Science.gov

Sample records for conrad gastropoda vetigastropoda

  1. Miocene Vetigastropoda and Neritimorpha (Mollusca, Gastropoda) of central Chile

    NASA Astrophysics Data System (ADS)

    Nielsen, Sven N.; Frassinetti, Daniel; Bandel, Klaus

    2004-09-01

    Species of Vetigastropoda (Fissurellidae, Turbinidae, Trochidae) and one species of Neritimorpha (Neritidae) from the Navidad area, south of Valparaı´so, and the Arauco Peninsula, south of Concepción, are described. Among these, the Fissurellidae comprise Diodora fragilis n. sp., Diodora pupuyana n. sp., two additional unnamed species of Diodora, and a species resembling Fissurellidea. Turbinidae are represented by Cantrainea sp., and Trochidae include Tegula (Chlorostoma) austropacifica n. sp., Tegula (Chlorostoma) chilena n. sp., Tegula (Chlorostoma) matanzensis n. sp., Tegula (Agathistoma) antiqua n. sp., Bathybembix mcleani n. sp., Gibbula poeppigii [Philippi, 1887] n. comb., Diloma miocenica n. sp., Fagnastesia venefica [Philippi, 1887] n. gen. n. comb., Fagnastesia matanzana n. gen. n. sp., Calliostoma mapucherum n. sp., Calliostoma kleppi n. sp., Calliostoma covacevichi n. sp., Astele laevis [Sowerby, 1846] n. comb., and Monilea riorapelensis n. sp. The Neritidae are represented by Nerita (Heminerita) chilensis [Philippi, 1887]. The new genus Fagnastesia is introduced to represent low-spired trochoideans with a sculpture of nodes below the suture, angulated whorls, and a wide umbilicus. This Miocene Chilean fauna includes genera that have lived at the coast and in shallow, relatively warm water or deeper, much cooler water. This composition therefore suggests that many of the Miocene formations along the central Chilean coast consist of displaced sediments. A comparison with different fossil and Recent faunas from around the Pacific and South America indicates that the vetigastropod and neritid fauna from the Miocene of Chile has only minor affinities with taxa living near New Zealand, Argentina, and the tropical eastern Pacific at that time.

  2. Joseph Conrad: International Narrator

    ERIC Educational Resources Information Center

    Walker, George

    2004-01-01

    This article discusses the contribution made by Joseph Conrad's fictional writing to our understanding of cultural awareness. Never comfortable with his adopted English culture, Conrad used his experiences in different parts of the world during his career in the merchant navy to explore in his writing aspects of cultural dissonance and cultural…

  3. Conrad Unfurls Flag

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Apollo 12 astronaut Charles 'Pete' Conrad stands beside the United States flag after is was unfurled on the lunar surface during the first extravehicular activity (EVA-1), on November 19, 1969. Several footprints made by the crew can be seen in the photograph.

  4. CONRAD Software Architecture

    NASA Astrophysics Data System (ADS)

    Guzman, J. C.; Bennett, T.

    2008-08-01

    The Convergent Radio Astronomy Demonstrator (CONRAD) is a collaboration between the computing teams of two SKA pathfinder instruments, MeerKAT (South Africa) and ASKAP (Australia). Our goal is to produce the required common software to operate, process and store the data from the two instruments. Both instruments are synthesis arrays composed of a large number of antennas (40 - 100) operating at centimeter wavelengths with wide-field capabilities. Key challenges are the processing of high volume of data in real-time as well as the remote mode of operations. Here we present the software architecture for CONRAD. Our design approach is to maximize the use of open solutions and third-party software widely deployed in commercial applications, such as SNMP and LDAP, and to utilize modern web-based technologies for the user interfaces, such as AJAX.

  5. Conrad Gessner's Paratexts.

    PubMed

    Blair, Ann

    2016-01-01

    Throughout his prolific publishing career Conrad Gessner composed abundant paratexts which offer valuable insight into his methods of working. Gessner wrote many dedications, only a minority of which were addressed to major patrons of his day. Instead he used them to thank dozens of physicians and scholars for sending him information, images, and manuscripts for his ongoing projects. Gessner acknowledged new arrivals in successive publications and invited further contributions explicitly. In "to the readers" and other passages Gessner called attention to his future publication plans and his skill in working with printers and in editing manuscripts of recently deceased scholars, thereby also encouraging new commissions. Gessner was also a master indexer and innovated especially in drawing up the first index of authors cited for his edition of Stobaeus in 1543 and a new all-purpose index in his Stobaeus of 1549. Many other aspects of Gessner's paratexts warrant further study. PMID:27349033

  6. Joseph Conrad's tormented Rescue (fantasy).

    PubMed

    Freedman, William

    2014-02-01

    Joseph Conrad was a notoriously tormented writer for whom the creative act was often a punishment severe enough to drive him into paralyzing depressions that delayed the completion of his novels, sometimes for years. By far the most agonizing of these projects was The Rescue, a novel he began in 1898, abandoned a year later, tried unsuccessfully to continue several times over the next two decades, but was only able to resume in 1918 and to complete, after another tortured two-year struggle, in 1920. An explanation for this incapacity, that is powerfully suggested by the novel's evocative title and perhaps unintentionally ironic subtitle (A Romance of the Shallows) has not yet been explored. Using Freud's 1910 essay on the rescue fantasy, "Contributions to the Psychology of Love: A Special Type of Choice of Object Made by Men," and Emanuel Berman's instructive revision and expansion of the concept in his 2003 American Imago essay, "Ferenczi, Rescue, and Utopia," I argue that a substantial explanation for Conrad's tormented history with The Rescue is ascribable to its quite remarkably faithful treatment of a rescue fantasy with deep and disabling resonance for its author. More specifically, the difficulty was compounded by the novel's dramatization of the soul-crushing conflict between two such fantasies: one in the service of the masculine ideal of unflinching dedication to a heroic purpose, the other promising satisfaction to the equally potent demands of emotional and sexual desire. Features of Conrad's narrative fit so tightly and consistently with the theory as Freud (and Abraham) proposed and as Berman elaborated it that The Rescue offers itself as one of those rare and reinforcing instances wherein the literary text seems to validate the psychoanalytic theory at least as persuasively as the theory "understands" the text. PMID:24555549

  7. Conrad: gene prediction using conditional random fields.

    PubMed

    DeCaprio, David; Vinson, Jade P; Pearson, Matthew D; Montgomery, Philip; Doherty, Matthew; Galagan, James E

    2007-09-01

    We present Conrad, the first comparative gene predictor based on semi-Markov conditional random fields (SMCRFs). Unlike the best standalone gene predictors, which are based on generalized hidden Markov models (GHMMs) and trained by maximum likelihood, Conrad is discriminatively trained to maximize annotation accuracy. In addition, unlike the best annotation pipelines, which rely on heuristic and ad hoc decision rules to combine standalone gene predictors with additional information such as ESTs and protein homology, Conrad encodes all sources of information as features and treats all features equally in the training and inference algorithms. Conrad outperforms the best standalone gene predictors in cross-validation and whole chromosome testing on two fungi with vastly different gene structures. The performance improvement arises from the SMCRF's discriminative training methods and their ability to easily incorporate diverse types of information by encoding them as feature functions. On Cryptococcus neoformans, configuring Conrad to reproduce the predictions of a two-species phylo-GHMM closely matches the performance of Twinscan. Enabling discriminative training increases performance, and adding new feature functions further increases performance, achieving a level of accuracy that is unprecedented for this organism. Similar results are obtained on Aspergillus nidulans comparing Conrad versus Fgenesh. SMCRFs are a promising framework for gene prediction because of their highly modular nature, simplifying the process of designing and testing potential indicators of gene structure. Conrad's implementation of SMCRFs advances the state of the art in gene prediction in fungi and provides a robust platform for both current application and future research. PMID:17690204

  8. Astronaut Charles Conrad using the bicycle ergometer

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., Skylab 2 commander, during an exercise session on the bicycle ergometer in the crew quarters of the Skylab Orbital Workshop (OWS) in the Skylab 2 space station cluster in Earth orbit.

  9. Conrad Hal Waddington: the last Renaissance biologist?

    PubMed

    Slack, Jonathan M W

    2002-11-01

    Conrad Hal Waddington was a leading embryologist and geneticist from the 1930s to the 1950s. He is remembered mainly for his concepts of the 'epigenetic landscape' and 'genetic assimilation'. This article reviews his life and work, and enquires to what extent his ideas are relevant tools for understanding the biological problems of today. PMID:12415319

  10. The British Novel: Conrad to the Present.

    ERIC Educational Resources Information Center

    Wiley, Paul L.

    Intended for advanced undergraduate and graduate students who desire a useful research tool, this bibliography cites the works of and about British novelists, beginning with Joseph Conrad and terminating in 1950. The listings are selective with proper emphasis given to less celebrated but distinctive writers. A preface explaining the numerous…

  11. Astronauts Weitz and Conrad suit up during prelaunch activity

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Paul J. Weitz, prime crew pilot of the first manned Skylab mission, is suited up in bldg 5 at JSC during prelaunch training activity. He is assisted by Astronaut Charles Conrad Jr., prime crew commander. The man in the left background is wearing a face mask to insure that Conrad, Joseph Kerwin, and Weitz are not exposed to disease prior to launch.

  12. CONRAD Evaluation Code: Development Status and Perspectives

    NASA Astrophysics Data System (ADS)

    Archier, P.; De Saint Jean, C.; Litaize, O.; Noguère, G.; Berge, L.; Privas, E.; Tamagno, P.

    2014-04-01

    CONRAD is an object-oriented code developed at CEA Cadarache since 2005 to treat issues occurring during the data assimilation process. The last new features of the code in terms of experimental, theoretical and interface aspects are presented in this paper. The experimental descriptions capabilities have been enhanced thanks to the implementation of both analytical (Chi-Square, Gaussian) and Monte-Carlo resolution functions which are required for neutron resonance shape analysis. On the theoretical aspects, efforts have been focused on the fast energy region with the wrapping of the ECIS and TALYS codes and the management of optical model and statistical parameters. These new features make it possible for CONRAD to currently perform evaluations from 0 to 20 MeV. Concerning the interfacing developments, a multigroup cross-sections generating tool and an ENDF parser have been recently improved to produce multigroup cross-section covariance matrices in the frame of the JEFF project. Several examples and comparisons with other codes (SAMMY, REFIT) are provided to validate each development.

  13. Neutron tomography instrument CONRAD at HZB

    NASA Astrophysics Data System (ADS)

    Kardjilov, N.; Hilger, A.; Manke, I.; Strobl, M.; Dawson, M.; Williams, S.; Banhart, J.

    2011-09-01

    The neutron tomography instrument CONRAD has been in operation since 2005 at the Hahn-Meitner research reactor at Helmholtz-Zentrum Berlin (HZB). Over the last 5 years, significant developmental work has been performed to expand the radiographic and tomographic capabilities of the beamline [1-3]. New techniques have been implemented, including imaging with polarized neutrons [4-9], Bragg-edge mapping [10,11], high-resolution neutron imaging and grating interferometry [12-15]. These methods have been provided to the user community as tools to help address scientific problems over a broad range of topics such as superconductivity, materials research, life sciences [16,17], cultural heritage and paleontology [18,19]. Industrial applications including fuel cell research [20-27] have also been improved through these new developments. Descriptions and parameters of the developed options will be presented, along with prominent examples.

  14. Astronaut Conrad tweaks Astronaut Cooper's beard for the cameramen

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Charles Conrad Jr. tweaks Astronaut L. Gordon Cooper's eight-day growth of beard for the cameramen while onboard the prime recovery vessel after their Gemini 5 flight. The NASA Headquarter alternative photo number is 65-H-680.

  15. ["Trema, apophany, apocalypse"--is Conrad's phase model empirically founded?].

    PubMed

    Hambrecht, M; Häfner, H

    1993-12-01

    Among several phase models of beginning schizophrenia, the study by Conrad ("Die beginnende Schizophrenie. Versuch einer Gestaltanalyse des Wahns") was particularly impressive in German psychiatry. The ABC-Schizophrenia-study with its representative sample of 267 first-admissions and a careful retrospective assessment of emerging symptomatology made it possible to test the empirical basis of Conrad's model. In this operationalization "trema" was confirmed as the frequent first stage of the disease process, whereas Conrad's hypothesized order of the two following phrases (first "apophany", then "apocalypse") could not be validated. Therefore, Conrad's model cannot completely be generalized. Because the methods employed so far have some limitations, analyses of additional data (especially reports by significant others) may control and probably enhance the presented results. PMID:8112705

  16. Astronaut Charles Conrad checks out Human Vestibular Function experiment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, checks out the Human Vestibular Function, Experiment M131, during Skylab training at JSC. Conrad is in the work and experiments compartment of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC. The reference sphere with a magnetic rod is used by the astronaut to indicate body orientation non-visually. The litter chair in which he is seated can be rotated by a motor at its base or, when not being rotated, can tilt forward, backward or to either side.

  17. Astronaut Charles Conrad following exercise session on bicycle ergometer

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, wipes perspiration from his face following an exercise session on the bicycle ergometer during Skylab training at JSC. Conrad is in the work and experiments compartment of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC. In addition to being the prime exercise for the crewmen, the ergometer is also used for the vector-cardiogram test and the metabolic activity experiment. The bicycle ergometer produces measured work loads for use in determining man's metabolic effectiveness.

  18. APOLLO 12: C.Conrad Jr. collects geological samples

    NASA Technical Reports Server (NTRS)

    1974-01-01

    APOLLO 12: 'Pete' Conrad collects samples from the lunar surface, while at the same time adjusting to, and remarking on, the working conditions. From the film documentary 'APOLLO 12: 'Pinpoint for Science'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLLO 12: Second manned lunar landing and return with Charles 'Pete' Conrad, Jr., Richard F. Gordon, and Alan F. Bean. Landed in the Ocean of Storms on November 19, 1969; deployed television camera and ALSEP experiments; two EVA's performed; collected core samples and lunar materials; photographed and retrieved parts from surveyor 3 spacecraft. Mission duration 244hrs 36min 24sec

  19. Astronaut Charles Conrad during visual acuity experiments over Laredo

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Charles Conrad Jr., pilot for the prime crew on the Gemini 5 space flight, takes pictures of predetermined land areas during visual acuity experiments over Laredo, Texas. The experiments will aid in learning to identify known terrestrial features under controlled conditions.

  20. Astronauts Cooper and Conrad prepare cameras during visual acuity tests

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts L. Gordon Cooper Jr. (left), command pilot, and Charles Conrad Jr., pilot, the prime crew of the Gemini 5 space flight, prepare their cameras while aboard a C-130 aircraft flying near Laredo. The two astronauts are taking part in a series of visual acuity experiments to aid them in learning to identify known terrestrial features under controlled conditions.

  1. Astronauts Conrad and Kerwin practice Human Vestibular Function experiment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, checks out the Human Vestibular Function, Experiment M131, during Skylab training at JSC. Scientist-Astronaut Joseph P. Kerwin, science pilot of the mission, goes over a checklist. The two men are in the work and experiments compartment of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC.

  2. Astronauts Conrad and Gordon demonstrate tethering procedures for news media

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts Charles Conrad (left), command pilot, and Richard F. Gordon (right), pilot, demonstrate tether procedure between their Gemini 11 spacecraft and the Agena Target Docking Vehicle at the post flight press conference. They use models of their spacecraft and its Agena to illustrate maneuvers.

  3. Astronauts Conrad and Gordon demonstrate tethering procedures for news media

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts Charles Conrad (center), command pilot, and Richard F. Gordon (right), pilot, demonstrate tether procedure between their Gemini 11 spacecraft and the Agena Target Docking Vehicle at the post flight press conference. They use models of their spacecraft and its Agena to illustrate maneuvers. At left is George Low, Deputy Director, Manned Spacecraft Center, Houston.

  4. The origins of Michael Conrad's research programs (1964-1979).

    PubMed

    Pattee, H H

    2002-01-01

    This paper summarizes Michael Conrad's academic and professional career from the time he began his Ph.D. studies in 1964 to his appointment at Wayne State University in 1979. It describes the origins of several of his major research interests and presents a personal evaluation of how this early work continues to be of fundamental importance. PMID:11755483

  5. Astronaut Charles Conrad trims hair of Astronaut Paul Weitz

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., Skylab 2 commander, trims the hair of Astronaut Paul J. Weitz, Skylab 2 pilot, during the 28-day Skylab 2 mission in Earth orbit. They are in the crew quarters wardroom of the Orbital Workshop of the Skylab 1 and 2 space station. Weitz is holding a vacuum hose in his right hand. This picture was taken by Scientist-Astronaut Joseph P. Kerwin, Skylab 2 science pilot.

  6. Astronaut Joseph Kerwin takes blood sample from Astronaut Charles Conrad

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Scientist-Astronaut Joseph P. Kerwin (right), Skylab 2 science pilot and a doctor of medicine, takes a blood sample from Astronaut Charles Conrad Jr., Sylab 2 commander, as seen in this reproduction taken from a color television transmission made by a TV camera aboard the Skylab 1 and 2 space station cluster in Earth orbit. The blood sampling was part of the Skylab Hematology and Immunology Experiment M110 series.

  7. Joseph Conrad's Empathy for Exploited Africans in "The Heart of Darkness."

    ERIC Educational Resources Information Center

    Farley, Ena L.

    1990-01-01

    Seemingly contradictory positions of J. Conrad as both a racist and an opponent of race-based imperial practices are discussed with reference to "The Heart of Darkness." It is argued that Conrad made a conscious effort to shake off the racial theories of the time and to deplore imperial racism. (SLD)

  8. Astronauts Alan Bean and Charles Conrad on Lunar Surface

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn Five launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Their lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. In this photograph, one of the astronauts on the Moon's surface is holding a container of lunar soil. The other astronaut is seen reflected in his helmet. Apollo 12 safely returned to Earth on November 24, 1969.

  9. Skylab beverage container filled with orange juice held by Astronaut Conrad

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An accordian-style beverage dispenser filled with orange juice is held by Astronaut Charles Conrad Jr., Skylab 2 commander, in this close-up view which is a reproduction taken from a color television transmission made by a TV camera aboard the Skylab 1 and 2 space station cluster in Earth orbit. Conrad (head and face not in view) is seated at the wardroom table in the crew quarters of the Orbital Workshop. The dispenser contained beverage crystals, and Conrad has just added the prescribed amount of water to make the orange drink.

  10. Recent Developments in the CONRAD Code regarding Experimental Corrections

    NASA Astrophysics Data System (ADS)

    Archier, P.; De Saint Jean, C.; Kopecky, S.; Litaize, O.; Noguère, G.; Schillebeeckx, P.; Volev, K.

    2013-03-01

    The CONRAD code is an object-oriented software tool developed at CEA Cadarache since 2005 to deal with problems arising during the evaluation process (data assimilation and analysis, physical modelling, propagation of uncertainties…). This paper will present recent developments concerning the experimental corrections, which are required when a neutron resonance shape analysis is performed. Several experimental aspects are detailed in this work: the possibility to use spectra in energy as well as in time, the implementation of both analytical (Chi-Square) and Monte-Carlo resolution functions, the sample homogeneity corrections using log-normal distributions. Each development aspect is illustrated with several examples and comparisons with other resonance analysis codes (SAMMY, REFIT).

  11. The CONRAD approach to biokinetic modeling of DTPA decorporation therapy.

    PubMed

    Breustedt, Bastian; Blanchardon, Eric; Bérard, Philippe; Fritsch, Paul; Giussani, Augusto; Lopez, Maria Antonia; Luciani, Andrea; Nosske, Dietmar; Piechowski, Jean; Schimmelpfeng, Jutta; Sérandour, Anne-Laure

    2010-10-01

    Diethylene Triamine Pentaacetic Acid (DTPA) is used for decorporation of plutonium because it is known to be able to enhance its urinary excretion for several days after treatment by forming stable Pu-DTPA complexes. The decorporation prevents accumulation in organs and results in a dosimetric benefit, which is difficult to quantify from bioassay data using existing models. The development of a biokinetic model describing the mechanisms of actinide decorporation by administration of DTPA was initiated as a task in the European COordinated Network on RAdiation Dosimetry (CONRAD). The systemic biokinetic model from Leggett et al. and the biokinetic model for DTPA compounds of International Commission on Radiological Protection Publication 53 were the starting points. A new model for biokinetics of administered DTPA based on physiological interpretation of 14C-labeled DTPA studies from literature was proposed by the group. Plutonium and DTPA biokinetics were modeled separately. The systems were connected by means of a second order kinetics process describing the chelation process of plutonium atoms and DTPA molecules to Pu-DTPA complexes. It was assumed that chelation only occurs in the blood and in systemic compartment ST0 (representing rapid turnover soft tissues), and that Pu-DTPA complexes and administered forms of DTPA share the same biokinetic behavior. First applications of the CONRAD approach showed that the enhancement of plutonium urinary excretion after administration of DTPA was strongly influenced by the chelation rate constant. Setting it to a high value resulted in a good fit to the observed data. However, the model was not yet satisfactory since the effects of repeated DTPA administration in a short time period cannot be predicted in a realistic way. In order to introduce more physiological knowledge into the model several questions still have to be answered. Further detailed studies of human contamination cases and experimental data will be needed in

  12. Gemini 11 Commander Conrad and Pilot Gordon at post flight press conference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Gemini 11 Commander Charles Conrad, Jr (left) and Pilot Richard F. Gordon, Jr describe mission activities during their post flight press conference at JSC. Gordon at the microphone talks about the extravehicular activity (EVA) photo projected behind the two crewmembers. During the EVA Gordon attached a tether to the Agena and retrieved a nuclear emulsion experiment package.

  13. Astronauts Conrad and Cooper slice cake on U.S.S. Lake Champlain

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts Charles Conrad Jr. (left) and L. Gordon Cooper Jr. prepate to slice into the huge cake prepared for them by the cooks onboard the aircraft carrier U.S.S. Lake Champlain. They are using ornamental Navy swords for knives.

  14. Holocene polar front migrations over the Conrad Rise in the Indian sector of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Ikehara, M.; Katsuki, K.; Yokoyama, Y.; Yamane, M.; Khim, B.

    2011-12-01

    The Southern Ocean has played a significant role in the global climate system during the geologic past. In order to understand the paleoceanographic variations with the polar front system and Antarctic Circumpolar Current (ACC), we conducted two cruises KH-07-4 and KH-10-7 in the Indian sector of the Southern Ocean. Two piston cores were collected from the Conrad Rise. We examined centennial-scale changes of diatom assemblages and stable isotopic ratios in planktic foraminifera during the Holocene in a high-accumulation-rate sediment core from the Conrad Rise. Although abundances of dominant diatom taxa (Fragilariopsis kerguelensis and Thalassiothrix antarctica) are comparatively constant, relative abundances of secondary taxa fluctuate. Before ca 9900 cal. yr BP, winter sea-ice and cold water covered the Conrad Rise. Following deglaciation the sea-ice retreated from the Conrad Rise. The Polar Front moved southward during the early Holocene optimum and north Antarctic Zone waters covered the Conrad Rise for about 650 yr. After 9300 cal. yr BP, solar insolation strongly influenced sea surface temperature and primary productivity in the Southern Ocean. In the high-latitude Indian Sector, productivity increased 1500 yr after the onset of late Holocene neoglaciation. Periodic δ18O and cold-water diatom taxa spikes (at intervals of 200 and 300-500 yr, respectively) occurred after 9300 cal. yr BP, probably associated with solar activity. Fluctuations in short-term sea surface temperature and cold-water taxa are synchronous with changes in dD observed in an east Antarctic ice core.

  15. Being a Stranger and the Strangeness of Being: Joseph Conrad's "The Secret Sharer" as an Allegory of Being in Education

    ERIC Educational Resources Information Center

    Schwieler, Elias

    2013-01-01

    Joseph Conrad's "The Secret Sharer" has often been associated with what can be called initiation stories. However, in this article I argue that Conrad's text is more than that. It can, I suggest, be read as an allegory of the inaccessibility to reveal the essence of being in command, being in education, and also the…

  16. Polarized neutron imaging at the CONRAD instrument at Helmholtz Centre Berlin

    NASA Astrophysics Data System (ADS)

    Manke, Ingo; Kardjilov, Nikolay; Hilger, André; Strobl, Markus; Dawson, Martin; Banhart, John

    2009-06-01

    Neutrons are highly sensitive to magnetic fields because of their intrinsic magnetic moment. At the same time, their zero net electrical charge allows them to penetrate thick layers of matter. In combination with standard radiographic and tomographic imaging techniques, these properties have been exploited to visualize magnetic fields in free space and within the bulk of solid, massive, opaque samples. In this paper, the basic principle of this new technique and its realization at the CONRAD instrument at the Helmholtz Centre Berlin (formerly Hahn-Meitner Institute Berlin) are explained. Two application examples will be given: the visualization of the magnetic field around a permanent magnet and the investigation of the displacement of the current density from the core of a conductor to the surface (the skin effect).

  17. Circulation of images and graphic practices in Renaissance natural history: the example of Conrad Gessner.

    PubMed

    Egmond, Florike; Kusukawa, Sachiko

    2016-01-01

    Conrad Gessner's Historia animalium is a compilation of information from a variety of sources: friends, correspondents, books, broadsides, drawings, as well as his own experience. The recent discovery of a cache of drawings at Amsterdam originally belonging to Gessner has added a new dimension for research into the role of images in Gessner's study of nature. In this paper, we examine the drawings that were the basis of the images in the volume of fishes. We uncovered several cases where there were multiple copies of the same drawing of a fish (rather than multiple drawings of the samefish), which problematizes the notion of unique "original" copies and their copies. While we still know very little about the actual mechanism of, or people involved in, commissioning or generating copies of drawings, their very existence suggests that the images functioned as an important medium in the circulation of knowledge in the early modern period. PMID:27349032

  18. The mitochondrial genome of Pomacea maculata (Gastropoda: Ampullariidae).

    PubMed

    Yang, Qianqian; Liu, Suwen; Song, Fan; Li, Hu; Liu, Jinpeng; Liu, Guangfu; Yu, Xiaoping

    2016-07-01

    The golden apple snail, Pomacea maculata Perry, 1810 (Gastropoda: Ampullariidae) is one of the most serious invasive alien species from the native range of South America. The mitochondrial genome of P. maculata (15 516 bp) consists of 37 genes (13 protein-coding genes, two rRNAs, and 22 tRNAs) and a non-coding region with a 16 bp repeat unit. Most mitochondrial genes of P. maculata are distributed on the H-strand, except eight tRNA genes, which are encoded on the L-strand. A phylogenetic analysis showed that there was a close relationship between P. maculata and another invasive golden apple snail species, Pomacea canaliculata (Lamarck, 1822). PMID:26099974

  19. Subsurface temporal variation of radon at the Conrad Geophysical Observatory, Austria

    NASA Astrophysics Data System (ADS)

    Leonhardt, Roman; Steinitz, Gideon; Piatibratova, Oksana

    2015-04-01

    The Conrad Observatory (COBS) housed the national geophysical observatory of Austria and is located 50 km south west of Vienna within the carbonate sequence of the "Wettersteinkalk". Parameters monitored at the facility comprise environmental data, seismic signals, gravity, geomagnetic components and also natural gamma rays. A subsurface tunnel, 150 meters long and oriented E-W is driven into the calcareous sequence at a depth of 50 meters. The tunnel is lined with a concrete carapace, ~20 cm thick. The tunnel observatory is separated from the external atmosphere by 3 tight doors, resulting in a stable temperature of 6.85±0.04°C. A gamma detector (3×3", NaI, SCA) is used measure the variation of the gamma radiation from radon in the air of the tunnel, at a resolution of 1 minute, which is accumulated to form a 15-minute count rate. The sensor is placed on a concrete block at 135 meters. Several SSNTD measurements in the tunnel indicated radon level in the level of 1.5 kBq/m^3. The background gamma radiation, due probably mainly to sources in the concrete is in the order to 2×105 counts (per 15-minutes). A long term variation of radon is reflected as an annual radon signal with large amplitude (2×105 counts) and a maximum in summer. Small to large (2×105 counts) non periodic multi-day signals lasting from two to several tens of days are superimposed. Daily periodic signals of much lower amplitude are observed, with amplitudes generally up to 4×104 counts. The amplitude of the non-periodic multi-day is coupled to amplitude of the annual signal, and the amplitude of the periodic daily signal is modulated by the multi-day variation. The source of the radon in the air of the tunnel is from the concrete lining the floor and walls of the tunnel. The variation patterns and their systematic characteristics cannot be ascribed to local variations of pressure and temperature (stable). These limitations indicate that other driver(s), external to the tunnel, are forcing

  20. Descriptions of three new species of Mitridae (Mollusca: Gastropoda) from South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Baoquan; Zhang, Suping; Li, Xinzheng

    2005-03-01

    Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANg, Neocancilla daidaleosa sp. nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.

  1. Gravity Variations Induced by Changing Snowpack Observed at Conrad Observatory (Austria)

    NASA Astrophysics Data System (ADS)

    Ressl, Hans; Dorninger, Manfred; Meurers, Bruno

    2016-04-01

    Hydrological processes are usually associated with mass transport. This induces gravity variations observed by superconducting gravimeter (SG) masking the pure geodynamical signal. The present study focusses specifically on gravity variations due to snow accumulation and melting. Measurements of the gravity signal are taken from the SG GWR C025 located at the Conrad Observatory (Austria) in an underground laboratory at about 1000m altitude. In snow rich winters a snowpack of one meter in depth or even more can be observed at this location. Snow height is measured at three different locations to get an idea of its variability. At one place additionally the weight of the snow pack is determined which allows to calculate the snow water equivalent. Gravitational signals are rather different for the accumulation and ablation phase, not only due to the different time scales of these processes but also due to the complex way path of melting water entering the ground beneath of the SG. Two methods, rainfall admittance function and Bouguer reduction, are used to account for the effect of the snow pack. Both have their strengths and weaknesses. They work better for short-term mass transports than for long lasting ones because in the latter case interference with signals of other environmental processes gets more prominent. A few case studies including both accumulation and ablation of snow on different time scales will be discussed.

  2. The new cold neutron radiography and tomography instrument CONRAD at HMI Berlin

    NASA Astrophysics Data System (ADS)

    Hilger, A.; Kardjilov, N.; Strobl, M.; Treimer, W.; Banhart, J.

    2006-11-01

    The new cold neutron radiography instrument CONRAD is a multifunctional facility for radiography and tomography with cold neutrons at Hahn-Meitner Institut, Berlin. It is located at the end of a curved neutron guide, which faces the cold-neutron source of the BER-II research reactor. The geometry provides a cold-neutron beam with wavelengths between 2 and 12 Å. Two measuring positions are available for radiography and tomography investigations. The first one is placed at the end of the guide and it is optimized for in situ experiments in which a high neutron flux is required. The available flux at this position is approximately 10 8 cm -2 s -1. The second measuring position uses a pin-hole geometry which allows better beam collimation ( L/ D up to 1000) and higher image resolution in the range of 200 μm in the CCD based detector system (10×10 cm 2). The use of cold neutrons for radiography purposes increases the image contrast and improves the sensibility e.g., the detection of small amounts of water and hydrogen-containing materials in metal matrixes. On the other hand the cold-neutron beam can be modified easily by using diffraction and neutron optical techniques. This enables to perform radiography and tomography experiments with more sophisticated measuring techniques. Recent examples of research and industrial applications will be presented.

  3. COMPARISON OF AQUEOUS AND SOLID-PHASE UPTAKE FOR HEXACHLOROBENZENE IN THE TELLINID CLAM MACOMA NASUTA (CONRAD): A MASS BALANCE APPROACH

    EPA Science Inventory

    The uptake of sediment-associated hexachlorobenzene (HCB) by the deposit-feeding clam Macoma nasuta (Conrad) was determined using a clam ventilation chamber. lams were exposed to [14C]HCB-dosed sediment, and the 14C amounts were measured in inhalant and exhalant waters, fecal pel...

  4. Rigorous noise test and calibration check of strong-motion instrumentation at the Conrad Observatory in Austria.

    NASA Astrophysics Data System (ADS)

    Steiner, R.; Costa, G.; Lenhardt, W.; Horn, N.; Suhadolc, P.

    2012-04-01

    In the framework of the European InterregIV Italy/Austria project: "HAREIA - Historical and Recent Earthquakes in Italy and Austria" the Central Institute for Meteorology and Geodynamics (ZAMG) and Mathematic and Geosciences Department of University of Trieste (DMG) are upgrading the transfrontier seismic network of South-Eastern Alps with new 12 accelerometric stations to enhance the strong motion instrument density near the Austria/Italy border. Various public institutions of the provinces Alto Adige (Bolzano Province), Veneto (ARPAV) and Friuli Venezia Giulia (Regional Civil Defense) in Italy and in the Austrian province of Tyrol are involved in the project. The site selection was carried out to improve the present local network geometry thus meeting the needs of public Institutions in the involved regions. In Tyrol and Alto Adige some strategic buildings (hospitals and public buildings) have been selected, whereas in Veneto and Friuli Venezia Giulia the sites are in the free field, mainly located near villages. The instruments will be installed in an innovative box, designed by ZAMG, that provides electric and water isolation. The common choice regarding the instrument selection has been the new Kinemetrics Basalt ® accelerograph to guarantee homogeneity with the already installed instrumentation and compatibility with the software already in use at the different seismic institutions in the area. Prior to deployment the equipment was tested at the Conrad Observatory and a common set-up has been devised. The Conrad Observatory, seismically particularly quiet, permits to analyze both the sensor and the acquisition system noise. The instruments were connected to the network and the data sent in real-time to the ZAMG data center in Vienna and the DMG data center in Trieste. The data have been collected in the database and analyzed using signal processing modules PQLX and Matlab. The data analysis of the recordings at the ultra-quiet Conrad Observatory pointed out

  5. Generation of 238U Covariance Matrices by Using the Integral Data Assimilation Technique of the CONRAD Code

    NASA Astrophysics Data System (ADS)

    Privas, E.; Archier, P.; Bernard, D.; De Saint Jean, C.; Destouche, C.; Leconte, P.; Noguère, G.; Peneliau, Y.; Capote, R.

    2016-02-01

    A new IAEA Coordinated Research Project (CRP) aims to test, validate and improve the IRDF library. Among the isotopes of interest, the modelisation of the 238U capture and fission cross sections represents a challenging task. A new description of the 238U neutrons induced reactions in the fast energy range is within progress in the frame of an IAEA evaluation consortium. The Nuclear Data group of Cadarache participates in this effort utilizing the 238U spectral indices measurements and Post Irradiated Experiments (PIE) carried out in the fast reactors MASURCA (CEA Cadarache) and PHENIX (CEA Marcoule). Such a collection of experimental results provides reliable integral information on the (n,γ) and (n,f) cross sections. This paper presents the Integral Data Assimilation (IDA) technique of the CONRAD code used to propagate the uncertainties of the integral data on the 238U cross sections of interest for dosimetry applications.

  6. The epigenetic landscape in the course of time: Conrad Hal Waddington's methodological impact on the life sciences.

    PubMed

    Baedke, Jan

    2013-12-01

    It seems that the reception of Conrad Hal Waddington's work never really gathered speed in mainstream biology. This paper, offering a transdisciplinary survey of approaches using his epigenetic landscape images, argues that (i) Waddington's legacy is much broader than is usually recognized--it is widespread across the life sciences (e.g. stem cell biology, developmental psychology and cultural anthropology). In addition, I will show that (ii) there exist as yet unrecognized heuristic roles, especially in model building and theory formation, which Waddington's images play within his work. These different methodological facets envisioned by Waddington are used as a natural framework to analyze and classify the manners of usage of epigenetic landscape images in post-Waddingtonian 'landscape approaches'. This evaluation of Waddington's pictorial legacy reveals that there are highly diverse lines of traditions in the life sciences, which are deeply rooted in Waddington's methodological work. PMID:23932231

  7. Bathymetric distribution patterns of Southern Ocean macrofaunal taxa: Bivalvia, Gastropoda, Isopoda and Polychaeta

    NASA Astrophysics Data System (ADS)

    Brandt, Angelika; Linse, Katrin; Schüller, Myriam

    2009-11-01

    The aim of this study is to compare the depth distributions of four major Southern Ocean macrobenthic epi- and infaunal taxa, the Bivalvia, Gastropoda, Isopoda, and Polychaeta, from subtidal to abyssal depth. All literature data up to summer 2008, as well as the unpublished data from the most recent ANDEEP I-III (Antarctic benthic deep-sea biodiversity: colonisation history and recent community patterns) expeditions to the Southern Ocean deep sea are included in the analysis. Benthic invertebrates in the Southern Ocean are known for their wide bathymetric ranges. We analysed the distributions of four of the most abundant and species-rich taxa from intertidal to abyssal (5200 m) depths in depth zones of 100 m. The depth distributions of three macrofaunal classes (Bivalvia, Gastropoda, Polychaeta) and one order (Isopoda) showed distinct differences. In the case of bivalves, gastropods and polychaetes, the number of species per depth zone decreased from the shelf to the slope at around 1000 m depth and then showed stable low numbers. The isopods showed the opposite trend; they were less species rich in the upper 1000 m but increased in species numbers from the slope to bathyal and abyssal depths. Depth ranges of families of the studied taxa (Bivalvia: 31 families, Gastropoda: 60, Isopoda: 32, and Polychaeta: 46 families) were compiled and illustrated. At present vast areas of the deep sea in the Southern Ocean remain unexplored and species accumulation curves showed that only a fraction of the species have been discovered to date. We anticipate that further investigations will greatly increase the number of species known in the Southern Ocean deep sea.

  8. Vertical density contrast and mapping of basement, Conrad and Moho morphologies through 2D spectral analysis of gravity data in and around Odisha, India

    NASA Astrophysics Data System (ADS)

    Kumar, Arbind; S. Roy, P. N.; Das, L. K.

    2016-07-01

    Power spectrum analysis of Complete Bouguer Anomaly (CBA) map of Eastern Ghat Mobile Belt (EGMB) and its surroundings in India through Two Dimensional (2D) spectral analysis has provided estimates of the ensemble average depths for the density discontinuities which represent crustal inhomogeneities. The spectral analysis method has helped to estimate the depths of a perturbing body sources which are obtained from the negative slopes of the linear relationship between the logarithmic power spectrum and the wave-numbers of the gravity field. The detailed analysis reveals three horizontal discontinuities (i) Phanerozoic sediment thickness (ii) Basement depth and (iii) Conrad discontinuity. The average thickness of Phanerozoic sediments is estimated to be 3 km whereas depth of basement and Conrad discontinuity are at 7 km and 14.5 km respectively. Additionally Mohorovicic discontinuity also estimated at a depth of 32.8 km in the study region.

  9. Pyramided QTL underlying tolerance to Phytophthora root rot in mega-environments from soybean cultivars 'Conrad' and 'Hefeng 25'.

    PubMed

    Li, Xiuping; Han, Yingpeng; Teng, Weili; Zhang, Shuzheng; Yu, Kangfu; Poysa, Vaino; Anderson, Terry; Ding, Junjie; Li, Wenbin

    2010-08-01

    Phytophthora root rot (PRR) of soybean (Glycine max (L.) Merr.) is the second most important cause of yield loss by disease in North America, surpassed only by soybean cyst nematode (Wrather et al. in Can J Plant Pathol 23:115-121, 2001). Tolerance can provide economically useful disease control, conditioning partial resistance of soybean to PRR. The aims of this study were to identify new quantitative trait loci (QTL) underlying tolerance to PRR, and to evaluate the effects of pyramided or stacked loci on the level of tolerance. A North American cultivar 'Conrad' (tolerant to PRR) was crossed with a northeastern China cultivar 'Hefeng 25' (tolerant to PRR). Through single-seed descent, 140 F2:5 and F2:6 recombinant inbred lines were advanced. A total of 164 simple sequence repeat (SSR) markers were used to construct a genetic linkage map. The percentage of seedling death was measured over 2 years (2007 and 2008) in the field at four naturally infested locations in Canada and China following additional soil infestation and in the greenhouse following inoculation with Phytophthora sojae isolate. A total of eight QTL underlying tolerance to PRR were identified, located in five linkage groups (F, D1b+w, A2, B1, and C2). The phenotypic variation contributed by the loci ranged from 4.24 to 27.98%. QPRR-1 (anchored in the interval of SSR markers Satt325 and Satt343 of LG F), QPRR-2 (anchored in the interval of Satt005 and Satt600 of LG D1b+w), and QPRR-3 (anchored in the interval of Satt579 and Sat_089 of LG D1b+w) derived their beneficial allele from 'Conrad'. They were located at chromosomal locations known to underlie PRR tolerance in diverse germplasm. Five QTL that derived beneficial alleles from 'Hefeng 25' were identified. The QTL (QPRR-1 to QPRR-7) that were detected across at least three environments were selected for loci stacking and to analyze the relationship between number of tolerance loci and disease loss percentage. The accumulation of tolerance loci was

  10. Original molluscan radula: comparisons among Aplacophora, Polyplacophora, Gastropoda, and the Cambrian fossil Wiwaxia corrugata.

    PubMed

    Scheltema, Amélie H; Kerth, Klaus; Kuzirian, Alan M

    2003-08-01

    As the original molluscan radula is not known from direct observation, we consider what the form of the original radula may have been from evidence provided by neomenioid Aplacophora (Solenogastres), Gastropoda, Polyplacophora, and the Cambrian fossil Wiwaxia corrugata (Matthews). Conclusions are based on direct observation of radula morphology and its accessory structures (salivary gland ducts, radular sac, anteroventral radular pocket) in 25 species and 16 genera of Aplacophora; radula morphogenesis in Aplacophora; earliest tooth formation in Gastropoda (14 species among Prosobranchia, Opisthobranchia, and Pulmonata); earliest tooth formation in four species of Polyplacophora; and the morphology of the feeding apparatus in W. corrugata. The existence of a true radula membrane and of membranoblasts and odontoblasts in neomenioids indicates that morphogenesis of the aplacophoran radula is homologous to that in other radulate Mollusca. We conclude from p redness of salivary gland ducts, a divided radular sac, and a pair of anteroventral pockets that the plesiomorphic state in neomenioids is bipartite, formed of denticulate bars that are distichous (two teeth per row) on a partially divided or fused radula membrane with the largest denticles lateral, as occurs in the genus Helicoradomenia. The tooth morphology in Helicoradomenia is similar to the feeding apparatus in W. corrugata. We show that distichy also occurs during early development in several species of gastropods and polyplacophorans. Through the rejection of the null hypothesis that the earliest radula was unipartite and had no radula membrane, we conclude that the original molluscan radula was similar to the radula found in Helicoradomena species. PMID:12833382

  11. From sea to land and beyond – New insights into the evolution of euthyneuran Gastropoda (Mollusca)

    PubMed Central

    2008-01-01

    Background The Euthyneura are considered to be the most successful and diverse group of Gastropoda. Phylogenetically, they are riven with controversy. Previous morphology-based phylogenetic studies have been greatly hampered by rampant parallelism in morphological characters or by incomplete taxon sampling. Based on sequences of nuclear 18S rRNA and 28S rRNA as well as mitochondrial 16S rRNA and COI DNA from 56 taxa, we reconstructed the phylogeny of Euthyneura utilising Maximum Likelihood and Bayesian inference methods. The evolution of colonization of freshwater and terrestrial habitats by pulmonate Euthyneura, considered crucial in the evolution of this group of Gastropoda, is reconstructed with Bayesian approaches. Results We found several well supported clades within Euthyneura, however, we could not confirm the traditional classification, since Pulmonata are paraphyletic and Opistobranchia are either polyphyletic or paraphyletic with several clades clearly distinguishable. Sacoglossa appear separately from the rest of the Opisthobranchia as sister taxon to basal Pulmonata. Within Pulmonata, Basommatophora are paraphyletic and Hygrophila and Eupulmonata form monophyletic clades. Pyramidelloidea are placed within Euthyneura rendering the Euthyneura paraphyletic. Conclusion Based on the current phylogeny, it can be proposed for the first time that invasion of freshwater by Pulmonata is a unique evolutionary event and has taken place directly from the marine environment via an aquatic pathway. The origin of colonisation of terrestrial habitats is seeded in marginal zones and has probably occurred via estuaries or semi-terrestrial habitats such as mangroves. PMID:18294406

  12. Migration of the Antarctic Circumpolar Current in the Late Neogene: reconstruction from sediment wave on the Conrad Rise, Indian Sector of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Oiwane, H.; Ikehara, M.; Suganuma, Y.; Nakamura, Y.; Nogi, Y.; Miura, H.; Sato, T.

    2012-12-01

    ACC is the largest and strongest ocean current in the world. It is important for the interoceanic exchange of water, exchange of gases to the atmosphere, and thermal isolation of the Antarctic continent. Fluctuation of the ACC has been reconstructed from several methods such as microfossils, anisotropy of magnetic susceptibilities, and statistical analysis of Ice-Rafted Debris. On the other hand, sediment waves are investigated and interpreted to reconstruct the fluctuation of the bottom- and contour currents. In this study, we tried reconstructing the ACC using sediment waves based on multidisciplinary survey on the Conrad Rise in the Indian sector of the Southern Ocean. The Conrad Rise is a topographic high that is elevated ca. 3000 m from the ocean floor. We conducted multibeam bathymetry, seismic reflection, and sediment coring on the southwestern slope of the rise. Seismic units on the Conrad Rise are divided into three units, A, B, and C in descending order. Unit A shows transparent to low amplitude with sediment wave structure. Sediment waves don't show systematic changes of its dimension and thickness. Sedimentary core showed that the surface sediment is composed of diatom ooze. Unit B shows higher amplitude than that of unit A, and shows planar, parallel configuration. Unit C has high-amplitude reflectors at its top and shows chaotic facies below. Based on morphological characteristics of the sediment waves, oceanographic setting of the Conrad Rise, and components of the surface sediment, it is most likely that the sedimentary structure and component of the Unit A is significantly constrained by the ACC. On the other hand, the Unit B shows planar configuration suggesting deposition without current effect. Additionally, higher amplitude suggests different component form that of the Unit A. These a series of evidence represent difference of sedimentary environment between units A and B, especially on the point of the influence of the ACC. Accordingly, onset

  13. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    González-Tizón, Ana M.; Rojo, Verónica; Vierna, Joaquín; Jensen, K. Thomas; Egea, Emilie; Martínez-Lage, Andrés

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linné 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  14. Use of axonal projection patterns for the homologisation of cerebral nerves in Opisthobranchia, Mollusca and Gastropoda

    PubMed Central

    2013-01-01

    Introduction Gastropoda are guided by several sensory organs in the head region, referred to as cephalic sensory organs (CSOs). These CSOs are innervated by distinct nerves. This study proposes a unified terminology for the cerebral nerves and the categories of CSOs and then investigates the neuroanatomy and cellular innervation patterns of these cerebral nerves, in order to homologise them. The homologisation of the cerebral nerves in conjunction with other data, e.g. ontogenetic development or functional morphology, may then provide insights into the homology of the CSOs themselves. Results Nickel-lysine axonal tracing (“backfilling”) was used to stain the somata projecting into specific nerves in representatives of opisthobranch Gastropoda. Tracing patterns revealed the occurrence, size and relative position of somata and their axons and enabled these somata to be mapped to specific cell clusters. Assignment of cells to clusters followed a conservative approach based primarily on relative location of the cells. Each of the four investigated cerebral nerves could be uniquely identified due to a characteristic set of soma clusters projecting into the respective nerves via their axonal pathways. Conclusions As the described tracing patterns are highly conserved morphological characters, they can be used to homologise nerves within the investigated group of gastropods. The combination of adequate number of replicates and a comparative approach allows us to provide preliminary hypotheses on homologies for the cerebral nerves. Based on the hypotheses regarding cerebral nerve homology together with further data on ultrastructure and immunohistochemistry of CSOs published elsewhere, we can propose preliminary hypotheses regarding homology for the CSOs of the Opisthobranchia themselves. PMID:23597272

  15. With a little help from DNA barcoding: investigating the diversity of Gastropoda from the Portuguese coast.

    PubMed

    Borges, Luísa M S; Hollatz, Claudia; Lobo, Jorge; Cunha, Ana M; Vilela, Ana P; Calado, Gonçalo; Coelho, Rita; Costa, Ana C; Ferreira, Maria S G; Costa, Maria H; Costa, Filipe O

    2016-01-01

    The Gastropoda is one of the best studied classes of marine invertebrates. Yet, most species have been delimited based on morphology only. The application of DNA barcodes has shown to be greatly useful to help delimiting species. Therefore, sequences of the cytochrome c oxidase I gene from 108 specimens of 34 morpho-species were used to investigate the molecular diversity within the gastropods from the Portuguese coast. To the above dataset, we added available COI-5P sequences of taxonomically close species, in a total of 58 morpho-species examined. There was a good match between ours and sequences from independent studies, in public repositories. We found 32 concordant (91.4%) out of the 35 Barcode Index Numbers (BINs) generated from our sequences. The application of a ranking system to the barcodes yield over 70% with top taxonomic congruence, while 14.2% of the species barcodes had insufficient data. In the majority of the cases, there was a good concordance between morphological identification and DNA barcodes. Nonetheless, the discordance between morphological and molecular data is a reminder that even the comparatively well-known European marine gastropods can benefit from being probed using the DNA barcode approach. Discordant cases should be reviewed with more integrative studies. PMID:26876495

  16. Neuromuscular development in Patellogastropoda (Mollusca: Gastropoda) and its importance for reconstructing ancestral gastropod bodyplan features

    PubMed Central

    Kristof, Alen; de Oliveira, André Luiz; Kolbin, Konstantin G.; Wanninger, Andreas

    2015-01-01

    Within Gastropoda, limpets (Patellogastropoda) are considered the most basal branching taxon and its representatives are thus crucial for research into evolutionary questions. Here, we describe the development of the neuromuscular system in Lottia cf. kogamogai. In trochophore larvae, first serotonin-like immunoreactivity (lir) appears in the apical organ and in the prototroch nerve ring. The arrangement and number of serotonin-lir cells in the apical organ (three flask-shaped, two round cells) are strikingly similar to those in putatively derived gastropods. First, FMRFamide-lir appears in veliger larvae in the Anlagen of the future adult nervous system including the cerebral and pedal ganglia. As in other gastropods, the larvae of this limpet show one main and one accessory retractor as well as a pedal retractor and a prototroch muscle ring. Of these, only the pedal retractor persists until after metamorphosis and is part of the adult shell musculature. We found a hitherto undescribed, paired muscle that inserts at the base of the foot and runs towards the base of the tentacles. An apical organ with flask-shaped cells, one main and one accessory retractor muscle is commonly found among gastropod larvae and thus might have been part of the last common ancestor. PMID:26869747

  17. The complete mitochondrial genome of the mudsnail Cipangopaludina cathayensis (Gastropoda: Viviparidae).

    PubMed

    Yang, Huirong; Zhang, Jia-En; Luo, Hao; Luo, Mingzhu; Guo, Jing; Deng, Zhixin; Zhao, Benliang

    2016-05-01

    We present the complete mitochondrial genome of Cipangopaludina cathayensis in this study. The mitochondrial genome is 17,157 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes. All of them are encoded on the heavy strand except 7 tRNA genes on the light strand. Overall nucleotide compositions of the light strand are 44.51% of A, 26.74% of T, 20.48% of C and 8.28% of G. All the protein-coding genes start with ATG initiation codon except ATP6 with ATA and ND4 with TTG, and 2 types of termination codons are TAA (ATP6, ND2, COX1, COX2, ATP8, ND1, ND6, Cytb, COX3, ND4) and TAG (ND4L, ND5, ND3). There are 29 intergenic spacers and 5 gene overlaps. The tandem repeat sequences are observed in COX2, tRNA(Asp), ATP6, tRNA(Cys), S-rRNA, ND1, Cytb, ND4 and COX3 genes. Gene arrangement and distribution are different from the typical vertebrates. The absence of D-loop is consistent with the Gastropoda, but at least one lengthy non-coding region is essential regulatory element for the initiation of transcription and replication. PMID:25319293

  18. Nanoindentations on conch shells of Gastropoda and Bivalvia molluscs reveal anisotropic evolution against external attacks.

    PubMed

    Bignardi, Cristina; Petraroli, Michele; Pugno, Nicola M

    2010-10-01

    Nanoindentation method has been used to explore, at the nanoscale, the mechanical properties of four different representative types of conch shells belonging to the two biggest classes of molluscs, Gastropoda and Bivalvia, in order to compare nanohardness and Young's modulus with respect to the microstructural anisotropic architectures. For the experimental tests a Nano Indenter XP (MTS Nano Instruments, Oak Ridge TN) has been used. The mechanical tests have been carried out on the inner and outer surfaces of the shells, as well as on their cross-section, near to the inner/outer surfaces and in the middle layer. The results confirm the three layered anisotropic architecture of the investigated conchs. On each of these 5 surfaces, 2 x 5 indentations have been performed at different maximum depth: from 250 nm to 4 microm, with a step of 250 nm, for a total of 3200 tests. The numerous observations have been analysed applying an ad hoc modification of the Weibull Statistics, suggesting a natural evolution of the shells against external attacks. PMID:21137746

  19. Relationships within Cladobranchia (Gastropoda: Nudibranchia) based on RNA-Seq data: an initial investigation

    PubMed Central

    Goodheart, Jessica A.; Bazinet, Adam L.; Collins, Allen G.; Cummings, Michael P.

    2015-01-01

    Cladobranchia (Gastropoda: Nudibranchia) is a diverse (approx. 1000 species) but understudied group of sea slug molluscs. In order to fully comprehend the diversity of nudibranchs and the evolution of character traits within Cladobranchia, a solid understanding of evolutionary relationships is necessary. To date, only two direct attempts have been made to understand the evolutionary relationships within Cladobranchia, neither of which resulted in well-supported phylogenetic hypotheses. In addition to these studies, several others have addressed some of the relationships within this clade while investigating the evolutionary history of more inclusive groups (Nudibranchia and Euthyneura). However, all of the resulting phylogenetic hypotheses contain conflicting topologies within Cladobranchia. In this study, we address some of these long-standing issues regarding the evolutionary history of Cladobranchia using RNA-Seq data (transcriptomes). We sequenced 16 transcriptomes and combined these with four transcriptomes from the NCBI Sequence Read Archive. Transcript assembly using Trinity and orthology determination using HaMStR yielded 839 orthologous groups for analysis. These data provide a well-supported and almost fully resolved phylogenetic hypothesis for Cladobranchia. Our results support the monophyly of Cladobranchia and the sub-clade Aeolidida, but reject the monophyly of Dendronotida. PMID:26473045

  20. Feeding clusters and olfaction in the mangrove snail Terebralia palustris (Linnaeus) (Potamididae: Gastropoda).

    PubMed

    Fratini, S; Cannicci, S; Vannini, M

    2001-07-01

    Large numbers of the snail Terebralia palustris (Linnaeus) (Potamididae; Gastropoda) are frequently observed feeding in a cluster on a single fallen mangrove leaf, yet none are present on leaves nearby. Consequently, we investigated the food-finding ability of T. palustris in a Kenyan mangrove forest using field experiments. We estimated the attractive effect of different cues and analysed the paths (video-recorded) of snails when approaching a food-related odour. This intertidal snail can potentially use both air-borne and water-borne odours to locate food. T. palustris is attracted to conspecifics feeding on leaves, while intact leaves as well as non-feeding snails are not attractive. Moreover, the guiding stimulus appears to be compounds released when the leaves are damaged.T. palustris also seems able to discriminate between different food items; it is more strongly attracted to green mangrove leaves than senescent or fallen ones or mangrove propagules, probably because green leaves release a greater amount of attractive cues.Feeding snails thus recruit more snails to feed on the same leaf. The ecological implications of this behaviour are discussed: a large number of snails on the same leaf counteracts the ability of crabs to remove the leaf being eaten by the snails. PMID:11399273

  1. With a little help from DNA barcoding: investigating the diversity of Gastropoda from the Portuguese coast

    PubMed Central

    Borges, Luísa M. S.; Hollatz, Claudia; Lobo, Jorge; Cunha, Ana M.; Vilela, Ana P.; Calado, Gonçalo; Coelho, Rita; Costa, Ana C.; Ferreira, Maria S. G.; Costa, Maria H.; Costa, Filipe O.

    2016-01-01

    The Gastropoda is one of the best studied classes of marine invertebrates. Yet, most species have been delimited based on morphology only. The application of DNA barcodes has shown to be greatly useful to help delimiting species. Therefore, sequences of the cytochrome c oxidase I gene from 108 specimens of 34 morpho-species were used to investigate the molecular diversity within the gastropods from the Portuguese coast. To the above dataset, we added available COI-5P sequences of taxonomically close species, in a total of 58 morpho-species examined. There was a good match between ours and sequences from independent studies, in public repositories. We found 32 concordant (91.4%) out of the 35 Barcode Index Numbers (BINs) generated from our sequences. The application of a ranking system to the barcodes yield over 70% with top taxonomic congruence, while 14.2% of the species barcodes had insufficient data. In the majority of the cases, there was a good concordance between morphological identification and DNA barcodes. Nonetheless, the discordance between morphological and molecular data is a reminder that even the comparatively well-known European marine gastropods can benefit from being probed using the DNA barcode approach. Discordant cases should be reviewed with more integrative studies. PMID:26876495

  2. The long way to diversity--phylogeny and evolution of the Heterobranchia (Mollusca: Gastropoda).

    PubMed

    Dinapoli, Angela; Klussmann-Kolb, Annette

    2010-04-01

    Heterobranchia are one of the most species rich groups within Gastropoda, with poorly resolved phylogenetic relationships especially in basal taxa. In order to resolve phylogenetic relationships within the Heterobranchia, we pursued a molecular systematic approach by sequencing and analysing a variety of genetic markers (including nuclear 28S rDNA+18S rDNA and mitochondrial 16S rDNA+COI sequences). Maximum likelihood as well as Bayesian inference methods were used for phylogenetic reconstruction. Moreover, data quality was estimated for the purpose of proving the plausibility of the novel phylogenetic hypothesis using a variety of statistical tests as well as network analyses. Finally, a case study was conducted in order to estimate divergence ages using a "relaxed" molecular clock approach with fossils as minimum age constraints. All phylogenetic analyses revealed the Heterobranchia as monophyletic. Within the Heterobranchia, several well supported clades could be resolved. However, the traditional classification based on morphological data could not be confirmed due to paraphyletic Euthyneura as well as paraphyletic Pulmonata and polyphyletic Opisthobranchia. The estimation of data quality yielded a high degree of substitution saturation in many of the nucleotide positions while the Relative-Rate-Test revealed the highest evolution rates within the "Lower Heterobranchia". Although the dataset shows much conflict, many of the proposed hypotheses are supported by splits of the network analysis. The molecular clock approach was able to confirm some evolutionary hypotheses based on fossils such as the late occurrence of Pulmonata and Stylommatophora, respectively, during the Mesozoic. However, large 95% highest posterior density (HPD) intervals at some of the nodes made a precise dating of these nodes difficult. This molecular phylogenetic investigation provides the most comprehensive molecular study of relationships within the Heterobranchia to date. Due to the

  3. The complete mitochondrial genome of the nudibranch Roboastra europaea (Mollusca: Gastropoda) supports the monophyly of opisthobranchs.

    PubMed

    Grande, Cristina; Templado, José; Cervera, J Lucas; Zardoya, Rafael

    2002-10-01

    The complete nucleotide sequence (14,472 bp) of the mitochondrial genome of the nudibranch Roboastra europaea (Gastropoda: Opisthobranchia) was determined. This highly compact mitochondrial genome is nearly identical in gene organization to that found in opisthobranchs and pulmonates (Euthyneura) but not to that in prosobranchs (a paraphyletic group including the most basal lineages of gastropods). The newly determined mitochondrial genome differs only in the relative position of the trnC gene when compared with the mitochondrial genome of Pupa strigosa, the only opisthobranch mitochondrial genome sequenced so far. Pupa and Roboastra represent the most basal and derived lineages of opisthobranchs, respectively, and their mitochondrial genomes are more similar in sequence when compared with those of pulmonates. All phylogenetic analyses (maximum parsimony, minimum evolution, maximum likelihood, and Bayesian) based on the deduced amino acid sequences of all mitochondrial protein-coding genes supported the monophyly of opisthobranchs. These results are in agreement with the classical view that recognizes Opisthobranchia as a natural group and contradict recent phylogenetic studies of the group based on shorter sequence data sets. The monophyly of opisthobranchs was further confirmed when a fragment of 2,500 nucleotides including the mitochondrial cox1, rrnL, nad6, and nad5 genes was analyzed in several species representing five different orders of opisthobranchs with all common methods of phylogenetic inference. Within opisthobranchs, the polyphyly of cephalaspideans and the monophyly of nudibranchs were recovered. The evolution of mitochondrial tRNA rearrangements was analyzed using the cox1+rrnL+nad6+nad5 gene phylogeny. The relative position of the trnP gene between the trnA and nad6 genes was found to be a synapomorphy of opisthobranchs that supports their monophyly. PMID:12270894

  4. Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia).

    PubMed

    Newcomb, James M; Sakurai, Akira; Lillvis, Joshua L; Gunaratne, Charuni A; Katz, Paul S

    2012-06-26

    How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left-right body flexions (LR) and rhythmic dorsal-ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

  5. Comparison of broad band time series recorded parallel by FGI type interferometric water level and Lippmann type pendulum tilt meters at Conrad observatory, Austria

    NASA Astrophysics Data System (ADS)

    Ruotsalainen, Hannu; Papp, Gabor; Leonhardt, Roman; Ban, Dora; Szücs, Eszter; Benedek, Judith

    2016-04-01

    The Finnish Geodetic Institute (FGI) the progenitor of Finnish Geospatial Research Institute of NLS designed and built a 5.5m long prototype of interferometric water level tiltmeter (iWT) in early 2014. Geodetic and Geophysical Institute (GGI), Sopron, Hungary bought the instrument and started tilt measurement in August 2014 at the Conrad observatory (COBS), Austria to monitor geodynamical phenomena like microseisms, free oscillations of the Earth, earth tides, mass loading effects and crustal deformations in cooperation with Austrian Central Institute for Meteorology and Geodynamics (ZAMG) and the FGI. On the July 16 2015 a Lippmann-type 2D tilt sensor (LTS) was also installed by GGI on the 6 m long pier where iWT was set up previously. This situation opens a possibility to do broad band (from secular to seismic variations up to 15 Hz) geophysical signal analysis comparing the responses of long (several meters) and short (a few decimeters) base instruments implementing different physical principles (relative height change of a level surface and inclination change of the plumb line). The characteristics of the sensors are studied by the evaluation of the spectra of recorded signals dominated by microseisms. The iWT has internal interferometric calibration and it can be compared to Lippmanns tilt meter one. Both instruments show good long term ( > 1 day) stability when earth tides and ocean and air mass loading tilts are modelled.

  6. A new freshwater snail genus (Hydrobiidae, Gastropoda) from Montenegro, with a discussion on gastropod diversity and endemism in Skadar Lake

    PubMed Central

    Pešić, Vladimir; Glöer, Peter

    2013-01-01

    Abstract Karucia sublacustrina a new species of freshwater snails (Hydrobiidae, Gastropoda) is described based on material collected from Skadar Lake (Montenegro, Albania). The new species belongs to monotypic genus Karucia gen. n. The shell morphology and body shape of the new genus resembles Radomaniola Szarowska, 2006 and Grossuana Radoman, 1973, from which it differs in the larger shells with relatively slim and a slightly, but clearly shouldered body whorl. The number of gastropods from Skadar Lake basin tallies now 50 species. The adjusted rate of gastropod endemicity for Skadar Lake basin is estimated to be 38%. By compiling faunal and taxonomic data we also aim to provide information of relevance as to conservation efforts. PMID:23794834

  7. Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia)

    NASA Astrophysics Data System (ADS)

    Kapan, Sevinç; Kabasakal, Sinem

    2016-04-01

    Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia) Sevinç KAPAN, Sinem KABASAKAL, Çanakkale Onsekiz Mart University, Engineering Faculty, Geological Engineering Department sevinckapan_yesilyurt@hotmail.com In this study, paleontology and stratigraphy of Neogene and Quaternary units around south of the Dardanelles have been examined using Gastropoda and Bivalvia fauna. In the investigation area, the base of the sediments that belongs to Neogene, consist of the volcanics which are formed with basalts, andesites and tuff. Neogene begins unconformity with basal conglomerate which are formed with basalt and tuff gravels. The measurable thickness of the Neogene sediments is approximately 200meters in total. First fossiliferius level which consist of Lymnocardium (Euxinicardium) nobile Sabba has showed similarities with the Pontian (Late Miocene) fauna of the Eastern Paratethys. The existence of Melanopsis and Psidium species indicate that the basin has been brackish water feeding by fresh water in the Early Pliocene. Theodoxus fluviatilis (Linne), Theodoxus (Calvertia) aff. imbricata Brusina, Theodoxus (Calvertia) licherdopoli scriptus (Stefanescu), Viviparus mammatus (Stefanescu), Valvata (Valavata) sulekiana Brusina, Valvata (Cincinna) crusitensis Fontannes, Hydrobia cf grandis Cobalcescu, Hydrobia ventrosa Monfort, Melanopsis (Melanopsis) cf. bergeroni Stefanescu, , Melanopsis (Melanopsis) sandbergeri rumana Tournouer, Melanopsis (Canthidomus) hybostoma anili Taner, Melanopsis (Canthidomus) hybostoma amaradica Fontannes, Melanopsis (Canthidomus) lanceolata Neumayr, Amphimelania fossariformis (Tournouer), Melanoides tuberculata monolithica (Bukowski), Radix (Radix) peregra (Müller), Planorbarius thiollierei (Michaud), Potamida (Potamida) craiovensis craiovensis (Tournouer), Potamida (Potamida) berbestiensis (Fontannes), Unio pristinus davilai Porumbaru, Unio subexquisitus Jatzko, Anadonta zmaji

  8. Phylogenetic relationships among Opisthobranchia (Mollusca: Gastropoda) based on mitochondrial cox 1, trnV, and rrnL genes.

    PubMed

    Grande, Cristina; Templado, Josè; Cervera, J Lucas; Zardoya, Rafael

    2004-11-01

    We reconstructed the phylogenetic relationships among 37 species representing seven main lineages within Opisthobranchia (Mollusca: Gastropoda) based on a mitochondrial fragment that included partial cox 1, complete trnV, and partial rrnL genes (about 2500 bp). Phylogenetic analyses confirmed tentatively that all studied main opisthobranch lineages conformed monophyletic groups except Nudibranchia. The sacoglossan Ascobulla was placed as the most basal lineage of opisthobranchs. The basommatophoran pulmonate Siphonaria was recovered within Opisthobranchia between Ascobulla and the remaining opisthobranchs. The latter were divided into two different lineages that await formal description: on one side, Cephalaspidea, Tylodinoidea, and Anaspidea (sharing features in the reproductive, digestive, and circulatory systems) were grouped together and, on the other Architectibranchia and Nudipleura (sharing similarities in the circulatory system) were recovered as sister group taxa. Two well-supported clades were recovered within Nudipleura: Pleuroanthobranchia (new taxon) and Cladobranchia. Pleuroanthobranchia (Pleurobranchoidea plus Anthobranchia) was defined by the presence of blood gland, the presence of calcareous spicules in the integument and the presence of a caecum with an opening directly into the stomach. The new molecular phylogeny provided a robust framework for comparative studies, and prompted a revision of the morphological synapomorphies diagnosing the main clades within opisthobranchs. PMID:15336672

  9. Assessing metal contamination from construction and demolition (C&D) waste used to infill wetlands: using Deroceras reticulatum (Mollusca: Gastropoda).

