Multiple mating increases cocoon hatching success in the earthworm Eisenia andrei (Oligochaeta: Lumbricidae)

In simultaneous hermaphrodites with reciprocal mating, multiple mating may be a male strategy that conflicts with female interests, and therefore an intra‐individual sexual conflict regarding the number of matings may be expected. The evolutionary outcome of this sexual conflict will depend on the costs and benefits that extra mating entails for each sexual function. In the present study, we investigated the costs and benefits of multiple mating on cocoon number, cocoon mass, and cocoon hatching success in the redworm Eisenia andrei, a simultaneous hermaphrodite with reciprocal insemination, by manipulating the number of matings with different partners. We did not detect any reduction in the female reproductive output (number and mass of cocoons) with increasing number of mating partners. However, we found that multiple mating showed benefits for female reproduction that increased the hatching success of the cocoons. This effect may be a result of increased quantity and/or diversity of sperm in the spermathecae of multiple mated earthworms. Further studies are required to clarify the mechanism underlying the increased cocoon hatching success when redworms engage in multiple matings. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Vermicomposting of tannery sludge mixed with cattle dung into valuable manure using earthworm Eisenia fetida (Savigny)

The present study revealed the role of earthworm in converting tannery sludge into a valuable product. Tannery sludge was toxic to earthworm, therefore it was mixed with cattle dung in different proportions viz. 0:100 (T₀), 10:90 (T₁₀), 25:75 (T₂₅), 50:50 (T₅₀) and 75:25 (T₇₅) on dry weight basis. The minimum mortality and highest population buildup of worms was in T₀ mixture. Nitrogen, sodium, phosphorus and pH increased from initial in the range of 7.3-66.6%, 16.90-70.58%, 8.57-44.8% and 2.8-13.65%, respectively. On the other hand potassium, organic carbon and electrical conductivity decreased in the range of 4.34-28.5%, 7.54-22.35% and 32.35-53.12%, respectively. C:N ratio decreased from 20.53% to 47.36% in the final products. Transition metals increased significantly from the initial value and within the permissible limit. The result indicated that vermicomposting with Eisenia fetida is better for changing this sludge into nutrient rich manure in a short period of time.     

Phoresy of the entomopathogenic nematode Steinernema feltiae by the earthworm Eisenia fetida

The free-living stage of entomopathogenic nematodes occurs in soil, and is an environmental-friendly alternative for biological control. However, their dispersal capability is limited. Earthworms improve soil characteristics, changing soil structure and influencing many edaphic organisms. Thus, earthworms could be used as vectors to introduce/disperse beneficial organisms. Nevertheless this interaction has not been studied in detail. This study presents the infectivity results of Steinernema feltiae after passing through the Eisenia fetida gut. Although entomopathogenic nematodes have no deleterious effects on earthworms, their passage through E. fetida gut seriously affected their mobility and virulence.     

Seasonal population dynamics of Eisenia fetida (Savigny, 1826) (Oligochaeta, Lumbricidae) in the field

In order to assess the response of epigeic earthworms to seasonal changes we monitored the population dynamics of Eisenia fetida (Oligochaeta, Lumbricidae) in a manure heap in the field during a year. Earthworms were hand-sorted from five 0.25 x 0.25 x 0.20 m blocks around the heap in November (autumn) 1999 and in January (winter), April (spring) and August (summer) 2000 to determine earthworm population dynamics. Earthworms of each block were classified into different age classes: mature, preclitellate, juvenile, hatchling and cocoon, and afterwards counted and weighed. Seasonality had a strong effect on the density, biomass and reproductive activity of the population. The population of E. fetida was characterized by a high density of individuals and the predominance of mature individuals throughout the year. Maximum density, mating activity and size of cocoons were achieved in spring, but there were not changes in the number of cocoons per mature earthworm throughout the year. Unexpectedly, the smallest cocoons were produced in winter by the largest individuals. These results suggest that E. fetida is able to allocate resources to growth and/or reproduction in response to environmental fluctuations.     

Evidence of lipofuscin and melanin in the brown body of the earthworm Eisenia fetida andrei

By means of histochemical and electron-microscopic techniques, two pigments were identified in the brown body of the earthworm Eisenia fetida andrei. Lipofuscin, often called the aging pigment, was the more abundant pigment and the first to be synthesized. Melanin was also found but was only present in the mature brown body. A computer-assisted image analysis was used to quantify the relative abundance of the two pigments at different stages of the formation of the brown body. A previous study showing phenoloxidase activity in the coelomocytes and the present demonstration of the ability of these cells to produce reactive oxygen systems when agglutinated can be correlated with the simultaneous presence of the two pigments in the brown body. The physiological significance of pigment synthesis by brown bodies is discussed with respect to the immune response in earthworms.     

