8 research outputs found

    Morphology of the Reproductive System of Tetrix arenosa angusta (Hancock) (Orthoptera, Tetrigidae)

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    The internal reproductive organs of the male include a pair of testes, each composed of about 37 follicles and connected to a short vas efferens; a pair of vasa deferentia; about 12 paired accessory glands; a twice folded ejaculatory duct and a membranous, extensible intromittent organ. The external structures of the male include a chitinous collar, pallial complex and ninth abdominal sternum. The internal reproductive organs of the female include a pair of ovaries, each composed of 11 ovarioles; paired lateral oviducts; a short median oviduct; a terminal genital chamber; a trilobed spermatheca attached to a spermathecal gland, and a pair of median glands. The external structures of the female include the ovipositor and its related sclerites and apodemes

    Transgenerational Effects of Heavy Metal Pollution on Immune Defense of the Blow Fly Protophormia terraenovae

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    Recently environmental conditions during early parental development have been found to have transgenerational effects on immunity and other condition-dependent traits. However, potential transgenerational effects of heavy metal pollution have not previously been studied. Here we show that direct exposure to heavy metal (copper) upregulates the immune system of the blow fly, Protophormia terraenovae, reared in copper contaminated food. In the second experiment, to test transgenerational effects of heavy metal, the parental generation of the P. terraenovae was reared in food supplemented with copper, and the immunocompetence of their offspring, reared on uncontaminated food, was measured. Copper concentration used in this study was, in the preliminary test, found to have no effect on mortality of the flies. Immunity was tested on the imago stage by measuring encapsulation response against an artificial antigen, nylon monofilament. We found that exposure to copper during the parental development stages through the larval diet resulted in immune responses that were still apparent in the next generation that was not exposed to the heavy metal. We found that individuals reared on copper-contaminated food developed more slowly compared with those reared on uncontaminated food. The treatment groups did not differ in their dry body mass. However, parental exposure to copper did not have an effect on the development time or body mass of their offspring. Our study suggests that heavy metal pollution has positive feedback effect on encapsulation response through generations which multiplies the harmful effects of heavy metal pollution in following generations

    Harmful Elements in Estuarine and Coastal Systems

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    Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

    bursa-pastoris

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    Capsella bursa-pastoris (Linnaeus) Medikuscommon shepherd's purse;shepherd's purse;pickpocketbourse-Ă -pasteur;capselle bourse-Ă -pasteur;tabouret;bourse Ă  pasteur communeCapsella bursa-pastorisAmes. Court enclosed by Science building, Iowa State College campus.Cour

    cucullaria

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    Dicentra cucullaria (Linnaeus) BernhardiDutchman's breechesdicentre Ă  capuchonApprox. 4 miles east of Gilbert. Skunk River.Wooded hillside bordering east side of Skunk River

    Feedbacks from Filter Feeders: Review on the Role of Mussels in Cycling and Storage of Nutrients in Oligo- Meso- and Eutrophic Cultivation Areas

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    Cultured and wild bivalve stocks provide ecosystem services through regulation of nutrient dynamics; both by regeneration of nutrients that become available again for phytoplankton production (positive feedback), and by extractionof nutrients through filtration and storage in tissue (negative feedback). Consequently, bivalves may fulfil a role in water quality management. The magnitude of regulating services by filter feeding bivalves varies between coastal ecosystems. This review uses the blue mussel as a model species and evaluates how cultured mussel stocks regulate nutrient dynamics in oligo- meso- and eutrophic ecosystems. We thereby examine (i) the eco-physiological response of mussels, and (ii) the positive and negative feedback mechanisms between mussel stocks and the surrounding ecosystem. Mussel culture in nutrient-poor areas (deep Norwegian fjords) are compared with cultures in other coastal systems with medium- to rich nutrient conditions. It was found that despite differences in eco-physiological rates under nutrient-poor conditions (higher clearance, lower egestion, similar excretion and tissue storage rates), the proportion of nutrients regenerated was similar between (deep) nutrient-poorand (shallow) nutrient-rich areas. Of the filtered nutrients, 40–50% is regeneratedand thus made available again for phytoplankton growth, and 10–50% of thefiltered nutrients is stored in tissue and could be removed from the system by harvest. A priori, we inferred that as a consequence of low background nutrient levels, mussels would potentially have a larger effect on ecosystem functioning in nutrient-poor systems and/or seasons. However, this review showed that due to the physical characteristics (volume, water residence time) and low mussel densities in nutrient-poor Norwegian fjord systems, the effects were lower for these sites, while estimates were more profound in shallow nutrient-rich areas with more intensive aquaculture activities, especially in terms of the negative feedback mechanisms (filtration intensity)

    Commodifying Compassion: Affective Economies of Human Milk Exchange

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