Roundworms

12 Key excerpts on "Roundworms"

• 

  eBook - ePub

  Animals Without Backbones

  An Introduction to the Invertebrates

  • Ralph Buchsbaum, Mildred Buchsbaum, John Pearse, Vicki Pearse(Authors)
  • 2013(Publication Date)
  • University of Chicago Press

    (Publisher)

  Chapter 13

  Roundworms

  Most people are host at some time or other to the cylindrical worms called “Roundworms.” Many different species of parasitic Roundworms have been found in humans, but relatively few are common. Of these, some are harmless and do not even make their presence known, while others cause mild to very serious diseases. Besides these of immediate human interest, there are many economically important species that parasitize domestic stock and crops, as well as parasites of wild animals and plants, and an even larger number of free-living types. Free-living kinds feed on bacteria or on other small organisms in all moist soils and in the bottom sediments of oceans and freshwaters. Among both free-living and parasitic types are ones with activities beneficial to humans, such as recycling of soil nutrients and destruction of various agricultural pests. And one free-living soil species (Caenorhabditis elegans) has become a well-established laboratory animal; its genetic and developmental biology are known in more detail than for almost any other organism on earth and promise to contribute much to unanswered questions about the biology of all organisms, including humans.

  Many Roundworms look like animated bits of fine sewing thread; and from the Greek word for thread, nēma, has been derived the technical name of the group, phylum

  Nematoda

  . This is by no means a small or obscure phylum. More than 15,000 species have so far been described, and the actual number has been estimated at close to half a million. Nematodes are so abundant that a square meter of garden soil teems with millions of them. When we see a sick dog, our first guess is that it has more Roundworms than it can tolerate. And even in the best-regulated cities, Roundworms occur in the drinking water.

  Vinegar eels are nematodes. They used to be easily collected from any jar of vinegar, by taking a bit of the fine sediment in the bottom. There they lived together with the bacteria responsible for making vinegar from fermented apple juice, wine, or other alcoholic liquids, by converting the alcohol to sour acetic acid. These worms are harmless, except to the vinegar bacteria on which they feed, but one may look for them in vain in most modern distilled, filtered, or pasteurized vinegars. Turbatrix aceti,

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Soilborne pathogens

  • Urvashi Swami(Author)
  • 2020(Publication Date)
  • Delve Publishing

    (Publisher)

  At the larval stage, these flatworms can cause severe damage to the host. Apart from affecting the host, it may lead to an infection to the consumers of the already infected host. For instance, when a sheep if infected by the tapeworm and a human being consumes the mutton, the human may be affected by the tapeworm. These flatworms carry with them some parasites known as rat lungworm that causes some meningitis to human beings. Other people are allergic to the toxic substances thatare secreted by the flatworms (Hotez et al, 2006). 5.2.3 Nematodes Nematodes are structurally simple organisms that are tubular, that meaning has openings at both ends. i.e., mouth and anus. Nematodes are also referred to as Roundworms. They are classified under phylum Nematoda. They have digestive, nervous, excretory, and reproductive systems. Besides, they have no specified circulatory or respiratory systems. Nematodes are on the most numerous multicellular animals on earth. Nematodes are microscopic, and one may not be able to see them unless they use a microscope. With a hand full of soil, there are thousands of nematodes. Nematodes feed on bacteria and fungi. They can also feed on other nematodes. Due to this, most of the species encountered are not well understood biologically. Nematodes are naturally free-living. Even though most of them are not harmful, some nematodes cause diseases in both human beings and animals. Nematode Wuchereriabancrofti, for instance, is spread by mosquito bites. It damages the lymphatic system and produces large, debilitating swellings in different parts of the body. These swellings are referred to as elephantiasis. Other nematodes invent the human and animal stomach leading then to insufficient absorb nutrients. They can also destroy plants by boring some holes in the plant parts like the roots and stems. They can, in one way or the other, even cause a plant to dye.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Parasitology

  An Integrated Approach

  • Alan Gunn, Sarah J. Pitt(Authors)
  • 2022(Publication Date)
  • Wiley

    (Publisher)

