles of cobia larviculture. Wet mounts from diseased larvae gills revealed the presence of cyst-like basophilic inclusions. DNA from the cysts was extracted and PCR amplified using the 16S rRNA gene universal primers for prokaryotes. The amplified products were sequenced and analyzed using BLAST, finding a similarity of 99% with Endozoicomonas elysicola, a Gram-negative bacterium. Confirmation of E. elysicola was conducted by designing a specific probe for in situ hybridization. Specific primers were also designed for diagnostic purposes. This is the first report of epitheliocystis in cobia larvae and also the first report of E. elysicola as an epitheliocystis-causing agent. PMID:24062550

  1. Variation in rates of early development in Haliotis asinina generate competent larvae of different ages

    PubMed Central

    2012-01-01

    Introduction Inter-specific comparisons of metazoan developmental mechanisms have provided a wealth of data concerning the evolution of body form and the generation of morphological novelty. Conversely, studies of intra-specific variation in developmental programs are far fewer. Variation in the rate of development may be an advantage to the many marine invertebrates that posses a biphasic life cycle, where fitness commonly requires the recruitment of planktonically dispersing larvae to patchily distributed benthic environments. Results We have characterised differences in the rate of development between individuals originating from a synchronised fertilisation event in the tropical abalone Haliotis asinina, a broadcast spawning lecithotrophic vetigastropod. We observed significant differences in the time taken to complete early developmental events (time taken to complete third cleavage and to hatch from the vitelline envelope), mid-larval events (variation in larval shell development) and late larval events (the acquisition of competence to respond to a metamorphosis inducing cue). We also provide estimates of the variation in maternally provided energy reserves that suggest maternal provisioning is unlikely to explain the majority of the variation in developmental rate we report here. Conclusions Significant differences in the rates of development exist both within and between cohorts of synchronously fertilised H. asinina gametes. These differences can be detected shortly after fertilisation and generate larvae of increasingly divergent development states. We discuss the significance of our results within an ecological context, the adaptive significance of mechanisms that might maintain this variation, and potential sources of this variation. PMID:22339806

  2. The spread of pathogens through trade in poultry hatching eggs: overview and recent developments.

    PubMed

    Cobb, S P

    2011-04-01

    The international trade in poultry hatching eggs could potentially facilitate the global dissemination of poultry disease. Provided the guidelines of the World Organisation for Animal Health (OIE) on breeding flock hygiene are followed, of those avian diseases currently listed by the OlE, only highly pathogenic avian influenza (HPAI), Newcastle disease (ND), and avian mycoplasmosis (caused by Mycoplasma gallisepticum or M. synoviae) should be considered likely to be spread though trade in this commodity. Furthermore, the impact of HPAI and ND on egg production and hatchability will constrain the potential for these agents to be spread by poultry hatching eggs.

  3. Diel and distributional abundance patterns of fish embryos and larvae in the lower Columbia and Deschutes rivers

    USGS Publications Warehouse

    Gadomski, D.M.; Barfoot, C.A.

    1998-01-01

    Diel and distributional abundance patterns of free embryos and larvae of fishes in the lower Columbia River Basin were investigated. Ichthyoplankton samples were collected in 1993 during day and night in the main-channel and a backwater of the lower Columbia River, and in a tributary, the Deschutes River. Fish embryos and larvae collected in the main-channel Columbia River were primarily (85.6%) of native taxa (peamouth Mylocheilus caurinus, northern squawfish Ptychocheilus oregonensis, suckers Catostomus spp., and sculpins Cottus spp.), with two introduced species (American shad Alosa sapidissima and common carp Cyprinus carpio) comprising a smaller percentage of the catch (13.3%). Similarly, in the Deschutes River native taxa [lampreys (Petromyzontidae), minnows (Cyprinidae), and suckers Catostomus spp.] dominated collections (99.5% of the catch). In contrast, 83.5% of embryos and larvae in the Columbia River backwater were of introduced taxa [American shad, common carp, and sunfishes (Centrarchidae)]. In all locations, all dominant taxa except sculpins were collected in significantly greater proportions at night. Taxon-specific differences in proportions of embryos and larvae collected at night can in some instances be related to life history styles. In the main-channel Columbia River, northern squawfish and peamouth were strongly nocturnal and high proportions still had yolksacs, suggesting that they had recently hatched and were drifting downriver to rearing areas. In contrast, sculpin abundances were similar during day and night, and sculpins mostly had depleted yolksacs, indicating sculpins were feeding and rearing in offshore limnetic habitats. Taxon-specific diel abundance patterns and their causes must be considered when designing effective sampling programs for fish embryos and larvae.

  4. Allometric growth and development of organs in ballan wrasse (Labrus bergylta Ascanius, 1767) larvae in relation to different live prey diets and growth rates.

    PubMed

    Gagnat, Maren Ranheim; Wold, Per-Arvid; Bardal, Tora; Øie, Gunvor; Kjørsvik, Elin

    2016-01-01

    Small fish larvae grow allometrically, but little is known about how this growth pattern may be affected by different growth rates and early diet quality. The present study investigates how different growth rates, caused by start-feeding with copepods or rotifers the first 30 days post-hatch (dph), affect allometric growth and development of nine major organs in ballan wrasse (Labrus bergylta) larvae up to experimental end at 60 dph. Feeding with cultivated copepod nauplii led to both increased larval somatic growth and faster development and growth of organ systems than feeding with rotifers. Of the organs studied, the digestive and respiratory organs increased the most in size between 4 and 8 dph, having a daily specific growth rate (SGR) between 30 and 40% in larvae fed copepods compared with 20% or less for rotifer-fed larvae. Muscle growth was prioritised from flexion stage and onwards, with a daily SGR close to 30% between 21 and 33 dph regardless of treatment. All larvae demonstrated a positive linear correlation between larval standard length (SL) and increase in total tissue volume, and no difference in allometric growth pattern was found between the larval treatments. A change from positive allometric to isometric growth was observed at a SL close to 6.0 mm, a sign associated with the start of metamorphosis. This was also where the larvae reached postflexion stage, and was accompanied by a change in growth pattern for most of the major organ systems. The first sign of a developing hepatopancreas was, however, first observed in the largest larva (17.4 mm SL, 55 dph), indicating that the metamorphosis in ballan wrasse is a gradual process lasting from 6.0 to at least 15-17 mm SL. PMID:27422903

  5. Allometric growth and development of organs in ballan wrasse (Labrus bergylta Ascanius, 1767) larvae in relation to different live prey diets and growth rates

    PubMed Central

    Wold, Per-Arvid; Bardal, Tora; Øie, Gunvor; Kjørsvik, Elin

    2016-01-01

    ABSTRACT Small fish larvae grow allometrically, but little is known about how this growth pattern may be affected by different growth rates and early diet quality. The present study investigates how different growth rates, caused by start-feeding with copepods or rotifers the first 30 days post-hatch (dph), affect allometric growth and development of nine major organs in ballan wrasse (Labrus bergylta) larvae up to experimental end at 60 dph. Feeding with cultivated copepod nauplii led to both increased larval somatic growth and faster development and growth of organ systems than feeding with rotifers. Of the organs studied, the digestive and respiratory organs increased the most in size between 4 and 8 dph, having a daily specific growth rate (SGR) between 30 and 40% in larvae fed copepods compared with 20% or less for rotifer-fed larvae. Muscle growth was prioritised from flexion stage and onwards, with a daily SGR close to 30% between 21 and 33 dph regardless of treatment. All larvae demonstrated a positive linear correlation between larval standard length (SL) and increase in total tissue volume, and no difference in allometric growth pattern was found between the larval treatments. A change from positive allometric to isometric growth was observed at a SL close to 6.0 mm, a sign associated with the start of metamorphosis. This was also where the larvae reached postflexion stage, and was accompanied by a change in growth pattern for most of the major organ systems. The first sign of a developing hepatopancreas was, however, first observed in the largest larva (17.4 mm SL, 55 dph), indicating that the metamorphosis in ballan wrasse is a gradual process lasting from 6.0 to at least 15-17 mm SL. PMID:27422903

  6. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae — can we identify the underlying factors?

    PubMed Central

    van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F.; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks. PMID:26038712

  7. Allometric growth and development of organs in ballan wrasse (Labrus bergylta Ascanius, 1767) larvae in relation to different live prey diets and growth rates.

    PubMed

    Gagnat, Maren Ranheim; Wold, Per-Arvid; Bardal, Tora; Øie, Gunvor; Kjørsvik, Elin

    2016-09-15

    Small fish larvae grow allometrically, but little is known about how this growth pattern may be affected by different growth rates and early diet quality. The present study investigates how different growth rates, caused by start-feeding with copepods or rotifers the first 30 days post-hatch (dph), affect allometric growth and development of nine major organs in ballan wrasse (Labrus bergylta) larvae up to experimental end at 60 dph. Feeding with cultivated copepod nauplii led to both increased larval somatic growth and faster development and growth of organ systems than feeding with rotifers. Of the organs studied, the digestive and respiratory organs increased the most in size between 4 and 8 dph, having a daily specific growth rate (SGR) between 30 and 40% in larvae fed copepods compared with 20% or less for rotifer-fed larvae. Muscle growth was prioritised from flexion stage and onwards, with a daily SGR close to 30% between 21 and 33 dph regardless of treatment. All larvae demonstrated a positive linear correlation between larval standard length (SL) and increase in total tissue volume, and no difference in allometric growth pattern was found between the larval treatments. A change from positive allometric to isometric growth was observed at a SL close to 6.0 mm, a sign associated with the start of metamorphosis. This was also where the larvae reached postflexion stage, and was accompanied by a change in growth pattern for most of the major organ systems. The first sign of a developing hepatopancreas was, however, first observed in the largest larva (17.4 mm SL, 55 dph), indicating that the metamorphosis in ballan wrasse is a gradual process lasting from 6.0 to at least 15-17 mm SL.