    PubMed

    Staunton, John A; Mc Donnell, Rory J; Gormally, Michael J; Williams, Chris D; Henry, Tiernan; Morrison, Liam

    2014-11-01

    Large quantities of construction and demolition waste (C&D) are produced globally every year, with little known about potential environmental impacts. In the present study, the slug, Deroceras reticulatum (Mollusca: Gastropoda) was used as the first biomonitor of metals (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Ti, Tl, V and Zn) on wetlands post infilling with construction and demolition (C&D) waste. The bioaccumulation of As, Ba, Cd, Co, Sb, Se and Tl were found to be significantly elevated in slugs collected on C&D waste when compared to unimproved pastures (control sites), while Mo, Se and Sr had significantly higher concentrations in slugs collected on C&D waste when compared to known contaminated sites (mining locations), indicating the potential hazardous nature of C&D waste to biota. Identifying exact sources for these metals within the waste can be problematic, due to its heterogenic nature. Biomonitors are a useful tool for future monitoring and impact studies, facilitating policy makers and regulations in other countries regarding C&D waste infill. In addition, improving separation of C&D waste to allow increased reuse and recycling is likely to be effective in reducing the volume of waste being used as infill, subsequently decreasing potential metal contamination. PMID:25298023

  10. Algivore or Phototroph? Plakobranchus ocellatus (Gastropoda) Continuously Acquires Kleptoplasts and Nutrition from Multiple Algal Species in Nature

    PubMed Central

    Maeda, Taro; Hirose, Euichi; Chikaraishi, Yoshito; Kawato, Masaru; Takishita, Kiyotaka; Yoshida, Takao; Verbruggen, Heroen; Tanaka, Jiro; Shimamura, Shigeru; Takaki, Yoshihiro; Tsuchiya, Masashi; Iwai, Kenji; Maruyama, Tadashi

    2012-01-01

    The sea slug Plakobranchus ocellatus (Sacoglossa, Gastropoda) retains photosynthetically active chloroplasts from ingested algae (functional kleptoplasts) in the epithelial cells of its digestive gland for up to 10 months. While its feeding behavior has not been observed in natural habitats, two hypotheses have been proposed: 1) adult P. ocellatus uses kleptoplasts to obtain photosynthates and nutritionally behaves as a photoautotroph without replenishing the kleptoplasts; or 2) it behaves as a mixotroph (photoautotroph and herbivorous consumer) and replenishes kleptoplasts continually or periodically. To address the question of which hypothesis is more likely, we examined the source algae for kleptoplasts and temporal changes in kleptoplast composition and nutritional contribution. By characterizing the temporal diversity of P. ocellatus kleptoplasts using rbcL sequences, we found that P. ocellatus harvests kleptoplasts from at least 8 different siphonous green algal species, that kleptoplasts from more than one species are present in each individual sea slug, and that the kleptoplast composition differs temporally. These results suggest that wild P. ocellatus often feed on multiple species of siphonous algae from which they continually obtain fresh chloroplasts. By estimating the trophic position of wild and starved P. ocellatus using the stable nitrogen isotopic composition of amino acids, we showed that despite the abundance of kleptoplasts, their photosynthates do not contribute greatly to the nutrition of wild P. ocellatus, but that kleptoplast photosynthates form a significant source of nutrition for starved sea slugs. The herbivorous nature of wild P. ocellatus is consistent with insights from molecular analyses indicating that kleptoplasts are frequently replenished from ingested algae, leading to the conclusion that natural populations of P. ocellatus do not rely on photosynthesis but mainly on the digestion of ingested algae. PMID:22848693

  11. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae)

    PubMed Central

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M.; Sun, Zhenyu J.; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O.; Falcão, Rosana; Cherobim, Mariana D.; Dias, Simoni C.; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L.; Otero-González, Anselmo J.

    2015-01-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.—López-Abarrategui, C., McBeth, C., Mandal, S. M., Sun, Z. J., Heffron, G., Alba-Menéndez, A., Migliolo, L., Reyes-Acosta, O., García-Villarino, M., Nolasco, D. O., Falcão, R., Cherobim, M. D., Dias, S. C., Brandt, W., Wessjohann, L., Starnbach, M., Franco, O. L., Otero-González, A. J. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae). PMID:25921828

  12. Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species.

    PubMed

    Fallon, Phillip J Jr

    2016-01-01

    A review of the literature and examination of over 3,200 specimens of shallow water (<200 m) tropical western Atlantic (TWA) Drilliidae Olson, 1964 in museum and private collections has resulted in the recognition of numerous previously undescribed species, 100 of which are proposed here for the first time. A total of 65 names were found in the literature. Of these, 48 are considered valid, 16 synonyms, and one nomen dubium. In addition, characteristics that distinguish each genus currently in use for TWA shallow water species have indicated the need for reassignment (new combinations within Drilliidae) of 15 species. Some nomenclatural actions have come about from the literature review and include one taxon placed in junior synonymy (under an older name recently re-discovered) and one new name for a junior homonym. Two neotypes, five lectotype designations, and one new name are also proposed. Altogether, nomenclatural actions on 17% of valid previously described taxa are proposed. The 100 proposed names are placed in 12 available and one new genus: Agladrillia Woodring, 1928 (2), Bellaspira Conrad, 1868 (7), Calliclava McLean, 1971 (3), Cerodrillia Bartsch & Rehder, 1939 (11), Clathrodrillia Dall, 1918 (6), Decoradrillia, new genus (4), Douglassia Bartsch, 1934 (4), Fenimorea Bartsch, 1934 (15), Leptadrillia Woodring, 1928 (12), Lissodrillia Bartsch & Rehder, 1939 (8), Neodrillia Bartsch, 1943 (2), Splendrillia Hedley, 1922 (13), and Syntomodrillia Woodring, 1928 (13). These are the first reports of Calliclava in the western Atlantic, previously known only from the eastern Pacific. The new genus, Decoradrillia, is proposed to hold four new species and one existing that share a unique shell microsculpture and other morphological traits. One genus, Drillia Gray, 1838, is not currently believed to have TWA representatives. Three genera comprised exclusively of bathyal species are not treated in this work: Clavus Monfort, 1810 (=Eldridgea Bartsch, 1934), Globidrillia

  13. The Cylindrobulla/Ascobulla complex--unraveling problems in identification and adding to Cylindrobulla diversity (Gastropoda, Heterobranchia, Sacoglossa) by describing a new species.

    PubMed

    Laetz, Elise; Christa, Gregor; Händeler, Katharina; Wägele, Heike

    2014-01-01

    Sacoglossa (Gastropoda: Heterobranchia) are generally considered a monophyletic group, previously associated within the now defunct "Opisthobranchia", but now basally located within Panpulmonata. In the light of this new phylogenetic hypothesis, detailed knowledge of the most basal groups within Sacoglossa is of paramount importance. This study focuses on the genus Cylindrobulla, which is usually considered the most basal group within the Sacoglossa from a morphological point of view, because it does not share the typical elongate radula teeth of all other Sacoglossa. We describe a new species, Cylindrobulla schuppi sp. nov., and provide data on its food. We reexamined and clarify the radula of the type species C. beauii, review the genus with all other valid species, provide new characters to aid in the proper identification of species within this genus, compare it to the very similar genus Ascobulla, present a determination key using external characters to ensure proper identification of the two similar genera, and discuss phylogenetic relationships within the shelled sacoglossan, the Oxynoacea. PMID:25544526

  14. Incorporated nematocysts in Aeolidiella stephanieae (Gastropoda, Opisthobranchia, Aeolidoidea) mature by acidification shown by the pH sensitive fluorescing alkaloid Ageladine A.

    PubMed

    Obermann, Dana; Bickmeyer, Ulf; Wägele, Heike

    2012-11-01

    The sequestration of nematocysts (a special group of cnidocysts) from cnidarian prey with subsequent use in defence is described for few metazoan phyla. Members of the taxon Aeolidoidea (Nudibranchia, Gastropoda) are well-known for this. Questions regarding the reasons some nematocysts do not discharge when the gastropod feeds and how these same nematocysts can be transported along the digestive tract into specialized morphological structures called cnidosacs, remain unanswered. Within the cnidosac, nematocysts are incorporated in cells and finally be used for defence against predators. The most plausible explanation for this phenomenon suggests there are immature and therefore non-functional nematocysts in the food. A recent study by Berking and Herrmann (2005) on cnidarians suggested that the nematocysts mature by acidification via proton transfer into the nematocyst capsule. According to this hypothesis only immature nematocysts are transported into the cnidosac where they are then made functional through an accumulation of protons. In this study we present a fluorescence staining method that tests the hypothesis by Berking and Herrmann (2005) and detects changes in the pH values of incorporated nematocysts, interpreted as changes in maturation stages. This marker, the fluorescent dye Ageladine A, stains nematocyst capsules according to their pH values. With Ageladine A we were able to show that kleptocnides indeed change their pH value after incorporation into the aeolidoidean cnidosac. PMID:22910369

  15. A new approach to an old conundrum--DNA barcoding sheds new light on phenotypic plasticity and morphological stasis in microsnails (Gastropoda, Pulmonata, Carychiidae).

    PubMed

    Weigand, Alexander M; Jochum, Adrienne; Pfenninger, Markus; Steinke, Dirk; Klussmann-Kolb, Annette

    2011-03-01

    The identification of microsnail taxa based on morphological characters is often a time-consuming and inconclusive process. Aspects such as morphological stasis and phenotypic plasticity further complicate their taxonomic designation. In this study, we demonstrate that the application of DNA barcoding can alleviate these problems within the Carychiidae (Gastropoda, Pulmonata). These microsnails are a taxon of the pulmonate lineage and most likely migrated onto land independently of the Stylommatophora clade. Their taxonomical classification is currently based on conchological and anatomical characters only. Despite much confusion about historic species assignments, the Carychiidae can be unambiguously subdivided into two taxa: (i) Zospeum species, which are restricted to karst caves, and (ii) Carychium species, which occur in a broad range of environmental conditions. The implementation of discrete molecular data (COI marker) enabled us to correctly designate 90% of the carychiid microsnails. The remaining cases were probably cryptic Zospeum and Carychium taxa and incipient species, which require further investigation into their species status. Because conventional reliance upon mostly continuous (i.e. nondiscrete) conchological characters is subject to fallibility for many gastropod species assignments, we highly recommend the use of DNA barcoding as a taxonomic, cutting-edge method for delimiting microsnail taxa. PMID:21429131

  16. An integrative taxonomic investigation of the diversity of digenean parasites infecting the intertidal snail Austrolittorina unifasciata Gray, 1826 (Gastropoda: Littorinidae) in Australia.

    PubMed

    O'Dwyer, Katie; Faltýnková, Anna; Georgieva, Simona; Kostadinova, Aneta

    2015-06-01

    We investigated for the first time the digenean parasites of Austrolittorina unifasciata Gray (Gastropoda: Littorinidae), a periwinkle snail inhabiting the rocky shores of Australia. Here we present detailed morphological descriptions and molecular data (sequences for the mitochondrial cox1 and the nuclear 28S rRNA gene) for the cercariae and intramolluscan stages of the digenean parasites found. Five species, one each of the families Notocotylidae Lühe, 1909, Gorgocephalidae Manter, 1966 and Philophthalmidae Looss, 1899, and two of the family Renicolidae Dollfus, 1939, were recorded and characterised molecularly. Phylogenetic analyses at the superfamily level provided evidence for the familial and generic affiliation of the species and their relationships with congeners. This study is the first to provide data on the life cycle of a species of the family Gorgocephalidae, a parasite of kyphosid fish for which only adult stages had, thus far, been described. The relatively high prevalence of this species allowed mapping of the cox1 haplotype distribution of Gorgocephalus sp. Aus along the southern coast of New South Wales. PMID:25866083

  17. An annotated catalogue and bibliography of the taxonomy, synonymy and distribution of the Recent Vetigastropoda of South Africa (Mollusca).

    PubMed

    Herbert, David G

    2015-01-01

    A complete inventory of the known Recent vetigastropod fauna of South Africa is provided. Bibliographic citations to works discussing the taxonomy, synonymy and distribution of the species in a southern African or south-western Indian Ocean context are provided. Additional explanatory notes are given where pertinent. New genus records for South Africa: Acremodontina B.A. Marshall, 1995; Choristella Bush, 1879; Cocculinella Thiele, 1909; Conjectura Finlay, 1926; Crosseola Iredale, 1924; Falsimargarita Powell, 1951; Lepetella Verrill, 1880; Profundisepta McLean & Geiger, 1998; Stomatella Lamarck, 1816; Stomatia Helbling, 1779; Stomatolina Iredale, 1937; Synaptocochlea Pilsbry, 1890; Tibatrochus Nomura, 1940; Visayaseguenzia Poppe, Tagaro & Dekker, 2006; Zetela Finlay, 1926. New species records for South Africa: Acremodontina aff. carinata Powell, 1940; Anatoma finlayi (Powell, 1937); Anatoma munieri (P. Fischer, 1862); Calliotropis acherontis B.A. Marshall, 1979; Calliotropis bucina Vilvens, 2006; Cocculinella minutissima (E.A. Smith, 1904); Diodora ruppellii (G.B. Sowerby (I), 1835); Emarginula costulata Deshayes, 1863; Emarginula decorata Deshayes, 1863; Jujubinus hubrechti Poppe, Tagaro & Dekker, 2006; Lepetella sp.; Seguenzia orientalis Thiele, 1925; Stomatella auricula Lamarck, 1816; Stomatia phymotis Helbling, 1779; Stomatolina angulata (A. Adams, 1850); Stomatolina cf. calliostoma (A. Adams, 1850); Stomatolina aff. danblumi Singer & Mienis, 1999; Stomatolina cf. rubra (Lamarck, 1822); Stomatolina sp.; Synaptocochlea concinna (Gould, 1845); Tectus mauritianus (Gmelin, 1791); Tibatrochus cf. incertus (Schepman, 1908); Turbo imperialis Gmelin, 1791; Turbo tursicus Reeve, 1848; Visayaseguenzia compsa (Melvill, 1904).New species: Spectamen martensi, replacement name for Spectamen semisculptum sensu Herbert (1987) (non Martens, 1904). New name: Oxystele antoni is proposed as a new name for Trochus (Turbo) variegatus (non Gmelin, 1791 =Heliacus) Anton, 1838. Revised taxonomy: Cyclostrema semisculptum Martens, 1904 is an earlier name for Solariella intermissa Thiele, 1925, and is referable to the genus Zetela Finlay, 1926; Margarita bicarinata A. Adams & Reeve, 1850 is considered to be a senior synonym of Solariella undata G.B. Sowerby (II), 1870, and is referable to the genus Ilanga Herbert, 1987. Validation of the name Trochus tigrinus Chemnitz, 1781 is credited to Dillwyn (1817) rather than Anton (1838). New synonyms: Clanculus exquisita Turton, 1932 =Calliostoma africanum Bartsch, 1915; Cyclostrema alfredensis Bartsch, 1915 =Parviturbo alfredensis (Bartsch, 1915); Cynisca gloriosa Bartsch, 1915 =Cinysca spuria (Gould, 1861); Herbertina hayesi Herbert, 1995 =Bruceina chenoderma (Barnard, 1963); Ilanga millardi Herbert, 1987 =Ilanga humillima (Thiele, 1925); Leptothyra africana Bartsch, 1915 =Cinysca spuria (Gould, 1861); Leptothyra albocincta Turton, 1932 =Tricolia striolata (Turton, 1932); Solariella undata G.B. Sowerby (II), 1870, S. gratiosa Thiele, 1925 and S. valdiviae Thiele, 1925 =Ilanga bicarinata bicarinata (A. Adams & Reeve, 1850); Solariella chuni Thiele, 1925, S. intermissa Thiele, 1925, S. gilchristi Barnard, 1963 and S. macleari Barnard, 1963 =Zetela semisculpta (Martens, 1904); Turbo (Collonia) armillatus G.B. Sowerby (III), 1886 =Cinysca spuria (Gould, 1861). New combinations: Basilissa (Ancistrobasis) compsa Melvill, 1904 is transferred to Visayaseguenzia; Calcar rhysopoma Barnard, 1964 is transferred to Bothropoma; Calliostoma glaucophaos Barnard, 1963 is transferred to Falsimargarita; Calliotropis chenoderma Barnard, 1963 is transferred to Bruceina; Collonia bicarinata Martens, 1902 is transferred to Cinysca; Crossea agulhasensis Thiele, 1925 is transferred to Conjectura; Cyclostrema semisculptum Martens, 1904 is transferred to Zetela; Cyclostremella farica Bartsch, 1915 is transferred to Dikoleps; Cynisca africana Bartsch, 1915 is transferred to Homalopoma; Leptogyra africana: Bartsch, 1915 is transferred to Cirsonella; Leptothyra agulhasensis Thiele, 1925 is transferred to Homalopoma; Leptothyra alfredensis Bartsch, 1915 is transferred to Parviturbo; Leptothyra sola Barnard, 1963 is transferred to a Parviturbo; Liotia (Cynisca) semiclausa Thiele, 1925 is transferred to Cinysca; Monilea spuria Gould, 1861 is transferred to Cinysca; Monodonta gibbula Thiele, 1925 is transferred to Cantrainea; Puncturella voraginosa Herbert & Kilburn, 1986 is transferred to Profundisepta; Solariella fuscomaculata G.B. Sowerby (III), 1892 is transferred to Skenea; Solariella turbynei Barnard, 1963 is transferred to Zetela; Turbo boswellae Barnard, 1969 is transferred to Cantrainea; Turbo foveolatus Barnard, 1963 is transferred to Crosseola; Turbo ponsonbyi G.B. Sowerby (III), 1897 is transferred to Bothropoma; Vitrinella agulhasensis Thiele, 1925 is transferred to Parviturbo; Vitrinella (Docomphala) arifca Bartsch, 1915 is transferred to Lodderena; Vitrinella inclinans Barnard, 1963 is transferred to Skenea. PMID:26624772

  18. Behavioral thermoregulation and critical thermal limits of giant keyhole limpet Megathura crenulata(Sowerby 1825) (Mollusca; Vetigastropoda).

    PubMed

    Díaz, Fernando; Denisse Re, Ana; Salas, Alfredo; Galindo-Sanchez, Clara E; Gonzalez, Marco A; Sanchez, Adolfo; Rosas, Carlos

    2015-12-01

    The thermoregulatory behavior of the giant keyhole limpet Megathura crenulata was determined in a horizontal thermal gradient during the day at 18.9 °C and 18.3 °C for the night. The final preferendum determined for giant keyhole limpets was of 18.6±1.2 °C. Limpets' displacement velocity was 10.0±3.9 cm h(-1) during the light phase and 8.4±1.6 cm h(-1) during the dark phase. The thermotolerance (measured as CTMax at 50%) was determined in a keyhole limpet in three acclimation temperatures 17, 20, and 23 °C. Limpets were subjected to water increasing temperatures at a rate of 1 °C every 30 min, until they detached from the substrate. The critical thermal maximum at 50% was 27.2, 27.9 and 28.3 °C respectively. PMID:26615735

  19. CERT tribal internship program. Final intern report: David Conrad, 1993

    SciTech Connect

    1998-09-01

    The intern`s report contains a Master`s thesis entitled, ``An implementation analysis of the US Department of Energy`s American Indian policy as part of its environmental restoration and waste management mission.`` This thesis examines the implementation of a working relationship between the Nez Perce Tribe and the US Department of Energy`s Office of Environmental Restoration and Waste Management at the Hanford reservation. It examines the relationship using a qualitative methodology and three generations of policy analysis literature to gain a clear understanding of the potential for successful implementation.

  20. Molecular phylogeny of euthyneura (mollusca: gastropoda).

    PubMed

    Grande, Cristina; Templado, José; Cervera, J Lucas; Zardoya, Rafael

    2004-02-01

    A new phylogenetic hypothesis for Euthyneura is proposed based on the analysis of primary sequence data (mitochondrial cox1, trnV, rrnL, trnL(cun), trnA, trnP, nad6, and nad5 genes) and the phylogenetic utility of two rare genomic changes (the relative position of the mitochondrial trnP gene, and an insertion/deletion event in a conserved region of the mitochondrial Cox1 protein) is addressed. Both sources of phylogenetic information clearly rejected the monophyly of pulmonates, a group of gastropods well supported so far by morphological evidence. The marine basommatophoran pulmonate Siphonaria was placed within opisthobranchs and shared with them the insertion of a Glycine in the Cox 1 protein. The marine systellommatophoran pulmonate Onchidella was recovered at the base of the opisthobranch + Siphonaria clade. Opisthobranchs, Siphonaria, and Onchidella shared the relative position of the mitochondrial trnP gene between the mitochondrial trnA and nad6 genes. The land snails and slugs (stylommatophoran pulmonates) were recovered as an early split in the phylogeny of advanced gastropods. The monophyly of the Euthyneura (Opisthobranchia + Pulmonata) was rejected by the inclusion of the heterostrophan Pyramidella. PMID:14660702

  1. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    EPA Science Inventory

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  2. Components of mucus of terrestrial slugs (Gastropoda).

    PubMed

    Deyrup-Olsen, I; Luchtel, D L; Martin, A W

    1983-09-01

    Mucous secretion by the body wall of the terrestrial slugs (Ariolimax columbianus, Arionidae; and other species) was found to involve at least three distinct stages--release of vesicles, formation of granules, and organization of strands. Mucus is stored intracellularly in membrane-bound vesicles, and these are shed intact from the mucous cells. Disruption of the vesicle membrane, with release of contents, can be effected by endogenous lytic agent(s), as well as by exogenous surfactants, lipid solvents, or hypotonic media. Thereupon 1-micron granules are released. These may be stable, or they may change to material that is finely granular or in the form of strands; the transition to strands is facilitated by shear stress exerted through the fluid containing the mucous components. Lectins organize, or are organized with, the strands, as evidenced by agglutination of erythrocytes on them. Mucous formation, as seen in the living slug, differs markedly from the one-step process of exocytosis of fluid mucus inferred from studies of mucous membranes fixed for ultrastructural investigation. PMID:6614215

  3. Taxonomical study on the mollusks collected in Marion-Dufresne (MD55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda).

    PubMed

    Simone, Luiz Ricardo L; Cunha, Carlo M

    2014-01-01

    The Fissurellidae collected by the Marion-Dufresne Expedition, as well as other regional expeditions to SE Brazil are examined taxonomically, treating 21 species, of which 20 are new. The following new species are described (order according to depth range; species marked with * are from expeditions other than MD55): Cornisepta uirapa (790-940 m), Cornisepta arrepiata (295-1,050 m), Cornisepta aninga (295-1,050 m), Cranopsis hycavis (637 m), Cranopsis nymphalis (295 m), Cranopsis enigmatica (790-940 m), Cranopsis cearensis* (250 m), Cranopsis apostrema (110-940 m), Cranopsis alaris (250-450 m), Cranopsis canopa* (250 m), Cranopsis columbaris* (250 m), Emarginula suspira (54-940 m), Emarginula icosisculpta (10-12 m), Manganesepta atiaia (950-1,570 m), Profundisepta denudata* (3,000 m), Puncturella volcano (607-620 m), Rimula leptarcis (85-105 m), Zeidora pussa (607-940 m), Zeidora crepidula (790-940 m), Hemimarginula hemitoma (1-105 m). Diodora mirifica Métivier, 1972 (10-12 m), common in Brazilian oceanic islands, is the only fissurellid species previously known from that area. The genera Cornisepta, Cranopsis, Manganesepta, Profundisepta, Zeidora, and Hemimarginula are reported for the first time from Brazil. Emarginula suspira is named for material that has been misidentified as E. tuberculosa, a Miocene Mediterranean fossil. PMID:25081465

  4. The Mitochondrial Genomes of the Nudibranch Mollusks, Melibe leonina and Tritonia diomedea, and Their Impact on Gastropod Phylogeny

    PubMed Central

    Sevigny, Joseph L.; Kirouac, Lauren E.; Thomas, William Kelley; Ramsdell, Jordan S.; Lawlor, Kayla E.; Sharifi, Osman; Grewal, Simarvir; Baysdorfer, Christopher; Curr, Kenneth; Naimie, Amanda A.; Okamoto, Kazufusa; Murray, James A.; Newcomb, James M.

    2015-01-01

    The phylogenetic relationships among certain groups of gastropods have remained unresolved in recent studies, especially in the diverse subclass Opisthobranchia, where nudibranchs have been poorly represented. Here we present the complete mitochondrial genomes of Melibe leonina and Tritonia diomedea (more recently named T. tetraquetra), two nudibranchs from the unrepresented Cladobranchia group, and report on the resulting phylogenetic analyses. Both genomes coded for the typical thirteen protein-coding genes, twenty-two transfer RNAs, and two ribosomal RNAs seen in other species. The twelve-nucleotide deletion previously reported for the cytochrome oxidase 1 gene in several other Melibe species was further clarified as three separate deletion events. These deletions were not present in any opisthobranchs examined in our study, including the newly sequenced M. leonina or T. diomedea, suggesting that these previously reported deletions may represent more recently divergent taxa. Analysis of the secondary structures for all twenty-two tRNAs of both M. leonina and T. diomedea indicated truncated d arms for the two serine tRNAs, as seen in some other heterobranchs. In addition, the serine 1 tRNA in T. diomedea contained an anticodon not yet reported in any other gastropod. For phylogenetic analysis, we used the thirteen protein-coding genes from the mitochondrial genomes of M. leonina, T. diomedea, and seventy-one other gastropods. Phylogenetic analyses were performed for both the class Gastropoda and the subclass Opisthobranchia. Both Bayesian and maximum likelihood analyses resulted in similar tree topologies. In the Opisthobranchia, the five orders represented in our study were monophyletic (Anaspidea, Cephalaspidea, Notaspidea, Nudibranchia, Sacoglossa). In Gastropoda, two of the three traditional subclasses, Opisthobranchia and Pulmonata, were not monophyletic. In contrast, four of the more recently named gastropod clades (Vetigastropoda, Neritimorpha

  5. The Mitochondrial Genomes of the Nudibranch Mollusks, Melibe leonina and Tritonia diomedea, and Their Impact on Gastropod Phylogeny.

    PubMed

    Sevigny, Joseph L; Kirouac, Lauren E; Thomas, William Kelley; Ramsdell, Jordan S; Lawlor, Kayla E; Sharifi, Osman; Grewal, Simarvir; Baysdorfer, Christopher; Curr, Kenneth; Naimie, Amanda A; Okamoto, Kazufusa; Murray, James A; Newcomb, James M

    2015-01-01

    The phylogenetic relationships among certain groups of gastropods have remained unresolved in recent studies, especially in the diverse subclass Opisthobranchia, where nudibranchs have been poorly represented. Here we present the complete mitochondrial genomes of Melibe leonina and Tritonia diomedea (more recently named T. tetraquetra), two nudibranchs from the unrepresented Cladobranchia group, and report on the resulting phylogenetic analyses. Both genomes coded for the typical thirteen protein-coding genes, twenty-two transfer RNAs, and two ribosomal RNAs seen in other species. The twelve-nucleotide deletion previously reported for the cytochrome oxidase 1 gene in several other Melibe species was further clarified as three separate deletion events. These deletions were not present in any opisthobranchs examined in our study, including the newly sequenced M. leonina or T. diomedea, suggesting that these previously reported deletions may represent more recently divergent taxa. Analysis of the secondary structures for all twenty-two tRNAs of both M. leonina and T. diomedea indicated truncated d arms for the two serine tRNAs, as seen in some other heterobranchs. In addition, the serine 1 tRNA in T. diomedea contained an anticodon not yet reported in any other gastropod. For phylogenetic analysis, we used the thirteen protein-coding genes from the mitochondrial genomes of M. leonina, T. diomedea, and seventy-one other gastropods. Phylogenetic analyses were performed for both the class Gastropoda and the subclass Opisthobranchia. Both Bayesian and maximum likelihood analyses resulted in similar tree topologies. In the Opisthobranchia, the five orders represented in our study were monophyletic (Anaspidea, Cephalaspidea, Notaspidea, Nudibranchia, Sacoglossa). In Gastropoda, two of the three traditional subclasses, Opisthobranchia and Pulmonata, were not monophyletic. In contrast, four of the more recently named gastropod clades (Vetigastropoda, Neritimorpha

  6. Details of gastropod phylogeny inferred from 18S rRNA sequences.

    PubMed

    Winnepenninckx, B; Steiner, G; Backeljau, T; De Wachter, R

    1998-02-01

    Some generally accepted viewpoints on the phylogenetic relationships within the molluscan class Gastropoda are reassessed by comparing complete 18S rRNA sequences. Phylogenetic analyses were performed using the neighbor-joining and maximum parsimony methods. The previously suggested basal position of Archaeogastropoda, including Neritimorpha and Vetigastropoda, in the gastropod clade is confirmed. The present study also provides new molecular evidence for the monophyly of both Caenogastropoda and Euthyneura (Pulmonata and Opisthobranchia), making Prosobranchia paraphyletic. The relationships within Caenogastropoda and Euthyneura data turn out to be very unstable on the basis of the present 18S rRNA sequences. The present 18S rRNA data question, but are insufficient to decide on, muricacean (Neogastropoda), neotaenioglossan, pulmonate, or stylommatophoran monophyly. The analyses also focus on two systellommatophoran families, namely, Veronicellidae and Onchidiidae. It is suggested that Systellommatophora are not a monophyletic unit but, due to the lack of stability in the euthyneuran clade, their affinity to either Opisthobranchia or Pulmonata could not be determined. PMID:9479694

  7. A Study of Ideational Metafunction in Joseph Conrad's "Heart of Darkness": A Critical Discourse Analysis

    ERIC Educational Resources Information Center

    Alaei, Mahya; Ahangari, Saeideh

    2016-01-01

    The linguistic study of literature or critical analysis of literary discourse is no different from any other textual description; it is not a new branch or a new level or a new kind of linguistics but the application of existing theories and methods (Halliday, 2002). This study intends to determine how ideology or opinion is expressed in Joseph…

  8. VizieR Online Data Catalog: Galactic open clusters in RAVE (Conrad+, 2014)

    NASA Astrophysics Data System (ADS)

    Conrad, C.; Scholz, R.-D.; Kharchenko, N. V.; Piskunov, A. E.; Schilbach, E.; Roser, S.; Boeche, C.; Kordopatis, G.; Siebert, A.; Williams, M.; Munari, U.; Matijevic, G.; Grebel, E. K.; Zwitter, T.; de Jong, R. S.; Steinmetz, M.; Gilmore, G.; Seabroke, G.; Freeman, K.; Navarro, J. F.; Parker, Q.; Reid, W.; Watson, F.; Gibson, B. K.; Bienayme, O.; Wyse, R.; Bland-Hawthorn, J.; Siviero, A.

    2014-01-01

    The presented tables summarise new radial velocities and average metallicities for Galactic open clusters extracted from the Catalogue of Open Cluster Data (COCD; Kharchenko et al. 2005, Cat. J/A+A/438/1163, J/A+A/440/403). The data were obtained from the RAdial Velocity Experiment (RAVE; Kordopatis et al. 2013AJ....146..134K) through a cross match with the stellar catalogues related to the COCD. The RV and [M/H] values were computed as weighted means, considering the individual uncertainties of the included members and their cluster membership probability based on position, proper motion, and photometry. The three uncertainties listed originate from different calculations: "RVRAVE" and "MetRAVE" are the weighted mean values for RV and [M/H] "errRV" and "errMet" are equivalent to the uncertainty of the mean values "sigRV" and "sigMet" are the standard deviations of the mean values "eRV" and "eMet" weighted mean values of the individual uncertainties of the included open cluster (OC) members For the calculations we primarily considered most probable OC members (best members) with a membership probability of at least 61%. Only in cases where just one or no most probable members was available we also included possible members (good members) with membership probabilities above 14%. In the table we include the numbers for both types of members separately: best members -> "bmem" and good members -> "gmem". We included reference values for RVs from the second version of the Catalogue of Radial Velocities with Astrometric Data (CRVAD-2) and the Catalogue of Radial Velocities of Open Clusters and Associations (CRVOCA) provided by Kharchenko et al. 2007, Cat. III/254). The CRVAD-2 reference values were computed according to the RAVE values for identified OC members. The CRVOCA references were directly extracted from the catalogue and number of OC members used are given in column "nmem". The reference values for [M/H] were obtained from the online compilation provided by Dias et al. (2002, See B/ocl), hereafter referred to as DAML. These were obtained through different techniques and the literature references from DAML are also included in our table. In DAML actual [M/H] values are mixed with [Fe/H] values and we only considered the actual [M/H], based on information given in the references. (2 data files).

  9. [Wilhelm Conrad Röntgen and the discovery of X-rays].

    PubMed

    Tubiana, M

    1996-01-01

    W.C. Röntgen reported the discovery of X-rays in December 1895 after seven weeks of assiduous work during which he had studied the properties of this new type of radiation able to go through screens of notable thickness. He named them X-rays to underline the fact that their nature was unknown. The news of this discovery immediately aroused an immense interest in the public and also initiated intense research in several directions. Physicians and physicists began as early as January 1896 to use X-rays on patients to investigate the skeleton and subsequently the lung and other organs. This was the birth or radiology. Rapidly they observed skin erythema, which led to the idea of using X-rays against a variety of lesions. In June 1896 the first patient was treated by radiotherapy. J.J. Thomson (Cambridge, U.K.) showed that X-rays were able to ionize gaz and the study of this phenomenon led to the discovery of electrons in 1897. In order to understand the emission of X-rays, H. Becquerel (Paris) investigated the role of the phosphorescence of the glass of the tube and while doing so discovered radioactivity in March 1896. X-rays and radioactivity were at the origin of the scientific revolution at the end of the 19th and the beginning of the 20th centuries. Research on radioactive materials demonstrated the existence of atoms which had been till then only a convenient hypothesis for explaining chemical reactions, but whose reality was considered as dubious by most physicists. Moreover, interaction of particles emitted by radionuclides and atoms enabled first the study of the structure of the atom and subsequently its nucleus. Matter, elements which were thought to be immutable were found to be transmutable, and eventually to disintegrate. The origin of the energy transferred to the radiation which was emitted appeared as a mystery and in order to explain it the physicist had to accept that matter could convert energy. In 1903 Einstein established the equivalence between matter and energy. Matter, energy, electricity, light which were formerly considered as continuous quantities were found to be discrete: there are particles of matter (elementary particles), energy (quanta, Planck 1905), electricity (electron), light (photons). Radioactive decay, particle interactions imposed a probabilistic physics which progressively replaced classic deterministic physics. Radioactivity can be used as a clock to measure time in the universe. Datations were made for fossils, art masterpieces and also for the earth, the solar system and universe. X-rays diffraction proved to be a powerful tool for studying crystals and molecules, in particular protein, and in 1953 enabled to demonstrate the DNA double helix. Hence X-rays and radioactivity originated a revolution in physics and science and in the vision of nature. The imperceptible and yet so powerful rays demonstrated the deficiencies of our senses. Mathematical entities and instrumentation must complement our sensations. The huge increment in our knowledge is accompanied by a divorce between the scientist and the layman who now often has great difficulties understanding new concepts not only in physics but also in biology. PMID:8696882

  10. Acid phosphatase localization in neurons of Bulla gouldiana (Gastropoda: Opisthobranchia.

    PubMed

    Robles, L J; Fisher, S K

    1975-01-01

    The organization of the ganglia and the ultrastructure of the neurons of Bulla gouldiana are similar to those described for other molluscs. Acid phosphatase positive reactions were found in the large pigmented granules, small dense bodies, multivesicular bodies, and Golgi lamellae and associated vesicles. The small dense bodies and multivesicular bodies may be stages in the formation of the larger pigmented granules which are interpreted as lysosomes. Comparison is made between the pigmented granules in Bulla and the lipofuscin bodies of vertebrate neurons. The possible involvement of these pigmented granules in the hyperpolarization of Bulla and Aplysia neurons to light is discussed. PMID:1122539

  11. Spermiogenesis in the vermetid gastropod Dendropoma petraeum (Gastropoda, Prosobranchia).

    PubMed

    D'Ancona Lunetta, G; Damiani, F

    2002-01-01

    The structure and maturation of the male gonad of the Mediterranean vermetid gastropod Dendropoma petraeum are described. Histological sections of the gonads were made throughout development and gonad activity was monitored at regular monthly intervals. During the autumn months the gonad is very small and is surrounded by a large quantity of connective tissue; it becomes more voluminous from December to August, with the highest growth peak in springtime. The stages of spermatogenesis were also observed and described. PMID:12044050

  12. Redescription of Spirodentalium Walcott ( Gastropoda: Late Cambrian) from Wisconsin ( USA).

    USGS Publications Warehouse

    Yochelson, E.L.

    1987-01-01

    Spirodentalium Walcott, 1890, was originally described as a scaphopod. A reinterpretation of the type lot suggests that its overall shape is that of an open-coiled gastropod. If so, this is probably the earliest known open-coiled form and it is sinistral in coiling direction. -Author

  13. Redescription of Bellerophon bittneri (Gastropoda: Triassic) from Wyoming.

    USGS Publications Warehouse

    Yochelson, E.L.; Boyd, D.W.; Wardlaw, B.

    1985-01-01

    Bellerophon bittneri Newell and Kummel is an Early Triassic bellerophontacean from the Dinwoody Formation in the Wind River Mountains. The available type material consists of one fair, but incomplete, external mold, which resembles a Bellerophon but is actually a Retispira. After repeated search, additional specimens were found at one locality in the southern Wind River Range of Wyoming; Retispira bittneri is redescribed from this new material. Like other Triassic bellerophontaceans, there is nothing unusual about the species apart from occurrence in the Mesozoic; it is clearly congeneric with Permian Retispira from underlying rocks. -Authors

  14. Helicopsis persica n. sp. from northern Iran (Gastropoda: Geomitridae).

    PubMed

    Hausdorf, Bernhard; Bössneck, Ulrich

    2016-01-01

    Helicopsis Fitzinger, 1833 is a mainly eastern European genus of the xerophilous Helicellinae (Geomitridae, Helicoidea; for family systematics see Razkin et al. 2015) that is characterized by two symmetrical dart and accessory sacs. This is probably the plesiomorphous character state within the Geomitridae and Hygromiidae. Therefore, the delimitation and relationships of Helicopsis remained questionable (Hausdorf 1996). Most Helicopsis species are characterized by a lateral attachment of the outer layer of the penial papilla at the penis wall so that a cavity is separated in the proximal part of the penis (Schileyko 1978; Giusti et al. 1992; Hausdorf 1996). However, a similar cavity is present in some other Helicellinae (e.g., Pseudoxerophila, Xerolenta, Xeromunda). Giusti et al. (1992) considered these cavities artefacts, but it cannot be excluded that they are actually homologous to the cavity of Helicopsis. Therefore, it is doubtful whether such a cavity can be considered as an autapomorphy of Helicopsis. About ten species of Helicopsis are spread from Turkey and Bulgaria to the Ukraine with a centre of diversity on the Crimean peninsula. Only the type species, Helicopsis striata (Müller, 1774) is more widespread from Alsace in the west, the island Öland in the Baltic Sea in the north to Bulgaria and Turkey in the south and western Russia in the east. Furthermore, species from Morocco, Greece, Cyprus, Iran and the Kopetdag were classified as Helicopsis. The relationships between these species have to be examined in more detail. Here we describe a new Helicopsis species from Iran. PMID:27395547

  15. Morphological analysis of the Chinese Cipangopaludina species (Gastropoda; Caenogastropoda: Viviparidae)

    PubMed Central

    LU, Hong-Fa; DU, Li-Na; LI, Zhi-Qiang; CHEN, Xiao-Yong; YANG, Jun-Xing

    2014-01-01

    Viviparidae are widely distributed around the globe, but there are considerable gaps in the taxonomic record. To date, 18 species of the viviparid genus Cipangopaludina have been recorded in China, but there is substantial disagreement on the validity of this taxonomy. In this study, we described the shell and internal traits of these species to better discuss the validity of related species. We found that C. ampulliformis is synonym of C. lecythis, and C. wingatei is synonym of C. chinensis, while C. ampullacea and C. fluminalis are subspecies of C. lecythis and C. chinensis, respectively. C. dianchiensis should be paled in the genus Margarya, while C. menglaensis and C. yunnanensis belong to genus Mekongia. Totally, this leaves 11 species and 2 subspecies recorded in China. Based on whether these specimens’ spiral whorl depth was longer than aperture depth, these species or subspecies can be further divided into two groups, viz. chinensis group and cathayensis group, which can be determined from one another via the ratio of spiral depth and aperture depth, vas deferens and number of secondary branches of vas deferens. Additionally, Principal Component Analysis indicated that body whorl depth, shell width, aperture width and aperture length were main variables during species of Cipangopaludina. A key to all valid Chinese Cipangopaludina species were given. PMID:25465086

  16. The phylogeny and systematics of the Nassariidae revisited (Gastropoda, Buccinoidea).

    PubMed

    Galindo, Lee Ann; Puillandre, Nicolas; Utge, José; Lozouet, Pierre; Bouchet, Philippe

    2016-06-01

    Nassariidae are a group of scavenging, predominantly marine, snails that are diversified on soft bottoms as well as on rocky shores, and are the subject of numerous research papers in ecology, ecotoxicology or paleontology. A weak and/or apparently continuous variation in shell characters has resulted in an intimidating taxonomy, with complex synonymy lists. Over 1320 extant nominal species have been described, of which 442 are currently regarded as valid. Above species level, the state of the art is equally hazy, with four subfamilies and twelve genera currently accepted, and many other names in the graveyard of synonymy. A molecular analysis based on three mitochondrial (COI, 16S, 12S) and two nuclear (28S, H3) markers was conducted. Our dataset includes 218 putative nassariid species, comprising 9 of the 12 valid genera, and 25 nominal genera represented by their type species. The monophyly of the Nassariidae as classically construed is not confirmed. Species of Antillophos, Engoniophos, Phos, Nassaria, Tomlinia and Anentome (formerly considered Buccinidae) are included inside the Nassariidae clade. Within the Nassariinae, the tree unexpectedly demonstrates that species from the Atlantic and the Indo-Pacific form different clades which represent several independent diversification events. Through an integrative approach, the reconstruction of ancestral states was addressed for eight characters supposedly informative for taxonomy. Using numerous fossil calibration points, Nassariidae appear to have originated 120 MYA ago in Atlantic temperate waters during the Lower Cretaceous. Our results have a profound impact on nassariid taxonomy, especially with regard to the validity of subfamily- and genus-level names. PMID:27012605

  17. Untersuchungen zum Harnsäuremetabolismus von Littorina littorea (Gastropoda)

    NASA Astrophysics Data System (ADS)

    Heil, K. P.; Eichelberg, D.

    1983-12-01

    Periwinkles, as typical inhabitants of sea-shores, are subjected to extreme changes of environmental conditions, which affect their excretion. In Littorina littorea uric acid, urea and ammonium were detected particularly in the kidney, but the only metabolite excreted was ammonium. Only the concentration of uric acid was dependent on the availability of water; decreasing periods of submersion during low tide and raised salinities caused a higher concentration of uric acid, while increasing periods of submersion and lowered salinities effected the opposite. Transfer of periwinkles within their intertidal habitat and laboratory experiments to test the effect of salinity showed that the concentration of uric acid in the kidney is adaptable. The dependence of uric acid concentration in the kidney on environmental conditions and the ammoniotelic excretion of L. littorea are discussed with regard to its particular living conditions. It is suggested that uric acid serves as nitrogen depot and has a particular function in osmoregulation.

  18. A cladistic phylogeny of the family Patellidae (Mollusca: Gastropoda)

    PubMed Central

    Ridgway, S. A.

    1998-01-01

    A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.

  19. Rediscovery of Leptoxis compacta (Anthony, 1854) (Gastropoda: Cerithioidea: Pleuroceridae).

    PubMed

    Whelan, Nathan V; Johnson, Paul D; Harris, Phil M

    2012-01-01

    The Mobile River Basin is a hotspot of molluscan endemism, but anthropogenic activities have caused at least 47 molluscan extinctions, 37 of which were gastropods, in the last century. Nine of these suspected extinctions were in the freshwater gastropod genus Leptoxis (Cerithioidea: Pleuroceridae). Leptoxis compacta, a Cahaba River endemic, has not been collected for >70 years and was formally declared extinct in 2000. Such gastropod extinctions underscore the imperilment of freshwater resources and the current biodiversity crisis in the Mobile River Basin. During a May 2011 gastropod survey of the Cahaba River in central Alabama, USA, L. compacta was rediscovered. The identification of snails collected was confirmed through conchological comparisons to the L. compacta lectotype, museum records, and radulae morphology of historically collected L. compacta. Through observations of L. compacta in captivity, we document for the first time that the species lays eggs in short, single lines. Leptoxis compacta is restricted to a single location in the Cahaba River, and is highly susceptible to a single catastrophic extinction event. As such, the species deserves immediate conservation attention. Artificial propagation and reintroduction of L. compacta into its native range may be a viable recovery strategy to prevent extinction from a single perturbation event. PMID:22905139

  20. A phylogeny of the land snails (Gastropoda: Pulmonata).

    PubMed Central

    Wade, C. M.; Mordan, P. B.; Clarke, B.

    2001-01-01

    We have undertaken the first large-scale molecular phylogenetic analysis of the Stylommatophora. Sequences of the ribosomal RNA gene-cluster were examined in 104 species of snails and slugs from 50 families, encompassing all the currently recognized major groups. It allows an independent test of the present classification based on morphology. At the level of families our molecular phylogeny closely supports the current taxonomy, but the deep branches within the tree do not. Surprisingly, a single assemblage including the families Achatinidae, Subulinidae and Streptaxidae lies near the base of the tree, forming a sister group to all remaining stylommatophorans. This primary division into 'achatinoid' and 'non-achatinoid' taxa is unexpected, and demands a radical reinterpretation of early stylommatophoran evolution. In particular, the Orthurethra appear to be relatively advanced within the 'non-achatinoid clade', and broadly equivalent to other super-familial clusters. This indicates that supposedly primitive features such as the orthurethran kidney are derived. The molecular tree also suggests that the origin of the Stylommatophora is much earlier than the main period of their diversification. PMID:11270439

  1. Leiostyla beatae n. sp. from eastern Georgia (Gastropoda: Lauriidae).

    PubMed

    Walther, Frank; Hausdorf, Bernhard

    2015-01-01

    Leiostyla R.T. Lowe, 1852 is a disjunctly distributed pupilloid group of land snails known from the Macaronesian islands, Western Europe, Algeria, Bulgaria, Turkey, the Caucasus region and Iran (Pilsbry 1922-1923; Schileyko 1984; Gittenberger & Pieper 1988; Hausdorf 1990). In the Neogene the genus was more widespread in Central and Western Europe (Pilsbry 1922). Thus, the Caucasus region and the Macaronesian islands, where the highest recent diversity of Leiostyla species is found (Pilsbry 1922-1923), can be considered refugial areas. PMID:25947501

  2. The Genus Cerion (Gastropoda: Cerionidae) in the Florida Keys

    PubMed Central

    2015-01-01

    The systematic relationships and phylogeography of Cerion incanum, the only species of Cerion native to the Florida Keys, are reviewed based on partial sequences of the mitochondrial COI and 16S genes derived from 18 populations spanning the range of this species and including the type localities of all four described subspecies. Our samples included specimens of Cerion casablancae, a species introduced to Indian Key in 1912, and a population of C. incanum x C. casablancae hybrids descended from a population of C. casablancae introduced onto Bahia Honda Key in the same year. Molecular data did not support the partition of C. incanum into subspecies, nor could populations be apportioned reliably into subspecies based on morphological features used to define the subspecies. Phylogenetic analyses affirmed the derived relationship of C. incanum relative to other cerionids, and indicated a Bahamian origin for the Cerion fauna of southern Florida. Relationships among the populations throughout the Keys indicate that the northernmost populations, closest to the Tomeu paleoislands that had been inhabited by Cerion petuchi during the Calabrian Pleistocene, are the oldest. The range of Cerion incanum expanded as the archipelago that is the Florida Keys was formed since the lower Tarantian Pleistocene by extension from the northeast to the southwest, with new islands populated as they were formed. The faunas of the High Coral Keys in the northeast and the Oölite Keys in the southwest, both with large islands that host multiple discontinuous populations of Cerion, are each composed of well supported clades that are characterized by distinctive haplotypes. In contrast, the fauna of the intervening Low Coral Keys consist of a heterogeneous series of populations, some with haplotypes derived from the High Coral Keys, others from the Oölite Keys. Individuals from the C. incanum x C. casablancae hybrid population inhabiting the southeastern coast of Bahia Honda Key were readily segregated based on their mitogenome lineage, grouping either with C. incanum or with C. casablancae from Indian Key. Hybrids with C. casablancae mitogenomes had haplotypes that were more divergent from their parent mitogenome than were hybrids with C. incanum mitogenomes. PMID:26378443

  3. The phylogeography of Indoplanorbis exustus (Gastropoda: Planorbidae) in Asia

    PubMed Central

    2010-01-01

    Background The freshwater snail Indoplanorbis exustus is found across India, Southeast Asia, central Asia (Afghanistan), Arabia and Africa. Indoplanorbis is of economic importance in that it is responsible for the transmission of several species of the genus Schistosoma which infect cattle and cause reduced livestock productivity. The snail is also of medical importance as a source of cercarial dermatitis among rural workers, particularly in India. In spite of its long history and wide geographical range, it is thought that Indoplanorbis includes only a single species. The aims of the present study were to date the radiation of Indoplanorbis across Asia so that the factors involved in its dispersal in the region could be tested, to reveal potential historical biogeographical events shaping the phylogeny of the snail, and to look for signs that I. exustus might be polyphyletic. Results The results indicated a radiation beginning in the late Miocene with a divergence of an ancestral bulinine lineage into Assam and peninsular India clades. A Southeast Asian clade diverged from the peninsular India clade late-Pliocene; this clade then radiated at a much more rapid pace to colonize all of the sampled range of Indoplanorbis in the mid-Pleistocene. Conclusions The phylogenetic depth of divergences between the Indian clades and Southeast Asian clades, together with habitat and parasitological differences suggest that I. exustus may comprise more than one species. The timescale estimated for the radiation suggests that the dispersal to Arabia and to Southeast Asia was facilitated by palaeogeographical events and climate change, and did not require human involvement. Further samples from Afghanistan, Africa and western India are required to refine the phylogeographical hypothesis and to include the African Recent dispersal. PMID:20602771

  4. Phylogenetic relationships among superfamilies of Neritimorpha (Mollusca: Gastropoda).

    PubMed

    Uribe, Juan E; Colgan, Don; Castro, Lyda R; Kano, Yasunori; Zardoya, Rafael

    2016-11-01

    Despite the extraordinary morphological and ecological diversity of Neritimorpha, few studies have focused on the phylogenetic relationships of this lineage of gastropods, which includes four extant superfamilies: Neritopsoidea, Hydrocenoidea, Helicinoidea, and Neritoidea. Here, the nucleotide sequences of the complete mitochondrial genomes of Georissa bangueyensis (Hydrocenoidea), Neritina usnea (Neritoidea), and Pleuropoma jana (Helicinoidea) and the nearly complete mt genomes of Titiscania sp. (Neritopsoidea) and Theodoxus fluviatilis (Neritoidea) were determined. Phylogenetic reconstructions using probabilistic methods were based on mitochondrial (13 protein coding genes and two ribosomal rRNA genes), nuclear (partial 28S rRNA, 18S rRNA, actin, and histone H3 genes) and combined sequence data sets. All phylogenetic analyses except one converged on a single, highly supported tree in which Neritopsoidea was recovered as the sister group of a clade including Helicinoidea as the sister group of Hydrocenoidea and Neritoidea. This topology agrees with the fossil record and supports at least three independent invasions of land by neritimorph snails. The mitochondrial genomes of Titiscania sp., G. bangueyensis, N. usnea, and T. fluviatilis share the same gene organization previously described for Nerita mt genomes whereas that of P. jana has undergone major rearrangements. We sequenced about half of the mitochondrial genome of another species of Helicinoidea, Viana regina, and confirmed that this species shares the highly derived gene order of P. jana. PMID:27456746

  5. Loss of trematode parthenitae in Planorbella trivolvis (Mollusca: Gastropoda).

    PubMed

    Sears, B F; Rohr, J R

    2013-08-01

    Infection by trematode parthenitae (larval, asexual trematodes) has severe consequences for molluscan hosts, resulting in cessation of reproduction and early mortality. Here we present evidence that the freshwater snail Planorbella trivolvis can lose infections by trematode parthenitae. Of 8 P. trivolvis infected by reniferin parthenitae, 6 died within 2 wk, whereas the remaining 2 snails lost their infections within 82 days after initial examination. This phenomenon might suggest that molluscs can resist established trematode infections (i.e., "self-cure") or at least out-survive some trematode parthenitae. PMID:23387507

  6. The complete mitochondrial genome of Babylonia borneensis (Gastropoda: Neogastropoda: Buccinidae).

    PubMed

    Sung, Chia-Hsuan; Tseng, Chen-Te; Wang, Liang-Jong; Li, Yu-Chi; Lu, Jenn-Kan

    2016-09-01

    The complete mitochondrial genome sequence of the Babylonia borneensis is reported for the first time in this study. The length of genome was 15 556 bp, including 13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes. The nucleotide composition of the mitogenome showed AT-rich feature, with the AT content of 68.2%. Comparison of the identity of the B. borneensis mitogenome with B. areolata, B. lani and B. lutosa was 87.5%, 87.4% and 86.9%, respectively. The construction of phylogenetic tree showed high bootstrap support value. Babylonia borneensis grouped together with other Babylons and the lineages of Buccinidae was strongly supported. In this study, our results could provide a further understanding in the phylogenetic relationships of the Neogastropoda. PMID:27158871

  7. Physella acuta: atypical mitochondrial gene order among panpulmonates (Gastropoda)

    PubMed Central

    Nolan, Journey R.; Bergthorsson, Ulfar; Adema, Coen M.

    2014-01-01

    Mitochondrial (mt) sequences are frequently used for phylogenetic reconstruction and for identification of species of molluscs. This study expands the phylogenetic range of Hygrophila (Panpulmonata) for which such sequence data are available by characterizing the full mt genome of the invasive freshwater snail Physella acuta (Physidae). The mt genome sequences of two P. acuta isolates from Stubblefield Lake, New Mexico, USA, differed in length (14,490 vs 14,314 bp) and showed 11.49% sequence divergence, whereas ITS1 and ITS2 sequences from the nuclear genome differed by 1.75%. The mt gene order of P. acuta (cox1, P, nad6, nad5, nad1, D, F, cox2, Y, W, nad4L, C, Q, atp6, R, E, rrnS, M, T, cox3, I, nad2, K, V, rrnL, L1, A, cytb, G, H, L2, atp8, N, nad2, S1, S2, nad4) differs considerably from the relatively conserved gene order within Panpulmonata. Phylogenetic trees show that the 13 protein-encoding mt gene sequences (equivalent codons) of P. acuta group according to gastropod phylogeny, yet branch lengths and dN/dS ratios for P. acuta indicate elevated amino acid substitutions relative to other gastropods. This study indicates that mt sequences of P. acuta are phylogenetically informative despite a considerable intraspecific divergence and the atypical gene order in its mt genome. PMID:25368439

  8. Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and C. margaritarius (Trochoidea; Gastropoda)

    PubMed Central

    Ito, S.; Wakamatsu, K.; Goral, T.; Edwards, N. P.; Wogelius, R. A.; Henkel, T.; de Oliveira, L. F. C.; Maia, L. F.; Strekopytov, S.; Speiser, D. I.; Marsden, J. T.

    2016-01-01

    Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pink-red) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since this study shows that homology of visible colour cannot be assumed without identification of pigments. PMID:27367426

  9. DNA barcoding reveals neritid diversity (Mollusca: Gastropoda) diversity in Malaysian waters.

    PubMed

    Chee, S Y; Mohd Nor, Siti Azizah

    2016-05-01

    This is the first study to identify and determine the phylogenetics of neritids found in Malaysia. In total, twelve species from the family Neritidae were recorded. Ten species were from the genus Nerita and two species were from the genus Neritina. DNA barcodes were successfully assigned to each species. Although some of these species were previously reported in the region, three are only presently reported in this study. The dendrogram showed Nerita and Neritina strongly supported in their respective monophyletic clades. Phylogenetic positions of some species appeared unstable in the trees. This could be due to the differences in a small number of nucleotides, thus minimizing genetic variation between each specimen and species. PMID:25471442

  10. Neuromuscular development of Aeolidiella stephanieae Valdéz, 2005 (Mollusca, Gastropoda, Nudibranchia)

    PubMed Central

    2010-01-01

    Background Studies on the development of the nervous system and the musculature of invertebrates have become more sophisticated and numerous within the last decade and have proven to provide new insights into the evolutionary history of organisms. In order to provide new morphogenetic data on opisthobranch gastropods we investigated the neuromuscular development in the nudibranch Aeolidiella stephanieae Valdéz, 2005 using immunocytochemistry as well as F-actin labelling in conjunction with confocal laser scanning microscopy (cLSM). Results The ontogenetic development of Aeolidiella stephanieae can be subdivided into 8 stages, each recognisable by characteristic morphological and behavioural features as well as specific characters of the nervous system and the muscular system, respectively. The larval nervous system of A. stephanieae includes an apical organ, developing central ganglia, and peripheral neurons associated with the velum, foot and posterior, visceral part of the larva. The first serotonergic and FMRFamidergic neural structures appear in the apical organ that exhibits an array of three sensory, flask-shaped and two non-sensory, round neurons, which altogether disappear prior to metamorphosis. The postmetamorphic central nervous system (CNS) becomes concentrated, and the rhinophoral ganglia develop together with the anlage of the future rhinophores whereas oral tentacle ganglia are not found. The myogenesis in A. stephanieae begins with the larval retractor muscle followed by the accessory larval retractor muscle, the velar or prototroch muscles and the pedal retractors that all together degenerate during metamorphosis, and the adult muscle complex forms de novo. Conclusions Aeolidiella stephanieae comprises features of the larval and postmetamorphic nervous as well as muscular system that represent the ground plan of the Mollusca or even the Trochozoa (e. g. presence of the prototrochal or velar muscle ring). On the one hand, A. stephanieae shows some features shared by all nudibranchs like the postmetamorphic condensation of the CNS, the possession of rhinophoral ganglia and the lack of oral tentacle ganglia as well as the de novo formation of the adult muscle complex. On the other hand, the structure and arrangement of the serotonergic apical organ is similar to other caenogastropod and opisthobranch gastropods supporting their sister group relationship. PMID:20205753

  11. Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).

    PubMed

    Márquez, Edna J; Castro, Erick R; Alzate, Juan F

    2016-01-01

    The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of gastropods. PMID:25186797

  12. [Growth of Strombus gigas (Gastropoda: Strombidae) snail in 4 environments of Quintana Roo, Mexico].

    PubMed

    Navarrete, A J

    2001-03-01

    The growth rate of queen conch cultured in pens was studied from October 1993 to March 1994. Sixteen pens (50 m2 each, four pens per environment), were set in four environments: Thalassia, Thalassia-sand, Sand and Coral within a reef lagoon on Punta Gavilan and Banco Chinchorro. Twenty conchs were introduced in each pen (sizes: 100-120, 120-140, 140-160 and 160-180 mm shell length) and measured monthly to the nearest mm. Growth rate was assessed by two methods: a) shell marginal mean increase and b) the Gulland-Holt method considering all conch within pens. In the first method, the environment Sand had the highest growth (3.21 +/- 0.26 mm/month) at Punta Gavilan, whereas at Banco Chinchorro, highest growth was recorded in Coral (2.31 +/- 0.44 mm/month). Considering the second method, highest asymptotic length conch in Punta Gavilan occurred in Thalassia-sand (287.5 mm), whereas in Banco Chinchorro the highest asymptotic length was measured in Sand (318.1 mm). There were significant differences in growth between sites; juvenile growth is related with habitat quality mainly food availability. PMID:11795173

  13. Pharyngeal movements during feeding sequences of Navanax inermis (Gastropoda: Opisthobranchia) in successive stages of dissection.

    PubMed

    Susswein, A J; Achituv, Y; Cappell, M S; Bennett, M V

    1987-03-01

    Feeding in Navanax inermis Cooper was filmed and analysed after various dissections. In preparations with a cut through the body wall exposing the pharynx and buccal ganglia, completely normal feeding was observed. In addition to seven motor acts previously described in intact animals, an eighth act, peristalsis, was observed. In preparations with the pharynx excised from the animal but attached to the buccal ganglia, four motor acts were observed: flaring, expansion, contraction and peristalsis. In addition to increasing information about the nature of feeding movements in Navanax, these data indicate that preparations suitable for neurophysiological studies are capable of producing a variety of feeding acts. PMID:3559467

  14. Catecholamines and dihydroxyphenylalanine in metamorphosing larvae of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia).

    PubMed

    Pires, A; Coon, S L; Hadfield, M G

    1997-09-01

    The content of catecholamines and dihydroxyphenylalanine in larvae of the nudibranch Phestilla sibogae was analyzed by high-performance liquid chromatography with electrochemical detection. Dihydroxyphenylalanine, norepinephrine and dopamine were identified in larvae of all ages examined (5 through 12 days post-fertilization). Dihydroxyphenylalanine could be accurately quantified only in larvae of ages 8 through 12 days, when its average concentration increased from 0.62 to 6.71 x 10(-2) pmol micrograms protein-1. Between ages 5 and 12 days dopamine rose from 0.081 to 0.616 pmol microgram protein-1, and norepinephrine from 0.45 to 2.17 x 10(-2) pmol micrograms protein-1. Dihydroxyphenylalanine, dopamine and norepinephrine were also measured at different stages of metamorphic progress in 10- to 12-day larvae. Dihydroxyphenylalanine increased by a factor of 2.4 between the onset and completion of metamorphosis, but levels of dopamine and norepinephrine remained stable. One millimolar alpha-methyl-DL-m-tyrosine, an inhibitor of catecholamine synthesis, inhibited natural metamorphosis and depleted endogenous norepinephrine and especially dopamine, respectively, to 75% and 35% of control values. The existence of unexpectedly high levels of catecholamines in metamorphically competent larvae, and the association of catecholamine depletion with inhibition of metamorphosis, indicate that these compounds may participate in the control of gastropod development. PMID:9309865

  15. New ultrastructural aspects of the spermatozoon of Aplysia depilans (Gastropoda, Opisthobranchia).

    PubMed

    Vita, P; Corral, L; Azevedo, C

    2001-01-01

    The spermatozoon of the sea hare Aplysia depilans was studied under scanning (SEM) and transmission electron microscopy (TEM). Previous descriptions of this sperm and related species, both from light and electron microscopy, were inconsistent with each other. These descriptions include A. depilans, A. punctata, A. fasciata, A. kurodai and Bursatella leachiplei. Several detailed micrographs provide a new ultrastructural model and reveal new aspects such as the presence of acrosome and the absence of a glycogen piece, therefore the modified dense ring is the terminal structure. Results also show that previous models are incorrect in many aspects. The spermatozoon is a long slender uniflagellated cell with a complex helical structure and a length of approximately 165 microm. Observed in SEM the spermatozoon has an undifferentiated head and tail. The nucleus is cord-shaped and helically intertwined with the axoneme/mitochondrial derivative complex. The mitochondrial derivative has only one glycogen helix. Glycogen presence was demonstrated by Thiéry's method. Typical heterobranchia spermatozoa features are recognised. From bibliographic analysis, a high degree of similarity was found with the sperm of Pleurobranchea maculata (Notaspidea). PMID:11686398

  16. A comparative ultrastructural investigation of the cephalic sensory organs in Opisthobranchia (Mollusca, Gastropoda).

    PubMed

    Göbbeler, K; Klussmann-Kolb, A

    2007-12-01

    Cephalic sensory organs (CSOs) are specialised structures in the head region of adult Opisthobranchia involved in perception of different stimuli. The gross morphology of these organs differs considerably among taxa. The current study aims at describing the cellular morphology of the CSOs in order to reveal cellular patterns, especially of sensory epithelia, common for opisthobranchs. Transmission electron microscopy was used to characterise the fine structure of the organs and to compare the CSOs of four different opisthobranch species. The cellular composition of the sensory system is conserved among taxa. The epidermal cells in sensory regions are always columnar and ciliated cells are frequently apparent. The sensory cells are primary receptors arranged in subepidermal cell clusters. They extend dendrites which penetrate the epithelium and reach the surface. Some of the dendrites bear cilia, whereas others only build a small protuberance. Processing of sensory information takes place in the peripheral glomeruli of all species. Moreover, few taxa possess additional peripheral ganglia at the base of their CSOs. The results of the present study might support other investigations indicating that the posterior CSOs are primarily involved in distance chemoreception, whereas the anterior CSOs might be used for contact chemoreception and mechanoreception. PMID:17881026

  17. Sperm tail differentiation in the nudibranch mollusc Hypselodoris tricolor (Gastropoda, Opisthobranchia).

    PubMed

    Medina, A; Moreno, F J; García-Herdugo, G

    1988-06-01

    The sperm axoneme of Hypselodoris tricolor forms from a single centriole that is located initially beneath the plasma membrane and then migrates to the nuclear surface. A conspicuous centriolar adjunct-like formation is present in the neck of midspermatids, but it becomes very reduced at the end of spermiogenesis. In spermatocyte and spermatid mitochondria, intracristal bodies originate from the accumulation of a dense material in some cristae. From our observations and foregoing reports, it may be concluded that the process of sperm tail differentiation in opisthobranchs resembles that in pulmonates, whereas it differs in many respects from that occurring in prosobranchs. The appearance of intracristal bodies in modified mitochondria seems to be a special feature of spermatogenesis in the opisthobranchs that does not occur in the two other groups of gastropod molluscs. PMID:3235038

  18. Reexamination of the gill withdrawal reflex of Aplysia californica Cooper (Gastropoda; Opisthobranchia).

    PubMed

    Leonard, J L; Edstrom, J; Lukowiak, K

    1989-06-01

    The gill withdrawal reflex (GWR), an important model system for neural mechanisms of learning, varies in form and amplitude within as well as between preparations and is therefore a heterogeneous collection of action patterns, not a reflex. At least 4 action patterns occur in response to mechanical stimulation of the siphon. It is often impossible to categorize a particular movement unambiguously. All may occur spontaneously. Gill movements may be described as combinations of 10 actions; 4 involving vein movements are described here. All actions and action patterns can occur in preparations lacking the central nervous system. Some vein movements may generate considerable force without markedly altering gill area. It is suggested that this explains why some early studies failed to identify the important role of the peripheral nervous system in the GWR. Studies based on the assumption that the GWR involves a single type of movement controlled by cells of the parietovisceral ganglion require reevaluation. PMID:2544202

  19. Accumulation and identification of lipofuscin-like pigment in the neurons of Bulla gouldiana (Gastropoda: Opisthobranchia).

    PubMed

    Robles, L J

    1978-01-01

    A few reports suggest that pigmented granules found in molluscan neurons accumulate with age as do lipofuscin granules in vertebrate cells; however, no reports on molluscan neurons include detailed descriptions of granule accumulation or histochemical tests to identify the pigment as lipofuscin-like. In this study light microscope observations of living ganglia from 1.7, 2.7, and 3.0 cm and larger (shell length) sized Bulla gouldiana showed an increasing accumulation of orange-red pigment in the perikaryon corresponding to increasing shell size (i.e. age). With the electron microscope similar results were obtained, and lipofuscin-like granules were seen in the nerve cell cytoplasm of veliger larvae and in all adult sized Bulla. Staining with Sudan black B, Nile blue, chrome alum hematoxylin, PAS reagents, and exposure of the neurons to u.v. light to observe subsequent autofluorescence, yielded positive results in the areas of pigmented granule accumulation. Thus, the brillant orange-red granules that accumulate with age in the peripheral cytoplasm of adult Bulla neurons, and which are probably also present in larval stages, chemically resemble the lipofuscin granules of vertebrates. Similarities and differences between molluscan pigmented granules and vertebrate lipofuscin granules, in relation to structure and mechanisms of development and accumulation, are discussed. PMID:625150

  20. Larval rearing, metamorphosis, growth and reproduction of the eolid nudibranch hermissenda crassicornis (eschscholtz, 1831) (gastropoda: opisthobranchia).

    PubMed

    Harrigan, J F; Alkon, D L

    1978-06-01

    1. Hermissenda crassicornis is a subannual nudibranch species that reproduces year-round. 2. There is a significant positive relationship between adult weight, diameter of the egg mass, estimated number of eggs per egg mass, and average number of eggs per capsule. 3. There is a planktonic veliger stage of 34 days minimum at 13 degrees -15 degrees C. 4. Larvae metamorphose on at least three species of hydroids. 5. To develop in reasonable numbers to a state competent to metamorphose veligers require a diet that includes phytoplankton of larger cell size (10-11 microm) than the commonly used Isochrysis and Monochrysis (5 microm). 6. Although Hermissenda feeds on a wide variety of sessile invertebrate species in the ocean, a diet of tunicate alone (Ciona intestinalis) promotes good growth and survival in the laboratory. 7. Egg mass deposition is initiated only after first copulation, except in the last month of life, and continues from about one-month post-metamorphosis to death, at about four months post-metamorphosis. Generation time (egg-to-egg) may be as short as 2.5 months. 8. A laboratory strain of Hermissenda is being established to provide animals of known history for research on the neural correlates of behavior. Animals, at least initially, are being selected for fast growth rate. PMID:20693369

  1. Microanatomy and ultrastructure of the excretory system of two pelagic opisthobranch species (Gastropoda: Gymnosomata and Thecosomata).