  6 Nematode Parasites

  CONTENTS

  • 6.1 Introduction
  • 6.2 Class Enoplea
  • 6.2.1 Genus Trichuris
  • 6.2.2 Genus Trichinella
  • 6.3 Class Rhabdita
  • 6.3.1 Genus Strongyloides
  • 6.3.2 Genus Ancylostoma
  • 6.3.3 Genus Necator
  • 6.3.4 Genus Ascaris
  • 6.3.5 Genus Enterobius: Enterobius vermicularis
  • 6.3.6 Genus Toxocara: Toxocara canis
  • 6.3.7 Genus Anisakis
  • 6.3.8 Family Onchocercidae
  • 6.3.9 Family Dracunculidae: Dracunculus medinensis

  6.1 Introduction

  The nematodes belong to the phylum Nematoda, which is also known as the phylum Nemata. Somewhat paradoxically, the nematodes are simultaneously one of the most abundant, important, and yet neglected groups of metazoan animals. Some estimates suggest that there may be over 100 million species but fewer than 30,000 have been described. Nematodes occupy all terrestrial and aquatic ecosystems whilst one species, Halicephalobus mephisto, lives over a kilometre below ground in a gold mine in South Africa. In marine sediments, nematodes may constitute up to 95% of the organisms present and they are responsible for much of the benthic invertebrate biomass. Many nematodes feed on bacteria, fungi, or are detritivores, but there are also examples of predators and many are parasites of plants, invertebrates, and vertebrates.

  Most nematodes, especially the free‐living species, are microscopic in size, but some of those parasitic in mammals can be several centimetres in length, whilst some giants are over a metre long. For example, the females of Placentonema gigantissima, which lives in the placenta of sperm whales, can reach at least 8.4 m in length and 2.5 cm in width. Nematodes are very uniform in their appearance, and their thin, elongate, and cylindrical shape explains why they are commonly known as ‘Roundworms’. They lack a well‐defined head and have a worm‐like (vermiform) body that tapers at the anterior and posterior ends. The body is covered by a complex layered cuticle that is secreted by the underlying epidermis and is periodically shed during the juvenile stages to enable growth. The cuticle is proteinaceous but, unlike that of insects, it is not chitinous. Nematodes do, however, contain chitin, and it occurs in their eggshells, their pharynx, and in the sheath of microfilarial nematodes. In common with other higher invertebrates, nematodes are triploblastic and bilaterally symmetrical. That is, they have three primary germ layers during embryonic development, and the left side of their body is arranged the same as the right side. Although some nematodes have annulations (ridges around the body) on the surface of their cuticle there are no body segments and unlike the trematodes and cestodes they do not have suckers. Their body cavity takes the form of a pseudocoelom that contains fluid (haemolymph) at exceptionally high pressure and serves to maintain the hydrostatic skeleton. For example, the pressure within A. suum is 6.6–37.6 kN m−2 , which is considerably higher than that of other invertebrates with hydrostatic skeletons: in earthworms the pressure is only 0.28–2.8 kN m−2 . The high internal pressure necessitates the cuticle to be extremely strong and affects other aspects of nematode biology. For a more familiar comparison, typical values for human blood pressure would be 16 kN m−2 systolic and 11 kN m−2

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Biotechnological Approaches in Crop Protection

  • Prasad, D(Authors)
  • 2021(Publication Date)
  • Biotech

    (Publisher)

  Chapter 32 Biology and Life-Cycle of Economically Important Plant Parasitic Nematodes Kabindra Singh Rathour * and D. Prasad Division of Nematology, I.A.R.I., New Delhi – 110 012 The word ‘Nematode’ is derived from the Greek words- ‘nema’ meaning thread, and ‘oides’ meaning resembling or form ( i.e. threadworms). They are also known as Roundworms being tubular in shape and rounded in cross section. In USA they are often nick-named nemas and Britishers call them eelworms. Nematodes may be defined as triploblastic, bilaterally symmetrical, unsegmented, pseudocoelomate, vermiform metazoans with well developed reproductive, digestive, excretory, nervous and musculature systems and with lacking specialized organs for respiration and circulation. They have tubular gonads which open separately in females but join elementary canal in males to open through a cloacal aperture. Life-Cycle The life-cycle of plant parasitic nematodes start with eggs, the embryonic and post-embryonic stages. Generally, there are six stages in the life cycle– the egg, four larval or juvenile stages, and the adult male or female. The life cycle is simple and direct ( Figures 32.1A and 1B ). This ebook is exclusively for this university only. Cannot be resold/distributed. After a series of cell divisions (transverse and longitudinal), the 1 st stage larva (lacking of stylet) is formed. However, in the dorylaims ( Longidorus spp.; Trichodorus spp. and Xiphinema spp. etc.), a weak stylet is discernible. In majority of plant parasitic nematodes except the dorylaims, after embryogenesis the 1 st stage larva (J1) is formed and still enclosed within the egg-shell and it is the only second stage larva (J2) which normally emerges as the infective stage. In the dorylaim nematodes, the first stage larva itself emerges from egg followed by a quick moult in to second-stage larva.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Parasites of Medical Importance

