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Sample records for acochlidian gastropod pseudunela

  1. Tiny but complex - interactive 3D visualization of the interstitial acochlidian gastropod Pseudunela cornuta (Challis, 1970

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    Heß Martin

    2009-09-01

    Full Text Available Abstract Background Mesopsammic acochlidians are small, and organ complexity may be strongly reduced (regressive evolution by progenesis, especially in microhedylacean species. The marine interstitial hedylopsacean Pseudunela cornuta (Challis, 1970, however, was suggested as having a complex reproductive system resembling that of much larger, limnic and benthic species. The present study aims to reconstruct the detailed anatomy and true complexity of P. cornuta from serial, semithin histological sections by using modern computer-based 3D visualization with Amira software, and to explain it in an evolutionary context. Results Our results demonstrate considerable discordance with the original species description, which was based solely on paraffin sections. Here, we show that the nervous system of P. cornuta has paired rhinophoral, optic and gastro-oesophageal ganglia, three distinct ganglia on the visceral nerve cord, and a putative osphradial ganglion, while anterior accessory ganglia are absent. The presence of an anal genital cloaca is clearly rejected and the anus, nephropore and gonopore open separately to the exterior; the circulatory and excretory systems are well-differentiated, including a two-chambered heart and a complex kidney with a long, looped nephroduct; the special androdiaulic reproductive system shows two allosperm receptacles, three nidamental glands, a cavity with unknown function, as well as highly complex anterior copulatory organs with two separate glandular and impregnatory systems including a penial stylet that measures approximately a third of the whole length of the preserved specimen. Conclusion In spite of its small body size, the interstitial hermaphroditic P. cornuta shows high complexity regarding all major organ systems; the excretory system is as differentiated as in species of the sister clade, the limnic and much larger Acochlidiidae, and the reproductive system is by far the most elaborated one ever observed

  2. MICROANATOMY, ULTRASTRUCTURE, AND SYSTEMATIC SIGNIFICANCE OF THE EXCRETORY SYSTEM AND MANTLE CAVITY OF AN ACOCHLIDIAN GASTROPOD (OPISTHOBRANCHIA).

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    Fahrner, A.; Haszprunar, G.

    2002-05-01

    The microanatomy and ultrastructure of the excretory system of an undescribed mesopsammic gastropod of the genus Hedylopsis have been examined by means of semithin serial sections, reconstructions, and transmission electron microscopy. The functional metanephridial system comprises a monotocardian heart with a single ventricle and auricle in a spacious pericardium as well as a single, large kidney. Podocytes in the auricular epicardium represent the site of ultrafiltration and formation of the primary urine, whereas the flat epithelium of the kidney with extensive basal infoldings, large vacuoles and the apical microvillous border indicates modification of the primary filtrate. Solitary rhogocytes (pore cells) represent additional loci of ultrafiltration with an identical fine-structure as those of the podocytes (meandering slits with diaphragms covered by extracellular matrix). The presence of podocytes situated in the epicardial wall of the auricle is regarded as plesiomorphic for the Opisthobranchia and is confirmed for the Acochlidia for the first time. Kidney and rectum both open into a small, yet distinct mantle cavity. Within the Acochlidia this condition represents a plesiomorphic character only known from one further Hedylopsis species until now. Special cells (here termed microvillous pit-cells) with a presumed absorptive function are interspersed between the epithelial cells of the mantle cavity. They are mainly characterized by a prominent invagination of the apical border with densely arranged, very large microvilli. The presence of a mantle cavity that has been lost in all other acochlidian genera supports the systematic placement of the Hedylopsidae at the base of the Achochlidia.

  3. Computer-based three-dimensional reconstruction of the anatomy of Microhedyle remanei (Marcus, 1953), an interstitial acochlidian gastropod from Bermuda.

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    Neusser, Timea P; Hess, Martin; Haszprunar, Gerhard; Schrödl, Michael

    2006-02-01

    Phylogenetic analysis of the highly enigmatic and aberrant acochlidian opisthobranch gastropods is mainly hindered by the lack of reliable anatomical data. Due to their small size, marine interstitial acochlidian species are not suitable for anatomical investigations by dissecting. The tinyness and complexity of, e.g., opisthobranch central nervous and reproductive systems make data derived from older paraffin-based histology and interpretation by hand-based graphical reconstruction questionable. In a former study, a hermaphroditic member of the basal acochlidian genus Hedylopsis ("Hedylopsacea") has been examined in detail. The present study uses the gonochoric Microhedyle remanei (Microhedylidae) as a model organism of the other traditional major acochlidian subgroup, the "Microhedylacea." More than 20 specimens with up to 2 mm body length were extracted from coarse subtidal sand near Castle Roads, Bermuda Islands. Their central nervous, digestive, circulatory, excretory, and genital systems were reconstructed three-dimensionally from serial semithin histological sections using AMIRA software. The radula was analyzed by SEM. Our specimens closely resemble the original description of M. remanei (Marcus, 1953; as Unela) from Brazil; apparent differences regarding the number of visceral loop ganglia or details of male genitalia are assumed to be due to oversights by the former author or because of different ontogenetic stages. Microhedyle remanei differs from all congeners due to the lack (vs. presence) of eyes; further distinguishing features are discussed. In contrast to members of the hedylopsacean Hedylopsidae, Acochlidiidae, and Tantulidae, M. remanei shows a nervous system with numerous precerebral accessory "ganglia" that are not differentiated into cortex and medulla. While all Microhedylidae previously were thought to lack a heart, M. remanei shows a two-chambered heart, as is usual for opisthobranchs. The oocytes of M. remanei are yolky and large in

  4. Evolution of gastropod mitochondrial genome arrangements

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    Zardoya Rafael

    2008-02-01

    Full Text Available Abstract Background Gastropod mitochondrial genomes exhibit an unusually great variety of gene orders compared to other metazoan mitochondrial genome such as e.g those of vertebrates. Hence, gastropod mitochondrial genomes constitute a good model system to study patterns, rates, and mechanisms of mitochondrial genome rearrangement. However, this kind of evolutionary comparative analysis requires a robust phylogenetic framework of the group under study, which has been elusive so far for gastropods in spite of the efforts carried out during the last two decades. Here, we report the complete nucleotide sequence of five mitochondrial genomes of gastropods (Pyramidella dolabrata, Ascobulla fragilis, Siphonaria pectinata, Onchidella celtica, and Myosotella myosotis, and we analyze them together with another ten complete mitochondrial genomes of gastropods currently available in molecular databases in order to reconstruct the phylogenetic relationships among the main lineages of gastropods. Results Comparative analyses with other mollusk mitochondrial genomes allowed us to describe molecular features and general trends in the evolution of mitochondrial genome organization in gastropods. Phylogenetic reconstruction with commonly used methods of phylogenetic inference (ME, MP, ML, BI arrived at a single topology, which was used to reconstruct the evolution of mitochondrial gene rearrangements in the group. Conclusion Four main lineages were identified within gastropods: Caenogastropoda, Vetigastropoda, Patellogastropoda, and Heterobranchia. Caenogastropoda and Vetigastropoda are sister taxa, as well as, Patellogastropoda and Heterobranchia. This result rejects the validity of the derived clade Apogastropoda (Caenogastropoda + Heterobranchia. The position of Patellogastropoda remains unclear likely due to long-branch attraction biases. Within Heterobranchia, the most heterogeneous group of gastropods, neither Euthyneura (because of the inclusion of P

  5. Aragonite twinning in gastropod nacre

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    Mukai, Hiroki; Saruwatari, Kazuko; Nagasawa, Hiromichi; Kogure, Toshihiro

    2010-10-01

    Aragonite twinning in gastropod nacre has been investigated using scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD), and transmission electron microscopy (TEM) with the focused ion beam (FIB) sample preparation technique. At the growth front of nacre, Haliotis discus hannai and Omphalius rusticus form a "stack-of-coins" structures, which consist of pseudo-hexagonal and elliptical aragonite tablets, respectively. SEM, EBSD, and TEM analyses revealed that these tablets are monolithic single crystal and almost free of the {1 1 0} twins that are common in aragonite of biotic or abiotic origin. The longest diagonal of the hexagon and the longer axis of the ellipse are parallel to the a-axis of aragonite. The crystal orientation of each tablet in a stack, measured by TEM-Kikuchi pattern analysis, is almost the same but there is occasionally {1 1 0} twin-like relationship between adjacent tablets along the stacking. On the other hand, the fibrous aragonite layer formed prior to the nacreous structure is composed of polycrystalline aragonite with high density of {1 1 0} twins. TEM observation suggests that the interlamellar organic sheet prevents the inheritance of the twins, by selecting only single domain of the twins, through the mineral bridge.

  6. The effects of organotin on female gastropods.

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    Titley-O'Neal, Cassander P; Munkittrick, Kelly R; Macdonald, Bruce A

    2011-09-01

    Female masculinisation (FM) in gastropods (imposex, intersex and ovo-testis) has been documented in > 260 species globally. Biomonitoring studies use FM to indirectly assess the presence of tributyltin (TBT), a once popular biocide in antifouling paint, which has since been regulated. Laboratory studies confirm that FM in gastropods can be induced not only by TBT, but other tin (Sn) compounds, Sn "cocktails", steroids, and other contaminants such as Aroclor 1260. Even though FM in gastropods in the field has been attributed to TBT from boating activity, there is evidence that imposex occurred prior to the advent use of TBT in the 1960s, and for some species imposex occurs naturally. There are roughly 42 species that do not elicit a FM response even if they are exposed to TBT under laboratory conditions, collected sympatrically with other species displaying FM, and/or have TBT in their tissues. A geographic analysis of field studies in four regions indicates that the bulk of studies were conducted in Europe > Asia and Oceania > North America > Latin America. More data are needed regarding FM in Africa, the Middle East, and Latin America since data regarding the masculinisation of female gastropods in these areas are lacking. The most studied gastropod species used in TBT biomonitoring studies is the dogwhelk, Nucella lapillus. This review summarizes the progression of the literature from 1962 to 2009 outlining how the terminology, science, and theories have evolved over time.

  7. Gastropod seed dispersal: an invasive slug destroys far more seeds in its gut than native gastropods.

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    Blattmann, Tamara; Boch, Steffen; Türke, Manfred; Knop, Eva

    2013-01-01

    Seed dispersal is one of the most important mechanisms shaping biodiversity, and animals are one of the key dispersal vectors. Animal seed dispersal can directly or indirectly be altered by invasive organisms through the establishment of new or the disruption of existing seed dispersal interactions. So far it is known for a few gastropod species that they ingest and defecate viable plant seeds and consequently act as seed dispersers, referred to as gastropodochory. In a multi-species experiment, consisting of five different plant species and four different gastropod species, we tested with a fully crossed design whether gastropodochory is a general mechanism across native gastropod species, and whether it is altered by the invasive alien slug species Arion lusitanicus. Specifically, we hypothesized that a) native gastropod species consume the seeds from all tested plant species in equal numbers (have no preference), b) the voracious invasive alien slug A. lusitanicus--similarly to its herbivore behaviour--consumes a higher amount of seeds than native gastropods, and that c) seed viability is equal among different gastropod species after gut passage. As expected all tested gastropod species consumed all tested plant species. Against our expectation there was a difference in the amount of consumed seeds, with the largest and native mollusk Helix pomatia consuming most seeds, followed by the invasive slug and the other gastropods. Seed damage and germination rates did not differ after gut passage through different native species, but seed damage was significantly higher after gut passage through the invasive slug A. lusitanicus, and their germination rates were significantly reduced.

  8. Cretaceous gastropods: contrasts between tethys and the temperate provinces.

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    Sohl, N.F.

    1987-01-01

    During the Cretaceous Period, gastropod faunas show considerable differences in their evolution between the Tethyan Realm (tropical) and the Temperate Realms to the north and south. Like Holocene faunas, prosobranch, gastropods constitute the dominant part of Cretaceous marine snail faunas. Entomotaeneata and opisthobranchs usually form all of the remainder. In Tethyan faunas the Archaeogastropoda form a consistent high proportion of total taxa but less than the Mesogastropoda throughout the period. In contrast, the Temperate faunas beginning in Albian times show a decline in percentages of archaeogastropod taxa and a significant increase in the Neogastropoda, until they constitute over 50 percent of the taxa in some faunas. The neogastropods never attain high diversity in the Cretaceous of the Tethyan Realm and are judged to be of Temperate Realm origin. Cretaceous Tethyan gastropod faunas are closely allied to those of the 'corallien facies' of the Jurassic and begin the period evolutionarily mature and well diversified. Three categories of Tethyan gastropods are analyzed. The first group consists of those of Jurassic ancestry. The second group orginates mainly during the Barremian and Aptian, reaches a climax in diversification during middle Cretaceous time, and usually declines during the latest Cretaceous. The third group originates late in the Cretaceous and consists of taxa that manage to either survive the Cretaceous-Tertiary crisis or give rise to forms of prominence among Tertiary warm water faunas. Temperate Realm gastropod faunas are less diverse than those of Tethys during the Early Cretaceous. They show a steady increase in diversity, primarily among the Mesogastropoda and Neogastropoda. This trend culminates in latest Cretaceous times when the gastropod assemblages of the clastic provinces of the inner shelf contain an abundance of taxa outstripping that of any other part of the Cretaceous of either realm. Extinction at the Cretaceous

  9. [Terrestrial gastropods from Misiones Province, Argentina].

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    Gregoric, Diego Eduardo Gutiérrez; Núñez, Verónica; Vogler, Roberto Eugenio; Beltramino, Ariel Aníbal; Rumi, Alejandra

    2013-12-01

    The Atlantic Forest represents one of the global priority eco-regions for biodiversity conservation. In Argentina, this is represented by the Paranense Forest, which occupies much of the Misiones Province. In this paper, an updated list of land mollusks from Misiones Province is presented, and its species richness was evaluated comparing protected and unprotected areas. For this, we reviewed La Plata Museum Mollusk Collection, updated the literature review, and developed some field work between 2009 and 2010. For the areographic work, a grid (50 x 50 km) was applied to a Misiones province map. In this region, large areas of native vegetation constituting the Paranaense Forest still persist, and include protected areas such as the Iguazú National Park and Puerto Peninsula Provincial Park. These areas have been the most explored at the malacological level (both terrestrial and aquatic environments), a fact that is consistent with the greater number of records found, which may also be the explanation for the highest number of species recorded in the region. A database containing 497 records was compiled. The number of species occurring in this Province was increased from 28 to 56; 11 of which were exotic species. A total of 38 of the species occurred in protected areas and 53 in unprotected areas; and 25 species were micro-mollusks. Orthalicidae was the family with the highest species number (10) and the widest distribution, occupying 16/20 sampling units. Megalobulimus was the genus found in a greater number of sampling units (14/20). The highest values of specific richness of land gastropods were found in Northern Misiones (R=32). This richness was similar to that previously reported for the Tucumán Province, although species occurring in both provinces were mostly different. The richness in Misiones Province border areas, as the Republic of Paraguay and the state of Santa Catarina (Brazil), was about twice that found in the province. The present study showed the

  10. Transcriptome of the Antarctic brooding gastropod mollusc Margarella antarctica.

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    Clark, Melody S; Thorne, Michael A S

    2015-12-01

    454 RNA-Seq transcriptome data were generated from foot tissue of the Antarctic brooding gastropod mollusc Margarella antarctica. A total of 6195 contigs were assembled de novo, providing a useful resource for researchers with an interest in Antarctic marine species, phylogenetics and mollusc biology, especially shell production.

  11. Gastropod skeletal defences: land, freshwater, and sea compared

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    Vermeij, Geerat J.

    2015-01-01

    Predation is a primary agency of natural selection affecting the evolution of skeletal form in gastropods. The nature of antipredatory defence depends on how predators attack their prey as well as on the types and quantities of resources that are available to the potential victims. Here I review the

  12. Radiocarbon dating of small terrestrial gastropod shells in North America

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    Pigati, J.S.; Rech, J.A.; Nekola, J.C.

    2010-01-01

    Fossil shells of small terrestrial gastropods are commonly preserved in wetland, alluvial, loess, and glacial deposits, as well as in sediments at many archeological sites. These shells are composed largely of aragonite (CaCO3) and potentially could be used for radiocarbon dating, but they must meet two criteria before their 14C ages can be considered to be reliable: (1) when gastropods are alive, the 14C activity of their shells must be in equilibrium with the 14C activity of the atmosphere, and (2) after burial, their shells must behave as closed systems with respect to carbon. To evaluate the first criterion, we conducted a comprehensive examination of the 14C content of the most common small terrestrial gastropods in North America, including 247 AMS measurements of modern shell material (3749 individual shells) from 46 different species. The modern gastropods that we analyzed were all collected from habitats on carbonate terrain and, therefore, the data presented here represent worst-case scenarios. In sum, ~78% of the shell aliquots that we analyzed did not contain dead carbon from limestone or other carbonate rocks even though it was readily available at all sites, 12% of the aliquots contained between 5 and 10% dead carbon, and a few (3% of the total) contained more than 10%. These results are significantly lower than the 20-30% dead carbon that has been reported previously for larger taxa living in carbonate terrain. For the second criterion, we report a case study from the American Midwest in which we analyzed fossil shells of small terrestrial gastropods (7 taxa; 18 AMS measurements; 173 individual shells) recovered from late-Pleistocene sediments. The fossil shells yielded 14C ages that were statistically indistinguishable from 14C ages of well-preserved plant macrofossils from the same stratum. Although just one site, these results suggest that small terrestrial gastropod shells may behave as closed systems with respect to carbon over geologic

  13. Pathology of Haplosporidium patagon affecting siphonariid gastropods in Patagonia.

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    Di Giorgio, Gisele; Gilardoni, Carmen; Ituarte, Cristián

    2014-11-13

    Haplosporidium patagon was found parasitizing Siphonaria lessonii and S. lateralis, 2 siphonariid gastropods co-occurring on the littoral rocky shore at Puerto Deseado, Santa Cruz, Argentina. Gastropods from 2 habitats representing 2 different levels of environmental harshness were studied. In both cases, S. lessonii showed a higher prevalence of infection (3.78%) over the entire 14 mo study period than S. lateralis (0.13%). Very different values of prevalence of infection were observed at the different sampling sites: Site 1, the more restrictive habitat (exposed for long periods to desiccation during low tides, higher ultraviolet exposure, and high ranges of temperature variation) showed a higher prevalence value (5.99%) than Site 2 (1.46%). Statistical differences in prevalence were also found between values corresponding to the austral spring (3.35% at Site 1 and 0.74% at Site 2) and winter (13.79% at Site 1 and 2.13% at Site 2). The presence/absence of H. patagon did not vary significantly with gastropod shell length. Infection affected the digestive gland, whose normal histology was greatly modified. The hermaphroditic gonads were also affected; the female germinal cells disappeared or only a few primary or previtellogenic oocytes were present, and vitellogenesis was inhibited. The function of the male germinal epithelium, as well as spermatogenesis and spermiogenesis processes and associated organs (seminal vesicles and seminal receptacles), were not affected. However, the glandular pallial complex of the reproductive systemwas affected, and we observed a significant reduction in development in parasitized gastropods. H. patagon sporocysts also invaded the supporting connective tissues of both the kidney and pseudobranch.

  14. Radular marks produced by grazing gastropods of the rocky intertidal

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    Yván Reyes

    2014-06-01

    Full Text Available We had used artificial surfaces to examine the radular marks of four common grazing gastropods from Ancon Bay. In this work we show radular marks on dental wax surface of the trochid Tegula atra (Lesson, 1830, the fissurellid Fissurella peruviana Lamarck, 1822, the lottid Lottia ceciliana (Orbigny, 1841 and the littorinid Nodilittorina peruviana (Lamarck, 1822. In addition, the radular type is described to each species to relate it to the produced mark.

  15. Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs?

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    Türke, Manfred; Andreas, Kerstin; Gossner, Martin M; Kowalski, Esther; Lange, Markus; Boch, Steffen; Socher, Stephanie A; Müller, Jörg; Prati, Daniel; Fischer, Markus; Meyhöfer, Rainer; Weisser, Wolfgang W

    2012-01-01

    Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon.

  16. Fauna of gastropod molluscs in the Curonian Lagoon littoral biotopes (Baltic Sea, Kaliningrad region, Russia

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    Dmitry Filippenko

    2011-12-01

    Full Text Available A survey of the gastropod mollusc fauna in the coastal waters of the southern part of the Curonian Lagoon (Kaliningrad region, Russia were carried out. Study revealed 34 aquatic gastropods representing 30% of Prosobranchia and 70% of Pulmonata. Obtained data showed higher mollusc diversity in the littoral biotopes in comparison with open areas of the Lagoon. The fauna is represented by a typical Central European species complex of freshwater gastropods. The reed zone along the coastline in the Lagoon functions as a barrier and provides shallow water habitats with slow moving and warmer water, where maximum gastropod species concentrate.

  17. The mechanics of the adhesive locomotion of terrestrial gastropods.

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    Lai, Janice H; del Alamo, Juan C; Rodríguez-Rodríguez, Javier; Lasheras, Juan C

    2010-11-15

    Research on the adhesive locomotion of terrestrial gastropods is gaining renewed interest as it provides a source of guidance for the design of soft biomimetic robots that can perform functions currently not achievable by conventional rigid vehicles. The locomotion of terrestrial gastropods is driven by a train of periodic muscle contractions (pedal waves) and relaxations (interwaves) that propagate from their tails to their heads. These ventral waves interact with a thin layer of mucus secreted by the animal that transmits propulsive forces to the ground. The exact mechanism by which these propulsive forces are generated is still a matter of controversy. Specifically, the exact role played by the complex rheological and adhesive properties of the mucus is not clear. To provide quantitative data that could shed light on this question, we use a newly developed technique to measure, with high temporal and spatial resolution, the propulsive forces that terrestrial gastropods generate while crawling on smooth flat surfaces. The traction force measurements demonstrate the importance of the finite yield stress of the mucus in generating thrust and are consistent with the surface of the ventral foot being lifted with the passage of each pedal wave. We also show that a forward propulsive force is generated beneath each stationary interwave and that this net forward component is balanced by the resistance caused by the outer rim of the ventral foot, which slides at the speed of the center of mass of the animal. Simultaneously, the animal pulls the rim laterally inward. Analysis of the traction forces reveals that the kinematics of the pedal waves is far more complex than previously thought, showing significant spatial variation (acceleration/deceleration) as the waves move from the tail to the head of the animal.

  18. Using microwaves to prepare gastropods for DNA barcoding.

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    Galindo, L A; Puillandre, N; Strong, E E; Bouchet, P

    2014-07-01

    Extracting DNA from gastropods presents particular difficulties due to the capacity of the living animal to retract into the shell, resulting in poor penetration of the ethanol into the tissues. Because the shell is essential to establish the link between sequences and traditional taxonomic identity, cracking the shell to facilitate fixation is not ideal. Several methods are currently in routine use to overcome this difficulty, including chemical relaxation, drilling the shell and boiling. Most of these methods are time-consuming, may be safety hazards and constitute a bottleneck in the preparation of large numbers of specimens in the field. We have experimented with a method traditionally used to clean shells that involves placing the living gastropods in a microwave (MW) oven; the electromagnetic radiation very quickly heats both the animal and the water trapped inside the shell, resulting in separation of the muscles that anchor the animal to the shell. Done properly, the body can be removed intact from the shell and the shell voucher is preserved undamaged. To test the method, the bodies of live-collected specimens from two gastropod species were separated from their shell by microwaving and by anesthetizing/drilling. After identical extraction and PCR procedures, the gels showed no difference in DNA quantity or quality, and the resulting sequences are identical within species. The method was then implemented on a large scale during expeditions, resulting in higher percentage of DNA extraction success. The MWs are also effective for quickly and easily removing other molluscs from their shells, that is, bivalves and scaphopods. Workflows implementing the MW technique show a three- to fivefold increase in productivity compared with other methods.

  19. [Conotoxins: from the biodiversity of gastropods to new drugs].

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    Fedosov, A É; Moshkovskiĭ, S A; Kuznetsova, K G; Olivera, B M

    2013-01-01

    A review describes general trends in research of conotoxins that are peptide toxins isolated from sea gastropods of the Conus genus, since the toxins were discovered in 1970th. There are disclosed a conotoxin classification, their structure diversity and different ways of action to their molecular targets, mainly, ion channels. In the applied aspect of conotoxin research, drug discovery and development is discussed, the drugs being based on conotoxin structure. A first exemplary drug is a ziconotide, which is an analgesic of new generation.

  20. Spatially explicit analysis of gastropod biodiversity in ancient Lake Ohrid

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    T. Hauffe

    2011-01-01

    Full Text Available The quality of spatial analyses of biodiversity is improved by (i utilizing study areas with well defined physiogeographical boundaries, (ii limiting the impact of widespread species, and (iii using taxa with heterogeneous distributions. These conditions are typically met by ecosystems such as oceanic islands or ancient lakes and their biota. While research on ancient lakes has contributed significantly to our understanding of evolutionary processes, statistically sound studies of spatial variation of extant biodiversity have been hampered by the frequently vast size of ancient lakes, their limited accessibility, and the lack of scientific infrastructure. The European ancient Lake Ohrid provides a rare opportunity for such a reliable spatial study. The comprehensive horizontal and vertical sampling of a species-rich taxon, the Gastropoda, presented here, revealed interesting patterns of biodiversity, which, in part, have not been shown before for other ancient lakes.

    In a total of 284 samples from 224 different locations throughout the Ohrid Basin, 68 gastropod species, with 50 of them (= 73.5% being endemic, could be reported. The spatial distribution of these species shows the following characteristics: (i within Lake Ohrid, the most frequent species are endemic taxa with a wide depth range, (ii widespread species (i.e. those occurring throughout the Balkans or beyond are rare and mainly occur in the upper layer of the lake, (iii while the total number of species decreases with water depth, the proportion of endemics increases, and (iv the deeper layers of Lake Ohrid appear to have a higher spatial homogeneity of biodiversity. Moreover, gastropod communities of Lake Ohrid and its feeder springs are both distinct from each other and from the surrounding waters. The analysis also shows that community similarity of Lake Ohrid is mainly driven by niche processes (e.g. environmental factors, but also by neutral processes (e.g. dispersal

  1. Morphological evidence for a morphogenetic field in gastropod mollusc eggs.

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    Tyler, S E; Butler, R D; Kimber, S J

    1998-01-01

    Eggs of the marine gastropod Crepidula fornicata examined by confocal imaging of FITC-lectin binding to the surface, and cryoscopic-SEM both reveal a surface architecture of linear structures organized around the animal-vegetal axis, which is spatially related to the anterior-posterior (a-p) axis of the subsequent embryo. A series of structures is also orientated with reference to specific micromere quartets formed during spiral cleavage. Thus, the surface architecture may provide a visible marker for a morphogenetic field which generates the a-p axis and organizes the cleavage pattern. Moreover, this architecture is co-extensive with that found on the vegetal, polar lobe-bearing region of eggs, as described by others, and which varies between gastropod taxa with varied types of body form. Confocal imaging reveals a distinct localization of F-actin to the architecture of the lobe region. However, the integrity of this F-actin is not responsible for the maintenance of the surface architecture. The significance of these findings to our understanding of the generation of diversity within the Gastropoda and general ontogenic mechanisms is discussed.

  2. Carbonate biomineralization in terrestrial gastropods: environmental vs. physiological constraints

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    Mierzwa, D.; Stolarski, J.

    2009-04-01

    Preservational potential of shells of terrestrial gastropods allows to use them as valuable (paleo)climatic proxies. Despite of the fact, that the elements incorporated in their skeleton derive almost entirely from their diet, details of the ion uptake routes have not been studied in details. This work is a first step in the investigations of element uptake and biomineralization processes in pulmonate gastropod Cepaea vindobonensis (Férussac, 1821). Although phenotypic plasticity in the shell characters of the species appears to be mainly genetic in nature, some differences seem to correlate with availability of ions used in biomineralization. For example, shells of individuals living in marginal parts of flood plains (environment extreme for the species and generally depleted in calcium) have weakened structure and faded color pattern, whereas individuals from the lime substrata form typically developed, pigmented shells with several cross-lamellar layers. Micro- and nanostructural characteristics of shells from different environments are visualized by SEM and AFM imaging techniques and some biogeochemical properties are characterized by spectroscopic and fluorescence methods. Further experiments are required to elucidate the ion/trace elements transfer between the substratum, nutrients, organism, and the shell.

  3. Variation in the diets of hydrothermal vent gastropods

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    Govenar, Breea; Fisher, Charles R.; Shank, Timothy M.

    2015-11-01

    A prevailing paradigm of hydrothermal vent ecology is that primary consumers feed on chemoautotrophic bacteria. However, for the purposes of reconstructing vent food webs and for tracking energy flow from the generation of rock and fluid chemistry through primary/ secondary productivity and consumption to the overlying water column, it remains unclear which consumers feed on which bacteria. In paired analyses of carbon and nitrogen tissue stable isotope values with unique 16S rRNA sequences from the stomach contents, we determined that two species of gastropod grazers appear to feed on epsilon-proteobacteria, while two other species have more diverse diets, including one species that consumes alpha-proteobacteria, planctomycetes, and non-green sulfur bacteria. Different carbon fixation pathways used by epsilon- and alpha-proteobacteria may account for the variation in the carbon stable isotope values among the consumers. Furthermore, our results indicate that trophic specialization and niche partitioning may contribute to the distribution and abundance of vent-endemic gastropods and support the hypothesis that consumers in the warmer habitats commonly feed on epsilon-proteobacteria that use the rTCA cycle, while in the cooler habitats they feed on additional bacteria that use the CBB cycle. These results suggest that the phylogenetic and metabolic diversity of free-living bacteria may play an important and previously overlooked role in facilitating species coexistence among primary consumers at hydrothermal vents and other chemosynthesis-based ecosystems.

  4. The advantage of mucus for adhesive locomotion in gastropods.

    Science.gov (United States)

    Iwamoto, Mayuko; Ueyama, Daishin; Kobayashi, Ryo

    2014-07-21

    For many gastropods, locomotion is driven by a succession of periodic muscular waves (contractions and relaxations) moving along the foot. The force generated by these waves is coupled to the substratum by a thin layer of pedal mucus. Gastropod pedal mucus has unusual physical properties: the mucus is a viscoelastic solid at small deformation and shows a sharp yield point; then, at greater strains, the mucus is a viscous liquid, although it will recover its solidity if allowed to heal for a certain period. In this paper, to clarify the role of the mucus and the flexible muscular waves in adhesive locomotion, we use a simple mathematical model to verify that directional migration can be realized through the interaction between the periodic muscular waves and the specific physical features of mucus. Our results indicate that the hysteresis property of mucus is essential in controlling kinetic friction for the realization of crawling locomotion. Furthermore, our numerical calculations show that both the hysteresis property of mucus and the contraction ratio of muscle give rise to two styles of locomotion, direct waves and retrograde waves, which until now have been explained by different mechanisms. The biomechanical effectiveness of mucus in adhesive locomotion is also discussed.

  5. A catalogue of Danian gastropods from the Baunekule facies, Faxe Formation, Denmark

    Directory of Open Access Journals (Sweden)

    Lauridsen, B.W.

    2014-12-01

    Full Text Available This catalogue of 194 gastropod taxa is based on the collection of Danian gastropods from the Baunekule facies, Faxe Formation in eastern Denmark. The gastropod fauna is extremely rich and well preserved. Most of the gastropods (106 species are referred to genus level only, 9 morphotypes to even higher taxonomical levels and 79 gastropods are referred to species level. The gastropods are classified following Bouchet & Rocroi (2005 as 4 different clades: Vetigastropoda (represented by 26 species and 10 superfamilies, Caenogastropoda (represented by 142 species and 17 superfamilies, Heterobranchia (represented by 23 species and 5 superfamilies and Opisthobranchia (represented by 1 species and 1 superfamily. The new species Zaclys? nuetzeli n. sp. is introduced. The Faxe Formation is recognised as a cold-water coral ecosystem with interfingering smaller bryozoan mounds. The Baunekule facies is found in the upper part of the coral mound complex of the Faxe Formation, where it forms isolated lensoidal bodies in the flanks of some of the coral mounds. It is characterised by a high diversity invertebrate fauna that occurs in weakly consolidated coraldominated floatstone to rudstone. The diagenesis of the Baunekule facies is of special significance because a high proportion of the originally aragonite-shelled fauna is preserved by recrystallization to calcite during early burial diagenesis. Most of the gastropods are not known from other parts of the Faxe Fm. The fauna is very important for comparative evolutionary studies of fossil and modern gastropods on cold-water coral mounds. Many of the genera have not previously been recorded from Danian strata. None of the gastropod species found in the Baunekule facies are known for certain to range below the Cretaceous–Palaeogene boundary. The fauna is comparable to gastropods found on modern cold-water coral mounds in the North Atlantic. The gastropod fauna from the Baunekule facies is characterised by a

  6. Atmospheric O2 Levels Compared to Gastropod Body Size in the Phanerozoic

    Science.gov (United States)

    Ha, C.; Seixas, G.; Payne, J.

    2012-12-01

    Body size greatly impacts the physiological and biological composition of an organism, and the tendency for body size to increase over time (Cope's Rule) indicates that large body size is evolutionally favored for some clades. However, many environmental and ecological factors driving Cope's Rule are poorly understood. In this study, we examine the effects of oxygen levels on gastropod body size during the Phanerozoic by taking numerous measurements of gastropod body size from the primary literature and comparing the resulting data with reconstructed atmospheric oxygen levels. Our graphs show that atmospheric oxygen levels had little effect on gastropod body size. Gastropod body size slowly decreased during the first half of the Paleozoic then stayed fairly constant, while atmospheric oxygen levels increased substantially through the same interval. This finding indicates that there must have been factors more dominant than oxygen in driving Gastropod body size during that time period. In contrast, starting 200mya, as oxygen levels steadily rose, gastropod body size also increased. Our findings act as strong motivation for future research in understanding whether or not oxygen became a dominant factor affecting Gastropod body size 200mya.

  7. Differences in retinoid levels and metabolism among gastropod lineages: imposex-susceptible gastropods lack the ability to store retinoids in the form of retinyl esters.

    Science.gov (United States)

    Gesto, Manuel; Castro, L Filipe C; Santos, Miguel Machado

    2013-10-15

    The presence of a complex retinoid system was long believed to be a chordate/vertebrate novelty. However, recent findings indicate otherwise since the gastropod mollusk Osilinus lineatus was found to have the capacity to store retinoids in the form of retinyl esters (REs), a key feature to maintain a homeostatic control of retinoid levels. Here, we investigated whether such a complex retinoid system is widely distributed among gastropod lineages. Additionally, since one of the most spectacular examples of endocrine disruption in the wild, the masculinization of female gastropods (imposex) by the retinoid X receptor (RXR) agonist, tributyltin (TBT), has been linked with perturbed retinoid signaling, we also investigated if retinoid storage mechanisms in the form of retinyl esters were present in imposex-susceptible gastropods. Initially, we determined the presence of both polar (active retinoic acid isomers) and nonpolar retinoids (retinol, REs) in selected gastropod species: the limpet Patella depressa and the imposex-susceptible whelks Nucella lapillus and Nassarius reticulatus. Although all species presented active retinoid forms, N. lapillus and N. reticulatus were shown to lack nonpolar retinoids. The absence of REs, which are the common retinoid storage form found in vertebrates and in O. lineatus suggest that those species are unable to use them to maintain a homeostatic control of their retinoid levels. In order to further clarify the retinoid metabolic pathways in imposex-susceptible gastropods, a retinoid exposure study was carried out with N. lapillus. The results demonstrate that although N. lapillus is able to metabolize several retinoid precursors, it lacks the capacity to store retinoids as REs. Whether the lack of retinoid storage mechanisms in the form of REs in imposex-susceptible gastropods plays an important role in the susceptibility to RXR agonists warrants additional studies.

  8. [New records of bacteria-spirochetes in crystalline style of fresh water gastropods].

    Science.gov (United States)

    Sitnikova, T Ia; Tulupopva, Iu R; Khanaeva, I V; Prozorova, L A

    2013-01-01

    Freshwater mollusks belonging to 17 species, in 7 families are examined purposely to search for spirochete bacteria in their crystalline style of the digestive system. As result of this study spirochetes are recorded in gastropod families Amnicolidae, Bithyniidae, Baicaliidae and Benedictiidae, represented by 12 species, occupying different habitats. Gastropods belonging to Valvatidae, Lymnaeidae and Planorbidae, characterized by lack of crystalline style did not include spirochetes in their stomachs. Studied gastropods having spirochetes or free of them are grazers or filter-feeders and mainly phyto-detrito-bacteriaphagous.

  9. Contribution to the knowledge of the terrestrial gastropods (Mollusca:Gastropoda from Vrachanska Planina Mountains

    Directory of Open Access Journals (Sweden)

    IVAILO K. DEDOV

    2016-05-01

    Full Text Available Gastropods fauna from the Vrachanska Planina Mountains (= Vrachanska Planina, Northwest Bulgaria, as well it presents the up to now unpublished results of several research trips of the authors and further collectors in the region. In total 90 terrestrial gastropods species are now known from this mountain area. 78 species were published from the beginning of research in this area up to recently. 56 species were confirmed with new findings and 22 species were not found again while the courses of our investigations. 12 gastropod species are newly recorded for the range.

  10. Mass mortality of the vermetid gastropod Ceraesignum maximum

    Science.gov (United States)

    Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.

    2016-09-01

    Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

  11. [Terrestrial gastropods zoogeography in Southern Tamaulipas, México].

    Science.gov (United States)

    Correa, Alfonso; Martínez, Víctor; Horta, Jorge; Castro, Iván

    2012-03-01

    Biogeography of Mexican terrestrial mollusks is poorly known, although many studies have described some of their biological aspects. This study aimed to contribute with new information on the distribution of terrestrial mollusks in this region of high altitudinal, topographic and climatic variations of Southern Tamaulipas State, México. For this, terrestrial gastropods were surveyed from December 1990 to November 2006. A total of 525 samples were obtained from 121 localities, characterized with different vegetation types. The primary zoogeographical feature was the presence of many endemic taxa, with 45 species or subspecies, representing the 43%, the highest value for Northeastern México. In addition, a total of 24 species (23%), were of Neotropical and Neartic distributions, and 15 species or subspecies (14%) exhibited Neotropical distributions. Furthermore, the family Spiraxidae showed the largest number of endemic species, with 17 species and two subspecies, and had the largest number of endemic species (27) for Northeastern México.

  12. Europe's Neogene and Quaternary lake gastropod diversity - a statistical approach

    Science.gov (United States)

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

    2014-05-01

    During the Neogene Europe's geodynamic history gave rise to several long-lived lakes with conspicuous endemic radiations. However, such lacustrine systems are rare today as well as in the past compared to the enormous numbers of "normal" lakes. Most extant European lakes are mainly results of the Ice Ages and are due to their (geologically) temporary nature largely confined to the Pleistocene-Holocene. As glacial lakes are also geographically restricted to glacial regions (and their catchment areas) their preservation potential is fairly low. Also deposits of streams, springs, and groundwater, which today are inhabited by species-rich gastropod assemblages, are rarely preserved. Thus, the pre-Quaternary lacustrine record is biased towards long-lived systems, such as the Late Miocene Lake Pannon, the Early to Middle Miocene Dinaride Lake System, the Middle Miocene Lake Steinheim and several others. All these systems have been studied for more than 150 years concerning their mollusk inventories and the taxonomic literature is formidable. However, apart from few general overviews precise studies on the γ-diversities of the post-Oligocene European lake systems and the shifting biodiversity in European freshwater systems through space and time are entirely missing. Even for the modern faunas, literature on large-scale freshwater gastropod diversity in extant lakes is scarce and lacks a statistical approach. Our preliminary data suggest fundamental differences between modern and pre-Pleistocene freshwater biogeography in central Europe. A rather homogenous central European Pleistocene and Holocene lake fauna is contrasted by considerable provincialism during the early Middle Miocene. Aside from the ancient Dessaretes lakes of the Balkan Peninsula, Holocene lake faunas are dominated by planorbids and lymnaeids in species numbers. This composition differs considerably from many Miocene and Pliocene lake faunas, which comprise pyrgulid-, hydrobiid-, viviparid-, melanopsid

  13. The effects of experimentally induced adelphophagy in gastropod embryos.

    Science.gov (United States)

    Thomsen, Olaf; Collin, Rachel; Carrillo-Baltodano, Allan

    2014-01-01

    Adelphophagy, development where embryos grow large by consuming morphologically distinct nutritive embryos or their own normal siblings is widespread but uncommon among animal phyla. Among invertebrates it is particularly common in some families of marine gastropods and segmented worms, but rare or unknown in other closely related families. In calyptraeid gastropods phylogenetic analysis indicates that adelphophagy has arisen at least 9 times from species with planktotrophic larval development. This pattern of frequent parallel evolution of adelphophagy suggests that the embryos of planktotrophic species might be predisposed to evolve adelphophagy. Here we used embryos of three species of planktotrophic calyptraeids, one from each of three major genera in the family (Bostrycapulus, Crucibulum, and Crepidula), to answer the following 3 questions: (1) Can embryos of species with planktotrophic development benefit, in terms of pre-hatching growth, from the ingestion of yolk and tissue from experimentally damaged siblings? (2) Does ingestion of this material from damaged siblings increase variation in pre-hatching size? and (3) Does this experimentally induced adelphophagy alter the allometry between the velum and the shell, increasing morphological similarity to embryos of normally adelphophagic species? We found an overall increase in shell length and velum diameter when embryos feed on damaged siblings within their capsules. There was no detectable increase in variation in shell length or velum diameter, or changes in allometry. The overall effect of our treatment was small compared to the embryonic growth observed in naturally adelphophagic development. However each embryo in our experiment probably consumed less than one sibling on average, whereas natural adelphophages often each consume 10-30 or more siblings. These results suggest that the ability to consume, assimilate, and benefit from yolk and tissue of their siblings is widespread across calyptraeids.

  14. The effects of experimentally induced adelphophagy in gastropod embryos.

    Directory of Open Access Journals (Sweden)

    Olaf Thomsen

    Full Text Available Adelphophagy, development where embryos grow large by consuming morphologically distinct nutritive embryos or their own normal siblings is widespread but uncommon among animal phyla. Among invertebrates it is particularly common in some families of marine gastropods and segmented worms, but rare or unknown in other closely related families. In calyptraeid gastropods phylogenetic analysis indicates that adelphophagy has arisen at least 9 times from species with planktotrophic larval development. This pattern of frequent parallel evolution of adelphophagy suggests that the embryos of planktotrophic species might be predisposed to evolve adelphophagy. Here we used embryos of three species of planktotrophic calyptraeids, one from each of three major genera in the family (Bostrycapulus, Crucibulum, and Crepidula, to answer the following 3 questions: (1 Can embryos of species with planktotrophic development benefit, in terms of pre-hatching growth, from the ingestion of yolk and tissue from experimentally damaged siblings? (2 Does ingestion of this material from damaged siblings increase variation in pre-hatching size? and (3 Does this experimentally induced adelphophagy alter the allometry between the velum and the shell, increasing morphological similarity to embryos of normally adelphophagic species? We found an overall increase in shell length and velum diameter when embryos feed on damaged siblings within their capsules. There was no detectable increase in variation in shell length or velum diameter, or changes in allometry. The overall effect of our treatment was small compared to the embryonic growth observed in naturally adelphophagic development. However each embryo in our experiment probably consumed less than one sibling on average, whereas natural adelphophages often each consume 10-30 or more siblings. These results suggest that the ability to consume, assimilate, and benefit from yolk and tissue of their siblings is widespread across

  15. Measurement of DNA integrity in marine gastropods as biomarker of genotoxicity

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Vashistha, D.; Gupta, N.; Malik, K.; Gaitonde, D.C.S.

    The occurrence of DNA strand breaks in marine gastropods such as Nerita chameleon, Morula granulata and Cerithidea cingulata collected from different sites (Tirakol, Arambol, Dona Paula and Velsao) along the Goa coast are evaluated. In order...

  16. Two problematic, troglophilous gastropods from the Peloponnese, Greece (Gastropoda: Pulmonata: Zonitidae)

    NARCIS (Netherlands)

    Gittenberger, E.

    2008-01-01

    Two species of pulmonate gastropods are described as new to science although their generic classification remains uncertain since only shells are available for study. The species might be troglodytes. Their shells indicate the presence of subterraneous material.

  17. Taphonomy and palaeoecology of the gastropod fauna from a Late Cretaceous rocky shore, Sweden

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Surlyk, Finn

    2011-01-01

    A gastropod fauna comprising 17 species, each represented by a limited number of specimens, is described from a Late Cretaceous, late early Campanian rocky shore at Ivö Klack, southern Sweden. The gastropod fauna is associated with the most diverse ancient rocky shore fauna ever found. However......, the low gastropod species diversity compared to the faunas of modern rocky shores is ascribed to taphonomic factors, notably dissolution of the aragonitic shells, but the predominance of epifaunal herbivores is indicative of a guild structure similar to that found on modern rocky shores. The presence...... preservation of such drill holes difficult, since the majority of infaunal prey such as burrowing bivalves has aragonitic shells which are not preserved. The relatively high number of species in comparison to many other Late Cretaceous rocky shore faunas, offers an opportunity to compare gastropod guild...

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

    Science.gov (United States)

    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.

  19. Gulf of Mannar Island coral reef associated gastropods assemblages:Distribution and diversity pattern

    Institute of Scientific and Technical Information of China (English)

    Jayaraj Mohanraj; Gurusamy Chelladurai; Srinivasan Balakrishnan; IruthayamVijaya Kuamr

    2015-01-01

    Objective: To study the spatial and temporal variations of the distribution and diversity pattern of coral reef associated gastropods assemblages in Gulf of Mannar Island and to clarify the relationship between gastropods and surrounding coral reef ecosystem. Methods: Gastropods were collected from three islands–Hare (Picnic spot), Vaan (Church Island) and Koswari (Karsuvar Island). The samples were taxonomically identified according to external structure of typical shells and classified according to their feeding habits. Statistical tool Primer (Ver. 6.1.11) was employed to find the species diversity, richness and evenness. Results: A total of forty species of gastropods from 19 families were identified. The gastropods population density varied differently at stations, 479 species from Vaan islands, 390 species from Koswari islands and 254 species from Hare island were recorded. The gastropods species diversity, richness and evenness indices also varied differently at stations. The highest species diversity indice was recorded at Vaan Island (2.968), while both the highest richness and evenness indices were recorded at Hare Island with 0.937 and 0.942 respectively. Conclusions: The results of present study provides useful informtation for biodiversity conservation as well as the management of coral reef habitat in India.

  20. Spatially explicit analyses of gastropod biodiversity in ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    T. Hauffe

    2010-07-01

    Full Text Available Spatial heterogeneity of biodiversity arises from evolutionary processes, constraints of environmental factors and the interaction of communities. The quality of such spatial analyses of biodiversity is improved by (i utilizing study areas with well defined physiogeographical boundaries, (ii limiting the impact of widespread species, and (iii using taxa with heterogeneous distributions. These conditions are typically met by ecosystems such as oceanic islands or ancient lakes and their biota. While research on ancient lakes has contributed significantly to our understanding of evolutionary processes, statistically sound studies of spatial variation of extant biodiversity have been hampered by the frequently vast size of ancient lakes, their limited accessibility, and the lack of infrastructure around them. The small European ancient Lake Ohrid provides a rare opportunity for such a reliable spatial study. The comprehensive horizontal and vertical sampling of a species-rich taxon, the Gastropoda, presented here, revealed interesting patterns of biodiversity, which, in part, have not been shown before for other ancient lakes.

    In a total of 224 locations throughout the Ohrid Basin, representatives of 68 gastropod species with 50 of them being endemic (=73.5% could be reported. The spatial distribution of these species shows the following characteristics:

    (i within Lake Ohrid, the most frequent species are endemic taxa with a wide depth range, (ii widespread species (i.e. those occurring throughout the Balkans or beyond are rare and mainly occur in the upper layer of the lake, (iii while the total number of species decreases with water depth, the share of endemics increases, (iv the deeper layers of Lake Ohrid appear to have a higher spatial homogeneity of biodiversity and related environmental factors, (v biotic interaction due to possible spillover effects may contribute to the establishment of hotspots, and (vi eco

  1. A Method for Quantifying, Visualising, and Analysing Gastropod Shell Form.

    Science.gov (United States)

    Liew, Thor-Seng; Schilthuizen, Menno

    2016-01-01

    Quantitative analysis of organismal form is an important component for almost every branch of biology. Although generally considered an easily-measurable structure, the quantification of gastropod shell form is still a challenge because many shells lack homologous structures and have a spiral form that is difficult to capture with linear measurements. In view of this, we adopt the idea of theoretical modelling of shell form, in which the shell form is the product of aperture ontogeny profiles in terms of aperture growth trajectory that is quantified as curvature and torsion, and of aperture form that is represented by size and shape. We develop a workflow for the analysis of shell forms based on the aperture ontogeny profile, starting from the procedure of data preparation (retopologising the shell model), via data acquisition (calculation of aperture growth trajectory, aperture form and ontogeny axis), and data presentation (qualitative comparison between shell forms) and ending with data analysis (quantitative comparison between shell forms). We evaluate our methods on representative shells of the genera Opisthostoma and Plectostoma, which exhibit great variability in shell form. The outcome suggests that our method is a robust, reproducible, and versatile approach for the analysis of shell form. Finally, we propose several potential applications of our methods in functional morphology, theoretical modelling, taxonomy, and evolutionary biology.

  2. A Method for Quantifying, Visualising, and Analysing Gastropod Shell Form

    Science.gov (United States)

    Liew, Thor-Seng; Schilthuizen, Menno

    2016-01-01

    Quantitative analysis of organismal form is an important component for almost every branch of biology. Although generally considered an easily-measurable structure, the quantification of gastropod shell form is still a challenge because many shells lack homologous structures and have a spiral form that is difficult to capture with linear measurements. In view of this, we adopt the idea of theoretical modelling of shell form, in which the shell form is the product of aperture ontogeny profiles in terms of aperture growth trajectory that is quantified as curvature and torsion, and of aperture form that is represented by size and shape. We develop a workflow for the analysis of shell forms based on the aperture ontogeny profile, starting from the procedure of data preparation (retopologising the shell model), via data acquisition (calculation of aperture growth trajectory, aperture form and ontogeny axis), and data presentation (qualitative comparison between shell forms) and ending with data analysis (quantitative comparison between shell forms). We evaluate our methods on representative shells of the genera Opisthostoma and Plectostoma, which exhibit great variability in shell form. The outcome suggests that our method is a robust, reproducible, and versatile approach for the analysis of shell form. Finally, we propose several potential applications of our methods in functional morphology, theoretical modelling, taxonomy, and evolutionary biology. PMID:27280463

  3. Assessing open-system behavior of 14C in terrestrial gastropod shells

    Science.gov (United States)

    Rech, Jason A.; Pigati, Jeffrey S.; Lehmann, Sophie B.; McGimpsey, Chelsea N.; Grimley, David A.; Nekola, Jeffrey C.

    2011-01-01

    In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190-130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent 14C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for 14C dating (e.g. charcoal), and typically sets the upper practical limit of the technique. Two aliquots of gastropod shells from the Illinoian-aged Petersburg Silt (Petersburg Section) in central Illinois, USA, however, yielded elevated 14C activities of 1.26 and 1.71 pMC, which correspond to apparent 14C ages of 35.1 and 32.7 ka. Together, these results suggest that while many fossil gastropods shells may not suffer from major (>1%) open-system problems, this is not always the case. We then examined the mineralogy, trace element chemistry, and physical characteristics of a suite of fossil and modern gastropod shells to identify the source of contamination in the Petersburg shells and assess the effectiveness of these screening techniques at identifying samples suitable for 14C dating. Mineralogical (XRD) and trace element analyses were inconclusive, which suggests that these techniques are not suitable for assessing open-system behavior in terrestrial gastropod shells. Analysis with scanning electron microscopy (SEM), however, identified secondary mineralization (calcium carbonate) primarily within the inner whorls of the Petersburg shells. This indicates that SEM examination, or possibly standard microscope examination, of the interior of gastropod shells should be used when selecting fossil gastropod shells for 14C dating.

  4. Conservation status of freshwater gastropods of Canada and the United States

    Science.gov (United States)

    Johnson, Paul D.; Bogan, Arthur E.; Brown, Kenneth M.; Burkhead, Noel M.; Cordeiro, James R.; Garner, Jeffrey T.; Hartfield, Paul D.; Lepitzki, Dwayne A.; Mackie, Gerry L.; Pip, Eva; Tarpley, Thomas A.; Tiemann, Jeremy S.; Whelan, Nathan V.; Strong, Ellen E.

    2013-01-01

    This is the first American Fisheries Society conservation assessment of freshwater gastropods (snails) from Canada and the United States by the Gastropod Subcommittee (Endangered Species Committee). This review covers 703 species representing 16 families and 93 genera, of which 67 species are considered extinct, or possibly extinct, 278 are endangered, 102 are threatened, 73 are vulnerable, 157 are currently stable, and 26 species have uncertain taxonomic status. Of the entire fauna, 74% of gastropods are imperiled (vulnerable, threatened, endangered) or extinct, which exceeds imperilment levels in fishes (39%) and crayfishes (48%) but is similar to that of mussels (72%). Comparison of modern to background extinction rates reveals that gastropods have the highest modern extinction rate yet observed, 9,539 times greater than background rates. Gastropods are highly susceptible to habitat loss and degradation, particularly narrow endemics restricted to a single spring or short stream reaches. Compilation of this review was hampered by a paucity of current distributional information and taxonomic uncertainties. Although research on several fronts including basic biology, physiology, conservation strategies, life history, and ecology are needed, systematics and curation of museum collections and databases coupled with comprehensive status surveys (geographic limits, threat identification) are priorities.

  5. Estrogen receptor genes in gastropods: phylogenetic divergence and gene expression responses to a synthetic estrogen.

    Science.gov (United States)

    Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C

    2016-11-01

    Endocrine disrupting chemicals (EDCs) have the potential to affect development and reproduction in gastropods. However, one is today lacking basic understanding of the Molluscan endocrine system and one can therefore not fully explain these EDC-induced affects. Furthermore, only a few genes that potentially may be connected to the endocrine system have been sequenced in gastropods. An example is the estrogen receptor gene (er) that have been identified in a restricted number of freshwater and marine gastropods. Here, we have identified a new partial coding sequence of an estrogen receptor gene (er) in the European common heterobranch Radix balthica. The following phylogenetic analysis divided the ers of heterobranchs and ceanogastropods in two branches. Furthermore, exposure to the synthetic estrogen 17α-ethinylestradiol (EE2) showed that exposure could significantly affect er expression level in the heterobranch R. balthica. This paper is the first that phylogenetically compares gastropods' er, basal er expression profiles, and transcriptional estrogenic responses in gastropods from two different evolutionary groups.

  6. Checklist of Gastropods from the Exclusive Economic Zone (EEZ), Sarawak, Malaysia

    Science.gov (United States)

    Morni, Wan Zabidii Wan; Rahim, Siti Akmar Khadijah Ab; Rumpet, Richard; Musel, Jamil; Hassan, Ruhana

    2017-01-01

    This study provides the first marine gastropod checklist from the Sarawak Exclusive Economic Zone (EEZ). Gastropod samples were collected from selected stations in the Sarawak EEZ using an otter trawl net with a stretched mesh size of 38 mm at the cod end. The trawling operations were conducted more than 12 nautical miles from the coast, and the area was divided into three depth strata: I) 20–50 m, II) 50–100 m and III) 100–200 m. A total of 23 gastropod species were identified during the two-month sampling period from 16 August until 6 October 2015, representing 8 superfamilies, 15 families and 20 genera. Superfamily Tonnoidea was represented by 7 species, followed by Muricoidea (5 species), Cypraeoidea (4 species), and Buccinoidea and Conoidea (both with 2 species). Other superfamilies were represented by a single species. Only 3 species were obtained in 2 depth strata, namely Melo melo, Murex aduncospinosus and Tonna galea. In addition, 9, 13 and 4 species of gastropods were found in strata I, II and III, respectively. The information on gastropod distributions at different depth strata in the Sarawak EEZ could be useful in updating the Malaysian species diversity database.

  7. The Environmental Context of Gastropods on Western Laurentia (Basin and Range Province) during the Great Ordovician Biodiversification Event

    Science.gov (United States)

    Dahl, Robyn Mieko

    2015-01-01

    Gastropods are a major component of modern marine ecosystems and can be found in nearly every type of marine ecosystem. They experienced their first notable radiation during the Great Ordovician Biodiversification Event (~470 Ma), during which their diversity tripled. This study examines the gastropod assemblage preserved in the Basin and Range…

  8. Cheсklist of gastropod molluscs in mangroves of Khanh Hoa province, Vietnam.

    Science.gov (United States)

    Zvonareva, Sofya; Kantor, Yuri

    2016-09-12

    Gastropod molluscs are one of the most important components of mangrove ecosystem. Mangroves in Central Vietnam have a rather limited distribution due to peculiarities of the coastline morphology and presently their fauna remains understudied. Extensive surveys were conducted in both natural vegetation and artificial mangrove plantations in several localities in Nha Trang Bay from 2005 to 2015. In total 65 species of gastropod molluscs were found alive, 17 of which can be considered as predominantly mangrove-associated. An illustrated guide is provided, with short synonymies and data on ecology and distribution. The recorded molluscan diversity is compared with published data on mangrove gastropods in different regions of the Indo-Pacific. Total species number and the proportion of mangrove-associated species are similar to studied faunas in Hong Kong, Malaysia and Thailand, but the diversity is much lower than that of the mangal fauna of the Philippines.

  9. 1-Phenoxy-2-propanol is a useful anaesthetic for gastropods used in neurophysiology.

    Science.gov (United States)

    Wyeth, Russell C; Croll, Roger P; Willows, A O Dennis; Spencer, Andrew N

    2009-01-30

    Anaesthesia is often used in neurophysiological, surgical, and neuroanatomical protocols. Several anaesthetics, including magnesium chloride, volatiles (halothane, etc.), and barbiturates, have been used in gastropod neurobiology. 1-Phenoxy-2-propanol (PP) is another anaesthetic option that has not yet been used extensively. We provide an analysis of the neural, muscular and behavioural effects of PP in gastropods. PP eliminates action potentials and reduces muscular contraction force in Hermissenda crassicornis, and eliminates behavioural activity in Tritonia diomedea. Our results show these effects are reversible, with complete action potential recovery, at least partial muscular recovery, and full behavioural recovery. Survival after surgery in T. diomedea was longer with PP than without anaesthetic, and PP also reduced contraction during tissue fixation in Lymnaea stagnalis. Moreover, PP can be bath applied, has low toxicity, and is biodegradable. Thus, PP is an effective anaesthetic in three species of gastropods, and useful in neurophysiological dissection, surgical, and fixation protocols.

  10. Antimicrobial secondary metabolites from marine gastropod egg capsules and egg masses

    Institute of Scientific and Technical Information of China (English)

    Kaviarasan T; Siva Sankar R; Yogamoorthi A

    2012-01-01

    Marine organisms have attracted special attention in the last three decades for their ability to produce interesting pharmacological active compounds. Even though all marine organisms have the potential to produce antimicrobial secondary metabolites, the gastropod has the vital sources of secondary metabolites particularly their egg capsule which has the promising antimicrobial secondary metabolites. In the present review, we intend to focus on marine secondary metabolites from marine gastropod egg capsule. The following compounds i.e. Kabiramid C, Aplysianin E, Aplysianin A, Thisaplysianin E and Tyrian purple have been documented in egg capsule of various gastropod and most of the antimicrobial secondary metabolites have not been isolated from the egg capsule because of the odious, and complex chemical structure. Stability of the compounds is unknown.

  11. Chemical cues released by an alien invasive aquatic gastropod drive its invasion success.

    Directory of Open Access Journals (Sweden)

    Jacqueline L Raw

    Full Text Available BACKGROUND: Chemical cues provide aquatic organisms with sensory information that guides behavioural responses and thus interactions among themselves, each other and the environment. Chemical cues are considered important for predator avoidance, foraging, larval settlement and broadcast spawning in aquatic environments. However, the significance of their role as drivers of direct interactions between heterospecifics has been largely overlooked. METHODOLOGY/PRINCIPAL FINDINGS: A video camera and a demarcated arena were used in situ to record behavioural responses of three native gastropod species, Assiminea cf. capensis, Melanoides tuberculata and Coriandria durbanensis, exposed to treatments representing chemical cues released by a non-native invasive gastropod, Tarebia granifera. The responses were measured quantitatively as displacement and orientation of movement at locations in St Lucia Estuary, within the iSimangaliso Wetland Park, a UNESCO World Heritage Site on the east coast of South Africa. All native gastropods exhibited a negative taxis response to chemical cues released by T. granifera, while T. granifera individuals responded randomly to conspecifics. Displacement was measured relative to the source of the extract, the number of steps taken were determined with path analysis and orientation was determined from the mean (±95% CIs turning angles, with significant negative turning angles representing negative taxis. Responses to treatments corresponding to the environment and conspecifics were random and undirected, indicating kinesis. CONCLUSION/SIGNIFICANCE: This study presents evidence for interactions driven by chemical cues between a non-native invasive gastropod and several gastropods native to South Africa. The results indicate that chemical cues can facilitate invasion success as the behavioural response of native gastropods is to move away allowing additional food and space resources to become available to T. granifera.

  12. Host-symbiont relationships in hydrothermal vent gastropods of the genus Alviniconcha from the Southwest Pacific.

    Science.gov (United States)

    Suzuki, Yohey; Kojima, Shigeaki; Sasaki, Takenori; Suzuki, Masae; Utsumi, Takashi; Watanabe, Hiromi; Urakawa, Hidetoshi; Tsuchida, Shinji; Nunoura, Takuro; Hirayama, Hisako; Takai, Ken; Nealson, Kenneth H; Horikoshi, Koki

    2006-02-01

    Hydrothermal vent gastropods of the genus Alviniconcha are unique among metazoans in their ability to derive their nutrition from chemoautotrophic gamma- and epsilon-proteobacterial endosymbionts. Although host-symbiont relationships in Alviniconcha gastropods from the Central Indian Ridge in the Indian Ocean and the Mariana Trough in the Western Pacific have been studied extensively, host-symbiont relationships in Alviniconcha gastropods from the Southwest Pacific remain largely unknown. Phylogenetic analysis using mitochondrial cytochrome c oxidase subunit I gene sequences of host gastropods from the Manus, North Fiji, and Lau Back-Arc Basins in the Southwest Pacific has revealed a new host lineage in a Alviniconcha gastropod from the Lau Basin and the occurrence of the host lineage Alviniconcha sp. type 2 in the Manus Basin. Based on 16S rRNA gene sequences of bacterial endosymbionts, two gamma-proteobacterial lineages and one epsilon-proteobacterial lineage were identified in the present study. The carbon isotopic compositions of the biomass and fatty acids of the gastropod tissues suggest that the gamma- and epsilon-proteobacterial endosymbionts mediate the Calvin-Benson cycle and the reductive tricarboxylic acid cycle, respectively, for their chemoautotrophic growth. Coupling of the host and symbiont lineages from the three Southwest Pacific basins revealed that each of the Alviniconcha lineages harbors different bacterial endosymbionts belonging to either the gamma- or epsilon-Proteobacteria. The host specificity exhibited in symbiont selection provides support for the recognition of each of the host lineages as a distinct species. The results from the present study also suggest the possibility that Alviniconcha sp. types 1 and 2 separately inhabit hydrothermal vent sites approximately 120 m apart in the North Fiji Basin and 500 m apart in the Manus Basin.

  13. [Gastropods associated with the calcareous alga Halimeda opuntia (Udoteaceae) in Puerto Rico].

    Science.gov (United States)

    García-Ríos, Cedar I; Soto-Santiago, Francisco J; Colón-Rivera, Ricardo J; Medina-Hernández, Javier R

    2008-12-01

    Gastropod communities associated with the calcareous green alga Halimeda opuntia are described and compared for two Puerto Rico coral reefs: one in the northeast with front tradewinds (windward zone) and one in the southwest (leeward zone). We analyzed the content of 21 lots (2432 g) of H. opuntia from leeward zone and 15 lots (2448 g) from the windward zone. In total we recovered 526 gastropods (prosobranchs) classified in 54 taxa. Thirteen species of gastropods represented 79.6% of the community. Differences between species richness and mean density values were not significant (p > 0.100). Forty species were identified from leeward and thirty one (31) species from windward. Gastropod mean density was 13.9/100 g of algae in leeward and 7.6/100 g in windward. Significant differences were found for the Simpson Diversity Index (0.91 in the leeward and 0.82 in the windward community; t = 3.44, alpha = 0.005). We found no correlation between the weight of the algae and the frequency of the gastropods (R2 = 0.0893 in leeward, 0.0249 windward and 0.0923 for both). The relationship between species composition in lots of windward and leeward study sites was explored via polar ordination and no segregation was found. When compared, the gastropod communities found in H. opuntia collected in coral reefs in Puerto Rico were more similar within them than any other communities found in other genera of seaweed and in other environments. Our results agree with the hypothesis that H. opuntia offers the interstitial community a protected microhabitat from water movement impact. H. opuntia creates more homogenous conditions than those of the habitat where we found the algae.

