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Fifteen days pre-decomposed seaweeds, Halimeda gracilis, Gracilaria corticata, Sargassum wightii and Sargassum swartzii spiked with cowdung (1:1) were vermicomposted using Perionyx excavatus for 60 days. The pH in the vermicompost showed insignificant reduction while electrical conductivity showed significant enhancement (P 0.05). The reduction of organic carbon in vermicomposts ranged from -37.78 to -50.97% over worm-unworked composts. Total NPK contents showed significant increment (26.72-78.17%) in vermicompost over worm-unworked composts. The difference in percentage increase/decrease between physicochemical parameters was statistically significant (P 0.001) and the same pattern was found between substrates. The total microbial population in vermicomposts was significantly higher than that of initial and composts of all seaweed + cowdung combinations (P 0.001). The growth and reproduction of Perionyx excavatus in seaweed + cowdung combinations showed equivalent or higher rates when compared with cowdung signifying that Perionyx excavatus is well suited to convert seaweed and cowdung combinations into nutrient rich vermicompost.

Earthworms are ecological engineers that can contribute to the displacement of biological control agents such as the entomopathogenic nematodes (EPNs) and fungi (EPF). However, a previous study showed that the presence of cutaneous excreta (CEx) and feeding behavior of the earthworm species Eisenia fetida (Haplotaxida: Lumbricidae) compromise the biocontrol efficacy of certain EPN species by reducing, for example, their reproductive capability. Whether this phenomenon is a general pattern for the interaction of earthworms-entomopathogens is still unknown. We hypothesized that diverse earthworm species might differentially affect EPN and EPF infectivity and reproductive capability. Here we investigated the interaction of different earthworm species (Eisenia fetida, Lumbricus terrestris, and Perionyx excavatus) (Haplotaxida) and EPN species (Steinernema feltiae, S. riojaense, and Heterorhabditis bacteriophora) (Rhabditida) or EPF species (Beauveria bassiana and Metarhizium anisopliae) (Hypocreales), in two independent experiments. First, we evaluated the application of each entomopathogen combined with earthworms or their CEx in autoclaved soil. Hereafter, we studied the impact of the earthworms' CEx on entomopathogens applied at two different concentrations in autoclaved sand. Overall, we found that the effect of earthworms on entomopathogens was species-specific. For example, E. fetida reduced the virulence of S. feltiae, resulted in neutral effects for S. riojaense, and increased H. bacteriophora virulence. However, the earthworm P. excavates increased the virulence of S. feltiae, reduced the activity of H. bacteriophora, at least at specific timings, while S. riojaense remained unaffected. Finally, none of the EPN species were affected by the presence of L. terrestris. Also, the exposure to earthworm CEx resulted in a positive, negative or neutral effect on the virulence and reproduction capability depending on the earthworm-EPN species interaction. Concerning EPF, the impact of earthworms was also differential among species. Thus, E. fetida was detrimental to M. anisopliae and B. bassiana after eight days post-exposure, whereas Lumbricus terrestris resulted only detrimental to B. bassiana. In addition, most of the CEx treatments of both earthworm species decreased B. bassiana virulence and growth. However, the EPF M. anisopliae was unaffected when exposed to L. terrestris CEx, while the exposure to E. fetida CEx produced contrasting results. We conclude that earthworms and their CEx can have positive, deleterious, or neutral impacts on entomopathogens that often coinhabit soils, and that we must consider the species specificity of these interactions for mutual uses in biological control programs. Additional studies are needed to verify these interactions under natural conditions., MC is supported by a Moroccan scholarship of the Ministry of National Education, Vocational Training, Higher Education and Scientific Research, and the travel assistance associated with the grant CSIC ICOOP + 2018 grant (COOPA20231). RBP is financed with an FPI contract (CAR-2018) by the Department of Economic Development and Innovation of The Government of La Rioja (Spain). IVD is supported with an FPI-UR fellowship by the Universidad de La Rioja (Spain). RCH is awarded by Ramon y Cajal contract award (RYC-2016-19939) of the Government of Spain. This study is supported by CSIC I-COOP + 2018 grant (COOPA20231).

Background Earthworm communities are generally very sensitive to physico-chemical properties of the soil in different agro-ecosystem i.e. cultivated or non-cultivated which directly or indirectly influence the earthworm survival. The difference in physico-chemical properties of soil at different sites contributed to the formation of population patches for earthworm species. Understanding the physico-chemical properties of soil at a particular site could facilitate the prediction of earthworm species at that site. The objective of the present study was to investigate the diversity, abundance, and distribution of earthworms in cultivated and non-cultivated agroecosystems and their physico-chemical properties affecting the earthworm diversity and abundance. Results Total 10 species of earthworms i.e. Amynthas alexandri, Amynthas morrisi, Eutyphoeus incommodus, Eutyphoeus waltoni, Metaphire birmanica, Metaphire houlleti, Metaphire posthuma, Octochaetona beatrix, Perionyx excavatus, and Polypheretima elongata, were reported. Out of all the reported species, Metaphire posthuma was found to be the most abundant earthworm species in both cultivated and non-cultivated agroecosystems with the occurrence at 56.81% sites. The Shannon-Wiener index (H), Margalef species richness index (DMg) and Pielou species evenness (E) was ranged from 0 to 0.86, 0 to 0.64 and 0.78 to 1 respectively. The principal component analysis resulted in four principal components i.e. PC1, PC2, PC3 and PC4 which contributing variance (%) of 22.96, 19.37, 14.23 and 10.10 respectively. The principal component analysis also showed that physico-chemical parameters of soil such as EC, pH, TDS, texture, OC, moisture, etc. play a critical role in earthworm distribution. Conclusion The conventional farming system has a negative effect on the earthworm diversity in the soil while the physico-chemical properties of soil also have a determinant effect on the same. Earthworms abundance in the present study have significant direct relation with soil properties at a particular site and vice versa. The diversity indices also change due to the conventional farming system which directly affects the earthworm abundance.

