DOCSLIB.ORG

(Bivalvia, Unionida)?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
(Bivalvia, Unionida)? Freshwater Mollusk Biology and Conservation 22:85–89, 2019 Ó Freshwater Mollusk Conservation Society 2019 NOTE ARE PARASITES AND DISEASES CONTRIBUTING TO THE DECLINE OF FRESHWATER MUSSELS (BIVALVIA, UNIONIDA)? Andrew McElwain Department of Biological Sciences, College of Liberal Arts and Sciences, State University of New York at Oswego, 392 Shineman Center, Oswego, NY 13126 USA, [email protected] These declines are thought to result primarily from human ABSTRACT activities that fall into one of four general categories. The first Freshwater mussels (Mollusca: Bivalvia: Unionida) includes activities (such as dam construction) that change the consist of 843 species in six families, but many are physical habitat of rivers and lakes. The second includes imperiled. Significant causes of mussel declines include activities that contaminate the benthos with chemical and contaminants and loss of substrate. Potentially, etiological physical waste from industrial and municipal sources (e.g., agents are also contributing factors, but parasites and pathogens of freshwater mussels are understudied relative Hornbach 2001; Grabarkiewicz and Davis 2008). The third to those affecting marine bivalves. Published accounts of category is the extensive harvesting of mussels for the button viral pathogens have been reported exclusively from and pearl industries, which has contributed to declines in some Hyriopsis cumingii (Unionidae) in China. There are species, especially in the USA (Haag 2012). The fourth limited records of possible bacterial and fungal pathogens category is the introduction of nonnative aquatic molluscs, from unionids in the USA and Finland. Parasitic and commensal organisms generally include ciliates (Cilioph- such as the zebra mussel (Dreissena polymorpha) or Asian ora), trematodes (Platyhelminthes: Aspidogastrea and clam (Corbicula fluminea), which compete with native Digenea), roundworms (Nematoda), moss animals (Ecto- mussels for food and available substrate or which foul waters, procta, Entoprocta), oligochaetes and leeches (Annelida: harming indigenous species (Cummings and Graf 2010). Sedentaria: Clitellata), mites (Arthropoda: Acari), cope- pods (Arthropoda: Copepoda), insects (Arthropoda: Additionally, nonnative molluscs potentially can introduce Insecta), and fish eggs (Chordata: Actinopterygii). Para- nonnative etiological agents that might negatively affect native sites injure the host through attachment or feeding or molluscs (Prenter et al. 2004). Although we lack data on the when they invade host tissue to complete their life cycles presence of nonnative etiological agents in freshwater mussels, (e.g., digeneans). Commensals are small organisms living Perkinsus marinus and Haplosporidium nelsoni are good in or on mussels that may use the mantle cavity or shell as a refuge or substrate, and commensals also may feed on examples of introduced pathogens that have affected signif- particulates that have been gathered by their molluscan icantly the USA marine shellfish industry (Burreson and Ford host. Typically, however, the relationship between the two 2004; Villalba et al. 2004). Because of declining populations parties is subject to speculation (e.g., leeches). We are in and mass mortality events known as ‘‘die-offs’’ and ‘‘mussel the midst of a biodiversity crisis, and this minireview kills,’’ the health of wild and hatchery-reared mussels is a highlights the relationships among these organisms and the need to understand the health of wild and captive growing concern (Neves 1987; Fleming et al. 1995; Lydeard et mussels. al. 2004). In an effort to shed light on the possibility of etiological KEY WORDS: freshwater mussels, Unionida, parasites, agents as causative factors of mussel declines, Grizzle and diseases, gross