    PubMed

    Fahrner, A; Haszprunar, G

    2000-04-01

    The microanatomy and ultrastructure of the excretory system of Pneumoderma sp. (Gymnosomata) and Creseis virgula Rang, 1828 (Thecosomata) have been investigated by means of semithin serial sections, reconstructions and transmission electron microscopy. The studies revealed a functional metanephridial system consisting of a heart with a single ventricle and auricle in a pericardial cavity and a single kidney in both species. Podocytes in the atrial wall of the pericardial epithelium are the site of ultrafiltration, whereas the flat epithelium of the kidney with numerous basal infoldings and a dense microvillous border on the luminal surface suggests modification of the ultrafiltrate. In Pneumoderma sp., additional loci of ultrafiltration with identical fine structure (meandering slits with diaphragms covered by extracellular matrix) occur in the solitary rhogocytes (pore cells). The presence of podocytes situated on the atrial wall in representatives of two higher opisthobranch taxa contradicts former ideas on the loss of the primary site of ultrafiltration in the ancestors of the Opisthobranchia. PMID:11085207

  2. Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda).

    PubMed

    Händeler, Katharina; Wägele, Heike; Wahrmund, Ute; Rüdinger, Mareike; Knoop, Volker

    2010-11-01

    Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter. PMID:21565106

  3. COMPARATIVE SPERM ULTRASTRUCTURE IN FIVE GENERA OF THE NUDIBRANCH FAMILY CHROMODORIDIDAE (GASTROPODA: OPISTHOBRANCHIA).

    PubMed

    Wilson, NERIDA G.; Healy, JOHN M.

    2002-05-01

    Sperm ultrastructure is examined in representatives of five genera of the nudibranch gastropod family Chromodorididae: (Chromodoris, Hypselodoris, Glossodoris, Risbecia and Pectenodoris) and the results compared with previous work on other gastropods, especially other nudibranchs. As chromodoridid phylogeny is still incompletely understood, this study partly focuses on the search for new and as yet untapped sources of informative characters. Like spermatozoa of most other heterobranch gastropods, those of the Chromodorididae are elongate, complex cells composed of an acrosomal complex (small, rounded acrosomal vesicle, and columnar acrosomal pedestal), a condensed nucleus, sub-nuclear ring, a highly modified mid-piece (axoneme + coarse fibres surrounded by a glycogen-containing, helically-coiled mitochondrial derivative) and terminally a glycogen piece (or homologue thereof). The finely striated acrosomal pedestal is a synapomorphy of all genera examined here, but interestingly also occurs in at least one dorid (Rostanga arbutus). Substantial and potentially taxonomically informative differences were also observed between genera in the morphology of the nucleus, the neck region of the mid-piece, and also the terminal glycogen piece. The subnuclear ring is shown for the first time to be a segmented, rather than a continuous structure; similarly, the annular complex is shown to consist of two structures, the annulus proper and the herein-termed annular accessory body. PMID:12011239

  4. A new phylogeny of the Cephalaspidea (Gastropoda: Heterobranchia) based on expanded taxon sampling and gene markers.

    PubMed

    Oskars, Trond R; Bouchet, Philippe; Malaquias, Manuel António E

    2015-08-01

    The Cephalaspidea is a diverse marine clade of euthyneuran gastropods with many groups still known largely from shells or scant anatomical data. The definition of the group and the relationships between members has been hampered by the difficulty of establishing sound synapomorphies, but the advent of molecular phylogenetics is helping to change significantly this situation. Yet, because of limited taxon sampling and few genetic markers employed in previous studies, many questions about the sister relationships and monophyletic status of several families remained open. In this study 109 species of Cephalaspidea were included covering 100% of traditional family-level diversity (12 families) and 50% of all genera (33 genera). Bayesian and maximum likelihood phylogenetics analyses based on two mitochondrial (COI, 16S rRNA) and two nuclear gene markers (28S rRNA and Histone-3) were used to infer the relationships of Cephalaspidea. The monophyly of the Cephalaspidea was confirmed. The families Cylichnidae, Diaphanidae, Haminoeidae, Philinidae, and Retusidae were found non-monophyletic. This result suggests that the family level taxonomy of the Cephalaspidea warrants a profound revision and several new family and genus names are required to reflect the new phylogenetic hypothesis presented here. We propose a new classification of the Cephalaspidea including five new families (Alacuppidae, Colinatydidae, Colpodaspididae, Mnestiidae, Philinorbidae) and one new genus (Alacuppa). Two family names (Acteocinidae, Laonidae) and two genera (Laona, Philinorbis) are reinstated as valid. An additional lineage with family rank (Philinidae "Clade 4") was unravelled, but no genus and species names are available to reflect the phylogeny and formal description will take place elsewhere. PMID:25916189

  5. New Indo-Pacific species of the genus Teretia Norman, 1888 (Gastropoda: Raphitomidae).

    PubMed

    Morassi, Mauro; Bonfitto, Antonio

    2015-01-01

    Four new species are assigned to the genus Teretia Norman, 1888 in the family Raphitomidae Bellardi, 1875 and herein described: Teretia neocaledonica sp. nov., T. sysoevi sp. nov., T. tongaensis sp. nov. from the southeastern Pacific and Teretia tavianii sp. nov. from the Gulf of Aden. The new species represent the first Indo-Pacific record of a genus previously known in the recent molluscan fauna by only two species from the Atlantic Ocean-Mediterranean Sea and Southern Africa. A possible Tethyan origin for the genus Teretia is suggested.  PMID:25661630

  6. Update on the distribution and phylogenetics of Biomphalaria (Gastropoda: Planorbidae) populations in Guangdong Province, China.

    PubMed

    Attwood, Stephen W; Huo, Guan-Nan; Qiu, Jian-Wen

    2015-01-01

    In 1973 planorbid snails then identified as Biomphalaria straminea were discovered in Hong Kong, China. It was assumed that these snails had been introduced to Hong Kong via the import of tropical fish by air from South America. In 2012 Biomphalaria were found for the first time in Guangdong Province, China. In view of the renewed interest in these invasive snails, a morphological and DNA-sequence based phylogenetic study was undertaken for seven populations of Biomphalaria snails collected in Guangdong. Morphologically and phylogenetically, five of the populations clustered more closely with Biomphalaria kuhniana than with B. straminea. Levels of genetic diversity among the populations were about half those of autochthonous populations in Brazil, the phylogenetic relationships did not correlate with a radiation from any one international port in China, and different lineages appeared associated with different ports. Consequently in explaining the current distribution of the snails, multiple colonization events, each establishing a new local snail population near to maritime international container ports, were considered more likely than the spread of snails from Hong Kong to China. The displacement of B. straminea by B. kuhniana in Guangdong is considered as an explanation for the habitat changes observed among the snails between Hong Kong in the 1980s and the present. The conclusions of the study are that any risk of Schistosoma mansoni transmission in China is more likely to come from parasite importation in the intramolluscan stage, than from transmission by migrant workers from South America or Africa. In addition, although likely to be rare, sporadic outbreaks of imported schistosomiasis (caused by invading infected snails) could be a threat to public health in the vicinity of International container ports (not only in Guangdong Province). Further work is called for to investigate further the presence of B. kuhniana and its potential interactions with B. straminea (the former is thought to be incompatible with S. mansoni), and the responses of Chinese Biomphalaria to potential competitors such as Thiaridae. The current expansion of container ports in Brazil and Venezuela, and the increase in trade with China, is likely to accentuate any current risk of imported schistosomiasis, and surveillance around ports in China, together with further research, are necessary. PMID:24811366

  7. The shallow-water New Caledonia Drilliidae of genus Clavus Montfort, 1810 (Mollusca: Gastropoda: Conoidea).

    PubMed

    Kilburn, Richard N; Fedosov, Alexander; Kantor, Yuri

    2014-01-01

    Species of the genus Clavus of the conoidean family Drilliidae that occur in the littoral and shallow waters of New Caledonia are here revised. This study is based primarily on recent expedition material from the Institut de Recherche pour le Développement (New Caledonia) and Muséum National d'Histoire Naturelle (France). A total of 22 species is recorded, of which eight are described as new. New species: Clavus boucheti, Clavus delphineae, Clavus virginieae, Clavus picoides, Clavus squamiferus, Clavus devexistriatus, Clavus hylikos, Clavus maestratii; New synonyms: Tylotiella Habe, 1958 = Clavus; Clavus leforestieri Hervier, 1896 = Pleurotoma obliquicostata Reeve, 1845; Pleurotoma mariei Crosse, 1869 = Pleurotoma lamberti Montrouzier, 1860; Clavus mighelsi Kay, 1979, new name for Pleurotoma acuminata Mighels, 1845, non J. Sowerby, 1816, was misidentified by Kay 1979; the lectotype of P. acuminata Mighels, 1845, is mangeliine. Clavus mighelsi sensu Kay 1979, is a synonym of Pleurotoma humilis E. A. Smith, 1879. It is suggested that Pleurotoma pulchella Reeve, 1845, sometimes treated as an Indo-Pacific species, may be a senior synonym of Fenimorea halidorema Schwengel, 1940, from the tropical western Atlantic. Nomen dubium: Pleurotoma mediocris Deshayes, 1863. PMID:24943803

  8. Iron-encrusted diatoms and bacteria epibiotic on Hydrobia ulvae (Gastropoda: Prosobranchia)

    NASA Astrophysics Data System (ADS)

    Gillan, D. C.; Cadée, G. C.

    2000-02-01

    Rust-coloured shells of the gastropod Hydrobia ulvae collected in the Wadden Sea near Texel and in the Jade Busen were analysed under the scanning electron microscope. Most of the shells were found to be covered with a microbial community encrusted with an iron-rich mineral containing traces of Mn, Mg, Ca and Si (EDAX analysis). The community formed a biofilm including two morphotypes of diatoms identified as Cocconeis placentula and Achnanthes lemmermanni, two morphotypes of slender filamentous bacteria resembling Leucothrix and Flexibacter, aggregates of coccoid cells and large trichomes resembling members of the cyanobacterial orders Pleurocapsales and Stigonematales, respectively. The most frequent microorganisms of the biofilm were diatoms and filamentous bacteria.

  9. Taxonomic revision of the rock-dwelling door snail genus Montenegrina Boettger, 1877 (Mollusca, Gastropoda, Clausiliidae)

    PubMed Central

    Fehér, Zoltán; Szekeres, Miklós

    2016-01-01

    Abstract The genus Montenegrina is revised on the basis of material available at the Hungarian Natural History Museum (Budapest), Naturhistorisches Museum Wien (Vienna), and the Naturmuseum Senckenberg (Frankfurt am Main), as well as newly discovered populations. The following new taxa are described: Montenegrina haringae sp. n., Montenegrina lillae sp. n., Montenegrina prokletiana sp. n., Montenegrina sturanyana sp. n., Montenegrina grammica erosszoltani ssp. n., Montenegrina grammica improvisa ssp. n., Montenegrina hiltrudae desaretica ssp. n., Montenegrina hiltrudae selcensis ssp. n., Montenegrina laxa delii ssp. n., Montenegrina nana barinai ssp. n., Montenegrina prokletiana kovacsorum ssp. n., Montenegrina rugilabris golikutensis ssp. n., Montenegrina rugilabris gregoi ssp. n., Montenegrina skipetarica danyii ssp. n., Montenegrina skipetarica gurelurensis ssp. n., Montenegrina skipetarica pifkoi ssp. n., Montenegrina skipetarica puskasi ssp. n., Montenegrina sporadica tropojana ssp. n., Montenegrina sturanyana gropana ssp. n., Montenegrina sturanyana ostrovicensis ssp. n., and Montenegrina tomorosi hunyadii ssp. n. A neotype is designated for Montenegrina helvola (Küster, 1860), and Montenegrina cattaroensis antivaricostata nom. n. was introduced to replace the junior homonym Clausilia umbilicata costata Boettger, 1907 (non Pfeiffer, 1928). Of each taxon types or specimens from the type localities are figured, and distribution maps are provided. PMID:27408595

  10. Redescription of Bellerophon asiaticus Wirth (Early Triassic: Gastropoda) from China, and a survey of Triassic Bellerophontacea.

    USGS Publications Warehouse

    Yochelson, E.Y.; Yin, Hongfu

    1985-01-01

    The bilaterally symmetrical gastropod Bellerophon asiaticus Wirth is redescribed from specimens collected in Guizhou Province, PRC. The species is reassigned to Retispira, a common late Paleozoic taxon. Retispira is another example of a Paleozoic gastropod genus that crossed the era boundary. Associated pelecypods that date these Guizhou occurrences as Early Triassic are well known species in PRC and are illustrated. Both Bellerophon and Euphemites probably occur in the Early Triassic, though the quality of illustrations leaves some uncertainty; the existence of Stachella in the Triassic is more problematic. There was no dramatic reduction of the Bellerophontacea from their abundance and diversity in the Permian. It may be a general phenomenon that most late Paleozoic family-level and many generic-level taxa of gastropods were unaffected by the late Permian 'crisis'. from Authors

  11. The phylogeny and taxonomy of austral monodontine topshells (Mollusca: Gastropoda: Trochidae), inferred from DNA sequences.

    PubMed

    Donald, Kirsten M; Kennedy, Martyn; Spencer, Hamish G

    2005-11-01

    The systematics of topshells (family Trochidae) is currently unresolved: at present even the generic boundaries within this group are poorly defined. In this study, we used sequence data of two mitochondrial genes (16S and cytochrome oxidase 1, COI) and one nuclear gene (actin) to resolve the phylogeny of a closely related subgroup of the Trochidae, 30 species of largely Southern Hemisphere monodontine topshells. The phylogenies constructed revealed five well-supported generic clades: a South African clade (genus Oxystele Philippi, 1847), which lay basally to four internal Pacific clades (genera Chlorodiloma Pilsbry, 1889; Monodonta Lamarck, 1799; Austrocochlea Fischer, 1885; and Diloma Philippi, 1845). The molecular phylogenies constructed in this study shed light on previously unresolved relationships between different groups of topshells, allowing for the first time assignation (based on DNA sequence) of clearly defined, well-supported taxonomic and nomenclatural classification of monodontine topshells species. Austrocochlea crinita (Philippi, 1849), A. odontis (Wood, 1828), A. adelaidae (Philippi, 1849), and A. millelineata (Bonnet, 1864) are placed in the genus Chlorodiloma, which we resurrect from synonymy with Austrocochlea. The Japanese M. confusa Tapparone-Canefri, 1874 is treated as a separate species from M. labio (Linné, 1758). Melagraphia Gray, 1847 is synonymised with Diloma and its sole member, M. aethiops (Gmelin, 1791), along with A. concamerata (Wood, 1828), is transferred to that genus. The Juan Fernandez endemic D. crusoeana (Pilsbry, 1889) is synonymised with D. nigerrima (Gmelin, 1791). We find that morphologically cryptic species are not necessarily close genetically. PMID:15936215

  12. Molecular phylogeny reveals the polyphyly of the snail genus Cepaea (Gastropoda: Helicidae).

    PubMed

    Neiber, Marco T; Hausdorf, Bernhard

    2015-12-01

    Snails in the genus Cepaea are important model organisms in ecogenetic studies because of their colour and banding polymorphism. The monophyly of this group has been almost unanimously assumed based on superficial similarities in shell form and colouration. However, molecular phylogenetic analyses based on mitochondrial and nuclear sequences of 20 genera of Helicidae unequivocally demonstrated that Cepaea as currently understood is a polyphyletic assemblage. Only C. nemoralis and C. hortensis are retained in Cepaea, whereas C. vindobonensis is referred to Caucasotachea and C. sylvatica to Macularia based on our molecular phylogeny. Cepaea and Macularia belong to the western clade of the Helicinae, whereas Caucasotachea is nested in the eastern clade which probably diverged in the late Eocene. Because of the large phylogenetic distances between Cepaea, Macularia and Caucasotachea, it has to be shown whether the genetic mechanism underlying the simpler banding polymorphism in C. vindobonensis and M. sylvatica is a simpler version of the supergene that determines the polymorphism in Cepaea in the strict sense. This case illustrates the importance of sound phylogenetic analyses as a basis for any predictions in comparative biology. PMID:26256642

  13. A nomenclator of extant and fossil taxa of the Melanopsidae (Gastropoda, Cerithioidea)

    PubMed Central

    Neubauer, Thomas A.

    2016-01-01

    Abstract This nomenclator provides details on all published names in the family-, genus-, and species-group, as well as for a few infrasubspecific names introduced for, or attributed to, the family Melanopsidae. It includes nomenclaturally valid names, as well as junior homonyms, junior objective synonyms, nomina nuda, common incorrect subsequent spellings, and as far as possible discussion on the current status in taxonomy. The catalogue encompasses three family-group names, 79 genus-group names, and 1381 species-group names. All of them are given in their original combination and spelling (except mandatory corrections requested by the Code), along with their original source. For each family- and genus-group name, the original classification and the type genus and type species, respectively, are given. Data provided for species-group taxa are type locality, type horizon (for fossil taxa), and type specimens, as far as available. PMID:27551193

  14. Late Paleozoic subulitacea (mollusca:gastropoda), mass extinctions and the replacement of evolutionary faunas

    SciTech Connect

    Erwin, D.H.

    1985-01-01

    Mesogastropod subulitaceans possess characteristics typical of active carnivores and occupied a trophic regime typical of the Mesozoic-Cenozoic evolutionary fauna. Despite occupying a vacant niche, subulitaceans are low in both diversity and abundance in late Paleozoic gastropod faunas. In addition, Paleozoic Archaeogastropoda and Mesogastropoda are taxonomically and functionally distinct from Mesozoic groups and display diversity dynamics typical of the Paleozoic evolutionary fauna, not the Mesozoic-Cenozoic fauna with which they were grouped by Sepkoski. Late Paleozoic gastropods are different from pre-Carboniferous taxa, but there is no preferential expansion of the major Mesozoic taxa, nor is there any pattern of exploitation of a major niche utilized by later groups but under-used by Paleozoic taxa. The high taxonomic level used Sepkoski's factor analysis neglects the finer scale of replacement and diversification. This distinct evolutionary behavior of Paleozoic gastropods may be typical of other taxa as well. It weakens the assertions of Kitchell and Carr and Sepkoksi and Miller that the replacement of evolutionary Fauna II by Fauna III began in the late Paleozoic and would have occurred even without the Guadelupian-Dzulfian mass extinction. Thus for gastropods at last, the Late Permian mass extinction did not merely speed up on ongoing process, but probably determined the evolutionary outcome.

  15. Histochemical research on metabolic pathways of glucose in some species of Mollusca Gastropoda.

    PubMed

    Bolognani Fantin, A M; Bolognani, L; Ottaviani, E; Franchini, A

    1987-01-01

    The metabolic pathways of glucose were studied by histochemical reactions in some species of gastropods living in different habitats. The glycolytic pathway is histochemically indicated by positive results for glucose-6-phosphate isomerase, fructose-1,6-biphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and D-lactate dehydrogenase. The enzymes of the Krebs cycle gave different responses: isocitrate dehydrogenase and L-malate dehydrogenase were positive, whilst succinate dehydrogenase was constantly negative. Malate synthetase activity was also demonstrated. Despite L-glutamate dehydrogenase is undetectable, the presence of transaminase indicates the gluconeogenetic route. Phosphoglucomutase and glucose-6-phosphate phosphatase appear also positive. The metabolic meaning of our results were discussed. PMID:3111150

  16. Family matters: The first molecular phylogeny of the Onchidorididae Gray, 1827 (Mollusca, Gastropoda, Nudibranchia).

    PubMed

    Hallas, Joshua M; Gosliner, Terrence M

    2015-07-01

    Recent investigations into the evolution of the Onchidorididae using morphological based methods have resulted in low support for relationships among genera. This study aims to determine if molecular data corroborates recent morphological interpretations of the evolution of Onchidorididae. Five genetic markers: 16S, 18S, 28S, cytochrome c oxidase 1 (COI) and histone 3 (H3), were sequenced from 32 species comprising Onchidorididae and five other families, three from Phanerobranchia and two from Cryptobranchia. Phylogenies were estimated using maximum likelihood, and Bayesian inference analyses; with both yielding similar topologies. Molecular analyses resulted in high support for the monophyly of the suctorian clade and the placement of the genera within Onchidorididae. However, the Onchidorididae forms a paraphyletic grouping due to the recovery of the Goniodorididae and the Akiodorididae nested within family. In addition, the placement of Corambe as the most derived member of Onchidorididae is contradicted by the present study. Rather it is sister to a large clade that includes Acanthodoris and the species traditionally placed in Onchidoris and Adalaria, now defined as Onchidorididae. We have chosen to maintain Corambidae as a distinct taxon (including Corambe and Loy), sister to Onchidorididae. We also maintain Goniodorididae, Akiodorididae and Calycidoridae (including Calycidoris and Diaphorodoris), which along with the Onchidorididae and Corambidae comprise the suctorian superfamily Onchidoridoidea. Ancestral character reconstruction also suggests that the formation of a gill pocket, a character that currently defines the Cryptobranchia, may have evolved multiple times from an ancestor that lacked the ability to retract its gills into a fully formed gill pocket. The diversity of gill morphology displayed by the Onchidoridoidea will help give new insight into the evolution of this complex character within the Nudibranchia. PMID:25837732

  17. Molecular phylogenetic analysis of mudflat snails (Gastropoda: Euthyneura: Amphiboloidea) supports an Australasian centre of origin.

    PubMed

    Golding, Rosemary E

    2012-04-01

    Amphiboloidea is a small but widespread group of snails found exclusively, and often abundantly, in mudflat and associated salt marsh or mangrove habitat. This study uses molecular data from three loci (COI, 16S and 28S) to infer phylogenetic relationships in Amphiboloidea and examine its position in Euthyneura. All but two of the named extant species of Amphiboloidea and additional undescribed taxa from across Southeast Asia and the Arabian Gulf were sampled. In contrast to the current morphology-based classification dividing Amphiboloidea into three families, analysis of molecular data supports revision of the classification to comprise two families. Maningrididae is a monotypic family basal to Amphibolidae, which is revised to comprise three subfamilies: Amphibolinae, Phallomedusinae and Salinatorinae. Sequence divergence between Asian populations of Naranjia is relatively large and possibly indicative of species complexes divergent across the Strait of Malacca. Salinatorrosacea and Salinator burmana do not cluster with other Salinator species, and require generic reassignment. In addition, sequences were obtained from an undescribed species of Lactiforis from the Malay Peninsula. Reconstruction of ancestral distributions indicates a plesiomorphic distribution and centre of origin in Australasia, with two genera subsequently diversifying throughout Asia. Increasing the sampling density of amphiboloid taxa in a phylogenetic analysis of Euthyneura did not resolve the identity of the sister taxon to Amphibolidae, but confirmed its inclusion in Pulmonata/Panpulmonata. PMID:22210412

  18. TEMPERATURE TOLERANCE OF RED-RIMMED MELANIA MELANOIDES TUBERCUATA, (GASTROPODA: PROSOBRANCHIA: THIARIDAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red-rimmed melania Melanoides tuberculata is an exotic aquatic snail of the family Thiaridae that is spreading across the southern United States and in geothermal waters in several midwestern and northwestern states. In addition to its potential to displace native mollusks it is known to harbor...

  19. Population biology of the gastropod Olivella minuta (Gastropoda, Olividae) on two sheltered beaches in southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Petracco, Marcelo; Camargo, Rita Monteiro; Tardelli, Daniel Teixeira; Turra, Alexander

    2014-10-01

    The structure, dynamics and production of two populations of the olivid gastropod Olivella minuta were analyzed through monthly sampling from November 2009 through October 2011 on two sandy beaches, Pernambuco (very sheltered) and Barequeçaba (sheltered) in São Paulo state (23°48'S), southeastern Brazil. On both beaches, samples were taken along five transects established perpendicular to the waterline. Parameters of the von Bertalanffy growth function were estimated for both populations from monthly length-frequency distributions. The production and turnover ratios were determined using the mass-specific growth rate method. The population on the less-sheltered Barequeçaba Beach was less abundant (120.02 ± 22.60 ind m-1) than on Pernambuco Beach (3295.30 ± 504.86 ind m-1 (±SE)), which we attribute to the greater environmental stability of the latter. Conversely, the mean length, size of the largest individual, and body mass were higher at Barequeçaba than at Pernambuco. The significant differences in the growth of individuals and the mortality rate (Z) between the beaches suggest that density-dependent processes were operating at Pernambuco Beach. The production and P/B ratio at Pernambuco (12.12 g AFDM m-1 year-1 and 1.91 year-1) were higher than at Barequeçaba (0.82 g AFDM m-1 year-1 and 1.06 year-1). The difference in production can be attributed to the higher abundance on Pernambuco, while the higher P/B ratio resulted from the scarcity of smaller individuals in the intertidal zone of Barequeçaba. The P/B ratio estimated for the Pernambuco population is the highest found so far for sandy-beach gastropods. This study reinforces the theory that biological interactions are important regulators of sheltered sandy-beach populations. Future studies with multi-beach sampling are needed to better understand the life-history variations of O. minuta along gradients of degree of exposure of sandy beaches.

  20. Burnaia Miller, 2001 (Gastropoda, Heterobranchia, Nudibranchia): a facelinid genus with an Aeolidiidae's outward appearance

    NASA Astrophysics Data System (ADS)

    Carmona, Leila; Pola, Marta; Gosliner, Terrence M.; Cervera, Juan Lucas

    2015-09-01

    In recent years, several morphological and molecular analyses have been undertaken to study the phylogenetic systematics of Aeolidiidae members. The monospecific genus Burnaia could not be included in the previous analysis, due to the lack of material. This study includes two specimens of Burnaia helicochorda from Australia and places them in their systematic position using two mitochondrial and one nuclear genes (COI and 16S, and H3, respectively). A description of its anatomy is also included with colour pictures of the animal and scanning electron micrographs of radula and jaws. Based on our results, B. helicochorda does not belong to Aeolidiidae since it appears nested among some facelinids.

  1. Dynamics and ecology of an Indo-Pacific conch, Conomurex persicus (Mollusca: Gastropoda) in southeastern Turkey.

    PubMed

    Mutlu, Erhan; Ergev, Mehmet Betil

    2006-03-01

    Conomurex persicus, one of the tropical conchs, has been introduced to one of the subtropical regions, the northeastern Mediterranean Sea, and invaded sandy bottoms between 1 and 10 m deep. Population dynamics were studied from specimens collected with a standard dredge (60 x 15 cm mouth opening, 0.5 x 0.5 cm eye opening of net). Samples of C persicus were collected monthly along the 5 and 10 m depth contours off Erdemli, Mersin, Turkey, in February and May 2000. Intra-annual density depended on salinity levels, while inter-annual density was correlated with bottom water temperature. Specimens underwent spring emergences and winter burial and sheltering (disappearance). Emergence took place in March when temperatures rose and the disappearance occurred in October-November when temperatures dropped. Adults live at 10 m, juveniles are recruited at a 5 m depth. Recruitment began in April and continued for the next 6 months. In contrast to shell width or shell lip thickness, shell length was not a convenient index for estimation of growth parameters. Annual production and mortality were calculated to be 7.86 g m(-2) and 3.80 g m(-2), respectively, in April-November. PMID:18457181

  2. [Individual growth of Lymnaea stagnalis (Lymnaeidae, Gastropoda): II. Late postlarval ontogeny].

    PubMed

    Zotin, A A

    2009-01-01

    Our investigation on the growth of 14 individuals of the great pond snail Lymnaea stagnalis was performed in an aquatic culture at 18 degrees C beginning from the 10th week after hatching until death. It has been demonstrated that the increase in the mollusk mass follows an S-like curve during the whole studied period. Linear growth (conch height) follows a parabolic (convex) curve until the age of 39 weeks. Both weight and linear growth during studied period significantly approximate to the Bertalanffy equation, while the interrelation between mass and conch height corresponds to the allometric equation. The meanings of the coefficients of these equations do not differ significantly in different individuals. At the age of 38 to 39 weeks, all mollusks demonstrate breakage in the curve of linear growth, then followed with abrupt slowing of growth until stopping or even decreasing in size in some cases. Neither the Bertalanffy equation nor the allometric relation describe the linear growth of individuals with ages exceeding 39 weeks. PMID:20143629

  3. Granopupa in Iran, monophyly, and the fossil Granariinae (Gastropoda, Pulmonata, Chondrinidae).

    PubMed

    Gittenberger, Edmund; Kokshoorn, Bas; Bößneck, Ulrich; Reijnen, Bastian T; Groenenberg, Dirk S J

    2016-01-01

    Indisputable Chondrinidae, Granariinae species, characterized by shell shape and apertural dentition, are known from Eocene deposits to the Recent. The generic classification of the extant species is based on conchological, anatomical and molecular data that are available now for most of the known species, including 'Granaria' persica as a representative of the once problematic group of so-called eastern Granaria species. According to molecular and anatomical characters, these eastern species have to be classified with Granopupa granum in Granopupa. Graniberia gen. n. is introduced for Granaria braunii on the basis of molecular and conchological data. For the pre-Pleistocene species, two generic names are equally well available now, viz. Granopupa and Granaria. Shell characters only do not enable a decision here. For the sake of nomenclatorial stability we propose to use Granaria for these species. Because both molecular and anatomical data most likely will never be known for the fossils, it will remain unclear whether the combined extant and extinct Granaria species form a monophyletic group. PMID:27408543

  4. Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae

    PubMed Central

    Breure, Abraham S.H.; Avila, Valentín Mogollón

    2016-01-01

    Abstract A faunal overview is presented of the molluscan families Amphibulimidae, Megaspiridae, Odontostomidae, Orthalicidae, Simpulopsidae in Bolivia, Ecuador, and Peru. These Central Andean countries are known for their biodiverse malacofauna, of which the superfamily Orthalicoidea takes relatively a large share. In this paper the five families containing 103 (sub)species, for which systematic information (original publication, type locality, type depository, summarizing literature) and distributional records are presented. All species are illustrated by photographs of the type material or, if this could not be located, by a reproduction of the original figure. The following new taxon is introduced: Thaumastus (Thaumastus) sumaqwayqu sp. n. Junior subjective synonyms are established for: Plekocheilus (Sparnotion) Pilsbry, 1944 = Plekocheilus (Eudolichotis) Pilsbry, 1896; Scholvienia (Thomsenia) Strebel, 1910 = Scholvienia Strebel, 1910; Sultana (Trachyorthalicus) Strebel, 1909 = Sultana (Metorthalicus) Pilsbry, 1899; Plekocheilus (Eurytus) conspicuus Pilsbry, 1932 = Thaumastus (Thaumastus) hartwegi (Pfeiffer in Philippi, 1846); Zebra gruneri Strebel, 1909 = Orthalicus maracaibensis (Pfeiffer, 1856); Scholvienia jaspidea minor Strebel, 1910 = Scholvienia alutacea (Reeve, 1850); Bulimus bifasciatus unicolor Philippi, 1869 = Scholvienia brephoides (d’Orbigny, 1835). A new status is given to Plekocheilus mcgintyi ‘Pilsbry’ H.B. Baker, 1963 (subspecies of Bulinus piperitus Sowerby I, 1837); Strophocheilus superstriatus var. prodeflexus Pilsbry, 1895 (subspecies of Bulinus piperitus Sowerby I, 1837); Thaumastus (Quechua) salteri maximus Weyrauch, 1967 (subspecies of Thaumastus (Quechua) olmosensis Zilch, 1954); Pseudoglandina agitata Weyrauch, 1967 (nomen inquirendum). New combinations are: Clathrorthalicus corydon (Crosse, 1869), and Cyclodontina chuquisacana (Marshall, 1930). Lectotypes are now designated for Bulimus incisus Hupé, 1857 and Bulinus piperitus Sowerby I, 1837. PMID:27408531

  5. Review of the genus Endothyrella Zilch, 1960 with description of five new species (Gastropoda, Pulmonata, Plectopylidae)

    PubMed Central

    Páll-Gergely, Barna; Budha, Prem B.; Naggs, Fred; Backeljau, Thierry; Asami, Takahiro

    2015-01-01

    Abstract All known taxa of the genus Endothyrella Zilch, 1960 (family Plectopylidae) are reviewed. Altogether 23 Endothyrella species are recognized. All species are illustrated and whenever possible, photographs of the available type specimens are provided. Five new species are described: Endothyrella angulata Budha & Páll-Gergely, sp. n., Endothyrella dolakhaensis Budha & Páll-Gergely, sp. n. and Endothyrella nepalica Budha & Páll-Gergely, sp. n. from Nepal, Endothyrella robustistriata Páll-Gergely, sp. n. from the Naga Hills, India, and Endothyrella inexpectata Páll-Gergely, sp. n. from Sichuan, China. Helix (Plectopylis) munipurensis Godwin-Austen, 1875 is synonymized with Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) gregorsoni Gude, 1915 is synonymized with Helix (Plectopylis) macromphalus W. Blanford, 1870. Plectopylis plectostoma var. exerta Gude, 1901 is a synonym of Plectopylis plectostoma var. tricarinata Gude, 1896, which is a species in its own right. Five species of the genus Chersaecia viz. Plectopylis (Chersaecia) bedfordi Gude, 1915, Helix (Plectopylis) brahma Godwin-Austen, 1879, Helix (Plectopylis) Oglei Godwin-Austen, 1879, Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) williamsoni Gude, 1915 are moved to Endothyrella. The holotype of Plectopylis hanleyi Godwin-Austen, 1879 seems to be lost; therefore, Plectopylis hanleyi is considered to be a nomen dubium. PMID:26692792

  6. The Vermetidae of the Gulf of Kachchh, western coast of India (Mollusca, Gastropoda)

    PubMed Central

    Joshi, Devanshi MukundRay; Mankodi, Pradeep C.

    2016-01-01

    Abstract Coral reefs are often termed underwater wonderlands due to the presence of an incredible biodiversity including numerous invertebrates and vertebrates. Among the dense population of benthic and bottom-dwelling inhabitants of the reef, many significant species remain hidden or neglected by researchers. One such example is the vermetids, a unique group of marine gastropods. The present study attempts for the first time to assess the density and identify preferred reef substrates in the Gulf of Kachchh, state of Gujarat, on the western coast of India. A total of three species of the family Vermetidae were recorded during the study and their substrate preferences identified. PMID:26877684

  7. Identification of sequestered chloroplasts in photosynthetic and non-photosynthetic sacoglossan sea slugs (Mollusca, Gastropoda)

    PubMed Central

    2014-01-01

    Background Sacoglossan sea slugs are well known for their unique ability among metazoans to incorporate functional chloroplasts (kleptoplasty) in digestive glandular cells, enabling the slugs to use these as energy source when starved for weeks and months. However, members assigned to the shelled Oxynoacea and Limapontioidea (often with dorsal processes) are in general not able to keep the incorporated chloroplasts functional. Since obviously no algal genes are present within three (out of six known) species with chloroplast retention of several months, other factors enabling functional kleptoplasty have to be considered. Certainly, the origin of the chloroplasts is important, however, food source of most of the about 300 described species is not known so far. Therefore, a deduction of specific algal food source as a factor to perform functional kleptoplasty was still missing. Results We investigated the food sources of 26 sacoglossan species, freshly collected from the field, by applying the chloroplast marker genes tufA and rbcL and compared our results with literature data of species known for their retention capability. For the majority of the investigated species, especially for the genus Thuridilla, we were able to identify food sources for the first time. Furthermore, published data based on feeding observations were confirmed and enlarged by the molecular methods. We also found that certain chloroplasts are most likely essential for establishing functional kleptoplasty. Conclusions Applying DNA-Barcoding appeared to be very efficient and allowed a detailed insight into sacoglossan food sources. We favor rbcL for future analyses, but tufA might be used additionally in ambiguous cases. We narrowed down the algal species that seem to be essential for long-term-functional photosynthesis: Halimeda, Caulerpa, Penicillus, Avrainvillea, Acetabularia and Vaucheria. None of these were found in Thuridilla, the only plakobranchoidean genus without long-term retention forms. The chloroplast type, however, does not solely determine functional kleptoplasty; members of no-retention genera, such as Cylindrobulla or Volvatella, feed on the same algae as e.g., the long-term-retention forms Plakobranchus ocellatus or Elysia crispata, respectively. Evolutionary benefits of functional kleptoplasty are still questionable, since a polyphagous life style would render slugs more independent of specific food sources and their abundance. PMID:24555467

  8. [Inheritance of the background shell color in the snails Littorina obtusata (Gastropoda, Littorinidae)].

    PubMed

    Kozminsky, E V

    2014-10-01

    We investigated in a gastropod mollusk Littorina obtusata (L. obtusata) the inheritance of background shell coloration of the shell, which arises on the basis of three pigments: purple, orange, and yellow. We found that the hypothesis on polyallelic inheritance, as in the genus Cepaea, cannot explain the inheritance of shell color in periwinkles. We demonstrated that a separate genetic system is responsible for incorporation of each pigment into the shell. The composition of these genetic systems includes at least tw genes each in the case of the yellow and purple pigments. Our analysis shows that caution should be applied when extending the results obtained in the studies of the Cepaea genus to the other species of gastropods. PMID:25720250

  9. [Inheritance of longitudinal shell bands in the snails Littorina obtusata and Littorina saxatilis (Gastropoda, Prosobranchia)].

    PubMed

    Kozminskiĭ, E V

    2011-08-01

    The hypothesis of a monogenic inheritance of dark longitudinal bands on the shell in the gastropods Littorina obtusata and L. saxatilis was checked. One gene having two alleles proved to be responsible for the shell banding pattern in both of the species. The presence of bands was a dominant character in either case. PMID:21954620

  10. [Inheritance of white spots on the shell of Littorina obtusata (Gastropoda, Prosobranchia)].

    PubMed

    Kozminskiĭ, E V; Lezin, P A; Fokin, M V

    2010-12-01

    The hypothesis on monogenic inheritance of white spot pattern on the shell of the gastropod snail Littorina obtusata was tested. Although in most cases our results did not contradict this assumption, the hypothesis cannot explain the observed segregation in general. An alternative hypothesis was suggested, according to which the presence of spot pattern is controlled by two complementary biallelic genes. PMID:21434418

  11. [Morphobiochemical adaptations of Mediterranean Littorina punctata (Gmelin, 1790) (Mollusca, Gastropoda) to survival under supralittoral conditions].

    PubMed

    Aliakrinskaia, I O

    2014-01-01

    Behavioral and morphobiochemical adaptations of Littorina punctata to dwelling under supralittoral condi- tions are analyzed. A quantitative estimation of the hemoglobin content in the radular tissues of the mollusk is given. PMID:25735161

  12. Terrestrial slugs (Gastropoda, Pulmonata) in the NATURA 2000 areas of Cyprus island.

    PubMed

    Vardinoyannis, Katerina; Demetropoulos, Simon; Mylonas, Moissis; A Triantis, Kostas; Makris, Christodoulos; Georgiou, Gabriel; Wiktor, Andrzej; Demetropoulos, Andreas

    2012-01-01

    Terrestrial slugs of the Island of Cyprus were recently studied in the framework of a study of the whole terrestrial malacofauna of the island. The present work was carried out in the Natura 2000 conservation areas of the island in 155 sampling sites over three years (2004-2007). Museum collections as well as literature references were included. In total six species are present in the Natura 2000 areas of the island, belonging to three families: Limacidae, Agriolimacidae and Milacidae. One of the species, Milax riedeli, is a new record for the island. The distribution of the species across the island and in the surrounding areas is discussed. PMID:22451785

  13. Patterns of Diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean Region

    PubMed Central

    Ávila, Sérgio P.; Goud, Jeroen; de Frias Martins, António M.

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species—those living between the intertidal and 50 m depth, and deep species—those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years. PMID:22693430

  14. A new species of Bothriembryon (Mollusca, Gastropoda, Bothriembryontidae) from south-eastern Western Australia

    PubMed Central

    Whisson, Corey S.; Breure, Abraham S.H.

    2016-01-01

    Abstract Bothriembryon sophiarum sp. n. is described, based on shell and anatomical morphology, from the coastal area of south-easternmost Western Australia. This is the first description of a new extant Australian bothriembryontid in 33 years. The shell of Bothriembryon sophiarum is slender with a unique teleoconch sculpture. It is found in low coastal scrub on cliff edges and escarpments and because of its restricted distribution, qualifies as a short range endemic. PMID:27199583

  15. Dutrochus, a new microdomatid (Gastropoda) genus from the Middle Devonian (Eifelian) of west-central Alaska

    USGS Publications Warehouse

    Blodgett, R.B.

    1993-01-01

    A new gastropod genus, Dutrochus, is established for members of the family Microdomatidae that are characterized by a reticulate ornament of spiral cords and intersecting, finer collabral threads, with all but one spiral cord being of nearly equal strength, and the single remaining cord being of stronger (nearly twice the order) magnitude and being situated at the periphery. It is represented by the type and only known species, Dutrochus alaskensis n. gen. and sp., from the upper part (lower Eifelian) of the Lower? and Middle Devonian Cheeneetnuk Limestone. The genus is very close and nearly homeomorphic to the Permian microdomatid genus Glyptospira. -from Author

  16. Reversal of density dependence of juvenile Littorina littorea (Gastropoda) growth in response to periphyton nutrient status

    NASA Astrophysics Data System (ADS)

    Sommer, Ulrich

    2001-05-01

    Experimental periphyton communities were grown in aquaria receiving media of differently enriched seawater (fully enriched, without Si enrichment, without N and P enrichment) and supplied differently with medium (batch and weekly replacement). Periphyton was subject to grazing by 1-6 individuals of juvenile Littorina littorea. Periphyton biomass was higher in the replacement aquaria than in the batch aquaria and higher in the full and the -Si medium than in the -NP medium. The N:C ratio of the periphyton increased with Littorina number in the batch aquaria and was unaffected by Littorina number in the replacement aquaria. Diatoms were most dominant in the -NP treatments and rarest in the -Si treatments. Chlorophytes were dominant in the -Si and the fully enriched treatments, but also Cyanobacteria contributed significantly to periphyton biomass in those treatments under nutrient replacement. Somatic growth of Littorina was negatively correlated to Littorina density in the replacement aquaria and positively density dependent in the batch aquaria. The latter is explained by improved food quality under stronger grazing pressure.

  17. Rediae of echinostomatid and heterophyid trematodes suppress phagocytosis of haemocytes in Littorina littorea (Gastropoda: Prosobranchia).

    PubMed

    Iakovleva, Nadya V; Shaposhnikova, Tania G; Gorbushin, Alexander M

    2006-05-01

    A modulation of the phagocytic activity of hemocytes from the common periwinkle Littorina littorea by secretory-excretory products (SEP) released by trematode rediae during axenic in vitro cultivation was studied. The SEP released by the parasites Himasthla elongata (Echinostomatidae) and Cryptocotyle lingua (Heterophyidae) were found to inhibit the phagocytosis of zymozan particles by periwinkle hemocytes. The specificity of SEP effects was assessed: SEP of Himasthla militaris and Cryptocotyle concavum, two trematodes belonging to the same genera but infecting another closely related prosobranch snail Hydrobia ulvae, were also shown to be able to suppress L. littorea hemocytes phagocytic activity. However, no decrease in phagocytosis rate was observed when SEP of H. elongata and C. lingua were applied to monolayers of hemocytes from the bivalve mollusc Mytilus edulis. SEP from H. elongata was fractionated; only those fractions containing proteins of molecular weight more than 50 kDa were shown to possess inhibitory activity. Different H. elongata SEP concentrations were tested in for their ability to suppress phagocytosis by L. littorea hemocytes. Even very low SEP concentrations were shown to retain their ability to decrease phagocytosis rate, the inhibitory effect being dose-dependent. Hemocytes derived from snails naturally infected with H. elongata were also found to have lower phagocytic ability as compared to healthy individuals. PMID:16438967

  18. Complete mitochondrial genome of the giant ramshorn snail Marisa cornuarietis (Gastropoda: Ampullariidae).

    PubMed

    Wang, Mingling; Qiu, Jian-Wen

    2016-05-01

    We report the complete mitochondrial genome (mitogenome) of the giant ramshorn snail Marisa cornuarietis, a biocontrol agent of freshwater weeds and snail vectors of schistosomes. The mitogenome is 15,923 bp in length, encoding 13 protein-coding genes, 22 transfer RNAs and 2 ribosomal RNAs. The mitogenome is A+T biased (70.0%), with 28.9% A, 41.1% T, 16.7% G, and 13.3% C. A comparison with Pomacea canaliculata, the other member in the same family (Ampullariidae) with a sequenced mitogenome, shows that the two species have an identical gene order, but their intergenic regions vary substantially in sequence length. The mitogenome data can be used to understand the population genetics of M. cornuarietis, and resolve the phylogenetic relationship of various genera in Ampullariidae. PMID:25259454

  19. Macroevolution of venom apparatus innovations in auger snails (Gastropoda; Conoidea; Terebridae)

    PubMed Central

    Castelin, M.; Puillandre, N.; Kantor, Yu. I.; Modica, M.V.; Terryn, Y.; Cruaud, C.; Bouchet, P.; Holford, M.

    2012-01-01

    The Terebridae are a diverse family of tropical and subtropical marine gastropods that use a complex and modular venom apparatus to produce toxins that capture polychaete and enteropneust preys. The complexity of the terebrid venom apparatus suggests that venom apparatus development in the Terebridae could be linked to the diversification of the group and can be analyzed within a molecular phylogenetic scaffold to better understand terebrid evolution. Presented here is a molecular phylogeny of 89 terebrid species belonging to 12 of the 15 currently accepted genera, based on Bayesian inference and Maximum Likelihood analyses of amplicons of 3 mitochondrial (COI, 16S and 12S) and one nuclear (28S) genes. The evolution of the anatomy of the terebrid venom apparatus was assessed by mapping traits of six related characters: proboscis, venom gland, odontophore, accessory proboscis structure, radula, and salivary glands. A novel result concerning terebrid phylogeny was the discovery of a previously unrecognized lineage, which includes species of Euterebra and Duplicaria. The non- monophyly of most terebrid genera analyzed indicates that the current genus-level classification of the group is plagued with homoplasy and requires further taxonomic investigations. Foregut anatomy in the family Terebridae reveals an inordinate diversity of features that covers the range of variability within the entire superfamily Conoidea, and that hypodermic radulae have likely evolved independently on at least three occasions. These findings illustrate that terebrid venom apparatus evolution is not perfunctory, and involves independent and numerous changes of central features in the foregut anatomy. The multiple emergence of hypodermic marginal radular teeth in terebrids are presumably associated with variable functionalities, suggesting that terebrids have adapted to dietary changes that may have resulted from predator-prey relationships. The anatomical and phylogenetic results presented serve as a starting point to advance investigations about the role of predator-prey interactions in the diversification of the Terebridae and the impact on their peptide toxins, which are promising bioactive compounds for biomedical research and therapeutic drug development. PMID:22440724

  20. A nomenclator of extant and fossil taxa of the Valvatidae (Gastropoda, Ectobranchia)

    PubMed Central

    Haszprunar, Gerhard

    2014-01-01

    Abstract A compilation of all supra- and (infra-) specific taxa of extant and fossil Valvatidae, a group of freshwater operculate snails, is provided, including taxa initially described in this family and subsequently classified in other families, as well as names containing errors or misspellings. The extensive reference list is directly linked to the available electronic source (digital view or pdf-download) of the respective papers. PMID:24578604

  1. Caribbean Bulimulus revisited: physical moves and molecular traces (Mollusca, Gastropoda, Bulimulidae)

    PubMed Central

    2016-01-01

    Twenty-five samples of Bulimulus species are studied, partly from localities within their known distribution range, partly based on interceptions where the material originates from localities where the species seem to be recently introduced and non-native. Molecular study of cytochrome oxidase 1 (CO1) reveals the origin of some of these introductions, but is less conclusive for others. Four different methods for species delimitation were applied, which did not result in unambiguous species hypotheses. For a rapid identification of morphologically indistinct species, a more comprehensive database of sequences is needed. PMID:27069787

  2. A new species of Lienardia (Gastropoda: Conoidea) from the Philippines and the Spratly Islands

    PubMed Central

    Rosenberg, Gary; Stahlschmidt, Peter

    2013-01-01

    A new species of Lienardia (Conoidea: Clathurellidae) is described from the Philippines and Spratly Islands and compared to L. giliberti Souverbie, 1874, with which it has been confused. The species is routinely found in lumun-lumun nets in the southern Philippines, particularly in the Panglao area, in depths of 50 and 110 m. Correlations between radular morphology and shell coloration support maintaining Lienardia and Clathurella as distinct genera. PMID:23913992

  3. Not so sluggish: the success of the Felimare picta complex (Gastropoda, Nudibranchia) crossing Atlantic biogeographic barriers

    PubMed Central

    Levy, André

    2016-01-01

    The molecular phylogeny of the Atlanto-Mediterranean species of the genus Felimare, particularly those attributed to the species F. picta, was inferred using two mitochondrial markers (16S and COI). A recent revision of the Chromodorididae clarified the taxonomic relationships at the family level redefining the genus Felimare. However, conflicting taxonomic classifications have been proposed for a restrict group of taxa with overlapping morphological characteristics and geographical distributions designated here as the Felimare picta complex. Three major groups were identified: one Mediterranean and amphi-Atlantic group; a western Atlantic group and a tropical eastern Atlantic group. F. picta forms a paraphyletic group since some subspecies are more closely related with taxa traditionaly classified as independent species (e.g. F. zebra) than with other subspecies with allopatric distributions (e.g. F. picta picta and F. picta tema). Usually, nudibranchs have adhesive demersal eggs, short planktonic larval phases and low mobility as adults unless rafting on floating materials occurs. Surprisingly however, the phylogeny of the F. picta complex suggests that they successfully cross main Atlantic biogeographic barriers including the mid-Atlantic barrier. This ability to cross different biogeographic barriers may be related to F. picta’s distinct life history and ecological traits. Compared to other Chromodorididae F. picta has larger eggs and planktotrophic larvae which could be related to a longer planktonic phase. PMID:26823995

  4. Bayerotrochus delicatus, a new species of pleurotomariid from Yap Seamount, near Palau, Western Pacific (Gastropoda: Pleurotomariidae).

    PubMed

    Zhang, Suping; Zhang, Shuqian; Wei, Peng

    2016-01-01

    A new pleurotomariid species, Bayerotrochus delicatus sp. nov., collected from the Yap Seamount, near Palau, Western Pacific (8°51'N, 137°47'E), is described and illustrated. The generic assignment is based on morphology and molecular evidence. The new species is characterized by a small, depressed trochoid shell sculptured with delicate spiral threads and axial riblets; the shell surface is lustrous orange mottled with iridescence. The radula has a formula of R + 3 + 23 + (ca. 30) + (ca. 65) + 9. These features can separate Bayerotrochus delicatus sp. nov. from its congeners. To determine the relationships of Bayerotrochus delicatus sp. nov. with other pleurotomariids, a neighbor-joining (NJ) tree was established using available sequences of cytochrome c oxidase I gene (COI) from this study and GenBank. PMID:27615927

  5. Synopsis of valid species-group taxa for freshwater Gastropoda recorded from the European Neogene

    PubMed Central

    Neubauer, Thomas A.; Kroh, Andreas; Harzhauser, Mathias; Georgopoulou, Elisavet; Mandic, Oleg

    2014-01-01

    Abstract Here we present a complete list of all valid species-group taxa of freshwater gastropods reported from Miocene and Pliocene deposits in Europe. The last comparable work dates back to the 1920s and covered about 1,600 names. The extensive literature research underlying the present work revealed considerable changes in the taxonomic and systematic frameworks of Neogene freshwater gastropods and yielded a total number of 2,156 accepted taxa. Each taxon is accompanied by a full citation of its first description; where the information is available, page number and illustration reference are provided. First descriptions available as open-access full-text sources on the web were linked via hyperlink to the first page of the publication. PMID:25152683

  6. Larval trematode infections in Galba truncatula (Gastropoda, Lymnaeidae) from the Brenne Regional Natural Park, central France.

    PubMed

    Rondelaud, D; Vignoles, P; Dreyfuss, G

    2016-05-01

    Adult Galba truncatula ( ≥ 4 mm in shell height) were collected from 135 habitats for 3 years (2012-2014) to identify parasite species via the study of cercariae, and to determine the prevalence of each digenean infection in relation to the type of snail habitat (six types). A total of 323 infected snails and ten digenean species were noted in the bodies of 11,025 G. truncatula after their dissection. Snails with Calicophoron daubneyi and/or Fasciola hepatica were found in 20.7% and 12.5% of the habitats, respectively, and most of these infected snails were collected from rainwater-draining furrows and pools in meadows. The percentages were lower for snails with Echinostoma revolutum (9.6% of habitats) and Haplometra cylindracea (7.4%), and were less than 5% for those parasitized by any of the other five species of digenean. The highest prevalence of all digenean infections was noted in pools (9.4%), followed by furrows located in meadows (8.3%) and ponds (5.1%). The prevalence noted for each digenean infection varied with the type of habitat. In furrows located in meadows, the infection rate of C. daubneyi in snails (3.5%) was significantly higher than that of F. hepatica (2.2%). In pools, values greater than 1.5% were noted for C. daubneyi, H. cylindracea and Opistoglyphe ranae. In ponds, E. revolutum was the dominant species (prevalence, 2.5%). Parasite species richness in G. truncatula was greater in the Brenne Natural Regional Park than in the nearby region of Limousin (ten instead of eight). The distribution and prevalence of each parasite species were dependent on the type and location of each snail habitat. PMID:25804319

  7. New taxa of terrestrial molluscs from Turkey (Gastropoda, Pristilomatidae, Enidae, Hygromiidae, Helicidae)

    PubMed Central

    Gümüş, Burçin Aşkım; Neubert, Eike

    2012-01-01

    Abstract This paper reports on results of several collecting trips of the authors in Turkey. In the course of this research, a long-lasting question was addressed. It could be proven that the nominal species Bulimus frivaldskyi L. Pfeiffer, 1847 is closely related to Meijeriella canaliculata Bank, 1985, and thus this species is shifted from the genus Ena Turton, 1831, to the genus Meijeriella Bank, 1985. Meijeriella canaliculata Bank, 1985, could be recorded from Turkey for the first time. The nomenclatural situation of the species Euchondrus septemdentatus (Roth, 1839) vs. its replacement name Euchondrus borealis (Mousson, 1874) is discussed. A new arrangement of the species formely comprised in the genus Zebrina Held, 1837 is presented, and the genera Rhabdoena Kobelt & Moellendorff, 1902, and Leucomastus A. Wagner, 1927 are re-established. The following species and subspecies new to science could be described: Vitrea gostelii sp. n. (Pristilomatidae), Turanena demirsoyi sp. n., Euchondrus paucidentatus sp. n., Rhabdoena gostelii sp. n. (all Enidae), Metafruticicola kizildagensis sp. n. (Hygromiidae), and Assyriella thospitis menkhorsti ssp. n. (Helicidae). For several other species, new distribution records are listed. PMID:22423194

  8. Mitochondrial genome sequences of landsnails Aegista diversifamilia and Dolicheulota formosensis (Gastropoda: Pulmonata: Stylommatophora).

    PubMed

    Huang, Chih-Wei; Lin, Si-Min; Wu, Wen-Lung

    2016-07-01

    The first mitochondrial genome sequences of Aegista and Dolicheulota belonging to Bradybaenidae are described in this report. Mitogenomic sequences were generated from Illumina paired-end sequencing. The complete mitogenome of Aegista diversifamilia was 14,039 bp in length and nearly complete mitogenome of Dolicheulota formosensis was 14,237 bp. Both mitogenomes consisted of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, and 22 transfer RNA genes. Most genes were overlapped with neighboring genes that the overlapping regions ranged from 2 to 64 bp in A. diversifamilia and from 1 to 45 bp in D. formosensis. Novel gene arrangement, tRNA-Tyr-ND3-tRNA-Trp, was identified in A. diversifamilia, whereas D. formosensis showed identical gene order to other Bradybaenidae mitogenomes. Maximum likelihood phylogenetic tree suggested Aegista as a sister clade to Euhadra and Dolicheulota. Bradybaenidae is monophyly sister clade to Camaenidae. PMID:26094989

  9. A new species of hydrobiid snails (Mollusca, Gastropoda, Hydrobiidae) from central Greece

    PubMed Central

    Radea, Canella

    2011-01-01

    Abstract Anew minute valvatiform species belonging to the genus Daphniola Radoman, 1973, Daphniola eptalophos sp. n., from mountain Parnassos, Greece is described. The new species has a transparent valvatiform-planispiral shell, wide and open umbilicus, grey-black pigmented soft body and head and a black penis with a small colorless outgrowth on the left side near its base. A comparative table of shell dimensions and a key to the species known for this endemic genus for Greece are provided. PMID:22144853

  10. Terrestrial slugs (Gastropoda, Pulmonata) in the NATURA 2000 areas of Cyprus island

    PubMed Central

    Vardinoyannis, Katerina; Demetropoulos, Simon; Mylonas, Moissis; A.Triantis, Kostas; Makris, Christodoulos; Georgiou, Gabriel; Wiktor, Andrzej; Demetropoulos, Andreas

    2012-01-01

    Abstract Terrestrial slugs of the Island of Cyprus were recently studied in the framework of a study of the whole terrestrial malacofauna of the island. The present work was carried out in the Natura 2000 conservation areas of the island in 155 sampling sites over three years (2004–2007). Museum collections as well as literature references were included. In total six species are present in the Natura 2000 areas of the island, belonging to three families: Limacidae, Agriolimacidae and Milacidae. One of the species, Milax riedeli, is a new record for the island. The distribution of the species across the island and in the surrounding areas is discussed. PMID:22451785

  11. Patterns of diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean region.

    PubMed

    Ávila, Sérgio P; Goud, Jeroen; de Frias Martins, António M

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species--those living between the intertidal and 50 m depth, and deep species--those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years. PMID:22693430

  12. Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora)

    PubMed Central

    Páll-Gergely, Barna; Hunyadi, András; Ablett, Jonathan; Lương, Hào Văn; Fred Naggs; Asami, Takahiro

    2015-01-01

    Abstract Vietnamese species from the family Plectopylidae are revised based on the type specimens of all known taxa, more than 600 historical non-type museum lots, and almost 200 newly-collected samples. Altogether more than 7000 specimens were investigated. The revision has revealed that species diversity of the Vietnamese Plectopylidae was previously overestimated. Overall, thirteen species names (anterides Gude, 1909, bavayi Gude, 1901, congesta Gude, 1898, fallax Gude, 1909, gouldingi Gude, 1909, hirsuta Möllendorff, 1901, jovia Mabille, 1887, moellendorffi Gude, 1901, persimilis Gude, 1901, pilsbryana Gude, 1901, soror Gude, 1908, tenuis Gude, 1901, verecunda Gude, 1909) were synonymised with other species. In addition to these, Gudeodiscus hemmeni sp. n. and Gudeodiscus messageri raheemi ssp. n. are described from north-western Vietnam. Sixteen species and two subspecies are recognized from Vietnam. The reproductive anatomy of eight taxa is described. Based on anatomical information, Halongella gen. n. is erected to include Plectopylis schlumbergeri and Plectopylis fruhstorferi. Additionally, the genus Gudeodiscus is subdivided into two subgenera (Gudeodiscus and Veludiscus subgen. n.) on the basis of the morphology of the reproductive anatomy and the radula. The Chinese Gudeodiscus phlyarius werneri Páll-Gergely, 2013 is moved to synonymy of Gudeodiscus phlyarius. A spermatophore was found in the organ situated next to the gametolytic sac in one specimen. This suggests that this organ in the Plectopylidae is a diverticulum. Statistically significant evidence is presented for the presence of calcareous hook-like granules inside the penis being associated with the absence of embryos in the uterus in four genera. This suggests that these probably play a role in mating periods before disappearing when embryos develop. Sicradiscus mansuyi is reported from China for the first time. PMID:25632253

  13. Odontomariinae, a new middle paleozoic subfamily of slit-bearing euophaloidean gastropods (Euophalomorpha, Gastropoda)

    USGS Publications Warehouse

    Fryda, J.; Heidelberger, D.; Blodgett, R.B.

    2006-01-01

    A new subfamily, the Odontomariinae subfam. nov., is established herein for a distinctive group of uncoiled, slit-bearing Middle Devonian euomphalid gastropods. Its taxonomic position is based on the recent discovery of open coiled protoconchs and it is placed within the Euomphalomorpha. The genera Odontomaria Odontomaria C. F. Roemer and Tubiconcha n. gen. belonging to this new subfamily are enlarged based on studies on new material of the following species: Odontomaria semiplicata (Sandberger & Sandberger), Odontomaria gracilis n. sp., Odontomaria jankei n. sp., Odontomaria cheeneetnukensis n. sp., Odontomaria cindiprellerae n. sp. and Tubiconcha leunissi (Heidelberger, 2001). Members of the Odontomariinae were mainly sedentary organisms in high-energy, moderately shallow water. ?? 2006 E. Schweizerbart'sche Verlagsbuchhandlung.

  14. The complete mitochondrial genome of Chinese land snail Aegista aubryana (Gastropoda: Pulmonata: Bradybaenidae).

    PubMed

    Yang, Xue; Xie, Guang-Long; Wu, Xiao-Ping; Ouyang, Shan

    2016-09-01

    Aegista aubryana is an endemic land snail in China. The complete mitochondrial genome of A. aubryana was first determined using long PCR reactions and primer walking method (accession number KT192071). The genome has a length of 14 238 bp, containing 37 typical mitochondrial genes (13 protein-coding genes, 22 tRNA genes and 2 rRNA genes). The base composition of the whole heavy strand is A 31.32%, T 37.86%, C 14.46% and G 16.36%. The results of phylogenetic analyses showed that the A. aubryana is most closely related to Mastigeulota kiangsinensis. This new complete mitochondrial genome can be the basic data for further studies on mitogenome comparison, molecular taxonomy and phylogenetic analyses in bradybaenid snails and Molluscs at large. PMID:26260173

  15. [Occurrence of Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda) in Brazil: intermediate snail host of angiostrongyliasis].

    PubMed

    Teles, H M; Vaz, J F; Fontes, L R; Domingos, M de F

    1997-06-01

    Achatina fulica, the intermediate snail host of angiostrongyliasis and also an agricultural pest, is being bred in Brazil for human consumption as "escargot". The snail has escaped from its artificial breeding sites and its dispersal in Itariri country, State of S. Paulo, is reported here for the first time. A. fulica is a transmitter of the rat lungworm Angiostrongylus cantonensis, nematode which causes meningoencephalic angiostrongyliasis; the risks of human contamination are commented on. PMID:9515269

  16. Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis

    PubMed Central

    2010-01-01

    Background Lymnaeidae snails play a prominent role in the transmission of helminths, mainly trematodes of medical and veterinary importance (e.g., Fasciola liver flukes). As this family exhibits a great diversity in shell morphology but extremely homogeneous anatomical traits, the systematics of Lymnaeidae has long been controversial. Using the most complete dataset to date, we examined phylogenetic relationships among 50 taxa of this family using a supermatrix approach (concatenation of the 16 S, ITS-1 and ITS-2 genes, representing 5054 base pairs) involving both Maximum Likelihood and Bayesian Inference. Results Our phylogenetic analysis demonstrates the existence of three deep clades of Lymnaeidae representing the main geographic origin of species (America, Eurasia and the Indo-Pacific region). This phylogeny allowed us to discuss on potential biological invasions and map important characters, such as, the susceptibility to infection by Fasciola hepatica and F. gigantica, and the haploid number of chromosomes (n). We found that intermediate hosts of F. gigantica cluster within one deep clade, while intermediate hosts of F. hepatica are widely spread across the phylogeny. In addition, chromosome number seems to have evolved from n = 18 to n = 17 and n = 16. Conclusion Our study contributes to deepen our understanding of Lymnaeidae phylogeny by both sampling at worldwide scale and combining information from various genes (supermatrix approach). This phylogeny provides insights into the evolutionary relationships among genera and species and demonstrates that the nomenclature of most genera in the Lymnaeidae does not reflect evolutionary relationships. This study highlights the importance of performing basic studies in systematics to guide epidemiological control programs. PMID:21143890

  17. Caribbean Bulimulus revisited: physical moves and molecular traces (Mollusca, Gastropoda, Bulimulidae).

    PubMed

    Breure, Abraham S H

    2016-01-01

    Twenty-five samples of Bulimulus species are studied, partly from localities within their known distribution range, partly based on interceptions where the material originates from localities where the species seem to be recently introduced and non-native. Molecular study of cytochrome oxidase 1 (CO1) reveals the origin of some of these introductions, but is less conclusive for others. Four different methods for species delimitation were applied, which did not result in unambiguous species hypotheses. For a rapid identification of morphologically indistinct species, a more comprehensive database of sequences is needed. PMID:27069787

  18. Sequential colonization and diversification of Galapágos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora).

    PubMed

    Parent, Christine E; Crespi, Bernard J

    2006-11-01

    Species richness on island or islandlike systems is a function of colonization, within-island speciation, and extinction. Here we evaluate the relative importance of the first two of these processes as a function of the biogeographical and ecological attributes of islands using the Galápagos endemic land snails of the genus Bulimulus, the most species-rich radiation of these islands. Species in this clade have colonized almost all major islands and are found in five of the six described vegetation zones. We use molecular phylogenetics (based on COI and ITS 1 sequence data) to infer the diversification patterns of extant species of Bulimulus, and multiple regression to investigate the causes of variation among islands in species richness. Maximum-likelihood, Bayesian, and maximum-parsimony analyses yield well-resolved trees with similar topologies. The phylogeny obtained supports the progression rule hypothesis, with species found on older emerged islands connecting at deeper nodes. For all but two island species assemblages we find support for only one or two colonization events, indicating that within-island speciation has an important role in the formation of species on these islands. Even though speciation through colonization is not common, island insularity (distance to nearest major island) is a significant predictor of species richness resulting from interisland colonization alone. However, island insularity has no effect on the overall bulimulid species richness per island. Habitat diversity (measured as plant species diversity), island elevation, and island area, all of which are indirect measures of niche space, are strong predictors of overall bulimulid land snail species richness. Island age is also an important independent predictor of overall species richness, with older islands harboring more species than younger islands. Taken together, our results demonstrate that the diversification of Galápagos bulimulid land snails has been driven by a combination of geographic factors (island age, size, and location), which affect colonization patterns, and ecological factors, such as plant species diversity, that foster within-island speciation. PMID:17236423

  19. The Vermetidae of the Gulf of Kachchh, western coast of India (Mollusca, Gastropoda).

    PubMed

    Joshi, Devanshi MukundRay; Mankodi, Pradeep C

    2016-01-01

    Coral reefs are often termed underwater wonderlands due to the presence of an incredible biodiversity including numerous invertebrates and vertebrates. Among the dense population of benthic and bottom-dwelling inhabitants of the reef, many significant species remain hidden or neglected by researchers. One such example is the vermetids, a unique group of marine gastropods. The present study attempts for the first time to assess the density and identify preferred reef substrates in the Gulf of Kachchh, state of Gujarat, on the western coast of India. A total of three species of the family Vermetidae were recorded during the study and their substrate preferences identified. PMID:26877684

  20. Granopupa in Iran, monophyly, and the fossil Granariinae (Gastropoda, Pulmonata, Chondrinidae)

    PubMed Central

    Gittenberger, Edmund; Kokshoorn, Bas; Bößneck, Ulrich; Reijnen, Bastian T.; Groenenberg, Dirk S. J.

    2016-01-01

    Abstract Indisputable Chondrinidae, Granariinae species, characterized by shell shape and apertural dentition, are known from Eocene deposits to the Recent. The generic classification of the extant species is based on conchological, anatomical and molecular data that are available now for most of the known species, including ‘Granaria’ persica as a representative of the once problematic group of so-called eastern Granaria species. According to molecular and anatomical characters, these eastern species have to be classified with Granopupa granum in Granopupa. Graniberia gen. n. is introduced for Granaria braunii on the basis of molecular and conchological data. For the pre-Pleistocene species, two generic names are equally well available now, viz. Granopupa and Granaria. Shell characters only do not enable a decision here. For the sake of nomenclatorial stability we propose to use Granaria for these species. Because both molecular and anatomical data most likely will never be known for the fossils, it will remain unclear whether the combined extant and extinct Granaria species form a monophyletic group. PMID:27408543

  1. Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae.