Carbon to nitrogen (C/N) ratio influences substrate combinations and earthworm performance in vermicomposting systems. To elucidate these factor effects, a comparative evaluation of species, C/N ratio combined with feed rate, was conducted on three local earthworm species: Perionyx excavatus, Eudrilus eugeniae, and Dichogaster annae. Earthworms were stocked at similar densities and fed shredded paper (SP), cattle manure (CM), and lawn clippings (LC) combined to form C/N ratios of 28, 36, and 53. Earthworms were fed at rates of 1, 1.25, and 2 g feed (dry wt.)/g worm/day for a period of 8 weeks. Percent vermiconversion, earthworm adult and juvenile biomass, and vermicast quality were measured. Vermicast production was significantly affected by the combination of C/N ratio and feed rate and varied among species. All treatment combinations resulted in > 70% conversion, except E. eugenaie fed at the medium rate. Vermiconversion increased for P. excavatus and D. annae with increasing C/N ratio but decreased with increasing the feed rate. Vermicast EC, pH, and C/N ratio was strongly affected by species, relative to other experimental factors. D. annae showed the greatest change in biomass, which peaked at the highest feed rate and lowest C/N ratio. Average adult biomass decreased for P. excavatus with increasing feed rate, while differences were nonsignificant for E. eugenaie and D. annae. Significant increases in average juvenile biomass were only evident for D. annae in response to increasing feed rates. Feed rate had a greater influence on earthworm population dynamics and vermicast quality compared to initial feedstock C/N ratio.

The earthworm Perionyx excavatus is a species highly capable of bidirectional regeneration. Pair-rule genes are thought to have an ancestral function in arthropod segmentation. However, orthologs in annelids (i.e. Capitella teleta) do not exhibit segmental expression in the ectoderm or mesoderm. Their role in regeneration is currently unclear. Here, we report the expression profile of primary pair-rule genes (Pex-EvxA, Pex-EvxB, Pex-RuntA, Pex-RuntB, Pex-Hes1A, Pex-Hes1B, Pex-Hes4A, and Pex-Hey) found in P. excavatus using semi-quantitative reverse transcription-polymerase chain reaction. Our results indicated these genes showed variable expression during bidirectional regeneration. Six of these genes might play diverse and potentially critical roles in head and/or tail regeneration.

Tri-n-butyl phosphate (TBP) is widely used in various industrial processes and has been detected in all environmental matrices. So far, little work has been done regarding the metabolism of TBP on terrestrial invertebrates. We investigated the metabolism of TBP in the earthworm, Perionyx excavatus, after acute exposure to TBP for one and two days in filter paper contact test, as well as after chronic exposure for 28 days in soil experiment. Biotransformation products were identified by using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and by exploiting the information dependent acquisition in tandem mass spectrometry. TBP exhibited low accumulation in earthworm-soil ecosystem at 10 mg/kg and 50 mg/kg. The presence of earthworms significantly enhanced TBP degradation at 50 mg/kg in soil. Dibutyl phosphate and hydroxylated TBP were the major phase I metabolites. Three novel phase II metabolites were identified: ethanol dibutyl phosphate and its sulfate conjugate, and the phosphate conjugate of hydroxylated TBP. Hydroxylation and further phosphorylation dominated metabolism in chronic exposure. An extensive metabolic pathway of TBP in earthworm was proposed. This is the first report of TBP metabolism in terrestrial invertebrates and highlights the necessity to identify metabolites of contaminants when evaluating their bioaccumulation and toxicity.

Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through composting has been reported; however, the process is lengthy due to its complex biochemical composition. Although vermitechnology is known for its high efficiency, it has rarely been applied to recycle SMS. In this study, the qualitative value of vermicomposted SMS mediated by three earthworm species (i.e., Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus) was evaluated on the basis of nutrient availability, microbial activity, phospholipid fatty acid (PLFA) profiles, and seed germination assays. Degradation profiles of the lignocellulosic substrate in the vermireactors were assessed by monitoring the changes in crystallinity and distribution of functional groups using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy, respectively. Total organic carbon decreased by 1.4–3.5 folds with approximately 2.1–2.4 folds increase in nitrogen and phosphorus availability in all vermibeds. Interestingly, pH declined in the Eisenia and Eudrilus systems but increased in the Perionyx-vermibeds. XRD-derived crystallinity index was reduced significantly by 1.37 folds in Perionyx-vermicompost with concurrent microbial enrichment. Further, profuse abundance of vital functional groups (C O, NH, and OH) was clearly observed in the vermicompost with Perionyx followed by that with Eisenia. Moreover, PLFA illustrated significant variations in fatty acid distributions and microbial communities of the three vermicomposting systems. The seed germination assay showed that the germination index and relative root-shoot vigor of Perionyx-vermicompost treated seeds were 1.05–1.30 times greater than those of Eisenia and Eudrilus vermicompost treated ones. The results suggest that SMS degradability was affected by the growth of a healthy microbial community through vermicomposting.

Vermicomposting is a dependable waste recycling technology which greatly augments N and P levels mainly through microbial action. This paper aims to identify efficient N-fixing (NFB) and P-solubilizing (PSB) bacteria from earthworm intestines. Various combinations of vegetable market waste, rice straw, and cowdung were fed to two earthworm species (Eisenia fetida and Perionyx excavatus). Total organic C decreased, pH shifted towards neutrality, and NPK availability, and microbial (NFB, PSB, and total bacteria) population increased remarkably during vermicomposting with E. fetida. Therefore, 45 NFB and 34 PSB strains isolated from Eisenia gut were initially screened, their inter-dominance assessed, and 8 prolific strains were identified through 16SrRNA sequencing. Interestingly, two novel N-fixing strains of Kluyvera ascorbata emerged as an efficient biofertilizer candidate. Moreover, both N-fixing and P-solubilizing strains of Serratia and Bacillus were isolated from earthworm gut. All the isolated strains significantly improved soil health and facilitated crop growth as compared to commercial biofertilizers.

The aim of this work was to study nutrient recovery and vermicompost production from livestock solid wastes of indigenous and exotic cow breeds with epigeic earthworms. Fourteen days pre-decomposed dung of Vechur native (CD1) and exotic Jersey (CD2) breeds were vermicomposted with Perionyx excavatus and Eudrilus eugeniae for 45 days (Cycle I) and 90 days (Cycle II) including respective controls without earthworms. Vermicomposts from CD1 and CD2 substrates during Cycle I and II showed increase in NPK, Ca and micro-nutrients (P 0.05); whereas, pH, total organic carbon, C/N and C/P ratios disclosed decrease (P 0.05) over initial levels for both the earthworms. E. eugeniae was found efficient in vermicomposting cattle solid wastes in 45 days and CD1 yielded nutrient rich vermicompost. The study concludes that Cycle I is suitable for nutrient recovery and vermicompost production, in addition to mass multiplication of earthworms in Cycle II.

