Platyhelminthes and Nematoda

Total Page:16

File Type:pdf, Size:1020Kb

Platyhelminthes and Nematoda The Phylum Nematoda Members of this phylum are referred to as roundworms. They have long, thin bodies that are tapered at both ends. Roundworms are pseudocoelomates. They have a “false” coelom. It is a hollow, fluid filled body cavity, but is only partially lined with mesoderm tissue. Roundworms have a “tube within a tube” digestive system: The digestive system has two openings: a mouth and an anus. Food enters the mouth and wastes leave the body through the anus. Examples of Roundworms Include: Ascaris Hookworms Trichinella Pinworms Ascaris Where is this worm commonly found? Ascaris lives in the intestines of pigs, horses, dogs, humans, etc. What happens if Ascaris becomes too numerous in the host? They can completely A female can block the produce 200,000 intestine of eggs per day. the host. Hookworms The hookworm’s mouth has cutting hooks that clamp to the intestinal wall of the host. Hookworm’s feed on the blood of the host. The larva live in the soil. They enter a host by boring through the bottom of the feet. Trichinella Trichinella species are the smallest nematode parasite of humans, have an unusual lifecycle, and are one of the most widespread and clinically important parasites in the world. The small adult worms mature in the intestines of a definitive host such as a pig. Each adult female produces batches of live larva, which bore through the intestinal wall, enter the blood (to feed on it) and lymphatic system, and are carried to striated. Once in the muscle, they encyst, or become enclosed in a capsule. Humans can be infected by eating infected pork, horsemeat, or wild carnivores such as fox, cat, or bear. Trichinella The best way to prevent trichinellosis Don’t eat is to cook meat to safe undercooked meat, temperatures. A food especially PORK! thermometer should be used to measure the internal temperature of cooked meat. Do not sample meat until it is cooked. Prevent Contamination •Wash your hands with warm water and soap after handling raw meat. •Curing (salting), drying, smoking, or microwaving meat alone does not consistently kill infective worms; homemade jerky and sausage were the cause of many cases of trichinellosis reported to CDC in recent years. •Freeze pork less than 6 inches thick for 20 days at 5°F (- 15°C) to kill any worms. •Freezing wild game meats, unlike freezing pork products, may not effectively kill all worms because some worm species that infect wild game animals are freeze-resistant. •Clean meat grinders thoroughly after each use. To help prevent Trichinella infection in animal populations, do not allow pigs or wild animals to eat uncooked meat, scraps, or carcasses of any animals, including rats, which may be infected withTrichinella. Pinworms Pinworms infect 16% of adults and 30% of the children living in the United States. Since the eggs are laid on the outside of the body, the eggs may be stick to a person’s hands. Anything the person touches will become infected with these eggs. Ways to control parasitic worms: Good meat inspection. Cook all meats thoroughly. Wear shoes in areas occupied by host animals, such as barns, pastures, etc. Wear protective clothing when wading in waters that may be infested with parasites. Evidence of Parasitic Worms in Humans Compare and contrast the body plans of flatworms with roundworms. Similarities: Both have three germ layers and bilateral symmetry. They both have anterior and posterior ends allowing cephalization to occur. Differences: 1.The roundworm has a body cavity called a coelom. It is a false coelom (pseudocoelom) because it is not completely lined with mesoderm tissue. A flatworm has no body cavity and is called an “acoelomate”. 2.A roundworm has fluids that circulate through the body; a flatworm does not. 3.A round worm has a tube within a tube digestive system, with a mouth at one end and an anus at the other end. A flatworm has a digestive system with only one opening. What is cephalization? What is the advantage of cephalization? Cephalization means that the brain and sense organs are concentrated in the anterior part of the body. This allows the organism to meet its environment head on, allowing quicker responses to the environment. How can parasitic worms survive when they no longer have a digestive system? What is this concept called? They have no need for a digestive system. They absorb food that has already been digested by the host. The loss of a body system is called “degeneration”. How is the body shape of a parasitic roundworm an adaptation for its way of life? The roundworm body is long and slender and tapered at both ends. This allows the roundworm to move easily through the tissues of the host. How can a flatworm survive without a circulatory or a respiratory system? A flatworm is so flat that none of its cells are ever very far away from the external environment. Oxygen and carbon dioxide move by diffusion between the body cells and the environment..
