Octodrilus Complanatus Research Articles

The effects of earthworm species on organic matter transformations and soil microbial communities are only partially related to their bioturbation activity

Earthworms are pivotal in shaping soil ecological processes through their bioturbation activity and organic matter consumption. Earthworm species are known to have different impacts on soil structure, but only a small number of species have been studied so far, and few studies have examined how earthworms simultaneously affect soil functions. Here, we measured the impact of different earthworm species on soil structure (bioturbation function), carbon (C) and nitrogen (N) dynamics and the microbial community (organic matter transformation function), while exploring the links between these functions, across distinct soil compartments (surface casts, below-ground drilosphere, and bulk soil). Six earthworm species (Lumbricus terrestris, Allolobophora chlorotica, Octolasion cyaneum, Octodrilus complanatus, Aporrectodea caliginosa meridionalis and Microscolex dubius) of different ecological categories and functional groups were incubated in soil cores with soil and alfalfa litter for 6 weeks. Our results on the bioturbation function illustrated a great diversity of behaviors and confirmed the relevance of a functional classification based on bioturbation metrics. The main microbial hotspots were surface casts, whose characteristics allowed to distinguish two groups of species. Octod. complanatus, L. terrestris and M. dubius induced high humidity (respectively, +57, +48, +74%), high C (respectively, 19.9, 24.8, 33.2 g kg⁻1 dry soil) and N (respectively, 2, 2.3, 3.2 g kg⁻1 dry soil) content and microbial community selection, promoting C and N mineralization. The three other species had a lower impact. The below-ground drilosphere only showed specific characteristics in the case of L. terrestris. The effects of the studied species on the organic matter transformation function did not align with their bioturbation activities nor with their ecological category. These findings show that the contribution of earthworms to C and N turnover is only partially dependent on their bioturbation effects and suggest the usefulness of developing distinct functional groups based on the specific soil functions under consideration.

Structure and diversity of earthworm communities in long-term irrigated soils with raw effluent and treated wastewater

Abstract This study was conducted in two natural meadows: first, soils were irrigated with raw wastewater (SIRWW) and in the second, soils were irrigated with treated wastewater (SITWW). Earthworms were sampled in eight soil blocks spaced 10 m apart at each site. Earthworm community was characterized and compared using density, biomass, composition, structure, species richness, and diversity parameters. At both meadows, 459 earthworm individuals from two families and seven species were collected. The highest earthworm density and species richness were recorded at SIRWW. Nicodrilus caligenus was the most abundant species. Most of earthworm community parameters decreased significantly at SITWW. Only two species (N. caligenus and Octodrilus complanatus) were common between the two grasslands. Among the seven species identified at both meadows, four (Allolobophora longa, Eisenia foetida, Allolobophora rosea, Allolobophora chlorotica) were exclusively present in SIRWW, whereas a single species (Amynthas sp.) was characterized in SITWW. Three ecological earthworm groups (epigeic, endogeic, and anectic) were represented in SIRWW, with the dominance of endogeics. Further studies are needed to quantify pollution in this soils and the accumulation of pollutant load in earthworms. It is also important to highlight the relationship between the abundance and diversity of earthworms in these two ecosystems with soil biological activity.

Rameal Chipped Wood as a tool for soil temperature regulation

The objective of our work is to study the influence of Rameal Chipped Wood (FCW) and cattle manure in the presence and absence of earthworms Octodrilus complanatus on the regulation of soil temperature of a sandy loam soil. The study station is located in a semi-arid zone (Constantine, Algeria). The results obtained show that the contribution of FCW cattle manure in the presence and absence of earthworms Octodrilus complanatus has a beneficial effect on soil temperature.

Effect of Ramial Fragmented Wood amendments on the germination rate (%) of durum wheat

The presence of organic matter in agricultural soils is an important factor in assessing the conditions of the soils. BRF and Manure are energy inputs that can improve the soil. The objective of our work is to study the influence of the contribution of Rameal Fragmented Wood (RFW) and cattle manure in the presence and absence of earthworms Octodrilus complanatus on the germination rate (%) of durum wheat (Tritucum durum) of the Hedba 3 variety. The study station is located in a semi-arid zone (Constantine, Algeria). the results obtained show that the contribution of RFW or RFW mixture and cattle manure in the presence and absence of earthworms Octodrilus complanatus has a beneficial effect on the the germination rate increased by 193.35% on average in the amended plots compared to the control plots.

