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In this study, an updated list of Turkish earthworm species is presented. In the last five years, several new species were added to the earthworm fauna of Turkey namely: Amynthas morrisi, Dendrobaena cevdeti, Dendrobaena cognettii, Dendrobaena pavliceki, Dendrobaena szalokii, Dendrobaena taurica, Eisenia andrei, Eisenia kontschani, Eisenia patriciae, Healyella zicsii and Octolasion cyaneum. According to the current list, 87 taxa have been recorded so far. Two of these taxa belong to Acanthodrilidae, one taxon of Criodrilidae, 80 taxa of Lumbricidae and four taxa of Megascolecidae; 32 taxa are endemic for the territory of Turkey. [ABSTRACT FROM AUTHOR]

Dendrobaena veneta is one of the most widely used compost worms now distributed all over Europe and has been described under several synonymous names. Besides the typical stripy red specimens, another form bearing pinkish pigmentation also exists, mostly found in natural habitats in the East Mediterranean. Here we provide the first integrative taxonomic analysis of D. veneta, including some closely related species. Both the morphological and molecular results highly support the resurrection of D. succinta, a former synonym of D. veneta. In addition, we describe a peculiar new species, D. karacadagi sp. n. from Anatolia, and prove the highly homoplasious character of the cross section of the longitudinal musculature. [ABSTRACT FROM AUTHOR]

Most subsoil carbon (C) turnover occurs in biopore hotspots such as root channels and earthworm burrows. Biopores allocate large C amounts into the subsoil, where a vast capacity for long-term C sequestration is predicted. We hypothesise that organic matter (OM) cycling in biopores depends on their origin. Earthworm and root biopores were induced under field conditions and were sampled from the subsoil (45–75 and 75–105 cm) after two years of biopore formation. The effects of biopore formation on OM decomposition were studied by biomarkers: neutral sugars, cutin and suberin-derived lipids, lignin-derived phenols and free lipids. The degradation stage of OM was biopore type-specific but was only governed by the soil depth in root biopores. Degradation of OM increased from earthworm biopores to root biopores and bulk soil. Hemicelluloses (GM/AX ratio) were more strongly degraded than lignin side-chains (relative change from initial values). Two years of microbial processing during biopore formation increased the GM/AX ratio in earthworm biopores from 0.65 to 1.05 and in root biopores from 0.15 to 1.35 (both relative to source biomasses). Root biopores and bulk soil had the highest GM/AX ratios (1.2–1.3), hinting to rapid processing of plant residues and accumulation of microbial residues. The regular, frequent OM inputs by earthworms stimulated microbial growth and processing of mostly bioavailable OM and, thus, relatively enriched more persistent OM (e.g. lignin). Syringyl subunits of lignin underwent low (ratio changed from 0.35 to 0.55 relative to initial input) and vanillyl subunits underwent almost no processing in earthworm biopores indicating the preferential microbial utilisation of the easily available compounds frequently replenished by earthworm activity. After two years of decomposition of the root detritus, mainly structural plant material was enriched in root biopores. Short periods (6 months) of earthworm activity effectively recharged the highly processed OM in root biopores with fresh OM. In total, deep-rooting catch crops and short-term earthworm activities promote C accumulation in the subsoil followed by biopore-specific microbial processing predominantly governed by the C input frequency. As root biopores are up to 40 times more common than earthworm biopores, they dominate the OM input into subsoils. Such C inputs create several years lasting hotspots for preferential root growth and nutrient mobilisation in the subsoil. We conclude that root- and earthworm-derived biopores are vertical pathways for plant C from the soil surface into the subsoil and for intensive processing of litter C and sequestration of microbial necromass. [ABSTRACT FROM AUTHOR]

This comprehensive study was undertaken to reveal the ovarian histomorphology in the oligochaetous clitellte, Dendrobaena atheca Cernosvitov. Efforts were, in fact, made to obtain proper histological preparations. So, various types of thin serial sections of ovaries were carefully obtained, stained and examined. Two small ovaries, at the beginning of breeding seasons, were seen in segment thirteen. Subsequently, they extremely increased in size and became fully formed. They demonstrated six principal cell types: peritoneal cell, follicular cell, stromal cell, oogonium, oocyte and trophocyte (nurse cell). The first three cell types were somatic, whereas the other three were germ and germ-line. All cell types were, as much as possible, properly described. Dividing oogonia were seen to produce oocytes and trophocytes simultaneously. The produced cells were seen to be interconnected. The stromal cell, a newly described cell type, exhibited several specific cell characteristics. Ovaries showed no internal lumens. The small ovaries showed only two distinct histological zones, whereas the large ones showed three such zones. Germ and germ-line cells showed an obvious arrangement in ovarian zones. Accordingly, the chief conclusions are: (1) ovaries are nutrimental due to presence of trophocytes (2) ovaries are solid and not sac-like organs due the lack of internal cavity (3) stromal cell can be considered a new cell type as it demonstrates several specific cell features (4) Ovarian zonation is caused by production and arrangement of germ and germ-line cells (5) intercellular connections are due to incomplete cell divisions. [ABSTRACT FROM AUTHOR]