pathology, histopathology Brunner (2009) reviewed the literature regarding parasites and infectious diseases reported from freshwater bivalves. Most of Freshwater mussels are a globally distributed group of the cited literature are observations of single-celled eukaryotic about 843 species in six families (Graf and Cummings 2007; organisms and metazoans that may engage in either a Williams et al. 2017). Approximately 29 species have gone commensal or parasitic relationship with unionids or margar- extinct in the USA as a result of human activities and many itiferids in North America and Europe. The other four families other mussel species have declining populations (Haag 2012). in Unionida are underrepresented in the parasite and disease 85 86 MCELWAIN literature. Additionally, there appears to be almost no peer- damage associated with attached ciliates. Curiously, Coker et reviewed literature on viral, bacterial, or fungal infections in al. (1921) reported Chaetogaster limnaei feeding on mussel freshwater mussels. A few exceptions include reports of RNA parasites but provided no other supporting details. Overall, few and DNA viruses infecting the digestive system of Hyriopsis studies have used light or electron microscopy to document the cumingii in China (Grizzle and Brunner 2009; Lei et al. 2011). pathological changes to tissues associated with pathogens, In 1931 mussel propagation personnel reported ‘‘adult mussels parasites, or commensals. became sterile through bacterial attacks on larval mussels’’ Since the publication of the work of Grizzle and Brunner in (Pritchard 2001). Intracellular microorganisms have been 2009, a few noteworthy studies have been published regarding observed in histological sections of the digestive gland of parasites in freshwater mussels. Levine et al. (2009) reported Elliptio complanata in the USA, but it was unclear if they Gomphus militarus (Arthropoda, Insecta, Odonata) as poten- were prokaryotic or eukaryotic (see Fig. 5 in Chittick et al. tially feeding on the gills of Popenaias popeii (Unionidae), a 2001). Fungal hyphae were observed in the marsupia of Unio critically endangered species restricted to two populations in pictorum, U. tumidus (Pekkarinen 1993a), and Pseudoano- the Rio Grande basin (Carman 2007). Some mussels were donta complanata in Finland (Pekkarinen 1993b). These latter missing the entire outer gills or all four gills. It is unclear how three studies or observations appear to have been overlooked often odonates occur in the mantle cavity of mussels, as there by Grizzle and Brunner (2009). It is possible that some appears to be no other literature on this topic (Grizzle and parasite or disease records may be missed because they appear Brunner 2009). Lopes et al. (2011) found third-stage larvae of in literature in which characterizing parasites or diseases was Hysterothylacium sp. (Nematoda, Anisakidae) in the pericar- not the primary objective, such as reports on surveys that detail dial cavity of Diplodon suavidicus (Hyriidae) in Brazil and population or community structure. Pekkarinen (1993a) presented photographs of nematodes coiled in the pericardial reported fungi and ciliates in the marsupium associated with cavity. In the early 20th century, Ascaris sp. or Ascaris-like degenerating glochidia, but it was unclear if the fungi were worms were reported in the digestive tract of unspecified pathogenic or saprophytic. Overall, parasitic or commensal unionids in the USA, but there were no accompanying species organisms have been reported primarily in wild mussels; there descriptions, no information about pathology, and no indica- is little information about disease problems that may occur in a tion that any specimens were deposited in a museum (Clark hatchery. and Wilson 1912; Wilson and Clark 1912; Coker et al. 1921). Ciliates (Ciliophora), trematodes (Platyhelminthes: Aspi- McElwain et