DOCSLIB.ORG

Classroom Applications Using Limulus Polyphemus: the American Horseshoe Crab

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Classroom Applications Using Limulus Polyphemus: the American Horseshoe Crab Classroom ApplicationsUsing Lim ulus polyphem us -The American Horseshoe Crab Downloaded from http://online.ucpress.edu/abt/article-pdf/43/8/440/39357/4447345.pdf by guest on 25 September 2021 FrederickC. Pearson III MarlysWeary The Horseshoe Crab T HROJUGHOUT its 300 million-yearhistory, the Amer- ican horseshoe crab (Limulus polyphemus) has been This 'living fossil," so-called because it has existed regarded at best as a scientific curiosity, and at worst as virtually unchanged since the Ordovician period, is indi- a nuisance. However, recent scientific publications have genous to the eastern coast of North America. Related changed that image. In 1970, Jack Levin of Johns Hop- species-Tachypleus tridentatus, Tachypleus gigas, and kins Universitypublished findings of a test for gram-nega- Carcinoscorpius rotundicaudo-are found in certain tive bacterialsepsis and endotoxemia based on an extract, areas of the Far East. Because the animals exist on a Limulus amebocyte lysate (LAL), made from the blood diet of shellfish and other marine invertebrates, they are cells of this ancient animal (Levin, Tomasulo, and Oser poorly regarded by fishermen, who hold them respon- 1970). The excitement generated in the scientific com - sible for everything from decimating valuable shellfish munity by this discovery has elevated the status of the beds to fouling nets. Consequently, in certain areas, lowly horseshoe crab to that of a valuable commodity, wholesale destruction of the crabs is encouraged. In Mass- and thus a unique naturalresource. achusetts, for example, clam diggers are instructed to throw any horseshoe crabs they find over the high water FrederickPearson is Manager- line, where the animals ultimately dehydrate and die. Pyrogen Technology and Microbiological Support, Cor- In addition, eel and conch fishermen use them as bait. porate Microbiology at Trav- As a result, some 60,000 crabs are destroyed annually. enol Laboratories, Morton The horseshoe crab is not a true crab at all, but is more Grove, Illinois 60053. He received his B.S. degree in OP"7 closely related to other members of its phylum, Arthro- biology from Nasson College poda, particularlyscorpions. The four extant species have and his Ph.D. degree in micro- a subclass, Xiphosura, to themselves. biology from University of New Hampshire. He has been Although their physical structure is relatively simple, at Travenol Laboratoriessince 1978 and heads a group which is respon - horseshoe crabs function very efficiently. Their bodies, sible for Limulus amebocyte lysate test development, among other which are covered by an exoskeleton called the carapace, things. He holds many professional memberships, both here and in the United Kingdom. He has published extensively. Marlys Weary is Senior are divided into two major portions-the prosoma and Supervisor-Pyrogen Technology and MicrobiologicalSupport at Trav- the opisthosoma (fig. 1). Although they can swim, adult enol Laboratories. She received her B.A. degree in biology from Val- crabs are bottom dwellers, and their usual mode of loco- paraiso University, her M.S. degree in anatomy from the University of Illinois, and her M.B.A. degree from Lake Forest School of Manage- motion is walking. ment. She has been at Travenol Laboratories since 1962 and has The horseshoe crab's tubular heart, located beneath worked in the field of pyrogen testing for 15 years. She is a member of the carapace and above the intestine, is large in relation to the New York Academy of Sciences and is chairman of the Biological Testing Division of the Pharmaceutical Manufacturers' Association. its body (measuring from five inches in length in an adult She also publishes and lectures on the subject of pyrogen testing. male to six inches in a female, and from 1/2 to 3/4 inch 440 THE AMERICAN BIOLOGYTEACHER, VOLUME43, NO. 8, NOVEMBER1981 Limulus polyphemus ventral view p dorsal view pedipalp simple eye \\ chelicera compound eye prosomaI mot -,-~gnathobase FIGURE1. Dorsal and ventral views of the | genital operculum American horseshoe crab, Limulus pOly- gillgil lamelle phemus. _a_Ia I \ [anus opisthosoma _ s ^ - - ~~caudalspinel Downloaded from http://online.ucpress.edu/abt/article-pdf/43/8/440/39357/4447345.pdf by guest on 25 September 2021 detail of terminal segments of pedipalps in diameter). Gaseous exchange takes place in the lam- The AnnualCycle ellae of the gills, which are also called "book lungs" be- The crabs hibernate during the winter months, digging cause of their resemblance to the leaves in a book. into the ocean bottom, and are found at water depths of The crab's blood is brightblue in color due to the pres- up to fifty to sixty feet. They have been shown to be ence in the plasma of a copper compound, hemocyanin, highly sensitive to heat and