  8. Export of newly formed LSW

    NASA Astrophysics Data System (ADS)

    Müller, Katharina; Klein, Birgit; Karstensen, Johannes; Fischer, Jürgen; Baumann, Till; Kanzow, Torsten

    2015-04-01

    The Atlantic meridional overturning circulation represents the strongest mechanism for oceanic northward heat transport. This is accomplished by moving warm water northward in the upper ocean compensated by a deep return flow of cold and dense North Atlantic Deep Water (NADW). Labrador Sea Water (LSW) constitutes the shallowest component of NADW. Since LSW is also supposed to be the most sensitive NADW component to climate change it is of particular interest. LSW is formed by deep convection not only in the centre of the Labrador Sea but also near its western boundary. Recent studies have suggested that LSW formed in the boundary region enters its export route from the Labrador Sea, the Deep Western Boundary Current, faster than LSW originating from the central Labrador Sea. In this study the spatial and temporal evolution of the export of newly formed LSW is investigated. For this purpose hydrographic mooring data from an array located at the western bounndary at 53°N starting in the late 1990s until 2014 and data from the Argo float network is used. The averaged seasonal salinity cycle at the array, particularly at the moorings further onshore, shows a pronounced freshwater signal in May indicating the arrival of newly formed LSW in the boundary current. In order to learn more about its preceding pathway and the corresponding export timescale the mooring data is complemented by data from Argo floats. Besides the annual cycles of LSW formation and export, their interannual variations are important aspects affecting the large-scale circulation. For instance, in years of relatively strong convection, as in 2008 and 2012, LSW is observed to pass the boundary current array at 53°N earlier, i.e. in February and March, respectively, than in years with weak convection, as in 2007 or 2010. Besides seasonal variations in the boundary current, a possible explanation for the earlier freshwater signal in years of enhanced convection might be a shift in convection sites

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Survival and behavioral responses of larvae of the caddis fly Hydropsyche angustipennis to copper and diazinon

    SciTech Connect

    Geest, H.G. van der; Greve, G.D.; Haas, E.M. De; Scheper, B.B.; Kraak, M.H.S.; Stuijfzand, S.C.; Augustijn, K.H.; Admiraal, W.

    1999-09-01

    This study reports on newly developed short-term survival and behavioral tests with larvae of the caddis fly Hydropsyche angustipennis using two model toxicants, copper and diazinon. Mortality of first instar larvae was shown to be a reliable endpoint, and it was demonstrated that H. angustipennis is among the more sensitive aquatic insects in terms of both copper and diazinon. In addition, short-term behavioral responses were found to be indicative of adverse effects of ecologically relevant low doses of copper. Using the tests developed in this study, hydropsychid species are excellent tools for discerning the effects of individual toxicants present in large European rivers, and these species may help in defining the conditions for ecological rehabilitation.

  11. Effect of inoculation and application methods on the performance of chemicals used to disinfect salmonella contaminated broiler hatching eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella can penetrate the shells and shell membranes of hatching eggs and this can critically affect final product contamination levels (processed broiler carcass). There have been numerous published studies on the efficacy of chemical disinfectants for hatching eggs. The objective of this stud...

  12. 76 FR 32188 - Hatch Solar Energy Center 1, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Hatch Solar Energy Center 1, LLC; Supplemental Notice That Initial... notice in the above-referenced proceeding of Hatch Solar Energy Center 1, LLC's application for...

  13. 76 FR 56791 - Notice of Availability of Record of Decision for the Tropic To Hatch (Garkane) 138 kV...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Land Management Notice of Availability of Record of Decision for the Tropic To Hatch (Garkane... (ROD) for the Tropic to Hatch (Garkane) 138 kilovolt (kV) Transmission Line Environmental...

  14. Comparison of Spectral and Image Morphological Analysis for Egg Early Hatching Property Detection Based on Hyperspectral Imaging

    PubMed Central

    Zhang, Wei; Pan, Leiqing; Tu, Kang; Zhang, Qiang; Liu, Ming

    2014-01-01

    The use of non-destructive methods to detect egg hatching properties could increase efficiency in commercial hatcheries by saving space, reducing costs, and ensuring hatching quality. For this purpose, a hyperspectral imaging system was built to detect embryo development and vitality using spectral and morphological information of hatching eggs. A total of 150 green shell eggs were used, and hyperspectral images were collected for every egg on day 0, 1, 2, 3 and 4 of incubation. After imaging, two analysis methods were developed to extract egg hatching characteristic. Firstly, hyperspectral images of samples were evaluated using Principal Component Analysis (PCA) and only one optimal band with 822 nm was selected for extracting spectral characteristics of hatching egg. Secondly, an image segmentation algorithm was applied to isolate the image morphologic characteristics of hatching egg. To investigate the applicability of spectral and image morphological analysis for detecting egg early hatching properties, Learning Vector Quantization neural network (LVQNN) was employed. The experimental results demonstrated that model using image morphological characteristics could achieve better accuracy and generalization than using spectral characteristic parameters, and the discrimination accuracy for eggs with embryo development were 97% at day 3, 100% at day 4. In addition, the recognition results for eggs with weak embryo development reached 81% at day 3, and 92% at day 4. This study suggested that image morphological analysis was a novel application of hyperspectral imaging technology to detect egg early hatching properties. PMID:24551130

  15. 75 FR 56504 - Action Affecting Export Privileges; Rigel Optics, Inc. and Donald Wayne Hatch; Order Denying...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... August 12, 2010 (75 FR 50681, August 16, 2010), has continued the Regulations in effect under the... Bureau of Industry and Security Action Affecting Export Privileges; Rigel Optics, Inc. and Donald Wayne Hatch; Order Denying Export Privileges In the Matter of: Rigel Optics, Inc., 477 South 28th...

  16. Benzyl isothiocyanate affects development, hatching and reproduction of the soybean cyst nematode Heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzyl isothiocyanate (BITC) applied at micromolar doses decreased Heterodera glycines J2 movement, H. glycines hatching, and reproduction of H. glycines on soybean, Glycine max. Direct exposure of J2 to 30 microM BITC caused an immediate decrease (17%; P < 0.05) in J2 movement relative to 1% methan...

  17. Inflatable O-ring seal would ease closing of hatch cover plate

    NASA Technical Reports Server (NTRS)

    Neary, K. J.

    1966-01-01

    Inflatable O-ring seal provides positive sealing means that does not require the manual exertion of a large compressive force during opening or closing of a rotary-type hatch cover plate. The O-ring is deflated during opening and closing and inflated after closure by a gas pressure source.

  18. Factors Affecting Growth of Tengmalm's Owl (Aegolius funereus) Nestlings: Prey Abundance, Sex and Hatching Order.

    PubMed

    Zárybnická, Markéta; Riegert, Jan; Brejšková, Lucie; Šindelář, Jiří; Kouba, Marek; Hanel, Jan; Popelková, Alena; Menclová, Petra; Tomášek, Václav; Šťastný, Karel

    2015-01-01

    In altricial birds, energy supply during growth is a major predictor of the physical condition and survival prospects of fledglings. A number of experimental studies have shown that nestling body mass and wing length can vary with particular extrinsic factors, but between-year observational data on this topic are scarce. Based on a seven-year observational study in a central European Tengmalm's owl population we examine the effect of year, brood size, hatching order, and sex on nestling body mass and wing length, as well as the effect of prey abundance on parameters of growth curve. We found that nestling body mass varied among years, and parameters of growth curve, i.e. growth rate and inflection point in particular, increased with increasing abundance of the owl's main prey (Apodemus mice, Microtus voles), and pooled prey abundance (Apodemus mice, Microtus voles, and Sorex shrews). Furthermore, nestling body mass varied with hatching order and between sexes being larger for females and for the first-hatched brood mates. Brood size had no effect on nestling body mass. Simultaneously, we found no effect of year, brood size, hatching order, or sex on the wing length of nestlings. Our findings suggest that in this temperate owl population, nestling body mass is more sensitive to prey abundance than is wing length. The latter is probably more limited by the physiology of the species.

