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Molecular Data and the Evolutionary History of Dinoflagellates by Juan Fernando Saldarriaga Echavarria Diplom, Ruprecht-Karls-Un
Molecular data and the evolutionary history of dinoflagellates by Juan Fernando Saldarriaga Echavarria Diplom, Ruprecht-Karls-Universitat Heidelberg, 1993 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES Department of Botany We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA November 2003 © Juan Fernando Saldarriaga Echavarria, 2003 ABSTRACT New sequences of ribosomal and protein genes were combined with available morphological and paleontological data to produce a phylogenetic framework for dinoflagellates. The evolutionary history of some of the major morphological features of the group was then investigated in the light of that framework. Phylogenetic trees of dinoflagellates based on the small subunit ribosomal RNA gene (SSU) are generally poorly resolved but include many well- supported clades, and while combined analyses of SSU and LSU (large subunit ribosomal RNA) improve the support for several nodes, they are still generally unsatisfactory. Protein-gene based trees lack the degree of species representation necessary for meaningful in-group phylogenetic analyses, but do provide important insights to the phylogenetic position of dinoflagellates as a whole and on the identity of their close relatives. Molecular data agree with paleontology in suggesting an early evolutionary radiation of the group, but whereas paleontological data include only taxa with fossilizable cysts, the new data examined here establish that this radiation event included all dinokaryotic lineages, including athecate forms. Plastids were lost and replaced many times in dinoflagellates, a situation entirely unique for this group. Histones could well have been lost earlier in the lineage than previously assumed. -
The Intestinal Protozoa
The Intestinal Protozoa A. Introduction 1. The Phylum Protozoa is classified into four major subdivisions according to the methods of locomotion and reproduction. a. The amoebae (Superclass Sarcodina, Class Rhizopodea move by means of pseudopodia and reproduce exclusively by asexual binary division. b. The flagellates (Superclass Mastigophora, Class Zoomasitgophorea) typically move by long, whiplike flagella and reproduce by binary fission. c. The ciliates (Subphylum Ciliophora, Class Ciliata) are propelled by rows of cilia that beat with a synchronized wavelike motion. d. The sporozoans (Subphylum Sporozoa) lack specialized organelles of motility but have a unique type of life cycle, alternating between sexual and asexual reproductive cycles (alternation of generations). e. Number of species - there are about 45,000 protozoan species; around 8000 are parasitic, and around 25 species are important to humans. 2. Diagnosis - must learn to differentiate between the harmless and the medically important. This is most often based upon the morphology of respective organisms. 3. Transmission - mostly person-to-person, via fecal-oral route; fecally contaminated food or water important (organisms remain viable for around 30 days in cool moist environment with few bacteria; other means of transmission include sexual, insects, animals (zoonoses). B. Structures 1. trophozoite - the motile vegetative stage; multiplies via binary fission; colonizes host. 2. cyst - the inactive, non-motile, infective stage; survives the environment due to the presence of a cyst wall. 3. nuclear structure - important in the identification of organisms and species differentiation. 4. diagnostic features a. size - helpful in identifying organisms; must have calibrated objectives on the microscope in order to measure accurately. -
A Fossilized Microcenosis in Triassic Amber