cold, and will dig into the sand that carries oxygen. It contains only one type of circulat- if the temperature drops even five degrees in twenty-four ing cell, the amebocyte. Amebocytes agglutinate in the hours. Further evidence of this sensitivity is provided by presence of lipopolysaccharides (endotoxin) found in the fact that the largest specimens and populations are the cell walls of gram negative bacteria. This agglutina- found within the most temperate areas of the animal's tion response is the basis of Levin's LAL test. habitat. Salinity also appears to affect size and distribution The horseshoe crab has two functional pairs of eyes. (Shuster 1967, 1970). There have been few studies of A third pair is degenerated in the adult, although it may either the extent or habits of typical populations. serve a function in the larval stage. The multilensed com- The average lifespan of a horseshoe crab has been es- pound eye, which is sensitive to polarized light, has been timated to be between fourteen and nineteen years, and of great interest to scientists because its structure allows the animals probably reach sexual maturity at between the relationship between light stimulus and axon firing nine and eleven years of age. Crabs breed during the to be studied easily. It seems probable that the eye can spring, males and females coming up to the beaches in detect movement, but is not capable of image formation tandem (fig. 2) during the spring tide (the highest of the (Kaestner 1968). There is no evidence that the eye aids high tides on the full of the moon). The female deposits the crab in navigation (Shuster 1979). some 200-300 eggs in each of a series of ten to fifteen There are chemoreceptors on the base of the crab's nests hollowed out in the sand. The eggs are fertilized legs (pedipalps) that are used for taste. Food is partially externally by the male and then covered. The next tide crushed by gnathobases at the base of the legs and on the full of the moon, roughly a month later, triggers pushed into the animal's mouth with the fifth pair of legs. the hatching of trilobite larvae. These larvae, which re- Further grinding takes place in the gizzard, aided by bits semble trilobites and the adult horseshoe crab, are im- of shell and sand. Actual digestion begins in the midgut mature specimens with incomplete digestive, nervous, and is completed in the digestive gland. Horseshoe crabs and circulatorysystems. The larvae receive nourishment do most of their feeding during the breeding season. from a yolk sac. HORSESHOE CRAB 441 Maturation,which involves several moltings (ecdysis), segment of the scientific community. The LAL test uses although not completely understood, appears to be con- material lysed from the amebocytes following the method trolled by hormonal secretions. The animals first molt developed by Levin and Bang (1972) to detect the pres- as early as three weeks after hatching, at which time the ence of endotoxin (pyrogens), a lipopolysaccharide rudiments of a telson first appear. The molting cycle per- present in the cell walls of gram-negative bacteria. Endo- sists until the crabs reach maturity, a period covering ten toxin can cause a variety of symptoms in man ranging to eleven years. Young crabs undergo frequent molts, from fever to shock and death if it is introduced directly each time increasing their size by roughly 25%. The cycle into the circulatory system. The LAL test therefore has is divided into four phases: premolt, molt, postmolt, and proved invaluable in the pharmaceutical industry where intermolt. The premolt phase is triggered by a hormonal a large variety of devices and preparations must be secretion of the Y-glands that lie in the head. This secre- certified as pyrogen-free. In addition, the test may be tion is probably related to the steroid ecdysone, which used as a diagnostic tool. One of the most promising initiates molting in insects (Russell-Hunter 1969). Action applications, in fact, is its use in the detection of gram- of the Y-glands is, in turn, inhibitedby hormones from the negative bacterial meningitis. The speed of the LAL test X-organ, a structure located within each eye stalk. It is makes it particularly valuable. As a test for meningitis, only when the latter hormones are absent that molting it can be completed in one hour, which compares favor- may begin. ably with eight to twenty-four hours for more traditional Downloaded from http://online.ucpress.edu/abt/article-pdf/43/8/440/39357/4447345.pdf by guest on 25 September 2021 methods (Siegel and Nachum 1977). It may also be used Limulus Amebocyte Lysate in the diagnosis of urinaryinfections, bacteremia, mastitis, certain corneal infections, and possibly endotoxemia Much of the data on horseshoe crabs has been (Levin,Tomasulo, and Oser 1970). gathered by a relatively small group of marine biologists Studies have shown the LAL test to be remarkably and naturalists.It was only with the development of the sensitive to small quantities of endotoxin.
