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PubMedDate not supplied

An enkephalin-like molecule in earthworm coelomic fluid modifies leukocyte behavior.

Substances that were immunoreactive in an RIA specific for met-enkephalin were detected following HPLC fractionation of earthworm coelomic fluid. Earthworm coelomocytes and human granulocytes were analyzed for changes in conformation based on measurements of cellular area and perimeter and expressed mathematically by using the Form Factor (FF). For coelomocytes the FF decreased following exposure to DAMA, a synthetic enkephalin analogue (D-Ala2, Met5-enkephalinamide). DAMA stimulated migration whereas untreated cells and those exposed to the specific opiate blocker naloxone did not move. The enkephalin-like molecule when exposed to human granulocytes stimulated an increased number of activated cells. Our results suggest a relationship between the immune and nervous systems of earthworms.

Animals↗

PubMed1989

On the terrestrial toxicity of the fungicide imazalil (enilconazole) to the earthworm species Eisenia foetida.

The toxicity of imazalil (enilconazole), of its sulfate salt, and of a principal environmental transformation product to the earthworm species Eisenia foetida was determined. The 48-hr contact test and the 14-day artificial soil test as described by OECD guideline 207 were carried out. Concentrations of the parent substance in earthworm tissues at the end of the exposure in soil were determined by gas chromatography. The LC50 of imazalil was 12.8 micrograms/cm2 in the contact test and 541 micrograms/g in the artificial soil test. The LC50 values of the sulfate salt were 11.6 micrograms/cm2 and 532 micrograms/g, respectively. The transformation product had a LC50 of 108 micrograms/cm2 in the contact test, and the survival in the soil test exceeded 90%, even at levels of 1000 micrograms/g. Tissue levels of imazalil in surviving worms were always lower than the concentrations in corresponding soil. The LC50 values largely exceeded the levels expected after normal use. Therefore, the fungicide is not considered to be harmful to earthworms in the soil environment.

Animals↗

PubMed1991

Effect of pH and calcium on lead and cadmium uptake by earthworms in water.

pH and calcium are important as factors determining heavy metal bioavailability to soil organisms. To study their intrinsic effect without the influence of soil adsorption, earthworms (Lumbricus rubellus) were exposed to lead and cadmium in reconstituted water adjusted to various levels of pH and calcium chloride. Concentration of cadmium in worms increased linearly with increasing concentration of exposure independent of pH. Concentration of Pb in worms, however, showed a pH-dependent increase with increasing concentration of exposure. The uptake of both metals was positively influenced by increasing pH. Calcium reduced the uptake of Cd, but had no significant effect on Pb uptake. It is suggested that Ca2+ and H+ compete with lead and cadmium ions for binding sites in the earthworm, and that the affinity for Pb is much greater than that for Cd. The results are discussed in relation to available data on Pb and Cd accumulation by earthworms in soil, showing the predominant importance of soil adsorption processes.

Animals↗

PubMed1992

Comparison of sublethal and lethal criteria for nine different chemicals in standardized toxicity tests using the earthworm Eisenia andrei.

In this study, the effects of nine different chemicals on the survival, growth, and reproduction of the earthworm species Eisenia andrei were determined using a recently developed method. Earthworms were exposed for 3 weeks to the test chemicals in an artificial soil substrate. Additional data on the acute toxicity of these chemicals were derived from the literature. For some chemicals, cocoon production was the most sensitive parameter (cadmium, chromium, paraquat, fentin, benomyl, phenmedipham), while for others cocoon hatchability was most sensitive (pentachlorophenol, parathion, carbendazim). In the case of parathion, growth of the worms seemed to be even more sensitive than reproduction. As an overall parameter for the effect on earthworm reproduction, the total number of juveniles produced per worm appeared to be a useful parameter. Differences between (acute) LC50 values and the lowest NOEC value for effects on growth and reproduction were different for each chemical. Difference was greatest for cadmium (a factor of greater than 100) and smallest for fentin, benomyl, and pentachlorophenol (a factor of 5-6).

Animals↗

PubMed1988

Calcium-lead interactions involving earthworms. Part 2: the effect of accumulated lead on endogenous calcium in Lumbricus rubellus.

