Nematodes

Vermicompost, a product of the composting system that utilizes earthworms for the decomposition of the biosolids and/or solid wastes is now considered in organic farming. But since it is applied in solid form, it is difficult for some plants to take up the nutrient contents. The liquid form is the vermi tea which facilitates the plants for fast absorption of the nutrients. The main objective of this study is to develop a vermi tea brewing machine taking into consideration system components and material specifications. Specifically, it aimed to establish the operating time of the machine and to evaluate its performance in terms of brewing efficiency and percent yield. The properties of the produced vermi tea were also evaluated. This is a developmental type of study which consists of development stage, preliminary testing stage and the performance testing stage. The vermi tea brewing machine comprised mainly of the cylindrical container, copper tubings, air pump, vermicompost container and support frame. During preliminary testing, the established machine's operating time was 24 hours. Performance testing of the machine resulted to 99.58% yield and the brewing efficiency was acceptable in terms of the dissolved oxygen after the process. Properties of the produced vermi tea were tested by accredited laboratories and resulted to ph of 4.23, total NPK of 0.033%, dissolved oxygen of 5.62 mg/L, total coliform of 4,500,000 CFU/ml, mold of 3,000 CFU/ml and yeast of 3,000 CFU/ml. These are acceptable values which indicated that it can be used to improve farming activities.

In this paper, Lagrangian coherent structure (LCS) concept is applied to wake flows generated in the up/down-stream of a swimming nematode C. elegans in an intermediate Re number range, i.e., 250-1200. It materializes Lagrangian hidden structures depicting flow transport barriers. To pursue the goals, nematode swimming in a quiescent fluid flow environment is numerically simulated by a two-way fluid-structure interaction (FSI) approach with the aid of immersed boundary method (IBM). In this regard, incompressible Navier-Stokes equations, fully-coupled with Lagrangian deformation equations for the immersed body, are solved using IB2d code. For all simulations, nematode's body is modeled with a parametrized spring-fiber built-in case available in the computational code. Reverse von-Kármán vortex street formation and vortex shedding characteristics are studied and discussed in details via LCS approach, including grid resolution, integration time and Reynolds number effects. Results unveil presence of different flow regions with distinct fluid particle fates in the swimming animal's wake and formation of so-called 'mushroom-shaped' structures in attracting LCS identities.

