DOCSLIB.ORG

Bivalve Response to Estuarine Eutrophication: the Balance Between Enhanced Food Supply and Habitat Alterations Author(S) :Ruth H

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bivalve Response to Estuarine Eutrophication: the Balance Between Enhanced Food Supply and Habitat Alterations Author(S) :Ruth H Bivalve Response to Estuarine Eutrophication: The Balance between Enhanced Food Supply and Habitat Alterations Author(s) :Ruth H. Carmichael, A. C. Shriver and I. Valiela Source: Journal of Shellfish Research, 31(1):1-11. 2012. Published By: National Shellfisheries Association DOI: http://dx.doi.org/10.2983/035.031.0101 URL: http://www.bioone.org/doi/full/10.2983/035.031.0101 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Journal of Shellfish Research, Vol. 31, No. 1, 1–11, 2012. BIVALVE RESPONSE TO ESTUARINE EUTROPHICATION: THE BALANCE BETWEEN ENHANCED FOOD SUPPLY AND HABITAT ALTERATIONS RUTH H. CARMICHAEL,1,2* A. C. SHRIVER3 AND I. VALIELA3 1Dauphin Island Sea Lab, 101 Bienville Boulevard, Dauphin Island, AL 36528; 2University of South Alabama, Mobile, AL 36688; 3The Ecosystems Center, Marine Biology Laboratory, Woods Hole, MA 02343 ABSTRACT As a result of insufficient sampling, differences in estuarine attributes, species variation, and poor links to anthropogenic sources, responses of bivalve mollucs to anthropogenic nutrient enrichment of coastal waters remains poorly defined for most systems worldwide. To establish the net effect of nutrient enrichment on bivalves, we compared changes in growth and survival of different bivalve species reported in 5 studies conducted in a representative estuarine system (on Cape Cod, MA) in which effects of eutrophication on food supply and habitat were quantified and related directly to land-derived nitrogen (N) sources. N-stable isotope ratios in suspended particulates and bivalve tissues demonstrated that N derived from anthropogenic wastewater was assimilated into bivalve tissues as N loads increased. Bivalve shell and soft-tissue growth also increased in response to increased chlorophyll a concentrations driven by land-derived N loads. Growth was accompanied by increased percent N content of tissues in some species, suggesting a change in tissue composition with N enrichment. In contrast, bivalve survival was lower in years of higher microalgal production, suggesting eutrophic-driven habitat degradation may have contributed to mortality. The net effect of eutrophication on bivalves, therefore, depended on the balance between enhanced food supply and habitat alterations that are mediated by attributes of the receiving estuary, and differences among species, particularly feeding habits, feeding physiology, and tolerance to hypoxia. KEY WORDS: nitrogen, stable isotope, chlorophyll, growth, survival INTRODUCTION lochs more than 60 y ago (Orr 1947, Raymont 1947), and to a lesser degree from more recent studies in the Baltic and North Increased nutrient enrichment to coastal waters worldwide Seas, the Kattegat, and Cape Cod estuaries (Tober et al. 2000, (National Research Council 2000, Paerl 2006) has increased Nixon & Buckley 2002). These studies show increases in abun- algal productivity, stimulated accumulation of organic matter dance or biomass of finfish through time or across locations as from detritus of algae, and increased nitrogen (N) content of N and/or phosphorus (P) inputs to water bodies increased. If particles in the water and sediment (Zeitzschel 1980, Grane´ li & enrichment-driven secondary production can be detected in some Sundba¨ ck 1985, Cloern 2001). The resulting eutrophication of finfish, which tend to be migratory and herbivorous, then pro- coastal waters ultimately may cause loss of seagrasses, anoxia duction in other primary consumers, particularly sedentary in near-bottom waters, and lower sediment redox (Paerl et al. bivalves, should be at least equally coupled to nutrient enrich- 1998, Gray et al. 2002, Hauxwell et al. 2003). Although the ment and quantifiable (Tober et al. 2000, Carmichael 2004). susceptibility of a coastal system to these effects depends on physical–chemical attributes of the water body, such as salinity, temperature, mixing, discharge, and flushing rates (Cloern 2001, BIVALVE RESPONSES TO NUTRIENT ENRICHMENT Paerl 2006), eutrophic-driven changes in water quality have Previous studies suggest the effects of nutrient enrichment resulted in widespread species loss in many estuaries (Baden on bivalves may be positive or negative, depending on whether et al. 1990, Cloern 2001, Gray et al. 2002). enrichment affected primarily food resources or habitat (Table 1). Because increased primary production often translates to in- Positive effects of nutrient enrichment on bivalves have in- creased food quantity and quality for primary consumers such cluded increased abundance, biomass, and