The influence of Ramial Fragmented Wood and manure on some physico-chemical parameters of a sandy loam soil in Constantine (Algeria)

The objective of our work is to study the influence of the contribution of Rameal Fragmented Wood (FRW) and cattle manure in the presence and absence of earthworms Octodrilus complanatus on some physicochemical parameters of a sandy loam soil such as porosity, carbon, nitrogen and C/N ratio. The study station is located in a semi-arid zone (Constantine, Algeria). The results obtained show that the contribution of FRW or FRW mixed with cattle manure in the presence and absence of earthworms Octodrilus complanatus has a beneficial effect on the studied physico-chemical parameters.

Effects of nitrogen fertilizers with two different inhibitors (urease and nitrification) on the survival and activity of earthworms (Octodrilus complanatus)

Effects of nitrogen fertilizers with two different inhibitors (urease and nitrification) on the survival and activity of earthworms (Octodrilus complanatus)

Spreading raw olive mill wastewater is compatible with the growth and the beneficial functions of the earthworm Octodrilus complanatus

Recycling Olive Mill Wastewater (OMW) by its application on agricultural land is considered to be a sustainable practice for soil enrichment and waste management, and recent legislation permits large scale OMW recycling in Mediterranean countries. Therefore, studies on the effects of OMW application on earthworms under experimental conditions that closely resemble those occurring in the field are urgently required to facilitate the safe and ecologically friendly use of OMW at large scale. In this study, the effects of three-phase OMW liquid on the survival and growth of the earthworm Octodrilus complanatus (Dugès, 1828), commonly present in olive groves, were assessed. The liquid was applied at a rate i) equal to the maximum authorized by Greek legislation for olive groves fertilization (80 m3 ha−1) and ii) half of this amount (40 m3 ha−1). The effects were tested in an indoor experiment conducted in plastic containers. The results showed no adverse effect on the survival of the earthworms over a period of 56 days post-treatment, at both application doses. The growth of earthworms, as estimated by their body weight change at 28 or 56 days post-treatment, was not negatively affected; instead, there was a relative increase seen at the higher dose (80 m3 ha−1), although the difference between the treatments was not significant. Qualitative observations indicated feeding of earthworms on the OMW liquids. Organic matter decomposition was not affected and there was no significant alteration in the soil properties, except the electrical conductivity that was increased at the higher level of OMW application. Therefore, the application of OMW liquids at the doses recommended by the legislation does not affect the survival and growth of the earthworms and is compatible with their activities to promote organic matter decomposition.

Anthropogenic disturbance and environmental factors drive the diversity and distribution of earthworms in São Miguel Island (Azores, Portugal)