al. (2016) described histopathological changes dogastrea, and Digenea), moss animals (Ectoprocta, Ento- associated with the eggs and larvae of Unionicola sp. from procta), roundworms (Nematoda), oligochaetes and leeches Strophitus connasaugaensis and provided a literature review (Annelida: Sedentaria: Clitellata), mites (Arthropoda: Acari), regarding pathologies associated with Unionicola spp. in copepods (Arthropoda: Crustacea: Copepoda), insects (Ar- unionids. Similarly, Abdel-Gaber et al. (2018) described thropoda: Insecta), and fish eggs (Chordata: Actinopterygii) injuries to the tissues of Coelatura aegyptiaca (Unionidae), are associated with the soft tissues or shells of freshwater Mutela rostrata, and Chambardia rubens (Mutelidae) associ- mussels (Grizzle and Brunner 2009; Wisniewski et al. 2013). ated with eggs and larvae of Unionicola tetrafurcatus.Muller¨ Aspidogastreans, digeneans, nematodes, mites, insect larvae, et al. (2015) described histopathological changes to the gonad and fish eggs either infect mussels or have been reported as and hepatopancreas associated with Rhipidocotyle campanula injurious agents. Interestingly, the eggs of both mites and Phyllodistomum sp. Few studies have demonstrated tissue (Najadicola ingens) and fishes (Rhodeus sericeus) sometimes damage associated with digeneans in unionids. may obstruct the water tubes of a marsupium and prevent or Parasite-induced pearl formation, shell deformities, and hinder the development of glochidia (Stadnichenko and neoplasms received little or no treatment by Grizzle and Stadnichenko 1980; McElwain et al. 2016 and references Brunner (2009). Mussels may form pearls in response to therein). Ciliates, oligochaetes, leeches, insect larvae, and digeneans (Clark and Wilson 1912; Wilson and Clark 1912; copepods have been found in the mantle cavity of mussels, but Gentner and Hopkins 1966; Hopkins
Load more

Recommended publications
  • Histological Changes and Biochemical Parameters in the Hepatopancreas of Terrestrial Gastropod Helix Aspersa As Biomarkers of Neonicotinoid Insecticide Exposure
    African Journal of Biotechnology Vol. 11(96), pp. 16277-16283, 29 November, 2012 Available online at http://www.academicjournals.org/AJB DOI: 10.5897/AJB12.1696 ISSN 1684–5315 ©2012 Academic Journals Full Length Research Paper Histological changes and biochemical parameters in the hepatopancreas of terrestrial gastropod Helix aspersa as biomarkers of neonicotinoid insecticide exposure Smina Ait Hamlet1*, Samira Bensoltane1,2, Mohamed Djekoun3, Fatiha Yassi2 and Houria Berrebbah1 1Cellular Toxicology Laboratory, Department of Biology, Faculty of Sciences, Badji-Mokhtar University, Annaba, P.O. Box 12, 23000, Algeria. 2Faculty of Medicine, Badji-Mokhtar University, Annaba, 23000, Algeria. 3Department of Biology, Faculty of Sciences and the Universe, University of May 08th, 1945, Guelma, 24000, Algeria. Accepted 22 June, 2012 In this study, adult snails, Helix aspersa were used to estimate the effect of aneonicotinoid insecticide (thiametoxam) on biochemical parameters and histological changes in the hepatopancreas of this gastropod after a treatment of six weeks. During this period, snails were exposed by ingestion and contact to fresh lettuce leaves which were soaked with an insecticide solution. The thiametoxam test solutions were 0, 25, 50, 100 and 200 mg/L. The results of the biochemical dosages (total carbohydrates, total proteins and total lipids) showed significant decreases at two concentrations (100 and 200 mg/L) of thiametoxam. However, the histological examination of the hepatopancreas of the treated snails showed alterations as a response to all the treatments, and revealed the degeneration of the digestive tubules and the breakdown of the basement membrane in a dose-dependent manner, leading to a severe deterioration of the tissues in the concentration of 200 mg/L thiametoxam.