assimilation effi- as bivalves (e.g., Bayne & Widdows 1978, Newell et al. 1982, ciency, largely attributed to increased food supply, whereas Smaal & Van Stralen 1990, Fegley et al. 1992, Carmichael et al. negative effects included increased mortality, reduced biomass, 2004), there may be corresponding increases in growth and and lower recruitment, resulting from habitat loss or degrada- abundance of consumers in nutrient-enriched estuaries (Nixon & tion (Table 1, Fig. 1). Some studies reported a combination of Buckley 2002, Kirby & Miller 2005). The extent to which these enrichment-related effects (Feinstein et al. 1996, Josefson & potentially positive effects of enrichment are detectable in coastal Rasmussen 2000, Kirby & Miller 2005, Verdelhos et al. 2005), food webs, however, is not well established (Micheli 1999). The suggesting that the response of bivalves to nutrient enrichment notion that nutrient enrichment may stimulate production of may be more complex than a simple positive or negative response. consumers has been largely overlooked in favor of efforts to Until recently, however, most studies regarding the effects of identify, diagnose, and remediate the negative effects of eutro- eutrophication on bivalves relied on circumstantial evidence. phication (Micheli 1999, Fluharty 2000, Nixon & Buckley 2002, For example, the Scottish loch studies reported increased Verdelhos et al. 2005). abundance among bivalves as they did for finfish, but did The bulk of evidence supporting eutrophic-driven secondary not similarly detail the effects on bivalves (Orr 1947, Raymont production comes from fertilization experiments in Scottish sea 1947). Until 2001, no studies provided direct links between bivalve responses and a specific source of nutrient enrichment *Corresponding author. E-mail: [email protected] across sites, and only 25% of the reported bivalve responses DOI: 10.2983/035.031.0101 were substantiated by measuring a potential mechanism of 1 TABLE 1. 2 Historically reported bivalve responses to nutrient enrichment, and mechanisms of effect (eutrophic-driven changes in food supply or habitat) across different species, locations, and enrichment types. Bivalve Response Mechanism of Effect Species Location Enrichment Type to Enrichment (food supply or habitat metric) Source Mytilus edulis Loch Craiglin, Scotland P and N fertilization Increased abundance Increased food supply Marshall (1947) Mya arenaria (phytoplankton abundance) Raymont (1947) Macoma balthica Cardium edule Paphia pullastra Scrobicularia plana Modiolus spp. Mytilus edulis Baltic Sea Urbanization: increased Increased abundance and tissue Presumed increased food supply Cederwal and Mya arenaria P and N (not measured) weight (Mya, Macoma only) (not measured) Elmgren (1980) Macoma balthica Cardium spp. Mytilus edulis Rı´ as Bajas, Spain Upwelling Increased tissue weight Presumed increased food supply Blanton et al. (1987) (not measured) C ARMICHAEL ET AL Mya arenaria Kettegat, Sweden Urbanization: N and P Mortality among most species Habitat change: hypoxia (measured Baden et al. (1990) Cardium edule oxygen concentrations) Abra alba Arctica islandica Corbula gibba Corbula gibba Adriatic Sea Urbanization: increased Increased abundance Presumed habitat change: anoxic Crema et al. (1991) . nutrients stress (not measured) Argopecten irradians Waquoit Bay, USA Urbanization: increased N Reduced catch Habitat change: eelgrass loss Valiela et al. (1992) (measured) and presumed anoxia (not measured) Ruditapes decussatus Ria Formosa, Urbanization (not measured) Increased respiration, reduced Increased organic content Costa et al. (1993) South Portugal absorption efficiency (not directly measured) Mya arenaria Waquoit Bay, USA Urbanization: increased N Increased shell growth Increased food supply Chalfoun et al. (1994) Mercenaria mercenaria (Mya only) (not directly measured) Nucula annulata Narragansett Bay, USA Increased organic matter; Increased mortality and Presumed habitat change: hypoxia, Craig (1994) N, P, and silica fertilization recruitment failure settlement interference (not measured) Katelysia spp. Princess Royal Harbor,
Load more

Recommended publications
  • Marine Bivalve Molluscs
    Marine Bivalve Molluscs Marine Bivalve Molluscs Second Edition Elizabeth Gosling This edition first published 2015 © 2015 by John Wiley & Sons, Ltd First edition published 2003 © Fishing News Books, a division of Blackwell Publishing Registered Office John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Offices 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030‐5774, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley‐blackwell. The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. Limit of Liability/Disclaimer of Warranty: While the publisher and author(s) have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose.
