DOCSLIB.ORG

I FLATWORM PREDATION on JUVENILE FRESHWATER

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read 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. Captive culture for even a few weeks might improve the survival of propagated juveniles if flatworm predation also occurs in nature. This abstract is approved as to form and content ___________________________________ Chairperson, Advisory Committee Southwest Missouri State University ii FLATWORM PREDATION ON JUVENILE FRESHWATER MUSSELS by Angela Delp A Thesis Submitted to the Graduate College of Southwest Missouri State University in Partial Fulfillment of the Requirements for the Degree of Master of Science July 2002 Approved: ____________________________________ Chairperson ____________________________________ Member ____________________________________ Member ____________________________________ Associate Vice President for Academic Affairs and Dean of the Graduate College iii ACKNOWLEDGEMENTS I first recognize my mentor Dr. Chris Barnhart. He has given me more confidence in myself and helped me develop my analytical abilities and writing skills. Dr. Barnhart is enthusiastic about science, constantly questioning the biological interactions in the world around him. He never ceases to amaze me with his seemingly unlimited interests and intelligence. I am proud to say I have worked with this outstanding malacologist. Thanks to Dr. John Havel and Dr. Alicia Mathis for being on my thesis committee. Dr. Havel helped me identify an ostracod I used in one of my pilot studies. Dr. Mathis helped me with the design of my alternative prey experiment. They both are exceptional scientists and have offered me valuable advice. I am honored to have been their pupil. I think Havel and Mathis are irreplaceable assets to this school. I received useful flatworm information from Dr. Jurek Kolasa and Dr. George Shinn. Kolasa had helped me identify the predator organism, when I was starting out. I was able to ask him any questions I had about the flatworms via email. Shinn informed me on the egg capsule structure of Macrostomum. He gave me some key references to help me with some questions I had. This thesis is dedicated to my mom, dad, sister, and grandparents. They have been loving and supportive throughout my life. I hope that I have influenced them as positively as they have influenced me. The Graduate College and the Department of Biology at Southwest Missouri State University provided funding for this project. Christian Hutson collected mussels for my project. Melissa Shiver, Shannon Bigham, Jeremy Myers, and Matt Stone assisted in the laboratory. Kristen Pattinson and Tina Tamme helped with identifying and culturing zooplankton. iv TABLE OF CONTENTS ABSTRACT .....................................................................................................................ii ACKNOWLEDGEMENTS ............................................................................................iv LIST OF TABLES AND FIGURES ...............................................................................vi INTRODUCTION ........................................................................................................... 1 METHODS ...................................................................................................................... 5 Effects of substrate on predation ............................................................................... 7 Effects of alternative prey on predation ..................................................................... 8 Effects of flatworm size on predation ......................................................................... 9 RESULTS ...................................................................................................................... 10 Flatworm identification ............................................................................................ 10 Occurrence of flatworms........................................................................................... 11 Culturing flatworms ................................................................................................. 12 Effect of substrate on predation ............................................................................... 13 Effect of alternative prey on predation .................................................................... 13 Effect of flatworm size on predation ........................................................................ 13 DISCUSSION ................................................................................................................ 14 Effect of substrate on predation ............................................................................... 14 Prey preference ........................................................................................................ 15 Effect of size on predation rate ................................................................................ 17 LITERATURE CITED .................................................................................................. 20 TABLES AND FIGURES ............................................................................................. 25 v LIST OF TABLES AND FIGURES Table 1. Rates of predation by Macrostomum tuba ..................................................... 25 Figure 1. Macrostomum flatworm ................................................................................ 26 Figure 2. Microstomum flatworm ................................................................................. 27 Figure 3. Extraction of glochidia .................................................................................. 28 Figure 4. Polyurethane foam used as substrate ............................................................. 29 Figure 5. Mesostoma flatworm ..................................................................................... 