We have shown previously that stubby worms Allolobophora chlorotica are sensitive to environmental stress, including metal-polluted soil. In order to discern the mechanisms of this sensitivity, adult (clitellate) Al. chlorotica were exposed in the laboratory to soil samples soaked with water (control) or Ni (1 and 2 mg/kg), Zn (1.25 and 2.5 g/kg) or Pb (5 and 10 g/kg) chlorides. Worms avoided contact with metal contaminants by prolonging burrowing time in metal-soaked samples, especially in the case of lead. Higher concentrations of the investigated metals were lethal for worms. During a 3 week exposure to lower metal concentrations, nickel and lead readily accumulated in the bodies of worms while zinc was efficiently regulated. However, body weights and numbers of non-invasively retrieved free coelomocytes (consisting of amoebocytes and riboflavin-loaded eleocytes) were significantly lower only in zinc-exposed worms. We assume that zinc regulation in worm bodies is more energy-demanding than nickel or lead bioaccumulation, thus this might be responsible for inhibition of the body gain and diminution of immunocompetent cells in zinc-exposed earthworms. Alternatively, missing free coelomocytes may actually be involved in Zn trafficking and removal through nephridia and/or in the formation of multicellular brown bodies, since metal can unbalance host/bacteria relationships.

Eisenia andrei (Ea) and E. fetida (Ef) lumbricid earthworms are simultaneous hermaphrodites potentially capable of self-fertilization and hybridization. We have shown previously that reproductive isolation in these species is incomplete in Ea and Ef earthworms of French provenance, as viable offspring appeared in inter-specific pairs. Fertile asymmetric hybrids developed from Ea-derived ova fertilized by Ef-derived spermatozoa, as well as Ea or Ef specimens derived after self-fertilization (resulting from admixture of endogenously produced spermatozoa with sperm from a partner), but never Ef-hybrids from Ef-ova fertilized by Ea-spermatozoa. The latter appeared only in backcrosses of Ea-hybrids with the Ef. Here we show that these phenomena are not unique for French Ea/Ef earthworms, but are shared by earthworms from French, Hungarian, and Polish laboratory cultures. Semi-quantitative studies on fertility of Ea-derived hybrids revealed gradually decreasing numbers of offspring in three successive generations, more rapid in backcrosses with Ef than with Ea, and the absence of progeny in pairs of hybrids, despite the presence of cocoons in almost all pairs. Based on species specific mitochondrial and nuclear DNA sequences, we provide the first examples of two unique sterile hybrids with mitonuclear mismatch and potential mitonuclear incompatibility among offspring of one of the hybrid+Ef pairs. Earthworms from the investigated populations did not reproduce when kept from hatching in isolation or with representatives of Dendrobaena veneta but started reproducing upon recognition of a related partner, such as Ea, Ef or their hybrids. The existence of Ea or Ef specimens among offspring of hybrid+Ea/Ef pairs might be explained either by partner-induced self-fertilization of Ea/Ef or hybrid-derived ova, or by cross-fertilization of Ea/Ef /hybrid ova by partner-derived spermatozoa; the latter might contribute to interspecific gene introgression.

Earthworms can be used in the vermicomposting process. The success of the process depends on many factors, including the choice of the appropriate earthworm species. Eisenia fetida and Dendrobaena veneta are treated as "compost earthworms". They are characterized by a relatively short...

Lumbricidae play a key role in the soil environment as “the ecosystem engineers”. They participate in all the categories of services pro¬vided by ecosystems. In agricultural areas, the conventional intensive farming practices have led to a significant decline in the biological diversity of...

This paper presents the results of the process of vermicomposting waste biomass of littoral plants Typha latifolia, Iris pseudacorus, Ceratophyllum demersum in vermireactors, with the use of earthworms Eisenia fetida. It was observed that E. fetida may be used for rapid utilization of pure I. pseudacorus and C. demersum waste, but using the technology presented in this paper and the assumed observation time, it was not possible to recycle T. latifolia waste. Vermicomposts obtained were characterized by higher N, P, K, Ca, and Mg content compared to the initial plant biomass. The content of Cu, Mn, Zn, Cd, and Pb in vermicomposts did not exclude their application as a fertilizer. During vermicomposting of all littoral plants, the earthworm population was maintained up to day 70 of the experiment, with a slight decrease in their number (on average by 6%, p > 0.05), and since day 35, a significant loss in earthworm biomass was observed. The greatest loss of mean sum of biomass (49%, p < 0.05) was noted in a group of earthworms utilizing T. latifolia. The earthworms reproduced, with the greatest mean number (and the sum of biomass) of cocoons observed in a group of earthworms processing C. demersum. These values were greater by 32% and 38% respectively (p < 0.05), for the aforementioned characteristics of cocoons produced in the remaining experimental groups.

Departure from waste storage and maximisation of its utilization is currently the basis of modern waste management. This is favoured by the requirements defined in numerous legal instruments, including both EU directives and local regulations of member states. This also applies to organic waste,...