  • A.J. Nappi(Author)
  • 2002(Publication Date)
  • CRC Press

    (Publisher)

  C hapter 7 General Morphology of Parasitic Nematodes Nematodes are unsegmented worms that typically are elongate and cylindrical in shape with tapered ends. Roundworms vary considerably in size from microscopic to over a meter in length. They possess a fluid-filled cavity or pseudocoel, and a complete digestive system comprised of an anterior mouth, a muscular esophagus (pharynx), an intestine, and a rectum that terminates posteriorly at the anus. The mouth may be surrounded by lips and a buccal cavity with cutting plates or teeth. Parasitic nematodes commonly feed on the semi-liquid contents of the host’s alimentary canal, intestinal mucosa, blood or other body fluids, and various lysed tissues. In some forms, the muscular esophagus is cylindrical and virtually of a uniform diameter throughout, and the parasite is termed filariform. This type of esophagus generally characterizes infective stage larvae. In certain other nematodes, the esophagus is expanded posteriorly into a valved bulb, and the parasite is termed rhabditiform (Fig. 1). The latter type frequently characterizes the free-living larval stages. Some nematodes have both filariform and rhabditiform stages in their life cycles. The body is covered by a non-cellular cuticle, which may exhibit longitudinal ridges, striations, wart-like structures, lateral expansions anteriorly and posteriorly, and spines. Before reaching sexual maturity, all nematode larvae undergo a series of four molts or ecdyses. Cuticular structures of some importance are amphids and phasmids. Amphids are a pair of minute sensory organs, considered to be chemoreceptors that open on each side of the head. Phasmids are a pair of caudal (post-anal) organs similar in structure to amphids. Some phasmids are glandular and serve an excretory function, while others are sensory and believed to be involved in chemoreception.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Principles of Veterinary Parasitology

  • Dennis Jacobs, Mark Fox, Lynda Gibbons, Carlos Hermosilla(Authors)
  • 2015(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  CHAPTER 6 Nematoda (‘Roundworms’) part 1: concepts and bursate nematodes

  1. 6.1 Introduction
  2. 6.2 Key concepts
     1. 6.2.1 Recognition features
        1. Surface structures
        2. Accessory sexual structures
        3. Head, mouth and associated structures
        4. Appearance in histological sections
     2. 6.2.2 General biology
        1. Feeding mechanisms
        2. Life-cycle
  3. 6.3 Bursate nematodes
     1. 6.3.1 Bursate superfamilies
        1. The ‘strongyles’
        2. General strongyle life-cycle
        3. General strongyle epidemiology
     2. 6.3.2 Trichostrongyloidea
        1. Important trichostrongyloids
        2. Ostertagia and Teladorsagia
        3. Haemonchus
        4. Trichostrongylus
        5. Nematodirus
     3. 6.3.3 Strongyloidea
        1. Important strongyloids
        2. Strongylus
        3. The cyathostomins
        4. Syngamus and Stephanurus
     4. 6.3.4 Ancylostomatoidea (hookworms)
        1. Important hookworms
        2. Ancylostoma
        3. Uncinaria
     5. 6.3.5 Metastrongyloidea (lungworms)
        1. General life-cycle
        2. Important lungworms
        3. Angiostrongylus
        4. Oslerus (Filaroides)
        5. Dictyocaulus
        6. Metastrongylus

