DOCSLIB.ORG

Life Strategies in the Long-Lived Bivalve Arctica Islandica on a Latitudinal Climate Gradient – Environmental Constraints and Evolutionary Adaptations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Life Strategies in the Long-Lived Bivalve Arctica Islandica on a Latitudinal Climate Gradient – Environmental Constraints and Evolutionary Adaptations Life strategies in the long-lived bivalve Arctica islandica on a latitudinal climate gradient – Environmental constraints and evolutionary adaptations Lebensstrategien der langlebigen Muschel Arctica islandica, untersucht an Populationen entlang eines Klimagradienten – Umwelteinflüsse und evolutionäre Anpassungen Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften -Dr. rer. nat.- Fachbereich 2 Biologie/Chemie Universität Bremen vorgelegt von Julia Strahl Bremen März 2011 Prüfungsausschuss: 1. Gutachter: Prof. Dr. Ralf Dringen (Zentrum für Biomolekulare Interaktionen Bremen, Universität Bremen) 2. Gutachter: PD Dr. Doris Abele (Funktionelle Ökologie, Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven) 1. Prüfer: Prof. Dr. Thomas Brey (Funktionelle Ökologie, Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven) 2. Prüfer: Prof. Dr. Kai Bischof (Marine Botanik, Universität Bremen) CONTENTS FREQUENTLY USED ABBREVATIONS I SUMMARY III ZUSAMMENFASSUNG V 1. INTRODUCTION 1 1.1. Bivalves as models in aging research 1 1.2. Why is Arctica islandica an interesting model in aging research? 2 1.3. What is aging? 4 1.4. Physiological parameters involved in the aging process 5 1.5. Is the aging process in ectotherms related to reactive oxygen species formation? 6 1.6. Cellular maintenance and longevity 7 1.7. Metabolic rate depression and longevity 9 1.8. Possible role of nitric oxide in metabolic rate depression 10 1.9. Metabolic rate depression, anaerobiosis and recovery from anoxia 10 1.10. Aims of the thesis 13 2. MATERIALS AND METHODS – A GENERAL OVERVIEW 14 2.1. Investigated species and sampling locations 14 2.2. Experimental studies 15 2.2.1. Incubation experiment for the determination of cell-turnover rates 15 2.2.2. Field and laboratory studies of burrowing behavior and self-induced metabolic rate depression in Iceland and German Bight Arctica islandica 15 2.2.3. Laboratory study of forced metabolic rate depression 17 2.2.4. Measurement of ROS-formation in isolated gill tissue 18 2.2.5. Measurement of aerobic metabolic rates 18 2.2.6. Investigation of nitric oxide formation and its possible role as modulator of cellular respiration 19 2.3. Biochemical Assays 20 2.3.1. Proliferation rates 20 2.3.2. Apopotosis intensities 20 2.3.3. Mitochondrial enzyme activity 20 2.3.4. Adenylate concentrations and energy charge 20 2.3.5. Antioxidant defense parameters 20 2.3.6. Anaerobic enzyme activity and accumulation of anaerobic metabolites 20 2.3.7. Nitrite and nitrate contents 21 2.4. Individual age determination 21 3. PUBLICATIONS 23 Publication I 25 Cell turnover in tissues of the long-lived ocean quahog Arctica islandica and the short-lived scallop Aequipecten opercularis Publication II 45 Metabolic and physiological responses in tissues of the long-lived bivalve Arctica islandica to oxygen deficiency Publication III 63 Metabolic rate depression: a key to longevity in the ocean quahog Arctica islandica 4. CONTRIBUTED WORK 87 Publication IV 89 A metabolic model for the ocean quahog Arctica islandica – Effects of animal mass and age, temperature, salinity, and geography on respiration rate Publication V 107 Age dependent patterns of antioxidants in Arctica islandica from six regionally separate populations with different life spans Publication VI 127 Aging in marine animals 5. ADDITIONAL RESULTS 149 5.1. Possible functions of the signaling molecule nitric oxide in the bivalve Arctica islandica 151 5.2. Hemocyte cell cultures 169 6. DISCUSSION 173 6.1. What contributes to the long live expectancy in Arctica islandica? 