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Introduction: 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. Materials and methods: Earthworm biomass and reproduction performance was tested in vermibeds with five different stocking density loads: 0.0680 mg cm (T), 0.1388 mg cm (T), 0.205 mg cm (T), 0.274 mg cm (T), and 0.342 mg cm (T). Results and conclusion: 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. [ABSTRACT FROM AUTHOR]

Abstract: Scientific knowledge of belowground biodiversity in the Himalaya, a biodiversity hotspot, is scarce. The aim of this study was to investigate density and biomass of earthworm populations and soil properties (texture, bulk density, organic C, total N and pH) in the full range of land use types viz., moderately degraded natural forests (MDNF), highly degraded natural forests (HDNF), rehabilitated forest land (RFL), traditional pure crop system (TPCS), traditional agroforestry system (TAS), abandoned agricultural land (AAL) and rehabilitated agricultural land (RAL) in a village landscape in Central Himalayan region of India. Of the 8 species present in the landscape, Amynthas alexandri and Metaphire anomala were the most widely distributed taxa, with the former absent only in RAL and the latter only in HDNF, while Bimastos parvus and Perionyx excavatus were confined to MDNF. TPCS and TAFS harboured the same species. AAL had only one (endogeics) and RAL all the three functional groups (endogeics, epigeics and anecics). All species except B. parvus showed a strong effect of season on population size, with the highest abundance and biomass values observed during rainy season. Only D. nepalensis and M. birmanica were a little bit abundant during dry season in TAFS. In the peak month of September, total density showed a trend of TAFS>TPCS>MDNF>RAL>AAL>RFL>HDNF (147, 132, 63, 27, 14, 8 and 5 individuals m−2, respectively) and biomass of TAFS>TPCS>MDNF>RFL>RAL>AAL>HDNF (266, 199, 51, 24, 21, 16 and 11gm−2, respectively). The study shows that (i) a change from TPCS to TAFS follows a substantial increase in earthworm density/biomass but not in species richness, (ii) TPCS/TAFS and MDNF host equal number of species but different species composition, with the former having much larger abundance than the latter, (iii) conversion of TPCS to AAL and of MDNF to HDNF cause drastic reduction in species richness and soil organic carbon (SOC), (iv) rehabilitation (change from AAL to RAL and HDNF to RFL) only partly recuperates SOC and earthworm fauna over a period of 20 years, (v) native species fail to survive in highly perturbed environment in HDNF and also in recuperating RFL but coexist with exotics in all other land use types, (vi) SOC explained around 60% of the variation in total density/biomass and (vii) heterogeneous landscapes with agriculture-forest mixed land uses are likely to support greater species richness than homogeneous agriculture/forest ones. Huge variability in land use histories, management practices and biophysical conditions warrant more research on spatio-temporal dynamics of earthworm communities and the linkages between belowground biodiversity, aboveground biodiversity and ecosystem functions. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Efforts have been made in this study to estimate the current status of earthworm biodiversity in western arid and semiarid lands of India. A total of 513 different locations (rural, urban, and sub-urban localities) covering both arid and semiarid areas were surveyed and 11 earthworm species: Perionyx sansibaricus (Perrier), Amynthas morrisi (Beddard), Metaphire posthuma (Vaillant), Lampito mauritti Kinberg, Dichogaster bolaui (Michaelsen), Octochaetona paliensis (Stephenson), Ramiella bishambari (Stephonson), Ocnerodrilus occidentalis Eisen, Malabaria sp, Allolobophora parva Eisen, and Pontoscolex corethrurus (Müller) belonging to five different families were rerecorded. A few earthworm species, e.g., L. mauritii, M. posthuma, O. occidentalis, and D. bolaui showed their presence in most of the sampling localities, while R. bishambari, Malabaria sp., A. parva, and P. corethrurus were restricted to a particular locality in arid land. Earthworm fauna of this region showed a patchy distribution pattern and the majority of the species were recorded from northern canal-irrigated and central alluvial plain belt (mid to eastern part) of the Thar Desert. Earthworm distribution and species-richness pattern were directly related to the local microclimatic factors and human activities. Thus, results suggested that human activities have been acted as important agency for invasion of earthworm communities in remote areas of western arid land of India. [ABSTRACT FROM AUTHOR]