Biological and behavioral responses of the tropical earthworm Perionyx excavatus towards different concentrations of abamectin were evaluated. Abamectin significantly reduced the biomass and reproduction (cocoon production) of P. excavatus as well as inducing histopathological alterations in the cuticle. Biomass loss was recorded in P. excavatus exposed to abamectin at a concentration as low as 0.1 mg active ingredient (a.i.) kg−1, while atrophy, another physiological response, was observed at an abamectin concentration of 0.21 μg cm−2 in a filter paper test. Cocoon production was significantly reduced in the presence of abamectin, and no cocoons were produced at doses of 20 mg a.i. kg−1 or higher, while abamectin at 50 mg a.i. kg−1 induced extreme pathology, characterized by the loss of the integrity of the whole body wall and intestine of P. excavatus. Histopathological alterations can be used as a biomarker to evaluate the toxicological impact of exposure to abamectin.

Fetal Bovine Serum (FBS) is used as a major supplement in culturing animal cells under in vitro conditions. Due to ethical concern, high cost, biosafety, and geographical as well as batchwise result variations, it is important to reduce or replace the use of FBS in animal cell culture. The major objective of this work is to evaluate the feasibility of heat-inactivated coelomic fluid (HI-CF) of the earthworm, Perionyx excavatus as a possible alternative for FBS in animal cell culture experiments. The coelomic fluid (CF) was extruded from the earthworm using electric shock method and used for the experiments. Electric shock method is a simple non-invasive technique, which has no harmful effect on earthworms. Mouse primary fibroblast and HeLa cell lines were used in this study. Among HI-CF, autoclaved CF and crude CF, the supplement of medium with HI-CF shows positive results. The processed HI-CF (90°C for 5 min) at 10% supplement in cell culture medium promote maximum cell growth but cells need the initial support of FBS for the attachment to the culture flask. Microscopic observation and immunofluorescence assay with actin and lamin A confirm that the cellular and molecular morphology of the cells is maintained intact. The HI-CF of earthworm, P. excavatus has shown better cellular viability when compared with FBS and making it possible as an alternative supplement to minimize the use of FBS.

Triphenyl phosphate (TPHP) is one of the most highly utilized organophosphorus flame retardants, and has been frequently detected in various environmental matrices, including soil. So far, limited information is known regarding the potential toxicity of TPHP to the earthworm-soil ecosystem. We investigated the metabolism of TPHP and the perturbation of the endogenous metabolome in the earthworm, Perionyx excavatus, using gas chromatography mass spectrometry (GC-MS) and liquid chromatography quadrupole time-of-flight (LC-QTOF)-based untargeted metabolomics approach after acute exposure to TPHP for one and two days through a filter paper contact test, as well as after chronic exposure for 28 days in a soil microcosm experiment. TPHP showed low bioaccumulation potential in the earthworm-soil ecosystem at concentrations of 10 mg/kg and 50 mg/kg. Identified phase I metabolites include diphenyl phosphate, mono-hydroxylated and di-hydroxylated TPHP. Two groups of phase II metabolites, thiol conjugates (including mercaptolactic acid, cysteine, cysteinylglycine, and mercaptoethanol conjugates) and glucoside conjugates (including glucoside, glucoside-phosphate, and C14H19O10P conjugates), were putatively identified. Only acute TPHP exposure caused significant perturbations of the endogenous metabolome in earthworms, featuring fluctuations in amino acids, glucose, inosine and phospholipids. These results reveal novel phase II metabolism and toxicity of TPHP in P. excavatus.

Two new earthworm species, one of Glossodrilus Cognetti, 1905 and the other of Martiodrilus (Maipure) Righi, 1995, are described from material collected from the coffee-growing region located in central-western Colombia: Glossodrilus chaguala sp. nov., and Martiodrilus (Maipure) quimbayaensis sp. nov. New records for this region are also reported for Glossodrilus griseus, Glossodrilus lacteus, Glossodrilus panikita, Aptodrilus fuhrmanni, Periscolex columbianus, Periscolex coreguaje, Pontoscolex (Pontoscolex) corethrurus, Dichogaster (Diplothecodrilus) affinis, Dichogaster (Diplothecodrilus) bolaui, Dichogaster (Diplothecodrilus) saliens, Amynthas (Amynthas) gracilis, Amynthas minimus, and Perionyx excavatus.

Methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) are among the major soil contaminants that threaten the health of soil ecosystems. Many MTBE-contaminated sites accumulate TBA, because TBA is the intermediate of MTBE biodegradation. To access the risk of MTBE and TBA in soil, we investigated the combined toxicities of MTBE and TBA using two earthworm species, Perionyx excavatus and Eisenia andrei, as well as the toxic effects via different exposure routes. The combined toxicity showed weak antagonistic effects (LC50mix values were slightly greater than 1.0), and sensitivity toward same pollutants differed in the two earthworm species. Moreover, the toxicity of MTBE and TBA was also affected by the exposure route; both filter paper and artificial soil tests showed that dermal-only exposure to MTBE had an even greater toxic effect than combined dermal and oral exposure. Thus, we suggest that diverse environmental factors including organic materials, the physicochemical properties of the contact media, and the exposure routes of the organism, should be taken into consideration when assessing the effects of pollutants on organisms in diverse environmental systems.

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.

In the present study, Eudrilus eugeniae and Perionyx excavatus were used for vermistabilization of textile mill sludge in different combinations with cowdung for 60 days. A higher percentage of metal removal was observed in earthworm treated mixtures for cadmium (54.5%) followed by copper (36.0%), chromium (37.0%) and zinc (35.9%). Vermistabilized textile mill sludge + cowdung (1:1) showed a maximum percentage increase in total NPK, a significant (P

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 vivo 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 100mg/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

In this study, (1)H nuclear magnetic resonance (NMR)-based metabolomics approach was used to characterize the metabolic response of the earthworm Perionyx excavatus in continuous vermifiltration for two months under hydraulic loading rates of 1m(3)m(-2)d(-1) (VF1) and 1.5m(3)m(-2)d(-1) (VF1.5). Both VF1 and VF1.5 showed higher removal of chemical oxygen demand and total nitrogen than the biofilter without earthworms. Principal component analysis of the NMR spectra of earthworm metabolites showed significant separations between those not subjected to wastewater filtration (control) and VF1 or VF1.5. Temporal variations of earthworm biomass, and the identified metabolites that are significantly different between control, VF1 and VF1.5 revealed that worms underwent increasing metabolic activity within 20days in VF1 and 14days in VF1.5, then decreasing metabolic activity. The use of NMR-based metabolomics in monitoring earthworm metabolism was demonstrated to be a novel approach in studying engineered vermifiltration systems.