J Eukaqlnr. Micmbrol., 46(6), 1999 pp. 571-584 0 1999 by the Society of Protozoologists A Fossilized Microcenosis in Triassic Amber WILFRIED SCHONBORN,a HEINRICH DORFELT? WILHELM FOISSNER,’ LOTHAR KRIENITZd and URSULA SCHAFER” “Friedrich-Schiller-UniversitatJena, Institut fur Okologie, Arbeitsgruppe Limnologie, Winzerlaer StraJe 10, 0-0774.5 Jena, Germany, and bFriedrich-Schiller-Univer.sitatJenn,lnstitut fiir Ernahrung und Umwelt, Lehrgebiet Lnndschaftsokologie und Naturschutz, DornburgerslraJe 159, 0-07743 Jena, Germany, and ‘Universitut Salzburg, Institut fur Zoologie, HellbrunnerstraJe 34, A-5020 Salzburg, Austria, and dInstitut fur Gewasseriikologie und Binnenjscherei, Alte Fischerhiitte 2, 0-16775 Neuglobsow, Germany ABSTRACT. Detailed data on bacterial and protistan microfossils are presented from a 0.003 mm3 piece of Triassic amber (Schlier- seerit, Upper Triassic period, 220-230 million years old). This microcenosis, which actually existed as such within a very small, probably semiaquatic habitat, included the remains of about two bacteria species, four fungi (Palaeodikaryomyces baueri, Pithomyces-like conidia, capillitium-like hyphae, yeast cells) two euglenoids, two chlamydomonas (Chlamydomonas sp., Chloromonas sp.), two coccal green microalgae (Chlorellu sp., Chorzcystis-like cells), one zooflagellate, three testate amoebae (Centropyxis aculeata var. oblonga-like, Cyclopyxis eurystoma-like, Hyalosphenia baueri n. sp.), seven ciliates (Pseudoplatyophrya nana-like, Mykophagophrys rerricola-like, Cvrtolophosis mucicola-like, Paracondylostoma -
Ciliate Diversity, Community Structure, and Novel Taxa in Lakes of the Mcmurdo Dry Valleys, Antarctica
Reference: Biol. Bull. 227: 175–190. (October 2014) © 2014 Marine Biological Laboratory Ciliate Diversity, Community Structure, and Novel Taxa in Lakes of the McMurdo Dry Valleys, Antarctica YUAN XU1,*†, TRISTA VICK-MAJORS2, RACHAEL MORGAN-KISS3, JOHN C. PRISCU2, AND LINDA AMARAL-ZETTLER4,5,* 1Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; 2Montana State University, Department of Land Resources and Environmental Sciences, 334 Leon Johnson Hall, Bozeman, Montana 59717; 3Department of Microbiology, Miami University, Oxford, Ohio 45056; 4The Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, Massachusetts 02543; and 5Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912 Abstract. We report an in-depth survey of next-genera- trends in dissolved oxygen concentration and salinity may tion DNA sequencing of ciliate diversity and community play a critical role in structuring ciliate communities. A structure in two permanently ice-covered McMurdo Dry PCR-based strategy capitalizing on divergent eukaryotic V9 Valley lakes during the austral summer and autumn (No- hypervariable region ribosomal RNA gene targets unveiled vember 2007 and March 2008). We tested hypotheses on the two new genera in these lakes. A novel taxon belonging to relationship between species richness and environmental an unknown class most closely related to Cryptocaryon conditions -
ABSTRACT Title of Dissertation: IDENTIFICATION, LIFE HISTORY
ABSTRACT Title of Dissertation: IDENTIFICATION, LIFE HISTORY, AND ECOLOGY OF PERITRICH CILIATES AS EPIBIONTS ON CALANOID COPEPODS IN THE CHESAPEAKE BAY Laura Roberta Pinto Utz, Doctor of Philosophy, 2003 Dissertation Directed by: Professor Eugene B. Small Department of Biology Adjunct Professor D. Wayne Coats Department of Biology and Smithsonian Environmental Research Center Epibiotic relationships are a widespread phenomenon in marine, estuarine and freshwater environments, and include diverse epibiont organisms such as bacteria, protists, rotifers, and barnacles. Despite its wide occurrence, epibiosis is still poorly known regarding its consequences, advantages, and disadvantages for host and epibiont. Most studies performed about epibiotic communities have focused on the epibionts’ effects on host fitness, with few studies emphasizing on the epibiont itself. The present work investigates species composition, spatial and temporal fluctuations, and aspects of the life cycle and attachment preferences of Peritrich epibionts on calanoid copepods in Chesapeake Bay, USA. Two species of Peritrich ciliates (Zoothamnium intermedium Precht, 1935, and Epistylis sp.) were identified to live as epibionts on the two most abundant copepod species (Acartia tonsa and Eurytemora affinis) during spring and summer months in Chesapeake Bay. Infestation prevalence was not significantly correlated with environmental variables or phytoplankton abundance, but displayed a trend following host abundance. Investigation of the life cycle of Z. intermedium suggested that it is an obligate epibiont, being unable to attach to non-living substrates in the laboratory or in the field. Formation of free-swimming stages (telotrochs) occurs as a result of binary fission, as observed for other peritrichs, and is also triggered by death or molt of the crustacean host. -