Abstract: Physico-chemical and microbiological investigations were carried out on rumen content material composted for nine months, fresh vermicasts (obtained after passing the same compost through the guts of a mixture of three species of earthworms: Eisenia fetida, Lumbricus rubellus and Perionyx excavates) and microbially enhanced extracts derived from rumen compost, vermicast and vermicast leachate incubated for up to 48h. Compared to composted rumen contents, vermicast was only improved in terms of microbial biomass C, while vermicast leached extract was significantly higher in , humic acid, bacterial counts and total microbial activity compared to rumen compost extract. Although no difference between treatments was observed in genetic diversity as indicated by DGGE analysis, community level functional diversity of vermicast leached extract (Biolog™) was higher than that of composted rumen contents, vermicast and rumen compost extract indicating an enhancement of microbial activity rather than diversity due to liquid incubation. [ABSTRACT FROM AUTHOR]

Abstract: Effects of alphamethrin (0.04ppm, 0.08ppm, 0.16ppm, 0.32ppm) on some metabolic dehydrogenases and proteins for 1, 2, 3, 4, 8 and 16days using three ecologically different earthworm species (Perionyx sansibaricus, Lampito mauritii and Metaphire posthuma) were studied. The first significant effect was on 2nd/3rd day and maximum response was achieved on 16th day of exposure of alphamethrin at all concentrations. Similarly, maximum effect was obtained at 0.32ppm alphamethrin at different exposure periods. It showed a dose- and duration-dependent inhibitory effects of a pyrethroid on enzymes and proteins of earthworms. There were approximately 47%, 43% and 41% declines in specific activities of cytoplasmic malate dehydrogenase (cMDH) of P. sansibaricus, L. mauritii and M. posthuma, respectively, in response to 0.32ppm exposure of alphamethrin for 16days. In case of similar treatment, specific activities of mitochondrial malate dehydrogenase (mMDH) showed 57%, 51% and 45% reductions in epigeic (P. sansibaricus), anecic (L. mauritii) and endogeic (M. posthuma) earthworms, respectively. Exposure of alphamethrin (0.32ppm) also decreased the specific activities of lactate dehydrogenase (LDH) by 47% (P. sansibaricus), 35% (L. mauritii) and 39% (M. posthuma) in different types of earthworms. The reductions in specific activities of a Krebs cycle enzyme (mMDH) were greater than that of a glycolytic enzyme (LDH). The protein contents declined significantly in the earthworms exposed to alphamethrin. The decreases of 41%, 36% and 30% were obtained in cytoplasmic proteins of P. sansibaricus, L. mauritii and M. posthuma, respectively. However, the mitochondrial proteins showed reductions of 45% in P. sansibaricus, 46% in L. mauritii and 38% in M. posthuma in response to alphamethrin (0.32ppm) intoxication for 16days. The decrease in the protein content reflected an inhibitory effect of alphamethrin on protein turnover. The most pronounced effect of alphamethrin was on metabolic enzymes and proteins of P. sansibaricus and least effect was found on M. posthuma. This clearly showed that surface dwelling species of earthworms (epigeic) are more vulnerable to toxic chemical than deep burrowing species (endogeic). Thus a possible ecophysiological link exists between the toxicological responses and ecological categories at metabolic level in tropical earthworms. [Copyright &y& Elsevier]

A cris-cross review on vermicompost from agricultural wastes reveals that C-N ratio, pH, moisture content and temperature of the substrates are the most important parameters for proper vermicomposting as they determine the litter palatability in detrivorus earthworms. Feed material having C-N ratio less than 40 can be used successfully for vermicomposting. A temperature of 18 to 250C and moisture content of 40 to 60% were most congenial. Substrate treatment by bioinoculants and or addition of rock phosphate enriches the vermicompost through increase in the total nitrogen and available phosphorus and potassium content of vermicompost. Vermicompost prepared out of the mixture of crop residues amended with cow-dung in the ratio of 1:1 also exhibits higher nutrient content. Mixed culture of Eisenia foetida, Eudrilus eugeniae and Perionyx excavatus in vermicomposting shows higher multiplication rate of the worms. Cow-dung has widely been accepted as the best substrate provided its pH is below 9.5. Cereal and leguminous wastes, tree leaves and weeds are also found suitable while fresh poultry and pig manure and glyricidia stems are unsuitable. Vermicompost from obnoxious weeds like Eichhornia crassipes, Salvinia molesta, Lantana camara, Trapa sp. can be prepared with in 6 to 7 weeks with recovery of about 50 to 53%. Substrates containing 1 to 5% green leaves of leguminous trees can be suitably used for vermicomposting but poisonous plants or plants sprayed with insecticides are always fatal to the earthworms. Overall high rate of growth and reproduction of earthworms in the substrates are the best indicators of effective vermicomposting. Storage of vermicompost beyond 10 weeks decreases the microbial biomass, plant hormone concentration and enzyme activity. [ABSTRACT FROM AUTHOR]