    [Show full text]
  • Atlas of the Freshwater Mussels (Unionidae)
    1 Atlas of the Freshwater Mussels (Unionidae) (Class Bivalvia: Order Unionoida) Recorded at the Old Woman Creek National Estuarine Research Reserve & State Nature Preserve, Ohio and surrounding watersheds by Robert A. Krebs Department of Biological, Geological and Environmental Sciences Cleveland State University Cleveland, Ohio, USA 44115 September 2015 (Revised from 2009) 2 Atlas of the Freshwater Mussels (Unionidae) (Class Bivalvia: Order Unionoida) Recorded at the Old Woman Creek National Estuarine Research Reserve & State Nature Preserve, Ohio, and surrounding watersheds Acknowledgements I thank Dr. David Klarer for providing the stimulus for this project and Kristin Arend for a thorough review of the present revision. The Old Woman Creek National Estuarine Research Reserve provided housing and some equipment for local surveys while research support was provided by a Research Experiences for Undergraduates award from NSF (DBI 0243878) to B. Michael Walton, by an NOAA fellowship (NA07NOS4200018), and by an EFFRD award from Cleveland State University. Numerous students were instrumental in different aspects of the surveys: Mark Lyons, Trevor Prescott, Erin Steiner, Cal Borden, Louie Rundo, and John Hook. Specimens were collected under Ohio Scientific Collecting Permits 194 (2006), 141 (2007), and 11-101 (2008). The Old Woman Creek National Estuarine Research Reserve in Ohio is part of the National Estuarine Research Reserve System (NERRS), established by section 315 of the Coastal Zone Management Act, as amended. Additional information on these preserves and programs is available from the Estuarine Reserves Division, Office for Coastal Management, National Oceanic and Atmospheric Administration, U. S. Department of Commerce, 1305 East West Highway, Silver Spring, MD 20910.
