DOCSLIB.ORG

Thyroid Hormone-Like Function in Echinoids: a Modular Signaling System Coopted for Larval Development and Critical for Life History Evolution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thyroid Hormone-Like Function in Echinoids: a Modular Signaling System Coopted for Larval Development and Critical for Life History Evolution THYROID HORMONE-LIKE FUNCTION IN ECHINOIDS: A MODULAR SIGNALING SYSTEM COOPTED FOR LARVAL DEVELOPMENT AND CRITICAL FOR LIFE HISTORY EVOLUTION By ANDREAS HEYLAND A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2004 Copyright 2004 by Andreas Heyland To my teacher Larry McEdward who inspired me to think differently. ACKNOWLEDGMENTS I greatly acknowledge the help and support of my late advisor, Larry McEdward, who introduced me to the field of marine larval ecology and the beauty of echinoderm larvae. I wish we could have spent more time together. Many thanks also to the entire Friday Harbor Laboratories (University of Washington) community and the Department of Zoology at the University of Florida for their help and support. Specifically I thank David Julian for taking the responsibility of being my dissertation advisor and for his great support at all times in all aspects of my dissertation. I am grateful to my collaborator Jason Hodin (Friday Harbor Laboratories) who in many respects served as an advisor and strongly influenced my scientific thinking. Leonid Moroz (Whitney Lab, University of Florida) critically evaluated my work in the last stages and gave me a truly new perspective on it. I am also very thankful for his generous financial support that allowed me to finish my thesis in a timely manner. Constructive criticism of my dissertation committee members, including Craig Osenberg, Lou Guillette, Charles Wood and Gustav Paulay, and several other researchers, including Richard Strathmann, Greg Wray, Marty Cohn, Cory Bishop, LeLand Johson, Chris Cameron, Benjamine Miner and Donald Brown significantly improved my work. My stay at various marine stations during the dissertation work has been extremely enjoyable. I would like to thank all the members of the 1999 Embryology and EvoDevo classes at the Friday Harbor Laboratories for sharing a great time with me. This place changed my life. I would like to thank all the people that made this possible including the iv director Dennis Willows and the staff. I thank Billie Swalla for supporting my work during the summer 2001 at the Friday Harbor Laboratories. Furthermore I thank the crew of the Smithsonian Marine Station at Fort Pierce for their great support and help, especially the former director, Marry Rice, and the current director, Valerie Paul, for giving me the opportunity to spend a few enjoyable and productive months at the station. I thank the Link Foundation for providing the financial support for this time. I had a great opportunity to work at the Rosenstiel School of Marine and Atmospheric Science in Miami thanks to Tom Capo and at the Woods Hole Oceanographic Institute thanks to Ken Halanych and Jesus Pineda. I would also like to thank Joel Rothman and Richard Harland for letting me use microscopes and the facilities during the MBL Embryology course 2002. Finally I thank the Director of the Station Biologique in Roscoff (France), Andre Toulmond, for his hospitality during our visit in the summer 2002. Several funding agencies made this work possible: NSF grant OCE-9819593 to Larry McEdward; PADI, Sigma Xi, Alan Kohn, Link Foundation grants and fellowships given to Andreas Heyland and NIH grants R01NS39103 and R01MH60261 given to Leonid Moroz. I benefited greatly from suggestions and help from members of the Laboratories I was working in. I would like particularly to thank my collaborators Adam Reitzel, David Price, Billie Swalla and Michaela Bodnarova for help and discussions. Lastly I thank my wife Svetlana Maslakova for her love, encouragement, help and support. I also thank my parents Sven and Maike and my brother Klaas for their support and continuous interest in my work. v TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iv LIST OF TABLES...............................................................................................................x LIST OF FIGURES ........................................................................................................... xi ABSTRACT..................................................................................................................... xiv CHAPTER 1 INTRODUCTION: HORMONE SIGNALING IN EVOLUTION AND DEVELOPMENT: A NON-MODEL SYSTEM APPROACH ...................................1 Cooption and Modularity: The Emergence of a New EvoDevo Paradigm ..................1 Comparative Biology: A Non-Model System Approach to Life History Evolution (LHE) .......................................................................................................................2 Defining Metamorphosis ..............................................................................................4 Nuclear Hormone Receptors: Modules and Development and Evolution....................7 Hormonal Signaling Networks: Modules Coopted for LHTs.....................................10 Hormones and Life History Evolution (LHE)............................................................15 2 HETEROCHRONIC DEVELOPMENTAL SHIFT CAUSED BY THYROID HORMONE IN LARVAL SAND DOLLARS AND ITS IMPLICATIONS FOR PHENOTYPIC PLASTICITY AND THE EVOLUTION OF NON-FEEDING DEVELOPMENT.......................................................................................................25 Introduction.................................................................................................................25 Materials and Methods ...............................................................................................28 Experimental Designs..........................................................................................29 Experimental Treatments.....................................................................................30 Morphometric Measurements and Rudiment Stages...........................................30 Metamorphic Competence and Settlement..........................................................31 Statistics...............................................................................................................32 Results.........................................................................................................................33 Analysis of Thyroxine Effects on Larval and Juvenile Morphology ..................33 Comparison of age and rudiment stage specific analysis.............................33 Analysis of larval, juvenile and stomach growth and development.............33 Metamorphic Competence and Juvenile Size......................................................36 vi Endogenous Hormone Synthesis.........................................................................37 Mortality and Abnormalities ...............................................................................38 Discussion...................................................................................................................39 Thyroid Hormone as a Cue for Adaptive Phenotypic Plasticity in Echinoid Larvae ..............................................................................................................40 Differences Between Thyroid Hormone and Food Effects: Stomach Size .........43 Thyroid Hormones As an Indicator of Larval Nutrition: Implications for Juvenile Size in Echinoids ...............................................................................43 Thyroid Hormones and Life History Evolution in Echinoderms ........................46 3 THYROID HORMONES DETERMINE DEVELOPMENTAL MODE IN ECHINODERMS .......................................................................................................62 Introduction.................................................................................................................62 Materials and Methods ...............................................................................................65 Animal Collection, Culturing of Larvae and Experimental Treatments .............65 Biochemistry........................................................................................................66 Morphological Analysis ......................................................................................68 Settlement and Metamorphosis ...........................................................................70 Statistics...............................................................................................................70 Results.........................................................................................................................70 Discussion...................................................................................................................73 Egg Size and TH as Determinants of Developmental Mode in Echinoids..........73 Juvenile Size in Echinoids...................................................................................76 TH and the Evolution of Lecithotrophy ..............................................................78 4 ENDOGENOUS THYROID HORMONE SYNTHESIS IN NON-FEEDING LARVAE OF THE SAND DOLLAR CLYPEASTER ROSACEUS........................88 Introduction.................................................................................................................88 Materials and Methods ...............................................................................................91 Larval Culturing ..................................................................................................91
Load more

Recommended publications
  • Biscuit Clypeaster Subdepressus (Echinodermata: Clypeasteroida)
    Embryonic, Larval, and Juvenile Development of the Sea Biscuit Clypeaster subdepressus (Echinodermata: Clypeasteroida) Bruno C. Vellutini1,2*, Alvaro E. Migotto1,2 1 Centro de Biologia Marinha, Universidade de Sa˜o Paulo, Sa˜o Sebastia˜o, Sa˜o Paulo, Brazil, 2 Departamento de Zoologia, Instituto de Biocieˆncias, Universidade de Sa˜o Paulo, Sa˜o Paulo, Sa˜o Paulo, Brazil Abstract Sea biscuits and sand dollars diverged from other irregular echinoids approximately 55 million years ago and rapidly dispersed to oceans worldwide. A series of morphological changes were associated with the occupation of sand beds such as flattening of the body, shortening of primary spines, multiplication of podia, and retention of the lantern of Aristotle into adulthood. To investigate the developmental basis of such morphological changes we documented the ontogeny of Clypeaster subdepressus. We obtained gametes from adult specimens by KCl injection and raised the embryos at 260C. Ciliated blastulae hatched 7.5 h after sperm entry. During gastrulation the archenteron elongated continuously while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larvae began to feed in 3 d and were *20 d old at metamorphosis; starved larvae died 17 d after fertilization. Postlarval juveniles had neither mouth nor anus nor plates on the aboral side, except for the remnants of larval spicules, but their bilateral symmetry became evident after the resorption of larval tissues. Ossicles of the lantern were present and organized in 5 groups. Each group had 1 tooth, 2 demipyramids, and 2 epiphyses with a rotula in between. Early appendages consisted of 15 spines, 15 podia (2 types), and 5 sphaeridia.