    PubMed

    Breure, Abraham S H; Avila, Valentín Mogollón

    2016-01-01

    A faunal overview is presented of the molluscan families Amphibulimidae, Megaspiridae, Odontostomidae, Orthalicidae, Simpulopsidae in Bolivia, Ecuador, and Peru. These Central Andean countries are known for their biodiverse malacofauna, of which the superfamily Orthalicoidea takes relatively a large share. In this paper the five families containing 103 (sub)species, for which systematic information (original publication, type locality, type depository, summarizing literature) and distributional records are presented. All species are illustrated by photographs of the type material or, if this could not be located, by a reproduction of the original figure. The following new taxon is introduced: Thaumastus (Thaumastus) sumaqwayqu sp. n. Junior subjective synonyms are established for: Plekocheilus (Sparnotion) Pilsbry, 1944 = Plekocheilus (Eudolichotis) Pilsbry, 1896; Scholvienia (Thomsenia) Strebel, 1910 = Scholvienia Strebel, 1910; Sultana (Trachyorthalicus) Strebel, 1909 = Sultana (Metorthalicus) Pilsbry, 1899; Plekocheilus (Eurytus) conspicuus Pilsbry, 1932 = Thaumastus (Thaumastus) hartwegi (Pfeiffer in Philippi, 1846); Zebra gruneri Strebel, 1909 = Orthalicus maracaibensis (Pfeiffer, 1856); Scholvienia jaspidea minor Strebel, 1910 = Scholvienia alutacea (Reeve, 1850); Bulimus bifasciatus unicolor Philippi, 1869 = Scholvienia brephoides (d'Orbigny, 1835). A new status is given to Plekocheilus mcgintyi 'Pilsbry' H.B. Baker, 1963 (subspecies of Bulinus piperitus Sowerby I, 1837); Strophocheilus superstriatus var. prodeflexus Pilsbry, 1895 (subspecies of Bulinus piperitus Sowerby I, 1837); Thaumastus (Quechua) salteri maximus Weyrauch, 1967 (subspecies of Thaumastus (Quechua) olmosensis Zilch, 1954); Pseudoglandina agitata Weyrauch, 1967 (nomen inquirendum). New combinations are: Clathrorthalicus corydon (Crosse, 1869), and Cyclodontina chuquisacana (Marshall, 1930). Lectotypes are now designated for Bulimus incisus Hupé, 1857 and Bulinus piperitus Sowerby I, 1837. PMID:27408531

  2. Identification of Shell Colour Pigments in Marine Snails Clanculus pharaonius and C. margaritarius (Trochoidea; Gastropoda).

    PubMed

    Williams, S T; Ito, S; Wakamatsu, K; Goral, T; Edwards, N P; Wogelius, R A; Henkel, T; de Oliveira, L F C; Maia, L F; Strekopytov, S; Jeffries, T; Speiser, D I; Marsden, J T

    2016-01-01

    Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised. Here, we use modern chemical and multi-modal spectroscopic techniques to identify two porphyrin pigments and eumelanin in the shell of marine snails Clanculus pharaonius and C margaritarius. The same porphyrins were also identified in coloured foot tissue of both species. We use high performance liquid chromatography (HPLC) to show definitively that these porphyrins are uroporphyrin I and uroporphyrin III. Evidence from confocal microscopy analyses shows that the distribution of porphyrin pigments corresponds to the striking pink-red of C. pharaonius shells, as well as pink-red dots and lines on the early whorls of C. margaritarius and yellow-brown colour of later whorls. Additional HPLC results suggest that eumelanin is likely responsible for black spots. We refer to the two differently coloured porphyrin pigments as trochopuniceus (pink-red) and trochoxouthos (yellow-brown) in order to distinguish between them. Trochopuniceus and trochoxouthos were not found in the shell of a third species of the same superfamily, Calliostoma zizyphinum, despite its superficially similar colouration, suggesting that this species has different shell pigments. These findings have important implications for the study of colour and pattern in molluscs specifically, but in other taxa more generally, since this study shows that homology of visible colour cannot be assumed without identification of pigments. PMID:27367426

  3. Prestonellinae-validation of the name as a new subfamily of Bothriembryontidae (Mollusca, Gastropoda, Orthalicoidea).

    PubMed

    Bruggen, A C Van; Herbert, David G; Breure, Abraham S H

    2016-01-01

    The affinities of the enigmatic South African land snail genus Prestonella Connolly, 1929 were discussed by Herbert (2007) and Herbert & Mitchell (2009), who showed, on the basis of morphological and molecular data, that the genus is referable to the superfamily Orthalicoidea. Currently, the three described species of Prestonella are the only known African representatives of this diverse superfamily. Earlier, van Bruggen (1978) had recognized that these species formed a distinct group and had placed them in the (new) family Prestonellidae. However, as noted by Bouchet & Rocroi (2005: 140), no diagnosis was provided by van Bruggen; the name Prestonellidae thus does not meet the requirements of ICZN Art. 13.1, and is not an available name. In this paper we will redress this issue, also taking into account more recent research which has shed light on the systematic position of this genus within the Orthalicoidea. PMID:27394284

  4. A new Middle Miocene Niveria Jousseaume, 1884 (Mollusca: Gastropoda: Trivioidea) from Hungary

    NASA Astrophysics Data System (ADS)

    Fehse, Dirk

    2011-02-01

    A new species of Niveria from the Middle Miocene (Badenian) of the Paratethys of Borsodbóta, Hungary is described. This species is characterized by its callused dorsum and dorsal depression. Niveria jozefgregoi sp. nov. is discussed with comparative species from the Badenian of Hungary, the Pliocene of the Mediterranean region, Florida and Recent species from Madeira and the Islas Galápagos.

  5. Severnsia strombeulima n. gen. & sp. from Hawaii (Mollusca, Gastropoda: Caenogastropoda: Eulimidae).

    PubMed

    Geiger, Daniel L

    2016-01-01

    The malacofauna of Hawaii is rather well-known, owing to Kay (1979) and Severns (2011). Both works stand out because they include a large number of the generally under-represented micromollusks (<5 mm). Here a striking new genus and species of a microsnail is reported from that region. PMID:27394283

  6. A new species of Bothriembryon (Mollusca, Gastropoda, Bothriembryontidae) from south-eastern Western Australia.

    PubMed

    Whisson, Corey S; Breure, Abraham S H

    2016-01-01

    Bothriembryon sophiarum sp. n. is described, based on shell and anatomical morphology, from the coastal area of south-easternmost Western Australia. This is the first description of a new extant Australian bothriembryontid in 33 years. The shell of Bothriembryon sophiarum is slender with a unique teleoconch sculpture. It is found in low coastal scrub on cliff edges and escarpments and because of its restricted distribution, qualifies as a short range endemic. PMID:27199583

  7. Rich and rare—First insights into species diversity and abundance of Antarctic abyssal Gastropoda (Mollusca)

    NASA Astrophysics Data System (ADS)

    Schwabe, Enrico; Michael Bohn, Jens; Engl, Winfried; Linse, Katrin; Schrödl, Michael

    2007-08-01

    The abyssal depths of the polar oceans are thought to be low in diversity compared with the shallower polar shelves and temperate and tropical deep-sea basins. Our recent study on the gastropod fauna of the deep Southern Ocean gives evidence of the existence of a rich gastropod assemblage at abyssal depths. During the ANDEEP I and II expeditions to the southern Drake Passage, Northwestern Weddell Sea, and South Sandwich Trench, gastropods were collected by bottom and Agassiz trawls, epibenthic sledge, and multicorer, at 40 stations in depths between 127 and 5194 m. On the whole, 473 specimens, corresponding to 93 species of 36 families, were obtained. Of those, 414 specimens were caught below 750 m depth and refer to 84 (90%) benthic species of 32 (89%) families. Most families were represented by a single species only. The numerically dominant families were Skeneidae and Buccinidae (with 10 and 11 species, respectively), Eulimidae and Trochidae (with 9 species each), and Turridae (6 species). Thirty-Seven benthic deep-sea species (44%) were represented by a single specimen, and another 20 species (24%) were found at a single station, suggesting that more than two thirds of Antarctic deep-sea gastropod species are very rare or have a very scattered distribution. Of the 27 species occurring at two or more deep-sea stations, 14 were collected with different gear. Approximately half of the deep-water species are new to science or have been recently described. The present investigation increases the total number of recorded benthic Antarctic deep-sea gastropods (below 750 m) from 115 to 177. The previously known depth ranges have been extended, often considerably, for 31 species. The collected deep-sea gastropods comprise both eurybathic shelf species (29%) and apparently true deep-sea species (58%); some of the latter may belong to a so far unknown Antarctic abyssal fauna. Geographical ranges of the collected Antarctic benthic deep-sea gastropod species appear limited, and all these 84 species seem endemic to Antarctica south of the Polar Front. Comparing diversity and abundances based on epibenthic sledge samples, there is no clear relationship between Antarctic deep-sea gastropod abundance and species richness with depth. However, both Antarctic and adjacent deep-sea areas are still far from being adequately sampled to allow more comprehensive conclusions.

  8. Quantification of midkine gene expression in Patella caerulea (Mollusca, Gastropoda) exposed to cadmium

    NASA Astrophysics Data System (ADS)

    Stillitano, Francesca; Mugelli, Alessandro; Cerbai, Elisabetta; Vanucci, Silvana

    2007-10-01

    The release of cadmium into many coastal areas represents a threat to ecosystems and human health; cadmium is carcinogenic in mammals and in both marine invertebrates and vertebrates. The use of molluscs to assess the ecologic risk associated with contaminants is strongly recommended on account of their ecological role and on their highly conserved control and regulatory pathways that are often homologous to vertebrate systems. We previously identified a midkine family protein in the limpet Patella caerulea; the midkine is a recently discovered cytokines family with unequivocal informative value on repairing injury and neoplastic processes in mammals. Here we report on midkine ( mdk) and α-tubulin ( α-tub) gene expression patterns in P. caerulea exposed to cadmium. Limpets, collected on two occasions from a breakwater at a marina (Tyrrhenian Sea) were exposed to sublethal cadmium concentrations (0.5 and 1 mg l -1 Cd) over a 10-day exposure period. RNA was extracted from the viscera of unexposed and exposed specimens. Real time TaqMan RT-PCR was performed to measure the relative mdk and α-tub gene expression levels. A remarkable mdk over-expression was observed in all exposed animals with respect to unexposed ones; mdk over-expression was significantly higher in both treatments when compared with un-treatment (mean expression levels: 23- and 38-fold, for 0.5 and 1 mg l -1 Cd treatment, respectively; ANOVA, for both P < 0.01). The study also indicates that the mdk up-regulation was significantly Cd-concentration dependent ( P < 0.05). A significant up-regulation of the constitutive α-tub gene was also observed in 1 mg l -1 Cd-treated animals (mean expression level: 4-fold; ANOVA, P < 0.05). In conclusion, these data provide the first evidence paving the way for the use of the midkine as a promising new biomarker of effect in the environment risk assessment policy.

  9. Atlanta ariejansseni, a new species of shelled heteropod from the Southern Subtropical Convergence Zone (Gastropoda, Pterotracheoidea)

    PubMed Central

    Wall-Palmer, Deborah; Burridge, Alice K.; Peijnenburg, Katja T.C.A.

    2016-01-01

    Abstract The Atlantidae (shelled heteropods) is a family of microscopic aragonite shelled holoplanktonic gastropods with a wide biogeographical distribution in tropical, sub-tropical and temperate waters. The aragonite shell and surface ocean habitat of the atlantids makes them particularly susceptible to ocean acidification and ocean warming, and atlantids are likely to be useful indicators of these changes. However, we still lack fundamental information on their taxonomy and biogeography, which is essential for monitoring the effects of a changing ocean. Integrated morphological and molecular approaches to taxonomy have been employed to improve the assessment of species boundaries, which give a more accurate picture of species distributions. Here a new species of atlantid heteropod is described based on shell morphology, DNA barcoding of the Cytochrome Oxidase I gene, and biogeography. All specimens of Atlanta ariejansseni sp. n. were collected from the Southern Subtropical Convergence Zone of the Atlantic and Indo-Pacific oceans suggesting that this species has a very narrow latitudinal distribution (37–48°S). Atlanta ariejansseni sp. n. was found to be relatively abundant (up to 2.3 specimens per 1000 m3 water) within this narrow latitudinal range, implying that this species has adapted to the specific conditions of the Southern Subtropical Convergence Zone and has a high tolerance to the varying ocean parameters in this region. PMID:27551204

  10. Taxonomic revision of the rock-dwelling door snail genus Montenegrina Boettger, 1877 (Mollusca, Gastropoda, Clausiliidae).

    PubMed

    Fehér, Zoltán; Szekeres, Miklós

    2016-01-01

    The genus Montenegrina is revised on the basis of material available at the Hungarian Natural History Museum (Budapest), Naturhistorisches Museum Wien (Vienna), and the Naturmuseum Senckenberg (Frankfurt am Main), as well as newly discovered populations. The following new taxa are described: Montenegrina haringae sp. n., Montenegrina lillae sp. n., Montenegrina prokletiana sp. n., Montenegrina sturanyana sp. n., Montenegrina grammica erosszoltani ssp. n., Montenegrina grammica improvisa ssp. n., Montenegrina hiltrudae desaretica ssp. n., Montenegrina hiltrudae selcensis ssp. n., Montenegrina laxa delii ssp. n., Montenegrina nana barinai ssp. n., Montenegrina prokletiana kovacsorum ssp. n., Montenegrina rugilabris golikutensis ssp. n., Montenegrina rugilabris gregoi ssp. n., Montenegrina skipetarica danyii ssp. n., Montenegrina skipetarica gurelurensis ssp. n., Montenegrina skipetarica pifkoi ssp. n., Montenegrina skipetarica puskasi ssp. n., Montenegrina sporadica tropojana ssp. n., Montenegrina sturanyana gropana ssp. n., Montenegrina sturanyana ostrovicensis ssp. n., and Montenegrina tomorosi hunyadii ssp. n. A neotype is designated for Montenegrina helvola (Küster, 1860), and Montenegrina cattaroensis antivaricostata nom. n. was introduced to replace the junior homonym Clausilia umbilicata costata Boettger, 1907 (non Pfeiffer, 1928). Of each taxon types or specimens from the type localities are figured, and distribution maps are provided. PMID:27408595

  11. Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus)

    PubMed Central

    Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

    2016-01-01

    Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants. PMID:27324580

  12. Molecular phylogeny of the Ellobiidae (Gastropoda: Panpulmonata) supports independent terrestrial invasions.

    PubMed

    Romero, Pedro E; Pfenninger, Markus; Kano, Yasunori; Klussmann-Kolb, Annette

    2016-04-01

    Gastropods of the family Ellobiidae are an interesting group in which to study transitions from intertidal to terrestrial realms. However, the phylogenetic relationships within this family still lack resolution. We present a phylogenetic hypothesis of the Ellobiidae based on Bayesian and maximum likelihood phylograms. We used nuclear (18S, 28S, H3) and mitochondrial (16S, 12S, COI) data, increasing the numbers of markers and data, and making this the most comprehensive phylogenetic study of the family to date. Our results support phylogenetic hypotheses derived from morphological data, and provide a supported framework to evaluate the internal relationships within Ellobiidae. The resulting phylogenetic trees support the previous hypothesis that the Ellobiidae are monophyletic only if the Trimusculinae (Otina, Smeagol and Trimusculus) are considered part of this family. In addition, we found that the Carychiinae, Ellobiinae and Pythiinae are reciprocally monophyletic and closely related, with the Carychiinae as sister group to Ellobiinae. Relationships within Melampodinae and Pedipedinae and their phylogenetic positions remain unresolved. Land invasion by the Ellobiidae occurred independently in Carychiinae and Pythia during different geological times (Mesozoic and Cenozoic, respectively). Diversification in the family does not appear to be related to past climate and biotic changes, neither the Cretaceous-Paleogene boundary nor the lowering of the sea level in the Oligocene. PMID:26724408

  13. Intracellular Immunohistochemical Detection of Tetrodotoxin in Pleurobranchaea maculata (Gastropoda) and Stylochoplana sp. (Turbellaria)

    PubMed Central

    Salvitti, Lauren R.; Wood, Susanna A.; Winsor, Leigh; Cary, Stephen Craig

    2015-01-01

    Tetrodotoxin (TTX), is a potent neurotoxin targeting sodium channels that has been identified in multiple marine and terrestrial organisms. It was recently detected in the Opisthobranch Pleurobranchaea maculata and a Platyhelminthes Stylochoplana sp. from New Zealand. Knowledge on the distribution of TTX within these organisms is important to assist in elucidating the origin and ecological role of this toxin. Intracellular micro-distribution of TTX was investigated using a monoclonal antibody-based immunoenzymatic technique. Tetrodotoxin was strongly localized in neutral mucin cells and the basement membrane of the mantle, the oocytes and follicles of the gonad tissue, and in the digestive tissue of P. maculata. The ova and pharynx were the only two structures to contain TTX in Stylochoplana sp. Using liquid chromatography-mass spectrometry, TTX was identified in the larvae and eggs, but not the gelatinous egg cases of P. maculata. Tetrodotoxin was present in egg masses of Stylochoplana sp. These data suggest that TTX has a defensive function in adult P. maculata, who then invest this in their progeny for protection. Localization in the digestive tissue of P. maculata potentially indicates a dietary source of TTX. Stylochoplana sp. may use TTX in prey capture and for the protection of offspring. PMID:25636158

  14. Progenesis in the evolution of the nudibranch mollusks genus Dendronotus (Gastropoda: Nudibranchia).

    PubMed

    Ekimova, I A; Malakhov, V V

    2016-03-01

    The morphology and postlarval ontogenesis of the radula in 11 species of the genus Dendronotus Alder et Hancock, 1845, has been studied. Four types of radula are recognized in adult mollusks. Proposed evidence suggests that small species of Dendronotus have evolved by progenesis. PMID:27193883

  15. Sphincterochilidae from Tunisia, with a note on the subgenus Rima Pallary, 1910 (Gastropoda, Pulmonata)

    PubMed Central

    Abbes, Intidhar; Nouira, Said; Neubert, Eike

    2011-01-01

    Abstract In order to establish an updated checklist of terrestrial gastropod from Tunisia, a revision of the species of Sphincterochilidae is presented, using bibliographic and museum records and the results of our own field work. As a result, only two species, Sphincterochila candidissima and Sphincterochila tunetana, are accepted to occur in Tunisia, and their type specimens are illustrated. The study of the morphological characters of the genital organs of both species clarified their subgeneric affiliation. Comparison of Sphincterochila tunetana with Sphincterochila cariosa from Lebanonshowed that the first has to be classified within the subgenus Albea, and the latter within Sphincterochila s. str.; the subgenus Rima Pallary, 1910 remains in the synonymy of Sphincterochila s. str. Bibliographic records of Sphincterochila baetica and Sphincterochila otthiana from Tunisia could not be confirmed, the latter probably lives close to the border with Algeria. PMID:22368450

  16. Venomous mollusks: the risks of human accidents by conus snails (gastropoda: conidae) in Brazil.

    PubMed

    Haddad, Vidal; de Paula Neto, João Batista; Cobo, Válter José

    2006-01-01

    Mollusks of the genus Conus present a venomous apparatus composed of radulae, a chitin structure linked to glands, which injects potent neurotoxic peptides, causing serious human envenomation and even death, associated with the blockage of certain receptors and muscular paralysis. No reported envenomation has occurred in Brazil, but certain populations are at risk of accidents. PMID:17160331

  17. Report of a human accident caused by Conus regius (Gastropoda, Conidae).

    PubMed

    Haddad, Vidal; Coltro, Marcus; Simone, Luiz Ricardo L

    2009-01-01

    Conus regius is a venomous mollusc in the Conidae family, which includes species responsible for severe or even fatal accidents affecting human beings. This is the first report on a clinical case involving this species. It consisted a puncture in the right hand of a diver who presented paresthesia and movement difficulty in the whole limb. The manifestations disappeared after around twelve hours, without sequelae. PMID:19802483

  18. Bisphenol A Induces Superfeminization in the Ramshorn Snail (Gastropoda: Prosobranchia) at Environmentally Relevant Concentrations

    PubMed Central

    Oehlmann, Jörg; Schulte-Oehlmann, Ulrike; Bachmann, Jean; Oetken, Matthias; Lutz, Ilka; Kloas, Werner; Ternes, Thomas A.

    2006-01-01

    Previous investigations have shown that bisphenol A (BPA) induces a superfeminization syndrome in the freshwater snail Marisa cornuarietis at concentrations as low as 1 μg/L. Superfemales are characterized by the formation of additional female organs, enlarged accessory sex glands, gross malformations of the pallial oviduct, and a stimulation of egg and clutch production, resulting in increased female mortality. However, these studies were challenged on the basis of incomplete experimentation. Therefore, the objective of the current approach was to bridge several gaps in knowledge by conducting additional experiments. In an initial series of experiments, study results from the reproductive phase of the snails were evaluated in the sub-micrograms per liter range. Before and after the spawning season, superfemale responses were observed [NOEC (no observed effect concentration) 7.9 ng/L, EC10 (effective concentration at 10%) 13.9 ng/L], which were absent during the spawning season. A further experiment investigated the temperature dependence of BPA responses by exposing snails at two temperatures in parallel. The adverse effect of BPA was at least partially masked at 27°C (EC10 998 ng/L) when compared with 20°C (EC10 14.8 ng/L). In M. cornuarietis, BPA acts as an estrogen receptor (ER) agonist, because effects were completely antagonized by a co-exposure to tamoxifen and Faslodex. Antiandrogenic effects of BPA, such as a significant decrease in penis length at 20°C, were also observed. Competitive receptor displacement experiments indicate the presence of androgen- and estrogen-specific binding sites. The affinity for BPA of the estrogen binding sites in M. cornuarietis is higher than that of the ER in aquatic vertebrates. The results emphasize that prosobranchs are affected by BPA at lower concentrations than are other wildlife groups, and the findings also highlight the importance of exposure conditions. PMID:16818258

  19. A Tale That Morphology Fails to Tell: A Molecular Phylogeny of Aeolidiidae (Aeolidida, Nudibranchia, Gastropoda)

    PubMed Central

    Carmona, Leila; Pola, Marta; Gosliner, Terrence M.; Cervera, Juan Lucas

    2013-01-01

    Aeolidida is one of the largest clades of nudibranchs with at least 560 known species. However, its systematics has not been studied in a comprehensive manner. Phylogenetic analyses of larger clades such as Nudibranchia or Cladobranchia have usually included a poor sample of aeolids. Furthermore, phylogenetic studies at the family or generic level in Aeolidida are a few and far between. The first molecular phylogeny of the aeolid family Aeolidiidae is presented here. This study, the most comprehensive for Aeolidida to date, uses new sequences of two mitochondrial (COI and 16S) genes and one nuclear gene (H3). 251 specimens from members of seven families of Aeolidida, including 39 species of Aeolidiidae were studied. Excluding Pleurolidia juliae, Aeolidiidae is monophyletic. Our results resolve the systematic relationships within the Aeolidiidae at a generic level, requiring changes in the systematics of this family. Spurilla, Anteaeolidiella, Limenandra and Aeolidia are well-supported and monophyletic clades. Aeolidiella stephanieae is transferred to Berghia and Aeolidiopsis ransoni and Spurilla salaamica to Baeolidia, to maintain the monophyletic lineages reflected in this study. The systematics of Cerberilla remains unclear. Some species earlier attributed to Aeolidiella are now grouped in a previously unnamed clade that we designate as Bulbaeolidia gen. nov. PMID:23658794

  20. Recognition of Macluritella ( Gastropoda) from the Upper Cambrian of Missouri and Nevada ( USA).

    USGS Publications Warehouse

    Yochelson, E.L.; Stinchcomb, B.L.

    1987-01-01

    Open-coiled euomphalacean gastropods have been identified for the first time in the Upper Cambrian Eminence Dolomite of Missouri. These gastropods have a triangular whorl profile and are conspecific with Hyolithes walcotti described from the Upper Cambrian of Nevada. That species is questionably reassigned to the gastropod genus Macluritella, hitherto known only from the Lower Ordovician of Colorado. -Authors Ordovician Colorado

  1. A new species of Cerithium (Gastropoda: Cerithiidae) from the South China Sea

    NASA Astrophysics Data System (ADS)

    Sun, Qimeng; Zhang, Suping

    2014-09-01

    Specimens of a new species of Cerithiidae, Cerithium mangrovum n. sp., were collected during two surveys along the coasts of Hainan and Guangdong Province, China. Usually associated with potamidid snails, this species often occurs in large populations between the mid-high tidal zones in a range of habitats, including mangroves, grass beds, silt, mud, and coral reefs. C. mangrovum n. sp. has a slender and tapering shell and the straight-sided whorl bears three aligned beaded spiral cords. The thick outer lip has a wide posterior sinus. It morphologically resembles C. coralium Kiener, 1841. The shell of C. coralium is usually larger and wider and the spiral cords are not as beaded as in C. mangrovum n. sp. Its radula has a rachidian tooth with a shallow, wide, median basal projection while the rachidian tooth of C. mangrovum n. sp. has a moderately long, median basal projection.

  2. A new species of Lataxiena Jousseaume, 1883 (Gastropoda: Muricidae) from the East and South China Seas

    NASA Astrophysics Data System (ADS)

    Zhang, Suping; Zhang, Shuqian

    2015-03-01

    A new muricid gastropod species, Lataxiena lutescena sp. nov., is described and illustrated. The new species was recognized during reidentification of the Muricidae collection in the Marine Biological Museum, Chinese Academy of Sciences, Qingdao. The specimens of the new species were collected from the East and South China Seas off Fujian, Guangdong, and Hainan Provinces. Lataxiena lutescena sp. nov. is similar to Lataxiena blosvillei (Deshayes, 1832) in general shape, but can be distinguished from the latter by the shell sculpture and radular characteristics. Lataxiena lutescena sp. nov. also resembles Lataxiena bombayana (Melvill, 1893), but differs from that species in the shell shape and anal notches and in lacking short spines on the shell.

  3. Lipoproteins of the egg perivitelline fluid of Pomacea canaliculata snails (Mollusca: Gastropoda).

    PubMed

    Garin, C F; Heras, H; Pollero, R J

    1996-12-01

    The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata was investigated. Two lipoproteins (PV 1 and PV 2) and one lipoprotein fraction (PV 3) were detected for the first time in gastropods. They represent 57.0, 7.5, and 35.5% of the egg total proteins, respectively. PV 1 is a glyco-carotene-protein complex with characteristics of a very high-density lipoprotein (VHDL). It has 0.33% lipids, mainly free sterols and phospholipids. The particle has a MW of 300 Kd and is composed of three subunits of 35, 32, and 28 Kd, respectively. PV 2 particle is a VHDL of 400 Kd and 3.75% lipids. The major lipid classes are free sterols and phospholipids and also have significant quantities of energy-providing triacylglycerides and free fatty acids. It is composed of two apoproteins of 67 and 31 Kd. PV 3 density corresponds to a high-density lipoprotein (HDL). It was fractionated into two subfractions "h" and "p". Fraction "h" contains 5.16% lipids, mainly free sterols, phospholipids, and free fatty acids, and two particles of 100 and 64 Kd. Dissociating electrophoresis showed two subunits of 34 and 29 Kd. Fraction "p" is composed of a single particle of 26 Kd that contains 9.5% lipids, which represents 30% of the total egg lipids. It has high levels of a carotenoid pigment. Besides it contains free fatty acids, hydrocarbons, sterified sterols, and triacylglycerides. These three fractions are probably the major supply of lipids and amino acids for the developing embryo. PMID:8972583

  4. Intraspecific and interspecific chemoattraction inBiomphalaria glabrata andHelisoma trivolvis (Gastropoda: Planorbidae).

    PubMed

    Marcopoulos, A A; Fried, B

    1994-10-01

    A Petri dish bioassay previously used to examine food preferences in planorbid snails was used to study intraspecific and interspecific chemoattraction inBiomphalaria glabrata (albino strain, M-line) andHelisoma trivolvis (Colorado strain) snails.B. glabrata snails showed significant intraspecific chemoattraction in the absence of visual cues and snail thigmotaxis.H. trivolvis snails also showed significant intraspecific chemoattraction. Interspecific chemoattraction between these species occurred in the bioassay, suggesting that the chemoattractants were not species specific. Artificial spring water conditioned by aqueous excretory-secretory products (snail-conditioned water) ofB. glabrata elicited significant intraspecific chemoattraction. However, lipophilic excretory-secretory products ofB. glabrata elicited significant chemorepulsion. Repellant factors in the lipophilic fraction were not characterized. PMID:24241838

  5. The Model Organism Hermissenda crassicornis (Gastropoda: Heterobranchia) Is a Species Complex

    PubMed Central

    Lindsay, Tabitha

    2016-01-01

    Hermissenda crassicornis is a model organism used in various fields of research including neurology, ecology, pharmacology, and toxicology. In order to investigate the systematics of this species and the presence of cryptic species in H. crassicornis, we conducted a comprehensive molecular and morphological analysis of this species covering its entire range across the North Pacific Ocean. We determined that H. crassicornis constitutes a species complex of three distinct species. The name Hermissensa crassicornis is retained for the northeast Pacific species, occurring from Alaska to Northern California. The name H. opalescens is reinstated for a species occurring from the Sea of Cortez to Northern California. Finally, the name H. emurai is maintained for the northwestern species, found in Japan and in the Russian Far East. These three species have consistent morphological and color pattern differences that can be used for identification in the field. PMID:27105319

  6. Annotated type catalogue of the Amphibulimidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S.H.; Ablett, Jonathan D.

    2011-01-01

    Abstract The type status is described of 39 taxa classified within the family Amphibulimidae (superfamily Orthalicoidea) and kept in the London museum. One taxon, Bulimus elaeodes Pfeiffer, 1853, is removed to the Strophocheilidae. Lectotypes are designated for Bulimus adoptus Reeve, 1849; Bulimus (Eurytus) eros Angas, 1878; Helix onca d'Orbigny, 1835; Amphibulima pardalina Guppy, 1868. The type status of the following taxon is changed to lectotype in accordance with Art. 74.6 ICZN: Strophocheilus (Dryptus) jubeus Fulton, 1908. As general introduction to this and following papers on Orthalicoid types in the Natural History Museum, a brief history of the London collection is given and several examples of handwriting from different authors are presented. PMID:22144852

  7. A phylogeny for the pomatiopsidae (Gastropoda: Rissooidea): a resource for taxonomic, parasitological and biodiversity studies

    PubMed Central

    2014-01-01

    Background The Pomatiopsidae are reported from northern India into southern China and Southeast Asia, with two sub-families, the Pomatiopsinae (which include freshwater, amphibious, terrestrial and marine species) and the freshwater Triculinae. Both include species acting as intermediate host for species of the blood-fluke Schistosoma which cause a public health problem in East Asia. Also, with around 120 species, triculine biodiversity exceeds that of any other endemic freshwater molluscan fauna. Nevertheless, the origins of the Pomatiopsidae, the factors driving such a diverse radiation and aspects of their co-evolution with Schistosoma are not fully understood. Many taxonomic questions remain; there are problems identifying medically relevant species. The predicted range is mostly unsurveyed and the true biodiversity of the family is underestimated. Consequently, the aim of the study was to collect DNA-sequence data for as many pomatiopsid taxa as possible, as a first step in providing a resource for identification of epidemiologically significant species (by non-malacologists), for use in resolving taxonomic confusion and for testing phylogeographical hypotheses. Results The evolutionary radiation of the Triculinae was shown to have been rapid and mostly post late Miocene. Molecular dating indicated that the radiation of these snails was driven first by the uplift of the Himalaya and onset of a monsoon system, and then by late-Pliocene global warming. The status of Erhaia as Anmicolidae is supported. The genera Tricula and Neotricula are shown to be non-monophyletic and the tribe Jullieniini may be polyphyletic (based on convergent characters). Triculinae from northern Vietnam could be derived from Gammatricula of Fujian/Yunnan, China. Conclusions The molecular dates and phylogenetic estimates in this study are consistent with an Australasian origin for the Pomatiopsidae and an East to West radiation via Oligocene Borneo-Philippines island hopping to Japan and then China (Triculinae arising mid-Miocene in Southeast China), and less so with a triculine origin in Tibet. The lack of monophyly in the medically important genera and indications of taxonomic inaccuracies, call for further work to identify epidemiologically significant taxa (e.g., Halewisia may be potential hosts for Schistosoma mekongi) and highlight the need for surveys to determine the true biodiversity of the Triculinae. PMID:24548800

  8. New species of the genus Elachisina (Gastropoda: Elachisinidae) from northeastern Brazil.

    PubMed

    Cunha, Carlo M; Santos, Franklin N; Lima, Silvio F B

    2016-01-01

    The family Elachisinidae Ponder, 1985 includes minute marine gastropods that live predominantly in the sublittoral zone (Ponder & Keyzer 1998; Rolán & Rubio 2001; Rolán & Gofas 2003). Most elachisinids have been included in the genus Elachisina Dall, 1918 based on their shell morphology (Warén 1996; Rolán & Rubio 2001; Rolán & Gofas 2003), consequently, very little is known about the habitat and ecological niche of the species (Ponder & Keyzer 1998; Rolán & Gofas 2003). Elachisina floridana (Rehder, 1943) is the only Atlantic congener collected alive, and is known to live beneath rocks and in rocky crevices in the intertidal zone to about 1 m depth in the Bahamas and Caribbean Sea (Ponder 1985; Ponder & Keyzer 1998; Rolán & Gofas 2003; Redfern 2013). Eastern Atlantic E. canarica (Nordsieck & García-Talavera, 1979) was also collected alive from the Canary Islands, but with no information on the habitat (Rolán & Gofas 2003). The islands of the northeastern Atlantic and West Africa are the regions with the greatest Elachisina richness known, totaling nine species (Rolán & Rubio 2001; Rolán & Gofas 2003). Only E. floridana has been recognized so far to be widely distributed throughout the Western Atlantic (Rolán & Gofas 2003; Rios 2009; Redfern 2013). PMID:27470791

  9. Review of the genus Endothyrella Zilch, 1960 with description of five new species (Gastropoda, Pulmonata, Plectopylidae).

    PubMed

    Páll-Gergely, Barna; Budha, Prem B; Naggs, Fred; Backeljau, Thierry; Asami, Takahiro

    2015-01-01

    All known taxa of the genus Endothyrella Zilch, 1960 (family Plectopylidae) are reviewed. Altogether 23 Endothyrella species are recognized. All species are illustrated and whenever possible, photographs of the available type specimens are provided. Five new species are described: Endothyrella angulata Budha & Páll-Gergely, sp. n., Endothyrella dolakhaensis Budha & Páll-Gergely, sp. n. and Endothyrella nepalica Budha & Páll-Gergely, sp. n. from Nepal, Endothyrella robustistriata Páll-Gergely, sp. n. from the Naga Hills, India, and Endothyrella inexpectata Páll-Gergely, sp. n. from Sichuan, China. Helix (Plectopylis) munipurensis Godwin-Austen, 1875 is synonymized with Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) gregorsoni Gude, 1915 is synonymized with Helix (Plectopylis) macromphalus W. Blanford, 1870. Plectopylis plectostoma var. exerta Gude, 1901 is a synonym of Plectopylis plectostoma var. tricarinata Gude, 1896, which is a species in its own right. Five species of the genus Chersaecia viz. Plectopylis (Chersaecia) bedfordi Gude, 1915, Helix (Plectopylis) brahma Godwin-Austen, 1879, Helix (Plectopylis) Oglei Godwin-Austen, 1879, Helix (Plectopylis) serica Godwin-Austen, 1875, and Plectopylis (Endothyra) williamsoni Gude, 1915 are moved to Endothyrella. The holotype of Plectopylis hanleyi Godwin-Austen, 1879 seems to be lost; therefore, Plectopylis hanleyi is considered to be a nomen dubium. PMID:26692792

  10. Atlanta ariejansseni, a new species of shelled heteropod from the Southern Subtropical Convergence Zone (Gastropoda, Pterotracheoidea).

    PubMed

    Wall-Palmer, Deborah; Burridge, Alice K; Peijnenburg, Katja T C A

    2016-01-01

    The Atlantidae (shelled heteropods) is a family of microscopic aragonite shelled holoplanktonic gastropods with a wide biogeographical distribution in tropical, sub-tropical and temperate waters. The aragonite shell and surface ocean habitat of the atlantids makes them particularly susceptible to ocean acidification and ocean warming, and atlantids are likely to be useful indicators of these changes. However, we still lack fundamental information on their taxonomy and biogeography, which is essential for monitoring the effects of a changing ocean. Integrated morphological and molecular approaches to taxonomy have been employed to improve the assessment of species boundaries, which give a more accurate picture of species distributions. Here a new species of atlantid heteropod is described based on shell morphology, DNA barcoding of the Cytochrome Oxidase I gene, and biogeography. All specimens of Atlanta ariejansseni sp. n. were collected from the Southern Subtropical Convergence Zone of the Atlantic and Indo-Pacific oceans suggesting that this species has a very narrow latitudinal distribution (37-48°S). Atlanta ariejansseni sp. n. was found to be relatively abundant (up to 2.3 specimens per 1000 m(3) water) within this narrow latitudinal range, implying that this species has adapted to the specific conditions of the Southern Subtropical Convergence Zone and has a high tolerance to the varying ocean parameters in this region. PMID:27551204

  11. Dating and biogeographical patterns in the sea slug genus Acanthodoris Gray, 1850 (Mollusca, Gastropoda, Nudibranchia).

    PubMed

    Hallas, Joshua M; Simison, W Brian; Gosliner, Terrence M

    2016-04-01

    Recent studies investigating vicariance and dispersal have been focused on correlating major geological events with instances of taxonomic expansion by incorporating the fossil record with molecular clock analyses. However, this approach becomes problematic for soft-bodied organisms that are poorly represented in the fossil record. Here, we estimate the phylogenetic relationships of the nudibranch genus Acanthodoris Gray, 1850 using three molecular markers (16S, COI, H3), and then test two alternative geologically calibrated molecular clock scenarios in BEAST and their effect on ancestral area reconstruction (AAR) estimates employed in LAGRANGE. The global temperate distribution of Acanthodoris spans multiple geological barriers, including the Bering Strait (∼5.32 Mya) and the Baja Peninsula (∼5.5 Mya), both of which are used in our dating estimates. The expansion of the Atlantic Ocean (∼95-105 Mya) is also used to calibrate the relationship between A. falklandica Eliot, 1905 and A. planca Fahey and Valdés, 2005, which are distributed in southern Chile and South Africa respectively. Phylogenetic analyses recovered strong biogeographical signal and recovered two major clades representing northern and southern hemispheric distributions of Acanthodoris. When all three geological events are applied to the calibration analyses, the age for Acanthodoris is estimated to be mid-Cretaceous. When the expansion of the Atlantic Ocean is excluded from our analyses, however, Acanthodoris is estimated to be much younger, with a divergence time estimate during the Miocene. Regardless of divergence estimates, our AAR suggests that Acanthodoris may have origins in the Atlantic Ocean with the Atlantic acting as a dispersal point to the northeastern Pacific. These results suggest that Acanthodoris exhibits a rare instance of western trans-arctic expansion. This study also shows that northeast Pacific specimens of A. pilosa should be regarded as A. atrogriseata and that A. serpentinotus should be regarded as a synonym of A. pina. PMID:26752594

  12. Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus).

    PubMed

    Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

    2016-01-01

    Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants. PMID:27324580

  13. Annotated type catalogue of the Bulimulidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S.H.; Ablett, Jonathan D.

    2014-01-01

    Abstract The type status is described of 404 taxa classified within the family Bulimulidae (superfamily Orthalicoidea) and kept in the London museum. Lectotypes are designated for Bulimus aurifluus Pfeiffer, 1857; Otostomus bartletti H. Adams, 1867; Helix cactorum d’Orbigny, 1835; Bulimus caliginosus Reeve, 1849; Bulimus chemnitzioides Forbes, 1850; Bulimus cinereus Reeve, 1849; Helix cora d’Orbigny, 1835; Bulimus fallax Pfeiffer, 1853; Bulimus felix Pfeiffer, 1862; Bulimus fontainii d’Orbigny, 1838; Bulimus fourmiersi d’Orbigny, 1837; Bulimus (Mesembrinus) gealei H. Adams, 1867; Bulimus gruneri Pfeiffer, 1846; Bulimus humboldtii Reeve, 1849; Helix hygrohylaea d’Orbigny, 1835; Bulimus jussieui Pfeiffer, 1846; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895; Helix lichnorum d’Orbigny, 1835; Bulimulus (Drymaeus) lucidus da Costa, 1898; Bulimus luridus Pfeiffer, 1863; Bulimus meleagris Pfeiffer, 1853; Bulimus monachus Pfeiffer, 1857; Bulimus montagnei d’Orbigny, 1837; Helix montivaga d’Orbigny, 1835; Bulimus muliebris Reeve, 1849; Bulimus nigrofasciatus Pfeiffer in Philippi 1846; Bulimus nitelinus Reeve, 1849; Helix oreades d’Orbigny, 1835; Helix polymorpha d’Orbigny, 1835; Bulimus praetextus Reeve, 1849; Bulinus proteus Broderip, 1832; Bulimus rusticellus Morelet, 1860; Helix sporadica d’Orbigny, 1835; Bulimus sulphureus Pfeiffer, 1857; Helix thamnoica var. marmorata d’Orbigny, 1835; Bulinus translucens Broderip in Broderip and Sowerby I 1832; Helix trichoda d’Orbigny, 1835; Bulinus ustulatus Sowerby I, 1833; Bulimus voithianus Pfeiffer, 1847; Bulimus yungasensis d’Orbigny, 1837. The type status of the following taxa is changed to lectotype in accordance with Art. 74.6 ICZN: Bulimulus (Drymaeus) caucaensis da Costa, 1898; Drymaeus exoticus da Costa, 1901; Bulimulus (Drymaeus) hidalgoi da Costa, 1898; Bulimulus (Drymaeus) interruptus Preston, 1909; Bulimulus (Drymaeus) inusitatus Fulton, 1900; Bulimulus latecolumellaris Preston, 1909; Bulimus (Otostomus) napo Angas, 1878; Drymaeus notabilis da Costa, 1906; Drymaeus notatus da Costa, 1906; Bulimulus (Drymaeus) nubilus Preston, 1903; Drymaeus obliquistriatus da Costa, 1901; Bulimus (Drymaeus) ochrocheilus E.A. Smith, 1877; Bulimus (Drymaeus) orthostoma E.A. Smith, 1877; Drymaeus expansus perenensis da Costa, 1901; Bulimulus pergracilis Rolle, 1904; Bulimulus (Drymaeus) plicatoliratus da Costa, 1898; Drymaeus prestoni da Costa, 1906; Drymaeus punctatus da Costa, 1907; Bulimus (Leptomerus) sanctaeluciae E.A. Smith, 1889; Bulimulus (Drymaeus) selli Preston, 1909; Drymaeus subventricosus da Costa, 1901; Bulimulus (Drymaeus) tigrinus da Costa, 1898; Drymaeus volsus Fulton, 1907; Drymaeus wintlei Finch, 1929; Bulimus zhorquinensis Angas, 1879; Bulimulus (Drymaeus) ziczac da Costa, 1898. The following junior subjective synonyms are established: Bulimus antioquensis Pfeiffer, 1855 = Bulimus baranguillanus Pfeiffer, 1853; Drymaeus bellus da Costa, 1906 = Drymaeus blandi Pilsbry, 1897; Bulimus hachensis Reeve 1850 = Bulimus gruneri Pfeiffer, 1846 = Bulimus columbianus Lea, 1838; Bulimus (Otostomus) lamas Higgins 1868 = Bulimus trujillensis Philippi, 1867; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895 = Bulimulus (Drymaeus) binominis E.A. Smith, 1895; Drymaeus multispira da Costa, 1904 = Helix torallyi d’Orbigny, 1835; Bulimulus (Drymaeus) plicatoliratus Da Costa, 1898 = Bulimus convexus Pfeiffer, 1855; Bulimus sugillatus Pfeiffer, 1857 = Bulimus rivasii d’Orbigny, 1837; Bulimus meridionalis Reeve 1848 [June] = Bulimus voithianus Pfeiffer, 1847. New combinations are: Bostryx montagnei (d’Orbigny, 1837); Bostryx obliquiportus (da Costa, 1901); Bulimulus heloicus (d’Orbigny, 1835); Drymaeus (Drymaeus) lusorius (Pfeiffer, 1855); Drymaeus (Drymaeus) trigonostomus (Jonas, 1844); Drymaeus (Drymaeus) wintlei Finch, 1929; Drymaeus (Mesembrinus) conicus da Costa, 1907; Kuschelenia (Kuschelenia) culminea culminea (d’Orbigny, 1835); Kusche

  14. Recent expansion and relic survival: Phylogeography of the land snail genus Helix (Mollusca, Gastropoda) from south to north Europe.

    PubMed

    Fiorentino, V; Manganelli, G; Giusti, F; Ketmaier, V

    2016-05-01

    Little is known about the evolutionary history of Helix, despite the fact that it includes the largest land snails in the western Palaearctic, some of which (e.g. H. pomatia Linnaeus, 1758) are valuable human food. We compared two groups of Helix with apparently contrasting evolutionary histories: the widespread species H. pomatia and the group distributed along the Italian Apennine chain, a relatively unknown set of species with a restricted distribution over a range of altitudes. To reconstruct the evolutionary trajectories of these two groups, we analysed morphological (shell and genitalia) and molecular characters (mitochondrial and nuclear markers) in a total of 59 populations from northern and central Europe (H. pomatia) and along the Apennine chain (various species). We also reconstructed the phylogeny and the evolutionary history of the genus by combining our data with that currently available in the literature. We found that spatial changes did not merely imply fragmentation of populations, but also implied environmental changes (woodlands vs. grasslands) that may have triggered the observed phenotypic diversification. We also found that Anatolia is the ancestral range of Helix and is therefore an important area for the Palaearctic diversity. The results provide insights into the evolutionary history of species richness and more generally into the processes that may have shaped the distribution and diversification of these organisms across Europe and the peri-Mediterranean area. PMID:26926944

  15. Population genetic structure of Bellamya aeruginosa (Mollusca: Gastropoda: Viviparidae) in China: weak divergence across large geographic distances.

    PubMed

    Gu, Qian H; Husemann, Martin; Ding, Baoqing; Luo, Zhi; Xiong, Bang X

    2015-11-01

    Bellamya aeruginosa is a widely distributed Chinese freshwater snail that is heavily harvested, and its natural habitats are under severe threat due to fragmentation and loss. We were interested whether the large geographic distances between populations and habitat fragmentation have led to population differentiation and reduced genetic diversity in the species. To estimate the genetic diversity and population structure of B. aeruginosa, 277 individuals from 12 populations throughout its distribution range across China were sampled: two populations were sampled from the Yellow River system, eight populations from the Yangtze River system, and two populations from isolated plateau lakes. We used seven microsatellite loci and mitochondrial cytochrome oxidase I sequences to estimate population genetic parameters and test for demographic fluctuations. Our results showed that (1) the genetic diversity of B. aeruginosa was high for both markers in most of the studied populations and effective population sizes appear to be large, (2) only very low and mostly nonsignificant levels of genetic differentiation existed among the 12 populations, gene flow was generally high, and (3) relatively weak geographic structure was detected despite large geographic distances between populations. Further, no isolation by linear or stream distance was found among populations within the Yangtze River system and no signs of population bottlenecks were detected. Gene flow occurred even between far distant populations, possibly as a result of passive dispersal during flooding events, zoochoric dispersal, and/or anthropogenic translocations explaining the lack of stronger differentiation across large geographic distances. The high genetic diversity of B. aeruginosa and the weak population differentiation are likely the results of strong gene flow facilitated by passive dispersal and large population sizes suggesting that the species currently is not of conservation concern. PMID:26640670

  16. Oxidative stress responses and toxin accumulation in the freshwater snail Radix swinhoei (Gastropoda, Pulmonata) exposed to microcystin-LR.

    PubMed

    Zhang, Junqian; Xie, Zhicai; Wang, Zhi

    2016-01-01

    Microcystin-LR (MCLR) is one of the most common toxins in eutrophic freshwater ecosystems. The ecotoxicological effects of MCLR in freshwater ecosystems have been widely documented; however, the physiological effects of MCLR on freshwater snails and the underlying toxicity/detoxification mechanisms have not been well investigated. In this laboratory study, antioxidant system responses in the hepatopancreas and the digestive tract of Radix swinhoei, a typical freshwater snail, exposed to 0.01 mg/L to 2 mg/L MCLR were explored. Antioxidant enzymes, particularly superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), in the digestive tracts were effectively generated at 0.2 and 2 mg/L MCLR. However, SOD and CAT activities in the hepatopancreas were activated only at 0.2 mg/L MCLR. Glutathione (GSH) concentrations in the digestive tracts significantly increased at 0.01 to 0.2 mg/L MCLR; by comparison, GSH concentrations in the hepatopancreas remained stable. No oxidative damage (lipid peroxidations) occurred in the digestive tracts and the hepatopancreas when the snail was exposed to ≤0.2 mg/L MCLR. MCLR accumulation in different snail tissues was also examined. MCLR accumulated in different tissues and showed the following pattern: hepatopancreas > gonads > digestive tracts > muscles. Bioaccumulated concentrations in these four tissues increased as MCLR exposure concentrations increased; by contrast, bioaccumulation factors decreased as MCLR exposure concentrations increased. Our results indicated that R. swinhoei is sensitively responsive to MCLR by changing antioxidant system status to cope with the toxicity. Snails may be vectors of MCs that transfer MCs in eutrophic lakes via food chains or food web. PMID:26362638

  17. [Genetic diversity in two populations of the snail Strombus gigas (Gastropoda: Strombidae) from Yucatan, Mexico, using microsatellite].

    PubMed

    Zamora-Bustillos, Roberto; Rodríguez-Canul, Rossanna; García de León, Francisco J; Tello Cetina, Jorge

    2011-09-01

    The pink conch Strombus gigas is an important fisheries resource in the Caribbean region, including the Yucatán Peninsula. We analyzed the genetic diversity and genetic structure of two populations (Alacranes Reef and Chinchorro Bank) with the use of five microsatellite molecular markers. The results indicate that the two populations are in the same rank of genetic diversity (He), from 0.613 to 0.692. Significant deviation from H-WE was observed in the both populations due to deficit to heterozygotes, this was attributed to inbreeding as a consequence of over-fishing; nevertheless, other possible causes considered are mixing of individuals from two or more populations, and the existence of null alleles. Levels of genetic differentiation indicated the existence of a single homogenous population in the Yucatan Peninsula (F(ST) de 0.003, p = 0.49), which fits with highest levels of gene flow is significant (2.3 individuals) between both populations. Results from this study support the hypothesis that S. gigas is part of a single panmictic population in the Yucatan Peninsula; therefore, this fishery resource should be regulated the same way for both areas. PMID:22017119

  18. Analysis of nitric oxide-cyclic guanosine monophosphate signaling during metamorphosis of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia)

    PubMed Central

    Bishop, Cory D.; Pires, Anthony; Norby, Shong-Wan; Boudko, Dmitri; Moroz, Leonid L.; Hadfield, Michael G.

    2014-01-01

    SUMMARY The gas nitric oxide (NO), and in some cases its downstream second messenger, cyclic guanosine monophosphate (cGMP) function in different taxa to regulate the timing of life-history transitions. Increased taxonomic sampling is required to foster conclusions about the evolution and function of NO/cGMP signaling during life-history transitions. We report on the function and localization of NO and cGMP signaling during metamorphosis of the nudibranch Phestilla sibogae. Pharmacological manipulation of NO or cGMP production in larvae modulated responses to a natural settlement cue from the coral Porites compressa in a manner that suggest inhibitory function for NO/cGMP signaling. However, these treatments were not sufficient to induce metamorphosis in the absence of cue, a result unique to this animal. We show that induction of metamorphosis in response to the settlement cue is associated with a reduction in NO production. We documented the expression of putative NO synthase (NOS) and the production of cGMP during larval development and observed no larval cells in which NOS and cGMP were both detected. The production of cGMP in a bilaterally symmetrical group of cells fated to occupy the distal tip of rhinophores is correlated with competence to respond to the coral settlement cue. These results suggest that endogenous NO and cGMP are involved in modulating responses of P. sibogae to a natural settlement cue. We discuss these results with respect to habitat selection and larval ecology. PMID:18460091

  19. Description and evaluation of imposex in Strombus canarium Linnaeus, 1758 (Gastropoda, Strombidae): a potential bio-indicator of tributyltin pollution.

    PubMed

    Cob, Zaidi Che; Arshad, Aziz; Bujang, Japar Sidik; Abd Ghaffar, Mazlan

    2011-07-01

    Strombus canarium Linnaeus, 1758 is an important gastropod species within the study area and was traditionally collected for food by the locals. The objective of the present study is to assess the incidence of imposex and its severity in this species. Adult conchs were sampled during their main reproductive period, from October 2005 to January 2006, at Sungai Pulai estuary, Johor Straits, Malaysia. A total of 32.81% of adult females showed imposex characteristics, with varying degrees of severity though. The relative penis size (RPS) index ranged from 1.74 to 33.29 (mean = 13.40 ± 2.27, n = 21), while the relative penis length (RPL) index ranged from 6.28 to 55.19 (mean = 25.83 ± 3.33, n = 21). The use of vas deferens sequence (VDS) index was however cannot be applied as the presence of egg groove obscured any vas deferens development in affected females. Sequence of imposex (male penis) development in female conch, from merely a small stump to an advance male penis homologous was therefore carefully analyzed and described, and an alternative imposex classification scheme was proposed. S. canarium can be a good indicator for monitoring of organotin pollution within the study area. However, more studies are needed in order to further develop and test its validity and application, such as its correlation with levels of pollutant within the tissues and the environment, as well as its application on other Strombus species. PMID:20824325

  20. No evidence for a culturable bacterial tetrodotoxin producer in Pleurobranchaea maculata (Gastropoda: Pleurobranchidae) and Stylochoplana sp. (Platyhelminthes: Polycladida).

    PubMed

    Salvitti, Lauren R; Wood, Susanna A; McNabb, Paul; Cary, Stephen Craig

    2015-02-01

    Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp. (Platyhelminthes). Tetrodotoxin production was tested utilizing a recently developed sensitive method to detect the C9 base of TTX via liquid chromatography-mass spectrometry. Bacterial strains were characterized by sequencing a region of the 16S ribosomal RNA gene. To account for the possibility that TTX is produced by a consortium of bacteria, a series of experiments using marine broth spiked with various P. maculata tissues were undertaken. Sixteen unique strains from P. maculata and one from Stylochoplana sp. were isolated, representing eight different genera; Pseudomonadales, Actinomycetales, Oceanospirillales, Thiotrichales, Rhodobacterales, Sphingomonadales, Bacillales, and Vibrionales. Molecular fingerprinting of bacterial communities from broth experiments showed little change over the first four days. No C9 base or TTX was detected in isolates or broth experiments (past day 0), suggesting a culturable microbial source of TTX in P. maculata and Stylochoplana sp. is unlikely. PMID:25635464

  1. Opisthobranchia (Mollusca, Gastropoda) - more than just slimy slugs. Shell reduction and its implications on defence and foraging.

    PubMed

    Wägele, Heike; Klussmann-Kolb, Annette

    2005-02-16

    BACKGROUND: In general shell-less slugs are considered to be slimy animals with a rather dull appearance and a pest to garden plants. But marine slugs usually are beautifully coloured animals belonging to the less-known Opisthobranchia. They are characterized by a large array of interesting biological phenomena, usually related to foraging and/or defence. In this paper our knowledge of shell reduction, correlated with the evolution of different defensive and foraging strategies is reviewed, and new results on histology of different glandular systems are included. RESULTS: Based on a phylogeny obtained by morphological and histological data, the parallel reduction of the shell within the different groups is outlined. Major food sources are given and glandular structures are described as possible defensive structures in the external epithelia, and as internal glands. CONCLUSION: According to phylogenetic analyses, the reduction of the shell correlates with the evolution of defensive strategies. Many different kinds of defence structures, like cleptocnides, mantle dermal formations (MDFs), and acid glands, are only present in shell-less slugs. In several cases, it is not clear whether the defensive devices were a prerequisite for the reduction of the shell, or reduction occurred before. Reduction of the shell and acquisition of different defensive structures had an implication on exploration of new food sources and therefore likely enhanced adaptive radiation of several groups. PMID:15715915

  2. mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): implications for comparative neurobiology.

    PubMed

    Medina, M; Collins, T M; Walsh, P J

    2001-01-01

    Sea hares within the genus Aplysia are important neurobiological model organisms; as more studies based on different Aplysia species are appearing in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include determination of ancestral traits, direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological bases. PMID:12116938

  3. Digestive system of the sacoglossan Plakobranchus ocellatus (Gastropoda: Opisthobranchia): light- and electron-microscopic observations with remarks on chloroplast retention.

    PubMed

    Hirose, Euichi

    2005-08-01

    The sacoglossan Plakobranchus ocellatus feeds by sucking the cytoplasmic contents from algae and retains intact algal chloroplasts within the cells of the digestive gland. Morphology of the entire digestive system of this species was firstly described by means of a combination of histology and electron microscopy (both SEM and TEM). The short alimentary canal is confined to the head, and the anus opens at the anterior right corner of the pericardial swelling, as is the case in many non-shelled sacoglossans. The alimentary canal of the specimens examined rarely contained ingesta, suggesting that the retained chloroplasts provide sufficient nourishment to the sacoglossan hosts and that sea slugs with empty stomachs survive well in the field. The digestive gland, with the retained chloroplasts, branches from the stomach and is sparsely distributed throughout the body, including the head region, but is aggregated mainly in the dorsal lamellae. Chloroplasts were occasionally found in the epithelial cells in the transitional region from the stomach wall to the digestive gland, which may be a site at which chloroplasts are incorporated into the animal cells by endocytosis. Numerous microvilli filling the lumen of the digestive gland suggest that molecules are actively transferred within the gland. The sea slug thus apparently provides a favorable environment to support the long-term retention and function of chloroplasts. PMID:16141704

  4. Myogenesis in Aplysia californica (Cooper, 1863) (Mollusca, Gastropoda, Opisthobranchia) with special focus on muscular remodeling during metamorphosis.

    PubMed

    Wollesen, Tim; Wanninger, Andreas; Klussmann-Kolb, Annette

    2008-07-01

    To date only few comparative approaches tried to reconstruct the ontogeny of the musculature in invertebrates. This may be due to the difficulties involved in reconstructing three dimensionally arranged muscle systems by means of classical histological techniques combined with light or transmission electron microscopy. Within the scope of the present study we investigated the myogenesis of premetamorphic, metamorphic, and juvenile developmental stages of the anaspidean opisthobranch Aplysia californica using fluorescence F-actin-labeling in conjunction with modern confocal laser scanning microscopy. We categorized muscles with respect to their differentiation and degeneration and found three true larval muscles that differentiate during the embryonic and veliger phase and degenerate during or slightly after metamorphosis. These are the larval retractor, the accessory larval retractor, and the metapodial retractor muscle. While the pedal retractor muscle, some transversal mantle fibers and major portions of the cephalopedal musculature are continued and elaborated during juvenile and adult life, the buccal musculature and the anterior retractor muscle constitute juvenile/adult muscles which differentiate during or after metamorphosis. The metapodial retractor muscle has never been reported for any other gastropod taxon. Our findings indicate that the late veliger larva of A. californica shares some common traits with veligers of other gastropods, such as a larval retractor muscle. However, the postmetamorphic stages exhibit only few congruencies with other gastropod taxa investigated to date, which is probably due to common larval but different adult life styles within gastropods. Accordingly, this study provides further evidence for morphological plasticity in gastropod myogenesis and stresses the importance of ontogenetic approaches to understand adult conditions and life history patterns. PMID:18157859

  5. Initial results on the molecular phylogeny of the Nudibranchia (Gastropoda, Opisthobranchia) based on 18S rDNA data.

    PubMed

    Wollscheid, E; Wägele, H

    1999-11-01

    This study investigated nudibranch phylogeny on the basis of 18S rDNA sequence data. 18S rDNA sequence data of 19 taxa representing the major living orders and families of the Nudibranchia were analyzed. Representatives of the Cephalaspidea, Anaspidea, Gymnomorpha, Prosobranchia, and Pulmonata were also sequenced and used as outgroups. An additional 28 gastropod sequences taken from GenBank were also included in our analyses. Phylogenetic analyses of these more than 50 gastropod taxa provide strong evidence for support of the monophyly of the Nudibranchia. The monophyly of the Doridoidea, Cladobranchia, and Aeolidoidea within the Nudibranchia are also strongly supported. Phylogenetic utility and information content of the 18S rDNA sequences for Nudibranchia, and Opisthobranchia in general, are examined using the program SplitsTree as well as phylogenetic reconstructions using distance and parsimony approaches. 0Results based on these molecular data are compared with hypotheses about nudibranch phylogeny inferred from morphological data. PMID:10603252

  6. Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile.

    PubMed

    Araya, Juan Francisco; Valdés, Ángel

    2016-01-01

    The coast of northern Chile has been sparsely studied in regards to its invertebrate fauna, with just a few works reviewing the distribution of local mollusks. This work presents a survey of the shallow water heterobranch sea slugs currently occurring around the port of Caldera (27 °S), in the Región de Atacama, northern Chile. Eight species of sea slugs were found in this study: Aplysiopsis cf. brattstroemi (Marcus, 1959), Baptodoris peruviana (d'Orbigny, 1837), Diaulula variolata (d'Orbigny, 1837), Doris fontainii d'Orbigny, 1837, Onchidella marginata (Couthouy in Gould, 1852), Phidiana lottini (Lesson, 1831), Tyrinna delicata (Abraham, 1877) and the new species Berthella schroedli sp. nov., described herein. All of the species found in the area are endemic to South America, having distributions in the southeastern Pacific and South Atlantic Oceans, from Ancash, Perú to Peninsula Valdés, Argentina, and two of them represent species which are endemic to the Chilean coasts (Aplysiopsis cf. brattstroemi and Berthella schroedli). The finding of a previously undescribed species emphasizes the need of further surveys, particularly in subtidal and deeper waters, in order to improve the knowledge on this neglected fauna in Atacama. PMID:27168975

  7. Analysis of nitric oxide-cyclic guanosine monophosphate signaling during metamorphosis of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia).

    PubMed

    Bishop, Cory D; Pires, Anthony; Norby, Shong-Wan; Boudko, Dmitri; Moroz, Leonid L; Hadfield, Michael G

    2008-01-01

    The gas nitric oxide (NO), and in some cases its downstream second messenger, cyclic guanosine monophosphate (cGMP) function in different taxa to regulate the timing of life-history transitions. Increased taxonomic sampling is required to foster conclusions about the evolution and function of NO/cGMP signaling during life-history transitions. We report on the function and localization of NO and cGMP signaling during metamorphosis of the nudibranch Phestilla sibogae. Pharmacological manipulation of NO or cGMP production in larvae modulated responses to a natural settlement cue from the coral Porites compressa in a manner that suggest inhibitory function for NO/cGMP signaling. However, these treatments were not sufficient to induce metamorphosis in the absence of cue, a result unique to this animal. We show that induction of metamorphosis in response to the settlement cue is associated with a reduction in NO production. We documented the expression of putative NO synthase (NOS) and the production of cGMP during larval development and observed no larval cells in which NOS and cGMP were both detected. The production of cGMP in a bilaterally symmetrical group of cells fated to occupy the distal tip of rhinophores is correlated with competence to respond to the coral settlement cue. These results suggest that endogenous NO and cGMP are involved in modulating responses of P. sibogae to a natural settlement cue. We discuss these results with respect to habitat selection and larval ecology. PMID:18460091

  8. Observations on Neotricula aperta (Gastropoda: Pomatiopsidae) population densities in Thailand and central Laos: implications for the spread of Mekong schistosomiasis

    PubMed Central

    2012-01-01

    Background The snail Neotricula aperta transmits Mekong schistosomiasis in southern Laos and Cambodia, with about 1.5 million people at risk of infection. Plans are under consideration for at least 12 hydroelectric power dams on the lower Mekong river and much controversy surrounds predictions of their environmental impacts. Unfortunately, there are almost no ecological data (such as long term population trend studies) available for N. aperta which could be used in impact assessment. Predictions currently assume that the impacts will be the same as those observed in Africa (i.e., a worsening of the schistosomiasis problem); however, marked ecological differences between the snails involved suggest that region specific models are required. The present study was performed as an initial step in providing data, which could be useful in the planning of water resource development in the Mekong. Snail population density records were analyzed for populations close to, and far downstream of, the Nam Theun 2 (NT2) project in Laos in order to detect any changes that might be attributable to impoundment. Results The population immediately downstream of NT2 and that sampled 400 km downstream in Thailand both showed a long term trend of slow growth from 1992 to 2005; however, both populations showed a marked decline in density between 2005 and 2011. The decline in Thailand was to a value significantly lower than that predicted by a linear mixed model for the data, whilst the population density close to NT2 fell to undetectable levels in 2011 from densities of over 5000 m-2 in 2005. The NT2 dam began operation in 2010. Conclusions The impact of the NT2 dam on N. aperta population density could be more complex than first thought and may reflect the strict ecological requirements of this snail. There was no indication that responses of N. aperta populations to dam construction are similar to those observed with Bulinus and Schistosoma haematobium in Africa, for example. In view of the present findings, more ecological data (in particular population density monitoring and surveillance for new habitats) are urgently required in order to understand properly the likely impacts of water resource development on Mekong schistosomiasis. PMID:22720904

  9. Distribution, feeding behavior and control strategies of the exotic land snail Achatina fulica (Gastropoda: Pulmonata) in the northeast of Brazil.

    PubMed

    Albuquerque, F S; Peso-Aguiar, M C; Assunção-Albuquerque, M J T

    2008-11-01

    The goal of this study was to document the distribution and establishment A. fulica such as their feeding preference and behavior in situ. The study was carried out at the city of Lauro de Freitas, Bahia state, Brazil, between November 2001 and November 2002. We used catch per unit effort methods to determine abundance, distribution, habitat choice and food preferences. The abundance and distribution of A. fulica was most representative in urban area, mainly near to the coastline. Lots and house gardens were the most preferred sites during active hours. The results indicated that A. fulica started their activity at the end of the evening and stopped in mid-morning. Their preferred food were vascular plants such as Hibiscus syriacus, Ricinus communis, Carica papaya, Galinsonga coccinea, Lippia alba, Ixora coccinea, Musa parasidisiaca, Mentha spicata and Cymbopogon citrates. Our results indicate that A. fulica are well adapted and established in this city and modified environments facilitate their establishment and dispersion. However, human perturbation, such as clearance of lots could be limiting for the persistence of A. fulica populations. PMID:19197503

  10. Phylogeographic analyses reveal Transpontic long distance dispersal in land snails belonging to the Caucasotachea atrolabiata complex (Gastropoda: Helicidae).

    PubMed

    Neiber, Marco T; Sagorny, Christina; Sauer, Jan; Walther, Frank; Hausdorf, Bernhard

    2016-10-01

    The phylogeography and population structure of land snails belonging to the Caucasotachea atrolabiata complex in the Caucasus region was investigated to obtain a better understanding of diversification processes in this biodiversity hotspot. So far the complex has been classified into three species, C. atrolabiata from the north-western Caucasus, C. calligera from Transcaucasia and C. intercedens from the eastern Pontus Mountains. Phylogenetic (neighbor-net and neighbor-joining tree) as well as admixture analyses based on AFLP data showed that the complex consists of two population clusters corresponding to C. atrolabiata and C. calligera. The populations assigned to C. intercedens in fact represent hybrids consisting of different proportions of the genomes of C. atrolabiata and C. calligera. There is a broad transition zone between C. atrolabiata and C. calligera in the Pontic Mountains and a second transition zone in Abkhazia. Because of evidence for gene flow, it is suggested to classify the two aforementioned taxa as subspecies, namely C. a. atrolabiata and C. a. calligera. The presence of mitochondrial C. a. atrolabiata haplotypes in Turkey can only be explained by passive dispersal across the Black Sea. The distribution of C. a. atrolabiata and additional cases of land snails with disjunct Transpontic distribution patterns cannot be ascribed to a common cause but are results of long distance dispersal events at different times. PMID:27450782

  11. Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda).

    PubMed

    Yonow, Nathalie

    2012-01-01

    Seventy species of opisthobranchs are described in this work based on collections from the Persian Gulf, Socotra, Kenya, Zanzibar, Madagascar, La Réunion, Mauritius, the Seychelles, the Maldives, and Sri Lanka. Ten species are newly recorded from the western Indian Ocean and four species are recorded in the scientific literature for the first time since their original descriptions. Two species are described as new: Cyerce bourbonicasp. n. from La Réunion and Doriopsilla nigrocerasp. n. from the Persian Gulf coast of Saudi Arabia. Chromodoris cavae is removed from its synonymy with Chromodoris tennentana and redescribed from specimens from La Réunion, while several new synonyms are proposed for some commonly occurring species. Risbecia bullockii is recorded for the second time from the Indian Ocean and assigned to its correct genus. PMID:22711992

  12. A taxonomic revision of two local endemic Radix spp. (Gastropoda: Lymnaeidae) from Khodutka geothermal area, Kamchatka, Russian Far East.