    [Show full text]
  • Copyrighted Material
    319 Index a oral cavity 195 guanocytes 228, 231, 233 accessory sex glands 125, 316 parasites 210–11 heart 235 acidophils 209, 254 pharynx 195, 197 hemocytes 236 acinar glands 304 podocytes 203–4 hemolymph 234–5, 236 acontia 68 pseudohearts 206, 208 immune system 236 air sacs 305 reproductive system 186, 214–17 life expectancy 222 alimentary canal see digestive setae 191–2 Malpighian tubules 232, 233 system taxonomy 185 musculoskeletal system amoebocytes testis 214 226–9 Cnidaria 70, 77 typhlosole 203 nephrocytes 233 Porifera 28 antennae nervous system 237–8 ampullae 10 Decapoda 278 ocelli 240 Annelida 185–218 Insecta 301, 315 oral cavity 230 blood vessels 206–8 Myriapoda 264, 275 ovary 238 body wall 189–94 aphodus 38 pedipalps 222–3 calciferous glands 197–200 apodemes 285 pharynx 230 ciliated funnel 204–5 apophallation 87–8 reproductive system 238–40 circulatory system 205–8 apopylar cell 26 respiratory system 236–7 clitellum 192–4 apopyle 38 silk glands 226, 242–3 coelomocytes 208–10 aquiferous system 21–2, 33–8 stercoral sac 231 crop 200–1 Arachnida 221–43 sucking stomach 230 cuticle 189 biomedical applications 222 taxonomy 221 diet 186–7 body wall 226–9 testis 239–40 digestive system 194–203 book lungs 236–7 tracheal tube system 237 dissection 187–9 brain 237 traded species 222 epidermis 189–91 chelicera 222, 229 venom gland 241–2 esophagus 197–200 circulatory system 234–6 walking legs 223 excretory system 203–5 COPYRIGHTEDconnective tissue 228–9 MATERIALzoonosis 222 ganglia 211–13 coxal glands 232, 233–4 archaeocytes 28–9 giant nerve
    [Show full text]
  • Guiding Species Recovery Through Assessment of Spatial And
    Guiding Species Recovery through Assessment of Spatial and Temporal Population Genetic Structure of Two Critically Endangered Freshwater Mussel Species (Bivalvia: Unionidae) Jess Walter Jones ( [email protected] ) United States Fish and Wildlife Service Timothy W. Lane Virginia Department of Game and Inland Fisheries N J Eric M. Hallerman Virginia Tech: Virginia Polytechnic Institute and State University Research Article Keywords: Freshwater mussels, Epioblasma brevidens, E. capsaeformis, endangered species, spatial and temporal genetic variation, effective population size, species recovery planning, conservation genetics Posted Date: March 16th, 2021 DOI: https://doi.org/10.21203/rs.3.rs-282423/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/28 Abstract The Cumberlandian Combshell (Epioblasma brevidens) and Oyster Mussel (E. capsaeformis) are critically endangered freshwater mussel species native to the Tennessee and Cumberland River drainages, major tributaries of the Ohio River in the eastern United States. The Clinch River in northeastern Tennessee (TN) and southwestern Virginia (VA) harbors the only remaining stronghold population for either species, containing tens of thousands of individuals per species; however, a few smaller populations are still extant in other rivers. We collected and analyzed genetic data to assist with population restoration and recovery planning for both species. We used an 888 base-pair sequence of the mitochondrial NADH dehydrogenase 1 (ND1) gene and ten nuclear DNA microsatellite loci to assess patterns of genetic differentiation and diversity in populations at small and large spatial scales, and at a 9-year (2004 to 2013) temporal scale, which showed how quickly these populations can diverge from each other in a short time period.