    [Show full text]
  • Geological-Geomorphological and Paleontological Heritage in the Algarve (Portugal) Applied to Geotourism and Geoeducation
    land Article Geological-Geomorphological and Paleontological Heritage in the Algarve (Portugal) Applied to Geotourism and Geoeducation Antonio Martínez-Graña 1,* , Paulo Legoinha 2 , José Luis Goy 1, José Angel González-Delgado 1, Ildefonso Armenteros 1, Cristino Dabrio 3 and Caridad Zazo 4 1 Department of Geology, Faculty of Sciences, University of Salamanca, 37008 Salamanca, Spain; [email protected] (J.L.G.); [email protected] (J.A.G.-D.); [email protected] (I.A.) 2 GeoBioTec, Department of Earth Sciences, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, 2829-516 Almada, Portugal; [email protected] 3 Department of Stratigraphy, Faculty of Geology, Complutense University of Madrid, 28040 Madrid, Spain; [email protected] 4 Department of Geology, Museo Nacional de Ciencias Naturales, 28006 Madrid, Spain; [email protected] * Correspondence: [email protected]; Tel.: +34-923294496 Abstract: A 3D virtual geological route on Digital Earth of the geological-geomorphological and paleontological heritage in the Algarve (Portugal) is presented, assessing the geological heritage of nine representative geosites. Eighteen quantitative parameters are used, weighing the scientific, didactic and cultural tourist interest of each site. A virtual route has been created in Google Earth, with overlaid georeferenced cartographies, as a field guide for students to participate and improve their learning. This free application allows loading thematic georeferenced information that has Citation: Martínez-Graña, A.; previously been evaluated by means of a series of parameters for identifying the importance and Legoinha, P.; Goy, J.L.; interest of a geosite (scientific, educational and/or tourist). The virtual route allows travelling from González-Delgado, J.A.; Armenteros, one geosite to another, interacting in real time from portable devices (e.g., smartphone and tablets), I.; Dabrio, C.; Zazo, C.
    [Show full text]
  • Effects of Ocean Warming and Acidification on Fertilization Success and Early Larval Development in the Green Sea Urchin, Lytechinus Variegatus Brittney L
    Nova Southeastern University NSUWorks HCNSO Student Theses and Dissertations HCNSO Student Work 12-1-2017 Effects of Ocean Warming and Acidification on Fertilization Success and Early Larval Development in the Green Sea Urchin, Lytechinus variegatus Brittney L. Lenz Nova Southeastern University, [email protected] Follow this and additional works at: https://nsuworks.nova.edu/occ_stuetd Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons Share Feedback About This Item NSUWorks Citation Brittney L. Lenz. 2017. Effects of Ocean Warming and Acidification on Fertilization Success and Early Larval Development in the Green Sea Urchin, Lytechinus variegatus. Master's thesis. Nova Southeastern University. Retrieved from NSUWorks, . (457) https://nsuworks.nova.edu/occ_stuetd/457. This Thesis is brought to you by the HCNSO Student Work at NSUWorks. It has been accepted for inclusion in HCNSO Student Theses and Dissertations by an authorized administrator of NSUWorks. For more information, please contact [email protected]. Thesis of Brittney L. Lenz Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science M.S. Marine Biology Nova Southeastern University Halmos College of Natural Sciences and Oceanography December 2017 Approved: Thesis Committee Major Professor: Joana Figueiredo Committee Member: Nicole Fogarty Committee Member: Charles Messing This thesis is available at NSUWorks: https://nsuworks.nova.edu/occ_stuetd/457 HALMOS COLLEGE OF NATURAL SCIENCES AND