Load more

Recommended publications
  • United States
    DEPARTMENT OF THE INTERIOR BULLETIN OF THE UNITED STATES ISTo. 146 WASHINGTON GOVERNMENT Pit IN TING OFFICE 189C UNITED STATES GEOLOGICAL SURVEY CHAKLES D. WALCOTT, DI11ECTOK BIBLIOGRAPHY AND INDEX NORTH AMEEICAN GEOLOGY, PALEONTOLOGY, PETEOLOGT, AND MINERALOGY THE YEA.R 1895 FEED BOUGHTON WEEKS WASHINGTON Cr O V E U N M K N T P K 1 N T I N G OFFICE 1890 CONTENTS. Page. Letter of trail smittal...... ....................... .......................... 7 Introduction.............'................................................... 9 List of publications examined............................................... 11 Classified key to tlio index .......................................... ........ 15 Bibliography ............................................................... 21 Index....................................................................... 89 LETTER OF TRANSMITTAL DEPARTMENT OF THE INTEEIOE, UNITED STATES GEOLOGICAL SURVEY, DIVISION OF GEOLOGY, Washington, D. 0., June 23, 1896. SIR: I have the honor to transmit herewith the manuscript of a Bibliography and Index of North American Geology, Paleontology, Petrology, and Mineralogy for the year 1895, and to request that it be published as a bulletin of the Survey. Very respectfully, F. B. WEEKS. Hon. CHARLES D. WALCOTT, Director United States Geological Survey. 1 BIBLIOGRAPHY AND INDEX OF NORTH AMERICAN GEOLOGY, PALEONTOLOGY, PETROLOGY, AND MINER­ ALOGY FOR THE YEAR 1895. By FRED BOUGHTON WEEKS. INTRODUCTION. The present work comprises a record of publications on North Ameri­ can geology, paleontology, petrology, and mineralogy for the year 1895. It is planned on the same lines as the previous bulletins (Nos. 130 and 135), excepting that abstracts appearing in regular periodicals have been omitted in this volume. Bibliography. The bibliography consists of full titles of separate papers, classified by authors, an abbreviated reference to the publica­ tion in which the paper is printed, and a brief summary of the con­ tents, each paper being numbered for index reference.
    [Show full text]
  • Conservation Status of the American Horseshoe Crab, (Limulus Polyphemus): a Regional Assessment
    Rev Fish Biol Fisheries DOI 10.1007/s11160-016-9461-y REVIEWS Conservation status of the American horseshoe crab, (Limulus polyphemus): a regional assessment David R. Smith . H. Jane Brockmann . Mark A. Beekey . Timothy L. King . Michael J. Millard . Jaime Zaldı´var-Rae Received: 4 March 2016 / Accepted: 24 November 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract Horseshoe crabs have persisted for more available scientific information on its range, life than 200 million years, and fossil forms date to 450 history, genetic structure, population trends and anal- million years ago. The American horseshoe crab yses, major threats, and conservation. We structured (Limulus polyphemus), one of four extant horseshoe the status assessment by six genetically-informed crab species, is found along the Atlantic coastline of regions and accounted for sub-regional differences in North America ranging from Alabama to Maine, USA environmental conditions, threats, and management. with another distinct population on the coasts of The transnational regions are Gulf of Maine (USA), Campeche, Yucata´n and Quintana Roo in the Yucata´n Mid-Atlantic (USA), Southeast (USA), Florida Atlan- Peninsula, Me´xico. Although the American horseshoe tic (USA), Northeast Gulf of Me´xico (USA), and crab tolerates broad environmental conditions, Yucata´n Peninsula (Me´xico). Our conclusion is that exploitation and habitat loss threaten the species. We the American horseshoe crab species is vulnerable to assessed the conservation status of the American local extirpation and that the degree and extent of risk horseshoe crab by comprehensively reviewing vary among and within the regions.
