Synthetic fibers released from sewage sludge and tire particles released from traffic are among the most common types of microplastics in soil. In soil, microplastics may interact with chemicals, ...such as plant protection products used in agriculture. Most studies on the interactions of microplastics and chemicals focused on aquatic environments and only few addressed soil arthropods. To increase the understanding of the combined effects of microplastics and chemicals on soil arthropods, we studied the effects of polyester fibers and tire particles on the toxicity of the insecticide chlorpyrifos. Springtails (Folsomia candida) and woodlice (Porcellio scaber) were exposed in Lufa 2.2 soil to a range of chlorpyrifos concentrations (0.0088–0.8 and 0.2–3.9 mg kg−1 dry soil, respectively) without or with 0.05 % w/w (“low”) or 0.5 % w/w (“high”) of microplastics. Tire particles reduced the lethality of chlorpyrifos to springtails (LC50 = 0.13–0.14 mg kg−1 dry soil) and isopods (LC50 = 1.6 mg kg−1 dry soil) by a factor of 2- > 2.5 and the chlorpyrifos-induced inhibition of acetylcholinesterase (AChE) activity and changes in electron transfer system (ETS) activity in P. scaber by a factor of 2–4. Polyester fibers reduced the chlorpyrifos-induced inhibition of AChE activity by a factor of 2 and increased (ETS) activity in P. scaber by a factor of >3. The fibers did not affect the toxicity of chlorpyrifos to the survival of P. scaber or the survival and reproduction of F. candida. These results indicate that the bioavailability of chlorpyrifos may be decreased by microplastics, especially by tire particles. This study shows the importance of applying a mixture toxicity approach for understanding the threats of microplastics to soil, but also suggests that the organism and the endpoints chosen are crucial for the interpretation of the effects of combined exposures to microplastics and chemicals.
Display omitted
•Microplastics affected the toxicity of chlorpyrifos to two soil arthropod species.•Chlorpyrifos lethality to arthropods decreased by tire particles but not by fibers.•Fibers and tire particles affected chlorpyrifos-induced biomarker changes in woodlice.•Tire particles changed chlorpyrifos effects on woodlice more than polyester fibers.•Microplastics did not affect chlorpyrifos toxicity to springtail reproduction.
The terrestrial crustacean Porcellio scaber is an established test organism in environmental research. We analysed the haemolymph proteome of P. scaber using a classical proteomic approach based on ...one-dimensional gel electrophoresis and tandem mass spectrometry. Using a publicly available protein database and our P. scaber transcriptome data, we have identified 76 proteins involved in cytoskeleton formation, protein degradation, vesicular transport, genetic information processing, detoxification, carbohydrate and lipid metabolism reflecting haemocyte metabolic activity, active intracellular transport, and intercellular communication. Compared with the data reported for other crustaceans, 28 of these P. scaber proteins have been linked to its immunity, among them hemocyanin, α-2-macroglobulin, phenoloxidase 3, superoxide dismutase, glutathione S-transferase, haemolymph clottable protein, and histones H4 and H2B. Our results thus provide a firm base for studying the innate immune response of P. scaber at the level of the haemolymph proteome. This knowledge is of particular importance in ecotoxicity studies with various environmental stressors where understanding physiological changes is important to reveal possible modes of action.
•This study presents proteome profile in the haemolymph of P. scaber under basal condition.•In total, 76 proteins were identified in the haemolymph without pre-treatment.•Many proteins are involved in intracellular trafficking and intercellular communication.•28 proteins were found associated with immunity.•The most abundant protein was hemocyanin.
Forests exhibit lower inter-seasonal climatic variation compared to open landscape types. Because fauna activity is influenced by a site's microclimate, we expect these more stable conditions ...translate into smaller intra-annual variation in activity patterns of soil fauna in forests. We assessed differences in activity of terrestrial isopods across more open (open landscape and anthropogenic habitat) and closed (forest) habitat based on recent field observations in Belgium. We related the species detectability chance (as a proxy for activity) to monthly average temperatures to establish linear relationships. The slopes of these relationships are combined in a meta-analytical model to investigate how species' responses relate to habitat type. We found that terrestrial isopod activity was more tempered in forests than in open landscape habitats, suggesting that climate stability in forests leads to more stable levels of terrestrial isopod activity. We also found that activity patterns in anthropogenic habitat are tempered compared to open landscape habitat but highly variable and more research is needed to unravel underlying mechanisms.
