DOCSLIB.ORG

Author's Personal Copy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Author's Personal Copy Author's personal copy Journal of Experimental Marine Biology and Ecology 371 (2009) 10–19 Contents lists available at ScienceDirect Journal of Experimental Marine Biology and Ecology journal homepage: www.elsevier.com/locate/jembe Predator–prey interactions from in situ time-lapse observations of a sublittoral mussel bed in the Gulf of Trieste (Northern Adriatic) Jennifer A. Sawyer a, Martin Zuschin a,⁎, Bettina Riedel b, Michael Stachowitsch b a Department of Paleontology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria b Department of Marine Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria article info abstract Article history: Hexaplex trunculus (Linnaeus, 1758) is one of the most abundant and widespread muricid gastropods in the Received 29 May 2008 Northern Adriatic Sea, but relatively little is known about the feeding ecology of this predator. We examined the Received in revised form 25 November 2008 activity of H. trunculus on a sublittoral mussel bed at 24 m depth through in situ time-lapse observations and bulk Accepted 21 December 2008 samples. The camera photographed a 0.25 m2 section of the mussel bed at 6-min intervals for ~23 h. Photos were examined frame-by-frame for gastropod movement and activities, especially interactions between H. trunculus Keywords: and Mytilus galloprovincialis (Lamarck, 1819). Our survey indicates high activity-levels of H. trunculus on the sea Benthos fl fi Hexaplex oor: all gastropods made minor movements, most made major movements, and most left the eld of view during Mediterranean the study-interval. On average, individuals remained stationary for only 7.3 h. Two predation attempts on Mytilus Mytilus involving conspecific competition were documented, and one Hexaplex was consuming a mussel at the onset of Predation the deployment. Additionally, 487 M. galloprovincialis from four diver-taken 0.25 m2 quadrates were measured and examined for traces of marginal chipping and drilling predation. Mytilus from surface samples ranged from 11.1 mm to 95.5 mm in length, and one of the four samples had a significantly different average shell length from the others. 114 H. trunculus were collected and measured. Hexaplex ranged from 22.1 mm to 86.1 mm and the mean shell length did not differ among samples, though they were overwhelmingly medium and large. Predation frequency (the ratio of successfully preyed upon bivalves to the total number of bivalves sampled) is high at the studied site (N55%), and large gastropods preferred a chipping mode of predation to drilling, supporting earlier laboratory studies showing a preference for M. galloprovincialis and this predation strategy. Prey effectiveness (the ratio of failed predatory attacks to total predatory attacks) is also high (63.8%), and no evidence of a size refuge was found. Feeding in H. trunculus is highly facultative, calling for caution when using drill holes to estimate predation intensities; whenever possible, traces of multiple predation modes should be considered. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Harper and Peck, 2003), marginal chipping (Peharda and Morton, 2006) and wedging (Vermeij and Kool,1994). Moreover, at least one laboratory Predator–prey interactions are frequently investigated in laboratory study has documented muricids killing mussels without producing any experiments (e.g., Freeman and Byers, 2006; Peharda and Morton, 2006; visible damage to the prey shell (Kowalewski, 2004). Drill holes are Chattopadhyay and Baumiller, 2007). While this approach allows a high preserved in the shell and can be easily quantified in bulk samples. level of control, it often does not accurately reflect the same interactions Marginal chipping leaves characteristic damage on the shell's exterior