Recommended publications
  • Flatworms Phylum Platyhelminthes
    Flatworms Phylum Platyhelminthes The flatworms include more than 13,000 species of free-living and parasitic species.There are 3 classes of flat- worms, the planarians, flukes and tapeworms. General Physical Traits (Anatomy): Flatworms are bilaterally symmetrical. This means that they can only be cut them length-wise to produce two mirror-image halves. They have a distinct right and left half. This is differ- ent from radially symmetrical animals, like the anemones, which can be cut anywhere top to bottom to get two similar halves. Flatworms have 3 tissue layers, compared to the 2 layers in sponges and cnidarians (jellyfishes, anemones and corals). They also have only one opening for food to enter and waste to leave, like the sponges and cnidarians. This is called a “sac” body plan. Planarian (class Tubellaria) Habitat: They live mostly in saltwater (marine) habitats, but are also found in freshwater. Habits: They are free-living flatworms (not parasites). Physical Traits (Anatomy): Planarians are small - less than a centimeter long. They have a head, brain and sense organs. This is called “cephalization.” The sense organs – called eyespots – look like eyes and are sensitive to light changes, but are not like human eyes. They are made up of simple nerve cells that respond to stimuli, like light. When many nerve cells are gathered in one place, they are called a “ganglion,” so the two eyespots are actually ganglia. They also have points on either side of the head that look a bit like ears, called “sensory lobes” or auricles. They do not hear, but can sense food.
    [Show full text]
  • Platyhelminthes, Nemertea, and "Aschelminthes" - A
    BIOLOGICAL SCIENCE FUNDAMENTALS AND SYSTEMATICS – Vol. III - Platyhelminthes, Nemertea, and "Aschelminthes" - A. Schmidt-Rhaesa PLATYHELMINTHES, NEMERTEA, AND “ASCHELMINTHES” A. Schmidt-Rhaesa University of Bielefeld, Germany Keywords: Platyhelminthes, Nemertea, Gnathifera, Gnathostomulida, Micrognathozoa, Rotifera, Acanthocephala, Cycliophora, Nemathelminthes, Gastrotricha, Nematoda, Nematomorpha, Priapulida, Kinorhyncha, Loricifera Contents 1. Introduction 2. General Morphology 3. Platyhelminthes, the Flatworms 4. Nemertea (Nemertini), the Ribbon Worms 5. “Aschelminthes” 5.1. Gnathifera 5.1.1. Gnathostomulida 5.1.2. Micrognathozoa (Limnognathia maerski) 5.1.3. Rotifera 5.1.4. Acanthocephala 5.1.5. Cycliophora (Symbion pandora) 5.2. Nemathelminthes 5.2.1. Gastrotricha 5.2.2. Nematoda, the Roundworms 5.2.3. Nematomorpha, the Horsehair Worms 5.2.4. Priapulida 5.2.5. Kinorhyncha 5.2.6. Loricifera Acknowledgements Glossary Bibliography Biographical Sketch Summary UNESCO – EOLSS This chapter provides information on several basal bilaterian groups: flatworms, nemerteans, Gnathifera,SAMPLE and Nemathelminthes. CHAPTERS These include species-rich taxa such as Nematoda and Platyhelminthes, and as taxa with few or even only one species, such as Micrognathozoa (Limnognathia maerski) and Cycliophora (Symbion pandora). All Acanthocephala and subgroups of Platyhelminthes and Nematoda, are parasites that often exhibit complex life cycles. Most of the taxa described are marine, but some have also invaded freshwater or the terrestrial environment. “Aschelminthes” are not a natural group, instead, two taxa have been recognized that were earlier summarized under this name. Gnathifera include taxa with a conspicuous jaw apparatus such as Gnathostomulida, Micrognathozoa, and Rotifera. Although they do not possess a jaw apparatus, Acanthocephala also belong to Gnathifera due to their epidermal structure. ©Encyclopedia of Life Support Systems (EOLSS) BIOLOGICAL SCIENCE FUNDAMENTALS AND SYSTEMATICS – Vol.