    [Show full text]
  • Deep Conservation of Bivalve Nacre Proteins Highlighted by Shell Matrix Proteomics of the Unionoida Elliptio Complanata and Villosa Lienosa
    Deep conservation of bivalve nacre proteins highlighted by shell matrix proteomics of the Unionoida Elliptio complanata and Villosa lienosa. Benjamin Marie, Jaison Arivalagan, Lucrèce Mathéron, Gérard Bolbach, Sophie Berland, Arul Marie, Frédéric Marin To cite this version: Benjamin Marie, Jaison Arivalagan, Lucrèce Mathéron, Gérard Bolbach, Sophie Berland, et al.. Deep conservation of bivalve nacre proteins highlighted by shell matrix proteomics of the Unionoida Elliptio complanata and Villosa lienosa.. Journal of the Royal Society Interface, the Royal Society, 2017, 14 (126), pp.20160846. 10.1098/rsif.2016.0846. hal-01470764 HAL Id: hal-01470764 https://hal.archives-ouvertes.fr/hal-01470764 Submitted on 27 Mar 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Deep conservation of bivalve nacre proteins highlighted by shell matrix 2 proteomics of the Unionoida Elliptio complanata and Villosa lienosa 3 4 Benjamin Marie1,*, Jaison Arivalagan1, Lucrèce Mathéron2, Gérard Bolbach2, Sophie Berland3, 5 Arul Marie1, Frédéric Marin4 6 7 1UMR 7245 CNRS/MNHN
    [Show full text]
  • Pearl Formation
    PEARL FORMATION B.Sc. Part I, paper I, Group A: Animal Diversity By: Dr. Vandana Kumari, Department of Zoology, R.C.S. College, Manjhaul INTRODUCTION Pearls are organic gemstone formed inside a living pearl producing molluscs. Pearls are formed when a molluscs secrete thousand of very thin concentric layers of nacre, a secretion of calcium carbonate in a matrix that finally coats an irritant either man made or natural. The pearl producing molluscs are the members of class Bivalvia. The most historically important source for fine natural pearl is Persian Gulf, where pearl oyster where once found in great abundance off the coast and island of present day Bahrain. Japan Has traditional been and continues to be the largest producer of pearls. In India the technological breakthrough in pearl culture was achieved in 1973 by the Marine Fisheries Research Institute(CMFRI)at Tuticorin. CULTURED AND NATURAL PEARLS Cultured pearls- These are the real pearls that are formed inside a living oyster with human intervention. Nucleus is surgically implanted in oyster ,and the oyster recognise it as an irritant and start coating it with smooth layers of nacre. Over time, the growing pearl gets completely covered with the beautiful iridescent substance, nacre or mother of pearl. Natural pearl- Are formed naturally by wild oysters without the human interventions. When a natural irritant lodged inside a oyster, it gets coated with concentric layer of nacre. FORMATION OF PEARL The formation of pearl occurs as a result of the defensive response of the oyster. Whenever a foreign object enters between the mantle and shell, the mantle epithelium get stimulated and surround foreign particle completely.
    [Show full text]
  • The Freshwater Bivalve Mollusca (Unionidae, Sphaeriidae, Corbiculidae) of the Savannah River Plant, South Carolina
    SRQ-NERp·3 The Freshwater Bivalve Mollusca (Unionidae, Sphaeriidae, Corbiculidae) of the Savannah River Plant, South Carolina by Joseph C. Britton and Samuel L. H. Fuller A Publication of the Savannah River Plant National Environmental Research Park Program United States Department of Energy ...---------NOTICE ---------, This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Depart­ mentof Energy.nor any of theircontractors, subcontractors,or theiremploy­ ees, makes any warranty. express or implied or assumes any legalliabilityor responsibilityfor the accuracy, completenessor usefulnessofanyinformation, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. A PUBLICATION OF DOE'S SAVANNAH RIVER PLANT NATIONAL ENVIRONMENT RESEARCH PARK Copies may be obtained from NOVEMBER 1980 Savannah River Ecology Laboratory SRO-NERP-3 THE FRESHWATER BIVALVE MOLLUSCA (UNIONIDAE, SPHAERIIDAE, CORBICULIDAEj OF THE SAVANNAH RIVER PLANT, SOUTH CAROLINA by JOSEPH C. BRITTON Department of Biology Texas Christian University Fort Worth, Texas 76129 and SAMUEL L. H. FULLER Academy of Natural Sciences at Philadelphia Philadelphia, Pennsylvania Prepared Under the Auspices of The Savannah River Ecology Laboratory and Edited by Michael H. Smith and I. Lehr Brisbin, Jr. 1979 TABLE OF CONTENTS Page INTRODUCTION 1 STUDY AREA " 1 LIST OF BIVALVE MOLLUSKS AT THE SAVANNAH RIVER PLANT............................................ 1 ECOLOGICAL