Annelida is a lophotrochozoan phylum whose members have a high degree of diversity in body plan morphology, reproductive strategies and ecological niches among others. Of the two traditional classes pertaining to the phylum Annelida (Polychaete and Clitellata), the structure and function of the Hox genes has not been clearly defined within the Oligochaeta class. Using a PCR-based survey, we were able to identify five new Hox genes from the earthworm Perionyx excavatus: a Hox3 gene (Pex-Hox3b), two Dfd genes (Pex-Lox6 and Pex-Lox18), and two posterior genes (Pex-post1 and -post2a). Our result suggests that the eleven earthworm Hox genes contain at least four paralog groups (PG) that have duplicated. We found the clitellates-diagnostic signature residues and annelid signature motif. Also, we show by semi-quantitative RT-PCR that duplicated Hox gene orthologs are differentially expressed in six different anterior–posterior body regions. These results provide essential data for comparative evolution of the Hox cluster within the Annelida.

The earthworm provides an excellent model for investigating regeneration. Here we report the full-length cloning of three labial genes (Pex-lab01, Pex-lab02, and Pex-lab03) in the earthworm Perionyx excavatus. To analyze their expression pattern during head and tail regeneration, we used the reverse transcription-polymerase chain reaction. Our results indicate that the three labial genes were expressed only in the head-regenerating tissues. Also, we found that the expression of Pex-lab01 and Pex-lab02 is up-regulated, and this indicates their involvement in wound healing and the blastema formation processes during early head regeneration.

Three different earthworm species Eisenia fetida, Eudrilus eugeniae and Perionyx excavatus in individual (Monocultures) and combinations (Polycultures) were utilized to compare the suitability of worm species for vermicomposting of filter mud as well as the quality of the end product. The filter mud blended with saw dust can be directly converted into good quality fertilizer (vermicompost). Eight different reactors including three monocultures and four polycultures of E. fetida, E. eugeniae and P. excavatus and one control were used for the experiment. Vermicomposting resulted in significant reduction in C/N ratio, pH, total organic matter (TOC) but increase in electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP) and macronutrients (K, Ca and Na). Oxygen uptake rate (OUR) dropped up to 1.64-1.95 mg/g (volatile solids) VS/day for monoculture reactors and 1.45-1.78 mg/g VS/day for polycultures reactors, respectively, after 45 days of vermicomposting. Cocoon production and the earthworm biomass increased as vermicomposting progressed. On an overall the mono as well as polyculture reactors produced high quality stable compost free from pathogens and no specific differentiation could be inferred between the reactors.

Terrestrial avoidance behavior is proposed as a fast and cost-effective method for assessing effects of pesticides on earthworms. Tropical species however, have rarely been used in avoidance tests. Avoidance tests were performed with Perionyx excavatus, a tropical species, and Eisenia andrei as the standard species, using chlorpyrifos and carbofuran in artificial and natural soil. Earthworms were exposed to concentrations of 1–900 (chlorpyrifos) and 1–32 (carbofuran) mg a.i. kg−1 dry soil in a two-chamber system under tropical conditions (26 ± 2 °C, 48 h). No significant difference was found in the control tests comparing the two soils used, suggesting soil type did not affect the distribution of the worms. The results suggest a higher sensitivity of E. andrei, with EC50S for the effect on avoidance behavior for both pesticides being a factor of 2–3 lowers than for P. excavatus. Earthworm avoidance tests with local species should therefore be used with caution when applied as a tool for pesticide risk assessment in the tropics. Endpoints generated through avoidance tests in this study are shown to be less sensitive than reproduction and more sensitive than survival. This was further confirmed by literature data available. Earthworm avoidance tests therefore can only replace survival tests as an initial screening tool for risk assessment.

The present paper is aimed at safe reuse and recycling of sewage sludge (SS) and production of good quality compost using vermicomposting. Three different earthworm species Eiseniafetida (E. fetida), Eudrilus eugeniae (E. eugeniae), Perionyx excavatus (P. excavatus) in individual and combinations were utilized to compare the suitability of worm species for composting of sewage sludge as well as the quality of the end product. The sewage sludge without blending can be directly converted into good quality fertilizer (vermicompost). Vermicomposting resulted in reduction in C/N ratio 25.6 to 6-9, TOC (25%) but increase in electrical conductivity (EC) (47-51%), total nitrogen (TN) (2.4-2.8 times), potassium (45-71%), calcium (49-62%), sodium (62-82%) and total phosphorous (TP) (1.5-1.8 times), which indicated that sewage sludge can be recycled as a good quality fertilizer. The present study also inferred that the application of sewage sludge in the agricultural fields after vermicomposting would not have any adverse effect as the heavy metals (Cu, Mn, Pb and Zn) are now within the permissible limits.

An earthworm assay was used to assess the toxicity of two main gasoline components. Ecotoxicities of toluene and methyl tert -butyl ether (MTBE) were compared for Asian earthworm Perionyx excavatus separately and in combination. Sum of toxic unit (TU) at 50% mortality for the mixture (LC50 mix ) was estimated from the dose (TU-based)–response relationships by the Trimmed Spearman–Karber method. Toluene was shown to be about five and two times more toxic to P. excavatus than MTBE in filter paper contact test and natural soil tests, respectively. This is primarily due to the adsorption of toluene to soil particles, leading to less bioavailability of toluene to the earthworm in soil. The combined effect of toluene and MTBE was investigated using toxic unit model, and it was found to be almost additive and synergistic responses to P. excavatus in filter paper contact test and soil tests, respectively. The combined effect of toluene and MTBE in filter paper contact test was not consistent with the results in soil toxicity tests. This phenomenon may be associated with the interaction of soil salts with pollutants. Treatment with toluene and MTBE also affected the behavior and morphology of P. excavatus . It indicates that the VOCs induce metabolic and functional damages in earthworms. Combined effects of gasoline components should be taken into account to soil risk assessment.