Information on the bioaccumulation of selenium (Se) in soil invertebrates (e.g. earthworms) is rather scarce. In the present study, bioaccumulation of Se in two eco-physiologically different earthworms, namely anecic Pheretima guillemi and epigeic Eisenia fetida , was determined after 28 days exposure to a successive doses of Se-spiked soil, specifically 0.5, 5, 50, and 200 μg Se g −1 soil. The results showed that Se concentration in earthworms elevated with increasing exposure levels, and maximums were up to 54.6 and 83.0 μg g −1 dry weight in Pheretima guillemi and Eisenia fetida , respectively, after 4 weeks exposure to 200 μg Se g −1 soil. Exposure to Se caused significant inhibition on earthworm growth, with the fresh weight loss ranging from 8.9% to 80.5%. Bioaccumulation factors (BAFs), empirically-derived and non-steady state, ranged from 0.12 to 4.17 and generally declined at higher exposure levels. Moreover, BAFs of Pheretima guillemi were higher than those of Eisenia fetida in low-dose Se-spiked soils, but the opposite was true in high-dose soils, indicating there is a species-specific response to exposure of Se between different earthworms. Further research is thus needed to reveal the accumulation pattern of Se in a wider range of earthworm species other than Eisenia fetida , which allows a better risk assessment of excessive Se to soil invertebrates and higher order organisms. [ABSTRACT FROM AUTHOR]

Earthworms play a key role in soil and ecosystem functioning. Predicting their abundance and spatial distribution is required to understand their ecological role. There is growing evidence that mechanistic models of earthworm population dynamics are promising tools to tackle this issue. However, this approach requires a fair amount of data because it explicitly integrates the three fundamental biological processes: growth, reproduction and mortality. Hitherto, the lack of comprehensive databases on life history parameters related to these three processes hampered the widespread development of mechanistic earthworm population dynamics models. As a consequence, predicting earthworm abundance in a variety of conditions across species is still difficult. The clear bottleneck for making progress is the lack of databases on the intraspecific variability of earthworm life history traits in response to environmental conditions. Data related to body growth and body size are critical because body size largely determines reproduction and mortality rates. Body growth is therefore the backbone of mechanistic models of earthworm population dynamics. Here I present EGrowth, the first comprehensive database on intraspecific variability of earthworm body growth in relation to environmental conditions. The EGrowth database contains 1073 growth curves of 51 species of earthworms, representing 16002 measures of body mass. It covers publications on earthworm body size from 1900 to 2016. The environmental conditions in which the growth curves were produced are also reported. The database is open access and can be browsed from a graphical user interface. EGrowth will be updated regularly in the future as new studies are published. I propose a standardized framework for reporting future data on body growth of earthworms. [ABSTRACT FROM AUTHOR]

This study has determined the relationship of culturable community of cellulose degrading bacteria (CDB) within the gut walls of two habitat-specific earthworm species, epigeic (compost heap inhabitant) earthworm, Perionyx excavatus (PE) and an endogeic (submerged rice field inhabitant), Glyphidrilus spelaeotes (GS) and their functional significance. The 16Sr RNA analysis for the isolated CDB from two ecologically distinct earthworms clearly showed the presence of distinct communities of CDB in their gut ecosystem. Enzymatic assay of cellulase for the isolated CDB showed significantly higher cellulase activity compared to the reference strain M-23, Cellulomonas cellulans (P < 0.01, one-way ANOVA). The functional significance of such high cellulase activity was also demonstrated by the enhancement of decomposition of rice straw and fresh vegetation biomass in the presence of native microbiota community. The growth rate of CDB of epigeic PE was approximately twice slower than that of CDBs of endogeic GS. The CDB of PE exhibited 12 polymorphs of esterase isozyme as against 4 polymorphs for CDB of GS. The present study emphasizes the functionally significant relationship of gut wall CDB and host earthworm for sustaining efficient C-cycling in agroecosystems. [ABSTRACT FROM AUTHOR]