•We assess intra-annual activity of terrestrial isopods in different habitat types.•Intra-annual activity patterns in forest are tempered compared to open landscape.•Patterns are also more tempered in anthropogenic habitat compared to open landscape.•Forest acts as a climatically stable environment for soil fauna throughout the year.
Tire particles pose a potential threat to terrestrial organisms because they are deposited in large quantities in the soil by tire wear abrasion, and moreover their chemical complexity poses an ...additional risk. Microplastics can affect several physiological processes in organisms, including those related to immunity. Therefore, we investigated the expression profile of selected immune-related genes (MnSod, Manganese Superoxide dismutase; Cat, Catalase; CypG, Cyclophilin G; Nos, Nitric oxide synthase; Ppae2a, Prophenoloxidase-activating enzyme 2a; Dscam, Down syndrome cell adhesion molecule; Myd88, Myeloid-differentiation factor 88; Toll4, Toll-like receptor 4; Mas-like, Masquerade-like protein) in haemocytes and the digestive gland hepatopancreas of terrestrial crustacean Porcellio scaber after two different time exposures (4 and 14 days) to tire particles in soil. Our results reveal for the first time the response of P. scaber after microplastic exposure at the transcriptome level. We observed time- and tissue-dependent changes in the expression of the analysed genes, with more pronounced alterations in haemocytes after 14 days of exposure. Some minor changes were also observed in hepatopancreas after 4 days. Changes in the expression profile of the analysed genes are a direct indication of a modulated immune status of the test organism, which, however, does not represent an adverse effect on the test organism under the given conditions. Nevertheless, the question remains whether the observed change in immune status affects the immunocompetence of the test organism.
Display omitted
•Exposure to tire particles in soil impacts the expression of tested genes in woodlice.•Modulations in immune-related gene expression were time- and tissue-dependent.•The most striking changes were observed in haemocytes after 14 days.•Some genes were also changed in hepatopancreas but only after 4 days.
Soil fauna, including terrestrial isopods, millipedes and earthworms, play an important role in the decomposition of litter through the process of shredding it during consumption. In the present ...study, the food preferences in two detritivores, the common woodlouse (Oniscus asellus) and the earthworm (Lumbricus rubellus) over the leaf litter of four common tree species: common black alder (Alnus glutinosa), silver birch (Betula pendula), small-leaved linden (Tilia cordata) and pedunculate oak (Quercus robur) were quantified in the laboratory. For each animal species, two sets of feeding mesocosms were prepared: one set with single litter species and another with mixed litter material (cafeteria-type test), where the animals were allowed to choose among the four litter species at once. The food preferences of the studied animals were determined on the basis of the consumption (mass loss) of litter for each litter species at the end of two-weeks lasting experiments. The results showed that the litter mass losses in both detritivores were significantly influenced by the tree species. The litter mass losses can be ranked in descending order as follows: alder, birch, linden, oak. In the case of O. asellus, litter mixing had no effect on litter mass loss when compared to single alder and birch litter, however mixing clearly accelerated litter mass loss compared to single lime or oak litter. For L. rubellus, litter mixing was found to slow litter mass loss compared to each single alder, birch and lime litter, while accelerating litter mass loss compared to single oak litter. For the interpretation of the results, the literature data on carbon to nitrogen ratio, as well as the proportion of difficult-to-degrade polyphenols and lignins in leaves of the studied tree species were used.
Microplastics are very common contaminants in the environment. Despite increasing efforts to assess the effects of microplastics on soil organisms, there remains a lack of knowledge on how organisms ...respond to diverse types of microplastics after different exposure durations. In the present study, we investigated the immune response of the terrestrial crustacean Porcellio scaber exposed to the two most common microplastic particles in the environment: polyester fibres and tyre particles. We also tested two natural particles: wood dust and silica powder, with all treatments performed at 1.5% w/w. The response of P. scaber was evaluated at the level of the immune system, and also the biochemical, organism and population level, after different exposure durations (1, 2, 4, 7, 14, 21 days). These data reveal dynamic changes in the levels of some immune parameters shortly after exposure, with a gradual return to control values. The total number of haemocytes was significantly decreased after 4 days of exposure to tyre particles, while the proportion of different haemocyte types in the haemolymph was altered shortly after exposure to both polyester fibres and tyre particles. Moreover, 7 days of exposure to tyre particles resulted in increased superoxide dismutase activity in the haemolymph, while metabolic activity in whole woodlice (measured as electron transport system activity) was increased after exposure for 7, 14 and 21 days. In contrast, the natural particles did not elicit any significant changes in the measured parameters. Survival and feeding of P. scaber were not altered by exposure to the microplastics and natural particles in soil. Overall, this study defines a time-dependent transient immune response of P. scaber, which indicates that immune parameters represent sensitive biomarkers of exposure to microplastics. We discuss the importance of using natural particles in studies of microplastics exposure and their effects.