30 Figure 6. Penis stylet of Macrostomum tuba ................................................................ 31 vi INTRODUCTION This study concerns the predatory behavior of flatworms in the Class Turbellaria of the Phylum Platyhelminthes. The phylogeny of Platyhelminthes is poorly understood and there is currently no universally accepted classification of the phylum (Tyler, 1999). The Class Turbellaria is probably not a monophyletic group, but it is retained in most recent classifications pending further clarification of relationships. Within the Turbellaria, the species considered in this study have historically been classified in the Order Rhabdocoela. Like Turbellaria, Rhabdocoela is also no longer thought to be a phylogenetic grouping, and the species in this taxon have recently been distributed into 3 orders, the Catenulida, Macrostomida, and Neorhabdocoela (Tyler, 1999; Pechenik, 2000). Nevertheless, small turbellarians with linear guts are still commonly referred to as rhabdocoels (="linear gut"). Small Turbellaria (~4 mm or smaller), which are mainly rhabodocoels, are also referred to as "microturbellaria". Species having larger body size (mainly triclads and polyclads) are referred to as "macroturbellaria" (Pennak, 1989; Tyler, 1999). There are approximately 400 species of freshwater microturbellaria, of which approximately 150 occur in North America (Kolasa, 2001). Diversity in lakes and ponds in temperate regions can range from 20 to 60 species in a single habitat, depending on nutrient availability and other factors (Kolasa, 2001). Freshwater turbellarians can be found in a variety of habitats including ponds, lakes, streams, and temporary pools. Most are negatively phototactic and many occupy interstitial spaces in benthic habitats (Pennak, 1989). The habitat of microturbellarians ranges from cold areas like Igloolik, NWT, Canada (68o north latitude) to warm tropical areas to caves and underground 1 waters. As many as 40,000 individuals per square meter can occur in littoral zones of oligotrophic lakes (Kolasa, 2001). Turbellaria may reproduce either asexually or
Load more

Recommended publications
  • 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]
  • Cumulated Bibliography of Biographies of Ocean Scientists Deborah Day, Scripps Institution of Oceanography Archives Revised December 3, 2001
    Cumulated Bibliography of Biographies of Ocean Scientists Deborah Day, Scripps Institution of Oceanography Archives Revised December 3, 2001. Preface This bibliography attempts to list all substantial autobiographies, biographies, festschrifts and obituaries of prominent oceanographers, marine biologists, fisheries scientists, and other scientists who worked in the marine environment published in journals and books after 1922, the publication date of Herdman’s Founders of Oceanography. The bibliography does not include newspaper obituaries, government documents, or citations to brief entries in general biographical sources. Items are listed alphabetically by author, and then chronologically by date of publication under a legend that includes the full name of the individual, his/her date of birth in European style(day, month in roman numeral, year), followed by his/her place of birth, then his date of death and place of death. Entries are in author-editor style following the Chicago Manual of Style (Chicago and London: University of Chicago Press, 14th ed., 1993). Citations are annotated to list the language if it is not obvious from the text. Annotations will also indicate if the citation includes a list of the scientist’s papers, if there is a relationship between the author of the citation and the scientist, or if the citation is written for a particular audience. This bibliography of biographies of scientists of the sea is based on Jacqueline Carpine-Lancre’s bibliography of biographies first published annually beginning with issue 4 of the History of Oceanography Newsletter (September 1992). It was supplemented by a bibliography maintained by Eric L. Mills and citations in the biographical files of the Archives of the Scripps Institution of Oceanography, UCSD.
    [Show full text]
  • Platyhelminthes Rhabdocoela
    Molecular Phylogenetics and Evolution 120 (2018) 259–273 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev Species diversity in the marine microturbellarian Astrotorhynchus bifidus T sensu lato (Platyhelminthes: Rhabdocoela) from the Northeast Pacific Ocean ⁎ Niels W.L. Van Steenkiste , Elizabeth R. Herbert, Brian S. Leander Beaty Biodiversity Research Centre, Department of Zoology, University of British Columbia, 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada ARTICLE INFO ABSTRACT Keywords: Increasing evidence suggests that many widespread species of meiofauna are in fact regional complexes of Flatworms (pseudo-)cryptic species. This knowledge has challenged the ‘Everything is Everywhere’ hypothesis and also Meiofauna partly explains the meiofauna paradox of widespread nominal species with limited dispersal abilities. Here, we Species delimitation investigated species diversity within the marine microturbellarian Astrotorhynchus bifidus sensu lato in the turbellaria Northeast Pacific Ocean. We used a multiple-evidence approach combining multi-gene (18S, 28S, COI) phylo- Pseudo-cryptic species genetic analyses, several single-gene and multi-gene species delimitation methods, haplotype networks and COI conventional taxonomy to designate Primary Species Hypotheses (PSHs). This included the development of rhabdocoel-specific COI barcode primers, which also have the potential to aid in species identification and delimitation in other rhabdocoels. Secondary Species Hypotheses (SSHs) corresponding to morphospecies and pseudo-cryptic species were then proposed based on the minimum consensus of different PSHs. Our results showed that (a) there are at least five species in the A. bifidus complex in the Northeast Pacific Ocean, four of which can be diagnosed based on stylet morphology, (b) the A.