  14. [Diversity of trematode larvae in gastropod molluscs in water bodies of Belarus].

    Science.gov (United States)

    Akimova, L N; Shimalova, V V; Bychkova, E I

    2011-01-01

    The analysis of literary data and own investigations of gastropod molluscs on existence of cercariae of trematodes in Belarus was carried out. 13 856 specimens of 11 species and 2 species complexes of freshwater gastropod molluscs were examined on infection with cercariae of trematodes in 2010 by the authors of this article. Total infestation was 13.1% and infection of some molluscs species varied from 0.4% (Dnieper River, Gomel region) to 66.7% (Lukomskoe reservoir, Vitebsk region). The cercariae of 90 trematode species were found. The majority (51 species) at the adult stage parasitize birds. The cercariae of 14 trematode species have medical significance.

  15. Convergence Caused Confusion: On the Systematics Of the Freshwater Gastropod Sulcospira pisum (Brot, 1868) (Cerithioidea, Pachychilidae)

    DEFF Research Database (Denmark)

    Koehler, Frank; Brinkmann, Nora; Glaubrecht, Matthias

    2008-01-01

    We document a case of shell convergence in sympatric freshwater cerithioidean gastropods that has caused confusion in traditional classifications emphasizing shell features. Based on the comparative study of the operculum, radula, and embryonic shell obtained from dry remains of soft bodies, we...... for the family. It is tentatively placed within the genus Sulcospira, which is endemic to Java. We assume that a similar shell shape has evolved in both species of not closely related gastropods through convergence, which once more reveals that purely shell-based classifications are particularly problematic....

  16. Late Mississippian gastropods of the Chainman Shale, west-central Utah

    Science.gov (United States)

    Gordon, Mackenzie; Yochelson, Ellis L.

    1987-01-01

    The Chainman Shale of Mississippian (Osagean to late Chesterian) age, well exposed in the Confusion Range of western Utah, has yielded a profusion of fossils during investigations conducted by the U.S. Geological Survey in the past 30 years. Conspicuous among these fossils are gastropods, which range in age from latest Meramecian to late Chesterian. In west-central Utah, not far from the State boundary, the Chainman outcrop belt stretches from Granite Mountain south to the northern part of the Needle Range, a distance of69 miles (110 km). The Chainman thickens from north to south; the section at Granite Mountain is 1,315 feet (401 m) thick and that at Jensen Wash in the Burbank Hills, 2,203 feet (671 m). The rocks of the Chainman Shale record a general though irregular shallowing of the area from moderate depths of 330 feet (100 m) or so to quite shallow depths of perhaps locally little more than 3-6 feet (1-2 m). Most of the gastropods occur with ammonoids in a facies of shale or shale containing phosphatic limestone concretions, In this lutaceous facies, Glabrocingulum is predominant and Lunulazona and Retispira are common; these genera are represented by a succession of species. A thick limestone unit is present in some areas in the upper part of the formation, particularly in the vicinity of Skunk Spring, where it is 318 feet (97 m) thick. This limestone unit represents a calcareous shoal facies having an entirely different gastropod fauna, characterized by Catazona and species of Naticopsis. The Chainman Shale could be easily zoned by gastropods, but we are not proposing such azonation. A framework of ammonoid and foraminiferal zones already is available, and we prefer to regard the gastropod assemblages as part of this framework. The assemblages are confined to the major ammonoid and foraminiferal zones, and only three of the gastropod species seem to range across major zonal boundaries. These species are Bellerophon (Bellerophon vespertinus Gordon and

  17. Digenean parasites of the marine gastropods Littorina littorea and Gibbula umbilicalis in the Northern Portuguese Atlantic coast, with a review of digeneans infecting the two gastropod genera

    Directory of Open Access Journals (Sweden)

    Graça Costa

    2016-05-01

    Full Text Available Objective: To study the digenean parasites of the prosobranch gastropods, Littorina littorea (L. littorea and Gibbula umbilicalis (G. umbilicalis from rocky shores of the Northern Atlantic coast of Portugal. Methods: A total of 413 L. littorea and 2603 G. umbilicalis were collected from rocky shores, at Aveiro estuary, Aguda Beach, and Foz Beach at Porto (Northern Atlantic coast of Portugal from January to July 2014 and February 2014 to January 2015, respectively. Gonads and digestive glands of the gastropods were examined under light microscopy for the presence of digeneans. Infected gonads of L. littorea were prepared for histological observation, whereas digeneans found in G. umbilicalis were studied and identified with the aid of light and scanning electron microscopy. Results: Two species of digeneans were found infecting the digestive gland and gonads of G. umbilicalis, namely, Cainocreadium labracis and Lecithochirium furcolabiatum with a combined prevalence of 3%. Histological observations of gonads of L. littorea revealed the infection with digeneans, with considerable replacement of gonadal tissues. These digeneans were not identified to species level. The prevalence of digeneans in this snail host was 0.7%. Conclusions: The present study adds G. umbilicalis as another first intermediate host for Cainocreadium labracis and extends its geographical range to the Portuguese Atlantic coast. Cercariae of Lecithochirium furcolabiatum were previously reported from G. umbilicalis. A literature review of digeneans occurring in the gastropod genera Gibbula and Littorina is given.

  18. Patterns of diatom treatment in two coexisting species of filter-feeding freshwater gastropods

    Directory of Open Access Journals (Sweden)

    Sitnikova T.Ya.

    2014-03-01

    Full Text Available To assess trophic partitioning among sympatric gastropod species in ancient lakes, we quantified diatoms in the guts of two coexistent Baikal gastropod species and tested for differences in species, size, and fracturing of large and small diatoms by taenioglossan radulae. In May 2010, the diatom Synedra acus dominated the littoral phytoplankton and gut contents of Baicalia turriformis and Teratobaikalia ciliata (Baicaliidae, both inhabiting the rocky Baikal littoral. In laboratory experiments, both ctenidial filter-feeding gastropods were fed with two diets of cultivated Synedra acus of different cell sizes: >150 μm and <100 μm. Field and laboratory studies revealed intact diatom cells (often with green chromatophores and fragmented frustules of diatoms <60 μm in the guts of both species. The two baicaliids varied in the number of ingested microalgae. In addition, they exhibited significantly different efficiencies for breaking large diatoms; B. turriformis broke large diatoms into more fragments than T. ciliata. The differences in the utilization of large and small diatoms by gastropods are discussed in terms of the relationships among coexisting species. Small diatom survival is considered from the view of interactions between producers and their consumers in the freshwater food web.

  19. A new alien gastropod Pseudorhaphitoma iodolabiata (Hornung & Mermod, 1928 (Mangeliidae, Mollusca in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    B. OZTURK

    2012-12-01

    Full Text Available The study documents the occurrence of a new alien gastropod Pseudorhaphitoma iodolabiata in the Mediterranean Sea, collected inIskenderun Bay, Turkey, on September 2011. This record increases to 213 the number of alien molluscs in the Mediterranean.

  20. The land and freshwater gastropods collected in Cuba by M.G. Rutten

    NARCIS (Netherlands)

    Jacobson, Morris K.

    1970-01-01

    While making geological studies in Cuba during 1933 Recent gastropods were collected by M.G. Rutten and H.J. MacGillavry in the provinces of Pinar del Río, Las Villas, and Camagüey. The collection of 54 species and subspecies is stored in the Zoölogisch Museum in Amsterdam. Some new locality records

  1. Paleobiogeographic affinities of emsian (late early devonian) gastropods from farewell terrane (west-central Alaska)

    Science.gov (United States)

    Fryda, J.; Blodgett, R.B.

    2008-01-01

    The vast majority of Emsian gastropods from Limestone Mountain, Medfra B-4 quadrangle, west-central Alaska (Farewell terrane) belong to species with lecithotrophic larval strategy. The present data show that there is no significant difference in the paleobiogeo-graphic distribution of Emsian gastropod genera with lecithotrophic and planktotrophic larval strategies. Numerical analysis of the faunal affinities of the Emsian gastropod fauna from the Farewell terrane reveals that this terrane has much stronger faunal connections to regions like Variscan Europe, eastern Australia, and the Alexander terrane of southeast Alaska than to cratonic North America (Laurentia). The Canadian Arctic Islands is the only region of cratonic North America (Laurentia) that shows significant faunal affinities to the Emsian gastropod faunas of the Farewell terrane. The analysis also indicates a close faunal link between the Farewell and Alexander terranes. Published paleontological and geological data suggest that the Farewell and Alexander terranes represents tectonic entities that have been rifted away from the Siberia, Baltica, or the paleo-Pacific margin of Australia. The results of the present numerical analysis are not in conflict with any of these possibilities. However, the principle of spatial continuity of the wandering path prefers Siberia as the most probable "parental" paleocontinent for the derivation of both the Farewell and Alexander terranes. ?? 2008 The Geological Society of America.

  2. Terrestrial gastropods of Srebarna Nature Reserve, North-Eastern Bulgaria (Gastropoda

    Directory of Open Access Journals (Sweden)

    Ivailo Dedov

    2015-01-01

    Full Text Available We give the results from the first investigation focused on the land snail fauna in Srebarna Nature Reserve in Bulgaria. A total of 23 localities were studied and 27 species of terrestrial gastropods were found, 23 of which were new observations for the Reserve.

  3. Terrestrial gastropods of Srebarna Nature Reserve, North-Eastern Bulgaria (Gastropoda).

    Science.gov (United States)

    Dedov, Ivailo; Antonova, Vera

    2015-01-01

    We give the results from the first investigation focused on the land snail fauna in Srebarna Nature Reserve in Bulgaria. A total of 23 localities were studied and 27 species of terrestrial gastropods were found, 23 of which were new observations for the Reserve.

  4. Comparative study on gill morphology of gastropods from Moreton Bay, Queensland

    NARCIS (Netherlands)

    Eertman, R.H.M.

    1996-01-01

    This paper reports the gill morphology of seven common gastropods from Moreton Bay, southeastern Queensland, to test the level of difference in gill structure between major taxa. The investigated species include representatives of the clades Patellogastropoda, Neritimorpha and Vetigastropda as well

  5. Attachment to gastropod veliger shells - a possible mechanism of dispersal in benthic foraminiferans

    DEFF Research Database (Denmark)

    Cedhagen, Tomas; Middelfart, Peter

    1998-01-01

    A benthic, calcareous foraminiferan c£ Pararotalia venusta (Brady, 1884) was in five cases found attached to the shell of the veliger larva of the muricid gastropod Thais javanica (Philippi, 1846). Observations showed that such foraminiferans are able to move onto and attach to the larval shell...

  6. Fossil predation: did some clavilithine fasciolariid gastropods employ valve-wedging to feed on bivalves?

    NARCIS (Netherlands)

    Vermeij, Geerat J.

    2015-01-01

    Several gastropods, including members of the Busyconinae, wedge or chip bivalve prey by inserting the outer lip between the valves. This habit, which is associated with an abapically downwardly convex outer lip, often results in breakage and subsequent repair of the lip. I tested the hypothesis that

  7. Determination of tetramine in marine gastropods by liquid chromatography/electrospray ionization-mass spectrometry.

    Science.gov (United States)

    Kawashima, Yoko; Nagashima, Yuji; Shiomi, Kazuo

    2004-08-01

    Tetramine (tetramethylammonium ion) is found at high levels (several mg/g) in the salivary gland of buccinid gastropods and has been involved in numerous poisoning incidents after ingestion of those gastropods. A sensitive and selective determination method for tetramine, which is based on a combination of liquid chromatography (LC) and electrospray ionization-single quadrupole mass spectrometry (ESI-MS), was developed. Following separation by LC on a cation-exchange column, tetramine was easily detected by simultaneous monitoring of a molecular ion (m/z 74) at a cone voltage of 30 V and a fragment ion (m/z 58) at 70 V. A linear calibration curve was obtained in the range of 0.1-100 ng by plotting the peak areas of the molecular ion versus the amounts of tetramine. Spiking experiments demonstrated that tetramine in gastropod tissues can be determined by the LC/ESI-MS method, without being affected by sample matrices as well as the extration procedure. Applications of the new method to gastropod samples revealed that a small amount of tetramine is contained even in mid-gut gland and muscle and that tetramine in the salivary gland diffuses to other tissues during boiling and slow thawing.

  8. First detection and seasonal variation of lipophilic toxins okadaic acid, dinophysistoxin-1, and yessotoxin in Korean gastropods.

    Science.gov (United States)

    Lee, Ka Jeong; Mok, Jong Soo; Song, Ki Cheol; Yu, Hongsik; Lee, Doo Seog; Jung, Jee Hyung; Kim, Ji Hoe

    2012-11-01

    Okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2, and yessotoxin (YTX) are classes of lipophilic toxins found in marine animals. OA and DTX1 accumulation causes diarrhetic shellfish poisoning, a worldwide public health problem. Diarrhetic shellfish poisoning has not previously been reported in gastropods, which are widely consumed in Korea. Seasonal variation in marine lipophilic toxins in gastropods was investigated using liquid chromatography-tandem mass spectrometry. Eighty specimens of Neptunea cumingii, 65 specimens of Rapana venosa, and 95 specimens of Batillus cornutus were collected at the Tongyeong fish market on the southern coast of Korea between May 2009 and December 2010. OA, DTX1, and YTX were detected in meat and digestive glands in all gastropod species studied. Pectenotoxin-2 was not found in any sample tested. Lipophilic toxins were detected in the digestive glands of gastropods; no lipophilic toxin was detected in the salivary glands of the carnivorous gastropods, N. cumingii and R. venosa. The highest concentrations of OA (21.5 ng/g) and DTX1 (8.4 ng/g) were detected in the digestive glands of R. venosa, and the maximum concentration of YTX (13.7 ng/g) was found in the digestive glands of N. cumingii. The maximum toxicities in gastropod tissues were lower than the European standard for acceptable levels. The concentrations of lipophilic toxins in carnivorous gastropods showed a high degree of seasonal variation; lipophilic toxins in carnivorous gastropods were found predominantly in spring and summer. This is the first report of the occurrence of lipophilic toxins in Korean gastropods.

  9. The "island rule" and deep-sea gastropods: re-examining the evidence.

    Directory of Open Access Journals (Sweden)

    John J Welch

    Full Text Available BACKGROUND: One of the most intriguing patterns in mammalian biogeography is the "island rule", which states that colonising species have a tendency to converge in body size, with larger species evolving decreased sizes and smaller species increased sizes. It has recently been suggested that an analogous pattern holds for the colonisation of the deep-sea benthos by marine Gastropoda. In particular, a pioneering study showed that gastropods from the Western Atlantic showed the same graded trend from dwarfism to gigantism that is evident in island endemic mammals. However, subsequent to the publication of the gastropod study, the standard tests of the island rule have been shown to yield false positives at a very high rate, leaving the result open to doubt. METHODOLOGY/PRINCIPAL FINDINGS: The evolution of gastropod body size in the deep sea is reexamined. Using an extended and updated data set, and improved statistical methods, it is shown that some results of the previous study may have been artifactual, but that its central conclusion is robust. It is further shown that the effect is not restricted to a single gastropod clade, that its strength increases markedly with depth, but that it applies even in the mesopelagic zone. CONCLUSIONS/SIGNIFICANCE: The replication of the island rule in a distant taxonomic group and a partially analogous ecological situation could help to uncover the causes of the patterns observed--which are currently much disputed. The gastropod pattern is evident at intermediate depths, and so cannot be attributed to the unique features of abyssal ecology.

  10. Large-scale spatial distribution patterns of gastropod assemblages in rocky shores.

    Directory of Open Access Journals (Sweden)

    Patricia Miloslavich

    Full Text Available Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1 describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2 identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3 identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed within 12 Large Marine Ecosystem regions (LME following the NaGISA (Natural Geography in Shore Areas standard protocol (www.nagisa.coml.org. A total of 393 gastropod taxa from 87 families were collected. Eight of these families (9.2% appeared in four or more different LMEs. Among these, the Littorinidae was the most widely distributed (8 LMEs followed by the Trochidae and the Columbellidae (6 LMEs. In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska. No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05. Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages.

  11. Large-scale spatial distribution patterns of gastropod assemblages in rocky shores.

    Science.gov (United States)

    Miloslavich, Patricia; Cruz-Motta, Juan José; Klein, Eduardo; Iken, Katrin; Weinberger, Vanessa; Konar, Brenda; Trott, Tom; Pohle, Gerhard; Bigatti, Gregorio; Benedetti-Cecchi, Lisandro; Shirayama, Yoshihisa; Mead, Angela; Palomo, Gabriela; Ortiz, Manuel; Gobin, Judith; Sardi, Adriana; Díaz, Juan Manuel; Knowlton, Ann; Wong, Melisa; Peralta, Ana C

    2013-01-01

    Gastropod assemblages from nearshore rocky habitats were studied over large spatial scales to (1) describe broad-scale patterns in assemblage composition, including patterns by feeding modes, (2) identify latitudinal pattern of biodiversity, i.e., richness and abundance of gastropods and/or regional hotspots, and (3) identify potential environmental and anthropogenic drivers of these assemblages. Gastropods were sampled from 45 sites distributed within 12 Large Marine Ecosystem regions (LME) following the NaGISA (Natural Geography in Shore Areas) standard protocol (www.nagisa.coml.org). A total of 393 gastropod taxa from 87 families were collected. Eight of these families (9.2%) appeared in four or more different LMEs. Among these, the Littorinidae was the most widely distributed (8 LMEs) followed by the Trochidae and the Columbellidae (6 LMEs). In all regions, assemblages were dominated by few species, the most diverse and abundant of which were herbivores. No latitudinal gradients were evident in relation to species richness or densities among sampling sites. Highest diversity was found in the Mediterranean and in the Gulf of Alaska, while highest densities were found at different latitudes and represented by few species within one genus (e.g. Afrolittorina in the Agulhas Current, Littorina in the Scotian Shelf, and Lacuna in the Gulf of Alaska). No significant correlation was found between species composition and environmental variables (r≤0.355, p>0.05). Contributing variables to this low correlation included invasive species, inorganic pollution, SST anomalies, and chlorophyll-a anomalies. Despite data limitations in this study which restrict conclusions in a global context, this work represents the first effort to sample gastropod biodiversity on rocky shores using a standardized protocol across a wide scale. Our results will generate more work to build global databases allowing for large-scale diversity comparisons of rocky intertidal assemblages.

  12. Comparative studies on biochemical analysis of some economically important marine gastropods along Gulf of Mannar region, southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    Jayanthi Govindarajalu; Anand Muthusamy; Chelladurai Gurusamy; Karthigarani Mani; KumaraguruArumugam

    2016-01-01

    Objective: To signify the economic importance of molluscan-gastropod food by estimating its biochemical composition. Methods: Samples were collected from the trawl net bycatch at the fish landing center of Mandapam coast of the Gulf of Mannar region. The total protein, carbohydrate, lipid, ash and moisture contents were estimated from nine gastropods i.e. Phalium glaucum, Tonna dolium, Hemifusus pugilinus, Babylonia spirata, Xancus pyrum, Chicoreus ramosus, Harpa articularis, Ficus ficus and Babylonia zeylanica. Results: The percentages of protein (41.2%), carbohydrate (17.5%) and lipid (6.6%) contents were found highest in Babylonia spirata, followed by other gastropods. The maximum ash content was observed in Chicoreus ramosus (1.21%) and the maximum moisture content was observed in Phalium glaucum (83.71%). Conclusions: The results show that all the nine gastropods contain good sources of protein and other biochemical constituents and can be used for edible purposes to prevent starvation.

  13. Determination of Acetylcholinesterase activities in marine gastropod (Morula granulata) as a biomarker of neurotoxic contaminants along the Goan coast.

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Tegur, P.M.; Jana, S.; Rao, P.V.S.S.D.P.

    diseases or even death. Hence it is considered as a suitable biomarker for detecting environmental pollution caused by the neurotoxic compounds. We have carried out experiments with marine gastropods (Morula granulate) at the selected sites, Arambol...

  14. Radiocarbon dating late Quaternary loess deposits using small terrestrial gastropod shells

    Science.gov (United States)

    Pigati, Jeff S.; McGeehin, John P.; Muhs, Daniel R.; Bettis, E. Arthur

    2013-01-01

    Constraining the ages and mass accumulation rates of late Quaternary loess deposits is often difficult because of the paucity of organic material typically available for 14C dating and the inherent limitations of luminescence techniques. Radiocarbon dating of small terrestrial gastropod shells may provide an alternative to these methods as fossil shells are common in loess and contain ∼12% carbon by weight. Terrestrial gastropod assemblages in loess have been used extensively to reconstruct past environmental conditions but have been largely ignored for dating purposes. Here, we present the results of a multi-faceted approach to understanding the potential for using small terrestrial gastropod shells to date loess deposits in North America. First, we compare highly resolved 14C ages of well-preserved wood and gastropod shells (Succineidae) recovered from a Holocene loess section in Alaska. Radiocarbon ages derived from the shells are nearly identical to wood and plant macrofossil ages throughout the section, which suggests that the shells behaved as closed systems with respect to carbon for at least the last 10 ka (thousands of calibrated 14C years before present). Second, we apply 14C dating of gastropod shells to late Pleistocene loess deposits in the Great Plains using stratigraphy and independent chronologies for comparison. The new shell ages require less interpretation than humic acid radiocarbon ages that are commonly used in loess studies, provide additional stratigraphic coverage to previous dating efforts, and are in correct stratigraphic order more often than their luminescence counterparts. Third, we show that Succineidae shells recovered from historic loess in the Matanuska River Valley, Alaska captured the 20th century 14C bomb spike, which suggests that the shells can be used to date late Holocene and historic-aged loess. Finally, results from Nebraska and western Iowa suggest that, similar to other materials, shell ages approaching ∼40 ka should

  15. Coastal coal pollution increases Cd concentrations in the predatory gastropod Hexaplex trunculus and is detrimental to its health

    Energy Technology Data Exchange (ETDEWEB)

    Siboni, N.; Fine, M.; Bresler, V.; Loya, Y. [Tel Aviv University, Tel Aviv (Israel). Dept. of Zoology

    2004-07-01

    Parameters of environmental health, including paracellular permeability of external epithelia, functional state of lysosomes and the level of metallothioneins (MTs), were examined using fluorescent markers and Vital microfluorometry in different tissues of the marine gastropod, Hexaplex trunculus, from a coal-polluted and coal-free site. Vital microfluorometrical examinations exhibited enhanced paracellular permeability of external epithelia to the anionic marker, fluorescein (FLU), lower lysosomal accumulation of neutral red (NR) as well as higher levels of MTs, when compared with epithelia of gastropods from the coal-free site. Those differences were particularly marked in the foot epithelium, which is in direct contact with the substrate. In addition, cadmium was measured by ICP-AES in the hepatopancreas of gastropods sampled from the coal-polluted site and two coal-free sites. Significantly higher levels of Cd were found in gastropod hepatopancreas from the coal-polluted site. In addition, two months feeding experiments conducted in aquaria containing: (a) coal pieces covered by barnacles; (b) natural rocks covered by barnacles; and (c) natural rocks with barnacles + bare coal pieces, demonstrated significant increase of Cd concentration in the hepatopancreas of the gastropods exposed to coal. We suggest that coal in the marine environment has detrimental effects on marine gastropods, both directly through contact with the organisms and indirectly through the food web.

  16. Organotins (TBT and DBT) in water, sediments, and gastropods of the southern Venice lagoon (Italy).

    Science.gov (United States)

    Berto, D; Giani, M; Boscolo, R; Covelli, S; Giovanardi, O; Massironi, M; Grassia, L

    2007-01-01

    The release of tributyltin (TBT) from maritime traffic represents one of the main problems of direct, diffuse, and continued contamination of the marine environment. In the present survey, the concentrations of TBT and dibultytin (DBT) in brackish waters, sediments, and the gastropods Nassarius nitidus were evaluated in order to estimate the contamination of the southern part of the Venice lagoon. TBT and DBT were determined by GC-MS/MS. Recent contamination of TBT was found in brackish waters near marinas, whereas the highest concentrations of TBT and DBT were observed in surface sediments at dockyards and harbours. High content of organotin in the gastropods sampled near the dockyards, harbours, and marinas showed a mobilisation from the sediments through the food web. The present study allowed assessment of whether, despite the ban on the use of TBT paints, waters, sediments, and biota were still being contaminated by organotin compounds in the southern Venice lagoon.

  17. Screening of antibacterial drugs from marine gastropod Chicoreus ramosus (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Pasiyappazham Ramasamy

    2013-10-01

    Full Text Available Objective: To screen the antibacterial drugs from different solvent extracts of tissue and egg of marine gastropods Chicoreus ramosus against clinically isolated human pathogenic bacteria. Methods: Different solvent extracts of Chicoreus ramosus was screened for their activity against Vibrio parehaemolyticus (J13300, Aeromonus hydrophilla (IDH1585, Salmonella typhi (C6953, Salmonella paratyphi A (C6915, Vibrio cholerae (IDH5439 and Escherichia coli (H10407 using standard well diffusion method and its minimum inhibitory concentration. Results: The study revealed that the acetone and chloroform extract of both the tissues and egg inhibited the growth of the tested pathogenic bacterial strains. The minimum inhibitory concentration of both the extract ranged from 4 to 12 mg/mL. Conclusions: These results suggest that marine gastropods tissue and egg extract contains comparatively good antibacterial activity.

  18. Screening of antibacterial drugs from marine gastropod Chicoreus ramosus (Linnaeus, 1758)

    Institute of Scientific and Technical Information of China (English)

    Pasiyappazham Ramasamy; Gurusamy Chelladurai; Natarajan Gautham; Sasirekhamani Mohanraj; Jeyaraj Mohanraj

    2013-01-01

    Objective: To screen the antibacterial drugs from different solvent extracts of tissue and egg of marine gastropods Chicoreus ramosus against clinically isolated human pathogenic bacteria.Methods:Vibrio parehaemolyticus (J13300), Aeromonus hydrophilla (IDH1585), Salmonella typhi (C6953), Salmonella paratyphi A (C6915), Vibrio cholerae (IDH5439) and Escherichia coli (H10407) using standard well diffusion method and its minimum inhibitory concentration.Results:Different solvent extracts of Chicoreus ramosus was screened for their activity against egg inhibited the growth of the tested pathogenic bacterial strains. The minimum inhibitory concentration of both the extract ranged from 4 to 12 mg/mL. The study revealed that the acetone and chloroform extract of both the tissues and Conclusions: These results suggest that marine gastropods tissue and egg extract contains comparatively good antibacterial activity.

  19. Comparisons of the metabolic responses of two subtidal nassariid gastropods to hypoxia and re-oxygenation.

    Science.gov (United States)

    Liu, C C; Shin, P K S; Cheung, S G

    2014-05-15

    Changes in the levels of carbohydrate, lipid, protein and anaerobic metabolites (succinate, lactate, acetate, fumarate and propionate), upon exposure to hypoxia (1.5 mg O2 l(-1)) and after reoxygenation in subtidal gastropods Nassarius siquijorensis and N. conoidalis, were compared. A significant decrease of the glycogen content was observed under hypoxia in N. conoidalis but not in N. siquijorensis. A greater increase in the concentrations of anaerobic metabolites was observed in N. conoidalis under hypoxia, and their levels did not return to baseline after returning to normoxia for 24h. In contrast, a lower rate of accumulation of the metabolites was observed in N. siquijorensis, and complete recovery from anaerobic metabolism was observed after reoxygenation. The results lend further support to the role of hypoxia in governing the different distributional patterns between the two subtidal gastropods in Hong Kong waters.

  20. The connection between oxidative stress and estivation in gastropods and anurans.

    Science.gov (United States)

    Ferreira-Cravo, Marlize; Welker, Alexis F; Hermes-Lima, Marcelo

    2010-01-01

    In situations of food and water deprivation associated with unfavorable environmental conditions, a number of animal species undergo estivation. This state of locomotor inactivity involves a drastic reduction in the metabolic rate, allowing the estivator to survive long periods of adverse situations. However, the arousal from dormancy causes a rapid increase in oxygen consumption, which may elevate the production of oxygen radicals. Thus, it is expected that animals that arouse from estivation suffer a physiological oxidative stress. The reported mechanisms that protect estivators (anurans and gastropods) from the potential dangers of increased oxyradical formation are discussed. This includes the modulation of endogenous antioxidant defenses (enzymes and glutathione) of gastropods during dormancy, preparing them for arousal. A different strategy used for estivating anurans is also discussed.

  1. The estrogen receptor of the gastropod Nucella lapillus: Modulation following exposure to an estrogenic effluent?

    Energy Technology Data Exchange (ETDEWEB)

    Castro, L. Filipe C. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Cellular and Molecular Studies, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal)], E-mail: filipe.castro@ciimar.up.pt; Melo, C. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Cellular and Molecular Studies, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Guillot, R.; Mendes, I.; Queiros, S.; Lima, D. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Reis-Henriques, M.A. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); ICBAS, Instituto Ciencias Biomedicas Abel Salazar, University of Porto, Largo Professor Abel Salazar 2, 4099-003 Porto (Portugal); Santos, M.M. [CIIMAR, Centre of Marine and Environmental Research, Laboratory of Environmental Toxicology, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal)], E-mail: santos@ciimar.up.pt

    2007-10-30

    The molecular targets of estrogenic endocrine disrupting chemicals have been studied in detail in vertebrates. The lack of basic endocrine knowledge impairs similar approaches for invertebrates. Evidence indicates that the signalling pathways of invertebrates may also be a target of estrogenic chemicals (ECs). In fact, the exposure to effluents containing ECs has been reported to impact mollusc reproduction. Despite the reported estrogen independence of the mollusc nuclear estrogen receptor (ER), its role in EC-induced toxicity has not been investigated in vivo. Therefore, we have cloned the ER of the gastropod Nucella lapillus and evaluated the effects of a mixture of estrogenic chemicals (sewage effluent) on its expression in the ovary. Here, we show that the exposure to a raw domestic/industrial effluent, impact ER expression with a simultaneous reproductive maturation. These results highlight the need to further investigate the role of ER on the reproductive process in prosobranch gastropods and whether this signalling pathway is prone to disruption by ECs.

  2. Paralytic toxins in three new gastropod (Olividae) species implicated in food poisoning in southern Taiwan.

    Science.gov (United States)

    Hwang, Pai-An; Tsai, Yung-Hsiang; Lu, Ya-Hui; Hwang, Deng-Fwu

    2003-03-01

    The toxins in the new gastropods Oliva miniacea, O. mustelina and O. nirasei implicated in a food paralytic poisoning incident in South Taiwan in February 2002 were studied. It was found that the three species of gastropods contained moderate amounts of toxin in edible portion only, and the highest toxicity score was 18 MU/g for O. miniacea, 10 MU/g for O. mustelina, and 27 MU/g for O. nirasei. The toxin was partially purified from the toxic specimens of each species by ultrafiltration using a YM-1 membrane, followed by chromatography on Bio-Gel P-2 column. Analyses by HPLC, GC-MS and LC-MS showed that the toxin from O. miniacea, O. nirasei and O. mustelina contained TTX, and related compounds 4-epi TTX and anhydro-TTX. The paralytic shellfish poisons were not found.

  3. A pioneer survey and DNA barcoding of some commonly found gastropod molluscs on Robben Island

    OpenAIRE

    2015-01-01

    Abstract Nineteen species of abundant gastropods were collected at Robben Island, including introduced dune snails and European brown garden snails. They were identified using morphology and DNA barcoding. It was expected that the species recorded would be similar to those from the Cape peninsula, South Africa, but we were surprised to find some exceptions: the very abundant invasive mussel species in South Africa, the South American bisexual mussel ( Semimytilus algosus ), and the beaded top...

  4. Non-Random Sibling Cannibalism in the Marine Gastropod Crepidula coquimbensis

    OpenAIRE

    Antonio Brante; Miriam Fernández; Frédérique Viard

    2013-01-01

    International audience; Sibling cannibalism is commonly observed in marine species. For instance, intrabrood cannibalism has been documented in marine gastropods with direct development, suggesting a relationship between embryo behavior and the evolution of life history strategies. However, there has been little effort to document the factors driving sibling cannibalism in marine species. The kin selection theory suggests that the level of relatedness plays an important role in cannibalism pa...

  5. Selectivity of terrestrial gastropod extinctions on an oceanic archipelago and insights into the anthropogenic extinction process

    OpenAIRE

    Chiba, Satoshi; Roy, Kaustuv

    2011-01-01

    Anthropogenic impacts have led to widespread extinctions of species on oceanic islands but the nature of many of these extinctions remains poorly known. Here we investigate extinction selectivities of terrestrial gastropods from the Ogasawara archipelago in the northwest Pacific, where anthropogenic threats have changed over time, shifting primarily from the effects of habitat loss to predation by a variety of different predators. Across all of the islands, extinct species had significantly s...

  6. [The Littorina species of the European coasts: No model for the evolution of terrestrial gastropods].

    Science.gov (United States)

    Remmert, Hermann

    1968-12-01

    The Littorina-species of the European coasts are completely isoosmotic with their environment.Small specimens (species) have very small gills; with increasing size the gills grow rapidly. The gills of different species of identical size show no difference. The reproduction does not trend towards direct development parallel to the habitat of the species.Therefore the Littorina species are no model for the evolution of terrestrial gastropods, their characteristics are merely those of intertidal animals.

  7. Cassiopidae gastropods, influence of Tethys Sea of the Romualdo Formation (Aptian-Albian), Araripe Basin, Brazil

    Science.gov (United States)

    Pereira, Priscilla Albuquerque; Cassab, Rita de Cassia Tardin; Barreto, Alcina Magnólia Franca

    2016-10-01

    The Cassiopidae family belongs to a group of gastropods of the Tethyan Realm, whose origin and dispersion are related a transgression of the Tethys Sea during the Early Cretaceous. The Romualdo Formation in the Araripe Basin, located in Northeast Brazil, presents fossil assemblages with echinoids, bivalves and cassiopid gastropods, indicating a marine sedimentation at the top of the formation. This research reveals three new species of this fauna: Gymnentome (Craginia) beurleni sp. nov., 'Pseudomesalia' ('Pseudomesalia') mennessieri sp. nov and 'Pseudomesalia' ('Pseudomesalia') santanensis sp. nov. We also review two other species: Craginia araripensisBeurlen, 1964 and Gymnentome romualdoiBeurlen, 1964, which we reclassify taxonomically as Paraglauconia (Diglauconia) araripensis and Gymnentome (Gymnentome) romualdoi, respectively; Paraglauconia (Diglauconia) lyrica Maury, 1936 and Gymnentome (Gymnentome) carregozica Maury, 1936 were the first recorded species in the Araripe Basin. The occurrence of these cassiopid gastropod fauna in other basins, such as Sergipe, Potiguar and Parnaíba, indicate the influence of waters coming from the north through the Tethys Sea in the Aptian-Albian and in the marginal continental basins of the Brazilian Northeast.

  8. Potential ZnS fossilization of gastropods (Middle Jurassic claystones from Central Poland).

    Science.gov (United States)

    Szczepanik, Patrycja; Sawlowicz, Zbigniew

    2008-09-01

    The rich fossil fauna in the Middle Jurassic claystones that crop out in the Krakow-Czestochowa Upland is extensively replaced by sulfide minerals, mainly pyrite. Sphalerite (ZnS) is rare and restricted to the internal casts of gastropods, often together with framboidal and euhedral pyrite and calcite. Scanning electron microscopy-energy dispersive spectrometer study was undertaken to explain this curious association. The results show that although direct infilling of the carbonate shell, similar to processes occurring during pyritization, is probable, it does not explain all textures observed. We propose that the carbonate shells were initially infilled by calcite and iron sulfides and sphalerite subsequently replaced the calcite casts. Preferential occurrence of ZnS in gastropods could result from accumulation of higher concentration of zinc during the organisms' life. After death, this Zn was introduced into the carbonate making gastropods more prone to ZnS replacement. Formation of ZnS casts was probably a late diagenetic event as zinc content of the surrounding sediment does not appear to influence sphalerite formation.

  9. Viscera-associated bacterial diversity among intertidal gastropods from Northern-Atlantic coast of Portugal.

    Science.gov (United States)

    Pratheepa, Vijaya K; Silva, Marisa; Vasconcelos, Vitor

    2014-02-01

    Culture-dependent evaluation of the bacteria was carried out on gastropods, such as Monodonta lineata, Gibbula umbilicalis, Nucella lapillus and Patella intermedia, and the environmental samples (biofilm and surrounding sea water) collected from six different locations of Northern Portugal coastal area to investigate the interactions between the microbes in the viscera of gastropods and in the environment. A total of 141 isolates and 39 operational taxonomic units were identified. Phylogenetic analysis based on the 16S rRNA gene showed that bacterial isolates are highly diverse and most of them were found in other marine environment. The observed bacterial diversity was distributed over five different classes (Gammaproteobacteria, Alphaproteobacteria, Flavobacteria, Bacilli and Actinobacteria) with the greatest number of 16S rRNA gene sequence derived from the Gammaproteobacteria (77 %). Vibrio is found to be the dominant one among the different bacterial species isolated. The results suggest that the microorganisms in the environment are maintained in the viscera of the gastropods which may have a key role in the metabolic functions.

  10. Geometric analysis and estimation of the growth rate gradient on gastropod shells.

    Science.gov (United States)

    Noshita, Koji; Shimizu, Keisuke; Sasaki, Takenori

    2016-01-21

    The morphology of gastropod shells provides a record of the growth rate at the aperture of the shell, and molecular biological studies have shown that the growth rate gradient along the aperture of a gastropod shell can be closely related to gene expression at the aperture. Here, we develop a novel method for deriving microscopic growth rates from the macroscopic shapes of gastropod shells. The growth vector map of a shell provides information on the growth rate gradient as a vector field along the aperture, over the growth history. However, it is difficult to estimate the growth vector map directly from the macroscopic shape of a specimen, because the degree of freedom of the growth vector map is very high. In order to overcome this difficulty, we develop a method of estimating the growth vector map based on a growing tube model, where the latter includes fewer parameters to be estimated. In addition, we calculate an aperture map specifying the magnitude of the growth vector at each location, which can be compared with the expression levels of several genes or proteins that are important in morphogenesis. Finally, we show a concrete example of how macroscopic shell shapes evolve in a morphospace when microscopic growth rate gradient changes.

  11. Snails under stress. Gastropods as models in ecophysiology and ecotoxicology; Schnecken unter Stress. Gastropoden als Modelle in Oekophysiologie und Oekotoxikologie

    Energy Technology Data Exchange (ETDEWEB)

    Triebskorn, Rita [Steinbeis-Transferzentrum fuer Oekotoxikologie und Oekophysiologie, Rottenburg (Germany); Physiologische Oekologie der Tiere, Univ. Tuebingen (Germany)

    2009-04-15

    Background: In ecophysiology and ecotoxicology, gastropods are important both as target organisms for molluscicides and non-target organisms for environmental pollutants or other environmental stressors. With respect to both aspects, biomarkers are investigated at different levels of biological organization in order to understand mechanisms which enable gastropods to cope with or even to benefit from unfavourable environmental conditions. Main topics: The paper focuses on the ecotoxicological and ecophysiological work of the author on gastropods which will be reviewed in the context of the state of knowledge in this field of research. In addition to cellular aspects in biomarker research, also biochemical responses of snails to environmental stress (stress proteins, metallothioneins, and metabolic enzymes) will be addressed. Conclusions: The paper highlights the suitability of terrestrial and aquatic gastropods as sensitive indicators of environmental stress induced by chemicals or other non-chemical factors. Biomarker studies have been shown not only to be applicable in environmental risk assessment but also to provide fundamental and background knowledge necessary to understand correlations of responses at different levels of biological organization. Recommendations and perspectives: A standardized toxicity test with the grapevine snail (ISO 15952) has been established for toxicity assessment in terrestrial habitats. However, freshwater gastropods display a high sensitivity as well, e.g. to endocrine disrupters, and should be incorporated into future standardized assays for aquatic toxicity testing on the basis of existing knowledge. (orig.)

  12. Increasing sea surface temperature and range shifts of intertidal gastropods along the Iberian Peninsula

    Science.gov (United States)

    Rubal, Marcos; Veiga, Puri; Cacabelos, Eva; Moreira, Juan; Sousa-Pinto, Isabel

    2013-03-01

    There are well-documented changes in abundance and geographical range of intertidal invertebrates related to climate change at north Europe. However, the effect of sea surface warming on intertidal invertebrates has been poorly studied at lower latitudes. Here we analyze potential changes in the abundance patterns and distribution range of rocky intertidal gastropods related to climate change along the Iberian Peninsula. To achieve this aim, the spatial distribution and range of sub-tropical, warm- and cold-water species of intertidal gastropods was explored by a fully hierarchical sampling design considering four different spatial scales, i.e. from region (100 s of km apart) to quadrats (ms apart). Variability on their patterns of abundance was explored by analysis of variance, changes on their distribution ranges were detected by comparing with previous records and their relationship with sea water temperature was explored by rank correlation analyses. Mean values of sea surface temperature along the Iberian coast, between 1949 and 2010, were obtained from in situ data compiled for three different grid squares: south Portugal, north Portugal, and Galicia. Lusitanian species did not show significant correlation with sea water temperature or changes on their distributional range or abundance, along the temperature gradient considered. The sub-tropical species Siphonaria pectinata has, however, increased its distribution range while boreal cold-water species showed the opposite pattern. The latter was more evident for Littorina littorea that was almost absent from the studied rocky shores of the Iberian Peninsula. Sub-tropical and boreal species showed significant but opposite correlation with sea water temperature. We hypothesized that the energetic cost of frequent exposures to sub-lethal temperatures might be responsible for these shifts. Therefore, intertidal gastropods at the Atlantic Iberian Peninsula coast are responding to the effect of global warming as it

  13. Bivalves and gastropods from the middle Campanian Anacacho limestone, South Central Texas

    Science.gov (United States)

    Elder, W.P.

    1996-01-01

    The Anacacho Limestone was deposited during the Campanian and represents two depositional intervals, one of early Campanian and one of middle Campanian age. These two intervals correspond to periods of major eustatic sea level rise. This study focuses on the molluscan paleontology of the middle Campanian interval in the eastern part of the Anacacho exposure belt in Medina County, Texas. Molluscan assemblages in this area are indicative of inner to mid-shelf environments. No significant reef components are present. These eastern Anacacho deposits are interpreted to represent more offshore, deeper water environments than those to the southwest, where reef and lagoonal deposits have been reported. Analysis of the macrofossil components from these eastern localities has expanded the number of invertebrate species known from the Anacacho Limestone by nearly three-fold. This increase in diversity, based on a small amount of new work, suggests that many more taxa are yet to be identified, particularly in the western part of the exposure belt in Uvalde and Kinney Counties. This paper documents the bivalve and gastropod fauna, discussing and illustrating 24 bivalve taxa and 11 gastropod species. Two new bivalve species are named, Panopea anacachoensis new species and Spondylus siccus new species, and two potentially new gastropod species are identified but not named herein due to inadequate material. This paper expands the distribution of many eastern Gulf Coast and Atlantic Coast taxa westward into Texas and shows strong ties between the Anacacho fauna and that of the Campanian Tar Heel and Bladen Formations of the Black Creek Group in North Carolina. The taxonomic ties between these two areas probably reflect the thorough documentation of the North Carolina fauna, which is the best documented Campanian bivalve fauna in the Gulf or Atlantic Coast regions.

  14. Diversity of Gastropods and Bivalves in mangrove ecosystem rehabilitation areas in Aceh Besar and Banda Aceh districts, Indonesia

    Directory of Open Access Journals (Sweden)

    Dewiyanti Irma

    2012-06-01

    Full Text Available Abstract. This study was conducted in mangrove rehabilitation area on May to November 2011. The objective of the present study was toevaluate the diversity of Gastropods and Bivalves based on the different level of vegetation age of mangrove. Sampling were conducted on 1x 1 m2 of square transects. We recorded 14 species of Gastropods and 5 species of Bivalves with abundance of 371 individuals/m2 and 28 individuals/m2, respectively. The highest abundance of Gastropod was found on 4 years vegetation age on Cerithidae cingulata (150 individuals/m2, while the highest abundance of Bivalves was found on 3 years vegetation age on Pedalion isognomum (8 individuals/m2. In conclusion,the condition of community structure post tsunami was unstable.

  15. Radiocarbon ages of terrestrial gastropods extend duration of ice-free conditions at the Two Creeks forest bed, Wisconsin, USA

    Science.gov (United States)

    Rech, Jason A.; Nekola, Jeffrey C.; Pigati, Jeffrey S.

    2012-01-01

    Analysis of terrestrial gastropods that underlie the late Pleistocene Two Creeks forest bed (~ 13,800–13,500 cal yr BP) in eastern Wisconsin, USA provides evidence for a mixed tundra-taiga environment prior to formation of the taiga forest bed. Ten new AMS 14C analyses on terrestrial gastropod shells indicate the mixed tundra-taiga environment persisted from ~ 14,500 to 13,900 cal yr BP. The Twocreekan climatic substage, representing ice-free conditions on the shore of Lake Michigan, therefore began near the onset of peak warming conditions during the Bølling–Allerød interstadial and lasted ~ 1000 yr, nearly 600 yr longer than previously thought. These results provide important data for understanding the response of continental ice sheets to global climate forcing and demonstrate the potential of using terrestrial gastropod fossils for both environmental reconstruction and age control in late Quaternary sediments.

  16. New porcellioidean gastropods from early Devonian of Royal Creek area, Yukon Territory, Canada, with notes on their early phylogeny

    Science.gov (United States)

    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.

  17. Snails and their trails: the multiple functions of trail-following in gastropods.

    Science.gov (United States)

    Ng, Terence P T; Saltin, Sara H; Davies, Mark S; Johannesson, Kerstin; Stafford, Richard; Williams, Gray A

    2013-08-01

    Snails are highly unusual among multicellular animals in that they move on a layer of costly mucus, leaving behind a trail that can be followed and utilized for various purposes by themselves or by other animals. Here we review more than 40 years of experimental and theoretical research to try to understand the ecological and evolutionary rationales for trail-following in gastropods. Data from over 30 genera are currently available, representing a broad taxonomic range living in both aquatic and terrestrial environments. The emerging picture is that the production of mucus trails, which initially was an adaptation to facilitate locomotion and/or habitat extension, has evolved to facilitate a multitude of additional functions. Trail-following supports homing behaviours, and provides simple mechanisms for self-organisation in groups of snails, promoting aggregation and thus relieving desiccation and predation pressures. In gastropods that copulate, trail-following is an important component in mate-searching, either as an alternative, or in addition to the release of water- or air-borne pheromones. In some species, this includes a capacity of males not only to identify trails of conspecifics but also to discriminate between trails laid by females and males. Notably, trail discrimination seems important as a pre-zygotic barrier to mating in some snail species. As production of a mucus trail is the most costly component of snail locomotion, it is also tempting to speculate that evolution has given rise to various ways to compensate for energy losses. Some snails, for example, increase energy intake by eating particles attached to the mucus of trails that they follow, whereas others save energy through reducing the production of their own mucus by moving over previously laid mucus trails. Trail-following to locate a prey item or a mate is also a way to save energy. While the rationale for trail-following in many cases appears clear, the basic mechanisms of trail

  18. Cap-shaped gastropods from Upper Jurassic and Lower Cretaceous deposits of northern East Siberia

    Science.gov (United States)

    Guzhov, A. V.; Zakharov, V. A.

    2015-09-01

    Cap-shaped gastropods are first identified in Upper Jurassic and Lower Cretaceous sections of northern East Siberia. They belong to three new genera of the subclass Pectinibranchia ( Boreioconus gen. nov., Nixepileolus gen. nov., and Taimyroconus gen. nov.), which are identified at the species level ( B. bojarkensis sp. nov., N. depressus sp. nov., T. zakharovi sp. nov.), and several species with the open nomenclature. The genus Taimyroconus attributed to the family Calyptraeidae is considered as an ancestral form of the genus Crepidula. The stratigraphic position of each taxon is determined for several sections. The facies confinement, habitat conditions, and ethology of defined genera are considered with the analysis of their geographic distribution.

  19. [Cryptosporidium parvum in wild gastropods as bioindicators of fecal contamination in terrestrial ecosystems].

    Science.gov (United States)

    Neira O, Patricia; Muñoz S, Nelson; Stanley V, Bárbara; Gosh C, Marianne; Rosales L, M José

    2010-06-01

    Cryptosporidium sp oocysts were detected in snails (Helix aspersa Miller) and slug (Deroceras reticulatum Miller) from the Valparaiso Region, Chile. Snails and slug were collected from public squares and private domestic gardens. Cryptosporidium sp oocysts were recovered from faeces of both species. Ziehl Neelsen stain, nested PCR, and sequencing analysis demonstrated a profile similar to that described for genotype C or 2 of the parasite. These results demonstrate that snails and slug could act as a reservoir and mechanic vector of C. parvum infection for humans and animals. Moreover, gastropods could serve as bioindicators of fecal soil contamination.

  20. A pioneer survey and DNA barcoding of some commonly found gastropod molluscs on Robben Island

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    Herman Van Der Bank

    2015-02-01

    Full Text Available Nineteen species of abundant gastropods were collected at Robben Island, including introduced dune snails and European brown garden snails. They were identified using morphology and DNA barcoding. It was expected that the species recorded would be similar to those from the Cape peninsula, South Africa, but we were surprised to find some exceptions: the very abundant invasive mussel species in South Africa, the South American bisexual mussel (Semimytilus algosus, and the beaded topshells (Oxystele impervia were not found on Robben Island. Possible explanations are presented for these differences.

  1. Identification and quantification of tetrodotoxin in the marine gastropod Nassarius by LC-MS.

    Science.gov (United States)

    Huang, Hong-Nan; Lin, Jie; Lin, Hong-Lin

    2008-04-01

    Tetrodotoxin (TTX) has been usually analyzed in marine and other sources by HPLC separation, followed by alkaline treatment and fluorescence assay. However, the applications of such methods were limited because of their tedious extraction and derivation procedures. A simpler, rapid LC-MS method, using selected ion-monitoring, has now been developed, and used to identify and quantitate TTX in a marine gastropod of the genus Nassarius, collected from Fijian province of China. The toxin was confirmed comparable to authentic TTX by MS and MSn. In addition, a moderate amount of TTX was detected in the Nassarius by this novel approach, suggesting that Nassarius would be a potential food poison source.

  2. Bivalves and Gastropods of the Gulf of Tehuantepec, Mexico: A Checklist of Species with Notes on Their Habitat and Local Distribution

    Directory of Open Access Journals (Sweden)

    Eduardo Ríos-Jara

    2009-01-01

    Full Text Available The taxonomic composition of 160 species of bivalves and gastropods recorded in the Gulf of Tehuantepec is presented with information on their habitat and distribution along 10 different localities of the shoreline and 42 stations of the continental shelf. The species were on sandy and rocky beaches, coastal lagoons, estuaries, mangroves, rocky breakwaters of ports, and shallow subtidal areas (14–47 m depth. A total of 78 bivalve species and 82 gastropod species were recorded. Most of these were associated with sandy and rocky beaches and breakwaters of ports. The estuaries host 30 species and the coastal lagoons only two. In the shallow subtidal there were 18 gastropod species and 40 bivalve species representing 36.3% of all. This study adds 24 bivalve species and 29 gastropod species not recorded in previous studies for a total count of 213 species (102 bivalves and 111 gastropods for Gulf of Tehuantepec.

  3. Nutritional value of gastropod Babylonia spirata (Linnaeus, 1758) from Thazhanguda, Southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    Periyasamy N; Srinivasan M; Devanathan K; Balakrishnan S

    2011-01-01

    Objective:To study the biochemical composition, i.e., protein, carbohydrate, lipid, and amino acids from Babylonia spirata (B. spirata). Methods:The gastropod (B. spirata) were collected from the Thazhanguda, Southeast coast of India. The animal shell was broken and body muscles (expected digestive gland) were dried at 60℃in an oven and used for biochemical analysis, such as protein, carbohydrate, lipid, amino acid and molecular size of muscle protein. Results:The results of proximate composition showed that the percentage of protein in the tissue was (53.86%), followed by the carbohydrate content(16.85%). The amount of lipid was 9.30%, and totally 10 essential and nonessential amino acids were analyzed in B. spirata and the content was 9.911 mg/g. The molecular weight of the gastropod sample was low as 2 kDa on SDS-PAGE. FT-IR analysis revealed the presence of amino acids signals at different ranges. Conclusions:The results of this research showed that B. spirata meat is a valuable food with high quality protein and well-balanced amino acids.

  4. Studies on bioprospecting potential of a gastropod mollusc Cantharus tranquebaricus(Gmelin,1791)

    Institute of Scientific and Technical Information of China (English)

    G; Sarumathi; M; Arumugam; S; Kumaresan; T; Balasubramanian

    2012-01-01

    Objective:To study the biological activities of the tissue extract of Cantharus tranquebaricus(C.tranquebaricus).Methods:Crude extract of gastropod was tested for inhibition of bacterial growth.Antibacterial assay was carried out by disc diffusion method and the activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract.Molecular weight of the extract was determined by using SDS-PAGE.Plasma coagulation,Fibrin plate assay and substrate SDS-PAGE were used to determine the effect of sample on plasma coagulation,fibrin(ogen)olytic and proteolytic;activity.Results:The maximum inhibition zone(10 mm)was observed against Vibrio cholera(V.cholera)and minimum inhibition zone(2 mm)was noticed against Proteus mirablis(P.mirablis).The molecular weight was determined as 47-106kDa.The tissue extract shows proteolytic activity above 48 kDa.SDS-PAGE analysis of fibrinogen after incubation with the tissue extract showed fibrinogenolytic activity.In plasma coagulation assay C.tranquebaricus tissue extract showed procoagulant property and it coagulated chicken plasma within 150 s,while control took 5 min to clot.The 9 HU hemolytic units were found against chicken blood and also exhibit high level of brine shrimp lethality.Conclusions:This study suggests that C.tranquebaricus could be used as potential source for isolating bioactive compounds,since it is explored first time and found with promising results.

  5. What can aquatic gastropods tell us about phenotypic plasticity? A review and meta-analysis.

    Science.gov (United States)

    Bourdeau, P E; Butlin, R K; Brönmark, C; Edgell, T C; Hoverman, J T; Hollander, J

    2015-10-01

    There have been few attempts to synthesise the growing body of literature on phenotypic plasticity to reveal patterns and generalities about the extent and magnitude of plastic responses. Here, we conduct a review and meta-analysis of published literature on phenotypic plasticity in aquatic (marine and freshwater) gastropods, a common system for studying plasticity. We identified 96 studies, using pre-determined search terms, published between 1985 and November 2013. The literature was dominated by studies of predator-induced shell form, snail growth rates and life history parameters of a few model taxa, accounting for 67% of all studies reviewed. Meta-analyses indicated average plastic responses in shell thickness, shell shape, and growth and fecundity of freshwater species was at least three times larger than in marine species. Within marine gastropods, species with planktonic development had similar average plastic responses to species with benthic development. We discuss these findings in the context of the role of costs and limits of phenotypic plasticity and environmental heterogeneity as important constraints on the evolution of plasticity. We also consider potential publication biases and discuss areas for future research, indicating well-studied areas and important knowledge gaps.

  6. Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): new insights from increased taxon sampling.

    Science.gov (United States)

    Dayrat, Benoît; Conrad, Michele; Balayan, Shaina; White, Tracy R; Albrecht, Christian; Golding, Rosemary; Gomes, Suzete R; Harasewych, M G; Martins, António Manuel de Frias

    2011-05-01

    Phylogenetic relationships among higher clades of pulmonate gastropods are reconstructed based on a data set including one nuclear marker (complete ribosomal 18S) and two mitochondrial markers (partial ribosomal 16S and Cytochrome oxidase I) for a total of 96 species. Sequences for 66 of these species are new to science, with a special emphasis on sampling the Ellobiidae, Onchidiidae, and Veronicellidae. Important results include the monophyly of Systellommatophora (Onchidiidae and Veronicellidae) as well as the monophyly of Ellobiidae (including Trimusculus, Otina, and Smeagol). Relationships within Ellobiidae, Onchidiidae, and Veronicellidae are evaluated here for the first time using molecular data. Present results are compared with those from the recent literature, and the current knowledge of phylogenetic relationships among pulmonate gastropods is reviewed: despite many efforts, deep nodes are still uncertain. Identification uncertainties about early fossils of pulmonates are reviewed. Impacts of those phylogenetic and fossil record uncertainties on our understanding of the macro-evolutionary history of pulmonates, especially transitions between aquatic and terrestrial habitats, are discussed.

  7. Vermetid gastropods reduce foraging by herbivorous fishes on algae on coral reefs

    Science.gov (United States)

    Tootell, Jesse S.; Steele, Mark A.

    2014-12-01

    Vermetid gastropods have the potential to reduce foraging by herbivorous fishes on algae on coral reefs because they produce mucous nets that cover the surfaces of coral skeletons, potentially inhibiting foraging by fishes. We assessed this possibility using both observational and experimental approaches in Moorea, French Polynesia. Foraging rates of herbivorous fishes (total number of bites by all species per minute) were recorded in plots that varied naturally in the cover of vermetid mucous nets. This study, done at six sites, revealed that foraging on algal turf declined with increasing cover of vermetid mucous nets, ranging from ~2 to 22 bites m-2 min-1 at 0 % coverage to 0-5 bites m-2 min-1 at 100 % coverage. The magnitude of this effect of vermetid nets varied among microhabitats (high, mid, and low bommies) and sites, presumably due to variation in the intensity of herbivory. Experimental removal of vermetid mucous nets from plots more than doubled the foraging intensity on turf algae relative to when vermetid nets were present at high (≥70 %) cover. Our results indicate that algal turf on coral reefs may benefit from associational refuge from grazing provided by vermetid gastropods, which might in turn harm corals via increased competition with algal turf.

  8. Pushing short DNA fragments to the limit: Phylogenetic relationships of 'hydrobioid' gastropods (Caenogastropoda: Rissooidea).

    Science.gov (United States)

    Wilke, Thomas; Haase, Martin; Hershler, Robert; Liu, Hsiu-Ping; Misof, Bernhard; Ponder, Winston

    2013-03-01

    Although phylogenetic studies are increasingly utilizing multi-locus datasets, a review of GenBank data for the Gastropoda indicates a strong bias towards a few short gene fragments (most commonly COI, LSU rRNA, and SSU rRNA). This is particularly the case for the Rissooidea, one of the largest and most taxonomically difficult gastropod superfamilies. Here we analyze fragments of these three genes from 90 species to determine whether they can well resolve higher relationships within this superfamily, whether structurally aligned sequence datasets increase phylogenetic signal, and whether the inclusion of highly variable regions introduces noise. We also used the resulting phylogenetic data in combination with morphological/anatomical evidence to re-evaluate the taxonomic status of 'hydrobioid' family-level groups. Our results indicate that all three of the alignment strategies that were used resulted in phylogenies having similar signal levels. However, there was a slight advantage to using structural alignment for inferring family-level relationships. Moreover, the set of 'standard' gastropod genes supported recognition of many previously recognized families and provides new insight into the systematics of several problematic groups. However, some family-group taxa were unresolved and the relationships among families were also poorly supported, suggesting a need for more extensive sampling and inclusion of additional genes.

  9. Traces (ichnospecies Oichnus paraboloides of predatory gastropods on bivalve shells from the Seogwipo Formation, Jejudo, Korea

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    Dal-Yong Kong

    2015-12-01

    Full Text Available Circular to subcircular drill holes were identified on the bivalve shells collected from the Seogwipo Formation, Jejudo, Korea. A great majority of the drill holes (>70% were found on the surfaces of a bivalve species Glycymeris rotunda. They are characterized by a beveled sharp edge and paraboloid in cross section with larger outer borehole diameter (OBD; mean 4.21 mm and smaller inner borehole diameter (mean 2.94 mm. Walls of the drill holes are generally smooth, and walls ornamented with etched relief-like structures were also recognized. A slightly raised central boss observed in an incomplete specimen may indicate a failure of predator’s attack. All drill holes collected are classified as a single ichnospecies Oichnus paraboloides Bromley, 1981. They are interpreted as boring traces produced by predatory gastropods, particularly naticid gastropods. Most O. paraboloides boreholes are observed in the central area of shell surfaces; a few boreholes lie marginally, which may reflect a borehole-site selectivity. No correlation between size of prey (shell height and size of predator (OBD is recognized. It is likely, however, that drilled shells of about 30 mm in height represent optimal prey size for naticid predators that lived in a benthic Seogwipo community.

  10. Studies on bioprospecting potential of a gastropod mollusc Cantharus tranquebaricus (Gmelin, 1791)

    Institute of Scientific and Technical Information of China (English)

    G Sarumathi; M Arumugam; S Kumaresan; T Balasubramanian

    2012-01-01

    To study the biological activities of the tissue extract of Cantharus tranquebaricus (C. tranquebaricus). Methods: Crude extract of gastropod was tested for inhibition of bacterial growth. Antibacterial assay was carried out by disc diffusion method and the activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract. Molecular weight of the extract was determined by using SDS-PAGE. Plasma coagulation, Fibrin plate assay and substrate SDS-PAGE were used to determine the effect of sample on plasma coagulation, fibrin (ogen) olytic and proteolytic activity. Results: The maximum inhibition zone (10 mm) was observed against Vibrio cholera (V. cholera) and minimum inhibition zone (2 mm) was noticed against Proteus mirablis (P. mirablis). The molecular weight was determined as 47-106 kDa. The tissue extract shows proteolytic activity above 48 kDa. SDS-PAGE analysis of fibrinogen after incubation with the tissue extract showed fibrinogenolytic activity. In plasma coagulation assay C. tranquebaricus tissue extract showed procoagulant property and it coagulated chicken plasma within 150 s, while control took 5 min to clot. The 9 HU hemolytic units were found against chicken blood and also exhibit high level of brine shrimp lethality. Conclusions: This study suggests that C. tranquebaricus could be used as potential source for isolating bioactive compounds, since it is explored first time and found with promising results.

  11. Parasitic infection alters the physiological response of a marine gastropod to ocean acidification.

    Science.gov (United States)

    Macleod, C D; Poulin, R

    2016-09-01

    Increased hydrogen ion concentration and decreased carbonate ion concentration in seawater are the most physiologically relevant consequences of ocean acidification (OA). Changes to either chemical species may increase the metabolic cost of physiological processes in marine organisms, and reduce the energy available for growth, reproduction and survival. Parasitic infection also increases the energetic demands experienced by marine organisms, and may reduce host tolerance to stressors associated with OA. This study assessed the combined metabolic effects of parasitic infection and OA on an intertidal gastropod, Zeacumantus subcarinatus. Oxygen consumption rates and tissue glucose content were recorded in snails infected with one of three trematode parasites, and an uninfected control group, maintained in acidified (7·6 and 7·4 pH) or unmodified (8·1 pH) seawater. Exposure to acidified seawater significantly altered the oxygen consumption rates and tissue glucose content of infected and uninfected snails, and there were clear differences in the magnitude of these changes between snails infected with different species of trematode. These results indicate that the combined effects of OA and parasitic infection significantly alter the energy requirements of Z. subcarinatus, and that the species of the infecting parasite may play an important role in determining the tolerance of marine gastropods to OA.

  12. The heritability of shell morphometrics in the freshwater pulmonate gastropod Physa.

    Directory of Open Access Journals (Sweden)

    Robert T Dillon

    Full Text Available The cosmopolitan freshwater pulmonate snail Physa acuta hybridizes readily with Physa carolinae in the laboratory, although their F1 progeny are sterile. The two species differ qualitatively in shell shape, the former bearing a more globose shell and the latter more fusiform. We performed a hybridization experiment, measuring a set of 14 traditional (linear and landmark-based shell morphological variables on even-aged parents and their offspring from both hybrids and purebred control lines. Parent-offspring regression yielded a strikingly high heritability estimate for score on the first relative warp axis, h2 = 0.819 ± 0.073, a result that would seem to confirm the value of geometric morphometrics as a tool for retrieving evolutionary relationships from gastropod shell form. Score on the second relative warp axis was also significantly heritable (h2 = 0.312 ± 0.123, although more moderate, as were scores on second principal components extracted from traditional measurements (correlation h2 = 0.308 ± 0.069, covariance h2 = 0.314 ± 0.050. Although score on the first relative warp axis was significantly correlated with centroid size (p < 0.001, scores on none of the three second axes were so correlated. This result suggests that second axis score might prove especially useful for estimating genetic divergence among mixed-age populations of gastropods sampled from the field.