We present an evaluation of earthworm fauna in São Miguel Island (Azores, Portugal) revealing that it is rich in species in relation to its size and nature. Four families (Acanthodrilidae, Lumbricidae, Megascolecidae and Rhinodrilidae), 15 genera and 27 species were inventoried. About 74% were Palearctic species and 26% were Intertropical, mainly invasive earthworms originating from South-East Asia, of which Amynthas corticis Kingberg, 1867 was most dominant. The first comprehensive checklist of São Miguel earthworms is detailed, and the outdated nomenclature is improved, unifying synonymous taxa such as Lumbricus azoricus Eisen, 1869 and Allolobophoridella eiseni Levinsen, 1884. Seven new earthworm species records are given, highlighting Lumbricus friendi Cognetti, 1904 and Amynthas diffringens Baird, 1869 as cited for the first time in Macaronesia, and therefore expanding their known geographic range to the northern border of this region. Moreover, richness and composition of species were evaluated in relation to environmental and anthropogenic characteristics, including soil properties, altitude, land use intensity or distance to urban nuclei. Our results demonstrated that soil pH affected the establishment of species and that organic matter is positively associated with abundance of some non-native lumbricids (e.g. the anecic Octodrilus complanatus Dugés, 1828) and negatively related to richness and abundance of exotic species such as Amynthas corticis, Amynthas gracilis Kingberg, 1867 and Pontoscolex corethrurus Müller, 1857. Results suggested that land use intensity, represented as five categories ranging from undisturbed sites with native vegetation to sites under intensive agriculture exploitation, is a good predictor of species composition. Higher values of diversity and density of Intertropical species were found in more intensively exploited locations. Moreover, the Palearctic lumbricids, although present in all the disturbance categories tested, were the most diverse group at higher altitudes. The species Dendrodrilus rubidus tenuis Eisen, 1864 and Lumbricus rubellus Hoffmeister, 1843, with narrow distribution range, showed a trend towards natural, non-intensive (NI) and low intensity (LI) systems. Our results indicate that anthropogenic disturbance and altitude are the main drivers of earthworm diversity on the island of São Miguel, making these animals good indicators for land use intensity. Therefore, earthworm surveys may help design conservation programs in protected areas.

Abundance and species richness of lombric macrofauna in a semi-arid forest ecosystem

The importance of earthworms for soils has evolved over time. Our study was conducted in the forest of Ouled yagoub (North East Algerian). Sampling at three different altitudes resulted in a total of forty-nine individuals (49) and only three species were identified: Octodrilus complanatus, Allolobophora molleri and Aporrectodea rosea. Spread over two ecological categories. The specific richness is higher in the site of 1400 m of altitude. The Simpson index (Is) varies between 0.44 and 0.49 for the three study sites. The Shannon index fluctuates between 0.41 and 0.74. The values of the Hill index vary between 1 and 1.5 in the three Sites.

Effects of different concentrations of glyphosate (Roundup 360®) on earthworms (Octodrilus complanatus, Lumbricus terrestris and Aporrectodea caliginosa) in vineyards in the North-East of Italy

The study aims to analyse the effects of the herbicide glyphosate (Roundup 360®) on three key earthworm species. The taxa collected from treated and untreated sites were subsequently bred in uncontaminated soil terraria with serial concentrations of the herbicide. The chosen taxa included two anecic (Lumbricus terrestris and Octodrilus complanatus) and one endogeic (Aporrectodea caliginosa) earthworms. Lumbricus terrestris collected from uncontaminated soil (Lt1) and in a conventionally managed vineyard (Lt2). Aporrectodea caliginosa and Octodrilus complanatus collected from the same uncontaminated site where L. terrestris (Lt1) were collected.Uncontaminated natural grassland soil filling the terraria was characterized for physical-chemical properties. The reproduction rate expressed in earthworms cocoon production was the measure for the effects on worms survival after 21 and 42 days of exposure to 0.59, 2.9, 5.79g/m2 of glyphosate, where the dose applied in vineyards in the North-East of Italy goes from 0.72g/m2 to 4.32g/m2.Earthworms in untreated terraria were found all alive, while specimens exposed to glyphosate (Roundup 360®) showed a decreasing survival rate and a sharp decline in the number of cocoons. L. terrestris (Lt2) showed a survival rate between 64% and 92% after 21 days, and between 44% and 76% after 42 days. L. terrestris (Lt1) showed a lower resistance to herbicide (survival rate: 36%–84% after 21 days and 12%–76% after 42 days). A. caliginosa was also affected (survival rate: 32%–76% after 21 days and 12%–68% after 42 days). Glyphosate demonstrated severe effects on Oc. complanatus, collected on non-contaminated soils, with the lowest values of survival rate (33% after 21 days and 7% after 42 days of exposure). A significant reduction in the cocoons number (about 70%) was observed for L. terrestris (Lt1) and A. caliginosa after 21 days of exposure, whereas L. terrestris (Lt2) showed about 50% of cocoon production.Results indicate the occurrence of some resistance mechanisms on anecic earthworms in vineyards that have been exposed to glyphosate for at least three decades.However in spite of the long period of application of glyphosate the impact of this largely applied herbicide is still serious (up to 26% of mortality) especially on the deep-burrowing earthworms species (Oc. complanatus and L. terrestris).

