DOCSLIB.ORG

A New Addition to the Tardigrada of Iceland with an Updated Checklist of Icelandic Species (Eohypsibiidae, Eutardigrada)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A New Addition to the Tardigrada of Iceland with an Updated Checklist of Icelandic Species (Eohypsibiidae, Eutardigrada) University of Plymouth PEARL https://pearl.plymouth.ac.uk 01 University of Plymouth Research Outputs University of Plymouth Research Outputs 1996-11-01 Amphibolous weglarskae Dastych, a new addition to the Tardigrada of Iceland with an updated checklist of Icelandic species (Eohypsibiidae, Eutardigrada). Marley, NJ http://hdl.handle.net/10026.1/12098 Quekett Journal of Microscopy All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. Quekett Journal of Microscopy, 1996, 37, 541-545 541 Amphibolus weglarskae (Dastych), a new addition to the Tardigrada of Iceland with an updated checklist of Icelandic species. (Eohypsibiidae, Eutardigrada) N. J. MARLEY & D. E. WRIGHT Department of Biological Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, England. Summary slides in the Morgan collection held at the During the examination of the extensive Tardigrada National Museums of Scotland, Edinburgh. collections held at the Royal Museums of Scotland, Due to the very sparse number of records specimens and sculptured eggs belonging to Amphibolus available on the Tardigrada from Iceland it weglarskae (Dastych) were identified in the Morgan was considered a significant find. An updated Icelandic collection. This species had not previously taxonomic checklist to Iceland's tardigrada been reported from Iceland. A checklist of Icelandic species has been included because of the Tardigrada species is also provided. progress made since Morgan (1980) on the systematics of the entire phylum. Introduction . Results THE Tardigrada are microscopic animals which Amphibolus weglarskae (Dastych) can be found around the world in a very wide Occurrence: Olasfsjordur, near Siglufjordur. variety of habitats including marine, brackish, Slide reference: Ice 18/S254 Aug. '75, from freshwater and terrestrial interstitial systems. the Morgan Collection held at the National As a phylum they show great diversity in their Museums of Scotland. feeding, reproductive and survival strategies. Feeding preferences range from bacteria and plant cells for some species, to Description Rotifer a, Nematoda and other Tardigrada Twenty-four specimens including fourteen for carnivorous species. There are even a eggs were examined. The specimens were well few parasitic species, including Tetrakentron preserved, although some were positioned synaptae Cuenot which lives on the tentacles underneath the edge of the coverslip and of the sea cucumber, Leptosynapta galienei covered by the transparent ringing material. Herapath, in the English Channel, (Ramazzotti The cuticle of the hatched specimens was & Maucci 1983). During unfavourable micro- smooth and without obvious pigmentation, climate conditions many of the freshwater unfortunately, however, many of the techniques species encyst until optimal conditions return. used for preserving Tardigrada dissolve their However, terrestrial species have been shown pigmentation. The claws were of the distinctive to have remarkable survival abilities. Many of Amphibolus-type, with the basal tract, primary the terrestrial species can retract their legs and and secondary arms clearly defined, Fig 1. shrink their bodies into a barrel-shaped tun. The primary arms had two well developed Inside this structure they lose almost all of accessory points. Smooth lunules were present their water content and can then either be at the base of all the claws. On each of the first dispersed by the wind to a more favourable three pairs of legs, two long thin cuticular bars niche, or remain quiescent until the return of were positioned posterior to the lunules of the more favourable conditions. Once optimal double claws. The buccal tube was short, rigid conditions have returned and rehydration has and relatively wide, (54.7].lm by 9.1].lm in a taken place, active life rapidly resumed. specimen 457].lm long). The buccal aperture was A summary of the few previous Icelandic surrounded by fourteen peribuccallamellae, but Tardigrada references was given by Morgan these were not visible on all specimens. The (1980). The present new addition to the aperture at the top of the buccal tube was wide Icelandic fauna record was identified