  19. Temperature effects on hatching and viability of Juvenile Gill Lice, Salmincola californiensis.

    PubMed

    Vigil, E M; Christianson, K R; Lepak, J M; Williams, P J

    2016-07-01

    Salmonids of the genus Oncorhynchus, distributed throughout the Pacific Rim, can be infected by the gill lice species Salmincola californiensis (Dana, 1852), which makes them one of the most broadly distributed gill lice species. Despite their broad distribution and valuable obligate salmonid hosts, relatively little is known about S. californiensis. We evaluated effects of temperature on timing of S. californiensis hatching and survival of copepodids, and provide information on brood size and variability. Our results suggest that temperature was a primary driver of timing of S. californiensis hatching and post-hatching survival. Prior to this study, the free-swimming stage of S. californiensis was reported to survive approximately 2 days without a suitable host. We observed active copepodids 13 days after hatch with some individuals from most (>90%) viable egg sacs at all temperature treatments surviving ≥5 days. Our findings indicate that warmer temperatures could increase development rates of gill lice at certain life stages, potentially increasing fecundity. This information coupled with predictions that warmer water temperatures could intensify crowding of coldwater fishes, stress, and parasite transmission suggests that climate change could exacerbate negative effects of S. californiensis on ecologically and economically important salmonids. PMID:26538200

  20. MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts.

    PubMed

    He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

    2016-01-19

    Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276-induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

  1. Involvement of Neptune in induction of the hatching gland and neural crest in the Xenopus embryo.

    PubMed

    Kurauchi, Takayuki; Izutsu, Yumi; Maéno, Mitsugu

    2010-01-01

    Neptune, a Krüppel-like transcription factor, is expressed in various regions of the developing Xenopus embryo and it has multiple functions in the process of development in various organs. In situ hybridization analysis showed that Neptune is expressed in the boundary region between neural and non-neural tissues at the neurula stage, but little is known about the function of Neptune in this region. Here, we examined the expression and function of Neptune in the neural plate border (NPB) in the Xenopus embryo. Depletion of Neptune protein in developing embryos by using antisense MO caused loss of the hatching gland and otic vesicle as well as malformation of neural crest-derived cranial cartilages and melanocytes. Neptune MO also suppressed the expression of hatching gland and neural crest markers such as he, snail2, sox9 and msx1 at the neurula stage. Subsequent experiments showed that Neptune is necessary and sufficient for the differentiation of hatching gland cells and that it is located downstream of pax3 in the signal regulating the differentiation of these cells. Thus, Neptune is a new member of hatching gland specifier and plays a physiological role in determination and specification of multiple lineages derived from the NPB region.

  2. WINTER FLOUNDER PSUEDOPLEURONECTES AMERICANUS HATCHING SUCCESS AS A FUNCTION OF BURIAL DEPTH IN THE LABORATORY

    EPA Science Inventory

    Previous experiments have shown that viable hatch of winter flounder eggs is reduced when the eggs are buried by as little as one half of one egg diameter (approximately 0.5 mm of sediment). This sensitivity to burial has resulted in seasonal banning of dredging in several north...

  3. The balance between innovation and competition: the Hatch-Waxman Act, the 2003 Amendments, and beyond.

    PubMed

    Kelly, Colleen

    2011-01-01

    In 1984, Congress passed the Hatch-Waxman Act, a landmark statute designed both to encourage innovation by pioneer drug companies and to increase competition by generic drug companies. After its enactment, drug companies attempted to "ga the regulatory regime to their respective economic advantage. In 2003, in an effort to address these issues, FDA promulgated a final rule and Congress passed the Medicare Modernization Act, amending the Hatch-Waxman Act. This article provides a comprehensive look at the 2003 statutory and regulatory changes. First, the article analyzes the history and provisions of the original Hatch-Waxman Act and the issues that arose after its enactment. Second, the article discusses the passage of the 2003 FDA rule and the 2003 Medicare Modernization Act. Next, the article demonstrates that, although the 2003 amendments may have definitively resolved some issues, the amendments did not resolve all interpretive issues and have even led to unintended consequences. In particular, the article discusses several areas of current controversy, including the effect of patent delisting and patent expiration on 180-day exclusivity, the patent delisting counterclaim provision, the declaratory judgment action provision, patent settlement agreements, and authorized generics. Finally, the article assesses the potential for future reform of the Hatch-Waxman Act. The article concludes that maintaining the balance between innovation and competition will likely remain a daunting task for legislators and regulators in the future.

  4. Effects of Injected Methylmercury on the Hatching of Common Loon (Gavia immer) Eggs

    EPA Science Inventory

    To determine the level of in ovo methylmercury (MeHg) exposure that results in detrimental effects on fitness and survival of loon embryos and hatched chicks, we conducted a field study in which we injected eggs with various doses of MeHg on day 4 of incubation. Eggs were collect...

  5. Enterobacteriaceae and Salmonella recovered from non-sanitized and sanitized broiler hatching eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sanitizing hatching eggs may reduce the chances that a flock will become colonized with Salmonella and reduce the numbers of other microorganisms, such as Enterobacteriaceae, that can depress hatchability. An experiment was conducted to determine if a quaternary-biguanide sanitizer applied as foam ...

  6. MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts

    PubMed Central

    He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

    2016-01-01

    Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276–induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

  7. 9. Acircuit weather cover in foreground, personnel access hatch, transporter/erector ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. A-circuit weather cover in foreground, personnel access hatch, transporter/erector grounding points at right center - Ellsworth Air Force Base, Delta Flight, Launch Facility D-6, 4 miles north of Badlands National Park Headquarters, 4.5 miles east of Jackson County line on county road, Interior, Jackson County, SD

  8. Unweathered and weathered aviation kerosine: Chemical characterization and effects on hatching success of duck eggs

    USGS Publications Warehouse

    Albers, P.H.; Gay, M.L.

    1982-01-01

    Effects of weathered aviation kerosine from a pipeline rupture in northern Virginia on mallard egg hatchability. Artificially-incubated mallard eggs were exposed by eggshell application to several amounts of weathered and unweathered aviation kerosine on day 6 of incubation. Measured hatching success of eggs and characterized the kerosine according to 14 aliphatic and 9 aromatic compounds.

  9. Factors Affecting Growth of Tengmalm's Owl (Aegolius funereus) Nestlings: Prey Abundance, Sex and Hatching Order.

    PubMed

    Zárybnická, Markéta; Riegert, Jan; Brejšková, Lucie; Šindelář, Jiří; Kouba, Marek; Hanel, Jan; Popelková, Alena; Menclová, Petra; Tomášek, Václav; Šťastný, Karel

    2015-01-01

    In altricial birds, energy supply during growth is a major predictor of the physical condition and survival prospects of fledglings. A number of experimental studies have shown that nestling body mass and wing length can vary with particular extrinsic factors, but between-year observational data on this topic are scarce. Based on a seven-year observational study in a central European Tengmalm's owl population we examine the effect of year, brood size, hatching order, and sex on nestling body mass and wing length, as well as the effect of prey abundance on parameters of growth curve. We found that nestling body mass varied among years, and parameters of growth curve, i.e. growth rate and inflection point in particular, increased with increasing abundance of the owl's main prey (Apodemus mice, Microtus voles), and pooled prey abundance (Apodemus mice, Microtus voles, and Sorex shrews). Furthermore, nestling body mass varied with hatching order and between sexes being larger for females and for the first-hatched brood mates. Brood size had no effect on nestling body mass. Simultaneously, we found no effect of year, brood size, hatching order, or sex on the wing length of nestlings. Our findings suggest that in this temperate owl population, nestling body mass is more sensitive to prey abundance than is wing length. The latter is probably more limited by the physiology of the species. PMID:26444564

  10. STS-44 MS Musgrave looks out OV-104's side hatch viewport on middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Mission Specialist (MS) F. Story Musgrave, wearing communications kit assembly lightweight headset (HDST), looks out side hatch viewport on Atlantis', Orbiter Vehicle (OV) 104's, middeck. Just behind him is the waste management compartment (WMC). The stainless steel cylinder is the temporary wet trash can.

  11. STS-44 OV-104's airlock hatch with tennis shoes and Presidential Sports Award

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 airlock hatch is decorated with two pairs of tennis shoes and a Presidential Sports Award Jogging patch (insignia) on the middeck of Atlantis, Orbiter Vehicle (OV) 104. With the crew having a treadmill-like device onboard for exercise and biomedical testing, tennis shoes were in plentiful stock on the eight-day mission.

  12. Hatching of Meloidogyne incognita Eggs in the Neutral Carbohydrate Fraction of Root Exudates of Gnotobiotically Grown Alfalfa

    PubMed Central

    Hamlen, R. A.; Bloom, J. R.; Lukezic, F. L.

    1973-01-01

    Meloidogyne incognita eggs were hatched in soil sterilized by gamma kradiation and wetted with root exudates from alfalfa plants in different stages of development and subjected to various levels of clipping. Carbohydrate components of the exudates were identified by gas chromatography-mass spectrometry. Although significant stimulation of hatch was detected in exudates of seedling and flowering plants, the practical importance of the increase is doubtful as hatch in distilled water was always greater than 50%. Hatch did not differ among exudate samples from clipped plants. Incubation of eggs in soil moistened with 10⁻⁷ to 10⁻³ M solutions of glucose did not result in increased hatching over that in distilled water. PMID:19319320

  13. Production characteristics of Hy-Line W36 laying hens hatched from white and tinted eggs.

    PubMed

    Kim, E J; Purswell, J L; Evans, J D; Branton, S L

    2014-08-01

    Eggshell color can greatly influence visual appeal of table eggs, and within the United States, table eggs are normally sorted and marked according to eggshell color to maximize consumer appeal. Recently, table egg producers have noted increased incidence of "off-color" or tinted (TT) eggs derived from white egg laying breeder hens. Therefore, the objectives of this study were to determine the production characteristics and resultant eggshell color of laying hens hatched from different colored eggs. Hy-Line W36 eggs were obtained from a commercial breeder operation and eggshell color was assessed with a colorimeter to separate eggs into groups of tinted (TT) and nontinted (NT) eggs before incubation. Treatment groups were placed into separate hatching trays. At hatching, chicks from each treatment group were individually wing-banded. Pullets were randomly allocated into cages according to treatment groups at 18 wk. Birds were placed into individual cages, with 5 consecutive cages representing a treatment replicate. Each treatment was replicated 24 times for a total of 120 birds per treatment and fed a nutritionally complete layer diet. Production performance was evaluated from 18 to 34 wk of age. Average weekly egg production was calculated. Feed intake, egg weights, egg mass, feed conversion ratio, and egg color were analyzed every 2 wk. Birds were weighed every 4 wk until completion of the study. Birds hatched from TT eggs had significantly increased BW throughout the experimental period. Hen-day egg production was significantly different when compared with the NT treatment at 19 and 20 wk of age. Eggshell color was also found to be significantly different for the NT and TT groups with TT eggs being significantly further from true white. Selection of progeny based on eggshell color may be a criterion for selecting white egg layers as layers hatched from TT eggs resulted in more off-color eggs, which may affect consumer acceptance for buying white table eggs.