    [Show full text]
  • Freshwater Bivalve (Unioniformes) Diversity, Systematics, and Evolution: Status and Future Directions Arthur E
    Natural Resource Ecology and Management Natural Resource Ecology and Management Publications 6-2008 Freshwater bivalve (Unioniformes) diversity, systematics, and evolution: status and future directions Arthur E. Bogan North Carolina State Museum of Natural Sciences Kevin J. Roe Iowa State University, [email protected] Follow this and additional works at: http://lib.dr.iastate.edu/nrem_pubs Part of the Evolution Commons, Genetics Commons, Marine Biology Commons, Natural Resources Management and Policy Commons, and the Terrestrial and Aquatic Ecology Commons The ompc lete bibliographic information for this item can be found at http://lib.dr.iastate.edu/ nrem_pubs/29. For information on how to cite this item, please visit http://lib.dr.iastate.edu/ howtocite.html. This Article is brought to you for free and open access by the Natural Resource Ecology and Management at Iowa State University Digital Repository. It has been accepted for inclusion in Natural Resource Ecology and Management Publications by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Freshwater bivalve (Unioniformes) diversity, systematics, and evolution: status and future directions Abstract Freshwater bivalves of the order Unioniformes represent the largest bivalve radiation in freshwater. The unioniform radiation is unique in the class Bivalvia because it has an obligate parasitic larval stage on the gills or fins of fish; it is divided into 6 families, 181 genera, and ∼800 species. These families are distributed across 6 of the 7 continents and represent the most endangered group of freshwater animals alive today. North American unioniform bivalves have been the subject of study and illustration since Martin Lister, 1686, and over the past 320 y, significant gains have been made in our understanding of the evolutionary history and systematics of these animals.
    [Show full text]
  • Scaleshell Mussel Recovery Plan
    U.S. Fish and Wildlife Service Scaleshell Mussel Recovery Plan (Leptodea leptodon) February 2010 Department of the Interior United States Fish and Wildlife Service Great Lakes – Big Rivers Region (Region 3) Fort Snelling, MN Cover photo: Female scaleshell mussel (Leptodea leptodon), taken by Dr. M.C. Barnhart, Missouri State University Disclaimer This is the final scaleshell mussel (Leptodea leptodon) recovery plan. Recovery plans delineate reasonable actions believed required to recover and/or protect listed species. Plans are published by the U.S. Fish and Wildlife Service and sometimes prepared with the assistance of recovery teams, contractors, state agencies, and others. Objectives will be attained and any necessary funds made available subject to budgetary and other constraints affecting the parties involved, as well as the need to address other priorities. Recovery plans do not necessarily represent the views or the official positions or approval of any individuals or agencies involved in plan formulation, other than the U.S. Fish and Wildlife Service. They represent the official position of the U.S. Fish and Wildlife Service only after being signed by the Regional Director. Approved recovery plans are subject to modifications as dictated by new findings, changes in species status, and the completion of recovery actions. The plan will be revised as necessary, when more information on the species, its life history ecology, and management requirements are obtained. Literature citation: U.S. Fish and Wildlife Service. 2010. Scaleshell Mussel Recovery Plan (Leptodea leptodon). U.S. Fish and Wildlife Service, Fort Snelling, Minnesota. 118 pp. Recovery plans can be downloaded from the FWS website: http://endangered.fws.gov i ACKNOWLEDGMENTS Many individuals and organizations have contributed to our knowledge of the scaleshell mussel and work cooperatively to recover the species.
    [Show full text]
  • Mir-29A Participated in Nacre Formation and Immune Response by Targeting Y2R in Pinctada Martensii
    Article miR-29a Participated in Nacre Formation and Immune Response by Targeting Y2R in Pinctada martensii Rongrong Tian 1, Zhe Zheng 1, Ronglian Huang 1, Yu Jiao 1,* and Xiaodong Du 1,2,* Received: 17 September 2015; Accepted: 1 December 2015; Published: 10 December 2015 Academic Editor: Constantinos Stathopoulos 1 Fishery College, Guangdong Ocean University, Zhanjiang 524025, China; [email protected] (R.T.); [email protected] (Z.Z.); [email protected] (R.H.) 2 Guangdong Technology Research Center for Pearl Aquaculture and Process, Guangdong Ocean University, Zhanjiang 524025, China * Correspondence: [email protected] (Y.J.); [email protected] (X.D.); Tel.: +86-759-238-3346 (Y.J. & X.D.); Fax: +86-759-238-2404 (Y.J. & X.D.) Abstract: miR-29a is a conserved miRNA that participates in bone formation and immune response in vertebrates. miR-29a of Pinctada martensii (Pm-miR-29a) was identified in the previous research though deep sequencing. In this report, the precise sequence of mature Pm-miR-29a was validated using miRNA rapid amplification of cDNA ends (miR-RACE) technology. The precursor sequence of Pm-miR-29a was predicted to have 87 bp. Stem loop qRT-PCR analysis showed that Pm-miR-29a was easily detected in all the tissues, although expressions in the mantle and gill were low. The microstructure showed the disrupted growth of the nacre after Pm-miR-29a over-expression, which was induced by mimic injection into P. martensii. Results of the target analysis indicated that neuropeptide Y receptor type 2 (Y2R) was the potential target of Pm-miR-29a. Meanwhile, Pm-miR-29a mimics could obviously inhibit the relative luciferase activity of the reporter containing 31 UTR (Untranslated Regions) of the Y2R gene.