from and deep, with a posterior band of teeth, 542 N. J. MARLEY & D. E. WRIGHT FIG 1. Claws on leg II of Amphibolus weglarskae (Dastych). Bare l Oprn FIG 2. Buccopharyngeal apparatus of Amphibolus variable in size and shape. The apophysis for weglarskae (Dastych). Bar=20pffi the insertion of the stylet muscles were large Discussion ridges without the sub-divisions discussed by This species had not previously been recorded Biserov (1992). The pharyngeal bulb contained in Iceland, however it had been reported large apophysis and three macroplacoids. in Poland, Greenland and Norway (Dastych, The macroplacoids were rod-shaped, the 1988). This species may have had a wide- second the shortest and the third the longest. spread distribution in Iceland and was The first two macroplacoids were touching in probably euryhydric or hydrophillic. During many specimens, thereby appearing as a single unfavourable micro climatic conditions, ie when very large macroplacoid with a heavy medial the interstitial water was lost, this species was constriction. The latter condition was reported recorded to form cysts, (Marley, unpublished). by some authors as the first two macroplacoids In addition to the A. weglarskae specimens looking similar to the number 1. There was examined on the slide, there were 2 specimens no microplacoid or septulum. The large and one sculptured egg belonging to Macro- furcae of the stylet supports had pronounced biotus harmsworthi. However, it should be lateroventral processes terminating with bulbous noted that the label on the slide indicated that expansions with a reticulate surface, Fig 2. Macrobiotus harmsworthi and Macrobiotus The identification of this species was pullari were present. Macrobiotus pullari was facilitated by the presence of a large number of transferred to another genus by Bertolani & sculptured eggs. None of the eggs contained Pilato (1988), and should now be referred to as well developed embryos. They ranged in Murrayon pullari (Murray). No specimens of diameter, excluding projections, from 77jlm to the latter species were present on the slide, 10Sjlm, projections were up to 37jlm high. The therefore the specimens identified as M. pullari species-specific chorionic pr jections consisted were in fact A. weglarskae. Murrayon pullari of a network of inter-connecting membranous had previously been reported in Iceland by walls which had a fine reticulate sculpturing on De Connick (1939). their surface. The egg surface between the membranous projects was reticulate with Checklist of Icelandic Tardigrada species approximately five or six irregularly shaped Since Morgan (1980), the nomenclature for pores per partitioned section the Tardigrada has been reorganised many Amphibolus weglarskae (Dastych), a new addition to the Tardigrada of Iceland 543 times. The following checklist, based on the micrographs of two eggs, (Morgan, 1982). In nomenclature used in Ramazzotti & Maucci light of Biserov (1990a, b) and Bertolani & (1983), includes relevant modifications pub- Rebecchi (1993) it was assumed that more than lished since that monograph being incorporated. one species from the Macrobiotus hufelandi The literature referenced for the new taxa group was present within the Icelandic fauna. designated since Morgan (1980) are as follows: Of the remaining amendments presented Echiniscidae, Testechiniscus (Kristensen, 1987); below: Pseudechiniscus tridentifer Bartos has Eohypsibiidae, Amphibolus (Bertolani, 1981; been synonymised with Pseudechiniscus victor Bertolani & Kristensen, 1987); H ebesuncus, (Ehrenberg) Dastych (1980); Isohypsibius sattleri Mesocrista, Diphascon (Diphascon), Diphascon (Richters) was designated as a nomen nudum in (Adropion), Itaquascoriinae (Pilato, 1987); Ramazzotti & Maucci (1983) in favour of Diphasconinae (Dastych, 1992); Pseudobiotus, Isohypsibius bakonyiensis (Richters), but this was Minibiotus, Dactylobiotus (Schuster et al, 1980); revised by Dastych (1990) who recognised Ramazzottius (Binda and Pilato, 1986); 1. sattleri as a valid species following the M urrayon (Bertolani and Pilato, 1988). re-discovery of some of Richters' preserved The designations of the sub-genera Macro- material. The status of Dactylobiotus macronyx biotus (Macrobiotus) and Macrobiotus (Ortho- remained in question, Ramazzotti & Maucci macrobiotus), (Biserov, 1990a, b), have not (1983) left the status open, as did Morgan (1980). been included within this checklist, due to the More recently, Biserov (1991), reclassified his questions raised in Bertolani and Rebecchi records of D.macronyx to Dactylobiotus (1993). Morgan (1980) noted that the processes selenicus Bertolani. Until specimens of all on the eggs of Macrobiotus hufelandi were questioned species can be re-examined they have variable and later published scanning electron all been left on the fauna list. TABLE 1 Checklist of Icelandic Tardigrades. Class Heterotardigrada Order Echiniscoidea reported by Morgan (1980) as Family Echiniscidae Bryodelphax parvulus Thulin Echiniscus (Bryodelphax) Echiniscus blumi Richters Echiniscus
