Anatomy of the Oyster Shell

Total Page：16

File Type：pdf, Size：1020Kb

ANATOMY OF THE OYSTER SHELL • All species of oysters share the same common anatomical parts. That is, there is a right shell and a left shell. The right shell is the top shell. The left shell is the one attached to the substrate and is called the bottom shell or cup. The left shell is usually more curved or cup-shaped than the right shell. • Oysters belong to the group Bivalvia and have two shells hinged together. The end with the hinge is referred to as the anterior end. The opposite end is referred to as the posterior end. • The mantle produces layers of tissue to form the shell. Calcium carbonate composes the chalky middle layer. The innermost layer is the nacre. • The umbo is the portion of the shell that formed when the oyster was a veliger larva. It is on the anterior end of the shell near the hinge. One can see concentric growth lines around the umbo. These are not uniformly secreted since they can be influenced by environmental changes, such as temperature, food, stress, and disease. These factors affect the oyster’s ability to produce more shell tissue. • The hinge is the area where the two valve join together. It consists of three parts. On the hinge there are small projections, hinge teeth, that align the valve and enable it to close correctly. Oysters have very small hinge teeth. Most bivalves have more prominent teeth that can be used to help identify the species. The hinge has two ligaments. The external ligament is flexible and provides the axis of move ment for the two halves of the shell. The internal ligament is called the resilium. When the adductor muscle of the oyster is relaxed, the external ligament and resilium work together to open the shell. To close its shell, the oyster contracts its adductor muscle. LEFT SHELL posterior end nacre umbo (hinge) anterior end 4 Education on the Halfshell: Creating A Dichotomous Key Louisiana Sea Grant College Program Blackline Master 2.

Copy Link

Recommended publications

Common Name: Chiton Class: Polyplacophora
Common Name: Chiton Class: Polyplacophora Scrapes algae off rock with radula 8 Overlapping Plates Phylum? Mollusca Class? Gastropoda Common name? Brown sea hare Class? Scaphopoda Common name? Tooth shell or tusk shell Mud Tentacle Foot Class? Gastropoda Common name? Limpet Phylum? Mollusca Class? Bivalvia Class? Gastropoda Common name? Brown sea hare Phylum? Mollusca Class? Gastropoda Common name? Nudibranch Class? Cephalopoda Cuttlefish Octopus Squid Nautilus Phylum? Mollusca Class? Gastropoda Most Bivalves are Filter Feeders A B E D C • A: Mantle • B: Gill • C: Mantle • D: Foot • E: Posterior adductor muscle I.D. Green: Foot I.D. Red Gills Three Body Regions 1. Head – Foot 2. Visceral Mass 3. Mantle A B C D • A: Radula • B: Mantle • C: Mouth • D: Foot What are these? Snail Radulas Dorsal HingeA Growth line UmboB (Anterior) Ventral ByssalC threads Mussel – View of Outer Shell • A: Hinge • B: Umbo • C: Byssal threads Internal Anatomy of the Bay Mussel A B C D • A: Labial palps • B: Mantle • C: Foot • D: Byssal threads NacreousB layer Posterior adductorC PeriostracumA muscle SiphonD Mantle Byssal threads E Internal Anatomy of the Bay Mussel • A: Periostracum • B: Nacreous layer • C: Posterior adductor muscle • D: Siphon • E: Mantle Byssal gland Mantle Gill Foot Labial palp Mantle Byssal threads Gill Byssal gland Mantle Foot Incurrent siphon Byssal Labial palp threads C D B A E • A: Foot • B: Gills • C: Posterior adductor muscle • D: Excurrent siphon • E: Incurrent siphon Heart G F H E D A B C • A: Foot • B: Gills • C: Mantle • D: Excurrent siphon • E: Incurrent siphon • F: Posterior adductor muscle • G: Labial palps • H: Anterior adductor muscle Siphon or 1.