  14. Bird mercury concentrations change rapidly as chicks age: toxicological risk is highest at hatching and fledging.

    USGS Publications Warehouse

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.

    2011-01-01

    Toxicological risk of methylmercury exposure to juvenile birds is complex due to the highly transient nature of mercury concentrations as chicks age. We examined total mercury and methylmercury concentrations in blood, liver, kidney, muscle, and feathers of 111 Forster's tern (Sterna forsteri), 69 black-necked stilt (Himantopus mexicanus), and 43 American avocet (Recurvirostra americana) chicks as they aged from hatching through postfledging at wetlands that had either low or high mercury contamination in San Francisco Bay, California. For each waterbird species, internal tissue, and wetland, total mercury and methylmercury concentrations changed rapidly as chicks aged and exhibited a quadratic, U-shaped pattern from hatching through postfledging. Mercury concentrations were highest immediately after hatching, due to maternally deposited mercury in eggs, then rapidly declined as chicks aged and diluted their mercury body burden through growth in size and mercury depuration into growing feathers. Mercury concentrations then increased during fledging when mass gain and feather growth slowed, while chicks continued to acquire dietary mercury. In contrast to mercury in internal tissues, mercury concentrations in chick feathers were highly variable and declined linearly with age. For 58 recaptured Forster's tern chicks, the proportional change in blood mercury concentration was negatively related to the proportional change in body mass, but not to the amount of feathers or wing length. Thus, mercury concentrations declined more in chicks that gained more mass between sampling events. The U-shaped pattern of mercury concentrations from hatching to fledging indicates that juvenile birds may be at highest risk to methylmercury toxicity shortly after hatching when maternally deposited mercury concentrations are still high and again after fledging when opportunities for mass dilution and mercury excretion into feathers are limited.

  15. Ontogeny changes and weaning effects in gene expression patterns of digestive enzymes and regulatory digestive factors in spotted rose snapper (Lutjanus guttatus) larvae.

    PubMed

    Moguel-Hernández, I; Peña, R; Andree, K B; Tovar-Ramirez, D; Bonacic, K; Dumas, S; Gisbert, E

    2016-10-01

    The study of digestive physiology is an important issue in species that have been introduced in aquaculture like the spotted rose snapper (Lutjanus guttatus). The aims of this study were to describe the expression of digestive enzymes (trypsinogen, chymotrypsinogen, α-amylase, lipoprotein lipase, phospholipase A and pepsinogen) and their relation with orexigenic (neuropeptide Y, NPY) and anorexigenic (cholecystokinin, CCK) factors during the larval development and to evaluate the effect of weaning in their expression. The results showed that the transcripts of all the assayed digestive enzymes, with the exception of pepsinogen, and NPY and CCK were already present in L. guttatus from the hatching stage. The expression of all the enzymes was low during the yolk-sac stage (0-2 days after hatching, DAH), whereas after the onset of exogenous feeding at 2 DAH, their expression increased and fluctuated throughout larval development, which followed a similar pattern as in other marine fish species and reflected changes in different types of food items and the progressive maturation of the digestive system. On the other hand, weaning of L. guttatus larvae from live prey onto a microdiet between 25 and 35 DAH significantly affected the relative expression of most pancreatic digestive enzymes during the first weaning days, whereas chymotrypsinogen 2 and lipoprotein lipase remained stable during this period. At the end of co-feeding, larvae showed similar levels of gene expression regardless of the diet (live prey vs. microdiet), which indicated that larvae of L. guttatus were able to adapt their digestive capacities to the microdiet. In contrast, feeding L. guttatus larvae with live feed or microdiet did not affect the expression of CCK and NPY. The relevance of these findings with regard to current larval rearing procedures of L. guttatus is discussed.

  16. Effects of breeder age and egg weight on morphological changes in the small intestine of chicks during the hatch window.

    PubMed

    Yalçin, S; Izzetoğlu, G T; Aktaş, A

    2013-01-01

    1. The objective of the study was to investigate the effects of breeder age and egg weight on hatching performance and morphological changes in segments of the small intestine of broiler chicks during a 21 h hatch window. 2. Eggs from Ross broiler breeder flocks aged 29 (young) and 48 weeks (old) were classified as light (LE) or heavy (HE) and incubated at the same conditions. At 475 h of incubation, eggs were checked every 3 h to determine time of external pipping and hatching. The first 42 chicks to emerge from each group were weighed and chick length was measured and 14 chicks from each group were sampled to collect residual yolk and intestine segments. The rest of chicks were placed back in the incubator and chick weight and length were measured individually at 9, 15 and 21 h after chicks hatched. At the end of 21 h, 14 chicks from each group were sampled again and the same procedure was followed. 3. The HE chicks pipped and hatched later than LE, regardless of breeder age. From hatch to the end of the hatch window, chick weight, but not yolk-free chick weight, gradually reduced. Relative residual yolk weight of chicks from both egg weights was similar at hatch, however, yolk sac utilisation was higher for LE chicks during the 21 h post-hatch period. At hatch, jejunum and ileum villus development was very similar for HE and LE chicks but greater development was observed for villus area with an increase in the jejunum villus length, width and goblet cell numbers in HE chicks. 4. The longest jejunum villus and the widest duodenum and jejunum villus were obtained for HE chicks from old breeders indicating that HE chicks from old breeders would have a greater surface area for nutrient absorption.

  17. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

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

    2016-01-01

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

  18. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

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

    2016-01-01

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

  19. Sensorimotor structure of Drosophila larva phototaxis

    PubMed Central

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

    2013-01-01

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

  20. Predators induce cloning in echinoderm larvae.

    PubMed

    Vaughn, Dawn; Strathmann, Richard R

    2008-03-14

    Asexual propagation (cloning) is a widespread reproductive strategy of plants and animals. Although larval cloning is well documented in echinoderms, identified stimuli for cloning are limited to those associated with conditions favorable for growth and reproduction. Our research shows that larvae of the sand dollar Dendraster excentricus also clone in response to cues from predators. Predator-induced clones were smaller than uncloned larvae, suggesting an advantage against visual predators. Our results offer another ecological context for asexual reproduction: rapid size reduction as a defense.

  1. Age at Which Larvae Are Orphaned Determines Their Development into Typical or Rebel Workers in the Honeybee (Apis mellifera L.)

    PubMed Central

    2015-01-01

    In the honeybee, diploid larvae fed with royal jelly develop into reproductive queens, whereas larvae fed with royal jelly for three days only and subsequently with honey and pollen develop into facultatively sterile workers. A recent study showed that worker larvae fed in a queenless colony develop into another female polyphenic form: rebel workers. These rebel workers are more queenlike and have greater reproductive potential than normal workers. However, it was unclear whether larvae orphaned at any time during their feeding period can develop into rebels. To answer this question, the anatomical features of newly emerged workers reared in queenless conditions at different ages during the larval period were evaluated. Our results showed that larvae orphaned during the final four or more days of their feeding life develop into rebel workers with more ovarioles in their ovaries, smaller hypopharyngeal glands, and larger mandibular and Dufour’s glands compared with typical workers with low reproductive potential that were reared with a queen or orphaned at the third to last or a later day of feeding life. PMID:25880669

  2. Determination of hatching date for eggs of black-crowned night-herons, snowy egrets and great egrets

    USGS Publications Warehouse

    Custer, T.W.; Pendleton, G.W.; Roach, R.W.

    1992-01-01

    Flotation of eggs in water and specific gravity of eggs of Black-crowned Night-Herons (Nycticorax nycticorax), Snowy Egrets (Egretta thula) and Great Egrets (Casmerodius albus) were evaluated as methods to determine date of hatching. Length of incubation and duration of hatching period were also documented for each species. Although species gravity was a better predictor of hatching date than egg flotation, both techniques were imprecise. The regression between specific gravity and the number of days before hatching differed among clutches, but not among eggs within clutches. Specific gravity of eggs predicted hatching data only to within 3.8 d for Snowy Egrets, adn 4.7 d for Black-crowned Night-Herons and Great Egrets. The mean incubation period was 27.3 d for Great Egrets, 23.7 d for Snowy Egrets and 22.8 d for Black-crowned Night-Herons. For all three species, the A egg (first egg laid) had a longer incubation period than the B or C egg. For all three species, the number of days between hatching of A and B eggs was significantly less (median - 1 d) than between hatching of B and C eggs (median = 2 d).

  3. Administration of insulin to newly hatched chicks improves growth performance via impairment of MyoD gene expression and enhancement of cell proliferation in chicken myoblasts.

