Guide to the Parasites of Fishes of Canada Part V: Nematoda

Total Page:16

File Type:pdf, Size:1020Kb

Guide to the Parasites of Fishes of Canada Part V: Nematoda Zootaxa 4185 (1): 001–274 ISSN 1175-5326 (print edition) http://www.mapress.com/j/zt/ Monograph ZOOTAXA Copyright © 2016 Magnolia Press ISSN 1175-5334 (online edition) http://doi.org/10.11646/zootaxa.4185.1.1 http://zoobank.org/urn:lsid:zoobank.org:pub:0D054EDD-9CDC-4D16-A8B2-F1EBBDAD6E09 ZOOTAXA 4185 Guide to the Parasites of Fishes of Canada Part V: Nematoda HISAO P. ARAI3, 5 & JOHN W. SMITH4 3Pacific Biological Station, Nanaimo, British Columbia V9R 5K6 4Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5. E-mail: [email protected] 5Deceased Magnolia Press Auckland, New Zealand Accepted by K. DAVIES (Initially edited by M.D.B. BURT & D.F. McALPINE): 5 Apr. 2016; published: 8 Nov. 2016 Licensed under a Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0 HISAO P. ARAI & JOHN W. SMITH Guide to the Parasites of Fishes of Canada. Part V: Nematoda* (Zootaxa 4185) 274 pp.; 30 cm. 8 Nov. 2016 ISBN 978-1-77670-004-2 (paperback) ISBN 978-1-77670-005-9 (Online edition) FIRST PUBLISHED IN 2016 BY Magnolia Press P.O. Box 41-383 Auckland 1346 New Zealand e-mail: [email protected] http://www.mapress.com/j/zt © 2016 Magnolia Press ISSN 1175-5326 (Print edition) ISSN 1175-5334 (Online edition) *Editors of the series: MICHAEL D. B. BURT & DONALD F. McALPINE 2 · Zootaxa 4185 (1) © 2016 Magnolia Press ARAI & SMITH Table of contents Dedications . 4 Preface . 5 Abstract . 5 Résumé . 5 Introduction . 6 Collection and Examination of Nematodes . 9 Geographical Distribution . 10 Glossary of Terms . 10 Keys and Descriptions. 15 Higher classification of the Phylum NEMATODA . 15 Phylum NEMATODA: diagnosis . 16 Keys to NEMATODA . 17 Keys to Classes of NEMATODA . 17 Keys to Orders of the Class ENOPLEA and Subclass DORYLAIMIA . 17 Keys to genera of larvae in the Family DIOCTOPHYMATIDAE . 18 Keys to Families of the Order TRICHINELLIDA . 21 Family CYSTOOPSIDAE . 21 Family CAPILLARIIDAE . 23 Family TRICHOSOMOIDIDAE . 33 Keys to higher taxonomic ranks of the Class CHROMADOREA . 34 Keys to Superfamilies of RHABDITIDA . 35 Superfamily ANGUILLICOLOIDEA. 36 Family ANGUILLICOLIDAE . 36 Keys to Families of the Superfamily DRACUNCULOIDEA. 37 Family DANICONEMATIDAE…………………… . 37 Family GUYANEMIDAE……………………………….. 39 Family PHILOMETRIDAE . 42 Superfamily GNATHOSTOMATOIDEA . 58 Family GNATHOSTOMATIDAE . 58 Superfamily OXYUROIDEA . 60 Superfamily CAMALLANOIDEA . 60 Family CAMALLANIDAE . 60 Superfamily THELAZIOIDEA . 66 Family RHABDOCHONIDAE . 66 Superfamily SPIRUROIDEA . 82 Superfamily HABRONEMATOIDEA . 83 Family CYSTIDICOLIDAE . 83 Family HEDRURIDAE. .114 Family TETRAMERIDAE . 114 Superfamily ACUARIOIDEA. 114 Family ACUARIIDAE . 115 Key to Superfamilies of the Infraorder ASCARIDOMORPHA . 119 Keys to Families of ASCARIDOIDEA. 119 Family ACANTHOCHEILIDAE . ..