    [Show full text]
  • Cephalopodologie
    Reprint Series W /~»T ¥7 "IVT^l? 18 May 1990, Volume 248, pp. 898-899 OvJ-lLllL/EJ Cephalopodologie CLYDE F. E. ROPER Copyright © 1990 by the American Association for the Advancement of Science Cephalopodologie work to be outdated, Portmann abandoned the notes and wrote a 200-page manuscript, which he submitted in 1954. Because the Traits de Zoologie. Anatomic, Systcmatique, recendy submitted gastropod and bivalve Biologic. PIERRE P. GRASSE, Ed. Tome 5, fasci- manuscripts ran to 4600 pages, Grasse re- cule 4, Cephalopodes. KATHARINA. MANGOLD, quired that the cephalopod section be in- Ed. Masson, Paris, 1989. 804 pp. F1100. creased to 400, a task the displeased Port- Comprehensive reference works frequent- mann was unwilling to undertake until the ly require a number of years to compile, are early 1960s. The resurgence of research on eagerly awaited by specialists, and once pub- cephalopods then prompted Portmann to lished gradually come into general use by enlist Katharina Mangold, a former student researchers, educators, and students. The and established cephalopod specialist at La- volumes of The Invertebrates inaugurated by boratoire Arago, Banyuls-sur-Mer, France, Libbie Hyman in 1940 provide an excellent to incorporate the new literature into the example of such a history, as does the classic manuscript. By the time one section was Traite de Zoologie directed by Pierre P. updated, preceding ones had become obso- Grasse. lete, and, as the objective of the Traite was to Among works of such lengthy gestation be "comprehensive," the project became the present installment of the Traite surely locked in a cycle of updates.
    [Show full text]
  • Metacommunities and Biodiversity Patterns in Mediterranean Temporary Ponds: the Role of Pond Size, Network Connectivity and Dispersal Mode
    METACOMMUNITIES AND BIODIVERSITY PATTERNS IN MEDITERRANEAN TEMPORARY PONDS: THE ROLE OF POND SIZE, NETWORK CONNECTIVITY AND DISPERSAL MODE Irene Tornero Pinilla Per citar o enllaçar aquest document: Para citar o enlazar este documento: Use this url to cite or link to this publication: http://www.tdx.cat/handle/10803/670096 http://creativecommons.org/licenses/by-nc/4.0/deed.ca Aquesta obra està subjecta a una llicència Creative Commons Reconeixement- NoComercial Esta obra está bajo una licencia Creative Commons Reconocimiento-NoComercial This work is licensed under a Creative Commons Attribution-NonCommercial licence DOCTORAL THESIS Metacommunities and biodiversity patterns in Mediterranean temporary ponds: the role of pond size, network connectivity and dispersal mode Irene Tornero Pinilla 2020 DOCTORAL THESIS Metacommunities and biodiversity patterns in Mediterranean temporary ponds: the role of pond size, network connectivity and dispersal mode IRENE TORNERO PINILLA 2020 DOCTORAL PROGRAMME IN WATER SCIENCE AND TECHNOLOGY SUPERVISED BY DR DANI BOIX MASAFRET DR STÉPHANIE GASCÓN GARCIA Thesis submitted in fulfilment of the requirements to obtain the Degree of Doctor at the University of Girona Dr Dani Boix Masafret and Dr Stéphanie Gascón Garcia, from the University of Girona, DECLARE: That the thesis entitled Metacommunities and biodiversity patterns in Mediterranean temporary ponds: the role of pond size, network connectivity and dispersal mode submitted by Irene Tornero Pinilla to obtain a doctoral degree has been completed under our supervision. In witness thereof, we hereby sign this document. Dr Dani Boix Masafret Dr Stéphanie Gascón Garcia Girona, 22nd November 2019 A mi familia Caminante, son tus huellas el camino y nada más; Caminante, no hay camino, se hace camino al andar.