  13. Genotoxicity of cadmium chloride in the marine gastropod Nerita chamaeleon using comet assay and alkaline unwinding assay

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Bhagat, J.; Ingole, B.S.; Rao, P.V.S.S.D.P.; Markad, V.L.

    This paper presents an evaluation of the genotoxic effects of cadmium chloride (CdCl2) on marine gastropod, Nerita chamaeleon following the technique of comet assay and the DNA alkaline unwinding assay (DAUA). In this study, the extent...

  14. Contribution to the knowledge of the gastropods (Gastropoda, Pulmonata of Ilinska and Plakinska Mountains (Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    IVAYLO DEDOV

    2015-06-01

    Full Text Available The work presents results of a collecting trip in July 2008 in the mountains Ilinska and Plakinska (Republic of Macedonia. The work summarizes data for distribution and ecology of 19 species from the mountains. The data collected during the expedition provide the first information for terrestrial gastropods in this region of Macedonia.

  15. Gastropod communities associated with Ulva spp. in the littoral zone in southeast Brazil

    Directory of Open Access Journals (Sweden)

    Gabriela C Zamprogno

    2013-11-01

    Full Text Available Phytal communities are characterized by spatial and temporal variation and are influenced by fluctuating biological and physical parameters. This study aimed to describe and compare the gastropods associated with Ulva spp., at three sites of the Espirito Santo coast with ferruginous laterite substrate and different modes of wave exposure. Camburi is characterized by the presence of iron ore particles. Samples were collected bimonthly. At each site, five sampling quadrats were launched at random in the intertidal region. Individuals of Ulva spp. were collected (2964 individuals and 53 taxa were found. In Camburi the dominant species was Amphitalamus vallei (Barleeidae, while in Capuba and Manguinhos Eulithidium affine (Phasianellidae predominated. The analyses indicated that Camburi is distinct from the other sites. The lesser wave impacts and the more complex structure of the algae in Camburi, due to the presence of iron ore, may explain this variation.

  16. Accumulation of Cu and Zn in discarded antifouling paint particles by the marine gastropod, Littorina littorea

    Science.gov (United States)

    Gammon, Melanie; Turner, Andrew; Brown, Murray T.

    2009-10-01

    The short-term (5 day) accumulation of Cu and Zn in different tissues of the marine gastropod, Littorina littorea, has been studied in the presence of ˜10 mg l -1 of antifouling paint particles and pre- or simultaneously contaminated algal food ( Ulva lactuca). Accumulation of Cu was observed in the head-foot, digestive gland-gonad complex and gills to extents dependent on how and when food was contaminated and administered. However, retention of Zn was only observed in the gills and only when L. littorea and U. lactuca were simultaneously exposed to paint particles. Relative to the alga, faecal material was highly enriched in Zn, suggesting that the animal is able to rapidly eliminate this metal, most likely through the formation and egestion of insoluble phosphate granules. Thus, L. littorea is a useful biomonitor of marine contamination by antifouling applications in respect of Cu but not Zn.

  17. Ocean acidification disrupts induced defences in the intertidal gastropod Littorina littorea.

    Science.gov (United States)

    Bibby, Ruth; Cleall-Harding, Polly; Rundle, Simon; Widdicombe, Steve; Spicer, John

    2007-12-22

    Carbon dioxide-induced ocean acidification is predicted to have major implications for marine life, but the research focus to date has been on direct effects. We demonstrate that acidified seawater can have indirect biological effects by disrupting the capability of organisms to express induced defences, hence, increasing their vulnerability to predation. The intertidal gastropod Littorina littorea produced thicker shells in the presence of predation (crab) cues but this response was disrupted at low seawater pH. This response was accompanied by a marked depression in metabolic rate (hypometabolism) under the joint stress of high predation risk and reduced pH. However, snails in this treatment apparently compensated for a lack of morphological defence, by increasing their avoidance behaviour, which, in turn, could affect their interactions with other organisms. Together, these findings suggest that biological effects from ocean acidification may be complex and extend beyond simple direct effects.

  18. Gastropods from the Campanian-Maastrichtian Aruma Formation, Central Saudi Arabia

    Science.gov (United States)

    Gameil, Mohamed; El-Sorogy, Abdelbaset S.

    2015-03-01

    The gastropod fauna of the Upper Cretaceous Aruma Formation in central Saudi Arabia comprises fifteen species belonging to fifteen genera, fourteen families, and five clades. The species are not abundant at any individual stratigraphic level but are equally and irregularly scattered in the formation. The studied species come mainly from the Hajajah Member of Upper Cretaceous Aruma Formation in central Saudi Arabia. Calliomphalus orientalis (Douvillé, 1916); Coelobolma corbarica Cossmann, 1918; Turritella (Torquesia) figarii Quaas, 1902; Neoptyxis olisiponensis (Sharpe, 1850) and Otostoma (Otostoma) divaricatum (d'Orbigny, 1847) are recorded from the Upper Cretaceous of central Arabia for the first time. The identified species have a close affinity to the Tethyan fauna known from other parts in Asia, Africa and Europe. Herbivores and predators are the dominant trophic groups which may indicate shallow marine lagoonal and relatively open marine environment.

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

    Science.gov (United States)

    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.

  20. [Length and structure of telomeric DNA in three species of Baikal gastropods (Caenogastropoda: Hydrobioidea: Benedictiidae)].

    Science.gov (United States)

    Koroleva, A G; Evtushenko, E V; Maximova, N V; Vershinin, A V; Sintnikova, T Y; Kirilchik, S V

    2015-03-01

    The structure of telomeric repeat (TTAGGG)n was determined and the length of telomeric DNA (tDNA) was measured in three species of gastropods from the family Benedictiidae that are endemic to Lake Baikal. Fluorescence in situ hybridization (FISH) confirmed the localization of a telomeric repeat at the chromosome ends. The sizes of tDNA in "giant" eurybathic, psammo-pelobiontic species Benedictia fragilis and shallow water litho-psammobiontic species B. baicalensis with medium shell sizes were similar (16 ± 2.9 and 15 ± 2.1 kb, respectively), but they had a greater length than that of the shallow water spongio-litobiontic species Kobeltocochlea martensiana with small shells (10.5 ± 1.5 kb). We discuss tendencies in age-related changes in tDNA length in snails and a possible mechanism for maintaining tDNA size in ontogeny.

  1. Protection mechanisms of the iron-plated armor of a deep-sea hydrothermal vent gastropod.

    Science.gov (United States)

    Yao, Haimin; Dao, Ming; Imholt, Timothy; Huang, Jamie; Wheeler, Kevin; Bonilla, Alejandro; Suresh, Subra; Ortiz, Christine

    2010-01-19

    Biological exoskeletons, in particular those with unusually robust and multifunctional properties, hold enormous potential for the development of improved load-bearing and protective engineering materials. Here, we report new materials and mechanical design principles of the iron-plated multilayered structure of the natural armor of Crysomallon squamiferum, a recently discovered gastropod mollusc from the Kairei Indian hydrothermal vent field, which is unlike any other known natural or synthetic engineered armor. We have determined through nanoscale experiments and computational simulations of a predatory attack that the specific combination of different materials, microstructures, interfacial geometries, gradation, and layering are advantageous for penetration resistance, energy dissipation, mitigation of fracture and crack arrest, reduction of back deflections, and resistance to bending and tensile loads. The structure-property-performance relationships described are expected to be of technological interest for a variety of civilian and defense applications.

  2. Biokinetics of different-shaped copper oxide nanoparticles in the freshwater gastropod, Potamopyrgus antipodarum

    DEFF Research Database (Denmark)

    Ramskov, Tina; Croteau, Marie-Noelle; Forbes, Valery E;

    2015-01-01

    to the sediment-dwelling gastropod, Potamopyrgus antipodarum. The influence of Cu added as CuCl2 (i.e., aqueous Cu treatment) was also examined. Exposure to sediment mixed with aqueous Cu or with different-shaped CuO NPs at an average measured exposure concentration of 207 μg Cu per g dry weight sediment for 14...... particle size, although NP size does not always predict effects. In contrast, not much is known about the influence of particle shape on bioaccumulation and toxicity. Here, we examined the influence of copper oxide (CuO) NP shape (rods, spheres, and platelets) on their bioaccumulation kinetics and toxicity...... days did not significantly affect snail mortality. However, growth decreased for snails exposed to sediment amended with CuO NP spheres and platelets. P. antipodarum accumulated Cu from all Cu forms/shapes in significant amounts compared to control snails. In addition, once accumulated, Cu...

  3. Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago

    Directory of Open Access Journals (Sweden)

    Kato Makoto

    2011-05-01

    Full Text Available Abstract Background Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion. Results Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began. Conclusions The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient

  4. Comparative ontogenetic changes in enzyme activity during embryonic development of calyptraeid gastropods.

    Science.gov (United States)

    Collin, Rachel; Starr, Matthew J

    2013-09-01

    A modification of a semi-quantitative color-based enzyme assay was used to quantify the activity of 19 enzymes (5 peptidases, 3 lipases, 3 phosphotases, and 8 carbohydrases) during five stages of development in eight species of calyptraeid gastropods. Sixteen of the 19 enzymes showed a significant effect of mode of development on the concentration of the reaction product after incubation of homogenates standardized for protein content. The overall pattern was that planktotrophs showed the highest activities, followed by adelphophages, and nonfeeding embryos, which had the lowest enzyme activities. Thirteen enzymes showed significant differences across developmental stages. Of these, eight showed a clear increase during development. Only one of the enzymes showed a sudden jump in activity between the unfed, pre-hatching stage and post-hatching stages that were fed Isochrysis galbana. In three cases, ANOVA identified two exclusive, significantly different groups of species. In naphthol-AS-BI-phosphohydrolase, the measured absorbance of Crucibulum spinosum samples was significantly higher than in all of the other species. The activity of α-fucosidase in Crepipatella occulta was significantly greater than in the other seven species. Finally, the activity of β-galactosidase was significantly higher in C. occulta, Crucibulum spinosum, and Bostrycapulus calyptraeformis than in the four Crepidula species. This is the only enzyme for which there is an indication of a phylogenetic effect. Relative enzyme activities were similar to those reported for other herbivorous gastropods, with the three phosphohydrolases, four carbohydrases (β-galactosidase, β-glucuronidase, N-acetyl-β-glucosaminidase, and α-fucosidase), and leucine arylamidase showing high activities.

  5. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    Directory of Open Access Journals (Sweden)

    Paula Pappalardo

    Full Text Available Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule, which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in

  6. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    Science.gov (United States)

    Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

    2014-01-01

    Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods.

  7. [Composition, abundance and distribution of populations of commercially important gastropods in La Guajira, Colombian Caribbean].

    Science.gov (United States)

    Nieto-Bernal, Ramón; Luis, Chasqui; Rodriguez, Angélica María; Castro, Erick; Gil-Agudelo, Diego L

    2013-06-01

    In the continental Colombian Caribbean the conch resource exploitation and the status of snails populations has been poorly studied, which are reflected in the lack of fisheries management. This study assesses composition, population density and distribution of the gastropods species that make conch resource in La Guajira region. Underwater visual censuses for snails were performed between September-November 2009 in 145100x4m (400m2) transects, spanning a total area of 56920m2 between Riohacha and Cabo de la Vela. The study was complemented with the evaluation of composition, abundance and size of gastropods conch found in the discarded-by-fishermen shell mounds in 13 beaches. In October 2010 another 40 transects were evaluated (16 000 m2) from the Southern of Riohacha to the Camarones village (La Guajira). We found a total of 9911 snails belonging to 12 species, the most abundant being Strombus pugilis with 8 912 individuals and an average density of 1 538.4 +/- 3 662.6 ind./ha, followed by Vasum muricatum with 374 individuals and an average density of 51.8 +/- 91.2 ind./ha. Calculating the importance value index (IVI) for both living organisms as the empty shells on beaches, shows that Turbinella angulata is the most used species by artisanal fishermen in the region. Cassis madagascariensis and Cassis tuberosa are also important snail resources in the region (as suggested by the number of empty shells found in beaches), but its densities were low. Strombus gigas, with only three living organisms found in the area, presented the lowest abundance ever found in the Colombian Caribbean (0.52 +/- 3.6 ind./ha), showing that queen conch population in La Guajira cannot support commercial exploitation. The abundance of discarded S. gigas shells on beaches suggests resource exploitation in the recent past. Results remarks the urgency of implementing management plans for snail fisheries in the region.

  8. 3D-ultrastructure, functions and stress responses of gastropod (Biomphalaria glabrata rhogocytes.

    Directory of Open Access Journals (Sweden)

    Maria Kokkinopoulou

    Full Text Available Rhogocytes are pore cells scattered among the connective tissue of different body parts of gastropods and other molluscs, with great variation in their number, shape and size. They are enveloped by a lamina of extracellular matrix. Their most characteristic feature is the "slit apparatus", local invaginations of the plasma membrane bridged by cytoplasmic bars, forming slits of ca. 20 nm width. A slit diaphragm creates a molecular sieve with permeation holes of 20×20 nm. In blue-blooded gastropods, rhogocytes synthesize and secrete the respiratory protein hemocyanin, and it has been proposed-though not proven-that in the rare red-blooded snail species they might synthesize and secrete the hemoglobin. However, the cellular secretion pathway for respiratory proteins, and the functional role(s of the enigmatic rhogocyte slit apparatus are still unclear. Additional functions for rhogocytes have been proposed, notably a role in protein uptake and degradation, and in heavy metal detoxification. Here we provide new structural and functional information on the rhogocytes of the red-blooded freshwater snail Biomphalaria glabrata. By in situ hybridization of mantle tissues, we prove that rhogocytes indeed synthesize hemoglobin. By electron tomography, the first three dimensional (3D reconstructions of the slit apparatus are provided, showing detail of highly dense material in the cytoplasmic bars close to the slits. By immunogold labelling, we collected evidence that a major component of this material is actin. By genome databank mining, the complete sequence of a B. glabrata nephrin was obtained, and localized to the rhogocytes by immunofluorescence microscopy. The presence of both proteins fit the ultrastructure-based hypothesis that rhogocytes are related to mammalian podocytes and insect nephrocytes. Reactions of the rhogocytes to deprivation of food and cadmium toxification are also documented, and a possible secretion pathway of newly synthesized

  9. Hermit crab (Decapoda, Anomura attraction to dead gastropod baits in an infralittoral algae bank

    Directory of Open Access Journals (Sweden)

    Juarez C. B. Pezzuti

    2002-06-01

    Full Text Available Hermit crabs use gastropod shells as shelter and are adapted to follow chemical cues released from tissues of dead or injured gastropods as a way to find new and more adequate shells. The species composition, crab size, shell types adequacy and physical condition were compared between attracted individuals and crabs collected in previous samples. The previous sampling was carried out in five areas before each experiment. Then, five baits of crushed gastropods in nylon net bags were installed in these areas. Three samples were taken at 30min intervals, capturing all crabs within a circle of 60cm diameter. Attraction of hermit crabs was tested for four different gastropod baits to verify specificity of the chemical cues. Clibanarius antillensis, Pagurus brevidactylus and Paguristes tortugae were collected in the study area. Pagurus brevidactylus, the smallest species, turned out to be more attracted than the 2 other species. The results showed that attracted crabs utilized more gastropod shell types than that collected in previous samples, however shell utilization pattern did not differ between them. Attracted animals were slightly smaller (shield length than those collected in the previous samples but did not present significant differences in shell adequacy and condition. The four experimental baits attracted the crabs in similar ways not indicating a specific response from the crabs. The fact that attracted animals were smaller suggested that the attraction to dead gastropods might enable the acquisition of a new and larger shell and, consequently, chains of shell exchange between the attracted crabs.Ermitões utilizam conchas de gastrópodes para abrigo. Conchas novas e mais adequadas podem ser encontradas pelos ermitões pois estes são atraídos por substâncias químicas liberadas pelos tecidos de gastrópodes feridos ou mortos. A adequação, condição e tipo das conchas e a composição de espécies e o tamanho dos ermitões foram

  10. An unusual taphocoenosis of a sea urchin and a rectally inserted turriform gastropod from the lowermost Paleocene of Stevs klint, Denmark

    DEFF Research Database (Denmark)

    Milan, Jesper; Rasmussen, Bo Wilhelm; Vallon, Lothar H.

    2015-01-01

    A specimen of the common irregular echinoid Echinocorys sulcata (Goldfuss, 1826), recovered from the lowermost Paleocene Stevns Klint Formation, at Stevns Klint, Denmark, is of note in revealing a perfect external mold of the turriform gastropod Cerithiella fenestrata (Ravn, 1902) in the anal ope...... combination resulted from the activities of bioturbators which, by chance, pushed the empty gastropod shell into the anal opening of the test of the dead echinoid, although other, more colorful, explanations cannot be excluded....

  11. Digenean parasites of the marine gastropodsLittorina littorea andGibbula umbilicalis in the Northern Portuguese Atlantic coast, with a review of digeneans infecting the two gastropod genera

    Institute of Scientific and Technical Information of China (English)

    Graa Costa; Snia Soares; Fernando Carvalho; Joo Bela

    2016-01-01

    Objective:To study the digenean parasites of the prosobranch gastropods,Littorina littorea(L. littorea) andGibbula umbilicalis (G. umbilicalis) from rocky shores of the Northern Atlantic coast of Portugal. Methods: A total of 413L. littorea and 2 603G. umbilicalis were collected from rocky shores, at Aveiro estuary, Aguda Beach, and Foz Beach at Porto (Northern Atlantic coast of Portugal) from January to July 2014 and February 2014 to January 2015, respectively. Gonads and digestive glands of the gastropods were examined under light microscopy for the presence of digeneans. Infected gonads ofL. littorea were prepared for histological observation, whereas digeneans found in G. umbilicalis were studied and identified with the aid of light and scanning electron microscopy. Results: Two species of digeneans were found infecting the digestive gland and gonads of G. umbilicalis, namely,Cainocreadium labracis andLecithochirium furcolabiatum with a combined prevalence of 3%. Histological observations of gonads ofL. littorearevealed the infection with digeneans, with considerable replacement of gonadal tissues. These digeneans were not identified to species level. The prevalence of digeneans in this snail host was 0.7%. Conclusions: The present study addsG. umbilicalis as another first intermediate host for Cainocreadium labracis and extends its geographical range to the Portuguese Atlantic coast. Cercariae ofLecithochirium furcolabiatum were previously reported fromG. umbilicalis. A literature review of digeneans occurring in the gastropod generaGibbulaandLittorina is given.

  12. Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands--a controlled mesocosm experiment.

    Science.gov (United States)

    Penha-Lopes, Gil; Bartolini, Fabrizio; Limbu, Samwel; Cannicci, Stefano; Mgaya, Yunus; Kristensen, Erik; Paula, José

    2010-01-01

    The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3-4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential.

  13. [Distribution of acetylcholinesterase activity in the digestive system of the gastropod molluscs Littorina littorea and Achatina fulica].

    Science.gov (United States)

    Zaĭtseva, O V; Kuznetsova, T V

    2008-01-01

    With the use of the histochemical procedure for the demonstration of acetylcholinesterase (AchE) activity, the distribution cholinergic regulatory elements was studied in the esophagus, the pharynx, the stomach, the liver (the digestive gland) and the intestine in sea and terrestrial gastropod molluscs that differed in their general organization level, lifestyle, habitat and feeding type. In both molluscs, all the parts of the digestive tract contained the significant amount of intraepithelial AchE-positive cells of the open type, single subepithelial neurons and the nervous fibers localized among the muscle cells of the wall of the organs. The basal processes of the AchE-positive intraepithelial cells were shown to form the intraepithelial nerve plexus and to pass under the epithelium. The peculiarities and common principles in the distribution of the nervous elements detected, their possible function and the regulatory role in the digestion in gastropod molluscs and other animals are discussed.

  14. Gastropods Associated with Fossil Traces from Yacoraite Formation (Maastrichtian-Danian), and its Paleoenvironmental Significance, Jujuy,Northwestern Argentina

    Institute of Scientific and Technical Information of China (English)

    Carlos A. C(O)NSOLE GONELLA; Miguel GRIFFIN; Florencio G. ACE(N)OLAZA

    2009-01-01

    We present results tending to characterize the new records of invertebrates from the Yacoraite Formation (Maastrichtian-Danian). The fossils reported come from two stratigraphic sections exposed in the surroundings of Maimara and Jueya, province of Jujuy, northwestern Argentina. The selection was based on geological and paleontological evidence. The recovered fossils include gastropods and invertebrate fossil traces, including Planolites, Skolithos and Gastrochanoelites ichnogenns. As result of our review, we discussed the possibility of assigning the analyzed gastropods to the family Zygopleuridae (gene. et. sp. indet.), as an approximation to the taxonomic resolution of this fossil fauna. The trace fossils were assigned to the archetypical Glossifungites ichnofacies. The study of the fossil assemblage allowed us to defme a shallow depositional environment, characteristic of a marine context with high-energy conditions.

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

    Directory of Open Access Journals (Sweden)

    Vladimir Pesic

    2013-03-01

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Joseph L Sevigny

    Full Text Available 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

  17. 腹足类性畸变研究进展%Advances of study on imposex in gastropods

    Institute of Scientific and Technical Information of China (English)

    施华宏; 朱小兰; 王蕾; 刘青坡

    2009-01-01

    Tributyltin (TBT) compounds are used as biocides in the antifouling paints and can induce the phenomenon of imposex in gastropods, and are characterized as the occurrence of imposition of male sex in female individuals. In present paper, other contaminants inducing imposex, species of gastropods showing imposex, and the morphological expressions, development and classification scheme of imposex were introduced. The analysis of degree of imposex in gastropods in some typical areas in the world was done. Five hypotheses for the molecular mechanism of imposex induced by TBT were deduced. In the end, several important aspects of the researches of imposex in gastropods in the future were prospected.%用于船舶防污漆的三丁基锡(TBT)能引起腹足类雌性个体发生雄性化的畸变现象.本文介绍了引起腹足类性畸变的其他污染物,存在性畸变现象的腹足类种类,以及腹足类性畸变的形态特征、发生过程和畸变划分图等,分析了目前全球一些典型区域腹足类性畸变程度的现状,归纳了TBT引起腹足类性畸变分子机理的5种假说,最后展望了在腹足类性畸变方面需要进一步研究的几个重要问题.

  18. Morphological and behavioral differences in the gastropod Trophon geversianus associated to distinct environmental conditions, as revealed by a multidisciplinary approach

    Science.gov (United States)

    Márquez, Federico; Nieto Vilela, Rocío Aimé; Lozada, Mariana; Bigatti, Gregorio

    2015-01-01

    The gastropod Trophon geversianus exhibits shell polymorphisms along its distribution in subtidal and intertidal habitats. Our hypothesis is that morphological and behavioral patterns of T. geversianus represent habitat-specific constrains; subsequently we expect an association between shell morphology, attachment behavior, and habitat. In order to test this hypothesis we compared individuals from intertidal and subtidal habitats, at three sites in Golfo Nuevo (Argentina). We analyzed shell morphology using classic morphometric variables, 3D geometric morphometrics and computing tomography scan. The results were complemented with field observations of attachment to substrate and turning time behavior, as well as of the number of shell scars produced by crab predation. Our results showed differences in shell size and shape between intertidal and subtidal-collected individuals. Centroid size, total weight and shell weight, as well as shell density and thickness were significantly lower in intertidal individuals than in subtidal ones. Gastropods from intertidal habitats presented a low-spired shell and an expanded aperture which might allow better attachment to the bottom substrate, while subtidal individuals presented a slender and narrower shell shape. The number of crab scars was significantly higher in shells from subtidal individuals. Observations of the behavior of gastropods placed at the intertidal splash zone showed 100% of attachment to the bottom in the intertidal individuals, while subtidal specimens only attached in average in 32% of the cases. These latter took 12 times longer to re-attach to the bottom when faced up. Phylogenetic analysis of COI gene fragments showed no consistent differences among individuals sampled in both habitats. All these results suggest that T. geversianus has developed two ecomorphs with distinct morphological and behavioral responses to physically stressful conditions registered in north Patagonian intertidals, as opposed to

  19. Gastropod growth and survival as bioindicators of stress associated with high nutrients in the intertidal of a shallow temperate estuary

    Science.gov (United States)

    Marsden, Islay D.; Baharuddin, Nursalwa

    2015-04-01

    The effects of multiple stressors on estuarine organisms are not well understood. Using cage experiments we measured the survival and growth of the pulmonate gastropod Amphibola crenata at five locations which differed contaminant levels. Water nutrients came from a nearby sewage treatment works and the sediment contained low levels of trace metals. Over 6 weeks of exposure, sediment surface chlorophyll levels varied amongst locations. The Chl a values were positively correlated with sediment N and P and trace metals As, Cd, Cu, Pb and Zn. Pulmonate survival depended on location, highest mortality was from a site close to the treatment plant and mortality rate of large individuals decreased significantly with distance away from it. For four locations, medium A. crenata had higher survival than small (juveniles) or adults. Growth rates of small individuals exceeded those for medium and large A. crenata. The mean length increment/week for medium gastropods ranged between 0.49 and 1.11 mm and was negatively correlated with the amount of Chl a in the surface sediment, suggesting the negative effects of eutrophication on gastropod growth. Growth rate of the pulmonate was not correlated with nutrient concentration or trace metal concentrations in the sediment. The dry weight condition index (CI) did not correlate with the growth rate, and for medium individuals, was unaffected by any of the environmental variables. The CI of small individuals was negatively affected by increasing water nutrient levels and the CI of large individuals negatively affected by increasing sediment nutrients and trace metal concentrations. The results from this study suggest that gastropod growth and survival could be used as tools to monitor the effects of changing nutrient levels and recovery from eutrophication within temperate estuaries.

  20. Population structure of an invasive parthenogenetic gastropod in coastal lakes and estuaries of northern KwaZulu-Natal, South Africa.

    Directory of Open Access Journals (Sweden)

    Nelson A F Miranda

    Full Text Available BACKGROUND: Estuaries and coastal lakes receive little attention despite being heavily invaded by non-indigenous invasive species (NIS. In these situations, studies of population dynamics in invaded habitats can provide valuable insights into how NIS interact with new environments. Tarebia granifera is a prosobranch gastropod from south-east Asia which has invaded other sub-tropical parts of the world. This study addresses whether a small number of key environmental factors influences gastropod communities, and specifically how the population density and size structure of T. granifera were influenced by environmental change in estuaries and coastal lakes in southern Africa. METHODOLOGY/PRINCIPAL FINDINGS: T. granifera's density, number of brooded juveniles and size structure were measured at the St. Lucia Estuary, Mgobozeleni Estuary, Lake Sibaya and Lake Nhlange. Size structure was classified according to shell height (SH. All dissected individuals were found to be female and free from trematode infection. Salinity, water depth, temperature, and pH were the main factors correlated with population density of gastropod communities. T. granifera often reached densities well over 1000 ind. m(-2, displacing indigenous gastropods and becoming a dominant component of the benthic community. T. granifera successfully invaded estuaries despite frequent exposure to high salinity and desiccation, which could together eliminate >97% of the population. The persistence of T. granifera was ensured due to its high fecundity and the environmental tolerance of large adults (20-30 mm SH which carried an average of 158±12.8 SD brooded juveniles. Repeat introductions were not essential for the success of this parthenogenetic NIS. CONCLUSION/SIGNIFICANCE: There is a need for a broader study on the reproductive biology of T. granifera (including the previously overlooked "brood pouch ecology", which affects population dynamics and may be relevant to other

  1. [Community structure of bivalves and gastropods in roots of red mangrove Rhizophora mangle (Rhizophoraceae) in isla Larga, Mochima Bay, Venezuela].

    Science.gov (United States)

    Acosta Balbas, Vanessa; Betancourt Tineo, Rafael; Prieto Arcas, Antulio

    2014-06-01

    The Rhizophora mangle roots form a complex ecosystem where a wide range of organisms are permanently established, reproduce, and find refuge. In this study, we assessed the diversity of bivalves and gastropods that inhabit red mangrove roots, in isla Larga, Mochima, Venezuela Sucre state. Bimonthly collections were made from January 2007 to May 2008, in four study areas denominated: South, North, East and West. In each area, five mangrove roots were sampled, and the specimens were obtained. We analyzed a total of 180 roots and a total of 35 bivalve species and 25 gastropod species were found. The most abundant bivalves were: Isognomon alatus, Isognomon bicolor, Ostrea equestris, Crassostrea rhizophorae and Brachidontes exustus; among gastropods, the most common where: Littorina angulifera, (Cymatium pileare and Diodora cayenensis. The months with the highest abundances and number of individuals for both groups were January and July 2007, and March 2008. The mangrove ecosystem in isla Larga, presented a number of individuals and species higher than those reported for other regions in Venezuela and the Caribbean.

  2. Temporal dynamics of gastropod fauna on subtidal sandy sediments of the Ensenada de Baiona (NW Iberian Peninsula)

    Science.gov (United States)

    Moreira, J.; Aldea, C.; Troncoso, J. S.

    2010-12-01

    The temporal variation of the gastropod fauna inhabiting sandy sediments of the Ensenada de Baiona (Galicia, Spain) was studied at three subtidal sites from February 1996 to February 1997 by means of quantitative sampling. A total of 5,463 individuals representing 51 gastropod species and 22 families were found. The family Pyramidellidae was the most diverse in number of species (11 species), followed by Rissoidae and Trochidae (4 species each). The dogwhelk, Nassarius reticulatus, and the rissoid snail, Rissoa parva, were the numerically dominant species at the three studied sites; those and other abundant species showed their greatest densities by the end of summer and the beginning of autumn. In general, univariate measures of the assemblage (number of species, abundance, diversity and evenness) showed variations through time; greater values were recorded between summer and autumn depending on the site. Multivariate analyses done on abundance data showed certain seasonality in the evolution of the assemblage as expected for shallow subtidal sandy sediments at temperate latitudes; those seasonal changes were mostly related to variations in abundance of numerically dominant species. Although the measured sedimentary variables did not show significant correlations with faunal univariate parameters, sediment heterogeneity due to the presence of mats of Zostera marina L. and shells of dead bivalves might explain the differences in composition of the gastropod assemblage among sampling sites.

  3. Comparative studies on the uptake and effects of cadmium and zinc on the cellular energy allocation of two freshwater gastropods.

    Science.gov (United States)

    Moolman, L; Van Vuren, J H J; Wepener, V

    2007-11-01

    The uptake and effects of cadmium (Cd) and zinc (Zn) as free metal ions were compared in the freshwater gastropods Melanoides tuberculata and Helisoma duryi. The Langmuir isotherm model was applied to determine the uptake of Cd, Zn, and a mixture of the metals at five different concentrations (Cd: 0.25, 0.51, 0.77, 1.03, 1.29 microM; Zn: 0.17, 0.43, 0.86, 2.17, 4.34 microM). The model gave a good description of metal uptake over a short exposure period (6 h). The gastropods showed interspecies differences in the uptake of Zn. The linear uptake of Cd was similar in these species, although the data did not yield a good fit to the model. No clear Cd/Zn interaction was observed with the mixed metal exposures and both species showed a reduced net uptake for the metals. Cellular energy allocation as a biomarker of exposure provided a measure of the net energy budget (total available energy reserves and total energy consumption). The gastropods were exposed to 0.51 microM Cd, 0.43 microM Zn, and mixture of the metals for a 2-week period. Both species elicited similar decreased net energy budgets following the metal exposures. A combined study on metal uptake and biomarker responses in organisms allows the ability to make interspecies sensitivity comparisons in ecotoxicological studies.

  4. Species diversity of planktonic gastropods (Pteropoda and Heteropoda) from six ocean regions based on DNA barcode analysis

    Science.gov (United States)

    Jennings, Robert M.; Bucklin, Ann; Ossenbrügger, Holger; Hopcroft, Russell R.

    2010-12-01

    Pteropods and heteropods are two distinct groups of holoplanktonic gastropods whose species and genetic diversity remain poorly understood, despite their ubiquity in the world's oceans. Some species apparently attain near cosmopolitan distributions, implying long-distance dispersal or cryptic species assemblages. We present the first multi-regional and species-rich molecular dataset of holoplanktonic gastropods, comprising DNA barcodes from the mitochondrial cytochrome c oxidase I subunit gene (COI) from 115 individuals of 41 species sampled from six ocean regions across the globe. Molecular analysis and assessment of barcoding utility supported the validity of several morphological subspecies and forms (e.g. of Creseis virgula and Limacina helicina), while others were not supported (e.g. Cavolinia uncinata). Significant genetic variation was observed among conspecific specimens collected in different geographic regions for some species, particularly in euthecosomatous pteropods. Several species of euthecosomes showed no evidence of genetic separation among distant ocean regions. Overall, we suggest some taxonomic revision of the holoplanktonic gastropods will be required, pending a more complete molecular inventory of these groups.

  5. Detection of spirorchiid trematodes in gastropod tissues by polymerase chain reaction: preliminary identification of an intermediate host of Learedius learedi.

    Science.gov (United States)

    Stacy, Brian A; Frankovich, Thomas; Greiner, Ellis; Alleman, A Rick; Herbst, Lawrence H; Klein, Paul; Bolten, Alan; McIntosh, Antoinette; Jacobson, Elliott R

    2010-08-01

    Marine spirorchiid trematodes are associated with morbidity and mortality in sea turtles worldwide. The intermediate hosts remain unknown, and discovery efforts are hindered by the large number and great diversity of potential hosts within sea turtle habitats, as well the potential for low prevalence and overdispersion. A high-throughput DNA extraction and polymerase chain reaction-based method was developed to detect the internal transcribed spacer 2 (ITS2) region of the ribosomal gene of 2 spirorchiid genera, Learedius and Hapalotrema , within pooled samples of gastropod tissues. A model system consisting of freshwater snail ( Pomacea bridgesii ) tissues and DNA extracts spiked with adult Learedius learedi and known quantities of spirorchiid DNA was used to develop and test the technique. Threshold of detection was found to be equivalent to an early prepatent infection within 1.5 g of gastropod tissue. This technique was used to screen approximately 25 species of marine gastropods at a captive facility where green turtles ( Chelonia mydas ) become infected by L. learedi . The parasite was detected in a sample of knobby keyhole limpet ( Fissurella nodosa ), thus providing the first evidence of an intermediate host for a marine spirorchiid trematode. This technique has many potential applications in trematode life cycle discovery studies.

  6. Genotoxicity of cadmium chloride in the marine gastropod Nerita chamaeleon using comet assay and alkaline unwinding assay.

    Science.gov (United States)

    Sarkar, Anupam; Bhagat, Jacky; Ingole, Baban S; Rao, Durga P; Markad, Vijaykumar L

    2015-02-01

    This paper presents an evaluation of the genotoxic effects of cadmium chloride (CdCl2 ) on marine gastropod, Nerita chamaeleon following the technique of comet assay and the DNA alkaline unwinding assay (DAUA). In this study, the extent of DNA damage in gill cells of N. chamaeleon was measured after in vivo exposure to four different concentrations (10, 25, 50, and 75 µg/L) of CdCl2 . In vitro exposure of hydrogen peroxide (H2 O2 ; 1, 10, 25, and 50 µM) of the gill cells showed a significant increase in the percentage tail DNA, Olive tail moment, and tail length (TL). Significant changes in percentage tail DNA by CdCl2 exposure were observed in all exposed groups of snails with respect to those in control. Exposure to 75 µg/L of CdCl2 produced significant decrease in DNA integrity as measured by DAUA at all duration with respect to control. In vivo exposure to different concentrations of CdCl2 (10, 25, 50, and 75 µg/L) to N. chamaeleon showed considerable increase in DNA damage as observed by both alkaline comet assay and the DAUA. The extent of DNA damage in marine gastropods determined by the application of alkaline comet assay and DAUA clearly indicated the genotoxic responses of marine gastropod, N. chamaeleon to a wide range of cadmium concentration in the marine environment.

  7. Bioactive potential of some economically important marine gastropods along the Gulf of Mannar region, southeast coast of India

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    JayanthiGovindarajalu

    2016-08-01

    Full Text Available Objective: To analyse the economically important gastropods for prospective antimicrobial, antioxidant and cytotoxic activities from the Gulf of Mannar region, southeast coast of India. Methods: The bioactive potential of some gastropods i.e. Babylonia spirata (B. spirata, Phalium glaucum, Tonna dolium, Hemifusus pugilinus, Xancus pyrum, Chicoreus ramosus (C. ramosus, Harpa articularis, Ficus ficus and Babylonia zeylanica were analysed. Antimicrobial activity was carried out against 8 human pathogenic bacteria and 3 fungal strains by well diffusion method. Antioxidant and cytotoxic activities were analyzed by standard methods. Results: In antibacterial and antifungal activities, methanolic extract of B. spirata significantly showed the highest inhibition zone against Aeromonas hydrophila and Fusarium spp. (P > 0.05. In the total antioxidant activity, the maximum activity was observed in B. spirata (510 µg/mg and in the 1.1-diphenyl-2-picrylhydrazyl scavenging activity, B. spirata showed the highest percentage of inhibition (76.7%. In the case of cytotoxicity i.e. brine shrimp lethality tests the methanolic extract of C. ramosus showed the lowest percentage of mortality and the LC50 values were found to be 523.9 µg/mL. Conclusions: The results revealed that all the gastropods in the present study possessed antimicrobial, antioxidant and cytotoxic effects. However, species like B. spirata and C. ramosus exhibited potent activity and can be used for further clinical studies.

  8. Constant diversification rates of endemic gastropods in ancient Lake Ohrid: ecosystem resilience likely buffers environmental fluctuations

    Science.gov (United States)

    Föller, K.; Stelbrink, B.; Hauffe, T.; Albrecht, C.; Wilke, T.

    2015-12-01

    Ancient lakes represent key ecosystems for endemic freshwater species. This high endemic biodiversity has been shown to be mainly the result of intra-lacustrine diversification. Whereas the principle role of this mode of diversification is generally acknowledged, actual diversification rates in ancient lakes remain little understood. At least four types are conceivable. Diversification rates may be constant over time, they may fluctuate, rates may be higher in the initial phase of diversification, or there may be a pronounced lag phase between colonization and subsequent diversification. As understanding the tempo of diversification in ancient lake environments may help reveal the underlying processes that drive speciation and extinction, we here use the Balkan Lake Ohrid as a model system and the largest species flock in the lake, the non-pyrgulinid Hydrobiidae, as a model taxon to study changes in diversification rates over time together with the respective drivers. Based on phylogenetic, molecular-clock, lineage-through-time plot, and diversification-rate analyses we found that this potentially monophyletic group is comparatively old and that it most likely evolved with a constant diversification rate. Preliminary data of the SCOPSCO (Scientific Collaboration On Past Speciation Conditions in Lake Ohrid) deep-drilling program do indicate signatures of severe environmental/climatic perturbations in Lake Ohrid. However, so far there is no evidence for the occurrence of catastrophic environmental events. We therefore propose that the constant diversification rate observed in endemic gastropods has been caused by two factors: (i) a potential lack of catastrophic environmental events in Lake Ohrid and/or (ii) a probably high ecosystem resilience, buffering environmental changes. Parameters potentially contributing to the lake's high ecosystem resilience are its distinct bathymetry, ongoing tectonic activities, and karst hydrology. The current study not only

  9. Freshwater gastropods diversity hotspots: three new species from the Uruguay River (South America)

    Science.gov (United States)

    de Lucía, Micaela

    2016-01-01

    Background: The Atlantic Forest is globally one of the priority ecoregions for biodiversity conservation. In Argentina, it is represented by the Paranense Forest, which covers a vast area of Misiones Province between the Paraná and Uruguay rivers. The Uruguay River is a global hotspot of freshwater gastropod diversity, here mainly represented by Tateidae (genus Potamolithus) and to a lesser extent Chilinidae. The family Chilinidae (Gastropoda, Hygrophila) includes 21 species currently recorded in Argentina, and three species in the Uruguay River. The species of Chilinidae occur in quite different types of habitats, but generally in clean oxygenated water recording variable temperature ranges. Highly oxygenated freshwater environments (waterfalls and rapids) are the most vulnerable continental environments. We provide here novel information on three new species of Chilinidae from environments containing waterfalls and rapids in the Uruguay River malacological province of Argentina. Materials and Methods: The specimens were collected in 2010. We analyzed shell, radula, and nervous and reproductive systems, and determined the molecular genetics. The genetic distance was calculated for two mitochondrial markers (cytochrome c oxidase subunit I–COI- and cytochrome b -Cyt b-) for these three new species and the species recorded from the Misionerean, Uruguay River and Lower Paraná-Río de la Plata malacological provinces. In addition, the COI data were analyzed phylogenetically by the neighbor-joining and Bayesian inference techniques. Results: The species described here are different in terms of shell, radula and nervous and reproductive systems, mostly based on the sculpture of the penis sheath. Phylogenetic analyses grouped the three new species with those present in the Lower Paraná-Río de la Plata and Uruguay River malacological provinces. Discussion: Phylogenetic analyses confirm the separation between the Uruguay River and the Misionerean malacological

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

    Science.gov (United States)

    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.

  11. Constant diversification rates of endemic gastropods in ancient Lake Ohrid: ecosystem resilience likely buffers environmental fluctuations

    Directory of Open Access Journals (Sweden)

    K. Föller

    2015-08-01

    Full Text Available Ancient lakes represent key ecosystems for endemic freshwater species. This high endemic biodiversity has been shown to be mainly the result of intra-lacustrine diversification. Whereas the principle role of this mode of diversification is generally acknowledged, actual diversification rates in ancient lakes remain little understood. At least four modes are conceivable. Diversification rates may be constant over time, they may fluctuate, rates may be higher in the initial phase of diversification, or there may be a pronounced lag phase between colonization and subsequent diversification. As understanding the tempo of diversification in ancient lake environments may help unrevealing the underlying processes that drive speciation and extinction, we here use the Balkan Lake Ohrid as a model system and the largest species flock in the lake, the non-pyrgulinid Hydrobiidae, as a model taxon to study changes in diversification rates over time together with the respective drivers. Based on phylogenetic, molecular-clock, lineage-through-time plot and diversification-rate analyses we found that this monophyletic group is comparatively old and that it most likely evolved with a constant diversification rate. Preliminary data of the SCOPSCO deep-drilling program do indicate signatures of severe environmental/climatic perturbations in Lake Ohrid. However, so far there is no evidence for the occurrence of catastrophic environmental events. We therefore propose that the rate homogeneity observed in endemic gastropods has been caused by two factors: (i a potential lack of catastrophic environmental events in Lake Ohrid and/or (ii a high ecosystem resilience, buffering environmental changes. Parameters potentially contributing to the lake's high ecosystem resilience are its distinct bathymetry, ongoing tectonic activities, and karst hydrology. The current study not only contributes to one of the overall goals of the SCOPSCO deep-drilling program – inferring

  12. Amino acid racemization dating of Upper Pleistocene - Holocene terrestrial gastropods from a Mediterranean region (Murcia, SE Spain)

    Science.gov (United States)

    Garcia-Mayordomo, Julian; Ortiz, Jose E.; Torres, Trinidad; Insua-Arevalo, Juan M.; Martinez-Diaz, Jose J.; Altolaguirre, Yul; Canales-Fernandez, Maria L.; Martin-Banda, Raquel

    2014-05-01

    The amino acid racemization method has become a widely used geochronological tool for dating Quaternary deposits. The method is based on the fact that living organisms contain only L-amino acids which gradually racemize into D-amino acids after death. Thus, the D/L ratio increases with time after death until it is equal to 1, that is, when equilibrium is reached. Gastropod shells are particularly useful for amino acid racemization dating. Because the amino acid racemization method is not a numerical dating method in isolation, it needs to be calibrated, mainly with radiometric dating methods. The racemization process is genus- and temperature-dependent. In this work we present a preliminary analysis that compares the radiometric age estimated from different dating methods of a number of gastropods recovered in localities from Murcia (Southeastern Spain), with the age obtained through the amino acid racemization method. Taking advantage of recent paleoseismological research in the Murcia region (SE Spain), 28 gastropods specimens were collected from different trenches dug in young Quaternary alluvial deposits. The specimens were subsequently classified and then analyzed according to the standards protocols of the Biomolecular Stratigraphy Laboratory (UPM, Madrid School of Mines). The species found were Otala lactea, Iberus gualterianus, Sphincterochila candidissima and Theba pisana. The D/L ratios of aspartic acid, leucine, phenylalanine and glutamic acid were determined, and the corresponding average age of each specimen was calculated introducing the D/L values in the age calculation algorithm of Torres et al. (1997) for gastropods of central and southern Spain. The racemization age for each locality was then compared to the radiometric age of the deposit where the specimens were collected. To this respect, the samples were classified in different groups considering the reliability on the age control method. The most reliable sample consists only on dates obtained

  13. Baseline trace metals in gastropod mollusks from the Beagle Channel, Tierra del Fuego (Patagonia, Argentina).

    Science.gov (United States)

    Conti, Marcelo Enrique; Stripeikis, Jorge; Finoia, Maria Grazia; Tudino, Mabel Beatriz

    2012-05-01

    With the aim to evaluate the mollusk Nacella (P)magellanica as biomonitor of elemental pollution in seawater of the Beagle Channel, more than one hundred individuals of the gastropod were sampled, separated in viscera and muscle, and then examined with respect to the accumulation of Cd, Cr, Cu, Ni, Pb and Zn. Collection was performed in seven strategic locations along 170 km of the coastal area of the Beagle Channel (Tierra del Fuego, Argentina) in two campaigns during 2005 and 2007. Samples of surrounding seawater in the different sites were obtained and tested for the same metals as well. The accumulation capacity of Nacella (P)magellanica and thus its aptitude as biomonitor, was evaluated through the calculus of the preconcentration factors of the metals assayed. A discussion involving the comparison with other mollusks previously tested will be given. Several statistical approaches able to analyze data with environmental purposes were applied. Non parametric univariate tests such as Kruskal-Wallis and Mann-Whitney were carried out to assess the changes of the metal concentrations with time (2005 and 2007) in each location. Multivariate methods (linear discriminant analysis on PCA factors) were also applied to obtain a more reliable site classification. Johnson's probabilistic method was carried out for comparison between different geographical areas. The possibility of employing these results as heavy metals' background levels of seawater from the Beagle Channel will be debated.

  14. Intraspecific Scaling Relationships Between Crawling Speed and Body Size in a Gastropod.

    Science.gov (United States)

    Hemmert, Heather M; Baltzley, Michael J

    2016-02-01

    Across various modes of locomotion, body size and speed are often correlated both between and within species. Among the gastropods, however, current data are minimal for interspecific and intraspecific scaling relationships. In this study, we tested the relationships between various measurements of body size and crawling speed in the terrestrial snail Cornu aspersum. We also investigated the relationships between crawling speed, muscular wave frequency, and muscular wavelength, because--while these relationships within individuals are well studied--the relationships among individuals are unknown. We recorded snails crawling on both a horizontal and a vertical surface. We found that when they crawled on a horizontal surface, foot length was positively correlated with pedal wavelength and crawling speed, but was not correlated with wave frequency. In comparison, when they crawled on a vertical surface, foot length was positively correlated with wavelength, negatively correlated with wave frequency, and not correlated with crawling speed. Body mass had no correlation with crawling speed when snails were crawling on a horizontal surface, but was negatively correlated with speed when snails crawled on a vertical surface.

  15. [NADPH-diaphorase activity in digestive system of gastropod molluscs Achatina fulica and Littorina littorea].

    Science.gov (United States)

    Zaĭtseva, O V; Kuznetsova, T V; Markosova, T G

    2009-01-01

    Localization and peculiarities of NO-ergic elements were studied for he first time throughout the entire length of digestive tract of the marine gastropod mollusc Achatina fulica (Prosobranchia) and the terrestrial molusc Littorina littorea (Pulmonata) by using histochemical method of detection of NADPH-diaphorase (NADPHd). NO-ergic cells and fibers were revealed in all parts of the mollusc digestive tract beginning from pharynx. An intensive NADPHd activity was found in many intraepithelial cells of the open type and in their processes in intra- and subepithelial nerve plexuses, single subepithelial neurons, granular connective tissue cells, and numerous nerve fibers among muscle elements of he digestive tract wall as well as in nerves innervating the tract. NADPHd was also present in receptor cells of he oral area and in the central A. fulica ganglia participating in innervation of the digestive tract. The digestive tract NO-ergic system ofA. fulica has a more complex organization that that of L. littorea. In the A. fulica pharynx, stomach, and midgut, directly beneath epithelium, there is revealed a complex system of glomerular structures formed by thin NADPHd-positive nerve fibers coming from the side of epithelium. More superficially under the main groups of muscle elements, small agglomerations of NADPHd-positive neurons are seen, which could be considered as primitive, non-formed microganglia. Peculiarities of distribution and a possible functional role of NO-ergic elements in the digestive tract of molluscs are discussed as compared with other invertebrate and vertebrate animals.

  16. Immunohistochemical localization of hepatopancreatic phospholipase in gastropods mollusc, Littorina littorea and Buccinum undatum digestive cells

    Directory of Open Access Journals (Sweden)

    Zarai Zied

    2011-11-01

    Full Text Available Abstract Background Among the digestive enzymes, phospholipase A2 (PLA2 hydrolyzes the essential dietary phospholipids in marine fish and shellfish. However, we know little about the organs that produce PLA2, and the ontogeny of the PLA2-cells. Accordingly, accurate localization of PLA2 in marine snails might afford a better understanding permitting the control of the quality and composition of diets and the mode of digestion of lipid food. Results We have previously producted an antiserum reacting specifically with mSDPLA2. It labeled zymogen granules of the hepatopancreatic acinar cells and the secretory materials of certain epithelial cells in the depths of epithelial crypts in the hepatopancreas of snail. To confirm this localization a laser capture microdissection was performed targeting stained cells of hepatopancreas tissue sections. A Western blot analysis revealed a strong signal at the expected size (30 kDa, probably corresponding to the PLA2. Conclusions The present results support the presence of two hepatopancreatic intracellular and extracellular PLA2 in the prosobranchs gastropods molluscs, Littorina littorea and Buccinum undatum and bring insights on their localizations.

  17. Growth rate of the gastropod Littorina littorea L. in the Kandalakshsky Gulf of the White Sea.

    Directory of Open Access Journals (Sweden)

    Akimova Evgeniya

    2016-03-01

    Full Text Available The study of the growth of mollusks, especially buccinid gastropod is a prospective research direction in biology, which helps to understand the processes in shallow-water ecosystems. The growth rate characterizes the state of the population, and the conditions of its habitat. Littorina littorea L. is an important component of the intertidal community. Some sea birds such as Somateria mollissima and Haematopus ostralegus use these mollusks as food. However, there are a little information about biology and ecology of Littorina littorea. The aim of this study was to evaluate the status of the Littorina littorea population by examining the growth rate of individuals in the sample. To conduct the study of Littorina littorea, 199 individuals were collected: 61 - in the Porya bay and 138 - in the island of Ryashkov. The data were processed using the method of regression analysis. The regression lines describing dependence of the height of the sheells in each clam on their age were plotted and compared for two studied habitats of Littorina littorea. The results showed no significant difference between the two studied samples regarding the mollusks shell height. The obtained data substantially complement the information on biology and ecology of Littorina littorea in particular habitats.

  18. The adaptive value of phenotypic plasticity in two ecotypes of a marine gastropod

    Directory of Open Access Journals (Sweden)

    Butlin Roger K

    2010-10-01

    Full Text Available Abstract Background Few surveys have concentrated on studying the adaptive value of phenotypic plasticity within genetically-distinct conspecific ecotypes. Here, we conduct a test to assess the adaptive value that partial phenotypic plasticity may have for survival in the marine gastropod Littorina saxatilis. This species has evolved canalized ecotypes but, nevertheless, the ecotypes show some phenotypic plasticity for the traits under divergent selection between wave-exposed and high-predation habitats. Results We exposed juveniles of each ecotype to several environmental treatments under laboratory conditions in order to produce shape variation associated with plasticity. The two ecotypes from different treatments were then transplanted to the wave-exposed habitat and the survival rate was monitored. Ecotype explained the largest distinction in survival rate while treatment caused variation in survival rate within the ecotype released into its parental habitat which was correlated with plastic changes in shell shape. Snails that had experienced a treatment mimicking the environment of the transplantation location survived with the highest rate, while individuals from the contrary experimental treatment had lower survivorship. Conclusions We conclude that the partial plastic response shown in Littorina saxatilis has a significant impact on fitness, although this remains small compared to the overall adaptive difference between ecotypes.

  19. Heavy-tailed distributions in the intermittent motion behaviour of the intertidal gastropod Littorina littorea

    Science.gov (United States)

    Seuront, Laurent; Duponchel, Anne-Charlotte; Chapperon, Coraline

    2007-11-01

    The two-dimensional motion behaviour of the common intertidal gastropod Littorina littorea is investigated as a function of the immersion time from three sampling sites on an exposed rocky shore. A total of 90 individuals have been individually marked and tracked over 14 consecutive daylight low tide. Successive displacements show very intermittent behaviour, with a few localised large displacements over a wide range of small displacements. We show that successive displacements are described by flight length l d heavy-tailed distributions with P(ld)∼ld-μ. The very low values of the exponent μ ( μ≈2.22, 2.43 and 2.67) indicate that L. littorea flights fall into the category of super-diffusive processes. These exponents were significantly higher than the special value μ≈2 analytically and theoretically predicted to be the most advantageous in optimising long-term encounter statistics, especially for low-prey-density scenario. As natural selection should favour flexible behaviour, leading to different optimum searching statistics, under different conditions, our results support the idea that the differences in food concentration and distribution encountered at the different sites by L. littorea led to different heavy-tailed distributions observed for the most extreme displacements.

  20. Metabolic mechanisms for anoxia tolerance and freezing survival in the intertidal gastropod, Littorina littorea.

    Science.gov (United States)

    Storey, Kenneth B; Lant, Benjamin; Anozie, Obiajulu O; Storey, Janet M

    2013-08-01

    The gastropod mollusk, Littorina littorea L., is a common inhabitant of the intertidal zone along rocky coastlines of the north Atlantic. This species has well-developed anoxia tolerance and freeze tolerance and is extensively used as a model for exploring the biochemical adaptations that support these tolerances as well as for toxicological studies aimed at identifying effective biomarkers of aquatic pollution. This article highlights our current understanding of the molecular mechanisms involved in anaerobiosis and freezing survival of periwinkles, particularly with respect to anoxia-induced metabolic rate depression. Analysis of foot muscle and hepatopancreas metabolism includes anoxia-responsive changes in enzyme regulation, signal transduction, gene expression, post-transcriptional regulation of mRNA, control of translation, and cytoprotective strategies including chaperones and antioxidant defenses. New studies describe the regulation of glucose-6-phosphate dehydrogenase by reversible protein phosphorylation, the role of microRNAs in suppressing mRNA translation in the hypometabolic state, modulation of glutathione S-transferase isozyme patterns, and the regulation of the unfolded protein response.

  1. Larval Diel Vertical Migration of the Marine Gastropod Kelletia kelletii (Forbes, 1850

    Directory of Open Access Journals (Sweden)

    Melissa R. Romero

    2012-01-01

    Full Text Available Documenting larval behavior is critical for building an understanding of larval dispersal dynamics and resultant population connectivity. Nocturnal diel vertical migration (DVM, a daily migration towards the surface of the water column at night and downward during the day, can profoundly influence dispersal outcomes. Via laboratory experiments we investigated whether marine gastropod Kelletia kelletii larvae undergo nocturnal DVM and whether the behavior was influenced by the presence of light, ontogeny, and laboratory culturing column height. Larvae exhibited a daily migration pattern consistent with nocturnal diel vertical migration with lower average vertical positioning (ZCM during day-time hours and higher vertical positioning at night-time hours. ZCM patterns varied throughout ontogeny; larvae became more demersal as they approached competency. There was no effect of column height on larval ZCM. DVM behavior persisted in the absence of light, indicating a possible endogenous rhythm. Findings from field plankton tows corroborated laboratory nocturnal DVM findings; significantly more K. kelletii were found in surface waters at midnight compared to at noon. Unraveling the timing of and the cues initiating DVM behavior in K. kelletii larvae can help build predictive models of dispersal outcomes for this emerging fishery species.

  2. Bioaccumulation of microcystins in two freshwater gastropods from a cyanobacteria-bloom plateau lake, Lake Dianchi.

    Science.gov (United States)

    Zhang, Junqian; Wang, Zhi; Song, Zhuoyan; Xie, Zhicai; Li, Lin; Song, Lirong

    2012-05-01

    To investigate the bioaccumulation patterns of microcystins (MCs) in organs of two gastropods, samples were collected in Lake Dianchi monthly from May to October, 2008, when cyanobacteria typically bloom. The average MCs concentrations for Radix swinhoei (pulmonate) and Margarya melanioides (prosobranch) tended to be similar for the different organs: the highest values in the hepatopancreas (9.33 by 3.74 μg/g DW), followed by digestive tracts (1.66 by 3.03 μg/g DW), gonads (0.45 by 1.34 μg/g DW) and muscles (0.22 by 0.40 μg/g DW). Pulmonate had higher value than prosobranch because of the stronger bioaccumulation ability in hepatopancreas. The levels in organs of R. swinhoei were correlated with environmentally dissolved MCs, but influenced by intracellular MCs for M. melanioides. The estimated MCs concentrations in edible parts of M. melanioides were beyond the WHO's provisional tolerable daily intake (0.04 μg/kg), suggesting the risk of consumption of M. melanioides from the lake.

  3. Species-specific and transgenerational responses to increasing salinity in sympatric freshwater gastropods

    Science.gov (United States)

    Suski, Jamie G.; Salice, Christopher J.; Patino, Reynaldo

    2012-01-01

    Freshwater salinization is a global concern partly attributable to anthropogenic salt contamination. The authors examined the effects of increased salinity (as NaCl, 250-4,000 µS/cm, specific conductance) on two sympatric freshwater gastropods (Helisoma trivolvis and Physa pomillia). Life stage sensitivities were determined by exposing naive eggs or naive juveniles (through adulthood and reproduction). Additionally, progeny eggs from the juvenile-adult exposures were maintained at their respective parental salinities to examine transgenerational effects. Naive H. trivolvis eggs experienced delayed development at specific conductance > 250 µS/cm; reduced survivorship and reproduction were also seen in juvenile H. trivolvis at 4,000 µS/cm. Survival and growth of P. pomilia were not affected by increased salinity following egg or juvenile exposures. Interestingly, the progeny of H. trivolvis exposed to higher salinity may have gained tolerance to increased salinity whereas P. pomilia progeny may have experienced negative transgenerational effects. The present study demonstrates that freshwater snail species vary in their tolerance to salinization and also highlights the importance of multigenerational studies, as stressor impacts may not be readily apparent from shorter term exposures.

  4. Investigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis.

    Science.gov (United States)

    Giusti, Arnaud; Lagadic, Laurent; Barsi, Alpar; Thomé, Jean-Pierre; Joaquim-Justo, Célia; Ducrot, Virginie

    2014-09-15

    The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests.

  5. Biokinetics of different-shaped copper oxide nanoparticles in the freshwater gastropod, Potamopyrgus antipodarum

    Science.gov (United States)

    Ramskov, Tina; Croteau, Marie-Noele; Forbes, Valery E.; Selck, Henriette

    2015-01-01

    Sediment is recognized as a major environmental sink for contaminants, including engineered nanoparticles (NPs). Consequently, sediment-living organisms are likely to be exposed to NPs. There is evidence that both accumulation and toxicity of metal NPs to sediment-dwellers increase with decreasing particle size, although NP size does not always predict effects. In contrast, not much is known about the influence of particle shape on bioaccumulation and toxicity. Here, we examined the influence of copper oxide (CuO) NP shape (rods, spheres, and platelets) on their bioaccumulation kinetics and toxicity to the sediment-dwelling gastropod, Potamopyrgus antipodarum. The influence of Cu added as CuCl2 (i.e., aqueous Cu treatment) was also examined. Exposure to sediment mixed with aqueous Cu or with different-shaped CuO NPs at an average measured exposure concentration of 207 μg Cu per g dry weight sediment for 14 days did not significantly affect snail mortality. However, growth decreased for snails exposed to sediment amended with CuO NP spheres and platelets. P. antipodarum accumulated Cu from all Cu forms/shapes in significant amounts compared to control snails. In addition, once accumulated, Cu was efficiently retained (i.e., elimination rate constants were generally not significantly different from zero). Consequently, snails are likely to concentrate Cu over time, from both aqueous and NP sources, resulting in a high potential for toxicity.

  6. Molluscan fauna from the Miocene sediments of Kachchh, Gujarat, India – Part 3. Gastropods

    Indian Academy of Sciences (India)

    Kantimati G Kulkarni; Satarupa Bhattacharjee Kapoor; Vidyadhar D Borkar

    2010-06-01

    Systematic description of 25 gastropod species from the Khari Nadi Formation (Aquitanian) and Chhasra Formation (Burdigalian) from the Kachchh District, Gujarat, India is given. A checklist of 116 forms including those reported by earlier researchers, emending taxonomic identifications wherever necessary, is also provided. Vredenburg had referred these two formations together as ‘the Gaj Beds of Kachchh’. He noticed the affinity of molluscs among the Miocene deposits of Kachchh and Kathiawar regions of Gujarat, and Sind province of Pakistan. He also observed that molluscs from his ‘Lower Gaj’ and ‘Upper Gaj’ Formations showed relationship respectively with the Rembang (Aquitanian) and Njalindung (Burdigalian) series of the East Indies. Aquitanian and Burdigalian ages assigned by him were later substantiated by Raju on the basis of foraminifera. Present studies corroborated that the molluscan assemblage from the Miocene rocks of Kachchh is closely related to that from the Gaj Beds of Sind and the Ashapura Clay Member of Kathiawar; besides revealing that the fauna from these three formations taken together is essentially endemic. Discovery of certain species from the Quilon Beds in the Miocene of Kachchh evinces a close affinity between these two formations. The present fauna includes five extant forms, while 29 forms have related species in the Recent fauna.

  7. Immune-related genes in gastropods and bivalves: a comparative overview

    Directory of Open Access Journals (Sweden)

    M Gerdol

    2017-04-01

    Full Text Available The biological diversity of molluscs and their adaptation to highly diverse environments offer a unique opportunity for studying the evolution of the innate immune system in invertebrates. This review provides an updated account about the progresses made over the past few years in the study of the molecular players involved in the recognition of pathogen associated molecular patters (PAMPs, in the transduction of immune signaling and in the elimination of potentially pathogenic microbes in gastropod and bivalve molluscs. A major focus will be put on the differences and peculiarities of the molecular immune system of the two major molluscan classes, which have developed specific adaptations to cope with diverse living environments, pathogenic and nonpathogenic microbes over the course of several hundred million years of independent evolution. Intriguing but still poorly understood aspects, such as antiviral response and immune priming, will be also explored, highlighting the present challenges and opportunities connected to the application of modern genomics techniques to the study of the immune system in these fascinating metazoans.

  8. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Science.gov (United States)

    Prudkovsky, Andrey A; Ivanenko, Viatcheslav N; Nikitin, Mikhail A; Lukyanov, Konstantin A; Belousova, Anna; Reimer, James D; Berumen, Michael L

    2016-01-01

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  9. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Directory of Open Access Journals (Sweden)

    Andrey A Prudkovsky

    Full Text Available Green Fluorescent Proteins (GFPs have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera found at night time in the southern Red Sea (Saudi Arabia living on shells of the gastropod Nassarius margaritifer (Dunker, 1847 (Neogastropoda: Buccinoidea: Nassariidae. We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  10. Microhabitat use by two rocky shore gastropods in an intertidal sandy substrate with rocky fragments.

    Science.gov (United States)

    Turra, A; Denadai, M R

    2006-02-01

    Sandy beaches in some areas of the São Sebastião Channel in southeastern Brazil have unremittingly undergone a variety of impacts, including the deposition of rock fragments in the intertidal region. Consequently, these environments support a rich fauna comprising both sandy beach and rocky shore organisms. Two rocky shore gastropods, Tegula viridula and Morula nodulosa, are particularly abundant in such environments. An evaluation of the use of microhabitats by these two species revealed that they occupy the available microhabitats in different proportions and the presence of one species is associated with the absence of the other. Morula nodulosa is randomly dispersed, occupying mostly areas with rock fragments covered with sediment and branching brown algae. Tegula viridula shows a clumped dispersion associated with the patchiness of the microhabitats used: the presence of encrusting green algae and absence of sediment and branching brown algae covering the rocks. These findings suggest T. viridula has a lower tolerance than M. nodulosa to sand inundation of the rocky fragments, a stochastic event common to the environment in question.

