DOCSLIB.ORG

Donax Variabilis Say, 1822 (Bivalvia: Donacidae)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Donax Variabilis Say, 1822 (Bivalvia: Donacidae) FAU Institutional Repository http://purl.fcla.edu/fau/fauir This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute. Notice: ©1985 California Malacozoological Society. This manuscript is an author version with the final publication available and may be cited as: Mikkelsen, P. S. (1985). A comparison of two Florida populations of the coquina clam, Donax variabilis Say, 1822 (Bivalvia: Donacidae). II. Growth rates. The Veliger, 27(3), 308-311. THE VELIGER © CMS, Inc., 1985 The Veliger 27(3):308-311 (January 2, 1985) A Comparison of Two Florida Populations of the Coquina Clam, Donax variabilis Say, 1822 (Bivalvia: Donacidae). II. Growth Rates by PAUL S. MIKKELSEN Harbor Branch Foundation, Inc., R.R. 1, Box 196, Fort Pierce, Florida 33450 Abstract. Average summer growth rates of 3.0 mm and 3.7 mm per month were obtained for samples of Donax variabilis from southwest Florida and central eastern Florida, respectively, using length­ frequency graphs. Individuals usually live only one year. INTRODUCTION beaches on the central eastern (Indialantic) and south­ western (Sanibel Island) coasts of Florida. Samples were PREVIOUS STUDIES ON the growth of Donax variabilis, the sieved using a 1.2-mm mesh. The number of monthly coquina clam, were done in Texas (LOESCH, 1957) and cores varied due to the varying width of the swash zone North Carolina (PEARSE et al., 1942). However, these being sampled at the time; the number of monthly cores studies were conducted prior to the designation of a new averaged 40 at Sanibel and 49 at Indialantic Beach. Half species, Donax dorotheae Morrison, 1971, which occurs of the transects were at 25-m intervals and half at 5-m from northwest Florida to northeast Texas. In addition, intervals to decrease the possibility of missing localized many of the "young" of D. variabilis from the eastern aggregations of animals. Donax paruula was collected along United States now in the collections of the Smithsonian with D. uariabilis at the Indialantic site, but specimens of Institution and the Academy of Natural Sciences were the former were separated and not analyzed for this study. determined to be Donax paruula Philippi, 1849 (see Other information concerning sampling locations, meth­ MORRISON, 1971), indicating identification problems in ods, and times have been given previously (MIKKELSEN, the past. MORRISON (1971) also split D. variabilis (as D. 1981). Shell lengths were measured with calipers to ±0.1 roemeri Philippi, 1849) into western (western Gulf of mm. The large samples of shells from Sanibel (excluding Mexico) and eastern (eastern Gulf of Mexico and eastern the April sample) were subsampled using a geological United States) subspecific forms. MARSH (1962) exam­ sediment sample splitter; all specimens from Indialantic ined length-frequency graphs of D. variabilis collected were measured. Groupings to determine "sets" of individ­ during the summer and early fall from Pawleys Island, uals on length-frequency graphs were determined accord­ South Carolina, but found no well-defined size classes. ing to CASSIE (1954). Therefore, the growth rates of the eastern and western forms of D. variabilis possibly remain undetermined. In this paper, summer growth rates of Donax variabilis are RESULTS given from two Florida populations, along with estimates At Indialantic Beach, 477 specimens of Donax variabilis of spawning periods and lifespan. were collected and analyzed. One portion of the year class had somewhat regular monthly growth increments from MATERIALS AND METHODS May through August (crosshatched area, Figure 1). The Specimens of Donax variabilis were collected monthly (pri­ mean shell length of these individuals increased from 7 marily for analysis of coloration and population density) mm in May to 18 mm in August, an increase of 11 mm from April through September 1976. Specimens were over a period of 3 months, or an average summer growth gathered from eight transects perpendicular to the beach, rate of about 7.3 mm per month. Another set of young each consisting of about eight 15-cm diameter cores spaced occurred, averaging 9 mm in length in the third week of at 1-m intervals within the intertidal zone of exposed sandy September (stippled area, Figure 1). P. S. Mikkelsen, 1985 Page 309 20 10 APRIL N' 29 0 z 0 I- 10 MAY <l --' N' 97 ::J Q. 0 0 10 Q. JUNE N'152 u, 0 0 20 I- JULY Z 10 w N'103 u a:: w 0 Q. 10 AUGUST N' 49 0 10 SEPT. 0 N' 47 2 4 6 8 10 12 14 16 18 20 22 LENGT H (mm) Figure 1 Length-frequency graphs of Donax variabilis from Indialantic (N = number of specimens). First set (crosshatched); second set (stippled). 