Fifteen chilli growing areas of Sindh (University of Karachi, Malir I, Malir II, Asoo Goth, Memon Goth I, Haji Ghafoor Goth, Memon Goth II, Gulshan-e-Iqbal, New Karachi, National Nematological Research Centre (NNRC, Univ. Karachi), Gadap, Ghotki, Khairpur, Larkana and Sukkur) were studied for soil and plant nematodes. Fifty two species (33 genera) of nematodes, including three new species (Helicotylenchus Siddiqii n. sp., Paratylenchus (P) karachiensis n.sp. and Bitylenchus. capsicumi n. sp.), were encountered during this survey. As evident from the literature survey, some 34 species were migratory ectoparasite. There were four endoparasite species. Bacteria / fungi feeders were five. There was one predatory carnivorous species (Mylonchulus sp.). There were three saprophytic species. Several of the ectoparasitic species were endoparasitic at their later stages of life. All Helicotylenchus spp. were obligatory parasites, Hemicriconemoides and Hoplolaimus species were obligatory root parasites. Ten species viz. Aporcelaimellus paracentrocercus, Acrobeloides sp., Cephalobus sp., Dorylaimus sp., Discolaimus sp., Ecuminicus monohystera, Geomonhystera sp. Moshajia sp. Mylonchulus sp. and Rhabditis sp. appeared to be free living bacteria. Rhabditis sp. was also entomopathogenic and Tylenchulus semipenetrans, a semi-endo-parasitic species. Frequency and density (abundance) of nematode species was highly variable from field to field and within a field. A substantial number of species (15 in number; c 29 % of the total species) occurred in one sample site each. Cephalobus sp. and Dorylaimus sp. occurred in 11 and 10 sites, respectively. By count, 48 species had less than 50% frequency in the sample sites. The mean density of a nematode species amounted to 15.93 ± 1.794 individuals varying by 81.74%. The nematode assemblage size of a site averaged to 200.67 ± 29.67 individuals per site. The population size varied greatly among the sites by 57.25%. The largest assemblage size build up was observed in Ghotki (415 individuals per 100g soil) followed by Sukkur (346). The population size was the lowest at Memon Goth (II). In other sites it ranged from 123 to 263 individuals per site. The number of nematode species recorded from various sites varied from 5 (Haji Ghaffor Goth of Malir) to 20 in another Malir field. The number of species per site averaged to 11.67 ± 1.18 varying substantially (CV= 39.22%). Different species were differentially successful. In 15 sites studied, on the basis of density, nine species of nematodes attained the rank of leading dominant, 12 species were second dominant and 11 species attained the status of the third dominant. Longidorus elongatus, was first dominant in two sites (University of Karachi and Ghotki), Acrobeles sp., a free living nematode was leading dominant in Malir, Memon Goth I and Gadap. And Cephalobus sp, another free-living nematode, was leading dominant in Haji Ghafoor Goth, Memon Goth II and Larkana chilli fields. Helicotylenchus siddiqii predominated in Malir, Tylenchorhynchus annulatus dominated in Gulshan-e-Iqbal, Rotylenchus reniformis in New Karachi and Xiphinema basiri and Acrobeloides sp. predominated in Asoo Goth (Malir) and Khairpur, respectively. Meloidogyne javanica was the leading dominant of chilli plants of NNRC (Karachi) and Sukkur. The structure and organization of the assemblages of different sites was simple as species diversity of the sites was low and the dominance concentration was high. On the basis of information theory function (H’), species diversity was comparatively higher in Sukkur, Ghotki, Gadap, Memon Goth and Malir I. Equitability was lower in Khairpur and maximum in Sukkur. The relative abundance pattern of the species in sample sites was geometric as was evident by the linear plots of densities on log scale. In present studies, Species richness appeared to control diversity relatively more than the equitability. The cluster analysis of the data indicated five discrete groups of the sites, on the basis of compositional similarity: Group A.: an agglomeration product of nine sites and comprised of four sites dominated by free-living Acrobeles sp., Cephalobus sp. with subordinates such as free-living Dorylaimus sp. or parasitic subordinates such as Tylenchorhynchus brassicae, Filenchus butteus in varying proportions. The other five sites were dominated by Longidorus elongatus in association of subordinate free-living Aphelenchoides sp., Helicotylenchus siddiqii, Tylenchorhynchus annulatus, T. brassicae, Rotylenchus reniformis or Filenchus filiformis. Group B: comprised of sites from NNRC (Karachi) and Sukkur. The dominant nematode species was Meloidogyne javanica in the two sites sub-ordinated by Tylenchorhynchus annulatus, Helicotylenchus pseudorobustus and a free-living species, Ecuminicus monohystera. Group C: comprised of two sites – Asoo Goth and Gadap dominated by Xiphinema basiri sub-ordinated by Meloidogyne incognita, Longidorus elongatus, Rotylenchulus reniformis and a free-living nematode, Acrobeloides sp. Group D: This was solely represented by the Khairpur site predominated by Acrobeloides sp, a free living species . Tylenchorhynchus tuberosus and Tylenchulus semipenetrans were the second and the third dominant species. Group E: represented by Ghotki site was predominated by three parasitic species – Longidorus elongatus, Aphelenchus avenae and Tylenchulus semipenetrans.