[Show full text]
Silicified Eocene Molluscs from the Lower Murchison District, Southern Carnarvon Basin, Western Australia
[<ecords o{ the Western A uslralian Museum 24: 217--246 (2008). Silicified Eocene molluscs from the Lower Murchison district, Southern Carnarvon Basin, Western Australia Thomas A. Darragh1 and George W. Kendrick2.3 I Department of Invertebrate Palaeontology, Museum Victoria, 1'.0. Box 666, Melbourne, Victoria 3001, Australia. Email: tdarragh(il.Illuseum.vic.gov.au :' Department of Earth and Planetary Sciences, Western Australian Museum, Locked Bag 49, Welshpool D.C., Western Australia 6986, Australia. 1 School of Earth and Ceographical Sciences, The University of Western Australia, 35 Stirling Highway, Crawlev, Western Australia 6009, Australia. Abstract - Silicified Middle to Late Eocene shallow water sandstones outcropping in the Lower Murchison District near Kalbarri township contain a silicified fossil fauna including foraminifera, sponges, bryozoans, solitary corals, brachiopods, echinoids and molluscs. The known molluscan fauna consists of 51 species, comprising 2 cephalopods, 14 bivalves, 1 scaphopod and 34 gastropods. Of these taxa three are newly described, Cerithium lvilya, Zeacolpus bartol1i, and Lyria lamellatoplicata. 25 of these molluscs are identical to or closely comparable with taxa from the southern Australian Eocene. The occurrence of this fauna extends the Southeast Australian Province during the Eocene from southwest Western Australia along the west coast north to at least 27° present day south latitude; consequently the province is here renamed the Southern Australian Province. Keywords: siliceous fossils, Eocene, Kalbarri, molluscs, new taxa, Carnarvon Basin, biogeography, Southern Australian Province. INTRODUCTION The source deposit, a pallid to ferruginous silicified Eocene marine molluscan assemblages from sandstone, forms a weakly defined, low breakaway coastal sedimentary basins in southern Australia trending N-S and sloping gently westward.
[Show full text]
Field Identification Guide to the Living Marine Resources In
Guide to Families 29 BIVALVES Coastal species are of great interest to fisheries and have potential for exportation for eating purposes. Bivalves are caught mainly by divers and are also fished for pearls. Their flesh is of excellent quality. Since oysters remain alive out of the water for over 12 hours, they may exported to far destinations when still alive. Moreover, some species are collected for their nacreous shell and ability to develop pearls. The shell can be used in the mother of pearl industry. The “Guide to Families’’ andTECHNICAL ‘‘Guide to Species’’ TERMS include 5AND families MEASUREMENTS and 10 species, respectively. ligament Dorsal margin umbo posterior adductor cardinal tooth muscle scar lateral tooth Posterior Anterior margin margin shell height anterior adductor muscle scar pallial sinus pallial shell length line left valve (interior) Ventral margin ligament left valve right valve lunule umbo Adductor muscle: Byssus: Chomata: Muscle connecting the two valves of a shell, tending to draw them together. Hinge: Clump of horny threads spun by the foot, by which a Bivalve can anchor to a hard substrate. Ligament: Small denticles and corresponding pits located on the inner margin of the valves (Ostreidae and Gryphaeidae). Mantle: Top interlocking margin of the valves, often with shelly projections (teeth) and corresponding recesses (sockets). Muscle scar: Horny, elastic structure joining the two valves dorsally. Pallial line: Fleshy sheet surrounding vital organs and composed of two lobes, one lining and secreting each valve. Umbo: Impression marking the place of attachment of a muscle inside the shell. A line near the internal margin of valve, marking the site of attachment of the mantle edge.
[Show full text]
Occurence of Pisidium Conventus Aff. Akkesiense in Gunma Prefecture
VENUS 62 (3-4): 111-116, 2003 Occurence Occurence of Pisidium conventus aff.α kkesiense in Gunma Prefecture, Japan (Bivalvia: Sphaeriidae) Hiroshi Hiroshi Ieyama1 and Shigeru Takahashi2 Faculty 1Faculty of Education, Ehime Universi η，Bun わ1ocho 3, 2 3, Ehime 790-857 スJapan; [email protected] Yakura Yakura 503-2, Agatsuma-cho, Gunma 377 同 0816, Japan Abstract: Abstract: Shell morphology and 姐 atomy of Pisidium conventus aff. akkesiense collect 巴d from from a fish-culture pond were studied. This species showed similarities to the subgenus Neopisidium Neopisidium with respect to ligament position and gill, res 巴mbling P. conventus in anatomical characters. characters. Keywords: Keywords: Pisidium, Sphaeriidae, gill, mantle, brood pouch Introduction Introduction Komiushin (1999) demonstrated that anatomical features are useful for species diagnostics 佃 d classification of Pisidium, including the demibranchs, siphons, mantle edge and musculature, brood brood pouch, and nephridium. These taxonomical characters are still poorly known in Japanese species species of Pisidium. An anatomical study of P. casertanum 仕om Lake Biwa (Komiushin, 1996) was 祖巴arly report. Onoyama et al. (2001) described differences in the arrangement of gonadal tissues tissues in P. parvum and P. casertanum. Mori (1938) classified Japanese Pisidium into 24 species and subspecies based on minor differences differences in shell characters. For a critical revision of Japanese Pisidium, it is important to study as as many species as possible from various locations in and around Japan. This study includes details details of shell and soft p 紅 t mo 中hology of Pisidium conventus aff. akkesiense from Gunma Prefecture Prefecture in central Honshu.