  11. Microhabitat use by two rocky shore gastropods in an intertidal sandy substrate with rocky fragments

    Directory of Open Access Journals (Sweden)

    A. Turra

    Full Text Available Sandy beaches in some areas of the São Sebastião Channel in southeastern Brazil have unremittingly undergone a variety of impacts, including the deposition of rock fragments in the intertidal region. Consequently, these environments support a rich fauna comprising both sandy beach and rocky shore organisms. Two rocky shore gastropods, Tegula viridula and Morula nodulosa, are particularly abundant in such environments. An evaluation of the use of microhabitats by these two species revealed that they occupy the available microhabitats in different proportions and the presence of one species is associated with the absence of the other. Morula nodulosa is randomly dispersed, occupying mostly areas with rock fragments covered with sediment and branching brown algae. Tegula viridula shows a clumped dispersion associated with the patchiness of the microhabitats used: the presence of encrusting green algae and absence of sediment and branching brown algae covering the rocks. These findings suggest T. viridula has a lower tolerance than M. nodulosa to sand inundation of the rocky fragments, a stochastic event common to the environment in question.

  12. Possible environmental chemical cues affecting behaviour of the mangrove gastropod Cerithidea decollata

    Science.gov (United States)

    Lazzeri, Anna Marta

    2017-03-01

    The Indo-West Pacific mangrove gastropod Cerithidea decollata feeds on the ground at low tide and climbs the trees (Avicennia marina) two hours before the arrival of water, settling well above the level that the incoming tide will reach at high tide (from 0 to 80 cm, depending on the tidal phase). In addition, it has been shown that these snails climb twice as high when translocated to lower shore sites (dominated by Rhizophora mucronata), where C. decollata is missing and the high water can reach 1.6 m instead of about 80 cm as within the snail home environment. The study assesses the possible role of chemical cues in the afore-mentioned behaviours. The hypothesis that snails may foresee the periodical tide level variation thanks to airborne chemical cues, possibly released by trees or sediments, has been rejected. On the other hand, airborne chemical cues released by R. mucronata may play a role in inducing snails translocated to low shore sites to climb much higher than control, allowing them to avoid submersion.

  13. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea

    KAUST Repository

    Prudkovsky, Andrey A.

    2016-02-03

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  14. Neural control of the velum in larvae of the gastropod, Ilyanassa obsoleta.

    Science.gov (United States)

    Braubach, Oliver R; Dickinson, Amanda J G; Evans, Carol C E; Croll, Roger P

    2006-12-01

    Larval molluscs commonly use ciliated vela to swim and feed. In this study we used immunohistochemistry to demonstrate innervation of velar cilia and muscles by monoaminergic and peptidergic fibres in the caenogastropod, Ilyanassa obsoleta. Photoelectric recordings from pre-oral cilia on isolated pieces of velum revealed that serotonin increased, whereas catecholamines (dopamine and norepinephrine) decreased beat frequency at concentrations of 10(-6) to 10(-9) mol l(-1). Catecholamines also increased the frequency of momentary, isolated arrests of pre-oral cilia, but failed to suppress beating of the post-oral cilia at these concentrations. The neuropeptides, FMRFamide and Leu-enkephalin, did not affect the frequency of ciliary beating or of isolated ciliary arrests, but did induce numerous muscular contractions, which were accompanied by sustained ciliary arrests. In terms of whole animal behaviour, serotonin caused larvae to concentrate toward the top of a water column and to increase feeding, whereas catecholamines caused larvae to concentrate toward the bottom of a water column and decrease feeding. Monoamine analogues which facilitated or opposed the effects of synthetic transmitters on larval behaviour, further suggested that these transmitters are released endogenously to control velar function. Finally, applications of peptides to whole larvae caused increased frequency of locomotory arrests. Together these findings demonstrate several potential roles for the nervous system in controlling larval behaviour in gastropods.

  15. Impact of toxic cyanobacteria on gastropods and microcystin accumulation in a eutrophic lake (Grand-Lieu, France) with special reference to Physa (= Physella) acuta

    Energy Technology Data Exchange (ETDEWEB)

    Lance, Emilie, E-mail: emilie.lance@live.fr [ECOBIO, CNRS, Universite de Rennes 1, Avenue du General Leclerc 35042 Rennes (France); Brient, Luc, E-mail: luc.brient@univ-rennes1.fr [ECOBIO, CNRS, Universite de Rennes 1, Avenue du General Leclerc 35042 Rennes (France); Carpentier, Alexandre, E-mail: alexandre.carpentier@univ-rennes1.fr [UMR 7208 BOREA, CRESCO, Museum National d' Histoire Naturelle, 38 rue du Port Blanc, 35800 Dinard (France); Acou, Anthony, E-mail: anthony.acou@mnhn.fr [UMR 7208 BOREA, CRESCO, Museum National d' Histoire Naturelle, 38 rue du Port Blanc, 35800 Dinard (France); Marion, Loic, E-mail: loic.marion@univ-rennes1.fr [ECOBIO, CNRS, Universite de Rennes 1, Avenue du General Leclerc 35042 Rennes (France); Bormans, Myriam, E-mail: myriam.bormans@univ-rennes1.fr [ECOBIO, CNRS, Universite de Rennes 1, Avenue du General Leclerc 35042 Rennes (France); Gerard, Claudia, E-mail: claudia.gerard@univ-rennes1.fr [ECOBIO, CNRS, Universite de Rennes 1, Avenue du General Leclerc 35042 Rennes (France)

    2010-08-01

    Hepatotoxic microcystins (MCs) produced by cyanobacteria are known to accumulate in gastropods following grazing of toxic cyanobacteria and/or absorption of MCs dissolved in water, with adverse effects on life history traits demonstrated in the laboratory. In the field, such effects may vary depending on species, according to their relative sensitivity and ecology. The aims of this study were to i) establish how various intensities of MC-producing cyanobacteria proliferations alter the structure of gastropod community and ii) compare MC tissue concentration in gastropods in the field with those obtained in our previous laboratory experiments on the prosobranch Potamopyrgus antipodarum and the pulmonate Lymnaea stagnalis. We explored these questions through a one-year field study at three stations at Grand-Lieu Lake (France) affected by different intensities of cyanobacteria proliferations. A survey of the community structure and MC content of both cyanobacteria and gastropods was associated with a caging experiment involving P. antipodarum and L. stagnalis. In total, 2592 gastropods belonging to 7 prosobranch and 16 pulmonate species were collected. However, distribution among the stations was unequal with 62% vs 2% of gastropods sampled respectively at the stations with the lowest vs highest concentrations of MC. Irrespective of the station, pulmonates were always more diverse, more abundant and occurred at higher frequencies than prosobranchs. Only the pulmonate Physa acuta occurred at all stations, with abundance and MC tissue concentration ({<=} 4.32 {mu}g g DW{sup -1}) depending on the degrees of MC-producing cyanobacteria proliferations in the stations; therefore, P. acuta is proposed as a potential sentinel species. The caging experiment demonstrated a higher MC accumulation in L. stagnalis ({<=} 0.36 {mu}g g DW{sup -1} for 71% of individuals) than in P. antipodarum ({<=} 0.02 {mu}g g DW{sup -1} for 12%), corroborating previous laboratory observations

  16. Impact of toxic cyanobacteria on gastropods and microcystin accumulation in a eutrophic lake (Grand-Lieu, France) with special reference to Physa (= Physella) acuta.

    Science.gov (United States)

    Lance, Emilie; Brient, Luc; Carpentier, Alexandre; Acou, Anthony; Marion, Loïc; Bormans, Myriam; Gérard, Claudia

    2010-08-01

    Hepatotoxic microcystins (MCs) produced by cyanobacteria are known to accumulate in gastropods following grazing of toxic cyanobacteria and/or absorption of MCs dissolved in water, with adverse effects on life history traits demonstrated in the laboratory. In the field, such effects may vary depending on species, according to their relative sensitivity and ecology. The aims of this study were to i) establish how various intensities of MC-producing cyanobacteria proliferations alter the structure of gastropod community and ii) compare MC tissue concentration in gastropods in the field with those obtained in our previous laboratory experiments on the prosobranch Potamopyrgus antipodarum and the pulmonate Lymnaea stagnalis. We explored these questions through a one-year field study at three stations at Grand-Lieu Lake (France) affected by different intensities of cyanobacteria proliferations. A survey of the community structure and MC content of both cyanobacteria and gastropods was associated with a caging experiment involving P. antipodarum and L. stagnalis. In total, 2592 gastropods belonging to 7 prosobranch and 16 pulmonate species were collected. However, distribution among the stations was unequal with 62% vs 2% of gastropods sampled respectively at the stations with the lowest vs highest concentrations of MC. Irrespective of the station, pulmonates were always more diverse, more abundant and occurred at higher frequencies than prosobranchs. Only the pulmonate Physa acuta occurred at all stations, with abundance and MC tissue concentration (cyanobacteria proliferations in the stations; therefore, P. acuta is proposed as a potential sentinel species. The caging experiment demonstrated a higher MC accumulation in L. stagnalis (< or = 0.36 microg g DW(-1) for 71% of individuals) than in P. antipodarum (< or = 0.02 microg g DW(-1) for 12%), corroborating previous laboratory observations. Results are discussed in terms of differential gastropod sensitivity and MC

  17. Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade

    Science.gov (United States)

    Tan, Siong Kiat; Wong, Wing Hing; Meier, Rudolf; Chan, Sow-Yan; Tan, Heok Hui; Yeo, Darren C. J.

    2016-01-01

    The ornamental pet trade is often considered a key culprit for conservation problems such as the introduction of invasive species (including infectious diseases) and overharvesting of rare species. Here, we present the first assessment of the biodiversity of freshwater molluscs in the ornamental pet trade in Singapore, one of the most important global hubs of the ornamental aquarium trade, and discuss associated conservation concerns. We recorded freshwater molluscs from ornamental pet shops and major exporters including non-ornamental species (e.g., hitchhikers, molluscs sold as fish feed). We recorded an unexpectedly high diversity—59 species—of freshwater bivalves and gastropods, with the majority (38 species or 64%) being from the Oriental region. In addition to morphological examination, we sequenced the DNA barcode region of mitochondrial CO1 and 16S genes to provide molecular data for the confirmation of the identification and for future re-identification. DNA barcodes were obtained for 50 species, and all but four were separated by > 3% uncorrected pairwise distances. The trade has been considered a main introduction pathway for non-native species to Singapore, and we found that out of 15 species in the trade as well as in the wild in Singapore, 12 are either introduced or of unknown origin, representing almost half of the known non-native freshwater molluscs in Singapore. Particularly prevalent are non-ornamental species: six hitchhikers on aquarium plants and six species sold as fish feed. We found that a quarter of the trade species have a history of introduction, which includes 11 known or potentially invasive species. We conclude that potential overharvesting is difficult to assess because only half of the trade species have been treated by IUCN. Of these, 21 species are of Least Concern and three are Data Deficient. Our checklist, with accompanying DNA barcodes, images, and museum vouchers, provides an important reference library for future

  18. Distribution of marine, benthic, shell bearing gastropods along the Norwegian coast

    Directory of Open Access Journals (Sweden)

    Tore Høisæter

    2009-12-01

    Full Text Available Based on literature data and my extensive material from along the coast, the distribution of shell bearing marine, benthic gastropods known from Norwegian waters, is outlined. The geographic area covered goes down to c. 1200 m on the continental slope, and extends from the Swedish borderin the south to the Russian border in the north-east. On the slope the distribution is restricted to an area east of 0°, and south of 72° N. Neither the North Sea nor the western ‘slope’ of the Norwegian Trench are included. Systematics and nomenclature follow Clemam (Check List of European Marine Mollusca closely. The emphasis is on the distribution of each species within the designated area, but taxonomic and nomenclaturial problems are discussed wherever considered relevant. Altogether 365 species level taxa are included, of which 326 are considered as definitely belonging to the Norwegian fauna. The rest are recorded as doubtful, either because only empty shells have been found, or their confirmed distribution falls outside the limits here defined. Of the ‘species’ included, I consider at least 18 to be undescribed, while another 16 were described from Norwegian material after Høisæter (1986 was published. The northern distributional limit is extended for 47 species, while 11 species have received a new southern limit. Sixty six species have a generic name diferent from the one used in Høisæter (1986, while 35 species have another specific name. All changes are listed in the main part of the article, and references are given to the sources for the changes. Four faunal components are recognized: a slope component, species mainly found in negative temperatures on the continental slope, between 500 and 1200 m; an Arctic component, species in Norway almost exclusively found in East Finnmark; a group of species in Norway found only or mainly on the Skagerrak coast or in Oslofjorden; and finally the main group found along most of the coast.

  19. Phenotypic differentiation of the Red Sea gastropods in response to the environmental deterioration: Geometric morphometric approach

    Science.gov (United States)

    Abdelhady, Ahmed Awad

    2016-03-01

    The negative impacts of degradation in the coastal zone of the Red Sea are becoming well known in upper portions of the trophic web (e.g., humans and fish), but are less well known among the benthic primary consumers. In addition, the degree to which heavy metals are entering the trophic web can be better-quantified using macrobenthos. Two-gastropod genera encompassing Echinolittorina subnodosa and Planaxis sulcatus from three different localities on the Egyptian coast of the Red Sea were examined in order to deduce the impact of environmental deterioration on the morphology of shells. The examined sites include clean pristine, slightly polluted, and markedly polluted rocky shores. Phosphate/lead industry is the main source of pollution in this zone. Because landmarks on the rugose Echinolittorina are difficult to define and to ensure finer resolution of the analyses, a newly 'grid-based' landmarks was implemented. Both Canonical Variate Analysis (CVA) and Thin Plate Spline (TPS) were particularly capable to capture and terrace the minor morphological variations accurately. Two phenotypes portioned among the environmentally different populations were recognized and interpreted as ecotypes with many intermediate forms. The first ecotype has a higher spire and smaller aperture and dominating the pristine site North of Marsa Alam, whereas the second ecotype has a globular shell shape with big aperture and dominating the markedly polluted site. The intermediate forms dominating the slightly polluted site. The shape differences are interpreted as an adaptive differentiation to different metal concentrations. As the morphological variation between the two-ecotypes of both taxa is still minors, and both ecotypes occur together with many intermediate forms, the phenotypic divergence stage has not yet accomplished. The gradational shape change among the investigated populations was positively correlated with index of Pollution (IP). As the human activities were the main

  20. Identifying factors linked to the occurrence of alien gastropods in isolated woodland water bodies.

    Science.gov (United States)

    Spyra, Aneta; Strzelec, Małgorzata

    2014-03-01

    Biological invasions are a significant component of human-caused global change and is widely regarded as one of the main threats to natural biodiversity. Isolated anthropogenic water bodies created in the areas that are deprived of natural freshwater habitats allow the survival and reproduction of alien species on newly settled sites. They are often small with water level fluctuations causing frequent environmental disturbances. The colonisation success may be the result of the rate of their degradation. The aims of the study were to determine the environmental conditions that affect the existence of alien species of gastropods in this type of aquatic environment and to examine whether the occurrence of non-native species affects the community structure of the native species. This study made it possible to group woodland ponds according to the occurrence of the three invasive species in snail communities and discuss the environmental conditions present in these pond types. Analysis of water properties emphasised the distinctiveness of the selected pond types. In ponds of the Potamopyrgus antipodarum type, we found the highest values of some parameters mainly hardness, conductivity, and content of calcium and chlorides, in contrast with the Physella acuta type, which were characterised by the lowest values except for phosphates and nitrites. In the Ferrissia fragilis type, we found the highest nitrate content. Data on the occurrence of alien species in different water environments play an important role in actions which are taken to prevent new invasions and spread of non-native species as well as to reduce future impacts of invaders.

  1. Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade.

    Science.gov (United States)

    Ng, Ting Hui; Tan, Siong Kiat; Wong, Wing Hing; Meier, Rudolf; Chan, Sow-Yan; Tan, Heok Hui; Yeo, Darren C J

    2016-01-01

    The ornamental pet trade is often considered a key culprit for conservation problems such as the introduction of invasive species (including infectious diseases) and overharvesting of rare species. Here, we present the first assessment of the biodiversity of freshwater molluscs in the ornamental pet trade in Singapore, one of the most important global hubs of the ornamental aquarium trade, and discuss associated conservation concerns. We recorded freshwater molluscs from ornamental pet shops and major exporters including non-ornamental species (e.g., hitchhikers, molluscs sold as fish feed). We recorded an unexpectedly high diversity-59 species-of freshwater bivalves and gastropods, with the majority (38 species or 64%) being from the Oriental region. In addition to morphological examination, we sequenced the DNA barcode region of mitochondrial CO1 and 16S genes to provide molecular data for the confirmation of the identification and for future re-identification. DNA barcodes were obtained for 50 species, and all but four were separated by > 3% uncorrected pairwise distances. The trade has been considered a main introduction pathway for non-native species to Singapore, and we found that out of 15 species in the trade as well as in the wild in Singapore, 12 are either introduced or of unknown origin, representing almost half of the known non-native freshwater molluscs in Singapore. Particularly prevalent are non-ornamental species: six hitchhikers on aquarium plants and six species sold as fish feed. We found that a quarter of the trade species have a history of introduction, which includes 11 known or potentially invasive species. We conclude that potential overharvesting is difficult to assess because only half of the trade species have been treated by IUCN. Of these, 21 species are of Least Concern and three are Data Deficient. Our checklist, with accompanying DNA barcodes, images, and museum vouchers, provides an important reference library for future monitoring

  2. Microsatellite evidence for high frequency of multiple paternity in the marine gastropod Rapana venosa.

    Directory of Open Access Journals (Sweden)

    Dongxiu Xue

    Full Text Available BACKGROUND: Inferring of parentage in natural populations is important in understanding the mating systems of a species, which have great effects on its genetic structure and evolution. Muricidae, a large group (approximately 1,600 species of marine gastropods, are poorly investigated in patterns of multiple paternity and sperm competition based on molecular techniques. The veined Rapa whelk, Rapana venosa, a commercially important muricid species with internal fertilization, is an ideal species to study the occurrence and frequency of multiple paternity and to facilitate understanding of their reproductive strategies. METHODOLOGY/PRINCIPAL FINDINGS: We developed five highly polymorphic microsatellites in R. venosa and applied them to identify multiple paternity in 19 broods (1381 embryos collected from Dandong, China. Multiple paternity was detected in 17 (89.5% of 19 broods. The number of sires per brood ranged from 1 to 7 (4.3 on average. Of the 17 multiply sired broods, 16 (94.1% were significantly skewed from equal paternal contributions, and had a dominant sire which was also dominant in each assayed capsule. CONCLUSIONS: Our results indicate that a high level of multiple paternity occurs in the wild population of R. venosa. Similar patterns of multiple paternity in the 2-6 assayed capsules from each brood imply that fertilization events within the body of a female occur mostly (but not entirely as random draws from a "well-but-not-perfectly blended sperm pool" of her several mates. Strongly skewed distributions of fertilization success among sires also suggest that sperm competition and/or cryptic female choice might be important for post-copulatory paternity biasing in this species.

  3. Effect of tidal regime on the thermal tolerance of the marine gastropod Lunella smaragda (Gmelin 1791).

    Science.gov (United States)

    Mortensen, B J D; Dunphy, B J

    2016-08-01

    The tidal cycle around New Zealand results in spring low tides consistently occurring during the hottest part of the day (mid-afternoon) in north-eastern New Zealand, and during the cooler dawn/dusk periods in the north-west of the country. We hypothesised that due to mid-afternoon spring low tides, intertidal populations residing at north-eastern sites would show greater thermotolerance than their north-west conspecifics. To test this we used the marine gastropod, Lunella smaragda, which were collected from sites on both the East and West coasts of the Auckland region and exposed to an acute heat shock. Thermotolerance was measured as survivorship (LT50), drop down time (time to heat coma) and thermal stability of the anaerobic energy producing enzyme Tauropine dehydrogenase. Furthermore, temperature loggers were deployed at each site so as to record and compare thermal regimes among sites. A strong temperature spike associated with spring low tide was found at all sites, and maximal temperatures of all East coast sites were higher than West coast sites (in some case by up to 10°C). In terms of thermotolerance, mortality of L. smaragda occurred at 42°C leading to 100% mortality at 45°C. However, comparison of LT50 showed snails were equally thermotolerant regardless of site of collection. Similar results were found in TDH thermal stability with animals from all sites showing an approximately 80% decrease in enzyme activity after 10min exposure to 42°C. Whilst drop down times were different among sites these were correlated with animal size as opposed to site of collection. Thus, East coast populations of L. smaragda appear no more thermotolerant than their West coast counterparts. Such a result is concerning as maximal temperatures at East coast sites already exceed the LT50 values of L. smaragda recorded in the lab suggesting these populations have less of a thermal safety margin.

  4. Population genetics of a trochid gastropod broadens picture of Caribbean Sea connectivity.

    Directory of Open Access Journals (Sweden)

    Edgardo Díaz-Ferguson

    Full Text Available BACKGROUND: Regional genetic connectivity models are critical for successful conservation and management of marine species. Even though rocky shore invertebrates have been used as model systems to understand genetic structure in some marine environments, our understanding of connectivity in Caribbean communities is based overwhelmingly on studies of tropical fishes and corals. In this study, we investigate population connectivity and diversity of Cittarium pica, an abundant rocky shore trochid gastropod that is commercially harvested across its natural range, from the Bahamas to Venezuela. METHODOLOGY/PRINCIPAL FINDINGS: We tested for genetic structure using DNA sequence variation at the mitochondrial COI and 16S loci, AMOVA and distance-based methods. We found substantial differentiation among Caribbean sites. Yet, genetic differentiation was associated only with larger geographic scales within the Caribbean, and the pattern of differentiation only partially matched previous assessments of Caribbean connectivity, including those based on larval dispersal from hydrodynamic models. For instance, the Bahamas, considered an independent region by previous hydrodynamic studies, showed strong association with Eastern Caribbean sites in our study. Further, Bonaire (located in the east and close to the meridional division of the Caribbean basin seems to be isolated from other Eastern sites. CONCLUSIONS/SIGNIFICANCE: The significant genetic structure and observed in C. pica has some commonalities in pattern with more commonly sampled taxa, but presents features, such as the differentiation of Bonaire, that appear unique. Further, the level of differentiation, together with regional patterns of diversity, has important implications for the application of conservation and management strategies in this commercially harvested species.

  5. Development of cardiovascular function in the marine gastropod Littorina obtusata (Linnaeus).

    Science.gov (United States)

    Bitterli, Tabitha S; Rundle, Simon D; Spicer, John I

    2012-07-01

    The molluscan cardiovascular system typically incorporates a transient extracardiac structure, the larval heart, early in development, but the functional importance of this structure is unclear. We documented the ontogeny and regulatory ability of the larval heart in relation to two other circulatory structures, the true heart and the velum, in the intertidal gastropod Littorina obtusata. There was a mismatch between the appearance of the larval heart and the velum. Velar lobes appeared early in development (day 4), but the larval heart did not begin beating until day 13. The beating of the larval heart reached a maximum on day 17 and then decreased until the structure itself disappeared (day 24). The true heart began to beat on day 17. Its rate of beating increased as that of the larval heart decreased, possibly suggesting a gradual shift from a larval heart-driven to a true heart-driven circulation. The true heart was not sensitive to acutely declining P(O(2)) shortly after it began to beat, but increased in activity in response to acutely declining P(O(2)) by day 21. Larval heart responses were similar to those of the true heart, with early insensitivity to declining P(O(2)) (day 13) followed by a response by day 15. Increased velum-driven rotational activity under acutely declining P(O(2)) was greatest in early developmental stages. Together, these findings point to cardiovascular function in L. obtusata larvae being the result of a complex interaction between velum, larval and true heart activities, with the functions of the three structures coinciding but their relative importance changing throughout larval development.

  6. Dietary preferences of two seagrass inhabiting gastropods: Allochthonous vs autochthonous resources

    Science.gov (United States)

    Doropoulos, C.; Hyndes, G. A.; Lavery, P. S.; Tuya, F.

    2009-06-01

    The movement of allochthonous resources between habitats can provide important trophic linkages in marine landscapes. In coastal south-western Australia, the kelp Ecklonia radiata is removed from reefs and accumulates in large quantities in neighbouring seagrass meadows. This study investigated the feeding preferences and grazing rates of two locally abundant gastropods, Pyrene bidentata and Cantharidus lepidus, which exhibit inverse distribution patterns with proximity to reefs in seagrass meadows, to determine whether allochthonous kelp has the potential to contribute to the seagrass food web. Using laboratory choice and no-choice feeding experiments, we tested whether detached kelp is consumed preferentially, and at greater rates, by these two species than autochthonous resources (i.e. seagrass, epiphytic red macroalgae and seagrass periphyton). Both species displayed a preference for macroalgae and seagrass periphyton over seagrass leaves. In choice experiments, neither species displayed any clear preference between kelp (fresh or aged), red macroalgae or periphyton (consumption rates ranged between 0.39 and 3.64 mg ind -1 day -1), but consumption rates were always higher relative to seagrass. In no-choice experiments, P. bidentata displayed minimal consumption of seagrass, but consumed fresh and aged kelp, red macroalgae and seagrass periphyton at similar rates (2.00-7.22 mg ind -1 day -1). In comparison, C. lepidus consumed periphyton at far greater rates than any other food source (3.61 vs 0.33-1.10 mg ind -1 day -1). The results indicate that both P. bidentata and C. lepidus showed a clear preference for macroalgae and periphyton over seagrass, but no consistent preference towards any autochthonous or allochthonous algal resource. Reef-derived kelp therefore has the potential to contribute to the food web of seagrass meadows, and subsidise secondary production.

  7. Surveys of arthropod and gastropod diversity in the geothermal resource subzones, Puna, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.E.; Burgett, J.; Bruegmann, M.

    1995-04-01

    The invertebrate surveys reported here were carried out as part of ecological studies funded by the Department of Energy in support of their environmental impact statement (EIS) for the Hawaii Geothermal Project. Currently, preparation of the EIS has been suspended, and all supporting information is being archived and made available to the public. The invertebrate surveys reported here assessed diversity and abundance of the arthropod and gastropod fauna in forested habitat and lava tubes in or near the three geothermal resource subzones. Recommendations for conservation of these organisms are given in this report. Surveys were conducted along three 100-m transect lines at each of the six forested locations. Malaise traps, baited pitfall traps, yellow pan traps, baited sponge lures, and visual examination of vegetation were used to assess invertebrate diversity along each transect line. Three of these locations were adjacent to roads, and three were adjacent to lava flows. Two of these lava-forest locations (Keauohana Forest Reserve and Pu`u O`o) were relatively remote from direct human impacts. The third location (Southeast Kula) was near a low-density residential area. Two lava tubes were surveyed. The forest over one of these tubes (Keokea tube) had recently been burned away. This tube was used to assess the effects of loss of forest habitat on the subterranean fauna. An undisturbed tube (Pahoa tube) was used as a control. Recommendations offered in this report direct geothermal development away from areas of high endemic diversity and abundance, and toward areas where natural Hawaiian biotic communities have already been greatly disturbed. These disturbed areas are mainly found in the lower half of the Kamaili (middle) geothermal subzone and throughout most of the Kapoho (lower) geothermal subzone. These recommendation may also generally apply to other development projects in the Puna District.

  8. The Mollusk Gastropod Lanistes carinatus (Olivier, 1804 as Abiomonitor for Some Trace Metals in the Nile River

    Directory of Open Access Journals (Sweden)

    S.S.I. Abd El Gawad

    2009-01-01

    Full Text Available The fresh water gastropod Lanistes carinatus was tested to be used as potential biomonitor for the trace metals, Copper, Cadmium and Lead. Some chemical and biological measurements were sampled and measured in two consecutive years 2005 and 2006 in different stations from Damietta Branch of Nile River. Cu level in water not detected in all investigated sites, while concentrations of Cd and Pb in water and the concentrations of Cu, Cd and Pb in sediment varied in different stations. It was found, metals concentrations were higher in sediment than those of water because sediments are important sinks for various pollutants like pesticides and heavy metals. The levels found for determined metals in water and sediment in the area are below of the permissible limits that set by the United States Environmental Protection Agency (EPA except some deviations in managements of water especially at Kafr Saad. Concentrations of these metals in soft tissues of gastropod Lanistes carinatus were higher than those of sediment and vary widely in different sites suggesting that this gastropod accumulate these metals and consequently would be of use for monitoring. The population density of Lanistes carinatus decreased sharply opposite to discharge point of Electric Plant of Talkha and Kafr Saad. This may be due to thermal pollution of the plant. The study suggested the use of Lanistes carinatus as Cu, Cd and Pb biomonitor in nature and also recommended a construction of closed cycle for cooling water of the power stations to prevent heated water from being discharged into the River and also controlling the discharge of wastes and industrial effluents into Nile.

  9. Beginning of a new age: How did freshwater gastropods respond to the Quaternary climate change in Europe?

    Science.gov (United States)

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

    2016-10-01

    The well documented fossil record of European Quaternary freshwater gastropods offers a unique resource for continental-scale biogeographical analyses. Here, we assembled a dataset including 338 freshwater gastropod taxa from 1058 localities across Europe, which we used to explore how freshwater gastropod communities varied in space and time across six distinct time intervals of the Quaternary, i.e. Gelasian, Calabrian, Middle Pleistocene, Last Interglacial, Last Glacial and Holocene. We took into consideration both species richness and qualitative structural patterns, comparing turnover rates between time intervals and examining variations in community nestedness-segregation patterns. Species richness differed significantly between time intervals. The Early Pleistocene showed the highest diversity, likely because of the contribution of long-lived aquatic systems like the lakes Bresse and Tiberino that promoted speciation and endemism. The rich Middle to Late Pleistocene and Holocene assemblages were mostly linked to fluvial and/or lacustrine systems with short temporal durations. We identified a major turnover event at the Plio-Pleistocene boundary, related to the demise of long-lived lakes and of their rich, endemic faunas at the end of the Pliocene. In the subsequent intervals, little or no turnover was observed. We also observed a pattern of high segregation in Early Pleistocene communities, associated with the abundance of endemic species with small distribution ranges, and reflecting the provincial character of the aquatic freshwater systems at that time. This structured pattern disintegrated gradually towards the Middle Pleistocene and remained unstructured up to present. In particular, spatial patterns of community nestedness-segregation in the Last Interglacial and Holocene suggest a random recolonization of freshwater habitats mostly by generalist species following deglaciation.

  10. Functional Authentication of a Novel Gastropod Gonadotropin-Releasing Hormone Receptor Reveals Unusual Features and Evolutionary Insight

    OpenAIRE

    Kavanaugh, Scott I.; Tsai, Pei-San

    2016-01-01

    A gonadotropin-releasing hormone (GnRH)-like molecule was previously identified in a gastropod, Aplysia californica, and named ap-GnRH. In this study, we cloned the full-length cDNA of a putative ap-GnRH receptor (ap-GnRHR) and functionally authenticated this receptor as a bona fide ap-GnRHR. This receptor contains two potential translation start sites, each accompanied by a Kozak sequence, suggesting the translation of a long and a short form of the receptor is possible. The putative ap-GnRH...

  11. Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands - A controlled mesocosm experiment

    Energy Technology Data Exchange (ETDEWEB)

    Penha-Lopes, Gil, E-mail: gil.penha-lopes@biology-research.co [Centro de Oceanografia - Laboratorio Maritimo da Guia, Departamento de Biologia Animal, Faculdade de Ciencias da Universidade de Lisboa, Avenida Na, Senhora do Cabo 939, 2750-374 Cascais (Portugal); Department of Analytical and Environmental Chemistry, Vrije Universiteit Brussels, Brussels (Belgium); Bartolini, Fabrizio [Dipartimento di Biologia Evoluzionistica, Universita degli Studi di Firenze, via Romana 17, I-50125 Firenze (Italy); Limbu, Samwel [University of Dar es Salaam, Department of Aquatic Sciences and Fisheries, P.O. Box 35064, Dar es Salaam (Tanzania, United Republic of); Cannicci, Stefano [Dipartimento di Biologia Evoluzionistica, Universita degli Studi di Firenze, via Romana 17, I-50125 Firenze (Italy); Mgaya, Yunus [University of Dar es Salaam, Department of Aquatic Sciences and Fisheries, P.O. Box 35064, Dar es Salaam (Tanzania, United Republic of); Kristensen, Erik [Institute of Biology, University of Southern Denmark, DK-5230 Odense M (Denmark); Paula, Jose [Centro de Oceanografia - Laboratorio Maritimo da Guia, Departamento de Biologia Animal, Faculdade de Ciencias da Universidade de Lisboa, Avenida Na, Senhora do Cabo 939, 2750-374 Cascais (Portugal)

    2010-01-15

    The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3-4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential. - Terebralia palustris high ecosystem engineering potential in constructed mangrove wetlands.

  12. [Taphonomy of the gastropod cf. Donaldina robusta (Heterobranchia: Streptacididae) from the Middle Pennsylvanian, La Joya Formation, Sonora, Mexico].

    Science.gov (United States)

    Gómez E, Catalina; Buitrón S, Blanca; Vachard, Daniel

    2010-03-01

    Gastropods are an important component in most of the fossil record; however, investigations have focused mainly on the characterization of the tafofacies and signatures in determined environments. We present qualitative and quantitative taphonomic data for the gastropod cf. Donaldina robusta assemblages from the La Joya Formation of the Sierra Agua Verde, Sonora State, (NW) Mexico. We analyzed 176 shells. Good preservation received ahigh taphonomic grade (A) and poor preservation a D. The shells were complete in 72% of cases (taphonomic grade B). Less than 10% are corroded or are parallel to the layer (grade A). This rock is petrographycally classified as wackestone, sedimentologically it is characterized by middle sorting (grade B) and low grading (grade A). The fossiliferous assemblage grades as A and B. Biostratinomic features of the skeletal assemblage are characteristic of sedimentologic concentrations of autochthonous-parautochthonous elements at the accumulation site. There was minimal reworking and transport in an environment of low energy, locally produced during a short period of accumulation.

  13. Bioactive potential of some economically important marine gastropods along the Gulf of Mannar region, southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    JayanthiGovindarajalu; Muthusamy Anand; Gurusamy Chelladurai; Arumugam Kumaraguru

    2016-01-01

    Objective:To analyse the economically important gastropods for prospective antimicrobial, antioxidant and cytotoxic activities from the Gulf of Mannar region, southeast coast of India. Methods: The bioactive potential of some gastropodsi.e. Babylonia spirata (B. spirata), Phalium glaucum, Tonna dolium, Hemifusus pugilinus, Xancus pyrum, Chicoreus ramosus (C. ramosus), Harpa articularis, Ficus ficus andBabylonia zeylanica were analysed. Antimicrobial activity was carried out against 8 human pathogenic bacteria and 3 fungal strains by well diffusion method. Antioxidant and cytotoxic activities were analyzed by standard methods. Results: In antibacterial and antifungal activities, methanolic extract ofB. spirata significantly showed the highest inhibition zone againstAeromonas hydrophila andFusarium spp. (P > 0.05). In the total antioxidant activity, the maximum activity was observed inB. spirata (510µg/mg) and in the 1.1-diphenyl-2-picrylhydrazylscavenging activity,B. spiratashowed the highest percentage of inhibition (76.7%). In the case of cytotoxicityi.e. brine shrimplethality tests the methanolic extract ofC. ramosus showed the lowest percentage of mortality and the LC50 values were found to be 523.9µg/mL. Conclusions: The results revealed that all the gastropods in the present study possessed antimicrobial, antioxidant and cytotoxic effects. However, species likeB. spirata andC. ramosus exhibited potent activity andcan be used for further clinical studies.

  14. Sequence and comparison of mitochondrial genomes in the genus Nerita (Gastropoda: Neritimorpha: Neritidae) and phylogenetic considerations among gastropods.

    Science.gov (United States)

    Arquez, Moises; Colgan, Donald; Castro, Lyda R

    2014-06-01

    In the present study, we determined the mitochondrial DNA (mtDNA) sequence of three Neritas, Nerita versicolor, Nerita tessellata, and Nerita fulgurans. We present an analysis of the features of their gene content and genome organization and compare these within the genus Nerita, and among the main gastropod groups. The new sequences were used in a phylogenetic analysis including all available gastropod mitochondrial genomes. Genomic lengths were quite conserved, being 15,866bp for N. versicolor, 15,741bp for N. tessellata and 15,343bp for N. fulgurans. Intergenic regions were generally short; genes are transcribed from both strands and have a nucleotide composition high in A and T. The high similarity in nucleotide content of the different sequences, gene composition, as well as an identical genomic organization among the Nerita species compared in this study, indicates a high degree of conservation within this diverse genus. Values ​​of Ka/Ks of the 13 protein coding genes (PCGs) of Nerita species ranged from 0 to 0.18, and suggested different selection pressures in gene sequences. Bayesian phylogenetic analyses using concatenated DNA sequences of the 13 PCGs and the two rRNAs, and of amino acid sequences strongly supported Neritimorpha and Vetigastropoda as sister groups.

  15. A study on the diversity of gastropods in Hormuz Island with first record of two species from the Iranian coast of the Persian Gulf

    Directory of Open Access Journals (Sweden)

    Nabiallah Kheirabadi

    2014-04-01

    Full Text Available This study was carried out to determine the diversity of gastropod species in the intertidal zone of Hormuz Island in the Persian Gulf. Seasonal sampling was conducted in 7 selected sites by throwing nine random quadrates (0.5×0.5 m in each site. Samples of each site were separately transferred to the laboratory and identified by the standard keys and verified by the Conchology Museum of Tokyo University of Science. Forty -nine gastropod species were identified, from which 2 species, Turicula nelliae and Linatella caudata were recorded for the first time from the Iranian coast of the Persian Gulf. The highest number of gastropods in one site was 28 species in site 1 (East of Marine Research Center, Also highest number of gastropods in one season was 35 species in winter and lowest number was in 28 species in summer. Simpson dominance index, Shannon-Wiener species diversity index, Margalef richness index and evenness index were calculated in the different sites and results showed that site 1 contained the most amount of the Shannon-Wiener and Margalef indices and site 6 (West of Island contained the most amount of the Simpson index. Also, site 3 (Mangrove forest showed the lowest amount of the Simpson, Shannon-Wiener and Margalef indices, while maximum amount of evenness index occurred in this site.

  16. The hydrobioid freshwater gastropods (Caenogastropoda, Truncatelloidea) of Greece: new records, taxonomic re-assessments using DNA sequence data and an update of the IUCN Red List Categories

    OpenAIRE

    2013-01-01

    Abstract Hydrobioid freshwater gastropods were collected from mainland and insular Greece. Several threatened taxa, such as Graecoanatolica vegorriticola, Pseudamnicola negropontina, Pseudamnicola pieperi, Pseudobithynia eubooensis and Pseudoislamia balcanica, were recorded from new localities. Trichonia trichonica, which has been considered extinct from its type locality for the last twenty eight years, was re-discovered, whereas the presence of Daphniola exigua, G. vegorriticola, Marstoniop...

  17. Heavy Metal Concentrations in Sediment and Intertidal Gastropod Nerita lineata from Two Opposing Sites in the Straits of Malacca

    Institute of Scientific and Technical Information of China (English)

    Bintal Amin; Ahmad Ismail; Chee Kong Yap

    2008-01-01

    The concentrations of Cd, Cu, Pb, Zn, Ni and Fe were determined in the surface sediment and marine gastropod Nerita lineata collected in May 2005 from the intertidal zone of Dumai, Sumatera, Indonesia and Johor, Peninsular Malaysia. The results showed that metal concentrations in sediment and the soft tissue of N. lineata varied at different sampling stations. Mean heavy metal concentrations were 0. 92 μg/g(Cd) ;6.40 μg/g(Cu) ;32.77 μg/g(Pb) ;54.41μg/g(Zn) ;11.56 μg/g(Ni) and 2.97%(Fe) in sediment from Dumai and 1.15 μg(Cd) ;26.73 μg/g(Cu) ;53.45μg/g(Pb) ;130.77 μg/g(Zn) ;20.79 μg/g( Ni ) and 2.72% (Fe) in sediment from Johor. Concentrations of metals in gastropod N. lineata were 0.71 μg/g(Cd) ;15.16 μg(Cu) ;9.35 μg/g(Pb) ;94.69 μg/g(Zn) ;5.08 μg/g(Ni) and 397.97 μg/g(Fe) in samples from Dumai and 1.24 μg(Cd) ;18.02 μg/g(Cu) ;19.75 μg/g(Pb) ;95.09 μg/g(Zn) ;5.57 μg/g ( Ni ) and 473. 56 μg/g (Fe) in samples from Johor. Although they were not statistically significant (p >0.05), heavy metal concentrations in N. lineata were correlated with the concentrations of respective metals in sediment in both samples from Dumai and Johor. In general, samples of sediment and gastropod from Johor accumulated significantly higher heavy metal concentrations when compared to samples from Dumai(p < 0. 05). Higher concentrations of metals were recorded in samples collected from the stations close to the industrial and anthropogenic activities in both Dumai and Johor areas. However, most of the concentrations were still comparable to the previous reported studies from other geographical areas.

  18. P/Ca in Gastropod Shells as a Nutrient Proxy in Tropical Marine Environments

    Science.gov (United States)

    Grossman, E. L.; Tao, K.; Robbins, J.; O'Dea, A.

    2013-12-01

    Nutrient status and its stability play key roles in the maintenance of marine ecosystems, both in modern and ancient oceans. Modern coral reef communities in the Caribbean are being threatened by anthropogenic input of nutrients whereas one to two million years ago, communities in this same region experienced dramatic overturn of corals and mollusks with the uplift of the Central American Isthmus and subsequent reduction of upwelling-derived nutrients. Thus the ability to record past and present nutrient delivery is paramount for understanding the role of environmental change in controlling past and future biodiversity. To test trace element chemistries in gastropod shells as nutrient proxies, we measured the trace element (Mg, Sr, Ba, Mn, Fe, P, and U ) and stable isotopic (δ18O, δ13C) compositions of 11 modern Conus specimens collected from upwelling and non-upwelling regions in the Caribbean and Pacific coasts of Panama. Four Caribbean shells represent non-upwelling conditions, while seven Pacific shells record conditions of seasonal upwelling (Gulf of Panama) or shoaling of the thermocline (Gulf of Chiriquí). Shells were serially sampled around the spire at 2-3 mm intervals, providing roughly monthly resolution. Shallow-dwelling Pacific specimens show large seasonal range in δ18O (>2‰) reflecting upwelling during the dry season and freshening during the rainy season. In contrast, shallow-dwelling Caribbean specimens show small δ18O range (mostly ≤1‰) indicating limited seasonal upwelling and freshening. For trace element analyses, about 100 μg of carbonate powder was dissolved in 2 ml of 2% HNO3 and analyzed on a high resolution, inductively-coupled plasma mass spectrometer (HR-ICP-MS). Among the wide array of trace elements analyzed, only Sr/Ca shows a significant correlation with upwelling intervals, as indicated by high δ18O. This reflects the positive relationship between Sr/Ca and temperature in Conus shells (Sosdian et al., 2006, G3, Q11023

  19. [SPECTRAL AND ACID-BASE PROPERTIES OF HEMOLYMPH PLASMA AND ITS FRACTIONS FROM GASTROPOD PULMONATE MOLLUSC ACHATINA FULICA].

    Science.gov (United States)

    Petrova, T A; Lianguzov, A Yu; Malygina, N M

    2016-01-01

    The set of normal biochemical indicators of the hemolymph plasma of gastropod pulmonate mollusc Achatinafulica is described. Comparative analysis of the whole plasma and its subfractions enriched and depleted of oxygen-carrying protein hemocyanin was performed by spectrophotometry and spectrofluorimetry methods. Individual features of the absorption spectra were analyzed using fourth derivatives. The optimum method for estimating protein concentration was chosen. To characterize acid-base properties of plasma hemolymph and its sub-fractions we calculated buffer capacity, equivalence points and pK values of dominant buffer groups. It is shown that the major role in maintaining the buffer capacity of hemolymph belongs to the bicarbonate system. These results are compared with data for Helix pomatia available in literature. In the future the indicators studied in this work will be used to develop ecotoxicological criteria for the environmental assessment.

  20. Mechanism of a plastic phenotypic response: predator-induced shell thickening in the intertidal gastropod Littorina obtusata.

    Science.gov (United States)

    Brookes, J I; Rochette, Rémy

    2007-05-01

    Phenotypic plasticity has been the object of considerable interest over the past several decades, but in few cases are mechanisms underlying plastic responses well understood. For example, it is unclear whether predator-induced changes in gastropod shell morphology represent an active physiological response or a by-product of reduced feeding. We address this question by manipulating feeding and growth of intertidal snails, Littorina obtusata, using two approaches: (i) exposure to predation cues from green crabs Carcinus maenas and (ii) reduced food availability, and quantifying growth in shell length, shell mass, and body mass, as well as production of faecal material and shell micro-structural characteristics (mineralogy and organic fraction) after 96 days. We demonstrate that L. obtusata actively increases calcification rate in response to predation threat, and that this response entails energetic and developmental costs. That this induced response is not strictly tied to the animal's behaviour should enhance its evolutionary potential.

  1. A Mox homeobox gene in the gastropod mollusc Haliotis rufescens is differentially expressed during larval morphogenesis and metamorphosis.

    Science.gov (United States)

    Degnan, B M; Degnan, S M; Fentenany, G; Morse, D E

    1997-07-07

    We have isolated a homeobox-containing cDNA from the gastropod mollusc Haliotis rufescens that is most similar to members of the Mox homeobox gene class. The derived Haliotis homeodomain sequence is 85% identical to mouse and frog Mox-2 homeodomains and 88.9% identical to the partial cnidarian cnox5-Hm homeodomain. Quantitative reverse transcription-polymerase chain reaction analysis of mRNA accumulation reveals that this gene, called HruMox, is expressed in the larva, but not in the early embryo. Transcripts are most prevalent during larval morphogenesis from trochophore to veliger. There are also transient increases in transcript prevalence 1 and 3 days after the intitiation of metamorphosis from veliger to juvenile. The identification of a molluscan Mox homeobox gene that is more closely related to vertebrate genes than other protostome (e.g. Drosophila) genes suggests the Mox class of homeobox genes may consist of several different families that have been conserved through evolution.

  2. Mox homeobox expression in muscle lineage of the gastropod Haliotis asinina: evidence for a conserved role in bilaterian myogenesis.

    Science.gov (United States)

    Hinman, V F; Degnan, B M

    2002-04-01

    Mox homeobox genes are expressed during early vertebrate somitogenesis. Here we describe the expression of Has-Mox, a Mox gene from the gastropod Haliotis asinina. Has-Moxis expressed in the trochophore larva in paraxial mesodermal bands. During larval development, Has-Mox expression remains restricted to mesodermal cells destined to form adult muscle in the foot. This restricted expression of Has-Mox in Haliotis is similar to that observed for vertebrate Mox genes, suggesting a conserved role in myogenesis in deuterostomes and lophotrochozoans. In contrast, Mox is not expressed in muscle lineages in the ecdysozoan representatives Caenorhabditis elegans or Drosophila; the C. elegansgenome has lost Mox altogether. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00427-002-0223-6.

  3. The role of vermetid gastropods in the development of the Florida Middle Ground, northeast Gulf of Mexico

    Science.gov (United States)

    Reich, Christopher D.; Poore, Richard Z.; Hickey, Todd D.

    2013-01-01

    The Florida Middle Ground is a complex of north to northwest trending ridges that lie approximately 180 km northwest of Tampa Bay, Florida. The irregular ridges appear on the otherwise gently sloping West Florida shelf and exhibit between 10-15 m of relief. Modern studies interpret the ridges as remnants of a Holocene coral-reef buildup that today provide a hard substrate for growth of a variety of benthic organisms including hydrocorals, scleractinians, alcyonarians, and algae. Recent rotary coring reveals that the core of the eastern ridge of the Florida Middle Ground complex consists of unconsolidated marine calcareous muddy sand that is capped by a boundstone composed primarily of the sessile vermetid gastropod Petaloconchus sp., and overlays a weathered, fossiliferous limestone. Accelerator Mass Spectrometry radiocarbon ages (uncalibrated) on the 3.6-m thick vermetid worm rock indicate that it developed during a sea-level stillstand in the early Holocene (8,225 ±30-8,910 ± 25 yr B.P.). Our observations suggest that the Florida Middle Ground is a remnant of a series of shore parallel bars that formed in the early Holocene and were capped by a 3.6-m thick unit of vermetid gastropods. During a rapid sea-level rise that began ~8,000 yr B.P. the vermetids growth ceased and the worm rock preserved the ridges structure. Diver observations document that the edges of the ridges are currently being eroded and undermined by biological activity and current action, leading to calving of large capstone blocks.

  4. Heavy metal concentrations in edible bivalves and gastropods available in major markets of the Pearl River Delta

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Molluscs are able to accumulate heavy metals and impose healthhazard to consumers. The main objective of the present study is to investigate the heavy metal concentrations in edible bivalves and gastropods available in major markets of the Pearl River Delta. Fourteen species of edible molluscs were purchased from six markets in Hong Kong and Guangdong Province. The fresh of these biota were tested for their cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn)concentrations (based on wet weight). The results indicated that amongst the 14 edible molluscs, only Cd, Pb, Ni, Cr, Sb and Sn concentrations in three species(Ruditapes philippinarum, Perna viridis and Hemifusus tuba) were within the local regulatory limits. Over 60% of bivalve species exceeded maximum permitted levels of Cd (2 μg/g) and Cr (1 μg/g), while over 40% of gastropod species exceeded the maximum levels of Sb (1 μg/g) and Cr(1 μg/g). Most of the samples collected from Hong Kong had significantly higher contents of Pb and Sb, but similar levels of Cd, Cu and Zn when compared with samples collected across the border (p<0.5; p<0.01; p<0.001 respectively). In general, the molluscs purchased in Guangdong markets had higher metal contents than those purchased from the Hong Kong markets. When compared with the Provisional Tolerable Weekly Intake or Maximum Acceptable Daily Load recommended by FAO/WHO Expert Committee on Food Additives, Cd levels of five species (Anadara ferruginea, Pinna pectinata, Chlamys nobilis, Babylonia lutosa and Hemifusus terntanus) and Cr levels of seven species (Anadara ferruginea, Paphia undulata, Pinna pectinata, Babylonia lutosa, Hemifusus terntanus, Cymbium melo and Cipangopaludina chinensis) were higher than both the human daily acceptable limits (for Cd and Cr respectively) and the local regulatory levels (for Cd and Cr respectively).

  5. You are what you eat: Stable isotopic evidence indicates that the naticid gastropod Neverita duplicata is an omnivore

    Directory of Open Access Journals (Sweden)

    Michelle Marie Casey

    2016-11-01

    Full Text Available Species belonging to the family Naticidae (commonly called moon snails are important infaunal gastropod predators found in soft-bottom marine communities worldwide that traditionally have been thought to prey on other mollusks, giving them the expected trophic position of a predator (trophic position = 3. Realized trophic position estimates of the naticid Neverita duplicata from Long Island Sound, however, range between 2.3 and 2.5, indicating omnivory or an anomalously low nitrogen (N fractionation factor. To evaluate the likelihood of omnivory, this study presents whole body stable isotopic analysis of nitrogen and carbon from the soft tissues of laboratory-reared and field-collected N. duplicata. Experimental organisms were maintained on a diet of the bivalve prey Mercenaria mercenaria for one year. The median N fractionation factor derived from the experimental moon snails was 3.58 ‰ thus precluding the presence of an atypical fractionation factor (substantially lower than 3.4 ‰. Numerous molluscan taxa were collected from Long Island Sound in order to evaluate the trophic ecology of N. duplicata in the context of a natural food web. Evidence from the carbon (C signatures of field-collected N. duplicata indicate a reliance on littoral food sources that is inconsistent with a diet of filter-feeding M. mercenaria, even when calculated using the species-specific C fractionation factor derived from the laboratory experiments. Field-collected N. duplicata also show considerable isotopic overlap (N and C with grazing Littorina littorea. For these reasons, we hypothesize that N. duplicata feeds on some combination of benthic primary producers (most likely macroalgae and/or epiphytic diatoms, carrion, and bivalve/gastropod tissue and discuss the ecological implications of potential naticid omnivory.

  6. Differential toxic effects of Ulva lactuca (Chlorophyta) on the herbivorous gastropods, Littorina littorea and L. obtusata (Mollusca).

    Science.gov (United States)

    Peckol, Paulette; Putnam, Alysha B

    2016-12-28

    Members of the genus Ulva are widespread and abundant in intertidal and shallow subtidal areas but there are conflicting data regarding susceptibility to herbivory. While some studies have documented that Ulva spp. were favored by a diversity of marine herbivores, other work has revealed herbivore deterrence. We investigated grazing and growth rates of the littorinid species, Littorina littorea and L. obtusata, when offered Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, and Chondrus crispus, highlighting distinctive vulnerabilities to toxic effects of U. lactuca. Ulva lactuca was the preferred food of L. littorea, while L. obtusata showed no grazing on this ephemeral algal species. In contrast, F. vesiculosus was highly preferred by L. obtusata. Although L. littorea demonstrated a grazing preference for U. lactuca, growth rate of this gastropod species was nearly 3× greater when fed F. vesiculosus, suggesting a non-lethal, negative effect of U. lactuca on L. littorea with long-term exposure. Mortality of L. obtusata ranged from 0% to 100% when held in the presence of various Ulva densities for 1 week, and Ulva exudate depressed herbivory of this gastropod. We conclude that the water-soluble, toxic exudate produced by U. lactuca in response to herbivory had allelochemical properties, and may contain a cleavage product (acrylic acid) of dimethylsulfoniopropionate or reactive oxygen species (i.e., H2 O2 ). Observed differences in susceptibility to Ulva toxicity by the littorinid species may be related to generalist versus specialist feeding and habitat strategies.

  7. Interactions between cyanobacteria and gastropods II. Impact of toxic Planktothrix agardhii on the life-history traits of Lymnaea stagnalis.

    Science.gov (United States)

    Lance, Emilie; Paty, Chrystelle; Bormans, Myriam; Brient, Luc; Gérard, Claudia

    2007-03-30

    Hepatotoxins are frequently produced by many cyanobacterial species. Microcystins (MCs) are the most frequent and widely studied hepatotoxins, with potentially hazardous repercussions on aquatic organisms. As a ubiquitous herbivore living in eutrophic freshwaters, the snail Lymnaea stagnalis (Gastropoda: Pulmonata) is particularly exposed to cyanobacteria. The toxic filamentous Planktothrix agardhii is common in temperate lakes and is therefore, a potential food resource for gastropods. In the first part of this study, we demonstrated the ingestion of toxic P. agardhii by L. stagnalis during a 5 weeks exposure, with concomitant accumulation of, on average, 60% of total MCs ingested. After 3 weeks of non-toxic food (lettuce), approximately 90% of MCs were eliminated from tissues. Here, we investigate the impact of toxic P. agardhii consumption on the life-history traits (survival, growth and fecundity), locomotion and the structure of digestive and genital glands of juvenile and adult L. stagnalis. We observed a decrease of growth regardless of age, although this was more marked in juveniles, and a reduction of fecundity in adults. Survival and locomotion were not affected. Reduction of growth and fecundity continued to be observed even after feeding of non-toxic food for 3 weeks. The structure of the digestive gland was altered during the intoxication period but not irreversibly as cells tended to recover a normal status after the 3-week detoxification period. No histopathological changes occurred in the genital gland and oocytes, and spermatozoids were present in the gonadic acini. The density of cyanobacterial suspensions used in this study was comparable to those regularly observed in lakes, particularly in eutrophic waters. These results are discussed in terms of the negative impact of toxic cyanobacteria on natural communities of freshwater gastropods, and potential cascading effects on the equilibrium and functioning of the ecosystem.

  8. QUASIMEME laboratory performance study of the biological effects of tributyltin (imposex and intersex) on two marine gastropod molluscs.

    Science.gov (United States)

    Davies, I M; Minchin, A; Bauer, B; Harding, M J; Wells, D E

    1999-06-01

    The disruption of the endocrine systems of gastropod molluscs and consequential physiological changes (imposex and intersex) are used as biomarkers for environmental contamination by tributyltin compounds. The first international laboratory performance study on the determination of imposex and intersex in neogastropod molluscs, Nucella lapillus and Littorina littorea has been undertaken by the QUASIMEME (Quality Assurance of Information for Marine Environmental Monitoring in Europe) project. Samples of live gastropods were distributed and participants were asked to record shell height and sex, together with penis length and vas deferens sequence stage (VDS) in Nucella or the intersex stage (IS) and prostate length in Littorina. Calculations were made of vas deferens sequence index (VDSI) and the relative penis size index (RPSI) in Nucella and of intersex stage index (ISI) and the average female prostate length (FPrL) in Littorina. Thirteen (87%) of the 15 participating laboratories returned data. The remaining two laboratories asked to participate in later exercises. For Nucella, seven laboratories reported sex ratios significantly different from the reference laboratory data. Differences in penis length measurements between laboratories were largely random, although there were indications of systematic errors affecting the data from three laboratories. Seven laboratories reported satisfactory data (Z-score magnitude of Z penis length or observation of reproductive organs would have a potentially greater impact on the final reported values of the summary imposex indices. The Littorina sample did not show a high degree of intersex (ISI = 0.41). The laboratories could determine the sex of Littorina reliably and only one laboratory reported data significantly different from the reference laboratory. All except two laboratories reported satisfactory data for ISI.

  9. Evolutionary dynamics in the southwest Indian ocean marine biodiversity hotspot: a perspective from the rocky shore gastropod genus Nerita.

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    Bautisse Postaire

    Full Text Available The Southwest Indian Ocean (SWIO is a striking marine biodiversity hotspot. Coral reefs in this region host a high proportion of endemics compared to total species richness and they are particularly threatened by human activities. The island archipelagos with their diverse marine habitats constitute a natural laboratory for studying diversification processes. Rocky shores in the SWIO region have remained understudied. This habitat presents a high diversity of molluscs, in particular gastropods. To explore the role of climatic and geological factors in lineage diversification within the genus Nerita, we constructed a new phylogeny with an associated chronogram from two mitochondrial genes [cytochrome oxidase sub-unit 1 and 16S rRNA], combining previously published and new data from eight species sampled throughout the region. All species from the SWIO originated less than 20 Ma ago, their closest extant relatives living in the Indo-Australian Archipelago (IAA. Furthermore, the SWIO clades within species with Indo-Pacific distribution ranges are quite recent, less than 5 Ma. These results suggest that the regional diversification of Nerita is closely linked to tectonic events in the SWIO region. The Reunion mantle plume head reached Earth's surface 67 Ma and has been stable and active since then, generating island archipelagos, some of which are partly below sea level today. Since the Miocene, sea-level fluctuations have intermittently created new rocky shore habitats. These represent ephemeral stepping-stones, which have likely facilitated repeated colonization by intertidal gastropods, like Nerita populations from the IAA, leading to allopatric speciation. This highlights the importance of taking into account past climatic and geological factors when studying diversification of highly dispersive tropical marine species. It also underlines the unique history of the marine biodiversity of the SWIO region.

  10. Evolutionary dynamics in the southwest Indian ocean marine biodiversity hotspot: a perspective from the rocky shore gastropod genus Nerita.

    Science.gov (United States)

    Postaire, Bautisse; Bruggemann, J Henrich; Magalon, Hélène; Faure, Baptiste

    2014-01-01

    The Southwest Indian Ocean (SWIO) is a striking marine biodiversity hotspot. Coral reefs in this region host a high proportion of endemics compared to total species richness and they are particularly threatened by human activities. The island archipelagos with their diverse marine habitats constitute a natural laboratory for studying diversification processes. Rocky shores in the SWIO region have remained understudied. This habitat presents a high diversity of molluscs, in particular gastropods. To explore the role of climatic and geological factors in lineage diversification within the genus Nerita, we constructed a new phylogeny with an associated chronogram from two mitochondrial genes [cytochrome oxidase sub-unit 1 and 16S rRNA], combining previously published and new data from eight species sampled throughout the region. All species from the SWIO originated less than 20 Ma ago, their closest extant relatives living in the Indo-Australian Archipelago (IAA). Furthermore, the SWIO clades within species with Indo-Pacific distribution ranges are quite recent, less than 5 Ma. These results suggest that the regional diversification of Nerita is closely linked to tectonic events in the SWIO region. The Reunion mantle plume head reached Earth's surface 67 Ma and has been stable and active since then, generating island archipelagos, some of which are partly below sea level today. Since the Miocene, sea-level fluctuations have intermittently created new rocky shore habitats. These represent ephemeral stepping-stones, which have likely facilitated repeated colonization by intertidal gastropods, like Nerita populations from the IAA, leading to allopatric speciation. This highlights the importance of taking into account past climatic and geological factors when studying diversification of highly dispersive tropical marine species. It also underlines the unique history of the marine biodiversity of the SWIO region.

  11. Assembly processes of gastropod community change with horizontal and vertical zonation in ancient Lake Ohrid: a metacommunity speciation perspective

    Science.gov (United States)

    Hauffe, Torsten; Albrecht, Christian; Wilke, Thomas

    2016-05-01

    The Balkan Lake Ohrid is the oldest and most diverse freshwater lacustrine system in Europe. However, it remains unclear whether species community composition, as well as the diversification of its endemic taxa, is mainly driven by dispersal limitation, environmental filtering, or species interaction. This calls for a holistic perspective involving both evolutionary processes and ecological dynamics, as provided by the unifying framework of the "metacommunity speciation model".The current study used the species-rich model taxon Gastropoda to assess how extant communities in Lake Ohrid are structured by performing process-based metacommunity analyses. Specifically, the study aimed (1) to identifying the relative importance of the three community assembly processes and (2) to test whether the importance of these individual processes changes gradually with lake depth or discontinuously with eco-zone shifts.Based on automated eco-zone detection and process-specific simulation steps, we demonstrated that dispersal limitation had the strongest influence on gastropod community composition. However, it was not the exclusive assembly process, but acted together with the other two processes - environmental filtering and species interaction. The relative importance of the community assembly processes varied both with lake depth and eco-zones, though the processes were better predicted by the latter.This suggests that environmental characteristics have a pronounced effect on shaping gastropod communities via assembly processes. Moreover, the study corroborated the high importance of dispersal limitation for both maintaining species richness in Lake Ohrid (through its impact on community composition) and generating endemic biodiversity (via its influence on diversification processes). However, according to the metacommunity speciation model, the inferred importance of environmental filtering and biotic interaction also suggests a small but significant influence of ecological

  12. Fossil gastropods from the Indian Upper Siwaliks and their stable carbon and oxygen isotope values indicate presence of cold climatic conditions in the Early Pleistocene.

    Science.gov (United States)

    Singh Kotla, Simran

    2016-04-01

    The Early Pleistocene in general is characterized by widespread glaciations in the Northern Hemisphere. Early to Middle Pleistocene freshwater Pinjor Formation (Upper Siwalik) exposed all along the Himalayan Foothills preserves a diverse faunal and floral assemblage. We carried out paleontological (gastropods) and stable isotope (carbon and oxygen isotope) studies of a 6 m thick swamp/pond deposit (that represents ~ 12,000 yrs) of Pinjor Formation, exposed near the Village Nadah, Panchkula (Haryana) and dated to ~ 1.8 Ma (Azzaroli and Napoleon,1982). We have identified four gastropod species in the assemblage, Lymnae sp., Gyraulus sp., Viviparous bengalensis and Hippeutis complantus. The first two are widespread throughout the globe. Lymnae can exist in temperature range of 19 to 24 ° C and occur in Palearctic and Neoartic regions (animalbase.org). Gyraulus occur in Holoarctic region with temperature ranging from 17.8 to 30 ° C (animalbase.org, theaquariumwiki.com), whereas Viviparous bengalensis typically exists in the Oriental region suggesting an overall warm and humid condition (Moore,1997). Hippeutis complantus on the other hand exists in palearctic regions upto 63 ° N (Aplinarska and Cisewka 2006) under cold (6 ° to 23.3 ° C) and dry climatic conditions (Spyra., 2014).The powdered gastropod shell samples were analyzed using Continues Flow Isotope Ratio Mass Spectrometer (CF-IRMS) at the Wadia Institute of Himalayan Geology, Dehradun, India. The δ13C values of gastropod shells fall between -2.56‰ and 6.14‰ VPDB and suggest the dominance of C4 vegetation. The δ18O value of gastropod shell fall between -0.64‰ and -7.80‰ VPDB, suggesting fluctuation of climate between warm and cold conditions . Presence of Hippeutis complantus may suggest the extension of palearctic region up to Panchkula (Haryana, India) in the Early Pleistocene which presently lies in the Oriental Province. Therefore, our results indicate that the overall climatic condition

  13. Differential fitness of allelic isozymes in the marine gastropods Littorina punctata and Littorina neritoides, exposed to the environmental stress of the combined effects of cadmium and mercury pollution

    Science.gov (United States)

    Lavie, Batia; Nevo, Eviatar

    1987-07-01

    The present study tested the separate and the interactive pollution effects of cadmium and mercury on the electrophoretically detected allelic isozyme frequencies of the enzyme phosphoglucose isomerase for two species of littoral marine gastropods — Littorina punctata and L. neritoides — and the enzyme amino peptidase for L. neritoides. Our results indicate differential survivorship of allelic isozyme genotypes specific for each type of pollutant and for their interaction, as well as trends common to all pollutants. Theoretically the results reflect the adaptive nature of at least some allozymic genotypes in these marine gastropods and seem inconsistent with the neutral theory of allozyme polymorphisms. Practically, the results reinforce earlier conclusions that changes in the frequency of allelic isozymes may be used as a genetic monitor of pollution.