    [Show full text]
  • Nematode Management for Bedding Plants1 William T
    ENY-052 Nematode Management for Bedding Plants1 William T. Crow2 Florida is the “land of flowers.” Surely, one of the things that Florida is known for is the beauty of its vegetation. Due to the tropical and subtropical environment, color can abound in Florida landscapes year-round. Unfortunately, plants are not the only organisms that enjoy the mild climate. Due to warm temperatures, sandy soil, and humidity, Florida has more than its fair share of pests and pathogens that attack bedding plants. Plant-parasitic nematodes (Figure 1) can be among the most damaging and hard-to-control of these organisms. What are nematodes? Nematodes are unsegmented roundworms, different from earthworms and other familiar worms that are segmented (annelids) or in some cases flattened and slimy (flatworms). Many kinds of nematodes may be found in the soil of any landscape. Most are beneficial, feeding on bacteria, fungi, or other microscopic organisms, and some may be used as biological control organisms to help manage important insect pests. Plant-parasitic nematodes are nematodes that Figure 1. Diagram of a generic plant-parasitic nematode. feed on live plants (Figure 1). Credits: R. P. Esser, Florida Department of Agriculture and Consumer Services, Division of Plant Industry; used with permission. Plant-parasitic nematodes are very small and most can only be seen using a microscope (Figure 2). All plant-parasitic nematodes have a stylet or mouth-spear that is similar in structure and function to a hypodermic needle (Figure 3). 1. This document is ENY-052, one of a series of the Department of Entomology and Nematology, UF/IFAS Extension.
    [Show full text]
  • Nematicidal Properties of Some Algal Aqueous Extracts Against Root-Knot Nematode, Meloidogyne Incognita in Vitro
    6 Egypt. J. Agronematol., Vol. 15, No.1, PP. 67-78 (2016) Nematicidal properties of some algal aqueous extracts against root-knot nematode, Meloidogyne incognita in vitro Ahmed H. Nour El-Deen(*,***)and Ahmed A. Issa(**,***) * Nematology Research Unit, Agricultural Zoology Dept., Faculty of Agriculture, Mansoura University, Egypt. ** Department of Botany, Faculty of Science, Assiut University, Assiut , Egypt. *** Biology Dept., Faculty of Science, Taif University, Saudi Arabia. Corresponding author: [email protected] Abstract The effectiveness of aqueous extracts derived from nine algal species at different concentrations on egg hatching and mortality of Meloidogyne incognita (Kofoid and White) Chitwood juveniles after various exposure times were determined in vitro. Results indicated that Enteromorpha flexuosa at the concentration of 80% was the best treatment for suppressing the egg hatching with value of 2 % after 5 days of exposure, followed by Dilsea carnosa extract (3%) and Codium fragile (4%) at the same concentration and exposure time. Likewise, application of C. fragile, D. carnosa , E. flexuosa and Cystoseira myrica extracts at the concentrations of 80 and 60% were highly toxic to the nematodes, killing more than 90 % of nematode larva after 72 hours of exposure while the others gave quite low mortalities. The characteristic appearances in shape of the nematodes killed by C. fragile, D. carnosa , C. myrica, E. flexuosa and Sargassum muticum was sigmoid (∑-shape) with some curved shape; whereas, the nematodes killed by other algal species mostly followed straight or bent shapes. The present study proved that four species of algae C. fragile, D. carnosa, C. myrica and E. flexuosa could be used for the bio-control of root-knot nematodes.