The bacteria Xenorhabdus nematophilus and Xenorhabdus bovienii, isolated from the entomopathogenic nematodes Steinernema carpocapsae and Stein-ernema feltiae respectively, were assayed against three stages of the insect Phaedon cochleariae (adults, larvae and pupae). The aim of this work was to assess the use of bacteria isolated from entomopathogenic nematodes (EPN) against insect in an attempt to propose new approaches of biocontrol insects. Experiments had the broad objective to investigate the mortality of P. cochleariae when exposed to the bacteria suspensions both in vivo and in vitro. High mortality was obtained in all experiments when the bacterial suspensions were applied to the insects. There was no significant difference between the mortality of the three different developmental stages of P. cochleariae, which indicates that the bacteria were high virulent to P. cochleariae. The mortality of P. cochleariae in vivo experiments was found to be lower than in vitro and the mortality in the assessment with X. bovienii in vivo was found higher than in X. nematophilus. In addition, a small experiment was carried out using Galleria mellonella larvae. The results from this experiment revealed the larvae of the larger G. mellonella took longer to die than the larva of P. cochleariae suggesting that body size is important. Also, it seems that bacteria isolated from entomopathogenic nematodes could be used successfully to control foliar insect pests.

Objective. The aim of this study was to investigate the relation among type and size of the farms related to the management of production and especially the presence and control of parasites. Materials and methods. To accomplish the above, 65 farms were used: 56 of semi-extensive system (cows in pastures), classified as low density farms (n=15, up to 15/cows), medium density farms (n=20; between 16-30/cows) and large density farms (n=21; over 31/cows). It was also included nine farms
freestall system (n=9; confinement, over 70 cows) as part of the study population. Results. In the farms visited for the study can be noticed that the farms that had the higher level of technological improvement in managements practice were properties in high level (3) and freestall (4). In most of the farms there were observed the presence of ticks and flies, regardless of density of farms. Feces samples collected from 650 cows (n=10/farm), and analyzed using McMaster showed that 191 cows were positive for parasites. The presence of antibodies in bulk milk tank occurred in 36 (55.38%; CI95% 42-67) to Neospora caninum of the studied farms. Conclusions. We also conclude that N. caninum is present in cattle herds in Western Santa Catarina, and may be linked to reproductive problems in cows.

A new nematode species, Capillaria plectropomi n. sp. (Capillariidae), is described from the intestine of the leopard coral grouper Plectropomus leopardus (Lacepède) from coral reefs off New Caledonia. The new species, belonging to the subgenus Neocapillaria Moravec, 1987, differs from other congeneric species of this subgenus from marine fishes mainly in the length (168–186 μm), shape and structure of the spicule. It is characterized, in the male, by the presence of two well-developed dorsolateral caudal lobes, a pair of lateral papillae, a heavily sclerotized spicule with many rough transverse grooves in the middle part, a spinose spicular sheath, and in the female, by eggs measuring 60–66 × 27 μm without protruding polar plugs. The buccal cavity contains a small finger-shaped stylet. Capillaria plectropomi n. sp. is the first known species of this genus parasitizing fishes of the perciform family Serranidae.

The Bermuda Principles for DNA sequence data sharing are an enduring legacy of the Human Genome Project (HGP). They were adopted by the HGP at a strategy meeting in Bermuda in February of 1996 and implemented in formal policies by early 1998, mandating daily release of HGP-funded DNA sequences into the public domain. The idea of daily sharing, we argue, emanated directly from strategies for large, goal-directed molecular biology projects first tested within the ''community'' of C. elegans researchers, and were introduced and defended for the HGP by the nematode biologists John Sulston and Robert Waterston. In the C. elegans community , and subsequently in the HGP, daily sharing served the pragmatic goals of quality control and project coordination. Yet in the HGP human genome, we also argue, the Bermuda Principles addressed concerns about gene patents impeding scientific advancement, and were aspirational and flexible in implementation and justification. They endured as an archetype for how rapid data sharing could be realized and rationalized, and permitted adaptation to the needs of various scientific communities. Yet in addition to the support of Sulston and Waterston, their adoption also depended on the clout of administrators at the US National Institutes of Health (NIH) and the UK nonprofit charity the Wellcome Trust, which together funded 90% of the HGP human sequencing effort. The other nations wishing to remain in the HGP consortium had to accommodate to the Bermuda Principles, requiring exceptions from incompatible existing or pending data access policies for publicly funded research in Germany, Japan, and France. We begin this story in 1963, with the biologist Sydney Brenner's proposal for a nematode research program at the Laboratory of Molecular Biology (LMB) at the University of Cambridge. We continue through 2003, with the completion of the HGP human reference genome,