Abstract: We present novel length to ash-free dry mass and preclitellar diameter to ash-free dry mass allometric equations for seven earthworm species from the families Megascolecidae and Lumbricidae, all of which are exotic and most of which are of ecological concern in North America: Eisenia hortensis, Eisenia fetida, Dendrodrilus rubidus, Lumbricus rubellus, Octolasion sp., Amynthas hilgendorfi, and Perionyx excavatus. We also present a length–biomass allometric equation for one enchytraeid, Mesenchytraeus sp. All relationships between length and biomass, and diameter and biomass were statistically significant at the species and family level (P<0.001). The predictive powers of these allometric regressions (as coefficients of determination, r 2) were species-specific, and ranged widely from 0.27 to 0.93. Length–biomass regressions provided more predictive power and precision overall than preclitellar diameter–biomass calculations at both the species and the family levels. An ANCOVA followed by orthogonal contrasts determined that, while the slopes of these regressions did not differ significantly between the two earthworm families, significant differences in slopes of length–biomass regressions existed among species within families, indicating the utility of having species-level equations for accurate biomass predictions. With these allometric relationships, we aim to improve the estimation of earthworm biomass in order to facilitate investigations of how exotic-invasive earthworm species impact soil ecosystems. [Copyright &y& Elsevier]

Abstract: Exposure of epigeic (Perionyx sansibaricus), anecic (Lampito mauritii) and endogeic (Metaphire posthuma) earthworms to four different concentrations (10ppm, 20ppm, 40ppm and 80ppm) of carbofuran for 16days induced specific activities of cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH) and lactate dehydrogenase (LDH). P. sansibaricus showed 33–52% increase in specific activities of aerobic (cMDH, mMDH) and anaerobic (LDH) enzymes and proteins (cytoplasmic and mitochondrial). In L. mauritii, the enhancement in enzyme and protein level was 30–46%. Similarly, M. posthuma indicated 29–43% increase in profile of enzymes and proteins. The significant increase was observed on 2nd or 3rd day and it was maximum on 16th day of carbofuran exposure. Maximum effect of carbofuran was on epigeic earthworm. The sensitivity of mitochondrial dehydrogenase and protein of different earthworm species to carbofuran appears to be associated with oxygen availability in different strata of soil habitats. Inductions in enzyme specific activity and protein content were concentration and time-dependent. The effect was more pronounced on aerobic enzymes (cMDH, mMDH) as compared to anaerobic (LDH) one. The increases in mitochondrial enzyme (47%) and protein (43%) were more than the cytoplasmic enzymes (35%) and protein (31%), which suggest a greater effect of carbofuran on respiratory metabolism of earthworms. The carbofuran-dependent increase in cytoplasmic and mitochondrial enzymes and proteins might be due to increased synthesis of metabolic enzymes and stress proteins. [Copyright &y& Elsevier]

Abstract: The effects of an organophosphate pesticide phorate on cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH), lactate dehydrogenase (LDH), supernatant and mitochondrial proteins of an epigeic (Perionyx sansibaricus), anecic (Lampito mauritii) and endogeic (Metaphire posthuma) earthworms were studied. The treatment of different concentrations (20, 40, 80 and 160ppm) of phorate for 16days gradually decreased the specific activities of cMDH, mMDH and LDH as well as cytoplasmic and mitochondrial protein contents. This showed the inhibitory effect of phorate on metabolic enzymes and proteins in tropical earthworms. The inhibition was dose- and time-dependent. The inhibitory response in mitochondrial enzyme (mMDH) and protein was somewhat earlier and more as compared to the inhibitory effect of phorate on cytoplasmic enzymes (cMDH, LDH) and protein. This indicates a greater interference of phorate in cellular respiration of earthworms. The phorate related decreases in enzyme and protein profiles were about 60% and 58% in P. sansibaricus, 54% and 49% in L. mauritii and 47% and 42% in M. posthuma, respectively. It reflects phorate-induced substantial decline in protein synthesis and aerobic and anaerobic capacity of earthworms. The maximum effect of phorate was on epigeic earthworm followed by anecic and endogeic species. The present findings suggest the differential sensitivity of different earthworm species in enzymatic and protein responses to phorate and the sensitivity was associated with the ecophysiological categories of earthworms. [Copyright &y& Elsevier]