    PubMed

    Bolotov, Ivan; Bespalaya, Yulia; Aksenova, Olga; Aksenov, Andrey; Bolotov, Nikita; Gofarov, Mikhail; Kondakov, Alexander; Paltser, Inga; Vikhrev, Ilya

    2014-01-01

    Khodutka geothermal area is located near Khodutka and Priemysh volcanoes and is one of the largest geothermal areas of the Kamchatka Peninsula. Vakin (2003) described geological, geochemical and geothermic conditions of this geothermal area in detail. The main thermal water sources have temperatures up to 87°C and a discharge of approximately 150 l×sec.-1 are flows out into the warm lake with dimensions of ca. 250 m length and 80 m width. This warm river is ca. 20 m in width beginning from the lake and flows to the Bolshaya Khodutka River basin. Two local endemic Radix species were described from this geothermal area, especially Lymnaea (Radix) hadutkae Kruglov & Starobogatov, 1989 and L. (R.) thermokamtschatica Kruglov & Starobogatov, 1989 (Kruglov & Starobogatov 1989, 1993; Kruglov 2005). These species were separated using proportions of shell and reproductive system (Kruglov & Starobogatov 1989, 1993; Starobogatov et al. 2004). According to the diagnosis, L. (R.) hadutkae differs in the ear-shape shell, a form of the provaginal duct with cylindrical distal part and conical proximal part, and larger value of the index of the copulatory apparatus (ICA: proportion of the preputium to phallotheca is 1.27) from other species within the section Thermoradix Kruglov & Starobogatov, 1989. The last whorl is large, 0.86-0.89 of the shell height; an excess of the last whorl over upper margin of the aperture is 0.15-0.16 of the aperture height. L. (R.) thermokamtschatica has the cylindrical provaginal duct, relatively short bursa duct (1.5X longer than the bursa copulatrix diameter) and very long phallotheca (ICA is 0.77). The last whorl is large, 0.85-0.87 of the shell height; an excess of the last whorl over upper margin of the aperture is 0.2-0.25 of the aperture height. In accordance with an identification key (Starobogatov et al. 2004), the main diagnostic feature is an excess of the last whorl over the shell aperture, which has ≤0.78 and ≥0.80 of the penultimate whorl width in the first and second species, respectively. In the present paper, we revised these taxa using newly collected topotypes and additional Radix spp. specimens from other areas of the Russian Far East.  PMID:25283942

  13. Host and ecology both play a role in shaping distribution of digenean parasites of New Zealand whelks (Gastropoda: Buccinidae: Cominella).

    PubMed

    Donald, Kirsten M; Spencer, Hamish G

    2016-08-01

    Digenean parasites infecting four Cominella whelk species (C. glandiformis, C. adspersa, C. maculosa and C. virgata), which inhabit New Zealand's intertidal zone, were analysed using molecular techniques. Mitochondrial 16S and cytochrome oxidase 1 (COI) and nuclear rDNA ITS1 sequences were used to infer phylogenetic relationships amongst digenea. Host species were parasitized by a diverse range of digenea (Platyhelminthes, Trematoda), representing seven families: Echinostomatidae, Opecoelidae, Microphallidae, Strigeidae and three, as yet, undetermined families A, B and C. Each parasite family infected between one and three host whelk species, and infection levels were typically low (average infection rates ranged from 1·4 to 3·6%). Host specificity ranged from highly species-specific amongst the echinostomes, which were only ever observed infecting C. glandiformis, to the more generalist opecoelids and strigeids, which were capable of infecting three out of four of the Cominella species analysed. Digeneans displayed a highly variable geographic range; for example, echinostomes had a large geographic range stretching the length of New Zealand, from Northland to Otago, whereas Family B parasites were restricted to fairly small areas of the North Island. Our results add to a growing body of research identifying wide ranges in both host specificity and geographic range amongst intertidal, multi-host parasite systems. PMID:27278710

  14. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae).

    PubMed

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M; Sun, Zhenyu J; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O; Falcão, Rosana; Cherobim, Mariana D; Dias, Simoni C; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L; Otero-González, Anselmo J

    2015-08-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability. PMID:25921828

  15. Organiser role of the stem cell of the mesoderm in prototroch patterning in Patella vulgata (Mollusca, Gastropoda).

    PubMed

    Damen, P; Dictus, W J

    1996-05-01

    During early development of the gastropod mollusc Patella vulgata, the stem cell of the mesoderm (3D-macromere) is induced. As a result of this induction, the embryo becomes dorsoventrally organised. At about the same time in development, ciliated cells, so-called trochoblasts, are formed. Later in development, some trochoblasts deciliate and, together with the ciliated trochoblast, form the dorsoventrally organised prototroch, the locomotory organ of the larva. In order to study the role of the 3D-macromere in the specification of trochoblasts and in the induction of the dorsoventral organisation of the prototroch, induction of 3D has been prevented in various ways. it is shown that preventing 3D-induction results in the formation of a radially symmetrical prototroch. The trochoblasts of all four quadrants developed like corresponding trochoblasts of the A-quadrant. Somewhere between 30 and 120 min after fifth cleavage the 3D-macromere induces the formation of specific trochoblasts and organises the dorsoventral pattern of the prototroch. Besides a role of the 3D-macromere, a role of other cells has been demonstrated in the conditionally specified deciliation of trochoblasts. PMID:8798146

  16. Gigantobilharzia melanoidis n.sp. (Trematoda: Schistosomatidae) from Melanoides tuberculata (Gastropoda: Thiaridae) in the United Arab Emirates.

    PubMed

    Schuster, Rolf K; Aldhoun, Jitka A; O'Donovan, Declan

    2014-03-01

    Delicate filamentous schistosomatids detected in the intestinal veins of experimentally infected chickens are here described as a new parasite species, Gigantobilharzia melanoidis, and details of its life cycle are given. It is the first complete description of a schistosome species that uses Melanoides tuberculata as an intermediate host. Apharyngeate ocellate brevifurcate cercariae found in 65 out of 950 M. tuberculata collected in a pond in Al Aweer, United Arab Emirates were used as infection material. The new species can be distinguished from the other species of the genus by the following combination of characters: caecal reunion in males situated anterior to seminal vesicle, a very short gynecophoric canal (gynecophoric canal length/body length ratio lower than 0.05) supported by 12-14 thickened bands. Cercariae of G. melanoidis can be distinguished from other Gigantobilharzia cercariae described in the literature based on the combination of these characters: flame cell formula 2[3 + 3 + (1)] = 14 and relatively longer tail stem in relation to body (tail stem length/body length ratio = 2). Under laboratory conditions at a temperature between 24 and 26 °C, M. tuberculata started to shed cercariae 7 weeks after exposure to miracidia. The prepatent period of G. melanoidis in experimentally infected chicken lasted between 43 and 49 days. The parasite inhabits the blood vessels mainly of the small intestine. Sections of adult worms and eggs were also found in histocuts of parenchymatous organs. Results of phylogenetic analysis corroborated that G. melanoidis is a distinct species; however, they also confirmed that the genus Gigantobilharzia is in need of revision and in future might be split into several genera. PMID:24322292

  17. The Pleistocene glaciations and the evolutionary history of the polytypic snail species Arianta arbustorum (Gastropoda, Pulmonata, Helicidae).

    PubMed

    Gittenberger, E; Piel, W H; Groenenberg, D S J

    2004-01-01

    The evolutionary history of the snail Arianta arbustorum is controversial. This diverse, polytypic species has two distinct forms: one, with a globular shell and closed umbilicus, is found from lowland to high altitudes; the other, with a depressed shell and open umbilicus, is found at a few scattered, high altitude localities. What is the origin of these two forms? Some believe that the depressed shell is a recent, local, ecotypic adaptation to alpine environments. Others believe that this form is a relic of an ancestral condition that may have survived the Pleistocene glaciations on nunatak-like montane refugia, while the globular shell is a derived condition and its presence at high altitudes follows post-Pleistocene recolonisation. We analysed a portion of the mitochondrial gene cytochrome oxidase I for 100 snails of the species A. arbustorum, three additional Arianta species, and nine outgroup taxa from five genera, in order to understand the phylogeographic history of the species. Despite some confounding artefacts that are likely due to introgression among the morphological forms, the resulting phylogeny shows that the depressed shell is plesiomorphic, while the globular shell is derived. Moreover, their disparate histories suggest that the depressed shell variety survived the glaciations in pockets of alpine refugia, while the globular shell variety recolonised the alpine environment post-glacially. PMID:15022758

  18. Exploring species level taxonomy and species delimitation methods in the facultatively self-fertilizing land snail genus Rumina (gastropoda: pulmonata).

    PubMed

    Prévot, Vanya; Jordaens, Kurt; Sonet, Gontran; Backeljau, Thierry

    2013-01-01

    Delimiting species in facultatively selfing taxa is a challenging problem of which the terrestrial pulmonate snail genus Rumina is a good example. These snails have a mixed breeding system and show a high degree of shell and color variation. Three nominal species (R. decollata, R. saharica and R. paivae) and two color morphs within R. decollata (dark and light) are currently recognized. The present study aims at evaluating to what extent these entities reflect evolutionary diverging taxonomic units, rather than fixed polymorphisms due to sustained selfing. Therefore, a phylogenetic analysis of nuclear (ITS1, ITS2) and mitochondrial DNA (COI, CytB, 12S rDNA, 16S rDNA) sequences was performed. Putative species in Rumina, inferred from the mitochondrial DNA phylogeny, were compared with those proposed on the basis of the COI gene by (1) DNA barcoding gap analysis, (2) Automatic Barcode Gap Discovery, (3) the species delimitation plug-in of the Geneious software, (4) the Genealogical Sorting Index, and (5) the General Mixed Yule Coalescent model. It is shown that these methods produce a variety of different species hypotheses and as such one may wonder to what extent species delimitation methods are really useful. With respect to Rumina, the data suggest at least seven species, one corresponding to R. saharica and six that are currently grouped under the name R. decollata. The species-level status of R. paivae is rejected. PMID:23577154

  19. The occurrence of Clithon retropictus (v. Martens, 1879) (Gastropoda: Neritidae) in an unusual habitat, northern Jeju Island, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Noseworthy, Ronald G.; Lee, Hee-Jung; Choi, Kwang-Sik

    2013-09-01

    Clithon retropictus is a neritid gastropod inhabiting mainly brackish water. Currently this species has been listed as a second grade endangered species of wildlife in Korea by the Ministry of Environment, due to the decrease in its population size. C. retropictus has previously been identified from estuaries on the south coast of Korea. In Jeju Island, this species has been reported only from the south coast. However, a population has recently been discovered on the north coast of the island in an apparently new type of habitat, under rocks adjacent to a dry riverbed on a muddy substrate. C. retropictus was found to be aggregated under some of the larger rocks, and the habitat was located near the high tide line. The present study reports some possible reasons for the occurrence of the population in this unusual habitat, and provides useful information on the biometry and population size which can be used in the management of this endangered species.

  20. Analysis of a deep transcriptome from the mantle tissue of Patella vulgata Linnaeus (Mollusca: Gastropoda: Patellidae) reveals candidate biomineralising genes.

    PubMed

    Werner, Gijsbert D A; Gemmell, Patrick; Grosser, Stefanie; Hamer, Rebecca; Shimeld, Sebastian M

    2013-04-01

    The gastropod Patella vulgata is abundant on rocky shores in Northern Europe and a significant grazer of intertidal algae. Here we report the application of Illumina sequencing to develop a transcriptome from the adult mantle tissue of P. vulgata. We obtained 47,237,104 paired-end reads of 51 bp, trialled de novo assembly methods and settled on the additive multiple K method followed by redundancy removal as resulting in the most comprehensive assembly. This yielded 29,489 contigs of at least 500 bp in length. We then used three methods to search for candidate genes relevant to biomineralisation: searches via BLAST and Hidden Markov Models for homologues of biomineralising genes from other molluscs, searches for predicted proteins containing tandem repeats and searches for secreted proteins that lacked a transmembrane domain. From the results of these searches we selected 15 contigs for verification by RT-PCR, of which 14 were successfully amplified and cloned. These included homologues of Pif-177/BSMP, Perlustrin, SPARC, AP24, Follistatin-like and Carbonic anhydrase, as well as three containing extensive G-X-Y repeats as found in nacrein. We selected two for further verification by in situ hybridisation, demonstrating expression in the larval shell field. We conclude that de novo assembly of Illumina data offers a cheap and rapid route to a predicted transcriptome that can be used as a resource for further biological study. PMID:22865210

  1. Imposex development in Hexaplex trunculus (Gastropoda: Caenogastropoda) involves changes in the transcription levels of the retinoid X receptor (RXR).

    PubMed

    Abidli, Sami; Castro, Luis Filipe Costa; Lahbib, Youssef; Reis-Henriques, Maria Armanda; Trigui El Menif, Najoua; Santos, Miguel Machado

    2013-10-01

    In order to further demonstrate that TBT-induced imposex through RXR signaling is not species-specific, Hexaplex trunculus was selected as an experimental model species. We first isolated RXR in H. trunculus, and determined gene transcription through quantitative real-time PCR in key tissues (e.g., penis/penis-forming area and central nervous system:- CNS), upon exposure to tributyltin (TBT) (5 and 50 ng TBTL(-1)). Two months of exposure to TBT induced imposex and led to a significant increase in the severity of the phenomenon in females and an increase in male penis lengths. Exposure to TBT altered RXR gene transcription in a tissue and sex-specific manner. In the CNS, there were no significant changes in RXR gene transcription between control and TBT-exposed females. A similar trend was observed in male CNS. On the contrary, in the penis-forming area/penis of females exposed to TBT, a significant increase in RXR gene transcription was observed in the 50 ng TBTL(-1) group. Furthermore, a positive correlation was observed between overall female penis lengths and RXR gene transcription. In males, although a trend towards an increase in RXR gene transcription in penis was observed, differences did not reach significance. Overall, the results of the present study give further support to a local role of RXR in the penis-forming area during the development of imposex by TBT, thus suggesting a conserved function of RXR in penis formation at least within prosobranch gastropods. PMID:23856468

  2. Development and validation of an OECD reproductive toxicity test guideline with the pond snail Lymnaea stagnalis (Mollusca, Gastropoda).

    PubMed

    Ducrot, Virginie; Askem, Clare; Azam, Didier; Brettschneider, Denise; Brown, Rebecca; Charles, Sandrine; Coke, Maïra; Collinet, Marc; Delignette-Muller, Marie-Laure; Forfait-Dubuc, Carole; Holbech, Henrik; Hutchinson, Thomas; Jach, Arne; Kinnberg, Karin L; Lacoste, Cédric; Le Page, Gareth; Matthiessen, Peter; Oehlmann, Jörg; Rice, Lynsey; Roberts, Edward; Ruppert, Katharina; Davis, Jessica Elphinstone; Veauvy, Clemence; Weltje, Lennart; Wortham, Ruth; Lagadic, Laurent

    2014-12-01

    The OECD test guideline development program has been extended in 2011 to establish a partial life-cycle protocol for assessing the reproductive toxicity of chemicals to several mollusk species, including the great pond snail Lymnaea stagnalis. In this paper, we summarize the standard draft protocol for a reproduction test with this species, and present inter-comparison results obtained in a 56-day prevalidation ring-test using this protocol. Seven European laboratories performed semi-static tests with cultured snails of the strain Renilys® exposed to nominal concentrations of cadmium chloride (from 53 to 608μgCdL(-1)). Cd concentrations in test solutions were analytically determined to confirm accuracy in the metal exposure concentrations in all laboratories. Physico-chemical and biological validity criteria (namely dissolved oxygen content >60% ASV, water temperature 20±1°C, control snail survival >80% and control snail fecundity >8 egg-masses per snail over the test period) were met in all laboratories which consistently demonstrated the reproductive toxicity of Cd in snails using the proposed draft protocol. Effect concentrations for fecundity after 56days were reproducible between laboratories (68

  3. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin

    PubMed Central

    Breure, Abraham S.H.

    2013-01-01

    Abstract The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007) and a partial list of letters present in the correspondence archives. PMID:23794831

  4. Differential transcriptomic responses of Biomphalaria glabrata (Gastropoda, Mollusca) to bacteria and metazoan parasites, Schistosoma mansoni and Echinostoma paraensei (Digenea, Platyhelminthes).

    PubMed

    Adema, Coen M; Hanington, Patrick C; Lun, Cheng-Man; Rosenberg, George H; Aragon, Anthony D; Stout, Barbara A; Lennard Richard, Mara L; Gross, Paul S; Loker, Eric S

    2010-01-01

    A 70-mer-oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail Biomphalaria glabrata to different immune challenges. In addition to sequences with relevant putative ID and Gene Ontology (GO) annotation, the array features non-immune factors and unknown B. glabrata ESTs for functional gene discovery. The transcription profiles of B. glabrata (3 biological replicates, each a pool of 5 snails) were recorded at 12h post-wounding, exposure to Gram negative or Gram positive bacteria (Escherichia coli and Micrococcus luteus, respectively), or infection with compatible trematode parasites (Schistosoma mansoni or Echinostoma paraensei, 20 miracidia/snail), relative to controls, using universal reference RNA. The data were subjected to Significance Analysis for Microarrays (SAM), with a false positive rate (FPR)

  5. Heavy metal levels in Nucella lapillus (gastropoda: prosobranchia) from sites with normal and penis-bearing females from New England

    SciTech Connect

    Miller, E.R. III; Pondick, J.S.

    1984-11-01

    Pseudohermaphroditism, as manifested by reproductively normal females possessing non-functioning penises, has been reported for more than thirty species of dioecious neogastropods. This anomaly was shown to be unrelated to age or parasitism, but the geographic distribution of this phenomenon indicated that it was environmentally induced rather than genetically controlled. In a survey of N. lapillus populations along the New England Coast, Pondick found abnormal females at sites directly under the influence of industrial discharges, sewage effluent, or vessel-related activities. Histological sections revealed the presence of a penial duct. The purpose of this study was to determine if there were differences in metal levels in the snail populations studied by Pondick, with particular attention to metals associated with boating activity.

  6. Antimicrobial activities of the tissue extracts of Babylonia spirata Linnaeus, 1758 (Mollusca: Gastropoda) from Thazhanguda, southeast coast of India

    PubMed Central

    Periyasamy, N; Srinivasan, M; Balakrishnan, S

    2012-01-01

    Objective To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata (B. spirata) against nine bacterial and three fungal pathogens. Methods Crude extract of gastropod was tested for inhibition of bacterial and fungal growth. Antibacterial assay was carried out by disc diffusion method and in vitro antifungal activity was determined against Czapex Dox agar. The antimicrobial activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract. Molecular size of muscle protein was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). And fourier transform infrared spectroscopy (FTIR) spectro photometry analysis was also studied. Results The maximum inhibition zone (12 mm) was observed against Pseudomonas aeruginosa in the crude ethanol extract of B. spirata and the minimum inhibition zone (2 mm) was noticed against Staphylococcus aureus in the crude methanol extract of B. spirata. Water extract of B. spirata showed the highest activity against Vibrio parahaemolyticus, Staphylococcus aureus and Candida albicans. Ethanol, acetone, methanol, chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus. Compared with water extracts, ethanol and methanol extracts showed higher activity against all pathogens. The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE. FTIR analysis revealed the presence of bioactive compounds signals at different ranges. Conclusions The research shows that the great medicinal value of the gastropod muscle of B. spirata may be due to high quality of antimicrobial compounds. PMID:23569831

  7. Developmental toxicity of metaldehyde in the embryos of Lymnaea stagnalis (Gastropoda: Pulmonata) co-exposed to the synergist piperonyl butoxide.

    PubMed

    Hallett, Katrina C; Atfield, Andrew; Comber, Sean; Hutchinson, Thomas H

    2016-02-01

    Metaldehyde is a widely used molluscicide in countries where damage to crops from slugs and snails is a major problem associated with warm and wet winters. In the UK it is estimated that over 8% of the area covered by arable crops is treated with formulated granular bait pellets containing metaldehyde as the main active ingredient. Metaldehyde is hydrophilic (log Kow=0.12), water soluble (200 mg·L(-1) at 17 °C) and has been detected in UK surface waters in the concentration range of typically 0.2-0.6 μg·L(-1) (maximum 2.7 μg·L(-1)) during 2008-2011. In the absence of chronic data on potential hazards to non-target freshwater molluscs, a laboratory study was conducted to investigate the impact of metaldehyde on embryo development in the gastropod Lymnaea stagnalis (RENILYS strain) and using zinc as a positive control. L. stagnalis embryos were exposed to metaldehyde under semi-static conditions at 20±1 °C and hatching success and growth (measured as shell height and intraocular distance) examined after 21 d. Exposure concentrations were verified using HPLC and gave 21 d (hatching)NOEC and (hatching)LOEC mean measured values of 36 and 116 mg MET·L(-1), respectively (equal to the 21 d (shell height)NOEC and (shell height)LOEC values). For basic research purposes, a second group of L. stagnalis embryos was co-exposed to metaldehyde and the pesticide synergist piperonyl butoxide (PBO). Co-exposure to the PBO (measured concentrations between 0.47-0.56 mg·L(-1)) reduced hatching success from 100% to 47% and resulted in a 30% reduction in embryo growth (shell height) in snail embryos co-exposed to metaldehyde at 34-36 mg·L(-1) over 21 d. In conclusion, these data suggest mollusc embryos may have some metabolic detoxication capacity for metaldehyde and further work is warranted to explore this aspect in order to support the recent initiative to include molluscs in the OECD test guideline programme. PMID:26575636

  8. Shallow water heterobranch sea slugs (Gastropoda: Heterobranchia) from the Región de Atacama, northern Chile

    PubMed Central

    Valdés, Ángel

    2016-01-01

    The coast of northern Chile has been sparsely studied in regards to its invertebrate fauna, with just a few works reviewing the distribution of local mollusks. This work presents a survey of the shallow water heterobranch sea slugs currently occurring around the port of Caldera (27 °S), in the Región de Atacama, northern Chile. Eight species of sea slugs were found in this study: Aplysiopsis cf. brattstroemi (Marcus, 1959), Baptodoris peruviana (d’Orbigny, 1837), Diaulula variolata (d’Orbigny, 1837), Doris fontainii d’Orbigny, 1837, Onchidella marginata (Couthouy in Gould, 1852), Phidiana lottini (Lesson, 1831), Tyrinna delicata (Abraham, 1877) and the new species Berthella schroedli sp. nov., described herein. All of the species found in the area are endemic to South America, having distributions in the southeastern Pacific and South Atlantic Oceans, from Ancash, Perú to Peninsula Valdés, Argentina, and two of them represent species which are endemic to the Chilean coasts (Aplysiopsis cf. brattstroemi and Berthella schroedli). The finding of a previously undescribed species emphasizes the need of further surveys, particularly in subtidal and deeper waters, in order to improve the knowledge on this neglected fauna in Atacama. PMID:27168975

  9. Standardization of a Patella spp. (Mollusca, Gastropoda) embryo-larval bioassay and advantages of its use in marine ecotoxicology.

    PubMed

    Pérez, Sara; Fernández, Nuria; Ribeiro, Pedro A

    2016-05-01

    The use of three limpet species, Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 as model organisms in marine ecotoxicology has been evaluated. Initial laboratory experiments were aimed to standardize a biological test with embryos and larvae of Patella spp, establishing the percentage of normal trochophore larvae as endpoint. Before conducting in vitro fertilization, oocytes must be maturated artificially by incubation in an alkaline solution; therefore, alkalinizing agent, pH and time of eggs alkalinization were evaluated. Moreover, time of sperm activation, optimum sperm and oocytes concentration during fertilization, gamete contact time, use of stirring during the fertilization, egg concentration and incubation temperature were examined. Minimum sample size per treatment was also estimated. Exposure of oocytes for 10min to FSW alkalinized with NH4OH at pH 9.0, the use of undiluted sperm pre-activated during 45min and a concentration of 200 oocytesmL(-1), a gamete-contact time of 180min and egg incubation at 18°C during 24h at a concentration of 80 eggsmL(-1) were the conditions allowing maximal embryo-larval development success. With an error of 0.05, a sampling size ≥320 allows a 95% confidence in the estimate. This Patella spp. acute bioassay fulfills a number of important a priori requirements to be used in ecotoxicological studies. Nevertheless, in vitro fertilization requires considerable handling, which may lead to failure in fecundation. Such difficulties are also addressed, in order to facilitate the routine use of this protocol by other laboratories. PMID:26845705

  10. DNA barcodes and phylogenetic affinities of the terrestrial slugs Arion gilvus and A. ponsi (Gastropoda, Pulmonata, Arionidae)

    PubMed Central

    Breugelmans, Karin; Jordaens, Kurt; Adriaens, Els; Remon, Jean Paul; Cardona, Josep Quintana; Backeljau, Thierry

    2013-01-01

    Abstract The Iberian Peninsula is a region with a high endemicity of species of the terrestrial slug subgenus Mesarion. Many of these species have been described mainly on subtle differences in their proximal genitalia. It therefore remains to be investigated 1) whether these locally diverged taxa also represent different species under a phylogenetic species concept as has been shown for other Mesarion species outside the Iberian Peninsula, and 2) how these taxa are phylogenetically related. Here, we analysed DNA sequence data of two mitochondrial (COI and 16S) genes, and of the nuclear ITS1 region, to explore the phylogenetic affinities of two of these endemic taxa, viz. Arion gilvus Torres Mínguez, 1925 and A. ponsi Quintana Cardona, 2007. We also evaluated the use of these DNA sequence data as DNA barcodes for both species. Our results showed that ITS did not allow to differentiate among most of the Mesarion molecular operational taxonomic units (MOTUs) / morphospecies in Mesarion. Yet, the overall mean p-distance among the Mesarion MOTUs / morphospecies for both mtDNA fragments (16.7% for COI, 13% for 16S) was comparable to that between A. ponsi and its closest relative A. molinae (COI: 14.2%; 16S: 16.2%) and to that between A. gilvus and its closest relative A. urbiae (COI: 14.4%; 16S: 13.4%). Hence, with respect to mtDNA divergence, both A. ponsi and A. gilvus, behave as other Mesarion species or putative species-level MOTUs and thus are confirmed as distinct ‘species’. PMID:24453553

  11. New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg

    PubMed Central

    2014-01-01

    Background The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg. Methods During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n = 2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n = 4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex® technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500–600 bp) (acting as an internal control) and a 124 bp fragment of repetitive DNA from Fasciola sp. Results Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle. Conclusions Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed. PMID:24524623

  12. Mitochondrial and nuclear DNA analysis revealed a cryptic species and genetic introgression in Littorina sitkana (Mollusca, Gastropoda).

    PubMed

    Azuma, Noriko; Yamazaki, Tomoyasu; Chiba, Susumu

    2011-12-01

    We investigated mitochondrial and nuclear DNA genotypes in nominal Littorina sitkana samples from 2 localities in Eastern Hokkaido, northern Japan. Our results indicated the existence of cryptic species. In the analysis of partial mitochondrial Cytchrome b gene sequences, haplotypes of L. sitkana samples were monophyletic in a phylogenetic tree with orthologous sequences from other Littorina species, but were apparently separated in 2 clades. One included typical L. sitkana (CBa clade) samples, which formed a clade with an allopatric species, L. horikawai. The other, CBb, was independent from CBa and L. horikawai. Haplotypes of the mitochondrial 16S rRNA gene also separated into 2 clades. We additionally examined intron sequence of the heat shock cognate 70 (HSC70) nuclear gene and identified 17 haplotypes. These were also separated into 2 clades, HSCa and HSCb. Among the examined Hokkaido samples, 60% of individuals were heterozygotes. However, each heterozygote consisted of haplotypes from the same clade, HSCa or HSCb, and no admixture of HSCa and HSCb haplotypes was observed. These results indicate reproductive isolation between the 2 clades. Among the genotyped Hokkaido samples, 93% of individuals had CBa + HSCa or CBb + HSCb genotypes, and 7% had CBb + HSCa genotypes. The discrepancy between the mtDNA and nuclear DNA haplotypes in a few individuals may have been caused by genetic introgression due to past hybridization. PMID:22374127

  13. Heat production in Littorina saxatilis Olivi and Littorina neritoides L. (gastropoda: Prosobranchia) during an experimental exposure to air

    NASA Astrophysics Data System (ADS)

    Kronberg, Inge

    1990-06-01

    The adaptation of littorinid molluscs to prolonged aerial exposure was investigated by the determination of heat production. Littorina saxatilis, inhabiting the upper eulittoral, reached a maximum metabolic activity during submersion (heat production: 3.26×10-3J s-1 (gadw)-1. On the first three days of desiccation, the heat production was continuously reduced to 40% of the submersed value. A prolonged aerial exposure was lethal for this species. In the supralittoral L. neritoides, three stages of energy metabolism could be observed: An intermediate heat production during submersion (1.97×10-3Js-1 (gadw)-1), an increased metabolism during the first hour of aerial exposure (heat production 204% of submersed value), and a minimal metabolism (39% of the submersed value and 19% of maximum value) during the following days and weeks of desiccation. Recovery depended on water salinity; L. saxatilis proved to be less euryhaline than L. neritoides. Thus, the metabolic adaptations correlate with the level of littoral habitat; inactivity combined with a drastically reduced energy consumption is a metabolically economic way to survive in periodically dry environments.

  14. Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S. H.; Ablett, Jonathan D.

    2015-01-01

    Abstract The type status is described for 65 taxa of the Orthalicoidea, classified within the families Megaspiridae (14), Orthalicidae (30), and Simpulopsidae (20); one taxon is considered a nomen inquirendum. Lectotypes are designated for the following taxa: Helix brephoides d’Orbigny, 1835; Simpulopsis cumingi Pfeiffer, 1861; Bulimulus (Protoglyptus) dejectus Fulton, 1907; Bulimus iris Pfeiffer, 1853. The type status of Bulimus salteri Sowerby III, 1890, and Strophocheilus (Eurytus) subirroratus da Costa, 1898 is now changed to lectotype according Art. 74.6 ICZN. The taxa Bulimus loxostomus Pfeiffer, 1853, Bulimus marmatensis Pfeiffer, 1855, Bulimus meobambensis Pfeiffer, 1855, and Orthalicus powissianus var. niveus Preston 1909 are now figured for the first time. The following taxa are now considered junior subjective synonyms: Bulimus marmatensis Pfeiffer, 1855 = Helix (Cochlogena) citrinovitrea Moricand, 1836; Vermiculatus Breure, 1978 = Bocourtia Rochebrune, 1882. New combinations are: Kuschelenia (Bocourtia) Rochebrune, 1882; Kuschelenia (Bocourtia) aequatoria (Pfeiffer, 1853); Kuschelenia (Bocourtia) anthisanensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) aquila (Reeve, 1848); Kuschelenia (Bocourtia) badia (Sowerby I, 1835); Kuschelenia (Bocourtia) bicolor (Sowerby I, 1835); Kuschelenia (Bocourtia) caliginosa (Reeve, 1849); Kuschelenia (Bocourtia) coagulata (Reeve, 1849); Kuschelenia (Bocourtia) cotopaxiensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) filaris (Pfeiffer, 1853); Kara indentata (da Costa, 1901); Clathrorthalicus magnificus (Pfeiffer, 1848); Simpulopsis (Eudioptus) marmartensis (Pfeiffer, 1855); Kuschelenia (Bocourtia) nucina (Reeve, 1850); Kuschelenia (Bocourtia) ochracea (Morelet, 1863); Kuschelenia (Bocourtia) peaki (Breure, 1978); Kuschelenia (Bocourtia) petiti (Pfeiffer, 1846); Clathrorthalicus phoebus (Pfeiffer, 1863); Kuschelenia (Bocourtia) polymorpha (d’Orbigny, 1835); Scholvienia porphyria (Pfeiffer, 1847); Kuschelenia (Bocourtia) purpurata (Reeve, 1849); Kuschelenia (Bocourtia) quechuarum Crawford, 1939; Quechua salteri (Sowerby III, 1890); Kuschelenia (Bocourtia) subfasciata Pfeiffer, 1853; Clathrorthalicus victor (Pfeiffer, 1854). In an addedum a lectotype is being designated for Bulimulus (Drymaeus) interruptus var. pallidus Preston, 1909. An index is included to all taxa mentioned in this paper and the preceding ones in this series (Breure and Ablett 2011, 2012, 2014). PMID:25632243

  15. Replacement names and nomenclatural comments for problematic species-group names in Europe's Neogene freshwater Gastropoda. Part 2.

    PubMed

    Neubauer, Thomas A; Harzhauser, Mathias; Kroh, Andreas; Elisavet, Georgopoulou; Mandic, Oleg

    2014-01-01

    In the course of a new database project on Miocene to Recent freshwater gastropods of Europe, a great many of primary and secondary homonyms were revealed. Such nomenclatural issues need clarification in order to avoid misunderstandings and wrong statements about geographical distributions and temporal ranges. The following 16 new names are introduced to replace existing homonyms: Theodoxus militaris jurisicpolsakae nom. n., Viviparus stevanovici nom. n., Melanopsis haueri ripanjensis nom. n., Melanopsis wolfgangfischeri nom. n., Micromelania ramacanensis nom. n., Pseudamnicola welterschultesi nom. n., Muellerpalia haszprunari nom. n., Muellerpalia pseudovalvatoides nom. n., Lithoglyphus gozhiki nom. n., Valvata heidemariae willmanni nom. n., Radix macaleti nom. n., Gyraulus okrugljakensis nom. n., Gyraulus rasseri nom. n., Gyraulus vrapceanus nom. n., Planorbarius halavatsi nom. n., and Segmentina mosbachensis nom. n. Additionally, six cases of homonyms are discussed that are not replaced by new names, because they are considered junior synonyms. PMID:25147468

  16. The nudibranch names mentioned as n.sp. in Bergh (1861) are almost all nomina nuda (Gastropoda: Heterobranchia: Nudibranchia).

    PubMed

    Jensen, Kathe; Nielsen, Claus

    2014-01-01

    In a publication in Danish from 1861, Bergh described the nematocysts found in a number of nudibranch species. Many of the species had been described previously, but a number were new and given names, but without a description. These species are nomina nuda. We have translated the "descriptions", including the foot-notes, and reproduced the original plate to show that only the nematocysts (real or assumed) were described. The only species given a short description fulfilling the requirements of the ICZN is Pleurophyllidia quadrilateralis, which was described as the only species in the new genus Sancara. This in turn was shown to be a junior synonym of Linguella de Blainville, 1823. All the species were subsequently described anatomically in detail and made valid in a number of papers, and most of the type material is located in the Zoological Museum, Copenhagen (Natural History Museum of Denmark). The names in current use have been given. PMID:24872286

  17. Cryptic Species in Tropic Sands - Interactive 3D Anatomy, Molecular Phylogeny and Evolution of Meiofaunal Pseudunelidae (Gastropoda, Acochlidia)

    PubMed Central

    Neusser, Timea P.; Jörger, Katharina M.; Schrödl, Michael

    2011-01-01

    Background Towards realistic estimations of the diversity of marine animals, tiny meiofaunal species usually are underrepresented. Since the biological species concept is hardly applicable on exotic and elusive animals, it is even more important to apply a morphospecies concept on the best level of information possible, using accurate and efficient methodology such as 3D modelling from histological sections. Molecular approaches such as sequence analyses may reveal further, cryptic species. This is the first case study on meiofaunal gastropods to test diversity estimations from traditional taxonomy against results from modern microanatomical methodology and molecular systematics. Results The examined meiofaunal Pseudunela specimens from several Indo-Pacific islands cannot be distinguished by external features. Their 3D microanatomy shows differences in the organ systems and allows for taxonomic separation in some cases. Additional molecular analyses based on partial mitochondrial cytochrome c oxidase subunit I (COI) and 16S rRNA markers revealed considerable genetic structure that is largely congruent with anatomical or geographical patterns. Two new species (Pseudunela viatoris and P. marteli spp. nov.) are formally described integrating morphological and genetic analyses. Phylogenetic analysis using partial 16S rRNA, COI and the nuclear 18S rRNA markers shows a clade of Pseudunelidae species as the sister group to limnic Acochlidiidae. Within Pseudunela, two subtypes of complex excretory systems occur. A complex kidney already evolved in the ancestor of Hedylopsacea. Several habitat shifts occurred during hedylopsacean evolution. Conclusions Cryptic species occur in tropical meiofaunal Pseudunela gastropods, and likely in other meiofaunal groups with poor dispersal abilities, boosting current diversity estimations. Only a combined 3D microanatomical and molecular approach revealed actual species diversity within Pseudunela reliably. Such integrative methods are recommended for all taxonomic approaches and biodiversity surveys on soft-bodied and small-sized invertebrates. With increasing taxon sampling and details studied, the evolution of acochlidian panpulmonates is even more complex than expected. PMID:21912592

  18. Seven new hypselostomatid species from China, including some of the world’s smallest land snails (Gastropoda, Pulmonata, Orthurethra)

    PubMed Central

    Páll-Gergely, Barna; Hunyadi, András; Jochum, Adrienne; Asami, Takahiro

    2015-01-01

    Abstract Seven new species of Hypselostomatidae are described from the Chinese province Guangxi: Angustopila dominikae Páll-Gergely & Hunyadi, sp. n., Angustopila fabella Páll-Gergely & Hunyadi, sp. n., Angustopila subelevata Páll-Gergely & Hunyadi, sp. n., Angustopila szekeresi Páll-Gergely & Hunyadi, sp. n., Hypselostoma socialis Páll-Gergely & Hunyadi, sp. n., Hypselostoma lacrima Páll-Gergely & Hunyadi, sp. n. and Krobylos sinensis Páll-Gergely & Hunyadi, sp. n. The latter species is reported from three localities. All other new species are known only from the type locality. Specimens nearly identical to the type specimens of Angustopila huoyani Jochum, Slapnik & Páll-Gergely, 2014 were found in a cave in northern Guangxi, 500 km from the type locality. Adult individuals of Angustopila subelevata sp. n. (shell height = 0.83–0.91 mm, mean = 0.87 mm) and Angustopila dominikae sp. n. (shell height of the holotype = 0.86 mm) represent the smallest known members of the Hypselostomatidae, and thus are amongst the smallest land snails ever reported. We note that Pyramidula laosensis Saurin, 1953 might also belong to Krobylos. Paraboysidia neglecta van Benthem Jutting, 1961, which was previously included in Angustopila, is classified in Hypselostoma. PMID:26478698

  19. A new member of troglobitic Carychiidae, Koreozospeum nodongense gen. et sp. n. (Gastropoda, Eupulmonata, Ellobioidea) is described from Korea.

    PubMed

    Jochum, Adrienne; Prozorova, Larisa; Sharyi-Ool, Mariana; Páll-Gergely, Barna

    2015-01-01

    A new genus of troglobitic Carychiidae Jeffreys, 1830 is designated from Nodong Cave, North Chungcheong Province, Danyang, South Korea. This remarkable find represents a great range extension and thus, a highly distant distribution of troglobitic Carychiidae in Asia. The Zospeum-like, carychiid snails were recently included, without a formal description, in records documenting Korean malacofauna. The present paper describes Koreozospeum Jochum & Prozorova, gen. n. and illustrates the type species, Koreozospeum nodongense Lee, Prozorova & Jochum, sp. n. using novel Nano-CT images, including a video, internal shell morphology, SEM and SEM-EDX elemental compositional analysis of the shell. PMID:26312456

  20. The Application of Electric Shock as a Novel Pest Control Method for Apple Snail, Pomacea canaliculata (Gastropoda: Ampullariidae)

    NASA Astrophysics Data System (ADS)

    Yagyu, Yoshihito; Tsuji, Satoshi; Satoh, Saburoh; Yamabe, Chobei

    The apple snail, Pomacea canaliculata, brought to Japan from Taiwan for human consumption in the 1980s, has come to be considered as deleterious for rice cultivation. The snail is unable to injure young rice plants while receiving electric shock because the snail retracts its entire body into its shell and shuts its aperture with its operculum. Electric shock should be applied intermittently to reduce the amount of energy that is wasted when the snail is in its shell made of one of the insulator. The minimum electric shock required for controlling snails and the time required for movement after application of electric shock to determine the frequency of each electric shock were investigated using two methods; vertical and horizontal application of the electrical stimulation. The results showed that there is a strong correlation between the strength of electric shock and the reaction of the snails, and electric shock made snails inactive when it was applied 0.35 A/m2 in the horizontal direction and 0.45 A/m2 in the vertical direction with water of 11 mS/m. A positive correlation was also found between electric shock and the reaction of the snails and shell height. In comparison with larger snails, the smaller snails had higher threshold levels against electric current density because their shorter feet tended to have lower voltage dorp. Moreover, the frequency of electric shock should be chosen the minimum duration for the inactive condition, and it was approximately 10 seconds. Consequently the direction of electric current should be in the horizontal direction above 0.35 A/m2 and the frequency of electric shock should be less than 10 seconds for practical use. However, electric shock would have to be maintained at greater than 0.35 A/m2 because snails might become habituated to electric shock and water in paddy field would have high electric conductivity.

  1. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin.

    PubMed

    Breure, Abraham S H

    2013-01-01

    The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007) and a partial list of letters present in the correspondence archives. PMID:23794831

  2. Revision of the genus Turris Batsch, 1789 (Gastropoda: Conoidea: Turridae) with the description of six new species

    PubMed Central

    Kilburn, Richard N.; Fedosov, Alexander E.; Olivera, Baldomero M.

    2012-01-01

    The taxonomy of the genus Turris Batsch, 1789, type genus of the family Turridae, widespread in shallow-water habitats of tropic Indo-Pacific, is revised. A total of 31 species of Turris, are here recognized as valid. New species described: Turris chaldaea, Turris clausifossata, Turris guidopoppei, Turris intercancellata, Turris kantori, T. kathiewayae. Homonym renamed: Turris bipartita nom. nov. for Pleurotoma variegata Kiener, 1839 (non Philippi, 1836). New synonymies: Turris ankaramanyensis Bozzetti, 2006 = Turris tanyspira Kilburn, 1975; Turris imperfecti, T. nobilis, T. pulchra and T. tornatum Röding, 1798, and Turris assyria Olivera, Seronay & Fedosov, 2010 = T. babylonia; Turris dollyi Olivera, 2000 = Pleurotoma crispa Lamarck, 1816; Turris totiphyllis Olivera, 2000 = Turris hidalgoi Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000; Turris kilburni Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000 = Turris pagasa Olivera, 2000; Turris (Annulaturris) munizi Vera-Peláez, Vega-Luz & Lozano-Francisco, 2000 = Gemmula lululimi Olivera, 2000. Revised status: Turris intricata Powell, 1964, Pleurotoma variegata Kiener, 1839 (non Philippi, 1836) and Pleurotoma yeddoensis Jousseaume, 1883, are regarded as full species (not subspecies of Turris crispa). Neotype designated: For Pleurotoma garnonsii Reeve, 1843, to distinguish it from Turris garnonsii of recent authors, type locality emended to Zanzibar. New combination: Turris orthopleura Kilburn, 1983, is transferred to genus Makiyamaia, family Clavatulidae. PMID:23847408

  3. [Predation of Lymnaea (Galba) truncatula Müller by Zonitoides nitidus Müller (Mollusca Gastropoda Pulmonata) (author's transl)].

    PubMed

    Rondelaud, D

    1975-01-01

    Zonitoides nitidus is omnivorous with carnivorous tendancies: the presence of food coming from snails is required for growth of this predator. This snail is not selective for the choice of its preys. Zonitoides cannot be taken for an absolute predator for all growing periods of Lymnaea truncatula: eggs and large snails are not eaten. This species can be cannibal. PMID:1211765

  4. A new species of Haplosporidium Caullery & Mesnil, 1899 in the marine false limpet Siphonaria lessonii (Gastropoda: Siphonariidae) from Patagonia.

    PubMed

    Ituarte, Cristián; Bagnato, Estefanía; Siddall, Mark; Cremonte, Florencia

    2014-05-01

    A new species of Haplosporidium Caullery & Mesnil, 1899 parasitising the pulmonate gastropod Siphonaria lessonii Blainville in Patagonia, Argentina, is described based on morphological (scanning and transmission electron microscopy) and sequence (small subunit ribosomal RNA gene) data. Different stages of sporulation were observed as infections disseminated in the digestive gland. Haplosporidium patagon n. sp. is characterised by oval or slightly subquadrate spores with an operculum that is ornamented with numerous short digitiform projections of regular height, perpendicular to and covering its outer surface. The operculum diameter is slightly larger than the apical diameter of the spore. Neither the immature nor mature spores showed any kind of projections of the exosporoplasm or of the spore wall. Regarding phylogenetic affinities, the new species was recovered as sister to an undescribed species of Haplosporidium Caullery & Mesnil, 1899 from the polychaete family Syllidae Grube from Japanese waters. The morphological characters (ornamentation of the operculum, spore wall structure, shape and size of spores, and the lack of spore wall projections) corroborate it as an as yet undescribed species of Haplosporidium and the first for the phylum in marine gastropods of South America. Siphonaria lessonii is the only known host to date. PMID:24711113

  5. Exploring Species Level Taxonomy and Species Delimitation Methods in the Facultatively Self-Fertilizing Land Snail Genus Rumina (Gastropoda: Pulmonata)

    PubMed Central

    Prévot, Vanya; Jordaens, Kurt; Sonet, Gontran; Backeljau, Thierry

    2013-01-01

    Delimiting species in facultatively selfing taxa is a challenging problem of which the terrestrial pulmonate snail genus Rumina is a good example. These snails have a mixed breeding system and show a high degree of shell and color variation. Three nominal species (R. decollata, R. saharica and R. paivae) and two color morphs within R. decollata (dark and light) are currently recognized. The present study aims at evaluating to what extent these entities reflect evolutionary diverging taxonomic units, rather than fixed polymorphisms due to sustained selfing. Therefore, a phylogenetic analysis of nuclear (ITS1, ITS2) and mitochondrial DNA (COI, CytB, 12S rDNA, 16S rDNA) sequences was performed. Putative species in Rumina, inferred from the mitochondrial DNA phylogeny, were compared with those proposed on the basis of the COI gene by (1) DNA barcoding gap analysis, (2) Automatic Barcode Gap Discovery, (3) the species delimitation plug-in of the Geneious software, (4) the Genealogical Sorting Index, and (5) the General Mixed Yule Coalescent model. It is shown that these methods produce a variety of different species hypotheses and as such one may wonder to what extent species delimitation methods are really useful. With respect to Rumina, the data suggest at least seven species, one corresponding to R. saharica and six that are currently grouped under the name R. decollata. The species-level status of R. paivae is rejected. PMID:23577154

  6. Parasitic castration of Buccinanops cochlidium (Gastropoda: Nassariidae) caused by a lepocreadiid digenean in San José Gulf, Argentina.

    PubMed

    Averbuj, A; Cremonte, F

    2010-12-01

    Parasitic castration of Buccinanops cochlidium from San José Gulf, Argentina, caused by a lepocreadiid digenean, is reported for the first time. Rediae and ophtalmotrichocercous cercariae probably belonging to Opechona sp. were identified in the gonad and digestive gland. Opechona sp. has been reported previously parasitizing B. monilifer from a northern locality in the Argentine Sea. Overall prevalence of infection was 15.5%; it varied seasonally, rising during the warm months after the host oviposition period. Cercariae were expelled at the same time as the hatching of snail embryos (during the higher water temperature period). Rediae affected male and female snails equally, but prevalence increases along with host size. The parasite causes the complete castration of the host. Parasitized adult snails showed a reduction of penis size in comparison with healthy males. It remains to be confirmed whether the peak of cercariae emission coincides with the presence of jellyfishes and scombrid or other fishes in the area, which could act as second intermediate and definitive hosts, respectively. PMID:20137105

  7. A new member of troglobitic Carychiidae, Koreozospeum nodongense gen. et sp. n. (Gastropoda, Eupulmonata, Ellobioidea) is described from Korea

    PubMed Central

    Jochum, Adrienne; Prozorova, Larisa; Sharyi-ool, Mariana; Páll-Gergely, Barna

    2015-01-01

    Abstract A new genus of troglobitic Carychiidae Jeffreys, 1830 is designated from Nodong Cave, North Chungcheong Province, Danyang, South Korea. This remarkable find represents a great range extension and thus, a highly distant distribution of troglobitic Carychiidae in Asia. The Zospeum-like, carychiid snails were recently included, without a formal description, in records documenting Korean malacofauna. The present paper describes Koreozospeum Jochum & Prozorova, gen. n. and illustrates the type species, Koreozospeum nodongense Lee, Prozorova & Jochum, sp. n. using novel Nano-CT images, including a video, internal shell morphology, SEM and SEM-EDX elemental compositional analysis of the shell. PMID:26312456

  8. Subgeneric division of the genus Orcula Held 1837 with remarks on Romanian orculid data (Gastropoda, Pulmonata, Orculidae)

    PubMed Central

    Páll-Gergely, Barna; Deli, Tamás; Irikov, Atanas; Harl, Josef

    2013-01-01

    Abstract The genital anatomy of Orcula jetschini (Romania), Orcula zilchi (Bulgaria), and Orcula wagneri (Albania) is described. Based on anatomical features (morphology of the penial caecum) shell characters (sculpture and shape) and unpublished molecular data the genus Orcula is subdivided into three subgenera. Orcula zilchi was classified within the monotypic subgenus Orcula (Hausdorfia) subgen. n.; Orcula jetschini, Orcula wagneri, and Orcula schmidtii were classified to Orcula (Illyriobanatica) subgen. n. (type species: Pupa schmidtii) whereas the other Orcula species remain in the nominotypical subgenus. Orcula (Hausdorfia) is known from South-Eastern Bulgaria and North-Western Turkey, Orcula (Illyriobanatica) inhabits Western Romania, North-Western Greece, Albania, Macedonia, Kosovo, and Montenegro. The nine species of Orcula (Orcula) are known mainly from the Alps and the Western Carpathians (from Eastern France to Eastern Hungary and Slovakia). The occurrence of only one Orcula species namely Orcula jetschini is verified from Romania. Available information suggests that data on the Romanian occurrence of Orcula dolium and Orcula gularis were based on wrongly identified specimens. Sphyradium dobrogicum (=Orcula dobrogica) is considered as a synonym of Sphyradium doliolum. PMID:23794893

  9. Genetic structure of Onchidium "struma" (Mollusca: Gastropoda: Eupulmonata) from the coastal area of China based on mtCO I.

    PubMed

    Zhou, Na; Shen, Heding; Chen, Cheng; Sun, Bianna; Zheng, Pei; Wang, Chengnuan

    2016-01-01

    The genetic diversity and population genetic structure of Onchidium "struma" were investigated using mitochondrial cytochrome c oxidase subunit I (CO I) gene sequences. A total of 240 individuals representing 10 collection sites from across a large portion of its known range were included in the analysis. Overall, 42 haplotypes were defined and 97 polymorphic sites were observed. The O. "struma" populations had high haplotype diversity (0.9280) and nucleotide diversity (0.0404). We inferred that the early maturity and extensive survival habitat led to high genetic diversity of O. "struma" populations in China. Bayesian analysis and SAMOVA analysis showed significant genetic differentiation among populations and all populations were divided into two groups, (HK and HN) versus (GY, DF, CX, CN, ND and XM). The Mantel test revealed no significant correlation between geographic distance and genetic distance (r = 0.251; p = 0.058). Restricted gene flow caused by a shorter term pelagic veliger stage and limited dispersal potential were inferred to result in genetic differentiation among populations based on nested analysis. HK population might be an invasive species by artificial transplantation. PMID:25103423

  10. Radix dolgini: The integrative taxonomic approach supports the species status of a Siberian endemic snail (Mollusca, Gastropoda, Lymnaeidae).

    PubMed

    Vinarski, Maxim V; Aksenova, Olga V; Bespalaya, Yulia V; Bolotov, Ivan N; Schniebs, Katrin; Gofarov, Mikhail Yu; Kondakov, Alexander V

    2016-01-01

    The molecular techniques are the standard tool for the study of the taxonomic position and phylogenetic affinities of the lymnaeid genus Radix Montfort, 1810, and the majority of the European representatives of this taxon have been studied in this respect. However, a plethora of nominal species of Radix described from Northern Asia (Siberia and the Russian Far East) are still characterized only morphologically, raising some doubts concerning their validity. In this paper, we present the triple (morphological, molecular, and zoogeographical) evidence that there is at least one endemic species of Radix, Radix dolgini (Gundrizer and Starobogatov, 1979), widely distributed in Siberia and Western Mongolia. Phylogenetically, it is a sister species to the European R. labiata (Rossmaessler, 1835) [=R. peregra auct.], and their common ancestor most probably lived in the Pliocene, nearly 3.25Myr ago. Our results assume the existence of an extended dispersal barrier for freshwater hydrobionts between Europe and Siberia in the Late Pliocene that may be important for biogeographical explanations. Three other nominal Siberian species of Radix: R. kurejkae (Gundrizer and Starobogatov, 1979), R. gundrizeri (Kruglov and Starobogatov, 1983), and R. ulaganica (Kruglov and Starobogatov, 1983) proved to be the junior synonyms of R. dolgini. PMID:26705968

  11. A molecular phylogeny of the Littorininae (Gastropoda: Littorinidae): unequal evolutionary rates, morphological parallelism, and biogeography of the Southern Ocean.

    PubMed

    Williams, S T; Reid, D G; Littlewood, D T J

    2003-07-01

    A molecular phylogeny is presented for the subfamily Littorininae (including representatives of all subgeneric taxa and all members of a group of southern-temperate species formerly classified as 'Nodilittorina'), based on sequence data from two nuclear (18S rRNA, 28S rRNA) and two mitochondrial (12S rRNA, CO1) genes. The phylogeny shows considerable disagreement with earlier hypotheses derived from morphological data. In particular, 'Nodilittorina' is polyphyletic and is here divided into four genera (Echinolittorina, Austrolittorina, Afrolittorina new genus, and the monotypic Nodilittorina s.s.). The phylogenetic relationships of 'Littorina' striata have been controversial and it is here transferred to the genus Tectarius, a surprising relationship for which there is little morphological support. The relationships of the enigmatic Mainwaringia remain poorly resolved, but it is not a basal member of the subfamily. The two living species of Mainwaringia are remarkable for a greatly elevated rate of evolution in all four genes examined; it is suggested that this may be connected with their protandrous hermaphroditism, which is unique in the family. The molecular phylogeny provides a new framework for the adaptive radiation of the Littorininae, showing more frequent shifts between habitats and climatic regimes than previously suspected, and striking parallelism of morphological characters. The fossil record of littorinids is poor, but ages of clades are estimated using a calibration based on a Lower Eocene age of the genus Littoraria. Using these estimates, the antitropical distribution of Littorina and Afrolittorina is an ancient pattern of possibly Cretaceous age. The five members of Austrolittorina show a Gondwanan distribution in Australia, New Zealand, and South America. Based on the morphological uniformity within this clade, relatively recent (Plio-Pleistocene) trans-Pacific dispersal events seemed a likely explanation, as proposed for numerous other congeneric marine taxa. However, molecular estimation of ages of divergence suggest an initial vicariance between Australian and South American lineages at 40-73Ma, contemporary with the later stages of fragmentation of the Gondwanan supercontinent, followed by more recent (but still mid-Cenozoic) dispersal events across the Tasman Sea and the Pacific Ocean. Afrolittorina is another Cretaceous clade, now restricted to southern Africa and southern Australia, but divergence between these lineages (29-55Ma) post-dates Gondwanan fragmentation. Within both Austrolittorina and Afrolittorina all sister-species divergences are estimated to fall in the range 10-47Ma, so that there is no evidence for speciation events in the Plio-Pleistocene. PMID:12801472

  12. Phylogeography of the land snail genus Circassina (Gastropoda: Hygromiidae) implies multiple Pleistocene refugia in the western Caucasus region.

    PubMed

    Neiber, Marco T; Hausdorf, Bernhard

    2015-12-01

    The phylogeny and historical biogeography of the Caucasian land snail genus Circassina was reconstructed using multilocus amplified fragment length polymorphism (AFLP) data and mitochondrial DNA sequences. Diversification within the group started with a divergence of populations from the western Lesser Caucasus from those of the Greater Caucasus during the late Miocene. Distinct AFLP clusters and major mitochondrial clades separated by long internal branches lend evidence to the hypothesis of separate glacial refuges in the Lesser and Greater Caucasus during the Pleistocene. High genetic distances across low geographic distances and admixture analysis revealed a phylogeographic boundary running through the Colchis lowlands, which may have been established and maintained in part by repeated transgressions of the Black Sea during the Pleistocene and Holocene. Localities in Ciscaucasia were probably colonised through long-distance dispersal across the main ridge of the Greater Caucasus. The phylogeny implies multiple independent losses of accessory genital organs, i.e. dart sac and mucus glands, within Circassina. None of the anatomically defined (sub-) species distinguished so far is monophyletic and there is gene flow between the two main population groups across the Colchis lowlands. Thus, we propose to classify these population groups as subspecies of a single species. PMID:26220841

  13. Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.

    PubMed

    Manríquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camaño, Andrés

    2013-12-01

    The Chilean abalone or "loco" (Concholepas concholepas, Bruguière 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. PMID:24099753

  14. Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

    PubMed

    Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natália; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragança; Nakano, Eliana

    2014-12-01

    A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies. PMID:25259848

  15. No Evidence for a Culturable Bacterial Tetrodotoxin Producer in Pleurobranchaea maculata (Gastropoda: Pleurobranchidae) and Stylochoplana sp. (Platyhelminthes: Polycladida)

    PubMed Central

    Salvitti, Lauren R.; Wood, Susanna A.; McNabb, Paul; Cary, Stephen Craig

    2015-01-01

    Tetrodotoxin (TTX) is a potent neurotoxin found in the tissues of many taxonomically diverse organisms. Its origin has been the topic of much debate, with suggestions including endogenous production, acquisition through diet, and symbiotic bacterial synthesis. Bacterial production of TTX has been reported in isolates from marine biota, but at lower than expected concentrations. In this study, 102 strains were isolated from Pleurobranchaea maculata (Opisthobranchia) and Stylochoplana sp. (Platyhelminthes). Tetrodotoxin production was tested utilizing a recently developed sensitive method to detect the C9 base of TTX via liquid chromatography—mass spectrometry. Bacterial strains were characterized by sequencing a region of the 16S ribosomal RNA gene. To account for the possibility that TTX is produced by a consortium of bacteria, a series of experiments using marine broth spiked with various P. maculata tissues were undertaken. Sixteen unique strains from P. maculata and one from Stylochoplana sp. were isolated, representing eight different genera; Pseudomonadales, Actinomycetales, Oceanospirillales, Thiotrichales, Rhodobacterales, Sphingomonadales, Bacillales, and Vibrionales. Molecular fingerprinting of bacterial communities from broth experiments showed little change over the first four days. No C9 base or TTX was detected in isolates or broth experiments (past day 0), suggesting a culturable microbial source of TTX in P. maculata and Stylochoplana sp. is unlikely. PMID:25635464

  16. A Good Compromise: Rapid and Robust Species Proxies for Inventorying Biodiversity Hotspots Using the Terebridae (Gastropoda: Conoidea)

    PubMed Central

    Modica, Maria Vittoria; Puillandre, Nicolas; Castelin, Magalie; Zhang, Yu; Holford, Mandë

    2014-01-01

    Devising a reproducible approach for species delimitation of hyperdiverse groups is an ongoing challenge in evolutionary biology. Speciation processes combine modes of passive and adaptive trait divergence requiring an integrative taxonomy approach to accurately generate robust species hypotheses. However, in light of the rapid decline of diversity on Earth, complete integrative approaches may not be practical in certain species-rich environments. As an alternative, we applied a two-step strategy combining ABGD (Automated Barcode Gap Discovery) and Klee diagrams, to balance speed and accuracy in producing primary species hypotheses (PSHs). Specifically, an ABGD/Klee approach was used for species delimitation in the Terebridae, a neurotoxin-producing marine snail family included in the Conoidea. Delimitation of species boundaries is problematic in the Conoidea, as traditional taxonomic approaches are hampered by the high levels of variation, convergence and morphological plasticity of shell characters. We used ABGD to analyze gaps in the distribution of pairwise distances of 454 COI sequences attributed to 87 morphospecies and obtained 98 to 125 Primary Species Hypotheses (PSHs). The PSH partitions were subsequently visualized as a Klee diagram color map, allowing easy detection of the incongruences that were further evaluated individually with two other species delimitation models, General Mixed Yule Coalescent (GMYC) and Poisson Tree Processes (PTP). GMYC and PTP results confirmed the presence of 17 putative cryptic terebrid species in our dataset. The consensus of GMYC, PTP, and ABGD/Klee findings suggest the combination of ABGD and Klee diagrams is an effective approach for rapidly proposing primary species proxies in hyperdiverse groups and a reliable first step for macroscopic biodiversity assessment. PMID:25003611

  17. Polycyclic aromatic hydrocarbons in Haliotis tuberculata (Linnaeus, 1758) (Mollusca, Gastropoda): Considerations on food safety and source investigation.

    PubMed

    Conte, Francesca; Copat, Chiara; Longo, Sabrina; Conti, Gea Oliveri; Grasso, Alfina; Arena, Giovanni; Dimartino, Angela; Brundo, Maria Violetta; Ferrante, Margherita

    2016-08-01

    Polycyclic aromatic hydrocarbons were analyzed in wild specimens of Haliotis tuberculata from three sites of the Sothern Ionian Sea. The species Ht is commonly found at these sites and has significant commercial value. Main results revealed mean values of benzo(a)pyrene higher than the threshold set by Regulation No. 835/2011/EU in all sampling sites and the sum of selected PAHs, expressed as ΣPAH4 by EC Regulation, were below the limit set by the same Regulation in ME and VSG. We found generally higher concentrations than literature finding, especially for low molecular weight PAHs, and results of diagnostic ratios highlighted both pyrolytic and petrogenic sources. The potential human health risks due consumption of Ht by local inhabitants have been assessed by exposure daily intake (EDI), target hazard quotient (THQ) and lifetime cancer risk (CR). EDI values were below the intake range reviewed by EFSA for each class of contaminant. BaP daily intake was below the value of 10 ng/Kg/day, suggested by JFCFA, and CRBaP was slightly higher than the acceptable risk level (ARL) of 1×10(-5). Conversely, target hazard quotient (THQ) resulted always below 1, thus the risk to develop chronic systemic effects due naphthalene, acenaphthene, fluorene, anthracene, fluoranthene and pyrene was low. PMID:27235950

  18. The family Plectopylidae (Gastropoda, Pulmonata) in Laos with the description of two new genera and a new species

    PubMed Central

    Páll-Gergely, Barna; Muratov, Igor V.; Asami, Takahiro

    2016-01-01

    Abstract Previously only a single plectopylid species, Helix laomontana L. Pfeiffer, 1862 was reported from Laos. Here we erect Naggsia Páll-Gergely & Muratov, gen. n. for Helix laomontana based on the description of its reproductive anatomy and radula. Another species, Hunyadiscus saurini Páll-Gergely, gen. & sp. n. is described from Northern Laos based on conchological data. Helix (Plectopylis) andersoni Blanford, 1869, which is known from the Burmese-Chinese border region, is also classified within Hunyadiscus Páll-Gergely, gen. n. A third species, Gudeodiscus (Gudeodiscus) messageri raheemi Páll-Gergely & Hunyadi, 2015 is reported from Laos for the first time. The new localities represent the westernmost sites of the genus Gudeodiscus. The reproductive anatomy of the latter species is described. PMID:27408542

  19. Spatial diversity of rocky midlittoral macro-invertebrates associated with the endangered species Patella ferruginea (Mollusca: Gastropoda) of Tunisian coastline

    NASA Astrophysics Data System (ADS)

    Tlig-Zouari, Sabiha; Rabaoui, Lotfi; Fguiri, Hosni; Diawara, Moctar; Ben Hassine, Oum Kalthoum

    2010-04-01

    The present study focuses on horizontal spatial variability of benthic macrofauna associated with Patella ferruginea. Thirty-six samples collected at 12 transects belonging to 4 midlittoral sites along the rocky Tunisian coastline, were examined. A total of 44 species belonging to 5 taxa were found. Multivariate analysis applied on gathered data did not show a horizontal spatial variability at small scale (between transects), but at large scale, between sites as well as sectors. Thus, three groups of communities were identified (GI: Korbous and El Haouaria; GIIa: Zembra Island and GIIb: Kelibia). The distribution of species abundance within these groups revealed that crustaceans were the most abundant taxon, due to the overwhelming dominance of Chthamalus stellatus. This substratum appeared to create favourable micro-habitats for the installation of molluscs including gastropods. Regarding the low diversity index ( H') and evenness ( J), they seemed to reflect a disturbance and a demographic unbalance within these communities. The heterogeneity of substrate surface, created by C. stellatus specimens appeared to be caused by various complex interactions established between the key components of these communities in particular suspension feeders, predators, herbivorous molluscs and macroalgae. Thus, the dynamic status of each of these communities is the result of these complex interactions.

  20. Phylogeographic patterns in New Zealand and temperate Australian cantharidines (Mollusca: Gastropoda: Trochidae: Cantharidinae): Trans-Tasman divergences are ancient.

    PubMed

    Donald, Kirsten M; Spencer, Hamish G

    2016-07-01

    Current taxonomic treatments of New Zealand and temperate Australian members of the gastropod subfamily Cantharidinae imply that species on either side of the Tasman Sea are closely related and, in some cases, congeneric. Such a close relationship, however, entails a relatively recent divergence of Australian and New Zealand lineages, which seems inconsistent with what is known about cantharidine larval development in general. In order to address these issues, mitochondrial and nuclear DNA sequences were used to ascertain how cantharidine genera became established over the wide geographical range of temperate Australia and New Zealand, including their subantarctic islands. Our robust and dated phylogenies (based on 16S, COI, 12S and 28S sequences) revealed that Australian and New Zealand species fall into endemic clades that have been separated for, at most, 35million years. This divergence date postdates a vicariant split by around 50million years and we suggest that, once again, long-distance trans-Tasman dispersal has played a pivotal role in molluscan evolution in this part of the world. Our results also show that the current classification requires revision. We recognize three genera (Cantharidus [comprising 2 subgenera: Cantharidus s.str. and Pseudomargarella n. subgen.], Micrelenchus [comprising 2 subgenera: Micrelenchus s.str. and Mawhero] and Roseaplagis n. gen.) for New Zealand cantharidine species. In our dated BEAST tree, these genera form a clade with the endemic Australian Prothalotia and South African Oxystele. Other temperate Australian cantharidines in our study fall into previously recognized genera (Phasianotrochus, Thalotia, Calthalotia), which are all quite distinct from Cantharidus in spite of some authors considering various of them to be possible synonyms. Finally, we remove the Australian genus Cantharidella from the Cantharidinae to the subfamily Trochinae and erect a new genus, Cratidentium n. gen., also in the Trochinae, to accommodate several Australian species previously considered to belong to Cantharidella. PMID:27118181

  1. Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We collected six species of freshwater snails from Dominica, including Biomphalaria kuhniana, Gundlachia radiata Helisoma (= Planorbella) trivolvis, Melanoides tuberculata, Neritina punctulata, and Physa marmorata. Our collections indicate that un-reported species such as Gundlachia radiata and Hel...

  2. Effects of parasitism and environment on shell size of the South American intertidal mud snail Heleobia australis (Gastropoda)

    NASA Astrophysics Data System (ADS)

    Alda, Pilar; Bonel, Nicolás; Cazzaniga, Néstor J.; Martorelli, Sergio R.

    2010-04-01

    The aim of this work was to evaluate the effects of parasitism and certain environmental factors on the shell size of Heleobia australis (Hydrobiidae, Cochliopinae). We report sporocysts and metacercariae of Microphallus simillimus (Microphallidae, Trematoda) parasitizing the gonad and digestive gland of H. australis specimens from two sites of Bahía Blanca estuary, Argentina. The prevalence of infection was significantly higher (34.17% in winter and 68.14% in late spring) in snails from the outer estuary at Site 2 than in those from the inner estuary at Site 1 (5.88% and 4.71% respectively). The only known definitive host for this digenean is the white-backed stilt Himantopus melanurus (Recurvirostridae, Aves), most abundant in the estuary during winter. Parasitism by M. simillimus causes variations in the shell dimensions of H. australis, the shells of infected snails being narrower than those of uninfected snails. Snails from Site 2 were found in general to be significantly smaller than those at Site 1, possibly as a result of differences in environmental factors such as the degree of exposure to wave energy, the allocation of energy to reproduction rather than growth (induced by predation and/or parasitic castrators) and anthropogenic stressors.