Load more

Recommended publications
  • An Introduction to Phylum Tardigrada - Review
    Volume V, Issue V, May 2016 IJLTEMAS ISSN 2278 – 2540 An Introduction to phylum Tardigrada - Review Yashas R Devasurmutt1, Arpitha B M1* 1: R & D Centre, Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, India 1*: Corresponding Author: Arpitha B M Abstract: Tardigrades popularly known as water bears are In cryptobiosis (extreme form of anabiosis), the metabolism is micrometazoans with four pairs of lobopod legs. They are the undetectable and the animal is known as tun in this phase. organisms which can live in extreme conditions and are known to Tuns have been known to survive very harsh environmental survive in vacuum and space without protection. Tardigardes conditions such as immersion in helium at -272° C (-458° F) survive in lichens and mosses, usually associated with water film or heating temperatures at 149° C (300° F), exposure to very on mosses, liverworts, and lichens. More species are found in high ionizing radiation and toxic chemical substances and milder environments such as meadows, ponds and lakes. They long durations without oxygen. [4] Figure 2 illustrates the are the first known species to survive in outer space. Tardigrades process of transition of the tardigrades[41]. are closely related to Arthropoda and nematodes based on their morphological and molecular analysis. The cryptobiosis of Figure 2: Transition process of Tardigrades Tardigrades have helped scientists to develop dry vaccines. They have been applied as research subjects in transplantology. Future research would help in more applications of tardigrades in the field of science. Keywords: Tardigrades, cryptobiosis, dry vaccines, Transplantology, space research I. INTRODUCTION ardigrade, a group of tiny arthropod-like animals having T four pairs of stubby legs with big claws, an oval stout body with a round back and lumbering gait.
    [Show full text]
  • Diapause in Tardigrades: a Study of Factors Involved in Encystment
    2296 The Journal of Experimental Biology 211, 2296-2302 Published by The Company of Biologists 2008 doi:10.1242/jeb.015131 Diapause in tardigrades: a study of factors involved in encystment Roberto Guidetti1,*, Deborah Boschini2, Tiziana Altiero2, Roberto Bertolani2 and Lorena Rebecchi2 1Department of the Museum of Paleobiology and Botanical Garden, Via Università 4, 41100, Modena, Italy and 2Department of Animal Biology, University of Modena and Reggio Emilia, Via Campi 213/D, 41100, Modena, Italy *Author for correspondence (e-mail: [email protected]) Accepted 12 May 2008 SUMMARY Stressful environmental conditions limit survival, growth and reproduction, or these conditions induce resting stages indicated as dormancy. Tardigrades represent one of the few animal phyla able to perform both forms of dormancy: quiescence and diapause. Different forms of cryptobiosis (quiescence) are widespread and well studied, while little attention has been devoted to the adaptive meaning of encystment (diapause). Our goal was to determine the environmental factors and token stimuli involved in the encystment process of tardigrades. The eutardigrade Amphibolus volubilis, a species able to produce two types of cyst (type 1 and type 2), was considered. Laboratory experiments and long-term studies on cyst dynamics of a natural population were conducted. Laboratory experiments demonstrated that active tardigrades collected in April produced mainly type 2 cysts, whereas animals collected in November produced mainly type 1 cysts, indicating that the different responses are functions of the physiological state at the time they were collected. The dynamics of the two types of cyst show opposite seasonal trends: type 2 cysts are present only during the warm season and type 1 cysts are present during the cold season.