  14. Tetrodotoxin and paralytic shellfish poisons in gastropod species from Vietnam analyzed by high-performance liquid chromatography and liquid chromatography–tandem mass spectrometry

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    Hsiao-Chin Jen

    2014-06-01

    Full Text Available Among marine toxins, tetrodotoxin (TTX and paralytic shellfish poisons (PSPs are known as notorious neurotoxins that induce serious food poisoning incidents in the Southeast Asia region. The aim of this study was to investigate whether TTX and PSP toxins are important issues of seafood safety. Paralytic toxicity was observed in mice exposed to 34 specimens from five species of gastropods using a PSP bioassay. Five species of gastropods, Natica vitellus, Natica tumidus, Oliva hirasei, Oliva lignaria, and Oliva annulata, were collected from the coastal seawaters in Nha Trang City, Vietnam, between August 2007 and October 2007. The average lethal potency of gastropod specimens was 90 ± 40 (mean ± standard deviation mouse units (MU for N. vitellus, 64 ± 19 MU for N. tumidus, 42 ± 28 MU for O. hirasei, 51 ± 17 MU for O. lignaria, and 39 ± 18 MU for O. annulata. All toxic extracts from the sample species were clarified using a C18 Sep-Pak solid-phase extraction column and a microcentrifuge filter prior to analysis. High-performance liquid chromatography coupled with fluorescence detection indicated that the toxins of the olive shell (O. hirasei, O. lignaria, and O. annulata were mainly composed of saxitoxin (STX (73–82%, gonyautoxin (GTX 2, 3 (12–22%, and minor levels of TTX (5–6%. The toxins of N. vitellus and N. tumidus were mainly composed of STX (76–81% and GTX 1, 4 (19–24%. Furthermore, liquid chromatography–tandem mass spectrometry analysis was used to verify the identity of the PSPs and TTX. Our evidence shows that these gastropods have novel toxin profiles.

  15. Trace elements in shells of common gastropods in the near vicinity of a natural CO2 vent: no evidence of pH-dependent contamination

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    J. B. McClintock

    2014-04-01

    Full Text Available There is concern that the use of natural volcanic CO2 vents as analogs for studies of the impacts of ocean acidification on marine organisms are biased due to physiochemical influences other than seawater pH alone. One issue that has been raised is whether potentially harmful trace elements in sediments that are rendered more soluble and labile in low pH environments are made more bioavailable, and sequestered in the local flora and fauna at harmful levels. In order to evaluate this hypothesis, we analyzed the concentrations of trace elements in shells (an established proxy for tissues of four species of gastropods (two limpets, a topshell and a whelk collected from three sites in Levante Bay, Vulcano Island. Each sampling site increased in distance from the primary CO2 vent and thus represented low, moderate, and ambient seawater pH conditions. Concentrations of As, Cd, Co, Cr, Hg, Mo, Ni, Pb, and V measured in shells using ICP-OES were below detection thresholds for all four gastropod species at all three sites. However, there were measurable concentrations of Sr, Mn, and U in the shells of the limpets Patella caerulea, P. rustica, and the snail Osilinus turbinatus, and similarly, Sr, Mn, U, and also Zn in the shells of the whelk Hexaplex trunculus. Levels of these elements were within the ranges measured in gastropod shells in non-polluted environments, and with the exception of U in the shells of P. caerulea, where the concentration was significantly lower at the collecting site closest to the vent (low pH site, there were no site-specific spatial differences in concentrations for any of the trace elements in shells. Thus trace element enhancement in sediments in low-pH environments was not reflected in greater bioaccumulations of potentially harmful elements in the shells of common gastropods.

  16. Evaluation of impairment of DNA integrity in marine gastropods (Cronia contracta) as a biomarker of genotoxic contaminants in coastal water around Goa, West coast of India.

    Science.gov (United States)

    Sarkar, A; Gaitonde, Dipak C S; Sarkar, Amit; Vashistha, D; D'Silva, Classy; Dalal, S G

    2008-10-01

    The measurement of the impairment of DNA in marine gastropod (Cronia contracta) provides an insight into the genotoxic effects of contaminants on marine organisms along the Goa coast. The impact of genotoxic contaminants on Goan coastal environment was evaluated in terms of the loss of DNA integrity (expressed as the value of 'I') in marine snails with respect to those from the reference site (Palolem) over a period from April 2004 to May 2005 using the technique of alkaline unwinding assay. The DNA integrity in marine snails was found to be significantly damaged at Dona Paula (58%), Vasco (73.5%), and Velsao (48.5%) during the monsoon period (July-August 2004). Similar trend in the loss of DNA integrity in marine gastropods was also detected during the post-monsoon (November-December 2004) and the pre-monsoon (April-May 2005) periods. The low integrities of DNA in marine gastropods at these sites can be attributed to exposure to genotoxic contaminants especially polycyclic aromatic hydrocarbons (PAHs) and toxic heavy metals (Pb, Cd, Cu, Fe, and Mn) prevalent in the marine environment as evident by their accumulation in the tissues of the marine snails inhabiting different sites along the Goa coast. The contaminant-induced DNA strand breaks in marine snails increased significantly at Dona Paula, Vasco, and Velsao clearly indicating the levels of contamination of the sites by genotoxic compounds in those regions. The genotoxic effects of contaminants were further substantiated by detection of the impairment (39%) of DNA integrity in marine snails in a field experiment in which the same species of marine snails (C. contracta) collected from the reference site, Palolem, were deployed at Dona Paula and caged for 25 days for exposure to ambient marine pollutants. The impairment of DNA integrity in marine gastropods along the Goa coast can thus act as a biomarker for marine pollution monitoring of genotoxic contaminants.

  17. Tetrodotoxin and Its Derivatives in Gastropods (Nassarius)%织纹螺体内的河豚毒素及其衍生物

    Institute of Scientific and Technical Information of China (English)

    张农; 刘海新; 苏捷; 叶孙忠; 李庐峰

    2012-01-01

    对2002年福建省引起食物中毒的织纹螺毒素进行研究.高效液相色谱-质谱联用(liquid chromatography/mass,LC/MS)的分析结果显示,织纹螺毒素的主要成分是河豚毒素类毒素(tetrodotoxin,TTX),另外还含有4-epi TTX、anhydroTTX、deoxyTTX等成分.生物法对织纹螺毒素的毒力测定结果表明:所收集的26个织纹螺样品中15个检测出毒性,毒素的毒力在5.7 ~ 47.3MU·g-1之间.毒力最高的织纹螺样品2003年5月1日来自福安,主要由半褶织纹螺和另一未定种组成.%Toxins in Nassarius gastropods during food intoxication event in Fujian Province in 2002 were studied.The toxin extracted from the gastropods was analyzed by high-performance liquid chromatography/mass spectrometry,and the result indicated that the toxin consisted of tetrodotoxin (TTX) and its derivatives,i.e,4-epiTTX,deoxyTTX,as well as anhydroTTX.The toxic equivalent of the toxins was also detected by the bioassay approach,and the results indicated that 15 gastropods were confirmed to be positive among 26 samples,the toxicity in samples ranged from 5.7 to 47.3 mouse units per gram (MU· g- 1).The gastropods with highest toxicity was collected from Fu'an on May 1,2003,which were consisted of two species,i.e.,Nassarius semiplicatus and a species not yet documented.

  18. An evaluation of Mesodon and other larger terrestrial gastropod shells for dating late Holocene and historic alluvium in the Midwestern USA

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    Rakovan, Monica T.; Rech, Jason A.; Pigati, Jeffery S.; Nekola, Jeffery C.; Wiles, Gregory C.

    2013-01-01

    Understanding the history of stream erosion and changes in channel morphology is important for managing and restoring unstable streams. One of the significant challenges in this type of research is establishing accurate dating of late Holocene and historic alluvium. Here we evaluate the potential of using 14C dating and amino acid racemization (AAR) to date large terrestrial gastropod shells that are often preserved within alluvial sediments. Many terrestrial gastropods incorporate old carbon from limestone or other carbonate rocks into their shells and therefore are unsuitable for radiocarbon dating. Recent studies, however, have shown that some taxa avoid this ‘limestone problem’ and can yield reliable 14C ages. In this study, we measured the 14C activity of specimens for the genera Mesodon, Ventridens, and Allogona collected live and from alluvial sequences dated independently by dendrochronology, 14C dating of wood, and/or 137Cs analyses. Mesodon zaletus contained old carbon in similar concentrations (up to ~ 30%) found in previous studies of other large taxa and should be avoided for 14C dating when possible. In contrast, shells of Ventridens ligera and Allogona profunda showed minimal limestone effects and therefore may be suitable for dating late Holocene alluvium. These results highlight the importance of taxonomic identification of gastropod taxa prior to their use for 14C dating and demonstrate that shell fragments that are not identifiable should be avoided. We also measured d/l ratios (n = 17) of aspartic and glutamic acid from eight different taxa of terrestrial gastropods recovered from four late Holocene and historic stratigraphic sequences. Average d/l ratios of aspartic and glutamic acid from historic sediments < 300 years old are lower in shells from younger stratigraphic units, indicating that AAR can be used to differentiate between multiple historic stratigraphic units.

  19. Reticulate phylogeny of gastropod-shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization

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    Blanc Michel

    2007-01-01

    Full Text Available Abstract Background The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty gastropod shells is probably the most peculiar. Although shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Results Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites evidence for ongoing hybridization among distantly related shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the shells of their mate, such that they have to release their sperm over the entrance of the shell to fertilize the eggs. With sperm

  20. Isolation and identification of crude oil degrading bacteria from gastropod Haustrum scobina collected from Persian Gulf (Bandar Abbas Shoreline provenance

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    Zinab Bayat

    2016-06-01

    Full Text Available Introduction: Biodegradation is a good alternative rather than chemical and physical methods for cleaning oil contaminated areas. Several factors like crude oil concentration, biosurfactant production, salinity and incubation time affect the biodegradation. Materials and methods: In this study, seawater sample and gastropod were collected from Persian Gulf. To isolate oil degrading bacteria from collected samples, ONR7a medium was used. The strains that had more growth and higher oil removal were selected and identified. The factors such as the effect of different concentrations of oil, incubation time, mixed cultures and salinity on the biodegradation were investigated. Results: Six crude oil degrading bacteria were isolated. Between these bacteria 2 strains were selected based on higher oil removal. These strains belonged to the genus Vibrio and Halomonas. Strains with higher Emulsification activity produce more biosurfactant and have higher oil biodegradation. Growth and oil degradation have increment pattern by prolonging the incubation time. Mixed culture of Vibrio and Halomonas strains have higher rates of degradation rather than culturing with one of them. Increase in crudeoil concentration to 2.5% caused reduction in growth of bacteria and degradation of oil. Discussion and conclusion: The results of this study show that crude oil degrading bacteria have high diversity in Persian Gulf. These bacteria have higher capability for oil degradation thus they can be used for remediation of oil contaminated areas.

  1. Determination of the toxic variability of lipophilic biotoxins in marine bivalve and gastropod tissues treated with an industrial canning process.

    Science.gov (United States)

    García, Carlos; Oyaneder-Terrazas, Javiera; Contreras, Cristóbal; Del Campo, Miguel; Torres, Rafael; Contreras, Héctor R

    2016-11-01

    Contamination of shellfish with lipophilic marine biotoxins (LMB), pectenotoxins (PTXs), yessotoxins (YTXs) and okadaic acid (OA) toxin groups in southern Chile is a constant challenge for the development of miticulture considering the high incidence of toxic episodes that tend to occur. This research is focused on using methodologies for assessing the decrease in toxins of natural resources in Chile with high value, without altering the organoleptic properties of the shellfish. The species were processed through steaming (1 min at 121°C) and subsequent canning (5 min at 121°C). Changes in the profiles of toxins and total toxicity levels of LMB in endemic bivalves and gastropods were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total reduction of toxicity (≈ 15%) was not related to the destruction of the toxin, but rather to the loss of LMB on removing the shells and packing media of canned products (***p < 0.001). Industrial processing of shellfish reduces LMB contents by up to 15% of the total initial contents, concomitant only with the interconversion of PTX-group toxins into PTX-2sa. In soft bottom-dwelling species with toxicities beyond the standard for safe human consumption (≥ 160 μg OA-eq kg(-)(1)), toxicity can be reduced to safe levels through industrial preparation procedures.

  2. Freezing and anoxia stresses induce expression of metallothionein in the foot muscle and hepatopancreas of the marine gastropod Littorina littorea.

    Science.gov (United States)

    English, Tamara E; Storey, Kenneth B

    2003-07-01

    Differential screening of cDNA libraries constructed from the foot muscle of marine snails Littorina littorea revealed several cDNAs that are upregulated during anoxia or freezing exposures, environmental stresses that are naturally endured by this species. One full-length clone of 1196 nucleotides (GenBank accession number AY034179) hybridized with a 1200-nucleotide band on northern blots and encoded a 100-amino-acid protein that was identified as belonging to the metallothionein (MT) family. L. littorea MT shared 45% and 56% identity with the copper- and cadmium-binding MT isoforms, respectively, from another gastropod, Helix pomatia and 43-47% identity with marine bivalve MTs. The L. littorea sequence included the mollusc-specific C-terminal motif Cys-X-Cys-X(3)-Cys-Thr-Gly-X(3)-Cys-X-Cys-X(3)-Cys-X-Cys-Lys that identifies it as a family 2 (mollusc) MT. Northern blot analysis showed that L. littorea MT was upregulated in both foot muscle and hepatopancreas in response to both freezing and anoxia stresses; within 1 h of the beginning of the stress transcript levels rose 2.5- to sixfold of control levels, reaching maximal levels at 12 or 24 h. After 24 h recovery from either stress, transcript levels were reduced again in three cases but remained elevated in hepatopancreas from anoxia-treated snails. Upregulation of MT during environmental stress could serve one or more possible roles, including a function in antioxidant defense.

  3. Oceanography in northwestern Europe during the last interglacial from intrashell δ 18O ranges in Littorina littorea gastropods

    Science.gov (United States)

    Burman, Johan; Påsse, Tore

    2008-07-01

    Coastal sea-surface temperature (SST) and sea-surface salinity (SSS), including seasonality, in northwest (NW) Europe during the early phase of the Eemian interglacial ca. 125 ka ago were reconstructed from Littorina littorea (common periwinkle) gastropods. The results were based on intra-annual δ 18O analyses in recent and fossil shells, mainly originating from the sea of Kattegat (Sweden) and the English Channel (United Kingdom), and confined to intertidal settings. The Eemian L. littorea shells indicated annual SSTs in the range 8-18°C for the English Channel and 8-26°C for Kattegat. All specimens from the Eemian sites experienced summer SSTs of ca. 1-3°C above recent conditions. The estimated winter SST in the English Channel during the Eemian was comparable to modern measurements of ca. 8°C. However, the Kattegat region displayed Eemian winter SST approximately 8°C warmer than today, and similar to conditions in the western English Channel. The recent-fossil isotope analogue approach indicated high SSS above 35 practical salinity units (psu) for a channel south of England in full contact with the North Atlantic Ocean during the last interglacial. In addition, the Kattegat shells indicated a SSS of ca. 29 psu, which points out a North Sea affinity for this region during the Eemian.

  4. Mid-Holocene paleoceanographic conditions in the Limfjord region from gastropod (Littorina littorea) oxygen and carbon isotopes

    Science.gov (United States)

    Burman, J.; Schmitz, B.

    2003-04-01

    Stable oxygen and carbon isotope intrashell transects of common intertidal gastropods Littorina littorea have been used to reconstruct environmental conditions in the Limfjord region during the mid-Holocene (late Atlantic time). The subfossil specimens studied are from the excavated Stone Age Kitchenmidden in Ertebølle, northern Denmark, dated between 5970±95 to 5070±90 B.P. In addition recent specimens were studied from different coastal localities within the Limfjord, along a salinity gradient from the west to east. These modern shells were used as control samples, in order to construct an oceanographic model for the Limfjord, in which the seasonal isotopic range from the Littorina subfossils could be interpreted. The coastal marine climate in the Ertebølle region during the mid-Holocene indicates summer-SST close to 22^oC and 4-5 ppm reduced salinity compared to fully marine conditions. The mid-Holocene central Limfjord can be described as a coastal area, which experienced similar salinity conditions (c. 30.5 PSU) that prevail in the western part (Odden area) today. In terms of summer-SST as compared with a 10-year average (1989-1998) for the Limfjord region, temperatures were 2-3^oC above recent climatic settings. These results point towards a mid-Holocene Limfjord in contact with the North Sea/Skagerrak with possibly more pronounced water exchange with the North Sea than today.

  5. The larvae of congeneric gastropods showed differential responses to the combined effects of ocean acidification, temperature and salinity.

    Science.gov (United States)

    Zhang, Haoyu; Cheung, S G; Shin, Paul K S

    2014-02-15

    The tolerance and physiological responses of the larvae of two congeneric gastropods, the intertidal Nassarius festivus and subtidal Nassarius conoidalis, to the combined effects of ocean acidification (pCO2 at 380, 950, 1250 ppm), temperature (15, 30°C) and salinity (10, 30 psu) were compared. Results of three-way ANOVA on cumulative mortality after 72-h exposure showed significant interactive effects in which mortality increased with pCO2 and temperature, but reduced at higher salinity for both species, with higher mortality being obtained for N. conoidalis. Similarly, respiration rate of the larvae increased with temperature and pCO2 level for both species, with a larger percentage increase for N. conoidalis. Larval swimming speed increased with temperature and salinity for both species whereas higher pCO2 reduced swimming speed in N. conoidalis but not N. festivus. The present findings indicated that subtidal congeneric species are more sensitive than their intertidal counterparts to the combined effects of these stressors.

  6. High gene flow due to pelagic larval dispersal among South Pacific archipelagos in two amphidromous gastropods (Neritomorpha: Neritidae).

    Science.gov (United States)

    Crandall, E D; Taffel, J R; Barber, P H

    2010-06-01

    The freshwater stream fauna of tropical oceanic islands is dominated by amphidromous species, whose larvae are transported to the ocean and develop in the plankton before recruiting back to freshwater habitat as juveniles. Because stream habitat is relatively scarce and unstable on oceanic islands, this life history would seem to favor either the retention of larvae to their natal streams, or the ability to delay metamorphosis until new habitat is encountered. To distinguish between these hypotheses, we used population genetic methods to estimate larval dispersal among five South Pacific archipelagos in two amphidromous species of Neritid gastropod (Neritina canalis and Neripteron dilatatus). Sequence data from mitochondrial cytochrome oxidase I (COI) revealed that neither species is genetically structured throughout the Western Pacific, suggesting that their larvae have a pelagic larval duration (PLD) of at least 8 weeks, longer than many marine species. In addition, the two species have recently colonized isolated Central Pacific archipelagos in three independent events. Since colonization, there has been little or no gene flow between the Western and Central Pacific archipelagos in N. canalis, and high levels of gene flow across the same region in N. dilatatus. Both species show departures from neutrality and recent dates for colonization of the Central Pacific archipelagos, which is consistent with frequent extinction and recolonization of stream populations in this area. Similar results from other amphidromous species suggest that unstable freshwater habitats promote long-distance dispersal capabilities.

  7. [Toxicity and toxin profile of scavenging and carnivorous gastropods from the coastal waters of Okinawa Prefecture, Japan].

    Science.gov (United States)

    Taniyama, Shigeto; Takatani, Tomohiro; Sorimachi, Taiki; Sagara, Takefumi; Kubo, Hirofumi; Oshiro, Naomasa; Ono, Kaname; Xiao, Ning; Tachibana, Katsuyasu; Arakawa, Osamu

    2013-01-01

    From January to June 2009, a total of 64 gastropod specimens of 15 species were collected from the coastal waters of Okinawa Prefecture, Japan, and examined for toxicity by means of mouse bioassay. Among the specimens tested, 5 species, Nassarius glans, Nassariuscoronatus, Olivaannulata, Oliva concavospira and Zeuxis sp., were toxic. The toxicity scores of N. glans were very high; 39.6-461 MU/g in muscle, and 98.6-189 MU/g in viscera including digestive gland, followed by Zeuxis sp. (12.7 MU/g in whole body), N. coronatus (5.64-11.1 MU/g in whole body), O. annulata (10.8 MU/g in the whole body), O. concavospira (6.65 MU/g in the muscle). Liquid chromatography/mass spectrometry (LC-MS) revealed that the major toxic component was tetrodotoxin (TTX), which accounting for 13-82% of the total toxicity. As for the remaining toxicity in the case of N. glans, 4,9-anhydroTTX, 4-epiTTX and 11-oxoTTX were contributors. Moreover, Niotha albescens showed no toxicity (less than 10 MU/g) in mouse bioassay, but TTX (5.08 MU/g) was detected by LC-MS. Paralytic shellfish poison was not detected in any of the specimens by high-performance liquid chromatography with fluorometric detection (HPLC-FLD).

  8. Fossil gastropods from the MGS3 stratigraphic segment in the Salawusu River Valley and their climatic and environmental implications

    Institute of Scientific and Technical Information of China (English)

    LI BaoSheng; YE JianPing; GUO YunHai; CHEN DeNiu; David Dian ZHANG; WEN XiaoHao; QIU ShiFan; OU XianJiao; DU ShuHuan; NIU DongFeng; YANG Yi

    2008-01-01

    Contemporaneous with MIS3, the MGS3 segment of the Milanggouwan stratigraphic section in the Salawusu River Valley, Mu Us Desert, China contains fossil gastropods (terrestrial and freshwater snails) in strata 33LS, 35LS, 37FL and 39LS. Examination of these fossils revealed 11 species belonging to 8 families and 10 genera. They can be classified as: (1) assemblage of Gyraulus and Galba mainly consisting of Gyraulus convexiusculus, Gyraulus sibiricus, Galba pervia and Galba superegra Gredler,etc. (2) assemblage of Vallonia mainly consisting of terrestrial snails, such as Vallonia patens, Pupilla muscorum and Discus paupe, etc. Based on the dating results, and the living habits, living conditions,and geographic distribution of their extant species, we suggest that: the ages of 33LS, 35LS, 37FL, and 39LS are 26000, 29000, 33000 and 38000 a, respectively, corresponding well to the interstadial period in GRIP 4,5, 6 and 10 in terms of chronology and climatic characters; 33LS, 35LS and 39LS represent very warm-humid periods, while 37FL represents a less warm-humid period; the four periods of climatic fluctuations recorded in MGS3 were related to the strong impact of the summer monsoon in East Asia in Mu Us Desert of China during the interstadial of MIS3 on a global climatic background.

  9. Fossil gastropods from the MGS3 stratigraphic segment in the Salawusu River Valley and their climatic and environmental implications

    Institute of Scientific and Technical Information of China (English)

    David; Dian

    2008-01-01

    Contemporaneous with MIS3, the MGS3 segment of the Milanggouwan stratigraphic section in the Salawusu River Valley, Mu Us Desert, China contains fossil gastropods (terrestrial and freshwater snails) in strata 33LS, 35LS, 37FL and 39LS. Examination of these fossils revealed 11 species belonging to 8 families and 10 genera. They can be classified as: (1) assemblage of Gyraulus and Galba mainly consisting of Gyraulus convexiusculus, Gyraulus sibiricus, Galba pervia and Galba superegra Gredler, etc. (2) assemblage of Vallonia mainly consisting of terrestrial snails, such as Vallonia patens, Pupilla muscorum and Discus paupe, etc. Based on the dating results, and the living habits, living conditions, and geographic distribution of their extant species, we suggest that: the ages of 33LS, 35LS, 37FL, and 39LS are 26000, 29000, 33000 and 38000 a, respectively, corresponding well to the interstadial period in GRIP 4, 5, 6 and 10 in terms of chronology and climatic characters; 33LS, 35LS and 39LS represent very warm-humid periods, while 37FL represents a less warm-humid period; the four periods of climatic fluctuations recorded in MGS3 were related to the strong impact of the summer monsoon in East Asia in Mu Us Desert of China during the interstadial of MIS3 on a global climatic background.

  10. Effects of low salinity on adult behavior and larval performance in the intertidal gastropod Crepipatella peruviana (Calyptraeidae).

    Science.gov (United States)

    Montory, Jaime A; Pechenik, Jan A; Diederich, Casey M; Chaparro, Oscar R

    2014-01-01

    Shallow-water coastal areas suffer frequent reductions in salinity due to heavy rains, potentially stressing the organisms found there, particularly the early stages of development (including pelagic larvae). Individual adults and newly hatched larvae of the gastropod Crepipatella peruviana were exposed to different levels of salinity stress (32(control), 25, 20 or 15), to quantify the immediate effects of exposure to low salinities on adult and larval behavior and on the physiological performance of the larvae. For adults we recorded the threshold salinity that initiates brood chamber isolation. For larvae, we measured the impact of reduced salinity on velar surface area, velum activity, swimming velocity, clearance rate (CR), oxygen consumption (OCR), and mortality (LC50); we also documented the impact of salinity discontinuities on the vertical distribution of veliger larvae in the water column. The results indicate that adults will completely isolate themselves from the external environment by clamping firmly against the substrate at salinities ≤24. Moreover, the newly hatched larvae showed increased mortality at lower salinities, while survivors showed decreased velum activity, decreased exposed velum surface area, and decreased mean swimming velocity. The clearance rates and oxygen consumption rates of stressed larvae were significantly lower than those of control individuals. Finally, salinity discontinuities affected the vertical distribution of larvae in the water column. Although adults can protect their embryos from low salinity stress until hatching, salinities <24 clearly affect survival, physiology and behavior in early larval life, which will substantially affect the fitness of the species under declining ambient salinities.

  11. Effects of low salinity on adult behavior and larval performance in the intertidal gastropod Crepipatella peruviana (Calyptraeidae.

    Directory of Open Access Journals (Sweden)

    Jaime A Montory

    Full Text Available Shallow-water coastal areas suffer frequent reductions in salinity due to heavy rains, potentially stressing the organisms found there, particularly the early stages of development (including pelagic larvae. Individual adults and newly hatched larvae of the gastropod Crepipatella peruviana were exposed to different levels of salinity stress (32(control, 25, 20 or 15, to quantify the immediate effects of exposure to low salinities on adult and larval behavior and on the physiological performance of the larvae. For adults we recorded the threshold salinity that initiates brood chamber isolation. For larvae, we measured the impact of reduced salinity on velar surface area, velum activity, swimming velocity, clearance rate (CR, oxygen consumption (OCR, and mortality (LC50; we also documented the impact of salinity discontinuities on the vertical distribution of veliger larvae in the water column. The results indicate that adults will completely isolate themselves from the external environment by clamping firmly against the substrate at salinities ≤24. Moreover, the newly hatched larvae showed increased mortality at lower salinities, while survivors showed decreased velum activity, decreased exposed velum surface area, and decreased mean swimming velocity. The clearance rates and oxygen consumption rates of stressed larvae were significantly lower than those of control individuals. Finally, salinity discontinuities affected the vertical distribution of larvae in the water column. Although adults can protect their embryos from low salinity stress until hatching, salinities <24 clearly affect survival, physiology and behavior in early larval life, which will substantially affect the fitness of the species under declining ambient salinities.

  12. Assessment of host-associated genetic differentiation among phenotypically divergent populations of a coral-eating gastropod across the Caribbean.

    Directory of Open Access Journals (Sweden)

    Lyza Johnston

    Full Text Available Host-associated adaptation is emerging as a potential driver of population differentiation and speciation for marine organisms with major implications for ecosystem structure and function. Coralliophila abbreviata are corallivorous gastropods that live and feed on most of the reef-building corals in the tropical western Atlantic and Caribbean. Populations of C. abbreviata associated with the threatened acroporid corals, Acropora palmata and A. cervicornis, display different behavioral, morphological, demographic, and life-history characteristics than those that inhabit other coral host taxa, indicating that host-specific selective forces may be acting on C. abbreviata. Here, we used newly developed polymorphic microsatellite loci and mitochondrial cytochrome b sequence data to assess the population genetic structure, connectivity, and demographic history of C. abbreviata populations from three coral host taxa (A. palmata, Montastraea spp., Mycetophyllia spp. and six geographic locations across the Caribbean. Analysis of molecular variance provided some evidence of weak and possibly geographically variable host-associated differentiation but no evidence of differentiation among sampling locations or major oceanographic regions, suggesting high gene flow across the Caribbean. Phylogenetic network and bayesian clustering analyses supported a hypothesis of a single panmictic population as individuals failed to cluster by host or sampling location. Demographic analyses consistently supported a scenario of population expansion during the Pleistocene, a time of major carbonate reef development in the region. Although further study is needed to fully elucidate the interactive effects of host-associated selection and high gene flow in this system, our results have implications for local and regional community interactions and impact of predation on declining coral populations.

  13. Assessment of host-associated genetic differentiation among phenotypically divergent populations of a coral-eating gastropod across the Caribbean.

    Science.gov (United States)

    Johnston, Lyza; Miller, Margaret W; Baums, Iliana B

    2012-01-01

    Host-associated adaptation is emerging as a potential driver of population differentiation and speciation for marine organisms with major implications for ecosystem structure and function. Coralliophila abbreviata are corallivorous gastropods that live and feed on most of the reef-building corals in the tropical western Atlantic and Caribbean. Populations of C. abbreviata associated with the threatened acroporid corals, Acropora palmata and A. cervicornis, display different behavioral, morphological, demographic, and life-history characteristics than those that inhabit other coral host taxa, indicating that host-specific selective forces may be acting on C. abbreviata. Here, we used newly developed polymorphic microsatellite loci and mitochondrial cytochrome b sequence data to assess the population genetic structure, connectivity, and demographic history of C. abbreviata populations from three coral host taxa (A. palmata, Montastraea spp., Mycetophyllia spp.) and six geographic locations across the Caribbean. Analysis of molecular variance provided some evidence of weak and possibly geographically variable host-associated differentiation but no evidence of differentiation among sampling locations or major oceanographic regions, suggesting high gene flow across the Caribbean. Phylogenetic network and bayesian clustering analyses supported a hypothesis of a single panmictic population as individuals failed to cluster by host or sampling location. Demographic analyses consistently supported a scenario of population expansion during the Pleistocene, a time of major carbonate reef development in the region. Although further study is needed to fully elucidate the interactive effects of host-associated selection and high gene flow in this system, our results have implications for local and regional community interactions and impact of predation on declining coral populations.

  14. An integrated approach to study the biomarker responses in marine gastropod Nerita chamaeleon environmentally exposed to polycyclic aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    J Bhagat

    2017-01-01

    Full Text Available Ecological risk assessment using multiple biomarkers produce a large amount of data that is hard to interpret and the result are often contradictory. In this context, Integrated Biomarker Response (IBR index was used to integrate the biomarkers effects to assess the impact of environmental contaminants in marine gastropod Nerita chamaeleon from Goa, India. Genotoxic (DNA damage as measured by comet assay and alkaline unwinding assay and biochemical [superoxide dismutase, catalase, glutathione S-transferase, lipid peroxidation and acetylcholinesterase] biomarkers were measured in snails collected from different sites (Arambol, Anjuna, Sinquerim, Dona Paula, Velsao, Betul and Palolem. Total polycyclic aromatic hydrocarbons in snail tissue were in the range from 5.29 - 12.14 µg/g wet weight. Standardized values of biomarker response were visualized using star plots, which show unique patterns for different biomarkers. The mean IBR value was found to be highest at Dona Paula (8.07 ± 0.91 followed by Sinquerim (6.95 ± 0.91, Velsao (4.48 ± 0.68, Anjuna (3.28 ± 1.05, Palolem (2.53 ± 0.73, Arambol (1.81 ± 0.21 and Betul (0.88 ± 0.77. Additionally, the IBR values were found to be positively correlated with PAH concentration in snail tissues. These results suggest that integration of biomarkers effects using IBR along with chemical analysis can be a useful tool for the assessment of environmental pollution and to identify spatial patterns of contamination in the aquatic ecosystem.

  15. Adult exposure to the synthetic hormone 17α-ethynylestradiol affects offspring of the gastropods Nassarius burchardi and Nassarius jonasii.

    Science.gov (United States)

    Borysko, Larissa; Ross, Pauline M

    2014-05-01

    The aim of this study was to determine whether adult exposure to endocrine disrupting compounds affects offspring using trans-generational testing. Adult estuarine dwelling gastropods Nassarius burchardi and Nassarius jonasii were exposed to the synthetic estrogen 17α-ethynylestradiol (EE2) to determine the effects on the development and survival of their offspring. Adults were maintained in synthetic seawater controls and EE2 treatments (0.005, 0.05, 0.5, 50µg/L) over a sixteen week period. Egg capsules were collected from the adults following four, ten and sixteen weeks of adult exposure and transferred to different EE2 exposure scenarios. Treatment concentrations were selected to represent changes in EE2 exposure that could occur over different periods in an organism's lifecycle. Egg capsules laid by adults were therefore transferred to control or EE2 treatments (0.005, 0.05, 0.5, 5, 50, 500µg/L) to develop until hatching. The percentage of egg capsules with unviable eggs and abnormalities, number of days for hatching to occur and hatching success were measured. The veliger larvae that hatched from egg capsules following two, eight and fourteen weeks of adult exposure to EE2 and controls were used in 96h acute toxicity tests with controls and EE2 treatments at concentrations of 0.5, 5, 50, 500, 1250, 2500, 4000µg/L. Exposure of adult N. burchardi and N. jonasii to EE2 affected the percentage of egg capsules with unviable eggs, the development and hatching success of embryos and survival of veligers. These toxicity tests produced a complex set of results with different responses in developing eggs and veliger larvae to the adult EE2 treatments and length of adult exposure. This study demonstrates the importance of trans-generational testing and adult exposure scenarios in toxicity investigations.

  16. Proteomic Analysis of the Reproductive Organs of the Hermaphroditic Gastropod Lymnaea stagnalis Exposed to Different Endocrine Disrupting Chemicals

    Science.gov (United States)

    Giusti, Arnaud; Leprince, Pierre; Mazzucchelli, Gabriel; Thomé, Jean-Pierre; Lagadic, Laurent; Ducrot, Virginie; Joaquim-Justo, Célia

    2013-01-01

    Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant

  17. Proteomic analysis of the reproductive organs of the hermaphroditic gastropod Lymnaea stagnalis exposed to different endocrine disrupting chemicals.

    Directory of Open Access Journals (Sweden)

    Arnaud Giusti

    Full Text Available Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range of endocrine disrupting chemicals (EDCs. However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD. In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin could

  18. Development of rearing and testing protocols for a new freshwater sediment test species: the gastropod Valvata piscinalis.

    Science.gov (United States)

    Ducrot, Virginie; Cognat, Claudine; Mons, Raphaël; Mouthon, Jacques; Garric, Jeanne

    2006-03-01

    This paper aimed at proposing rearing and testing protocols for Valvata piscinalis, a new potential species for sediment toxicity testing. Such tests were developed since this species reliably represents the bio/ecological characteristics of other gastropods. It may thus be representative of their sensitivity to chemicals. V. piscinalis was successfully cultured in our laboratory for six generations. Cultures provided a high productivity for a low working time and low costs. The tests conditions we proposed seemed to be relevant for the development of reliable tests with this species. Indeed, hatching probability of egg-capsules, as well as embryo, newborn and juvenile survival rates, were close to 100%. Moreover, growth rates and fecundity were significantly higher than in field and in other laboratory studies. Partial life-cycle tests on clean sediments were achieved for various feeding levels to determine survival, growth and reproduction patterns, ad libitum feeding level and life cycle parameters values. Ad libitum feeding levels for newborn, juveniles and adults were 0.1, 0.4 and 0.8 mg Tetramin/individual/working day. Growth tests with zinc-spiked sediments provided a no-effect concentration and a lowest effect concentration of respectively 200 and 624 mg zinc/kg dry sediment. Other growth tests on spiked sediments we ran at our laboratory with second, third and fourth instars larvae of Chironomus riparius pointed out that V. piscinalis was more sensible to zinc than the chironomid, which is a routine test species in ecotoxicology. According to these results, V. piscinalis is a promising candidate species for sediment toxicity testing.

  19. Functional Authentication of a Novel Gastropod Gonadotropin-Releasing Hormone Receptor Reveals Unusual Features and Evolutionary Insight.

    Science.gov (United States)

    Kavanaugh, Scott I; Tsai, Pei-San

    2016-01-01

    A gonadotropin-releasing hormone (GnRH)-like molecule was previously identified in a gastropod, Aplysia californica, and named ap-GnRH. In this study, we cloned the full-length cDNA of a putative ap-GnRH receptor (ap-GnRHR) and functionally authenticated this receptor as a bona fide ap-GnRHR. This receptor contains two potential translation start sites, each accompanied by a Kozak sequence, suggesting the translation of a long and a short form of the receptor is possible. The putative ap-GnRHR maintains the conserved structural motifs of GnRHR-like receptors and shares 45% sequence identity with the octopus GnRHR. The expression of the putative ap-GnRHR short form is ubiquitous in all tissues examined, whereas the long form is only expressed in parts of the central nervous system, osphradium, small hermaphroditic duct, and ovotestis. The cDNA encoding the long or the short receptor was transfected into the Drosophila S2 cell line and subject to a radioreceptor assay using 125I-labeled ap-GnRH as the radioligand. Further, the transfected cells were treated with various concentrations of ap-GnRH and measured for the accumulation of cAMP and inositol monophosphate (IP1). Radioreceptor assay revealed that only the long receptor bound specifically to the radioligand. Further, only the long receptor responded to ap-GnRH with an increased accumulation of IP1, but not cAMP. Our studies show that despite the more prevalent expression of the short receptor, only the long receptor is the functional ap-GnRHR. Importantly, this is only the second report on the authentication of a protostome GnRHR, and based on the function and the phylogenetic grouping of ap-GnRHR, we suggest that this receptor is more similar to protostome corazonin receptors than chordate GnRHRs.

  20. Functional Authentication of a Novel Gastropod Gonadotropin-Releasing Hormone Receptor Reveals Unusual Features and Evolutionary Insight

    Science.gov (United States)

    Kavanaugh, Scott I.

    2016-01-01

    A gonadotropin-releasing hormone (GnRH)-like molecule was previously identified in a gastropod, Aplysia californica, and named ap-GnRH. In this study, we cloned the full-length cDNA of a putative ap-GnRH receptor (ap-GnRHR) and functionally authenticated this receptor as a bona fide ap-GnRHR. This receptor contains two potential translation start sites, each accompanied by a Kozak sequence, suggesting the translation of a long and a short form of the receptor is possible. The putative ap-GnRHR maintains the conserved structural motifs of GnRHR-like receptors and shares 45% sequence identity with the octopus GnRHR. The expression of the putative ap-GnRHR short form is ubiquitous in all tissues examined, whereas the long form is only expressed in parts of the central nervous system, osphradium, small hermaphroditic duct, and ovotestis. The cDNA encoding the long or the short receptor was transfected into the Drosophila S2 cell line and subject to a radioreceptor assay using 125I-labeled ap-GnRH as the radioligand. Further, the transfected cells were treated with various concentrations of ap-GnRH and measured for the accumulation of cAMP and inositol monophosphate (IP1). Radioreceptor assay revealed that only the long receptor bound specifically to the radioligand. Further, only the long receptor responded to ap-GnRH with an increased accumulation of IP1, but not cAMP. Our studies show that despite the more prevalent expression of the short receptor, only the long receptor is the functional ap-GnRHR. Importantly, this is only the second report on the authentication of a protostome GnRHR, and based on the function and the phylogenetic grouping of ap-GnRHR, we suggest that this receptor is more similar to protostome corazonin receptors than chordate GnRHRs. PMID:27467252

  1. Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity.

    Science.gov (United States)

    Ma, Taowu; Gong, Shuangjiao; Zhou, Ke; Zhu, Cheng; Deng, Kaidong; Luo, Qinghua; Wang, Zijian

    2010-01-01

    This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snail x day), respectively. Mean survival rates of juveniles were higher than 90%. The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female x day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 gg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 microg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

  2. Molecular identification of marine symbiont bacteria of gastropods from the waters of the Krakal coast Yogyakarta and its potential as a Multi-Drug Resistant (MDR) antibacterial agent

    Science.gov (United States)

    Bahry, Muhammad Syaifudien; Pringgenies, Delianis; Trianto, Agus

    2017-01-01

    The resistance of pathogenic bacteria may occur to many types of antibiotics, especially in cases of non-compliance use of antibiotics, which likely to allow the evolution of Multi-Drug Resistant (MDR) bacteria. Gastropods seas are marine invertebrates informed capable of production of secondary metabolites as antibacterial MDR. The purpose of the study was the isolation and identification of gastropod symbiont bacteria found in the waters of Krakal, Gunung Kidul, Yogyakarta, which has the ability to produce antibacterial compounds against MDR(Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, MRSA (methicillin-Resistant Staphylococcus aureus), Staphylococcus aureus, and Staphylococcus homunis) molecular. Stages of this research began with the isolation of bacteria, bacteria screening for anti-MDR compound, mass culture, and extraction, antibacterial activity test, DNA extraction, amplification by PCR 16S rDNA and sequencing. The results of the study showed that 19 isolates of bacteria were isolated from three species of gastropods namely Littorina scabra, Cypraea moneta and Conus ebraeus. Among them, 4 isolates showed activity against MDR test bacteria (E. coli, E. cloacae, K. pneumoniae, S. aureus and S. homunis). The highest activity was displayed by code LS.G1.8 isolate with the largest inhibition zone 15.47±0.45mm on S. humonis at 250 µg/disk concentration. Isolate CM.G2.1 showed largest inhibition zone, with 21.5±0.07mm on MRSA at 1000 µg/disk concentration and isolate the largest inhibition zone CM.G2.5 14.37±0.81mm on MRSA 14.37±0.81mm at concentrations 1000 µg/disk. The molecular identification of isolates LS.G1.8 has 99% homology with Bacillus subtilis and isolates CM.G2.1 has 99% homology with Bacillus pumillus.

  3. [Effects mangrove conversion to pasture on density and shell size of two gastropods in the Turbo River Delta (Urabá Gulf, Caribbean coast of Colombia)].

    Science.gov (United States)

    Blanco, Juan F; Castaño, María C

    2012-12-01

    Mangrove deforestation is widespread in the Greater Caribbean but its impact on macrobenthos has not been evaluated to date. In order to assess the impact of mangrove conversion to pasture, densities and shell sizes of two dominant gastropods (Neritina virginea and Melampus coffeus) were compared among four mangrove types: 1) Rhizophora mangle-dominated fringing mangroves, 2) Avicennia germinans-dominated basin mangroves, 3) Mixed-species basin mangroves, and 4) A. germinans- basin mangroves converted to pastures, in the Turbo River Delta (Urabá Gulf, Colombia). Mangrove types were polygon-delimited with satellite images and color aerial photographs were taken in 2009. Various (nmangrove type were sampled in January, July and December 2009, and a total (nmangrove types. Mean density and size of both gastropod species were measured. The results showed that the mean density and size of both species were significantly greater in R. mangle-fringing mangroves. N. virginea density decreased gradually towards the A. germinans-basin mangroves seemly related to the diadromous life-history. This species nearly disappeared in the neighboring pastures because individuals were constrained to a few remaining flooded areas. In the pastures, M. coffeus individuals were clumped in the remaining A. germinans trees due to its climbing behavior as a pulmonate. We hypothesize that the decline of these two gastropods was related to physical microhabitat (e.g. trees, prop roots, and seedlings) degradation, and alteration of soil properties (e.g. temperature, pH, organic matter content). Finally, we also hypothesize that the local extinction of N. virginea due to clear-cutting may exert strong negative effects on the ecosystem function because it is a dominant omnivore.

  4. Phylogenetic analysis of euthyneuran gastropods from sea to land mainly based on comparative mitogenomic of four species of Onchidiidae (Mollusca: Gastropoda: Pulmonata).

    Science.gov (United States)

    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).

  5. [Distribution of the mangrove gastropods Neritina virginea (Neritidae) and Littoraria angulifera (Littorinidae) within the Colombian Caribbean Darién Ecoregion].

    Science.gov (United States)

    Ferney Ortiz, Luis; Blanco, Juan Felipe

    2012-03-01

    Gastropods are one of the most abundant groups within the Caribbean mangroves, however, little is known about the distribution of particular species at a regional scale. With this aim, we studied the geographic distribution of Littoraria (Littorinopsis) angulifera and Neritina (Vitta) virginea within the Darién Ecoregion in the Caribbean coast of Colombia, from 77 sampling stations along 609km between the Colombian-Panamá border and Córdoba State, Colombia. The fieldwork was conducted in June-August 2009, and a total of 3 963 individuals of both species were hand-picked from the ground, prop-roots and trunks along 50m transects, and shell sizes were measured. The description of geographic patterns considered surface water salinity, mangrove cover and gastropod distribution within the Gulf of Urabá. In the outer-most part of the Gulf, L. angulifera was present in 84.8% of the stations, while N. virginea was only present in 15.2% of the stations. In this part, mangroves areas were patchily distributed, and the gastropods (mainly L. angulifera) were found on woody debris along the supralittoral zone in sandy shores. In the inner-most part, in contrast, N. virginea occurred in 84.6% of the stations, mostly in estuaries, deltas and river margins, while L. angulifera only appeared in Turbo Bay (15.4%). Mean shell size also exhibited a clear geographic pattern: size range was 6-22mm in L. angulifera, and 6-12mm in N. virginea. L. angulifera was found in open-water stations with water salinities >10PSU, but it was absent in sites with lower salinities like the Atrato River Delta and other small rivers. Its presence on coastal woody debris suggests that despite of the recruitment of small individuals from the nearshore stock of larvae, populations are unable to establish due to the absence of mangroves protection. Oppositely, N. virginea was found under estuarine conditions on mangrove roots and ground. Our results confirm that L. angulifera is an esteno-tolerant marine

  6. 舟山海域腹足类动物性畸变研究%Studies on Imposex of Marine Gastropods in Zhoushan

    Institute of Scientific and Technical Information of China (English)

    黄晓丹; 吴海莲; 沈青; 胡耀户; 许森磊; 朱四喜

    2011-01-01

    The paper carries out an imposex research on eight species of five families of marine gastropods in Zhoushan, and finds out that five species has different degrees of imposex,indicating that Zhoushan sea water is polluted by organotin to a certain degree.%对舟山海域5科8种的腹足类动物进行了性畸变研究,发现其中5种均有不同程度的性畸变,这说明舟山海域受到一定程度的有机锡污染.

  7. Development of biomarkers of stress related to endocrine disruption in gastropods: alkali-labile phosphates, protein-bound lipids and vitellogenin-like proteins.

    Science.gov (United States)

    Gagnaire, Beatrice; Gagné, François; André, Chantale; Blaise, Christian; Abbaci, Khedidja; Budzinski, Hélène; Dévier, Marie-Hélène; Garric, Jeanne

    2009-05-05

    The occurrence in aquatic environments of compounds capable of acting as endocrine disruptors (ED) is of concern for wildlife. Elevated levels of the egg-yolk precursor protein vitellogenin (Vg) are widely accepted as a biomarker for xenoestrogen exposure in aquatic organisms. The purpose of this study was to develop a method for tracking changes in levels of Vg-like proteins in gastropods. Vg-like and egg-yolk proteins were analyzed in three freshwater gastropods having different modes of reproduction: Potamopyrgus antipodarum (asexual reproduction), Valvata piscinalis (hermaphroditism) and Lithoglyphus naticoides (sexual reproduction). Vitellogenin-like protein levels were examined by the alkali-labile phosphate (ALP) technique, a novel protein-bound lipid (PBL) assay, and by gradient gel electrophoresis with silver staining. The first phase of the study was dedicated to the development and optimization of an analytical method for detecting Vg-like proteins in these three gastropod species. In the second phase, the snails P. antipodarum and V. piscinalis were exposed to bisphenol A (BPA), octylphenol (OP) and tributyltin (TBT) for 14 and 28 days. Vg-like proteins were resolved in one major band at 250-300 kDa for L. naticoides and V. piscinalis and in two bands at 100 and 30 kDa for P. antipodarum. After 14 days of exposure, all techniques showed an increase in Vg-like protein levels at 100 microg/L BPA and at 1 microg/L OP in P. antipodarum. A decrease in these proteins was observed with high concentrations of OP (100 microg/L) and TBT (>or=5 ng/L). In V. piscinalis, a decrease in Vg-like proteins was shown after 14 days of exposure for OP >or=10 microg/L and TBT >or=5 ng/L; however, at 28 days, gel electrophoresis revealed an increase in these proteins. Histological observations showed significant necrosis in ovotestes of V. piscinalis with the three endocrine-disrupting compounds, while tissue modifications were not detected for P. antipodarum. A method for

  8. A Novel Toll-Like Receptor (TLR Influences Compatibility between the Gastropod Biomphalaria glabrata, and the Digenean Trematode Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Emmanuel A Pila

    2016-03-01

    snails, which shed S. mansoni cercariae 1-week before the susceptible controls. Our results represent the first functional characterization of a gastropod TLR, and demonstrate that BgTLR is an important snail immune receptor that is capable of influencing infection outcome following S. mansoni challenge.

  9. Cleavage pattern and fate map of the mesentoblast, 4d, in the gastropod Crepidula: a hallmark of spiralian development

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    Lyons Deirdre C

    2012-09-01

    Full Text Available Abstract Background Animals with a spiral cleavage program, such as mollusks and annelids, make up the majority of the superphylum Lophotrochozoa. The great diversity of larval and adult body plans in this group emerges from this highly conserved developmental program. The 4d micromere is one of the most conserved aspects of spiralian development. Unlike the preceding pattern of spiral divisions, cleavages within the 4d teloblastic sublineages are bilateral, representing a critical transition towards constructing the bilaterian body plan. These cells give rise to the visceral mesoderm in virtually all spiralians examined and in many species they also contribute to the endodermal intestine. Hence, the 4d lineage is an ideal one for studying the evolution and diversification of the bipotential endomesodermal germ layer in protostomes at the level of individual cells. Little is known of how division patterns are controlled or how mesodermal and endodermal sublineages diverge in spiralians. Detailed modern fate maps for 4d exist in only a few species of clitellate annelids, specifically in glossiphoniid leeches and the sludge worm Tubifex. We investigated the 4d lineage in the gastropod Crepidula fornicata, an established model system for spiralian biology, and in a closely related direct-developing species, C. convexa. Results High-resolution cell lineage tracing techniques were used to study the 4d lineage of C. fornicata and C. convexa. We present a new nomenclature to name the progeny of 4d, and report the fate map for the sublineages up through the birth of the first five pairs of teloblast daughter cells (when 28 cells are present in the 4d sublineage, and describe each clone’s behavior during gastrulation and later stages as these undergo differentiation. We identify the precise origin of the intestine, two cells of the larval kidney complex, the larval retractor muscles and the presumptive germ cells, among others. Other tissues that arise

  10. [Proceedings of the symposium 'Molluscan Palaeontology' : 11th International Malacological Congress, Siena (Italy) 30th August - 5th September 1992 / A.W. Janssen and R. Janssen (editors)]: Biostratigraphic studies on planktonic gastropods from the Tertiary of the Central Paratethys

    NARCIS (Netherlands)

    Bohn-Havas, M.; Zorn, I.

    1992-01-01

    In the present paper the latest studies on the distribution and biostratigraphy of planktonic gastropods in the Central Paratethys are summarised. The research was carried out on material from Tertiary deposits of Austria, Hungary and Poland, mainly concentrating on the Badenian (Middle Miocene). In

  11. ANÁLISIS COMPARATIVO DEL GENOMA MITOCONDRIAL EN GASTRÓPODOS Comparative Analysis of the Mitochondrial Genomes in Gastropods

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    MOISES ARQUEZ

    2012-05-01

    Full Text Available En este trabajo presentamos un análisis comparativo de los genomas mitocondriales en gastrópodos. Se calculó la composición de nucleótidos y de aminoácidos de todas las secuencias y se hizo un análisis visual comparativo de los codones de inicio y de parada. La organización del genoma se comparó calculando el número de secuencias intergénicas, la ubicación de los genes y el número de reorganizaciones génicas (breakpoints en comparación con la secuencia que se presume ancestral para el grupo. Para calcular si existen variaciones en las tasas de evolución molecular en el grupo, estas últimas se calcularon utilizando el relative rate test. A pesar de las diferencias en el tamaño de los genomas, el número de aminoácidos es más conservado. La composicion nucleotídica y aminoacídica es similar entre los Vetigastropoda, Ceanogastropoda y Neritimorpha en comparacion con Heterobranchia y Patellogastropoda. Los genomas mitocondriales para el grupo son muy compactos con pocas secuencias intergenicas, la unica excepción es el genoma de Patellogastropoda con 26.828 pb. Existe una alta variabilidad en cuanto a codones de inicio para los grupos Heterobranchia y Patellogastropoda y un aumento en el número de genes reorganizados con respecto a la secuencia de O. vulgaris también para estos dos grupos. En general, se rechaza la hipótesis de tasas de evolución molecular constante entre los grupos, excepto cuando se comparan los genomas de Caenogastropoda y Vetigastropoda.In this work we presented a comparative analysis of the mitochondrial genomes in gastropods. Nucleotide and amino acids composition was calculated and a comparative visual analysis of the start and termination codons was performed. The organization of the genome was compared calculating the number of intergenic sequences, the location of the genes and the number of reorganized genes (breakpoints in comparison with the sequence that is presumed to be ancestral for the

  12. Comparison of sample preparation methods, validation of an UPLC-MS/MS procedure for the quantification of tetrodotoxin present in marine gastropods and analysis of pufferfish.

    Science.gov (United States)

    Nzoughet, Judith Kouassi; Campbell, Katrina; Barnes, Paul; Cooper, Kevin M; Chevallier, Olivier P; Elliott, Christopher T

    2013-02-15

    Tetrodotoxin (TTX) is one of the most potent marine neurotoxins reported. The global distribution of this toxin is spreading with the European Atlantic coastline now being affected. Climate change and increasing pollution have been suggested as underlying causes for this. In the present study, two different sample preparation techniques were used to extract TTX from Trumpet shells and pufferfish samples. Both extraction procedures (accelerated solvent extraction (ASE) and a simple solvent extraction) were shown to provide good recoveries (80-92%). A UPLC-MS/MS method was developed for the analysis of TTX and validated following the guidelines contained in the Commission Decision 2002/657/EC for chemical contaminant analysis. The performance of this procedure was demonstrated to be fit for purpose. This study is the first report on the use of ASE as a mean for TTX extraction, the use of UPLC-MS/MS for TTX analysis, and the validation of this method for TTX in gastropods.

  13. The hydrobioid freshwater gastropods (Caenogastropoda, Truncatelloidea of Greece: new records, taxonomic re-assessments using DNA sequence data and an update of the IUCN Red List Categories

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    Canella Radea

    2013-11-01

    Full Text Available Hydrobioid freshwater gastropods were collected from mainland and insular Greece. Several threatened taxa, such as Graecoanatolica vegorriticola, Pseudamnicola negropontina, Pseudamnicola pieperi, Pseudobithynia eubooensis and Pseudoislamia balcanica, were recorded from new localities. Trichonia trichonica, which has been considered extinct from its type locality for the last twenty eight years, was re-discovered, whereas the presence of Daphniola exigua, G. vegorriticola, Marstoniopsis graeca, P. pieperi and Pseudobithynia trichonis in their type localities was verified. The taxonomic status of P. negropontina and the newly discovered populations of G. vegorriticola was elucidated using COI sequence data. The new data recorded during this survey indicate that the IUCN status of some Greek endemic hydrobioids needs to be updated.

  14. Endoscopy of gastropods: A novel view of the mantle cavities and gills of the keyhole limpet Diodora aspera and the abalone Haliotis rufescens.

    Science.gov (United States)

    Voltzow, Janice

    2015-07-01

    The gills, or ctenidia, of marine gastropods serve as the sites for respiratory gas exchange. Cilia on the surface provide the pump that moves water through the mantle cavity and enhance diffusion. Because the gills are housed inside the shell, it is difficult to view them while they are functioning. Published images of gills show contracted, fragile structures that are distorted by the processes of dissection and preservation. Members of the families Fissurellidae (keyhole limpets) and Haliotidae (abalone) have openings in their shells through which water enters and/or exits. I inserted an endoscope connected to a video camera into the openings of the shells of living, non-anaesthetized individuals of the fissurellid Diodora aspera and the haliotid Haliotis rufescens. In both species, the dorsal afferent branchial vessel of the afferent gill axis appeared large and inflated, as did the leaflets that extended from either side of the axis. In D. aspera, the leaflets appeared to fill the mantle cavity and responded to touch, particles, and dye in the water by contracting quickly and slowly re-extending. In contrast, the gills of H. rufescens did not noticeably respond to disturbance. On the other hand, these gills showed a regular pattern of pleats that had not been described in the extensive anatomical literature of these common and economically significant animals. These results provide a novel view of the gastropod mantle cavity as a dynamic space filled by the gills, which divide the mantle cavity into distinct incurrent and excurrent chambers and produce a laminar flow of water through the cavity.

  15. Determination of the variability of both hydrophilic and lipophilic toxins in endemic wild bivalves and carnivorous gastropods from the southern part of Chile.

    Science.gov (United States)

    Zamorano, Ruben; Marín, Michelle; Cabrera, Fabiola; Figueroa, Diego; Contreras, Cristóbal; Barriga, Andrés; Lagos, Néstor; García, Carlos

    2013-01-01

    The aim of this study was to analyse and determine the composition of paralytic shellfish poisoning (PSP) toxins and lipophilic toxins in the Region of Aysén, Chile, in wild endemic mussels (Mytilus chilensis, Venus antiqua, Aulacomya ater, Choromytilus chorus, Tagelus dombeii and Gari solida) and in two endemic carnivorous molluscs species (Concholepas concholepas and Argobuccinum ranelliforme). PSP-toxin contents were determined by using HPLC with fluorescence detection, while lipophilic toxins were determined by using LC-MS/MS. Mean concentrations for the total of PSP toxins were in the range 55-2505 μg saxitoxin-equivalent/100 g. The two most contaminated samples for PSP toxicity were bivalve Gari solida and carnivorous Argobuccinum ranelliforme with 2505 ± 101 and 1850 ± 137 μg saxitoxin-equivalent/100 g, respectively (p < 0.05). The lipophilic toxins identified were okadaic acid, dinophysistoxin-1 (DTX-1), azaspiracid-1 (AZA-1), pectenotoxin-2 (PTX-2) and yessotoxins (YTX). All analysed molluscs contained lipophilic toxins at levels ranging from 56 ± 4.8 to 156.1 ± 8.2 μg of okadaic acid-equivalent/kg shellfish together with YTX at levels ranging from 1.0 ± 0.1 to 18 ± 0.9 μg of YTX-equivalent/kg shellfish and AZA at levels ranging from 3.6 ± 0.2 to 31 ± 2.1 μg of AZA-equivalent/kg shellfish. Furthermore, different bivalves and gastropods differ in their capacity of retention of lipophilic toxins, as shown by the determination of their respective lipophilic toxins levels. In all the evaluated species, the presence of lipophilic toxins associated with biotransformation in molluscs and carnivorous gastropods was not identified, in contrast to the identification of PSP toxins, where the profiles identified in the different species are directly related to biotransformation processes. Thus, this study provides evidence that the concentration of toxins in the food intake of the evaluated species (Bivalvia and Gastropoda class) determines the degree of

  16. The complete mitochondrial genome of a turbinid vetigastropod from MiSeq Illumina sequencing of genomic DNA and steps towards a resolved gastropod phylogeny.

    Science.gov (United States)

    Williams, S T; Foster, P G; Littlewood, D T J

    2014-01-01

    A need to increase sampling of mitochondrial genomes for Vetigastropoda has been identified as an important step towards resolving relationships within the Gastropoda. We used shotgun sequencing of genomic DNA, using an Illumina MiSeq, to obtain the first mitochondrial genome for the vetigastropod family Turbinidae, doubling the number of genomes for the species-rich superfamily Trochoidea. This method avoids the necessity of finding suitable primers for long PCRs or primer-walking amplicons, resulting in a timely and cost-effective method for obtaining whole mitochondrial genomes from ethanol-preserved tissue samples. Bayesian analysis of amino acid variation for all available gastropod genomes including the new turbinid mtgenome produced a well resolved tree with high nodal support for most nodes. Major clades within Gastropoda were recovered with strong support, with the exception of Littorinimorpha, which was polyphyletic. We confirm here that mitogenomics is a useful tool for molluscan phylogenetics, especially when using powerful new models of amino acid evolution, but recognise that increased taxon sampling is still required to resolve existing differences between nuclear and mitochondrial gene trees.

  17. Redescription of Marstonia comalensis (Pilsbry & Ferriss, 1906), a poorly known and possibly threatened freshwater gastropod from the Edwards Plateau region (Texas).

    Science.gov (United States)

    Hershler, Robert; Liu, Hsiu-Ping

    2011-01-26

    Marstonia comalensis, a poorly known nymphophiline gastropod (originally described from Comal Creek, Texas) that has often been confused with Cincinnatia integra, is re-described and the generic placement of this species, which was recently allocated to Marstonia based on unpublished evidence, is confirmed by anatomical study. Marstonia comalensis is a large congener having an ovate-conic, openly umbilicate shell and penis having a short filament and oblique, squarish lobe bearing a narrow gland along its distal edge. It is well differentiated morphologically from congeners having similar shells and penes and is also genetically divergent relative to those congeners that have been sequenced (mtCOI divergence 3.0-8.5%). A Bayesian analysis of a small COI dataset resolved Marstonia comalensis in a poorly supported sub-clade together with Marstonia hershleri, Marstonia lustrica and Marstonia pachyta. The predominantly new records presented herein indicate that Marstonia comalensis was historically distributed in the upper portions of the Brazos, Colorado, Guadalupe and Nueces River basins, south-central Texas. The species has been live collected at only 12 localities and only two of these have been re-visited since 1993. These data suggest that the conservation status of this snail, which has a critically imperiled (G1) NatureServe ranking and was recently proposed for federal listing, needs to be re-assessed.

  18. Molecular phylogeny and a modified approach of character-based barcoding refining the taxonomy of New Caledonian freshwater gastropods (Caenogastropoda, Truncatelloidea, Tateidae).

    Science.gov (United States)

    Zielske, Susan; Haase, Martin

    2015-08-01

    The islands of New Caledonia represent one of the world's biodiversity hotspots with many endemic species including freshwater gastropods of the family Tateidae. A phylogenetic analysis based on the mitochondrial COI and 16S rRNA and the nuclear ITS2 genes revealed two cryptic genera, Crosseana gen. n. and Novacaledonia gen. n. In order to provide character-based diagnoses we modified a DNA barcoding approach identifying strings of pairwise diagnostic characters, i.e. alignment positions, at which two genera are alternatively fixed for different nucleotides. The combination or string of all pairwise diagnostic characters was unique for each genus. Inconsistent mitochondrial and nuclear topologies suggest that Hemistomia cockerelli Haase and Bouchet, 1998 and H. fabrorum Haase and Bouchet, 1998, two morphologically well-defined species, hybridize. The age of the most recent common ancestor of the New Caledonian radiation of Tateidae was estimated at 24.6±9.5 MY. These findings are in line with the notion that New Caledonia is rather a Darwinian island that was colonized after an extended phase of submergence - in case of the tateids probably from Australia - despite being a fragment of Gondwanaland.