The calcium and lead burdens of tissue fractions of Lumbricus rubellus were quantified in 'native' animals from acidic and calcareous disused lead mines, and from control ('naive') animals exposed to lead-polluted soils under laboratory conditions. Most of the body burden of lead was accumulated within the posterior alimentary canal, and significant positive correlations were generally found between the calcium and lead burdens in this tissue fraction, which were evident in both the naturally and laboratory lead-exposed animals. The calcium:lead correlation is probably due to a proliferation of the calcium-rich, lead-sequestering chloragosome granules, and may thus be regarded as a specific tissue response to cellular lead incursion. No calcium-lead relationship was recorded in the rest (largely composed of the body wall) fraction of earthworms inhabiting the lead-polluted sites. However, a concomitant increase in calcium and lead in this tissue fraction of the laboratory lead-exposed control animals was noted. It is concluded that in naturally lead-exposed earthworms, the cells of this tissue fraction may be relatively resistant to the toxic effects of the metal. By contrast, it is apparent that a non-specific cytotoxic response by the cells of the rest of 'naive' animals occurs, as demonstrated by the concurrent increase in its calcium and lead burdens. These results suggest that a tolerance mechanism to lead, perhaps with a genetic basis, may exist in earthworms naturally exposed to lead.

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PubMed1993

Seasonal changes in the tissue-metal (Cd, Zn and Pb) concentrations in two ecophysiologically dissimilar earthworm species: pollution-monitoring implications.

Metal (Cd, Pb, Zn) concentrations and contents were measured each month for thirteen consecutive months in two ecophysiologically distinct earthworm species, sampled from the vicinity of a disused Pb/Zn mine. Aporrectodea caliginosa, an endogeic species, enters diapause during unfavourable conditions; Lumbricus rubellus, an epigeic species, does not enter diapause. Cd concentrations were higher in A. caliginosa than in L. rubellus throughout the year: Pb concentrations were also usually higher in the endogenic species. Zn concentrations were fairly similar in both species, except during Winter and early Spring, when L. rubellus has significantly higher concentrations. Analysis of covariance indicated that the concentrations of Cd, Pb and Zn varied significantly over the thirteen-month period in L. rubellus, but only the non-essential metals (Pb, Cd) varied significantly in A. caliginosa. During diapause (observed only in the July sample), tissue concentrations of Cd and Zn in A. caliginosa were significantly lower than in 'active' worms; Pb concentrations were significantly higher during diapause. Since diapause was accompanied by a significant decrease in dry body mass, it was concluded that Pb is retained by earthworm tissues during the resting phase; but Cd and Zn are actively eliminated from the tissues before or during diapause. The implications of these findings on the use of earthworms for monitoring the relative degrees of metal contamination at different sites are discussed.

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PubMed1995

Bioconcentration and biokinetics of heavy metals in the earthworm.

This study examines the steady state and non-steady state kinetics of five metals, cadmium, copper, lead, nickel, and zinc in earthworms. The steady state kinetics are based on field studies in which worms from contaminated and uncontaminated sites were collected and measurements were made of concentrations in the earthworms and soils. For each of the metals, evidence suggests that bioconcentration depends on the metal concentrations in the soil; bioconcentration is greater at lower soil concentrations. The studies of non-steady state kinetics involve uptake and elimination experiments in which worms are transferred from an uncontaminated soil to a contaminated soil (uptake studies) or from a contaminated soil to an uncontaminated soil (elimination studies). The voiding time is shown to be an important experimental variable in determining the measured levels of metal in earthworms because experimental measurements are usually made on a worm-soil complex (i.e. the soft tissue of the worm and the soil in the gut of the worm). Thus, for metals that are bioconcentrated in worm tissue, increasing the voiding period increases the concentration of the metal in the worm-soil complex. Conversely, for metals that are not bioconcentrated, increasing the voiding time leads to a decrease in concentrations in the worm-soil complex.

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PubMed1994

PB uptake by ecologically dissimilar earthworm (Lumbricidae) species near a lead smelter in south Finland.