Isolation of genomic DNA from the earthworm speciesEisenia fetida

Our interest in detecting genotoxic exposure in earthworms led us to isolate high quality DNA from theEisenia fetida species. For that, we compared a modification of the conventional phenol-chloroform extraction procedure, usually refered to as the Maniatis procedure, to two commercially available kits reportedly eliminating multiple partitions in phenol and chloroform, namely the Qiagen and Nucleon protocols. From the 260 nm optical density values, the commercial kits extracts hinted toward higher DNA recovery with those procedures. However, the 260/280 nm ratios indicated that the quality of the DNA isolated with the modified Maniatis procedure was purer than that isolated with the commercial kits, the latter being most probably contaminated by proteins and/or RNA. The Maniatis procedure was slightly modified by the introduction of a potassium acetate step for protein precipitation and by shortening the proteinase K treatment from 12–18 h to only 2 h. The higher quality of the DNA isolated by phenol-chloroform extraction was confirmed by quantification with the fluorescent 3,5-diaminobenzoic acid assay. Preliminary results suggest that the modified Maniatis procedure herein described is not only applicable for DNA adducts studies using³²P-postlabelling techniques but is also suitable for DNA extraction from other earthworm species such asLumbricus terrestris.     

Self-assemblage and quorum in the earthworm Eisenia fetida (Oligochaete, Lumbricidae)

Despite their ubiquity and ecological significance in temperate ecosystems, the behavioural ecology of earthworms is not well described. This study examines the mechanisms that govern aggregation behaviour specially the tendency of individuals to leave or join groups in the compost earthworm Eisenia fetida, a species with considerable economic importance, especially in waste management applications. Through behavioural assays combined with mathematical modelling, we provide the first evidence of self-assembled social structures in earthworms and describe key mechanisms involved in cluster formation. We found that the probability of an individual joining a group increased with group size, while the probability of leaving decreased. Moreover, attraction to groups located at a distance was observed, suggesting a role for volatile cues in cluster formation. The size of earthworm clusters appears to be a key factor determining the stability of the group. These findings enhance our understanding of intra-specific interactions in earthworms and have potential implications for extraction and collection of earthworms in vermicomposting processes.     

Enzyme Activities and Chemical Changes in Wet Olive Cake after Treatment with Pleurotus ostreatus or Eisenia fetida

A laboratory experiment was conducted to evaluate the enzyme activities and chemical changes recorded in a recalcitrant phenolic-rich waste after treatment with Pleurotus ostreatus or Eisenia fetida. The waste used was wet olive cake (alperujo in Spanish), a waste produced in huge amounts by the olive oil industry. Both P. ostreatus and E. fetida were very effective in removing phenolic compounds, the initial concentration in the wet olive cake being reduced in both cases by around 90%. Laccase and manganese peroxidase activities were measured in the growth medium of P. ostreatus, and catechol 2,3 dioxygenase activity was only detected in the waste treated with Eisenia; these could be the main factors responsible for the oxidation of phenolic compounds. Increases of dehydrogenase and β-glucosidase activities were detected in the degraded wet olive cake by fungi or earthworms. In comparison with the natural wet olive cake, the degraded products had lower total organic carbon and humic acid contents but were rich in nitrogen and other nutrients, having lower C:N ratios. In addition, the toxicity of the wet olive cake against the seeds of Lepidium sativum significantly decreased after degradation. The low toxicity as well as moderate stability and maturity recorded in the wet olive cake treated with P. ostreatus or E. fetida imply that these products could be used as soil amendments.     