    [Show full text]
  • A New Devonian Euthycarcinoid Reveals the Use of Different Respiratory Strategies During the Marine-To-Terrestrial Transition In
    A new Devonian euthycarcinoid reveals the use of different respiratory strategies during the marine-to-terrestrial transition in the myriapod lineage Pierre Gueriau, James Lamsdell, Roy Wogelius, Phillip Manning, Victoria Egerton, Uwe Bergmann, Loïc Bertrand, Julien Denayer To cite this version: Pierre Gueriau, James Lamsdell, Roy Wogelius, Phillip Manning, Victoria Egerton, et al.. A new Devo- nian euthycarcinoid reveals the use of different respiratory strategies during the marine-to-terrestrial transition in the myriapod lineage. Royal Society Open Science, The Royal Society, 2020, 7 (10), pp.201037. 10.1098/rsos.201037. hal-02974805 HAL Id: hal-02974805 https://hal.archives-ouvertes.fr/hal-02974805 Submitted on 24 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A new Devonian euthycarcinoid reveals the royalsocietypublishing.org/journal/rsos use of different respiratory strategies during the marine- Research Cite this article: Gueriau P, Lamsdell JC, to-terrestrial transition in the Wogelius RA, Manning PL, Egerton VM, Bergmann U, Bertrand L, Denayer J. 2020 A new myriapod lineage Devonian euthycarcinoid reveals the use of different respiratory strategies during the marine- 1,2 3 4 to-terrestrial transition in the myriapod lineage.
    [Show full text]
  • Effects of Habitat Size and Temperature on Success and Growth of Larval Horseshoe Crabs (Limulus Polyphemus) Gaitlyn Malone Marine Biology Faculty Mentor: Dr
    Effects of habitat size and temperature on success and growth of larval horseshoe crabs (Limulus polyphemus) Gaitlyn Malone Marine Biology Faculty Mentor: Dr. Carmela Cuomo Abstract The horseshoe crab (Limulus polyphemus) is an important component of the marine ecosystem and is frequently used in biomedical research as well as other laboratory studies. When this research is conducted, a large number of horseshoe crabs are often contained in a limited amount of space, and therefore experience overcrowded conditions. These conditions often lead to the spread of various etiologies and result in developmental issues for the horseshoe crabs. Through this research, the effect of habitat size and temperature on the success of growth and development of larval and juvenile horseshoe crab was examined. After exposing the horseshoe crabs to two different temperatures (18°C and 24°C) and two different habitat sizes (large and small), it was determined that horseshoe crabs are most successful in smaller habitats and warmer temperatures. This research suggests that at least for horseshoe crab populations in Long Island Sound increasing water temperatures alone may not adversely affect larval success. Introduction (Shuster et al. 2003). From that point, embryonic Considered to be a living fossil, the horseshoe crab development occurs. (Limulus polyphemus) has been an important As described by Patten (1912), Limulus component of the marine ecosystem for the last goes through fifteen different embryonic stages. 360 million years (Dunlap 1999). There are four The first part of the body to experience growth is extant species of horseshoe crab, however only the opisthosoma, or the posterior portion. The Limulus polyphemus is found along the eastern prosoma, which is the fused anterior portion of the coast of North America.