  3. The South American radiation of Jerrybuccinum (Gastropoda, Buccinidae), with a new deep-water species from Chile.

    PubMed

    Fraussen, Koen; Sellanes, Javier; Stahlschmidt, Peter

    2014-01-01

    A new deep water species from off the Chilean coast, Jerrybuccinum kantori sp. n., is described. The animal is equipped with a large statocyst. Kryptos explorator Fraussen & Sellanes, 2008 from off Concepción is found to be congeneric and transferred to the genus Jerrybuccinum. Differences in size and sculpture serve to distinguish the new species from J. explorator. Both Chilean species are associated with methane seep or low oxygen environments. They are compared with J. malvinense Kantor & Pastorino, 2009 and two still unnamed species from the Falkland Plateau. PMID:24899844

  4. Seasonal Variations in Maternal Provisioning of Crepidula fornicata (Gastropoda): Fatty Acid Composition of Females, Embryos and Larvae

    PubMed Central

    Leroy, Fanny; Meziane, Tarik; Riera, Pascal; Comtet, Thierry

    2013-01-01

    Recruitment success of marine invertebrate populations not only depends on the number of recruits but also on their quality which affects their survival. In species characterized by a mixed development (encapsulated embryonic development and release of planktotrophic larvae), the offspring quality depends on both maternal provisioning and larval feeding. Here, we investigated potential changes of maternal provisioning over the whole reproductive period in a gastropod with a mixed development: Crepidulafornicata. In its introduction area, C. fornicata reproduces from February to October, which implies that both adults and larvae are exposed to different food availabilities. Maternal provisioning was assessed by measuring the fatty acid (FA) composition of females, encapsulated embryos and larvae, in February, May, July and September 2009. FA are essential resources for the development of embryos and larvae, and are key biomarkers of offspring quality. Our results showed differences in FA composition between muscles, visceral masses, and encapsulated embryos. In particular, FA composition of embryos was similar to that of the visceral mass. Seasonal variations in FA composition were observed: in the middle of the reproductive season (May and July), female tissues and embryos showed a higher proportion of polyunsaturated fatty acids and especially ω3, as compared to the beginning and end of the reproductive season (February and September). This showed that through maternal provisioning the quality of C. fornicata offspring was higher in the middle of the reproductive season. Whether this would result in an increase of recruitment success and juvenile performance would require further investigations. PMID:24086505

  5. Surviving the Messinian Salinity Crisis? Divergence patterns in the genus Dendropoma (Gastropoda: Vermetidae) in the Mediterranean Sea.

    PubMed

    Calvo, Marta; Alda, Fernando; Oliverio, Marco; Templado, José; Machordom, Annie

    2015-10-01

    Four genetically distinct clades were recently described under the name Dendropoma petraeum, a Mediterranean endemic vermetid gastropod. The aim of this work is to date the processes that drove to the diversification within this taxon and to relate them to the corresponding historical events occurred in the Mediterranean Sea. Sequences from mitochondrial and nuclear markers were obtained from specimens collected in 29 localities spanning over 4000km across the entire distribution range of D. petraeum species complex. The phylogenetic and coalescent-based analyses confirmed the four well-supported and largely differentiated lineages of D. petraeum, clearly delimited geographically along a west-east axis within the Mediterranean Sea: Western, Tyrrhenian-Sicilian, Ionian-Aegean and Levantine lineages. Divergence time estimates, obtained using a range of known substitution rates for other marine gastropods, indicated two main stages of diversification. In the first period (between 9.5 and 4.5mya), the ancestral D. petraeum diverged into the current four lineages. The most recent period occurred between 3.72 and 0.66mya in the late Pliocene-early Pleistocene, and included the main within-lineage diversification events. Therefore, if the divergence time between the major lineages of Dendropoma in the Mediterranean actually predated or coincided with the Messinian Salinity Crisis, then they should have survived to this dramatic period within the Mediterranean, as supported by Bayes Factors model comparison. Conversely, if the divergence started after the crisis, congruent with the idea that no true marine organism survived the Messinian Salinity Crisis, then our results indicate substitution rates of Dendropoma much higher than usual (5.16% per million years for COI, 3.04% for 16S). More recent climate changes seem to have conditioned the demographic history of each lineage differently. While Western and Tyrrhenian-Sicilian lineages both underwent an increase in their effective population sizes from 1.5 to 0.6mya coinciding with a long interglacial period, the Ionian-Aegean and Levantine lineages showed constant effective population sizes since 2-2.5mya, suggesting that these eastern lineages might represent small and relict populations surviving the subsequent Quaternary glaciations in isolated refugia. PMID:26002830

  6. The South American radiation of Jerrybuccinum (Gastropoda, Buccinidae), with a new deep-water species from Chile

    PubMed Central

    Fraussen, Koen; Sellanes, Javier; Stahlschmidt, Peter

    2014-01-01

    Abstract A new deep water species from off the Chilean coast, Jerrybuccinum kantori sp. n., is described. The animal is equipped with a large statocyst. Kryptos explorator Fraussen & Sellanes, 2008 from off Concepción is found to be congeneric and transferred to the genus Jerrybuccinum. Differences in size and sculpture serve to distinguish the new species from J. explorator. Both Chilean species are associated with methane seep or low oxygen environments. They are compared with J. malvinense Kantor & Pastorino, 2009 and two still unnamed species from the Falkland Plateau. PMID:24899844

  7. Annotated type catalogue of the Bothriembryontidae and Odontostomidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S.H.; Ablett, Jonathan D.

    2012-01-01

    Abstract The type status is described for specimens of 84 taxa classified within the families Bothriembryontidae and Odontostomidae (superfamily Orthalicoidea) and kept in the Natural History Museum, London. Lectotypes are designated for Bulimus (Liparus) brazieri Angas, 1871; Bulimus broderipii Sowerby I, 1832; Bulimus fuligineus Pfeiffer, 1853; Helix guarani d’Orbigny, 1835; Bulimus (Tomigerus) ramagei E.A. Smith, 1890; Helix rhodinostoma d’Orbigny, 1835; Bulimus (Bulimulus) ridleyi E.A. Smith, 1890. The type status of the following taxa is changed to lectotype in accordance with Art. 74.6 ICZN: Placostylus (Euplacostylus) cylindricus Fulton, 1907; Bulimus pyrostomus Pfeiffer, 1860; Bulimus turneri Pfeiffer, 1860. The following taxon is synonymised: Bulimus oblitus Reeve, 1848 = Bahiensis neglectus (Pfeiffer, 1847). PMID:22539914

  8. Postembryonic stages of Nucellicola holmanae Lamb et al., 1996 (copepoda, poecilostomatoida), an endoparasite of the dog whelk Nucella lapillus (gastropoda)

    NASA Astrophysics Data System (ADS)

    Lamb, E. J.; Boxshall, G. A.; Mill, P. J.; Grahame, J.

    1998-06-01

    The external morphology of the first three larval stages of Nucellicola holmanae is described. These stages were cultured from eggs found with the adults in the viscera of dog whelks collected from Robin Hood's Bay, North Yorkshire. The nauplius develops within the whelk. It moults to a metanauplius which is released as a free-swimming stage. The metanauplius moults to a free copepodid stage which exhibits a combination of characters typical of the first, second and third copepodid stages of other poecilostomatoid copepods. The infective copepodid stage which locates and penetrates the host is visible through the integument of this free-swimming copepodid.

  9. mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): Implications for comparative neurobiology

    SciTech Connect

    Medina, Monica; Collins, Timothy M.; Walsh, Patrick J.

    2000-08-10

    Sea hares within the genus Aplysia are important neurobiological model organisms, and as studies based on different Aplysia species appear in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists in order to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include the determination of ancestral traits, the direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological basis.

  10. Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda)

    PubMed Central

    Yonow, Nathalie

    2012-01-01

    Abstract Seventy species of opisthobranchs are described in this work based on collections from the Persian Gulf, Socotra, Kenya, Zanzibar, Madagascar, La Réunion, Mauritius, the Seychelles, the Maldives, and Sri Lanka. Ten species are newly recorded from the western Indian Ocean and four species are recorded in the scientific literature for the first time since their original descriptions. Two species are described as new: Cyerce bourbonica sp. n. from La Réunion and Doriopsilla nigrocerasp. n. from the Persian Gulf coast of Saudi Arabia. Chromodoris cavae is removed from its synonymy with Chromodoris tennentana and redescribed from specimens from La Réunion, while several new synonyms are proposed for some commonly occurring species. Risbecia bullockii is recorded for the second time from the Indian Ocean and assigned to its correct genus. PMID:22711992

  11. A review of the microgastropod genus Systenostoma Bavay & Dautzenberg, 1908 and a new subterranean species from China (Gastropoda, Pulmonata, Hypselostomatidae)

    PubMed Central

    Jochum, Adrienne; Slapnik, Rajko; Kampschulte, Marian; Martels, Gunhild; Heneka, Markus; Páll-Gergely, Barna

    2014-01-01

    Abstract A review of the microgastropod genus Systenostoma is provided. Thai and Malaysian species are transferred to a new genus, Angustopila (type species: Systenostoma tamlod Panha & Burch, 1999). A new subterranean Angustopila species is described here. Conchologically, the new species is most similar to the cave-dwelling, Thai A. tamlod (Panha & Burch, 1999). One Thai species (Systenostoma edentata) is transferred to the genus Hypselostoma. Vietnamese members remain in the genus Tonkinospira (nomen novum) for Systenostoma Bavay & Dautzenberg, 1908 (non Systenostoma Marsson, 1887). A comprehensive map of former Systenostoma species is presented. SEM and NanoCT images, including a video of A. huoyani sp. n. internal shell morphology, provide novel perspectives of the shells of Angustopila and of the scarcely known Vietnamese Tonkinospira species. The biology of these snails is not yet known but collection localities suggest a troglophilic ecology. PMID:24899848

  12. Impact of mercury contamination on the population dynamics of Peringia ulvae (Gastropoda): Implications on metal transfer through the trophic web

    NASA Astrophysics Data System (ADS)

    Cardoso, P. G.; Sousa, E.; Matos, P.; Henriques, B.; Pereira, E.; Duarte, A. C.; Pardal, M. A.

    2013-09-01

    The effects of mercury contamination on the population structure and dynamics of the gastropod Peringia ulvae (also known as Hydrobia ulvae) and its impact on the trophic web were assessed along a mercury gradient in Ria de Aveiro (Portugal). The gastropod was revealed to be a tolerant species to the contaminant, since the highest densities, biomasses and growth productivity values were recorded at the intermediate contaminated area followed by the most contaminated one and finally the least contaminated area. P. ulvae was however negatively affected by mercury in terms of growth and life span. So, in the most contaminated area the population was characterised mainly by the presence of juveniles and young individuals. The intermediate contaminated area showed a greater equilibrium in terms of groups' proportion, being the adults the dominant set. The least contaminated area presented intermediate values. P. ulvae life spans were shortest in the most contaminated area (7-8 mo), followed by the least contaminated area (10-11 mo) and finally, the intermediate one (11-14 mo). P. ulvae revealed to be an important vehicle of mercury transfer from sediments to the trophic web, incorporating approximately 15 g of Hg, annually, in the inner area of the Laranjo Bay (0.6 Km2). Therefore, despite P. ulvae being revealed to be not a good bio-indicator of mercury contamination, since it did not suffer profound modifications in its structure and functioning, it is a crucial element in the mercury biomagnification processes throughout the food web.

  13. Food-induced esterase electromorphs in Carinarion spp. and their effects on taxonomic data analysis (Gastropoda, Pulmonata, Arionidae).

    PubMed

    Jordaens, K; Van Riel, P; Verhagen, R; Backeljau, T

    1999-03-01

    Nonspecific esterases (EST) are often used to measure genetic variation, yet they may be influenced by environmental factors such as food, climate and age. This may produce misleading similarity indices and genetic diversity estimates (i.e., clone or strain diversities in uniparental organisms). Therefore, polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing (IEF) were used to investigate environmental effects on the EST variation in natural Carinarion populations, as well as in 45 individuals that were raised individually on carrots to produce offspring by selfing. Food effects on EST profiles in these progenies were examined by raising them on different food items (lettuce, nettle, or paper). Our results indicated that: (i) Arion (Carinarion) fasciatus and A. (C.) silvaticus show species-specific EST profiles, (ii) A. fasciatus-like outcrossers most probably are conspecific with A. fasciatus s.s., (iii) not all EST variation has a Mendelian basis since lettuce and nettle altered EST profiles, and (iv) food effects on EST profiles differed strongly between individuals. Although food-induced EST profiles did not affect taxonomic interpretations, they did inflate genetic diversity estimates and thus provided misleading population-genetic data. PMID:10217156

  14. DNA barcodes and phylogenetic affinities of the terrestrial slugs Arion gilvus and A. ponsi (Gastropoda, Pulmonata, Arionidae).

    PubMed

    Breugelmans, Karin; Jordaens, Kurt; Adriaens, Els; Remon, Jean Paul; Cardona, Josep Quintana; Backeljau, Thierry

    2013-12-30

    The Iberian Peninsula is a region with a high endemicity of species of the terrestrial slug subgenus Mesarion. Many of these species have been described mainly on subtle differences in their proximal genitalia. It therefore remains to be investigated 1) whether these locally diverged taxa also represent different species under a phylogenetic species concept as has been shown for other Mesarion species outside the Iberian Peninsula, and 2) how these taxa are phylogenetically related. Here, we analysed DNA sequence data of two mitochondrial (COI and 16S) genes, and of the nuclear ITS1 region, to explore the phylogenetic affinities of two of these endemic taxa, viz. Arion gilvus Torres Mínguez, 1925 and A. ponsi Quintana Cardona, 2007. We also evaluated the use of these DNA sequence data as DNA barcodes for both species. Our results showed that ITS did not allow to differentiate among most of the Mesarion molecular operational taxonomic units (MOTUs) / morphospecies in Mesarion. Yet, the overall mean p-distance among the Mesarion MOTUs / morphospecies for both mtDNA fragments (16.7% for COI, 13% for 16S) was comparable to that between A. ponsi and its closest relative A. molinae (COI: 14.2%; 16S: 16.2%) and to that between A. gilvus and its closest relative A. urbiae (COI: 14.4%; 16S: 13.4%). Hence, with respect to mtDNA divergence, both A. ponsi and A. gilvus, behave as other Mesarion species or putative species-level MOTUs and thus are confirmed as distinct 'species'. PMID:24453553

  15. Extreme mtDNA divergences in a terrestrial slug (Gastropoda, Pulmonata, Arionidae): accelerated evolution, allopatric divergence and secondary contact.

    PubMed

    Pinceel, J; Jordaens, K; Backeljau, T

    2005-09-01

    Extremely high levels of intraspecific mtDNA differences in pulmonate gastropods have been reported repeatedly and several hypotheses to explain them have been postulated. We studied the phylogeny and phylogeography of 51 populations (n = 843) of the highly polymorphic terrestrial slug Arion subfuscus (Draparnaud, 1805) across its native distribution range in Western Europe. By combining the analysis of single stranded conformation polymorphisms (SSCP) and nucleotide sequencing, we obtained individual sequence data for a fragment of the mitochondrial 16S rDNA and a fragment of the nuclear ITS1. Additionally, five polymorphic allozyme loci were scored. Based on the 16S rDNA phylogeny, five monophyletic haplotype groups with sequence divergences of 9-21% were found. Despite this deep mitochondrial divergence, the haplotype groups were not monophyletic for the nuclear ITS1 fragment and haplotype group-specific allozyme alleles were not found. Although there is evidence for an accelerated mtDNA clock, the divergence among the haplotype groups is older than the Pleistocene and their current allopatric ranges probably reflect allopatric divergence and glacial survival in separate refugia from which different post-glacial colonization routes were established. A range-overlap of two mtDNA groups (S1 and S2, 21% sequence divergence) stretched from Central France and Belgium up to the North of the British Isles. The nuclear data suggest that this secondary contact resulted in hybridization between the allopatrically diverged groups. Therefore, it seems that, at least for two of the groups, the deep mtDNA divergence was only partially accompanied by the formation of reproductive isolation. PMID:16135122

  16. Opisthobranchia (Mollusca, Gastropoda) – more than just slimy slugs. Shell reduction and its implications on defence and foraging

    PubMed Central

    Wägele, Heike; Klussmann-Kolb, Annette

    2005-01-01

    Background In general shell-less slugs are considered to be slimy animals with a rather dull appearance and a pest to garden plants. But marine slugs usually are beautifully coloured animals belonging to the less-known Opisthobranchia. They are characterized by a large array of interesting biological phenomena, usually related to foraging and/or defence. In this paper our knowledge of shell reduction, correlated with the evolution of different defensive and foraging strategies is reviewed, and new results on histology of different glandular systems are included. Results Based on a phylogeny obtained by morphological and histological data, the parallel reduction of the shell within the different groups is outlined. Major food sources are given and glandular structures are described as possible defensive structures in the external epithelia, and as internal glands. Conclusion According to phylogenetic analyses, the reduction of the shell correlates with the evolution of defensive strategies. Many different kinds of defence structures, like cleptocnides, mantle dermal formations (MDFs), and acid glands, are only present in shell-less slugs. In several cases, it is not clear whether the defensive devices were a prerequisite for the reduction of the shell, or reduction occurred before. Reduction of the shell and acquisition of different defensive structures had an implication on exploration of new food sources and therefore likely enhanced adaptive radiation of several groups. PMID:15715915

  17. A review of the microgastropod genus Systenostoma Bavay & Dautzenberg, 1908 and a new subterranean species from China (Gastropoda, Pulmonata, Hypselostomatidae).

    PubMed

    Jochum, Adrienne; Slapnik, Rajko; Kampschulte, Marian; Martels, Gunhild; Heneka, Markus; Páll-Gergely, Barna

    2014-01-01

    A review of the microgastropod genus Systenostoma is provided. Thai and Malaysian species are transferred to a new genus, Angustopila (type species: Systenostoma tamlod Panha & Burch, 1999). A new subterranean Angustopila species is described here. Conchologically, the new species is most similar to the cave-dwelling, Thai A. tamlod (Panha & Burch, 1999). One Thai species (Systenostoma edentata) is transferred to the genus Hypselostoma. Vietnamese members remain in the genus Tonkinospira (nomen novum) for Systenostoma Bavay & Dautzenberg, 1908 (non Systenostoma Marsson, 1887). A comprehensive map of former Systenostoma species is presented. SEM and NanoCT images, including a video of A. huoyani sp. n. internal shell morphology, provide novel perspectives of the shells of Angustopila and of the scarcely known Vietnamese Tonkinospira species. The biology of these snails is not yet known but collection localities suggest a troglophilic ecology. PMID:24899848

  18. The status of the genus Bostryx Troschel, 1847, with description of a new subfamily (Mollusca, Gastropoda, Bulimulidae)

    PubMed Central

    Breure, Abraham S.H.

    2012-01-01

    Abstract The status of the genus Bostryx is discussed and, based on morphological and molecular data, restricted to a group of species related to Bostryx solutus, for which the new subfamily name Bostrycinae is introduced. PMID:22936873

  19. Record of a new species of Obornella Cox 1959 (Gastropoda) from the Tithonian of Kutch, western India

    NASA Astrophysics Data System (ADS)

    Das, Shiladri Shekhar

    2007-04-01

    Obornella Cox 1959, is an extremely depressed genus of the family Pleurotomariidae. It first appeared during Toarcian in France and continued up to the Tithonian. Obornella is a Tethyan genus restricted only to western Europe except previous reports of migration of a species to Kutch during the Late Bathonian. The present find describes a new species of Obornella, i.e., Obornella lakhaparensis from immediately below the Jurassic-Cretaceous boundary in Kutch. The present species is quite distinct from other Obornella species and has many novelties. A detailed systematic description is provided.

  20. The complete mitochondrial genome of Haliotis laevigata (Gastropoda: Haliotidae) using MiSeq and HiSeq sequencing.

    PubMed

    Robinson, Nick A; Hall, Nathan E; Ross, Elizabeth M; Cooke, Ira R; Shiel, Brett P; Robinson, Andrew J; Strugnell, Jan M

    2016-01-01

    The mitochondrial genome of greenlip abalone, Haliotis laevigata, is reported. MiSeq and HiSeq sequencing of one individual was assembled to yield a single 16,545 bp contig. The sequence shares 92% identity to the H. rubra mitochondrial genome (a closely related species that hybridize with H. laevigata in the wild). The sequence will be useful for determining the maternal contribution to hybrid populations, for investigating population structure and stock-enhancement effectiveness. PMID:24660910

  1. The genus Pirenella Gray, 1847 (= Cerithideopsilla Thiele, 1929) (Gastropoda: Potamididae) in the Indo-West Pacific region and Mediterranean Sea.

    PubMed

    Reid, David G; Ozawa, Tomowo

    2016-01-01

    Members of the genus Pirenella are abundant inhabitants of intertidal sedimentary shores, often found in association with mangroves, on the continental margins of the western Pacific and Indian Oceans, and eastern Mediterranean Sea. Until recently, four morphological species were recognised in the tropical Indo-West Pacific region and classified in the genus Cerithideopsilla, while another species occupying the Mediterranean and Indian Ocean was classified as Pirenella conica. Molecular phylogenetic analysis has demonstrated that all these species are congeneric and here it is shown that the valid name for the genus is Pirenella. A recently published molecular study recognised a total of 16 species and the present work is a systematic account of these species. Of the 16, nine are described as new. Other significant nomenclatural acts are: fixation of type species of Pirenella as Pirenella mammillata J.E. Gray, 1847; designation of neotypes for Cerithium alatum Philippi, 1849, Cerithium microptera Kiener, 1841, Cerithium conicum Blainville, 1829, Pirenella mammillata J.E. Gray, 1847 and Murex cingulatus Gmelin, 1791; designation of lectotype for Cerithium retiferum G.B. Sowerby II, 1855. The species accounts include full synonymies, detailed descriptions of shells (based on 831 museum samples), distribution records and maps, reviews of life history, of habitat and of ecology, and some images of radulae. Details of shell sculpture are adequate for the diagnosis of most species. Distorted shells are common in some populations and are suggested to represent parasitised individuals. Some species are pests of fishponds in Southeast Asia and P. conica is the intermediate host of a trematode responsible for the human disease heterophyiasis, while others are threatened by habitat destruction. PMID:27395955

  2. Philinidae, Laonidae and Philinorbidae (Gastropoda: Cephalaspidea: Philinoidea) from the northeastern Pacific Ocean and the Beaufort Sea (Arctic Ocean).

    PubMed

    Valdés, Ángel; Cadien, Donald B; Gosliner, Terrence M

    2016-01-01

    Based on morphological data a total of nine native species of Philinidae are recognized from the northeastern Pacific including the Bering Sea and the adjacent Arctic Ocean (Beaufort Sea). Four of them have been previously described: Philine ornatissima Yokoyama, 1927, Philine bakeri Dall, 1919, Philine polystrigma (Dall, 1908), and Philine hemphilli Dall, 1919. Five of them are new and described herein: Philine mcleani sp. nov., Philine baxteri sp. nov., Philine malaquiasi sp. nov., Philine wareni sp. nov., and Philine harrisae sp. nov. These species display a substantial degree of variation in internal and external morphological traits (i.e., presence/absence of gizzard plates, different radular structure and tooth morphology, various reproductive anatomical features) and it is likely that they belong to different clades (genera). However, in the absence of a comprehensive phylogeny for Philine, they are here provisionally regarded as Philine sensu lato. In addition to the nine native species, two introduced species: Philine orientalis A. Adams, 1854 and Philine auriformis Suter, 1909 are here illustrated and compared to the native species to facilitate identification. Finally, two species previously considered members of Philinidae are examined anatomically and confirmed as members of Laonidae, Laona californica (Willett, 1944) and Philinorbidae, Philinorbis albus (Mattox, 1958), based on morphological data. PMID:27515632

  3. Ultrastructure and Glycoconjugate Pattern of the Foot Epithelium of the Abalone Haliotis tuberculata (Linnaeus, 1758) (Gastropoda, Haliotidae)

    PubMed Central

    Bravo Portela, I.; Martinez-Zorzano, V. S.; Molist- Perez, I.; Molist García, P.

    2012-01-01

    The foot epithelium of the gastropod Haliotis tuberculata is studied by light and electron microscopy in order to contribute to the understanding of the anatomy and functional morphology of the mollusks integument. Study of the external surface by scanning electron microscopy reveals that the side foot epithelium is characterized by a microvillus border with a very scant presence of small ciliary tufts, but the sole foot epithelium bears a dense field of long cilia. Ultrastructural examination by transmission electron microscopy of the side epithelial cells shows deeply pigmented cells with high electron-dense granular content which are not observed in the epithelial sole cells. Along the pedal epithelium, seven types of secretory cells are present; furthermore, two types of subepithelial glands are located just in the sole foot. The presence and composition of glycoconjugates in the secretory cells and subepithelial glands are analyzed by conventional and lectin histochemistry. Subepithelial glands contain mainly N-glycoproteins rich in fucose and mannose whereas secretory cells present mostly acidic sulphated glycoconjugates such as glycosaminoglycans and mucins, which are rich in galactose, N-acetyl-galactosamine, and N-acetyl-glucosamine. No sialic acid is present in the foot epithelium. PMID:22645482

  4. 50 CFR 665.621 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Zoanthinaria. Hydrozoans, Bryzoans. sea squirts Tunicates. sea cucumbers and sea urchins Echinoderms. Those species not listed as CHCRT Mollusca. sea snails Gastropoda. Trochus. sea slugs Opistobranchs....

  5. 50 CFR 665.621 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Zoanthinaria. Hydrozoans, Bryzoans. sea squirts Tunicates. sea cucumbers and sea urchins Echinoderms. Those species not listed as CHCRT Mollusca. sea snails Gastropoda. Trochus. sea slugs Opistobranchs....

  6. 50 CFR 665.621 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Zoanthinaria. Hydrozoans, Bryzoans. sea squirts Tunicates. sea cucumbers and sea urchins Echinoderms. Those species not listed as CHCRT Mollusca. sea snails Gastropoda. Trochus. sea slugs Opistobranchs....

  7. 50 CFR 665.621 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Zoanthinaria. Hydrozoans, Bryzoans. sea squirts Tunicates. sea cucumbers and sea urchins Echinoderms. Those species not listed as CHCRT Mollusca. sea snails Gastropoda. Trochus. sea slugs Opistobranchs....

  8. Description of two new species of Rissoella Gray, 1847 (Mollusca, Gastropoda, Heterobranchia) from Venezuela, with a key to the Caribbean species known for the genus.

    PubMed

    Caballer, Manuel; Ortea, Jesus; Narciso, Samuel

    2011-01-01

    Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensissp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicolasp. n.Rissoella morrocoyensissp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon and it lives on the leaves of the seagrass Thalassia testudinum Banks & König, 1805. Rissoella venezolanicolasp. n. has an angled preumbilical cord which extends to the columella delimiting a trapezoid, a hypobranchial gland marked by a yellow quaver-shaped ribbon and protoconch with fuchsia highlights. It lives on the brown alga Dictyota spp. The records of Rissoella in the Caribbean are revised and illustrations, a comparative table and a key to the Caribbean species known for the genus are provided. PMID:21976997

  9. Description of two new species of Rissoella Gray, 1847 (Mollusca, Gastropoda, Heterobranchia) from Venezuela, with a key to the Caribbean species known for the genus

    PubMed Central

    Caballer, Manuel; Ortea, Jesus; Narciso, Samuel

    2011-01-01

    Abstract Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensis sp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicola sp. n. Rissoella morrocoyensis sp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon and it lives on the leaves of the seagrass Thalassia testudinum Banks & König, 1805. Rissoella venezolanicola sp. n. has an angled preumbilical cord which extends to the columella delimiting a trapezoid, a hypobranchial gland marked by a yellow quaver-shaped ribbon and protoconch with fuchsia highlights. It lives on the brown alga Dictyota spp. The records of Rissoella in the Caribbean are revised and illustrations, a comparative table and a key to the Caribbean species known for the genus are provided. PMID:21976997

  10. Natural Prey Preferences and Spatial Variability of Predation Pressure by Cyphoma gibbosum (Mollusca: Gastropoda) on Octocoral Communities off La Parguera, Puerto Rico

    PubMed Central

    Lucas, Matthew Q.; Rodríguez, Luis R.; Sanabria, Duane J.

    2014-01-01

    This study evaluated the natural prey preferences and spatial variability of predation pressure (PP = proportion of colonies with snails and/or clear predation signs) by the gastropod Cyphoma gibbosum on octocoral communities off the La Parguera Natural Reserve, Puerto Rico. All octocoral colonies were checked for presence of C. gibbosum and/or clear predation signs in four permanent band-transects (2 × 10 m), along three depth intervals (0–5, 7–12, >15 m deep) in each of six reefs along an inshore offshore gradient. Results indicate that C. gibbosum preys on at least 16 species, six of which (Briareum asbestinum, Gorgonia ventalina, Pseudoterogorgia americana, P. acerosa, Plexaura flexuosa, and Pseudoplexaura porosa) consistently showed significantly higher (K-W, P < 0.05) (17–37%) PP compared to all other species. Plexaura flexuosa, P. americana, and P. porosa had significantly higher PP (11–38%) among inner and mid-shelf reefs, and G. ventalina had higher PP in shelf-edge reefs (16–20%). A combination of differential spatial distributions and octocoral species abundances seems to explain the observed patterns of predation by C. gibbosum. Prey preference and higher abundances of 3-dimensional octocorals providing increased refuge or microhabitats utilized for mating or egg-deposition could be driving the spatial distribution of C. gibbosum and the observed differential predation pressure.

  11. Fluctuating Helical Asymmetry and Morphology of Snails (Gastropoda) in Divergent Microhabitats at ‘Evolution Canyons I and II,’ Israel

    PubMed Central

    Raz, Shmuel; Schwartz, Nathan P.; Mienis, Hendrik K.; Nevo, Eviatar; Graham, John H.

    2012-01-01

    Background Developmental instability of shelled gastropods is measured as deviations from a perfect equiangular (logarithmic) spiral. We studied six species of gastropods at ‘Evolution Canyons I and II’ in Carmel and the Galilee Mountains, Israel, respectively. The xeric, south-facing, ‘African’ slopes and the mesic, north-facing, ‘European’ slopes have dramatically different microclimates and plant communities. Moreover, ‘Evolution Canyon II’ receives more rainfall than ‘Evolution Canyon I.’ Methodology/Principal Findings We examined fluctuating asymmetry, rate of whorl expansion, shell height, and number of rotations of the body suture in six species of terrestrial snails from the two ‘Evolution Canyons.’ The xeric ‘African’ slope should be more stressful to land snails than the ‘European’ slope, and ‘Evolution Canyon I’ should be more stressful than ‘Evolution Canyon II.’ Only Eopolita protensa jebusitica showed marginally significant differences in fluctuating helical asymmetry between the two slopes. Contrary to expectations, asymmetry was marginally greater on the ‘European’ slope. Shells of Levantina spiriplana caesareana at ‘Evolution Canyon I,’ were smaller and more asymmetric than those at ‘Evolution Canyon II.’ Moreover, shell height and number of rotations of the suture were greater on the north-facing slopes of both canyons. Conclusions/Significance Our data is consistent with a trade-off between drought resistance and thermoregulation in snails; Levantina was significantly smaller on the ‘African’ slope, for increasing surface area and thermoregulation, while Eopolita was larger on the ‘African’ slope, for reducing water evaporation. In addition, ‘Evolution Canyon I’ was more stressful than Evolution Canyon II’ for Levantina. PMID:22848631

  12. Evaluation of the cholinomimetic actions of trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana (Gastropoda, Opisthobranchia).

    PubMed

    Kerchove, C M; Markus, R P; Freitas, J C; Costa-Lotufo, L V

    2002-04-01

    Trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana, negatively modulates vagal response, indicating a probable ability to inhibit cholinergic responses. In the present study, the pharmacological profile of trimethylsulfonium was characterized on muscarinic and nicotinic acetylcholine receptors. In rat jejunum the contractile response induced by trimethylsulfonium (pD2 = 2.46 +/- 0.12 and maximal response = 2.14 +/- 0.32 g) was not antagonized competitively by atropine. The maximal response (Emax) to trimethylsulfonium was diminished in the presence of increasing doses of atropine (P<0.05), suggesting that trimethylsulfonium-induced contraction was not related to muscarinic stimulation, but might be caused by acetylcholine release due to presynaptic stimulation. Trimethylsulfonium displaced [3H]-quinuclidinyl benzilate from rat cortex membranes with a low affinity (Ki = 0.5 mM). Furthermore, it caused contraction of frog rectus abdominis muscles (pD2 = 2.70 +/- 0.06 and Emax = 4.16 +/- 0.9 g), which was competitively antagonized by d-tubocurarine (1, 3 or 10 microM) with a pA2 of 5.79, suggesting a positive interaction with nicotinic receptors. In fact, trimethylsulfonium displaced [3H]-nicotine from rat diaphragm muscle membranes with a Ki of 27.1 microM. These results suggest that trimethylsulfonium acts as an agonist on nicotinic receptors, and thus contracts frog skeletal rectus abdominis muscle and rat jejunum smooth muscle via stimulation of postjunctional and neuronal prejunctional nicotinic cholinoreceptors, respectively. PMID:11960200

  13. The functional anatomy of the mantle complex and columellar muscle of tectibranch molluscs (Gastropoda: Opisthobranchia), and its bearing on the evolution of opisthobranch organization.

    PubMed

    Brace, R C

    1977-02-15

    An account is given of the anatomy of a series of opisthobranch molluscs principally to assess the change in importance and functioning of the mantle cavity and columellar muscle throughout the transition from prosobranch to opisthobranch organization. Intermediate steps are represented by living tectibranchs, of which Philine and Scaphander are investigated in detail, Acteon, Bulla, Haminoea, Akera, Aglaja and Gastropteron more briefly. Though an opisthobranch, Acteon has an organization typical of a monotocardian prosobranch; the remainder show trends affecting the shell and visceral mass, mantle cavity and head-foot, which resulted finally in the production of nudibranch types. It is confirmed that the adaptations exhibited by primitive tectibranchs relate to the assumption of a burrowing mode of life. Initial changes were the reduction of the nuchal area and sealing of the mantle cavity anteriorly so that it opened on the right, where it became restricted, the first perhaps prompting the sealing. A broadening and an anterior elongation of the head-foot produced a wedge to facilitate burrowing. Change in disposition of the mantle edge, incurred by differential growth, produced an involute shell with a large body whorl, alignment changing from erect to horizontal. The resultant streamlining eased infaunal progression; no vertical insinking of the viscera was involved. Subsequently the shell became reduced and finally lost. A section of the mantle edge enlarged to produce a posterior mantle lobe upon which sit both the shell and viscera, and which later became redundant as posterior elongation of the head-foot produced a slug-like form, the viscera being incorporated within the head-foot. As the nuchal area became reduced, mechanical needs prompted alteration to both the form and attachment of the columellar muscle. In Acteon the muscle is like that of a prosobranch, but the proximal region has broadened, a change of proportion required by primitive tectibranchs in order to support the floor of the mantle cavity formed from the section of mantle skirt which in prosobranchs lies on the right. This was followed by reduction and re-alignment of the entire muscle along an anteroposterior axis as emphasis changed from the muscle effecting retraction into a shell to producing contorsions of the head-foot. The shell, similarly reduced, instead of providing anchorage, became itself anchored by additional anterior and posterior attachment zones with, in more advanced forms, dorsoventral muscles of the body wall rather than longitudinal muscles fastening to the former. Importance was placed on the mutual stabilization of constituent parts of the posterior body region. Re-alignments of the muscle induced breaking up of the longitudinal muscle sheet of the head-foot to produce muscle tracts, best exhibited in those tectibranchs which swim; they are derived from both the columellar muscle and intrinsic body wall muscles... PMID:15290

  14. A NEW SPECIES OF DIAPHANA FROM BATHYAL DEPTHS IN THE WEDDELL SEA, ANTARCTICA AND FIRST RECORD OF DIAPHANA INFLATA (STREBEL, 1908) IN THE HIGH ANTARCTIC (GASTROPODA: OPISTHOBRANCHIA).

    PubMed

    Linse, KATRIN; SchiØtte, TOM

    2002-05-01

    Diaphana haini n.sp. is described from Antarctica. With a depth range from about 400 to 2100 m, D. haini is the second Antarctic species of this genus to extend into the deep sea, the other being D. inflata (Strebel, 1908). Phylogenetic analysis has allowed D. haini to be incorporated within Schiøtte's (1998) cladogram for this genus and, thereby clarify its historical zoogeography. A record of D. inflata from the Weddell Sea extends its known distribution range. The recorded geographic distribution now ranges from South Georgia to the Antarctic continent, and the depth range is extended considerably, from 252-310 m to 1645 m. PMID:12011240

  15. Phylogenetic relationships elucidate colonization patterns in the intertidal grazers Osilinus Philippi, 1847 and Phorcus Risso, 1826 (Gastropoda: Trochidae) in the northeastern Atlantic Ocean and Mediterranean Sea.

    PubMed

    Donald, Kirsten M; Preston, Joanne; Williams, Suzanne T; Reid, David G; Winter, David; Alvarez, Raquel; Buge, Barbara; Hawkins, Stephen J; Templado, Jose; Spencer, Hamish G

    2012-01-01

    Snails in the closely related trochid genera Phorcus Risso, 1826 and Osilinus Philippi, 1847 are ecologically important algal grazers in the intertidal zone of the northeastern Atlantic Ocean and Mediterranean Sea. Here we present the first complete molecular phylogeny for these genera, based on the nuclear 28S rRNA gene and the mitochondrial 16S rRNA and COI genes, and show that the current classification is erroneous. We recognize nine species in a single genus, Phorcus: estimated by BEAST analysis, this arose 30 (± 10) Ma; it consists of two subgenera, Phorcus and Osilinus, which we estimate diverged 14 (± 4.5) Ma. Osilinus kotschyi, from the Arabian and Red Seas, is not closely related and is tentatively referred to Priotrochus Fischer, 1879. Our phylogeny allows us to address biogeographical questions concerning the origins of the Mediterranean and Macaronesian species of this group. The former appear to have evolved from Atlantic ancestors that invaded the Mediterranean on several occasions after the Zanclean Flood, which ended the Messinian Salinity Crisis 5.3 Ma; whereas the latter arose from several colonizations of mainland Atlantic ancestors within the last 3 (± 1.5) Ma. PMID:21945534

  16. Population genetic structure of the freshwater snail, Bulinus globosus, (Gastropoda: Planorbidae) from selected habitats of KwaZulu-Natal, South Africa.

    PubMed

    Mkize, Lwamkelekile Sitshilelo; Mukaratirwa, Samson; Zishiri, Oliver Tendayi

    2016-09-01

    The freshwater snail Bulinus globosus is an important intermediate host of Schistosoma haematobium, the causative agent of urinary schistosomiasis. This disease is of major health concern, especially in Africa where the majority of cases have been reported. In this study the inter- and intra-genetic diversity and population genetic structure of B. globosus from nine locations in the KwaZulu-Natal province of South Africa was studied using four polymorphic microsatellite loci (BgZ1-BgZ4). Moderate genetic diversity was detected within populations with a mean diversity (HE) of 0.49±0.09. The majority of populations significantly deviated from Hardy-Weinberg equilibrium (p<0.05), due to a deficit of heterozygotes. Such deviations may be due to founder events that were caused by bottlenecks that occurred as a result of frequent droughts and flooding that these snails' habitats are exposed to. Overall, the populations studied seem to be partially inbreeders/selfers with mean estimates of 0.24/0.38. A discernable genetic structure was elucidated among populations as evident by the mean pairwise FST of 0.58±0.13. There was no significant association between genetic and geographical distance among populations, an indication of limited gene flow. This increases the chances of populations losing alleles due to genetic drift. Populations in close proximity demonstrated high genetic differentiation (58.77% total variation) due to allelic differences between them. The sample populations fell into 12 clusters, however, the populations from uMkhanyakude and uThungulu exhibited no discernable genetic structure. Genetically, the Bhobhoyi site found within the uGu district was equidistant to the two main sampling regions. PMID:27267152

  17. New species of Rissoidae (Mollusca, Gastropoda) from the Archipelago of the Azores (northeast Atlantic) with an updated regional checklist for the family

    PubMed Central

    Cordeiro, Ricardo; Ávila, Sérgio P.

    2015-01-01

    Abstract Four new species of shallow-water marine gastropods belonging to the family Rissoidae are described from the Archipelago of the Azores: Setia alexandrae sp. n., Setia ermelindoi sp. n., Setia netoae sp. n., and Manzonia martinsi sp. n. These novelties increase the regional rissoid fauna to 39 species, of which 29 live in shallow-water habitats. A list of the species of Rissoidae from the Azores is presented based on data from the literature and new material examined. PMID:25685020

  18. Biochemical and immunohistochemical analyses of a GnRH-like peptide in the neural ganglia of the Pacific abalone Haliotis discus hannai (Gastropoda).

    PubMed

    Amano, Masafumi; Moriyama, Shunsuke; Okubo, Kataaki; Amiya, Noriko; Takahashi, Akiyoshi; Oka, Yoshitaka

    2010-08-01

    We examined whether gonadotropin-releasing hormone (GnRH)-like peptides are present in the neural ganglia of the gastropod Pacific abalone (Haliotis discus hannai) by reverse-phase high performance liquid chromatography (rpHPLC) combined with time-resolved fluoroimmunoassay (TR-FIA) analysis and by immunohistochemistry. Cerebral ganglion extracts showed a similar retention time to lamprey GnRH-II (lGnRH-II) in rpHPLC combined with TR-FIA analysis. GnRH-like-immunoreactive (ir) cell bodies (which reacted with a mouse monoclonal antibody raised against the common amino acid sequence of vertebrate GnRH) were detected in the peripheral region of the cerebral ganglion, and they were observed to send fibers into the neuropil. GnRH-like-ir fibers were also detected in the neuropil of the pedal ganglion, the visceral nerve, and the nerve originating from the pedal ganglion. Chicken GnRH-II (cGnRH-II)-like-ir fibers (which reacted with a rabbit polyclonal antibody raised against cGnRH-II) were also observed in the neuropil of the cerebral ganglion. GnRH-like-ir fibers and cGnRH-II-like-ir fibers were distinguishable in the neuropil of the cerebral ganglion by double-staining immunohistochemistry. These results suggest that multiple GnRH-like peptides exist in the neural ganglia of the Pacific abalone. PMID:20695781

  19. Environmental epidemiology of intestinal schistosomiasis in Uganda: population dynamics of biomphalaria (gastropoda: planorbidae) in Lake Albert and Lake Victoria with observations on natural infections with digenetic trematodes.

    PubMed

    Rowel, Candia; Fred, Besigye; Betson, Martha; Sousa-Figueiredo, Jose C; Kabatereine, Narcis B; Stothard, J Russell

    2015-01-01

    This study documented the population dynamics of Biomphalaria and associated natural infections with digenetic trematodes, along the shores of Lake Albert and Lake Victoria, recording local physicochemical factors. Over a two-and-a-half-year study period with monthly sampling, physicochemical factors were measured at 12 survey sites and all freshwater snails were collected. Retained Biomphalaria were subsequently monitored in laboratory aquaria for shedding trematode cercariae, which were classified as either human infective (Schistosoma mansoni) or nonhuman infective. The population dynamics of Biomphalaria differed by location and by lake and had positive relationship with pH (P < 0.001) in both lakes and negative relationship with conductivity (P = 0.04) in Lake Albert. Of the Biomphalaria collected in Lake Albert (N = 6,183), 8.9% were infected with digenetic trematodes of which 15.8% were shedding S. mansoni cercariae and 84.2% with nonhuman infective cercariae. In Lake Victoria, 2.1% of collected Biomphalaria (N = 13,172) were infected with digenetic trematodes with 13.9% shedding S. mansoni cercariae, 85.7% shedding nonhuman infective cercariae, and 0.4% of infected snails shedding both types of cercariae. Upon morphological identification, species of Biomphalaria infected included B. sudanica, B. pfeifferi, and B. stanleyi in Lake Albert and B. sudanica, B. pfeifferi, and B. choanomphala in Lake Victoria. The study found the physicochemical factors that influenced Biomphalaria population and infections. The number and extent of snails shedding S. mansoni cercariae illustrate the high risk of transmission within these lake settings. For better control of this disease, greater effort should be placed on reducing environmental contamination by improvement of local water sanitation and hygiene. PMID:25705680

  20. When everything converges: integrative taxonomy with shell, DNA and venomic data reveals Conus conco, a new species of cone snails (Gastropoda: Conoidea).

    PubMed

    Puillandre, Nicolas; Stöcklin, Reto; Favreau, Philippe; Bianchi, Estelle; Perret, Frédéric; Rivasseau, Audrey; Limpalaër, Loïc; Monnier, Eric; Bouchet, Philippe

    2014-11-01

    Cone snails have long been studied both by taxonomists for the diversity of their shells and by biochemists for the potential therapeutic applications of their toxins. Phylogenetic approaches have revealed that different lineages of Conus evolved divergent venoms, a property that is exploited to enhance the discovery of new conotoxins, but is rarely used in taxonomy. Specimens belonging to the Indo-West Pacific Conus lividus species complex were analyzed using phenetic and phylogenetic methods based on shell morphology, COI and 28S rRNA gene sequences and venom mRNA expression and protein composition. All methods converged to reveal a new species, C. conco n. sp. (described in Supplementary data), restricted to the Marquesas Islands, where it diverged recently (∼3mya) from C. lividus. The geographical distribution of C. conco and C. lividus and their phylogenetic relationships suggest that the two species diverged in allopatry. Furthermore, the diversity of the transcript sequences and toxin molecular masses suggest that C. conco evolved unique toxins, presumably in response to new selective pressure, such as the availability of new preys and ecological niches. Furthermore, this new species evolved new transcripts giving rise to original toxin structures, probably each carrying specific biological activity. PMID:25132129

  1. Solariella quadricincta Quinn, 1992 and S. staminea Quinn, 1992 are synonyms of S. carvalhoi Lopes & Cardoso, 1958 from the SW Atlantic (Gastropoda: Solariellidae).

    PubMed

    Cavallari, Daniel C; Salvador, Rodrigo B; Simone, Luiz R L

    2016-01-01

    Solariellidae is a diverse family of small (5-20 mm) marine snails of worldwide distribution. They usually live on fine sediment to unconsolidated substrates in deep-waters of extra-tropical to tropical latitudes (Hickman 1998; Williams et al. 2013). Initially described as a subfamily of Trochidae, it has been recently raised to family level (Bouchet et al. 2005; Williams et al. 2008). The evolutionary relationships among solariellids have been extensively investigated in the light of morphological and molecular data, but the family still lacks a comprehensive taxonomic revision that reflects recent discoveries (Williams et al. 2010, 2013). The family's fossil record possibly dates back to the Campanian of Torallola, Spain (Kiel & Bandel 2001; Williams et al. 2013). PMID:27394855

  2. First molecular identification of Australapatemon burti (Miller, 1923) (Trematoda: Digenea: Strigeidae) from an intermediate host Radix labiata (Rossmaessler) (Gastropoda: Lymnaeidae) in Europe.

    PubMed

    Aksenova, Olga V; Bespalaya, Yulia V; Bolotov, Ivan N; Kondakov, Alexander V; Sokolova, Svetlana E

    2016-01-01

    The strigeid digenean species Australapatemon burti (Miller, 1923) (Trematoda: Digenea: Strigeidae) was originally described from North America, but recorded in the Neotropical region (Drago et al. 2007; Hernández-Mena et al. 2014; Blasco-Costa et al. 2016) and in Central Europe (Faltýnková et al. 2007). In Europe, this species is rare, and there is not much information about its range (Faltýnková et al. 2007; Soldánová et al. 2012). Australapatemon burti has a complex life cycle with three larval stages, two of which (sporocyst and cercaria) use several species of freshwater snails, and the third stage (metacercaria) use non-specific host hirudineans (Dubois 1968; Davies & Ostrowski de Núñez 2012; Blasco-Costa et al. 2016). Adult flukes are parasitic in the intenstines of various waterfowl species, such as ducks and swans (Drago et al. 2007; Hernández-Mena et al. 2014). Currently, the molecular data on this parasite species includes only nucleotide sequences of four adult specimens from Mexico (Hernández-Mena et al. 2014). Their hosts were Mexican duck, Anas diazi Ridgway, American Wigeon, Anas americana Gmelin, Cinnamon Teal, Anas cyanoptera Vieillot, and Ruddy Duck, Oxyura jamaicensis (Gmelin) (Anserformes: Anatidae). PMID:27395696

  3. Four new species of splanchnotrophid copepods (Poecilostomatoida) parasitic on doridacean nudibranchs (Gastropoda, Opistobranchia) from Japan, with proposition of one new genus

    PubMed Central

    Uyeno, Daisuke; Nagasawa, Kazuya

    2012-01-01

    Abstract Four new species of splanchnotrophid copepods are described based on specimens collected from 5 species of doridacean nudibranchs from coastal waters of Japan. They belong to 3 genera, one of which, Majimun gen. n., is new. The parasites and their hosts are as follows: Ceratosomicola japonica sp. n. ex Hypselodoris festiva (A. Adams); Splanchnotrophus helianthus sp. n. ex Thecacera pennigera (Montagu); Splanchnotrophus imagawai sp. n. ex Trapania miltabrancha Gosliner & Fahey; and Majimun shirakawai gen. et sp. n. ex Roboastra luteolineata (Baba) and Roboastra gracilis (Bergh). Ceratosomicola japonica sp. n. is the fifth species of Ceratosomicola and is characterized by the shape and armature of the prosome in females. Both Splanchnotrophus helianthus sp. n. and Splanchnotrophus imagawai sp. n. are differentiated from 4 known congeners by the absence of posterolateral processes or lobes on the prosome in females, and the females of these 2 new species are separated from each other by the shape and armature of the genito-abdomen, the mandible, and the swimming legs. Majimun gen. n. is distinguished from other splanchnotrophid genera by the segmentation of the antennule as well as the combination of the following characters in females: 2 postgenital somites and the shape of the antenna, the mandible and the swimming legs. PMID:23275753

  4. Population structure, density and food sources of Terebralia palustris (Potamididae: Gastropoda) in a low intertidal Avicennia marina mangrove stand (Inhaca Island, Mozambique)

    NASA Astrophysics Data System (ADS)

    Penha-Lopes, Gil; Bouillon, Steven; Mangion, Perrine; Macia, Adriano; Paula, José

    2009-09-01

    Population structure and distribution of Terebralia palustris were compared with the environmental parameters within microhabitats in a monospecific stand of Avicennia marina in southern Mozambique. Stable carbon and nitrogen isotope analyses of T. palustris and potential food sources (leaves, pneumatophore epiphytes, and surface sediments) were examined to establish the feeding preferences of T. palustris. Stable isotope signatures of individuals of different size classes and from different microhabitats were compared with local food sources. Samples of surface sediments 2.5-10 m apart showed some variation (-21.2‰ to -23.0‰) in δ13C, probably due to different contributions from seagrasses, microalgae and mangrove leaves, while δ15N values varied between 8.7‰ and 15.8‰, indicating that there is a very high variability within a small-scale microcosm. Stable isotope signatures differed significantly between the T. palustris size classes and between individuals of the same size class, collected in different microhabitats. Results also suggested that smaller individuals feed on sediment, selecting mainly benthic microalgae, while larger individuals feed on sediment, epiphytes and mangrove leaves. Correlations were found between environmental parameters and gastropod population structure and distribution vs. the feeding preferences of individuals of different size classes and in different microhabitats. While organic content and the abundance of leaves were parameters that correlated best with the total density of gastropods (>85%), the abundance of pneumatophores and leaves, as well as grain size, correlated better with the gastropod size distribution (>65%). Young individuals (height < 3 cm) occur predominantly in microhabitats characterized by a low density of leaf litter and pneumatophores, reduced organic matter and larger grain size, these being characteristic of lower intertidal open areas that favour benthic microalgal growth. With increasing shell height, T. palustris individuals start occupying microhabitats nearer the mangrove trees characterized by large densities of pneumatophores and litter, as well as sediments of smaller grain size, leading to higher organic matter availability in the sediment.

  5. Identification and qualification of 500 nuclear, single-copy, orthologous genes for the Eupulmonata (Gastropoda) using transcriptome sequencing and exon capture.

    PubMed

    Teasdale, Luisa C; Köhler, Frank; Murray, Kevin D; O'Hara, Tim; Moussalli, Adnan

    2016-09-01

    The qualification of orthology is a significant challenge when developing large, multiloci phylogenetic data sets from assembled transcripts. Transcriptome assemblies have various attributes, such as fragmentation, frameshifts and mis-indexing, which pose problems to automated methods of orthology assessment. Here, we identify a set of orthologous single-copy genes from transcriptome assemblies for the land snails and slugs (Eupulmonata) using a thorough approach to orthology determination involving manual alignment curation, gene tree assessment and sequencing from genomic DNA. We qualified the orthology of 500 nuclear, protein-coding genes from the transcriptome assemblies of 21 eupulmonate species to produce the most complete phylogenetic data matrix for a major molluscan lineage to date, both in terms of taxon and character completeness. Exon capture targeting 490 of the 500 genes (those with at least one exon >120 bp) from 22 species of Australian Camaenidae successfully captured sequences of 2825 exons (representing all targeted genes), with only a 3.7% reduction in the data matrix due to the presence of putative paralogs or pseudogenes. The automated pipeline Agalma retrieved the majority of the manually qualified 500 single-copy gene set and identified a further 375 putative single-copy genes, although it failed to account for fragmented transcripts resulting in lower data matrix completeness when considering the original 500 genes. This could potentially explain the minor inconsistencies we observed in the supported topologies for the 21 eupulmonate species between the manually curated and 'Agalma-equivalent' data set (sharing 458 genes). Overall, our study confirms the utility of the 500 gene set to resolve phylogenetic relationships at a range of evolutionary depths and highlights the importance of addressing fragmentation at the homolog alignment stage for probe design. PMID:27289081

  6. Irrigation canals in Melo creek basin (Rio Espera and Capela Nova municipalities, Minas Gerais, Brazil): habitats to Biomphalaria (Gastropoda: Planorbidae) and potential spread of schistosomiasis.

    PubMed

    Leite, M G P; Pimenta, E C; Fujaco, M A G; Eskinazi-Sant'Anna, E M

    2016-04-19

    This study analyzed the presence of Biomphalaria in Melo creek basin, Minas Gerais state, and its relationship to irrigation canals. Seventeen of these canals were used to determine a limnological, morphological and hydrological characterization during an annual seasonal cycle. Biomphalaria samples were sent to René Rachou Research Center/FIOCRUZ for identification and parasitological examination. Six canals were identified as breeding areas for mollusks and in one of them it was registered the coexistence of B. tenagophila (first report to this basin) and B. glabrata species. Results indicated that the low flow rate and speed of water flow were the main characteristics that contributed to this specific growth of the mollusks in the area. These hydraulic characteristics were created due to anthropogenic action through the canalization of lotic areas in Melo creek, which allowed ideal ecological conditions to Biomphalaria outbreak. The results emphasize the need of adequate handling and constant monitoring of the hydrographic basin, subject to inadequate phytosanitary conditions, aiming to prevent the occurrence and propagation of schistosomiasis. PMID:27097093

  7. Three new species of Ammonicera from the Eastern Pacific coast of North America, with redescriptions and comments on other species of Omalogyridae (Gastropoda, Heterobranchia).

    PubMed

    Sartori, André F; Bieler, Rüdiger

    2014-01-01

    The family Omalogyridae comprises some of the smallest known marine snails. Like all micromolluscs, they have been historically neglected and are underrepresented in faunistic surveys. Based on a few focused studies of the family, 15 valid omalogyrid species were previously recognised in the Indian and Pacific Oceans. To these, we add 3 new species based on a morphological analysis of material in the dry collection of the Natural History Museum of Los Angeles County, applying light and scanning electron microscopies. The new species, Ammonicera mcleani, A. mexicana and A. sleursi, are the first omalogyrid species described from the Eastern Pacific coast of North America. Redescriptions of the Australian omalogyrids Ammonicera sucina (Laseron, 1954) and Omalogyra liliputia (Laseron, 1954) are also presented, detailing for the first time ultrastructural aspects of their shell morphology. Additionally, we present here the first record of Ammonicera binodosa Sleurs, 1985b in Sri Lanka, introduce the new combination Ammonicera vangoethemi (Sleurs, 1985c) for Omalogyra vangoethemi, and formally remove Transomalogyra Palazzi & Gaglini, 1979 from Omalogyridae by fixing its type species as Homalogyra densicostata Jeffreys, 1884. Finally, we present lists, geographic records and a bibliography of all currently recognised omalogyrid species in the Indian, Pacific and Antarctic Oceans, as well as an update to a previously published compilation of the Atlantic and Mediterranean representatives of the family. PMID:25544067

  8. Long-term changes in Prosobranchia (Gastropoda) abundances on the German North Sea coast: the role of the anti-fouling biocide tributyltin

    NASA Astrophysics Data System (ADS)

    Nehring, S.

    2000-05-01

    Tributyltin (TBT) has been used as a biocide in marine anti-fouling paints since the early 1970s. Due to its strong ecotoxicity and the relatively high levels in the water column as well as in port sediments on the German North Sea coast, it probably has negative ecological effects on organisms other than those targeted. An analysis of the long-term development of prosobranch stocks in the inner German Bight reveals a decrease in abundance of many species. For most species the decline cannot be attributed to TBT, but in four prosobranch species ( Buccinum undatum, Hydrobia ulvae, Littorina littorea and Nucella lapillus) significant ecological effects by TBT pollution are very probable. Although research for alternative non-TBT anti-fouling paints (e.g. biocide-free types on the basis of silicone) has been intensified, the potential threats to ecosystems and the ecotoxicological profiles of these alternatives have to be carefully evaluated.

  9. Characterisation by X-ray microanalysis of metal granules in the mucus trails of Littorina littorea (Gastropoda) along a putative pollution gradient.

    PubMed

    Reboreda, R; Davies, Mark S

    2006-07-01

    Metal-containing granules in the mucus trails of the marine gastropod Littorina littorea from nine sites in north-east England were analysed for elemental composition by X-ray microanalysis and characterised relative to a putative gradient of pollution. Overall granule density varied significantly between sites, means of 6.5-17.0 per field of view (2688 microm2). Most granules found (64%) were poly-metal of a wide variety of compositions, but could be classified as Si+X, Mg+X, S+X, Na+X, P+Ca, P+Al, where X indicates any other combination of elements. Si+Al+X accounted for 61% of the poly-metal granules found and was considered to be contamination from the beach substratum. In single-metal granule form only Ca, Si, Fe, Ti, Al and Na were found. The most common single-metal granule at each site was of Ca, except at two sites, where the most common single-metal granule was of Si. The densities of these granule types varied between sites but differences were found to be significant only in the case of Si granules. Across all sites, single-metal granules of Si (mean = 2.49 microm +/- 1.44 SD, n = 141) and Ca (2.22 microm +/- 1.08 SD, n = 147) were significantly larger than granules of Fe (1.74 microm +/- 0.95 SD, n = 63) and Ti (1.24 microm +/- 0.52 SD, n = 18). The range of sizes was large: Ca (0.5-6 microm), Si (0.5-10 microm), Fe (0.3-4.1 microm), Ti (0.5-2.5 microm). Between the sites there were significant differences in the size of Fe and Si granules but not Ca or Ti granules. Despite these variations in granule type and size, there was no evidence of a relationship with pollution and consequently a detoxifying function of the mucus trail in metal polluted environments is not apparent. PMID:16622800

  10. The population genetic structure of Littorina littorea (Mollusca: Gastropoda) along a pollution gradient in the Scheldt estuary (The Netherlands) using RAPD analysis.

    PubMed

    De Wolf, Hans; Blust, Ronny; Backeljau, Thierry

    2004-06-01

    The population genetic structure of the periwinkle Littorina littorea was analysed using random amplified polymorphic DNA (RAPD). Three primers, coding for six putative polymorphic loci were surveyed to infer the genetic structure of seven populations located along the heavily polluted Western (i.e. in order of decreasing pollution load W1, W2, W3 and R1) and the relatively clean Eastern Scheldt (E1, E2 and E3) estuary (The Netherlands). A genetic distance based UPGMA (Unweighted pair group method with arithmetic mean) dendrogram revealed an estuary-related structuring, as Eastern and Western Scheldt sites formed two separate clusters. The Western Scheldt cluster was, however, much more heterogeneous, with three RAPD loci revealing a significant genetic heterogeneity compared to none when the Eastern Scheldt sites were compared. Overall mean heterozygosity levels were high, but did not reveal a difference between the estuaries. The current data (1) confirm the patterns of variation previously observed with electrophoretic analyses of esterases and (2) strongly support that these patterns of variation have a genetic basis, in the presence of intense gene flow. In addition, it is suggested that selection, rather than bottleneck effects, induced by the less favourable living conditions at W1, W2 and W3 are responsible for the genetic patterning. PMID:15144778

  11. Acute and chronic toxicity of the herbicide benzofenap (Taipan 300) to Chironomus tepperi Skuse (Diptera: Chironomidae) and Isidorella newcombi (Adams and Angas) (Gastropoda: Planorbidae).

    PubMed

    Wilson, A L; Stevens, M M; Watts, R J

    2000-02-01

    Acute and chronic toxicity tests were conducted on the herbicide benzofenap (Taipan 300) using two Australian freshwater invertebrates. The commercial formulation of benzofenap and a blank formulation containing only the adjuvants of Taipan 300 were tested against final instar larvae of the midge Chironomus tepperi and adults of the aquatic snail Isidorella newcombi. In 24-h acute bioassays the midge larvae did not show significant mortality at a nominal concentration of 1.2 mg/L active ingredient (AI), double the maximum notional concentration expected in rice fields after application of Taipan 300 at the permit rate of 2 L/ha. No significant snail mortality was recorded in acute bioassays (24-h exposure, 48-h recovery) at nominal concentrations up to 76 mg/L AI, which is over 120 times the maximum notional field concentration. In chronic assays, the pupation and emergence of C. tepperi was monitored after a 4-h pulse exposure of final instar larvae to Taipan 300 (nominal concentrations 0.001 to 0.1 mg/L AI) and adjuvant-only (0.1 mg/L equivalent) treatments. No statistically significant effects were observed, although emergence appeared to be delayed by higher benzofenap concentrations and by the adjuvant-only treatment. During snail bioassays, egg and feces production were monitored for 21 days after 24-h exposure to Taipan 300 (nominal concentrations 1.2 mg/L to 60 mg/L AI) and adjuvant-only treatments (60 mg/L equivalent). No significant chronic effects were proven against I. newcombi, despite a decline in egg mass production following exposure to all treatments and a reduction in the total numbers of eggs produced at the highest nominal concentrations tested (60 mg/L AI and adjuvant-only treatments). Similarly, feces production by snail pairs exposed to the majority of treatments declined, but these differences were not statistically significant. It is concluded that Taipan 300 does not represent a significant risk to mature C. tepperi larvae or adult I. newcombi in downstream environments when applied to rice fields at the permit rate of 2 L/ha. PMID:10629279

  12. Environmental Epidemiology of Intestinal Schistosomiasis in Uganda: Population Dynamics of Biomphalaria (Gastropoda: Planorbidae) in Lake Albert and Lake Victoria with Observations on Natural Infections with Digenetic Trematodes

    PubMed Central

    Rowel, Candia; Fred, Besigye; Sousa-Figueiredo, Jose C.; Kabatereine, Narcis B.; Stothard, J. Russell

    2015-01-01

    This study documented the population dynamics of Biomphalaria and associated natural infections with digenetic trematodes, along the shores of Lake Albert and Lake Victoria, recording local physicochemical factors. Over a two-and-a-half-year study period with monthly sampling, physicochemical factors were measured at 12 survey sites and all freshwater snails were collected. Retained Biomphalaria were subsequently monitored in laboratory aquaria for shedding trematode cercariae, which were classified as either human infective (Schistosoma mansoni) or nonhuman infective. The population dynamics of Biomphalaria differed by location and by lake and had positive relationship with pH (P < 0.001) in both lakes and negative relationship with conductivity (P = 0.04) in Lake Albert. Of the Biomphalaria collected in Lake Albert (N = 6,183), 8.9% were infected with digenetic trematodes of which 15.8% were shedding S. mansoni cercariae and 84.2% with nonhuman infective cercariae. In Lake Victoria, 2.1% of collected Biomphalaria  (N = 13,172) were infected with digenetic trematodes with 13.9% shedding S. mansoni cercariae, 85.7% shedding nonhuman infective cercariae, and 0.4% of infected snails shedding both types of cercariae. Upon morphological identification, species of Biomphalaria infected included B. sudanica, B. pfeifferi, and B. stanleyi in Lake Albert and B. sudanica, B. pfeifferi, and B. choanomphala in Lake Victoria. The study found the physicochemical factors that influenced Biomphalaria population and infections. The number and extent of snails shedding S. mansoni cercariae illustrate the high risk of transmission within these lake settings. For better control of this disease, greater effort should be placed on reducing environmental contamination by improvement of local water sanitation and hygiene. PMID:25705680

  13. Scanning electron microscopy and molecular characterization of a new Haplosporidium species (Haplosporidia), a parasite of the marine gastropod Siphonaria pectinata (Mollusca: Gastropoda: Siphonariidae) in the Gulf of Mexico.

    PubMed

    Vea, Isabelle M; Siddall, Mark E

    2011-12-01

    Based on scanning electron microscopy and the small subunit ribosomal RNA (SSU rRNA), Haplosporidium tuxtlensis n. sp. (Haplosporidia), a parasite found in the visceral tissues of the false limpet Siphonaria pectinata (Linnaeus, 1758), is described. The spores are ellipsoidal (3.61 ± 0.15 µm × 2.69 ± 0.19 µm), with a circular lid (2.94 ± 0.5 µm) representing the operculum. The spore wall bears filaments occurring singly, or in clusters, of 2 to 8, fusing distally. Phylogenetic relationships of H. tuxtlensis n. sp. were assessed with other described species using the SSU rRNA sequence. Haplosporidium tuxtlensis n. sp. is sister taxon to Haplosporidium pickfordi Barrow, 1961. The morphological characteristics (spore wall structure, shape, size, and filament structure) and the unique host identity corroborate it as a new species. Additionally, this is the first record of Haplosporidia infecting striped false limpets in the Gulf of Mexico. PMID:21787213

  14. Sclerochronology - a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, textit{Strombus gigas} (Gastropoda)

    NASA Astrophysics Data System (ADS)

    Radermacher, Pascal; Schöne, Bernd R.; Gischler, Eberhard; Oschmann, Wolfgang; Thébault, Julien; Fiebig, Jens

    2010-05-01

    The shell of the queen conch Strombus gigas provides a rapidly growing palaeoenvironmental proxy archive, allowing the detailed reconstruction of important life-history traits such as ontogeny, growth rate and growth seasonality. In this study, modern sclerochronological methods are used to cross-date the palaeotemperatures derived from the shell with local sea surface temperature (SST) records. The growth history of the shell suggests a bimodal seasonality in growth, with the growing season confined to the interval between April and November. In Glovers Reef, offshore Belize, the queen conch accreted shell carbonate at rates of up to 6 mm day-1 during the spring (April-June) and autumn (September-November). However a reduced period of growth occurred during the mid-summer months (July-August). The shell growth patterns indicate a positive response to annual seasonality with regards to precipitation. It seems likely that when precipitation levels are high, food availability is increased as the result of nutrient input to the ecosystem in correspondence with an increase in coastal runoff. Slow growth rates occur when precipitation, and as a consequence riverine runoff, is low. The SST however appears to influence growth only on a secondary level. Despite the bimodal growing season and the winter cessation in growth, the growth rates reconstructed here from two S. gigas shells are among the fastest yet reported for this species. The S. gigas specimens from Belize reached their final shell height (of 22.7 and 23.5 cm in distance between the apex and the siphonal notch) at the transition to adulthood in just 2 years. The extremely rapid growth as observed in this species permits detailed, high-resolution reconstructions of life-history traits where sub-daily resolutions can be achieved with ease. The potential for future studies has yet to be further explored. Queen conch sclerochronology provides an opportunity to recover extremely high-resolution palaeotemperature records, which could be used to improve numeric climate models, where the shells essentially function as mineralized buoys. The shell recorder may also help to reveal changes in biogeochemical dynamics in benthic ecosystems on intra-seasonal timescales in the fossil record. Furthermore, sclerochronology provides a rapid, effective and highly versatile investigative strategy when compared to time- and cost-consuming fieldwork for improving fisheries management and maricultural pursuits.

  15. Glowing Seashells: Diversity of Fossilized Coloration Patterns on Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells from the Neogene of the Dominican Republic

    PubMed Central

    Hendricks, Jonathan R.