10 APRIL N' 49 0 z 10 MAY 0 i= N' 5,239 <l 0 --' ::J Q. 10 JUNE 0 N' 2,436 Q. 0 u, 0 JULY 10 N ' 8,970 I- z w 0 u a:: AUGUST w 10 Q. N' 4,686 0 SEPT. 10 N = 7,452 0 2 4 6 8 10 12 14 16 18 20 22 LEN GTH (mm) Figure 2 Length-frequency graphs of Donax variabilis from Sanibel (N number of specimens). First set (crosshatched); second set (stippled). Page 310 The Veliger, Vol. 27, No.3 At Sanibel, because 28,832 specimens were collected, average over the year. Sanibel Island presented no iden­ subsamples provided manageable numbers, yielding tification difficulties because D. oariabilis was the only monthly subsamples consisting of about 500 specimens donacid that occurred there. each. The size classes could be followed from May through Assuming a constant growth rate, the occurrence of nu­ July (crosshatched area, Figure 2). The means of the dis­ merous individuals in the May sample at Indialantic Beach tributions pass from 5 to 11 mm over a period of 2 months whose lengths were clustered around 7 mm indicates a (May to July) and from 6 to 9 mm over 1 month (August settlement approximately 7.5 weeks prior to that time, or to September), indicating an average summer growth rate about the first to second week of March. Thus, with a of 3.0 mm per month. The Sanibel Island population also larval stage of 3 weeks average duration (CHANLEY, 1969), showed a second set of young (stippled area, Figure 2) spawning may have been centered around the third week around the first week of June; these had subsequently in February. The second group of young at Indialantic grown to a mean size of 6 mm by August and to 9 mm (averaging 9 mm in the third week of September) indicates in September. a second spawning occurred on the east coast about 13 weeks earlier, or about the second week of June. DISCUSSION Following the same assumptions at Sanibel, settlement may have occurred, at 275 to 340 ,urn (CHANLEY, 1969), Constant movement of beach sands and contained clams, around the second week of March, with spawning cen­ as well as the migratory ability of Donax variabilis, pre­ tered around the third week of February. This is essen­ vented use of a "mark-and-recapture" technique of growth tially identical to the first spawning that occurred at In­ measurement. Thus, repeated sampling of the population dialantic Beach. The second group of young at Sanibel to construct length-frequency graphs was used, although indicated that a second spawning probably occurred about problems exist with its use. the second week of May and settlement about the first LOESCH (1957) in a study of two species of Donax week of June. This second spawning at Sanibel was about pointed out that length-frequency curves can indicate 4 weeks earlier than the second spawning and settlement growth only if (1) the mortality rate is the same for all at Indialantic Beach. sizes of individuals, (2) the clams enter the population as Although spawning dates were extrapolated from length­ an entire group, and (3) there is no drift of specimens frequency graphs, they may be reasonable estimates. along the beach. In addition, permanent or temporary Causes of error would include a more rapid growth rate removal of individuals by wave action may wash speci­ for individuals younger than those examined. Correction mens into the subtidal region (MIKKELSEN, 1981). Also, for this error would yield spawning dates somewhat later predators may selectively remove a particular size of clam. in time. The dates reported herein differ, however, from Many of the predators listed by LOESCH (1957) were con­ those given for the North Carolina populations that were firmed during the present study, and to that list is added reported to have planktonic larvae from summer to fall the Sheepshead fish, Archosargus probatocephalus (Wal­ (WILLIAMS & PORTER, 1971). LEBER (1982a) observed baum, 1792); LEBER (1982a, b) added others. Selective settlement of Donax variabilis in North Carolina during removal by each of these predators seems likely and prob­ February and November. ably varied monthly depending upon the type, abundance, The general absence of an abundance of large Donax and size of the predators. This selectivity could have con­ variabilis throughout the summer months indicates that tributed to the skewing of the length-frequency data (Fig­ most of those specimens that had matured the previous ures 1, 2), seemingly altering regular monthly growth in­ fall and winter had probably died, although some may crements present in individuals. Thus, growth alone may have moved and remained offshore. This suggests that the not be the reason for the position and rate of advancement majority of individuals probably live for approximately 1 of the modes and means present in the length-frequency year, with a few entering a second year. This is consistent graphs. with the findings of LOESCH (1957) and PEARSE et al.