Recommended publications
  • 1756-3305-1-23.Pdf
    Parasites & Vectors BioMed Central Research Open Access Composition and structure of the parasite faunas of cod, Gadus morhua L. (Teleostei: Gadidae), in the North East Atlantic Diana Perdiguero-Alonso1, Francisco E Montero2, Juan Antonio Raga1 and Aneta Kostadinova*1,3 Address: 1Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, PO Box 22085, 46071, Valencia, Spain, 2Department of Animal Biology, Plant Biology and Ecology, Autonomous University of Barcelona, Campus Universitari, 08193, Bellaterra, Barcelona, Spain and 3Central Laboratory of General Ecology, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria Email: Diana Perdiguero-Alonso - [email protected]; Francisco E Montero - [email protected]; Juan Antonio Raga - [email protected]; Aneta Kostadinova* - [email protected] * Corresponding author Published: 18 July 2008 Received: 4 June 2008 Accepted: 18 July 2008 Parasites & Vectors 2008, 1:23 doi:10.1186/1756-3305-1-23 This article is available from: http://www.parasitesandvectors.com/content/1/1/23 © 2008 Perdiguero-Alonso et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Although numerous studies on parasites of the Atlantic cod, Gadus morhua L. have been conducted in the North Atlantic, comparative analyses on local cod parasite faunas are virtually lacking. The present study is based on examination of large samples of cod from six geographical areas of the North East Atlantic which yielded abundant baseline data on parasite distribution and abundance.
    [Show full text]
  • A Preliminary Assessment of the Native Fish Stocks of Jasper National Park
    A Preliminary Assessment of the Native Fish Stocks of Jasper National Park David W. Mayhood Part 3 of a Fish Management Plan for Jasper National Park Freshwater Research Limited A Preliminary Assessment of the Native Fish Stocks of Jasper National Park David W. Mayhood FWR Freshwater Research Limited Calgary, Alberta Prepared for Canadian Parks Service Jasper National Park Jasper, Alberta Part 3 of a Fish Management Plan for Jasper National Park July 1992 Cover & Title Page. Alexander Bajkov’s drawings of bull trout from Jacques Lake, Jasper National Park (Bajkov 1927:334-335). Top: Bajkov’s Figure 2, captioned “Head of specimen of Salvelinus alpinus malma, [female], 500 mm. in length from Jaques [sic] Lake.” Bottom: Bajkov’s Figure 3, captioned “Head of specimen of Salvelinus alpinus malma, [male], 590 mm. in length, from Jaques [sic] Lake.” Although only sketches, Bajkov’s figures well illustrate the most characteristic features of this most characteristic Jasper native fish. These are: the terminal mouth cleft bisecting the anterior profile at its midpoint, the elongated head with tapered snout, flat skull, long lower jaw, and eyes placed high on the head (Cavender 1980:300-302; compare with Cavender’s Figure 3). The head structure of bull trout is well suited to an ambush-type predatory style, in which the charr rests on the bottom and watches for prey to pass over. ABSTRACT I conducted an extensive survey of published and unpublished documents to identify the native fish stocks of Jasper National Park, describe their original condition, determine if there is anything unusual or especially significant about them, assess their present condition, outline what is known of their biology and life history, and outline what measures should be taken to manage and protect them.
    [Show full text]
  • North Carolina Wildlife Resources Commission Gordon Myers, Executive Director
    North Carolina Wildlife Resources Commission Gordon Myers, Executive Director March 1, 2016 Honorable Jimmy Dixon Honorable Chuck McGrady N.C. House of Representatives N.C. House of Representatives 300 N. Salisbury Street, Room 416B 300 N. Salisbury Street, Room 304 Raleigh, NC 27603-5925 Raleigh, NC 27603-5925 Senator Trudy Wade N.C. Senate 300 N. Salisbury Street, Room 521 Raleigh, NC 27603-5925 Dear Honorables: I am submitting this report to the Environmental Review Committee in fulfillment of the requirements of Section 4.33 of Session Law 2015-286 (H765). As directed, this report includes a review of methods and criteria used by the NC Wildlife Resources Commission on the State protected animal list as defined in G.S. 113-331 and compares them to federal and state agencies in the region. This report also reviews North Carolina policies specific to introduced species along with determining recommendations for improvements to these policies among state and federally listed species as well as nonlisted animals. If you have questions or need additional information, please contact me by phone at (919) 707-0151 or via email at [email protected]. Sincerely, Gordon Myers Executive Director North Carolina Wildlife Resources Commission Report on Study Conducted Pursuant to S.L. 2015-286 To the Environmental Review Commission March 1, 2016 Section 4.33 of Session Law 2015-286 (H765) directed the N.C. Wildlife Resources Commission (WRC) to “review the methods and criteria by which it adds, removes, or changes the status of animals on the state protected animal list as defined in G.S.