Iodination activity in Eisenia foetida (Annelida,Oligochaeta)

Summary In the nervous system of the earthworm Eisenia foetida, we have previously found thyroglobulin-like immunoreactive neurons. In the present study iodination activity was investigated by injecting worms or incubating them in vivo with radioiodine; animals treated with methimazole (MMI), an inhibitor of peroxidase-catalyzed iodination, served as controls. Radioiodinated proteins were identified in soluble extracts from ¹²⁵I-incubated animals; the sedimentation pattern of soluble proteins from cephalic segments showed a peak of radioactivity in the 3–4 S region. In animals pretreated with 10^-3 M MMI for 48 h, ¹²⁵I-incorporation into soluble proteins from cephalic segments was drastically reduced. Light-microscopic autoradiographic studies showed silver-grains selectively concentrated in the brain and ventral nerve cord of ¹²⁵I-injected animals. The highest grain-density occurred in the cerebral ganglion beginning 5 min after tracer injection; the reaction product was mainly distributed between the neurosecretory cells and neuropile fibres in the zone of the presumptive plexiform neurohaemal complex. In MMI-pretreated animals the reaction product was not visible in either cerebral ganglion or ventral nerve cord. Of interest, the setae appeared consistently positive with or without MMI treatment. These observations indicate that protein iodination involving peroxidase occurs in the nervous system of earthworms and suggest that iodination mechanisms, other than peroxidase-catalyzed, may be operating in some scleroprotein structures such as setae.     

Eisenia fetida (Oligochaeta, Lumbricidae) Activates Fungal Growth, Triggering Cellulose Decomposition During Vermicomposting

Cellulose is the most abundant polymer in nature and constitutes a large pool of carbon for microorganisms, the main agents responsible for soil organic matter decomposition. Cellulolysis occurs as the result of the combined action of fungi and bacteria with different requirements. Earthworms influence decomposition indirectly by affecting microbial population structure and dynamics and also directly because the guts of some species possess cellulolytic activity. Here we assess whether the earthworm Eisenia fetida (Savigny 1826) digests cellulose directly (i.e., with its associated gut microbiota) and also whether the effects of E. fetida on microbial biomass and activity lead to a change in the equilibrium between fungi and bacteria. By enhancing fungal communities, E. fetida would presumably trigger more efficient cellulose decomposition. To evaluate the role of E. fetida in cellulose decomposition, we carried out an experiment in which pig slurry, a microbial-rich substrate, was treated in small-scale vermireactors with and without earthworms. The presence of earthworms in vermireactors significantly increased the rate of cellulose decomposition (0.43 and 0.26% cellulose loss day⁻¹, with and without earthworms, respectively). However, the direct contribution of E. fetida to degradation of cellulose was not significant, although its presence increased microbial biomass (C_mic) and enzyme activity (cellulase and β-glucosidase). Surprisingly, as fungi may be part of the diet of earthworms, the activity of E. fetida triggered fungal growth during vermicomposting. We suggest that this activation is a key step leading to more intense and efficient cellulolysis during vermicomposting of organic wastes.     

Description of the first endemic earthworm species from Cyprus (Oligochaeta: Lumbricidae)

New earthworm samples from Cyprus are assessed and discussed. A re-evaluation of specimens previously relegated to the Southern Alpine species Perelia nematogena (Rosa, 1903), revealed two independent species: Perelia phoebea (Cognetti, 1913 Cognetti, L. (1913): Escursioni zoologiche del Dr. E. Festa nell’Isola di Rodi V. Oligocheti. Bollettino dei Musei di zoologia ed anatomia comparata della R. Università di Torino, 28, 1–6. [Google Scholar]) ,described originally from Rhodes Island, (Greece) and an undescribed species Perelia makrisi sp. n. The new species is similar also to the Levantine Pe. galileana Csuzdi &; Pavlí?ek, 2005 and corroborates the hypotheses that the autochthonous earthworm fauna of Cyprus is of Levantine origin.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:FD1996DC-2FFC-42D5-A1D2-005B50E6FC64     

Neurochemical characterization of nervous elements innervating the body wall of earthworms (Lumbricus, Eisenia): immunohistochemical and pharmacological studies