in the natural environment: natural settings are complex, and most (Carriker, 1951; Warren, 1916) that can easily be quantified in complete laboratory experiments are designed to eliminate such complexities. shells with limited marginal damage from other sources. Moreover, most field data tend to be from more accessible intertidal Predation is a key process in structuring benthic communities habitats (e.g., Sanford et al., 2003; Meyer and Byers, 2005; Edgell and (MacArthur, 1972; Holt, 1977; Palmer, 1979; Bohannan and Lenski, Rochette, 2008) than from the methodologically more demanding 2000), and recent literature proposes low predation pressure as a general subtidal settings (e.g., Breen et al., 1982; Wahle and Steneck, 1992). We background condition in the Northern Adriatic (e.g., McKinney and build upon recent laboratory studies on the predatory behavior of Hex- Hageman, 2006; McKinney, 2007). McKinney (2007) lists asteroids, aplex trunculus (Peharda and Morton, 2006; Morton et al., 2007)to bottom-feeding fish, cephalopods, crustaceans, gastropods and poly- better understand its ecology in its natural setting. chaetes as carnivores in the Adriatic basin, but few studies have examined Three modes of predatory attack are documented in muricid the effects of these predators. Muricid gastropods play an important role gastropods: drilling (Peharda and Morton, 2006; Harding et al., 2007; in regulating the population dynamics of mussel, barnacle, tubeworm and limpet prey (Menge, 1974; Morton, 2004). H. trunculus is one of the ⁎ Corresponding author. most abundant and widespread muricid gastropods in the Northern E-mail address: [email protected] (M. Zuschin). Adriatic, where it is fished for human consumption and used as fish bait. 0022-0981/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jembe.2008.12.010 Author's personal copy J.A. Sawyer et al. / Journal of Experimental Marine Biology and Ecology 371 (2009) 10–19 11 Also, Hexaplex's heavy consumption of cultured bivalve prey has rendered it a pest species (Benović,1997). Densities of up to 120 individuals/m2 have been reported at black mussel (Mytilus galloprovincialis)and European flat oyster (Ostrea edulis, Linnaeus, 1758) aquaculture fisheries (Zavodnik and Šimunović,1997). Wurzian (1982) studied the function of carnivores from epifaunal communities in the Northern Adriatic and determined that H. trunculus has a homogeneous distribution there (average density 0.2±0.1 individuals/m2). In a baiting experiment using a dead fish, 39 individuals were attracted, equivalent to every H. trunculus within 200 m2. The gastropod's diet consisted of Arca noae (Linnaeus, 1758), Chlamys varia (Linnaeus, 1758), Corbula gibba (Olivi, 1792), Venus sp. (Linnaeus, 1758), and Ophiothrix quinquemaculata (DelleChiaje, 1828); it also grazed on sponges. Despite its abundance and relative importance as a consumer of cultured bivalves, little is known about the ecology of H. trunculus.Most studies deal with the occurrence of imposex (Axiak et al., 1995; Terlizzi et al., 1998; Chiavarini et al., 2003) and its purple dye (Andreotti et al., 2004). Peharda and Morton (2006) and Morton et al. (2007) studied a variety of aspects of H. trunculus feeding behavior in laboratory settings, including predator size, mode of attack, prey choice, handling time and feeding rates using three species of bivalves common in the Northern Fig. 1. Study area: mussel bed located about 2 km off coast of Piran, Slovenia (Northern Adriatic: A. noae, M. galloprovincialis and Modiolus barbatus (Linnaeus, Adriatic Sea; 45° 32.69_N 13°34.94_E). 