Load more

Recommended publications
  • Donacidae - Bivalvia)
    Bolm. Zool., Univ. S. P aub 3:121-142, 1978 FUNCTIONAL ANATOMY OF DON AX HANLEY ANUS PHILIPPI 1847 (DONACIDAE - BIVALVIA) Walter Narchi Department o f Zoology University o f São Paulo, Brazil ABSTRACT Donax hanleyanus Philippi 1847 occurs throughout the southern half o f the Brazilian littoral. The main organ systems were studied in the living animal, particular attention being paid to the cilia­ ry feeding and cleasing mechanisms in the mantle cavity. The anatomy, functioning of the stomach and the ciliary sorting mechanisms are described. The stomach unlike that of almost all species of Donax and like the majority of the Tellinacea belongs to type V, as defined by Purchon, and could be regarded as advanced for the Donacidae. A general comparison has been made between the known species of Donax and some features of Iphigenia brasiliensis Lamarck 1818, also a donacid. INTRODUCTION Very little is known of donacid bivalves from the Brazilian littoral. Except for the publications of Narchi (1972; 1974) on Iphigenia brasiliensis and some ecological and adaptative features on Donax hanleyanus, all references to them are brief descrip­ tions of the shell and cheklists drawn up from systematic surveys. Beach clams of the genus Donax inhabit intertidal sandy shores in most parts of the world. Donax hanleyanus Philippi 1847 is one of four species occuring through­ out the Brazilian littoral. Its known range includes Espirito Santo State and the sou­ thern Atlantic shoreline down to Uruguay (Rios, 1975). According to Penchaszadeh & Olivier (1975) the species occur in the littoral of Argentina. 122 Walter Narchi The species is fairly common in São Paulo, Parana and Santa Catarina States whe­ re it is used as food by the coastal population (Goffeijé, 1950), and is known as “na- nini” It is known by the name “beguara” (Ihering, 1897) in the Iguape region, but not in S.
    [Show full text]
  • Donax Exploitation on the Pacific Coast: Spatial and Temporal Limits
    DONAX EXPLOITATION ON THE PACIFIC COAST: SPATIAL AND TEMPORAL LIMITS Don Laylander Caltrans District 11 P.O. Box 85406 San Diego, CA 92186-5406 and Dan Saunders Brian F. Mooney Associates 9903 Businesspark Drive, Suite B San Diego, CA 92131 ABSTRACT The marine mollusk genus Donax spp. is widely distributed and was exploited prehistorically in several regions of the world. On the west coast of North America, the focused exploitation of Donax gouldii seems to have been largely limited, in space, to the San Luis Rey River - Buena Vista Creek area of northern San Diego County and, in time, to the Late Prehistoric period. Possible explanations for these limits are discussed. DISCUSSION northern Florida (Larson 1980:71; Miller 1980). The marine mollusk genus Donax spp. is represented in the intertidal zone of open, Two species of Donax are present along sandy beaches along the tropical and temp­ the southern California coastline: D. goul­ erate margins of the continents washed by dii, which ranges south from Santa Cruz or the Atlantic, Pacific, and Indian Oceans. San Luis Obispo, and D. californicus, which ranges south from Santa Barbara (McLean Most species ofDonax consist ofrather 1978; Morris 1966; Rehder 1981). Five other small individuals, and their size would seem Donax species are found in the Gulf of Cali­ likely to have limited the appeal ofthese fornia. Aboriginal Donax exploitation in the clams as efficient food packages for littoral region seems to have focused primarily or collecting peoples. Despite this drawback, exclusively on D. gouldii. Donax is known archaeologically to have been exploited prehistorically in several re­ Donax gouldii lives in the intertidal zone gions.