    [Show full text]
  • BURSA İLİ LİMNOKARASAL TARDIGRADA FAUNASI Tufan ÇALIK
    BURSA İLİ LİMNOKARASAL TARDIGRADA FAUNASI Tufan ÇALIK T.C. ULUDA Ğ ÜN İVERS İTES İ FEN B İLİMLER İ ENST İTÜSÜ BURSA İLİ LİMNOKARASAL TARDIGRADA FAUNASI Tufan ÇALIK Yrd. Doç. Dr. Rah şen S. KAYA (Danı şman) YÜKSEK L İSANS TEZ İ BİYOLOJ İ ANAB İLİM DALI BURSA-2017 ÖZET Yüksek Lisans Tezi BURSA İLİ LİMNOKARASAL TARDIGRADA FAUNASI Tufan ÇALIK Uluda ğ Üniversitesi Fen Bilimleri Enstitüsü Biyoloji Anabilim Dalı Danı şman: Yrd. Doç. Dr. Rah şen S. KAYA Bu çalı şmada, Bursa ili limnokarasal Tardigrada faunası ara ştırılmı ş, 6 familyaya ait 9 cins içerisinde yer alan 12 takson tespit edilmi ştir. Arazi çalı şmaları 09.06.2016 ile 22.02.2017 tarihleri arasında gerçekle ştirilmi ştir. Arazi çalı şmaları sonucunda 35 lokaliteden toplanan kara yosunu ve liken materyallerinden toplam 606 örnek elde edilmi ştir. Çalı şma sonucunda tespit edilen Cornechiniscus sp., Echiniscus testudo (Doyere, 1840), Echiniscus trisetosus Cuenot, 1932, Milnesium sp., Isohypsibius prosostomus prosostomus Thulin, 1928, Macrobiotus sp., Paramacrobiotus areolatus (Murray, 1907), Paramacrobiotus richtersi (Murray, 1911), Ramazzottius oberhaeuseri (Doyere, 1840) ve Richtersius coronifer (Richters, 1903) Bursa ilinden ilk kez kayıt edilmi ştir. Anahtar kelimeler: Tardigrada, Sistematik, Fauna, Bursa, Türkiye 2017, ix+ 85 sayfa i ABSTRACT MSc Thesis THE LIMNO-TERRESTRIAL TARDIGRADA FAUNA OF BURSA PROVINCE Tufan ÇALIK Uludag University Graduate School of Natural andAppliedSciences Department of Biology Supervisor: Asst. Prof. Dr. Rah şen S. KAYA In this study, the limno-terrestrial Tardigrada fauna of Bursa province was studied and 12 taxa in 9 genera which belongs to 6 families were identified. Field trips were conducted between 09.06.2016 and 22.02.2017.
    [Show full text]
  • Pseudechiniscus in Japan: Re-Description of Pseudechiniscus Asper
    Pseudechiniscus in Japan re-description of Pseudechiniscus asper Abe et al., 1998 and description of Pseudechiniscus shintai sp. nov. Voncina, Katarzyna; Kristensen, Reinhardt M.; Gsiorek, Piotr Published in: Zoosystematics and Evolution DOI: 10.3897/zse.96.53324 Publication date: 2020 Document version Publisher's PDF, also known as Version of record Document license: CC BY Citation for published version (APA): Voncina, K., Kristensen, R. M., & Gsiorek, P. (2020). Pseudechiniscus in Japan: re-description of Pseudechiniscus asper Abe et al., 1998 and description of Pseudechiniscus shintai sp. nov. Zoosystematics and Evolution, 96(2), 527-536. https://doi.org/10.3897/zse.96.53324 Download date: 27. sep.. 2021 Zoosyst. Evol. 96 (2) 2020, 527–536 | DOI 10.3897/zse.96.53324 Pseudechiniscus in Japan: re-description of Pseudechiniscus asper Abe et al., 1998 and description of Pseudechiniscus shintai sp. nov. Katarzyna Vončina1, Reinhardt M. Kristensen2, Piotr Gąsiorek1 1 Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland 2 Section for Biosystematics, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, Copenhagen Ø DK-2100, Denmark http://zoobank.org/F79B0B2D-728D-4A3D-B3C3-06A1C3405F00 Corresponding author: Piotr Gąsiorek ([email protected]) Academic editor: Pavel Stoev ♦ Received 16 April 2020 ♦ Accepted 2 June 2020 ♦ Published 1 September 2020 Abstract The classification and identification of species within the genusPseudechiniscus Thulin, 1911 has been considered almost a Sisyphe- an work due to an extremely high homogeneity of its members. Only recently have several contributions made progress in the tax- onomy feasible through their detailed analyses of morphology and, crucially, by the re-description of the ancient, nominal species P.