    PubMed

    Sato, Kan; Aoki, Michiru; Kondo, Ryota; Matsushita, Kohichi; Akiba, Yukio; Kamada, Tosihiko

    2012-02-01

    The insulin/PI3K/Akt signaling pathway is strongly involved in the differentiation of C2C12 cells, as has been demonstrated by the addition of IGFs and insulin to culture media. In this study, we have characterized the role of insulin in chick myoblast proliferation and differentiation in vitro and in vivo, and have revealed novel details of how this exogenous hormone influences myogenic genes during differentiation. Chick myoblast cells cultured in differentiation medium (DMEM containing 2% FBS) supplemented with insulin exhibited a significant decrease in MyoD and myogenin mRNA expression after 12h of culture compared to cells cultured in differentiation media alone. MyoD and myogenin immunoreactive proteins in cells cultured in differentiation medium supplemented with insulin were quite low compared to those in control culture. Supplementation of the differentiation media containing insulin with LY294002 (a PI3K inhibitor) induced myoblast differentiation. A significant increase in MyoD and myogenin mRNA expression was observed in these cells after incubation for 12h, and the level of expression was similar to that of control cells incubated with differentiation media alone. The DNA content and the phosphor-Erk1/2 protein level were increased by the addition of insulin to the differentiation medium. These results suggest that insulin and its signaling pathway play an inhibitory role in chick myoblast differentiation. A high level of Pax7 mRNA was observed in the skeletal muscle of 3-day-old chicks administered insulin or tolbutamide at 1-day-of-age. In addition, body weight at 21 and 50 days-of-age was significantly greater for chickens administered insulin or tolbutamide at 1-day-of-age than for control chickens. These results detail not only species-specific differences in insulin action for myoblasts but also provide novel information that may be used for the improvement of chicken meat production. PMID:22172340

  4. Administration of insulin to newly hatched chicks improves growth performance via impairment of MyoD gene expression and enhancement of cell proliferation in chicken myoblasts.

    PubMed

    Sato, Kan; Aoki, Michiru; Kondo, Ryota; Matsushita, Kohichi; Akiba, Yukio; Kamada, Tosihiko

    2012-02-01

    The insulin/PI3K/Akt signaling pathway is strongly involved in the differentiation of C2C12 cells, as has been demonstrated by the addition of IGFs and insulin to culture media. In this study, we have characterized the role of insulin in chick myoblast proliferation and differentiation in vitro and in vivo, and have revealed novel details of how this exogenous hormone influences myogenic genes during differentiation. Chick myoblast cells cultured in differentiation medium (DMEM containing 2% FBS) supplemented with insulin exhibited a significant decrease in MyoD and myogenin mRNA expression after 12h of culture compared to cells cultured in differentiation media alone. MyoD and myogenin immunoreactive proteins in cells cultured in differentiation medium supplemented with insulin were quite low compared to those in control culture. Supplementation of the differentiation media containing insulin with LY294002 (a PI3K inhibitor) induced myoblast differentiation. A significant increase in MyoD and myogenin mRNA expression was observed in these cells after incubation for 12h, and the level of expression was similar to that of control cells incubated with differentiation media alone. The DNA content and the phosphor-Erk1/2 protein level were increased by the addition of insulin to the differentiation medium. These results suggest that insulin and its signaling pathway play an inhibitory role in chick myoblast differentiation. A high level of Pax7 mRNA was observed in the skeletal muscle of 3-day-old chicks administered insulin or tolbutamide at 1-day-of-age. In addition, body weight at 21 and 50 days-of-age was significantly greater for chickens administered insulin or tolbutamide at 1-day-of-age than for control chickens. These results detail not only species-specific differences in insulin action for myoblasts but also provide novel information that may be used for the improvement of chicken meat production.

  5. Faces Are Special for Newly Hatched Chicks: Evidence for Inborn Domain-Specific Mechanisms Underlying Spontaneous Preferences for Face-Like Stimuli

    ERIC Educational Resources Information Center

    Rosa-Salva, Orsola; Regolin, Lucia; Vallortigara, Giorgio

    2010-01-01

    It is currently being debated whether human newborns' preference for faces is due to an unlearned, domain-specific and configural representation of the appearance of a face, or to general mechanisms, such as an up-down bias (favouring top-heavy stimuli, which have more elements in their upper part). Here we show that 2-day-old domestic chicks,…

  6. 49 CFR 231.27 - Box and other house cars without roof hatches or placed in service after October 1, 1966.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Box and other house cars without roof hatches or... SAFETY APPLIANCE STANDARDS § 231.27 Box and other house cars without roof hatches or placed in service...) Number. (i) Each box or other house car without roof hatches shall be equipped with an efficient...

  7. Evolution of foraging behavior in Drosophilid larvae

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  8. Suppressing bullfrog larvae with carbon dioxide

    USGS Publications Warehouse

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

    2014-01-01

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

  9. Growth Attenuation with Developmental Schedule Progression in Embryos and Early Larvae of Sterechinus neumayeri Raised under Elevated CO2

    PubMed Central

    Yu, Pauline C.; Sewell, Mary A.; Matson, Paul G.; Rivest, Emily B.; Kapsenberg, Lydia; Hofmann, Gretchen E.

    2013-01-01

    The Southern Ocean, a region that will be an ocean acidification hotspot in the near future, is home to a uniquely adapted fauna that includes a diversity of lightly-calcified invertebrates. We exposed the larvae of the echinoid Sterechinus neumayeri to environmental levels of CO2 in McMurdo Sound (control: 410 µatm, Ω = 1.35) and mildly elevated pCO2 levels, both near the level of the aragonite saturation horizon (510 µatm pCO2, Ω = 1.12), and to under-saturating conditions (730 µatm, Ω = 0.82). Early embryological development was normal under these conditions with the exception of the hatching process, which was slightly delayed. Appearance of the initial calcium carbonate (CaCO3) spicule nuclei among the primary mesenchyme cells of the gastrulae was synchronous between control and elevated pCO2 treatments. However, by prism (7 days after the initial appearance of the spicule nucleus), elongating arm rod spicules were already significantly shorter in the highest CO2 treatment. Unfed larvae in the 730 µatm pCO2 treatment remained significantly smaller than unfed control larvae at days 15–30, and larvae in the 510 µatm treatment were significantly smaller at day 20. At day 30, the arm lengths were more differentiated between 730 µatm and control CO2 treatments than were body lengths as components of total length. Arm length is the most plastic morphological aspect of the echinopluteus, and appears to exhibit the greatest response to high pCO2/low pH/low carbonate, even in the absence of food. Thus, while the effects of elevated pCO2 representative of near future climate scenarios are proportionally minor on these early developmental stages, the longer term effects on these long-lived invertebrates is still unknown. PMID:23300974

  10. Is chemically dispersed oil more toxic to Atlantic cod (Gadus morhua) larvae than mechanically dispersed oil? A transcriptional evaluation

    PubMed Central

    2012-01-01

    Background The use of dispersants can be an effective way to deal with acute oil spills to limit environmental damage, however very little is known about whether chemically dispersed oil have the same toxic effect on marine organisms as mechanically dispersed oil. We exposed Atlantic cod larvae to chemically and mechanically dispersed oil for four days during the first-feeding stage of development, and collected larvae at 14 days post hatch for transcriptional analysis. A genome-wide microarray was used to screen for effects and to assess whether molecular responses to chemically and mechanically dispersed oil were similar, given the same exposure to oil (droplet distribution and concentration) with and without the addition of a chemical dispersant (Dasic NS). Results Mechanically dispersed oil induced expression changes in almost three times as many transcripts compared to chemically dispersed oil (fold change >+/−1.5). Functional analyses suggest that chemically dispersed oil affects partly different pathways than mechanically dispersed oil. By comparing the alteration in gene transcription in cod larvae exposed to the highest concentrations of either chemically or mechanically dispersed oil directly, the chemically dispersed oil affected transcription of genes involved nucleosome regulation, i.e. genes encoding proteins participating in DNA replication and chromatin formation and regulation of cell proliferation, whereas the mechanically dispersed oil most strongly affected genes encoding proteins involved in proteasome-mediated protein degradation. Cyp1a was the transcript that was most strongly affected in both exposure groups, with a 60-fold induction in the two high-exposure groups according to the RT-qPCR data, but no significant difference in transcriptional levels was observed between the two treatments. Conclusions In summary, dispersants do not appear to add to the magnitude of transcriptional responses of oil compounds but rather appear to lower or

  11. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda:Palinuridae)

    PubMed Central

    Day, Ryan D.; McCauley, Robert D.; Fitzgibbon, Quinn P.; Semmens, Jayson M.

    2016-01-01

    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8–12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa2·s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages. PMID:26947006

  12. Effects of nickel chloride and oxygen depletion on behaviour and vitality of zebrafish (Danio rerio, Hamilton, 1822) (Pisces, Cypriniformes) embryos and larvae.

    PubMed

    Kienle, Cornelia; Köhler, H-R; Filser, Juliane; Gerhardt, Almut

    2008-04-01

    We examined acute (2 h exposure of 5-day-old larvae) and subchronic (exposure from fertilization up to an age of 11 days) effects of NiCl(2).6H2O on embryos and larvae of zebrafish (Danio rerio), both alone and in combination with oxygen depletion. The following endpoints were recorded: acute exposure: locomotory activity and survival; subchronic exposure: hatching rate, deformations, locomotory activity (at 5, 8 and 11 days) and mortality. In acute exposures nickel chloride (7.5-15 mg Ni/L) caused decreasing locomotory activity. Oxygen depletion (or=10 mg Ni/L resulted in delayed hatching at an age of 96 h, in decreased locomotory activity at an age of 5 days, and increased mortality at an age of 11 days (LC20=9.5 mg Ni/L). The observed LOEC for locomotory activity (7.5 mg Ni/L) is in the range of environmentally relevant concentrations. Since locomotory activity was already affected by acute exposure, this parameter is recommended to supplement commonly recorded endpoints of toxicity.