The number of species and individuals, and the total biomass of earthworms decreased with decreasing distance from a lead smelter in southern Finland, as the Pb load of the soil increased. In soils highly polluted with Pb significant interspecific differences were found in the Pb concentration and the Pb concentration factor of lumbricids, whereas in slightly Pb polluted 'control' soils there were no significant interspecific differences. Near the smelter, the Pb concentration of the endogeic Aporrectodea caliginosa was higher than in the epigeic Lumbricus rubellus and L. casteneus. Pb concentration factors of these three species were lower in the highly polluted soil than in the 'control' soil, indicating that they were able to regulate their Pb accumulation. Contradicting these field observations, of the worms from the 'control' soil but reared in highly Pb polluted soil for up to 70 days, the epigeic L. castaneus, L. rubellus and Dendrodrilus rubidus took up more Pb than did the endogeic A. caliginosa and A. rosea. They also accumulated more Pb during the rearing periods than their counterparts permanently living in the highly Pb polluted soil, indicating that besides interspecific differences in Pb accumulation there seem to be intraspecific differences as well. Acclimatization and/or genotype differences can underlie earthworms' adaptation to Pb polluted soil, where they may have dissimilar physiological pathways to cope with high soil Pb concentrations. The amount of Pb rendered available to a local food chain by a population of earthworms will depend on the ability of the worms to accumulate Pb in their tissues, which in turn, is a function of the population's history of Pb exposure. Species such as A. caligonosa, which accumulate and continuously withstand high Pb concentrations in their tissues, are most appropriate for biomonitoring.

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PubMed1995

Earthworms and radionuclides, with experimental investigations on the uptake and exchangeability of radiocaesium.

The potential influence of earthworm activity on the mobility of radionuclides in soils and their subsequent availability for uptake by plants and transfer to higher trophic levels is briefly reviewed. The accumulation of caesium by the earthworm Aporrectodea longa from soil and from plant litter was investigated in laboratory experiments, as was the effect of reworking (through burrowing and ingestion) soil and soil with added organic material, on the extractability of caesium (ammonium acetate extraction). Soil was spiked with (134)Cs, organic matter with (137)Cs. In soil-fed worms, most of the radioactivity measured was eliminated with the gut contents; 5-25% of the ingested radioactivity was retained or assimilated. Loss of caesium from soil-fed worms followed a two component curve, with an initial rapid loss due to gut clearance (half-life of loss (Tb1/2) of about 0.2-0.6 days) and a slower loss of assimilated caesium (Tb1/2 of 15-26 days). Loss rates of assimilated caesium from worms fed on fragmented apple leaves were found to have half-lives of 18-54 days. Assimilation of caesium from apple leaves was higher than from soil, ranging from 55-100% of the activity measured before gut clearance. Dry weight transfer factors (concentration in worm tissue/concentration in substrate) for worms cleared of their gut contents were similar for the two substrates 0.04 and 0.04 for two loss experiments with worms fed on radioactive soil, and 0.03 and 0.05 for worms fed on apple leaves. After three months of reworking soil and soil/organic mixtures, A. longa was found to have no measurable effect on the extractable fraction of caesium. If earthworms have any subtle effects they were masked by changes in availability that occurred when the spiked soil and organic substrates were mixed together. Only about half of the extractable fraction in soil was recovered when soil was mixed with organic material suggesting that some of the labile fraction in soil had become complexed with organic material. This exchange occurred in substrate mixtures with and without worms. The limitation of chemical extraction procedures is discussed and suggestions for further work are presented.

Journal Article↗

PubMed1983

Methods for the assessment of the toxicity of environmental chemicals to earthworms.

In view of the impending publication of standards for earthworm toxicity testing by the Commission of the European Communities, a review has been made of the recent literature on earthworm toxicology. Relevant studies are reviewed from the standpoints of methods used, reproducibility of results, and ability to extrapolate laboratory results to field situations. Eisenia foetida, a commonly used test species, is much less sensitive to agricultural chemicals than other, native earthworms and is of doubtful utility for extrapolating laboratory data to field conditions, but when native soil organisms are used, such extrapolations show good general agreement. Standardization of test conditions and broadening of the data base are encouraged.

Benomyl↗

PubMed1984

Immunochemical evidence for met-enkephalin-like and leu-enkephalin-like peptides in tissues of the earthworm, Lumbricus terrestris.

The presence of met- and leu-enkephalin-like immunoreactive materials in nerve, gut, seminal vesicle and body wall tissues of the earthworm Lumbricus terrestris has been demonstrated by means of radioimmunoassay technique. The greatest activity of met- and leu-enkephalin-like immunoreactivity in earthworm gut appears in regions of high digestive enzyme activity and gastrin-like immunoreactivity where it presumably plays a role in regulation of gut function. In all tissues studied the levels of met-enkephalin-like immunoreactivity were higher than that of leu-enkephalin-like immunoreactivity. Dual localization of met- and leu-enkephalin-like immunoreactivity in earthworm gut and nerve tissues follows the pattern observed of peptide hormones in vertebrates which are common to both endocrine and non-endocrine tissues.