    [Show full text]
  • I FLATWORM PREDATION on JUVENILE FRESHWATER
    FLATWORM PREDATION ON JUVENILE FRESHWATER MUSSELS A Thesis Presented to the Graduate College of Southwest Missouri State University In Partial Fulfillment of the Requirements for the Master of Science Degree By Angela Marie Delp July 2002 i FLATWORM PREDATION OF JUVENILE FRESHWATER MUSSELS Biology Department Southwest Missouri State University, July 27, 2002 Master of Science in Biology Angela Marie Delp ABSTRACT Free-living flatworms (Phylum Platyhelminthes, Class Turbellaria) are important predators on small aquatic invertebrates. Macrostomum tuba, a predominantly benthic species, feeds on juvenile freshwater mussels in fish hatcheries and mussel culture facilities. Laboratory experiments were performed to assess the predation rate of M. tuba on newly transformed juveniles of plain pocketbook mussel, Lampsilis cardium. Predation rate at 20 oC in dishes without substrate was 0.26 mussels·worm-1·h-1. Predation rate increased to 0.43 mussels·worm-1·h-1 when a substrate, polyurethane foam, was present. Substrate may have altered behavior of the predator and brought the flatworms in contact with the mussels more often. An alternative prey, the cladoceran Ceriodaphnia reticulata, was eaten at a higher rate than mussels when only one prey type was present, but at a similar rate when both were present. Finally, the effect of flatworm size (0.7- 2.2 mm long) on predation rate on mussels (0.2 mm) was tested. Predation rate increased with predator size. The slope of this relationship decreased with increasing predator size. Predation rate was near zero in 0.7 mm worms. Juvenile mussels grow rapidly and can escape flatworm predation by exceeding the size of these tiny predators.
    [Show full text]
  • Control Root-Knot Nematodes in Your Garden
    Agriculture and Natural Resources FSA7529 Control Root-Knot Nematodes in Your Garden Stephen Vann Introduction plants to any extent. A female Assistant Professor ­ root-knot nematode (Figure 2) can lay Urban Plant Pathologist Root-knot nematodes are up to 500 eggs at a time, and root microscopic worms that live in soil damage results from the sheer T.L. Kirkpatrick and feed on the roots of many common number of nematodes feeding on roots Professor - garden crops (Figures 1 and 2). The by the end of the summer. Root-knot Plant Pathologist nematode gets its name because its nematodes tend to be more of a feeding causes galls (swellings or problem in sandy soils. Rick Cartwright “knots”) to form on the roots of infected Professor ­ plants (Figure 3). Root-knot nematodes Symptoms Plant Pathologist are scientifically classified in the genus Meloidogyne. There are several species So how do you tell if root-knot of Meloidogyne, but M. incognita, also nematodes are a problem in your known as the southern root-knot garden? nematode, is the most common one in gardens in Arkansas. First, look for plants that are not performing well. Usually, not all of Some of the crops that may be your plants will be affected to the severely damaged are tomato, pepper, same degree, and some will be “more okra, watermelon, cantaloupe, onion, sick” than others. Symptoms can pumpkin, squash, sweet potato, sweet include stunting, yellowing, wilting corn, carrot, eggplant, bean and pea. during the heat of the day with recov­ Root-knot nematodes also feed and ery at night, fewer and smaller fruit multiply on many garden weeds, and general decline – usually during although they may not injure these the summer as the plants get bigger.
    [Show full text]
  • Worms, Nematoda
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications from the Harold W. Manter Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of 2001 Worms, Nematoda Scott Lyell Gardner University of Nebraska - Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/parasitologyfacpubs Part of the Parasitology Commons Gardner, Scott Lyell, "Worms, Nematoda" (2001). Faculty Publications from the Harold W. Manter Laboratory of Parasitology. 78. https://digitalcommons.unl.edu/parasitologyfacpubs/78 This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from the Harold W. Manter Laboratory of Parasitology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in Encyclopedia of Biodiversity, Volume 5 (2001): 843-862. Copyright 2001, Academic Press. Used by permission. Worms, Nematoda Scott L. Gardner University of Nebraska, Lincoln I. What Is a Nematode? Diversity in Morphology pods (see epidermis), and various other inverte- II. The Ubiquitous Nature of Nematodes brates. III. Diversity of Habitats and Distribution stichosome A longitudinal series of cells (sticho- IV. How Do Nematodes Affect the Biosphere? cytes) that form the anterior esophageal glands Tri- V. How Many Species of Nemata? churis. VI. Molecular Diversity in the Nemata VII. Relationships to Other Animal Groups stoma The buccal cavity, just posterior to the oval VIII. Future Knowledge of Nematodes opening or mouth; usually includes the anterior end of the esophagus (pharynx). GLOSSARY pseudocoelom A body cavity not lined with a me- anhydrobiosis A state of dormancy in various in- sodermal epithelium.