    [Show full text]
  • Echinoidea: Clypeasteroida)
    Zootaxa 3857 (4): 501–526 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2014 Magnolia Press ISSN 1175-5334 (online edition) http://dx.doi.org/10.11646/zootaxa.3857.4.3 http://zoobank.org/urn:lsid:zoobank.org:pub:76021E0C-7542-455B-82F4-C670A3DC8806 Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida) RICH MOOI1, ANDREAS KROH2,4 & DINESH K. SRIVASTAVA3 1Department of Invertebrate Zoology and Geology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, California 94118, USA. E-mail: [email protected] 2Naturhistorisches Museum Wien, Burgring 7, 1010 Vienna, Austria. E-mail: [email protected] 3Centre of Advanced Study in Geology, University of Lucknow, Lucknow 226 007, India. E-mail: [email protected] 4Corresponding author Abstract Tridium kieri Tandon & Srivastava, 1980, a clypeasteroid micro-echinoid from the Middle Eocene of Kachchh, India, has an apical system with just 3 gonopores. This condition is otherwise almost unknown among clypeasteroids, yet the mor- phology of Tridium is very similar to that of extant Fibularia, including members of another relatively poorly known ge- nus from the Indian subcontinent and Western Australia, Cyamidia Lambert & Thiéry, 1914. Re-examination of the type and additional material of T. kieri and Cyamidia paucipora Brunnschweiler, 1962, along with specimens identified as C. nummulitica nummulitica (Duncan & Sladen, 1884), allows for redescription of these forms. For the first time, maps of coronal plate architecture of Tridium and Cyamidia are developed, and SEM images of test surface details of the former are provided.
    [Show full text]
  • Biological Oceanography - Legendre, Louis and Rassoulzadegan, Fereidoun
    OCEANOGRAPHY – Vol.II - Biological Oceanography - Legendre, Louis and Rassoulzadegan, Fereidoun BIOLOGICAL OCEANOGRAPHY Legendre, Louis and Rassoulzadegan, Fereidoun Laboratoire d'Océanographie de Villefranche, France. Keywords: Algae, allochthonous nutrient, aphotic zone, autochthonous nutrient, Auxotrophs, bacteria, bacterioplankton, benthos, carbon dioxide, carnivory, chelator, chemoautotrophs, ciliates, coastal eutrophication, coccolithophores, convection, crustaceans, cyanobacteria, detritus, diatoms, dinoflagellates, disphotic zone, dissolved organic carbon (DOC), dissolved organic matter (DOM), ecosystem, eukaryotes, euphotic zone, eutrophic, excretion, exoenzymes, exudation, fecal pellet, femtoplankton, fish, fish lavae, flagellates, food web, foraminifers, fungi, harmful algal blooms (HABs), herbivorous food web, herbivory, heterotrophs, holoplankton, ichthyoplankton, irradiance, labile, large planktonic microphages, lysis, macroplankton, marine snow, megaplankton, meroplankton, mesoplankton, metazoan, metazooplankton, microbial food web, microbial loop, microheterotrophs, microplankton, mixotrophs, mollusks, multivorous food web, mutualism, mycoplankton, nanoplankton, nekton, net community production (NCP), neuston, new production, nutrient limitation, nutrient (macro-, micro-, inorganic, organic), oligotrophic, omnivory, osmotrophs, particulate organic carbon (POC), particulate organic matter (POM), pelagic, phagocytosis, phagotrophs, photoautotorphs, photosynthesis, phytoplankton, phytoplankton bloom, picoplankton, plankton,