  6.1 Introduction

  As most nematode Roundworms are tiny and unpretentious, they escape public attention and are generally ignored by wild-life filmmakers. Nevertheless, they are one of the most numerous and diverse metazoan life-forms on this planet. The great majority are free-living, with species adapted to virtually every habitable aquatic or terrestrial ecological niche. A small minority are parasitic on plants and an even smaller proportion exploit animals for part or all of their life-cycle. Even so, the number of animal parasitic nematodes can be daunting for the student. Luckily, a detailed knowledge of every pathogenic species is unnecessary. This is because closely related nematodes tend to have similar life-cycles, epidemiology, pathogenesis and drug susceptibilities. An appreciation of group characteristics therefore saves a lot of repetitive learning. In this context, the best taxonomic level for our consideration is the superfamily (with names ending in –oidea; see Section 1.2.2). This chapter and the next provide an overview of these shared traits and outline the biology of an illustrative selection of important nematode parasites within each category.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Nematology

  Concepts, Diagnosis and Control

  • Mohammad Manjur Shah, Mohammad Mahamood, Mohammad Manjur Shah, Mohammad Mahamood(Authors)
  • 2017(Publication Date)
  • IntechOpen

    (Publisher)

  Section 1 Recent Nematode Diagnostic Methods and Tools Chapter 1 Introductory Chapter: Nematodes - A Lesser Known Group of Organisms Mohammad Manjur Shah and Mohammad Mahamood Additional information is available at the end of the chapter http://dx.doi.org/10.5772/intechopen.68589 1. Introduction Nematodes are a group of lesser-known but the most abundant group of multicellular organ-isms on earth. They can be defined as a group of thread/worm-like, transparent, bilaterally symmetrical, pseudocoelomate and multicellular organisms that are free-living or parasitic to plants or animals. Numerically, they form the most abundant phylum within the meio- and mesofauna. However, for many of us, nematodes are something unseen and unheard. It is assumed to be due to their small size as well as their habit of remaining hidden in soil, water, plant and animal tissues. Nematodes, being ubiquitous, are associated with plants, insects, other invertebrate and vertebrate animals including domestic animals and even human beings. They exhibit different modes of life—parasitic (plant and animal), free-living, preda -tory, insect associates, entomopathogenic, terrestrial, aquatic (marine and freshwater) etc. The plant parasites may be migratory ectoparasites (feeding at different places but the body remaining outside of plant tissue) or migratory endoparasites (feeding at different places at the same time migrates inside the plant tissue) and some of them may be sedentary (in the forms with obese females like Meloidogyne sp.). Some are semiendoparasites (half of the body embedded in plant tissues while half remains outside), for example, Tylenchulus semipenetrans . 2. Brief history Our knowledge of animal parasitic nematodes is much more ancient than that of plant-parasitic and free-living forms. Animal parasitic forms were known to us as early as 1500 BC. Large round worm like Ascaris lumbricoides and the dreaded Guinea worm, Dracunculus medinensis , etc., were known at that time [1].

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Extraordinary Animals

  An Encyclopedia of Curious and Unusual Animals

  • Ross Piper(Author)
  • 2007(Publication Date)
  • Greenwood

    (Publisher)

  These upward wanderings are made easier when the host is sleeping and the worms don’t have to tackle gravity. In the sleeping, horizontal host, the worm will reach the throat and may head for the lungs or will crawl even further up and in to the ear and nose, causing a lot of damage. Sometimes, a slumbering person infected with these worms may awake to find an adult giant roundworm popping out of their nose or mouth. • At least 16,000 species of nematode have been identified, but there are many more yet to be identified. It is difficult to estimate how many species there are, but it is not in the realm of fiction to suggest that there may be a million different species. Nematodes are found everywhere, from the deepest ocean trench to the highest mountain, and from the miniscule spaces between the cells of a plant leaf to the gut of a grasshopper. Every- where! Not only are they found in every conceivable habitat, but they are also found in profusion. In one rotting apple, there may be as many as 90,000 nematodes belonging to a number of species, and in 1 sq. m of mud from the seabed, there may be well over 4 million nematodes. Since they are normally so small, they are often forgotten about, but they are instrumental in the functioning of entire ecosystems. • Although there are many free-living nematodes, they have turned parasitism into an art form. No animal or plant is safe from the depredations of parasitic nematodes. They display the whole range of parasitic interactions, from those species that are parasitic for only a small part of their life cycle to those species that have lived a para- sitic way of life for so long they require a number of hosts and complex transmission routes to complete their development. They are extraordinary! • The human giant roundworm is very closely related to the pig giant roundworm, but it is still unclear in which host this worm evolved.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Clinical Infectious Disease