Abstract: With the important infection of small ruminants by gastrointestinal nematodes, and in the face of reduced efficacy of anthelminthic treatments, a search for other biological options is necessary. The effect of earthworms on the free-living stages of Haemonchus contortus and Trichostrongylus colubriformis in faeces from goats naturally infected in tropical pastures was evaluated. Two levels (0 vs 14 individuals per container) of indigenous earthworms (50% Pontoscolex corethrus and 50% Perionyx excavatus) were added to containers filled with soil and faeces collected from 20 grazing goats. After 1 week, the numbers of free-living stages of each infective larvae species was measured. The addition of earthworms reduced by 34% (P <0.006) the number of infective larvae recovered in the faeces of goats. The reduction was significant for both larvae species, 29% and 33% for H. contortus and T. colubriformis, respectively. The ratio of the two species of larvae, without or with earthworms, did not vary significantly (P >0.21). These results must be confirmed in experiments on pasture, with other ratios and combinations of earthworms. [Copyright &y& Elsevier]

Reed beds (horizontal subsurface flow constructed wetlands) have been employed as secondary treatment devices in on-site and decentralised wastewater management systems in the northeast of the Australian state of New South Wales (NSW) for over a decade. This paper summarises some of the practical and research findings that have come to light in that time. Experience with various aspects of reed bed structure is discussed. A study of the evaporative performance of four small beds planted with Phragmites australis yielded an annual crop factor of 2.6. A total of 28 studies on reed beds treating a variety of commonly encountered wastewater streams yielded the following mean pollutant removal efficiencies: total suspended solids (TSS) 83%, biochemical oxygen demand (BOD) 81%, total nitrogen (TN) 57%, total phosphorus (TP) 35% and faecal coliforms (FC) 1.9 logs. The reed bed is becoming the preferred on-site technology for removing TN and BOD and polishing TSS from primary settled domestic wastewater. Sizing beds for a residence time of approximately five days has become standard practice. A study of six reed beds found six different species of earthworm present, mainly Perionyx excavatus (Indian Blue). A mesocosm experiment subsequently showed that the worms were translocating clogging material from the substrate interstices to the surface of the bed thereby indicating a possible method for prolonging reed bed life. [ABSTRACT FROM AUTHOR]

Abstract: Epigeics, such as Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus are humus-feeder earthworms which, in natural environments, mostly dwell in the humus and leaf litter lying over the top soil and have very shallow borrows. In order to make the most of this characteristic of the epigeics, we have simplified the design of epigeic-based vermireactors by doing away with layers of gravel, sand and soil, normally used for maintaining the other types (anecic and endogeic) of earthworms in the vermireactors. Instead, we have laid a moistened cotton cloth at the bottom of the circular vermireaction tank and have laid the feed over it. This arrangement provides the epigeics with a thin, moisture-rich, layer of solids beneath the humus-like compost used in the reactors as feed. The bottom layer mimics the moist soil below the mulch and humus which the epigeics use for their shallow burrows in natural environments. By doing away with the conventionally used elaborate vermibed, which used to take up ∼5% of the vermireactor volume in conventional systems, we have effectively increased the utilizable fraction of the reactor volume, thereby enabling a much higher feed throughput per litre of the reactor. Six month long operation of the conventional and the modified vermireactors in two concurrently run batches – one operating at low density of E. eugeniae and the other in high-rate mode – revealed that vermicast production per litre of reactor volume in both batches of modified reactors was dramatically higher than the output in the corresponding conventional reactors. [Copyright &y& Elsevier]

Biomass production and reproduction of tropical epigeic earthworms (Eisenia fetida, Perionyx excavatus, and Dicogaster bolaui) were studied using in-sit u vermicomposts to assess the suitability of different forest litters, i.e., Tectona grandis (teak), Madhuca indica (mahua), and Butea monosperma (palas) and crop residues, i.e., Triticum aestivum L. (wheat), Glycine max Merri. L. (soybean), and Brasica juncea L. (mustard) as food materials. The leaf litter of T. grandis and the wheat crop residue (T. aestivum L.) were found to be the most suitable food material for these earthworms. Comparisons of the survival and reproduction rate of three epigeic earthworms revealed that the higher reproduction rate was maintained in case of E. fetida compared to P. excavatus and D. bolaui in these vermicomposts. The progressive decrease in total organic carbon, C/N ratios, water-soluble carbohydrates, and biodegradability index was observed irrespective of treatments in the progressive stage of decomposition. The total organic carbon decreased significantly and C/N ratios narrowed down about 17 percent to 45 percent and water-soluble carbohydrates decreased to about 11 percent to 25 percent by the application of earthworms compared to control. Application of earthworms accelerated the decomposition of forest litters and crop residues, which ultimately resulted in larger cation exchange capacity/total organic carbon (CEC/TOC) ratios than their respective control values. The use of earthworm application accelerated the compost maturity in the order: T. grandis litter compost> wheat straw > Madhuca indica > B. monosperma > soybean straw > mustard straw compost. The lignin content of decomposed organic wastes increased with maturation, and comitant decrease of cellulose giving rise to higher lignin/cellulose ratios. Irrespective of earthworms inoculation, levels of available nutrient such as NH4-N, NO3-N and available P were increased significantly (p =<0.05). [ABSTRACT FROM AUTHOR]