    [Show full text]
  • Animal Origins and the Evolution of Body Plans 621
    Animal Origins and the Evolution 32 of Body Plans In 1822, nearly forty years before Darwin wrote The Origin of Species, a French naturalist, Étienne Geoffroy Saint-Hilaire, was examining a lob- ster. He noticed that when he turned the lobster upside down and viewed it with its ventral surface up, its central nervous system was located above its digestive tract, which in turn was located above its heart—the same relative positions these systems have in mammals when viewed dorsally. His observations led Geoffroy to conclude that the differences between arthropods (such as lobsters) and vertebrates (such as mammals) could be explained if the embryos of one of those groups were inverted during development. Geoffroy’s suggestion was regarded as preposterous at the time and was largely dismissed until recently. However, the discovery of two genes that influence a sys- tem of extracellular signals involved in development has lent new support to Geof- froy’s seemingly outrageous hypothesis. Genes that Control Development A A vertebrate gene called chordin helps to establish cells on one side of the embryo human and a lobster carry similar genes that control the development of the body as dorsal and on the other as ventral. A probably homologous gene in fruit flies, called axis, but these genes position their body sog, acts in a similar manner, but has the opposite effect. Fly cells where sog is active systems inversely. A lobster’s nervous sys- become ventral, whereas vertebrate cells where chordin is active become dorsal. How- tem runs up its ventral (belly) surface, whereas a vertebrate’s runs down its dorsal ever, when sog mRNA is injected into an embryo (back) surface.
    [Show full text]
  • Phylum Chordata
    Phylum Chordata 48,000 species very diverse phylum but still more unity in major characteristics than in most other phyla most advanced phylum of animal kingdom one to which we belong along with fish, amphibians reptiles, birds and other mammals some of the largest or most massive animals true coelom 4 major identifying characteristics: 1. Notochord flexible rodlike structure enclosed by a fibrous sheath extends the length of the body in larva and/or adult provides basic support and serves as main axis for muscle attachments to permit “fishlike” undulatory movements first part of skeleton to form in embryo in primitive chordates the notochord persists through life Animals: Chordates & Introduction to Vertebrates; Ziser Lecture Notes, 2006 1 in most chordates the notochord is replaced by a vertebral column of bone remnants of the notochord remain as “intervertebral discs” 2. Dorsal tubular nerve cord in most invert groups; nerve cord is ventral & paired in chordates the nerve cord is a single dorsal hollow nerve cord front end usually enlarged to form brain 3. Pharyngeal (gill) slits slit-like opening sleading from throat to outside first evolved as a filter feeding apparatus still used by some to filter water for food in others as gills in some groups they are only found in embryo and lost as adults 4. endostyle or thyroid gland specific kind of tissue found only in chordates was originally part of the feeding apparatus endostyle secretes mucus and traps food inside the pharyngeal cavity eg. lamprey larva in most chordates the same tissue has become an endocrine Animals: Chordates & Introduction to Vertebrates; Ziser Lecture Notes, 2006 2 gland in the neck region that helps control metabolism 5.
    [Show full text]
  • Examine Clematis Roots for Nematode Infestation, Vol.4, Issue 3
    OREGON H.J. Jensen December 1960 AND Plant Pathology Department ORNAMENTAL Vol. 4, Issue 3 Oregon State College NURSERY DIGEST Pages 1,2 Corvallis, OR EXAMINE CLEMATIS ROOTS FOR NEMATODE INFESTATION Clematis, like many other flowers, has its share of mutilating pests and disfiguring plant diseases. One of the most devastating pests is a root knot nematode. Meloidogyne hapla, which commonly afflicts this choice flowering shrub wherever grown. The first sign of imminent disaster is usually pronounced stunting which during warm weather is accompanied by excessive wilting. Frequently these symptoms are associated with chlorotic foliage. In general, however, foliage symptoms alone are not necessarily specific for root-feeding nematodes, but do indicate the probability of a disorder due to activities of these pests. A much more accurate diagnosis is made by examining the root system. If small, bead-like swellings occur on roots, root knot nematodes are most likely responsible. Verification can be made easily by routine microscopic examination. These swellings, usually called "galls" or "knots," vary somewhat in size depending upon the population density and age of nematodes in root tissues. A recent invasion of nematodes is hardly noticeable because plant tissues have barely had time to react to this penetration. By the time nematodes complete their lifespan, galls are very conspicuous, and may contain several white, pear-shaped objects which are the adult females. Each female may produce 300 eggs from which hatch a new generation of young nematodes. Since these pests complete a life cycle in approximately two months, vast numbers build up rapidly during a single year.