Recycling of guar gum industrial waste through vermitechnology was studied under laboratory conditions by using composting earthworm Perionyx excavatus (Perrier). Three different combination of guar gum industrial waste namely guar gum industrial waste:cow dung:saw dust in 40:30:30 ratio (T1), guar gum industrial waste:cow dung:saw dust in 60:20:20 ratio (T2), and guar gum industrial waste:cow dung:saw dust in 75:15:10 ratio (T3) were used for vermicomposting experiments. Chemical changes during vermicomposting were measured and comparatively T2 showed great increase (from its initial level) for total N (25.4%), phosphorus (72.8%) and potassium (20.9%) than the other treatments. T2 also showed higher vermicomposting coefficient (VC), higher mean biomass for P. excavatus (146.68 mg) and higher cocoon production (about 21.9% and 645.5% more than the T1 and T3, respectively). Maximum earthworm mortality during vermicomposting was recorded with T3 treatment while zero mortality was recorded for T2 treatment after 150 days. Overall, T2 treatment appeared to be an ideal combination for enhancing maximum biopotential of earthworms to management guar gum industrial waste as well as for earthworm biomass and cocoon production.

To establish the use of Metaphire posthuma as a sensitive model for ecotoxicological studies, the comparative effects of five metals on the hatching profiles of the cocoons of the earthworms, Metaphire posthuma, Eisenia foetida and Perionyx excavatus, were studied. The cocoons of the three species of earthworms were exposed to copper, chromium (III), chromium (VI), lead and zinc at 1.25, 2.5, 5.0 and 10.0ppm. Viable cocoons were incubated at 20 ± 1°C by using the immersion method. The results indicated that the inhibition of cocoon hatching was concentration dependent. The normal hatching, delayed hatching and non-viability of cocoons were recorded. At a concentration of 1.25ppm, there was almost no effect on the hatching of the cocoons of all three species of earthworms, except when exposed to chromium (VI), but higher concentrations (2.5 and 5.0ppm) caused severe effects. It was concluded that M. posthuma was more sensitive than the other two species, and that it is a suitable model for use in eco-toxicity testing.

An earthworm bioassay was conducted to assess ecotoxicity in methyl tert-butyl ether (MTBE)-amended soils. Ecotoxicity of MTBE to earthworms was evaluated by a paper contact method, natural field soil test, and an OECD artificial soil test. All tests were conducted in closed systems to prevent volatilization of MTBE out of test units. Test earthworm species were Perionyx excavatus and Eisenia andrei. Mortality and abnormal morphology of earthworms exposed to different concentrations of MTBE were examined. MTBE was toxic to both earthworm species and the severity of response increased with increasing MTBE concentrations. Perionyx excavatus was more sensitive to MTBE than Eisenia andrei in filter papers and two different types of soils. MTBE toxicity was more severe in OECD artificial soils than in field soils, possibly due to the burrowing behavior of earthworms into artificial soils. The present study demonstrated that ecotoxicity of volatile organic compounds such as MTBE can be assessed using an earthworm bioassay in closed soil microcosm with short-term exposure duration.

The performance of four species of earthworm––Eudrilus eugeniae, Kinberg, Drawida willsi Michaelsen, Lampito mauritii, Kinberg and Perionyx excavatus, Perrier––born and grown in vermireactors fed with paper waste was studied over six months, in terms of vermicast output per unit feed, production of offspring, and increase in worm zoomass. These were compared with the performance of the previous generation which had been raised to adulthood on cowdung as principal feed before shifting them to vermireactors operating on cowdung-spiked paper waste. The results indicated that except with D. willsi of which the second generation performed only a shade better than the first, there was significant improvement in vermicast output, animal growth, and reproduction in the second generation compared to the first. The results indicated that cowdung-spiked paper waste can be an adequate food for successive generations of earthworms and that reactors can be operated indefinitely on this feed. The results also indicated that the earthworm generations born and raised in vermireactors operated on this feed become better vermiconverters of this feed than the parent earthworms.

An experiment was conducted during 1998-1999, in a deciduous forest located in the semi-arid tropics of central India, to evaluate the suitability of different forest litters as food material for the tropical epigeic earthworms i.e. Eisenia fetida (Savigny), Perionyx excavatus (Perrier) and Dicogaster bolaui (michaelsen). The aim was to examine the influence of these earthworms on the decomposition processes of three types of forest litters i.e. Tectona grandis (teak), Madhuca indica (mahua) and Butea monosperma (palas), on the maintenance of quality in a vermicomposting system, and to assess the effect of applications of in situ prepared vermicomposts on the growth of forest trees. The results indicated that T. grandis litter was the most suitable food material for the earthworms possibly because it contained high reserves of mineral nutrients. Comparisons of the survival and reproduction rates of the three epigeic earthworm species indicated that a higher reproduction rate was maintained for E. fetida compared to P. excavatus and D. bolaui in the decomposition of these forest litters. The rates of growth and population increases of E. fetida approximately doubled after 12 weeks of litter decomposition. The litter decomposition process was associated strongly with the quality of the materials and their chemical composition. Irrespective of earthworm inoculations, the levels of available nutrient such as NH(4)-N, NO(3)-N, available P and K increased significantly (p/=0.05) in the order T. grandis litter compostM. indica litter compostB. monosperma litter compost. The mature decomposed litter had lower C/N ratios (11.3-24.8:1), water-soluble carbon (0.30-0.58%), water-soluble carbohydrates (0.35-0.71%) and larger cation exchange capacity/total organic carbon ratios than the values in the parent forest litter. The lignin content increased with maturation with a concomitant decrease in cellulose resulting in higher lignin/cellulose ratios. Application of all three vermicomposts to forest trees significantly improved their heights and diameters over those of control trees, although the increases were lower than those resulting from the chemical fertilizer applications. However, soil biological activities i.e. soil respiration, soil microbial biomass carbon and dehydrogenase activity were greater by application of vermicomposts over that after application of inorganic fertilizer in a new plantation of T. grandis.