[Show full text]
Clam Dissection Guideline
Clam Dissection Guideline BACKGROUND: Clams are bivalves, meaning that they have shells consisting of two halves, or valves. The valves are joined at the top, and the adductor muscles on each side hold the shell closed. If the adductor muscles are relaxed, the shell is pulled open by ligaments located on each side of the umbo. The clam's foot is used to dig down into the sand, and a pair of long incurrent and excurrent siphons that extrude from the clam's mantle out the side of the shell reach up to the water above (only the exit points for the siphons are shown). Clams are filter feeders. Water and food particles are drawn in through one siphon to the gills where tiny, hair-like cilia move the water, and the food is caught in mucus on the gills. From there, the food-mucus mixture is transported along a groove to the palps (mouth flaps) which push it into the clam's mouth. The second siphon carries away the water. The gills also draw oxygen from the water flow. The mantle, a thin membrane surrounding the body of the clam, secretes the shell. The oldest part of the clam shell is the umbo, and it is from the hinge area that the clam extends as it grows. I. Purpose: The purpose of this lab is to identify the internal and external structures of a mollusk by dissecting a clam. II. Materials: 2 pairs of safety goggles 1 paper towel 2 pairs of gloves 1 pair of scissors 1 preserved clam 2 pairs of forceps 1 dissecting tray 2 probes III.
[Show full text]
Methods and Materials for Aquaculture Production of Sea Scallops (Placopecten Magellanicus)
Methods and Materials for Aquaculture Production of Sea Scallops (Placopecten magellanicus) Dana L. Morse • Hugh S. Cowperthwaite • Nathaniel Perry • Melissa Britsch Contents Rationale and background. .1 Scallop biology . 1 Spat collection . 2 Nursery culture. 3 Growout. .4 Bottom cages . 4 Pearl nets. 5 Lantern nets. 5 Suspension cages . 6 Ear hanging. 6 Husbandry and fouling control. 7 Longline design and materials . 7 Moorings and mooring lines. 7 Longline (or backline) . 7 Tension buoys . 7 Marker buoys . 7 Compensation buoys . 8 Longline weights. 8 Site selection . 8 Economic considerations & recordkeeping . 8 Scallop products, biotoxins & public health . 8 Literature Cited. 9 Additional Reading. 9 Appendix I . 9 Example of an annual cash flow statement. 9 Acknowledgements . 9 Authors’ contact information Dana L. Morse Nathaniel Perry Maine Sea Grant and University of Maine Pine Point Oyster Company Cooperative Extension 10 Pine Ridge Road, Cape Elizabeth, ME 04107 193 Clark’s Cove Road, Walpole, ME 04573 [email protected] [email protected] Melissa Britsch Hugh S. Cowperthwaite University of Maine, Darling Marine Center Coastal Enterprises, Inc. 193 Clark’s Cove Road, Walpole, ME 04573 30 Federal Street, Brunswick, ME 04011 [email protected] [email protected] The University of Maine is an EEO/AA employer and does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender expression, national origin, citizenship status, age, disability, genetic information or veteran’s status in employment, education, and all other programs and activities. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 101 North Stevens Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System).