1758). According to their results, H. trunculus is capable of two modes of attack: drilling a hole through the shell and chipping, in which the gastropod uses a labral spine to chip or wedge the posterior portion of the to 11:01 on 25 September 2007. These photographs were examined bivalve shell. M. galloprovincialis was the preferred prey, and medium- frame-by-frame to document H. trunculus activity, including mobility, and large-sized predators (~55 mm and ~70 mm shell length, prey consumption, and potential predatory attempts. Every individual respectively) chose chipping over drilling when attacking these mussels gastropod was also examined for minor movements (less than one (Peharda and Morton, 2006). The authors calculated that an medium- body-length), major movements (greater than one body-length), sized H. trunculus consumes approximately 18 large M. galloprovinicalis conspecific interactions, predatory behavior, and time spent consuming (~65 mm long) per year. prey. Peharda and Morton's (2006) illustration of a Hexaplex drilling a According to Morton et al.'s (2007) results, H. trunculus tended to Mytilus shows the gastropod positioned atop the posterior portion of chip thin-shelled prey, but drilled bivalves with thicker shells. H. the mussel's shell. Those individuals that made movements ending in trunculus attacked M. galloprovincialis by drilling (either marginally or such prey grappling and manipulation were interpreted to be actively laterally) or chipping, based on the predator and prey size (Peharda searching for prey. These activities were noted, as were potential and Morton, 2006; Morton et al., 2007). Small gastropods tended to attempts to chip or drill the prey shell, and prey consumption. A short drill at the valve margin, medium gastropods tended to chip or drill (at time-lapse film was created from the full series of photographs (see the valve margin) in about equal proportions, and in contrast to online supplementary material). Peharda and Morton (2006), large gastropods tended to laterally drill medium and large-sized Mytilus. 2.2. Quantitative samples 2. Materials and Methods To evaluate predation frequency,
Load more

Recommended publications
  • National Monitoring Program for Biodiversity and Non-Indigenous Species in Egypt
    UNITED NATIONS ENVIRONMENT PROGRAM MEDITERRANEAN ACTION PLAN REGIONAL ACTIVITY CENTRE FOR SPECIALLY PROTECTED AREAS National monitoring program for biodiversity and non-indigenous species in Egypt PROF. MOUSTAFA M. FOUDA April 2017 1 Study required and financed by: Regional Activity Centre for Specially Protected Areas Boulevard du Leader Yasser Arafat BP 337 1080 Tunis Cedex – Tunisie Responsible of the study: Mehdi Aissi, EcApMEDII Programme officer In charge of the study: Prof. Moustafa M. Fouda Mr. Mohamed Said Abdelwarith Mr. Mahmoud Fawzy Kamel Ministry of Environment, Egyptian Environmental Affairs Agency (EEAA) With the participation of: Name, qualification and original institution of all the participants in the study (field mission or participation of national institutions) 2 TABLE OF CONTENTS page Acknowledgements 4 Preamble 5 Chapter 1: Introduction 9 Chapter 2: Institutional and regulatory aspects 40 Chapter 3: Scientific Aspects 49 Chapter 4: Development of monitoring program 59 Chapter 5: Existing Monitoring Program in Egypt 91 1. Monitoring program for habitat mapping 103 2. Marine MAMMALS monitoring program 109 3. Marine Turtles Monitoring Program 115 4. Monitoring Program for Seabirds 118 5. Non-Indigenous Species Monitoring Program 123 Chapter 6: Implementation / Operational Plan 131 Selected References 133 Annexes 143 3 AKNOWLEGEMENTS We would like to thank RAC/ SPA and EU for providing financial and technical assistances to prepare this monitoring programme. The preparation of this programme was the result of several contacts and interviews with many stakeholders from Government, research institutions, NGOs and fishermen. The author would like to express thanks to all for their support. In addition; we would like to acknowledge all participants who attended the workshop and represented the following institutions: 1.