  • David Schlossberg(Author)
  • 2015(Publication Date)
  • Cambridge University Press

    (Publisher)

  PART XXIV Specific organisms: parasites 195. Intestinal Roundworms 1250 Kathryn N. Suh and Jay S. Keystone 196. Tissue nematodes 1258 Thomas A. Moore 197. Schistosomes and other trematodes 1268 James H. Maguire 198. Tapeworms (cestodes) 1274 Zbigniew S. Pawlowski 199. Toxoplasma 1279 Roderick Go and Benjamin J. Luft 200. Malaria 1285 Jessica K. Fairley and Henry M. Wu 201. Human babesiosis 1295 Tempe K. Chen, Choukri Ben Mamoun, and Peter J. Krause 202. Trypanosomiases and leishmaniases 1302 Anasta´cio de Queiroz Sousa, Selma M. B. Jeronimo, and Richard D. Pearson 203. Intestinal protozoa 1313 Paul Kelly 204. Extraintestinal amebic infection 1318 Robert Huang and Sharon L. Reed 195. Intestinal Roundworms Kathryn N. Suh and Jay S. Keystone Nematodes (Roundworms) are the most common parasites infecting humans worldwide. Of almost half a million species of Roundworms, approxi- mately 60 are known to be pathogenic to humans. Among the most prevalent human infections are those due to the intestinal (lumen-dwelling) nematodes. Ascaris lumbricoides and Trichuris tri- chiura each infect over 1 billion people worldwide; hookworms (Ancylostoma duodenale and Necator americanus) infect almost the same number. Other important nematodes of humans include Strongyloides stercoralis and Enterobius ver- micularis. Coinfection, in particular with A. lum- bricoides and T. trichiura, is common. Ascaris lumbricoides, hookworm, and T. tri- chiura, collectively referred to as geohelminths (or soil-transmitted helminths), share the require- ment for eggs or larvae to mature in soil in order to be infective to humans. Due to this obligate soil stage of maturation, these parasites cannot be transmitted from person to person. In contrast, S. stercoralis is able to complete its entire life cycle within the human host, and like E. vermicularis, both person-to-person transmission and autoin- fection can occur.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Fauna in Soil Ecosystems

  Recycling Processes, Nutrient Fluxes, and Agricultural Production

  • Gero Benckiser(Author)
  • 1997(Publication Date)
  • CRC Press

    (Publisher)

  The gut is a simple tube from the esophagus to the rectum, and secretory glands are associated with the gut. Nematodes are normally bisexual but in some species, where males are rare or unknown or nonfunctional, reproduction is parthenogenetic. Sex determination is frequently influenced by environmental factors, including trophic influences. Nematodes are classified on the basis of morphological and anatomical features observed by light or electron microscopy, but identification is often very difficult even for experienced taxonomists. Molecular biological techniques, such as deoxyribonucleic acid (DNA) probes and use of monoclonal antibodies, show Nematodes 91 potential for diagnostic purposes and may be especially important in the future for the identification of pathotypes, or races, of economically important species. B. Economically Important Genera Sasser and Freckman (1987) reported that the eight most important genera of plant parasitic nematodes worldwide were Meloidogyne, Pratylenchus , Heterodera, Ditylenchus , Globodera , Tylenchulus, Xiphinema , and Radopholus , and the total estimated monetary loss of world crops due to nematodes was over U.S.$77 billion. The crops with the greatest economic loss worldwide due to nematodes are given in Fig. 4 together with the causal species of nematodes and a description of the damage symptoms. Only three of these are principal crops in European agriculture, and this is reflected in the different order of importance of the nematode genera in Europe: the cyst forming genera Heterodera and Globodera occupy the first two places, followed by Meloidogyne , Ditylenchus , Pratylenchus , Aphelenchoides , Xiphinema , and Trichodorus. Although other genera, such as Tylenchorhynchus , Paratylenchus, and Rotylenchus , are locally important when present in large numbers, the following descriptions of nematode biological characteristics will be based on the genera most influential on agricul­ tural production in Europe.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Parasitology