    [Show full text]
  • Gastrointestinal Helminthic Parasites of Habituated Wild Chimpanzees
    Aus dem Institut für Parasitologie und Tropenveterinärmedizin des Fachbereichs Veterinärmedizin der Freien Universität Berlin Gastrointestinal helminthic parasites of habituated wild chimpanzees (Pan troglodytes verus) in the Taï NP, Côte d’Ivoire − including characterization of cultured helminth developmental stages using genetic markers Inaugural-Dissertation zur Erlangung des Grades eines Doktors der Veterinärmedizin an der Freien Universität Berlin vorgelegt von Sonja Metzger Tierärztin aus München Berlin 2014 Journal-Nr.: 3727 Gedruckt mit Genehmigung des Fachbereichs Veterinärmedizin der Freien Universität Berlin Dekan: Univ.-Prof. Dr. Jürgen Zentek Erster Gutachter: Univ.-Prof. Dr. Georg von Samson-Himmelstjerna Zweiter Gutachter: Univ.-Prof. Dr. Heribert Hofer Dritter Gutachter: Univ.-Prof. Dr. Achim Gruber Deskriptoren (nach CAB-Thesaurus): chimpanzees, helminths, host parasite relationships, fecal examination, characterization, developmental stages, ribosomal RNA, mitochondrial DNA Tag der Promotion: 10.06.2015 Contents I INTRODUCTION ---------------------------------------------------- 1- 4 I.1 Background 1- 3 I.2 Study objectives 4 II LITERATURE OVERVIEW --------------------------------------- 5- 37 II.1 Taï National Park 5- 7 II.1.1 Location and climate 5- 6 II.1.2 Vegetation and fauna 6 II.1.3 Human pressure and impact on the park 7 II.2 Chimpanzees 7- 12 II.2.1 Status 7 II.2.2 Group sizes and composition 7- 9 II.2.3 Territories and ranging behavior 9 II.2.4 Diet and hunting behavior 9- 10 II.2.5 Contact with humans 10 II.2.6
    [Show full text]
  • Biology Two DOL38 - 41
    III. Phylum Platyhelminthes A. General characteristics All About Worms! 1. flat worms a. distinct head & tail ends 2. bilateral symmetry 3. habitat = free-living aquatic or parasitic *a. Parasite = heterotroph that gets its nutrients from the living organisms in/on which they live Ph. Platyhelminthes Ph. Nematoda Ph. Annelida 4. motile 5. carnivores or detritivores 6. reproduce sexually & asexually Biology Two DOL38 - 41 7/4/2016 B. Anatomy 3. Simple nervous system 1. have 3 body layers w/ true tissues a. brain-like ganglia in head & organs b. 2 longitudinal nerves with a. inner = endoderm transverse nerves across body b. middle = mesoderm 4. Lack respiratory, circulatory systems c. outer = ectoderm 5. Parasitic forms lack digestive & excretory systems 2. are acoelomates - lack a coelom around internal organs a. use diffusion to supply needs from host organisms a. digestive tract is formed of endoderm 6. Planaria anat. 7. Tapeworm anat. a. flat body w/ arrow-shaped head & a. head = scolex tapered tail 1) has hooks to help hold onto host b. light-sensitive eyespots on head 2) has suckers to ingest food c. body covered in cilia & mucus to aid b. body segments = proglottids movement 1) new ones form right behind head d. digestive tract only open at mouth 2) each segment produces gametes 1) in center of ventral surface 3) each houses excretory organs 2) used for feeding, excretion C. Physiology 1. Digestion (free-living) a. pharynx extends out of mouth b. sucks food into intestines for digestion c. excretory pores & mouth/pharynx remove wastes 2. Reproduction varies a. Sexual for free-living (& some parasites) 1) hermaphrodites a) cross-fertilize or self-fertilize internally b.