  19. A gonadotropin-releasing hormone-like molecule modulates the activity of diverse central neurons in a gastropod mollusk, Aplysia californica

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    Biao eSun

    2011-09-01

    Full Text Available In vertebrates, gonadotropin-releasing hormone (GnRH is a crucial decapeptide that activates the hypothalamic-pituitary-gonadal (HPG axis to ensure successful reproduction. Recently, a GnRH-like molecule has been isolated from a gastropod mollusk, Aplysia californica. This GnRH (ap-GnRH is deduced to be an undecapeptide, and its function remains to be explored. Our previous study demonstrated that ap-GnRH did not stimulate a range of reproductive parameters. Instead, it affected acute behavioral and locomotive changes unrelated to reproduction. In this study, we used electrophysiology and retrograde tracing to further explore the central role of ap-GnRH. Sharp electrode intracellular recordings revealed that ap-GnRH had diverse effects on central neurons that ranged from excitatory, inhibitory, to the alteration of membrane potential. Unexpectedly, extracellular recordings revealed that ap-GnRH suppressed the onset of electrical afterdischarge (AD in bag cell neurons, suggesting an inhibitory effect on female reproduction. Lastly, using immunocytochemistry (ICC coupled with nickel-backfill, we demonstrated that some ap-GnRH neurons projected to efferent nerves known to innervate the foot and parapodia, suggesting ap-GnRH may directly modulate the motor output of these peripheral tissues. Overall, our results suggested that in A. californica, ap-GnRH more likely functioned as a central modulator of complex behavior and motor regulation rather than as a conventional reproductive stimulator.

  20. Determination of Gonyautoxin-4 in Echinoderms and Gastropod Matrices by Conversion to Neosaxitoxin Using 2-Mercaptoethanol and Post-Column Oxidation Liquid Chromatography with Fluorescence Detection.

    Science.gov (United States)

    Silva, Marisa; Rey, Verónica; Botana, Ana; Vasconcelos, Vitor; Botana, Luis

    2015-12-30

    Paralytic Shellfish Toxin blooms are common worldwide, which makes their monitoring crucial in the prevention of poisoning incidents. These toxins can be monitored by a variety of techniques, including mouse bioassay, receptor binding assay, and liquid chromatography with either mass spectrometric or pre- or post-column fluorescence detection. The post-column oxidation liquid chromatography with fluorescence detection method, used routinely in our laboratory, has been shown to be a reliable method for monitoring paralytic shellfish toxins in mussel, scallop, oyster and clam species. However, due to its high sensitivity to naturally fluorescent matrix interferences, when working with unconventional matrices, there may be problems in identifying toxins because of naturally fluorescent interferences that co-elute with the toxin peaks. This can lead to erroneous identification. In this study, in order to overcome this challenge in echinoderm and gastropod matrices, we optimized the conversion of Gonyautoxins 1 and 4 to Neosaxitoxin with 2-mercaptoethanol. We present a new and less time-consuming method with a good recovery (82.2%, RSD 1.1%, n = 3), requiring only a single reaction step.

  1. Redescription of Marstonia comalensis (Pilsbry & Ferriss, 1906, a poorly known and possibly threatened freshwater gastropod from the Edwards Plateau region (Texas

    Directory of Open Access Journals (Sweden)

    Robert Hershler

    2011-01-01

    Full Text Available Marstonia comalensis, a poorly known nymphophiline gastropod (originally described from Comal Creek, Texas that has often been confused with Cincinnatia integra, is re-described and the generic placement of this species, which was recently allocated to Marstonia based on unpublished evidence, is confirmed by anatomical study. Marstonia comalensis is a large congeneran ovate-conic, openly umbilicate shell and penisa short filament and oblique, squarish lobe bearing a narrow gland along its distal edge. It is well differentiated morphologically from congenerssimilar shells and penes and is also genetically divergent relative to those congeners that have been sequenced (mtCOI divergence 3.0–8.5%. A Bayesian analysis of a small COI dataset resolved M. comalensis in a poorly supported sub-clade together with M. hershleri, M. lustrica and M. pachyta. The predominantly new records presented herein indicate that M. comalensis was historically distributed in the upper portions of the Brazos, Colorado, Guadalupe and Nueces River basins, south-central Texas. The species has been live collected at only 12 localities and only two of these have been re-visited since 1993. These data suggest that the conservation status of this snail, which has a critically imperiled (G1 NatureServe ranking and was recently proposed for federal listing, needs to be re-assessed.

  2. Which Specialized Metabolites Does the Native Subantarctic Gastropod Notodiscus hookeri Extract from the Consumption of the Lichens Usnea taylorii and Pseudocyphellaria crocata?

    Directory of Open Access Journals (Sweden)

    Alice Gadea

    2017-03-01

    Full Text Available Notodiscus hookeri is the only representative of terrestrial gastropods on Possession Island and exclusively feeds on lichens. The known toxicity of various lichen metabolites to plant-eating invertebrates led us to propose that N. hookeri evolved means to protect itself from their adverse effects. To validate this assumption, the current study focused on the consumption of two lichen species: Usnea taylorii and Pseudocyphellaria crocata. A controlled feeding experiment was designed to understand how the snail copes with the unpalatable and/or toxic compounds produced by these lichen species. The occurrence of two snail ecophenotypes, represented by a mineral shell and an organic shell, led to address the question of a metabolic response specific to the phenotype. Snails were fed for two months with one of these lichens and the chemical profiles of biological samples of N. hookeri (i.e., crop, digestive gland, intestine, and feces were established by HPLC-DAD-MS and compared to that of the lichens. N. hookeri appears as a generalist lichen feeder able to consume toxic metabolite-containing lichens, independently of the ecophenotype. The digestive gland did not sequester lichen metabolites. The snail metabolism might be based on four non-exclusive processes according to the concerned metabolites (avoidance, passive transport, hydrolysis, and excretion.

  3. Contamination of terrestrial gastropods Helix aspersa maxima with {sup 137}Cs, {sup 85}Sr, {sup 133}Ba and {sup 123m}Te by direct and trophic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Madoz-Escande, C.; Querrec, N.; Bonhomme, T.; Poncet-Bonnard, D. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Contaminations of terrestrial gastropod Helix aspersa Maxima by direct deposition or labelled food ingestion of {sup 137}Cs, {sup 85}Sr, {sup 133}Ba and {sup 123m}Te were carried out in laboratory conditions. This study was performed to compare the two pathways of contamination: direct and trophic in terms of individual mortality and, radionuclide uptake, depuration and tissular distribution. A first group of 30 snails (2-year old) was exposed to radioactive aerosols during a twenty-hour period. These aerosols were supposed to be representative of those produced during a nuclear accident occurring on a PWR. A second group of 40 snails (same ages) was submitted to twice-a-week ingestion of food during 10 days (flour at a feeding rate of about 0,2 g) contaminated by these same aerosols. During the 21 days observation period, comparison among the two groups and a reference group (not contaminated by radionuclides) was performed. No significant difference between the three groups was observed neither on the growth nor on the mortality. One day after the deposit, the cesium was the most bioavailable element, distributed homogeneously within the whole body (from 15 to 25% of total Cs respectively in shell and muscle). The strontium accumulated in the shell (about 70%). The barium was found in the muscle (20%) and the shell (65%). Tellurium was mainly present in the shell (70%) and in digestive gland (20%), Later, this element was mostly present in faeces. As regards the contamination by ingestion, it was mainly accumulated in digestive gland. (author)

  4. Ecological barcoding of corallivory by second internal transcribed spacer sequences: hosts of coralliophiline gastropods detected by the cnidarian DNA in their stomach.

    Science.gov (United States)

    Oliverio, Marco; Barco, Andrea; Modica, Maria Vittoria; Richter, Alexandra; Mariottini, Paolo

    2009-01-01

    The second internal transcribed spacer (ITS2) of the nuclear ribosomal RNA cluster (rDNA) is significantly smaller in the Cnidaria (120-260 bp) than in the rest of the Metazoa. ITS2 is one of the fastest evolving DNA regions among those commonly used in molecular systematics and has been proposed as a possible barcoding gene for Cnidaria to replace the currently problematic mitochondrial sequences used. We have reviewed the intraspecific and interspecific variation of ITS2 rRNA sequences in the Anthozoa. We have observed that the lower limits of the interspecific DNA divergence ranges very often overlap with intraspecific ranges, and identical sequences from individuals of different species are not rare. This finding can result in problems similar to those encountered with the mitochondrial COI, and we conclude that ITS2 does not prove significantly better than COI for standard taxonomic DNA barcoding in Anthozoa. However, ITS2 appears to be a promising gene in the ecological DNA barcoding of corallivory, where taxonomic accuracy at genus or even family level may represent a significant improvement of current knowledge. We have successfully amplified and sequenced ITS2 from template DNA extracted from foot muscle and from stomach contents of corallivorous gastropods, and from their anthozoan hosts. The small size of cnidarian ITS2 makes it a very easy and efficient tool for ecological barcoding of associations. Ecological barcoding of corallivory is an indispensable approach to the study of the associations in deep water, where direct observation is severely limited by logistics and costs.

  5. Accumulation and detoxication responses of the gastropod Lymnaea stagnalis to single and combined exposures to natural (cyanobacteria) and anthropogenic (the herbicide RoundUp(®) Flash) stressors.

    Science.gov (United States)

    Lance, Emilie; Desprat, Julia; Holbech, Bente Frost; Gérard, Claudia; Bormans, Myriam; Lawton, Linda A; Edwards, Christine; Wiegand, Claudia

    2016-08-01

    Freshwater gastropods are increasingly exposed to multiple stressors in the field such as the herbicide glyphosate in Roundup formulations and cyanobacterial blooms either producing or not producing microcystins (MCs), potentially leading to interacting effects. Here, the responses of Lymnaea stagnalis to a 21-day exposure to non-MC or MC-producing (33μgL(-1)) Planktothrix agardhii alone or in combination with the commercial formulation RoundUp(®) Flash at a concentration of 1μgL(-1) glyphosate, followed by 14days of depuration, were studied via i) accumulation of free and bound MCs in tissues, and ii) activities of anti-oxidant (catalase CAT) and biotransformation (glutathione-S-transferase GST) enzymes. During the intoxication, the cyanobacterial exposure induced an early increase of CAT activity, independently of the MC content, probably related to the production of secondary cyanobacterial metabolites. The GST activity was induced by RoundUp(®) Flash alone or in combination with non MC-producing cyanobacteria, but was inhibited by MC-producing cyanobacteria with or without RoundUp(®) Flash. Moreover, MC accumulation in L. stagnalis was 3.2 times increased when snails were concomitantly exposed to MC-producing cyanobacteria with RoundUp(®), suggesting interacting effects of MCs on biotransformation processes. The potent inhibition of detoxication systems by MCs and RoundUp(®) Flash was reversible during the depuration, during which CAT and GST activities were significantly higher in snails previously exposed to MC-producing cyanobacteria with or without RoundUp(®) Flash than in other conditions, probably related to the oxidative stress caused by accumulated MCs remaining in tissues.

  6. The Assemblage of Gastropod Fossils in Zanda Basin of Tibet and Its Biostratigraphy%西藏札达盆地腹足类组合及生物地层学

    Institute of Scientific and Technical Information of China (English)

    韩建恩; 余佳; 贺承广; 孟庆伟; 朱大岗; 孟宪刚; 邵兆刚; 杨朝斌

    2012-01-01

    A number of gastropod fossils were discovered in the 4th lithologic member of Guge Formation within Zanda basin of Tibet, with the identification of an assemblage of Adelinella regularis-Velutinopsi which comprises Adelinella regularis Yü, Velutinopsis spiralis Yü, Radix zandaensis sp. Nov and Hippeutis cf.minor (Ping). Based on the distribution characteristics of these gastropod fossils in southwest Tibet, the authors regards them as a biological assemblage located in the intermontane fault basin in northern Himalayas, between the Rhino fossils layer and Unio douglasiae Giiffithet Pidgeon-Unio tschiliensis Sturany layer and with a paleomagnetic age of late Pliocene-Early Pleistocene. Based on a comparison with the existing species of gastropod, the authors hold that the gastropod in the fossil strata in Zanda basin might have lived in a shallow littoral lake environment. The sporopollen reveals that the place where the gastropod in the fossil strata lived was an environment of warm and moist forest-grasslands. Hipparion in the lower gastropods fossil layer in Zanda basin indicates a warm and arid shrub-grassland environment. Consequently, the paleo-climate during the deposition of the Tuolin Formation and Guge Formation experienced a transition from a warm and dry environment to a warm and humid environment.%在西藏札达盆地古格组第四岩性段发现大量腹足类化石:Adelinella regularis Yü(规则小隐螺)、Velutinopsis spiralis Yü(旋纹似天鹅绒螺)、Radix zandaensis sp.nov.(札达萝卜螺)、Hippeutis cf.minor (Ping)(微小圆扁卷螺),称为小隐螺-似天鹅绒螺组合.根据这些腹足类化石在西藏西南部的分布特征,认为它们是分布于北喜马拉雅山间断陷盆地的一个腹足类组合,介于西藏犀类化石与杜氏珠蚌-河北珠蚌层之间,时代处于晚上新世-早更新世之间.对比现生种属研究认为,札达盆地腹足类应生活于近岸的浅湖环境.孢粉分析认为化石层形成

  7. Review of palaeozygopleurid gastropods (Palaeozygopleuridae, Gastropoda) from Devonian strata of the Perunica microplate (Bohemia), with a re-evaluation of their stratigraphic distribution, notes on their ontogeny, and descriptions of new taxa.

    Science.gov (United States)

    Frýda, Jiři; Ferrová, Lenka; Frýdová, Barbora

    2013-01-01

    Review of all species of the family Palaeozygopleuridae Horný, 1955 (Gastropoda) known from the Perunica microplate (Bohemia) is presented with a description of three new species, Palaeozygopleura lukesi sp. nov., Cimrmaniela sveraki gen. et sp. nov. and Cimrmaniela smoljaki gen. et sp. nov. The stratigraphic distributions of the most of Bohemian palaeozygopleurid species are either corrected or refined, based on new records or modern stratigraphic studies. A complete list of the geographic occurrences of all known palaeozygopleurid gastropods from the Perunica microplate is also given together with notes on their ontogeny.

  8. [Proceedings of the symposium 'Molluscan Palaeontology' : 11th International Malacological Congress, Siena (Italy) 30th August - 5th September 1992 / A.W. Janssen and R. Janssen (editors)]: Early rissoid gastropods from the Jurassic of Italy: the meaning of first appearances

    NARCIS (Netherlands)

    Conti, M.A.; Monari, S.; Oliviero, M.

    1992-01-01

    Studies of Jurassic outcrops from Veneto, Central Italy and Sicily improved our knowledge on the gastropods of these areas, characterised by the presence, aside of archaic forms, of some modern ones. Noteworthy is the record from those outcrops of several species, which can be referred to the family

  9. The hydrobioid freshwater gastropods (Caenogastropoda, Truncatelloidea) of Greece: new records, taxonomic re-assessments using DNA sequence data and an update of the IUCN Red List Categories.

    Science.gov (United States)

    Radea, Canella; Parmakelis, Aristeidis; Papadogiannis, Vassilis; Charou, Despoina; Triantis, Kostas A

    2013-01-01

    Hydrobioid freshwater gastropods were collected from mainland and insular Greece. Several threatened taxa, such as Graecoanatolica vegorriticola, Pseudamnicola negropontina, Pseudamnicola pieperi, Pseudobithynia eubooensis and Pseudoislamia balcanica, were recorded from new localities. Trichonia trichonica, which has been considered extinct from its type locality for the last twenty eight years, was re-discovered, whereas the presence of Daphniola exigua, G. vegorriticola, Marstoniopsis graeca, P. pieperi and Pseudobithynia trichonis in their type localities was verified. The taxonomic status of P. negropontina and the newly discovered populations of G. vegorriticola was elucidated using COI sequence data. The new data recorded during this survey indicate that the IUCN status of some Greek endemic hydrobioids needs to be updated.

  10. Is a vertebrate a better host for a parasite than an invertebrate host? Fecundity of Proctoeces cf lintoni (Digenea: Fellodistomidae), a parasite of fish and gastropods in northern Chile.

    Science.gov (United States)

    Oliva, Marcelo Enrique; Alvarez, Carlos

    2011-12-01

    The fecundity, the relationship between fecundity and worm size, as well as abundance of the adult worm Proctoeces cf. lintoni (Digenea: Fellodistomidae) in four gastropod hosts (keyhole limpets of the genus Fissurella) and one vertebrate host, the clingfish Sicyases sanguineus from northern Chile, were compared. Worms obtained from Fissurella latimarginata were smaller than those from Fissurella maxima, Fissurella limbata, and S. sanguineus. The mean fecundity of parasites from Fissurella crassa was significantly lower than those from F. limbata, F. maxima and S. sanguineus. For all invertebrate hosts, there were significant, positive relationships between worm size and fecundity, and the slopes of the regression did not differ significantly for the invertebrate hosts. Parasites of the keyhole limpet F. limbata and the clingfish showed the highest intensity, prevalence, and mean fecundity, and these species must be considered to be the hosts in which P. cf lintoni shows the best fitness.

  11. Biogeography and biodiversity of gastropod molluscs from the eastern Brazilian continental shelf and slope Biogeografía y biodiversidad de moluscos gastrópodos de la plataforma y talud continental brasileño

    Directory of Open Access Journals (Sweden)

    Gabriela Benkendorfer

    2009-01-01

    Full Text Available Biogeographic distributional patterns of gastropods are proposed based on the species' geo-graphic and bathymetric distribution. Samples were collected along the Brazilian continental margin between 18° S and 23° S, at 37 stations with depths from 20 m to 1,330 m. The analysis of the biogeographic distribution patterns confirmed the existence of a transitional zone from tropical to subtropical waters in the area of both the continental shelf and slope, suggesting a relationship with water mass circulation. We observed a high species turnover rate between the shelf and slope. The analysis of gastropod species distribution revealed a similar pattern on the shelf and slope and a large difference between shallow and deep-water faunas.Los patrones de distribución biogeográfica de gastrópodos fueron propuestos basados en la distribución geográfica y batimétrica de las especies. Los muestreos fueron realizados en el margen continental brasileño entre 18°S y 23°S, en 37 estaciones de 20 m a 1.330 m de profundidad. El análisis de los patrones de distribución biogeográfica confirmó la existencia de una zona de transición de aguas tropicales a aguas subtropicales, que se encuentra en la zona de la plataforma continental y también en la zona del talud continental, esto puede sugerir una relación con la circulación de las masas de agua. Se observó una elevada tasa de turnover de las especies entre la plataforma y el talud continental. El análisis de las especies de gastrópodos reveló un patrón similar tanto en la plataforma como en el talud y una gran diferencia entre las faunas de las aguas someras y profundas.

  12. 磷的不同动态变化对模拟湖泊生态系统中附草螺类的影响%Effects of Phosphorus Dynamics on Snails of Epiphytic Gastropods in Mesocosm Lake Ecosystem

    Institute of Scientific and Technical Information of China (English)

    操瑜; 张昭; 尹黎燕; 刘帆; 常锋毅; 李伟

    2011-01-01

    采用试验围隔模拟湖泊富营养化过程,选取磷的不同动态变化,研究其动态输入模式对附草螺类的影响。结果表明,总量相同时,中短期内低频次的磷输入比高频次的磷输入对螺类生物量的影响更显著,而长期条件下高低频次的磷输入对螺类生物量的影响无显著差异(P〉0.05)。营养的添加显著促进螺类生物量(密度和丰度)的增长。试验系统中附植藻类的生物量与螺类的生物量成显著负相关(P〈0.05),沉水植物刺苦草(Vallisneria spinulosa)与螺类(Radix)生物量的相关性不显著(P〉0.05),表明螺类是螺类-附着%Snails of epiphytic gastropods play a key role in the shallow lake ecosystem. This study aimed to investigate the effects of different phosphorus dynamics on snails of epiphytic gastropods.The enclosures were used to simulate the process of eutrophication

  13. Spatial and temporal population genetic structure of four northeastern Pacific littorinid gastropods: the effect of mode of larval development on variation at one mitochondrial and two nuclear DNA markers.

    Science.gov (United States)

    Lee, Hyuk Je; Boulding, Elizabeth G

    2009-05-01

    We investigated the effect of development mode on the spatial and temporal population genetic structure of four littorinid gastropod species. Snails were collected from the same three sites on the west coast of Vancouver Island, Canada in 1997 and again in 2007. DNA sequences were obtained for one mitochondrial gene, cytochrome b (Cyt b), and for up to two nuclear genes, heat shock cognate 70 (HSC70) and aminopeptidase N intron (APN54). We found that the mean level of genetic diversity and long-term effective population sizes (N(e)) were significantly greater for two species, Littorina scutulata and L. plena, that had a planktotrophic larval stage than for two species, Littorina sitkana and L. subrotundata, that laid benthic egg masses which hatched directly into crawl-away juveniles. Predictably, two poorly dispersing species, L. sitkana and L. subrotundata, showed significant spatial genetic structure at an 11- to 65-km geographical scale that was not observed in the two planktotrophic species. Conversely, the two planktotrophic species had more temporal genetic structure over a 10-year interval than did the two direct-developing species and showed highly significant temporal structure for spatially pooled samples. The greater temporal genetic variation of the two planktotrophic species may have been caused by their high fecundity, high larval dispersal, and low but spatially correlated early survivorship. The sweepstakes-like reproductive success of the planktotrophic species could allow a few related females to populate hundreds of kilometres of coastline and may explain their substantially larger temporal genetic variance but lower spatial genetic variance relative to the direct-developing species.

  14. 荣成天鹅湖大叶藻(Zostera marina)间2种小型腹足类的分类学研究%TAXONOMY OF 2 SMALL GASTROPODS AMONG ZOSTERA MARINA L.IN THE SWAN LAKE, RONGCHENG

    Institute of Scientific and Technical Information of China (English)

    刘静; 管洪在; 张素萍; 郭小芳; 杨学伶; 王海艳

    2013-01-01

    小型腹足类生物在我国种类繁多,但其相关研究在国内基本属于空白.本文对荣成天鹅湖大叶藻间的2种小型腹足类生物进行了形态学及分子生物学(16S和28S rRNA基因片段)研究.结果表明,根据形态学所鉴定的短剑螺属未定种Machaeroplax sp.,应为畦螺属未定种Lirularia sp.;分子生物学研究结果支持形态学对刺绣翼螺Alaba picta的鉴定.同时,与A.picta有一定形态学差异的其它4种相近形态的小型腹足类,在基因序列及遗传距离上与刺绣翼螺非常接近,亦应为刺绣翼螺Alaba picta.%There is a great diversity of small gastropods in China, however, the related researches are nearly vacant. We sampled 2 species of small gastropods habitating among the Zostera marina L. from the Swan Lake, Rongcheng Bay, China and the 16S and 28S rRNA were sequenced. Based on the molecular data, sequences alignment, genetic distances and phylogenetic studies were conducted. The results showed that Machaeroplax sp. identified according to the morphology should be Lirularia sp.; and that 4 gastropods with obvious morphological variances from Alaba picta had been classified as Alaba picta according to the molecular analysis.

  15. The unique deep sea—land connection: interactive 3D visualization and molecular phylogeny of Bathyhedyle boucheti n. sp. (Bathyhedylidae n. fam.)—the first panpulmonate slug from bathyal zones

    Science.gov (United States)

    Jörger, Katharina M.; Lodde-Bensch, Eva; Schrödl, Michael

    2016-01-01

    The deep sea comprises vast unexplored areas and is expected to conceal significant undescribed invertebrate species diversity. Deep waters may act as a refuge for many relictual groups, including elusive and enigmatic higher taxa, but the evolutionary pathways by which colonization of the deep sea has occurred have scarcely been investigated. Sister group relationships between shallow water and deep sea taxa have been documented in several invertebrate groups, but are unknown between amphibious/terrestrial and deep-sea species. Here we describe in full and interactive 3D morphoanatomical detail the new sea slug species Bathyhedyle boucheti n. sp., dredged from the continental slope off Mozambique. Molecular and morphological analyses reveal that it represents a novel heterobranch gastropod lineage which we establish as the new family Bathyhedylidae. The family is robustly supported as sister to the recently discovered panpulmonate acochlidian family Aitengidae, which comprises amphibious species living along the sea shore as well as fully terrestrial species. This is the first marine-epibenthic representative among hedylopsacean Acochlidiida, the first record of an acochlidian from deep waters and the first documented panpulmonate deep-sea slug. Considering a marine mesopsammic ancestor, the external morphological features of Bathyhedyle n. gen. may be interpreted as independent adaptations to a benthic life style in the deep sea, including the large body size, broad foot and propodial tentacles. Alternatively, the common ancestor of Bathyhedylidae and Aitengidae may have been a macroscopic amphibious or even terrestrial species. We hypothesize that oophagy in the common ancestor of Aitengidae and Bathyhedylidae might explain the impressive ecological and evolutionary flexibility in habitat choice in the Acochlidiida. PMID:27957391

  16. Conducta de forrajeo del gastrópodo Acanthina monodon Pallas, 1774 (Gastropoda: Muricidae en el intermareal rocoso de Chile central Foraging behavior of the gastropod Acanthina monodon Pallas, 1774 (Gastropoda: Muricidae in the intertidal rocky shores of central Chile

    Directory of Open Access Journals (Sweden)

    RUBÉN E. SOTO

    2004-03-01

    Full Text Available En el presente trabajo investigamos aspectos de la ecología y conducta de forrajeo de Acanthina monodon, un gastrópodo murícido que habita en el intermareal rocoso de Chile central. En terreno, estudiamos las variaciones temporales en su distribución, densidad y dieta. En el laboratorio, cuantificamos la tasa de consumo, las preferencias alimentarias, el tiempo de ingestión y la rentabilidad energética obtenida con distintos tipos de presas mediante experimentos y registros en video. Las mayores densidades de individuos de A. monodon fueron observadas en la franja intermareal cercana al nivel cero de marea. En terreno, A. monodon realiza sus actividades de forrajeo principalmente durante la noche y su dieta consistió principalmente de mitílidos (95 % y cirripedios (5 %. La composición de la dieta de A. monodon en terreno presentó variaciones temporales las cuales dependerían principalmente de cambios en la oferta de los distintos tipos de mitílidos presentes en terreno durante los dos años de muestreo. En el laboratorio, los individuos de Acanthina presentaron preferencias alimentarias significativas por el mitílido Semimytilus algosus. En general, A. monodon bajo condiciones de laboratorio presentó una conducta de forrajeo en la cual maximizó la ganancia neta de energía, mediante la selección de las especies y tamaños de presas que le retribuyen la mayor rentabilidad energéticaWe investigated the ecology and foraging behavior of Acanthina monodon, a muricid gastropod that inhabits in the intertidal rocky shores of central Chile. In the field, we studied temporal variation of their spatial distribution, density, and diet composition. While in the laboratory, we quantified the consumption rate, alimentary preferences, ingestion times and energy profitability obtained with different types of prey using experiments and video recording. High densities of A. monodon individuals were observed in the intertidal fringe near at the

  17. Contamination of terrestrial gastropods, Helix aspersa maxima, with {sup 137}Cs, {sup 85}Sr, {sup 133}Ba and {sup 123m}Te by direct, trophic and combined pathways

    Energy Technology Data Exchange (ETDEWEB)

    Madoz-Escande, C. [Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, IRSN/DEI/SECRE/LRE, Cadarache, Bld 186, BP 3, 13115 St-Paul-lez-Durance Cedex (France)]. E-mail: chantal.madoz-escande@irsn.fr; Simon, O. [Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, IRSN/DEI/SECRE/LRE, Cadarache, Bld 186, BP 3, 13115 St-Paul-lez-Durance Cedex (France)

    2006-07-01

    {sup 137}Cs, {sup 85}Sr, {sup 133}Ba and {sup 123m}Te contaminations of terrestrial gastropods, Helix aspersa maxima, by direct deposition, labelled food ingestion or combined (trophic and direct pathways) exposure were carried out under laboratory conditions. The aim of this study was to compare the three contamination pathways: direct, trophic and combined, in terms of individual mortality, radionuclide uptake, depuration and distribution in the tissues. An initial group of 30 snails (2 years old) was exposed to radioactive aerosols during a 20-h period. These aerosols were assumed to be representative of those that would be released during a nuclear accident occurring in a PWR. A second group of 50 snails (same age) was submitted to an ingestion of commercial food contaminated by the same aerosols, twice a week for 21 days (flour at a feeding rate of about 0.2 g). A third group of 40 snails was submitted to a combined exposure: exposure to radioactive aerosols (20 h), followed by ingestion of flour contaminated by the same aerosols, twice a week for 21 days. No significant difference between the three groups and a reference group of 10 snails was observed, neither in growth nor in mortality. Concerning the direct pathway, at the end of direct deposition (about 1 day after the beginning), cesium was the most bioavailable element, distributed rather homogeneously throughout the whole body (13% of the total Cs in all organs excepting the digestive system and 28% in the muscle). Strontium was measured in the shell (about 70%). Barium was found in the muscle (20%) and in the shell (65%). Tellurium was mainly present in the shell (70%) and in the digestive system (20%). After 21 days of depuration, the faeces eliminated 42% of the Te. As for contamination by ingestion, Te mainly accumulated in the digestive system (72% of Te present in the total body), Ba accumulated in the muscle (75%) and Sr in the shell (70%). Concerning contamination by combined pathways, at the

  18. Four new African turriform gastropods (Mollusca: Conoidea).

    Science.gov (United States)

    Morassi, Mauro; Bonfitto, Antonio

    2013-01-01

    Four new species, belonging to four distinct conoidean families, are described from east Africa and Mozambique Channel. Iredalea adenensis sp. nov. (Drilliidae Olsson, 1964), from Gulf of Aden, and Buchema shearmani sp. nov. (Horaiclavidae Bouchet et al., 2011), from off Mogadishu (Somalia), both trawled by local fishermen, represent the first record of their respective genera in eastern Africa. Crassispira somalica sp. nov. (Pseudomelatomidae Morrison, 1965), also collected offshore from Modagishu (Somalia), represents the first eastern Africa species bearing "typical" Crassispira features. Tropidoturris vizcondei sp. nov. (Borsoniidae Bellardi, 1875), from the Mozambique Channel, increases the knowledge of a genus considered endemic to southeastern Africa.

  19. PROTEIN N-GLYCOSYLATION OF GASTROPODS

    OpenAIRE

    2009-01-01

    Glycosylation plays an important role in several types of recognition processes associated with fertilisation and development, allergies, pathological events and cell death. Whereas the amino acid sequence of a protein is fixed by the DNA, the glycosylation abilities depend on enzymes and substrates currently present in the cell.

  20. Multiscale Mechanics and Optimization of Gastropod Shells

    Institute of Scientific and Technical Information of China (English)

    Mostafa Yourdkhani; Damiano Pasini; Francois Barthelat

    2011-01-01

    A vast majority of mollusks grow a hard shell for protection.The structure of these shells comprises several levels of hierarchy that increase their strength and their resistance to natural threats.This article focuses on nacreous shells,which are composed of two distinct layers.The outer layer is made of calcite,which is a hard but brittle material,and the inner layer is made of nacre,a tough and ductile material.The inner and outer layers are therefore made of materials with distinct structures and properties.In this article,we demonstrate that this system is optimum to defeat attacks from predators.A two-scale modeling and optimization approach was used.At the macroscale,a two-layer finite element model of a seashell was developed to capture shell geometry.At the microscale,a representative volume element of the microstructure of nacre was used to model the elastic modulus of nacre as well as a multiaxial failure criterion,both expressed as function of microstructural parameters.Experiments were also performed on actual shells of red abalone to validate the results obtained from simulations and gain insight into the way the shell fails under sharp perforation.Both optimization and experimental results revealed that the shell displays optimum performance when two modes of failure coincide within the structure.Finally,guidelines for designing two-layer shells were proposed to improve the performance of engineered protective systems undergoing similar structural and loading conditions.

  1. 两种淡水腹足类动物对90Sr的浓集与分布的生物学特性%BIOLOGICAL CHARACTERISTICS OF CONCENTRATION FACTORS AND DISTRIBUTION OF 90Sr IN TWO KINDS OF FRESH WATER GASTROPODS

    Institute of Scientific and Technical Information of China (English)

    陈舜华; 钟创光; 赵小奎; 张奕强

    2001-01-01

    本文报道了两种淡水腹足类动物对90Sr的浓集与分 布的过程,大瓶螺(Ampullaria gigas Spix)4h开始便迅速浓集90Sr并转至 螺体 各个部位,小个体各器官组织对90Sr的浓集系数大于大个体,刚孵化的幼螺在 15min内便对90Sr有浓集作用,并随时间的延长而增加。石螺(Bellarnya puri ficata)对90Sr于4h开始有吸收浓集作用,但其浓集系数低于大瓶螺,在各自 积累 高峰期大瓶螺的贝壳对90Sr的浓集系数为石螺的14倍。两种母螺的卵 和子螺的90Sr比活度均高于同时间两种螺贝壳的比活度,说明90Sr 通过母体迅速转移至子体。%The concentration factors(CFs) and the distribution of 90Sr in two kinds of fresh water gastropod, Ampullaria gigus Spix and Bellarnya purificata.A .Gigas were studied. Spix absorbs and transfers 90Sr rapidly withi n 4 hours. The CFs of the organs or tissues in smaller individuals are higher than those of the bigger ones. The newly hatched juveniles absorb 90Sr in a very short period of time (15min), and the 90Sr concentration increase s with time. B. purificata also accumulates 90Sr in 4h, but the CF sare lower than those of A. gigas Spix. The CF peak of 90Sr in the shell of A. gigas Spix is fourteen times higher than that of B. purificat a. It shows that the specific radioactivity of 90Sr in the juveniles of both gastropods is higher than that of the parents in the same period of time, demonstrating that 90Sr is transferred from the parents to their de scendants.

  2. Riesgo de establecimiento del gasterópodo dulceacuícola invasor Melanoides tuberculatus (Thiaridae en el Río de la Plata (Argentina-Uruguay Colonization risks of the invading freshwater gastropod Melanoides tuberculatus (Thiaridae in Río de la Plata (Argentina-Uruguay

    Directory of Open Access Journals (Sweden)

    Diego E. Gutiérrez-Gregoric

    2010-08-01

    Full Text Available Melanoides tuberculatus es un gasterópodo cosmopolita que ha invadido y se ha establecido en casi todos los países del continente americano, desconociéndose en la mayoría de los casos el origen de su introducción. En este trabajo se menciona el riesgo de establecimiento de esta especie en áreas de influencia del Río de la Plata como consecuencia de su registro en acuarios de la ciudad de La Plata (Buenos Aires, Argentina dedicados a la venta de flora y fauna limnética. A principios de 2009, la especie fue identificada a partir de 26 ejemplares procedentes de un comercio, siendo éste el registro más austral de la especie para una localidad de la cuenca del Plata. Revisiones posteriores en 3 locales comerciales de la ciudad confirmaron la presencia de la especie en 2 de ellos. Dicha presencia se relacionó con la adquisición de plantas ornamentales por parte de los establecimientos. La identificación del gasterópodo en la ciudad de La Plata debe considerarse cuidadosamente, debido a las posibles consecuencias que tendría la liberación accidental de este molusco en el Río de la Plata en lo relacionado con el desplazamiento de fauna local y salud pública.Melanoides tuberculatus is a cosmopolitan gastropod that has invaded and has now spread into most countries of the American continent. Introduction pathways remain unknown in most cases. This work draws attention on the colonization risks of this species in the Río de la Plata area as a consequence of its record in flower and pet shops - in the city of La Plata (Buenos Aires, Argentina - in which limnic species are sold. The species was identified at the beginning of 2009 within a lot of 29 specimens from a shop, and this is the southernmost record of this species in the Plata Basin. Subsequent surveys in 3 commercial shops in the same city revealed its presence in 2 of them. This was related to the purchase of ornamental plants by the shops. Identification of this species in the

  3. Location of The Carbohydrate and Identification of The Glycosylation Sites in Functional Unit e of βc-haemocyanin of The Gastropod Helix Pomatia%腹足纲Helix pomatia βC-血清蛋白的功能单位e中碳水化合物的定位和糖基化位置的鉴定

    Institute of Scientific and Technical Information of China (English)

    蔡皓; Gielens Constant; Preaux Gisele

    2004-01-01

    The carbohydrate in functional unit e of βC-haemocyanin of the gastropod Helix pomatia was studied. The limited trypsinolysis on tenth molecules of βC-haemocyanin of Helix pomatia at pH = 8. 2 yielded the fragments αc, e f, and the functional units d, g, and h (present as dimers h2). The mixture of functional units e and f after limited fragmentation of fragment ef on storage, were further fractionated with an affinity chromatography in the presence of α-methylglucoside, yielded functional unit e2. Further separation of trypsinolysis of pyridylethylated functional unit e2 yielded a fraction I (contain glycopeptides). The analysis of carbohydrate content and the N-terminal sequence allowed the location of the carbohydrate and the identification of the glycosylation sites in functional unit e: site A at Asn-111 and site B at Asn-387. From a comparison with the glycosylation sites of Hp d and Hp g, it follows that the site B is a conserved one.%对腹足纲软体动物罗曼蜗牛Helix pomatia的氧运输蛋白(βC-血清蛋白)的功能单位e中的碳水化合物进行了研究.以该βC-血清蛋白为载体,通过限制性胰蛋白酶水解,产生片段a-c,ef,以及功能单位d,g,和h.以片段ef降解后的产物为研究对象,通过亲合色谱的分离纯化,得到功能单位e的一个馏分e2.该馏分经还原、吡啶乙基化和胰蛋白酶水解后,通过柱色谱的分离纯化,得到一个含有糖肽的成分.对该糖肽中糖组分和肽序列的分析,最终确定了功能单位e的两个糖基化位置:Asn-111和Asn-387.通过与功能单位d和g的糖基化位置的比较得出结论:Asn-387为一恒定的糖基化位置.

  4. Variabilidad geográfica en la tolerancia térmica y economía hídrica del gastrópodo intermareal Nodilittorina peruviana (Gastropoda: Littorinidae, Lamarck, 1822 Geographic variability in thermal tolerance and water economy of the intertidal gastropod Nodilittorina peruviana. (Gastropoda: Littorinidae, Lamarck, 1822

    Directory of Open Access Journals (Sweden)

    JOSE MIGUEL ROJAS

    2000-09-01

    Full Text Available El gastrópodo Nodilittorina peruviana es un habitante común de la zona intermareal rocosa de la costa norte y centro de Chile. Las poblaciones de esta especie se caracterizan por presentar distribuciones agregadas. Por medio de mediciones de terreno y ensayos de laboratorio se evaluó la influencia de la agregación sobre las habilidades de termorregulación y conservación de agua, en individuos pertenecientes a dos localidades de la costa de Chile que presentan distintos regímenes termales (Taltal 25º 25' S; 70º 29' W y Las Cruces 33º 35' S; 71º 38' W. Los resultados indican que la influencia de la agregación sobre las habilidades termorregulatorias es dependiente de las condiciones locales. A pesar de que los individuos de ambas localidades presentaron puntos de tolerancia térmica similares, los caracoles de Taltal mostraron tasas de pérdidas de agua menores. El tamaño de las agregaciones se relacionó en forma negativa con la tasa de pérdida de agua de los individuos de ambas localidades. En el caso de Taltal se observó un límite de tolerancia menor que en Las Cruces y una relación positiva entre tamaño de la agregación y temperatura grupal. Los resultados demuestran que las condiciones ambientales locales puede ser determinante para la efectividad de los mecanismos de termorregulación.The gastropod Nodilittorina peruviana inhabit rocky intertidal of the north and center Chile. Populations of this species exhibits aggregated distributions. Through field and lab records we studied the effect of spatial distribution of snails on their thermoregulatory and water conservation efficiencies. We studied individuals from two localities of the Chilean coast with different climatic conditions (Taltal 25° 25 ` S; 70° 29 ` W and Las Cruces 33° 35 ` S; 71° 38 ` W. Results indicate that the influence of spatial distribution thermoregulatory efficiency is dependent of the local conditions. Although individuals from both localities

  5. Review of intersex in gastropods and other molluscs

    DEFF Research Database (Denmark)

    Strand, Jakob

    signs of endocrine disruption causing sex reversal, characterized as intersex, have been reported for marine molluscs. Intersex can more generally be defined as disturbance of the phenotypic sex characters and different types of intersex have been recorded for both female and male molluscs...

  6. Mollusca (terrestrial and marine Gastropods et Bivalvia from Morocco

    Directory of Open Access Journals (Sweden)

    Atanas Irikov

    2013-12-01

    Full Text Available Fifteen samples with molluscs are collected from various habitats and regions of Morocco, located in the seashore zone, as well as the central and the eastern parts of the country. We recorded 21 terrestrial and 15 marine species of molluscs. New localities and new species for the fauna of Morocco and the African continent are reported for the first time.

  7. Spontaneous regeneration of the central nervous system in gastropods.

    Science.gov (United States)

    Matsuo, Ryota; Ito, Etsuro

    2011-08-01

    Of all organs in mammals including humans, the brain has the most limited regenerative capacity after injury or damage. In spite of extensive efforts to treat ischemic/stroke injury of the brain, thus far no reliable therapeutic method has been developed. However, some molluscan species show remarkable brain regenerative ability and can achieve full functional recovery following injury. The terrestrial pulmonates are equipped with a highly developed olfactory center, called the procerebrum, which is involved in olfactory discrimination and odor-aversion learning. Recent studies revealed that the procerebrum of the land slug can spontaneously recover structurally and functionally relatively soon after injury. Surprisingly, no exogenous interventions are required for this reconstitutive repair. The neurogenesis continues in the procerebrum in adult slugs as in the hippocampus and the olfactory bulb of mammals, and the reconstitutive regeneration seems to be mediated by enhanced neurogenesis. In this review, we discuss the relationship between neurogenesis and the regenerative ability of the brain, and also the evolutionary origin of the brain structures in which adult neurogenesis has been observed.

  8. Shell repair in the freshwater gastropod Bithynia tentaculata (Linnaeus, 1758)

    NARCIS (Netherlands)

    Cadée, Gerhard C.

    2015-01-01

    A large sample rich in empty Bithynia tentaculata (Linnaeus, 1758) was collected in a drift-line along Lake IJssel, The Netherlands. Of 400 adult Bithynia shells 62 (15.5%) showed repair of a damaged outer lip, most probably due to failed attacks by predators. The roach Rutilus rutilus (Linnaeus, 17

  9. Acetylcholinesterase activity in marine gastropods as biomarker of neurotoxic contaminants

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Gaitonde, D.C.S.; Vashistha, D.

    with white or yellowish spots. The shell opens wide with grooves on the inner surface. Operculum dark coloured and is made of a horny material. The females have a special brood pouch in the foot where the embryos are reared before they are released...

  10. Rodriguesic acids, modified diketopiperazines from the gastropod mollusc Pleurobranchus areolatus

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fabio R.; Santos, Mario F.C.; Berlinck, Roberto G.S., E-mail: rgsberlinck@iqsc.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica; Williams, David E.; Andersen, Raymond J. [Departments of Chemistry and Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver (Canada); Padula, Vinicius [SNSB-Zoologische Staatssammlung München, München, Germany and Department Biology II and GeoBio-Center, Ludwig-Maximilians-Universität München, (Germany); Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

    2014-04-15

    In the present investigation, two specimens of the nudipleuran mollusc Pleurobranchus areolatus have shown to accumulate oxidized rodriguesin A derivatives. Rodriguesic acid presents a carboxylic acid replacing the terminal methyl group of the alkyl chain of rodriguesin A. A hydroxamate group was also present on the diketopiperazine moiety of a rodriguesic acid derivative. The structures of both rodriguesic acid and of rodriguesic acid hydroxamate have been established by analysis of spectroscopic data, including their absolute configuration. Two methyl esters of the rodriguesic acids have been isolated as major compounds, but were considered to be isolation artifacts. (author)

  11. Soil manganese enrichment from industrial inputs: a gastropod perspective.

    Directory of Open Access Journals (Sweden)

    Despina-Maria Bordean

    Full Text Available Manganese is one of the most abundant metal in natural environments and serves as an essential microelement for all living systems. However, the enrichment of soil with manganese resulting from industrial inputs may threaten terrestrial ecosystems. Several studies have demonstrated harmful effects of manganese exposure by cutaneous contact and/or by soil ingestion to a wide range of soil invertebrates. The link between soil manganese and land snails has never been made although these invertebrates routinely come in contact with the upper soil horizons through cutaneous contact, egg-laying, and feeding activities in soil. Therefore, we have investigated the direct transfer of manganese from soils to snails and assessed its toxicity at background concentrations in the soil. Juvenile Cantareus aspersus snails were caged under semi-field conditions and exposed first, for a period of 30 days, to a series of soil manganese concentrations, and then, for a second period of 30 days, to soils with higher manganese concentrations. Manganese levels were measured in the snail hepatopancreas, foot, and shell. The snail survival and shell growth were used to assess the lethal and sublethal effects of manganese exposure. The transfer of manganese from soil to snails occurred independently of food ingestion, but had no consistent effect on either the snail survival or shell growth. The hepatopancreas was the best biomarker of manganese exposure, whereas the shell did not serve as a long-term sink for this metal. The kinetics of manganese retention in the hepatopancreas of snails previously exposed to manganese-spiked soils was significantly influenced by a new exposure event. The results of this study reveal the importance of land snails for manganese cycling in terrestrial biotopes and suggest that the direct transfer from soils to snails should be considered when precisely assessing the impact of anthropogenic Mn releases on soil ecosystems.

  12. Identification of A Cysteine-Histidine Thioether Bridge Bond in Functional Units d, e and f of βC-haemocyanin of The Gastropod Helix Pomatia%腹足纲Helix pomatia βC-血清蛋白的功能单位d,e和f中一个半胱氨酸-组氨酸之间硫醚桥键的鉴定

    Institute of Scientific and Technical Information of China (English)

    蔡皓; Gielens Constant; Préaux Gisele

    2007-01-01

    A thioether bridge between a cysteine and a histidine residue in functional units d, e and f of βC-haemocyanin of the gastropod Helix pomatia was investigated. The limited trypsinolysis on tenth molecules of βC-haemocyanin of Helix pomatia at pH=8.2 yielded the fragments a-c, e f, and the functional units d, g, and h (present as dimers h2 ). The mixture of functional units e and f after limited fragmentation of fragment e f,were further fractionated with an affinity chromatography in the presence of α-methylglucoside, yielded functional units e and f. A tetrapeptide which contained a thioether bridge between cysteine-60 and histidine-62 was obtained after treatment of the carboxymethylated functional unit d with trypsin and pronase. As could be deduced from the analysis of the peptides, strongly absorbing at 255nm and found in the sediments (cores) after trypsinolysis of the pyridylethylated functional units e and f, one of these cysteine residues (cysteine-60 in the numbering of functional unit d) was involved in the formation of a thioether bridge with histidine-62. Thus the presence of a cysteine- histidine thioether bridge seems to be a general feature of functional units from the βC-haemocyanin of the gastropod Helix Pomatia.%对腹足纲软体动物罗曼蜗牛Helix pomatia的氧运输蛋白(βC-血清蛋白)的功能单位d,e和f中的一个半胱氨酸-组氨酸之间的硫醚桥键进行了研究.以该βC-血清蛋白为载体,通过限制性胰蛋白酶水解,产生片段a-c,ef,以及功能单位d,g,和h.以片段ef降解后的产物为研究对象,通过亲合色谱的分离纯化,得到功能单位e和f.通过对羧甲基化功能单位d的胰蛋白酶和链霉蛋白酶水解,得到一个含有硫醚桥键的4肽.同样在吡啶乙基化功能单位e和f的胰蛋白酶水解产物中也分离得到一个含有相同硫醚桥键的小肽.因此一个半胱氨酸-组氨酸之间硫醚桥键的存在似乎是腹足

  13. Divergence of gastropod life history in contrasting thermal environments in a geothermal lake.

    Science.gov (United States)

    Johansson, M P; Ermold, F; Kristjánsson, B K; Laurila, A

    2016-10-01

    Experiments using natural populations have provided mixed support for thermal adaptation models, probably because the conditions are often confounded with additional environmental factors like seasonality. The contrasting geothermal environments within Lake Mývatn, northern Iceland, provide a unique opportunity to evaluate thermal adaptation models using closely located natural populations. We conducted laboratory common garden and field reciprocal transplant experiments to investigate how thermal origin influences the life history of Radix balthica snails originating from stable cold (6 °C), stable warm (23 °C) thermal environments or from areas with seasonal temperature variation. Supporting thermal optimality models, warm-origin snails survived poorly at 6 °C in the common garden experiment and better than cold-origin and seasonal-origin snails in the warm habitat in the reciprocal transplant experiment. Contrary to thermal adaptation models, growth rate in both experiments was highest in the warm populations irrespective of temperature, indicating cogradient variation. The optimal temperatures for growth and reproduction were similar irrespective of origin, but cold-origin snails always had the lowest performance, and seasonal-origin snails often performed at an intermediate level compared to snails originating in either stable environment. Our results indicate that central life-history traits can differ in their mode of evolution, with survival following the predictions of thermal optimality models, whereas ecological constraints have shaped the evolution of growth rates in local populations.

  14. Pleistocene gastropods from Toca da Esperança, municipality of Central, State of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Lais Clark Lima

    1992-09-01

    Full Text Available Fossil shells collected during excavations in Toca da Esperança, BA, were identified on morphological grounds as: Artemon intermedius intermedius (Albers, 1857; Gastrocopta (Privatula corticaria (Say; Bulimulus (Rhinus heterotrichus (Moricand, 1836 and Polygyratia polygyrata polygyrata (Born, 1780. Bone samples found associated with these shells were dated by the Uranium - Thorium method as being between 204,000 and 295,000 years old (Middle - Upper Pleistocene. Species of the mastofauna also found associated, on the other hand, were identified as being of the Upper Pleistocene or even of the beginning of the Holocene. The material studied here was not dated.

  15. Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis.

    Science.gov (United States)

    Giusti, Arnaud; Barsi, Alpar; Dugué, Maël; Collinet, Marc; Thomé, Jean-Pierre; Joaquim-Justo, Célia; Roig, Benoit; Lagadic, Laurent; Ducrot, Virginie

    2013-07-01

    Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed to compare the relative toxicity of TBT and TPT under similar laboratory conditions in the range of 0 ng Sn/L to 600 ng Sn/L. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length, and reproduction were monitored in a 21-d semistatic test. Frequency of abnormal eggs was assessed as an additional endpoint. Triphenyltin hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, because snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the 2 compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared with the sensitivity of prosobranch mollusks with different habitats and different reproductive strategies.

  16. Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki.

    Directory of Open Access Journals (Sweden)

    Michael L Middlebrooks

    Full Text Available It has been well documented that nutritional state can influence the foraging behavior of animals. However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize. To test this hypothesis we subjected groups of the kleptoplastic sea slug, Elysia clarki, to a gradient of starvation treatments of 4, 8, and 12 weeks plus a satiated control. Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a]. The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control. This suggests that photosynthesis in E. clarki, thought to be linked to horizontally-transferred algal genes, delays a behavioral response to starvation. This is the first demonstration of a link between photosynthetic capability in an animal and a modification of foraging behavior under conditions of starvation.

  17. Physical and Chemical Interactions with Conspecifics Mediate Sex Change in a Protandrous Gastropod Crepidula fornicata.

    Science.gov (United States)

    Cahill, Abigail E; Juman, Alia Rehana; Pellman-Isaacs, Aaron; Bruno, William T

    2015-12-01

    The protandrous marine snail Crepidula fornicata has been a theoretical and empirical model for studies of sex change for many decades. We investigated the social conditions under which sex change occurs in this species by manipulating physical and chemical contact with conspecifics. Male snails were either in physical and chemical contact with females or in chemical contact with, but physically isolated from, females. Males were tested both with living females and with empty, sterilized shells. Males that were physically touching a living female were less likely to change sex than the isolated controls, while males in chemical (but not physical) contact with females changed sex no slower than the isolated controls. These results provide experimental evidence that the factor controlling sex change in C. fornicata is due to a contact-borne inhibitor associated with female conspecifics. These findings serve as a basis for future studies of sex change in this model system.

  18. Recurrent camouflaged invasions and dispersal of an Asian freshwater gastropod in tropical Africa

    OpenAIRE

    Van Bocxlaer, Bert; Clewing, Catharina; Mongindo Etimosundja, Jean-Papy; Kankonda, Alidor; Wembo Ndeo, Oscar; Albrecht, Christian

    2015-01-01

    Background Non-indigenous taxa currently represent a large fraction of the species and biomass of freshwater ecosystems. The accumulation of invasive taxa in combination with other stressors in these ecosystems may alter the habitats to which native taxa are adapted, which could elicit evolutionary changes in native populations and their ecological interactions. Assessing ecological and evolutionary consequences of invasions simultaneously may therefore be the most effective approach to study...

  19. The usefulness of a sediment bioassay with the gastropod Nassarius reticulatus in tributyltin monitoring programs.

    Science.gov (United States)

    Laranjeiro, Filipe; Pérez, Sara; Navarro, Patricia; Carrero, José Antonio; Beiras, Ricardo

    2015-11-01

    Despite the use of tributyltin (TBT) had been banned worldwide in 2008 there is still evidence of its deleterious presence in environment. We evaluate the usefulness of a 28days sediment bioassay with Nassarius reticulatus females to monitor TBT pollution, using imposex as endpoint. In addition, butyltins were determined in sediments and tissues, and, whenever posible, imposex was assessed in native N. reticulatus at the same sites where sediments were sampled. In the bioassay, a significant increase in imposex parameters was obtained with three sediments (Vi2, Vi3, and Vi4). No correlation was found between this and TBT concentrations in sediment although good correlations were obtained for TBT in tissues, putting in evidence TBT bioavailability in sediment. A significant decrease in imposex from 2008 to 2013 in native snails was only observed at sites that did not cause any effect in the bioassay. In contrast, imposex levels in 2013 were kept as high as 2008 in one of the sites where a significant imposex increase in the bioassay was observed. The bioassay proves thus to be a practical and ecological relevant tool, as: (i) it can be conducted in sites with no native populations of snails, (ii) it provides early identification of polluted sites, anticipating future imposex levels or early identification of recovering, and (iii) it yields information on the bioavailable fraction of the TBT in the sediment. Therefore, this tool can be of extreme usefulness under the scope of recent European legislative frameworks.

  20. [PROTEOMIC ANALYSIS OF ADAPTIVE MECHANISMS TO SALINITY STRESS IN MARINE GASTROPODS LITTORINA SAXATILIS].

    Science.gov (United States)

    Muraeva, O A; Maltseva, A L; Mikhailova, N A; Granovitch, A I

    2015-01-01

    Salinity is one of the most important abiotic environmental factors affecting marine animals. If salinity deviate from optimum, adaptive mechanisms switch on to maintain organism's physiological activity. In this study, the reaction of the snails Littorina saxatilis from natural habitats and in response to experimental salinity decreasing was analyzed on proteomic level. The isolation of all snails inside their shells and gradually declining mortality was observed under acute experimental salinity decrease (down to 10 per hundred). Proteomic changes were evaluated in the surviving experimental mollusks compared to control individual using differential 2D gel-electrophoresis (DIGE) and subsequent LC-MS/MS-identification of proteins. Approximately 10% of analyzed proteins underwent up- or down regulation during the experiment. Proteins of folding, antioxidant response, intercellular matrix, cell adhesion, cell signaling and metabolic enzymes were identified among them. Proteome changes observed in experimental hypoosmotic stress partially reproduced in the proteomes of mollusks that live in conditions of natural freshening (estuaries). Possible mechanisms involved in the adaptation process of L. saxatilis individuals to hypo-osmotic stress are discussed.

  1. Accumulation of platinum group elements by the marine gastropod Littorina littorea.

    Science.gov (United States)

    Mulholland, Rachel; Turner, Andrew

    2011-04-01

    The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 μg L⁻¹) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd ≥ Pt ≥ Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase.

  2. Mitochondrial DNA variation in space and time in the northeastern Pacific gastropod, Littorina keenae.

    Science.gov (United States)

    Lee, Hyuk Je; Boulding, Elizabeth G

    2007-08-01

    The present population structure of a species reflects the influence of population history as well as contemporary processes. To examine the relative importance of these factors in shaping the current population structure of Littorina keenae, we sequenced 762 base pairs of the mitochondrial ND6 and cytochrome b genes in 584 snails from 13 sites along the northeastern Pacific coast. Haplotype network analysis revealed a 'star-like' genealogy indicative of a recent population expansion. Nested clade and mismatch analyses also supported the hypothesis of sudden population expansion following a population bottleneck during the Last Glacial Maximum. Analysis of molecular variance and pairwise Phi(ST) showed no significant spatial population differentiation from Mexico to Oregon - not even across the recognized biogeographic boundary at Point Conception. This is probably due to high contemporary gene flow during the free-swimming larval stage of this snail. Surprisingly, we found a highly significant temporal population differentiation between a San Pedro sample from 1996 and one from 2005, which gave an estimate of effective population size (N(e)) of only 135. Nearly statistically significant changes in the frequency of a particular haplotype in three other populations over 2-3 years further support Hedgecock's 'sweepstakes' hypothesis. When by chance nearly all of the progeny from an aggregation of highly fecund sisters that possess a rare haplotype successfully recruit to become the next generation, the rare haplotype can become temporarily common across the entire species' range. This modification of the sweepstakes hypothesis can explain why the temporal variation that we observed was much greater than the spatial variation.

  3. [Macrogeographic genetic variability in the gastropod mollusk Littorina sitkana from the northwest Pacific].

    Science.gov (United States)

    Zaslavskaya, N I; Pudovkin, A I

    2005-03-01

    Variation at four highly polymorphic allozyme loci (inorganic pyrophosphatase, peptidase, and two esterase loci) was examined in 25 settlements of the marine snail Littorina sitkana (Mollusca, Gastropoda). The sampling localities covered a wide part of the species range: from the Peter the Great Bay (the Sea of Japan) at the southwest to the Mednyi Island (Commander Islands) at the northeast. Like other littorines lacking the pelagic stage, L. sitkana was characterized by significant genetic differentiation (G(ST) for the pooled sample was 0.310). Cluster analysis and nonmetric multidimensional scaling conducted on a matrix of pairwise genetic distances between all of the settlements studied revealed four genetically different groups: southern Primorye, northern Prymorye, Sakhalin, and Kuril-Commanders. The population-genetic structure of the L. sitkana settlements is close to that described by the isolation-by-distance and stepping-stone models: the geographic and the genetic distances between the most settlements examined are distinctly correlated.

  4. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species.

    Science.gov (United States)

    Gutiérrez, Manuel Caballer; Ortea, Jesús; Rivero, Nelsy; Tucker, Gabriela Carias; Malaquias, Manuel António E; Narciso, Samuel

    2015-10-29

    The Caribbean waters of Venezuela are composed by a large variety of habitats, with over 2800 km of coastline, islands, and islets. This area is a transitional zone between two main biogeographic provinces, the Caribbean and the Brazilian, separated by the fresh water outflows of the Orinoco and Amazon rivers, and is therefore expected to be an area of high species diversity. However, concerning the study of molluscs, Venezuela is probably the poorest known region in the Caribbean. The best compilation of opisthobranch species known in Venezuela was produced almost a decade ago, mentioning the occurrence of 57 species, plus seven determined only to genus level. In this work, 134 species are reported for Venezuela (71 are illustrated), representing about 40 % of the entire diversity of opisthobranchs known in the Caribbean. Among the species occurring in Venezuela, 49 have here the southern limit of their distribution range and only one the northern limit. Forty-six species are recorded for the first time to the country and one is a new record for the Caribbean Sea, namely Placida cremoniana. In addition, the distribution and ecology of the species are given based in literature and new data.

  5. [Biodiversity of land gastropods (Mollusca) in Sierra de San Javier Park, Tucumán, Argentina].

    Science.gov (United States)

    Miranda, María José; Cuezzo, María Gabriela

    2010-09-01

    Studies related to land mollusk diversity in tropical and subtropical forests are scarce. To assess this, a study on land snail diversity of subtropical cloudforest (Yungas) and dry forest (Chaco) areas of Sierra de San Javier Park, Tucumán, Argentina, was carried out. Taxonomic identifications were performed to species level and built a species per stations data matrix to analyze diversity patterns on qualitative and quantitative samples processed from 10x10m quadrates in altitudinal transects. Non parametric analysis (ICE, ACE, Chao 1 and Chao 2) were used to estimate the true diversity of the area, as well as the degree of undersampling and spatial aggregation of the data. Diversity was also calculated using Shannon, Simpson, Whittaker and Jaccard indices. The richness of the San Javier Park was estimated to be 32 species distributed into 13 families and 21 genera. From the total number of species collected, a single one belongs to Caenogastropoda, while the rest of the species are classified into Pulmonata Stylommatophora and Systellommatophora. The most representative family was the micromollusc Charopidae, while the most relatively abundant species was another micromollusc snail, Adelopoma tucma. Richness and diversity were slightly more elevated in dry forest areas of the Chacoan Ecoregion than in cloud forest areas of Yungas. Non parametric estimators showed that the inventory was complete. Diversity values obtained were high in comparison to previously studied areas of Northwestern Argentina. The total number of specimen collected (22 169 specimens), was higher than other published studies.

  6. Antidiabetic potential and secondary metabolites screening of mangrove gastropod Cerithidea obtusa

    Institute of Scientific and Technical Information of China (English)

    Reni Tri Cahyani; Sri Purwaningsih; Azrifitria

    2015-01-01

    Objective: To study the possible effects of Cerithidea obtusa extract as antidiabetic and to screen the secondary metabolites presence. Methods: Antidiabetic activity of Cerithidea obtusa extract was measured in vitro usingα-glucosidase inhibition method. Whereas, secondary metabolites screening was measured qualitatively. Results: The methanol extract had antidiabetic activity (IC50 = 36.40 mg/mL). However, the control drug acarbose had significantly higher antidiabetic activity (IC50 = 0.32 mg/mL). Secondary metabolites screening showed the presence of alkaloids, flavonoids, triterpenoids and saponins. Conclusions: The methanol extract had antidiabetic activity and the presence of alkaloids, flavonoids and triterpenoids might contribute to the activity.

  7. Biodiversity of cone snails and other venomous marine gastropods: evolutionary success through neuropharmacology.

    Science.gov (United States)

    Olivera, Baldomero M; Showers Corneli, Patrice; Watkins, Maren; Fedosov, Alexander

    2014-02-01

    Venomous marine snails (superfamily Conoidea) are a remarkably biodiverse marine invertebrate lineage (featuring more than 10,000 species). Conoideans use complex venoms (up to 100 different components for each species) to capture prey and for other biotic interactions. Molecular phylogeny and venom peptide characterization provide an unusual multidisciplinary view of conoidean biodiversity at several taxonomic levels. Venom peptides diverge between species at an unprecedented rate through hypermutation within gene families. Clade divergence within a genus occurs without recruiting new gene families when a saltatory event, such as colonization of new prey types (e.g., fish), leads to a new radiation. Divergence between genera in the same family involves substantial divergence in gene families. In the superfamily Conoidea, the family groups recruited distinct sets of different venom gene superfamilies. The associated morphological, behavioral, and prey-preference changes that accompany these molecular changes are unknown for most conoidean lineages, except for one genus, Conus, for which many associated phenotypic changes have been documented.

  8. Terrestrial gastropods (Helix spp) as sentinels of primary DNA damage for biomonitoring purposes: a validation study.

    Science.gov (United States)

    Angeletti, Dario; Sebbio, Claudia; Carere, Claudio; Cimmaruta, Roberta; Nascetti, Giuseppe; Pepe, Gaetano; Mosesso, Pasquale

    2013-04-01

    We validated the alkaline comet assay in two species of land snail (Helix aspersa and Helix vermiculata) to test their suitability as sentinels for primary DNA damage in polluted environments. The study was conducted under the framework of a biomonitoring program for a power station in Central Italy that had recently been converted from oil to coal-fired plant. After optimizing test conditions, the comet assay was used to measure the % Tail DNA induced by in vitro exposure of hemocytes to different concentrations of a reactive oxygen species (H2 O2 ). The treatment induced significant increases in this parameter with a concentration effect, indicating the effectiveness of the assay in snail hemocytes. After evaluating possible differences between the two species, we sampled them in three field sites at different distances from the power station, and in two reference sites assumed to have low or no levels of pollution. No species differences emerged. Percent Tail DNA values in snails from the sites near the power station were higher than those from control sites. An inverse correlation emerged between % Tail DNA and distance from the power station, suggesting that the primary DNA damage decreased as distance increased away from the pollution source. Detection of a gradient of heavy metal concentration in snail tissues suggests that these pollutants are a potential cause of the observed pattern. The comet assay appears to be a suitable assay and Helix spp. populations suitable sentinels to detect the genotoxic impact of pollutants.

  9. Raman spectroscopy as a tool for polyunsaturated compound characterization in gastropod and limnic terrestrial shell specimens

    Science.gov (United States)

    de Oliveira, Leandra N.; de Oliveira, Vanessa E.; D'ávila, Sthefane; Edwards, Howell G. M.; de Oliveira, Luiz Fernando C.