Animals↗

PubMed2005

Vermicomposting of Taro (Colocasia esculenta) with two epigeic earthworm species.

The bioconversion potential of two epigeic species (Eisenia foetida Sav. and Eudrilus eugeniae Kinberg) of earthworms was assessed in terms of efficiency and sustainability of vermicomposting of Taro (Colocasia esculenta (Linn) Schott in Schott and Endl). In different vermireactors, each run in triplicates with one of the two species of earthworms, and 60 g of 6:1 Colocasia:cowdung as feed, vermicasts were produced with steadily increasing output in all the reactors. E. eugeniae was found to be more efficient producer of vermicasts than E. foetida. In all reactors, the earthworms grew well, increasing their weights and number.

Animals↗

PubMed2005

Measuring bioavailability of polychlorinated biphenyls in soil to earthworms using selective supercritical fluid extraction.

If the release mechanisms during selective chemical extraction of persistent organic pollutants (POP) mimic release mechanisms in natural systems during biological uptake, then a selective non-exhaustive extraction could give a quantitative measure of the bioavailable POP fraction. Supercritical fluid extraction (SFE) is suggested as a possible technique to estimate the amount of bioavailable polychlorinated biphenyls (PCBs) at contaminated sites and hence serve as a new tool in risk assessment. The uptake of PCBs by earthworm (Eisenia foetida) was investigated. PCB contaminated soil was pre-extracted with selective non-exhaustive SFE (50 degrees C, 350 bar, 1h), which removed on average 70% of the individual PCBs. Earthworms were placed in this pre-extracted soil, as well as in untreated soil. After 10 days, the PCB uptake by earthworms in the two systems was compared. The bioaccumulation factor (BAF) was 83% lower in the pre-extracted system than in the untreated system, demonstrating that SFE extracts primarily bioavailable contaminants. From the data, the bioavailable fraction could also be calculated to be 75%, which is very close to the 70% removed by SFE under the applied conditions. This suggests that the chemical methodology is capable of measuring the bioavailable fraction very accurately in this system.

Animals↗

PubMed2004

Assessing 2,4,6-trinitrotoluene (TNT)-contaminated soil using three different earthworm test methods.

Within the scope of a phytoremediation project, the toxicity of 2,4,6-trinitrotoluene (TNT) contaminated soil (and its toxic metabolites) on earthworms was assessed. In addition to the standard acute and reproduction tests (ISO 11268), an avoidance response test was applied. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). At a concentration of 1142 mg/kg, TNT caused significant toxic effects in all test methods, but at lower test concentrations no significant acute or reproduction toxic effects could be observed. The avoidance response test, however, showed significant repellent effects at a concentration of 29 mg/kg TNT and therefore proved to be more sensitive than the other tests in this case. Results of the earthworm tests compared well with results of an ecotoxicological biotest battery. Thus, earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). Whereas higher concentrations of a pollutant can easily be assessed with the acute test (which requires lethal concentrations to show an effect), contaminated soils with lower (sublethal) pollutant concentrations require more sensitive test methods such as reproduction or behavioral tests in their risk assessment.

Animals↗

PubMed2005

Toxicity of chromium(III) and chromium(VI) to the earthworm Eisenia fetida.

The effects of Cr(III) and Cr(VI) on the survival, behavior, and morphology of the earthworm, Eisenia fetida, in water at pH 6, 7, and 8 and their toxicity in 10 different soils and an organic substrate have been assessed. A decrease in the pH of water resulted in increased toxicity of Cr to the earthworm. In water, both Cr species produced behavioral changes and morphological symptoms. The 48-h LC(50) values of Cr(III) at pH 6, 7, and 8 were 1.93, 2.55, and 2.78 mg/L, and those of Cr(VI) were 0.47, 0.61, and 0.63 mg/L, respectively. The 14-day median lethal concentrations (LC(50)) of Cr(III) and Cr(VI) for earthworm range from 1656 to 1902 mg/kg for Cr(III) and from 222 to 257 mg/kg for Cr(VI) in soil. In the organic substrate, the LC(50) values of Cr(III) and Cr(VI) were 1635 and 219 mg/kg, respectively. Stepwise multiple regression analysis predicted that clay content of soils accounted for 92% and 88% of the variation in the LC(50) values of Cr(III) and Cr(VI), respectively.

Animals↗

PubMed2006

Assessment of the effects of imidacloprid on the behavior of two earthworm species (Aporrectodea nocturna and Allolobophora icterica) using 2D terraria.