Biomass production and reproduction of a group of four adult Perionyx excaratus were studied in limited supplies of four experimental diets; cowdung alone and its mixtures with straw, bamboo leaf litter or kitchen waste, in order to select a suitable diet medium for vermiculture. P. excavatus showed maximum rate of biomass increase and reproduction in the mixtures with straw and bamboo leaf litter. In spite of achieving the highest final biomass value. P. excavatus showed the lowest rate of biomass increase and reproduction in the mixture with kitchen waste. Cowdung, a natural food of P. excavatus, was marginally better than the mixture with kitchen waste with regard to the rate of biomass increase and reproduction.

The recently developed concept of high rate vermicomposting was successfully used to enable direct vermicomoposting of neem leaves—without any pre-composting or cow dung supplementation as previously reported processes had necessitated. All the three epigeic species of earthworms that were explored, Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus, provided efficient vermicast production with no mortality, persistent gain in body mass and good fecundity over the 16 months long period of reactor operation. In this period, all reactors were pulse-fed at the solid retention time of 20 days and were operated in the pseudo discretized continuous operation protocol developed earlier by the authors. With this, it was possible to almost completely dampen the influence of natural biodegradation of the feed or grazing by the earthworm born in the vermireactors. The findings, thus, conclusively prove that, all-through, the brisk vermicomposting was caused almost entirely by the action of the ‘parent’ earthworms on fresh feed.

Four specices of detritivorous (humus-former) earthworms were tested for their ability to vermicompost paper waste blended with cowdung in 6:1 (w/w) ratio. The anecic Lampito mauritii, Kinberg and the epigeic Eudrilus eugeniae, Kinberg were the most effective of the four species employed; 20 animals of each of these species generated castings amounting to about 52% of the feed mass (75 g) per fortnight. The performance of these two species was followed by the anecic Drawida willsi, Michaelsen and the epigeic Perionyx excavatus, Perrier; they achieved approximately 46% vermiconversion in comparable settings. The vermireactors were sustainable as the animals have remained consistently healthy and reproductive over a period of six months, and are continuing to remain so, turning in a steadily rising vermicast output. During this period E. eugeniae have grown to 2.3 times their original weight while the other three species have more than trebled their weights. The studies establish the feasibility of vermicomposting as a viable process for the gainful utilization of paper waste in an environmentally clean manner. They also indicate that all the four species of the worms screened by us are suitable for the process, with L. mauritii and E. eugeniae a shade more efficient than the other two species.

A ParaHox gene cluster is composed of three genes (Gsx, Xlox, and Cdx). It has been proposed that all three ParaHox genes were present in the last common ancestor to the lophotrochozoan protostomes and the deuterostomes and that gene loss event has occurred in the ecdysozoan lineage. In this paper, we report the existence of all three ParaHox genes in Perionyx excavatus, a clitellate annelid. Although orthologs of each of the three ParaHox genes were previously discovered from other lopotrochozoan taxa, this study constitutes the first reported isolation of all three ParaHox genes in the same clitellate species.

A survey of the earthworms of Guadeloupe was undertaken to improve knowledge of the diversity of native and introduced earthworms of the island and to evaluate native species for use in vermicomposting. Twenty-eight species were found, 8 introduced, 4 uncertain, and 16 presumed native. The introduced species are Pontoscolex corethrurus, Pontoscolex spiralis, Amynthas rodericensis, Perionyx excavatus, Polypheretima elongata, Dichogaster affinis, Eudrilus eugeniae, and Drawida sp. Juveniles of the genera Righiodrilus, Glossodrilus and Periscolex were found, but one cannot say if they are introduced or not without a confirmed identification. Omodeoscolex divergens was collected in several locations, with variation in color, size and male sexual function suggestive of long residence on the island, but we are counting this as of uncertain status and tentatively placing all in the same species. Late juveniles of a large endogeic species of a heretofore unknown genus of the Rhinodrilidae were found only in the most remote location sampled and are presumed to be native. Seven previously reported native Dichogaster were found. Eight non-recorded species of Dichogaster were found, five represented by single specimens or juveniles, for which we give only a brief precis. The three described here are Dichogaster spolstoni n. sp., Dichogaster caraibensis n. sp.,.and Dichogaster etaspiqui n. sp. These are compared to and differentiated from previously known Dichogaster species of the world and of Guadeloupe.

Effects of sub-lethal doses of carbaryl (1-Naphthyl-methylcarbamate), chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridinyl-phosphorothioate) and endosulfan (6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), respectively a carbamate, an organophosphate and an organochlorine insecticide on growth, reproduction and respiration of the tropical earthworm, Perionyx excavatus (Perrier) were investigated under laboratory conditions. The results showed significant reduction in biomass, production and hatching of cocoon and production of juveniles of the worms exposed to 0.75 to 3.03 mg/kg soil of carbaryl, 0.91 to 3.65 mg/kg soil of chlorpyrifos and 3.75 to 15.0 μg/kg soil of endosulfan corresponding to 12.5 to 50 % of LC(50) value of the respective insecticide for P. excavatus. Endosulfan was found most dangerous among the three insecticides followed by carbaryl and chlorpyrifos. There was no hatching of the worms at endosulfan treatment 5.0 μg/kg soil (25 % LC(50)) or above while the highest dose of carbaryl and chlorpyrifos (50 % of LC(50)) rendered respectively 87.13 and 24.84 % reductions in hatching as compared to control. Chlorpyrifos produced no change in respiration of the worms except at the highest dose, while the worms showed an increase in evolution of CO(2) at all doses of carbaryl and endosulfan. Based on the recommended agricultural dose of each insecticide, it was concluded that application of endosulfan and carbaryl was potentially dangerous to earthworms.

Laboratory investigation on vermicomposting efficacy of Perionyx excavatus for recycling of distillation waste biomass of java citronella (Cymbopogon winterianus Jowitt) was carried out in two seasonal trials i.e. summer and winter periods. The experiment was conducted in earthen pots using a mixture of citronella waste material and cowdung in the proportion of 5:1. A control treatment without earthworms was setup for comparison of the results. The vermicompost had shown 5.8 folds reduction in C/N ratio and 5.6 folds enhancement in ash content. The nutrient contents (N, P, K, Ca and Mg) in the vermicompost had increase in the range of 1.2 – 4.1 fold than the initial level. The FT-IR spectra of the vermicompost confirmed increase in nitrogen rich compounds and decrease in aliphatic/aromatic compounds as compared to the initial level of the biowaste materials. The vermicomposting process is influenced by seasonal variation and summer was more productive than winter.