    2013-10-01

    The colours of mollusc shells were determined using the Raman spectroscopy and these analyses suggest that the conjugated polyenes (carotenoids) and psittacofulvins are the organic pigments incorporated into their skeletal structures responsible by their colorations. The symmetric stretching vibration of the carbonate ion gives rise to a very strong Raman band at ca. 1089 cm-1 and a weak band at 705 cm-1, for all samples; the second band characterizes the aragonite as the inorganic matrix and can be used as a marker. The specimens show bands at 1523-1500 and at 1130-1119 cm-1, assigned to the ν1 and ν2 modes of the polyenic chain vibrations, respectively. Another band at 1293 cm-1, assigned to the CHdbnd CH in-plane rocking mode of the olefinic hydrogen is also observed in all samples, which reinforces the psittacofulvin compound as the main pigment present in the analyzed samples.

  10. Evaluation of impairment of DNA in marine gastropod, Morula granulata as a biomarker of marine pollution.

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Bhagat, J.; Sarker, S.

    of electrophilic metabolites which can bind to nucleophilic DNA molecules producing a variety of DNA lesions (Shugart et al., 1989; Shugart, 1999, 1988a, b; Ostling and Contents lists available at ScienceDirect journal homepage: www...

  11. Some ecological aspects and potential threats to an intertidal gastropod, Umbonium vestiarium

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.; Ingole, B.S.; Sen, A

    Kalbadevi Bay in Ratgnairi has been identified as potential site for placer mining along the west coast of India. Since, Umbonium vestiarium is a keystone species of the region; study on some ecological aspect was carried out. The paper also...

  12. Diversity and abundance of epibiota on invasive and native estuarine gastropods depend on substratum and salinity

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Brunbjerg, Ane Kirstine

    2015-01-01

    for the concurrent influence of many environmental factors on epibiota communities. This study aimed to determine the importance of salinity, depth, wave exposure, habitat and shell type for community structure of sessile epibiota in the Swan River Estuary, Western Australia. We quantified the epibiota on 3...... factors. The five factors accounted for 3-34% of the total deviance explained of the models, with shell type and salinity levels being the only significant factors in nine of 14 models. These results highlight an overwhelming importance of shell type and salinity in explaining estuarine epibiota...

  13. Paternity Outcomes in the Freshwater Gastropod, Chilina dombeiana in the Biobío River, Chile

    Science.gov (United States)

    2017-01-01

    Studying the mating system of obligate aquatic organisms that inhabit river ecosystems is important for understanding its evolution as well as the role of biological and environmental factors in modulating population dynamics and species distributional patterns. Here, we studied the reproductive strategy of the Chilean endemic freshwater snail, Chilina dombeiana, in the Biobío River, one of the largest rivers in Chile. This species has a low potential for dispersal given the absence of a free-swimming larval stage (benthic larval development) and given that adults have a low capacity for mobility. We hypothesized that: 1. Females would mate with different males (polyandry) resulting in intrabrood multiple paternity, 2. Individuals from closer sites would be more related than individuals from distant sites, and 3. Male parental contributions would be unevenly distributed within broods. Individuals from three different sites were sampled along the river: upper, mid, and river mouth. In the laboratory, hatching juveniles from a total of 15 broods were collected for paternity analyses. We used microsatellite markers and the programs GERUD and COLONY to determine whether multiple paternity exists and to estimate the contribution of different males to the brood. We found that multiple paternity was very common at all of the sites analyzed with as many as 8 males fertilizing a single female and a mean of 4.2 fathers per brood estimated by COLONY. Sire contribution was skewed to particular males in several broods. In addition, overall relatedness among broods for the three sites ranged from 0.17 to 0.45 with evidence of many half-siblings. Relatedness differed among the three sites. Particularly in upstream sites or in anthropogenically disturbed populations, the high levels of multiple paternity observed in C. dombeiana may be an efficient strategy to avoid inbreeding and prevent the loss of genetic diversity within populations. PMID:28068418

  14. Ocean Warming and CO2-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod

    Directory of Open Access Journals (Sweden)

    Roselyn Valles-Regino

    2015-09-01

    Full Text Available Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO2-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52% with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO2 on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO2 acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted.

  15. Heterophysiasis, an intestinal fluke infection of man and vertebrates transmitted by euryhaline gastropods and fish

    Science.gov (United States)

    Taraschewski, H.

    1984-03-01

    Heterophyes heterophyes, agent of human heterophyiasis in the Near East, is transmitted in marine lagoons and saline inland waters, where the euryhaline intermediate hosts are abundant. In Egypt, mullets, the predominant second intermediate hosts, are customarily consumed raw; thus man becomes infected easily. Symptoms of human infections are usually considered mild. Mullets do not seem to be affected by the metacercariae encysted in the muscles, whereas the growth of the snail host Pirenella conica was found to be enhanced due to the infestation by the trematodes. In laboratory experiments, the flukes were found to be well developed in dogs, foxes and cats, but failed to reach sexual maturity in several other potentially piscivorous mammals and birds. In nature, dogs probably serve as the major reservoir hosts. Heterophyiasis is most prevalent in the Nile Delta, a huge brackish water area which is densely populated by humans and, consequently, also by dogs and cats. In the Far East, besides Heterophyes nocens, several other heterophysids with marine or fresh-water life-cycles are known to infect humans.

  16. The endemic gastropod fauna of Lake Titicaca: correlation between molecular evolution and hydrographic history.

    Science.gov (United States)

    Kroll, Oliver; Hershler, Robert; Albrecht, Christian; Terrazas, Edmundo M; Apaza, Roberto; Fuentealba, Carmen; Wolff, Christian; Wilke, Thomas

    2012-07-01

    Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had a complex history that included at least five major hydrological phases during the Pleistocene. It is generally assumed that these physical events helped shape the evolutionary history of the lake's biota. Herein, we study an endemic species assemblage in Lake Titicaca, composed of members of the microgastropod genus Heleobia, to determine whether the lake has functioned as a reservoir of relic species or the site of local diversification, to evaluate congruence of the regional paleohydrology and the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses indicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital taxa) forms a species flock. A molecular clock analysis suggests that the most recent common ancestor (MRCAs) of the Altiplano taxa evolved 0.53 (0.28-0.80) My ago and the MRCAs of the Altiplano taxa and their extralimital sister group 0.92 (0.46-1.52) My ago. The endemic species of Lake Titicaca are younger than the lake itself, implying primarily intralacustrine speciation. Moreover, the timing of evolutionary branching events and the ages of two precursors of Lake Titicaca, lakes Cabana and Ballivián, is congruent. Although Lake Titicaca appears to have been the principal site of speciation for the regional Heleobia fauna, the contemporary spatial patterns of endemism have been masked by immigration and/or emigration events of local riverine taxa, which we attribute to the unstable hydrographic history of the Altiplano. Thus, a hierarchical distribution of endemism is not evident, but instead there is a single genetic break between two regional clades. We also discuss our findings in relation to studies of other regional biota and suggest that salinity tolerance was the most likely limiting factor in the evolution of Altiplano species flocks.

  17. DNA damage and oxidative stress in marine gastropod Morula granulata exposed to phenanthrene

    Digital Repository Service at National Institute of Oceanography (India)

    Bhagat, J.; Sarkar, A.; Ingole, B.S.

    ., De Jonge, M., & Bervoets, L. (2013). Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata). Sci. Total Environ. 449, 470-481. Campillo, J.A., Albentosa, M., Valdés, N.J., Moreno-González, R., & León, V...

  18. Genotoxic potency of mercuric chloride in gill cells of marine gastropod Planaxis sulcatus using comet assay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhagat, J.; Ingole, B.S.

    In vivo and in vitro exposures were used to investigate the genotoxicity of mercuric chloride (HgCl2) to the marine snail, Planaxis sulcatus. The comet assay protocol was validated on gill cells exposed in vitro to hydrogen peroxide (H...

  19. The evolutionary history of parasitic gastropods and their coral hosts in the Indo-Pacific

    NARCIS (Netherlands)

    Gittenberger, Adriaan

    2006-01-01

    This thesis deals with the associations between parasitic snails and their mushroom coral hosts. Gittenberger has spent 800 hours under water and searched about 60,000 coral discs for these parasites. He dived in Egypt, the Maldives, Thailand, Malaysia, Japan, Palau, the Philippines, Indonesia and A

  20. Accumulation of platinum group elements by the marine gastropod Littorina littorea

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Rachel [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew, E-mail: aturner@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2011-04-15

    The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 {mu}g L{sup -1}) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd {>=} Pt {>=} Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase. - Research highlights: > Platinum group elements are accumulated by, Littorina littorea. > The aqueous phase and diet are important vehicles for Rh and Pd accumulation by the snail. > Grazing molluscs may serve as biomonitors of coastal PGE contamination. - Platinum group elements are accumulated by the marine snail, Littorina littorea, from both the aqueous phase and the diet.

  1. Ocean Warming and CO₂-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod.

    Science.gov (United States)

    Valles-Regino, Roselyn; Tate, Rick; Kelaher, Brendan; Savins, Dale; Dowell, Ashley; Benkendorff, Kirsten

    2015-09-24

    Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO₂-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52%) with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO₂ on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO₂ acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted.

  2. Acute toxicity of ammonia and copper to the gastropod Potamopyrgus jenkinsi (Smith)

    Energy Technology Data Exchange (ETDEWEB)

    Watton, A.J.; Hawkes, H.A.

    1984-01-01

    96-h acute toxicity tests were made, using a flow-through system, to determine the toxicity of ammonia and copper to Potamopyrgus jenkinsi. Both lethal and sub-lethal behavioral responses were monitored for three different age groups of snail - juvenile, prime adult and senescent. Juvenile snails were much less tolerant than adults of both toxicants. Senescent adults were also less tolerant of ammonia than prime adults. 96-h LC/sub 50/ values of 0.315, 0.49 and 0.85 mg N liter/sup -1/ unionized N - NH/sub 3/ and 0.054, 0.079 and 0.077 mg Cu liter/sup -1/ total copper were recorded for juveniles, senescent adults and prime adults, respectively, in separate experiments. EC/sub 50/ values were clearly lower in adult snails. Potamopyrgus jenkinsi was relatively intolerant of both ammonia and copper compared with other invertebrate taxa reported in the literature. It is concluded that Potamopyrgus jenkinsi could be a valuable indicator species of these pollutants. 29 references, 1 figure, 5 tables.

  3. Catalogue systématique des mollusques (gastropodes prosobranches et polyplacophores)

    NARCIS (Netherlands)

    Horst, R.; Schepman, M.M.

    1908-01-01

    La collection conchyliologique du Musée d’Histoire Naturelle des Pays-Bas est d’origine très hétérogène. Au premier lieu elle dérive du Cabinet de Zoologie, d’Anatomie Comparée et de Minéralogie de l’Université de Leide, qui surtout sous la direction du professeur Brugmans (1786—1819) s’était énormé

  4. A gastropod scavenger serving as paratenic host for larval helminth communities in shore crabs

    DEFF Research Database (Denmark)

    Latham, A D M; Fredensborg, Brian Lund; McFarland, L H;

    2003-01-01

    The whelk Cominella glandiformis is an important predator-scavenger of New Zealand intertidal ecosystems; a few whelks can quickly eat all the soft tissues of recently dead crabs. In this study, we demonstrate that whelks can also ingest and act as paratenic hosts for at least 4 helminth species ...

  5. First proteome of the egg perivitelline fluid of a freshwater gastropod with aerial oviposition

    KAUST Repository

    Sun, Jin

    2012-08-03

    Pomacea canaliculata is a freshwater snail that deposits eggs on solid substrates above the water surface. Previous studies have emphasized the nutritional and protective functions of the three most abundant perivitelline fluid (PVF) protein complexes (ovorubin, PV2, and PV3) during its embryonic development, but little is known about the structure and function of other less abundant proteins. Using 2-DE, SDS-PAGE, MALDI TOF/TOF, and LC-MS/MS, we identified 59 proteins from the PVF of P. canaliculata, among which 19 are novel. KEGG analysis showed that the functions of the majority of these proteins are "unknown" (n = 34), "environmental information processing" (10), 9 of which are related to innate immunity, and "metabolism" (7). Suppressive subtractive hybridization revealed 21 PVF genes to be specific to the albumen gland, indicating this organ is the origin of many of the PVF proteins. Further, the 3 ovorubin subunits were identified with 30.2-35.0% identity among them, indicating their common origin but ancient duplications. Characterization of the PVF proteome has opened the gate for further studies aiming to understand the evolution of the novel proteins and their contribution to the switch to aerial oviposition. © 2012 American Chemical Society.

  6. Gastropod diversity, distribution and abundance in habitats with and without anthropogenic disturbances in Lake Victoria, Kenya

    DEFF Research Database (Denmark)

    Lange, C. N.; Kristensen, Thomas K.; Madsen, Henry

    2013-01-01

    species were recorded, 14 from Mbita and 12 from Ndere. Two species, Ferrissia kavirondica and Cleopatra cridlandi, which were recorded only from undisturbed habitats, could be indicators of least disturbed habitats. Water chemistry did differ between fish landing sites and undisturbed habitats at some...

  7. The role of MAPK signaling in patterning and establishing axial symmetry in the gastropod Haliotis asinina

    DEFF Research Database (Denmark)

    Koop, Demian; Richards, Gemma S; Wanninger, Andreas;

    2007-01-01

    , the embryo begins to gastrulate and assumes a bilateral cleavage pattern. Here we inhibit MAPK activation in 3D with U0126 and examine its effect on the formation and patterning of the trochophore, using a suite of territory-specific markers. The head (pretrochal) region appears to maintain quadri......-radial symmetry in U0126-treated embryos, supporting a role for MAPK signaling in 3D in establishing dorsoventral polarity in this region. Posterior (posttrochal) structures - larval musculature, shell and foot--fail to develop in MAPK inhibited trochophores. Inhibition of 3D specification by an alternative...... method--monensin treatment--yields similar abnormal trochophores. However, genes that are normally expressed in the ectodermal structures (shell and foot) are detected in U0126- and monensin-perturbed larvae in patterns that suggest that this region has latent dorsoventral polarity that is manifested...

  8. Redescription of the meiofaunal gastropod Parhedyle cryptophthalma, with focus on nervous system and sensory organs

    DEFF Research Database (Denmark)

    Jörger, Katharina M.; Kristof, Alen; Klussmann-Kolb, Annette

    2010-01-01

    Parhedyle cryptophthalma (Westheide & Wawra, 1974) is a poorly known meiofaunal slug from the Mediterranean, inhabiting intertidal sands under direct wave impact. The present study is the first redescription of the acochlid P. cryptophthalma, confirming original results on general morphology, int...

  9. The gastropod menace: slugs on Brassica plants affect caterpillar survival through consumption and interference with parasitoid attraction

    Science.gov (United States)

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small ...

  10. Reduced genetic diversity and increased reproductive isolation follow population-level loss of larval dispersal in a marine gastropod.

    Science.gov (United States)

    Ellingson, Ryan A; Krug, Patrick J

    2016-01-01

    Population-level consequences of dispersal ability remain poorly understood, especially for marine animals in which dispersal is typically considered a species-level trait governed by oceanographic transport of microscopic larvae. Transitions from dispersive (planktotrophic) to nondispersive, aplanktonic larvae are predicted to reduce connectivity, genetic diversity within populations, and the spatial scale at which reproductive isolation evolves. However, larval dimorphism within a species is rare, precluding population-level tests. We show the sea slug Costasiella ocellifera expresses both larval morphs in Florida and the Caribbean, regions with divergent mitochondrial lineages. Planktotrophy predominated at 11 sites, 10 of which formed a highly connected and genetically diverse Caribbean metapopulation. Four populations expressed mainly aplanktonic development and had markedly reduced connectivity, and lower genetic diversity at one mitochondrial and six nuclear loci. Aplanktonic dams showed partial postzygotic isolation in most interpopulation crosses, regardless of genetic or geographic distance to the sire's source, suggesting that outbreeding depression affects fragmented populations. Dams from genetically isolated and neighboring populations also exhibited premating isolation, consistent with reinforcement contingent on historical interaction. By increasing self-recruitment and genetic drift, the loss of dispersal may thus initiate a feedback loop resulting in the evolution of reproductive isolation over small spatial scales in the sea.

  11. Mechanisms driving diversity-productivity relationships differ between exotic and native communities and are affected by gastropod herbivory.

    Science.gov (United States)

    Korell, Lotte; Schmidt, Robin; Bruelheide, Helge; Hensen, Isabell; Auge, Harald

    2016-04-01

    Biodiversity experiments have shown that productivity usually increases with plant species richness. However, most of those studies disregarded the importance of trophic interactions to the diversity-productivity relationship, and focused on the loss of native species while ignoring invasions by exotic species. Yet, as functional complementarity and the impact of plant antagonists are likely to differ between native and exotic communities, the diversity-productivity relationship may change when native communities are invaded by exotic species. We conducted a mesocosm experiment to test how diversity effects, evenness, and productivity differed between exotic and native assemblages of grassland plants, and how these communities were influenced by slug herbivory. In line with other experiments, we found higher productivity in exotic than in native communities. However, different mechanisms (complementarity vs. selection effect) contributed to the positive diversity-productivity relationships in exotic vs. native communities. Against expectations, native communities showed much lower evenness and a greater selection effect, suggesting that competitive dominance among native species may be even stronger than among exotic species. Slug herbivory decreased productivity independently of species origin and species diversity. However, exotic communities showed a threefold higher complementarity effect than native communities in the absence of slugs, which was mainly driven by differences in the responses of native and exotic legumes and nonleguminous herbs. Our results imply that underlying mechanisms for the positive diversity-productivity relationship differ between native and exotic communities in the early stages of community development, and that differential responses of plant functional groups to generalist herbivory can contribute to this pattern.

  12. Conservation of ParaHox genes' function in patterning of the digestive tract of the marine gastropod Gibbula varia

    Directory of Open Access Journals (Sweden)

    Steiner Gerhard

    2010-07-01

    Full Text Available Abstract Background Presence of all three ParaHox genes has been described in deuterostomes and lophotrochozoans, but to date one of these three genes, Xlox has not been reported from any ecdysozoan taxa and both Xlox and Gsx are absent in nematodes. There is evidence that the ParaHox genes were ancestrally a single chromosomal cluster. Colinear expression of the ParaHox genes in anterior, middle, and posterior tissues of several species studied so far suggest that these genes may be responsible for axial patterning of the digestive tract. So far, there are no data on expression of these genes in molluscs. Results We isolated the complete coding sequences of the three Gibbula varia ParaHox genes, and then tested their expression in larval and postlarval development. In Gibbula varia, the ParaHox genes participate in patterning of the digestive tract and are expressed in some cells of the neuroectoderm. The expression of these genes coincides with the gradual formation of the gut in the larva. Gva-Gsx patterns potential neural precursors of cerebral ganglia as well as of the apical sensory organ. During larval development this gene is involved in the formation of the mouth and during postlarval development it is expressed in the precursor cells involved in secretion of the radula, the odontoblasts. Gva-Xolx and Gva-Cdx are involved in gut patterning in the middle and posterior parts of digestive tract, respectively. Both genes are expressed in some ventral neuroectodermal cells; however the expression of Gva-Cdx fades in later larval stages while the expression of Gva-Xolx in these cells persists. Conclusions In Gibbula varia the ParaHox genes are expressed during anterior-posterior patterning of the digestive system. This colinearity is not easy to spot during early larval stages because the differentiated endothelial cells within the yolk permanently migrate to their destinations in the gut. After torsion, Gsx patterns the mouth and foregut, Xlox the midgut gland or digestive gland, and Cdx the hindgut. ParaHox genes of Gibbula are also expressed during specification of cerebral and ventral neuroectodermal cells. Our results provide additional support for the ancestral complexity of Gsx expression and its ancestral role in mouth patterning in protostomes, which was secondarily lost or simplified in some species.

  13. Comparative assessment of reproductive impairment in the gastropod mollusc Littorina littorea along the Belgian North Sea coast.

    Science.gov (United States)

    Van den Broeck, Heidi; De Wolf, Hans; Backeljau, Thierry; Blust, Ronny

    2009-04-01

    In this study we present the results of an intersex survey of Littorina littorea along the Belgian coast. Levels of female intersex and sterility were determined to assess TBT related adverse effects. In addition, we determined the levels of male penis shedding and trematode infestation and investigated the morphology of the shell. Significant differences were found for all these variables which clearly differentiated periwinkles from Zeebrugge (B2) from those at other locations. Intersex index (ISI) values were relatively low (i.e. 0.00-0.39), except at B2 where they ranged up to 3.52, the highest value ever reported in literature. Consequently, female reproductive impairment at B2 was severe. Indeed, up to 95% of female periwinkles were sterile at B2. In addition, 61% of the male periwinkles had shed their penis. Furthermore, no trematode infestation could be detected at B2 and specimens from this location had the largest and heaviest shells, which may be related to population demography and/or a different use of energy budgets.

  14. Quaternary gastropods in Raoping, Guangdong%广东饶平海山区第四纪腹足类

    Institute of Scientific and Technical Information of China (English)

    冯伟民; 张素萍; 黄宝玉; 马锈同; 林碧萍; 张偲

    2005-01-01

    首次报道了广东饶平海山区腹足类.经整理和分类研究,共鉴定出腹足类16科25属30种.这些种均为现生分布种,主要分布在中国沿海,特别是浙江以南海区,少数分布在黄海较北部海区.大多数种类栖息于低潮线至浅海几十米水深的沙泥质或泥沙质海底,也出现一些潮间带岩礁栖息型种类.可能反映了具较高海水能量的浅水沉积环境.根据动物群的组合特征,它们应为第四纪全新世的产物.

  15. [Plasticity of stastocyst inertial mass in terraneous gastropods helix lucorum and pomatias rivulare in altering gravitational field (microgravity, hypergravity)].

    Science.gov (United States)

    Gorgiladze, G I; Bukiia, R D; Kalandarishvili, É L; Korotkova, E V; Taktakishvili, A D; Davitashvili, M T; Gelashvili, N Sh

    2011-01-01

    Light and scanning electron microscopy was used to study the morphological parameters and ultrastructure of Helix lucorum statocysts and statoliths in Pomatias rivulare statocysts after 56, 93 and 110-day exposure to microgravity aboard the ISS. Increased gravity was simulated by 30-d centrifugation at 6 g. On the first day of recovery, many statoconia and statoliths were found to carry numerous warts. Moreover, statoconia grew in number significantly as compared with the ground control. On the contrary centrifugation caused massive destruction of statoconia. In a month after orbital flight and centrifugation morphology of both statoconia and stastoliths was nearly normal. These results evidence, that the gravitational field is an important factor for the abiotic medium responsible for building up the inertial mass in the equilibrium organ of animals.

  16. Impact of the exotic gastropod Melanoides tubercula on native molluscan fauna at Springs National Wildlife Refuge, Utah

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report discusses changes in numbers of individual molluscan species at Fish Springs National Wildlife Refuge. It was concluded that changes cannot be ascribed...

  17. Modelling effects of diquat under realistic exposure patterns in genetically differentiated populations of the gastropod Lymnaea stagnalis.

    Science.gov (United States)

    Ducrot, Virginie; Péry, Alexandre R R; Lagadic, Laurent

    2010-11-12

    Pesticide use leads to complex exposure and response patterns in non-target aquatic species, so that the analysis of data from standard toxicity tests may result in unrealistic risk forecasts. Developing models that are able to capture such complexity from toxicity test data is thus a crucial issue for pesticide risk assessment. In this study, freshwater snails from two genetically differentiated populations of Lymnaea stagnalis were exposed to repeated acute applications of environmentally realistic concentrations of the herbicide diquat, from the embryo to the adult stage. Hatching rate, embryonic development duration, juvenile mortality, feeding rate and age at first spawning were investigated during both exposure and recovery periods. Effects of diquat on mortality were analysed using a threshold hazard model accounting for time-varying herbicide concentrations. All endpoints were significantly impaired at diquat environmental concentrations in both populations. Snail evolutionary history had no significant impact on their sensitivity and responsiveness to diquat, whereas food acted as a modulating factor of toxicant-induced mortality. The time course of effects was adequately described by the model, which thus appears suitable to analyse long-term effects of complex exposure patterns based upon full life cycle experiment data. Obtained model outputs (e.g. no-effect concentrations) could be directly used for chemical risk assessment.

  18. A review of the Polystira clade--the Neotropic's largest marine gastropod radiation (Neogastropoda: Conoidea: Turridae sensu stricto).

    Science.gov (United States)

    Todd, Jonathan A; Rawlings, Timothy A

    2014-11-18

    The Polystira clade (here comprising Polystira and Pleuroliria) is a poorly known but hyper-diverse clade within the neogastropod family Turridae (sensu stricto). It has extensively radiated within the tropics and subtropics of the Americas, to which it is endemic. In this paper we present a synthetic overview of existing information on this radiation together with new information on estimated species diversity, systematic relationships, a species-level molecular phylogenetic analysis and preliminary macroecological and diversification analyses, to serve as a platform for further study. We currently estimate that about 300 species (122 extant) are known from its 36 million year history but this number will undoubtedly increase as we extend our studies. We discuss the relationships of Polystira to other Neotropical Turridae (s.s.) and examine the taxonomy and systematics of the geologically oldest described members of the clade. To aid taxonomic description of shells we introduce a new notation for homologous major spiral cords. Focusing on key publications, we discuss in detail the changing historical understanding of the taxonomy of the clade and the relationships of its component genus-level taxa: Polystira Woodring, 1928, Pleuroliria de Gregorio, 1890, Josephina Gardner, 1945 and Oxytropa Glibert, 1955. We designate a neotype for Pleurotoma (Pleuroliria) supramirifica de Gregorio, 1890, to stabilize our understanding of this, the type species of Pleuroliria. Application of the name Oxytropa is restricted to the type species. The genus Polystira is conchologically re-described and for the first time we synthesize available information on the anatomy, feeding and toxinology, reproduction and life history, larval modes and life habits, and geographic and bathymetric ranges of its species. We give an updated list of the 19 formally described living species and present the pitfalls of the currently poor species-level taxonomy of Polystira using case examples. We present a molecular phylogenetic analysis of 22 extant species using three mitochondrial gene fragments (COI, 12S rRNA and 16S rRNA). This reveals undescribed species and indicates that Recent genetic clades ('biospecies') are consistent with finely divided conchological 'morphospecies'. Historically, there has been a slow realisation of the high species diversity of the Polystira clade and we consider that this may be due to inadequate precision of morphological description of shells and a lack of clear homology statements. We suggest how these both might be improved. Finally, using a data compilation based on museum specimens we examine species range-size distributions and species abundance distributions for 85 of the 112 extant western Atlantic species that we have delimited to date. Our results indicate that the majority of species are rare and have short geographic ranges; only a few are wide-ranging and abundant. This has important implications for surveys of biodiversity.

  19. An integrated approach to study the biomarker responses in marine gastropod Nerita chamaeleon environmentally exposed to polycyclic aromatic hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Bhagat, J.; Sarkar, A.; Deepti, V.; Singh, V.; Raiker, L.; Ingole, B.S.

    from 5.29 - 12.14 μg/g wet weight. Standardized values of biomarker response were visualized using star plots, which show unique patterns for different biomarkers. The mean IBR value was found to be highest at Dona Paula (8.07 ± 0.91) followed...

  20. C-terminal functional unit of Rapana thomasiana (marine snail, gastropod) hemocyanin isoform RtH1: isolation and characterization.

    Science.gov (United States)

    Parvanova, Katja; Idakieva, Krassimira; Todinova, Svetla; Genov, Nicolay

    2003-09-23

    Rapana thomasiana hemocyanin (RtH) is a mixture of two hemocyanin (Hc) isoforms termed RtH1 and RtH2. Both subunit types are built up of eight functional units (FUs). The C-terminal functional unit (RtH1-h) of the Rapana Hc subunit 1 has been isolated by limited trypsinolysis of the subunit polypeptide chain. The oxy- and apo-forms of the unit are characterized by fluorescence spectroscopy. Upon excitation of RtH1-h at 295 or 280 nm, tryptophyl residues buried in the hydrophobic interior of the protein globule determine the fluorescence emission. This is confirmed by quenching experiments with acrylamide, cesium chloride and potassium iodide. The copper-dioxygen system at the binuclear active site quenches the indole emission of the oxy-RtH1-h. The removal of this system increases the fluorescence quantum yield and causes structural rearrangement of the microenvironment of the emitting tryptophyl residues in the apo-RtH1-h. The thermal stability of the apo-RtH1-h is characterized fluorimetrically by the "melting" temperature T(m) (65 degrees C) and by the transition temperature T(m) (83 degrees C) obtained by differential scanning calorimetry for oxy-RtH1-h. The results confirm the role of the copper-dioxygen complex for the stabilization of the Hc structure in solution.

  1. Interclonal variation in the acute and delayed toxicity of cadmium to the European prosobranch gastropod Potamopyrgus antipodarum (Gray).

    Science.gov (United States)

    Jensen, A; Forbes, V E

    2001-02-01

    The lethal responses of three European clones--A, B, and C-of the prosobranch snail Potamopyrgus antipodarum to acute cadmium exposure were examined by the use of a conventional LC50 test and a delayed toxicity test. The questions addressed were: (1) Are there differences in susceptibility (LC50 values and uniformity of response) among the three European clones of P. antipodarum? (2) Are the patterns of differences in susceptibility among clones observed in the LC50 test also observed for the delayed toxicity test? (3) Is there concordance in the ranking of susceptibility among clones under acute cadmium exposure and under chronic cadmium exposure? The results showed that the widths of the tolerance distribution differed among clones. Clones A and B had a steeper slope than clone C (for clone A the difference was marginally significant), which indicates that individuals from clones A and B showed a more uniform response to acute lethal cadmium stress than individuals from clone C. On the basis of the measured differences in LC50 values, clone A individuals showed the highest tolerance to acute cadmium (LC50 value: 1.92 mg Cd L(-1)) followed by clone B (LC50 value: 1.29 mg Cd L(-1)) and clone C (LC50 value: 0.56 mg Cd L(-1)). Clone C was significantly less tolerant than clones A and B. The delayed toxicity test showed a similar pattern to the LC50 test with regard to tolerance differences among clones; however, mortality continued following transfer to clean water, indicating that cadmium was lethal at much lower concentrations than indicated by the conventional LC50 test. Results of the LC50 test and the delayed toxicity test in the present study were in general agreement with results from chronic cadmium exposure experiments (Jensen et al. [2000] Ecol Appl [submitted]), i.e., the least susceptible clone A in the acute cadmium exposure test was also the least susceptible clone in the chronic cadmium exposure test. Based on the dramatic differences between the LC50 and the cadmium exposure concentrations causing delayed toxicity, we suggest that the potential for delayed toxicity should be given greater consideration in ecotoxicity testing.

  2. Comparing the efficacy of morphologic and DNA-based taxonomy in the freshwater gastropod genus Radix (Basommatophora, Pulmonata

    Directory of Open Access Journals (Sweden)

    Streit Bruno

    2006-11-01

    Full Text Available Abstract Background Reliable taxonomic identification at the species level is the basis for many biological disciplines. In order to distinguish species, it is necessary that taxonomic characters allow for the separation of individuals into recognisable, homogeneous groups that differ from other such groups in a consistent way. We compared here the suitability and efficacy of traditionally used shell morphology and DNA-based methods to distinguish among species of the freshwater snail genus Radix (Basommatophora, Pulmonata. Results Morphometric analysis showed that shell shape was unsuitable to define homogeneous, recognisable entities, because the variation was continuous. On the other hand, the Molecularly defined Operational Taxonomic Units (MOTU, inferred from mitochondrial COI sequence variation, proved to be congruent with biological species, inferred from geographic distribution patterns, congruence with nuclear markers and crossing experiments. Moreover, it could be shown that the phenotypically plastic shell variation is mostly determined by the environmental conditions experienced. Conclusion Contrary to DNA-taxonomy, shell morphology was not suitable for delimiting and recognising species in Radix. As the situation encountered here seems to be widespread in invertebrates, we propose DNA-taxonomy as a reliable, comparable, and objective means for species identification in biological research.

  3. Susceptibility of 7 freshwater gastropod species in Zimbabwe to infection with Gastrodiscus aegyptiacus (Cobbold, 1876 Looss, 1896 : short communication

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    S. Mukaratirwa

    2004-06-01

    Full Text Available Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1 of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. Pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments.

  4. 78 FR 78783 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

    Science.gov (United States)

    2013-12-27

    ... gastropods, commonly referred to as whelks, conchs, and snails. This temporary rule, first published in 2005.... In addition, this emergency rule also prohibits the harvest of gastropods from the Temporary PSP... closure does not include gastropods. Gastropods include carnivorous snails, conchs, and whelks that...

  5. Molecular cloning of precursors for TEP-1 and TEP-2: The GGNG peptide-related peptides of a prosobranch gastropod, Thais clavigera.

    Science.gov (United States)

    Morishita, Fumihiro; Furukawa, Yasuo; Kodani, Yu; Minakata, Hiroyuki; Horiguchi, Toshihiro; Matsushima, Osamu

    2015-06-01

    TEP (Thais excitatory peptide)-1 and TEP-2 are molluscan counterparts of annelidan GGNG-peptides, identified in a neogastropod, Thais clavigera (Morishita et al., 2006). We have cloned two cDNAs encoding TEP-1 and TEP-2 precursor protein, respectively, by the standard molecular cloning techniques. Predicted TEP-1 precursor protein consists of 161 amino acids, while predicted TEP-2 precursor protein has 118 amino acids. Only a single copy of TEP was found on the respective precursor. The semi-quantitative RT-PCR showed that expression of TEP-1 was high in sub-esophageal, pleural, pedal and visceral ganglia, while it was low in supra-esophageal ganglion. By contrast, expression level of TEP-2 was high in pedal and visceral ganglia. In situ hybridization visualized different subsets of TEP-1 and TEP-2 expressing neurons in Thais ganglia. For example, supra-esophageal ganglion contained many TEP-2 expressing neuron, but not TEP-1 expressing ones. These results suggest that expression of TEP-1 and TEP-2 is differently regulated in the Thais ganglia.

  6. Collagen study and regulation of the de novo synthesis by IGF-I in hemocytes from the gastropod mollusc, Haliotis tuberculata.

    Science.gov (United States)

    Serpentini, A; Ghayor, C; Poncet, J M; Hebert, V; Galéra, P; Pujol, J P; Boucaud-Camou, E; Lebel, J M

    2000-09-01

    To evidence a collagen synthesis and identify which type(s) of collagen is present in hemocytes from the mollusc Haliotis tuberculata, we have performed three separate approaches, namely, de novo synthesis by cultured cells, immunological approaches, and northern blot analysis. We demonstrated first that after 40-hr labeling, the de novo synthesis of collagen in the cell layer of cultured hemocytes represents 9.48 +/- 1.25% with respect to the total [(3)H]proline-labeled protein synthesis. In addition, IGF-I elicited a significant stimulation of collagen synthesis in cultured hemocytes in a dose-dependent manner from 10(-10) to 10(-8) M. The maximal stimulation (10(-9) M) induced an increase of 286 +/- 56% with respect to 100% control. By immunocytochemistry and immunoblotting, we showed that hemocytes present immunoreactive molecules to antibodies directed against the type I fibrillar collagen. In addition, using as a probe Hf 677 corresponding to a human pro alpha1(I) collagen cDNA and which encompasses the (Gly-X-Y) repeated sequence found in all Metazoa, four collagen transcripts of approximately 6.4, 5, 2.2, and 2 kb in length have been detected. These data suggest the presence of fibrillar type I collagen in hemocytes and are compatible with the concept that these cells are involved in the extracellular matrix deposition, a cardinal function in tissue repair as well as in developmental processes. Our model may appear as an excellent system to study the role of growth factors on the regulation of collagen synthesis by molluscan hemocytes. J. Exp. Zool. 287:275-284, 2000.

  7. Preliminary observations on the effects of vector-averaged gravity on the embryonic and larval development of the gastropod mollusk, Ilyanassa obsoleta Stimpson

    Science.gov (United States)

    Conrad, G. W.; Stephens, A. P.; Conrad, A. H.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    Fertilized eggs of Ilyanassa obsoleta Stimpson were collected immediately after their deposition in egg capsules. Unopened egg capsules then were affixed to glass slides, and incubated either statically (controls) or on a clinostat (experimentals). After incubation for 9-14 days, hatching occurred sooner and in a higher percentage of clinostated capsules than in controls. Embryos that hatched while undergoing clinostat incubation were abnormal in morphology, whereas other embryos present in non-hatched capsules in the same tubes appeared normal, as did embryos in the control tubes. Although the results are compatible with a conclusion that vector-averaged gravity in the experimental tubes caused the altered development, some other aspects of how the incubations were done may have contributed to the differences between the control and experimental results.

  8. Evaluation of impairment of DNA integrity in marine gastropods (Cronia contracta) as a biomarker of genotoxic contaminants in coastal water around Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Gaitonde, D.C.S.; Sarkar, Amit; Vashistha, D.; DeSilva, C.; Dalal, S.G.

    was evaluated in terms of the loss of DNA integrity (expressed as the value of 'I') in marine snails with respect to those from the reference site (Palolem) over a period from April 2004 to May 2005 using the technique of alkaline unwinding assay. The DNA...

  9. Duration of pairing and use of allosperm in Biomphalaria glabrata (Gastropoda: Planorbidae Duração do acasalamento e uso do aloesperma em Biomphalaria glabrata (Gastropode: Planorbidae

    Directory of Open Access Journals (Sweden)

    Marc Vianey-Liaud

    1989-03-01

    Full Text Available Virgin homozygous black pigmented and albino Biomphalaria glabrata are paired during a period varying from 1 to 20 days. The rate of cross-fertilized parents is statistically similar for the various lengths of pairing. As a whole, nearly 80% of the albino snails produce a pigmented progeny. This production begins as soon as the snails are mated and continues after their separation. To measure the actual use of the allosperm, its use during the postmating period must be added to the length of mating. So, it appears that the real use of the allosperm is statistically constant (mean slightly inferior to 8 weeks and not related to the length of the previous pairing.Espécimes virgens de Biomphalaria glabrata (um melâncio e um albino são acasalados durante um período variável de 1 a 20 dias. A proporção de espécimes parentais albinos fecundados por cruzamento é semelhante estatisticamente para os diversos períodos de acasalamento. Em conjunto, cerca de 80% dos albinos produziram descendência pigmentada. Essa produção começa assim que os moluscos são acasalados e continua depois que são separados. Para medir a utilização real do aloesperma, sua utilização durante o período de pós-acasalamento. Parece, assim, que a utilização real do aloesperma é estatisticamente constante (média ligeiramente inferior a oito semanas e não relacionada a duração do acasalamento anterior.

  10. Contribution of planktonic and benthic food sources to the diet of the reef-forming vermetid gastropod Dendropoma petraeum in the western Mediterranean

    Science.gov (United States)

    Vizzini, Salvatrice; Colombo, Francesca; Costa, Valentina; Mazzola, Antonio

    2012-01-01

    In the Mediterranean Sea, the vermetid Dendropoma petraeum (Monterosato, 1884) forms highly biodiverse reefs that have received increasing attention in recent years although very little is known about the food habit of this species. The main goal of this study was to describe the trophic role of planktonic and benthic food sources for D. petraeum. Specimens from three morphological zones of the reef (inner edge, cuvette and outer edge) at two sites with different wave exposure along the north-western coast of Sicily (Italy; western Mediterranean) were compared for δ 13C and δ 15N. Isotopic determinations were also carried out on potential food sources identified in epilithon, reef macroalgae and suspended particulate organic matter. δ 13C for D. petraeum showed significantly more depleted values in the more exposed conditions (i.e. the site with higher wave exposure and outer edge of the reef), while δ 15N did not differ appreciably. These results suggest greater exploitation of benthic sources in the sheltered than in the exposed site and reveal diet shift and trophic flexibility at a small spatial scale for the reef-former D. petraeum.

  11. Gastropod Shells from Excavations of the “Antic Forum” Complex in the City Of Plovdiv (Bulgaria: IV-VI Century

    Directory of Open Access Journals (Sweden)

    Rumen Ivanov

    2016-06-01

    Full Text Available Total of 35 shells were found and identified during the archeological excavations 2012-2014, studied Slavic dwellings-dugouts which reuse earlier structures of the roman forum inPlovdiv, Bulgaria. From both localities shells from 7 species of snails were found. Most of the shellswere from two species: Zebrina detrita and Helix philibinensis – total of 28 shells, other wererepresented by 1-3 specimens per species. The lack of shell materials from Eobania vermiculatasupports the theory of later introduction of this species in the city of Plovdiv.

  12. 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.

    Science.gov (United States)

    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.

  13. 有机锡污染与海产腹足类性畸变%Tributyltin (TBT) pollution and imposex in marine gastropod

    Institute of Scientific and Technical Information of China (English)

    施华宏; 黄长江

    2001-01-01

    综述了海产腹足类性畸变发生的原因和形态变化,并对利用海产腹足类性畸变进行有机锡污染的生物监测、海产腹足类性畸变的生态毒理学等方面的研究进展及我国的研究现状作了详细的介绍.

  14. Freshwater gastropods of the Baixada Maranhense Microregion, an endemic area for schistosomiasis in the State of Maranhão, Brazil: I - qualitative study

    Directory of Open Access Journals (Sweden)

    Selma Patricia Diniz Cantanhede

    2014-01-01

    Full Text Available Introduction: The Baixada Maranhense Microregion currently has the highest prevalence of schistosomiasis in the State of Maranhão, likely because this parasitosis is characterized as an occupational disease, and increased contact with water increases the risk of infection by Schistosoma mansoni. This paper reports the results of the first comprehensive freshwater malacological survey performed in the Baixada Maranhense Microregion. Methods: Freshwater mollusks were collected from the twenty-one municipalities of the Baixada Maranhense Microregion and from Bacurituba and Cajapió and were evaluated for infection by trematodes. Results: A total of 9,129 mollusks were collected (sixteen species, which included the first records of six species in the State of Maranhão: Gundlachia radiata, G. ticaga, Hebetancylus moricandi, Plesiophysa guadeloupensis, Pomacea bridgesii diffusa and Omalonyx sp. Biomphalaria glabrata was found in five municipalities, whereas B. straminea was found in nine. Biomphalaria glabrata and B. straminea were observed in syntopy in Pinheiro and São Bento. Of the 990 specimens of B. glabrata and the 2,109 specimens of B. straminea that were exposed to and/or analyzed for the presence of larval trematodes, only a single specimen of B. glabrata (0.1% from São Bento shed S. mansoni. Other larval trematodes were first observed in mollusks from the State of Maranhão. Conclusions: These results indicate that the study area is epidemiologically important due to the presence of two natural vectors of schistosomiasis and the active transmission of schistosomiasis, which was confirmed in the infected specimen that was collected in this study.

  15. Species Diversity of Soil Gastropods from Changbai Mountain%长白山土壤腹足类物种多样性初步研究

    Institute of Scientific and Technical Information of China (English)

    王忠明; 张卫红; 陈德牛

    2004-01-01

    自1993年5月至10月对吉林长白山森林生态系统定位站的土壤腹足类进行了多样性调查.据初步调查的结果显示,长白山地区土壤腹足类种类少而单调,采样区仅发现15种,隶属于腹足纲9科13属.采样区土壤腹足类物种多样性指数和丰富度指数都是5月份最低,8月份达最大值,之后逐渐减小;均匀度指数5月份最高,7月份最低;单纯度指数也是5月份最高,最低值出现在10月份.土壤表层的陆生贝类物种多样性指数高于上层.

  16. AN INVESTIGATION ON THE STARVATION METABOLISM OF FOUR GASTROPODS%四种底栖螺类饥饿代谢的研究

    Institute of Scientific and Technical Information of China (English)

    闫云君; 梁彦龄

    2005-01-01

    研究了四种常见优势底栖螺类的饥饿代谢(R,mgO2/jnd.d)与温度(T,℃)、体重(Wd,mg dry-wt或Ww,mg wetwt)的关系,并计算出三者间的复合关系,分别是:铜锈环棱螺,R=0.044Wd0.537e0.061T;长角涵螺,R=0.0004WW09405·e0.0735T;纹沼螺,R=0.004Wd1.072e0.091T;短沟蜷,R=0.023Wd0.777e0042T.

  17. Methods for analysis of organotin compounds in marine gastropods%海产腹足类有机锡化合物的检测方法

    Institute of Scientific and Technical Information of China (English)

    黄长江; 雷瓒; 董巧香

    2005-01-01

    三丁基锡(TBT)等有机锡化合物因其毒性及结构上的特点被广泛应用于船舶、网箱渔排等的防污涂料中.它的主要作用是在水体中持久地释放出可以有效杀死海洋污损生物的毒性物质,从而达到防护船舶、渔排等体表的目的,然而进入海洋环境的有机锡化合物在防污的同时也会影响到许多非靶生物,

  18. 海产腹足类性畸变现象的形态特征%Morphological characters of imposex in marine gastropod

    Institute of Scientific and Technical Information of China (English)

    施华宏; 黄长江

    2001-01-01

    本文选取我国东南沿海的重要港口海口、北海、湛江、汕头和厦门港等作为海产腹足类性畸变现象的现场调查区,结果发现有11种海产腹足类存在性畸变.文中对分布广泛、易采集、性畸变现象普遍的疣荔枝螺的性畸变特征的解剖观察结果进行了详细的描述,同时对其他几种海产腹足类性畸变特征作了对比.根据研究结果将疣荔枝螺性畸变雌体的阴茎和输精管的畸变程度划分为5个阶段.

  19. Development of partial life-cycle experiments to assess the effects of endocrine disruptors on the freshwater gastropod Lymnaea stagnalis: a case-study with vinclozolin.

    Science.gov (United States)

    Ducrot, Virginie; Teixeira-Alves, Mickaël; Lopes, Christelle; Delignette-Muller, Marie-Laure; Charles, Sandrine; Lagadic, Laurent

    2010-10-01

    Long-term effects of endocrine disruptors (EDs) on aquatic invertebrates remain difficult to assess, mainly due to the lack of appropriate sensitive toxicity test methods and relevant data analysis procedures. This study aimed at identifying windows of sensitivity to EDs along the life-cycle of the freshwater snail Lymnaea stagnalis, a candidate species for the development of forthcoming test guidelines. Juveniles, sub-adults, young adults and adults were exposed for 21 days to the fungicide vinclozolin (VZ). Survival, growth, onset of reproduction, fertility and fecundity were monitored weekly. Data were analyzed using standard statistical analysis procedures and mixed-effect models. No deleterious effect on survival and growth occurred in snails exposed to VZ at environmentally relevant concentrations. A significant impairment of the male function occurred in young adults, leading to infertility at concentrations exceeding 0.025 μg/L. Furthermore, fecundity was impaired in adults exposed to concentrations exceeding 25 μg/L. Biological responses depended on VZ concentration, exposure duration and on their interaction, leading to complex response patterns. The use of a standard statistical approach to analyze those data led to underestimation of VZ effects on reproduction, whereas effects could reliably be analyzed by mixed-effect models. L. stagnalis may be among the most sensitive invertebrate species to VZ, a 21-day reproduction test allowing the detection of deleterious effects at environmentally relevant concentrations of the fungicide. These results thus reinforce the relevance of L. stagnalis as a good candidate species for the development of guidelines devoted to the risk assessment of EDs.

  20. Dynamic energy budget as a basis to model population-level effects of zinc-spiked sediments in the gastropod Valvata piscinalis.

    Science.gov (United States)

    Ducrot, Virginie; Péry, Alexandre R R; Mons, Raphaël; Quéau, Hervé; Charles, Sandrine; Garric, Jeanne

    2007-08-01

    This paper presents original toxicity test designs and mathematical models that may be used to assess the deleterious effects of toxicants on Valvata piscinalis (Mollusca, Gastropoda). Results obtained for zinc, used as a reference toxicant, are presented. The feeding behavior, juvenile survival, growth, age at puberty, onset of reproduction, number of breedings during the life cycle, and fecundity were significantly altered when the snails were exposed to zinc-spiked sediments. Dynamic energy budget models (DEBtox) adequately predicted the effects of zinc on the V. piscinalis life cycle. They also provided estimates for lifecycle parameters that were used to parameterize a demographic model, based on a Z-transformed life-cycle graph. The effect threshold for the population growth rate (lambda) was estimated at 259 mg/kg dry sediment of zinc, showing that significant changes in abundance may occur at environmental concentrations. Significant effects occurring just above this threshold value were mainly caused by the severe impairment of reproductive endpoints. Sensitivity analysis showed that the value of lambda depended mainly on the juvenile survival rate. The impairment of this latter parameter may result in extinction of V. piscinalis. Finally, the present study highlights advantages of the proposed modeling approach in V. piscinalis and possible transfer to other test species and contaminants.

  1. Accumulation and detoxication responses of the gastropod Lymnaea stagnalis to single and combined exposures to natural (cyanobacteria) and anthropogenic (the herbicide RoundUp® Flash) stressors

    DEFF Research Database (Denmark)

    Lance, Emilie; Desprat, J.; Holbech, B. F.

    2016-01-01

    metabolites. The GST activity was induced by RoundUp® Flash alone or in combination with non MC-producing cyanobacteria, but was inhibited by MC-producing cyanobacteria with or without RoundUp® Flash. Moreover, MC accumulation in L. stagnalis was 3.2 times increased when snails were concomitantly exposed...... to MC-producing cyanobacteria with RoundUp®, suggesting interacting effects of MCs on biotransformation processes. The potent inhibition of detoxication systems by MCs and RoundUp® Flash was reversible during the depuration, during which CAT and GST activities were significantly higher in snails...... previously exposed to MC-producing cyanobacteria with or without RoundUp® Flash than in other conditions, probably related to the oxidative stress caused by accumulated MCs remaining in tissues. © 2016 Elsevier B.V....

  2. Palaeartic gastropod gains a foothold in the dominion of endemics: range expansion and morphological change of Lymnaea (Radix) auricularia in Lake Baikal

    NARCIS (Netherlands)

    M. Stift; E. Michel; N.L. Sitnikova; Y. Mamonova; D.Y. Sherbakov

    2004-01-01

    In and around the endemic-dominated Lake Baikal, palaearctic species are generally restricted to shallow, sheltered bays and in- and out-flowing river floodplains. However, we observed populations of the palaearctic snail Lymnaea (Radix) auricularia on the steep, rocky littoral of Lake Baikal proper

  3. Gastropod (Otala lactea) shell nanomechanical and structural characterization as a biomonitoring tool for dermal and dietary exposure to a model metal

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Paul G. [Univ. of Alabama, Tuscaloosa, AL (United States); Seiter, Jennifer M. [U.S. Army Engineer Research and Development Center, Vicksburg, MS (United States); Diaz, Alfredo [Univ. of Puerto Rico, Mayaguez (Puerto Rico); Lindsay, James H. [U.S. Army Engineer Research and Development Center, Vicksburg, MS (United States); Moser, Robert D. [U.S. Army Engineer Research and Development Center, Vicksburg, MS (United States); Tappero, Ryan V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kennedy, Alan J. [U.S. Army Engineer Research and Development Center, Vicksburg, MS (United States)

    2016-01-01

    Metallic tungsten (W) was initially assumed to be environmentally benign and a green alternative to lead. However, subsequent investigations showed that fishing weights and munitions containing elemental W can fragment and oxidize into complex monomeric and polymeric tungstate (WO4) species in the environment; this led to increased solubility and mobility in soils and increased bioaccumulation potential in plant and animal tissues. Here we expand on the results of our previous research, which examined tungsten toxicity, bioaccumulation, and compartmentalization into organisms, and present in this research that the bioaccumulation of W was related to greater than 50% reduction in the mechanical properties of the snail (Otala lactea), based on depth-sensing nanoindentation. Synchrotron-based X-ray fluorescence maps and X-ray diffraction measurements confirm the integration of W in newly formed layers of the shell matrix with the observed changes in shell biomechanical properties, mineralogical composition, and crystal orientation. With further development, this technology could be employed as a biomonitoring tool for historic metals contamination since unlike the more heavily studied bioaccumulation into soft tissue, shell tissue does not actively eliminate contaminants.

  4. Retraction notice to "Antimicrobial secondary metabolites from marine gastropod egg capsules and egg masses" [APJTB Volume 2 Issue 11(2012) 916-922

    Institute of Scientific and Technical Information of China (English)

    Kaviarasan; T; Siva; Sankar; R; Yogamoorthi; A

    2015-01-01

    <正>This article has been retracted:please see Elsevier Policy on Article Withdrawal(http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the Editor-in-Chief and the First Author.Both the first author and the journal’s editor confirmed that Dr.A Yogamoorthi is not responsible for the plagiarism since his/her name was added without consent.

  5. Primary Studies on the Morphology and Shell Strength of Four Species of Gastropods in the Liangzi Lake, Hubei%湖北梁子湖四种螺的形态与壳强度初步研究

    Institute of Scientific and Technical Information of China (English)

    朱挺兵; 张丽红; 程庆武; 李为; 张堂林

    2013-01-01

    测定了湖北梁子湖的铜锈环棱螺(Bellamya aeruginosa)、长角涵螺(Alocinma longicornis)、中华沼螺(Parafossarulus sinensis)和耳萝卜螺(Radix auricularia)的壳形态性状和壳强度.4种螺壳形态可量性状之间以及壳形态可量性状与壳强度之间均呈显著的正相关,且存在明显的种间差异.探讨了螺类形态和壳强度与反捕食功能的关系.

  6. 扁担塘螺类生产力的研究Ⅱ.纹沼螺的周年生产量%PRODUCTION OF GASTROPODS IN LAKE BIANDANTANG Ⅱ.ANNUAL PRODUCTION OF PARAFOSSARULUS STRIATULUS

    Institute of Scientific and Technical Information of China (English)

    阎云君; 梁彦龄; 王洪铸

    2001-01-01

    The production of Parafossarulus striatulus in Lake Biandantang was calculated by using four method.The results were:178.07 mg*m-2*a-1 of dry weight shell-free or 4998.40 mg*m-2*a-1 of wet weight with shell by size-frequency method;174.5 mg*m-2*a-1 of dry weight shell-free or 4898.20 mg*m-2*a-1 of wet weight with shell by removal-summation method;174.5 mg*m-2*a-1 of dry weight shell-free or 4898.20 mg*m-2*a-1 of wet weight with shell by Allen curve method;178.14 mg*m-2*a-1 of dry weight shell-free or 5000.40 mg*m-2*a-1 of wet weight with shell by instantaneous growth method.The corresponding P/B ratios are 4.3,4.4,4.4,4.5, respectively. Therefore,the results by the four methods are in well agreement,which might be of great significance in the estimation of invertebrate production.%采用四种方法对扁担塘纹沼螺的周年生产量进行了测算,结果表明,四种方法得到的生产量吻合极好。生产量的去壳干重和带壳湿重分别是:体长频度法,178.07mg*m-2*a-1,4998.40mg*m-2*a-1;减员累计法,174.50mg*m-2*a-1,4898.20mg*m-2*a-1;Allen曲线法,174.50mg*m-2*a-1,4898.20m-2*a-1;瞬时生长率法,178.14mg*m-2*a-1,5000.40mg*m-2*a-1。对应的P/B系数分别为4.3,4.4,4.4,4.5。

  7. Interventional Micro-robot Based on Motion Mechanism of Gastropod%一种基于腹足动物运动机理的介入机器人

    Institute of Scientific and Technical Information of China (English)

    陈柏; 陈笋; 杨朋飞; 吴洪涛

    2009-01-01

    在对腹足动物运动机理研究的基础上,基于仿生学原理提出一种介入机器人设计方案.通过理论建模及实验手段对机器人仿生设计效果及运动性能进行研究.结果表明:对粘液功能的模拟方案正确;机器人正常运行速度由直线微马达伸缩速度决定,但过快的微马达运动方向变化会导致机器人运行效率的降低.

  8. A SIMPLE FEEDING BEHAVIOR ASSAY TO STUDY THE ATTRACTANTS FOR CARNIVOROUS GASTROPODS%一种简单的研究肉食性腹足类诱食物质的摄食行为方法

    Institute of Scientific and Technical Information of China (English)

    林琛; 曾嶒; 罗霞; 冯永勤; 陈学敏

    2008-01-01

    迄今为止,国内外有关腹足类诱食物质的研究工作还很少,且主要集中在鲍等一些植食性种类上。这些工作大多套用在鱼类上常用的相关研究思路与实验装置。Sakata,et al.则专门建立了微晶纤维素平板法(Avicel plate method)利用摄食痕迹检索了皱纹盘鲍Haliotis discus等的诱食物质。在肉食性种类,Hodgson,et al.利用直接施加溶液的方法研究过氨基酸溶液、贻贝抽提液等与织纹螺(Bullia digitalis)伸吻行为的关系。但在肉食性腹足类上尚未见到有关用摄食指标检索诱食物质的研究报道。

  9. Catalogue of Gastropods (Gastropoda: Bradybaenidae)Distrbuted in South Gansu%甘肃南部巴蜗牛科(腹足纲:巴蜗牛科)的种类名录

    Institute of Scientific and Technical Information of China (English)

    王洪建

    2005-01-01

    本文根据甘肃南部所辖地区采集的腹足目巴蜗牛科标本和国内外报道,对其进行系统整理研究,列出巴蜗牛科动物76种,分隶11属1科,其中30种为甘肃省新纪录.

  10. 饥饿对两种织纹螺肉体化学组分的影响%Effects of hunger on somatic chemical composition of two subtidal nassariid gastropods,Nassarius siquijorensis and Nassarius conoidalis

    Institute of Scientific and Technical Information of China (English)

    赵倩

    2013-01-01

    目的 研究饥饿对两种海洋食腐动物(Nassarius siquijorensis和Nassarius conoidalis)肉体化学组分的影响.方法 采用标准生化测定法研究了饥饿状态下这两种织纹螺肉体组织中营养成分组成:粗脂肪的测定采用索氏抽提法;粗灰分的测定采用高温灰化法;凯氏定氮法测定粗蛋白质.结果 经过32天的饥饿处理,发现两种织纹螺肉体的粗蛋白质和粗脂肪含量显著降低,碳水化合物含量显著升高(P<0.05).结论 研究结果表明当食物缺乏的时候,N.conoidalis和N.Siquijorensis会通过调动像蛋白质和脂肪这样的内源性生理学燃料,来满足其进行基本生命活动所需的能量.

  11. SOME EARLY CRETACEOUS MARINE AND BRACKISH-WATER GASTROPODS FROM EASTERN HEILONGJIANG PROVINCE%黑龙江省东部早白垩世的一些海相和半咸水相腹足类

    Institute of Scientific and Technical Information of China (English)

    潘华璋; 朱祥根

    2004-01-01

    描述黑龙江省东部上云山组和大架山组腹足类化石4属(Mathilida,Uchauxia ,Nododelphinula,Trochactaeon )7种,其中2 新种: Uchauxia yunshanensis sp. nov., Nododelphinula dajiashanensis sp. nov.. 它们均是特提斯海区早白垩世腹足动物群中常见分子,根据这些腹足类化石的分布和对比,其地层时代应为早白垩世阿普第期-阿尔必期.文内阐述上云山组沉积环境--近高潮附近的泥滩或泥湾,而大架山组沉积环境--低潮线附近浅水.

  12. 扁担塘螺类生产力的研究Ⅰ.铜锈环棱螺的周年生产量%PRODUCTION OF GASTROPODS IN LAKE BIANDANTANG Ⅰ. ANNUAL PRODUCTION OF BELLAMYA AERUGINOSA

    Institute of Scientific and Technical Information of China (English)

    阎云君; 梁彦龄; 王洪铸

    1999-01-01

    1996~1997年对扁担塘螺类优势种之一铜锈环棱螺进行了周年研究,结果表明其种群含四个年龄组,其中1996年组生长最快,其带壳湿重瞬时生长率为4.15,去壳干重瞬时生长率为3.40.采用瞬时生长率法测算其周年生产量为:带壳湿重,15.77g·m-2·a-1;去壳干重,0.8624g·m-2·a-1.P/B系数基本一致,分别为0.50,0.5l.铜锈环棱螺的生产量的去壳干重(Wd,g·m-2·a-1)和带壳湿重(Ww,g·m-2·a-1)满足下列关系:Ww=17.20Wd.

  13. THE SEQUENCE AND DISTRIBUTION OF CRETACEOUS NON-MARINE GASTROPOD ASSEMBLAGES IN CHINA%中国非海相白垩纪腹足类组合序列和分布

    Institute of Scientific and Technical Information of China (English)

    潘华璋

    2012-01-01

    Four assemblages of Cretaceous non-marine gastropodas are recognized in China. These assemblages are: 1) the Probaicalia vitimensis-Ptychostylus-Reesidella robusta (operculum fossil) Assemblage from the Valangin- ian-Barremian Stage; 2) the Bellamya clavilithiformis-Mesocoshliopa cretacea-Zaptychius costatus-Brotiopsis Assem- blage from the Aptian-Albian Stage, which can be divided into two sub-assemlages on the basis of biogeographical differentiation (the Brotiopsis sub-assemblage and the Bellamya clavilithiformis-Mesocoshliopa cretacea-Zaptychius costatus sub-assemblage); 3) the Mesolanistes-nanxion gensis assemblage from the Middle-Upper Maastrichtian-Coniacian Stage, which can also be divided into two sub-assemblages ( the Mesolanistes ziziformis sub-assemblage probably of Coniacian Stage and, the Mesolanistes-nanxiongensis sub-assemblage of the Middle-Upper Maastrichtian-Coniacian age); and 4) the Palaeoancylus nanxiongensis assemblage from the uppermost Maastrichtian Stage.%中国白垩纪非海相腹足类可划分为4个组合:1)早白垩世凡兰吟期-巴列姆期Probaicaliavitimen.sis—Ptychostylus-口盖化石Reesidellarobusta组合;2)早白垩世阿普特期一阿尔必期Bellamyaclavilithi—formis-Mesocoshliopacretacea-Zaptychiuscostatus-Brotiopsis组合,由于环境的不同,这一组合可分为2个亚组合:Brotiopsis亚组合和Bellamyaclavilithiformis-Mesocoshliopacretacea-Zaptychiuscostatus亚组合;3)晚白垩世科尼亚克期一中马斯特里赫特晚期Mesolanistesnanxiongensis组合,由于产出的层位不同,这一组合又可分为2个亚组合Mesolanistes ziziformis亚组合和Mesolanistes—nanxiongensis亚组合;4)晚白垩世马斯特里赫特期最晚期Palaeoancylusnanxiongensi组合。

  14. Current knowledge on population studies on five continental molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State (SC, Central Southern Brazil region

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-03-01

    Full Text Available Although still very scarce, available knowledge on population studies on continental (land and freshwatermolluscs in the territory of Santa Catarina State is shortly analyzed and discussed. Based on the IUCN“Restricted Distribution” criterion, a total of 54 nominal species, including 31 terrestrial gastropods, 15freshwater gastropods and 8 limnic bivalves, were considered strong candidates as threatened taxa. Out of allthese endangered species, only 5 limnic forms (2 gastropods and 3 bivalves were previously analysed, in someway, at population level.

  15. 75 FR 61871 - Endangered and Threatened Wildlife and Plants; Proposed Listing Determinations for Three Distinct...

    Science.gov (United States)

    2010-10-06

    ... mollusks, gastropods, amphipods, isopods, and fish. Juvenile sturgeon feed on aquatic insects and other... reproduction among river subpopulations. Tagging studies and genetic analyses provide evidence that...

  16. Double-staining techniques allows electrophysiological identification of monoamine-containing neurons.

    Science.gov (United States)

    Audesirk, T E; Audesirk, G J

    1985-08-01

    Electrophysiological recording provides important evidence for positive identification of many neurons in gastropods. We describe a technique which combines intracellular recording and injection of a persistent, non-fluorescent dye (Fast Green) with subsequent histofluorescence treatment using a modification of the wholemount glyoxylic acid procedure developed by Barber (1983) to establish the presence or absence of monoamine transmitters in positively identified single gastropod neurons.

  17. A query and display system based on GIS for marine gastropod imposex and organotin contamination in sea areas along southeast coast of China%基于GIS的中国东南沿岸海域海产腹足类性畸变与有机锡污染查询显示系统

    Institute of Scientific and Technical Information of China (English)

    谢文勇; 黄长江; 陈志远; 施华宏

    2002-01-01

    本研究工作采用基于组件式集成方案的ArcInfo GIS 软件、Microsoft Access数据库、MapObjects 2.0软件、AutoCAD软件、VB6.0开发语言作为软件平台, 以Le-gend Pentium III (933)作为硬件平台,利用ADO数据接口实现与属性库连接,通过ShellExecute函数达到与ArcView软件、相关网址连接,在此基础上建立了中国东南沿岸海域海产腹足类性畸变与有机锡污染查询显示系统,并使其具有显示、缩放、漫游、定位、查询、统计、分析、编辑、输出等功能.这是将GIS技术应用于海洋生态系统的调查、管理和保护的新尝试.