    [Show full text]
  • The Marine and Brackish Water Mollusca of the State of Mississippi
    Gulf and Caribbean Research Volume 1 Issue 1 January 1961 The Marine and Brackish Water Mollusca of the State of Mississippi Donald R. Moore Gulf Coast Research Laboratory Follow this and additional works at: https://aquila.usm.edu/gcr Recommended Citation Moore, D. R. 1961. The Marine and Brackish Water Mollusca of the State of Mississippi. Gulf Research Reports 1 (1): 1-58. Retrieved from https://aquila.usm.edu/gcr/vol1/iss1/1 DOI: https://doi.org/10.18785/grr.0101.01 This Article is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Gulf and Caribbean Research by an authorized editor of The Aquila Digital Community. For more information, please contact [email protected]. Gulf Research Reports Volume 1, Number 1 Ocean Springs, Mississippi April, 1961 A JOURNAL DEVOTED PRIMARILY TO PUBLICATION OF THE DATA OF THE MARINE SCIENCES, CHIEFLY OF THE GULF OF MEXICO AND ADJACENT WATERS. GORDON GUNTER, Editor Published by the GULF COAST RESEARCH LABORATORY Ocean Springs, Mississippi SHAUGHNESSY PRINTING CO.. EILOXI, MISS. 0 U c x 41 f 4 21 3 a THE MARINE AND BRACKISH WATER MOLLUSCA of the STATE OF MISSISSIPPI Donald R. Moore GULF COAST RESEARCH LABORATORY and DEPARTMENT OF BIOLOGY, MISSISSIPPI SOUTHERN COLLEGE I -1- TABLE OF CONTENTS Introduction ............................................... Page 3 Historical Account ........................................ Page 3 Procedure of Work ....................................... Page 4 Description of the Mississippi Coast ....................... Page 5 The Physical Environment ................................ Page '7 List of Mississippi Marine and Brackish Water Mollusca . Page 11 Discussion of Species ...................................... Page 17 Supplementary Note .....................................
    [Show full text]
  • Worms, Germs, and Other Symbionts from the Northern Gulf of Mexico CRCDU7M COPY Sea Grant Depositor
    h ' '' f MASGC-B-78-001 c. 3 A MARINE MALADIES? Worms, Germs, and Other Symbionts From the Northern Gulf of Mexico CRCDU7M COPY Sea Grant Depositor NATIONAL SEA GRANT DEPOSITORY \ PELL LIBRARY BUILDING URI NA8RAGANSETT BAY CAMPUS % NARRAGANSETT. Rl 02882 Robin M. Overstreet r ii MISSISSIPPI—ALABAMA SEA GRANT CONSORTIUM MASGP—78—021 MARINE MALADIES? Worms, Germs, and Other Symbionts From the Northern Gulf of Mexico by Robin M. Overstreet Gulf Coast Research Laboratory Ocean Springs, Mississippi 39564 This study was conducted in cooperation with the U.S. Department of Commerce, NOAA, Office of Sea Grant, under Grant No. 04-7-158-44017 and National Marine Fisheries Service, under PL 88-309, Project No. 2-262-R. TheMississippi-AlabamaSea Grant Consortium furnish ed all of the publication costs. The U.S. Government is authorized to produceand distribute reprints for governmental purposes notwithstanding any copyright notation that may appear hereon. Copyright© 1978by Mississippi-Alabama Sea Gram Consortium and R.M. Overstrect All rights reserved. No pari of this book may be reproduced in any manner without permission from the author. Primed by Blossman Printing, Inc.. Ocean Springs, Mississippi CONTENTS PREFACE 1 INTRODUCTION TO SYMBIOSIS 2 INVERTEBRATES AS HOSTS 5 THE AMERICAN OYSTER 5 Public Health Aspects 6 Dcrmo 7 Other Symbionts and Diseases 8 Shell-Burrowing Symbionts II Fouling Organisms and Predators 13 THE BLUE CRAB 15 Protozoans and Microbes 15 Mclazoans and their I lypeiparasites 18 Misiellaneous Microbes and Protozoans 25 PENAEID
    [Show full text]