PROTISTAS MARINOS Viviana A
PROTISTAS MARINOS Viviana A. Alder INTRODUCCIÓN plantas y animales. Según este esquema básico, a las plantas les correspondían las características de En 1673, el editor de Philosophical Transac- ser organismos sésiles con pigmentos fotosinté- tions of the Royal Society of London recibió una ticos para la síntesis de las sustancias esenciales carta del anatomista Regnier de Graaf informan- para su metabolismo a partir de sustancias inor- do que un comerciante holandés, Antonie van gánicas (nutrición autótrofa), y de poseer células Leeuwenhoek, había “diseñado microscopios rodeadas por paredes de celulosa. En oposición muy superiores a aquéllos que hemos visto has- a las plantas, les correspondía a los animales los ta ahora”. Van Leeuwenhoek vendía lana, algo- atributos de tener motilidad activa y de carecer dón y otros materiales textiles, y se había visto tanto de pigmentos fotosintéticos (debiendo por en la necesidad de mejorar las lentes de aumento lo tanto procurarse su alimento a partir de sustan- que comúnmente usaba para contar el número cias orgánicas sintetizadas por otros organismos) de hebras y evaluar la calidad de fibras y tejidos. como de paredes celulósicas en sus células. Así fue que construyó su primer microscopio de Es a partir de los estudios de Georg Gol- lente única: simple, pequeño, pero con un poder dfuss (1782-1848) que estos diminutos organis- de magnificación de hasta 300 aumentos (¡diez mos, invisibles a ojo desnudo, comienzan a ser veces más que sus precursores!). Este magnífico clasificados como plantas primarias -
Protist Phylogeny and the High-Level Classification of Protozoa
Europ. J. Protistol. 39, 338–348 (2003) © Urban & Fischer Verlag http://www.urbanfischer.de/journals/ejp Protist phylogeny and the high-level classification of Protozoa Thomas Cavalier-Smith Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK; E-mail: [email protected] Received 1 September 2003; 29 September 2003. Accepted: 29 September 2003 Protist large-scale phylogeny is briefly reviewed and a revised higher classification of the kingdom Pro- tozoa into 11 phyla presented. Complementary gene fusions reveal a fundamental bifurcation among eu- karyotes between two major clades: the ancestrally uniciliate (often unicentriolar) unikonts and the an- cestrally biciliate bikonts, which undergo ciliary transformation by converting a younger anterior cilium into a dissimilar older posterior cilium. Unikonts comprise the ancestrally unikont protozoan phylum Amoebozoa and the opisthokonts (kingdom Animalia, phylum Choanozoa, their sisters or ancestors; and kingdom Fungi). They share a derived triple-gene fusion, absent from bikonts. Bikonts contrastingly share a derived gene fusion between dihydrofolate reductase and thymidylate synthase and include plants and all other protists, comprising the protozoan infrakingdoms Rhizaria [phyla Cercozoa and Re- taria (Radiozoa, Foraminifera)] and Excavata (phyla Loukozoa, Metamonada, Euglenozoa, Percolozoa), plus the kingdom Plantae [Viridaeplantae, Rhodophyta (sisters); Glaucophyta], the chromalveolate clade, and the protozoan phylum Apusozoa (Thecomonadea, Diphylleida). Chromalveolates comprise kingdom Chromista (Cryptista, Heterokonta, Haptophyta) and the protozoan infrakingdom Alveolata [phyla Cilio- phora and Miozoa (= Protalveolata, Dinozoa, Apicomplexa)], which diverged from a common ancestor that enslaved a red alga and evolved novel plastid protein-targeting machinery via the host rough ER and the enslaved algal plasma membrane (periplastid membrane). -
The Life Cycle of Trypanosoma Cruzi