Mitochondrial cytochrome oxidase subunit I (COI) and 16S rRNA gene sequence data were analysed for 43 specimens of Drawida ghilarovi – earthworms of a tropical genus on the northern boundary of their natural habitat, including two ecological forms and three colour morphs collected from different regions of the southern Russian Far East. Intraspecific genetic differentiation of these clitellata was analysed with different criteria that characterise different forms and morphs. A sample of anecic worms was shown to possess higher genetic variation than a sample of epigeic worms. Haplotype network reconstructions showed that the meadow-swamp epigeic black-coloured D. ghilarovi is more highly diverged from the anecic forest grey- and brown-coloured worms than the grey and brown colour morphs are from each other. Genetic differentiation between three colour morphs ranged from 9.89 ± 0.58 to 11 ± 0.59% using COI and 16S data. An AMOVA test and an exact test showed a high probability of non-differentiation between grey and brown earthworms. A multimodal mismatch distribution was revealed for the whole D. ghilarovi sample and for each colour morph. The minimum spanning tree showed that the differentiation of specimens is associated with ecological and geographical criteria. Molecular data for Drawida showed high genetic differentiation between epigeic and anecic using COI and 16S gene sequence data as well as the various phylogenetic relationships among the studied forms. The anecic earthworms possibly represent different genetic lineages of the D. ghilarovi species complex. The epigeic Drawida , based on the complex data, can be considered a new species of this genus. [ABSTRACT FROM AUTHOR]

Bioaccumulation factors for heavy metals (Cd, Zn, Cu, and Pb) were examined for selected earthworm species ( Metaphire californica, Amynthas homochaetus, Amynthas pecteniferus , and Amynthas heterochaetus ) that inhabit metal-polluted soils in a subtropical area (Hunan Province) of South China. The earthworms had high plasticity in inhabiting in situ contaminated areas and showed high uptake of the heavy metals and capability for their accumulation in the tissues. The bioaccumulation factor (BAF) were greatest for cadmium and ranked as follows: Cd (10.6–18.8) >> Zn (1.15–1.75) > Cu (1.01–1.35) > Pb (0.56–0.95). Earthworm species with the similar BAF of heavy metals ( p > 0.05) belong to the same ecological group. Within individual groups, Cd, Cu, Zn, Cu, and Pb concentrations in earthworms are consistently predicted by total and extractable fraction (DTPA-extractable) in soil. Our results provide insights into the ecological relationships and variations in the uptake and accumulation of heavy metals in different earthworm species in contaminated soils in China. [ABSTRACT FROM AUTHOR]

Copper oxide nanoparticles and copper sulfate are established contaminants of water and soil. Metaphire posthuma is a common variety of earthworm distributed in moist soil of Indian subcontinent. Comparative toxicity of copper nanoparticles and copper sulfate were investigated with reference to selected immune associated parameters of earthworm. Total count, phagocytic response, generation of cytotoxic molecules (superoxide anion, nitric oxide), activities of enzymes like phenoloxidase, superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase and total protein of coelomocytes were estimated under the exposures of 100, 500, 1000 mg of copper oxide nanoparticles and copper sulfate per kg of soil for 7 and 14 d. A significant decrease in the total coelomocyte count were recorded with maximum depletion as 15.45 ± 2.2 and 12.5 ± 2 × 10 4 cells/ml under the treatment of 1000 mg/kg of copper nanoparticles and copper sulfate for 14 d respectively. A significant decrease in generation of nitric oxide and activity of phenoloxidase were recorded upon exposure of both toxins for 7 and 14 d indicating possible decline in cytotoxic status of the organism. A maximum inhibition of superoxide dismutase activity was recorded as 0.083 ± 0.0039 and 0.055 ± 0.0057 unit/mg protein/minute against 1000 mg/kg of copper nanoparticles and copper sulfate treatment for 14 d respectively. Activities of catalase and alkaline phosphatase were inhibited by all experimental concentrations of both toxins in the coelomocytes of earthworm. These toxins were recorded to be modifiers of the major immune associated parameters of M. posthuma. Unrestricted contamination of soil by sulfate and oxide nanoparticles of copper may lead to an undesirable shift in the innate immunological status of earthworm leading to a condition of immune compromisation and shrinkage in population density of this species in its natural habitat. This article is the first time report of immunological toxicity of nanoparticles and sulfate salt of copper in M.posthuma inhabiting the soil of India, an agriculture based country. [ABSTRACT FROM AUTHOR]

Introduction: The earthworm coelomic fluid (ECF) has shown proven antiproliferative effect against breast, liver, gastrointestinal and brain cancer, but it is least explored in oral cancer. The present in vitro study is an attempt to investigate the antiproliferative activity of ECF on oral cancer cell line squamous cell carcinoma (SCC)-9. Materials and Methods: ECF was collected from the species Eudrilus eugeniae (EE), Eisenia foetida (EF) and Perionyx excavatus (PE) stored at -80°C. Percentage inhibition of ECF on squamous cell carcinoma-9 cells in vitro was recorded at 24 h. Protein estimation was done using Bradford protein assay validated by the biuret method. Cytotoxicity was tested at 2.5, 5, 10, 20, 40 and 80 μg/ml concentrations by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay in SCC-9 cells in vitro. GraphPad Prism 7.0 software was used to calculate the inhibitory concentration (IC50). Chi-square test was used to analyze the difference between samples. Results: The test samples EE, EF and PE inhibited the growth of SCC-9 cells significantly in a dose-dependent manner and the IC50 values were found to be 4.6, 44.69 and 5.27 μg/ml, respectively. The antiproliferative effect was found to be variable among the three earthworm species with EE showing the most promising effect followed by PE and EF. Conclusion: Establishing the antiproliferative effect of ECF on oral cancer cells could be an initial step toward drug development and future anticancer research. The preliminary investigation has shown that ECF has a promising antiproliferative effect on oral cancer cells in vitro. [ABSTRACT FROM AUTHOR]