    [Show full text]
  • Early Stages of Fishes in the Western North Atlantic Ocean Volume
    ISBN 0-9689167-4-x Early Stages of Fishes in the Western North Atlantic Ocean (Davis Strait, Southern Greenland and Flemish Cap to Cape Hatteras) Volume One Acipenseriformes through Syngnathiformes Michael P. Fahay ii Early Stages of Fishes in the Western North Atlantic Ocean iii Dedication This monograph is dedicated to those highly skilled larval fish illustrators whose talents and efforts have greatly facilitated the study of fish ontogeny. The works of many of those fine illustrators grace these pages. iv Early Stages of Fishes in the Western North Atlantic Ocean v Preface The contents of this monograph are a revision and update of an earlier atlas describing the eggs and larvae of western Atlantic marine fishes occurring between the Scotian Shelf and Cape Hatteras, North Carolina (Fahay, 1983). The three-fold increase in the total num- ber of species covered in the current compilation is the result of both a larger study area and a recent increase in published ontogenetic studies of fishes by many authors and students of the morphology of early stages of marine fishes. It is a tribute to the efforts of those authors that the ontogeny of greater than 70% of species known from the western North Atlantic Ocean is now well described. Michael Fahay 241 Sabino Road West Bath, Maine 04530 U.S.A. vi Acknowledgements I greatly appreciate the help provided by a number of very knowledgeable friends and colleagues dur- ing the preparation of this monograph. Jon Hare undertook a painstakingly critical review of the entire monograph, corrected omissions, inconsistencies, and errors of fact, and made suggestions which markedly improved its organization and presentation.
    [Show full text]
  • Some Aspects of the Taxonomy and Biology of Adult Spirurine Nematodes Parasitic in Fishes: a Review
    FOLIA PARASITOLOGICA 54: 239–257, 2007 REVIEW ARTICLE Some aspects of the taxonomy and biology of adult spirurine nematodes parasitic in fishes: a review František Moravec Institute of Parasitology, Biology Centre, Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic Key words: Nematoda, Spirurina, Cystidicolidae, Rhabdochonidae, parasites, fish, taxonomy, biology Abstract. About 300 species belonging to four superfamilies (Gnathostomatoidea, Habronematoidea, Physalopteroidea and Thelazioidea) of the nematode suborder Spirurina are known as the adult parasites of freshwater, brackish-water and marine fishes. They are placed in four families, of which the Gnathostomatidae, including Echinocephalus with a few species and the monotypic Metaleptus, are parasites of elasmobranchs, whereas Ancyracanthus contains one species in teleosts; the Physalopteri- dae is represented in fish by four genera, Bulbocephalus, Heliconema, Paraleptus and Proleptus, each with several species in both elasmobranchs and teleosts. The majority of fish spirurines belongs to the Rhabdochonidae, which includes 10 genera (Beaninema, Fellicola, Hepatinema, Heptochona, Johnstonmawsonia, Megachona, Pancreatonema, Prosungulonema, Rhabdo- chona and Vasorhabdochona) of species parasitizing mainly teleosts, rarely elasmobranchs, and the Cystidicolidae with about 23 genera (Ascarophis, Caballeronema, Capillospirura, Comephoronema, Crenatobronema, Cristitectus, Ctenascarophis, Cyclo- zone, Cystidicola, Cystidicoloides, Johnstonmawsonoides,
    [Show full text]
  • Syn. Capillaria Plica) Infections in Dogs from Western Slovakia
    ©2020 Institute of Parasitology, SAS, Košice DOI 10.2478/helm­2020­0021 HELMINTHOLOGIA, 57, 2: 158 – 162, 2020 Case Report First documented cases of Pearsonema plica (syn. Capillaria plica) infections in dogs from Western Slovakia P. KOMOROVÁ1,*, Z. KASIČOVÁ1, K. ZBOJANOVÁ2, A. KOČIŠOVÁ1 1University of Veterinary Medicine and Pharmacy in Košice, Institute of Parasitology, Komenského 73, 041 81 Košice, Slovakia, *E-mail: [email protected]; 2Lapvet - Veterinary Clinic, Osuského 1630/44, 851 03 Bratislava, Slovakia Article info Summary Received November 12, 2019 Three clinical cases of dogs with Pearsonema plica infection were detected in the western part of Accepted February 20, 2020 Slovakia. All cases were detected within fi ve months. Infections were confi rmed after positive fi ndings of capillarid eggs in the urine sediment in following breeds. The eight years old Jack Russell Terrier, one year old Italian Greyhound, and eleven years old Yorkshire terrier were examined and treated. In one case, the infection was found accidentally in clinically healthy dog. Two other patients had nonspecifi c clinical signs such as apathy, inappetence, vomiting, polydipsia and frequent urination. This paper describes three individual cases, including the case history, clinical signs, examinations, and therapies. All data were obtained by attending veterinarian as well as by dog owners. Keywords: Urinary capillariasis; urine bladder; bladder worms; dogs Introduction prevalence in domestic dog population is unknown. The occur- rence of P. plica in domestic dogs was observed and described Urinary capillariasis caused by Pearsonema plica nematode of in quite a few case reports from Poland (Studzinska et al., 2015), family Capillariidae is often detected in wild canids.