    [Show full text]
  • Impacts of Climate Change on Marine Fisheries and Aquaculture in Chile
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/319999645 Impacts of Climate Change on Marine Fisheries and Aquaculture in Chile Chapter · September 2017 DOI: 10.1002/9781119154051.ch10 CITATIONS READS 0 332 28 authors, including: Nelson A Lagos Ricardo Norambuena University Santo Tomás (Chile) University of Concepción 65 PUBLICATIONS 1,052 CITATIONS 13 PUBLICATIONS 252 CITATIONS SEE PROFILE SEE PROFILE Claudio Silva Marco A Lardies Pontificia Universidad Católica de Valparaíso Universidad Adolfo Ibáñez 54 PUBLICATIONS 432 CITATIONS 70 PUBLICATIONS 1,581 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Irish moss - green crab interactions View project Influence of environment on fish stock assessment View project All content following this page was uploaded by Pedro A. Quijón on 11 November 2017. The user has requested enhancement of the downloaded file. 239 10 Impacts of Climate Change on Marine Fisheries and Aquaculture in Chile Eleuterio Yáñez1, Nelson A. Lagos2,13, Ricardo Norambuena3, Claudio Silva1, Jaime Letelier4, Karl-Peter Muck5, Gustavo San Martin6, Samanta Benítez2,13, Bernardo R. Broitman7,13, Heraldo Contreras8, Cristian Duarte9,13, Stefan Gelcich10,13, Fabio A. Labra2, Marco A. Lardies11,13, Patricio H. Manríquez7, Pedro A. Quijón12, Laura Ramajo2,11, Exequiel González1, Renato Molina14, Allan Gómez1, Luis Soto15, Aldo Montecino16, María Ángela Barbieri17, Francisco Plaza18, Felipe Sánchez18,
    [Show full text]
  • TEXT-BOOKS of ANIMAL BIOLOGY a General Zoology of The
    TEXT-BOOKS OF ANIMAL BIOLOGY * Edited by JULIAN S. HUXLEY, F.R.S. A General Zoology of the Invertebrates by G. S. Carter Vertebrate Zoology by G. R. de Beer Comparative Physiology by L. T. Hogben Animal Ecology by Challes Elton Life in Inland Waters by Kathleen Carpenter The Development of Sex in Vertebrates by F. W. Rogers Brambell * Edited by H. MUNRO Fox, F.R.S. Animal Evolution / by G. S. Carter Zoogeography of the Land and Inland Waters by L. F. de Beaufort Parasitism and Symbiosis by M. Caullery PARASITISM AND ~SYMBIOSIS BY MAURICE CAULLERY Translated by Averil M. Lysaght, M.Sc., Ph.D. SIDGWICK AND JACKSON LIMITED LONDON First Published 1952 !.lADE AND PRINTED IN GREAT BRITAIN BY WILLIAM CLOWES AND SONS, LlMITED, LONDON AND BECCLES CONTENTS LIST OF ILLUSTRATIONS vii PREFACE TO THE ENGLISH EDITION xi CHAPTER I Commensalism Introduction-commensalism in marine animals-fishes and sea anemones-associations on coral reefs-widespread nature of these relationships-hermit crabs and their associates CHAPTER II Commensalism in Terrestrial Animals Commensals of ants and termites-morphological modifications in symphiles-ants.and slavery-myrmecophilous plants . 16 CHAPTER III From Commensalism to Inquilinism and Parasitism Inquilinism-epizoites-intermittent parasites-general nature of modifications produced by parasitism 30 CHAPTER IV Adaptations to Parasitism in Annelids and Molluscs Polychates-molluscs; lamellibranchs; gastropods 40 CHAPTER V Adaptation to Parasitism in the Crustacea Isopoda-families of Epicarida-Rhizocephala-Ascothoracica
    [Show full text]
  • Taxonomy and Diversity of the Sponge Fauna from Walters Shoal, a Shallow Seamount in the Western Indian Ocean Region
    Taxonomy and diversity of the sponge fauna from Walters Shoal, a shallow seamount in the Western Indian Ocean region By Robyn Pauline Payne A thesis submitted in partial fulfilment of the requirements for the degree of Magister Scientiae in the Department of Biodiversity and Conservation Biology, University of the Western Cape. Supervisors: Dr Toufiek Samaai Prof. Mark J. Gibbons Dr Wayne K. Florence The financial assistance of the National Research Foundation (NRF) towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the author and are not necessarily to be attributed to the NRF. December 2015 Taxonomy and diversity of the sponge fauna from Walters Shoal, a shallow seamount in the Western Indian Ocean region Robyn Pauline Payne Keywords Indian Ocean Seamount Walters Shoal Sponges Taxonomy Systematics Diversity Biogeography ii Abstract Taxonomy and diversity of the sponge fauna from Walters Shoal, a shallow seamount in the Western Indian Ocean region R. P. Payne MSc Thesis, Department of Biodiversity and Conservation Biology, University of the Western Cape. Seamounts are poorly understood ubiquitous undersea features, with less than 4% sampled for scientific purposes globally. Consequently, the fauna associated with seamounts in the Indian Ocean remains largely unknown, with less than 300 species recorded. One such feature within this region is Walters Shoal, a shallow seamount located on the South Madagascar Ridge, which is situated approximately 400 nautical miles south of Madagascar and 600 nautical miles east of South Africa. Even though it penetrates the euphotic zone (summit is 15 m below the sea surface) and is protected by the Southern Indian Ocean Deep- Sea Fishers Association, there is a paucity of biodiversity and oceanographic data.