The distribution and chemical neuroanatomy of nervous elements and certain pharmacological–physiological characteristics of the innervation of the body wall in earthworms are described. Solitary sensory bipolar cells can be found among the epithelial cells. These bipolar cells contain serotonin, tyrosine hydroxylase, histamine, gamma-amino-butyric acid (GABA), Eisenia tetradecapeptide, proctolin or rhodopsin in various combinations. In the body wall, the plexus submuscularis is composed of nerve fibres only, whereas the plexus subepithelialis and muscularis also contain solitary nerve cells. These cells display histamine, GABA or neuropeptide Y immunoreactivity. The fibres of the three plexuses are reactive to serotonin, histamine, Eisenia tetradecapeptide, proctolin, GABA and neuropeptide Y antibodies. FMRFamide-immunoreactive fibres of the plexus muscularis originate from the central nervous system, whereas axons containing the other studied molecules are derived from both peripheral and central structures. High pressure liquid chromatography assays have revealed serotonin, dopamine and histamine in the body wall. Contractions of the body wall musculature can be elicited with serotonin and FMRFamide. Serotonin-evoked contractions are suppressed by the application of GABA. Serotonin acts both directly on the muscle cell receptors and indirectly through initiating transmitter release from the nervous elements, whereas the FMRFamide-induced contractions seem to be mediated through the muscle cell receptors only. The pharmacological profiles of the serotonin and GABA receptors resemble those of the vertebrate 5-HT₃ and GABA_B receptor types. Our findings indicate that both the sensory and efferent system of the annelid body wall operate by means of a variety of neuroactive compounds, suggesting a complex role of signalling systems in the regulation of this organ.This work was supported by the Hungarian Scientific Research Fund (OTKA; grant nos. T 34106 and T 34160). Márta Wilhelm is in receipt of a János Bolyai Scholarship.     

Ranges and cold hardiness of two earthworm subspecies (Eisenia nordenskioldi, Lumbricidae, Oligochaeta)

The ranges of two earthworm subspecies, Eisenia nordenskioldi nordenskioldi (Eisen 1879) and E. n. pallida Malevi 1956, differ in area and partially overlap. E. n. nordenskioldi populates the entire Asian Russia and eastern regions of the Russian Plain, from the lower reaches of the Volga and Don rivers to the Arctic Ocean coasts, while E. n. pallida has not expanded to the Asian permafrost zone and does not occur in European Russia and in the Urals. These subspecies “hold the record” in cold hardiness: the worms and cocoons of the nominotypical subspecies withstand temperatures down to ?34 and ?40°C, and those of E. n. pallida, to ?28 and ?23°C, respectively. Hence, their distribution is independent of subzero temperatures, and their ability to overwinter at any phase of the life cycle makes them also independent of heat supply during the summer period. Differences in geographic range may also be due to biological features of the subspecies. The nominotypical subspecies feeds belongs to the epiendogeic morphoecological type (feeding on the ground surface), whereas E. n. pallida is a true endogeic earthworm. Both subspecies have similar requirements for soil acidity; however, conditions in coarse-humus organomineral horizons of frozen soils appear to be unfavorable for E. n. pallida, which accounts for the absence of this subspecies in the permafrost zone.     

Effects of chronic gamma irradiation on reproduction in the earthworm Eisenia fetida (Oligochaeta)

Eisenia fetida were exposed continuously to (60)Co gamma radiation during two generations (F(0) and F(1)). Adult F(0) reproduction capacity (i.e., number of cocoons produced, hatchability and number of F(1) hatchlings) in controls and at five dose rates (0.18, 1.7, 4, 11 and 43 mGy/h) was measured over a 13-week exposure period. Survival, growth and sexual maturation of F(1) hatchlings were observed for 11 weeks. F(1) adults were exposed for a further 13 weeks to determine their reproduction capacity. There was no radiation-induced effect on the cocoon production rate in either F(0) or F(1). For F(0), hatchability of cocoons produced during the first 4 weeks was reduced to 60% at 43 mGy/h (98% in controls), and none of the cocoons produced at 5-13 weeks hatched. At 11 mGy/h the cocoon hatchability was reduced to 25% at 9-13 weeks. In addition, the number of hatchlings per hatched cocoon was reduced at 11 and 43 mGy/h. Correspondingly, at these dose rates, the total number of F(1) hatchlings per adult F(0) was significantly lower than in the control. This number was also reduced at 4 mGy/h, but the effect was of borderline significance. For adult F(1), the hatchability of cocoons at 11 mGy/h was reduced to 45-69% during the 13-week exposure period. The number of hatchlings (F(2)) per cocoon and the total number of F(2) individuals produced was also reduced. However, and in contrast to the results observed for F(0), hatchability increased with time, suggesting a possible acclimatization or adaptation of the F(1) individuals. In conclusion, chronic irradiation reduced the reproduction capacity of E. fetida, but extensive exposure periods (13 weeks) were needed for these effects to be expressed. The lowest dose rates at which an effect was observed were 4 mGy/h in F(0) and 11 mGy/h in F(1).     