Two little-known nematode species of the family Camallanidae, intestinal parasites of marine perciform fishes, are reported from off New Caledonia: Procamallanus (Procamallanus) annulatus Yamaguti, 1955 from the goldenlined spinefoot Siganus lineatus (Valenciennes) (Siganidae) and Procamallanus (Spirocamallanus) monotaxis (Olsen, 1952) from the longspine emperor Lethrinus genivittatus Valenciennes and the slender emperor Lethrinus variegatus Valenciennes (both Lethrinidae). Detailed light and electron microscopical studies (the latter used for the first time in these species) revealed some taxonomically important, previously not observed features, such as the presence of deirids, six crescent-shaped elevations surrounding the mouth, three poorly developed protuberances on the female tail tip and circumcloacal papillae and phasmids on the male tail in P. annulatus, and the presence of a circumoral flange, only 12 (instead of 14 reported) cephalic papillae, the shape of deirids and similar numbers (14 – 17 and 14 – 15) of spiral ridges in the male and female buccal capsules in P. monotaxis. The fourth-stage larva of P. annulatus is described for the first time. First stage larvae of both species were found to possess several digital processes at the tail tip. The present findings represent new host and geographical records of these parasite species.

How multiple, interacting components of complex soil communities assemble within forefields of receding glaciers is still largely unknown, especially at high-elevation sites (>5000 m a.s.l.) where plant succession is very slow. To examine succession of soil communities across different trophic levels, we investigated four major soil groups: bacteria, fungi, nematodes, and other non-fungal non-nematode microbial eukaryotes at the Puca Glacier in the Peruvian Andes spanning 9-, 24-, and 89-year-old deglaciated soils. This is the first study of microbial communities, other than bacteria, at a high-elevation chronosequence in the Andes Mountains. In addition, we characterized soil biogeochemical properties (e.g., C, N, moisture, and pH) and rates of microbial enzyme activities associated with C, N, and P acquisition. We found significantly correlated increases in estimated richness and high species turnover in all soil groups along the chronosequence. These shifts in soil communities were significantly correlated with microbial enzyme activities and measures of C, N, moisture, and pH. Stoichiometric comparisons of enzyme activities showed phosphorus (P) and carbon (C) limitation of microbial activity across the entire chronosequence with no hint of nitrogen (N) limitation. Taken together, the observed shifts in soil communities and biogeochemistry indicate coordinated increases in trophic complexity and ecosystem functioning during the initial 90 yr of microbial succession along the post-glacial chronosequence of the Puca Glacier.

Functional diversity can be defined as the distribution of trait values within a community. Hence, functional diversity can be an indicator of habitat filtering and a reliable environmental predictor of ecosystem functioning. However, there is a serious lack of studies that test how functional diversity indices change depending on the environmental conditions. The aim of this study is to provide such evidence by analyzing the distribution and variation of continuous body-mass values (i.e. functional diversity) and related shifts in body length and width in a nematode community. We used a large online dataset on nematode traits to analyze: (i) the distribution of body mass using three functional diversity indices, i.e. functional richness, functional divergence and functional evenness; (ii) the shifts in body-size traits (length and width); and (iii) the body-mass distributions of five trophic groups and of the entire nematode community. Managed grasslands exhibited the widest range of body-mass values while body-mass distribution in arable fields covered the greatest area in comparison to the other ecosystem types. The shift in body size revealed environmental filters that could not have been identified by the study of functional diversity indices per se. We found low values of functional evenness to be associated with high values of functional richness. We provide novel empirical evidence that body-mass distribution within a trophic group mirrors the effects of habitat filtering more than the distribution in the community as a whole. Hence, our trait-based approach, more than functional diversity itself, disclosed soil food-web structure and identified community responses.

Intraspecific variability was studied in Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 with the help of a Benzecri's factorial analysis of correspondences. Body shape and size can vary according to the type of humus in which the nematodes are living. Two morphometric characters (body and tail lengths) can be used to distinguish populations, thus like the other mononch Prionchulus punctatus, Clarkus papillatus can be considered as a good indicator of humus type differentiation. A seasonal variability also was demonstrated in several biotopes representative of each investigated humus type. Environmental and nutritional influences upon morphometric characters have been discussed.