    [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]
  • Biology of the Polyclad Prosthiostomum (Prosthiostomum) Sp
    Pacific Science (1974), Vol. 28, No.4, p. 361-373 Printed in Great Britain Biology of the Polyclad Prosthiostomum (Prosthiostomum) sp., a New Coral Parasite from Hawaii I PAUL L. JOKIEL2 AND SIDNEY J. TOWNSLEy3 ABSTRACT: Prosthiostomum (Prosthiostomum) sp., a species of polyclad flatworm yet to be described, is an obligate ectoparasitic symbiont of the hermatypic coral Montipora. Field and laboratory studies have demonstrated an intimate parasite/host association involving the utilization of host corals as food and sub­ strate by the parasite. Development of larvae is within the immediate host en­ vironment; consequently, infections are produced through direct infection. Various aspects of the biology, such as the developmental history, feeding habits, and parasite/host response to thermal environment, are reported. It is concluded that all aspects ofthe life history ofthis species show adaptations toward host specificity. This represents a rare example oftrue coral parasitism since most animals known to feed on coral tissues are considered to be facultative predators. The optimal thermal environment for the parasite appears to coincide with that of the coral host, a phenomenon which may tend to produce a seasonally stable parasite/host inter­ action. The parasite appears to become a serious coral pest only in disrupted systems such as artificial laboratory situations or in the polluted sections of Kaneohe Bay, Oahu. UNTIL THE LAST DECADE the Scleractinia and identified by Jean Poulter as Prosthiostomum their relatives were believed to be nearly im­ (Prosthiostomum) sp. This discovery led us to mune to predation and parasitism (Wells 1957). invesdgate the host specificity, the method However, records ofanimals known to feed on and frequency of infection, and various other living coral tissues and coral mucus have been aspects of its biology.
    [Show full text]
  • Platyhelminthes: Polycladida) in Botany Bay, New South Wales, Australia
    TAXONOMY AND ECOLOGY OF PREDATORY MARINE FLATWORMS (PLATYHELMINTHES: POLYCLADIDA) IN BOTANY BAY, NEW SOUTH WALES, AUSTRALIA by Ka-Man Lee A thesis submitted in fulfilment of the requirements for the degree of Master of Science by research University of New South Wales April 2006 ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project’s design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed Ka-Man Lee April 2006 II ACKNOWLEDGEMENTS Without the encouragement and enthusiasm of my supervisor, Dr. Emma Johnston, this thesis would not have been possible. Thank you for allowing me to pursue some innovative experiments and for your inspiration and criticism along the way. I thoroughly appreciated your patience and guidance. I am eternally grateful to my co-supervisors, Assoc. Prof A. Michel Beal and Dr. Alistair Poore. Assoc. Prof Michel Beal has been incredibly supportive and generous with his time. I thoroughly enjoyed and appreciated your endless supply of patience and guidance.
    [Show full text]
  • R E S E a R C H / M a N a G E M E N T Aquatic and Terrestrial Flatworm (Platyhelminthes, Turbellaria) and Ribbon Worm (Nemertea)
    RESEARCH/MANAGEMENT FINDINGSFINDINGS “Put a piece of raw meat into a small stream or spring and after a few hours you may find it covered with hundreds of black worms... When not attracted into the open by food, they live inconspicuously under stones and on vegetation.” – BUCHSBAUM, et al. 1987 Aquatic and Terrestrial Flatworm (Platyhelminthes, Turbellaria) and Ribbon Worm (Nemertea) Records from Wisconsin Dreux J. Watermolen D WATERMOLEN Bureau of Integrated Science Services INTRODUCTION The phylum Platyhelminthes encompasses three distinct Nemerteans resemble turbellarians and possess many groups of flatworms: the entirely parasitic tapeworms flatworm features1. About 900 (mostly marine) species (Cestoidea) and flukes (Trematoda) and the free-living and comprise this phylum, which is represented in North commensal turbellarians (Turbellaria). Aquatic turbellari- American freshwaters by three species of benthic, preda- ans occur commonly in freshwater habitats, often in tory worms measuring 10-40 mm in length (Kolasa 2001). exceedingly large numbers and rather high densities. Their These ribbon worms occur in both lakes and streams. ecology and systematics, however, have been less studied Although flatworms show up commonly in invertebrate than those of many other common aquatic invertebrates samples, few biologists have studied the Wisconsin fauna. (Kolasa 2001). Terrestrial turbellarians inhabit soil and Published records for turbellarians and ribbon worms in leaf litter and can be found resting under stones, logs, and the state remain limited, with most being recorded under refuse. Like their freshwater relatives, terrestrial species generic rubric such as “flatworms,” “planarians,” or “other suffer from a lack of scientific attention. worms.” Surprisingly few Wisconsin specimens can be Most texts divide turbellarians into microturbellarians found in museum collections and a specialist has yet to (those generally < 1 mm in length) and macroturbellari- examine those that are available.