  13. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda: Palinuridae).

    PubMed

    Day, Ryan D; McCauley, Robert D; Fitzgibbon, Quinn P; Semmens, Jayson M

    2016-03-07

    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8-12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa(2) · s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages.

  14. Adaptive and innate immune molecules in developing rainbow trout, Oncorhynchus mykiss eggs and larvae: expression of genes and occurrence of effector molecules.

    PubMed

    Heinecke, Rasmus D; Chettri, Jiwan K; Buchmann, Kurt

    2014-05-01

    The ontogenetic development of the immune system was studied during the egg phase and the early post-hatch period of rainbow trout. Quantitative real-time PCR (qPCR) was used to assess the timing and degree of expression of 9 important immune relevant genes and EF1-α. Further, immunohistochemical staining using monoclonal antibodies was applied on rainbow trout embryos and larvae in order to localize five different protein molecules (MHCII, CD8, IgM, IgT and SAA) in the developing tissue and immune organs. Maternally transferred transcripts of EF1-α mRNA were detected in the unfertilized egg. Early onset of expression was seen for all immune genes at very low levels. The amount of mRNA slowly increased and peaked around and after hatching. The highest increases were seen for MHCII, C3, C5 and SAA. Immunohistochemistry using five monoclonal antibodies showed positive staining from day 84 post fertilization. Skin, gills, intestine, pseudobranch and thymus showed reactivity for MHCII, thymus for CD8, gill mucus for IgT and pseudobranch and cartilage associated tissue for SAA. The importance of detected factors for early protection of eggs and larvae is discussed. PMID:24561127

  15. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda: Palinuridae).

    PubMed

    Day, Ryan D; McCauley, Robert D; Fitzgibbon, Quinn P; Semmens, Jayson M

    2016-01-01

    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8-12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa(2) · s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages. PMID:26947006

  16. Interactions between hatch dates, growth rates, and mortality of Age-0 native Rainbow Smelt and nonnative Alewife in Lake Champlain

    USGS Publications Warehouse

    Parrish, Donna; Simonin, Paul W.; Rudstam, Lars G.; Pientka, Bernard; Sullivan, Patrick J.

    2016-01-01

    Timing of hatch in fish populations can be critical for first-year survival and, therefore, year-class strength and subsequent species interactions. We compared hatch timing, growth rates, and subsequent mortality of age-0 Rainbow Smelt Osmerus mordax and Alewife Alosa pseudoharengus, two common open-water fish species of northern North America. In our study site, Lake Champlain, Rainbow Smelt hatched (beginning May 26) almost a month earlier than Alewives (June 20). Abundance in the sampling area was highest in July for age-0 Rainbow Smelt and August for age-0 Alewives. Late-hatching individuals of both species grew faster than those hatching earlier (0.6 mm/d versus 0.4 for Rainbow Smelt; 0.7 mm/d versus 0.6 for Alewives). Mean mortality rate during the first 45 d of life was 3.4%/d for age-0 Rainbow Smelt and was 5.5%/d for age-0 Alewives. Alewife mortality rates did not differ with hatch timing but daily mortality rates of Rainbow Smelt were highest for early-hatching fish. Cannibalism is probably the primary mortality source for age-0 Rainbow Smelt in this lake. Therefore, hatching earlier may not be advantageous because the overlap of adult and age-0 Rainbow Smelt is highest earlier in the season. However, Alewives, first documented in Lake Champlain in 2003, may increase the mortality of age-0 Rainbow Smelt in the summer, which should favor selection for earlier hatching.

  17. Alterations in the mantle epithelium during transition from hatching gland to adhesive organ of Idiosepius pygmaeus (Mollusca, Cephalopoda).

    PubMed

    Cyran, Norbert; Klepal, Waltraud; Städler, Yannick; Schönenberger, Jürg; von Byern, Janek

    2015-02-01

    Epithelial gland systems play an important role in marine molluscs in fabricating lubricants, repellents, fragrances, adhesives or enzymes. In cephalopods the typically single layered epithelium provides a highly dynamic variability and affords a rapid rebuilding of gland cells. While the digestive hatching gland (also named Hoyle organ) is obligatory for most cephalopods, only four genera (Nautilus, Sepia, Euprymna and Idiosepius) produce adhesive secretions by means of glandular cells in an adhesive area on the mantle or tentacles. In Idiosepius this adhesive organ is restricted to the posterior part of the fin region on the dorsal mantle side and well developed in the adult stage. Two gland cell types could be distinguished, which produce different contents of the adhesive. During the embryonic development the same body area is occupied by the temporary hatching gland. The question arises, in which way the hatching gland degrades and is replaced by the adhesive gland. Ultrastructural analyses as well as computer tomography scans were performed to monitor the successive post hatching transformation in the mantle epithelium from hatching gland degradation to the formation of the adhesive organ. According to our investigations the hatching gland cells degrade within about 1 day after hatching by a type of programmed cell death and leave behind a temporary cellular gap in this area. First glandular cells of the adhesive gland arise 7 days after hatching and proceed evenly over the posterior mantle epithelium. In contrast, the accompanying reduction of a part of the dorsal mantle musculature is already established before hatching. The results demonstrate a distinct independence between the two gland systems and illustrate the early development of the adhesive organ as well as the corresponding modifications within the mantle.

  18. Neural regulation of pupariation in tsetse larvae.

    PubMed

    Zdárek, J; Denlinger, D L

    1992-12-01

    A neural mechanism coordinates pupariation behavior and tanning in the tsetse larva. At parturition, the mature larva has already received sufficient ecdysteroid to commit the epidermal cells to metamorphosis but, before sclerotization and tanning of the cuticle can begin, the larva must first select a pupariation site and then proceed through a stereotypic sequence of pupariation behavior that culminates in the formation of a smooth, ovoid puparium. Both pupariation behavior and tanning are inhibited by the central nervous system (CNS) during the wandering phase. This central inhibition is maintained by sensory input originating in the extreme posterior region of the body. At the transition from wandering to pupariation, the posterior signal that induces inhibition of pupariation behavior is removed and the larva begins the contractions associated with pupariation, but the CNS inhibition of tanning persists. At this point, separation of the body into two halves by ligation or nerve transection prevents tanning of the anterior half (containing the CNS), whereas the denervated integument of the posterior half tans completely. Transection of nerves to the midline of the body produces larvae with a tanning pattern that ends abruptly along a sagittal plane, implying that the central control of this process is uncoupled between the left and right regions of the CNS. A few minutes later, when the final shape of the puparium is completed, the CNS inhibition is lifted and the tanning process begins. At this time, separation of the body into two halves by ligation or nerve transection has no inhibitory effects on either part. Exogenous ecdysteroids fail to release the CNS inhibition, and hemolymph containing the pupariation factors from Sarcophaga bullata have no accelerating effects on tsetse pupariation. These results imply that regulation of metamorphosis in the insect integument is not the exclusive domain of blood-borne hormones.

  19. Appetitive associative olfactory learning in Drosophila larvae.

    PubMed

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

    2013-02-18

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

  20. Invertebrate bioassays with North Sea water samples. I. Structural effects on embryos and larvae of serpulids, oysters and sea urchins

    NASA Astrophysics Data System (ADS)

    Klöckner, K.; Rosenthal, H.; Willführ, J.

    1985-03-01

    Structural effects of bottom and surface water samples from two dumping grounds in the inner German Bight on the development of three meroplanktonic organisms (Pomatoceros triqueter: Polychaeta, Psammechinus miliaris: Echinodermata and Crassostrea gigas, Mollusca) were investigated. The titaniumdioxide dumping site was sampled immediately after dumping (within the visible waste trail 1 km behind the vessel), and 10 h after dumping. Samples were taken in the sewage sludge deposition area in the intervals between the usual dumping activities, regardless of the exact dumping schedule. The preserved bioassay test organisms were inspected microscopically to count percentages of “normal” larval hatch in test water samples, reference water samples and laboratory aged control water samples (5 to 10 replicates). The relative water quality at various dumping sites was expressed in terms of “net risk”-values (Woelke, 1972) compared to hatching rates observed in the controls. Larval development of P. triqueter was significantly suppressed (up to -22 % “net risk”) in trail water of the titanium dioxide dump site while the development of sea urchin larvae was still affected in the 10 h surface samples. Hatching of all test organisms in bottom-water samples from the centre of the sewage sludge dump site was affected to different degrees when compared to reference areas about 4 km north or 6 km northwest of the dumping area. The general usefulness of standardized bioassay procedures in pollution monitoring programmes is discussed. The results presented here call for further verification to minimize experimental background variability and to enlarge the catalogue of suitable effects criteria.