    [Show full text]
  • Field Keys to Common Hawaiian Marine Animals and Plants
    DOCUMENT RESUME ED 197 993 SE 034 171 TTTTE Field Keys to Common Hawaiian Marine Animals and Plants: INSTITUTTON Hawaii State Dept. of Education, Honolulu. Officeof In::tructional Services. SEPOPT NO RS-78-5247 PUB DATE Mar 78 NOT? 74p.: Not available in he*:dcopy due to colored pages throughout entire document. EDRS PRICE MFO1 Plus Postage. PC Not Available frcm EPRS. DESCRIPTORS *Animals: Biology: Elementary Secondary Education: Environmental Education: *Field Trips: *Marine Biology: Outdoor Education: *Plant Identification: Science Educat4on TDENTIFTERS Hawaii ABSTRACT Presented are keys for identifyingcommon Hawaiian marine algae, beach plants, reef corals,sea urci.ins, tidepool fishes, and sea cucumbers. Nearly all speciesconsidered can be distinguished by characte-istics visible to- thenaked eye. Line drawings illustrate most plants atd animals included,and a list of suggested readings follows each section. (WB) *********************************************************************** Reproductions supplied by FDPS are the best thatcan be lade from the original document. **************************t***************************************** Field Keys to Common Hawaiian Marine Animals and Plants Office of Instructional Services/General Education Branch Department of Education State of Hawaii RS 78-5247 March 1978 "PERMISSION TO REPRODUCE THIS U S DEPARTMENT OF HEALTH. MATERIAL HAS BEEN GRANTED BY EDUCATION &WELFARE NATIONAL INSTITUTE OF EDUCATION P. Tz_urylo THIS DOCUMENT HAS BEEN qEPRO. DuCED EXACTLY AS PECE1VEDPO.` THE PE PSON OP OPC,AN7ATION ORIGIN. TING IT POINTS Or vIEW OR OPINIONS SATED DO NOT NECESSARILY PE PPE. TO THE EDUCATIONAL RESOURCES SENTO<<IC I AL NATIONAL INSTITUTE 0, INFORMATION CENTER (ERIC)." EDuCA T,ON POSIT.ON OR CY O A N 11 2 The Honorable George R. Arlyoshl Governor, State of Hawaii BOARD OF EDUCATION Rev.
    [Show full text]
  • For Peer Review
    Page 1 of 40 Geological Journal Page 1 of 32 1 2 3 Neogene echinoids from the Cayman Islands, West Indies: regional 4 5 6 implications 7 8 9 10 1 2 3 11 STEPHEN K. DONOVAN *, BRIAN JONES and DAVID A. T. HARPER 12 13 14 15 1Department of Geology, Naturalis Biodiversity Center, Leiden, the Netherlands 16 17 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada, T6G 2E3 18 For Peer Review 19 3 20 Department of Earth Sciences, Durham University, Durham, UK 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 *Correspondence to: S. K. Donovan, Department of Geology, Naturalis Biodiversity Center, 49 50 Darwinweg 2, 2333 CR Leiden, the Netherlands. 51 52 E-mail: [email protected] 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/gj Geological Journal Page 2 of 40 Page 2 of 32 1 2 3 The first fossil echinoids are recorded from the Cayman Islands. A regular echinoid, Arbacia? sp., the 4 5 spatangoids Brissus sp. cf. B. oblongus Wright and Schizaster sp. cf. S. americanus (Clark), and the 6 7 clypeasteroid Clypeaster sp. are from the Middle Miocene Cayman Formation. Test fragments of the 8 9 mellitid clypeasteroid, Leodia sexiesperforata (Leske), are from the Late Pleistocene Ironshore 10 11 Formation. Miocene echinoids are preserved as (mainly internal) moulds; hence, all species are left 12 13 14 in open nomenclature because of uncertainties regarding test architecture.