  • Donax Trunculus (Bivalvia: Donacidae) by Means of Karyotyping, Fluorochrome Banding and Fluorescent in Situ Hybridization1
    Cytogenetic characterization of Donax trunculus (Bivalvia: Donacidae) by means of karyotyping, fluorochrome banding and fluorescent in situ hybridization1 A. Martínez, L. Mariñas, A. González-Tizón and J. Méndez2 Departamento de Biología Celular y Molecular, Universidade da Coruña, A Zapateira s/n, 15071- La Coruña, Spain Journal of Molluscan Studies, volume 68, issue 4, pages 393-396, november 2002 Received 02 april 2002, accepted 21 may 2002, first published 01 november 2002 How to cite: A. Martínez, L. Mariñas, A. González-Tizón, J.Méndez, Cytogenetic characterization of Donax trunculus (Bivalvia: Donacidae) by means of karyotyping, fluorochrome banding and fluorescent in situ hybridization, Journal of Molluscan Studies, volume 68, issue 4, November 2002, pages 393-396, https://doi.org/10.1093/mollus/68.4.393 Abstract The chromosomes of Donax trunculus were analysed by means of Giemsa staining, chromomycin A3 (CA3), DAPI and fluorescent in situ hybridization (FISH) with an 18S-5.8S-28S rDNA probe. The diploid number is 38 chromosomes and the karyotype consists of nine pairs of metacentric chromosomes, two pairs of submetacentric-metacentric, seven pairs of submetacentric and one pair of telocentric chromosomes. CA3- positive bands are located on eight chromosome pairs and DAPI treatment resulted in uniform staining. Major ribosomal clusters 18S-5.8S-28S are located on the short arm of one submetacentric chromosome pair. Introduction Banding techniques are useful to identify chromosomes and to analyse genomic regions. Some of these techniques
    [Show full text]
  • EMERITA TALPOIDA and DONAX VARIABILIS DISTRIBUTION THROUGHOUT CRESCENTIC FORMATIONS; PEA ISLAND NATIONAL WILDLIFE REFUGE a Thesi
    EMERITA TALPOIDA AND DONAX VARIABILIS DISTRIBUTION THROUGHOUT CRESCENTIC FORMATIONS; PEA ISLAND NATIONAL WILDLIFE REFUGE A thesis submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE in ENVIRONMENTAL STUDIES by BLAIK PULLEY AUGUST 2008 at THE GRADUATE SCHOOL OF THE COLLEGE OF CHARLESTON Approved by: Dennis Stewart, Thesis Advisor Dr. Robert Dolan Dr. Scott Harris Dr. Lindeke Mills Dr. Amy T. McCandless, Dean of the Graduate School 1454471 1454471 2008 ABSTRACT EMERITA TALPOIDA AND DONAX VARIABILIS DISTRIBUTION THROUGHOUT CRESCENTIC FORMATIONS; PEA ISLAND NATIONAL WILDLIFE REFUGE A thesis submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE in ENVIRONMENTAL STUDIES by BLAIK PULLEY JULY 2008 at THE GRADUATE SCHOOL OF THE COLLEGE OF CHARLESTON Pea Island National Wildlife Refuge is a 13-mile stretch of shoreline located on the Outer Banks of North Carolina, 40 miles north of Cape Hatteras and directly south of Oregon Inlet. This Federal Navigation Channel is periodically dredged and sand is placed on the north end of the Pea Island beach. While the sediment nourishes the beach in a particularly sand-starved environment, it also alters the physical and ecological conditions. Most affected are invertebrates living in the swash, the most dominant being the mole crab (Emerita talpoida) and the coquina clam (Donax variabilis). These two species serve as a major food source for shorebirds on the island. It is especially important to protect this food resource on the federal Wildlife Refuge, which operates under a mandate to protect resources for migratory birds. For this research, beach cusps of various sizes were sampled to determine whether there is a correlation between invertebrate populations and the physical characteristics associated with these crescentic features.