    [Show full text]
  • Examples of Sea Sponges
    Examples Of Sea Sponges Startling Amadeus burlesques her snobbishness so fully that Vaughan structured very cognisably. Freddy is ectypal and stenciling unsocially while epithelial Zippy forces and inflict. Monopolistic Porter sailplanes her honeymooners so incorruptibly that Sutton recirculates very thereon. True only on water leaves, sea of these are animals Yellow like Sponge Oceana. Deeper dives into different aspects of these glassy skeletons are ongoing according to. Sponges theoutershores. Cell types epidermal cells form outer covering amoeboid cells wander around make spicules. Check how These Beautiful Pictures of Different Types of. To be optimal for bathing, increasing with examples of brooding forms tan ct et al ratios derived from other microscopic plants from synthetic sponges belong to the university. What is those natural marine sponge? Different types of sponges come under different price points and loss different uses in. Global Diversity of Sponges Porifera NCBI NIH. Sponges EnchantedLearningcom. They publish the outer shape of rubber sponge 1 Some examples of sponges are Sea SpongeTube SpongeVase Sponge or Sponge Painted. Learn facts about the Porifera or Sea Sponges with our this Easy mountain for Kids. What claim a course Sponge Acme Sponge Company. BG Silicon isotopes of this sea sponges new insights into. Sponges come across an incredible summary of colors and an amazing array of shapes. 5 Fascinating Types of what Sponge Leisure Pro. Sea sponges often a tube-like bodies with his tiny pores. Sponges The World's Simplest Multi-Cellular Creatures. Sponges are food of various nudbranchs sea stars and fish. Examples of sponges Answers Answerscom. Sponges info and games Sheppard Software.
    [Show full text]
  • A Soft Spot for Chemistry–Current Taxonomic and Evolutionary Implications of Sponge Secondary Metabolite Distribution
    marine drugs Review A Soft Spot for Chemistry–Current Taxonomic and Evolutionary Implications of Sponge Secondary Metabolite Distribution Adrian Galitz 1 , Yoichi Nakao 2 , Peter J. Schupp 3,4 , Gert Wörheide 1,5,6 and Dirk Erpenbeck 1,5,* 1 Department of Earth and Environmental Sciences, Palaeontology & Geobiology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany; [email protected] (A.G.); [email protected] (G.W.) 2 Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan; [email protected] 3 Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University Oldenburg, 26111 Wilhelmshaven, Germany; [email protected] 4 Helmholtz Institute for Functional Marine Biodiversity, University of Oldenburg (HIFMB), 26129 Oldenburg, Germany 5 GeoBio-Center, Ludwig-Maximilians-Universität München, 80333 Munich, Germany 6 SNSB-Bavarian State Collection of Palaeontology and Geology, 80333 Munich, Germany * Correspondence: [email protected] Abstract: Marine sponges are the most prolific marine sources for discovery of novel bioactive compounds. Sponge secondary metabolites are sought-after for their potential in pharmaceutical applications, and in the past, they were also used as taxonomic markers alongside the difficult and homoplasy-prone sponge morphology for species delineation (chemotaxonomy). The understanding Citation: Galitz, A.; Nakao, Y.; of phylogenetic distribution and distinctiveness of metabolites to sponge lineages is pivotal to reveal Schupp, P.J.; Wörheide, G.; pathways and evolution of compound production in sponges. This benefits the discovery rate and Erpenbeck, D. A Soft Spot for yield of bioprospecting for novel marine natural products by identifying lineages with high potential Chemistry–Current Taxonomic and Evolutionary Implications of Sponge of being new sources of valuable sponge compounds.