    [Show full text]
  • Eutardigrada: Parachela) from Antarctica That Reveals an Intraspecifc Variation in Tardigrade Egg Morphology Ji-Hoon Kihm1,2, Sanghee Kim 3, Sandra J
    www.nature.com/scientificreports OPEN Integrative description of a new Dactylobiotus (Eutardigrada: Parachela) from Antarctica that reveals an intraspecifc variation in tardigrade egg morphology Ji-Hoon Kihm1,2, Sanghee Kim 3, Sandra J. McInnes 4, Krzysztof Zawierucha 5, Hyun Soo Rho6, Pilmo Kang1 & Tae-Yoon S. Park 1,2 ✉ Tardigrades constitute one of the most important group in the challenging Antarctic terrestrial ecosystem. Living in various habitats, tardigrades play major roles as consumers and decomposers in the trophic networks of Antarctic terrestrial and freshwater environments; yet we still know little about their biodiversity. The Eutardigrada is a species rich class, for which the eggshell morphology is one of the key morphological characters. Tardigrade egg morphology shows a diverse appearance, and it is known that, despite rare, intraspecifc variation is caused by seasonality, epigenetics, and external environmental conditions. Here we report Dactylobiotus ovimutans sp. nov. from King George Island, Antarctica. Interestingly, we observed a range of eggshell morphologies from the new species, although the population was cultured under controlled laboratory condition. Thus, seasonality, environmental conditions, and food source are eliminated, leaving an epigenetic factor as a main cause for variability in this case. Phylum Tardigrada is a microscopic metazoan group, characterized by having four pairs of legs usually termi- nated with claws, and is considered to be related to the arthropods and onychophorans1. Tey have attracted attention due to their cryptobiotic ability2–7, which helps them to occupy a variety of habitats throughout the world, including the harsh environments of Antarctica. Te challenging environments of Antarctica are rep- resented by a depauperate biodiversity, in which tardigrades have become one of the dominant invertebrate groups8–13.
    [Show full text]
  • Tardigrade Reproduction and Food
    Glime, J. M. 2017. Tardigrade Reproduction and Food. Chapt. 5-2. In: Glime, J. M. Bryophyte Ecology. Volume 2. Bryological 5-2-1 Interaction. Ebook sponsored by Michigan Technological University and the International Association of Bryologists. Last updated 18 July 2020 and available at <http://digitalcommons.mtu.edu/bryophyte-ecology2/>. CHAPTER 5-2 TARDIGRADE REPRODUCTION AND FOOD TABLE OF CONTENTS Life Cycle and Reproductive Strategies .............................................................................................................. 5-2-2 Reproductive Strategies and Habitat ............................................................................................................ 5-2-3 Eggs ............................................................................................................................................................. 5-2-3 Molting ......................................................................................................................................................... 5-2-7 Cyclomorphosis ........................................................................................................................................... 5-2-7 Bryophytes as Food Reservoirs ........................................................................................................................... 5-2-8 Role in Food Web ...................................................................................................................................... 5-2-12 Summary ..........................................................................................................................................................
    [Show full text]
  • Two New Species of Tardigrada from the Canadian Subarctic with Some
    ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Entomologische Mitteilungen aus dem Zoologischen Museum Hamburg Jahr/Year: 1984 Band/Volume: 8 Autor(en)/Author(s): Dastych Hieronymus Artikel/Article: Two new species of Tardigrada from the Canadian Subarctic with some notes on sexual dimorphism in the family Echiniscidae 319-334 ©Zoologisches Museum Hamburg, www.zobodat.at Entomol. Mitt. zool. Mus. Hamburg Bd. 8 (1987) Nr. 129 Two new species of Tardigrada from the Canadian Subarctic with some notes on sexual dimorphism in the family Echiniscidae H ieronim D astych (With 15 figures) Abstract Two new terrestrial water-bears, Pseudechiniscus alberti sp. n. (Heterotardigrada) and Diphascon behanae sp. n. (Eutardigrada) are described from mosses collected in the Canadian Subarctic (Ogilvie Mtns). The latter species also occurs in West Spitsbergen. Until recently males were unknown in the genus Echiniscus, which was thought to be a purely parthenogenetic taxon. The description and illustration of a male Pseudechiniscus alberti sp. n. is given and the presence of males in four species of the genus Echiniscus is reported and discussed. Introduction The vast areas of Arctic and Subarctic zones in North America are very poorly studied with respect to the tardi­ grade fauna, despite the fact that the role of these animals in polar ecosystems is much greater than commonly judged. Very little has been published about tardigrades of this region (MATHEWS 1938, SCHUSTER & GRIGARICK 1965, DASTYCH 1982, MEININGER & NELSON in press, WEGLARSKA 1970, WEGLARSKA & KUC 1980) and only the papers of WEGLARSKA are devoted to the Canadian Arctic.