Background: Sustainable use of our soils is a key goal for environmental protection. As many ecosystem services are supported belowground at different trophic levels by nematodes, soil nematodes are expected to provide objective metrics for biological quality to integrate physical and chemical soil variables. Trait measurements of body mass carried out at the individual level can in this way be correlated with environmental properties that influence the performance of soil biota. Results: Soil samples were collected across 200 sites (4 soil types and 5 land-use types resulting in 9 combinations) during a long-term monitoring programme in the Netherlands and the functional diversity of nematode communities was investigated. Using three commonly used functional diversity indices applicable to single traits (Divergence, Evenness and Richness), a unified index of overall body-mass distribution is proposed to better illustrate the application of functional metrics as a descriptor of land use. Effects of land use and soil chemistry on the functional diversity of nematodes were demonstrated and a combination of environmental factors accounts for the low functional value of Scots Pine forest soils in comparison to the high functional value of heathland soils, whereas human factors account for the low functional and chemical values of arable fields. Conclusions: These findings show an unexpected high functional vulnerability of nematodes inhabiting clay-rich soils in comparison to sandy soils and support the notion that soil C:N ratio is a major driver of biodiversity. The higher the C:N ratio, the higher the overall diversity, as soil nematodes cope better with nutrient-poor agroecosystems under less intense fertilization. A trait-based way focusing on size distribution of nematodes is proposed to maintain environmental health by monitoring the overall diversity in soil biota, keeping agriculture and forestry sustainable.

The reactions and behaviours of the nematode fauna in an acid mull of a deciduous forest (State Forest of Orleans, France) have been monitored for four years in the course of an experimental deprivation and doubling of annual litter supplies as well as of a deprivation of litter and rain-leaching arrivals. The deprivation of litter rapidly entails, from the year following the withholding, a regression in the density of the populations, firstly at surface (0-3 cm) then at depth (-3-10 cm), as well as a modification in the intensity of the two seasonal activity peaks. In contrast to the other trophic groups, the density of the plant feeder nematodes increases during the two years after the litter withholding. Furthermore, a different behaviour in the animal activity at the surface and at depth occurs. As part of the two-fold litter supply, in addition to a decrease of the density of the nematode fauna, we have observed an enhancement of the dominance of fungal feeder nematodes compared to bacterial feeder nematodes, a particular trend of the level (-1-3 cm) that behaves, in the beginning of the experiment, as a surface level (0-1 cm) then evolves like a depth level (- 3-6 cm and - 6-10 cm), thus emphasizing the surface-depth imbalance in the vertical animal distribution. Also we have pointed out an increase of the density of Cephalobidae and Plectidae contrarily to the other bacterial feeder nematodes. The experiment of litter and rain-leaching arrival deprivation has allowed us to give some elements of comparison in situ on the nematode resistance to a deficient soil hydric regime but also on the aptitude and rapidity of some species to react when the environmental conditions become favourable again; then the ecological significance of the behaviour of the colonizing bacterial feeder species is discussed. Referring to a previous experiment of litter supply withholding and literature data (clear-cutting soil acidification, nematode behaviour in desert soils) the authors draw attention to the role of the litter and the underground vegetative system on the maintenance of the biological activity and on the organization of the nematode populations. Furthermore the role of these animals as potential indicators of the environmental conditions is emphasized.

Grasslands, being one of most important ecosystems on earth, provide not only forage, livestock and fur, but also biodiversity and other ecosystem service functionalities. How to prevent grasslands from overgrazing, disertification, and other types of over-exploitation is a pressing issue. In recent years, grasslands have been dramatically changing as the changes of global climate and aggravation of human activities. Protection and reasonable use of grasslands are thus attracting more attention worldwide. This book provides researchers with diverse aspects of the latest advances in grasslands research. This book also covers a varied range of topics, for example, global biodiversity review, biotic interactions in the Rhizosphere, evaluation of soil quality, insect assemblages, orchard grass, soil microbial communities, grassland biodiversity management and soil nematodes.