    [Show full text]
  • BIO 313 ANIMAL ECOLOGY Corrected
    NATIONAL OPEN UNIVERSITY OF NIGERIA SCHOOL OF SCIENCE AND TECHNOLOGY COURSE CODE: BIO 314 COURSE TITLE: ANIMAL ECOLOGY 1 BIO 314: ANIMAL ECOLOGY Team Writers: Dr O.A. Olajuyigbe Department of Biology Adeyemi Colledge of Education, P.M.B. 520, Ondo, Ondo State Nigeria. Miss F.C. Olakolu Nigerian Institute for Oceanography and Marine Research, No 3 Wilmot Point Road, Bar-beach Bus-stop, Victoria Island, Lagos, Nigeria. Mrs H.O. Omogoriola Nigerian Institute for Oceanography and Marine Research, No 3 Wilmot Point Road, Bar-beach Bus-stop, Victoria Island, Lagos, Nigeria. EDITOR: Mrs Ajetomobi School of Agricultural Sciences Lagos State Polytechnic Ikorodu, Lagos 2 BIO 313 COURSE GUIDE Introduction Animal Ecology (313) is a first semester course. It is a two credit unit elective course which all students offering Bachelor of Science (BSc) in Biology can take. Animal ecology is an important area of study for scientists. It is the study of animals and how they related to each other as well as their environment. It can also be defined as the scientific study of interactions that determine the distribution and abundance of organisms. Since this is a course in animal ecology, we will focus on animals, which we will define fairly generally as organisms that can move around during some stages of their life and that must feed on other organisms or their products. There are various forms of animal ecology. This includes: • Behavioral ecology, the study of the behavior of the animals with relation to their environment and others • Population ecology, the study of the effects on the population of these animals • Marine ecology is the scientific study of marine-life habitat, populations, and interactions among organisms and the surrounding environment including their abiotic (non-living physical and chemical factors that affect the ability of organisms to survive and reproduce) and biotic factors (living things or the materials that directly or indirectly affect an organism in its environment).
    [Show full text]
  • Ascendency As Ecological Indicator for Environmental Quality Assessment at the Ecosystem Level: a Case Study
    Hydrobiologia (2006) 555:19–30 Ó Springer 2006 H. Queiroga, M.R. Cunha, A. Cunha, M.H. Moreira, V. Quintino, A.M. Rodrigues, J. Seroˆ dio & R.M. Warwick (eds), Marine Biodiversity: Patterns and Processes, Assessment, Threats, Management and Conservation DOI 10.1007/s10750-005-1102-8 Ascendency as ecological indicator for environmental quality assessment at the ecosystem level: a case study J. Patrı´ cio1,*, R. Ulanowicz2, M. A. Pardal1 & J. C. Marques1 1IMAR- Institute of Marine Research, Department of Zoology, Faculty of Sciences and Technology, University of Coimbra, 3004-517, Coimbra, Portugal 2Chesapeake Biological Laboratory, Center for Environmental and Estuarine Studies, University of Maryland, Solomons, Maryland, 20688-0038, USA (*Author for correspondence: E-mail: [email protected]) Key words: network analysis, ascendency, eutrophication, estuary Abstract Previous studies have shown that when an ecosystem consists of many interacting components it becomes impossible to understand how it functions by focussing only on individual relationships. Alternatively, one can attempt to quantify system behaviour as a whole by developing ecological indicators that combine numerous environmental factors into a single value. One such holistic measure, called the system ‘ascen- dency’, arises from the analysis of networks of trophic exchanges. It deals with the joint quantification of overall system activity with the organisation of the component processes and can be used specifically to identify the occurrence of eutrophication. System ascendency analyses were applied to data over a gradient of eutrophication in a well documented small temperate intertidal estuary. Three areas were compared along the gradient, respectively, non eutrophic, intermediate eutrophic, and strongly eutrophic. Values of other measures related to the ascendency, such as the total system throughput, development capacity, and average mutual information, as well as the ascendency itself, were clearly higher in the non-eutrophic area.