    [Show full text]
  • The Effect of Caffeine and Ethanol on Flatworm Regeneration
    East Tennessee State University Digital Commons @ East Tennessee State University Electronic Theses and Dissertations Student Works 8-2007 The ffecE t of Caffeine nda Ethanol on Flatworm Regeneration. Erica Leighanne Collins East Tennessee State University Follow this and additional works at: https://dc.etsu.edu/etd Part of the Chemical and Pharmacologic Phenomena Commons Recommended Citation Collins, Erica Leighanne, "The Effect of Caffeine nda Ethanol on Flatworm Regeneration." (2007). Electronic Theses and Dissertations. Paper 2028. https://dc.etsu.edu/etd/2028 This Thesis - Open Access is brought to you for free and open access by the Student Works at Digital Commons @ East Tennessee State University. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Digital Commons @ East Tennessee State University. For more information, please contact [email protected]. The Effect of Caffeine and Ethanol on Flatworm Regeneration ____________________ A thesis presented to the faculty of the Department of Biological Sciences East Tennessee State University In partial fulfillment of the requirements for the degree Master of Science in Biology ____________________ by Erica Leighanne Collins August 2007 ____________________ Dr. J. Leonard Robertson, Chair Dr. Thomas F. Laughlin Dr. Kevin Breuel Keywords: Regeneration, Planarian, Dugesia tigrina, Flatworms, Caffeine, Ethanol ABSTRACT The Effect of Caffeine and Ethanol on Flatworm Regeneration by Erica Leighanne Collins Flatworms, or planarian, have a high potential for regeneration and have been used as a model to investigate regeneration and stem cell biology for over a century. Chemicals, temperature, and seasonal factors can influence planarian regeneration. Caffeine and ethanol are two widely used drugs and their effect on flatworm regeneration was evaluated in this experiment.
    [Show full text]
  • Animal Phylum Poster Porifera
    Phylum PORIFERA CNIDARIA PLATYHELMINTHES ANNELIDA MOLLUSCA ECHINODERMATA ARTHROPODA CHORDATA Hexactinellida -- glass (siliceous) Anthozoa -- corals and sea Turbellaria -- free-living or symbiotic Polychaetes -- segmented Gastopods -- snails and slugs Asteroidea -- starfish Trilobitomorpha -- tribolites (extinct) Urochordata -- tunicates Groups sponges anemones flatworms (Dugusia) bristleworms Bivalves -- clams, scallops, mussels Echinoidea -- sea urchins, sand Chelicerata Cephalochordata -- lancelets (organisms studied in detail in Demospongia -- spongin or Hydrazoa -- hydras, some corals Trematoda -- flukes (parasitic) Oligochaetes -- earthworms (Lumbricus) Cephalopods -- squid, octopus, dollars Arachnida -- spiders, scorpions Mixini -- hagfish siliceous sponges Xiphosura -- horseshoe crabs Bio1AL are underlined) Cubozoa -- box jellyfish, sea wasps Cestoda -- tapeworms (parasitic) Hirudinea -- leeches nautilus Holothuroidea -- sea cucumbers Petromyzontida -- lamprey Mandibulata Calcarea -- calcareous sponges Scyphozoa -- jellyfish, sea nettles Monogenea -- parasitic flatworms Polyplacophora -- chitons Ophiuroidea -- brittle stars Chondrichtyes -- sharks, skates Crustacea -- crustaceans (shrimp, crayfish Scleropongiae -- coralline or Crinoidea -- sea lily, feather stars Actinipterygia -- ray-finned fish tropical reef sponges Hexapoda -- insects (cockroach, fruit fly) Sarcopterygia -- lobed-finned fish Myriapoda Amphibia (frog, newt) Chilopoda -- centipedes Diplopoda -- millipedes Reptilia (snake, turtle) Aves (chicken, hummingbird) Mammalia
    [Show full text]