Tyler et al. THE LIFE CYCLE OF TRYPANOSOMA CRUZI K. M. Tyler, C. L. Olson and D. M. Engman Departments of Microbiology-Immunology and Pathology Feinberg Medical School of Northwestern University, Chicago, IL 60611 ABSTRACT Since the discovery of Trypanosoma cruzi as the parasite that causes Chagas disease, nearly a century ago, the details of the organism's life cycle have fascinated scientists. T. cruzi is a single-celled eukaryote with a complex life cycle alternating between reduviid bug vectors and vertebrate hosts. It is able to adapt via the process of cellular differentiation to replicate within the diverse environments represented of the insect's gut and host cell cytoplasm. These adaptive transformations take the form of coordinated changes in morphology, metabolism and cell cycle regulation. Different life cycle stages of T. cruzi show dramatically different protein and RNA profiles, which are the end result of unusual mechanisms for regulating gene expression. In recent years, new molecular techniques have been brought to bear on the life cycle dramatically increasing our knowledge of the strategies employed by the parasite to ensure its continued survival. INTRODUCTION Chagas disease The etiologic agent of the chronic and often fatal Chagas disease is the American trypanosome, Trypanosoma cruzi , a flagellated protozoan of the order Kinetoplastida. The survival of T. cruzi is dependent on the successful transmission between, and the colonization of, two radically different environments: the midgut of the reduviid bug vector and the cytoplasm of the mammalian host cell. As is true of all infections, interruption of the pathogen's life cycle will lead to eradication of the disease. -
A PRELIMINARY NOTE on TETRAMITUS, a STAGE in the LIFE CYCLE of a COPROZOIC AMOEBA by MARTHA BUNTING
294 Z6OL6G Y.- M. BUNTING PROC. N. A. S. A PRELIMINARY NOTE ON TETRAMITUS, A STAGE IN THE LIFE CYCLE OF A COPROZOIC AMOEBA By MARTHA BUNTING DEPARTMENT OF ZOOLOGY, UNIVERSITY OF PENNSYLVANIA Communicated July 24, 1922 In 1920 a study of the Entamoeba of the rat was begun and in a culture on artificial medium a number of Coprozoic amoeba appeared, one of which exhibited a flagellate phase which seems to be identical with Tetramitus rostratus Perty.1 The appearance of flagellate phases in cultures of Coprozoic amoeba (Whitmore,2 etc.) as well as of soil amoeba (Kofoid,1 Wilson,4 etc.) has been recorded a number of times, but the flagellates which appeared were relatively simple in organization and very transitory in occurrence. Fur- thermore, some of the simpler flagellates have been observed (Pascher5) to lose their flagella and become amoeboid. In the case here described, however, there is a transformation of a simple amoeba into a relatively complex flagellate which multiplies for several days then returns to the amoeboid condition and becomes encysted. Tetramitus rostratus has been studied by a number of investigators since its discovery in 1852, by Perty,' yet no one has given a full account of its life history. The lack of cysts in previous accounts, mentioned by Dobell and O'Connor,6 is explained by the transformation into an amoeba before encystment. It is believed that this animal presents the extreme in transformations of this sort and serves to emphasize the close relationship between amoebae and flagellates, and the need for careful studies of life cycles, in pure cultures where possible, in investigations of coprozoic and other Protozoa. -
Protistology an International Journal Vol
Protistology An International Journal Vol. 10, Number 2, 2016 ___________________________________________________________________________________ CONTENTS INTERNATIONAL SCIENTIFIC FORUM «PROTIST–2016» Yuri Mazei (Vice-Chairman) Welcome Address 2 Organizing Committee 3 Organizers and Sponsors 4 Abstracts 5 Author Index 94 Forum “PROTIST-2016” June 6–10, 2016 Moscow, Russia Website: http://onlinereg.ru/protist-2016 WELCOME ADDRESS Dear colleagues! Republic) entitled “Diplonemids – new kids on the block”. The third lecture will be given by Alexey The Forum “PROTIST–2016” aims at gathering Smirnov (Saint Petersburg State University, Russia): the researchers in all protistological fields, from “Phylogeny, diversity, and evolution of Amoebozoa: molecular biology to ecology, to stimulate cross- new findings and new problems”. Then Sandra disciplinary interactions and establish long-term Baldauf (Uppsala University, Sweden) will make a international scientific cooperation. The conference plenary presentation “The search for the eukaryote will cover a wide range of fundamental and applied root, now you see it now you don’t”, and the fifth topics in Protistology, with the major focus on plenary lecture “Protist-based methods for assessing evolution and phylogeny, taxonomy, systematics and marine water quality” will be made by Alan Warren