In India the exotic epigeic species, Eisenia fetida is mostly used for vermicomposting. The introduction of exotic species into local bio system may affect the indigenous earthworm species population. A comparative study between exotic species ( Eisenia fetida) and indigenous species Perionyx sansibaricus and Perionyx excavates was performed to determine the potential of indigenous species of the area vis-à-vis the exotic species for composting of domestic organic waste blended with cattle manure. The results of the study show a significant reduction in initial C/N ratio from 55 to 13 for P. excavates and 15 for P. sansibaricus of the ready product which was within the agronomic acceptable limit ( −1 up to 13.2 g kg−1. Overall, by employing above indigenous species, domestic organic waste can be directly converted into high-quality hygienic stable fertilizer (vermicompost) which is rich in nitrogen, phosphorus and potassium and free from pathogens.

This work illustrates the productivity of composting earthworm Perionyx excavatus under different stocking density (in milligrams biomass per cubic centimeter vermibed space) gradients in cattle dung decomposing system.Earthworm biomass and reproduction performance was tested in vermibeds with five different stocking density loads: 0.0680 mg cm⁻³ (T₁), 0.1388 mg cm⁻³ (T₂), 0.205 mg cm⁻³ (T₃), 0.274 mg cm⁻³ (T₄), and 0.342 mg cm⁻³ (T₅).Results thus suggested the direct relationship between earthworm performance and stocking density load in vermicomposting system. P. excavatus showed the maximum individual biomass production in low-stocking density trials, while cocoon production rate was better in vermibeds with high-density trials. The statistical interrelationships between stocking density load and individual growth parameters of inoculated earthworms were also tested. The statistical interpretation also suggested the impact of stocking density load on earthworm growth and reproduction parameters in vermicomposting system, although further detailed studies are required to measure the earthworm growth behavior under the maximum carrying capacity load of a vermibed.

Introduction: Earthworms respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretions. Most of the humoral defense proteins are synthesized in the skin itself. Materials and methods: In the present study, a dried powder was prepared from two indigenous earthworms (Lampito mauritii and Perionyx excavatus) and tested against two gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and five gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, and Pseudomonas aeruginosa). Results: The dried earthworm powder of two species shows a strong antibacterial activity against the S. aureus, P. mirabilis, and P. aeruginosa bacterial strains. Of these, the 60 μg/mL/disc of P. excavatus earthworm powder shows more activity than the L. mauritii.

Effects of pesticides on structural and functional properties of ecosystems are rarely studied under tropical conditions. In this study litterbag and earthworm field tests were performed simultaneously at the same tropical field site sprayed with chlorpyrifos (CPF). The recommended dose of CPF (0.6 kg a.i. ha−1) and two higher doses (4.4–8.8 kg a.i. ha−1) significantly decreased litter decomposition during the first 3 months after application, which could be explained from lower earthworm and termite abundances during this period. Species-specific effects of CPF on organism abundance and biomass were observed, with termites being mostly affected followed by the earthworm Perionyx excavatus; the earthworm Megascolex sp. was least affected. Recovery was completed within 6 months. Decomposition in the controls and lowest two treatments was completed within 4 months, which suggests the need for modification of standard test guidelines to comply with faster litter degradation under tropical conditions.

The 96 h LC(50) values of six insecticides were determined on a non-target epigeic earthworm Perionyx excavatus under laboratory conditions. Cypermethrin was found most toxic to P. excavatus (LC(50)-0.008 mg/kg), followed by endosulfan (LC(50)-0.03 mg/kg), carbaryl (LC(50)-6.07 mg/kg), chlorpyrifos (LC(50)-7.3 mg/kg), aldicarb (LC(50)-10.63 mg/kg) and monocrotophos (LC(50)-13.04 mg/kg). When these LC(50) values were compared with their respective recommended agricultural doses, aldicarb and carbaryl appeared more dangerous than other pesticides because of their lower LC(50) values than their respective recommended agricultural dose. Mean lethal time to cause 50% mortality at recommended agricultural dose (LT(50)) also indicated that aldicarb achieved the fastest LT(50) (26 h) followed by endosulfan (38 h) and carbaryl (44 h) indicating the danger of these pesticides to P. excavatus.

In order to gain insight into the gene expression profiles associated with anterior regeneration of the earthworm, Perionyx excavatus, we analyzed 1,159 expressed sequence tags (ESTs) derived from cDNA library early anterior regenerated tissue. Among the 1,159 ESTs analyzed, 622 (53.7%) ESTs showed significant similarity to known genes and represented 338 genes, of which 233 ESTs were singletons and 105 ESTs manifested as two or more ESTs. While 663 ESTs (57.2%) were sequenced only once, 308 ESTs (26.6%) appeared 2 to 5 times, and 188 ESTs (16.2%) were sequenced more than 5 times. A total of 803 genes were categorized into 15 groups according to their biological functions. Among 1,159 ESTs sequenced, we found several gene encoding signaling molecules, such as Notch and Distal-less. The ESTs used in this study should provide a resource for future research in earthworm regeneration.

The antimicrobial activity of vermiextract was assessed against four human pathogenic microorganisms. Especially strains of Proteus species are a prominent cause of urinary tract infection in children. The present investigation deals with particular urinary tract pathogenic organisms like E. coli, Proteus, Providencia, Morganella species. Screening was performed by disc diffusion method. The zone of inhibition range from 17 to 19 mm against 1.0x10(8) cells of each culture at 1 mg concentration of vermiextract. Vermiextract was most effective against Proteus species. The MIC (Minimum Inhibitory Concentration) was estimated by microdilution method.