173 6.2. Metabolic rate depression as life-prolonging strategy in Arctica islandica and the possible role of NO in regulating cellular respiration in this species 177 6.3. What are the reasons for the differences in maximum life span in geographically separated Arctica islandica populations? Intrinsic vs. extrinsic determinants 179 6.4. Reproduction and longevity in Arctica islandica 182 7. CONCLUSIONS AND PERSPECTIVES 185 8. REFERENCES 189 ACKNOWLEDGEMENTS 199 Abbreviations FREQUENTLY USED ABBREVIATIONS ADP Adenosine diphosphate AFDM Ash free dry mass ATP Adenosine triphosphate B Burrowed BrdU 5-Bromo-2-deoxyuridine CAT Catalase CS Citrate synthase EC Energy charge GB German Bight GSH Reduced glutathione GSSG Oxidized glutathione GSx Total glutathione (GSH + 2 x GSSG) IC Iceland LDH Lactate dehydrogenase MLSP Maximum life span potential MRD Metabolic rate depression MSR Mass specific respiration NE North East NW North West ODH Octopine dehydrogenase PO2 Oxygen partial pressure Pcrit Critical PO2 NO Nitric oxide NOS Nitric oxide synthase RLU Relative luminescence units ROS Reactive oxygen species SMR Standard metabolic rate SOD Superoxide dismutase SST Sea surface temperature VBGF Von Bertalanffy growth function I II Summary SUMMARY The ocean quahog, Arctica islandica is the longest-lived non-colonial animal known to science. A maximum individual age of this bivalve of 405 years has been found in a population off the north western coast of Iceland. Conspicuously shorter maximum lifespan potentials (MLSPs) were recorded from other populations of A. islandica in European waters (e.g. Kiel Bay: 30 years, German Bight: 150 years) which experience wider temperature and salinity fluctuations than the clams from Iceland. The aim of my thesis was to identify possible life-prolonging physiological strategies in A. islandica and to examine the modulating effects of extrinsic factors (e.g. seawater temperature, food availa- bility) and intrinsic factors (e.g. species-specific behavior) on these strategies. Burrowing behavior and metabolic rate depression (MRD), tissue-specific antioxidant and anaerobic capacities as well as cell-turnover (= apoptosis and proliferation) rates were investigated in A. islandica from Iceland and the German Bight. An inter-species comparison of the quahog with the epibenthic scallop Aequipecten opercularis (MLSP = 8-10 years) was carried out in order to determine whether bivalves with short lifespans and different lifestyles also feature a different pattern in cellular maintenance and repair. The combined effects of a low-metabolic lifestyle, low oxidative damage accumulation, and constant investment into cellular protection and tissue maintenance, appear to slow-down the process of physiological aging in A. islandica and to afford the extraordinarily long MLSP in this species. Standard metabolic rates were lower in A. islandica when compared to the shorter-lived A. opercularis. Furthermore, A. islandica regulate mantle cavity water PO2 to mean values < 5 kPa, a PO2 at which the formation of reactive oxygen species (ROS) in isolated gill tissues of the clams was found to be 10 times lower than at normoxic conditions (21 kPa). Burrowing and metabolic rate depression (MRD) in Icelandic specimens were more pronounced in winter, possibly supported by low seawater temperature and food availability, and seem to be key energy-saving and life-prolonging parameters in A. islandica. The signaling molecule nitric oxide (NO) may play an important role during the onset of MRD in the ocean quahog by directly inhibiting cytochome-c-oxidase at low internal oxygenation upon shell closure. In laboratory experiments, respiration of isolated A. islandica gills was completely inhibited by chemically produced NO at low experimental PO2 ≤ 10 kPa. During shell closure, mantle cavity water PO2 decreased to 0 kPa for longer than 24 h, a state in which ROS production is supposed to subside. Compared to other mollusk species, onset of anaerobic metabolism is late in A. islandica in the metabolically reduced state. Increased accumulation of the anaerobic metabolite succinate was initially detected in the adductor muscle of the clams after 3.5 days under anoxic incubation or in burrowed specimens. A ROS-burst was absent in isolated gill tissue of the clams following hypoxia (5 kPa)-reoxygenation (21 kPa). Accordingly, neither the activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), nor the specific content of the ROS-scavenger glutathione (GSH) was enhanced in different tissues of the ocean quahog after 3.5 days of self-induced or forced hypoxia/anoxia to prepare for an oxidative burst. III Summary While reduced ROS formation compared to routine levels lowers oxidative stress during MRD and also