Effects of the herbicides benfluralin, metribuzin and propyzamide on the survival and weight of earthworms (Octodrilus complanatus)

Extended pesticide use might be of high risk for several non-target organisms like earthworms. Herbicides represent a major part of the total pesticides used; however, their effects on soil organisms have been only partially studied. The effects of the herbicides benfluralin, metribuzin and propyzamide at different rates on the survival and weight of earthworms (Octodrilus complanatus) were determined and compared in this study. Our results revealed significant effects of benfluralin, metribuzin and propyzamide on growth and survival of earthworms. Moreover, there was a significant effect of herbicide rate and time after treatment. For several herbicides, the highest weight reduction was obtained for double the recommended rate and was up to 70% compared to the untreated soil. This study highlights the importance of not exceeding the recommended rates of herbicides, while further studies in a range of conditions are certainly required.

Selection of focal earthworm species as non-target soil organisms for environmental risk assessment of genetically modified plants

By means of a literature survey, earthworm species of significant relevance for soil functions in different biogeographical regions of Europe (Atlantic, Boreal, Mediterranean) were identified. These focal earthworm species, defined here according to the EFSA Guidance Document on the environmental risk assessment (ERA) of genetically modified plants, are typical for arable soils under crop rotations with maize and/or potatoes within the three regions represented by Ireland, Sweden and Spain, respectively. Focal earthworm species were selected following a matrix of four steps: Identification of functional groups, categorization of non-target species, ranking species on ecological criteria, and final selection of focal species. They are recommended as appropriate non-target organisms to assess environmental risks of genetically modified (GM) crops; in this case maize and potatoes. In total, 44 literature sources on earthworms in arable cropping systems including maize or potato from Ireland, Sweden and Spain were collected, which present information on species diversity, individual density and specific relevance for soil functions. By means of condensed literature data, those species were identified which (i) play an important functional role in respective soil systems, (ii) are well adapted to the biogeographical regions, (iii) are expected to occur in high abundances under cultivation of maize or potato and (iv) fulfill the requirements for an ERA test system based on life-history traits. First, primary and secondary decomposers were identified as functional groups being exposed to the GM crops. In a second step, anecic and endogeic species were categorized as potential species. In step three, eight anecic and endogeic earthworm species belonging to the family Lumbricidae were ranked as relevant species: Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea longa, Allolobophora chlorotica, Lumbricus terrestris, Lumbricus friendi, Octodrilus complanatus and Octolasion cyaneum. Five out of these eight species are relevant for each biogeographical region with an overlap in the species. Finally, the earthworm species Ap. caliginosa (endogeic, secondary decomposer) and L. terrestris (anecic, primary decomposer) were selected as focal species. In the Mediterranean region L. terrestris may be substituted by the more relevant anecic species L. friendi. The selected focal species are recommended to be included in a standardized laboratory ERA test system based on life-history traits.

Effects of aluminum and moisture levels on aluminum bioaccumulation and protein content in the earthworm Octodrilus complanatus

Laboratory experiments were conducted to determine the effects of soil aluminum levels and moisture content on aluminum (Al) bioaccumulation and protein content in the earthworm (Octodrilus complanatus). The experimental design was a completely randomized block with 2 factors (aluminum content [C-0: 0 mg kg -1 , C-1: 1000 mg kg -1 , C-2: 2000 mg kg -1 , C-3: 3000 mg kg -1 ] and moisture level [M1: 100% of soil water capacity, M2: 60% of soil water capacity] and 3 replications. The lowest pH was noted in the C-0 treatment. There were no significant differences in the electrical conductivity, cation exchange capacity or total nitrogen in soil between the aluminum treatments. Moreover, there were no significant differences in soil properties between the moisture treatments. The highest soil Al content was noted in the C-3 treatment. No earthworm mortality was observed in soil contaminated with Al. Moreover, the highest aluminum content in earthworms was observed in the C-3 treatment. The aluminum content in the earthworms was significantly positively correlated with the aluminum content in the soil (r=0.984***, p<0.001). Our results indicated that the growth of earthworms was affected by the Al level. Lastly, Al caused a reduction in earthworm protein content.