    [Show full text]
  • Geological History and Phylogeny of Chelicerata
    Arthropod Structure & Development 39 (2010) 124–142 Contents lists available at ScienceDirect Arthropod Structure & Development journal homepage: www.elsevier.com/locate/asd Review Article Geological history and phylogeny of Chelicerata Jason A. Dunlop* Museum fu¨r Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity at the Humboldt University Berlin, Invalidenstraße 43, D-10115 Berlin, Germany article info abstract Article history: Chelicerata probably appeared during the Cambrian period. Their precise origins remain unclear, but may Received 1 December 2009 lie among the so-called great appendage arthropods. By the late Cambrian there is evidence for both Accepted 13 January 2010 Pycnogonida and Euchelicerata. Relationships between the principal euchelicerate lineages are unre- solved, but Xiphosura, Eurypterida and Chasmataspidida (the last two extinct), are all known as body Keywords: fossils from the Ordovician. The fourth group, Arachnida, was found monophyletic in most recent studies. Arachnida Arachnids are known unequivocally from the Silurian (a putative Ordovician mite remains controversial), Fossil record and the balance of evidence favours a common, terrestrial ancestor. Recent work recognises four prin- Phylogeny Evolutionary tree cipal arachnid clades: Stethostomata, Haplocnemata, Acaromorpha and Pantetrapulmonata, of which the pantetrapulmonates (spiders and their relatives) are probably the most robust grouping. Stethostomata includes Scorpiones (Silurian–Recent) and Opiliones (Devonian–Recent), while
    [Show full text]
  • ARTHROPOD LABORATORY Phylum Arthropoda Subphylum Cheliceriformes Class Celicerata Subclass Merostomata 1. Limulus Polyphemus
    ARTHROPOD LABORATORY Phylum Arthropoda Subphylum Cheliceriformes Class Celicerata Subclass Merostomata 1. Limulus polyphemus – horseshoe crab, identify external characteristics (see lecture notes) Subclass Arachnida 1. Latrodectus mactans – Southern black widow spider 2. Aphonopelma sp. – Tarantula 3. Lycosal tarantula – Wolf spider 4. Pruroctonus sp. – American scorpion 5. Slides of ticks and mites (identify different body parts) Sublcass Pycnogonida 1. sea spider demonstration specimens Subphylum Crustacea Class Brachiopoda 1. Daphnia magna – live specimens to study feeding activity and monitor heart rate using several stimulatory and inhibitory chemicals 2. Daphnia magna – body components (see lecture notes) 3. Artemia salina – brine shrimp, living specimens Class Ostracoda Class Copepoda 1. live representative specimen to observe movement and body components (see lecture notes) Class Branchiura No representatives Class Cirripedia 1. Lepas sp. – gooseneck barnacle 2. Balanus balanoides – acorn barnacle 3. Live barnacles to observe movement of cirri and feeding activity Class Malacostraca Order Stomatopoda 1. Lysiosquilla sp. – Mantis shrimp Order Amphipoda 1. Armadillium sp. – pillbug or roly poly Order Isopoda Live isopods to observe movement Order Decapoda Suborder Natancia – swimming decapods 1. Penaeus – common shrimp Suborder Reptancia 1. Cambarus sp. – freshwater crawfish for dissection 2. Homarus americanus – American lobster 3. Pagurus sp. – hermit crab 4. Emerita sp. – mole crab 5. Callinectes sapidus – blue crab 6. Libinia
    [Show full text]
  • Immunological Mechanisms of the Horseshoe Crab, Limulus Polyphemus John Irvin Stagner Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1974 Immunological mechanisms of the horseshoe crab, Limulus polyphemus John Irvin Stagner Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Zoology Commons Recommended Citation Stagner, John Irvin, "Immunological mechanisms of the horseshoe crab, Limulus polyphemus " (1974). Retrospective Theses and Dissertations. 5172. https://lib.dr.iastate.edu/rtd/5172 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image.
    [Show full text]
  • Enhanced Growth of Juvenile Tachypleus Tridentatus (Chelicerata: Xiphosura) in the Laboratory: a Step Towards Population Restocking for Conservation of the Species
    Vol. 11: 37–46, 2010 AQUATIC BIOLOGY Published online November 10 doi: 10.3354/ab00289 Aquat Biol Enhanced growth of juvenile Tachypleus tridentatus (Chelicerata: Xiphosura) in the laboratory: a step towards population restocking for conservation of the species Yan Chen1, 2, C. W. Lau1, S. G. Cheung1, 3, C. H. Ke4, Paul K. S. Shin1, 3,* 1Department of Biology and Chemistry, and 3State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR 2College of Marine Sciences, Shanghai Ocean University, No. 999, Hu Cheng Loop-road, Lingang New City, Shanghai, PR China 4State Key Laboratory of Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen, Fujian, PR China ABSTRACT: Juveniles of artificially bred Tachypleus tridentatus were reared in the laboratory for 15.5 mo. Fast growth (at least 3 times faster than in previous studies) and low mortality were observed, with juveniles reaching the 9th instar stage and having a cumulative mortality of 61.3% at the end of the rearing period. Such enhanced growth can potentially be attributed to high seawater temperature, sufficient living space and constant water flow. Isometric growth of prosomal width and other growth parameters including opisthosoma width, eye distance and prosomal length was found. Two distinct growth phases were detected for the opisthosoma length, with zero growth from the 1st to 2nd instar but isometric growth from the 2nd to 9th instar stage. Growth in telson length was pos- itively allometric from the 1st to 3rd instar and isometric from the 3rd to 9th instar stage.