    [Show full text]
  • Enzymatic Degradation of Organophosphorus Pesticides and Nerve Agents by EC: 3.1.8.2
    catalysts Review Enzymatic Degradation of Organophosphorus Pesticides and Nerve Agents by EC: 3.1.8.2 Marek Matula 1, Tomas Kucera 1 , Ondrej Soukup 1,2 and Jaroslav Pejchal 1,* 1 Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; [email protected] (M.M.); [email protected] (T.K.); [email protected] (O.S.) 2 Biomedical Research Center, University Hospital Hradec Kralove, Sokolovska 581, 500 05 Hradec Kralove, Czech Republic * Correspondence: [email protected] Received: 26 October 2020; Accepted: 20 November 2020; Published: 24 November 2020 Abstract: The organophosphorus substances, including pesticides and nerve agents (NAs), represent highly toxic compounds. Standard decontamination procedures place a heavy burden on the environment. Given their continued utilization or existence, considerable efforts are being made to develop environmentally friendly methods of decontamination and medical countermeasures against their intoxication. Enzymes can offer both environmental and medical applications. One of the most promising enzymes cleaving organophosphorus compounds is the enzyme with enzyme commission number (EC): 3.1.8.2, called diisopropyl fluorophosphatase (DFPase) or organophosphorus acid anhydrolase from Loligo Vulgaris or Alteromonas sp. JD6.5, respectively. Structure, mechanisms of action and substrate profiles are described for both enzymes. Wild-type (WT) enzymes have a catalytic activity against organophosphorus compounds, including G-type nerve agents. Their stereochemical preference aims their activity towards less toxic enantiomers of the chiral phosphorus center found in most chemical warfare agents. Site-direct mutagenesis has systematically improved the active site of the enzyme. These efforts have resulted in the improvement of catalytic activity and have led to the identification of variants that are more effective at detoxifying both G-type and V-type nerve agents.
    [Show full text]
  • Littorina Littorea
    Zarai et al. Lipids in Health and Disease 2011, 10:219 http://www.lipidworld.com/content/10/1/219 RESEARCH Open Access Immunohistochemical localization of hepatopancreatic phospholipase in gastropods mollusc, Littorina littorea and Buccinum undatum digestive cells Zied Zarai1, Nicholas Boulais2, Pascale Marcorelles3, Eric Gobin3, Sofiane Bezzine1, Hafedh Mejdoub1 and Youssef Gargouri1* Abstract Background: Among the digestive enzymes, phospholipase A2 (PLA2) hydrolyzes the essential dietary phospholipids in marine fish and shellfish. However, we know little about the organs that produce PLA2, and the ontogeny of the PLA2-cells. Accordingly, accurate localization of PLA2 in marine snails might afford a better understanding permitting the control of the quality and composition of diets and the mode of digestion of lipid food. Results: We have previously producted an antiserum reacting specifically with mSDPLA2. It labeled zymogen granules of the hepatopancreatic acinar cells and the secretory materials of certain epithelial cells in the depths of epithelial crypts in the hepatopancreas of snail. To confirm this localization a laser capture microdissection was performed targeting stained cells of hepatopancreas tissue sections. A Western blot analysis revealed a strong signal at the expected size (30 kDa), probably corresponding to the PLA2. Conclusions: The present results support the presence of two hepatopancreatic intracellular and extracellular PLA2 in the prosobranchs gastropods molluscs, Littorina littorea and Buccinum undatum and bring insights on their localizations. Keywords: phospholipase A2, digestive enzyme, littorina littorea, Buccinum undatum hepatopancreas, immunolocalisation Background in littoral dwellers Littorina, the activity of which Snails require lipids for metabolic energy and for main- depends on the tide level. The presence of massive shell taining the structure and integrity of cell membranes in enhances demands in energy needed for supporting common with other animals to tolerate environemental movement and activity.