The effects of farming practices on earthworm dynamics in olive groves of central Greece

We compared species richness, species composition, density and biomass of earthworm communities in organically and conventionally managed olive groves in central Greece. Earthworm biomass and density was significantly higher (p<0.05) in organic olive groves than in conventional olive groves. The highest species richness was recorded in the organic olive groves. Six species were recorded in total: Octodrilus complanatus, O. croaticus, Dendrobaena byblica, D. veneta, Aporrectodea caliginosa, and Microscolex phosphoreus. Only four of these were found in conventional olive groves, where D. veneta and M. phosphoreus were absent. The most abundant species were O. complanatus, D. veneta, and D. byblica.

The effect of crops and farming practices on earthworm communities in Soummam valley, Algeria

The response of earthworm communities to farming practices was assessed in 33 farms of the Soummam valley (Algeria). Market gardening was the most intensive practice with frequent tillage (94% farms), application of chemical (94%) and organic (70%) fertilizers and pesticides (70%). Orange tree plantations also received organic fertilization (42% of farms), NPK (95%), pesticides (71%) and tillage (95%) whereas in Olive plantations only 30% farmers used fertilizers and pesticide application was rare. Earthworm communities comprised 5 species: the ubiquitous Apporrectodea caliginosa, Aporrectodea rosea, Allolobophora chlorotica and Microscolex dubius and the native Octodrilus complanatus. Average density decreased from market farming areas (176 ± 27.6 ind m −2) to olive tree (149 ± 10.4 ind m −2) and orange tree plantations (73 ± 9.2 ind m −2). Biomass followed a slightly different order with a maximum of 44.0 ± 10.2 g fw m −2 in market farming areas followed by orange plantations (38.3 ± 8.0 g fw m −2) and olive plantations (35.6 ± 2.78 g fw m −2). Earthworm populations were comprised of 90% A. rosea and A. caliginosa. A. rosea favored market garden and olive systems while A. caliginosa did not show any clear preference. O. complanatus were abundant in market gardening sites with organic fertilizers whereas M. dubius was absent from orange tree plantations. Communities significantly covaried with farming practices and not with soil characteristics. In general, the density of all species was affected by intensification although the native species O. complanatus benefited from organic fertilization. Farming practices in the valley maintain rather high earthworm activities in spite of significant uses of chemical inputs. Further intensification might however affect these communities that showed clear sensitivity to all chemical inputs and tillage.

Collagen distribution in the tissue of the earthworm Octodrilus complanatus

Octodrilus complanatus (Lumbricidae) is a relatively large earthworm species widespread in the Hellenic territory and beyond. The main objective of our study was the histological description of O. complanatus and the determination of collagen distribution in its tissues. The histological study was carried out by means of hematoxylineosin staining in paraffin sections. The distribution of collagen was examined by histochemical techniques: CAB and Trichrom masson. The paraffin sections were examined by a light microscope after staining and the internal organs of the earthworm (alimentary canal, nervous, excretory, circulatory, and reproductive systems) were described. Most of the collagen was found in the cuticle, in the muscles under the epidermis and in the nervous system.

Contribution to the Knowledge of Pedofauna in Šumadija (Central Part of Serbia)

ABSTRACTIntensive investigations of some groups of soil fauna in Šumadija were permanent more than 20 years. This central part of Serbia, has an interesting geological history. It's interesting flora and fauna partially is result of continuous anthropogenic influences in the last centuries. In these investigations were included: (Insecta, Coleoptera), Lumbricidae (Oligochaeta), and Protura and Diplura (Insecta, Apterygota). The studieed ecosystems were natural (forests and meadows) and anthropogenous (orchards, gardens, fiels and artificial meadows). Earthworms from family Lumbricidae, were established 14 genera with 30 taxa and 6 new species for Šumadija: Dendrobaena alpina, Helodrilus cernosvitovianus, Octolasion cyaneum, Octodrilus complanatus, Serbiona serbica and Serbiona paratuleskovi. From the subfamily Cryptorhynchinae (Curculionidae) founded 5 genera, 12 species and three dominant species: Ruteria hypocrita, Echinodera behnei and Acallocrates colonnellii. New records of five weevils: Acalles (Acalles) aubei, Acalles papei, Acelles petryszaki, Echinodera behnei, Echinodera valida are given for Serbia. From Protura founded 3 families, 7 genera with 16 species, from Diplura founded 2 families which belong to 7 genera with 16 species.