    [Show full text]
  • Application to the South Dakota Public Utilities Commission for a Facility Permit
    Application to the South Dakota Public Utilities Commission for a Facility Permit Wind Quarry Operations, LLC Willow Creek Wind Energy Facility Burns & McDonnell Project No. 84046 May 2015 Application to the South Dakota Public Utilities Commission for a Facility Permit Wind Quarry Operations, LLC Willow Creek Wind Energy Facility Butte County, South Dakota Burns & McDonnell Project No. 84046 May 2015 prepared by Burns & McDonnell Engineering Company, Inc. Denver, Colorado COPYRIGHT © 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC. Application for Facility Permit Table of Contents TABLE OF CONTENTS Page No. 1.0 INTRODUCTION ............................................................................................... 1-1 2.0 FACILITY PERMIT APPLICATION ................................................................... 2-1 3.0 COMPLETENESS CHECK ............................................................................... 3-1 4.0 NAMES OF PARTICIPANTS (ARSD 20:10:22:06) .......................................... 4-1 5.0 NAME OF OWNER AND MANAGER (ARSD 20:10:22:07) ............................. 5-1 6.0 PURPOSE OF, AND DEMAND FOR, THE WIND ENERGY FACILITY (ARSD 20:10:22:08, 20:10:22:10) .................................................................... 6-1 6.1 Wind Resources Areas ......................................................................................... 6-2 6.2 Renewable Power Demand .................................................................................. 6-3 7.0 ESTIMATED COST OF THE WIND ENERGY FACILITY
    [Show full text]
  • Arthropod Phylogeny Based on Eight Molecular Loci and Morphology
    letters to nature melanogaster (U37541), mosquito Anopheles quadrimaculatus (L04272), mosquito arthropods revealed by the expression pattern of Hox genes in a spider. Proc. Natl Acad. Sci. USA 95, Anopheles gambiae (L20934), med¯y Ceratitis capitata (CCA242872), Cochliomyia homi- 10665±10670 (1998). nivorax (AF260826), locust Locusta migratoria (X80245), honey bee Apis mellifera 24. Thompson, J. D., Higgins, D. G. & Gibson, T. J. CLUSTALW: Improving the sensitivity of progressive (L06178), brine shrimp Artemia franciscana (X69067), water ¯ea Daphnia pulex multiple sequence alignment through sequence weighting, position-speci®c gap penalties and weight (AF117817), shrimp Penaeus monodon (AF217843), hermit crab Pagurus longicarpus matrix choice. Nucleic Acids Res. 22, 4673±4680 (1994). (AF150756), horseshoe crab Limulus polyphemus (AF216203), tick Ixodes hexagonus 25. Foster, P. G. & Hickey, D. A. Compositional bias may affect both DNA-based and protein-based (AF081828), tick Rhipicephalus sanguineus (AF081829). For outgroup comparison, phylogenetic reconstructions. J. Mol. Evol. 48, 284±290 (1999). sequences were retrieved for the annelid Lumbricus terrestris (U24570), the mollusc 26. Castresana, J. Selection of conserved blocks from multiple alignments for their use in phylogenetic Katharina tunicata (U09810), the nematodes Caenorhabditis elegans (X54252), Ascaris analysis. Mol. Biol. Evol. 17, 540±552 (2000). suum (X54253), Trichinella spiralis (AF293969) and Onchocerca volvulus (AF015193), and 27. Muse, S. V. & Kosakovsky Pond, S. L. Hy-Phy 0.7 b (North Carolina State Univ., Raleigh, 2000). the vertebrate species Homo sapiens (J01415) and Xenopus laevis (M10217). Additional 28. Strimmer, K. & von Haeseler, A. Quartet puzzlingÐa quartet maximum-likelihood method for sequences were analysed for gene arrangements: Boophilus microplus (AF110613), Euhadra reconstructing tree topologies.