    [Show full text]
  • TROPICAL AGRICULTURAL SCIENCE Fisheries Assessment
    Pertanika J. Trop. Agric. Sc. 42 (1): 103 - 124 (2019) TROPICAL AGRICULTURAL SCIENCE Journal homepage: http://www.pertanika.upm.edu.my/ Review Article Fisheries Assessment, Gametogenesis and Culture Practice of Local Bivalve: A Review Hadi Hamli1*, Mohd Hanafi Idris2, Mustafa Kamal Abu Hena1 and Amy Halimah Rajaee1 1Department of Animal Science and Fishery, Faculty of Agriculture and Food Sciences, Universiti Putra Malaysia Bintulu Sarawak Campus, Nyabau Road, P.O. Box 396, 97008 Bintulu, Sarawak, Malaysia 2School of Fisheries and Aquaculture Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu Malaysia ABSTRACT Hard clams are found to overwhelm the benthic territory from the remote oceans in the marsh region, especially the tropical region. It is a filtered feeder that feeds upon microorganisms, debris and dissolved primal matter as the metabolic vitality hotspot for development. The abundance of food source caused mariculture of hard clam a possible practice in the open sea. Although harvested hard clams through mariculture progressively increase each year, they are still found to be less than oyster and cockle production. Knowledge of gametogenesis is essential for shellfish culture with a specific end goal to resolve the appropriate conditions for breeding. The gametogenesis is ordered into six phases, i.e. resting, early advancement, late advancement, ripe, spawning and spent. Fertilisation between sperm and egg occurs after hard clam spawning by chemical and physical incitement in the environment. Inseminated eggs experience several phases, i.e.; trochopores, D shape hatchlings, umbonal hatchlings and juvenile phase before ending up as mature shellfish. This review is chiefly intended to cover the biology and culture capability of hard clams, especially in Malaysia.
    [Show full text]
  • Bivalve Biology - Glossary
    Bivalve Biology - Glossary Compiled by: Dale Leavitt Roger Williams University Bristol, RI A Aberrant: (L ab = from; erro = wonder) deviating from the usual type of its group; abnormal; wandering; straying; different Accessory plate: An extra, small, horny plate over the hinge area or siphons. Adapical: Toward shell apex along axis or slightly oblique to it. Adductor: (L ad = to; ducere = to lead) A muscle that draws a structure towards the medial line. The major muscles (usually two in number) of the bivalves, which are used to close the shell. Adductor scar: A small, circular impression on the inside of the valve marking the attachment point of an adductor muscle. Annulated: Marked with rings. Annulation or Annular ring: A growth increment in a tubular shell marked by regular constrictions (e.g., caecum). Anterior: (L ante = before) situated in front, in lower animals relatively nearer the head; At or towards the front or head end of a shell. Anterior extremity or margin: Front or head end of animal or shell. In gastropod shells it is the front or head end of the animal, i.e. the opposite end of the apex of the shell; in bivalves the anterior margin is on the opposite side of the ligament, i.e. where the foot protrudes. Apex, Apexes or Apices: (L apex = the tip, summit) the tip of the spire of a gastropod and generally consists of the embryonic shell. First-formed tip of the shell. The beginning or summit of the shell. The beginning or summit or the gastropod spire. The top or earliest formed part of shell-tip of the protoconch in univalves-the umbos, beaks or prodissoconch in bivalves.