The intent of this paper was to give an overview of the distribution of the earthworm taxa across the ecoregions of continental USA and Alaska. It contains a descriptive summary of each of the 104 ecoregions and the citation of 81 papers each giving a more detailed description of the earthworm taxa including the number of families, genera and species recorded in each. The 81 ecoregion papers include 10 families, 43 genera and 191 species. Additionally, there is a summary table of the taxa in the American Ecoregions and an Appendix Table of collections or records, omitted or received after the individual ecoregions were published. There are colour maps of the Continental Ecoregions, the Alaskan Ecoregions, and the Hawaiian Ecoregions. [ABSTRACT FROM AUTHOR]

Earthworm collecting trips to different parts of Austria - the Karawanks, Carinthia, Lower and Western Austria - resulted in recording altogether 17 species. Based on the morphological data, Dendrobaena velkovrhia Mršić, 1988 is found to be a synonym of Dendrobaena auriculifera Zicsi, 1969. The problems with the previously published Eisenia lucens (Waga, 1857) records and these specimens’ supposed identity with E. spelaea (Rosa, 1901) are also discussed. [ABSTRACT FROM AUTHOR]

The application of herbicides in agricultural practices may pose certain toxic effects on non-target species including molluscs (snails), earthworms and other soil-dwelling organisms, which would in turn put the lives of humans at great risk. This study considered the lethal and sublethal effects of Grassate®, a non-selective glyphosate-based herbicide on snails (Archachatina marginata) and earthworms (Aporrectodea longa) with regards to ecotoxicological risk assessment. The lethal concentration LC50for the test chemical averaged at 1.731 ± 0.05 and 3.045 ± 0.08 mg kg−1for snails and earthworms, respectively. There was decrease in growth and biomass with increased concentration for the species. Growth inhibition of 11–38% in size and 7–43% in length was obtained for earthworms while 26–65% reduction in weight was reported for snails. Using the ecotoxicological risk assessment matrix, the herbicide was classified as D 4 (A; P; E) or 16 (A; P; E), which could be considered as high risk to animals, plant and the environment. Thus, if these herbicides are used uncontrollably and unregulated, further consequence could lead to harmful effects on humans who feed on snails, a rich source of protein and depend on earthworms for nutrient. [ABSTRACT FROM PUBLISHER]

Taxonomic studies on scolopendrid centipedes have often documented variability at the individual and population levels and applied those data to questions of species delimitation, but these investigations have mostly lacked an explicit phylogenetic framework. A molecular phylogeny and recent taxonomic revision for Indian species of the scolopendrid Digitipes Attems, 1930, permit variability of traditional taxonomic characters for Scolopendridae to be mapped onto a phylogeny. Based on their fit to the tree using maximum likelihood, reliable species-level characters include the number of glabrous antennal articles, presence of a median ridge on the tergites, and presence or absence of a tarsal spur on leg 20. Characters that are conserved within and diagnostic for particular species but labile within others (typically with geographic structure) include the first tergite with paramedian sutures, presence or absence of a lateral spine on the coxopleuron, and the number of spines in a ventromedial row on the ultimate leg prefemur. Comparisons with published accounts of variability in species of other scolopendrid genera, particularly Scolopendra and Otostigmus, show that Indian Digitipes has conserved morphology in some characters that are taxonomically useful elsewhere in the family, and most of its taxonomically informative characters have analogous patterns of variability in other genera. The approach used in this study to evaluate morphological variation in a phylogenetic framework can be applied to other taxa in which morphologically cryptic species have been reported and where species diagnosis requires a combination of characters. [ABSTRACT FROM AUTHOR]