    [Show full text]
  • The Effect of Light Intensity and Tidal Cycle on the Hatching and Larval Behaviour of the Muricid Gastropod Chorus Giganteus
    Journal of Experimental Marine Biology and Ecology 440 (2013) 69–73 Contents lists available at SciVerse ScienceDirect Journal of Experimental Marine Biology and Ecology journal homepage: www.elsevier.com/locate/jembe The effect of light intensity and tidal cycle on the hatching and larval behaviour of the muricid gastropod Chorus giganteus José A. Gallardo a,⁎, Antonio Brante b, Juan Miguel Cancino b a Pontificia Universidad Católica de Valparaíso, Avenida Altamirano 1480, Valparaíso, Chile b Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile article info abstract Article history: Encapsulation is a common strategy observed among marine caenogastropods. Although the capsule confers Received 20 August 2012 protection for embryos, its rigidity and strength pose a significant challenge as the larvae hatch. The factors Received in revised form 19 November 2012 that drive hatching among these benthic marine gastropods have scarcely been studied. In this study, we exper- Accepted 22 November 2012 imentally evaluated whether the capsule plug opening and larval release processes were synchronised with day/ Available online xxxx night or tidal cycles in the muricid gastropod Chorus giganteus. In addition, we tested the effect of different levels of light intensity on the swimming behaviour of pre- and post-hatching larvae. The results showed that capsule Keywords: Chorus giganteus plug rupture occurred in synchronous pulses of capsule groups during both day and night. A periodogram anal- Day/night cycle ysis did not show circatidal rhythmicity in either the plug rupture or total number of capsules hatched. The Hatching highest percentage of larvae hatched at sunset and during the night (82.9%), whereas only 17% of them hatched Intracapsular development during the day.
    [Show full text]
  • 2018 Final LOFF W/ Ref and Detailed Info
    Final List of Foreign Fisheries Rationale for Classification ** (Presence of mortality or injury (P/A), Co- Occurrence (C/O), Company (if Source of Marine Mammal Analogous Gear Fishery/Gear Number of aquaculture or Product (for Interactions (by group Marine Mammal (A/G), No RFMO or Legal Target Species or Product Type Vessels processor) processing) Area of Operation or species) Bycatch Estimates Information (N/I)) Protection Measures References Detailed Information Antigua and Barbuda Exempt Fisheries http://www.fao.org/fi/oldsite/FCP/en/ATG/body.htm http://www.fao.org/docrep/006/y5402e/y5402e06.htm,ht tp://www.tradeboss.com/default.cgi/action/viewcompan lobster, rock, spiny, demersal fish ies/searchterm/spiny+lobster/searchtermcondition/1/ , (snappers, groupers, grunts, ftp://ftp.fao.org/fi/DOCUMENT/IPOAS/national/Antigua U.S. LoF Caribbean spiny lobster trap/ pot >197 None documented, surgeonfish), flounder pots, traps 74 Lewis Fishing not applicable Antigua & Barbuda EEZ none documented none documented A/G AndBarbuda/NPOA_IUU.pdf Caribbean mixed species trap/pot are category III http://www.nmfs.noaa.gov/pr/interactions/fisheries/tabl lobster, rock, spiny free diving, loops 19 Lewis Fishing not applicable Antigua & Barbuda EEZ none documented none documented A/G e2/Atlantic_GOM_Caribbean_shellfish.html Queen conch (Strombus gigas), Dive (SCUBA & free molluscs diving) 25 not applicable not applicable Antigua & Barbuda EEZ none documented none documented A/G U.S. trade data Southeastern U.S. Atlantic, Gulf of Mexico, and Caribbean snapper- handline, hook and grouper and other reef fish bottom longline/hook-and-line/ >5,000 snapper line 71 Lewis Fishing not applicable Antigua & Barbuda EEZ none documented none documented N/I, A/G U.S.