during surfacing, the general preservation of high cellular defense and the efficient removal and replacement of damaged cells over lifetime seem to be of crucial importance in decelerating the senescent decline in tissues of A. islandica. Along with stable antioxidant protection over 200 years of age, proliferation rates and apoptosis intensities in most investigated tissues of the ocean quahog were low, but constant over 140 years of age. Accordingly, age-dependent accumu- lations of protein and lipid oxidation products are lower in A. islandica tissues when compared to the shorter-lived bivalve A. opercularis. The short-lived swimming scallop is a model bivalve species representing the opposite life and aging strategy to A. islandica. In this species permanently high energy throughput, reduced invest- ment into antioxidant defense with age, and higher accumulation of oxidation products are met by higher cell turnover rates than in the ocean quahog. The only symptoms of physiological change over age ever found in A. islandica were decreasing cell turnover rates in the heart muscle over a lifetime of 140 years. This may either indicate higher damage levels and
Load more

Recommended publications
  • WHELKS Scientific Names: Busycon Canaliculatum Busycon Carica
    Colloquial Nicknames: Channeled Whelk Knobbed Whelk WHELKS Scientific names: Busycon canaliculatum Busycon carica Field Markings: The shell of open with their strong muscular foot. As both species is yellow-red or soon as the valves open, even the tiniest orange inside and pale gray amount, the whelk wedges in the sharp edge outside. of its shell, inserts the proboscis and Size: Channeled whelk grows up devours the soft body of the clam. to 8 inches long; knobbed whelk Mating occurs by way of internal grows up to 9 inches long and 4.5 inches wide fertilization; sexes are separate. The egg casing of the whelk is a Habitat: Sandy or muddy bottoms long strand of yellowish, parchment-like disks, resembling a Seasonal Appearance: Year-round necklace - its unique shape is sculpted by the whelk’s foot. Egg cases can be two to three feet long and have 70 to 100 capsules, DISTINGUISHING FEATURES AND each of which can hold 20 to 100 eggs. Newly hatched channeled BEHAVIORS whelks escape from small holes at the top of each egg case with Whelks are large snails with massive shells. The two most their shells already on. Egg cases are sometimes found along common species in Narragansett Bay are the knobbed whelk the Bay shoreline, washed up with the high tide debris. and the channeled whelk. The knobbed whelk is the largest marine snail in the Bay. It Relationship to People is pear-shaped with a flared outer lip and knobs on the shoulder Both channeled and knobbed whelks scavenge and hunt for of its shell.
    [Show full text]
  • §4-71-6.5 LIST of CONDITIONALLY APPROVED ANIMALS November
    §4-71-6.5 LIST OF CONDITIONALLY APPROVED ANIMALS November 28, 2006 SCIENTIFIC NAME COMMON NAME INVERTEBRATES PHYLUM Annelida CLASS Oligochaeta ORDER Plesiopora FAMILY Tubificidae Tubifex (all species in genus) worm, tubifex PHYLUM Arthropoda CLASS Crustacea ORDER Anostraca FAMILY Artemiidae Artemia (all species in genus) shrimp, brine ORDER Cladocera FAMILY Daphnidae Daphnia (all species in genus) flea, water ORDER Decapoda FAMILY Atelecyclidae Erimacrus isenbeckii crab, horsehair FAMILY Cancridae Cancer antennarius crab, California rock Cancer anthonyi crab, yellowstone Cancer borealis crab, Jonah Cancer magister crab, dungeness Cancer productus crab, rock (red) FAMILY Geryonidae Geryon affinis crab, golden FAMILY Lithodidae Paralithodes camtschatica crab, Alaskan king FAMILY Majidae Chionocetes bairdi crab, snow Chionocetes opilio crab, snow 1 CONDITIONAL ANIMAL LIST §4-71-6.5 SCIENTIFIC NAME COMMON NAME Chionocetes tanneri crab, snow FAMILY Nephropidae Homarus (all species in genus) lobster, true FAMILY Palaemonidae Macrobrachium lar shrimp, freshwater Macrobrachium rosenbergi prawn, giant long-legged FAMILY Palinuridae Jasus (all species in genus) crayfish, saltwater; lobster Panulirus argus lobster, Atlantic spiny Panulirus longipes femoristriga crayfish, saltwater Panulirus pencillatus lobster, spiny FAMILY Portunidae Callinectes sapidus crab, blue Scylla serrata crab, Samoan; serrate, swimming FAMILY Raninidae Ranina ranina crab, spanner; red frog, Hawaiian CLASS Insecta ORDER Coleoptera FAMILY Tenebrionidae Tenebrio molitor mealworm,