[Show full text]
Freshwater Mussels of the Pacific Northwest
Freshwater Mussels of the Pacifi c Northwest Ethan Nedeau, Allan K. Smith, and Jen Stone Freshwater Mussels of the Pacifi c Northwest CONTENTS Part One: Introduction to Mussels..................1 What Are Freshwater Mussels?...................2 Life History..............................................3 Habitat..................................................5 Role in Ecosystems....................................6 Diversity and Distribution............................9 Conservation and Management................11 Searching for Mussels.............................13 Part Two: Field Guide................................15 Key Terms.............................................16 Identifi cation Key....................................17 Floaters: Genus Anodonta.......................19 California Floater...................................24 Winged Floater.....................................26 Oregon Floater......................................28 Western Floater.....................................30 Yukon Floater........................................32 Western Pearlshell.................................34 Western Ridged Mussel..........................38 Introduced Bivalves................................41 Selected Readings.................................43 www.watertenders.org AUTHORS Ethan Nedeau, biodrawversity, www.biodrawversity.com Allan K. Smith, Pacifi c Northwest Native Freshwater Mussel Workgroup Jen Stone, U.S. Fish and Wildlife Service, Columbia River Fisheries Program Offi ce, Vancouver, WA ACKNOWLEDGEMENTS Illustrations,
[Show full text]
Transposed Hinge Structures in Lamellibranches
TRANSACTIONS OF THE • SAN DIEGO SOCIETY OF NATURAL HISTORY ,/ VoLUME VII, No. 26, pp. 299-318, plate 19 • TRANSPOSED HINGE STRUCTURES IN LAMELLIBRANCHS BY P. PoPENOE AND FINDLAY W. W. A. • Balch Graduate School of the Geological Sciences California Institute of Technology Pasadena, California SAN DIEGO, CALIFORNIA PRINTED FOR THE SOCIETY OCTOBER 6, 1933 • • COMMITTEE ON PUBLICATION U.S. GRANT, IV, Chairman FRED BAKER CLINTON G. ABBOTT, Editor • TRANSPOSED HINGE STRUCTURES IN LAMELLIBRANCHS 1 BY W. P. PoPENOE AND W. A. FINDLAY California Institute of Technology INTRODUCTION In the course of study of a collection of Eocene fossils from Claiborne Bluff, Alabama, the senior author of tl1is paper noticed two valves, one right and one left, of the lamellibranch Venericardia parva Lea, in whicl1 the dentition is partially transposed. Subsequently, the authors made an examination of more than five thousand lamellibranch valves, representit1g both recent and fossil shells, in search of further exa1nples of hinge-trans position. We have found a total number of twenty-six valves exhibiting this variation. Study of these specimens has revealed some hitherto unreported facts regarding the principles of hinge-transposition. Therefore in this paper, we shall describe and discuss these specimens, and shall present such con clusions as seem justified by the data assembled. Citations to the literature are made by author, date, and page, referring to the list at the end of the paper. DEFINITION OF T ERMS A transposed lamellibranch hinge is defined as one that exhibits in the right valve the hinge ele1nents normally occurring in the left valve, and vice-versa.
[Show full text]
Early Ontogeny of Jurassic Bakevelliids and Their Bearing on Bivalve Evolution
Early ontogeny of Jurassic bakevelliids and their bearing on bivalve evolution NIKOLAUS MALCHUS Malchus, N. 2004. Early ontogeny of Jurassic bakevelliids and their bearing on bivalve evolution. Acta Palaeontologica Polonica 49 (1): 85–110. Larval and earliest postlarval shells of Jurassic Bakevelliidae are described for the first time and some complementary data are given concerning larval shells of oysters and pinnids. Two new larval shell characters, a posterodorsal outlet and shell septum are described. The outlet is homologous to the posterodorsal notch of oysters and posterodorsal ridge of arcoids. It probably reflects the presence of the soft anatomical character post−anal tuft, which, among Pteriomorphia, was only known from oysters. A shell septum was so far only known from Cassianellidae, Lithiotidae, and the bakevelliid Kobayashites. A review of early ontogenetic shell characters strongly suggests a basal dichotomy within the Pterio− morphia separating taxa with opisthogyrate larval shells, such as most (or all?) Praecardioida, Pinnoida, Pterioida (Bakevelliidae, Cassianellidae, all living Pterioidea), and Ostreoida from all other groups. The Pinnidae appear to be closely related to the Pterioida, and the Bakevelliidae belong to the stem line of the Cassianellidae, Lithiotidae, Pterioidea, and Ostreoidea. The latter two superfamilies comprise a well constrained clade. These interpretations are con− sistent with recent phylogenetic hypotheses based on palaeontological and genetic (18S and 28S mtDNA) data. A more detailed phylogeny is hampered by the fact that many larval shell characters are rather ancient plesiomorphies. Key words: Bivalvia, Pteriomorphia, Bakevelliidae, larval shell, ontogeny, phylogeny. Nikolaus Malchus [[email protected]], Departamento de Geologia/Unitat Paleontologia, Universitat Autòno− ma Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain.