Earthworms are "ecosystem engineers" and changes in their main activities (creation of burrows and burial of organic matter) due to pollutants can have important effects on soil functions and indirectly on other components of the soil ecosystem. Using 2D terraria, we studied the behavior of two earthworm species (the endogeic Allolobophora icterica and the anecic Aporrectodea nocturna) exposed to sublethal concentrations (0.5 and 1 mg kg(-1) of dry soil) of imidacloprid, a widely used neonicotinoid insecticide. A second experiment was carried out to determine whether such imidacloprid concentrations were avoided by the two earthworm species we studied. In polluted soils, significant weight loss was observed in both species. No significant avoidance of imidacloprid was detected, whereas several modifications of the behavior were observed directly (burrowing dynamics, number of oscillations in the burrow system) or indirectly in the resulting burrow system architecture (area, topology, sinuosity maximal depth) according to the species and concentration tested. When exposed to imidacloprid (0.5 or 1 mg kg(-1)), A. icterica almost stopped burrowing after 24 h, whereas A. nocturna burrowed continuously but with a significantly lower rate compared to the control. Moreover, in both species, the burrow systems were always shallower when worms were exposed to imidacloprid. Since this last endpoint is easy to measure and is linked to water transfer in soils, it could be used in ecotoxicological studies provided it could be validated for a wide range of pollutants and concentrations.

Animals↗

PubMed2005

Early-phase immunodetection of metallothionein and heat shock proteins in extruded earthworm coelomocytes after dermal exposure to metal ions.

This paper provides direct evidence that earthworm immune cells, coelomocytes, are exposed to bio-reactive quantities of metals within 3 days after dermal exposure, and that they respond by upregulating metallothionein (MT) and heat shock protein (HSP70, HSP72) expression. Indirect support for the hypothesis that coelomocytes are capable of trafficking metals was also obtained. Coelomocytes were expelled from adult individuals of Eisenia fetida after 3-day exposure either to metal ions (Zn, Cu, Pb, Cd) or to distilled water (controls) via filter papers. The number of coelomocytes was significantly decreased after Cu, Pb, or Cd treatment. Cytospin preparations of coelomocytes were subjected to immunoperoxidase staining with monoclonal antibodies against human heat shock proteins (HSP70 or HSP72), or rabbit polyclonal antibodies raised against metallothionein 2 (w-MT2) of Lumbricus rubellus. Applied antibodies detected the respective proteins of E. fetida and revealed that the expression of HSP70, HSP72 and w-MT2 proteins was either induced or significantly enhanced in coelomocytes from metal-exposed animals. In conclusion, stress protein expression in earthworm coelomocytes may be used as sensitive biomarkers of metal contaminations. Further experimentation is needed for quantitative analysis of kinetics of metal-induced stress protein expression in earthworm coelomocytes.

Animals↗

PubMed2005

Earthworm responses to Cd and Cu under fluctuating environmental conditions: a comparison with results from laboratory exposures.

Laboratory toxicity tests are usually conducted under stable ambient conditions, while exposures in ecosystems occur in a fluctuating climate. To assess how climate influences the toxicity of Cu and Cd for the earthworm Lumbricus rubellus, this study compared effects for life-cycle parameters (survival, reproduction), cellular status (lysosomal membrane stability), gene expression (transcript of the metal binding protein metallothionein-2) and tissue metal concentration measured under outdoor conditions, with the same responses under constant conditions as measured by Spurgeon et al. [Spurgeon, D.J., Svendsen, C., Weeks, J.M., Hankard, P.K., Stubberud, H.E., Kammenga, J.E., 2003. Quantifying copper and cadmium impacts on intrinsic rate of population increase in the terrestrial oligochaete Lumbricus rubellus. Environmental Toxicology and Chemistry 22, 1465-1472]. Both metals were found to significantly influence earthworm reproduction, compromise lysosomal membrane stability and induce MT-2 gene expression in the outdoor system. Comparison with physiological and life-cycle responses in the laboratory indicated similar response patterns and effect concentrations for Cu. For Cd, lysosomal membrane stability and MT-2 expression showed comparable responses in both exposures. Juvenile production rate, however, gave different dose response relationships, with the EC-(50) in the outdoor test approximately half that in the laboratory test. A difference in Cd accumulation was also seen. Overall, however, the comparison indicated only a marginal effect of environmental fluctuations typical for northern temperate Europe on earthworm sensitivity to the two metals.

Animals↗