    [Show full text]
  • Geoducks—A Compendium
    34, NUMBER 1 VOLUME JOURNAL OF SHELLFISH RESEARCH APRIL 2015 JOURNAL OF SHELLFISH RESEARCH Vol. 34, No. 1 APRIL 2015 JOURNAL OF SHELLFISH RESEARCH CONTENTS VOLUME 34, NUMBER 1 APRIL 2015 Geoducks — A compendium ...................................................................... 1 Brent Vadopalas and Jonathan P. Davis .......................................................................................... 3 Paul E. Gribben and Kevin G. Heasman Developing fisheries and aquaculture industries for Panopea zelandica in New Zealand ............................... 5 Ignacio Leyva-Valencia, Pedro Cruz-Hernandez, Sergio T. Alvarez-Castaneda,~ Delia I. Rojas-Posadas, Miguel M. Correa-Ramırez, Brent Vadopalas and Daniel B. Lluch-Cota Phylogeny and phylogeography of the geoduck Panopea (Bivalvia: Hiatellidae) ..................................... 11 J. Jesus Bautista-Romero, Sergio Scarry Gonzalez-Pel aez, Enrique Morales-Bojorquez, Jose Angel Hidalgo-de-la-Toba and Daniel Bernardo Lluch-Cota Sinusoidal function modeling applied to age validation of geoducks Panopea generosa and Panopea globosa ................. 21 Brent Vadopalas, Jonathan P. Davis and Carolyn S. Friedman Maturation, spawning, and fecundity of the farmed Pacific geoduck Panopea generosa in Puget Sound, Washington ............ 31 Bianca Arney, Wenshan Liu, Ian Forster, R. Scott McKinley and Christopher M. Pearce Temperature and food-ration optimization in the hatchery culture of juveniles of the Pacific geoduck Panopea generosa ......... 39 Alejandra Ferreira-Arrieta, Zaul Garcıa-Esquivel, Marco A. Gonzalez-G omez and Enrique Valenzuela-Espinoza Growth, survival, and feeding rates for the geoduck Panopea globosa during larval development ......................... 55 Sandra Tapia-Morales, Zaul Garcıa-Esquivel, Brent Vadopalas and Jonathan Davis Growth and burrowing rates of juvenile geoducks Panopea generosa and Panopea globosa under laboratory conditions .......... 63 Fabiola G. Arcos-Ortega, Santiago J. Sanchez Leon–Hing, Carmen Rodriguez-Jaramillo, Mario A.
    [Show full text]
  • Improving the NEFSC Clam Survey for Atlantic Surfclams and Ocean Quahogs
    Northeast Fisheries Science Center Reference Document 19-06 Improving the NEFSC Clam Survey for Atlantic Surfclams and Ocean Quahogs by Larry Jacobson and Daniel Hennen May 2019 Northeast Fisheries Science Center Reference Document 19-06 Improving the NEFSC Clam Survey for Atlantic Surfclams and Ocean Quahogs by Larry Jacobson and Daniel Hennen NOAA Fisheries, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA 02543 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service Northeast Fisheries Science Center Woods Hole, Massachusetts May 2019 Northeast Fisheries Science Center Reference Documents This series is a secondary scientific seriesdesigned to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. If you do not have Internet access, you may obtain a paper copy of a document by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author’s name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center’s Woods Hole Labora- tory Library (166 Water St., Woods Hole, MA 02543-1026). Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report.
    [Show full text]
  • Paleoenvironmental Interpretation of Late Glacial and Post
    PALEOENVIRONMENTAL INTERPRETATION OF LATE GLACIAL AND POST- GLACIAL FOSSIL MARINE MOLLUSCS, EUREKA SOUND, CANADIAN ARCTIC ARCHIPELAGO A Thesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment of the Requirements for the Degree of Master of Science in the Department of Geography University of Saskatchewan Saskatoon By Shanshan Cai © Copyright Shanshan Cai, April 2006. All rights reserved. i PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis. Requests for permission to copy or to make other use of material in this thesis in whole or part should be addressed to: Head of the Department of Geography University of Saskatchewan Saskatoon, Saskatchewan S7N 5A5 i ABSTRACT A total of 5065 specimens (5018 valves of bivalve and 47 gastropod shells) have been identified and classified into 27 species from 55 samples collected from raised glaciomarine and estuarine sediments, and glacial tills.