    [Show full text]
  • TUNEL Apoptotic Cell Detection in Stony Coral Tissue Loss Disease (SCTLD): Evaluation of Potential and Improvements
    Nova Southeastern University NSUWorks All HCAS Student Capstones, Theses, and Dissertations HCAS Student Theses and Dissertations 12-2-2020 TUNEL apoptotic cell detection in stony coral tissue loss disease (SCTLD): evaluation of potential and improvements E. Murphy McDonald Nova Southeastern University Follow this and additional works at: https://nsuworks.nova.edu/hcas_etd_all Part of the Biology Commons, Cell and Developmental Biology Commons, Immunology and Infectious Disease Commons, and the Marine Biology Commons Share Feedback About This Item NSUWorks Citation E. Murphy McDonald. 2020. TUNEL apoptotic cell detection in stony coral tissue loss disease (SCTLD): evaluation of potential and improvements. Master's thesis. Nova Southeastern University. Retrieved from NSUWorks, . (32) https://nsuworks.nova.edu/hcas_etd_all/32. This Thesis is brought to you by the HCAS Student Theses and Dissertations at NSUWorks. It has been accepted for inclusion in All HCAS Student Capstones, Theses, and Dissertations by an authorized administrator of NSUWorks. For more information, please contact [email protected]. Thesis of E. Murphy McDonald Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science Marine Science Nova Southeastern University Halmos College of Arts and Sciences December 2020 Approved: Thesis Committee Major Professor: Joana Figueiredo, Ph.D. Committee Member: Esther C. Peters, Ph.D. Committee Member: Dorothy A. Renegar, Ph.D. This thesis is available at NSUWorks: https://nsuworks.nova.edu/hcas_etd_all/32
    [Show full text]
  • Dissodactylus Crinitichelismoreira, 1901 and Leodia Sexiesperforata
    Nauplius 19(1): 63-70, 2011 63 Dissodactylus crinitichelis Moreira, 1901 and Leodia sexiesperforata (Leske, 1778): first record of this symbiosis in Brazil Vinicius Queiroz, Licia Sales, Elizabeth Neves and Rodrigo Johnsson LABIMAR (Crustacea, Cnidaria & Fauna Associada), Universidade Federal da Bahia. Avenida Adhemar de Barros s/nº, Campus Ondina. CEP 40170- 290. Salvador, BA, Brazil. E-mail: (VQ) [email protected]; (LS) [email protected]; (EN) [email protected]; (RJ) [email protected] Abstract The crabs of the genusDissodactylus are well known as ectosymbionts of irregular echinoids belonging to Clypeasteroida and Spatangoida. Dissodactylus crinitichelis is the only species of the genus reported in Brazil. The pea crab species has been already recorded associated with four species of echinoids in Brazilian waters. This paper reviews the known hosts for D. crinitichelis and registers for the first time the association between the pea crab and the sand dollar Leodia sexiesperforata increasing to five the number of known hosts for the crab. Key Words: Ecological association, ectosymbiont, Pinnotheridae. Introduction includes about 302 species of little crabs (Ng et al., 2008) highly specialized in living The diversity of the marine environment, in close association with other invertebrates. specially the benthic substratum is commonly The family is known for their association reflected by many interactions among with various invertebrate taxa, such as organisms, even free living ones. Such event molluscs, polychaetes, ascidians, crustaceans is quite common since many of these species or echinoderms (holothurians and irregular act as substratum or environment for others. echinoids) (Schmitt et al., 1973; Powers, 1977; The existence of many organisms living in Williams, 1984; Takeda et al., 1997; Thoma association and their close relation allows for et al., 2005, 2009; Ahyong and Ng, 2007).
    [Show full text]
  • Mollusca: Cassidae), a Heavily Exploited Marine Gastropod?
    SHORT REVIEW Ethnobiology and Conservation 2017, 6:16 (27 August 2017) doi:10.15451/ec2017­08­6.16­1­13 ISSN 2238­4782 ethnobioconservation.com What do we know about Cassis tuberosa (Mollusca: Cassidae), a heavily exploited marine gastropod? Thelma Lúcia Pereira Dias1*, Ellori Laíse Silva Mota1,2, Rafaela Cristina de Souza Duarte1,2 and Rômulo Romeu Nóbrega Alves1 ABSTRACT Cassis tuberosa is a key species in reefs and sandy beaches, where it plays an essential role as a predator of sea urchins and sand dollars. Due to the beauty of its shell, it is one of the most exploited species for trade as marine souvenirs throughout its distribution in the Western Atlantic. Despite its ecological importance, there is little available information about population and biological data or the impacts of its removal from its natural habitats. Considering the economic and ecological importance of this species, this study provides a short review of existing studies and highlights research and conservation needs for this highly exploited marine gastropod. Keywords: Brazil; Predatory Gastropod; Marine Curio Trade; Species Conservation; Shell Trade 1 Departamento de Biologia, Universidade Estadual da Paraíba, Av. Baraúnas, 351, Bairro Universitário, Campina Grande, PB, 58429­500, Brazil 2 Programa de Pós­Graduação em Ciências Biológicas (Zoologia), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, João Pessoa, PB, 58059­970, Brazil * E­mail address: DIAS, T.L.P. ([email protected]), MOTA, E.L.S. ([email protected]), DUARTE, R.C.S. ([email protected]), ALVES, R.R.N. ([email protected]) INTRODUCTION species has a heavy and large shell, reaching up to 30 cm in total length (Ardila et The king helmet Cassis tuberosa al.