    2015-01-01

    The biology of modern Conidae (cone snails)—which includes the hyperdiverse genus Conus—has been intensively studied, but the fossil record of the clade remains poorly understood, particularly within an evolutionary framework. Here, ultraviolet light is used to reveal and characterize the original shell coloration patterns of 28 species of cone snails from three Neogene coral reef-associated deposits from the Cibao Valley, northern Dominican Republic. These fossils come from the upper Miocene Cercado Fm. and lower Pliocene Gurabo Fm., and range in age from about 6.6-4.8 Ma. Comparison of the revealed coloration patterns with those of extant species allow the taxa to be assigned to three genera of cone snails (Profundiconus, Conasprella, and Conus) and at least nine subgenera. Thirteen members of these phylogenetically diverse reef faunas are described as new species. These include: Profundiconus? hennigi, Conasprella (Ximeniconus) ageri, Conus anningae, Conus lyelli, Conus (Atlanticonus?) franklinae, Conus (Stephanoconus) gouldi, Conus (Stephanoconus) bellacoensis, Conus (Ductoconus) cashi, Conus (Dauciconus) garrisoni, Conus (Dauciconus?) zambaensis, Conus (Spuriconus?) kaesleri, Conus (Spuriconus?) lombardii, and Conus (Lautoconus?) carlottae. Each of the three reef deposits contain a minimum of 14–16 cone snail species, levels of diversity that are similar to modern Indo-Pacific reef systems. Finally, most of the 28 species can be assigned to modern clades and thus have important implications for understanding the biogeographic and temporal histories of these clades in tropical America. PMID:25830769

  16. Evaluation of the mitochondrial system in the gonad-digestive gland complex of Biomphalaria glabrata (Mollusca, Gastropoda) after infection by Echinostoma paraensei (Trematoda, Echinostomatidae).

    PubMed

    Tunholi, Victor Menezes; Tunholi-Alves, Vinícius Menezes; Santos, Anderson Teixeira; Garcia, Juberlan da Silva; Maldonado, Arnaldo; da-Silva, Wagner Seixas; Rodrigues, Maria de Lurdes de Azevedo; Pinheiro, Jairo

    2016-05-01

    The effect of infection by Echinostoma paraensei on the mitochondrial physiology of Biomphalaria glabrata was investigated after exposure to 50 miracidia. The snails were dissected one, two, three and four weeks after infection for collection and mechanical permeabilization of the gonad-digestive gland (DGG) complex. The results obtained indicate that prepatent infection by this echinostomatid fluke significantly suppresses the phosphorylation state (respiratory state 3) and basal oxygen consumption of B. glabrata, demonstrating that the infection reduces the ability of the intermediate host to carry out aerobic oxidative reactions. Additionally, relevant variations related to the uncoupled mitochondrial (state 3u) of B. glabrata infected by E. paraensei were observed. Four weeks after exposure, a significant reduction in mitochondrial oxygen consumption after addition of ADP (3.68±0.26pmol O2/mg proteins) was observed in the infected snails in comparison with the respective control group (5.14±0.25). In the uncoupled state, the infected snails consumed about 62% less oxygen than the infected snails (7.87±0.84pmol O2/mg proteins) in the same period. These results demonstrate a reduction in oxidative decarboxylation rate of the tricarboxylic acid cycle and faster anaerobic degradation of carbohydrates in the infected snails. The possible mechanisms that explain this new metabolic condition in the infected organisms are discussed. PMID:27079167

  17. A new species of Tambja (Mollusca, Gastropoda, Nudibranchia) from the Mediterranean Sea: description of the first species of the genus from the Balearic Islands and Malta

    NASA Astrophysics Data System (ADS)

    Domínguez, M.; Pola, M.; Ramón, M.

    2015-06-01

    A new species of polycerid nudibranchs of the genus Tambja is described from Mallorca Island (Spain) and Malta. So far, only two species of Tambja had been recorded in the Mediterranean Sea with a distribution limited to southern Spain. With Tambja mediterranea sp. nov., the distribution of the genus in the Mediterranean Sea is extended, and the new species represents the first occurrence of Tambja at the Balearic Islands and Malta. Externally, the new species is mainly characterized by having ground orange-red colour, dorsum covered with rounded whitish tubercles, rhinophores red with whitish tips and three gill branches with orange-reddish rachis and whitish branches. In the present paper, external and internal features of T. mediterranea are described and compared with other species of the genus, especially with its most similar species, T. limaciformis. Additionally, phylogenetic analyses (Bayesian and maximum likelihood) based on mitochondrial sequences (COI) show that T. mediterranea sp. nov. is sister to T. divae and that both species cluster together with T. limaciformis and T. amakusana with the maximum support.

  18. Sub-seasonal oxygen and carbon isotope variations in shells of modern Radix sp. (Gastropoda) from the Tibetan Plateau: potential of a new archive for palaeoclimatic studies

    NASA Astrophysics Data System (ADS)

    Taft, Linda; Wiechert, Uwe; Riedel, Frank; Weynell, Marc; Zhang, Hucai

    2012-02-01

    Carbon and oxygen isotope ratios have been measured for nine aragonite shells of the gastropod genus Radix from the lake Bangda Co (30°29'N, 97°04'E, 4450 m a.s.l.) at the south-eastern edge and from two characteristic sites at the lake Kyaring Co (31°09'N, 88°17'E, 4650 m a.s.l.) on the central Tibetan Plateau. Radix shells were sampled for isotope ratio analysis with high spatial resolution along the ontogenetic spiral of growth providing the basis of isotope records with a sub-seasonal time-resolution. δ18O values of shells from Bangda Co are on average ˜-15.0‰ relative to PDB and the pattern exhibits a clear onset and progression of the summer monsoon precipitation indicated by a strong "amount effect". This pattern mirrors the precipitation pattern in the respective year and region as expected for a small (surface area ca 0.3 km2) and shallow (<5 m) lake or habitat with short water residence times and little evaporative 18O enrichment of the lake water. In contrast, δ18O values of Radix shells from Kyaring Co habitat A which is connected to the deep (several tens of metres) and big (surface area ca 660 km2) lake, average at ˜-13.0‰ consistent with a higher evaporation rate and longer water residence time. The latter is supported by more 18O enriched water in this habitat. The δ18O values of Radix shells from Kyaring Co habitat B are nearly as low as shells from Bangda Co due to the similar habitat characteristic but isotopic patterns of these shells exhibit a weaker "amount effect". In both lake systems δ13C values of the shells are coupled with oxygen isotopes because a large amount of isotopically light carbon is washed from mountain slopes into the lake during the rainy season. Although other processes influence the isotopic patterns, e.g. biological productivity (δ13C) or temperature (δ18O), these influences are minor compared with the monsoon signal or the effect of evaporation in the Radix shell records. The overall weaker amount effect in Radix shells from Kyaring Co habitat B compared with shells from Bangda Co are consistent with a current decreasing monsoon influence from the south-eastern edge towards the central Tibetan Plateau. Thus, fossil shells of the gastropod genus Radix are a valuable archive for reconstructing climatic and environmental changes on the Tibetan Plateau and provide information about former habitat sizes and depths.

  19. Phylogenetic analysis of euthyneuran gastropods from sea to land mainly based on comparative mitogenomic of four species of Onchidiidae (Mollusca: Gastropoda: Pulmonata).

    PubMed

    Sun, Bian Na; Wei, Luan Luan; Shen, He Ding; Wu, Hong Xi; Wang, Dong Feng

    2016-09-01

    We generated complete mitochondrial genome sequences data for 4 genera (Onchidium, Platevindex, Paraoncidium and Peronia) in Onchidiidae to construct a phylogenetic tree in conjunction with other 9 existing data among gastropods. The topology showed that the taxa clustered into two main groups of four species, one of which included Onchidium struma and the Platevindex mortoni, the other Paraoncidium reevesii and Peronia verruculata. The process in Pulmonata from sea to land in accordance with the evolution of respiratory organs from branchial gills to pulmonary cavity has been shown. This will also constitute a framework for phylogeny evolution analysis, systematic classfication of Onchidiidae and other euthyneurans (pulmonates and opisthobranchs). PMID:25648917

  20. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Royal Belgian Institute of Sciences, Brussels, with descriptions of two new species

    PubMed Central

    Breure, Abraham S.H.

    2011-01-01

    Abstract The type status is described of 57 taxa from the superfamily Orthalicoidea in the collection of the Brussels museum. Two new species are described: Stenostylus perturbatus sp. n., and Suniellus adriani sp. n. New lectotypes are designated for Bulimulus (Naesiotus) amastroides Ancey, 1887; Bulimulus blanfordianus Ancey, 1903; Bulimulus montivagus chacoensis Ancey, 1897; Bulimus coloratus Nyst, 1845; Plecochilus dalmasi Dautzenberg, 1900; Placostylus porphyrostomus elata Dautzenberg, 1923; Bulimulus ephippium Ancey, 1904; Bulimus fulminans Nyst, 1843; Bulimus funckii Nyst, 1843; Orphnus thompsoni lutea Cousin, 1887; Bulimus melanocheilus Nyst, 1845; Orphnus thompsoni nigricans Cousin, 1887; Orphnus thompsoni olivacea Cousin, 1887; Bulimulus pollonerae Ancey, 1897; Orphnus thompsoni zebra Cousin, 1887. New combinations are: Bostryx borellii (Ancey, 1897); Bostryx carandaitiensis (Preston, 1907); Protoglyptus mazei (Crosse, 1874); Kuschelenia (Vermiculatus) sanborni (Haas, 1947). New synonymies are established for the following nominal taxa: Orphnus thompsoni var. lutea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Orphnus thompsoni var. nigricans Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Thaumastus nystianus var. nigricans Cousin, 1887 = Drymaeus (Drymaeus) nystianus (Pfeiffer, 1853); Orphnus thompsoni var. olivacea Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845); Orphnus thompsoni var. zebra Cousin, 1887 = Kara thompsonii (Pfeiffer, 1845). PMID:21747669

  1. DNA sequence characterisation and phylogeography of Lymnaea cousini and related species, vectors of fascioliasis in northern Andean countries, with description of L. meridensis n. sp. (Gastropoda: Lymnaeidae)

    PubMed Central

    2011-01-01

    Background Livestock fascioliasis is a problem throughout Ecuador, Colombia and Venezuela, mainly in Andean areas where the disease also appears to affect humans. Transmission patterns and epidemiological scenarios of liver fluke infection have shown to differ according to the lymnaeid vector snail species involved. These Andean countries present the vectors Lymnaea cousini, L. bogotensis and L. ubaquensis, unknown in the rest of Latin America. An exhaustive combined haplotype study of these species is performed by means of DNA sequencing of the nuclear ribosomal 18S RNA gene, ITS-2 and ITS-1, and mitochondrial DNA cox1 gene. Results The conserved 5.8S rDNA sequence corroborated that no pseudogenes are involved in the numerous non-microsatellite/minisatellite-related indels appearing between the ITS-2 and ITS-1 sequences when comparing different L. cousini - L. bogotensis populations. Sequence analyses and phylogenetic reconstruction methods including other lymnaeid vector species show that (i) L. bogotensis is a synonym of L. cousini, (ii) L. ubaquensis is a synonym of Pseudosuccinea columella, and (iii) populations of L. cousini hitherto known from Venezuelan highlands indeed belong to a new species for which the name L. meridensis n. sp. is proposed. This new species is described and a complete phenotypic differentiation provided. Conclusions ITS-2, ITS-1 and cox1 prove to be good markers for specimen classification and haplotype characterisation of these morphologically similar lymnaeids in endemic areas. Analysis of the 18S gene and phylogenetic reconstructions indicate that L. cousini and L. meridensis n. sp. cluster in an evolutionary line different from the one of P. columella, despite their external resemblance. This suggests an evolutionary phenotypic convergence related to similar environments and which has given rise to frequent specimen misclassification. Body size and phylogenetic relationships of L. meridensis n. sp. with well-known vectors as Lymnaea cousini and P. columella, as well as with Galba/Fossaria species, suggest that the new species may participate in disease transmission to both animals and humans in altitude areas during the yearly window in which temperatures are higher than the F. hepatica minimum development threshold. The involvement of L. cousini and P. columella in the transmission and geographical/altitudinal distribution of fascioliasis in these Andean countries is analysed. PMID:21749718

  2. Hsp70 and lipid peroxide levels following heat stress in Xeropicta derbentina (Krynicki 1836) (Gastropoda, Pulmonata) with regard to different colour morphs.

    PubMed

    Dieterich, A; Troschinski, S; Schwarz, S; Di Lellis, M A; Henneberg, A; Fischbach, U; Ludwig, M; Gärtner, U; Triebskorn, R; Köhler, H-R

    2015-01-01

    Terrestrial snails which live under dry and hot conditions need efficient mechanisms of adaptation to counteract the problems of desiccation and over-heating. A profoundly heat tolerant snail species is the Mediterranean Xeropicta derbentina, exhibiting different shell colour morphs ranging from pale white to darkly banded. Considering that dark-pigmented snails are believed to have a disadvantage due to faster heating, we investigated possible differences in the stress markers Hsp70 and lipid peroxideation between four pre-defined colour morphs which were exposed to different temperatures for eight hours. The highest Hsp70 levels were observed in response to 38-40 °C. Levels decreased when this temperature was exceeded. Snails of a pre-defined colour category 3 (with a large black band at the umbilicus side of the shell) showed the most prominent Hsp70 response. Lipid peroxideation levels also showed a maximum at 38 °C but displayed a second peak at rather high temperatures at which the Hsp70 level already had decreased (45-48 °C). Particularly pure white snails (category 1) and the most pigmented ones (category 4) were found to have different levels of lipid peroxidation at 38 °C and 45 °C compared to the other morphs. A hypothesis involving a combined two-phase defence mechanism, to which both, the Hsp70 protection system and the antioxidant defence system, may contribute, is discussed. PMID:25108358

  3. Population genetics and identity of an introduced terrestrial slug: Arion subfuscus s.l. in the North-East USA (Gastropoda, Pulmonata, Arionidae).

    PubMed

    Pinceel, Jan; Jordaens, Kurt; Van Houtte, Natalie; Bernon, Gary; Backeljau, Thierry

    2005-11-01

    Several European species of the terrestrial slug genus Arion have been introduced into North America. A case in point is the species complex A. subfuscus s.l. which has become one of the most abundant slug taxa in North America. In Europe this complex consists of at least two cryptic species, viz. A. fuscus and A. subfuscus s.s., the latter of which is further subdivided in five strongly divergent mtDNA lineages (A. subfuscus S1-S5). In order to determine which of these A. subfsucus s.l. taxa are present in the NE USA and in order to assess their population genetic structure, we compared mtDNA, nDNA and allozyme variation between populations from the NE USA and Europe. Our results show that (1) at least A. subfuscus S1 has become successfully established in the NE USA, (2) founder effects are the most likely explanation for the loss of a large amount of molecular genetic variation in populations from the NE USA (i.e. a loss of 96% of the 16S rDNA haplotypes, 67% of the ITS1 alleles and 46% of the alleles at polymorphic allozyme loci), and (3) part of the remaining genetic variation in NE USA populations was probably due to multiple introductions from the British Isles and the European mainland, and the hybrid structure of most of these source populations. Apparently, the extreme loss of molecular genetic variation in this introduced species has not prevented it from successfully establishing and spreading in novel environments. PMID:16247689

  4. Phylogenetic analysis of Euthyneura (Gastropoda) by means of the 16S rRNA gene: use of a 'fast' gene for 'higher-level' phylogenies

    PubMed Central

    Thollesson, M.

    1999-01-01

    The phylogeny of Euthyneura is analysed by using DNA sequences of the mitochondrial 16S rRNA gene. Despite the common notion that this gene is too variable to provide useful information at high taxonomic levels, such as in the present study, bootstrap proportions are high for several clades in the study. This indicates that there is a useful amount of variation despite the noise due to multiple substitutions. The analyses furthermore indicate that (i) Gymnosomata (represented by Clione) is not a part of Euthyneura, but Clione forms a clade with the caenogastropods; (ii) Acteon is the sister group to the remaining euthyneuran taxa in the study; (iii) the nudibranch taxa form two clades, one comprising Dendronotoidea, Arminoidea and Aeolidoidea (together Cladobranchia) with Notaspidea (represented by Berthella) as sister group, while the fourth nudibranch taxon, Doridoidea, forms a separate clade; (iv) Cephalaspidea s.s. and Anaspidea form clades that are each other's sister groups (together Pleurocoela). Finally, there is no clade present in the analyses corresponding to the taxon Opisthobranchia in the traditional sense, and the use of this name is probably better abandoned altogether.

  5. Individual growth of Heleobia piscium in natural populations (Gastropoda: Cochliopidae) from the multiple use natural Reserve Isla Martin Garcia, Buenos Aires, Argentina.

    PubMed

    Martin, S M

    2008-08-01

    The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34 degrees 11' 25" S and 58 degrees 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied. PMID:18833484

  6. Calyptraeotheres sp. nov. (Crustacea: Decapoda: Pinnotheridae), symbiont of the slipper shell Crepidula striolata Menke, 1851 (Mollusca: Gastropoda: Calyptraeidae) from the Gulf of California, Mexico.

    PubMed

    Ayón-Parente, Manuel; Hendrickx, Michel E

    2014-01-01

    Calyptraeotheres camposi sp. nov. is described from the Gulf of California, Mexico. The new species is close to C. granti (Glassell, 1933) and C. pepeluisi Campos & Hernández-Ávila, 2010 from the Mexican Pacific and to C. hernandezi Hernández-Ávila & Campos 2006 from the Western Atlantic. These four species feature a third maxilliped with a 2-segmented endopod palp and the exopod with unsegmented flagellum. Calyptraeotheres camposi sp. nov. differs from C. granti and C. hernandezi by having the eyes visible in dorsal view, the carapace with arcuate anterolateral margins, the dorsal, longitudinal depressions connected with the transversal depression, and the propodus of pereiopod 2 equal or slightly longer than the carpus. From C. pepeluisi it is distinguished by the absence of a transversal depression on the carapace and the longitudinal depressions not connecting, the carpus and propodus of the third maxilliped being sub-trapezoidal and sub-conical, respectively, in lieu of subrectangular, and the inner surface of the fixed finger nude instead of bearing short setae near the cutting edge and ventral margin. PMID:25544074

  7. Rapana thomasiana grosse (gastropoda) haemocyanin: spectroscopic studies of the structure in solution and the conformational stability of the native protein and its structural subunits.

    PubMed

    Dolashka, P; Genov, N; Parvanova, K; Voelter, W; Geiger, M; Stoeva, S

    1996-04-01

    1. The stability towards pH changes, thermal and chemical (guanidine hydrochloride) denaturation of the oxy- and apo-forms of the native Rapana thomasiana haemocyanin and its structural subunits, RHSS1 and RHSS2, has been investigated using fluorescence and CD spectroscopy. The association of the subunits into haemocyanin aggregates increases considerably the melting temperature and the free energy of stabilization in water. The guanidine hydrochloride denaturation of the aggregated oxygen-transporting protein depends slightly on the protein concentration. The denaturation of the individual subunits is concentration-independent. Rapana haemocyanin is 5.9-7.5 kJ/mol more stable than the constituent polypeptide chains. 2. Upon excitation of the native haemocyanin and the subunits at 295 or 280 nm the fluorescence emission is determined by tryptophyl residues 'buried' deeply in the hydrophobic interior of the protein globules. This is confirmed by quenching experiments with acrylamide, caesium and iodide ions. The efficiency of the radiationless energy transfer between the phenol (donor) and indole (acceptor) fluorophores in the three species, native haemocyanin, RHSS1 and RHSS2, has been determined. An efficient 'interchain' energy transfer between tyrosyl and tryptophyl residues from different polypeptide chains occurs in the non-dissociated form of the haemocyanin. 3. The tryptophan emission of the oxyhaemocyanin, oxy-RHSS1 and oxy-RHSS 2 is strongly quenched by the copper-dioxygen complex at the active site and the respective quantum yields of fluorescence of the oxygenated species are 4-7 times lower than those of the apo-forms. Protonated imidazole groups quench the fluorescence of neighbouring exited indole rings, probably by charge-transfer complex formation. PMID:8670098

  8. A new Chinese species of Eostrobilops Pilsbry, 1927 with a checklist of Eostrobilops and Enteroplax Gude, 1897 species (Gastropoda, Pulmonata, Strobilopsidae)

    PubMed Central

    Páll-Gergely, Barna; Hunyadi, András; Asami, Takahiro

    2015-01-01

    Abstract Eostrobilops humicolus Páll-Gergely & Hunyadi, sp. n. is described from Guangxi Province, China. It is characterized by the combination of a small shell (diameter: 2.3–2.4 mm), strongly ribbed dorsal surface, an infraparietal lamella not reaching the callus, and long basal folds. The new species is found approximately 500 and 800 km from the two nearest species Eostrobilops infrequens (northern Vietnam), and Eostrobilops diodontina (Hunan, China), respectively. A checklist of extant Eostrobilops Pilsbry, 1927 and Enteroplax Gude, 1899 species is provided. Enteroplax yaeyamensis Habe & Chinen, 1974, Enteroplax kanjiokuboi Minato & Tada, 1992 and Enteroplax taiwanica Minato & Tada, 1992 are moved to the genus Eostrobilops because of the lack of an elevated parietal callus and a peripheral thread. A map showing all Eostrobilops records is provided. PMID:26167122

  9. A new species of Gudeodiscus Páll-Gergely, 2013 from China, with extraordinary conchological and anatomical features (Gastropoda, Pulmonata, Plectopylidae)

    PubMed Central

    Páll-Gergely, Barna; Asami, Takahiro

    2016-01-01

    Abstract A new species of the Plectopylidae, Gudeodiscus longiplica is described from northern Guangxi Province, southern China. The shell, anatomical and radular characters are figured and described. This new species is characterized by long plicae on its parietal shell wall, which have not been observed in any other Gudeodiscus species. In contrast, the long parietal plicae are characteristic for the genera Plectopylis and Chersaecia, which mainly inhabit Thailand and Myanmar. These two genera are, however, only distantly related to the new species, as other characters (anatomy, protoconch sculpture, parietal plicae) suggest. The male portion of the genital structure of the new species is characterized by two separate penial caeca with different lengths, but similar in outer and inner structure. The relevance of this anatomical character is discussed. Gudeodiscus longiplica sp. n. occurs sympatrically with Gudeodiscus soosi Páll-Gergely, 2013. The anatomy and radula characters of the latter species are also described and figured. PMID:27081330

  10. Fertilization causes a single Ca2+ increase that fully depends on Ca2+ influx in oocytes of limpets (Phylum Mollusca, Class Gastropoda).

    PubMed

    Deguchi, Ryusaku

    2007-04-15

    Mature limpet oocytes arrested at the first metaphase (MI) of meiosis are activated by the stimulation of fertilizing sperm. The aim of the present study was to clarify the spatiotemporal property and mechanism of intracellular Ca2+ increase in limpet oocytes, which is a prerequisite signal for initiation of development at fertilization. In all of the five limpet species tested, the initial Ca2+ rising phase just after fertilization took the form of a centripetal Ca2+ wave spreading from the whole cortex to the center (cortical flash), yielding a homogeneous Ca2+ elevation throughout the oocyte. The Ca2+ level remained high during the subsequent plateau phase lasting for several minutes and then returned nearly to the original value. No additional Ca2+ increase followed the plateau phase at least by the time of first cleavage. Both rising and plateau phases of Ca2+ increase at fertilization were inhibited by removal of external Ca2+, suggesting that continuous Ca2+ entry occurs throughout the Ca2+ increase. Injection of inositol 1,4,5-trisphosphate (IP3) was effective in generating a Ca2+ increase in mature limpet oocytes arrested at MI; however, their ability to show an IP3-induced Ca2+ increase was extremely low, as compared with other animals. Responsiveness to IP3 injection in immature oocytes arrested at the first prophase (PI) was similar to that in the mature oocytes, suggesting that the IP3-induced Ca2+ release system does not develop during the process of meiotic maturation in limpet oocytes. Caffeine, cyclic adenosine diphosphate ribose (cADPR), and nicotinic acid adenine dinucleotide phosphate (NAADP), the agents known to stimulate internal Ca2+ release mechanisms distinct from an IP3-dependent pathway, had no effect on intracellular Ca2+ changes in mature limpet oocytes. Labeling of the endoplasmic reticulum (ER) with DiI revealed that cortical ER clusters are only present in the localized region around meiotic chromosomes in mature oocytes. These data strongly suggest that Ca2+ release and its propagating mechanisms are undeveloped in limpet oocytes and that Ca2+ influx is the only Ca2+-mobilizing system available and functioning at fertilization. PMID:17292344

  11. Brokering at the boundary: A prospective science teacher engages students in inquiry

    NASA Astrophysics Data System (ADS)

    Meis Friedrichsen, Patricia; Munford, Danusa; Orgill, Marykay

    2006-05-01

    Using a theoretical perspective of communities of practice, this case study examines a prospective chemistry teacher's inquiry-based teaching during his practicum. Conrad was a former student of an inquiry-oriented science course, Inquiry Empowering Technologies (IET). The research questions were (a) How did Conrad translate the IET inquiry practices during his practicum?; (b) How did the mentor teacher shape Conrad's participation?; (c) In what ways did Conrad negotiate new meanings of inquiry as a result of his practicum? Interview transcripts were the primary data source. Conrad carried many of the IET inquiry practices into his practicum. He equated inquiry with the use of evidence and had students create evidence-based explanations for how soap works. He chose not to incorporate the tentative nature of science. Although traditional in his own teaching, the mentor teacher supported Conrad by allowing him to teach through inquiry and by removing time constraints. As a result of his practicum, Conrad negotiated new meanings of inquiry teaching and developed an expanded view of technology. Conrad believed that high school students needed guidance when engaging in inquiry and that the tentative nature of science does not transfer to secondary chemistry. Implications for theory and practice are given.

  12. Folklore and the College Selection Process Revisited

    ERIC Educational Resources Information Center

    Caruso, Pete

    2012-01-01

    This paper is a response to Clinton F. Conrad's article, "Beyond the Folklore." Conrad's strategy for assessing undergraduate quality echoes the sentiments espoused by many admission and college counseling professionals over the years at various workshops for students and families that focus on navigating the process. As transcendent as the…

  13. Skylab Dental Examination

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Skylab 2 Commander Charles Conrad is seen undergoing a dental examination by the Medical Officer, Joseph Kerwin in the Skylab Medical Facility. In the absence of an examination chair, Conrad simply rotated his body to an upside down position to facilitate the procedure.

  14. Context view from southwest corner of property showing the office ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Context view from southwest corner of property showing the office and warehouse building (right), outhouse (center), boiler house (left center), laboratory (left foreground), and bulk fuel tanks (right background). View east - Conrad Refining Company Oil Refinery, Montana Secondary Highway 219, 1.6 miles southwest of Interstate Highway 15, Conrad, Pondera County, MT

  15. Teachers Steer Their Own Learning: Colorado Middle School becomes a School to Watch

    ERIC Educational Resources Information Center

    Lauer, Diane; Matthews, Melissa

    2007-01-01

    Conrad Ball Middle School in Loveland, Colorado, earned a "School to Watch" Award in 2005 from the National Forum to Accelerate Middle-Grades Reform and was designated as high-performing by the state. However, in 2002, the school had its lowest test scores ever. Teachers at Conrad Ball received the news and determined they would turn things…

  16. Brokering at the Boundary: A Prospective Science Teacher Engages Students in Inquiry

    ERIC Educational Resources Information Center

    Friedrichsen, Patricia Meis; Munford, Danusa; Orgill, MaryKay

    2006-01-01

    Using a theoretical perspective of communities of practice, this case study examines a prospective chemistry teacher's inquiry-based teaching during his practicum. Conrad was a former student of an inquiry-oriented science course, "Inquiry Empowering Technologies" (IET). The research questions were (a) How did Conrad translate the IET inquiry…

  17. 76 FR 56607 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List 42 Great...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    ... States (August 18, 2009; 74 FR 41649); thus, these three species are not included in this finding. In the... from the phylum Mollusca, class Gastropoda, superorder Caenogastropoda (Bouchet and Rocroi 2005, pp....

  18. 50 CFR 665.421 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Tetradontidae. Blue corals Heliopora. Organpipe corals Tubipora. Ahermatypic corals Azooxanthellates. Sea cucumbers, Sea urchins (Those species not listed as CHCRT) Echinoderms.Mollusca. Sea snails Gastropoda. Turban shells Trochus spp. Sea slugs Opistobranchs. Black lipped pearl oyster Pinctada...

  19. 50 CFR 665.421 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Tetradontidae. Blue corals Heliopora. Organpipe corals Tubipora. Ahermatypic corals Azooxanthellates. Sea cucumbers, Sea urchins (Those species not listed as CHCRT) Echinoderms.Mollusca. Sea snails Gastropoda. Turban shells Trochus spp. Sea slugs Opistobranchs. Black lipped pearl oyster Pinctada...

  20. 50 CFR 665.421 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Tetradontidae. Blue corals Heliopora. Organpipe corals Tubipora. Ahermatypic corals Azooxanthellates. Sea cucumbers, Sea urchins (Those species not listed as CHCRT) Echinoderms.Mollusca. Sea snails Gastropoda. Turban shells Trochus spp. Sea slugs Opistobranchs. Black lipped pearl oyster Pinctada...

  1. Evapotranspiration of Mixed Shrub Communities in Phreatophytic Zones of the Great Basin D.A. Devitt1, L.K. Fenstermaker2, M. Young2, B. Conrad1 and B. Bird1 1 School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 2 Desert Research Institute, Las Vegas, NV

    NASA Astrophysics Data System (ADS)

    Devitt, D. A.; Fenstermaker, L. K.; Young, M.; Conrad, B.; Bird, B.

    2009-12-01

    Water limitations in the arid and semiarid regions of the southwestern United States have led many water managers of municipalities to begin the process of diversifying their water resource portfolios. Las Vegas in particular, is pursuing groundwater exportation from east central basins in Nevada. Estimating evapotranspiration (ET) is a critical component to closing hydrologic balances in these basins. As such, ET was estimated for three valleys in the Great Basin Region of Nevada (USA) during a three year period. ET estimates were made based on an energy balance approach using the eddy covariance method. ET estimates at the basin scale were made by developing empirical relationships between ET and remotely sensed spectral data (Landsat). Groundwater, soil moisture, rainfall and leaf level measurements were used to validate the differences in ET estimates based on site, year and basin. When the ET correlations were based on average NDVI values during the growing period and incorporated previously published values attained for the same valleys during the same time period, we could account for 97% of the variation in the ET estimate for the May 10 to September 5 growing period and 93% of the variation in the ET estimates based on measured or projected yearly ET totals. Variations in yearly ET estimates at the different shrub and grassland sites ranged from 20 to 50 cm during the two dry years (2006, 2007, not including the irrigated site). The amount of winter precipitation was shown to be a significant driving force in the physiological response of the plants and the yearly ET totals. In the case of White River Valley the ratio of winter precipitation to reference evapotranspiration declined from 79% to 11% over the 3 year monitoring period. Such changes led to a direct impact on leaf xylem water potential values of greasewood (Sarcobatus vermiculatus). During the two drier years (2006 and 2007) greasewood plants entered into the growing period with lower mid day levels of ψL reflecting the significant step down in the ratio of winter precipitation to reference evapotranspiration. ET rates in 2007 were highly correlated with the percent cover of greasewood at the monitoring sites (R2=0.96***), regardless of the depth to groundwater. In 2006 both sites which were monitored for an entire 12 month period, ET was shown to exceed precipitation by 55 to 60%. Although a certain amount of uncertainty must be attached to the basin level ET estimates, results suggested that all three basins had annual ET totals in the 150 to 300 million m3 range, with a significant decline from the wetter 2005 year to the drier 2007 year (30 to 47% decline).The utility of the equations generated in this study will need to be further tested over time to capture the intra and inter annual variability in ET at these sites and basins before long term hydrologic balances can be properly assessed.

  2. Off-shore to near-shore transects of ferromanganese crusts adjacent to the California margin Tracey A. Conrad1, James R. Hein2, Adina Paytan1 1University of California Santa Cruz, CA, 95064 (tconrad@ucsc.edu) 2USGS, Menlo Park, CA, 94025, USA (jhein@usgs.gov)

    NASA Astrophysics Data System (ADS)

    Conrad, T. A.; Hein, J. R.; Paytan, A.

    2012-12-01

    Marine ferromanganese (Fe-Mn) crusts growing on seamounts along the California Margin (CM) are influenced by terrestrial and biogenic input. These continental margin crusts have higher concentrations of Si, K, Fe, Na, Ag, Cr, B, and Ba than Fe-Mn crusts from the global open-ocean. Al is also higher but only relative to Pacific open-ocean crusts. These relative enrichments may reflect the high primary productivity near the CM caused by seasonal upwelling and high sediment transport to the region from river/eolian input and cliff erosion. Two transects with samples from five seamounts each are used to compare seaward changes. Transect A includes analyses of 66 bulk samples from Flint, Ben, and Little Joe seamounts, Patton Escarpment, and Northeast Bank. It spans ~400 km of seafloor heading ~58N and coming within ~220 km of the shoreline with samples collected at water depths ranging from 570-2925 m. Transect B includes analyses of 136 bulk samples from Adam, Hoss, San Marcos, San Juan, and Rodriguez seamounts at water depths ranging from 692-3880 m. This transect spans ~240 km heading ~10N and comes within ~75 km of the shoreline near the base of the continental slope. For both transects, mean water depth increases with mean longitude, and latitude is fairly constant varying by approximately 2 degree latitude for transect A and 1degree for B. Both transects show statistically significant trends at the 99% confidence level for element concentrations versus water depth. Concentrations of Fe, Ca, P, Co, and Pb increase as water depth decreases. For transect (A), Mn and Mg also follow this trend, as do Mo and Al for transect (B); Mn also shows this trend for transect (B) but at the 95% confidence level. For both transects, Cu and Zn show the opposite trend, with concentrations increasing in crusts with increasing water depth. For Transect (B), Ni and Al also show this trend. Si and K show no statistically significant trends for either transect. In open-ocean samples concentrations of Si generally increase in crusts with increasing water depth. The Si/Al ratio for the CM samples is 6.2 for transect (A) and 6.1 for (B). Global open-ocean crusts have a Si/Al ratio averaging about 4. This variation in CM crusts is due to input of biogenic Si; the ratio for terrestrial input would be much lower as concentrations of Al would be relatively higher. In global open-ocean samples Ca, Co, Mn, and P increase as water depth decreases while Cu and Fe increase as water depth increases. Element concentrations are influenced by the OMZ and by the chemical cycle of elements in the water column, including whether depth profiles are conservative, scavenged, or biologic. Element trends in CM Fe-Mn crusts can therefore be explained by high biological productivity, proximity to the OMZ, element profiles in the water column, and input of terrigenous debris.

  3. Multiple forms of octopine dehydrogenase in Strombus luhuanus (mollusca, gastropoda, strombidae): genetic basis of polymorphism, properties of the enzymes, and relationship between the octopine dehydrogenase phenotype and the accumulation of anaerobic end products during exercise.

    PubMed

    Baldwin, J; England, W R

    1982-10-01

    Octopine dehydrogenase (ODH) is electrophoretically polymorphic in the gastropod mollusk Strombus luhuanus. The frequencies of the six electrophoretic phenotypes in the Heron Island population, together with the molecular weight values of 38,000 obtained for each of the three forms of the enzyme, demonstrate that the monomeric enzyme is encoded by three codominant alleles at a single locus. The purified allozymes are indistinguishable in terms of Km values for substrates, product inhibition by octopine and NAD, pH optima, and substrate inhibition by pyruvate. No statistically significant correlations were found between the ODH phenotype and the maximum activities of ODH or alanopine dehydrogenase, the capacity for anaerobic muscle work, or the accumulation of octopine or strombine/alanopine during exercise. It would appear that the ODH allozymes may be functionally equivalent both in vitro and in vivo. PMID:7181845

  4. THERMAL LIMITS OF RED-RIMMED MELANIA MELANOIDES TUBERCUATA, (GASTROPODA: PROSOBRANCHIA: THIARIDAE): IMPLICATIONS FOR CONTROL AND DISTRIBUTION OF A SNAIL THAT VECTORS A GILL TREMATODE CAUSING SERIOUS INFECTIONS IN FISH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red-rimmed melania Melanoides tuberculata, an exotic aquatic snail of the family Thiaridae, is spreading across the southern United States and through geothermal waters in several midwestern and northwestern states. There is little specific information on the temperature tolerance of M. tubercu...

  5. A new species of Haliotis (Gastropoda) from São Tomé & Príncipe Islands, Gulf of Guinea, with comparisons to other Haliotis found in the Eastern Atlantic and Mediterranean.

    PubMed

    Owen, Buzz

    2014-01-01

    The Haliotidae from the Gulf of Guinea, West Africa are reviewed. The distribution of the mainland species Haliotis marmorata Linnaeus, 1758 is confirmed and compared to the insular species from the island nation of São Tomé and Príncipe which is described as Haliotis geigeri n. sp. Both species are illustrated and compared to the other known Haliotidae from the eastern Atlantic. PMID:25081762

  6. A snail in the long tail: a new Plekocheilus species collected by the ‘Comisión Científica del Pacífico’ (Mollusca, Gastropoda, Amphibulimidae)

    PubMed Central

    Breure, Abraham S. H.; Araujo, Rafael

    2015-01-01

    Abstract Among the historical collection gathered by the ‘Comisión Científica del Pacífico’ during 1862–1865, type material was found of one of the species described on the basis of the material collected shortly afterwards. Inspection of the types revealed that only one specimen may be considered as type material of Bulimus aristaceus Crosse, 1869; this specimen is now designated as the lectotype. The other specimens are described as a new species, Plekocheilus (Plekocheilus) cecepeus. PMID:26312021

  7. Revision of the dwarf cannibal snails (Nata s.l.) of southern Africa-Nata s.s. and Natella (Mollusca: Gastropoda: Rhytididae), with description of three new species.

    PubMed

    Herbert, David G; Moussalli, Adnan

    2016-01-01

    This paper represents the second part of our revisionary studies on the rhytidid fauna of southern Africa. The species discussed belong to the taxon Nata s.l. in which we recognise two genus-level lineages, Nata s.s. and Natella with six (three new) and one species respectively. We update the species-level taxonomy extensively in the light of new molecular and morphological data, and provide a comprehensive revision of all species, including keys. Detailed comparative morphological observations are provided for the distal reproductive tract, pulmonary cavity, mantle edge, radula and suprapedal gland. In addition, we present a summary of biological and ecological data including information on habitat preferences, feeding, prey items and mating behaviour. Although the two genera are well circumscribed in terms of both internal anatomy and molecular data, shell morphology is highly conserved, and species discrimination using shell characters alone is difficult. We have discovered three undescribed species within Nata and there is evidence that further research of a phylogeographic nature may uncover additional cryptic diversity. The geographic distributions of the species are discussed in relation to regional vegetation patterns and, as with the larger cannibal snail radiation, the Albany Thicket Biome emerges as a focus of endemism. Observations on the conservation status of all species are provided.New species: Nata aequiplicata sp. nov., Nata erugata sp. nov. and Nata watsoni sp. nov. Revised status: Natalina caffrula Melvill & Ponsonby, 1898 is transferred to the genus Nata and thought to be a synonym of Nata dumeticola (Benson, 1851). PMID:27394520

  8. Revision of three camaenid and one bradybaenid species (Gastropoda, Stylommatophora) from China based on morphological and molecular data, with description of a new bradybaenid subspecies from Inner Mongolia, China

    PubMed Central

    Wang, Pei; Xiao, Qiong; Zhou, Wei-Chuan; Hwang, Chung-Chi

    2014-01-01

    Abstract We have revised the taxonomy of three camaenid and one bradybaenid species from China and described one new subspecies of the genus Bradybaena (Family Bradybaenidae) from Inner Mongolia, China. The genitalia of three Satsuma (Family Camaenidae) species S. mellea stenozona (Moellendorff, 1884), S. meridionalis (Moellendorff, 1884), comb. n. and S. uncopila (Heude, 1882), comb. n. assigned to the genus Bradybaena previously,lack a dart sac and mucous glands. Moreover, the molecular phylogeny has revealed close relationships between the three species and the genus Satsuma. Two species, S. stenozona (Moellendorff, 1884) from Fuzhou and Ganesella citrina Zilch, 1940 from Wuyi Mountain, are considered as synonymous and should be a subspecies of S. mellea mellea (Pfeiffer, 1866) because of the morphological and molecular similarities. Meanwhile, the other two are placed in the genus Satsuma: S. meridionalis (Moellendorff, 1884), comb. n. and S. uncopila (Heude, 1882), comb. n. G. virgo Pilsbry, 1927 differs from species of the genera Ganesella and Satsuma not only in its shell, but also in anatomical characters, such as having a dart sac and mucous gland, and lacking a flagellum. Additionally, phylogenetic analyses highly support the sister relationship with other Bradybaena species. Thus, placement of G. virgo Pilsbry, 1927 in the genus Bradybaena issuggested. PMID:24493955

  9. Revision of three camaenid and one bradybaenid species (Gastropoda, Stylommatophora) from China based on morphological and molecular data, with description of a new bradybaenid subspecies from Inner Mongolia, China.

    PubMed

    Wang, Pei; Xiao, Qiong; Zhou, Wei-Chuan; Hwang, Chung-Chi

    2014-01-01

    We have revised the taxonomy of three camaenid and one bradybaenid species from China and described one new subspecies of the genus Bradybaena (Family Bradybaenidae) from Inner Mongolia, China. The genitalia of three Satsuma (Family Camaenidae) species S. mellea stenozona (Moellendorff, 1884), S. meridionalis (Moellendorff, 1884), comb. n. and S. uncopila (Heude, 1882), comb. n. assigned to the genus Bradybaena previously,lack a dart sac and mucous glands. Moreover, the molecular phylogeny has revealed close relationships between the three species and the genus Satsuma. Two species, S. stenozona (Moellendorff, 1884) from Fuzhou and Ganesella citrina Zilch, 1940 from Wuyi Mountain, are considered as synonymous and should be a subspecies of S. mellea mellea (Pfeiffer, 1866) because of the morphological and molecular similarities. Meanwhile, the other two are placed in the genus Satsuma: S. meridionalis (Moellendorff, 1884), comb. n. and S. uncopila (Heude, 1882), comb. n. G. virgo Pilsbry, 1927 differs from species of the genera Ganesella and Satsuma not only in its shell, but also in anatomical characters, such as having a dart sac and mucous gland, and lacking a flagellum. Additionally, phylogenetic analyses highly support the sister relationship with other Bradybaena species. Thus, placement of G. virgo Pilsbry, 1927 in the genus Bradybaena issuggested. PMID:24493955

  10. 8. Historic American Buildings Survey, Arthur W. Stewart, Photographer June ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Historic American Buildings Survey, Arthur W. Stewart, Photographer June 26, 1936 GENERAL VIEW AFTER 1919 STORM (SOUTHWEST ELEVATION). - Conrad Meuly House & Store, 210 Chaparral Street, Corpus Christi, Nueces County, TX

  11. 7. Historic American Buildings Survey, Arthur W. Stewart, Photographer June ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, Arthur W. Stewart, Photographer June 26, 1936 GENERAL VIEW PRIOR TO 1919 STORM (EAST ELEVATION). - Conrad Meuly House & Store, 210 Chaparral Street, Corpus Christi, Nueces County, TX

  12. Bean with Tools on the Ocean of Storms

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, Lunar Module pilot, pauses near a tool carrier during extravehicular activity (EVA) on the Moon's surface. Commander Charles Conrad Jr., who took the black and white photo, is reflected in Bean's helmet visor.

  13. Analysis of wind tunnel test results for a 9.39-per cent scale model of a VSTOL fighter/attack aircraft. Volume 3: Effects of configuration variations from baseline

    NASA Technical Reports Server (NTRS)

    Lummus, J. R.; Joyce, G. T.; Omalley, C. D.

    1980-01-01

    The aerodynamic characteristics of the components of the baseline E205 configuration is presented. Geometric variations from the baseline E205 configuration are also given including a matrix of conrad longitudinal locations and strake shapes.

  14. 27. Photocopy of original architect's drawing from Texas State Library ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Photocopy of original architect's drawing from Texas State Library Conrad Stremme, designer and delineator 1854 NORTH 'END ELEVATION' DETAIL OF SOUTH DOORWAY - Land Office, 108 East Eleventh Street, Austin, Travis County, TX

  15. TROPHIC TRANSFER OF CONTAMINANTS FROM ORGANISMS LIVING BY CHROMATED-COPPER-ARSENATE (CCA)-TREATED WOOD TO THEIR PREDATORS

    EPA Science Inventory

    Oysters, Crassostrea virginica (Gmelin), collected from a residential canal lined with wood treated with chromated copper arsenate (CCA) had elevated levels of the metals in their tissues. arnivorous snail, Thais haemastoma floridana (Conrad), fed the oysters gradually ate less t...

  16. Too Little too Soon: The Literature of Deaf Education in 17th-Century Britain (Part II).

    ERIC Educational Resources Information Center

    Hoolihan, Christopher

    1985-01-01

    The article describes the growth in literature on deaf education in 17th century Britain. Noted is the work of John Wallis, William Holder, George Dalgarno, Anton Deusing, and Johann Conrad Amman. (CL)

  17. New porcellioidean gastropods from early Devonian of Royal Creek area, Yukon Territory, Canada, with notes on their early phylogeny

    USGS Publications Warehouse

    Fryda, J.; Blodgett, R.B.; Lenz, A.C.; Manda, S.

    2008-01-01

    This paper presents a description of new gastropods belonging to the superfamily Porcellioidea (Vetigastropoda) from the richly diverse Lower Devonian gastropod fauna of the Road River Formation in the Royal Creek area, Yukon Territory. This fauna belongs to Western Canada Province of the Old World Realm. The Pragian species Porcellia (Porcellia) yukonensis n. sp. and Porcellia (Paraporcellia) sp. represent the oldest presently known members of subgenera Porcellia (Porcellia) and Porcellia (Paraporcellia). Their simple shell ornamentation fits well with an earlier described evolutionary trend in shell morphology of the Porcellinae. Late Pragian to early Emsian Perryconcha pulchra n. gen. and n. sp. is the first member of the Porcellioidea bearing a row of tremata on adult teleoconch whorls. The occurrence of this shell feature in the Porcellioidea is additional evidence that the evolution of the apertural slit was much more complicated than has been proposed in classical models of Paleozoic gastropod evolution. Copyright ?? 2008, The Paleontological Society.

  18. 78 FR 14503 - Amendment 4 to the Corals and Reef Associated Plants and Invertebrates Fishery Management Plan of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... 30, 2011 (76 FR 82414). The 2011 Caribbean ACL Amendment included Amendment 3 to the Coral FMP... Amendment 2 to the Queen Conch FMP and Amendment 5 to the Reef Fish FMP (2010 Caribbean ACL Amendment)(76 FR..., Christmas tree worm IV. Mollusks--Phylum Mollusca A. Gastropods--Class Gastropoda Family Elysiidae...

  19. Identification of Genes Related to Learning and Memory in the Brain Transcriptome of the Mollusc, "Hermissenda Crassicornis"

    ERIC Educational Resources Information Center

    Tamvacakis, Arianna N.; Senatore, Adriano; Katz, Paul S.

    2015-01-01

    The sea slug "Hermissenda crassicornis" (Mollusca, Gastropoda, Nudibranchia) has been studied extensively in associative learning paradigms. However, lack of genetic information previously hindered molecular-level investigations. Here, the "Hermissenda" brain transcriptome was sequenced and assembled de novo, producing 165,743…

  20. Neostusakia, a new name for preoccupied Stusakia Kment and Henry, 2008 (Hemiptera: Heteroptera: Berytidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A case of homonymy in the heteropteran family Berytidae is addressed. The genus Stusakia Kment and Henry, 2008 (Hemiptera) is preoccupied by Stusakia Frýda, 1998 (Mollusca: Gastropoda). As a consequence, the replacement name Neostusakia, new name, is proposed. In addition, the only two included s...

  1. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Antennariidae. pipefishes and seahorses Syngnathidae. namako, lole, wana sea cucumbers and sea urchins (Those... clams Other Bivalves. sea squirts Tunicates. sponges Porifera. tako, he`e octopi Cephalopods. sea snails Gastropoda. sea slugs Opistobranchs. Limu seaweed Algae. Live rock. segmented worms (Those species not...

  2. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Antennariidae. pipefishes and seahorses Syngnathidae. namako, lole, wana sea cucumbers and sea urchins (Those... clams Other Bivalves. sea squirts Tunicates. sponges Porifera. tako, he`e octopi Cephalopods. sea snails Gastropoda. sea slugs Opistobranchs. Limu seaweed Algae. Live rock. segmented worms (Those species not...

  3. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Antennariidae. pipefishes and seahorses Syngnathidae. namako, lole, wana sea cucumbers and sea urchins (Those... clams Other Bivalves. sea squirts Tunicates. sponges Porifera. tako, he`e octopi Cephalopods. sea snails Gastropoda. sea slugs Opistobranchs. Limu seaweed Algae. Live rock. segmented worms (Those species not...

  4. 50 CFR 665.221 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Antennariidae. pipefishes and seahorses Syngnathidae. namako, lole, wana sea cucumbers and sea urchins (Those... clams Other Bivalves. sea squirts Tunicates. sponges Porifera. tako, he`e octopi Cephalopods. sea snails Gastropoda. sea slugs Opistobranchs. Limu seaweed Algae. Live rock. segmented worms (Those species not...

  5. 50 CFR 665.121 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and soles Bothidae, Soleidae. moamoa trunkfishes Ostraciidae. fugafuga, tuitui, sava'e sea cucumbers and sea urchins Echinoderms. amu blue corals Heliopora. amu organpipe corals Tubipora. ahermatypic... species not listed as CHCRT) Zoanthinaria.Mollusca. sisi-sami sea snails Gastropoda. aliao, alili...

  6. 50 CFR 665.121 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and soles Bothidae, Soleidae. moamoa trunkfishes Ostraciidae. fugafuga, tuitui, sava'e sea cucumbers and sea urchins Echinoderms. amu blue corals Heliopora. amu organpipe corals Tubipora. ahermatypic... species not listed as CHCRT) Zoanthinaria.Mollusca. sisi-sami sea snails Gastropoda. aliao, alili...

  7. 50 CFR 665.121 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and soles Bothidae, Soleidae. moamoa trunkfishes Ostraciidae. fugafuga, tuitui, sava'e sea cucumbers and sea urchins Echinoderms. amu blue corals Heliopora. amu organpipe corals Tubipora. ahermatypic... species not listed as CHCRT) Zoanthinaria.Mollusca. sisi-sami sea snails Gastropoda. aliao, alili...

  8. Overland Flow Generation and Soil Hydraulic Properties in Two Catchments in Central Panama

    NASA Astrophysics Data System (ADS)

    Godsey, S.; Elsenbeer, H.; Stallard, R.

    2003-12-01

    Land management decisions in the Panama Canal watershed directly impact the hydrological functioning of the canal itself. Knowledge of the hydrological conditions in the forested portions of the watershed provides a baseline comparison for future land use changes. We chose to work on two streams on Barro Colorado Island that are representative of large regions of the watershed. These two streams respond differently to the same storm events: Conrad Trail Stream exhibits a fairly subdued and delayed response and Lutz Creek stream is flashier. In order to understand these differences, we investigated the soil saturated hydraulic conductivity (Ks) of the two catchments and studied the frequency of overland flow generation. The Ks measurements in dominant geologies in Lutz Creek as well as in Conrad Trail Stream are great enough at shallow depths (median Ks = 29.7, 65.6 and 38.3 mm/hr) that Hortonian overland flow is rare, but a marked decrease in Ks in Lutz Creek catchment at 30 cm (to 1.4 and 5.8 mm/hr) indicates that a perched water table leading to saturated overland flow is the likely runoff mechanism in Lutz Creek. In Conrad, Ks does not decrease as markedly with soil depth, and a perched water table would form at about 60 cm below the surface (median Ks = 0.7 mm/hr). Therefore, more water is able to infiltrate into the soil in Conrad Trail Stream and saturated overland flow is less common. Overland flow was generated much more frequently in Lutz Creek than in Conrad Trail Stream, with lower thresholds of storm magnitude, duration, antecedent wetness and intensity required to generate overland flow. We also quantified the importance of microtopographic features such as concentrated flow lines and the results have implications for experimental design at other field sites. The Lutz Creek and Conrad Trail stream information will provide a useful baseline for land management decisions.

  9. Skylab 2 prime crew suit up during prelaunch training activity

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Paul J. Weitz, prime crew pilot of the first manned Skylab mission, is suited up in bldg 5 at JSC during prelaunch training activity. He is assisted by Astronaut Charles Conrad Jr., prime crew commander. The man in the left background is wearing a face mask to insure that Conrad, Joseph Kerwin, and Weitz are not exposed to disease prior to launch (25399); Scientist-Astronaut Joseph P. Kerwin (on left), and Weitz assist each other in suiting up in bldg 5 at JSC during pre-launch training activity (25400).

  10. The National Women's Leadership Conference on Fitness. Proceedings. (Washington, D.C., April 6-7, 1984).

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    The principal addresses at this Women's Leadership Conference on Fitness were: (1) "Keynote Address" (C. Carson Conrad); (2) "Essential Nature of Fitness" (Lawrence E. Lamb); (3) "Effects of Exercise on Women from 20-50 Years Old" (Sharon Plowman); (4) "Fitness in Older Women" (Everett L. Smith); (5) "Female Musculo-Skeletal System" (Robert P.…

  11. Henry James: A Collection of Critical Essays. Twentieth Century Views Series.

    ERIC Educational Resources Information Center

    Edel, Leon, Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection includes essays by Leon Edel, Joseph Conrad, Max Beerbohm, Ezra Pound, Edith Wharton, Percy Lubbock, Virginia Woolf, T. S. Eliot, Van Wyck Brooks, Edmund Wilson, E. M. Forster, William Troy, Pelham Edgar, Stephen Spender, Graham Greene,…

  12. Romanian rocketry in the 16th century

    NASA Technical Reports Server (NTRS)

    Carafoli, E.; Nita, M.

    1977-01-01

    A medieval manuscript discovered recently in Sibiu, Rumania, is outlined. The manuscript contained important new information on the development and construction of powder rockets. Conrad Haas, the Chief of the Artillery Arsenal in Sibiu from 1529 to 1569, is the author whose work is primarily considered.

  13. Radiation in the universe

    NASA Technical Reports Server (NTRS)

    Stuhlinger, Ernst; Truemper, Joachim; Weisskopf, Martin

    1992-01-01

    When Wilhelm Conrad Roentgen discovered radiation one hundred years ago, it seemed that what was discovered was one of the rarest and most volatile members of the family of the basic modules of our natural world. Today cosmologists report that a substantial part of the universe's radiation energy consists of X-rays, which travel through cosmic space with the speed of light.

  14. Multifaceted Approach to Designing an Online Masters Program.

    ERIC Educational Resources Information Center

    McNeil, Sara G.; Chernish, William N.; DeFranco, Agnes L.

    At the Conrad N. Hilton College of Hotel and Restaurant Management at the University of Houston (Texas), the faculty and administrators made a conscious effort to take a broad, extensive approach to designing and implementing a fully online masters program. This approach was entered in a comprehensive needs assessment model and sought input from…

  15. Success of Breast Cancer Startup Challenge Inspires Second Challenge | Poster

    Cancer.gov

    By Thomas Stackhouse, Joseph Conrad, and Michele Newton, Contributing Writers, and Rosemarie Truman, Guest Writer Sixty-one teams have been accepted into, and are now competing in, the Neuro Startup Challenge, a new collaboration established by the National Institutes of Health (NIH) with The Center for Advancing Innovation (CAI) and Heritage Provider Network, Inc.

  16. Concordancing in L2 Writing Class: An Overview of Research and Issues

    ERIC Educational Resources Information Center

    Yoon, Choongil

    2011-01-01

    Direct corpus use by learners or learner concordancing has been hailed as one of the promising areas that can revolutionize L2 writing and language pedagogy as a whole ([Conrad, 2000] and [Hyland, 2003]). It has been discussed to promote data-driven learning (Johns, 1988), to provide authentic contexts in which linguistic items are used, and to…

  17. Two Views of Criminology and Criminal Justice: Definitions, Trends, and the Future.

    ERIC Educational Resources Information Center

    Conrad, John P.; Myren, Richard A.

    The question of whether criminology and criminal justice are distinct fields is addressed in two papers. Differences between criminology and criminal justice are delineated by emphasizing formal definitions of the field(s), occupational roles, contemporary educational trends, and future development. According to John P. Conrad, criminology is the…

  18. Testing the Engagement Theory of Program Quality in CACREP-Accredited Counselor Education Programs

    ERIC Educational Resources Information Center

    Warden, Shannon P.; Benshoff, James M.

    2012-01-01

    This study examined the engagement theory of program quality (Haworth & Conrad, 1997), which highlights positive student learning outcomes that result from stakeholder involvement in program evaluation within master's-level graduate programs. A total of 481 master's-level counseling students and 63 faculty members, representing 68 Council for…

  19. When Good Gifts Go Bad

    ERIC Educational Resources Information Center

    Strout, Erin

    2006-01-01

    Conrad Colbrandt gave Saint Mary's College of California a financial permission slip to dream big--a $112-million pledge to support new construction and endowments. From the time that Colbrandt made his pledge in 1997 until 2004, talk of new athletics facilities and classroom buildings became real architectural plans. However, all of those plans…

  20. Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education/L'Association Canadienne pour L'Etude de L'Education des Adultes (17th, Ontario, Canada, May 29-31, 1998).

    ERIC Educational Resources Information Center

    Taylor, Maurice, Ed.

    These proceedings on the theme, Adult Education Research: Shaping the Future, contain 52 papers. The papers are: "Virtual Adult Education" (W. Archer and D. Conrad); "Reversal Theory Approach to Adult Learning and Education" (M. Atleo); "Objectiver L'Action" (A. Balleux et al.); "Cultural Constructions of Literacy" (A. Blunt); "Prior Learning…

  1. Apollo 12 crewment briefed in preparation for water egress training

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The three crewmen of the Apollo 12 lunar landing mission are briefed aboard the NASA Motor Vessel Retriever in preparation for water egress training in the Gulf of Mexico. Left to right, are Astronauts Richard F. Gordon Jr., command module pilot; Charles Conrad Jr., commander; and Alan L. Bean, lunar module pilot. Two training personnel are in the background.

  2. Gemini 11 prime crew during water egress training in Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts Charles Conrad Jr. (left) and Richard F. Gordon Jr. (right), prime crew for Gemini 11 space flight, practice water egress procedures in the Gulf of Mexico. Static Article 5 was used in the training exercise. A Manned Spaceflight Center (MSC) swimmer is in the water assisting in the training.

  3. Art as science: scientific illustration, 1490-1670 in drawing, woodcut and copper plate.

    PubMed

    Pyle, C M

    2000-01-01

    Observation, depiction and description are active forces in the doing of science. Advances in observation and analysis come with advances in techniques of description and communication. In this article, these questions are related to the work of Leonardo da Vinci, 16th-century naturalists and artists like Conrad Gessner and Teodoro Ghisi, and 17th-century micrographers like Robert Hooke. PMID:10969482

  4. Cultivating Inquiry-Driven Learners: A College Education for the Twenty-First Century

    ERIC Educational Resources Information Center

    Conrad, Clifton; Dunek, Laura

    2012-01-01

    Inquiry-driven learners anticipate, embrace, and adapt to disruptive change. Clifton Conrad and Laura Dunek advance a transformative purpose of a college education. They invite stakeholders from across higher education to engage in vigorous dialogue about the aims of a college education--and how to realize those aims. Increasingly influenced by…

  5. The secret sharer as a guide to compassion.

    PubMed

    Young-Mason, J

    1991-01-01

    Joseph Conrad's novella demonstrates the ways in which over-identification with a stranger influences and clouds the critical judgment of a young professional. It provides rich material for discussion on the caution needed by young nurses to make decisions based on critical judgment and not personal feelings. PMID:1705323

  6. Research in Correctional Rehabilitation.

    ERIC Educational Resources Information Center

    Rehabilitation Services Administration (DHEW), Washington, DC.

    Forty-three leaders in corrections and rehabilitation participated in the seminar planned to provide an indication of the status of research in correctional rehabilitation. Papers include: (1) "Program Trends in Correctional Rehabilitation" by John P. Conrad, (2) "Federal Offenders Rahabilitation Program" by Percy B. Bell and Merlyn Mathews, (3)…

  7. Astronaut Alan Bean deploys ALSEP during first Apollo 12 EVA on moon

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, Apollo 12 lunar module pilot, deploys components of the Apollo Lunar Surface Experiments Package (ALSEP) during the first Apollo 12 extravehicular activity (EVA) on the moon. The photo was made by Astronaut Charles Conrad Jr., Apollo 12 commander, using a 70mm handheld Haselblad camera modified for lunar surface usage.

  8. Astronaut Alan Bean holds Special Environmental Sample Container

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 lunar landing mission, holds a Special Environmental Sample Container filled with lunar soil collected during the extravehicular activity (EVA) in which Astronauts Charles Conrad Jr., commander, and Bean participated. Connrad, who took this picture, is reflected in the helmet visor of the lunar module pilot.

  9. Astronaut Alan Bean steps from ladder of Lunar Module for EVA

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 lunar landing mission, steps from the ladder of the Lunar Module to join Astronaut Charles Conrad Jr., commander, in extravehicular activity on November 19, 1969. Astronaut Ricard F. Gordon Jr., command module pilot, remained with the Command/Service Modules in lunar orbit.

  10. Bean Samples The Ocean of Storms

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, Lunar Module pilot for the Apollo 12 lunar landing mission, holds a Special Environmental Sample Container filled with lunar soil collected during the extravehicular activity (EVA) in which Astronauts Charles Conrad Jr., commander, and Bean participated. Connrad, who took this picture, is reflected in the helmet visor of the Lunar Module pilot.

  11. Preparing Technicians for the Twenty-First Century in Agriculture, Agribusiness, and Natural Resources. Summary Report of a Conference (Columbus, Ohio, April 15-16, 1985).

    ERIC Educational Resources Information Center

    Mokma, Arnold L., Ed.; Barrick, Kirby, Ed.

    This report contains summaries of various portions of a conference dealing with preparing technicians for various agricultural occupations as well as the texts of several papers presented at the conference. The keynote address, "Technology for the 21st Century" by John A. Conrads, is presented together with the following reaction panel papers:…

  12. An Investigation of Language Teachers' Explorations of the Use of Corpus Tools in the English for Academic Purposes (EAP) Class

    ERIC Educational Resources Information Center

    Bunting, John David

    2013-01-01

    Despite claims that the use of corpus tools can have a major impact in language classrooms (e.g., Conrad, 2000, 2004; Davies, 2004; O'Keefe, McCarthy, & Carter, 2007; Sinclair, 2004b; Tsui, 2004), many language teachers express apparent apathy or even resistance towards adding corpus tools to their repertoire (Cortes, 2013b). This study…

  13. Milestones in the Secondary English Curriculum in the United States. ICTE Occasional Paper No. 11.

    ERIC Educational Resources Information Center

    Bleakley, Lou Ann

    Written for students pursuing graduate study, this chronological table lists landmark publications in the secondary English curriculum occurring between 1893 and 1971. For each of the 27 milestones--e.g., "Report of the Committee of Ten on Secondary School Studies" (1893), "Teaching Creative Writing" by Lawrence Conrad (1937), "The Uses of…

  14. "The Mirror of the Sea": Narrative Identity, Sea Kayak Adventuring and Implications for Outdoor Adventure Education

    ERIC Educational Resources Information Center

    Miles, Beau; Wattchow, Brian

    2015-01-01

    This paper explores the complex and changing nature of adventure as a form of cultural practice. Borrowing from Joseph Conrad's memoirs "The Mirror of The Sea" (1907), sea kayaking is contextualized here as a journey that takes place just as much between "landfall and departure" as it does between the paddler's ears (i.e., in…

  15. Religion on Campus.

    ERIC Educational Resources Information Center

    Cherry, Conrad; DeBerg, Betty A.; Porterfield, Amanda

    Case studies at four colleges explored students religious studies, values, and practices. Observations and interviews show that both the practice and the study of religion are thriving and supported by campus cultures. The chapters are: (1) Introduction; (2) West University (Betty A. Deberg); (3) South University (Conrad Cherry); (4) East…

  16. The Most Frequently Used English Phrasal Verbs in American and British English: A Multicorpus Examination

    ERIC Educational Resources Information Center

    Liu, Dilin

    2011-01-01

    This study uses the Corpus of Contemporary American English and the British National Corpus as data and Biber, Johansson, Leech, Conrad, and Finegan's (1999) and Gardner and Davies' (2007) informative studies as a starting point and reference. The study offers a cross-English variety and cross-register examination of the use of English phrasal…

  17. Lexical Bundle Analysis in Mathematics Classroom Discourse: The Significance of Stance

    ERIC Educational Resources Information Center

    Herbel-Eisenmann, Beth; Wagner, David; Cortes, Viviana

    2010-01-01

    In this article, we introduce the lexical bundle, defined by corpus linguists as a group of three or more words that frequently recur together, in a single group, in a particular register (Biber, Johansson, Leech, Conrad, & Finegan, 2006; Cortes, "English for Specific Purposes" 23:397-423, 2004). Attention to lexical bundles helps to explore…

  18. A Framework for Interaction and Cognitive Engagement in Connectivist Learning Contexts

    ERIC Educational Resources Information Center

    Wang, Zhijun; Chen, Li; Anderson, Terry

    2014-01-01

    Interaction has always been highly valued in education, especially in distance education (Moore, 1989; Anderson, 2003; Chen, 2004a; Woo & Reeves, 2007; Wang, 2013; Conrad, in press). It has been associated with motivation (Mahle, 2011; Wen-chi, et al., 2011), persistence (Tello, 2007; Joo, Lim, & Kim, 2011), deep learning (Offir, et al.,…

  19. MICA, 1972-73. Outcome Evaluation Report.

    ERIC Educational Resources Information Center

    Koch, Richard R.

    The Mathematics Inquiry in the Conrad Area (MICA) Project had as its general focus the installation of a variety of teaching approaches, with emphases on open-ended units. The purpose was to give teachers exposure to the diversity of possible approaches, to use and test the effectiveness of the methods, and to familiarize other teachers with the…

  20. Enlightenment and the "Heart of Darkness": (Neo)Imperialism in the Congo, and Elsewhere

    ERIC Educational Resources Information Center

    Stronach, Ian

    2006-01-01

    This article approaches the current state of qualitative inquiry by constructing an allegory of neo-imperialism. It is based substantively on a history and contemporary anthro-politics of the Congo and in particular the city of Kisangani; metaphorically on Conrad's unsettling deployment of that same place as "the heart of darkness"; and ironically…

  1. RESISTIVITY METHODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistivity methods were among the first geophysical techniques developed. The basic concept originated with Conrad Schlumberger, who conducted the initial resistivity field tests in Normandy, France during 1912. The resistivity method, employed in its earliest and most conventional form, uses an ex...

  2. Strengthening At-Risk and Homeless Young Mothers and Children

    ERIC Educational Resources Information Center

    Medeiros, Debra; Vaulton, Wendy

    2010-01-01

    The Strengthening At Risk and Homeless Young Mothers and Children Initiative, funded by the Conrad N. Hilton Foundation, aims to improve the housing, health, and development of homeless and at-risk young families. This article describes the services provided in four program sites (Pomona, CA; Antelope Valley, CA; Minneapolis, MN; and Chicago, IL)…

  3. DETERMINATION OF THE VENTILATION RATES OF INTERSTITIAL AND OVERLYING WATER BY THE CLAM MACOMA NASUTA

    EPA Science Inventory

    The ventilation rates of interstitial and overlying water for the deposit-feeding, tellinid clam Macoma nasuta (Conrad) were determined using two water-soluble dyes to differentiate between the two water sources. nique exposure chamber, the clambox, was used to separate the inhal...

  4. DIRECT MEASUREMENT TECHNIQUE FOR THE DETERMINING VENTILATION RATE IN THE DEPOSIT FEEDING CLAM, MACOMA NASUTA (BIVALVIA, TELLINACEAE)

    EPA Science Inventory

    An exposure chamber, the "clambox", was developed to measure ventilation rate, sediment processing rate, and efficiency of pollutant uptake byMacoma nasuta Conrad, a surface surface deposit-feeding clams. Clams, collected from Yaquina, Bay, Oregon, USA, were cemented into a hole ...

  5. Recherches en phonetique et en phonologie au Quebec (Research in Phonetics and Phonology in Quebec). Publication B-206.

    ERIC Educational Resources Information Center

    Dolbec, Jean, Ed.; Ouellet, Marise, Ed.