    [Show full text]
  • Testing the Hypothesis of Tolerance Strategies in Hiatella Arctica L. (Mollusca: Bivalvia)
    Helgol Mar Res (2005) 59: 187–195 DOI 10.1007/s10152-005-0218-6 ORIGINAL ARTICLE Vjacheslav V. Khalaman Testing the hypothesis of tolerance strategies in Hiatella arctica L. (Mollusca: Bivalvia) Received: 15 April 2004 / Revised: 14 February 2005 / Accepted: 14 February 2005 / Published online: 6 April 2005 Ó Springer-Verlag and AWI 2005 Abstract The physiological and biocenotic optima of Keywords Fluctuating asymmetry Æ Directional Hiatella arctica L. inhabiting shallow water fouling asymmetry Æ Hiatella arctica Æ Biofouling Æ communities of the White Sea were compared. The Tolerance strategy Æ The White Sea biomass and proportion of H. arctica in communities were used for the estimation of biocenotic optima or community success. The physiological state of popula- tions was assessed by means of the fluctuating asym- Introduction metry. The fluctuating asymmetry of H. arctica was calculated using the valve weights. It was determined Ramenskii (1935) described three main survival strat- that the shell of H. arctica possesses a slight directional egies in terrestrial plants: tolerance (S), ruderal (R) asymmetry, the right valve usually being larger (and and competitive (K) strategies. This classification was heavier) than the left one. The relationship between adopted in the Russian literature, but received little fluctuating and directional asymmetries is discussed. attention elsewhere. Almost 40 years later the classifi- High biomass and proportion of H. arctica in the cation of survival strategies was ‘‘rediscovered’’ by community generally correspond with high levels of Grime (1974), became widely adopted by plant ecol- fluctuating asymmetry. Thus, a discrepancy between ogists, and was then developed further. Tolerance physiological and ecological optima is observed, which strategies were divided into two categories, referring to is recognised as being characteristic of a tolerance plants that are tolerant to unfavourable abiotic envi- strategy.
    [Show full text]
  • Functional Traits of a Native and an Invasive Clam of the Genus Ruditapes Occurring in Sympatry in a Coastal Lagoon
    www.nature.com/scientificreports OPEN Functional traits of a native and an invasive clam of the genus Ruditapes occurring in sympatry Received: 19 June 2018 Accepted: 8 October 2018 in a coastal lagoon Published: xx xx xxxx Marta Lobão Lopes1, Joana Patrício Rodrigues1, Daniel Crespo2, Marina Dolbeth1,3, Ricardo Calado1 & Ana Isabel Lillebø1 The main objective of this study was to evaluate the functional traits regarding bioturbation activity and its infuence in the nutrient cycling of the native clam species Ruditapes decussatus and the invasive species Ruditapes philippinarum in Ria de Aveiro lagoon. Presently, these species live in sympatry and the impact of the invasive species was evaluated under controlled microcosmos setting, through combined/manipulated ratios of both species, including monospecifc scenarios and a control without bivalves. Bioturbation intensity was measured by maximum, median and mean mix depth of particle redistribution, as well as by Surface Boundary Roughness (SBR), using time-lapse fuorescent sediment profle imaging (f-SPI) analysis, through the use of luminophores. Water nutrient concentrations (NH4- N, NOx-N and PO4-P) were also evaluated. This study showed that there were no signifcant diferences in the maximum, median and mean mix depth of particle redistribution, SBR and water nutrient concentrations between the diferent ratios of clam species tested. Signifcant diferences were only recorded between the control treatment (no bivalves) and those with bivalves. Thus, according to the present work, in a scenario of potential replacement of the native species by the invasive species, no signifcant diferences are anticipated in short- and long-term regarding the tested functional traits.