    [Show full text]
  • Reproductive Cycle of E Cycle of Mellita Quinquiesperf
    Reproductive cycle of Mellita quinquiesperforata (Leske) (Echinodermata, Echinoidea) in two contrasting beach environments Yara A. G. Tavares & Carlos A. Borzone Centro de Estudos do Mar, Universidade Federal do Paraná. Avenida Beira Mar, Caixa Postal 50002, 832555-000 Pontal do Paraná, Paraná, Brasil. E-mail: [email protected]; [email protected] ABSTRACT. The reproductive cycle of the irregular echinoid Mellita quinquiesperforata (Leske, 1778) was studied in populations from two sand beaches with different morphodynamic conditions in Parana coast, from February 1992 through July 1994. Gametogenesis was described by histological and gonad index methods and the differ- ences between both populations were observed in the extension of nutrient storage and spawning period. Both populations exhibited a main reproductive period during spring/summer and a nutrient storage period during autumn/winter months. The spawning period at the intermediate-dissipative beach was shorter than at the reflective beach. Meanwhile, a nutrient storage stage was more extensive in the latter. Gonad index varied between both sexes and it was influenced by population characteristics. Different strategies in allocation of resources between maintenance and reproduction effort (oocyte size) confirm the high adaptive plasticity developed by this species to live in contrasting beach environments. KEY WORDS. Reproductive plasticity; sand dollar; sandy beach. RESUMO. Reprodução de Mellita quinquiesperforata (Leske) (Echinodermatamata, Echinoidea) em dois ecossistemas praiais contrastantes. O ciclo reprodutivo do equinóide irregular Mellita quinquiesperforata (Leske, 1778) foi estudado em populações de duas praias com diferentes condições morfodinâmicas na costa paranaense, de fevereiro de 1992 a julho de 1994. A gametogênese foi descrita pela análise histológica das gônadas e pela variação do índice gonadal.
    [Show full text]
  • T Memo Y of Dr. Reuben Lasker Who, Until
    HIS ISMOF THE Fishery Bulletin is in memoy of Dr. Reuben Lasker who, until This death, was Chiefofthe Coastal Fisheries Division of the Southwest Fisheries Center, National Marine Fisheries Service. The contri- butors and I feel both a debt ofgratitude and a strong bond ofpiendship to this scientist who profoundly influenced our investigations, our careers, and the field ofmarine larval ecology. Our regret is that Reuben will not see this tribute. Andrew E. Dizon, Ph.D. Scientific Editor 375 .. REUBEN LASKER. A Remembrance.. It is the spring of 1989 in La Jolla, California, almost with a minor in chemistry, from the University in a year since our friend and colleague, Reuben 1950. When a graduate research fellowship Lasker, left us after a valiant battle against cancer. became available in marine biology, Reuben made We remember him fondly, with respect and admira- a fateful career decision to abandon medicine and tion for the man and for the scientist whose intellec- applied for the post. He was awarded a full tuition tual honesty and humanity endeared him to his scholarship with stipend for studies in marine associates. We, therefore, dedicate this Festschrift biology at the University of Miami where he concen- to the memory of a remarkable human being, a trated on studies on the physiology and cellulose warm and caring man, who combined a lifelong digestion in the shipworm, Teredo. He was granted passion and dedication to the marine sciences with his M.S. in marine biology from the University of a bright intelligence, a lively curiosity, and an abid- Miami in 1952.
    [Show full text]