Changes in bacterial numbers and microbial activity of pig slurry during gut transit of epigeic and anecic earthworms

In soils, organic matter decomposition and stabilization largely occur as a result of microbial activity, although when present, earthworms are important drivers of the processes through their interactions with microflora which begin during organic matter digestion by earthworms. Here, we studied the effects of gut transit on the number of bacteria and the microbial activity in pig slurry, using three epigeic ( Eisenia fetida, Eisenia andrei, Eudrilus eugeniae) and one anecic ( Octodrilus complanatus) species of earthworm. Bacterial counts revealed that the effect of gut transit on microbes differed depending on the earthworm species. Thus, no changes in the number of bacteria were found in the gut contents of E. fetida and E. eugeniae, whereas large decreases were recorded in those of O. complanatus and E. andrei (2.7 and 1.3 times, respectively). We suggest that, unlike in the three epigeic earthworm species, microorganisms are preferentially utilized by O. complanatus to meet its nutrient requirements, because of its limited digestive capacity. Despite the decrease in bacterial numbers, there were no differences in the gut contents of the four earthworm species or undigested pig slurry in terms of dehydrogenase activity. Therefore, we suggest that after gut transit in the four earthworm species under study the potential microbial degradation of pig slurry remains unaltered.

Life cycle of the earthworm Octodrilus complanatus (Oligochaeta, Lumbricidae)

The earthworm Octodrilus complanatus (Dugès, 1828) is a large-sized species often found in grasslands and pastures, with a wide distribution area in Europe and North Africa. In order to determine the characteristics of its life cycle, earthworms of this species were cultured from hatching until they reached maturity. Development rates, cocoon production, and incubation period were recorded under controlled conditions. On average, individuals of O. complanatus reared in isolation from hatching reached maturity at day 150 and body weight at maturity ranged between 6 and 8 g. The cocoon incubation period was 66 days, and only one individual hatched from each cocoon, with a mean hatchability of 55%. Reproductive rate showed by O. complanatus after mating was of 52 cocoons per earthworm per year. The results showed that the life cycle of O. complanatus was characterized by both low growth rates and low fecundity. Specific features in life history traits of O. complanatus were compared with those of species of the genus Octodrilus and other related earthworms. To cite this article: F. Monroy et al., C. R. Biologies 330 (2007).

Species richness and zoogeographic affinities of earthworms in Cyprus

A new survey taken in the East Mediterranean island of Cyprus showed an increase in the number of earthworm species (from the six recorded earlier to 16). These species belong to two earthworm families: Lumbricidae (15 species) and Acanthodrilidae (one species). The majority of these species are autochthonous (57–64%) and five to seven species (36–44%) were introduced. The autochthonous species are (i) endemic of the Levant ( Dendrobaena semitica), (ii) distributed in Anatolia and the Caucasus ( D. pentheri), (iii) distributed from Europe up to Anatolia ( Allolobophora nematogena, D. pantaleonis, Proctodrilus tuberculatus) (iv) distributed from Europe up to the Levant ( Murchieona minuscula), (v) distributed in the Transcaucasian region and in the East Mediterranean ( Helodrilus patriarchalis), or (vi) widely distributed along the Mediterranean basin ( D. byblica, Eiseniella neapolitana, and Octodrilus complanatus). The data obtained indicate that the Cypriote earthworm fauna is significantly richer in species than previously thought and that it has more zoogeographic affinities with the Anatolian fauna than with those of Levant.