The species-area relationship of European Lumbricidae (Annelida,Oligochaeta)

Summary Studies throughout Europe reporting species lists of lumbricid earthworms and ranging from 100 m² to >500000 km² are analysed for the regression of species number S on size of area A [km²]. This species-area relation is described by: S=7.9*A ^0.09 (r=0.76).Revised version of a poster presented at the Wilhelm Michaelsen Memorial Symposium (International Symposium on Terrestrial Oligochaeta), Hamburg Sept. 14–18th 1987     

Evidence for the presence of thyroid stimulating hormone, thyroglobulin and their receptors in Eisenia fetida: a multilevel hormonal interface between the nervous system and the peripheral tissues

The present study describes the localization and distribution of thyroid-stimulating hormone (TSH), thyroglobulin (TGB) and their receptors in Eisenia fetida (Annelida, Oligochaeta) as revealed by immunohistological methods. Immunopositive neuronal and non-neuronal cells are present in both the central nervous system and some peripheral organs (e.g. foregut and coelomocytes). TSH- and TGB-immunopositive neurons in the various ganglia of the central nervous system are differentailly distributed. Most of the immunoreactive cells are found in the suboesophageal ganglion. The stained cells also differ in their shapes (round, oval, pear-shaped) and sizes (small, 12–25 μm; medium, 20–35 μm; large, 30–50 μm). In all ganglia of the central nervous system, TSH-positive neurons additionally show gamma aminobutyric acid (GABA) immunopositivity. Non-neuronal cells also take part in hormone secretion and transport. Elongated TSH-positive cells have been detected in the capsule of the central ganglia and bear granules or vacuoles in areas lacking neurons. Many of capillaries show immunoreactivity for all four tested antibodies in the entire central nervous system and foregut. Among the coelomocytes, granulocytes and eleocytes stain for TSH and its receptor and for TGB but not for thyroid hormone receptor. Most of the granulocytes are large (25–50 μm) but a population of small cells (10–25 μm) are also immunoreactive. None of the coelomocytes stain for GABA. We therefore suggest that the members of this hormone system can modify both metabolism and immune functions in Eisenia. Coelomocytes might be able to secrete, transport and eliminate hormones in this system.This work was supported by the MTA-PTE Adaptation Biology Research Group and National Research and Developmental Fund (NKP 1/048/2001). M.W. is in receipt of a János Bolyai Scholarship.     

Characterization of two endoglucanases for the classification of the earthworm,Eisenia fetida Waki

Eisenia fetida and Eisenia andrei are vermicomposting species that are used as model animals for testing chemical material toxicology. Eisenia spp. are grown commercially in various fields in Japan. However, these two species have not been classified because it is difficult to distinguish them morphologically; thus, all bred earthworms are called E. fetida. However, it has been proposed that these two species have different expression regulation mechanisms. Here, we classified a sample of earthworms purchased from several farms, confirming that both E. fetida and E. andrei are present in Japanese earthworm breeding programs. We also characterized two highly active endoglucanases (EfEG1 and EfEG2) from the E. fetida Waki strain, which contained strong fibrinolytic enzymes for improving human health. We confirmed that EfEG1 is 1371 bp long and belongs to GHF9. Thus, E. fetida Waki may have commercial application for biomass utilization and as a dietary health supplement.     

Reorganization of the GABAergic system following brain extirpation in the earthworm (Eisenia fetida,Annelida, Oligochaeta)

The reorganization of the GABAergic system was studied by means of immunohistochemistry after the symmetrical and asymmetrical (unilateral) extirpation of the brain of the annelid Eisenia fetida. GABA-immunoreactive neurons were first observed in the wound tissue on the 3rd postoperative day. Thereafter the number of labelled cells gradually increased, and by postoperative days 76-80 all GABA-immunoreactive cells (approx. 140 neurons) could be found in their final positions in the symmetrically regenerated brain. After asymmetrical brain extirpation, nearly all cells (70-75) could be detected in the regenerating hemisphere by postoperative days 50-56. In the early stages of the asymmetrical regeneration of the brain, more GABAergic cells were concentrated dorsally and laterally in the preganglion than during the symmetrical type of regeneration. In both types of regeneration, the immunoreactive neurons in the regenerated brain originated in part from undifferentiated neuroblasts situated in different parts of the body, and in part from dividing neurons localized mainly in the pharyngeal nerve plexus. Both exogenous GABA and picrotoxin, applied during the early stages (days 10- 12) of brain regeneration, inhibited the development of the wound tissue and the migration of the neuroblasts and the enteric neurons. At the same time, exogenous GABA application accelerated the proliferation of the pharyngeal neurons. No effect on the process of regeneration could be demonstrated when exogenous GABA and picrotoxin were given together.