    [Show full text]
  • LOUISIANA SCIENTIST Vol. 3 No. 1
    LOUISIANA SCIENTIST THE NEWSLETTER of the LOUISIANA ACADEMY OF SCIENCES Volume 3, Number 1 (2012 Annual Meeting Abstracts) Published by THE LOUISIANA ACADEMY OF SCIENCES 15 July 2012 Louisiana Academy of Sciences Abstracts of Presentations 2012 Annual Meeting Louisiana State University at Alexandria Alexandria, Louisiana 03 March 2012 Table of Contents Division/Section Page Division of Agriculture, Forestry, and Wildlife . 4 Division of Biological Sciences . 8 Botany Section . 8 Environmental Sciences Section . 9 Microbiology Section . 12 Molecular and Biomedical Biology Section . 18 Zoology Section . 21 Division of Physical Sciences . 30 Chemistry Section . 30 Computer Science Section . 34 Earth Sciences Section . 39 Materials Science and Engineering Section . 40 Mathematics and Statistics Section . 43 Physics Section . 44 Division of Science Education . 47 Higher Education Section . 47 K-12 Education Section . 47 Division of Sciences and Humanities . 49 Division of Social Sciences . 52 Acknowledgement . 58 2 The following abstracts of oral and poster presentations represent those received by the Abstract Editor. Authors’ affiliations are abbreviated as follows: CC Cedar Creek School, Ruston, LA CCTPCC Cal-Cam Termite and Pest Control Co., Lake Charles CPRUHS College of Pharmacy, Roseman University of Health Sciences, Henderson, NV CU Covenant University, Ota, Nigeria ECOFS El Colegio de la Frontera Sur, Mexico EHS Episcopal High School, Baton Rouge GSU Grambling State University HCS Holy Cross School, New Orleans IPN Instituto Politécnico
    [Show full text]
  • A Checklist of Norwegian Tardigrada
    Fauna norvegica 2017 Vol. 37: 25-42. A checklist of Norwegian Tardigrada Terje Meier1 Meier T. 2017. A checklist of Norwegian Tardigrada. Fauna norvegica 37: 25-42. Animals of the phylum Tardigrada are microscopical metazoans that seldom exceed 1 mm in length. They are recorded from terrestrial, limnic and marine habitats and they have a distribution from Arctic to Antarctica. Tardigrades are also named ‘water bears’ referring to their ‘walk’ that resembles a bear’s gait. Knowledge of Norwegian tardigrades is fragmented and distributed across numerous sources. Here this information is gathered and validity of some records is discussed. In total 146 different species are recorded from the Norwegian mainland and Svalbard. Among these, 121 species and subspecies are recorded in previous publications and another 25 species are recorded from Norway for the first time. doi: 10.5324/fn.v37i0.2269. Received: 2017-05-22. Accepted: 2017-12-06. Published online: 2017-12.20. ISSN: 1891-5396 (electronic). Keywords: Tardigrada, Norway, Svalbard, checklist, taxonomy, literature, biodiversity, new records 1. Prinsdalsfaret 20, NO-1262 Oslo, Norway. Corresponding author: Terje Meier E-mail: [email protected] INTRODUCTION terminating in claws or sucking disks. The first three pairs of legs are directed ventrolaterally and are used to moving over the The phylum Tardigrada (water bears) currently holds about substrate. The hind legs are directed posteriorly and are used for 1250 valid species and subspecies (Degma et al. 2007, Degma grasping. Adult Tardigrades usually range from 250 µm to 700 et al. 2017) and are found in a great variety of habitats. They µm in length.
    [Show full text]
  • The Wonders of Mauritius
    Evolutionary Systematics. 5 2021, 93–120 | DOI 10.3897/evolsyst.5.59997 Echiniscidae in the Mascarenes: the wonders of Mauritius Yevgen Kiosya1, Katarzyna Vončina2, Piotr Gąsiorek2 1 School of Biology, V. N. Karazin Kharkiv National University, Svobody Sq. 4, 61022 Kharkiv, Ukraine 2 Department of Invertebrate Evolution, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland http://zoobank.org/22050C34-40A5-4B7A-9969-222AE927D6AA Corresponding author: Piotr Gąsiorek ([email protected]) Academic editor: A. Schmidt-Rhaesa ♦ Received 24 October 2020 ♦ Accepted 7 December 2020 ♦ Published 9 April 2021 Abstract Many regions of the world remain unexplored in terms of the tardigrade diversity, and the islands of the Indian Ocean are no excep- tion. In this work, we report four species of the family Echiniscidae representing three genera from Mauritius, the second largest is- land in the Mascarene Archipelago. Two species belong in the genus Echiniscus: Echiniscus perarmatus Murray, 1907, a pantropical species, and one new species: Echiniscus insularis sp. nov., one of the smallest members of the spinulosus group and the entire genus, being particularly interesting due to the presence of males and supernumerary teeth-like spicules along the margins of the dorsal plates. The new species most closely resembles Echiniscus tropicalis Binda & Pilato, 1995, for which we present extensive mul- tipopulation data and greatly extend its distribution eastwards towards islands of Southeast Asia. Pseudechiniscus (Meridioniscus) mascarenensis sp. nov. is a typical member of the subgenus with elongated (dactyloid) cephalic papillae and the pseudosegmental plate IV’ with reduced posterior projections in males. Finally, a Bryodelphax specimen is also recorded.