    [Show full text]
  • Os Nomes Galegos Dos Moluscos
    A Chave Os nomes galegos dos moluscos 2017 Citación recomendada / Recommended citation: A Chave (2017): Nomes galegos dos moluscos recomendados pola Chave. http://www.achave.gal/wp-content/uploads/achave_osnomesgalegosdos_moluscos.pdf 1 Notas introdutorias O que contén este documento Neste documento fornécense denominacións para as especies de moluscos galegos (e) ou europeos, e tamén para algunhas das especies exóticas máis coñecidas (xeralmente no ámbito divulgativo, por causa do seu interese científico ou económico, ou por seren moi comúns noutras áreas xeográficas). En total, achéganse nomes galegos para 534 especies de moluscos. A estrutura En primeiro lugar preséntase unha clasificación taxonómica que considera as clases, ordes, superfamilias e familias de moluscos. Aquí apúntase, de maneira xeral, os nomes dos moluscos que hai en cada familia. A seguir vén o corpo do documento, onde se indica, especie por especie, alén do nome científico, os nomes galegos e ingleses de cada molusco (nalgún caso, tamén, o nome xenérico para un grupo deles). Ao final inclúese unha listaxe de referencias bibliográficas que foron utilizadas para a elaboración do presente documento. Nalgunhas desas referencias recolléronse ou propuxéronse nomes galegos para os moluscos, quer xenéricos quer específicos. Outras referencias achegan nomes para os moluscos noutras linguas, que tamén foron tidos en conta. Alén diso, inclúense algunhas fontes básicas a respecto da metodoloxía e dos criterios terminolóxicos empregados. 2 Tratamento terminolóxico De modo moi resumido, traballouse nas seguintes liñas e cos seguintes criterios: En primeiro lugar, aprofundouse no acervo lingüístico galego. A respecto dos nomes dos moluscos, a lingua galega é riquísima e dispomos dunha chea de nomes, tanto específicos (que designan un único animal) como xenéricos (que designan varios animais parecidos).
    [Show full text]
  • Ageing Research Reviews Revamping the Evolutionary
    Ageing Research Reviews 55 (2019) 100947 Contents lists available at ScienceDirect Ageing Research Reviews journal homepage: www.elsevier.com/locate/arr Review Revamping the evolutionary theories of aging T ⁎ Adiv A. Johnsona, , Maxim N. Shokhirevb, Boris Shoshitaishvilic a Nikon Instruments, Melville, NY, United States b Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, CA, United States c Division of Literatures, Cultures, and Languages, Stanford University, Stanford, CA, United States ARTICLE INFO ABSTRACT Keywords: Radical lifespan disparities exist in the animal kingdom. While the ocean quahog can survive for half a mil- Evolution of aging lennium, the mayfly survives for less than 48 h. The evolutionary theories of aging seek to explain whysuchstark Mutation accumulation longevity differences exist and why a deleterious process like aging evolved. The classical mutation accumu- Antagonistic pleiotropy lation, antagonistic pleiotropy, and disposable soma theories predict that increased extrinsic mortality should Disposable soma select for the evolution of shorter lifespans and vice versa. Most experimental and comparative field studies Lifespan conform to this prediction. Indeed, animals with extreme longevity (e.g., Greenland shark, bowhead whale, giant Extrinsic mortality tortoise, vestimentiferan tubeworms) typically experience minimal predation. However, data from guppies, nematodes, and computational models show that increased extrinsic mortality can sometimes lead to longer evolved lifespans. The existence of theoretically immortal animals that experience extrinsic mortality – like planarian flatworms, panther worms, and hydra – further challenges classical assumptions. Octopuses pose another puzzle by exhibiting short lifespans and an uncanny intelligence, the latter of which is often associated with longevity and reduced extrinsic mortality.
    [Show full text]
  • Growth O[ Juvenile Arctica Islandica Under Experimental Conditions
    HELGOL*NI)ER MEERESUNTERSUCHUNGEN Helgol~inder Meeresunters. 51, 417-431 (1997) Growth o[ juvenile Arctica islandica under experimental conditions R. Witbaard*, R. Franken & B. Visser Netherlands Institute for Sea Research, PO Box 59 1790 AB Den Burg, The Netherlands ABSTRACT: In two laboratory experiments, the effects of temperature and food availability on the growth of 10- to 23-mm high specimens of the bivalve Arctica islrmdica were estimated. Each experimental set-up consisted of 5 treatments in which either the food supply or the temperature differed. It was demonslrated that Arctica is able to grow at temperatures as low as 1 ~ A tenfold incredse of shell growth was observed at temperatures between 1~ and 12 :C. The greatest change in growth rate took place between 1~ and 6 ~ Average instantaneous shell growth varies between 0.00t)3 at I ~ to 0.0032/day at 12 ~C'. The results suggest that temperature hardly alfects the time spent in filtration, whereas particle density strongly influences that response. Starved am- reals at 9 ~ have their siphons open durmg only 12% of the time, whereas the siphons ol opti- mally fed animals were open on average during 76% of the observations. Increased siphon activity corresponded to high shell and tissue growth. At 9 ~ average shell growth at the optimum cell density o[ 20xlO" cell/1 was 3 I mm corresponding to an instantaneous rate of 0.0026/day. An algal cell density (Lsochry.sis gulbanu, Dunuliella marina) ranging between 5 and 7x10" cell/l is just enough to keep shells alive at 9 ~ (.'arbon conversion efticiency at 9 ~ is estimated to vary between 11 and 14 %.