    [Show full text]
  • Classification of Parasites BLY 459 First Lab Test (October 10, 2010)
    Classification of Parasites BLY 459 First Lab Test (October 10, 2010) If a taxonomic name is not in bold type, you will not be held responsible for it on the lab exam. Terms and common names that may be asked are also listed. I have attempted to be consistent with the taxonomic schemes in your text as well as to list all slides and live specimens that were displayed. In addition to highlighted taxa, be familiar with, material in lab handouts (especially proper nomenclature), lab display sheets, as well as material presented in lecture. Questions about vectors and locations within hosts will be asked. Be able to recognize healthy from infected tissue. Phylum Platyhelminthes (Flatworms) Class Turbellaria Dugesia (=Planaria ) Free-living, anatomy, X-section Bdelloura horseshoe crab gills Class Monogenea Gyrodactylus , Neobenedenis, Ergocotyle gills of freshwater fish Neopolystoma urinary bladder of turtles Class Trematoda ( Flukes ) Subclass Digenea Life-cycle stages: Recognize miracidia, sporocyst, redia, cercaria , metacercaria, adults & anatomy, model Order ?? Hirudinella ventricosa wahoo stomach Nasitrema nasal cavity of bottlenose dolphin Order Strigeiformes Family Schistosomatidae Schistosoma japonicum adults, male & female, liver granuloma & healthy liver, ova, cercariae, no metacercariae, adults in mesenteric intestinal veins Order Echinostomatiformes Family Fasciolidae Fasciola hepatica sheep & human liver, liver fluke Order Plagiorchiformes Family Dicrocoeliidae Dicrocoelium & Eurytrema Cure for All Diseases by Hulda Clark, Paragonimus
    [Show full text]
  • (Almindelig Ålebrosme), Lycodes Gracilis
    Atlas over danske saltvandsfisk Almindelig ålebrosme Lycodes gracilis Sars, 1867 Af Henrik Carl & Peter Rask Møller Ålebrosme på 11,5 cm fanget ca. 53 km nordvest for Hirtshals, 10. april 2016. © Henrik Carl. Projektet er finansieret af Aage V. Jensen Naturfond Alle rettigheder forbeholdes. Det er tilladt at gengive korte stykker af teksten med tydelig kildehenvisning. Teksten bedes citeret således: Carl, H. & Møller, P.R. 2019. Almindelig ålebrosme. I: Carl, H. & Møller, P.R. (red.). Atlas over danske saltvandsfisk. Statens Naturhistoriske Museum. Online-udgivelse, december 2019. Systematik og navngivning Slægten Lycodes Reinhardt, 1831 omfatter 64 arter (Froese & Pauly 2019), og den adskilles fra andre af familiens slægter på tilstedeværelsen af nogle bruskudvækster på underkæben, der muligvis har en funktion i forbindelse med fødesøgningen (Andersson 1994). Slægtens arter er udbredt i arktiske og tempererede farvande, flest arter i det nordlige Stillehav og arktiske farvande. Der findes også en enkelt art, som når helt ned til Sydafrika. Mange arter udviser stor geografisk, størrelses- og kønsbetinget variation, og slægtens systematik har derfor været ret turbulent. Den almindelige ålebrosmes systematik er ingen undtagelse. Lycodes gracilis blev beskrevet fra Norge i 1867. I 1880 blev arten beskrevet ved Island under navnet Lycodes lugubris (Lütken, 1880). Jensen (1904), reducerede arterne til underarter af Vahls ålebrosme (Lycodes vahlii), som Reinhardt havde beskrevet allerede i 1831. I 1906 blev underarten Lycodes vahlii septentrionalis beskrevet af Knipowitsch fra den sydlige del af Barentshavet. Ligeledes blev fiskene ved Canada og Vestgrønland opfattet som to forskellige underarter. Andriashev (1954, 1986) reducerede de fem underarter til to: Lycodes vahlii vahlii med 113-119 ryghvirvler (vest for Grønland) og Lycodes vahlii gracilis med 98-108 ryghvirvler (øst for Grønland).