    The collection of essays on phonetics and phonology, entirely in French, includes: "Le calcul de la frequence intrinseque. Necessite du rapport a une ligne de reference" (calculation of intrinsic frequency; necessity of a line of reference) (Conrad Ouellon); "Caracteristiques microprosodiques de duree et d'intensite en lecture et en conversation…

  6. Mental Retardation 1970: Selected Papers from the 94th Annual Meeting of the American Association on Mental Deficiency (Washington, D.C., May, 1970).

    ERIC Educational Resources Information Center

    Gardner, James M., Ed.

    Research papers on behavior modification, presented at the 94th annual meeting of the American Association on Mental Deficiency, are cited in Volume 2 of a two part series. Presentations by James Gardner, Maurice Dayan, Luke Watson, Robert Wahler, and Robert Conrad are given. Volume 1 (EC 031 272) deals with theoretical papers and complements…

  7. The History of Molecular Structure Determination Viewed through the Nobel Prizes.

    ERIC Educational Resources Information Center

    Jensen, William P.; Palenik, Gus J.; Suh, Il-Hwan

    2003-01-01

    Discusses the importance of complex molecular structures. Emphasizes their individual significance through examination of the Nobel Prizes of the 20th century. Highlights prizes awarded to Conrad Rontgen, Francis H.C. Crick, James D. Watson, Maurice H.F. Wilkins, and others. (SOE)

  8. Shut Out

    ERIC Educational Resources Information Center

    Roach, Ronald

    2009-01-01

    As director of the Lawyering in the Digital Age Clinic at the Columbia University Law School, law professor Conrad Johnson knows that digital technology has the power to highlight and amplify social justice concerns and to enable people to take direct action. Under Johnson's leadership, the clinic has developed and maintained the Columbia-hosted…

  9. Hearing on Telecommunications Policy Reform. Hearing of the Committee on Commerce, Science, and Transportation. United States Senate, One Hundred Fourth Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Commerce, Science, and Transportation.

    This document presents witness testimony and supplemental materials from a Congressional hearing regarding reform to national telecommunications policy, namely, replacing a regime of heavy regulation with a true market system. Statements are featured by Senators John Ashcroft, Conrad Burns, Ernest Hollings, Kay Baily Hutchison, John D. Rockefeller…

  10. Dissection of two soybean QTL conferring partial resistance to Phytophthora sojae through sequence and gene expression analysis

    PubMed Central

    2012-01-01

    Background Phytophthora sojae is the primary pathogen of soybeans that are grown on poorly drained soils. Race-specific resistance to P. sojae in soybean is gene-for-gene, although in many areas of the US and worldwide there are populations that have adapted to the most commonly deployed resistance to P. sojae ( Rps) genes. Hence, this system has received increased attention towards identifying mechanisms and molecular markers associated with partial resistance to this pathogen. Several quantitative trait loci (QTL) have been identified in the soybean cultivar ‘Conrad’ that contributes to the expression of partial resistance to multiple P. sojae isolates. Results In this study, two of the Conrad QTL on chromosome 19 were dissected through sequence and expression analysis of genes in both resistant (Conrad) and susceptible (‘Sloan’) genotypes. There were 1025 single nucleotide polymorphisms (SNPs) in 87 of 153 genes sequenced from Conrad and Sloan. There were 304 SNPs in 54 genes sequenced from Conrad compared to those from both Sloan and Williams 82, of which 11 genes had SNPs unique to Conrad. Eleven of 19 genes in these regions analyzed with qRT-PCR had significant differences in fold change of transcript abundance in response to infection with P. sojae in lines with QTL haplotype from the resistant parent compared to those with the susceptible parent haplotype. From these, 8 of the 11 genes had SNPs in the upstream, untranslated region, exon, intron, and/or downstream region. These 11 candidate genes encode proteins potentially involved in signal transduction, hormone-mediated pathways, plant cell structural modification, ubiquitination, and basal resistance. Conclusions These findings may indicate a complex defense network with multiple mechanisms underlying these two soybean QTL conferring resistance to P. sojae. SNP markers derived from these candidate genes can contribute to fine mapping of QTL and marker assisted breeding for resistance to P. sojae

  11. [Functional-ecological and age-specific regularities in radionuclide concentration in freshwater molluscs from the Chernobyl Atomic Energy Station exclusion zone].

    PubMed

    Gudkov, D I; Derevets, V V; Kuz'menko, M I; Nazarov, A B

    2001-01-01

    The results of the studies on 90Sr and 137Cs content in the tissues of bivalve and gastropod mollusks of water basins in the exclusion zone of the Chernobyl NPP have been analyzed. The dependence of radionuclide accumulation factors on the peculiarities of morphological structure, functional ecology and nutrition type was found. The age dynamics of 137Cs content in some species of Gastropoda was studied. PMID:11458648

  12. UV Light Reveals the Diversity of Jurassic Shell Colour Patterns: Examples from the Cordebugle Lagerstätte (Calvados, France)

    PubMed Central

    Caze, Bruno; Merle, Didier; Schneider, Simon

    2015-01-01

    Viewed under UV light the diverse and exceptionally well-preserved molluscs from the Late Jurassic Cordebugle Konservat Lagerstätte (Calvados, Normandy, France) reveal fluorescent fossil shell colour patterns predating the oldest previously known instance of such patterns by 100 Myr. Evidently, residual colour patterns are observable in Mesozoic molluscs by application of this non-destructive method, provided the shells are not decalcified or recrystallized. Among 46 species which are assigned to twelve gastropod families and eight bivalve families, no less than 25 species yielded positive results. Out of nine colour pattern morphologies that have been distinguished six occur in gastropods and three in bivalves. The presence of these variant morphologies clearly indicates a significant pre-Cenozoic diversification of colour patterns, especially in gastropods. In addition, the occurrence of two distinct types of fluorescence highlights a major difference in the chemical composition of the pigments involved in colour pattern formation in gastropods. This discovery enables us to discriminate members of higher clades, i.e. the Vetigastropoda emitting red fluorescence from the Caenogastropoda and Heterobranchia emitting whitish-beige to yellow fluorescence. Consequently, fluorescent colour patterns may help to allocate part of the numerous enigmatic Mesozoic gastropod taxa to their correct systematic position. PMID:26039592

  13. Phylogenomic analyses of deep gastropod relationships reject Orthogastropoda

    PubMed Central

    Zapata, Felipe; Wilson, Nerida G.; Howison, Mark; Andrade, Sónia C. S.; Jörger, Katharina M.; Schrödl, Michael; Goetz, Freya E.; Giribet, Gonzalo; Dunn, Casey W.

    2014-01-01

    Gastropods are a highly diverse clade of molluscs that includes many familiar animals, such as limpets, snails, slugs and sea slugs. It is one of the most abundant groups of animals in the sea and the only molluscan lineage that has successfully colonized land. Yet the relationships among and within its constituent clades have remained in flux for over a century of morphological, anatomical and molecular study. Here, we re-evaluate gastropod phylogenetic relationships by collecting new transcriptome data for 40 species and analysing them in combination with publicly available genomes and transcriptomes. Our datasets include all five main gastropod clades: Patellogastropoda, Vetigastropoda, Neritimorpha, Caenogastropoda and Heterobranchia. We use two different methods to assign orthology, subsample each of these matrices into three increasingly dense subsets, and analyse all six of these supermatrices with two different models of molecular evolution. All 12 analyses yield the same unrooted network connecting the five major gastropod lineages. This reduces deep gastropod phylogeny to three alternative rooting hypotheses. These results reject the prevalent hypothesis of gastropod phylogeny, Orthogastropoda. Our dated tree is congruent with a possible end-Permian recovery of some gastropod clades, namely Caenogastropoda and some Heterobranchia subclades. PMID:25232139

  14. Mobile Element Evolution Playing Jigsaw—SINEs in Gastropod and Bivalve Mollusks

    PubMed Central

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc—snail and SCoica—mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain—Snail—is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5′ end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves—extending the distribution range of this superfamily. PMID:26739168

  15. Mobile Element Evolution Playing Jigsaw - SINEs in Gastropod and Bivalve Mollusks.

    PubMed

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc-snail and SCoica-mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain-Snail-is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5' end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves-extending the distribution range of this superfamily. PMID:26739168

  16. New gastropods from deep-sea hydrocarbon seeps off West Africa

    NASA Astrophysics Data System (ADS)

    Warén, Anders; Bouchet, Philippe

    2009-12-01

    Thirteen new species of gastropods are described from the Zairov 1-2 and Biozaire 1-3 cruises to the methane seeps off the Congo River: Patellogastropoda: Paralepetopsis sasakii sp. nov. (Neolepetopsidae); Cocculiniformia: Pyropelta oluae sp. nov. and P. sibuetae sp. nov. (Pyropeltidae); Tentaoculus granulatus sp. nov. (Pseudococculinidae); Neomphalina: Leptogyra costellata sp. nov. (Family uncertain); Vetigastropoda: Puncturella similis sp. nov. (Fissurellidae); Lepetodrilus shannonae sp. nov. (Lepetodrilidae); Caenogastropoda: Provanna reticulata sp. nov. and P. chevalieri sp. nov., Cordesia provannoides gen. et sp. nov. (Provannidae); Phymorhynchus coseli sp. nov. and P. cingulata sp. nov. (Conidae); Heterobranchia: Hyalogyrina rissoella sp. nov. (Hyalogyrinidae). All species except T. granulatus (from a settlement trap) belong to groups known from cold seeps and the entire seep fauna here is new to science. Biogeographical affinity of this gastropod fauna is to the West Atlantic seeps, not to the Mediterranean seeps or Mid-Atlantic vents. Fragments of the autecology of the species are presented. The evolution of the seep gastropod fauna is briefly discussed and a continuous immigration of taxa is supported. The oldest verified occurrences of modern taxa in the seeps date back to Cenomanian (Cretaceous) time, while some taxa seem not to appear until very late Tertiary.

  17. The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities.

    PubMed

    Bilski, P; Blomgren, J; d'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2007-01-01

    The European Commission is funding within its Sixth Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organisational framework for this project is provided by the European Radiation Dosimetry Group EURADOS. One task within the CONRAD project, Work Package 6 (WP6), was to provide a report outlining research needs and research activities within Europe to develop new and improved methods and techniques for the characterisation of complex radiation fields at workplaces around high-energy accelerators, but also at the next generation of thermonuclear fusion facilities. The paper provides an overview of the report, which will be available as CERN Yellow Report. PMID:17496292

  18. Evaluation of the calibration procedure of active personal dosemeters for interventional radiology.

    PubMed

    Bordy, J-M; Daures, J; Clairand, I; Denozière, M; Donadille, L; d'Errico, F; Gouriou, J; Itié, C; Struelens, L

    2008-01-01

    An overview of the use of active personal dosemeters (APD) in interventional radiology is presented. It is based on the work done by the working package 7 of the CONRAD coordinated action supported by the EC within the frame of the 6th FP. This study was done in collaboration with the working package 4 of CONRAD to deal with the calculations required for studying the new calibration facility. The main requirements of the standard for the APD and the difficulties caused by the use of pulsed radiations are presented through the results of an intercomparison organised in a realistic calibration facility similar to the workplace situation in interventional radiology. The main characteristics of this facility are presented. PMID:18757898

  19. Skylab 2 astronauts eat space food in wardroom of Skylab trainer

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The three members of the prime crew of the first manned Skylab mission dine on specially prepared Skylab space food in the wardromm of the crew quarters of the Skylab Orbital Workshop (OWS) trainer during Skylab training at the Johnson Space Center. They are, left to right, Scientist-Astronaut Joseph P. Kerwin, science pilot; Astronaut Paul J. Weitz, pilot; and Astronaut Charles Conrad Jr., commander.

  20. Astronaut Paul Weitz gets physical examination from Astronaut Joseph Kerwin

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Paul J. Weitz, Skylab 2 pilot, gets a physical examination by a fellow crewman during the 28-day Skylab 2 mission. Scientist-Astronaut Joseph P. Kerwin, Skylab 2 science pilot and a doctor of medicine, uses a stethoscope to check the Weitz's heartbeat. They are in the Orbital Workshop crew quarters of the Skylab 1 and 2 space station in Earth orbit. This photograph was taken by Charles Conrad Jr., Skylab 2 commander.

  1. Physicists and Physics in Munich

    NASA Astrophysics Data System (ADS)

    Teichmann, Jürgen; Eckert, Michael; Wolff, Stefan

    We give a tour of Munich and some outlying sites that focuses on the lives and work of the most prominent physicists who lived in the city, Count Rumford, Joseph Fraunhofer, Georg Simon Ohm, Max Planck, Ludwig Boltzmann, Albert Einstein, Wilhelm Conrad Röntgen, Wilhelm Wien, Arnold Sommerfeld, Max von Laue, and Werner Heisenberg. We close with a self-guided tour that describes how to reach these sites in Munich.

  2. Study on neutron scattering in light water

    NASA Astrophysics Data System (ADS)

    Scotta, Juan Pablo; Marquez Damian, Ignacio; Noguere, Gilles; Bernard, David

    2016-03-01

    It is presented a method to produce covariance matrices of the light water total cross section from thermal scattering laws of the JEFF-3.1.1 nuclear data library and CAB model. The generalized least square method was used to fit the LEAPR module parameters of the processing tool NJOY with light water experimental transmission measurements at 293.6K with CONRAD code. The marginalization technique was applied to account for systematic uncertainties.

  3. Apollo 9 backup crew participate in water egress training

    NASA Technical Reports Server (NTRS)

    1968-01-01

    The backup crew of the Apollo 9 (Spacecraft 104/Lunar Module 3/Saturn 504) space mission stands on the deck of the NASA Motor Vessel Retriever prior to participating in water egress training in the Gulf of Mexico. Left to right, are Astronauts Charels Conrad Jr. (holding hatch), RIchard F. Gordon Jr., and Alan L. Bean. They are standing by the Apollo command module trainer which was used in the exercise.

  4. Astronaut Alan Bean assisted with egressing command module after landing

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, lunar module pilot, is assisted with egressing the Apollo 12 Command Module by a U.S. Navy underwater demolition team swimmer during recovery operations in the Pacific Ocean. Already in the life raft are Astronauts Charles Conrad Jr., commander; and Richard F. Gordon Jr., command module pilot. The Apollo 12 splashdown occured at 2:58 p.m., November 24, 1969 near American Samoa.

  5. Success of Breast Cancer Startup Challenge Inspires Second Challenge | Poster

    Cancer.gov

    By Thomas Stackhouse, Joseph Conrad, and Michele Newton, Contributing Writers, and Rosemarie Truman, Guest Writer Sixty-one teams have been accepted into, and are now competing in, the Neuro Startup Challenge, a new collaboration established by the National Institutes of Health (NIH) with The Center for Advancing Innovation (CAI) and Heritage Provider Network, Inc.

  6. Skylab 2 crew during 'open house' press day at Manned Spacecraft Center (MSC)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    These three men are the crewmen for the first manned Skylab mission. They are astronaut Charles Conrad Jr., commander, standing left; scientist-astronaut Joseph P. Kerwin, seated; and Astronaut Paul J. Weitz, pilot. They were photographed and interviewed during an 'open house' press day in the realistic atmosphere of the Multiple Docking Adapter (MDA) trainer in the Mission Simulation and Training Facility at the Manned Spacecraft Center (MSC). The control and display panel for the Apollo Telescope Mount (ATM) is at right.

  7. The unionid (Bivalvia) fauna of the Sipsey River in northwestern Alabama, an aquatic hotspot

    USGS Publications Warehouse

    McCullagh, W.H.; Williams, J.D.; McGregor, S.W.; Pierson, J.M.; Lydeard, C.

    2002-01-01

    Recent surveys for unionid bivalves were conducted in the mainstem of the Sipsey River and headwater tributaries (Tombigbee River drainage) during the summer and autumn of 1996-1999. A total of 35 species and 22 genera were found. Museum records from the upper Sipsey, based largely on the efforts of H. H. Smith during 1910-11, raised the total number of recorded unionids in the Sipsey to 42. Smith documented 25 species in the river; however, most of his collections were made in the mid- to upper-Sipsey, which has lower diversity. The three most common recently observed species in descending order of abundance were Quadrula asperata (I. Lea, 1861), Pleurobema decisum (I. Lea, 1831), and Tritogonia verrucosa (Rafinesque, 1820). Federally listed species observed recently include Lampsilis perovalis (Conrad, 1834) (threatened), Medionidus acutissimus (I. Lea, 1831) (threatened), P. decisum (endangered), P. perovatum (Conrad, 1834) (endangered), and Potamilus inflatus (I. Lea, 1831) (threatened). Species not observed recently but recorded in prior surveys include Anodontoides radiatus (Conrad, 1834), Arcidens confragosus (Say, 1829), Plectomerus dombeyanus (Valenciennes, 1827), Q. metanevra (Rafinesque, 1820), Q. stapes (I. Lea, 1831) (federally endangered), P. taitianum (I. Lea, 1834) (federally endangered), and Toxolasma parvus (Barnes, 1823). Many, species are known recently or historically by only five or fewer recorded specimens including: A. radiatus, Elliptio arctata (Conrad, 1834), Ligumia recta (Lamarck, 1819), P. taitianum, P. inflatus, Q. aspera (Lea, 1831), Q. metanevra, Q. stapes, T. parvus, Truncilla donaciformis (I. Lea, 1828), Uniomerus tetralasmus (Say, 1831), Utterbackia imbecillis (Say, 1829), A. confragosus, and P. dombeyanus. Unlike the mussel fauna of most Alabama streams, that of the Sipsey River is still relatively intact in terms of species richness despite impacts from mining, silvicultural, and agricultural activities. A concerted effort

  8. Astronaut Joseph Kerwin during EVA at Skylab 1 and 2 space station cluster

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Scientist-Astronaut Joseph P. Kerwin, Skylab 2 science pilot, performs extravehicular activity (EVA) at the Skylab 1 and 2 space station cluster in Earth orbit, as seen in this reproduction taken from a color television transmission made by a TV camera aboard the station. Kerwin is just outside the Airlock Module. Kerwin assisted Astronaut Charles Conrad Jr., Skylab 2 commander, during the successful EVA attempt to free the stuck solar array system wing on the Orbital Workshop.

  9. Seismometer reading from impact made by Lunar Module ascent stage

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The seismometer reading from the impact made by the Lunar Module ascent stage when it struck the lunar surface. The impact was registered by the Passive Seismic Experiment Package (PSEP) which was deployed on the Moon by the Apollo 12 astronauts. The Lunar module's ascent stage was jettisoned and sent toward impact on the Moon after Astronauts Charles Conrad Jr. and Alan L. Bean returned to lunar orbit and rejoined Astronaut Richard F. Gordon Jr., in the Command/Service Modules.

  10. Inertial confinement fusion reactor cavity analysis: Progress report for the period 1 July 1986 to 30 June 1987

    SciTech Connect

    Peterson, R.R.; MacFarlane, J.J.; Moses, G.A.; El-Afify, M.; Corradini, M.L.

    1987-07-01

    This is a process report for research performed from July 1, 1986 to June 30, 1987, for Lawrence Livermore National Laboratory under subcontract number 9265205 with the project title: Inertial Confinement Fusion Reactor Cavity Analysis. This research generally considers the problems of vaporization and condensation of liquid metal or solid first surface materials in high yield ICF facilities such as reactors or high yield target test experiments. The past year's research consisted of 1.2 man years of effort on three tasks. These tasks were: verify the current vaporization-condensation models in CONRAD through literature surveys of relevant published data, and evaluation and comparison of these data with predictions by CONRAD on condensation phenomena, and with predictions by CONRAD, ZPINCH, and/or MIXERG on radiation phenomena, design a small-scale vaporization experiment by evaluating existing experimental facilities, selecting a primary facility, and conceptually designing an experiment complete with facility parameters and measurables, and design a small-scale condensation experiment including experimental parameters, measurables, and diagnostics. 48 refs.

  11. A surface-associated activity trap for capturing water surface and aquatic invertebrates in wetlands

    USGS Publications Warehouse

    Hanson, M.A.; Roy, C.C.; Euliss, N.H., Jr.; Zimmer, K.D.; Riggs, M.R.; Butler, Malcolm G.

    2000-01-01

    We developed a surface-associated activity trap (SAT) for sampling aquatic invertebrates in wetlands. We compared performance of this trap with that of a conventional activity trap (AT) based on non-detection rates and relative abundance estimates for 13 taxa of common wetland invertebrates and for taxon richness using data from experiments in constructed wetlands. Taxon-specific non-detection rates for ATs generally exceeded those of SATs, and largest improvements using SATs were for Chironomidae and Gastropoda. SATs were efficient at capturing cladocera, Chironomidae, Gastropoda, total Crustacea, and multiple taxa (taxon richness) but were only slightly better than ATs at capturing Dytiscidae. Temporal differences in capture rates were observed only for cladocera, Chironomidae, Dytiscidae, and total Crustacea, with capture efficiencies of SATs usually decreasing from mid-June through mid-July for these taxa. We believe that SATs may be useful for characterizing wetland invertebrate communities and for developing improved measures of prey available to foraging waterfowl and other aquatic birds.

  12. A surface-associated activity trap for capturing water-surface and aquatic invertebrates in wetlands

    USGS Publications Warehouse

    Hanson, M.A.; Roy, C.C.; Euliss, N.H., Jr.; Zimmer, K.D.; Riggs, M.R.; Butler, Malcolm G.

    2000-01-01

    We developed a surface-associated activity trap (SAT) for sampling aquatic invertebrates in wetlands. We compared performance of this trap with that of a conventional activity trap (AT) based on non-detection rates and relative abundance estimates for 13 taxa of common wetland invertebrates and for taxon richness using data from experiments in constructed wetlands. Taxon-specific non-detection rates for ATs generally exceeded those of SATs, and largest improvements using SATs were for Chironomidae and Gastropoda. SATs were efficient at capturing cladocera, Chironomidae, Gastropoda, total Crustacea, and multiple taxa (taxon richness) but were only slightly better than ATs at capturing Dytiscidae. Temporal differences in capture rates were observed only for cladocera, Chironomidae, Dytiscidae, and total Crustacea, with capture efficiencies of SATs usually decreasing from mid-June through mid-July for these taxa. We believe that SATs may be useful for characterizing wetland invertebrate communities and for developing improved measures of prey available to foraging waterfowl and other aquatic birds.

  13. Changes in the bottom fauna of western Lake Erie from 1930 to 1961

    USGS Publications Warehouse

    Carr, John F.; Hiltunen, Jarl K.

    1965-01-01

    Samples were collected at 40 stations in western Lake Erie in 1961 to determine the species composition, distribution, and abundance of macrobenthonic organisms and to document changes since 1930, when a similar survey was made. The fauna in 1961 was composed principally of Oligochaeta, Tendipedidae (7 genera), Sphaeriidae (15 species), and Gastropoda (at least 8 species). Stations with a high density of Oligochaeta were near the principal sources of pollution (Maumee, Raisin, and Detroit rivers). Stations with fewer Oligochaeta and a more diverse fauna were farthest from the river mouths. The population density of the burrowing mayfly, Hexagenia spp., was reduced from an average of 139/m2 in 1930 to less than 1/m2 in 1961. Organisms more abundant near the sources of pollution than in other areas were, in addition to Oligochaeta: the midge, Procladius; the fingernail clam, Sphaerium transversum; and the snail, Valvata sincera (sens. lat.). Organisms sensitive to pollution, such as amphipods, mayfly nymphs, caddisfly larvae, and naiad clams, were scarce and usually at the more lakeward stations. The most important changes in fauna during the 31-year period were: ninefold increase in Oligochaeta; fourfold increase in Tendipedidae; twofold increase in Sphaeriidae; sixfold increase in Gastropoda; and a reduction of Hexagenia to less than 1% of former abundance. The area of pollution (as judged from the abundance of Oligochaeta) increased from 263 km2 in 1930 to 1,020 km2 in 1961.

  14. Observations and modeling of the crustal structure and Moho strength variation along the Lesser Antilles Arc

    NASA Astrophysics Data System (ADS)

    Schlaphorst, D.; Kendall, J. M.; Blundy, J. D.; Melekhova, E.; Baptie, B.; Latchman, J. L.; Bouin, M. P.; Tait, S.

    2014-12-01

    Subduction processes influence the crustal structure in their vicinity. The Mohorovičić discontinuity (Moho), separating the crust from the mantle, can be influenced both in its depth and strength. Normally it is stronger than any crustal discontinuity, but a change in subducted material can weaken the Moho. We are investigating the change in crustal structure along the Lesser Antilles Arc using three component broadband stations on various islands along the arc. This arc is formed by the slow subduction (~2cm/yr) of the North and South American plates beneath the Caribbean plate. We are using receiver functions and H-κ stacking to constrain the depth (H) of the strongest discontinuity and the average crustal P-to-S wave velocity ratio (κ) to that depth. The ratio constrains the subsurface material. Results in this field of study can easily be ground-truthed with the composition of materials found in samples from the same area to find uniform patterns. Our results show significant depth variations of the discontinuity. Some of our results match the depth of an inter-crustal boundary (Conrad) found in a previous study (Boynton, 1979, GJRAS). This suggests a comparably weak Moho in these areas, a theory that is supported by models based on petrological results. We compare our results to synthetic data from inversion models that determine the depth location of the Conrad and the Moho. For this purpose we use a combined method of different inversion approaches and include petrological constraints. Where we previously see agreement between the depth of the Conrad in Boynton's study and the H-κ stacking, the models now confirm this result.

  15. Overland flow generation in two lithologically distinct rainforest catchments

    USGS Publications Warehouse

    Godsey, S.; Elsenbeer, H.; Stallard, R.

    2004-01-01

    Streams on uniformly rainforest-covered, but lithologically very diverse Barro Colorado Island in central Panama?? show remarkable differences in their runoff response to rainfall. This lithological diversity is reflected in equally diverse soilscapes, and our objective was to test the hypothesis that contrasting runoff responses derive from soilscape features that control the generation of overland flow. We determined the soil saturated hydraulic conductivity (Ks) of two neighboring, but hydrologically contrasting catchments (Lutz Creek with a flashy and Conrad Trail with a delayed response to rainfall), and quantified the spatial and temporal frequency of overland flow occurrence. The median Ks values at a depth of 12.5 cm are large enough to rule out Hortonian overland flow, but a marked decrease in K s in Lutz Creek catchment at 30 cm suggests the formation of a perched water table and the generation saturation overland flow; the decrease in Ks in the Conrad Trail catchment is more gradual, and a perched water table is expected to form only at depths below 50 cm. In Lutz Creek, overland flow was generated frequently in time and space and regardless of topographic position, including near the interfluve, with very low thresholds of storm magnitude, duration, intensity and antecedent wetness, whereas in Conrad Trail, overland flow was generated much less frequently and then only locally. We conclude that soilscape features and microtopography are important controls of overland flow generation in these catchments. Our results contribute to the growing evidence that overland flow and forests are not a priori a contradiction in terms. ?? 2004 Elsevier B.V. All rights reserved.

  16. Decision making software for site remediation

    SciTech Connect

    Kulik, C.; Aroeste, H.

    1995-12-31

    Choosing the appropriate technologies to remediate a contaminated site can be a problem. AccOn Services, a joint venture of Accord Services, Inc. (Henry Aroeste, Pres., software development) and ANCON International (Conrad Kulik) are developing a computer program capable of determining whether the Simplified Clean Soil Process being commercially demonstrated in 1995 is the appropriate technology for remediating a particular site. Dr. Aroeste (Ph.D., physical chemistry) has, over the past 15 years, applied his innovation of GIST (Guided Inquiry System Technique) for acquiring and processing information in an easily comprehensible framework at NASA, EPRI and elsewhere. This program has been adapted to the field of environmental remediation.

  17. The roles of retinoic acid and retinoic acid receptors in inducing epigenetic changes.

    PubMed

    Urvalek, Alison; Laursen, Kristian Bruun; Gudas, Lorraine J

    2014-01-01

    Epigenetics is "the branch of biology which studies the causal interactions between genes and their products which bring the phenotype into being" as defined by Conrad Waddington in 1942 in a discussion of the mechanisms of cell differentiation. More than seven decades later we know that these mechanisms include histone tail post-translational modifications, DNA methylation, ATP-dependent chromatin remodeling, and non-coding RNA pathways. Epigenetic modifications are powerful drugs targets, and combined targeting of multiple pathways is expected to significantly advance cancer therapy. PMID:24962884

  18. Waddington's widget: Hsp90 and the inheritance of acquired characters.

    PubMed

    Ruden, Douglas M; Garfinkel, Mark D; Sollars, Vincent E; Lu, Xiangyi

    2003-10-01

    Conrad Waddington published an influential model for evolution in his 1942 paper, Canalization of Development and Inheritance of Acquired Characters. In this classic, albeit controversial, paper, he proposed that an unknown mechanism exists that conceals phenotypic variation until the organism is stressed. Recent studies have proposed that the highly conserved chaperone Hsp90 could function as a "capacitor," or an "adaptively inducible canalizer," that masks silent phenotypic variation of either genetic or epigenetic origin. This review will discuss evidence for, and arguments against, the role of Hsp90 as a capacitor for morphological evolution, and as a key component of what we call "Waddington's widget." PMID:14986860

  19. Plasticity in the Adult: How Should the Waddington Diagram Be Applied to Regenerating Tissues?

    PubMed

    Rajagopal, Jayaraj; Stanger, Ben Z

    2016-01-25

    Conrad Waddington's eponymous 1957 diagram provided a metaphorical framework for considering how sequential developmental fate decisions allow an egg to develop into an embryo. In recent years, the Waddington diagram has been repurposed to illustrate how cellular identity changes in the context of reprogramming. In this Perspective, we revisit the Waddington diagram in light of the emerging recognition that plasticity is part and parcel of adult regeneration. Specifically, we speculate that the "epigenetic landscapes" that define identity in adult tissues are dynamic, facilitating cellular de-differentiation and trans-differentiation in the setting of injury. PMID:26812013

  20. NOAA Budget Increases to $4.1 Billion, But Some Key Items Are Reduced

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-02-01

    The Bush administration has proposed a US$4.1 billion budget for fiscal year (FY) 2009 for the U.S. National Oceanic and Atmospheric Administration (NOAA). The proposed budget, which would be the agency's largest ever, is $202.6 million, or 5.2%, above the FY 2008 enacted budget. By topping $4 billion and the amount Congress passed for FY 2008, the budget proposal crosses into ``a new threshold,'' according Navy Vice Admiral Conrad Lautenbacher, undersecretary of commerce for oceans and atmosphere and NOAA administrator.

  1. Behavior Analysis in the Era of Medicalization: The State of the Science and Recommendations for Practitioners

    PubMed Central

    2009-01-01

    Recent decades have witnessed an increase in biological explanations of common disorders such as depression and anxiety, a phenonmenon termed “medicalization” (Conrad, 2007). Behavior analysts may find it difficult to implement non-drug treatment with a populace that has become inundated with biological explanations and a preference for medication as the treatment of choice. Research frequently cited in support of medicalization includes studies of drug effectiveness, as well as family studies and studies of brain structure and function. Methodological and interpretation difficulties within those bodies of research are described and recommendations are made so that behavioral practitioners may function optimally within the culture of biological causation. PMID:22477707

  2. Chemistry Data for Geothermometry Mapping of Deep Hydrothermal Reservoirs in Southeastern Idaho

    DOE Data Explorer

    Earl Mattson

    2016-01-18

    This dataset includes chemistry of geothermal water samples of the Eastern Snake River Plain and surrounding area. The samples included in this dataset were collected during the springs and summers of 2014 and 2015. All chemical analysis of the samples were conducted in the Analytical Laboratory at the Center of Advanced Energy Studies in Idaho Falls, Idaho. This data set supersedes #425 submission and is the final submission for AOP 3.1.2.1 for INL. Isotopic data collected by Mark Conrad will be submitted in a separate file.

  3. Nutrition and food concerns of long-term space travel: recommendations for research.

    PubMed

    Sherman, A R; Vodovotz, Y

    1999-01-01

    In order to establish a research agenda for nutrition and food concerns associated with long-duration space travel, a conference was sponsored by the New Jersey-NASA Specialized Center of Research & Training (NJ-NSCORT), NASA, and the University of Houston Conrad N. Hilton College of Hotel & Restaurant Management. Invited papers were presented and are published in this special issue. Following intensive panel discussions and workshops the participants developed recommendations for a research agenda. The recommendations are listed in this introductory article. PMID:11541536

  4. CONRAD—A software framework for cone-beam imaging in radiology

    SciTech Connect

    Maier, Andreas; Choi, Jang-Hwan; Riess, Christian; Keil, Andreas; Fahrig, Rebecca; Hofmann, Hannes G.; Berger, Martin; Fischer, Peter; Schwemmer, Chris; Wu, Haibo; Müller, Kerstin; Hornegger, Joachim

    2013-11-15

    Purpose: In the community of x-ray imaging, there is a multitude of tools and applications that are used in scientific practice. Many of these tools are proprietary and can only be used within a certain lab. Often the same algorithm is implemented multiple times by different groups in order to enable comparison. In an effort to tackle this problem, the authors created CONRAD, a software framework that provides many of the tools that are required to simulate basic processes in x-ray imaging and perform image reconstruction with consideration of nonlinear physical effects.Methods: CONRAD is a Java-based state-of-the-art software platform with extensive documentation. It is based on platform-independent technologies. Special libraries offer access to hardware acceleration such as OpenCL. There is an easy-to-use interface for parallel processing. The software package includes different simulation tools that are able to generate up to 4D projection and volume data and respective vector motion fields. Well known reconstruction algorithms such as FBP, DBP, and ART are included. All algorithms in the package are referenced to a scientific source.Results: A total of 13 different phantoms and 30 processing steps have already been integrated into the platform at the time of writing. The platform comprises 74.000 nonblank lines of code out of which 19% are used for documentation. The software package is available for download at http://conrad.stanford.edu. To demonstrate the use of the package, the authors reconstructed images from two different scanners, a table top system and a clinical C-arm system. Runtimes were evaluated using the RabbitCT platform and demonstrate state-of-the-art runtimes with 2.5 s for the 256 problem size and 12.4 s for the 512 problem size.Conclusions: As a common software framework, CONRAD enables the medical physics community to share algorithms and develop new ideas. In particular this offers new opportunities for scientific collaboration and

  5. APOLLO 12: A heartstopping launch

    NASA Technical Reports Server (NTRS)

    1974-01-01

    APOLLO 12: A heartstopping launch as the rocket is struck by lightning. From the film documentary 'APOLLO 12: 'Pinpoint for Science'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLLO 12: Second manned lunar landing and return with Charles 'Pete' Conrad, Jr., Richard F. Gordon, and Alan F. Bean. Landed in the Ocean of Storms on November 19, 1969; deployed television camera and ALSEP experiments; two EVA's performed; collected core samples and lunar materials; photographed and retrieved parts from surveyor 3 spacecraft. Mission duration 244hrs 36min 24sec

  6. VARIFORC: a powerful FORC analysis tool specially suited to environmental magnetic applications

    NASA Astrophysics Data System (ADS)

    Egli, Ramon

    2015-04-01

    VARIFORC is a new tool for the analysis of first-order reversal curves (FORC), especially developed for the highly demanding applications typically occurring in environmental magnetism (e.g. quantitative magnetic component unmixing in weak samples). The currently unique capabilities of VARIFORC are illustrated with examples where the magnetic signature of authigenic minerals (e.g. magnetofossils) is isolated from other magnetic contributions associated with detrital or aeolian inputs in pelagic carbonates. Life demonstrations at the poster stand are possible. VARIFORC is freely available at http://www.conrad-observatory.at/cmsjoomla/de/download.

  7. [Latin American malacology. Freshwater mollusks from Argentina].

    PubMed

    Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A

    2008-03-01

    A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country

  8. Effects of Silver and Other Metals on the Cytoskeleton

    NASA Technical Reports Server (NTRS)

    Conrad, Gary W.

    1997-01-01

    Directly or indirectly, trace concentrations of silver ion (Ag(+)) stabilize microtubules (Conrad, A.H., et al. Cell Motil. & Cytoskel. 27:117-132), as does taxol (Conrad, A.H., et al. J. Exp. Zool. 262:154-165), an effect with major consequences for cellular shape changes and development. Polymerization of microtubules is gravity-sensitive (Tabony and Job, Proc. Natl. Acad. Sci. USA 89:6948-6952), so trace amounts of Ag(+) may alter cellular ability to respond to gravity. If Ag electrolysis is used to purify water on NASA space vehicles, plants and animals/astronauts will be exposed continuously to Ag(+), a regimen with unknown cellular and developmental consequences. Fertilized eggs of the marine mudsnail, Ilyanassa obsoleta, are the cells in which the effects of A(+) on microtubules were discovered. They distribute visible cytoplasmic contents according to gravity and contain cytoplasmic morphogenetic determinants for heart development. The objectives are to determine if the effects of Ag(+), AU(3+), (of biosensor relevance), or Gd(3+) (inhibitor of some stretch-activated ion channels) on the cytoskeleton (in the presence and absence of mechanical loading) will affect cellular responses to gravity.

  9. View Nine of Lunar Panoramic Scene

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The second manned lunar landing mission, Apollo 12, launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. This is the ninth of 25 images captured by the crew in attempt to provide a 360 degree Lunar surface scene. Apollo 12 safely returned to Earth on November 24, 1969.

  10. The effects of artificially impounded water on tide gauge measurements of sea level over the last century

    NASA Astrophysics Data System (ADS)

    Haberling, S.; Zhang, Y.; Rothacher, M.; Geiger, A.; Clinton, J. F.

    2011-12-01

    Tide gauge measurements spanning the last century reveal global scale and regionally varying changes in sea level. These changes are comprised of signals from a number of natural and anthropogenically forced processes, including ongoing glacial isostatic adjustment, mass flux from polar ice sheets and glaciers, thermosteric effects, and variability in patterns of ocean circulation. We present a new analysis of sea-level changes arising from the impoundment over the last century of more than 6,100 km3 of water (plus estimates of seepage into surrounding soils) in ~6,800 reservoirs around the globe (Chao et al., Science, 2008; Fiedler & Conrad, Geophys. Res. Lett., 2010). In particular, we extend the analysis of Fiedler & Conrad (2010) by adopting a database that includes an additional ~30% of water impoundment. Our calculations are based on a gravitationally self-consistent theory that incorporates the full suite of gravitational, rotational and (elastic) deformational effects on sea level (Kendall et al., Geophys. J. Int., 2005). The signal associated with impoundment at each reservoir is characterized by a sea level fall that is ~30% higher than the globally averaged (eustatic) value of the impoundment. In contrast, in the near field, sea level rises in response to both deformational and gravitational effects with an amplitude that is roughly an order of magnitude greater than the eustatic amplitude. We present global maps of the total sea-level change associated with the reservoirs, and report on an effort to detect the impoundment signal at individual tide gauges.

  11. Astronaut Richard F. Gordon Aboard Command Module Yankee Clipper

    NASA Technical Reports Server (NTRS)

    1969-01-01

    This is a view of astronaut Richard F. Gordon attaching a high resolution telephoto lens to a camera aboard the Apollo 12 Command Module (CM) Yankee Clipper. The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what's known as the Ocean of Storms. Their lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. Astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Apollo 12 safely returned to Earth on November 24, 1969.

  12. Food habits and seasonal variation of stomach contents of tongue sole Cynoglossus semilaevis (Günther) in the Bohai Sea

    NASA Astrophysics Data System (ADS)

    Dou, Shuozeng

    1993-03-01

    Examination of the food habits and seasonal variation of the stomach contents of adult tongue sole, Cynoglossus semilaevis (Günther) taken in July 1982 July 1983 from Laizhou Bay and the Huanghe River estuary of the Bohai Sea showed crustacea, bivalvia and small fishes comprised the main prey. Invertebrates such as polychaeta, cephalopoda, gastropoda, echinodermata and actiniaria were also intermittently found in them. They intensively fed all the year found (monthly feeding rate of over 80%). The main food items were Alpheus japonica, Alpheus distinguendus. Oratosquilla oratoria, Eucrate crenata and Carcinoplax vestitus, etc. In summer and autumn, the portion of bivalvia such as Cultellus attenuatus and Musculus senhousei increased steadily. From summer to winter, a stable proportion of small fishes such as Rhinogobius pflaumi and Setipinna taty was in the diet.

  13. Diet of Lipophrys pholis (L.) (Teleostei, Blenniidae) in Cantabrian coastal waters (Spain)

    NASA Astrophysics Data System (ADS)

    Mazé, Raquel A.; Domínguez, Josefa; Pérez-Cardenal, David

    1999-07-01

    Between February and December 1988, a total of 261 specimens of Lipophrys pholis were caught in eleven intertidal pools on the western coast of Asturias. This blenniid species mainly feeds on different groups of invertebrates, although algal remains also appear. Mollusca is the most highly represented taxon with the largest number of prey being Gastropoda, followed by Bivalvia and, to a lesser degree, Polyplacophora. Crustacea is well represented by Cirripedia. Isopoda also stands out and Amphipoda, Tanaidacea and Decapoda appear sporadically. Temporal diet analysis throughout the year shows no great differences. Likewise, a great similarity was observed among the feeding of L. pholis specimens collected in pools at a different tidal level, of variable size and with different algal cover. Changes in diet are appreciable as size increases, especially from a length of 6 cm on.

  14. Crawling through time: Transition of snails to slugs dating back to the Paleozoic, based on mitochondrial phylogenomics.

    PubMed

    Medina, Mónica; Lal, Shruti; Vallès, Yvonne; Takaoka, Tori L; Dayrat, Benoît A; Boore, Jeffrey L; Gosliner, Terrence

    2011-03-01

    Sea slugs (Gastropoda: Opisthobranchia) are characterized by extensive morphological homoplasy. In particular, reduced or absent shells are predominant throughout the group. This trend towards shell loss has resulted in a poor fossil record. DNA-based phylogenies have been helpful in improving our understanding of the evolution of this group and major clades are emerging. We report 13 new complete opisthobranch mitochondrial genomes that provide robust support for some of these emerging nodes. We name three new clades within the Opisthobranchia, the Actopleura (Acteonoidea plus Nudipleura), Placoesophaga (Cephalaspidea plus Anaspidea), and Siphoglossa (Sacoglossa plus the Siphonaria). Finally we use molecular clock dating that suggests an earlier opisthobranch divergence than previously reported. The implications of this evolutionary scenario are discussed. PMID:21429465

  15. Life cycle and structure of the fish digenean Brachyphallus crenatus (Hemiuridae).

    PubMed

    Køie, M

    1992-04-01

    Cystophorous cercariae from Retusa obtusa (Montagu) (Gastropoda, Opisthobranchia, Retusidae) develop into adults of Brachyphallus crenatus (Rudolphi, 1802) Odhner, 1905 (Hemiuridae). The free-swimming cercariae were ingested by laboratory-reared Acartia tonsa Dana, and the cercarial body was injected into the hemocoel of the copepod. Two-week-old metacercariae held at 15 C were infective to stickleback Gasterosteus aculeatus Linnaeus. The cercariae of B. crenatus are very similar to the cercariae of Hemiurus luehei Odhner, 1905, and Lecithocladium excisum (Rudolphi, 1819) Lühe, 1901 (Hemiuridae), which develop in closely related opisthobranch snails. Scanning electron microscopy of metacercariae and adults of B. crenatus revealed the annular plications of most of the external surface to be scalelike. The area surrounding the genital pore and the presomatic pit was densely plicated. PMID:1556648

  16. Discrete potential waves in the photoreceptors of a gastropod mollusc, Hermissenda crassicornis.

    PubMed

    Takeda, T

    1982-01-01

    Intracellular recording of dark adapted photoreceptors of Hermissenda crassicornis (Opisthobranchia, Gastropoda, Mollusca) revealed the occurrence of depolarizing waves even after blockade of synaptic transmission and postsynaptic potentials by application of low Ca2+ and high Mg2+ solution. Dim illumination increased the frequency of depolarizing waves. These observations show that Hermissenda photoreceptors have discrete waves which have been demonstrated mainly in arthropod photoreceptors. An histogram of intervals between successive discrete waves under continuous dim illumination was exponential, which is characteristic of a Poisson process. Frequency of discrete waves increased linearly depending on numbers of incident photons to the eye. Comparison of probabilities of eliciting a response to brief dim flashes of various intensities to theoretical Poisson sum curves, together with statistical analysis, indicate that the absorption of single photon is sufficient to evoke a discrete wave. PMID:7101766

  17. Ocean Sciences Best Student Papers for 1988 Joint AGU/ASLO Meeting

    NASA Astrophysics Data System (ADS)

    The Ocean Sciences Section has selected four students to receive Best Student Paper Awards for the 1988 Joint AGU and American Society for Limnology and Oceanography (ASLO) Meeting held last January in New Orleans.Brad M. Bebout received a Best Student Paper Award for his paper “The Use of Agricultural Waste (Corn Slash) to Support Microzone-Associated Nitrogen Fixation by Marine Microorganisms.” Bebout is an M.S. candidate in marine sciences at the University of North Carolina at Chapel Hill. His thesis is on “The Role of Marine Fungi in Food Selection and Nutrition of the Salt Marsh Periwinkle Littorina irrorata Say (Gastropoda).” He received his B.A. in biology from the University of California, Santa Cruz.

  18. [Bounds of change in unsaturation index of fatty acid composition of phospholipids at adaptation of molluscs to biogenic and abiogenic factors of external medium].

    PubMed

    Chebotareva, M A; Zabelinskiĭ, S A; Shukoliukova, E P; Krivchenko, A I

    2011-01-01

    Comparative study of fatty acid composition of total phospholipids, as well as of phosphatidylcholine and phosphatidylethanolamine from hepatopancreas and leg muscle was performed on several representatives of gasteropods (Gastropoda) molluscs and bivalve (Bivalvia) mussel (Mytilus edulus). The objects of our study were marine litorins (Littorina saxsatilis) adapted to different temperature conditions of White Sea and Barents Sea, freshwater lymnaea (Lymnaea stagnalis) infested by Trematoda and mussels from White Sea and Black Sea. It was shown that depending on the existence conditions of studied tissue or lipid, the maximal change is observed in the percentage of saturated acids (4-83 %), the percentage of unsaturated acids was less expressed (1-14 %) and the changes in unsaturation index (UI) did not exceed 20 % on average. It was supposed that observed quantitative bounds of UI change under the action of different external factors is utmost for maintenance of membrane fluidity necessary for normal vital activity of cell, particularly in studied ectothermic molluscs. PMID:22145319

  19. Energy saving through trail following in a marine snail.

    PubMed

    Davies, Mark S; Blackwell, Janine

    2007-05-01

    Most snails and slugs locomote over a layer of mucus and although the resultant mucus trail is expensive to produce, we show that this expense can be reduced by trail following. When tracking over fresh conspecific trails, the marine intertidal snail Littorina littorea (L.) produced only approximately 27% of the mucus laid by marker snails. When tracking over weathered trails, snails adjusted their mucus production to recreate a convex trail profile of similar shape and thickness to the trail as originally laid. Maximum energy saving occurs when following recently laid trails which are little weathered. Many and diverse ecological roles for trail following have been proposed. Energy saving is the only role that applies across the Gastropoda and so may help to explain why trail following is such a well-established behaviour. PMID:17327203

  20. Effects of sea lamprey (Petromyzon marinus) control in the Great Lakes on aquatic plants, invertebrates and amphibians

    USGS Publications Warehouse

    Gilderhus, P.A.; Johnson, B.G.H.

    1980-01-01

    The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2a??,5-dichloro-4a??-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.

  1. Foods of Spectacled Eiders Somateria fischeri in the Bering Sea, Alaska

    USGS Publications Warehouse

    Petersen, M.R.; Piatt, J.F.; Trust, K.A.

    1998-01-01

    The winter diet of Spectacled Eiders living in marine habitats is known only from two individuals described by Cottam (1939). Here we examine marine diets from 36 stomachs collected near St. Lawrence Island, Bering Sea, Alaska, during May-June in 1987 and 1992. All Spectacled Eiders ate Mollusca, including Gastropoda (snails; frequency of occurrence 20.0%; sole taxon 0.0%) and Bivalvia (bivalves; 80.0%; 48.0%), and Crustacea (barnacles, amphipods and crabs; 30.6%; 0.0%). One bird ate a cod. The predominant species group eaten was Macoma Clams (72.0%; 36.0%). Prey species of Spectacled Eiders occur predominantly in waters 25-60 m deep in the Bering Sea. To obtain these prey, especially the bivalves, on the winter area Spectacled Eiders must forage in waters exceeding 40 m. We speculate that Spectacled Eiders regularly forage at depths of 45-70 m throughout winter.

  2. Bioaccumulation of 210Po in common gastropod and bivalve species from the northern Gulf.

    PubMed

    Uddin, S; Bebhehani, M

    2014-06-01

    This study sets the baseline for the concentration of the natural-series radionuclide polonium-210 in two species of gastropods and four species of bivalves that are common to the Northern Arabian/Persian Gulf. (210)Po is primarily absorbed from water and via ingestion of detrital material by gastropoda and bivalves. This concentrated (210)Po can then be passed along to the next trophic level of the marine food web. The lowest (210)Po concentration was measured in the gastropod Stomatella auricular (10.36-12.39Bq kg(-1)dry) and the highest in the bivalve Marica marmorata (193.51-215.60Bq kg(-1)dry). The measured concentration factor for these molluscs in the northern Gulf varied between 4.8 and 115×10(3), values very similar to the IAEA recommended value for bivalves and gastropods of 2×10(4). PMID:24675441

  3. Is Response to Fire Influenced by Dietary Specialization and Mobility? A Comparative Study with Multiple Animal Assemblages

    PubMed Central

    Bros, Vicenç; Brotons, Lluís; De Mas, Eva; Herraiz, Joan A.; Herrando, Sergi; Miño, Àngel; Olmo-Vidal, Josep M.; Quesada, Javier; Ribes, Jordi; Sabaté, Santiago; Sauras-Yera, Teresa; Serra, Antoni; Vallejo, V. Ramón; Viñolas, Amador

    2014-01-01

    Fire is a major agent involved in landscape transformation and an indirect cause of changes in species composition. Responses to fire may vary greatly depending on life histories and functional traits of species. We have examined the taxonomic and functional responses to fire of eight taxonomic animal groups displaying a gradient of dietary and mobility patterns: Gastropoda, Heteroptera, Formicidae, Coleoptera, Araneae, Orthoptera, Reptilia and Aves. The fieldwork was conducted in a Mediterranean protected area on 3 sites (one unburnt and two burnt with different postfire management practices) with five replicates per site. We collected information from 4606 specimens from 274 animal species. Similarity in species composition and abundance between areas was measured by the Bray-Curtis index and ANOSIM, and comparisons between animal and plant responses by Mantel tests. We analyze whether groups with the highest percentage of omnivorous species, these species being more generalist in their dietary habits, show weak responses to fire (i.e. more similarity between burnt and unburnt areas), and independent responses to changes in vegetation. We also explore how mobility, i.e. dispersal ability, influences responses to fire. Our results demonstrate that differences in species composition and abundance between burnt and unburnt areas differed among groups. We found a tendency towards presenting lower differences between areas for groups with higher percentages of omnivorous species. Moreover, taxa with a higher percentage of omnivorous species had significantly more independent responses of changes in vegetation. High- (e.g. Aves) and low-mobility (e.g. Gastropoda) groups had the strongest responses to fire (higher R scores of the ANOSIM); however, we failed to find a significant general pattern with all the groups according to their mobility. Our results partially support the idea that functional traits underlie the response of organisms to environmental changes caused

  4. Attributes of quality programs in universities in developing countries: Case studies of two private universities in Ecuador and beyond

    NASA Astrophysics Data System (ADS)

    Uriguen, Monica I.

    This study sought to identify the key attributes of high-quality programs with an eye toward helping developing countries such as Ecuador advance program quality. The dissertation is divided into five chapters: (1) introduction to high-quality programs; (2) literature review of attributes of high-quality programs; (3) grounded theory method (including interviews with 60 individuals) used to identify program attributes that enhance student learning; (4) findings; and (5) conclusions and recommendations. Following are the five clusters and thirteen attributes of high-quality programs that I identified: Cluster One: Highly Qualified Participants: (1) Highly Qualified Faculty, and (2) Highly Qualified Students; Cluster Two: Learning-Centered Cultures: (3) Shared Program Direction Focused on Learning, (4) Real-World Learning Experiences, (5) Reading-Centered Culture, and (6) Supportive and Risk-Taking Environment; Cluster Three: Interactive Teaching and Learning: (7) Integrative learning: Theory with Practice, Self with Subject, and (8) Exclusive Tutoring and Mentoring; Cluster Four: Connected Program Requirements: (9) Planned Breadth and Depth Course Work, and (10) Tangible Products; and Cluster Five: Adequate Resources: (11) Support for Students, (12) Support for Faculty, and (13) Support for Campus Infrastructure. The study was guided by Haworth and Conrad's (1997) "Engagement Theory of High-Quality Programs." Eleven of the attributes of high-quality programs are closely connected to Haworth and Conrad's theory and the other two attributes---real-world learning experiences and a reading-centered culture---make the signature theoretical contributions of the study. Real-world learning experiences encourage the active involvement of stakeholders in designing curricula with real-world learning experiences. The second attribute---a reading-centered culture---has never before been identified in the literature. There are four key differences between Haworth and Conrad

  5. Jung's quest for the Aurora consurgens.

    PubMed

    Haaning, Aksel

    2014-02-01

    The paper focuses on the year 1929 when Jung published 'A European commentary' to Richard Wilhelm's German translation of the Taoist text The Secret of the Golden Flower. This shows that Jung had already started on the track of European alchemy by following up Conrad Waldkirch's preface in Artis Auriferae (1593); and it raises the question of whether this could be the possible missing link to Jung's subsequent research in Alchemy and Hermetic Philosophy in the years to come. It is argued that here was the beginning of Jung's quest for the Aurora consurgens, the publication of which concludes the Mysterium Conuinctionis more than twenty years later. It is further maintained that this choice of the Aurora is a profound expression of Jung's ambition to revitalize the past from within the individual, and helps explain Jung's deep concern with the welfare and future of modern society. PMID:24467350

  6. Photosynthetic, respiratory and extracellular electron transport pathways in cyanobacteria.

    PubMed

    Lea-Smith, David J; Bombelli, Paolo; Vasudevan, Ravendran; Howe, Christopher J

    2016-03-01

    Cyanobacteria have evolved elaborate electron transport pathways to carry out photosynthesis and respiration, and to dissipate excess energy in order to limit cellular damage. Our understanding of the complexity of these systems and their role in allowing cyanobacteria to cope with varying environmental conditions is rapidly improving, but many questions remain. We summarize current knowledge of cyanobacterial electron transport pathways, including the possible roles of alternative pathways in photoprotection. We describe extracellular electron transport, which is as yet poorly understood. Biological photovoltaic devices, which measure electron output from cells, and which have been proposed as possible means of renewable energy generation, may be valuable tools in understanding cyanobacterial electron transfer pathways, and enhanced understanding of electron transfer may allow improvements in the efficiency of power output. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. PMID:26498190

  7. Mathematical modeling of pattern formation caused by drying of colloidal film under a mask.

    PubMed

    Tarasevich, Yuri Yu; Vodolazskaya, Irina V; Sakharova, Lyudmila V

    2016-02-01

    In our model, we simulate an experiment (D.J. Harris, H. Hu, J.C. Conrad, J.A. Lewis, Patterning colloidal films via evaporative lithography, Phys. Rev. Lett. 98, 148301 (2007)). A thin colloidal sessile droplet is allowed to dry out on a horizontal hydrophilic surface. A mask just above the droplet predominantly allows evaporation from the droplet free surface directly beneath the holes in the mask. We consider one special case, when the holes in the mask are arranged so that the system has rotational symmetry of order m . We use a speculative evaporative flux to mimic the real system. Advection, diffusion, and sedimentation are taken into account. FlexPDE is utilized to solve an advection-diffusion equation using the finite element method. The simulation demonstrates that the colloidal particles accumulate below the holes as the solvent evaporates. Diffusion can reduce this accumulation. PMID:26920529

  8. An analysis of auditory alphabet confusions.

    PubMed

    Walker, M E

    1989-04-01

    The present study, using the nonhierarchical overlapping clustering algorithm MAPCLUS to fit the Shepard-Arabie (1979) ADCLUS model, attempted to derive a set of features that would accurately describe the auditory alphabet confusions present in the data matrices of Conrad (1964) and Hull (1973). Separate nine-cluster solutions accounted for 80% and 89% of the variance in the matrices, respectively. The clusters revealed that the most frequently confused letter names contained common vowels and phonetically similar consonants. Further analyses using INDCLUS, an individual differences extension of the MAPCLUS algorithm and ADCLUS model, indicated that while the patterns of errors in the two matrices were remarkably similar, some differences were also apparent. These differences reflected the differing amounts of background noise present in the two studies. PMID:2710632

  9. Analysis of photosystem II biogenesis in cyanobacteria.

    PubMed

    Heinz, Steffen; Liauw, Pasqual; Nickelsen, Jörg; Nowaczyk, Marc

    2016-03-01

    Photosystem II (PSII), a large multisubunit membrane protein complex found in the thylakoid membranes of cyanobacteria, algae and plants, catalyzes light-driven oxygen evolution from water and reduction of plastoquinone. Biogenesis of PSII requires coordinated assembly of at least 20 protein subunits, as well as incorporation of various organic and inorganic cofactors. The stepwise assembly process is facilitated by numerous protein factors that have been identified in recent years. Further analysis of this process requires the development or refinement of specific methods for the identification of novel assembly factors and, in particular, elucidation of the unique role of each. Here we summarize current knowledge of PSII biogenesis in cyanobacteria, focusing primarily on the impact of methodological advances and innovations. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. PMID:26592144

  10. From epigenesis to epigenetics: the case of C. H. Waddington.

    PubMed

    Van Speybroeck, Linda

    2002-12-01

    One continuous thread in this volume is the name of Conrad H. Waddington (1905-1975), the developmental biologist known as the inventor of the term epigenetics. After some biographical notes on his life, this article explores the meaning of the Waddingtonian equation and the context wherein it was developed. This equation holds that epigenesis + genetics = epigenetics, and refers in retrospect to the debate on epigenesis versus preformationism in neoclassical embryology. Whereas Waddington actualized this debate by linking epigenesis to developmental biology and preformation to genetics, thereby stressing the importance of genetic action in causal embryology, today's epigenetics more and more offers the possibility to enfeeble biological thinking in terms of genes only, as it expands the gene-centric view in biology by introducing a flexible and pragmatically oriented hierarchy of crucial genomic contexts that go beyond the organism. PMID:12547674

  11. [The meaning of epigenetics].

    PubMed

    Hu, Kai

    2002-11-01

    Epigenetics, the term was introduced by Conrad H.Waddington, in 1942,he said that to compare genetics with epigenetics, the study of the processes by which genotype gives rise to phenotype. In 1987, Robin Holliday redefined epigenetic as "Nuclear inheritance which is not based on differences in DNA sequence". The author of this paper introduced that in Science,10 August 2001,there was a special collection of review articles focused on the topic of epigenetics. The new "histone code" hypothesis states that the highly modifiable amino termini could carry their own combinatorial codes to help control phenotype,and that part of this code is heritable. And in light of this hypothesis,researchers are approaching further possibilities in human biology and types of cancer and other diseases. PMID:15979980

  12. The changing concept of epigenetics.

    PubMed

    Jablonka, Eva; Lamb, Marion J

    2002-12-01

    We discuss the changing use of epigenetics, a term coined by Conrad Waddington in the 1940s, and how the epigenetic approach to development differs from the genetic approach. Originally, epigenetics referred to the study of the way genes and their products bring the phenotype into being. Today, it is primarily concerned with the mechanisms through which cells become committed to a particular form or function and through which that functional or structural state is then transmitted in cell lineages. We argue that modern epigenetics is important not only because it has practical significance for medicine, agriculture, and species conservation, but also because it has implications for the way in which we should view heredity and evolution. In particular, recognizing that there are epigenetic inheritance systems through which non-DNA variations can be transmitted in cell and organismal lineages broadens the concept of heredity and challenges the widely accepted gene-centered neo-Darwinian version of Darwinism. PMID:12547675

  13. Basaltic continental intraplate volcanism as sustained by shear-driven upwelling

    NASA Astrophysics Data System (ADS)

    Ballmer, M. D.; Conrad, C. P.; Smith, E. I.

    2012-04-01

    While most volcanism on Earth occurs at plate boundaries, the study of intraplate basaltic volcanism may provide an opportunity to scrutinize the make-up and dynamics of the mantle. In continental settings, a range of mechanisms were proposed to sustain mantle decompression and hence to support such volcanism. These include mantle plumes, fertile melting anomalies, self-sustaining buoyant decompression melting, lithospheric dripping, and edge-driven small-scale convection. Recently, Conrad et al. showed that basaltic continental volcanism occurs more often where shear across the asthenosphere is greatest, and hence propose shear-driven upwelling (SDU) to support such volcanism¹. SDU does not require density heterogeneity to drive convection, in contrast to other mechanisms. Rather, it develops when rapid shear across the asthenosphere meets lateral viscosity variation2. For example, in a case with a low-viscosity pocket in the mantle, asthenospheric shear is accommodated in a different manner across the pocket than across the ambient mantle. This contrast drives vertical flow close to the margins of the pocket, and may be sufficient to sustain decompression melting, particularly if the viscosity anomaly is supported by higher water contents or temperatures2. Mantle melting is also expected for situations in which asthenospheric shear flow enters a lithospheric cavity, or decompresses across a step in lithospheric thickness3 - and even more so if a low-viscosity pocket is entrained in such a flow. Seismic observations indicate that sublithospheric topography, and heterogeneity in mantle viscosity are indeed common beneath continents (regardless of whether the imaged anomalies are thermal or compositional in origin). We use three-dimensional numerical models to explore shear-driven flow, and investigate a range of cases with pockets of variable viscosity contrast and shape, lithospheric steps of variable offset and spacing, and asthenospheric flow with variable

  14. Apollo 12 Mission Summary and Splashdown

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This NASA Kennedy Space Center (KSC) video release presents footage of the November 14, 1969 Apollo-12 space mission begun from launch complex pad 39-A at Kennedy Space Center, Florida. Charles Conrad, Jr., Richard F. Gordon, Jr., and Alan L. Bean make up the three-man spacecrew. The video includes the astronaut's pre-launch breakfast, President Nixon, his wife, and daughter arriving at Cape Kennedy in time to see the launch, as well as countdown and liftoff. After the launch, President Nixon gives a brief congratulatory speech to the members of launch control at KSC. The video also presents views of the astronauts and spacecraft in space as well as splashdown of the command module on November 24, 1969. The video ends with the recovery, by helicopter and additional personnel, of the spacecrew from the command module floating in the waters of the Atlantic.

  15. Large Binocular Telescope Observations of Europa Occulting Io's Volcanoes at 4.8 μm

    NASA Astrophysics Data System (ADS)

    Skrutskie, Michael F.; Conrad, Albert; Resnick, Aaron; Leisenring, Jarron; Hinz, Phil; de Pater, Imke; de Kleer, Katherine; Spencer, John; Skemer, Andrew; Woodward, Charles E.; Davies, Ashley Gerard; Defrére, Denis

    2015-11-01

    On 8 March 2015 Europa passed nearly centrally in front of Io. The Large Binocular Telescope observed this event in dual-aperture AO-corrected Fizeau interferometric imaging mode using the mid-infrared imager LMIRcam operating behind the Large Binocular Telescope Interferometer (LBTI) at a broadband wavelength of 4.8 μm (M-band). Occultation light curves generated from frames recorded every 123 milliseconds show that both Loki and Pele/Pillan were well resolved. Europa's center shifted by 2 kilometers relative to Io from frame-to-frame. The derived light curve for Loki is consistent with the double-lobed structure reported by Conrad et al. (2015) using direct interferometric imaging with LBTI.

  16. Distribution and dynamics of electron transport complexes in cyanobacterial thylakoid membranes.

    PubMed

    Liu, Lu-Ning

    2016-03-01

    The cyanobacterial thylakoid membrane represents a system that can carry out both oxygenic photosynthesis and respiration simultaneously. The organization, interactions and mobility of components of these two electron transport pathways are indispensable to the biosynthesis of thylakoid membrane modules and the optimization of bioenergetic electron flow in response to environmental changes. These are of fundamental importance to the metabolic robustness and plasticity of cyanobacteria. This review summarizes our current knowledge about the distribution and dynamics of electron transport components in cyanobacterial thylakoid membranes. Global understanding of the principles that govern the dynamic regulation of electron transport pathways in nature will provide a framework for the design and synthetic engineering of new bioenergetic machinery to improve photosynthesis and biofuel production. This article is part of a Special Issue entitled: Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. PMID:26619924

  17. Heteromorph ammonites from the Upper Campanian (Upper Cretaceous) Baculites cuneatus and Baculites reesidei zones of the Pierre Shale in Colorado, USA

    USGS Publications Warehouse

    Kennedy, W.J.; Cobban, W.A.; Scott, G.R.

    2000-01-01

    Calcareous sandstone concretions in the Upper Cretaceous Pierre Shale in Middle Park and in the Fort Collins area of Colorado in the U.S. Western Interior contain heteromorph ammonites of the families Nostoceratidae HYATT, 1894, and Diplomoceratidae SPATH, 1926. The following species are described: Nostoceras cf. N. approximans (CONRAD, 1855), Nostoceras cf. N. obtusum HOWARTH, 1965, N. larimerense sp. nov., Nostoceras cf. N. splendidum (SHUMARD, 1861). Didymoceras aurarium sp. nov., D. draconis (STEPHENSON, 1941), Cirroceras conradi (MORTON, 1841), Anaklinoceras minutum sp. nov., Solenoceras texanum (SHUMARD, 1861), Solenoceras cf. S. reesidei STEPHENSON, 1941, Lewyites oronensis (LEWY, 1969), and Lewyites? sp. All these species are migrants from the Gulf coastal region. Didymoceras draconis and Cirroceras conradi are also known from the Delaware-New Jersey area, and these two species, together with Solenoceras texanum are known from as far away as Israel.

  18. Molecular dynamics simulations of low temperature Cu/Cu(100) growth

    NASA Astrophysics Data System (ADS)

    Borovikov, Valery; Shim, Yunsic; Amar, Jacques G.

    2008-03-01

    Recent X-ray scattering studies [1] of Cu/Cu(100) growth indicate the existence of a sharp transition from epitaxial growth at high temperatures to growth with a high vacancy concentration at lower temperatures (T < 150 K). Here we present the results of molecular dynamics (MD) simulations carried out in order to understand the detailed mechanisms of incorporation of vacancies and voids (vacancy clusters) into the growing film during low temperature deposition. The dependence of compressive strain, vacancy concentration and vacancy-cluster size distribution in deposited thin film, as well as the surface roughness and morphology on deposition conditions, such as the growth temperature, deposition angle, and incident kinetic energy will be discussed and compared with experiments. [1] C. E. Botez, K. Li, E. D. Lu, W. C. Elliott, P. F. Miceli, E. H. Conrad, and P.W. Stephens, Appl. Phys. Lett. 81, 4718 (2002).

  19. Study on sources of charging lead acid batteries

    NASA Astrophysics Data System (ADS)

    Diniş, C. M.; Popa, G. N.; Iagăr, A.

    2015-06-01

    The paper presents the general characteristics of lead acid batteries and two charging methods of these batteries. For charging of lead batteries was used an intelligent power source K 8012 (from Velleman). The power source allows fixing the level of the battery voltage and battery capacity. The intelligent power source uses the joint method (at constant current and, then, at constant voltage) and warning that indicates different situations in the charging process. Other method of charging presented in the paper is at constant voltage using a stabilized power source. In the paper experimental measurements were carried out using data acquisition card SER 10 BIT (from Conrad) for charging/ discharging of a lead acid battery 12V/9Ah (using an intelligent power source) and charging of another high capacity lead acid battery 12V/47Ah/390 A (using a stabilized power source). At the discharging of the lead acid batteries it were used automotive lamps as electric loads.

  20. An experimental study of the flow in a wing with a partial span drooped leading edge

    NASA Technical Reports Server (NTRS)

    Winkelmann, A. E.; Tsao, C. P.

    1981-01-01

    The flow field produced by a low aspect ratio wing (AR = 3.0) with a partial span leading edge droop was investigated in a series of low speed wind tunnel tests (Reynolds number based on 17.8 cm chord = 560,000). Photographs were obtained of surface oil flow patterns over an angle of attack range of alpha = 0 to 29 deg. Flow field surveys of the partially stalled wing at alpha = 25 deg were completed using a hot-wire probe, a split-film probe and a Conrad probe. The flow field survey data was presented using a color video display. The data indicated regions of apparent reversed flow in the separation region behind the wing and indicated the general cross-sectional shape of the separated wake flow.