Background: Earthworms (Crassiclitellata) are a diverse group of annelids of substantial ecological and economic importance. Earthworms are primarily terrestrial infaunal animals, and as such are probably rather poor natural dispersers. Therefore, the near global distribution of earthworms reflects an old and likely complex evolutionary history. Despite a long-standing interest in Crassiclitellata, relationships among and within major clades remain unresolved. Methods: In this study, we evaluate crassiclitellate phylogenetic relationships using 38 new transcriptomes in combination with publicly available transcriptome data. Our data include representatives of nearly all extant earthworm families and a representative of Moniligastridae, another terrestrial annelid group thought to be closely related to Crassiclitellata. We use a series of differentially filtered data matrices and analyses to examine the effects of data partitioning, missing data, compositional and branch-length heterogeneity, and outgroup inclusion. Results and discussion: We recover a consistent, strongly supported ingroup topology irrespective of differences in methodology. The topology supports two major earthworm clades, each of which consists of a Northern Hemisphere subclade and a Southern Hemisphere subclade. Divergence time analysis results are concordant with the hypothesis that these north-south splits are the result of the breakup of the supercontinent Pangaea. Conclusions: These results support several recently proposed revisions to the classical understanding of earthworm phylogeny, reveal two major clades that seem to reflect Pangaean distributions, and raise new questions about earthworm evolutionary relationships. [ABSTRACT FROM AUTHOR]

Partitioning tissue metal concentration into subcellular compartments reflecting toxicologically available pools may provide good descriptors of the toxicological effects of metals on organisms. Here we investigated the relationships between internal compartmentalization of Cd, Pb and Zn and biomarker responses in a model soil organism: the earthworm. The aim of this study was to identify metal fractions reflecting the toxic pressure in an endogeic, naturally occurring earthworm species (Aporrectodea caliginosa) exposed to realistic field-contaminated soils.After a 21 days exposure experiment to 31 field-contaminated soils, Cd, Pb and Zn concentrations in earthworms and in three subcellular fractions (cytosol, debris and granules) were quantified. Different biomarkers were measured: the expression of a metallothionein gene (mt), the activity of catalase (CAT) and of glutathione-s-transferase (GST), and the protein, lipid and glycogen reserves. Biomarkers were further combined into an integrated biomarker index (IBR).The subcellular fractionation provided better predictors of biomarkers than the total internal contents hence supporting its use when assessing toxicological bioavailability of metals to earthworms. The most soluble internal pools of metals were not always the best predictors of biomarker responses. metallothionein expression responded to increasing concentrations of Cd in the insoluble fraction (debris + granules). Protein and glycogen contents were also mainly related to Cd and Pb in the insoluble fraction. On the other hand, GST activity was better explained by Pb in the cytosolic fraction. CAT activity and lipid contents variations were not related to metal subcellular distribution. The IBR was best explained by both soluble and insoluble fractions of Pb and Cd.This study further extends the scope of mt expression as a robust and specific biomarker in an ecologically representative earthworm species exposed to field-contaminated soils. The genetic lineage of the individuals, assessed by DNA barcoding with cytochrome c oxidase subunit I, did not influence mt expression. [ABSTRACT FROM AUTHOR]

Soil dwelling earthworms are now adopted more widely in ecotoxicology, so it is vital to establish if standardised test parameters remain applicable. The main aim of this study was to determine the influence of OECD artificial soil on selected soil-dwelling, endogeic earthworm species. In an initial experiment, biomass change in mature Allolobophora chlorotica was recorded in Standard OECD Artificial Soil (AS) and also in Kettering Loam (KL). In a second experiment, avoidance behaviour was recorded in a linear gradient with varying proportions of AS and KL (100% AS, 75% AS + 25% KL, 50% KS + 50% KL, 25% AS + 75% KL, 100% KL) with either A. chlorotica or Octolasion cyaneum. Results showed a significant decrease in A. chlorotica biomass in AS relative to KL, and in the linear gradient, both earthworm species preferentially occupied sections containing higher proportions of KL over AS. Soil texture and specifically % composition and particle size of sand are proposed as key factors that influenced observed results. This research suggests that more suitable substrates are required for ecotoxicology tests with soil dwelling earthworms. [ABSTRACT FROM AUTHOR]

A total of 20 species of earthworms belonging to 13 genera and five families are recorded from northern Indian state of Haryana. Among them, five new records of Ocnerodrilus occidentalis Eisen, Lennogaster pusillus (Stephenson), Ramiella bishambari (Stephenson), Metaphire houlleti (Perrier) and Metaphire birmanica (Rosa) are reported. A simple key for the identification of earthworms of the area is provided. [ABSTRACT FROM AUTHOR]

The Central Great Plains Ecoregion in the United States occurs in a portion of four states in the American mid-west (Kansas, Nebraska, Oklahoma and Texas). There are 25 species and one subspecies found here, representing seven genera and three families (Acanthodrilidae, Lumbricidae and Megascolecidae). Eighteen of the species are native (endemic) to North America; all are European or Oriental (exotic) introductions. A description of the ecoregion and five colour photographs are also included. [ABSTRACT FROM AUTHOR]