[Show full text]
Mechanics Unlocks the Morphogenetic Puzzle of Interlocking Bivalved Shells
Mechanics unlocks the morphogenetic puzzle of interlocking bivalved shells Derek E. Moultona,1 , Alain Gorielya , and Regis´ Chiratb aMathematical Institute, University of Oxford, Oxford, OX2 6GG, United Kingdom; and bCNRS 5276, LGL-TPE (Le Laboratoire de Geologie´ de Lyon: Terre, Planetes,` Environnement), Universite´ Lyon 1, 69622 Villeurbanne Cedex, France Edited by Sean H. Rice, Texas Tech University, Lubbock, TX, and accepted by Editorial Board Member David Jablonski November 11, 2019 (received for review September 24, 2019) Brachiopods and mollusks are 2 shell-bearing phyla that diverged tal events causing shell injuries. Yet, in all cases the interlocking from a common shell-less ancestor more than 540 million years ago. of the 2 shell edges is tightly maintained. These observations Brachiopods and bivalve mollusks have also convergently evolved imply that the interlocking pattern emerges as the result of epi- a bivalved shell that displays an apparently mundane, yet strik- genetic interactions modulating the behavior of the secreting ing feature from a developmental point of view: When the shell mantle during shell development. is closed, the 2 valve edges meet each other in a commissure that Here, we provide a geometric and mechanical explanation forms a continuum with no gaps or overlaps despite the fact that for this morphological trait based on a detailed analysis of the each valve, secreted by 2 mantle lobes, may present antisymmet- shell geometry during growth and the physical interaction of the ric ornamental patterns of varying regularity and size. Interlock- shell-secreting soft mantle with both the rigid shell edge and ing is maintained throughout the entirety of development, even the opposing mantle lobe.
[Show full text]
Freshwater Mussels of Maritime Canada: a Flashcard Guide
Freshwater Mussels of Maritime Canada: A Flashcard Guide In Wolastoqey, Mi’kmaw, French and English UMBO DORSAL MARGIN ANTERIOR POSTERIOR MARGIN MARGIN VENTRAL MARGIN Donald F. McAlpine, Mary C. Sollows, Jacqueline B. Madill and André L. Martel ISBN 978-0-919326-80-4 All photos copyright the Canadian Museum of Nature Acknowledgements: Funding for this publication provided by the Department of Fisheries and Oceans and the New Brunswick Museum. Special thanks to Ree Brennin Houston, Department of Fisheries and Oceans; Anne Hamilton, Brent Suttie, New Brunswick Archaeological Services Branch, and indigenous language translators Allan Tremblay (Wolastoqiyk), George Paul, Howard Augustine, and Karen Narvey (Mi’kmaw). Citation: McAlpine, D.F., M.C. Sollows, J. B. Madill, and A. L. Martel. 2018. Freshwater Mussels of Maritime Canada: A Flashcard Guide in Wolastoqey, Mi’kmaw, French and English. New Brunswick Museum, Saint John, New Brunswick, and Canadian Museum of Nature, Ottawa, Canada. Use in conjunction with Martel, A. L.,D.F. McAlpine, J. Madill, D. Sabine, A. Paquet, M. Pulsifer and M. Elderkin. 2010. Pp. 551-598. Freshwater Mussels (Bivalvia: Margaritiferidae, Unionidae) of the Atlantic Maritime Ecozone. In D.F. McAlpine and I.M. Smith (eds.). Assessment of Species Diversity in the Atlantic Maritime Ecozone. NRC Research Press, National Research Council of Canada, Ottawa, ON. 785 pp. Nedeau, E.J., M.A. McCollough, and B.I. Swartz. 2000. Freshwater Mussels of Maine. Maine Department of Inland Fisheries and Wildlife, Augusta, ME, 118 pp.
[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]