  • Jack Chernin(Author)
  • 2000(Publication Date)
  • CRC Press

    (Publisher)

  ■ The environm ent m ust provide easily digestible nourishm ent to satisfy the high level of egg production. ■ An interm ediate host — a mollusc — which presum ably provides som e selective advantage related to the enorm ous asexual reproduction that occurs within a die mollusc. Examples are Fasciola hepatica (the liver fluke; see section 7.5 .7 ) and Schistosoma spp (see section 7.5.4). 37 P A R A S I T O L O G Y • Figure 3.8 A nematode is a round cylindrical worm with a fluid-filled body cavity, the pseudocoel. At the anterior end is an opening, the mouth, that leads into the buccal cavity, the pharynx and then into the intestine which runs the length of the body. The gut ends in an opening, the anus, at the posterior end. ■ All nem atodes have a non-segm ented cylindrical body. They are triploblastic w ith a fluid-filled body cavity know n as a pseudocoelom e (not a true ceolom e). ■ They have both free-living and parasitic form s. The free-living form s inhabit fresh-w ater, m arine and terrestrial environm ents. M ost free-living form s are relatively small (only just visible to the naked eye). ■ Adult parasitic form s are found in both plants and animals. The adult parasitic form s range in size from m icroscopic to 10 cm plus. ■ 3.11.1 MORPHOLOGY A typical nem atode has an elongated cylindrical shape, limbless w ithout cilia and no respiratory organs (see Fig. 3.8). A typical nem atode has the following body openings: ■ A m outh at the anterior end. Slightly behind are small openings for the excretory organs — the amphids. ■ The female opening — a genital pore — midway along the body length. ■ N ear the posterior end is the anus, the rear opening of the alim entarycanal. ■ In the male the genital organ opens alm ost at same place as the anus. ■ 3.11.2 INTERNAL ANATOMY The internal structure of a nem atode consists of tw o ‘tu b es’, the alim entary canal and the reproductive organs, contained w ithin a fluid-filled cavity, the pseudoceolom e (see Fig. 3.9).

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Nematoda

  • Andreas Schmidt-Rhaesa(Author)
  • 2013(Publication Date)
  • De Gruyter

    (Publisher)

  Wilfrida Decraemer, August Coomans and James Baldwin 1 Morphology of Nematoda Nematode morphology forms the basis for understanding nematode development, function, behavior, evolution and relationships. Nematodes are apparently simple orga-nisms, but their similar appearance is deceiving as these animals possess amazing plasticity to adapt to a wide range of conditions and habitats. In the last decade, mor-phological studies have developed toward a more integra-ted approach, combining classical and modern tools and techniques, such as electron, confocal and 4D microscopy (Bumbarger et al. 2007, Ragsdale & Baldwin 2010), with information from molecular analyses and gene studies (Bert et al. 2008). Nematodes are generally described as small, non-segmented animals with typical thread-like bodies ( nema = thread in Greek). They are mostly translucent, allowing observation of their internal anatomy by light microscopy without dissection or sectioning. Nematodes possess an apparently simple and relatively conserved basic body plan that consists of an external cylinder (the body wall) and an internal cylinder (the digestive system), which are separated by a pseudocoelomic body cavity filled with fluid under pressure and containing a number of cells and other organs, such as the reproduc-tive tract. 1.1 General and external morphology 1.1.1 Size Free-living and plant-parasitic nematodes are usually smaller than 1 mm. The smallest free-living marine nematode species so far recorded was a female of Hapa-lomus minutus (Desmoscolecida), 82 μm long, that was described from a sandy beach in Togo, whereas the longest species is Cylicolaimus magnus (Leptosomati-dae, Enoplida), 21 – 34 mm long, first recorded from the English Channel. The shortest plant-parasitic nemato-des are less than 300 μm long ( Neopsilenchus minor , Tylenchidae), and the longest may grow up to 12 mm ( Paralongidorus epimikis , Longidoridae).

  Sign up to read

  Learn more about book