    [Show full text]
  • Regulating Services of Bivalve Molluscs in the Context of the Carbon Cycle and Implications for Ecosystem Valuation
    Chapter 12 Regulating Services of Bivalve Molluscs in the Context of the Carbon Cycle and Implications for Ecosystem Valuation R. Filgueira, T. Strohmeier, and Ø. Strand Abstract The role of marine bivalves in the CO2 cycle has been commonly evalu- ated as the balance between respiration, shell calcium carbonate sequestration, and CO2 release during biogenic calcification; however, this individual-based approach neglects important ecosystem interactions that occur at the population level, e.g. the interaction with phytoplankton populations and benthic-pelagic coupling, which in turn can significantly alter the CO2 cycle. Therefore, an ecosystem approach that accounts for the trophic interactions of bivalves, including the role of dissolved and particulate organic and inorganic carbon cycling, is needed to provide a rigorous assessment of the role of bivalves as a potential sink of CO2. Conversely, the discus- sion about this potential role needs to be framed in the context of non-harvested vs. harvested populations, given that harvesting represents a net extraction of matter from the ocean. Accordingly, this chapter describes the main processes that affect CO2 cycling and discuss the role of non-harvested and harvested bivalves in the context of sequestering carbon. A budget for deep-fjord waters is presented as a case study. Abstract in Chinese 摘要:海水双壳贝类在二氧化碳循环中的作用通常根据 基于呼吸作用、钙化作用和钙化期间二氧化碳释放进行评价。 然而,这种基 于个体的评估方法并没有考虑种群水平的贝类与生态系统的相互作用。例 如,贝类与浮游植物种群和底栖生物的相互作用,这种相互作用可以明显改变 CO2循环过程。因此,需要建立一套综合考虑溶解有机碳、溶解无机碳、颗粒 有机碳、颗粒无机碳等碳存在形态的生态系统方法来评估双壳贝类潜在的碳 汇作用。然而,关于这种潜在作用的讨论需要在区分自然种群和养殖种群的 情况下进行,因为养殖种群的最终收获其实是从海水中进行相关营养成分的 净提取。因此,本章介绍了影响CO2循环的主要过程,并讨论了自然和养殖的 双壳贝类在碳移除过程中的作用。在挪威峡湾内的一个双壳贝类养殖区的碳 收支会作为一个案例研究进行展示。 R. Filgueira (*) Marine Affairs Program, Dalhousie University, Halifax, NS, Canada Institute of Marine Research, Bergen, Norway T. Strohmeier · Ø. Strand Institute of Marine Research, Bergen, Norway e-mail: [email protected]; [email protected] © The Author(s) 2019 231 A.
    [Show full text]
  • Fossil Bivalves and the Sclerochronological Reawakening
    Paleobiology, 2021, pp. 1–23 DOI: 10.1017/pab.2021.16 Review Fossil bivalves and the sclerochronological reawakening David K. Moss* , Linda C. Ivany, and Douglas S. Jones Abstract.—The field of sclerochronology has long been known to paleobiologists. Yet, despite the central role of growth rate, age, and body size in questions related to macroevolution and evolutionary ecology, these types of studies and the data they produce have received only episodic attention from paleobiologists since the field’s inception in the 1960s. It is time to reconsider their potential. Not only can sclerochrono- logical data help to address long-standing questions in paleobiology, but they can also bring to light new questions that would otherwise have been impossible to address. For example, growth rate and life-span data, the very data afforded by chronological growth increments, are essential to answer questions related not only to heterochrony and hence evolutionary mechanisms, but also to body size and organism ener- getics across the Phanerozoic. While numerous fossil organisms have accretionary skeletons, bivalves offer perhaps one of the most tangible and intriguing pathways forward, because they exhibit clear, typically annual, growth increments and they include some of the longest-lived, non-colonial animals on the planet. In addition to their longevity, modern bivalves also show a latitudinal gradient of increasing life span and decreasing growth rate with latitude that might be related to the latitudinal diversity gradient. Is this a recently developed phenomenon or has it characterized much of the group’s history? When and how did extreme longevity evolve in the Bivalvia? What insights can the growth increments of fossil bivalves provide about hypotheses for energetics through time? In spite of the relative ease with which the tools of sclerochronology can be applied to these questions, paleobiologists have been slow to adopt sclerochrono- logical approaches.
    [Show full text]
  • Bivalves: Mollusks That Matter Objective
    Bivalves: Mollusks that Matter Objective Students will understand the anatomy and physiology of mussels, and understand why they may pose health risks to humans. National Science Education Standards Content Standard C: Life Science Structure and Function in Living Systems (5-8) Organism Regulation and Behavior (5-8) Diversity and Adaptation of Organisms (5-8) Behavior of Organisms (9-12) Warm-Up Bring in, or ask students to bring in any seashells they have found, or go on a short preliminary field trip to collect them. Ask them to note which ones are bivalves, or those that have (or look like they had) two shell halves hinged at the top. Using identification keys, have students identify the shells by their common and scientific names. Introduction Bivalves are aquatic mollusks (Phylum Mollusca) that belong to the Class Pelecypoda (or Bivalvia), meaning "hatchet-foot." Mussels, clams, scallops and oysters are examples of bivalves, which have two shells (valves) covering the left and right sides of the body. There are many different types of both freshwater and marine bivalves, and their shells come in a wide variety of sizes, shapes, and colors. They may range in size from 2 millimeters to over four feet (the giant clam of the South Pacific). Mussels attach themselves to rocks with bundles of tough threads called "byssal threads" so that they can remain stable in intertidal areas. The narrow end of the mussel points toward the breaking waves to protect the animal. Some examples of mussels are the Blue mussel (Mytilus edulis), which is common along the east coast, and the California mussel (Mytilus californianus), which is found on the west coast in exposed rocky intertidal zones.