  1. Hatch-Waxman Turns 30: Do We Need a Re-Designed Approach for the Modern Era?

    PubMed

    Kesselheim, Aaron S; Darrow, Jonathan J

    2015-01-01

    In 1984, Congress passed the Hatch-Waxman Act, which catalyzed the creation of the modem generic drug industry. Generic drugs today account for eighty-four percent of all prescriptions dispensed, but less than twenty percent of drug costs. Despite this success, numerous problems in the generic drug market have emerged. Some involve the deliberate manipulation of the Hatch-Waxman system, while others have arisen more unexpectedly, such as the Supreme Court's 2011 decision in Pliva v. Mensing that could undermine consumer confidence in generic drugs. We discuss these emerging challenges and propose updates to the Hatch-Waxman Act to continue support for the timely emergence of safe generic drugs.

  2. Carabid larvae as predators of weed seeds: granivory in larvae of Amara eurynota (Coleoptera: Carabidae).

    PubMed

    Saska, Pavel

    2004-01-01

    Up to date we do not have much information about predation on seeds by larvae of ground beetles. One of the reasons why such knowledge is important is that granivorous larvae contribute to predation of weed seeds. In this study, the food requirements of larvae of autumn breeding carabid species Amara eurynota (Panzer) were investigated in the laboratory and a hypothesis, that they are granivorous was tested. Insect diet (Tenebrio molitor larvae), three seed diets (seeds of Artemisia vulgaris, Tripleurospermum inodorum or Urtica dioica or a mixed diet (T. molitor + A. uulgaris) were used as food. For larvae of A. eurynota, seeds are essential for successful completion of development, because all those fed pure insect diet died before pupation. However, differences in suitability were observed between pure seed diets. Larvae fed seeds of A. vulgaris had the lowest mortality and fastest development of the seed diets. Those fed seeds of T. inodorum had also low mortality, but the development was prolonged in the third instar. In contrast, development of larvae reared on seeds of U. dioica was slowest of the tested diets and could not be completed, as all individuals died before pupation. When insects were included to seed diet of A. vulgaris (mixed diet), the duration of development shortened, but mortality remained the same when compared to seed diet of A. vulgaris. According to the results it was concluded that larvae of A. eurynota are granivorous. A mixed diet and seed diets of A. uulgaris and T. inodorum were suitable and insect diet and seeds of U. dioica were unsuitable diets in this experiment.

  3. Effects of Mycoplasma anatis and cold stress on hatching success and growth of mallard ducklings

    USGS Publications Warehouse

    Samuel, M.D.; Goldberg, D.R.; Thomas, C.B.; Sharp, P.

    1995-01-01

    We inoculated game-farm mallard (Anas platyrhynchos) eggs and 1-day-old birds with Mycoplasma anatis to determine its effect on hatching success and growth rates of ducklings. Inoculations of eggs reduced hatching success, hatchling size, and duckling growth rates, compared to controls. Intratracheal inoculations of 1-day-old birds did not affect growth rates. Hatchlings and 1-day-old ducklings grew much slower for the first 7 to 10 days when raised at 17 to 19 C, compared to controls raised at 30 to 35 C. The effect of cold stress on growth was greater than the effect of M. anatis infection; we found no synergistic effects between cold stress and M. anatis infection.

  4. Heart rates increase after hatching in two species of natricine snakes

    PubMed Central

    Aubret, Fabien

    2013-01-01

    Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits. PMID:24287712

  5. Chrysopa septempunctata (Neuroptera: Chrysopidae) Vitellogenin Functions Through Effects on Egg Production and Hatching.

    PubMed

    Liu, C; Mao, J; Zeng, F

    2015-12-01

    Vitellogenin (Vg) is a precursor of major egg storage protein, vitellin (Vt), and plays primary roles in reproduction of oviparous vertebrates and invertebrates. Chrysopa septempunctata Wesmael is an important and common predator of various insect pests. Here, we first cloned C. septempunctata Vg gene, CsVg. The complete CsVg cDNA was 5664 bp, which encodes an 1810-residues protein with a predicted molecular mass of 206.23 kDa. Expression profile revealed that CsVg mRNA first appeared on day 4 after emergence, maximally accumulated on day 10, and then declined gradually. RNAi mediated by injection of dsRNA depleted CsVg transcripts, significantly reduced egg-laying amount, and decreased egg hatching rate, suggesting that CsVg functions through effects on egg production and hatching in C. septempunctata. PMID:26470375

  6. Development of cross-hatch grid morphology and its effect on ordering growth of quantum dots

    NASA Astrophysics Data System (ADS)

    Zhang, C. L.; Xu, B.; Wang, Z. G.; Jin, P.; Zhao, F. A.

    2005-01-01

    We investigate the development of cross-hatch grid surface morphology in growing mismatched layers and its effect on ordering growth of quantum dots (QDs). For a 60° dislocation (MD), the effective part in strain relaxation is the part with the Burgers vector parallel to the film/substrate interface within its b⇀edge component; so the surface stress over a MD is asymmetric. When the strained layer is relatively thin, the surface morphology is cross-hatch grid with asymmetric ridges and valleys. When the strained layer is relatively thick, the ridges become nearly symmetrical, and the dislocations and the ridges inclined-aligned. In the following growth of InAs, QDs prefer to nucleate on top of the ridges. By selecting ultra-thin In0.15Ga0.85As layer (50 nm) and controlling the QDs layer at just formed QDs, we obtained ordered InAs QDs.

  7. Heart rates increase after hatching in two species of Natricine snakes.

    PubMed

    Aubret, Fabien

    2013-11-29

    Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits.

  8. Chrysopa septempunctata (Neuroptera: Chrysopidae) Vitellogenin Functions Through Effects on Egg Production and Hatching.

    PubMed

    Liu, C; Mao, J; Zeng, F

    2015-12-01

    Vitellogenin (Vg) is a precursor of major egg storage protein, vitellin (Vt), and plays primary roles in reproduction of oviparous vertebrates and invertebrates. Chrysopa septempunctata Wesmael is an important and common predator of various insect pests. Here, we first cloned C. septempunctata Vg gene, CsVg. The complete CsVg cDNA was 5664 bp, which encodes an 1810-residues protein with a predicted molecular mass of 206.23 kDa. Expression profile revealed that CsVg mRNA first appeared on day 4 after emergence, maximally accumulated on day 10, and then declined gradually. RNAi mediated by injection of dsRNA depleted CsVg transcripts, significantly reduced egg-laying amount, and decreased egg hatching rate, suggesting that CsVg functions through effects on egg production and hatching in C. septempunctata.

  9. [Larvae of barnacles (Cirripedia: Thoracica) in the White sea plankton].

    PubMed

    Poltarukha, O P

    2003-01-01

    The barnacle fauna in the White Sea is briefly described. The morphology of barnacle larvae in this water body is comparatively analyzed. The characters important for the larvae identification are given particular attention. A classification key was developed for the nauplius and cyprid larvae of barnacles in the White Sea.

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

    ERIC Educational Resources Information Center

    Pratt, Harry D.; Stojanovich, Chester J.

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

  11. An Introduction to the Identification of Chironomid Larvae.

    ERIC Educational Resources Information Center

    Mason, William T., Jr.

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

  12. The effects of ammonium sulphate and urea upon egg hatching and miracidial survival of Schistosoma mansoni.

    PubMed

    Tchounwou, P B; Englande, A J; Malek, E A; Anderson, A C; Abdelghani, A A

    1991-04-01

    The effects of various concentrations of ammonium sulphate and urea on egg hatching and miracidial survival of S. mansoni were tested in order to determine if the use of these fertilizers in the ricelands of the Republic of Cameroon could affect the transmission of schistosomiasis. Results indicate that hatching of eggs and survival of miracidia varied with concentrations of tested chemicals and times of exposure. Exposure of S. mansoni eggs to 0.20%-1.00% ammonium sulphate or to 0.50%-4.00% urea reduced their ability to hatch and produce miracidia. A chemical concentration of 1.00% ammonium sulphate or 4.00% urea was found to be sufficient to produce complete inhibition of hatching. High concentrations of both chemicals not only inhibited miracidial emergence but also may be ovocidal. Results obtained from miracidial survival tests indicated that LC5, LC50 and LC95 values for ammonium sulphate were 0.07%, 0.80% and 10.61% after 2 hours of exposure; 0.03%, 0.16% and 0.90% after 4 hours of exposure; and 0.30%, 0.20% and 0.40% after 6 hours of exposure respectively. Similar statistical analyses revealed that the LC5, LC50 and LC95 values for urea were 0.22%, 1.90% and 16.25% after 2 hours of exposure; 0.28%, 0.57% and 1.14% after 4 hours of exposure; and 0.13%, 0.27% and 0.57% after 6 hours of exposure respectively. Although the two fertilizers exerted some adverse effects on S. mansoni eggs and miracidia at relatively high concentrations, neither of them was found to be of practical value. Ammonium sulphate and urea concentrations effective in killing S. mansoni eggs and miracidia were about one to two orders of magnitude greater than the actual field application rates.

  13. Unweathered and weathered aviation kerosine: chemical characterization and effects on hatching success of duck eggs

    SciTech Connect

    Albers, P.H.; Gay, M.L.