DNA barcoding, genomics and molecular biology, (Natural History Museum, United Kingdom). cell biology, organismal biology, parasitology, diversity and biogeography, ecology of soil and There will be two symposia sponsored by ISoP: aquatic protists, bioindicators and palaeoecology. “Integrative co-evolution between mitochondria and their hosts” organized by Sergio A. Muñoz- The Forum is organized jointly by the International Gómez, Claudio H. Slamovits, and Andrew J. Society of Protistologists (ISoP), International Roger, and “Protists of Marine Sediments” orga- Society for Evolutionary Protistology (ISEP), nized by Jun Gong and Virginia Edgcomb. -
Uroleptus Willii Nov. Sp., a Euplanktonic Freshwater Ciliate
Uroleptus willii nov. sp., a euplanktonic freshwater ciliate (Dorsomarginalia, Spirotrichea, Ciliophora) with algal symbionts: morphological description including phylogenetic data of the small subunit rRNA gene sequence and ecological notes * Bettina S ONNTAG , Michaela C. S TRÜDER -K YPKE & Monika S UMMERER Abstract : The eUplanktonic ciliate Uroleptus willii nov. sp. (Dorsomarginalia) was discovered in the plankton of the oligo- mesotrophic PibUrgersee in AUstria. The morphology and infraciliatUre of this new species were stUdied in living cells as well as in specimens impregnated with protargol and the phylogenetic placement was inferred from the small sUbUnit ribosomal RNA (SSrRNA) gene seqUence. In vivo, U. willii is a grass-green fUsiform spirotrich of 100– 150 µm length. It bears aboUt 80–100 sym - biotic green algae and bUilds a lorica. Uroleptus willii is a freqUent species in the sUmmer ciliate assemblage in the Upper 12 m of PibUrgersee with a mean abUndance of aboUt 170 individUals l -1 from May throUgh November. The algal symbionts of this ciliate are known to synthesise Ultraviolet radiation – absorbing compoUnds. At present, the taxonomic position of Uroleptus has not yet been solved since the morphological featUres of the genUs agree well with those of the Urostyloidea, while the molecUlar analy - ses place the genUs within the Oxytrichidae. Uroleptus willii follows this pattern and groUps UnambigUoUsly with other Uroleptus species. We assign oUr new species to the Dorsomarginalia BERGER , 2006. However, this placement is preliminary since it is based on the assUmption that the genUs Uroleptus and the Oxytrichidae are both monophyletic taxa, and the monophyly of the latter groUp has still not been confirmed by molecUlar data. -
Dynamic of the Sargassum Tide Holobiont in the Caribbean Islands
From the Sea to the Land: Dynamic of the Sargassum Tide Holobiont in the Caribbean Islands Pascal Jean Lopez ( [email protected] ) CNRS Délégation Paris B https://orcid.org/0000-0002-9914-4252 Vincent Hervé Max-Planck-Institut for Terrestrial Microbiology Josie Lambourdière Centre National de la Recherche Scientique Malika René-Trouillefou Universite des Antilles et de la Guyane Damien Devault Centre National de la Recherche Scientique Research Keywords: Macroalgae, Methanogenic archaea, Sulfate-reducing bacteria, Epibiont, Microbial communities, Nematodes, Ciliates Posted Date: June 9th, 2020 DOI: https://doi.org/10.21203/rs.3.rs-33861/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/27 Abstract Background Over the last decade, intensity and frequency of Sargassum blooms in the Caribbean Sea and central Atlantic Ocean have dramatically increased, causing growing ecological, social and economic concern throughout the entire Caribbean region. These golden-brown tides form an ecosystem that maintains life for a large number of associated species, and their circulation across the Atlantic Ocean support the displacement and maybe the settlement of various species, especially microorganisms. To comprehensively identify the micro- and meiofauna associated to Sargassum, one hundred samples were collected during the 2018 tide events that were the largest ever recorded. Results We investigated the composition and the existence of specic species in three compartments, namely, Sargassum at tide sites, in the surrounding seawater, and in inland seaweed storage sites. Metabarcoding data revealed shifts between compartments in both prokaryotic and eukaryotic communities, and large differences for eukaryotes especially bryozoans, nematodes and ciliates.