The forest floor litter decomposition rate followed in the order: Tectona grandis (teak) > Madhuka indica (mahua) > Butea monosperma (palas). Higher decomposition rates were observed during rainy season and lowest during winter. The decay rate was significantly correlated with rainfall and soil moisture, and with population densities of earthworms. The lumbricid distribution under three plantations of semi-arid and sub-humid regions of central India in relation to several environmental factors including climate, soil moisture and litter quality was studied. Native species of earthworms and their densities were not abundant in this forest due to less moisture content in soil and accidental forest fires. Eight earthworms were identified and three of them were epigeic earthworms, viz., Eisenia fetida (Savigny), Perionyx excavatus (Perrier) and Dichogaster bolaui (Michaelsen), which were predominant throughout the year. [ABSTRACT FROM AUTHOR]

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 NH4-N, NO3-N, available P and K increased significantly (p&les;0.05) in the order T. grandis litter compost > M. indica litter compost > B. 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. [Copyright &y& Elsevier]

Abstract 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.

Maintaining genomic stability is inevitable for organism survival and it is challenged by mutagenic agents, which include ultraviolet (UV) radiation. Whenever DNA damage occurs, it is sensed by DNA-repairing proteins and thereby performing the DNA-repair mechanism. Specifically, in response to DNA damage, H2AX is a key protein involved in initiating the DNA-repair processes. In this present study, we investigate the effect of UV-C on earthworm, Perionyx excavatus and analyzed the DNA-damage response. Briefly, we expose the worms to different doses of UV-C and find that worms are highly sensitive to UV-C. As a primary response, earthworms produce coelomic fluid followed by autotomy. However, tissue inflammation followed by death is observed when we expose worm to increased doses of UV-C. In particular, UV-C promotes damages in skin layers and on the contrary, it mediates the chloragogen and epithelial outgrowth in intestinal tissues. Furthermore, UV-C promotes DNA damages followed by upregulation of H2AX on dose-dependent manner. Our finding confirms DNA damage caused by UV-C is directly proportional to the expression of H2AX. In short, we conclude that H2AX is present in the invertebrate earthworm, which plays an evolutionarily conserved role in DNA damage event as like that in higher animals. [ABSTRACT FROM AUTHOR]

The effects of varying temperatures (12 - 44° C) on the specific activity of cytoplasmic malate dehydrogenase ((cMDH), mitochondrial malate dehydrogenase (mMDH) and lactate dehydrogenase (LDH) of some earthworms (Metaphire posthuma, Perionyx sansibaricus and Lampito mauritii) were studied. The effects of different temperatures on supernatant and mitochondrial protein contents were also investigated. The specific activities of cMDH, mMDH and LDH of the earthworms decreased gradually as a function of increasing temperature from 12 to 44°C. Higher metabolic energy was needed to maintain the activity at low temperatures. Hence, the earthworms showed increased enzyme specific activity at low temperatures. However, the protein content increased upto 28°C. Afterwards, with the increase in the temperature from 28 to 42°C, the proteins in the earthworms showed a significant decrease. The temperature-associated changes in the protein content could be explained by the fact that protein synthesizing capacity was hampered above and below the optimum temperature range. The most pronounced effects of varying temperatures were on P. sansibaricus. It might be due to the epigeic nature of the earthworm species. Then minimum effect was on the endogeic earthworm M. posthuma. Virtually, the differences in the enzymes physiology were associated with the differences in the ecological categories of the earthworms. This clearly demonstrate a possible link between the physiology and ecology at aerobic (cMDH, mMDH) and anaerobic (LDH) levels in the tropical earthworms.

Highlights: [•] ATR FT-IR spectroscopy helps to analyze biomolecular profile of micro-samples. [•] It also analyses metabolites in the coelomic fluid of earthworms. [•] The spectral bands may serve as biomarkers for monitoring environmental pollution. [•] Each molecule can provide a unique spectral pattern through the entire IR spectrum. [ABSTRACT FROM AUTHOR]