    1982-04-01

    The results of a study of the effects of unweathered and weathered aviation kerosine on the hatchability of mallard duck eggs are reported. Egg hatching succes of the control group was not significantly different from that of any of the groups treated with unweathered or weathered aviation kerosine. These results mean that the eggs of waterfowl are probably not endangered by plumage transfer of small amounts of partially weathered kerosine to the eggs. (JMT)

  14. Age-Related Degeneration of the Egg-Laying System Promotes Matricidal Hatching in Caenorhabditis elegans

    PubMed Central

    Pickett, Christopher L.; Kornfeld, Kerry

    2014-01-01

    Summary The identification and characterization of age-related degenerative changes is a critical goal because it can elucidate mechanisms of aging biology and contribute to understanding interventions that promote longevity. Here we document a novel, age-related degenerative change in C. elegans hermaphrodites, an important model system for the genetic analysis of longevity. Matricidal hatching—intra-uterine hatching of progeny that causes maternal death—displayed an age-related increase in frequency and affected ∼70% of mated, wild-type hermaphrodites. The timing and incidence of matricidal hatching were largely independent of the levels of early and total progeny production and the duration of male exposure. Thus, matricidal hatching appears to reflect intrinsic age-related degeneration of the egg-laying system rather than use-dependent damage accumulation. Consistent with this model, mutations that extend longevity by causing dietary restriction significantly delayed matricidal hatching, indicating age-related degeneration of the egg-laying system is controlled by nutrient availability. To identify the underlying tissue defect, we analyzed serotonin signaling that triggers vulval muscle contractions. Mated hermaphrodites displayed an age-related decline in the ability to lay eggs in response to exogenous serotonin, indicating that vulval muscles and/or a further downstream function that is necessary for egg-laying degenerate in an age-related manner. By characterizing a new, age-related degenerative event displayed by C. elegans hermaphrodites, these studies contribute to understanding a frequent cause of death in mated hermaphrodites and establish a model of age-related reproductive complications that may be relevant to the birthing process in other animals such as humans. PMID:23551912

  15. STS-56 Commander Cameron and Pilot Oswald at CCT hatch during JSC training

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron (right) and Pilot Stephen S. Oswald, wearing launch and entry suits (LESs), stand at the side hatch of the crew compartment trainer (CCT), a shuttle mockup, prior to entering the mockup. Once inside the CCT, they will don their launch and entry helmets (LEHs) and participate in emergency egress (bailout) procedures. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  16. An evolutionary insight into the hatching strategies of pipefish and seahorse embryos.

    PubMed

    Kawaguchi, Mari; Nakano, Yuko; Kawahara-Miki, Ryouka; Inokuchi, Mayu; Yorifuji, Makiko; Okubo, Ryohei; Nagasawa, Tatsuki; Hiroi, Junya; Kono, Tomohiro; Kaneko, Toyoji

    2016-03-01

    Syngnathiform fishes carry their eggs in a brood structure found in males. The brood structure differs from species to species: seahorses carry eggs within enclosed brood pouch, messmate pipefish carry eggs in the semi-brood pouch, and alligator pipefish carry eggs in the egg compartment on abdomen. These egg protection strategies were established during syngnathiform evolution. In the present study, we compared the hatching mode of protected embryos of three species. Electron microscopic observations revealed that alligator pipefish and messmate pipefish egg envelopes were thicker than those of seahorses, suggesting that the seahorse produces a weaker envelope. Furthermore, molecular genetic analysis revealed that these two pipefishes possessed the egg envelope-digesting enzymes, high choriolytic enzyme (HCE), and low choriolytic enzyme (LCE), as do many euteleosts. In seahorses, however, only HCE gene expression was detected. When searching the entire seahorse genome by high-throughput DNA sequencing, we did not find a functional LCE gene and only a trace of the LCE gene exon was found, confirming that the seahorse LCE gene was pseudogenized during evolution. Finally, we estimated the size and number of hatching gland cells expressing hatching enzyme genes by whole-mount in situ hybridization. The seahorse cells were the smallest of the three species, while they had the greatest number. These results suggest that the isolation of eggs from the external environment by paternal bearing might bring the egg envelope thin, and then, the hatching enzyme genes became pseudogenized. J. Exp. Zool. (Mol. Dev. Evol.) 9999B:XX-XX, 2016. © 2016 Wiley Periodicals, Inc.

  17. AMPK is involved in the differential neonatal performance of chicks hatching at different time.

    PubMed

    Wang, Yufeng; Buyse, Johan; Song, Zhigang; Decuypere, Eddy; Everaert, Nadia

    2016-03-01

    We have recently reported that the hatching time may be in relation to the distinct neonatal performance of female chicks. The present study was aimed to investigate the potential involvement of AMPK, an energy sensor which plays a pivotal role in energy homeostasis, in the distinct performance of the spread of hatching time model. As a result, hypothalamic AMPKα1 isoform gene expression was significantly higher in the late hatcher as compared to that of their early counterparts, whereas the total and phosphorylated levels of AMPKα subunit did not differ between the three hatchers. The hypothalamic orexigenic NPY and AgRP mRNA levels were higher in the late hatchers as compared to the early, and that of the middle hatchers was at an intermediate level. However, the anorexigenic POMC and CRH was also higher expressed in the late hatchers as compared to the early hatchers. In the liver, AMPKα2 mRNA level and the phosphorylation ratio of AMPKα was significantly lower in the late hatchers, as compared to their early counterparts. The hepatic phosphorylated GS levels of the late and middle hatchers were lower than that of their early counterparts. The expression of hepatic FTO gene of the late hatchers was significantly higher than that of their early and middle counterparts. Taken together, AMPK may play a significant role in the different neonatal performance of the spread of hatching time model. The central and peripheral AMPK in late hatchers exhibited a pattern of higher energy intake and lower energy expenditure, which resulted in a faster post-hatch growth.

  18. Circulatory changes associated with the closure of the ductus arteriosus in hatching emu (Dromaius novaehollandiae).

    PubMed

    Shell, Lauren; Burggren, Warren; Muirhead, David; Nelson, Thomas C; Dzialowski, Edward M

    2016-01-01

    In developing avian embryos, the right and left ductus arteriosi (DA) allow for a shunt of systemic venous return away from the lungs to the body and chorioallantoic membrane (CAM). Unlike in mammals where the transition from placental respiration to lung respiration is instantaneous, in birds the transition from embryonic CAM respiration to lung respiration can take over 24h. To understand the physiological consequences of this long transition we examined circulatory changes and DA morphological changes during hatching in the emu (Dromaius novaehollandiae), a primitive ratite bird. By tracking microspheres injected into a CAM vein, we observed no change in DA blood flow between the pre-pipped to internally pipped stages. Two hours after external pipping, however, a significant decrease in DA blood flow occurred, evident from a decreased systemic blood flow and subsequent increased lung blood flow. Upon hatching, the right-to-left shunt disappeared. These physiological changes in DA blood flow correspond with a large decrease in DA lumen diameter from the pre-pipped stages to Day 1 hatchlings. Upon hatching, the right-to-left shunt disappeared and at the same time apoptosis of smooth muscle cells began remodeling the DA for permanent closure. After the initial smooth muscle contraction, the lumen disappeared as intimal cushioning formed, the internal elastic lamina degenerated, and numerous cells underwent regulated apoptosis. The DA closed rapidly between the initiation of external pipping and hatching, resulting in circulatory patterns similar to the adult. This response is most likely produced by increased DA constriction in response to increased arterial oxygen levels and the initiation of vessel remodeling. PMID:26549875

  19. Locomotor behavior of fish hatched from embryos exposed to flight conditions

    NASA Technical Reports Server (NTRS)

    Kleerekoper, H.

    1978-01-01

    Embryos of Fundulus heteroclitus in various stages of development were exposed to space flight conditions aboard Apollo spacecraft and Cosmos satellites. The objective of the study was to ascertain whether fish hatched from these embryos displayed locomotor behavior different from that of control fish of the same age. An electronic monitoring technique was used to record behavior. Results indicate no change in locomotor behavior in fish on Apollo Spacecraft, but inexplicable significant changes were noted in fish aboard Cosmos Satellites.

  20. An evolutionary insight into the hatching strategies of pipefish and seahorse embryos.

    PubMed

    Kawaguchi, Mari; Nakano, Yuko; Kawahara-Miki, Ryouka; Inokuchi, Mayu; Yorifuji, Makiko; Okubo, Ryohei; Nagasawa, Tatsuki; Hiroi, Junya; Kono, Tomohiro; Kaneko, Toyoji

    2016-03-01

    Syngnathiform fishes carry their eggs in a brood structure found in males. The brood structure differs from species to species: seahorses carry eggs within enclosed brood pouch, messmate pipefish carry eggs in the semi-brood pouch, and alligator pipefish carry eggs in the egg compartment on abdomen. These egg protection strategies were established during syngnathiform evolution. In the present study, we compared the hatching mode of protected embryos of three species. Electron microscopic observations revealed that alligator pipefish and messmate pipefish egg envelopes were thicker than those of seahorses, suggesting that the seahorse produces a weaker envelope. Furthermore, molecular genetic analysis revealed that these two pipefishes possessed the egg envelope-digesting enzymes, high choriolytic enzyme (HCE), and low choriolytic enzyme (LCE), as do many euteleosts. In seahorses, however, only HCE gene expression was detected. When searching the entire seahorse genome by high-throughput DNA sequencing, we did not find a functional LCE gene and only a trace of the LCE gene exon was found, confirming that the seahorse LCE gene was pseudogenized during evolution. Finally, we estimated the size and number of hatching gland cells expressing hatching enzyme genes by whole-mount in situ hybridization. The seahorse cells were the smallest of the three species, while they had the greatest number. These results suggest that the isolation of eggs from the external environment by paternal bearing might bring the egg envelope thin, and then, the hatching enzyme genes became pseudogenized. J. Exp. Zool. (Mol. Dev. Evol.) 9999B:XX-XX, 2016. © 2016 Wiley Periodicals, Inc. PMID:26987447