    [Show full text]
  • Larval Development of the Coquina Clam, Donax Variabilis Say, with a Discussion of the Structure of the Larval Hinge on the Tellinacea
    W&M ScholarWorks VIMS Articles Virginia Institute of Marine Science 1969 Larval development of the coquina clam, Donax variabilis Say, with a discussion of the structure of the larval hinge on the Tellinacea Paul Chanley Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/vimsarticles Part of the Marine Biology Commons Recommended Citation Chanley, Paul, Larval development of the coquina clam, Donax variabilis Say, with a discussion of the structure of the larval hinge on the Tellinacea (1969). Virginia Journal of Science, 19(1), 214-224. https://scholarworks.wm.edu/vimsarticles/2122 This Article is brought to you for free and open access by the Virginia Institute of Marine Science at W&M ScholarWorks. It has been accepted for inclusion in VIMS Articles by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. LARVAL DEVELOPMENT OF THE COQUINA CLAM, DONAX VARIABILIS SAY, WITH A DISCUSSION OF THE STRUC­ TURE OF THE LARVAL HINGE IN THE TELLINACEA1 PAUL CHANLEY Virginia Institute of Marine Science, Wachapreague, Virginia2 ABSTRACT Adult specimens of Donax variabilis were spawned in the laboratory and the larvae reared to metamorphosis. Larval length increases from 70 µ. to 340 µ. during pelagic stages. Height is originally 10 µ. to 15 µ. less than length. Height increases less rapidly than length and may be 50 µ. less than length at metamorphosis. Depth is originally 50 µ. less than length. It also increases more slowly than length and may be 150 µ. to 170 µ. less than length at metamorphosis.
    [Show full text]
  • Coquina Clam Donax Variabilis
    Coquina clam Robert C. Hermes. Photo Researchers, Inc. Donax variabilis Contributor: Larry DeLancey DESCRIPTION Taxonomy and Basic Description This small species of clam, described by Say in 1822 (Adamkewicz and Harasewych 1996), is well known to most beach goers where its shells are found in abundance. Live coquinas are often exposed by retreating waves on sandy oceanic beaches and seem to be more active in the warmer months. This bivalve possesses wedge-shaped shells, generally less than 2.5 cm (1 inch) in length, and is characterized by variously colored bands radiating along the shells (Miner 1950). It is a member of the bivalve family Donacidae, with coquinas being larger and more abundant than D. fossor along sandy beaches in the southeastern U.S. STATUS The seemingly abundant coquina clam is considered an indicator species for the sandy beach- ocean front habitat. This filter-feeder is an important link in food webs, feeding on small particles such as unicellular algae and detritus and, in turn, being consumed by fish such as pompano (Trachinotus carolinus) and “whiting” (Menticirrhus spp.), as well as shorebirds (Finucane 1969, Nelson 1986, DeLancey 1989, Wilson 1999). Coquina clams can also be consumed by humans (Miner 1950). POPULATION DISTRIBUTION AND SIZE The coquina clam ranges from Virginia, down the Atlantic coast, through the Gulf of Mexico and into Texas (Ruppert and Fox 1988). It is common on most ocean front beach types that occur in South Carolina. The prevalence of coquina clams in this habitat makes it an excellent indicator of the health of this ecosystem. Although current population status for these species is unknown, it appears to be common or abundant on the beaches in South Carolina.