Potential of an oriental composting earthworm: Perionyx excavatus (Perrier) to decompose waste resources generated from agricultural practices (crop residues, farm yard manure, and cattle dung) was studied for 150days under laboratory conditions. At the end of experiment, all vermibeds showed significant decrease in their organic C content ( approximately 21-29%), while increase in total N ( approximately 91-144%), available P ( approximately 63-105%), and exchangeable K ( approximately 45-90%). P. excavatus showed maximum individual live weight (662.05mg) after 120days in MIXED (mixed crop residues+cow dung in 1:1) substrate. The maximum growth rate (mg worm(-1)day(-1)) was between 3.79+/-0.08 and 2.35+/-0.16 on different substrates. The mean number of cocoon production was between 394.3+/-23.2 and 690.7+/-23.2 for different experimental beddings. MIXED bedding showed maximum reproduction rate (0.23+/-0.004 cocoons worm(-1) day(-1)), whereas farmyard manure bedding (FYM) showed least value (0.15+/-0.002 cocoons worm(-1)day(-1)). During vermicomposting, the total mortality in worms' population was recorded between 0% (in MIXED) and 21.7% (in Jowar straw (Sorghum vulgare)+millet straw (Pennisenum typhoides)+sheep manure in 1:1:2 ratio (JMS)). The waste decomposition and earthworm production was associated strongly with the quality of the substrate, especially with their chemical as well as biological composition.

The Hox genes of the oligochaete, Perionyx excavatus, were surveyed using PCR and phylogenetic analysis. We were able to identify 11 different Hox gene fragments. Comparative and phylogenetic analyses revealed that this oligochaete would have at least five Hox genes of the anterior group, including three copies of labial-type, five of the central group and one of the posterior group. This is the first report regarding sequence information and phylogenetic analysis of Hox genes in the earthworm.

Data on the reproductive biology of seven Indian species of earthworms, viz. Perionyx excavatus Perrier, Lampito mauritii Kinberg, Polypheretima elongata (Perrier), Pontoscolex corethrurus (Muller), Eutyphoeus gammiei (Beddard), Dichogaster modiglianii (Rosa) and Drawida nepalensis Michaelsen are presented. The peregrine earthworms such as Perionyx excavatus, Pontoscolex corethrurus, Dichogaster modiglianii, and Polypheretima elongata are considered to be continuous breeders with high fecundity. Native Lampito mauritii and Drawida nepalensis are semi-continuous and Eutyphoeus gammiei discrete breeders. There is a dramatic increase in cocoon production by most earthworm species of Tripura in the summer and monsoon with a corresponding peak during April and July. Cocoon production decreased or ceased during winter. Temperature affected the incubation period of cocoons. With increase in temperature, incubation period increased in the endogeic worms, Pontoscolex corethrurus, Polypheretima elongata and Drawida nepalensis and decreased in the epigeic worms, Perionyx excavatus and Dichogaster modiglianii, within a temperature range between 28-32 degrees C under laboratory conditions. There was a significant (P < 0.05) positive correlation between number of hatchlings per cocoon and incubation period in Lampito mauritii. High rate of cocoon production, short development time with high hatching success, as well as continuous breeding strategies in the epigeic species Perionyx excavatus and Dichogaster modiglianii and the top soil endogeic species, Pontoscolex corethrurus, Drawida nepalensis and Lampito mauritii, indicate their possible usefulness in vermiculture. The giant anecic worm, Eutyphoeus gammiei, which has a very long cocoon development time, discrete breeding strategy and very low rate of cocoon production, is not a suitable species for vermiculture.

The potential of two epigeic species (Eudrilus eugeniae Kinberg, and Perionyx excavatus Perrier) and two anecic species (Lampito mauritii Kinberg and Drawida willsi Michaelson) of earthworms was assessed in terms of efficiency and sustainability of vermicomposting water hyacinth (Eichhornia crassipes, Mart. Solm.). In different vermireactors, each run in duplicate with one of the four species of earthworms, and 75 g of 6:1 water hyacinth: cowdung as feed, vermicasts were produced with steadily increasing output in all the reactors. E. eugeniae was by far the most efficient producer of vermicasts, followed by the other epigeic P. excavatus. The two anecics came next, with D. willsi being the least effective which could generate only about half the quantity of vermicasts achieved in a corresponding time by E. eugeniae. In all the reactors, the earthworms grew well, increasing their weights by more than 250%. The maximum net gain of weight (average 30.7 g) was by E. eugeniae, followed by P. excavatus, L. mauritii and D. willsi. This trend, which followed the efficiency of vermicast production, was also shown in terms of reproductive ability as measured by the number of offspring produced by the four species.

The effects of sublethal concentrations of lead nitrate on growth and reproduction of the Asian composting earthworm species Perionyx excavatus was studied experimentally by exposing worms in an organic substrate to lead nitrate-contaminated food over a period of 76 days. The results revealed that growth was affected negatively by the presence of lead while maturation rate and cocoon production was not affected. In agreement with other studies on Eisenia fetida, cocoon viability was affected negatively by lead, making this a sensitive toxicity endpoint. Lead accumulation was of the same order of magnitude as for other previously studied species.

Background Epigeic earthworms are key organisms in organic matter decomposition because of the interactions they establish with microorganisms. The earthworm species and the quality and/or substrate availability are expected to be major factors influencing the outcome of these interactions. Here we tested whether and to what extent the epigeic earthworms Eisenia andrei, Eisenia fetida and Perionyx excavatus, widely used in vermicomposting, are capable of altering the microbiological properties of fresh organic matter in the short-term. We also questioned if the earthworm-induced modifications to the microbial communities are dependent on the type of substrate ingested. Methodology/Principal Findings To address these questions we determined the microbial community structure (phospholipid fatty acid profiles) and microbial activity (basal respiration and microbial growth rates) of three types of animal manure (cow, horse and rabbit) that differed in microbial composition, after being processed by each species of earthworm for one month. No differences were found between earthworm-worked samples with regards to microbial community structure, irrespective of type of manure, which suggests the existence of a bottleneck effect of worm digestion on microbial populations of the original material consumed. Moreover, in mesocosms containing cow manure the presence of E. andrei resulted not only in a decrease in bacterial and fungal biomass, but also in a reduced bacterial growth rate and total microbial activity, while no such reduction was found with E. fetida and P. excavatus. Conclusions/Significance Our results point to the species of earthworm with its associated gut microbiota as a strong determinant of the process shaping the structure of microbial communities in the short-term. This must nonetheless be weighed against the fact that further knowledge is necessary to evaluate whether the changes in the composition of microbiota in response to the earthworm species is accompanied by a change in the microbial community diversity and/or function.