    [Show full text]
  • Fossils – Adriano Kury’S Harvestman Overviews and the Third Edition of the Manual of Acarology for Mites
    A summary list of fossil spiders and their relatives compiled by Jason A. Dunlop (Berlin), David Penney (Manchester) & Denise Jekel (Berlin) with additional contributions from Lyall I. Anderson, Simon J. Braddy, James C. Lamsdell, Paul A. Selden & O. Erik Tetlie 1 A summary list of fossil spiders and their relatives compiled by Jason A. Dunlop (Berlin), David Penney (Manchester) & Denise Jekel (Berlin) with additional contributions from Lyall I. Anderson, Christian Bartel, Simon J. Braddy, James C. Lamsdell, Paul A. Selden & O. Erik Tetlie Suggested citation: Dunlop, J. A., Penney, D. & Jekel, D. 2016. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 17.5, accessed on {date of access}. Last updated: 09.08.2016 INTRODUCTION Fossil spiders have not been fully cataloged since Bonnet’s Bibliographia Araneorum and are not included in the current World Spider Catalog. Since Bonnet’s time there has been considerable progress in our understanding of the fossil record of spiders – and other arachnids – and numerous new taxa have been described. For an overview see Dunlop & Penney (2012). Spiders remain the single largest fossil group, but our aim here is to offer a summary list of all fossil Chelicerata in their current systematic position; as a first step towards the eventual goal of combining fossil and Recent data within a single arachnological resource. To integrate our data as smoothly as possible with standards used for living spiders, our list for Araneae follows the names and sequence of families adopted in the previous Platnick Catalog.
    [Show full text]
  • Valloisella Lievinensis RACHEBOEUF, 1992 (Chelicerata; Xiphosura) from the Westphalian B of England
    N.Jb. Geol. Palaont. Mh. 1995, H. 11 647-658 Stuttgart, Nov. 1995 Valloisella lievinensis RACHEBOEUF, 1992 (Chelicerata; Xiphosura) from the Westphalian B of England By Lyall I. Anderson and Carl Horrocks, Manchester With 3 figures in the text ANDERSON, L. I. & HORROCKS, C. (1995): Valloisella lievinensis RACHEBOUEF, 1992 (Chelicerata; Xiphosura) from the Westphalian B of England. - N. Jb. Geol. Palaont. Mh., 1995 (11): 647-658; Stuttgart. Abstract: Two small xiphosurans are described from geographically separate Westphalian B sites in England and assigned to Valloisella lievinensis RACHEBOEUF, 1992. Valloisella is removed from Euproopidae ELLER, 1938 and placed in Paleoli- mulidae RAYMOND, 1944. Zusammenfassung: Zwei kleine Xiphosuren aus geographisch getrennten Fundorten in England (Alter: Westfal B) werden beschrieben und der Art Valloi­ sella lievinensis RACHEBOEUF 1992 zugeordnet. Valloisella wird von den Euproo­ pidae ELLER, 1938 in die Paleolimulidae RAYMOND, 1994 iibertragen. Introduction Dix &JONES (1932) reported a small arthropod from the roof shales of the Little Vein coal in the lower part of the A. pulchra zone (Westphalian B) from Blaina Colliery, Pantyffynon, South Wales. The specimen was illustrated by way of a line drawing and was reported to have been deposited in the collections of the University College of Swansea under the acquisition number A. 152. The arthropod was found associated with non-marine bivalves and the other, more commonly encountered, Coal Measures xiphosuran, Bellinurus PICTET, 1846. The tripartite division of the fossil into a prosoma, opisthosoma and tail spine led Dix & JONES (1932) to compare their specimen with the extant xiphosuran Limulus polyphemus. They concluded that it was a post-larval, but immature, stage of an aquatic chelicerate but did not formally assign it a name.
    [Show full text]