Display omitted
•We studied natural particles and microplastics for immune effects in Porcellio scaber•Haemocyte proportions in haemolymph rapidly and transiently changed for microplastics•Exposure to tyre particles significantly increased whole woodlouse metabolic activity•There were no changes in measured parameters for exposure to natural particles
Five new species of Pectenoniscus are described from Bahia state: Pectenoniscus monsviridis n. sp. and Pectenoniscus revelatus n. sp. from Serra do Ramalho Karst area; Pectenoniscus archaeos n. sp. ...and Pectenoniscus sepultus n. sp. from Serra de Iuiú Karst area; and Pectenoniscus caesarius n. sp. from Campo Formoso Karst area. Additional notes are provided on their habitats and threats.
http://www.zoobank.org/urn:lsid:zoobank.org:pub:1C9A1DD9-D1C0-454A-9157-098A14FA739B
Four new records of Oniscidea from Iran including Armadillidium azerbaidzhanum, A. nasatum, Platyarthrus schoeblii, and Armadillo alievi are provided. Important diagnostic characters of the recorded ...species are photographed.
The exposure of organisms to microplastics could compromise their ability to cope with other environmental stressors, such as infections. In this context, we investigated the effects of a 14-day ...exposure of the terrestrial isopod Porcellio scaber to tire particles in soil (1.5 % w w−1 dry weight) on the organisms' response to a secondary exposure, i.e., injection of the bacterial endotoxin lipopolysaccharide. In addition, the insecticide chlorpyrifos (2 mg kg−1 dry weight) was tested as a positive control. The survival and immune response of P. scaber was assessed at the end of the 7- and 14-day primary exposure and two days after the secondary exposure, by analyzing selected haemolymph immune parameters (total haemocyte count, differential haemocyte count, and haemocyte viability). No change in survival was observed after primary exposure of P. scaber to tire particles or chlorpyrifos. However, primary exposure to chlorpyrifos triggered a strong activation of the immune response, which was not the case following exposure to the tire particles. Further injection of lipopolysaccharide into the body did not affect the survival of animals exposed to tire particles or chlorpyrifos, while a strong immunomodulatory change was observed, particularly with chlorpyrifos, and to some extent, tire particles. Based on these results, we conclude that exposure of P. scaber to tire particles or chlorpyrifos has no significant effect on the susceptibility of the organism to lipopolysaccharide in terms of their mortality, but primary exposure to an insecticide significantly modulates the immune response of the organisms to a second stressor. We discuss the “stress on stress” approach for testing low-toxic substances, such as microplastics, where an environmentally realistic exposure is followed by a secondary exposure.
Display omitted
•Microplastics as a low-toxic and highly persistent pollutant in the environment•The use of secondary stress to assess the effects of primary exposure on organisms•Microplastic pre-exposure has no effect on Porcellio scaber susceptibility to LPS.•Exposure to chlorpyrifos modulates P. scaber immune response after LPS challenge.
A new cave-restricted species of Benthana and two cave-restricted species of Benthanoides are described from iron-ore caves located in the Serra dos Carajás complex, Pará state, in the Amazon biome. ...Benthana alba n. sp. occurs only in one cave in the south of Serra Norte, in the plateau N5 (cave N5SM2_0077); Benthanoides amazonicus n. sp. occurs in several caves in the north of Serra Norte, in the plateau N1; and Benthanoides tarzan n. sp. occurs in several caves in the Serra do Tarzan. This record represents an important distribution data for Benthana that typically occurs in the Brazilian Atlantic Forest, indicating that such species may represent a relict lineage of this genus. Additionally, efforts must be directed towards the conservation of these species, all of which are associated with caves occurring in areas of intense mining activity.
PDF