    [Show full text]
  • Morphological Description of Cyrtopleura Costata (Bivalvia: Pholadidae) from Southern Brazil
    ARTICLE Morphological description of Cyrtopleura costata (Bivalvia: Pholadidae) from southern Brazil Nicole Stakowian¹ & Luiz Ricardo L. Simone² ¹ Universidade Federal do Paraná (UFPR), Setor de Ciências Biológicas, Departamento de Zoologia (DZOO), Programa de Pós-Graduação em Zoologia. Curitiba, PR, Brasil. ORCID: http://orcid.org/0000-0002-3031-783X. E-mail: [email protected] ² Universidade de São Paulo (USP), Museu de Zoologia (MZUSP). São Paulo, SP, Brasil. ORCID: http://orcid.org/0000-0002-1397-9823. E-mail: [email protected] Abstract. The aim of the study is to describe in detail, for the first time, the internal and external anatomy of Cyrtopleura costata, which displays ellipsoid and elongated valves with beige periostracum, the anterior adductor muscle unites the valves in the pre- umbonal region, with abduction capacity in its dorsal half, sparing the ligament. Two accessory valves are identified: the mesoplax (calcified) located in the umbonal region; and the protoplax (corneus) above the anterior adductor muscle. Internally there is a pair of well-developed apophysis that supports the labial palps and the pedal muscles, and support part of the gills. The posterior half of mantle ventral edge is fused and richly muscular, working as auxiliary adductor muscle. The siphons are completely united with each other, the incurrent being larger than the excurrent. The foot is small (about ⅛ the size of the animal). The kidneys extend laterally on the dorsal surface, solid, presenting a brown/reddish color. The style sac is well developed and entirely detached from the adjacent intestine. The intestine has numerous loops and curves within the visceral mass. The fecal pellets are coin-shaped.
    [Show full text]
  • Phylum Mollusca
    Lab exercise 4: Molluscs General Zoology Laborarory . Matt Nelson phylum Mollusca Molluscs The phylum Mollusca (Latin mollusca = “soft”) is the largest, most diverse phylum in the clade Lophotrochozoa. Like the annelids, they are triploblastic eucoelomates that develop from a trochophore larva. However, they do not possess the characteristic segmentation of annelids. Also, unlike annelids, most molluscs possess an open circulatory system. It is thought that closed circulatory systems evolved at least three times in the Animalia: in an ancestor of the Annelida, an ancestor of the Chordates, and within the Mollusca. One group of modern molluscs, the cephalopods, has a closed circulatory system. Organization Molluscs generally have soft, muscular bodies that are protected by a calcareous shell. Molluscs have two main parts of the body: head-foot - Usually involved in locomotion and feeding, the muscular head foot contains most of the sensory structures of the mollusc, as well as the radula that is used for feeding. visceral mass - The viscera of a mollusc are contained in the visceral mass, which is usually surrounded by the mantle, a thick, tough layer of tissues that produces the shell. radular tooth Head Foot odontophore The head of the mollusc contains feeding and sensory structures, and is generally connected to the foot. However, there is a great deal of diversity in the molluscs, with in many adaptations of the foot for various purposes. Most molluscs feed using a radula. The radula is an autapomorphy for molluscs (relative to other animal phyla), which is usually used for scraping food particles such as algae from a substrate.
    [Show full text]