The Cross Timbers Ecoregion in the United States occurs in portions ofthree states in the American central region (Kansas, Oklahoma and Texas). There are 17 species found here, representing eight genera and four families (Acanthodrilidae, Lumbricidae, Megascolecidae, Sparganophilidae). Thirteen of the species are native (endemic) to North America; all are European or Oriental (exotic) introductions. A description of six ecoregion and three colour photographs are also included. [ABSTRACT FROM AUTHOR]

The Western Corn Belt Plains Ecoregion in the United States occurs in a portion ofseven states in the American midwest. There are 26 species found here, representing 12 genera and four family (Acanthodrilidae, Lumbricidae, Megascolecidae and Sparganophilidae). Twelve of the species are native (endemic) to North America; all are European or Oriental (exotic) introductions. A description of the ecoregion and eight colour photographs are also included. [ABSTRACT FROM AUTHOR]

The Flint Hills Ecoregion in the United States occurs in portions of two states (Kansas and Oklahoma). There are 17 species found here, representing five genera and three families (Acanthodrilidae, Lumbricidae and Megascolecidae). Twelve of the species are considered native (endemic) to North America; all others are European or Oriental introductions (exotics). A description of the ecoregion and five colour photographs are also included. [ABSTRACT FROM AUTHOR]

A new species, Araguanema mutabile sp. nov., from the coelomic cavity of a glossoscolecid earthworm Aptodrilus fuhrmanni Michaelsen, 1918 deposited in the collection of Natural History Museum of Geneva, is described and illustrated. The new species is characterised by the presence of two types of somatic sensory organs, i.e. vesicular and fimbriate, four cephalic papillae, a small cuticularised stoma, a muscular, clavate pharynx, a nerve ring encircling isthmus, no distinct spermatheca, and a posterior position of vulva and thick-shelled eggs. From the only known species of the genus, A. venezuelae Ivanova & Hope, 2004, it differs by the differently shaped pharynx, indistinct vs distinct amphids, a stoma with cuticularised vs non-cuticularised walls, the different arrangement of the sensory organs, and more numerous eggs with ornamented vs smooth egg-shells. The significance of the number of somatic organs for the species identification is discussed. [ABSTRACT FROM AUTHOR]

Many soft-bodied invertebrates use a flexible, fluid-filled hydrostatic skeleton for burrowing. The aim of our study was to compare the scaling and morphology between surface-dwelling and burrowing earthworm ecotypes to explore the specializations of non-rigid musculoskeletal systems for burrowing locomotion. We compared the scaling of adult lumbricid earthworms across species and ecotypes to determine whether linear dimensions were significantly associated with ecotype. We also compared the ontogenetic scaling of a burrowing species, Lumbricus terrestris, and a surface-dwelling species, Eisenia fetida, using glycol methacrylate histology.We show that burrowing species are longer, thinner and have higher length-to-diameter ratios than non-burrowers, and that L. terrestris is thinner for any given body mass compared with E. fetida. We also found differences in the size of the musculature between the two species that may correlate with surface crawling or burrowing. Our results suggest that adaptations to burrowing for soft-bodied animals include a disproportionately thin body and strong longitudinal muscles. [ABSTRACT FROM AUTHOR]

Epigeic earthworms can significantly hasten the decomposition of organic matter, which is known to be mediated by gut associated microflora. However, there is scanty information on the abundance and diversity of the gut bacterial flora in different earthworm genera fed with a similar diet, particularly Eisenia foetida and Perionyx excavatus . In this context, 16S rDNA based clonal survey of gut metagenomic DNA was assessed after growth of these two earthworms on lignocellulosic biomass. A set of 67 clonal sequences belonging to E. foetida and 75 to P. excavatus were taxonomically annotated using MG-RAST and RDP pipeline servers. Highest number of sequences were annotated to Proteobacteria (38–44%), followed by unclassified bacteria (14–18%) and Firmicutes (9.3–11%). Comparative analyses revealed significantly higher abundance of Actinobacteria and Firmicutes in the gut of P. excavatus. The functional annotation for the 16S rDNA clonal libraries of both the metagenomes revealed a high abundance of xylan degraders (12.1–24.1%). However, chitin degraders (16.7%), ammonia oxidizers (24.1%) and nitrogen fixers (7.4%) were relatively higher in E. foetida , while in P. excavatus ; sulphate reducers and sulphate oxidizers (12.1–29.6%) were more abundant. Lignin degradation was detected in 3.7% clones of E. foetida , while cellulose degraders represented 1.7%. The gut microbiomes showed relative abundance of dehalogenators (17.2–22.2%) and aromatic hydrocarbon degraders (1.7–5.6%), illustrating their role in bioremediation. This study highlights the significance of differences in the inherent microbiome of these two earthworms in shaping the metagenome for effective degradation of different types of biomass under tropical conditions. [ABSTRACT FROM AUTHOR]