    [Show full text]
  • APPENDIX 1 Classified List of Fishes Mentioned in the Text, with Scientific and Common Names
    APPENDIX 1 Classified list of fishes mentioned in the text, with scientific and common names. ___________________________________________________________ Scientific names and classification are from Nelson (1994). Families are listed in the same order as in Nelson (1994), with species names following in alphabetical order. The common names of British fishes mostly follow Wheeler (1978). Common names of foreign fishes are taken from Froese & Pauly (2002). Species in square brackets are referred to in the text but are not found in British waters. Fishes restricted to fresh water are shown in bold type. Fishes ranging from fresh water through brackish water to the sea are underlined; this category includes diadromous fishes that regularly migrate between marine and freshwater environments, spawning either in the sea (catadromous fishes) or in fresh water (anadromous fishes). Not indicated are marine or freshwater fishes that occasionally venture into brackish water. Superclass Agnatha (jawless fishes) Class Myxini (hagfishes)1 Order Myxiniformes Family Myxinidae Myxine glutinosa, hagfish Class Cephalaspidomorphi (lampreys)1 Order Petromyzontiformes Family Petromyzontidae [Ichthyomyzon bdellium, Ohio lamprey] Lampetra fluviatilis, lampern, river lamprey Lampetra planeri, brook lamprey [Lampetra tridentata, Pacific lamprey] Lethenteron camtschaticum, Arctic lamprey] [Lethenteron zanandreai, Po brook lamprey] Petromyzon marinus, lamprey Superclass Gnathostomata (fishes with jaws) Grade Chondrichthiomorphi Class Chondrichthyes (cartilaginous
    [Show full text]
  • Structure and Function of the Digestive System in Molluscs
    Cell and Tissue Research (2019) 377:475–503 https://doi.org/10.1007/s00441-019-03085-9 REVIEW Structure and function of the digestive system in molluscs Alexandre Lobo-da-Cunha1,2 Received: 21 February 2019 /Accepted: 26 July 2019 /Published online: 2 September 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The phylum Mollusca is one of the largest and more diversified among metazoan phyla, comprising many thousand species living in ocean, freshwater and terrestrial ecosystems. Mollusc-feeding biology is highly diverse, including omnivorous grazers, herbivores, carnivorous scavengers and predators, and even some parasitic species. Consequently, their digestive system presents many adaptive variations. The digestive tract starting in the mouth consists of the buccal cavity, oesophagus, stomach and intestine ending in the anus. Several types of glands are associated, namely, oral and salivary glands, oesophageal glands, digestive gland and, in some cases, anal glands. The digestive gland is the largest and more important for digestion and nutrient absorption. The digestive system of each of the eight extant molluscan classes is reviewed, highlighting the most recent data available on histological, ultrastructural and functional aspects of tissues and cells involved in nutrient absorption, intracellular and extracellular digestion, with emphasis on glandular tissues. Keywords Digestive tract . Digestive gland . Salivary glands . Mollusca . Ultrastructure Introduction and visceral mass. The visceral mass is dorsally covered by the mantle tissues that frequently extend outwards to create a The phylum Mollusca is considered the second largest among flap around the body forming a space in between known as metazoans, surpassed only by the arthropods in a number of pallial or mantle cavity.