    [Show full text]
  • The Regenerative Flatworm Macrostomum Lignano, a Model
    Int. J. Dev. Biol. 62: 551-558 (2018) https://doi.org/10.1387/ijdb.180077eb www.intjdevbiol.com The regenerative flatwormMacrostomum lignano, a model organism with high experimental potential STIJN MOUTON#, JAKUB WUDARSKI#, MAGDA GRUDNIEWSKA and EUGENE BEREZIKOV* European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands ABSTRACT Understanding the process of regeneration has been one of the longstanding sci- entific aims, from a fundamental biological perspective, as well as within the applied context of regenerative medicine. Because regeneration competence varies greatly between organisms, it is essential to investigate different experimental animals. The free-living marine flatworm Macros- tomum lignano is a rising model organism for this type of research, and its power stems from a unique set of biological properties combined with amenability to experimental manipulation. The biological properties of interest include production of single-cell fertilized eggs, a transparent body, small size, short generation time, ease of culture, the presence of a pluripotent stem cell popula- tion, and a large regeneration competence. These features sparked the development of molecular tools and resources for this animal, including high-quality genome and transcriptome assemblies, gene knockdown, in situ hybridization, and transgenesis. Importantly, M. lignano is currently the only flatworm species for which transgenesis methods are established. This review summarizes
    [Show full text]
  • Potential of Macrostomum Lignano to Recover from Γ-Ray Irradiation
    Cell Tissue Res (2010) 339:527–542 DOI 10.1007/s00441-009-0915-6 REGULAR ARTICLE Potential of Macrostomum lignano to recover from γ-ray irradiation Katrien De Mulder & Georg Kuales & Daniela Pfister & Bernhard Egger & Thomas Seppi & Paul Eichberger & Gaetan Borgonie & Peter Ladurner Received: 14 July 2009 /Accepted: 10 December 2009 /Published online: 2 February 2010 # The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Stem cells are the only proliferating cells in irradiation. During recovery, stem cells did not cross the flatworms and can be eliminated by irradiation with no midline but were restricted within lateral compartments. An damage to differentiated cells. We investigated the effect of accumulated dose of 210 Gy resulted in a lethal phenotype. fractionated irradiation schemes on Macrostomum lignano, Our findings demonstrate that M. lignano represents a namely, on survival, gene expression, morphology and suitable model system for elucidating the effect of regeneration. Proliferating cells were almost undetectable irradiation on the stem cell system in flatworms and for during the first week post-treatment. Cell proliferation and improving our understanding of the recovery potential of gene expression were restored within 1 month in a dose- severely damaged stem-cell systems. dependent manner following exposure to up to 150 Gy Keywords Irradiation . Stem cells . Planaria . Flatworm . Macrostomum lignano (Platyhelminthes) This work was supported by a predoctoral FWO grant to K.D.M (Belgium) and FWF grant no. 18099 to P.L (Austria). Electronic supplementary material The online version of this article Introduction (doi:10.1007/s00441-009-0915-6) contains supplementary material, which is available to authorized users.
    [Show full text]
  • When Prey Mating Increases Predation Risk: the Relationship Between the Flatworm Mesostoma Ehrenbergii and the Copepod Boeckella Gracilis
    Arch. Hydrobiol. 163 4 555–569 Stuttgart, August 2005 When prey mating increases predation risk: the relationship between the flatworm Mesostoma ehrenbergii and the copepod Boeckella gracilis Carolina Trochine, Beatriz Modenutti and Esteban Balseiro1 Centro Regional Universitario Bariloche, UN Comahue, Argentina With 4 figures and 4 tables Abstract: The zooplanktivorous flatworm Mesostoma ehrenbergii and the calanoid copepod Boeckella gracilis were observed to coexist in Patagonian fishless ponds. In laboratory experiments, we studied the vulnerability of B. gracilis to M. ehrenbergii predation, testing the attack rates on copulating pairs and single adults in different abundances. We also determined B. gracilis dimorphism, sex ratio and copulating pair ratio on two occasions in a temporary pond, with and without M. ehrenbergii. Our results indicated that B. gracilis exhibited a male-skewed sex ratio irrespective of the presence of the predator. A marked dimorphism characterized this copepod species (females are about 40 % larger than males) and a large proportion of adults were observed participating in copulating pairs that lasted for days. M. ehrenbergii ate sim- ilar quantities of single males and females of B. gracilis but significantly more copu- lating pairs. The use of mucus threads allowed Mesostoma to ingest both members of the pairs instead of only one in most attacks. Larger prey may create more turbulence in the water while swimming, so the hydrodynamic signals produced by pairs should be greater than those produced by single individuals, making them more vulnerable. Besides, the attack rates obtained in the different prey abundances showed that en- counter rate is the factor that determines M.
    [Show full text]