    [Show full text]
  • Joint PINRO/IMR Report on the State of the Barents Sea Ecosystem 2006, with Expected Situation and Considerations for Management
    IMR/PINRO J O S I E N I 2 R T 2007 E R E S P O R T JOINT PINRO/IMR REPORT ON THE STATE OFTHE BARENTS SEA ECOSYSTEM IN 2006 WITH EXPECTED SITUATION AND CONSIDERATIONS FOR MANAGEMENT Institute of Marine Research - IMR Polar Research Institute of Marine Fisheries and Oceanography - PINRO This report should be cited as: Stiansen, J.E and A.A. Filin (editors) Joint PINRO/IMR report on the state of the Barents Sea ecosystem 2006, with expected situation and considerations for management. IMR/PINRO Joint Report Series No. 2/2007. ISSN 1502-8828. 209 pp. Contributing authors in alphabetical order: A. Aglen, N.A. Anisimova, B. Bogstad, S. Boitsov, P. Budgell, P. Dalpadado, A.V. Dolgov, K.V. Drevetnyak, K. Drinkwater, A.A. Filin, H. Gjøsæter, A.A. Grekov, D. Howell, Å. Høines, R. Ingvaldsen, V.A. Ivshin, E. Johannesen, L.L. Jørgensen, A.L. Karsakov, J. Klungsøyr, T. Knutsen, P.A. Liubin, L.J. Naustvoll, K. Nedreaas, I.E. Manushin, M. Mauritzen, S. Mehl, N.V. Muchina, M.A. Novikov, E. Olsen, E.L. Orlova, G. Ottersen, V.K. Ozhigin, A.P. Pedchenko, N.F. Plotitsina, M. Skogen, O.V. Smirnov, K.M. Sokolov, E.K. Stenevik, J.E. Stiansen, J. Sundet, O.V. Titov, S. Tjelmeland, V.B. Zabavnikov, S.V. Ziryanov, N. Øien, B. Ådlandsvik, S. Aanes, A. Yu. Zhilin Joint PINRO/IMR report on the state of the Barents Sea ecosystem in 2006, with expected situation and considerations for management ISSUE NO.2 Figure 1.1. Illustration of the rich marine life and interactions in the Barents Sea.
    [Show full text]
  • Endangered Species
    FEATURE: ENDANGERED SPECIES Conservation Status of Imperiled North American Freshwater and Diadromous Fishes ABSTRACT: This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society’s Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133 genera and 36 families, a 92% increase over the 364 listed in 1989. The increase reflects the addition of distinct populations, previously non-imperiled fishes, and recently described or discovered taxa. Approximately 39% of described fish species of the continent are imperiled. There are 230 vulnerable, 190 threatened, and 280 endangered extant taxa, and 61 taxa presumed extinct or extirpated from nature. Of those that were imperiled in 1989, most (89%) are the same or worse in conservation status; only 6% have improved in status, and 5% were delisted for various reasons. Habitat degradation and nonindigenous species are the main threats to at-risk fishes, many of which are restricted to small ranges. Documenting the diversity and status of rare fishes is a critical step in identifying and implementing appropriate actions necessary for their protection and management. Howard L. Jelks, Frank McCormick, Stephen J. Walsh, Joseph S. Nelson, Noel M. Burkhead, Steven P. Platania, Salvador Contreras-Balderas, Brady A. Porter, Edmundo Díaz-Pardo, Claude B. Renaud, Dean A. Hendrickson, Juan Jacobo Schmitter-Soto, John Lyons, Eric B. Taylor, and Nicholas E. Mandrak, Melvin L. Warren, Jr. Jelks, Walsh, and Burkhead are research McCormick is a biologist with the biologists with the U.S.
    [Show full text]