    [Show full text]
  • Genetic Structure and Diversity of Squids with Contrasting Life Histories in the Humboldt Current System Estructura Y Diversidad
    Genetic diversity of squids Hidrobiológica 204, 24 (): 1-0 Genetic structure and diversity of squids with contrasting life histories in the Humboldt Current System Estructura y diversidad genética de calamares con historias de vida contrastantes en el Sistema de Corrientes de Humboldt Christian Marcelo Ibáñez and Elie Poulin Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile. Las Palmeras # 3425, Ñuñoa. Chile e-mail: [email protected] Ibáñez C. M and Elie Poulin. 204. Genetic structure and diversity of squids with contrasting life histories in the Humboldt Current System. Hidrobiológica 24 (): -0. ABSTRACT Dosidiscus gigas and Doryteuthis gahi are the most abundant squids in the Humboldt Current System (HCS). These species have contrasting life histories. To determine the genetic structure and diversity of these species, we collected samples from different places in the HCS and amplified a fragment of the mitochondrial cytochrome C oxidase I gene. The molecular analysis of D. gigas revealed low genetic diversity, absence of population structure and evidence for a demographic expansion during the transition from the last glacial period to the current interglacial. These results sug- gest that D. gigas is composed of one large population with high levels of gene flow throughout the HCS. In the case of D. gahi, the sequences indicated the presence of two population units in the HCS, one in south-central Chile and one in Peru. The Chilean unit had greater genetic diversity, suggesting that it is an old, relatively stable population. In the Peruvian unit there was less genetic diversity and evidence of a recent demographic expansion.
    [Show full text]
  • Review of the Literature on Bivalve Cytogenetics in the Last Ten Years
    Cah. Biol. Mar. (2002) 43 : 17-26 Review of the literature on bivalve cytogenetics in the last ten years Catherine THIRIOT-QUIEVREUX Observatoire Océanologique, Université P. et M. Curie – CNRS - INSU, BP 28, 06230 Villefranche-sur-Mer, France Fax: (33) 4 93 76 38 48; E-mail: [email protected] Abstract: This paper provides a review of the studies on bivalve chromosomes since 1992, in order to gather available data and to highlight the recent progress in different fields of cytogenetics: karyotype and chromosome markers, genome size, aneuploidy, natural and induced polyploidy, and hybridization. Résumé: Revue des travaux des dix dernières années sur l’étude cytogénétique des bivalves. Cet article présente une revue sur l’étude des chromosomes des bivalves depuis 1992 afin de rassembler les données disponibles et de souligner les pro- grès récents dans les différents domaines de la cytogénétique : caryotype et marqueurs chromosomiques, taille du génome, aneuploïdie, polyploïdie naturelle et induite, et hydridisation. Keywords: Bivalvia, Chromosomes, Cytogenetics Introduction review, 1985). Later, the development of banding techniques which allowed chromosome identification in Cytogenetic studies encompass different levels of biological karyotypes began to be applied in bivalves (see Thiriot- organization ranging from the morphological to the Quiévreux review, 1994). Since these reviews, the study of molecular, depending on the applicable technology. bivalve chromosomes has greatly progressed in Chromosomes can be studied as a morphological karyological as well as molecular information, as a result of manifestation of the genome in terms of their routine application of several banding techniques and the microscopically visible size, shape, number and behaviour development of techniques for in situ hybridization.
    [Show full text]