    [Show full text]
  • The Effects of Environment on Arctica Islandica Shell Formation and Architecture
    Biogeosciences, 14, 1577–1591, 2017 www.biogeosciences.net/14/1577/2017/ doi:10.5194/bg-14-1577-2017 © Author(s) 2017. CC Attribution 3.0 License. The effects of environment on Arctica islandica shell formation and architecture Stefania Milano1, Gernot Nehrke2, Alan D. Wanamaker Jr.3, Irene Ballesta-Artero4,5, Thomas Brey2, and Bernd R. Schöne1 1Institute of Geosciences, University of Mainz, Joh.-J.-Becherweg 21, 55128 Mainz, Germany 2Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany 3Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011-3212, USA 4Royal Netherlands Institute for Sea Research and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel, the Netherlands 5Department of Animal Ecology, VU University Amsterdam, Amsterdam, the Netherlands Correspondence to: Stefania Milano ([email protected]) Received: 27 October 2016 – Discussion started: 7 December 2016 Revised: 1 March 2017 – Accepted: 4 March 2017 – Published: 27 March 2017 Abstract. Mollusks record valuable information in their hard tribution, and (2) scanning electron microscopy (SEM) was parts that reflect ambient environmental conditions. For this used to detect changes in microstructural organization. Our reason, shells can serve as excellent archives to reconstruct results indicate that A. islandica microstructure is not sen- past climate and environmental variability. However, animal sitive to changes in the food source and, likely, shell pig- physiology and biomineralization, which are often poorly un- ment are not altered by diet. However, seawater temperature derstood, can make the decoding of environmental signals had a statistically significant effect on the orientation of the a challenging task.
    [Show full text]
  • Shellfish Hatchery
    EAST HAMPTON TOWN SHELLFISH HATCHERY The 2015 Crew, left to right: Kate, Pete, Carissa, Shelby, and Barley 2015 ANNUAL REPORT AND 2016 OPERATING PLAN Prepared by Kate Rossi-Snook Edited by Barley Dunne East Hampton Town Shellfish Hatchery The skiff loaded for seeding in Lake Montauk Annual Report of Operations Mission Statement With a hatchery on Fort Pond Bay, a nursery on Three Mile Harbor, and a floating raft field growout system in Napeague Harbor, the East Hampton Town Shellfish Hatchery produces large quantities of oyster (Crassostrea virginica), clam (Mercenaria mercenaria), and bay scallop (Argopecten irradians) seed to enhance valuable shellfish stocks in local waterways. Shellfish are available for harvest by all permitted town residents. Cooperative research and experimentation concerning shellfish culture, the subsequent success of seed in the wild, and the status of the resource is undertaken and reported upon regularly, often funded and validated by scientific research grants. Educational opportunities afforded by the work include school group and open house tours and educational displays at community functions. Annual reporting includes production statistics and values, seed dissemination information, results of research initiatives, a summary of outreach efforts, the status of current and developing infrastructure, and a plan for the following year’s operations. 2015 Full-time Staff Part-time and Contractual Volunteers John “Barley” Dunne – Director Carissa Maurin – Environmental Aide Romy Macari Kate Rossi-Snook – Hatchery Manager Shelby Joyce – Environmental Aide (summer) Christopher Fox-Strauss Pete Topping – Algae Culturist Adam Younes – Environmental Aide (fall) Jeremy Gould – Maintenance Mechanic Carissa and Pete unloading OysterGros Special Thanks to: Barnaby Friedman for producing our annual seeding maps.
    [Show full text]