    [Show full text]
  • The Evolution of Extreme Longevity in Modern and Fossil Bivalves
    Syracuse University SURFACE Dissertations - ALL SURFACE August 2016 The evolution of extreme longevity in modern and fossil bivalves David Kelton Moss Syracuse University Follow this and additional works at: https://surface.syr.edu/etd Part of the Physical Sciences and Mathematics Commons Recommended Citation Moss, David Kelton, "The evolution of extreme longevity in modern and fossil bivalves" (2016). Dissertations - ALL. 662. https://surface.syr.edu/etd/662 This Dissertation is brought to you for free and open access by the SURFACE at SURFACE. It has been accepted for inclusion in Dissertations - ALL by an authorized administrator of SURFACE. For more information, please contact [email protected]. Abstract: The factors involved in promoting long life are extremely intriguing from a human perspective. In part by confronting our own mortality, we have a desire to understand why some organisms live for centuries and others only a matter of days or weeks. What are the factors involved in promoting long life? Not only are questions of lifespan significant from a human perspective, but they are also important from a paleontological one. Most studies of evolution in the fossil record examine changes in the size and the shape of organisms through time. Size and shape are in part a function of life history parameters like lifespan and growth rate, but so far little work has been done on either in the fossil record. The shells of bivavled mollusks may provide an avenue to do just that. Bivalves, much like trees, record their size at each year of life in their shells. In other words, bivalve shells record not only lifespan, but also growth rate.
    [Show full text]
  • Population Dynamics of the Argentinean Surf Clams Donax Hanleyanus and Mesodesma Mactroides from Open-Atlantic Beaches Off Argentina
    Population dynamics of the Argentinean surf clams Donax hanleyanus and Mesodesma mactroides from open-Atlantic beaches off Argentina Populationsdynamik der Argentinischen Brandungsmuscheln Donax hanleyanus und Mesodesma mactroides offener Atlantikstrände vor Argentinien Marko Herrmann Dedicated to my family Marko Herrmann Alfred Wegener Institute for Polar and Marine Research (AWI) Section of Marine Animal Ecology P.O. Box 120161 D-27515 Bremerhaven (Germany) [email protected] Submitted for the degree Dr. rer. nat. of the Faculty 2 of Biology and Chemistry University of Bremen (Germany), October 2008 Reviewer and principal supervisor: Prof. Dr. Wolf E. Arntz 1 Reviewer and co-supervisor: Dr. Jürgen Laudien 1 External Reviewer: Dr. Pablo E. Penchaszadeh 2 1 Alfred Wegener Institute for Polar and Marine Research (AWI) Section of Marine Animal Ecology P.O. Box 120161 D-27515 Bremerhaven (Germany) 2 Director of the Ecology Section at the Museo Argentino de Ciencias Naturales (MACN) - Bernardino Rivadavia Av. Angel Gallardo 470, 3° piso lab. 80 C1405DJR Buenos Aires (Argentina) Contents 1 Summary .................................................................................................... 5 1.1 English Version ........................................................................................... 5 1.2 Deutsche Version ........................................................................................ 9 1.3 Versión Español ........................................................................................ 13 2 Introduction
    [Show full text]
  • Marine Aspidogastrids (Trematoda) from Fishes in the Northern Gulf of Mexico
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications from the Harold W. Manter Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of 10-1977 Marine Aspidogastrids (Trematoda) from Fishes in the Northern Gulf of Mexico Sherman S. Hendrix Gettysburg College, [email protected] Robin M. Overstreet Gulf Coast Research Laboratory, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/parasitologyfacpubs Part of the Parasitology Commons Hendrix, Sherman S. and Overstreet, Robin M., "Marine Aspidogastrids (Trematoda) from Fishes in the Northern Gulf of Mexico" (1977). Faculty Publications from the Harold W. Manter Laboratory of Parasitology. 487. https://digitalcommons.unl.edu/parasitologyfacpubs/487 This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from the Harold W. Manter Laboratory of Parasitology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. THE JOURNAL OF PARASITOLOGY Vol. 63, No. 5, October 1977, p. 810-817 MARINE ASPIDOGASTRIDS(TREMATODA) FROM FISHES IN THE NORTHERNGULF OF MEXICO* Sherman S. Hendrixt and Robin M. Overstreett ABSTRACT: Of the aspidogastrids Multicalyx cristata, Lobatostomaringens, Cotylogaster basiri, and C. dinosoides sp. n., the last two had not been previously known from the Gulf of Mexico. The latter dif- fers from other members of its genus by having relatively large equatorial marginal alveoli in compari- son to those at the anterior and posterior ends of the holdfast. It also possesses extensive transverse mus- culature connecting opposed lateral alveoli.
    [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]