    [Show full text]
  • Xerces Society's
    Conserving the Gems of Our Waters Best Management Practices for Protecting Native Western Freshwater Mussels During Aquatic and Riparian Restoration, Construction, and Land Management Projects and Activities Emilie Blevins, Laura McMullen, Sarina Jepsen, Michele Blackburn, Aimée Code, and Scott Homan Black CONSERVING THE GEMS OF OUR WATERS Best Management Practices for Protecting Native Western Freshwater Mussels During Aquatic and Riparian Restoration, Construction, and Land Management Projects and Activities Emilie Blevins Laura McMullen Sarina Jepsen Michele Blackburn Aimée Code Scott Hoffman Black The Xerces Society for Invertebrate Conservation www.xerces.org The Xerces® Society for Invertebrate Conservation is a nonprot organization that protects wildlife through the conservation of invertebrates and their habitat. Established in 1971, the Society is at the forefront of invertebrate protection, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs worldwide. The Society uses advocacy, education, and applied research to promote invertebrate conservation. The Xerces Society for Invertebrate Conservation 628 NE Broadway, Suite 200, Portland, OR 97232 Tel (855) 232-6639 Fax (503) 233-6794 www.xerces.org Regional oces from coast to coast. The Xerces Society is an equal opportunity employer and provider. Xerces® is a trademark registered in the U.S. Patent and Trademark Oce © 2018 by The Xerces Society for Invertebrate Conservation Primary Authors and Contributors The Xerces Society for Invertebrate Conservation: Emilie Blevins, Laura McMullen, Sarina Jepsen, Michele Blackburn, Aimée Code, and Scott Homan Black. Acknowledgements Funding for this report was provided by the Oregon Watershed Enhancement Board, The Nature Conservancy and Portland General Electric Salmon Habitat Fund, the Charlotte Martin Foundation, Meyer Memorial Trust, and Xerces Society members and supporters.
    [Show full text]
  • Repaired Damage to a Shell of Mutela Alata (Lea) (Bivalvia, Unionoida) from Lake Malaŵi
    Basteria73(1-3)-TOTAAL:Basteria-basis.qxd 05/10/2009 23:37 Page 81 BASTERIA, 73: 81-84, 2009 Repaired damage to a shell of Mutela alata (Lea) (Bivalvia, Unionoida) from Lake Malaŵi A.C. VAN BRUGGEN National Museum of Natural History, P.O. Box 9517, 2300 RA Leiden, The Netherlands [email protected] and [email protected] A 68 mm long left valve of Mutela alata (Lea, 1864) from near Monkey Bay in the southern part of Lake Malaŵi shows well repaired trauma more or less in the centre. It is obvious that the animal has lived and prospered for some time after the event. Speculations on what may have caused this type of damage (predation by Openbill Stork Anastomus lamelligerus?) are presen- ted. Key words: Bivalvia, Mutelidae, Mutela, repaired damage, Openbill Stork, Anastomus lamellige- rus, Lake Malaŵi, Malaŵi . Recently Mr H.P.M.G. Menkhorst (Krimpen aan de IJssel) donated the malacological fruits of his two trips to Malaŵi (1983, 1985) to the National Museum of Natural History, Leiden (abbreviated RMNH). This valuable material is complementary to the already copious holdings of mollusc material of this south central African country in the Leiden Museum. From time to time these specimens will be reported upon. Among the freshwater bivalve material there is a beautifully repaired damaged left valve of Mutela alata (Lea, 1864) from the southern parts of Lake Malaŵi; unfortunately the companion right valve is not available. For details of the freshwater bivalves of Lake Malaŵi we refer to Mandahl-Barth (1972, 1988) and Scholz (2003). M.
    [Show full text]