This study describes a new and sensitive method for measuring the in vivo and in vitro cytotoxicity of 2 earthworm species, Eisenia andrei and Perionyx excavatus , exposed to copper. Specifically, we measured the number of coelomocyte cells that were affected by copper following in viv o and in vitro exposure by flow cytometry, after calcein acetoxymethyl ester (calcein-AM) staining. We found that the coelomocyte viability of both earthworm species was noticeably reduced in the in vivo cytotoxicity test at concentrations of 100 mg/kg copper in dry soil. However, pathological symptoms, such as mucous secretion and bleeding, swelling, thinning, and fragmentation, and burrowing symptoms were not evident following exposure to copper levels of <400 mg/kg dry soil. In conclusion, the present study demonstrates that calcein-AM is a more sensitive test of earthworm coelomocyte cytotoxicity compared to the traditional individual level toxicity test. Therefore, this test could be used to detect low levels of metal contamination in soils. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the capability of earthworms from the same ecological group as heavy metal bioindicators. Three earthworm species from the endogeic group were studied: Aporrectodea caliginosa (Savigny, 1826), Perelia kaznakovi (Michaelsen, 1910) and Octolasion lacteum (Örley, 1885). Their accumulation of the heavy metals lead (Pb) and cadmium (Cd) were studied from three stations in Tehran province, Iran. O. lacteum was used to compare metal accumulations in two sites located next to a highway. A. caliginosa and P. kaznakovi were used at a third site located near the edge of a sewage system to compare metal accumulations between the two endogeic species in this area. At both locations, the concentrations of Cd and Pb in earthworms were higher than in the surrounding soil. The results of the study revealed that P. kaznakovi and A. caliginosa were better bioindicators for Pb, but O. lacteum was a better bioindicator for Cd. These earthworms can therefore be used as Cd and Pb bioindicators in environmental assessment. [ABSTRACT FROM AUTHOR]

We report the nonlinear response of tissue and nerve fibers in the earthworm Lumbricus terrestris to sinusoidal electric field excitations. A High-Tc Superconducting Quantum Interference Device (SQUID) magnetometer detects the magnetic field generated by complex currents in the animal. SQUID signals are processed on a Fast Fourier Transform (FFT) spectrum analyser. Use of the SQUID eliminates low frequency polarization impedance and field distortion that would be present near pickup electrodes. Electrical 4-probe harmonic response measurements of the excised nerve fiber are then compared to the driven Hodgkin-Huxley active transport model. [ABSTRACT FROM AUTHOR]

Summary: This paper re-evaluated the use of DNA barcodes in earthworm species identification by re-analyzing sequence data for the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This analysis unveiled and confirmed taxonomic inconsistencies which significantly affect data interpretation. When considering synonymy and misidentification in published records, our results revealed no shared COI haplotypes between morphologically distinct species and higher interspecific than intraspecific divergence in most cases, with interspecific and intraspecific distances averaging 18.7% and 1.3% respectively. However, a few earthworm species endemic to Taiwan have deep intraspecific divergences which may represent potential cases of cryptic diversity, although incomplete lineage sorting cannot be ruled out without further study. We recognize the potential of DNA barcoding for earthworm taxonomy, but have identified several issues regarding the evolution of the COI gene in these organisms which remain to be further elucidated. [Copyright &y& Elsevier]

The reaction of soil bacteria and fungi to the digestive fluid of the earthworm Aporrectodea caliginosa was studied. The fluid was obtained by centrifugation of the native enzymes of the digestive tract. The inhibition of growth of certain bacteria, spores, and fungal hyphae under the effect of extracts from the anterior and middle sections of the digestive tract of A. caliginosa was discovered for the first time. In bacteria, microcolony formation was inhibited as early as 20–30 s after the application of the gut extracts, which may indicate the nonenzymatic nature of the effect. The digestive fluid exhibited the same microbicidal activity whether the earthworms were feeding on soil or sterile sand. This indicates that the microbicidal agents are formed within the earthworm’s body, rather than by soil microorganisms. The effect of the digestive fluid from the anterior and middle divisions is selective in relation to different microorganisms. Of 42 strains of soil bacteria, seven were susceptible to the microbicidal action of the fluid ( Alcaligenes faecalis 345-1, Microbacterium sp. 423-1, Arthrobacter sp. 430-1, Bacillus megaterium 401-1, B. megaterium 413-1, Kluyvera ascorbata 301-1, Pseudomonas reactans 387-2). The remaining bacteria did not die in the digestive fluid. Of 13 micromycetes, the digestive fluid inhibited spore germination in Aspergillus terreus and Paecilomyces lilacinus and the growth of hyphae in Trichoderma harzianum and Penicillium decumbens. The digestive fluid stimulated spore germination in Alternaria alternata and the growth of hyphae in Penicillium chrysogenum. The reaction of the remaining micromycetes was neutral. The gut fluid from the posterior division of the abdominal tract did not possess microbicidal activity. No relation was found between the reaction of microorganisms to the effects of the digestive fluid and the taxonomic position of the microorganisms. The effects revealed are similar to those shown earlier for millipedes and wood lice in the following parameters: quick action of the digestive fluid on microorganisms, and the selectivity of the action on microorganisms revealed at the strain level. The selective effect of the digestive gut fluid of the earthworms on soil microorganisms is important for animal feeding, maintaining the homeostasis of the gut microbial community, and the formation of microbial communities in soils. [ABSTRACT FROM AUTHOR]