    [Show full text]
  • Tardigrada, Heterotardigrada)
    bs_bs_banner Zoological Journal of the Linnean Society, 2013. With 6 figures Congruence between molecular phylogeny and cuticular design in Echiniscoidea (Tardigrada, Heterotardigrada) NOEMÍ GUIL1*, ASLAK JØRGENSEN2, GONZALO GIRIBET FLS3 and REINHARDT MØBJERG KRISTENSEN2 1Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales de Madrid (CSIC), José Gutiérrez Abascal 2, 28006, Madrid, Spain 2Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, Copenhagen, Denmark 3Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA Received 21 November 2012; revised 2 September 2013; accepted for publication 9 September 2013 Although morphological characters distinguishing echiniscid genera and species are well understood, the phylogenetic relationships of these taxa are not well established. We thus investigated the phylogeny of Echiniscidae, assessed the monophyly of Echiniscus, and explored the value of cuticular ornamentation as a phylogenetic character within Echiniscus. To do this, DNA was extracted from single individuals for multiple Echiniscus species, and 18S and 28S rRNA gene fragments were sequenced. Each specimen was photographed, and published in an open database prior to DNA extraction, to make morphological evidence available for future inquiries. An updated phylogeny of the class Heterotardigrada is provided, and conflict between the obtained molecular trees and the distribution of dorsal plates among echiniscid genera is highlighted. The monophyly of Echiniscus was corroborated by the data, with the recent genus Diploechiniscus inferred as its sister group, and Testechiniscus as the sister group of this assemblage. Three groups that closely correspond to specific types of cuticular design in Echiniscus have been found with a parsimony network constructed with 18S rRNA data.
    [Show full text]
  • Extreme Tolerance in the Eutardigrade Species H. Dujardini
    EXTREME TOLERANCE IN THE EUTARDIGRADE SPECIES H. DUJARDINI EXTREME TOLERANCE IN THE EUTARDIGRADE SPECIES HYPSIBIUS DUJARDINI BY: TARUSHIKA VASANTHAN, B. Sc., M. Sc. A Thesis Submitted to the School of Graduate Studies in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy McMaster University © Copyright by Tarushika Vasanthan, September 2017 DOCTOR OF PHILOSOPHY OF SCIENCE (2017) McMaster University (Biology) Hamilton, Ontario TITLE: Examining the Upper and Lower Limits of Extreme Tolerance in the Eutardigrade Species Hypsibius dujardini AUTHOR: Tarushika Vasanthan, M. Sc. (McMaster University), B. Sc. (McMaster University) SUPERVISOR: Professor Jonathon R. Stone NUMBER OF PAGES: 124 ii Ph.D. Thesis - T. Vasanthan McMaster University – Biology – Astrobiology LAY ABSTRACT While interest in tardigrade extreme tolerance research has increased over the last decade, many research areas continue to be underrepresented or non- existent. And, while recognized tardigrade species have been increasing steadily in number, fundamental biological details, like individual life history traits, remain unknown for most. The main objectives in this thesis therefore were to survey the life history traits for the freshwater tardigrade species Hypsibius dujardini, increase knowledge about its extreme-tolerance abilities and describe its utility in astrobiological and biological studies. Research involved tardigrade tolerance to hypergravity, pH levels and radiation exposure (and associated radiation-induced bystander effects) as well as responses to temperature changes during development. Findings reported in this dissertation provide new data about H. dujardini, thereby narrowing the information gap that currently exists in the literature for this species. iii Ph.D. Thesis - T. Vasanthan McMaster University – Biology – Astrobiology ABSTRACT Tardigrades are microscopic animals that can survive exposure to multiple extreme conditions.
    [Show full text]