In the ventral nervous system of the earthworm, a central pattern generator and motor neurons are activated during locomotion. We have previously reported that bath application of octopamine (OA) induces fictive locomotion in the earthworm, and the burst frequency of electrical activity from the first lateral nerves increases with OA concentration. However, there are no reports concerning locomotor neural networks in the earthworm. To identify neural networks involved in fictive locomotion, we optically monitored activity-dependent fluorescent staining in the earthworm ventral nerve cord (VNC) with a styryl dye, N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide (FM1–43), and a confocal laser scanning microscope. OA induces FM1–43 fluorescence in a dose-dependent manner, with bright fluorescent spots of 3–10 μm in diameter observed to be localized around specified neurons in the segmental ganglion of the VNC. We compared OA dose-response curves for FM1–43 fluorescence with the bursting frequency for fictive locomotion, and found that two types of curves could be identified: one fluorescence response shows a similar dose-dependency to that of the burst frequency, while another response has a higher sensitivity to OA. From these results, we suggest that OA acts as one of the neuromodulators for the earthworm locomotion. This is the first attempt to record motor and inter-neuronal activities simultaneously in a locomotor network in the earthworm. [Copyright &y& Elsevier]

Discusses the testing of cadmium (Cd) effects on the ovary structure and oocytes in earthworms Dendrobaena veneta exposed to Cd in soil. Damage caused by Cd to the structure of the ovary; Degenerative changes in cell nuclei; Increase in number of cell organelles in the cytoplasm of oocytes and trophocytes.

Examines the ontogenic effects of body size on force production in the earthworm Lumbricus terrestris. Mechanics of burrowing; Comparison of pushing forces in adult and hatchlings; Impact of soil characteristics on burrowing force; Muscle stress; Comparison of locomotion between soft-bodied organisms with hydrostatic skeletons versus rigid skeletons.

Presents a study which looked at the reproductive system of the Perionyx excavatus, a earthworm. Examination of the gross anatomy and histology; Components of the male reproductive system; What is the seminal vesicles; Insight on the female reproductive structures.

Provides information on a study measuring the resting geometry of the skeletons of earthworms (Lumbricus terrestris). Methodology and materials used to conduct the study; Application of the scaling hypotheses to Lumbricus terrestris; Information on the gravity and the scaling of hydrostatic skeleton function; Findings of the study.

The article provides answers to a question on how earthworms function, covering topics such as their movement, digestive system, and circulatory system.

By means of radioimmunoassay, we studied the concentration of pituitary adenylate cyclase-activating polypeptide (PACAP)-like proteins in intact and regenerating earthworms. Transection of animals increased the concentration of PACAP-like compounds in coelomocytes, and a decreasing rostrocaudal gradient was detected in the regenerating animals. Western blot analysis revealed a range of PAC1-receptor proteins with molecular weights from 40 to 80 kDa. Electron microscopic immunocytochemistry showed that PAC1 receptors were located on distinct sets of coelomocytes (mainly on amebocytes and on some granulocytes). Based on our results we hypothesize a link between PACAP and coelomocytes, suggesting that PACAP modulates the function of amebocytes and certain granulocytes that play a role in tissue remodeling of regenerating earthworms. [ABSTRACT FROM AUTHOR]

The article describes a three-day classroom exploration called Worms Out of This World. According to the author, the activity is a unit designed to help second-grade students observed live earthworms and recorded their observations in a learning log. According to the author, the exploration was a great success since her students' observations in their learning logs showed that second graders are capable of being keen observers as well as participants in fruitful discussions. In addition, these simple exploration activities helped students develop their observation skills and learn about collecting data.

An introduction is presented in which the editor discusses articles in the issue on topics including earthworm gut bacteria, weedicides, and carbon capture for climate change.

The article studies the organization of cytoskeleton and the distribution of cell organelles during male germ-line cysts development in earthworms.

The article provides information about earthworms. These creatures do not have legs, but they do have four pairs of hair-like bristles, called setae, on the side of each body segment. These tiny bristles or setae help the worm crawl about or hold fast to its burrow. Whenever the worm shortens itself, the body segments get fatter and the setae are pushed out. The setae are pulled in as the worm extends its body. The information is from the Web site of The Electronic Naturalist at address, www.enaturalist.org/unit/16.