  18. 腹足纲土壤动物在监测和评价重金属污染中的应用研究进展%Progress on Application of Gastropod for Monitoring and Evaluating the Heavy Metal Contamination of Terrestrial Environment

    Institute of Scientific and Technical Information of China (English)

    孙雷; 李武艳; 胡玲

    2008-01-01

    重金属污染正日益受到人们的关注.利用指示生物监测和评价重金属污染是一种简单可行的方法,但是却能提供具有重要价值的信息,特别是在反映生态系统功能变化方面具有独特的优势.在指示生物和生物监测研究领域,软体动物可以被用来获取陆地、海洋和淡水生态系统的环境质量信息.本文综述了腹足纲土壤动物应用于重金属污染监测和评价中的研究进展.

  19. 温度和盐度对两种潮下带织纹螺(西格织纹螺和方格织纹螺)幼体存活率的影响%The Effects of Temperature and Salinity on the Survival Rates of Two Subtidal Nassariid Gastropod Larvae, Nassarius Siquijorensis and Nassarius Conoidalis

    Institute of Scientific and Technical Information of China (English)

    赵倩

    2013-01-01

    本实验研究了温度和盐度两个主要环境因素如何影响两种主要的腐生性腹足类动物(西格织纹螺Nassarius siquijorensis和方格织纹螺Nassarius conoidalis)的幼体存活率.在6个不同温度条件(10,15,20,25,30和35℃)和7个不同盐度条件(0,5,10,15,20,25和30)下,经过观察分别得到两种幼体的24 h和48 h时的存活率.结果显示,当盐度<10或者温度<15℃时,Nassarius siquijorensis和Nassarius conoidalis均具有较高的幼体死亡率.

  20. 保安湖扁担塘螺类生产力的研究 Ⅲ.长角涵螺的周年生产量%PRODUCTION OF GASTROPODS IN BIANDANTANG LAKE OF BAO'ANHU, Ⅲ. ANNUAL PRODUCTION OF ALOCINMA LONGICORNIS

    Institute of Scientific and Technical Information of China (English)

    闫云君; 梁彦龄; 王洪铸

    2002-01-01

    采用三种方法对扁担塘长角涵螺的周年生产量进行了测算,结果表明,三种方法得到的生产量及P/B系数吻合较好.生产量的带壳湿重和去壳干重分别是:体长频率法,2.088 g*m-2*a-1,0.103 g*m-2*a-1;Allen 曲线法,2.122 g*m-2*a-1, 0.106 g*m-2*a-1;瞬时生长率法,2.273 g*m-2*a-1, 0.114 g*m-2*a-1.对应的P/B系数为4.3,4.3,4.0.

  1. Toxic effects of domestic sewage on zooplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Desai, B.N.

    The toxic effects of raw domestic sewage on different groups of zooplank-ton, was tested in the laboratory for evaluating acute toxicity. 24 hr., LC-50 values for larvae of stomatopods, gastropods and chaetognaths (2-7% concentration) indicated...

  2. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Southern California: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for sensitive bivalves, gastropods, insects, crustaceans, and other invertebrate species in Southern...

  3. Evaluation and selection of test methods for assessment of contaminated sediments in the Baltic Sea

    DEFF Research Database (Denmark)

    Lehtonen, Kari; Ahvo, Aino; Berezina, Nadya;

    toxicity), sediment avoidance (C. volutator), bacterial luminescence (Vibrio fischeri), algae growth inhibition (Pseudokirchneriella subcapitata, Ceramium tenuicorne), SOS/umu genotoxicity (Salmonella) and imposex in female gastropods (Nassarius reticulata). The results of this first round of experiments...

  4. Recent history of the European Nassarius nitidus (Gastropoda) : phylogeographic evidence of glacial refugia and colonization pathways

    NARCIS (Netherlands)

    Albaina, Naiara; Olsen, Jeanine L.; Couceiro, Lucia; Miguel Ruiz, Jose; Barreiro, Rodolfo

    2012-01-01

    Because marine species respond differentially to factors governing survival and gene flow, closely related taxa may display dissimilar phylogeographic histories. New data for the patchily distributed gastropod Nassarius nitidus throughout its Atlantic-Mediterranean range (collected during 2008 and 2

  5. Optimizing the design of a reproduction toxicity test with the pond snail Lymnaea stagnalis

    DEFF Research Database (Denmark)

    Charles, Sandrine; Ducrot, Virginie; Azam, Didier

    2016-01-01

    This paper presents the results from two ring-tests addressing the feasibility, robustness and reproducibility of a reproduction toxicity test with the freshwater gastropod Lymnaea stagnalis (RENILYS strain). Sixteen laboratories (from inexperienced to expert laboratories in mollusc testing) from...

  6. The ecology of shell shape difference in chirally dimorphic snails

    NARCIS (Netherlands)

    Schilthuizen, M.; Haase, M.; Koops, K.; Looijes, S.M.; Hendrikse, S.

    2012-01-01

    The Southeast-Asian tree snail subgenus Amphidromus s. str. (Gastropoda Pulmonata: Camaenidae) is unusual among all gastropods for its genetic antisymmetry: populations consist of stable mixtures of individuals with clockwise (dextral) and counterclockwise (sinistral) coiling directions. Although pr

  7. Feeding ecology of the white sea bream, Diplodus sargus cadenati (Perciformes: Sparidae) and the ballan wrasse, Labrus bergylta (Perciformes: Labridae), from Faial Island – Azores

    OpenAIRE

    2005-01-01

    Copyright © 2005 Elsevier Science B.V. All rights reserved To make a first approach in the assessment of the sea urchin predators in the Azores, the diet of white seabream (Diplodus sargus) and ballan wrasse (Labrus bergylta), were studied by the analyses of their stomach contents. The white seabream is a diurnal omnivore, feeding on algae, sea-urchins, worms, gastropods and amphipods, while ballan wrasse fed mainly on echinoderms (sea-urchins), gastropods and decapods. Both species tended...

  8. The Mitochondrial Genome of Conus textile, coxI-coxII Intergenic Sequences and Conoidean Evolution

    OpenAIRE

    2007-01-01

    The cone snails belong to the superfamily Conoidea, comprising ∼10,000 venomous marine gastropods. We determined the complete mitochondrial DNA sequence of Conus textile. The gene order is identical in Conus textile, Lophiotoma cerithiformis (another Conoidean gastropod), and the neogastropod Ilyanassa obsoleta, (not in the superfamily Conoidea). However, the intergenic interval between the coxI/coxII genes, was much longer in C. textile (165 bp) than in any other previously analyzed gastropo...

  9. Experimental Studies on Pressure and Temperature Effects on Deep Dea Organisms.

    Science.gov (United States)

    1980-02-28

    of the specific synthesis of DNA -RNA proteins, will change and become species-specific. The data presented in this paper show evidence of phenotypical...gations of the trench have given us a relatively comprehen- and wood-infesting cocculinid gastropods are common in sive understanding of its topography...Ischnomesus and Heteromesus, Osmotrophic Organisms: A comparison of major trophic along with cocculinid gastropods (Fig 6) were found in the types

  10. Central Asia, Physical Geography Handbook.

    Science.gov (United States)

    2007-11-02

    over 2,000 m) is not applicable to Central Asia, partly because the general hypsometric level of this region is high and unstable, as a consequence of...organic fossils in them, gastropods have been discovered. On the main territory of the Tarim massif, which evidently represented a weakly elevated...places seams of gypsum and rock salt, and, in a part to the west of the town of Aksu, also a bed of gray limestone with small fresh- water gastropods

  11. Molluscan cells in culture: primary cell cultures and cell lines

    OpenAIRE

    2013-01-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as bi...

  12. Transcriptomic and Proteomic Analysis of Arion vulgaris—Proteins for Probably Successful Survival Strategies?

    OpenAIRE

    2016-01-01

    The Spanish slug, Arion vulgaris, is considered one of the hundred most invasive species in Central Europe. The immense and very successful adaptation and spreading of A. vulgaris suggest that it developed highly effective mechanisms to deal with infections and natural predators. Current transcriptomic and proteomic studies on gastropods have been restricted mainly to marine and freshwater gastropods. No transcriptomic or proteomic study on A. vulgaris has been carried out so far, and in the ...

  13. Transcriptome analysis in Concholepas concholepas (Gastropoda, Muricidae): mining and characterization of new genomic and molecular markers.

    Science.gov (United States)

    Cárdenas, Leyla; Sánchez, Roland; Gomez, Daniela; Fuenzalida, Gonzalo; Gallardo-Escárate, Cristián; Tanguy, Arnaud

    2011-09-01

    The marine gastropod Concholepas concholepas, locally known as the "loco", is the main target species of the benthonic Chilean fisheries. Genetic and genomic tools are necessary to study the genome of this species in order to understand the molecular basis of its development, growth, and other key traits to improve the management strategies and to identify local adaptation to prevent loss of biodiversity. Here, we use pyrosequencing technologies to generate the first transcriptomic database from adult specimens of the loco. After trimming, a total of 140,756 Expressed Sequence Tag sequences were achieved. Clustering and assembly analysis identified 19,219 contigs and 105,435 singleton sequences. BlastN analysis showed a significant identity with Expressed Sequence Tags of different gastropod species available in public databases. Similarly, BlastX results showed that only 895 out of the total 124,654 had significant hits and may represent novel genes for marine gastropods. From this database, simple sequence repeat motifs were also identified and a total of 38 primer pairs were designed and tested to assess their potential as informative markers and to investigate their cross-species amplification in different related gastropod species. This dataset represents the first publicly available 454 data for a marine gastropod endemic to the southeastern Pacific coast, providing a valuable transcriptomic resource for future efforts of gene discovery and development of functional markers in other marine gastropods.

  14. Composição de gastrópodes terrestres em duas áreas do Centro de Estudos Ambientais e Desenvolvimento Sustentado (CEADS, Vila Dois Rios, Ilha Grande, Rio de Janeiro, Brasil: um estudo-piloto Composition of terrestrial gastropods in two areas of the Center to Environmental Studies and Sustainable Development (CEADS, Vila Dois Rios, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil: a preliminary study

    Directory of Open Access Journals (Sweden)

    Sonia Barbosa dos Santos

    2001-07-01

    Full Text Available A survey of the Ilha Grande land snails was carried out in order to compare the diversity and similarity among two regions of secondary Atlantic Rain Forest. The diversity was estimated using the richness and the equitatibility; the alpha diversity was calculated using the Simpson index (γ. The Sörensen and Jaccard indexes were used to calculate the similarity. A quantitative survey of two 600 m² area, one in each studied region, recorded 336 individuals snails distributed in 23 species and 13 families. The region with more altered secondary forest showed higher richness (17 and diversity (γ = 3,6 than the region more preserved (richness = 14; γ = 2,78, but, the same equitatibility (0,20. The similarity was medium by Jaccard index (IJ = 0,52 and low by Sorensen index (IS = 0,15. These differences could be explained by the dominance of Subulinidae (four species and 117 specimens in the more altered region and Systrophiidae in the more preserved (four species and 97 specimens.

  15. Shell occupation and microhabitat use by hermit crabs (Decapoda: Anomura on Fortaleza beach, Ubatuba, São Paulo

    Directory of Open Access Journals (Sweden)

    Giuliano Buzá Jacobucci

    2009-06-01

    Full Text Available Most species of hermit crabs use the empty shells of gastropods as mobile shelters. The variation of shell availability in different microhabitats can reduce competitive interactions between sympatric species, favoring their coexistence. This work aimed to characterize the occupation of gastropod shells by three species of hermit crabs, and assessing the availability of shells and evaluating the use of microhabitats crabs and gastropods in an infralitoral area on the north coast of São Paulo state. For this purpose, transect lines were established and all hermit crabs, gastropods and empty shells found were collected, recording the type of microhabitat used. In a sub-sample, the hermit crabs were identified and classified into reproductive categories. The shells used by the crabs were identified and evaluated according to physical damage and incrustation. Three species of hermit crabs (Paguristes tortugae, Pagurus brevidactylus and Pagurus criniticornis were recorded, using 15 species of gastropod shells and one of scaphopod (Dentalium sp.. Physical damage and incrustation of shells were significantly different among the hermit crab species. Considering microhabitat use, P. tortugae and P. brevidactylus were mainly found in calcareous algae, while P. criniticornis mainly occurred in sand substrate. Despite the differences in shell and microhabitat use, the high resource overlap, especially by the pagurids, indicates that competitive interactions are important regulatory factors for these populations.

  16. Epidemiological survey of Angiostrongylus vasorum in dogs and slugs around a new endemic focus in Scotland.

    Science.gov (United States)

    Helm, J; Roberts, L; Jefferies, R; Shaw, S E; Morgan, E R

    2015-07-11

    The nematode parasite Angiostrongylus vasorum is an increasingly important cause of respiratory and other diseases in dogs. Geographical spread from previously limited endemic foci has occurred rapidly. This paper investigates parasite epidemiology around the location of the first reported case in Scotland in 2009: by detection of A vasorum-specific DNA in gastropod intermediate hosts, and in dogs circulating DNA and specific antibodies, and first stage larvae in faeces. Overall prevalence in gastropods was 6.7 per cent (16/240), with parasite DNA found in slugs in the Arion ater and Arion hortensis species aggregates and the snail Helix aspersa (syn. Cornu aspersum). Of 60 dogs presenting with clinical signs compatible with angiostrongylosis, none tested positive using PCR on peripheral blood or Baermann test on faeces, and none of 35 tested for circulating anti-A vasorum antibodies were positive. PCR prevalence in gastropods was highest (11 per cent) in the park frequented by the canine angiostrongylosis index case. Molecular survey for infection in gastropods is a potentially informative and efficient method for characterising the distribution of A vasorum and therefore local risk of canine infection. However, there appears to be a complex relationship between prevalence in gastropods and emergence of canine clinical disease, which requires further work to advance understanding of parasite transmission and geographical disease spread.

  17. [Combined effect of environmental temperature and trematodes on fatty acids composition of lipids of Littorina saxatilis (Olivi 1792) (Gastropoda, Prosobranchia)].

    Science.gov (United States)

    Arakelova, E S; Chebotareva, M A; Zabelinskiĭ, S A

    2004-01-01

    An effect of environmental temperatures and invasion by helminthes larvae on fatty acids composition of digestive gland lipids of marine littoral gastropod Littorina saxatilis from White Sea and Barents Sea was investigated. We have compared gastropods from boreal and subarctic populations. It was found that gastropods from waters of lower temperature have increased omega3/omega6 fatty acids ratio. However, saturation index of individual membrane phospholipids was not affected. Also, content of eicosenoic acid (20:1) in individual phospholipids was not affected by temperature. Invasion increases the omega3/omega6 ratio of common lipids but not the omega3/omega6 ratio of common and individual phospholipids with the exception of phosphatidilcholine of cold water mollusks from Barents Sea that had this ratio doubled. In contrast to temperature, invasion affects the content of eicosenoic acid that was increased in the investigated organs. Adaptability of these effects is discussed regarding parasite-host system.

  18. Cenozoic seawater Sr/Ca evolution

    Science.gov (United States)

    Sosdian, Sindia M.; Lear, Caroline H.; Tao, Kai; Grossman, Ethan L.; O'Dea, Aaron; Rosenthal, Yair

    2012-10-01

    Records of seawater chemistry help constrain temporal variations in geochemical processes that impact the global carbon cycle and climate through Earth's history. Here we reconstruct Cenozoic seawater Sr/Ca (Sr/Casw) using fossil Conus and turritellid gastropod Sr/Ca. Combined with an oxygen isotope paleotemperature record from the same samples, the gastropod record suggests that Sr/Caswwas slightly higher in the Eocene (˜11.4 ± 3 mmol/mol) than today (˜8.54 mmol/mol) and remained relatively stable from the mid- to late Cenozoic. We compare our gastropod Cenozoic Sr/Casw record with a published turritellid gastropod Sr/Casw record and other published biogenic (benthic foraminifera, fossil fish teeth) and inorganic precipitate (calcite veins) Sr/Caswrecords. Once the uncertainties with our gastropod-derived Sr/Casw are taken into account the Sr/Casw record agrees reasonably well with biogenic Sr/Caswrecords. Assuming a seawater [Ca] history derived from marine evaporite inclusions, all biogenic-based Sr/Casw reconstructions imply decreasing seawater [Sr] through the Cenozoic, whereas the calcite vein Sr/Casw reconstruction implies increasing [Sr] through the Cenozoic. We apply a simple geochemical model to examine the implications of divergence among these seawater [Sr] reconstructions and suggest that the interpretation and uncertainties associated with the gastropod and calcite vein proxies need to be revisited. Used in conjunction with records of carbonate depositional fluxes, our favored seawater Sr/Ca scenarios point to a significant increase in the proportion of aragonite versus calcite deposition in shelf sediments from the Middle Miocene, coincident with the proliferation of coral reefs. We propose that this occurred at least 10 million years after the seawater Mg/Ca threshold was passed, and was instead aided by declining levels of atmospheric carbon dioxide.

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

    Science.gov (United States)

    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

  20. Ultrastructure of spermatozoa of Bullacta exarata (philippi) and its significance on reproductive evolution and physio-ecological adaptation

    Institute of Scientific and Technical Information of China (English)

    应雪萍; 杨万喜; 姜乃澄; 张永普

    2004-01-01

    The morphology and ultrastructure ofBullacta exarata spermatozoa observed by light and transmission electronmicroscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal complex and anelongated nucleus, and tail with a midpiece, principal piece and an end piece. The midpiece consists of a mitochondrial ring,and the principal piece is composed of axoneme and lateral fin. The structure orB. exarata spermatozoa differs significantlyfrom that of other gastropods, especially in the lateral fin and the principal piece, which was described scarcely before. Acomparison is made between B. exarata and other gastropods, and its significance on reproductive evolution andphysio-ecological adaptation is preliminarily discussed.

  1. Microfossils from loess of the Miaodao Islands, Bohai Sea

    Institute of Scientific and Technical Information of China (English)

    赵泉鸿

    1996-01-01

    Microfossils from the Malan Loess profiles, Miaodao Islands, have been quantitatively studied. The microfauna is composed mainly of benthic foraminifers together with a few planktonic foraminifers, ostracods, gastropods, bivalves and echinoid spines. With the exception of indigenous gastropods, benthic foraminifers, ostracods, bivalves and echinoid spines were transported from the north or northwest of the Bohai Sea in the glacial period by the prevailing winter monsoon, while planktonic foraminifers were probably driven from the Yellow Sea or even the northern East China Sea by southerly winds. The upward decrease of marine microfossil abundance and diversity in the Malan Loess profiles shows that the microfossil transportation occurred mainly at the beginning of the regression.

  2. Studies on Cercariae from Kuwait Bay. XI. Description and surface topography of Cercaria kuwaitae XI sp.n. (Digenea: Echinostomatidae

    Directory of Open Access Journals (Sweden)

    Abdul-Salam J

    1999-01-01

    Full Text Available A new echinostome cercaria, Cercaria kuwaitae XI sp.n., from the prosobranch gastropod Cerithidea cingulata (Gmelin from Kuwait Bay is described. The new cercaria is characterized by 23 collar spines and primary excretory tubules with distinct diverticula. The cercaria encysts in the snail host and is similar to those of Acanthoparyphium sp. The surface topography of the redia, cercaria and metacercarial cyst wall is studied by scanning electron microscopy. This is the first echinostome cercaria to be recorded in a gastropod from the Arabian Gulf region.

  3. Non-Detriment Finding Regarding the Export of Queen conch (Lobatus gigas) from St Eustatius (Caribbean Netherlands)

    NARCIS (Netherlands)

    Graaf, de M.; Meijer zu Schlochteren, M.; Boman, E.

    2014-01-01

    Queen conch (Lobatus gigas (Strombidae; Gastropoda) is a large, long-lived marine gastropod that is widely distributed throughout the coastal zones of the Wider Caribbean region. Because of concern for its future the species was listed in Appendix II of the Convention on International Trade in Endan

  4. Can essential oils be used as novel drench treatments for the eggs and juveniles of the pest snail Cornu aspersum in potted plants?

    Science.gov (United States)

    The horticultural trade is an important pathway for the introduction and spread of invasive gastropods because potted plants are essentially portable microhabitats, which protect snails and slugs, especially buried eggs and juveniles, from desiccation and molluscicides. The identification of a drenc...

  5. Pseudo-imposex: male features in female volutes not TBT-induced (Gastropoda: Volutidae)

    NARCIS (Netherlands)

    Swennen, C.; Horpet, P.

    2008-01-01

    The occurrence of a penis in female gastropods of the superfamily Muricoidea (infraorder Neogastropoda) has commonly been accepted as an indicator of tributyltin (TBT) pollution. Some species seem less sensitive than others, and one belonging to the family Columbellidae has been reported that it lac

  6. Organotins in North Sea brown shrimp (Crangon crangon L.) after implementation of the TBT ban

    NARCIS (Netherlands)

    Verhaegen, Y.; Monteyne, E.; Neudecker, T.; Tulp, I.Y.M.; Smagghe, G.; Cooreman, K.; Roose, P.; Parmentier, K.

    2012-01-01

    The organotin (OT) compounds tributyltin (TBT) and triphenyltin (TPhT) are potent biocides that have been used ubiquitously in antifouling paints and pesticides since the mid-1970s. These biocides are extremely toxic to marine life, particularly marine gastropod populations. The European Union there

  7. Imposex in the common whelk, Buccinum undatum

    NARCIS (Netherlands)

    Mensink, B.

    1999-01-01

    The research described in this thesis concerned the perhaps best known and studied common gastropod from the open North Sea of which only limited information was available. With the present research more insight has been obtained concerning this long-lived, off-shore snail species, which existence i

  8. Global Hindcasts and Future Projections of Coastal Nitrogen and Phosphorus Loads Due to Shellfish and Seaweed Aquaculture

    NARCIS (Netherlands)

    Bouwman, A.F.; Pawlowski, M.; Liu, C.; Beusen, A.W.H.; Shumway, S.E.; Glibert, P.M.; Overbeek, C.C.

    2011-01-01

    A model was developed to estimate nitrogen and phosphorus budgets for aquaculture production of crustaceans, bivalves, gastropods, and seaweed, using country production data for the 1970–2006 period from the Food and Agriculture Organi- zation and scenarios based on the Millenium Assessment for 2006

  9. Neurogenesis of cephalic sensory organs of Aplysia californica

    DEFF Research Database (Denmark)

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

    2007-01-01

    The opisthobranch gastropod Aplysia californica serves as a model organism in experimental neurobiology because of its simple and well-known nervous system. However, its nervous periphery has been less intensely studied. We have reconstructed the ontogeny of the cephalic sensory organs (labial te...

  10. Tungsten: A Preliminary Environmental Risk Assessment

    Science.gov (United States)

    2011-05-01

    David Ringelberg (CRREL): Microbiology  Linda Winfield (retired): Plant Biology  Robert Boyd (EL): Terrestrial Ecotoxicology (plants & earthworms...Alan Kennedy & Jay Lindsay (EL): Terrestrial Ecotoxicology (gastropods)  ChooYaw Ang (BTS): Cellular Biology  Laura Inouye (Washington State...Dept. of Ecology): Terrestrial Ecotoxicology & Cellular Biology This project was funded by the Army’s Environmental Quality & Installations Basic

  11. Rissoa parva (da Costa, 1778) présence en Mer d’Alboran

    OpenAIRE

    Delongueville, C.; Scaillet, R.

    2014-01-01

    The presence of two live specimens of Rissoa parva (da Costa, 1778) in a sample of gastropods collected off Cala Iris (Mediterranean coast of Morocco) attests that the species considered by some as exclusively Atlantic is present in the Mediterranean (Alboran Sea).

  12. Eutrophication and Dreissena invasion as drivers of biodiversity: a century of change in the mollusc community of Oneida Lake.

    Directory of Open Access Journals (Sweden)

    Vadim A Karatayev

    Full Text Available Changes in nutrient loading and invasive species are among the strongest human-driven disturbances in freshwater ecosystems, but our knowledge on how they affect the biodiversity of lakes is still limited. We conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lakewide study in 2012 and previous surveys dating back to 1915. In the early 20th century, the lake had a high water clarity, with abundant macrophytes and benthic algae, and hosted the most diverse molluscan community in New York State, including 32 gastropod and 9 unionid species. By the 1960s, lake turbidity increased during a period of anthropogenic eutrophication, resulting in a 38% decline in species richness and a 95% reduction in abundance of native gastropods grazing on benthic algae. Following the invasion of Dreissena spp. in 1991 and subsequent increases in water clarity, native gastropod species richness expanded by 37% and abundance increased 20-fold by 2012. In contrast, filter-feeding unionids were unaffected by increased turbidity during the period of eutrophication but were extirpated by dreissenids. Through contrasting effects on turbidity, eutrophication and Dreissena spp. have likely driven the observed changes in native grazing gastropods by affecting the abundance of light-limited benthic algae. Given the high species richness and ecological importance of benthic grazers, monitoring and managing turbidity is important in preserving molluscan diversity.

  13. Newly-discovered muscle in the larva of Patella coerulea (Mollusca, Gastropoda) suggests the presence of a larval extensor

    NARCIS (Netherlands)

    Damen, Peter; Dictus, Wim J.A.G.

    2002-01-01

    The development of the muscular system of the gastropod mollusc Patella has been thoroughly studied. As a result, two larval retractors, the main and accessory larval retractor, had been described in the larva of Patella. These muscles were supposed to be responsible for the retraction of the larval

  14. Spatial and temporal distribution of macrobenthos in different mangrove ecosystems of Tamil Nadu Coast, India.

    Science.gov (United States)

    Samidurai, K; Saravanakumar, A; Kathiresan, K

    2012-07-01

    This paper deals with the spatial distribution and diversity of macrobenthos and their relationships between physico-chemical parameters of the water and sediment in different mangrove habitats of Tamil Nadu, India during different seasons (2008). Among the different ecosystems of mangrove benthic faunal assemblages, macrofauna species number, density, richness, and Shannon-Wiener index were the highest and the Simpson dominance index was medial at riverine mangrove community. However, the Pielou Evenness index of riverine mangrove community was slightly lower than other communities. The similarities among the macrobenthic communities at different sampling sites were determined using Bray-Curtis similarity coefficient and ordinations of non-metric multidimensional scaling (MDS). Thirty-one species were recorded in developing (16 polychaetes, six bivalves, seven gastropods, and two crustaceans), 35 species were recorded in riverine (20 polychaetes, six bivalves, five gastropods, and four crustaceans) and 31 species were recorded in island mangrove ecosystem (19 polychaetes, four bivalves, five gastropods, and three crustaceans). Among the three ecosystems, a total of 46 benthic macrofauna consisting of 27 species of polychaetes, eight species of gastropods, seven species of bivalves, and four species of crustaceans were recorded. However, there were obvious differences among the community structures in the three mangrove habitats. This result implied that the different mangrove ecosystem had different effects on the macrofauna communities and shed light on the macrofauna adaptation capability to specific habitats.

  15. Exotic molluscs (Mollusca, Gastropoda et Bivalvia in Santa Catarina State, Southern Brazil region: check list and regional spatial distribution

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-06-01

    Full Text Available A total of twenty-one exotic mollusc taxa were assessed for Santa Catarina State (SC, fifteen Gastropoda andsix Bivalvia (twelve terrestrial, five limnic/freshwater - three gastropods and two bivalves, and four marinebivalves. Of these, fourteen are confirmed as invasive species (nine terrestrial, three limnic/freshwater, andtwo marine.

  16. Marine geophysical surveys off Kaverppattinam for archaeological investigations

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.

    extending parallel to the coast on 8 m water depth is recorded for a distance of more than 2 km between Chinnakudi and Chinnamodu. From the diving operations, it is confirmed that they correspond to heaps of shells (Gastropods) with their relief varying from...

  17. Global hindcasts and future projections of coastal nitrogen and phosphorus loads due to shellfish and seaweed aquaculture

    NARCIS (Netherlands)

    Bouwman, A.F.; Pawlowski, M.; Liu, C.; Beusen, A.H.W.; Shumway, S.E.; Glibert, P.M.; Overbeek, C.C.

    2011-01-01

    A model was developed to estimate nitrogen and phosphorus budgets for aquaculture production of crustaceans, bivalves, gastropods, and seaweed, using country production data for the 1970–2006 period from the Food and Agriculture Organization and scenarios based on the Millenium Assessment for 2006–2

  18. Habitat heterogeneity in the assemblages and shell use by the most abundant hermit crabs (Anomura: Diogenidae and Paguridae: does the occupied shell species differ according to gender and species?

    Directory of Open Access Journals (Sweden)

    Gilson Stanski

    Full Text Available Abstract The goal of this study was to identify patterns of shell occupation by different species of hermit crabs from the southern Brazilian coast. In total, 644 individuals were collected, represented by six hermit species. Isocheles sawayai Forest & Saint Laurent, 1968 showed the highest abundance, with 575 individuals, followed by Loxopagurus loxochelis (Moreira, 1901 (n = 56. The other species were Petrochirus diogenes (Linnaeus, 1758, Dardanus insignis (Saussure, 1858, Pagurus exilis (Benedict, 1892 and Pagurus leptonyx Forest & Saint Laurent, 1968. Loxopagurus loxochelis was found associated with shells of 12 gastropod species, with 75% of males occupying shells of Olivancilaria urceus (Roding, 1798 and 78% of females inhabiting shells of Semicassis granulata (Born, 1778. Shells of Semicassis granulata were the lightest of all gastropod shells, demonstrating differential resource utilization. Additionally, I. sawayai occupied shells of 10 species, highlighting Stramonita haemastoma (Linnaeus, 1767 with the highest occupation percentage in all demographic classes, confirming a pattern of occupation with a strong relationship to the availability of the resource. The comparison of our results with those of other studies corroborated the influence of region and gastropod diversity on gastropod shell occupation.

  19. Does bisphenol A induce superfeminization in Marisa cornuarietis? Part II

    DEFF Research Database (Denmark)

    Forbes, Valery E.; Aufderheide, John; Warbritton, Ryan;

    2007-01-01

    This study presents results of the effects of bisphenol A (BPA) on adult egg production, egg hatchability, egg development rates and juvenile growth rates in the freshwater gastropod, Marisa cornuarietis. We observed no adult mortality, substantial inter-snail variability in reproductive output...

  20. MOLLUSC SPECIES PROTECTED IN POLAND AND THREATENED IN EUROPE RECORDED IN STEPNICA RIVER (NW POLAND

    Directory of Open Access Journals (Sweden)

    Małgorzata Raczyńska

    2014-10-01

    Full Text Available In the course of the study two bivalve species protected in Poland were found in the river Stepnica: Sphaerium solidum and Sphaerium rivicola. Moreover, the study material collected from the river contained gastropod and bivalve specimens representing the following species from the IUCN Red List of Threatened Species: Theodoxus fluviatilis, Pisidium henslowanum, Pisidium casertanum and Pisidium pseudosphaerium.

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

    Science.gov (United States)

    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.

  2. The influence of trematodes on the macroalgae consumption by the common periwinkle Littorina littorea

    DEFF Research Database (Denmark)

    Clausen, Karin T.; Larsen, Martin H.; Iversen, Nina K.;

    2008-01-01

    gastropod Littorina littorea (L.) (Mollusca: Gastropoda), in turn affecting the composition of the macroalgal community on which the snail grazes. Here, we examine the effect of two species of trematodes, Renicola roscovita and Himasthla elongata, on L. littorea's consumption in two outdoor microcosm...

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

    Science.gov (United States)

    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.

  4. Novas ocorrências de gastrópodes e bivalves marinhos no Brasil (Mollusca

    Directory of Open Access Journals (Sweden)

    Absalão Ricardo Silva

    2003-01-01

    Full Text Available The gastropods Costaclis egregia (Dall, 1889, Thaleia nisonis (Dall, 1889, Tjaernoeia michaeli Engl, 2001 and the bivalves Bathyarca sp., Myonera aff. ruginosa (Jeffreys, 1882 are recorded for the first time in Brazilian waters. This paper presents a brief description of these species and also include ilustrations.

  5. How well-known is the Cephalaspidean fauna (Mollusca: Opisthobranchia) in the Indo-Pacific region?

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1998-01-01

    The gastropod group Cephalaspidea contains about 700 recent species worldwide. The status of the research on the group, indicated as the number of described species, in the tropical Indo-Pacific region is compared with other areas. The number ofspecies are 118 in the Indo-Pacific, 168 in Japan, a...

  6. The first record of Anisus vorticulus (Troschel, 1834 (Gastropoda: Planorbidae in Croatia?

    Directory of Open Access Journals (Sweden)

    Luboš Beran

    2009-12-01

    Full Text Available A threatened planorbid gastropod Anisus vorticulus (Troschel, 1834, listed in the EU Habitat Directive, was found in the Krka National Park in Croatia in August 2009. This find is the first known record at least in the western part of Croatia belonging to the Adriatic Sea drainage area.

  7. Measuring feeding traits of a range of litter-consuming terrestrial snails : Leaf litter consumption, faeces production and scaling with body size

    NARCIS (Netherlands)

    Astor, Tina; Lenoir, Lisette; Berg, Matty P.

    2015-01-01

    Plant litter decomposition is an essential ecosystem function that contributes to energy and nutrient cycling above- and belowground. Terrestrial gastropods can affect this process in various ways: they consume and fragment leaf litter and create suitable habitats for microorganisms through the prod

  8. Host diversity and latitude drive the trematode diversity patterns in the European freshwater fauna

    DEFF Research Database (Denmark)

    Thieltges, David W.; Hof, Christian; Dehling, D. Matthias;

    2011-01-01

    biogeographical regions in Europe from the Limnofauna Europaea and used multiple regression analyses to test for correlations between the diversity of definitive (vertebrates) or first intermediate (gastropods) hosts and that of trematodes, and for latitudinal gradients in trematode diversity. In particular, we...

  9. Primeiro registro de Antillorbis nordestensis (Lucena (Mollusca, Gastropoda, Planorbidae para a Ilha Grande, Angra dos Reis, Rio de Janeiro First record of Antillorbis nordestensis (Lucena (Mollusca, Gastropoda, Planorbidae to Ilha Grande, Angra dos Reis, Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Sônia Barbosa dos Santos

    1999-01-01

    Full Text Available A malacological survey has been done by the sênior author in Ilha Grande, State of Rio de Janeiro, since 1996. Up to this date the only freshwater gastropods found were specimens of Antillorbis nordestensis (Lucena, 1954. The snails were collected at a swampy area situated behind the late Penal Colony Cândido Mendes (Ilha Grande Prison.

  10. Ichnotaxa for bite traces of thetrapods : A new area of research or a total waste of time?

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland; Bromley, Richard Granville

    as a whole, as in Gnathichnus for echinoid bioerosion and Radulichnus for chiton and gastropod bioerosion, it is our conviction that tetrapod biting trace fossil nomenclature generally should be based on the damage caused by single teeth. Where several teeth have left traces as a group, this may...

  11. Host specificity and phylogenetic relationships among Atlantic Ovulidae (Mollusca: Gastropoda)

    NARCIS (Netherlands)

    Reijnen, B.T.; Hoeksema, B.W.; Gittenberger, E.

    2010-01-01

    Ovulid gastropods and their octocoral hosts were collected along the leeward coast of Curaçao, Netherlands Antilles. New molecular data of Caribbean and a single Atlantic species were combined with comparable data of Indo-Pacific Ovulidae and a single East-Pacific species from GenBank. Based on two

  12. Evidence for the validity of Protatlanta sculpta (Gastropoda: Pterotracheoidea)

    NARCIS (Netherlands)

    Wall-Palmer, D.; Burridge, A.K.; Peijnenburg, K.C.T.A.; Janssen, A.; Goetze, E.; Kirby, R.; Hart, M.B.; Smart, C.W.

    2016-01-01

    The genus Protatlanta is thought to be monotypic and is part of the Atlantidae, a family of shelled heteropods. These microscopic planktonic gastropods are poorly known, although research on their ecology is now increasing in response to concerns about the effects of ocean acidification on calcareou

  13. Global biogeography and evolution of Cuvierina pteropods

    NARCIS (Netherlands)

    Burridge, A.K.; Goetze, E.; Raes, N.; Huisman, J.; Peijnenburg, K.T.C.A.

    2015-01-01

    Background: helled pteropods are planktonic gastropods that are potentially good indicators of the effects of ocean acidification. They also have high potential for the study of zooplankton evolution because they are metazoan plankton with a good fossil record. We investigated phenotypic and genetic

  14. An in situ study using caged Nucella lapillus and Crassostrea gigas to monitor TBT induced bio-effects in Irish coastal waters

    DEFF Research Database (Denmark)

    Giltrap, M.; Macken, A.; Minchin, D.

    /L. TBT has been linked to shell thickening and reduced meat yields in oysters and perhaps more significantly to the onset of imposex, i.e. the imposition of male sexual organs on female gastropods, with this index being internationally recognised as a bio-indicator of TBT pollution. Species...

  15. Omnivory and grazer functional composition moderate cascading trophic effects in experimental Fucus vesiculosus habitats

    NARCIS (Netherlands)

    Eriksson, Britas Klemens; van Sluis, Christiaan; Sieben, Karin; Kautsky, Lena; Raberg, Sonja

    2011-01-01

    We tested the relative strength of direct versus indirect effects of an aquatic omnivore depending on the functional composition of grazers by manipulating the presence of gastropod and amphipod grazers and omnivorous shrimp in outdoor mesocosms. By selectively preying upon amphipods and reducing th

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

    Institute of Scientific and Technical Information of China (English)

    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 againstStaphylococcus aureus in the crude methanol extract of B. spirata. Water extract of B. spirata showed the highest activity against Vibrio parahaemolyticus, Staphylococcus aureus and Candidaalbicans. 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.

  17. Transport of Optically Active Particles from the Surface Mixed Layer

    Science.gov (United States)

    2005-09-30

    aragonite in the form of abundant coccoliths and coccospheres, and occasional forams, pteropods and larval gastropods . The δ18O signature of the 2003... APPLICATIONS These experiments were designed to identify the major loss terms of optically-active particles. This indeed was accomplished. Such

  18. Novel Acoustic Techniques for Assessing Fish Schooling in the Context of an Operational Ocean Observatory

    Science.gov (United States)

    2008-09-30

    and onshore waters. A unique acoustic scattering source was identified during the experiment as dense, monotypic aggregations of a pelagic gastropod ...can often reveal hidden coherent structure. IMPACT/ APPLICATIONS The distribution of fish and the variability in their distribution has...direct and waveguide scattering for application to fish. REFERENCES Pitcher, T. J., and J. K. Parrish. 1993. Function of shoaling behavior in teleosts

  19. Zooplankton Avoidance of a Profiled Open-Path Fluorometer

    Science.gov (United States)

    2010-01-01

    gastropods , or those with air inclusions suggest that we can reasonably use 200 kHz scattering as an estimate of relative abundance of these...finite-length cylinders with applications to sound scattering by zooplankton. J. Acoust. Soc. Am., 103, 254. Stearns, D. and Forward, R. (1984

  20. Pedicularia vanderlandi spec. nov., a symbiotic snail (Caenogastropoda: Ovulidae) on the hydrocoral Distichopora vervoorti Cairns & Hoeksema, 1998 (Hydrozoa: Stylasteridae), from Bali, Indonesia

    NARCIS (Netherlands)

    Goud, J.; Hoeksema, B.W.

    2001-01-01

    A new species of ovulid gastropod is described from Bali as Pedicularia vanderlandi spec. nov. It was predominantly found in shallow water on the stylasterid hydrocoral Distichopora vervoorti Cairns & Hoeksema, 1998. The snails are compared with type specimens of congeneric taxa and with material of

  1. A new genus and species of Aclididae (Gastropoda) from off Tenerife, Canary Islands

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Warén, A.

    1987-01-01

    Dr. Manuel Carrillo Pèrez (Universidad de la Laguna) has sent some dredge-samples to the first author. This material contained many interesting molluscs, not mentioned by Nordsieck & Talavera (1979). Amongst them was a very peculiar gastropod species, which was difficult to identify. Based on some s

  2. General characteristics of the diet of Trachinotus paitensis (Teleostei: Carangidae) from San Ignacio Lagoon, Baja California Sur, Mexico.

    Science.gov (United States)

    Cruz Escalona, V H; Abitia Cárdenas, L A

    2004-03-01

    The food habits of Trachinotus paitensis, in San Ignacio Lagoon B.C.S., Mexico, were investigated. We observed that T. paitensis is carnivorous, feeding mainly on benthic invertebrates (the gastropods Anachis spp., Bittium spp., and the crustacean larvae). We concluded that T. paitensis is an opportunist predator that impacts mainly on epibenthic invertebrates.

  3. Stratigraphy Konkian-Sarmatian deposits in the south of Ukraine by molluscs (Middle - Upper Miocene

    Directory of Open Access Journals (Sweden)

    Staryn D.A.

    2014-12-01

    Full Text Available The results of study marine bivalve and gastropod from konkian-sarmatian deposits of the Southern Ukraine are gave. Their lateral and vertical distribution is studied. Local stratigraphic schemes for the Northern Black Sea region,Flat Crimea and Kerch peninsula.

  4. Seasonal variation in organotins in the waters of the Dona Paula Bay, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Meena, R.M.; Garg, A.; Jadhav, S.

    . 2000; Zhou et al. 2003), shell thickening in oysters (Alzieu et al. 1986), imposex in gastropods and snails (Law et al. 1998; Zhou et al. 2003; Evans et al. 2000; Gomez-Ariza et al. 2006), and immunological dysfunction in fishes (Zhou et al. 2003...

  5. Records of Auger shells (Negastropoda: Terebridae) from Andaman and Nicobar Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Abidi, S.A.H.; Haridevi, C.K.

    are the modern marine snails and include many well-known gastropods such as the cones, conchs, mud snails, olive snails, oyster drill, turnip snails and auger shells. They have one auricle, one kidney and one monopectinate gill. Family Terebridae (Adams, 1938...

  6. Marine ecology — some chemical aspects

    Science.gov (United States)

    Scheuer, Paul J.

    1982-11-01

    Relationships among biota on tropical coral reefs are frequently governed by chemical phenomena. This article describes some of the ecological events that may lead to a human intoxication known as ciguatera, and a few examples of the survival strategy that is used by physically unprotected gastropod mollusks.

  7. Accumulation and effects of sediment-associated silver nanoparticles to sediment-dwelling invertebrates

    DEFF Research Database (Denmark)

    Ramskov, Tina; Forbes, Valery E; Gilliland, Douglas;

    2015-01-01

    are in high demand. Here, we examine the effects of exposure to sediment mixed with either aqueous Ag (administered as AgNO3) or Ag NPs (13 nm, citrate-capped) at a nominal exposure concentration of 100 μg Ag/g dry weight sediment on four benthic invertebrates: two clones of the gastropod Potamopyrgus...

  8. Cellular Neurophysiology of the Rat Suprachiasmatic Nucleus: Electrical Properties, Neurotransmission, and Mechanisms of Synchronization

    Science.gov (United States)

    1994-07-29

    of potentials from motoneurones with an intracellular electrode. J. Physiol., Lond 117, 431-460. 16. Bruner G. and Murphy S. (1990) ATP-evoked...gastropod, Bulla. J. Neurocytol. 12, 673-696. 63. Jacklet J. W. and Geronimo J. (1971) Circadian rhythm: population of interacting neurons. Science 174, 299

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Mitochondrial and morphological differentiation in a previously unrecognized radiation of the land snail genus Parachloritis Ehrmann, 1912 on Timor (Pulmonata: Camaenidae)

    NARCIS (Netherlands)

    Köhler, F.; Kessner, V.

    2014-01-01

    The present work revises the taxonomy of one group of camaenid gastropods from Timor-Leste based on the study of a large number of recently collected ethanol preserved samples as well as historic museum material, including types. By employing comparative analyses of the variation in morphological fe

  11. 78 FR 40104 - Endangered and Threatened Wildlife; 12-Month Finding on Petitions To List the Northeastern...

    Science.gov (United States)

    2013-07-03

    ... include marine reptiles (mostly sea turtles), larger cephalopods, gastropods, and crustaceans. White... located approximately midway between the west coast of North America and the Hawaiian Islands and then... movements are restricted to the coastal waters of North America. Results from genetic studies using...

  12. The snails' tale in deep-sea habitats in the Gulf of Cadiz (NE Atlantic)

    Science.gov (United States)

    Génio, L.; Warén, A.; Matos, F. L.; Cunha, M. R.

    2013-07-01

    Bridging the Atlantic and Mediterranean continental margins, the South Iberian region has recently been the focus for geological and biological investigations. In this region, the Gulf of Cadiz (GoC) encompasses a great variety of deep-sea habitats that harbour highly diverse biological communities. In this study, we describe the composition of gastropod assemblages obtained from in situ colonization experiments and benthic sampling of deep-sea habitats in the GoC. Gastropod distributional patterns, such as bathymetric ranges, bathymetric turnover, affinity to substrate types and abundance-occupancy relationships, are analysed and interpreted in relation to their inferred dispersal capabilities and substrate availability. Overall, the GoC comprises a high diversity of gastropods (65 species), and distinct assemblages were found in typical sedimentary environments at mud volcanoes and in association with carbonate and coral samples or organic substrata. The number of taxa peaked at the Carbonate Province in the middle slope (600-1200 m depth), a highly heterogeneous area with numerous mud volcanoes, carbonate mounds and corals. Darwin (1100 m) and Captain Arutyunov (1300 m) mud volcanoes harboured the most species-rich and abundant gastropod assemblages, respectively. Colonization experiments with organic substrata (wood and alfalfa grass) also yielded diverse and abundant gastropod assemblages. These organic inputs allowed the recruitment of local species but mainly of wood specialist taxa that were not previously known from the GoC. Our results suggest that the distribution of gastropod assemblages may be primarily determined by the occurrence of suitable habitats, probably due to the effect of the substrate type on the structural complexity of the habitat and availability and diversity of adequate food sources. The type of larval development is apparently not a limiting factor for colonization of deep-sea habitats. However, the predominance of non

  13. The snails' tale in deep-sea habitats in the Gulf of Cadiz (NE Atlantic

    Directory of Open Access Journals (Sweden)

    L. Génio

    2013-07-01

    Full Text Available Bridging the Atlantic and Mediterranean continental margins, the South Iberian region has recently been the focus for geological and biological investigations. In this region, the Gulf of Cadiz (GoC encompasses a great variety of deep-sea habitats that harbour highly diverse biological communities. In this study, we describe the composition of gastropod assemblages obtained from in situ colonization experiments and benthic sampling of deep-sea habitats in the GoC. Gastropod distributional patterns, such as bathymetric ranges, bathymetric turnover, affinity to substrate types and abundance-occupancy relationships, are analysed and interpreted in relation to their inferred dispersal capabilities and substrate availability. Overall, the GoC comprises a high diversity of gastropods (65 species, and distinct assemblages were found in typical sedimentary environments at mud volcanoes and in association with carbonate and coral samples or organic substrata. The number of taxa peaked at the Carbonate Province in the middle slope (600–1200 m depth, a highly heterogeneous area with numerous mud volcanoes, carbonate mounds and corals. Darwin (1100 m and Captain Arutyunov (1300 m mud volcanoes harboured the most species-rich and abundant gastropod assemblages, respectively. Colonization experiments with organic substrata (wood and alfalfa grass also yielded diverse and abundant gastropod assemblages. These organic inputs allowed the recruitment of local species but mainly of wood specialist taxa that were not previously known from the GoC. Our results suggest that the distribution of gastropod assemblages may be primarily determined by the occurrence of suitable habitats, probably due to the effect of the substrate type on the structural complexity of the habitat and availability and diversity of adequate food sources. The type of larval development is apparently not a limiting factor for colonization of deep-sea habitats. However, the predominance of non

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

    Science.gov (United States)

    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.

  15. Discovery of new hydrothermal activity and chemosynthetic fauna on the Central Indian Ridge at 18°-20° S.

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    Kentaro Nakamura

    Full Text Available Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called 'scaly-foot' gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean. Here we report two newly discovered hydrothermal vent fields, the Dodo and Solitaire fields, which are located in the Central Indian Ridge (CIR segments 16 and 15, respectively. Chemosynthetic faunal communities at the Dodo field are emaciated in size and composition. In contrast, at the Solitaire field, we observed faunal communities that potentially contained almost all genera found at CIR hydrothermal environments to date, and even identified previously unreported taxa. Moreover, a new morphotype of 'scaly-foot' gastropod has been found at the Solitaire field. The newly discovered 'scaly-foot' gastropod has similar morphological and anatomical features to the previously reported type that inhabits the Kairei field, and both types of 'scaly-foot' gastropods genetically belong to the same species according to analyses of their COI gene and nuclear SSU rRNA gene sequences. However, the new morphotype completely lacks an iron-sulfide coating on the sclerites, which had been believed to be a novel feature restricted to 'scaly-foot' gastropods. Our new findings at the two newly discovered hydrothermal vent sites provide important insights into the biodiversity and biogeography of vent-endemic ecosystems in the Indian Ocean.

  16. The snails' tale at deep-sea habitats in the Gulf of Cadiz (NE Atlantic)

    Science.gov (United States)

    Génio, L.; Warén, A.; Matos, F. L.; Cunha, M. R.

    2013-02-01

    Bridging the Atlantic and Mediterranean continental margins, the South Iberian region has recently been the focus for geological and biological investigations. The Gulf of Cadiz (GoC) encompasses a great variety of deep-sea habitats that harbour highly diverse biological communities. In this study, we describe the taxa composition of gastropod assemblages from deep-sea habitats in the GoC and analyse the species distributional patterns in relation to their dispersal capabilities and substrate availability. Distinct gastropod assemblages were found at mud volcanoes, carbonate and coral sites, and organic-falls. Overall, the GoC comprises a high diversity of gastropods that include 65 taxa representing 32 families, 48 genera and 30 named species. The highest number of taxa was found at the highly heterogeneous carbonate province in the middle slope (500-1500 m depth), and higher abundance of individuals was observed in Captain Arutyunov mud volcano, one of the most active sites found in the GoC. Faunal similarities were found with Mediterreanean cold-seeps (species- and genus-level) and other chemosynthetic environments in the Atlantic and Pacific Oceans (genus-level). Colonization experiments with organic substrata (wood and alfalfa grass) yielded high abundances of gastropod species. These organic inputs allowed the recruitment of local species but also of wood specialist taxa that were not known to occur in the GoC. Our results suggest that distribution of gastropod assemblages may be primarily determined by the occurrence of suitable habitats probably due to effect of the substrate type on feeding strategies and that larval development is not a limiting factor for colonization of the deep sea. However, the predominance of non-planktotrophy, and especially lecithotrophy, suggests that the trade-off between a more limited dispersal capability and the higher potential for self-recruitment may be favoured by the gastropod species inhabiting reducing environments and

  17. The snails' tale at deep-sea habitats in the Gulf of Cadiz (NE Atlantic

    Directory of Open Access Journals (Sweden)

    L. Génio

    2013-02-01

    Full Text Available Bridging the Atlantic and Mediterranean continental margins, the South Iberian region has recently been the focus for geological and biological investigations. The Gulf of Cadiz (GoC encompasses a great variety of deep-sea habitats that harbour highly diverse biological communities. In this study, we describe the taxa composition of gastropod assemblages from deep-sea habitats in the GoC and analyse the species distributional patterns in relation to their dispersal capabilities and substrate availability. Distinct gastropod assemblages were found at mud volcanoes, carbonate and coral sites, and organic-falls. Overall, the GoC comprises a high diversity of gastropods that include 65 taxa representing 32 families, 48 genera and 30 named species. The highest number of taxa was found at the highly heterogeneous carbonate province in the middle slope (500–1500 m depth, and higher abundance of individuals was observed in Captain Arutyunov mud volcano, one of the most active sites found in the GoC. Faunal similarities were found with Mediterreanean cold-seeps (species- and genus-level and other chemosynthetic environments in the Atlantic and Pacific Oceans (genus-level. Colonization experiments with organic substrata (wood and alfalfa grass yielded high abundances of gastropod species. These organic inputs allowed the recruitment of local species but also of wood specialist taxa that were not known to occur in the GoC. Our results suggest that distribution of gastropod assemblages may be primarily determined by the occurrence of suitable habitats probably due to effect of the substrate type on feeding strategies and that larval development is not a limiting factor for colonization of the deep sea. However, the predominance of non-planktotrophy, and especially lecithotrophy, suggests that the trade-off between a more limited dispersal capability and the higher potential for self-recruitment may be favoured by the gastropod species inhabiting reducing

  18. Sex steroid imbalances in the muricid Stramonita haemastoma from TBT contaminated sites.

    Science.gov (United States)

    Rossato, M; Castro, I B; Paganini, C L; Colares, E P; Fillmann, G; Pinho, G L L

    2016-04-01

    Imposex incidence, organotin tissue levels, and sex steroid (free and esterified testosterone and estradiol) levels were assessed in Stramonita haemastoma from Babitonga Bay (Santa Catarina State, Southern Brazil). The imposex levels showed a reduction when compared to a previous evaluation performed in the same area. In spite of that, the detected imposex incidence indicated the occurrence of tributyltin (TBT) inputs that were still able to produce endocrine disruption in local gastropods. In addition, a high level of organotins was observed in tissues of imposexed females. These females also showed a hormonal imbalance, especially in the total testosterone/total estradiol ratio. These findings obtained under realistic field conditions suggest that the steroid pathway could be responsible by the imposex induction after exposure to TBT. In this case, measurements of sex steroid levels can be an additional evidence for monitoring sites and impose affected gastropod populations.

  19. BIOGEOGRAPHY. The dispersal of alien species redefines biogeography in the Anthropocene.

    Science.gov (United States)

    Capinha, César; Essl, Franz; Seebens, Hanno; Moser, Dietmar; Pereira, Henrique Miguel

    2015-06-12

    It has been argued that globalization in human-mediated dispersal of species breaks down biogeographic boundaries, yet empirical tests are still missing. We used data on native and alien ranges of terrestrial gastropods to analyze dissimilarities in species composition among 56 globally distributed regions. We found that native ranges confirm the traditional biogeographic realms, reflecting natural dispersal limitations. However, the distributions of gastropods after human transport are primarily explained by the prevailing climate and, to a smaller extent, by distance and trade relationships. Our findings show that human-mediated dispersal is causing a breakdown of biogeographic barriers, and that climate and to some extent socioeconomic relationships will define biogeography in an era of global change.

  20. Molecular approaches to understand biomineralization of shell nacreous layer.

    Science.gov (United States)

    Xie, Li-Ping; Zhu, Fang-Jie; Zhou, Yu-Juan; Yang, Chao; Zhang, Rong-Qing

    2011-01-01

    The nacreous layer of molluskan shells, which consists of highly oriented aragonitic crystals and an organic matrix (including chitin and proteins), is a product of biomineralization. This paper briefly introduces the recent research advances on nacre biomineralization of shells from bivalves and gastropods, which mainly focus on analysis of the micro- and nano-structure and components of shell nacreous layers, and investigations of the characteristics and functions of matrix proteins from nacre. Matrix proteins not only participate in construction of the organic nacre framework, but also control the nucleation and growth of aragonitic crystals, as well as determine the polymorph specificity of calcium carbonate in nacre. Moreover, the inorganic aragonite phase also plays an active role in organizing nacre microstructure. Based on these studies, several models to illustrate the formation mechanism related to lamellar nacre in bivalves, and columnar nacre in gastropods are introduced.

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

    Science.gov (United States)

    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.

  2. Extensive mitochondrial genome rearrangements between Cerithioidea and Hypsogastropoda (Mollusca; Caenogastropoda) as determined from the partial nucleotide sequences of the mitochondrial DNA of Cerithidea djadjariensis and Batillaria cumingi.

    Science.gov (United States)

    Kojima, Shigeaki

    2010-06-01

    Partial nucleotide sequences ( approximately 8000 bp) of the mitochondrial DNA of two cerithioidean gastropod species-Cerithidea djadjariensis and Batillaria cumingi-were determined. The order of mitochondrial genes (eight protein genes, two ribosomal RNA genes, and nine transfer RNA genes) was identical between these two species. and remarkably different from the previously reported order in other gastropods. The results indicate that the genome structure of the common ancestor of Cerithioidea and its sister group, Hypsogastropoda, is almost identical to that of the common ancestor of Gastropoda; moreover, independent mitochondrial genome rearrangements were identified between the lineages of Cerithioidea and Hypsogastropoda. The rearrangements within Cerithioidea can be explained by the inversion of a single tRNA gene, two translocations of a single tRNA gene, and three translocations of a genome fragment containing a tRNA gene and protein-coding gene(s).

  3. Ultrastructure of spermatozoa of Bullacta exarata (philippi) and its significance on reproductive evolution and physio-ecological adaptation

    Institute of Scientific and Technical Information of China (English)

    应雪萍; 杨万喜; 姜乃澄; 张永普

    2004-01-01

    The morphology and ultrastructure of Bullacta exarata spermatozoa observed by light and transmission electron microscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal complex and an elongated nucleus, and tail with a midpiece, principal piece and an end piece. The midpiece consists of a mitochondrial ring, and the principal piece is composed of axoneme and lateral fin. The structure of B. exarata spermatozoa differs significantly from that of other gastropods, especially in the lateral fin and the principal piece, which was described scarcely before. A comparison is made between B. exarata and other gastropods, and its significance on reproductive evolution and physio-ecological adaptation is preliminarily discussed.

  4. The nonmarine environment of Quaternary foraminifers in Yanshuzhuang, China: Evidence from boron and strontium isotopes

    Institute of Scientific and Technical Information of China (English)

    XIAO YingKai; XIAO Jun; ZHAO ZhiQi; HE MaoYong; LI ShiZhen

    2008-01-01

    The concentrations and isotopic compositions of boron and strontium of Quaternary foraminifers and bivalve fossils collected in the Yanghuzhuang section of Yanqing, Beijing and of modern gastropods living in the Guishui River and of river water were measured. The concentrations and isotopic compo-sitions of Quaternary foraminifers and bivalve fossils differed from those of modern marine fo-raminifers and were similar to those of modern terrestrial gastropods from the Guishui River. These results indicate that early Quaternary foraminifers in the Yanghuzhuang section inhabited a nonmarine environment and that these foraminifers were not the result of a transgression or sea flooding. The foraminifers were not special halobios and can survive in the terrestrial condition that resembled those of the ocean.

  5. Silurian Gastropoda from the Alexander terrane, southeast Alaska

    Science.gov (United States)

    Rohr, D.M.; Blodgett, R.B.

    2008-01-01

    Gastropods are described from Ludlow-age strata of the Heceta Limestone on Prince of Wales Island, southeast Alaska. They are part of a diverse megabenthic fauna of the Alexander terrane, an accreted terrane of Siberian or Uralian affinities. Heceta Limestone gastropods with Uralian affinities include Kirkospira glacialis, which closely resembles "Pleurotomaria" lindstromi Oehlert of Chernyshev, 1893, Retispira cf. R. volgulica (Chernyshev, 1893), and Medfracaulus turriformis (Chernyshev, 1893). Medfracaulus and similar morphotypes such as Coelocaulus karlae are unknown from rocks that are unquestionably part of the North American continent (Laurentia) during Late Silurian time. Beraunia is previously known only from the Silurian of Bohemia. Pachystrophia has previously been reported only from western North American terranes (Eastern Klamath, York, and Farewell terranes) and Europe. Bathmopterus Kirk, 1928, is resurrected and is only known from the Silurian of southeast Alaska. Newly described taxa include Hecetastoma gehrelsi n. gen. and n. sp. and Baichtalia tongassensis n. gen. and n. sp. ??2008 The Geological Society of America.

  6. Macrozoobenthos of the danubean lake Crivoe in the conditions of anthropogenous influence

    Directory of Open Access Journals (Sweden)

    Y. M. Dzhurtubaev

    2012-01-01

    Full Text Available In the summer of 2009 macrozoobenthos of the danubean Lake Crivoe, located in the Odessaarea was studied. 26 species of sponges, annelids, crustaceans, insects, gastropods and bivalves were revealed. In the upper and middle part of the lake 24 were found, in the lower one 9 species were detected. Oligochetes, and larvae of dragonflies and chironomids are characterised by the greatest number (up to 300 spec/m², the greatest biomass was found for gastropod molluscs (to 17 g/m². The total maximal number of the macrozoobenthos reached 880 spec/m² and biomass – 40.2 g/m². Benthic faunas of two lakes, Crivoe and Lung, were compared.

  7. Doplněk k poznání vodních měkkýšů Labe mezi Hřenskem a Střekovem a srovnání s malakofaunou Labe v jiných úsecích

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    Luboš Beran

    2009-11-01

    Full Text Available This paper completes knowledge on aquatic molluscs of the free flowing part of the Elbe River between Hřensko and the weir with lock in Ústí nad Labem – Střekov. Altogether, 21 species of aquatic molluscs (9 gastropods, 12 bivalves were found in 2009. Viviparus viviparus, Potamopyrgus antipodarum, Bithynia tentaculata, Ancylus fluviatilis, Unio pictorum, Anodonta anatina, Corbicula fluminea, Sphaerium corneum and Pisidium supinum were the most frequently occurring molluscs found during this research. The occurrence of two endangered bivalves Pseudanodonta complanata and Pisidium moitessierianum was recorded. No significant difference from the previous author’s research was found. Molluscan communities of this part of the river were compared with those of the upper canalized part of the Elbe River which contain more species (especially gastropods living predominantly in stagnant or slowly flowing waters e. g. Stagnicola palustris, S. corvus, Lymnaea stagnalis, Planorbis planorbis, Bathyomphalus contortus, Anisus vortex, Hippeutis complanatus, Ferrissia fragilis.

  8. A late Burdigalian bathyal mollusc fauna from the Vienna Basin (Slovakia)

    Science.gov (United States)

    Harzhauser, Mathias; Mandic, Oleg; Schlögl, Jan

    2011-06-01

    This is the first record of a bathyal mollusc fauna from the late Early Miocene of the Central Paratethys. The assemblage shows clear affinities to coeval faunas of the Turin Hills in the Mediterranean area and the Aquitaine Basin in France. The overall biostratigraphic value of the assemblage is hard to estimate due to the general very poor knowledge of Miocene bathyal faunas. Several species, however, are known from deep water deposits of the Middle Miocene Badenian stage as well. This implies Early Miocene roots of parts of the Middle Miocene deep water fauna and suggests a low turnover for bathyal mollusc communities at the Early-Middle Miocene boundary. The nassariid gastropod Nassarius janschloegli Harzhauser nov. sp. and the naticid gastropod Polinices cerovaensis Harzhauser nov. sp. are introduced as new species.

  9. Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

    OpenAIRE

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

    While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lem...

  10. Hábitos de Vida da Associação “Schuchertella”agassizi – Pthychopteria eschwegei, Formação Maecuru,Devoniano, Bacia do Amazonas, Brasil.

    Directory of Open Access Journals (Sweden)

    Luiza Corral Martins de Oliveira Ponciano

    2007-07-01

    Full Text Available The fossils studied came from outcrops of the Maecuru and Curuá rivers, State of Pará, belonging to the upper strata of theMaecuru Formation, Eifelian age. In this formation, two associations of marine benthic invertebrate can be identified, each inferring adistinct paleoenvironment. The association analyzed occurs in medium and coarse sandstones and shows “Schuchertella” agassizi andPtychopeteria eschwegei as predominant organisms. It was idnetified 12 species of brachiopods, 20 species of bivalves, 12 of trilobites,8 of gastropods, 6 of bellerophonts, 3 of crinoids and 3 of tentaculitids in this association. Brachiopods are the most abundant organisms,responsible for approximately 50% of it, followed by tentaculitids and bivalves. Trilobites, gastropods and bellerophonts sum less than10% of the aforementioned association. Crinoids were not included in the quantitative analysis because they are only found as calicinalplates and disarticulated column disks. The brachiopods showed, through their morphofunctional characteristics, suspension feedersrecumbent (free-lying epifaunal life habit or a pedicle attached mode of life. The bivalves showed a predominant suspension feeder semiinfaunalhabit, attached by byssus threads to the substratum, and an infaunal mode of life. All the trilobites showed a predator/scavengerand vagile epifaunal habit. The epifaunal platyceratids represents the gastropods with low mobility (coprophagous/suspension feeders.The bellerophonts showed an epifaunal highly/medium mobility and grazing/predator habit. The tentaculitids having a semi-infaunal,suspension feeder habit. The suspension feeder forms (brachiopods, bivalves and tentaculitids account for over 90% of the organisms, withthe remaining percentage distributed among the predator/scavenger (trilobites, coprophagous/suspension feeders (gastropods, grazers/predators (bellerophonts and deposit feeders (rare bivalves. The predominance of suspension feeder forms

  11. Responses of the molluscan fauna to environmental variations in a Halodule wrightii Ascherson ecosystem from Northeastern Brazil

    OpenAIRE

    BARROS,KCRISHNA V.S.; Rocha-Barreira,Cristina A

    2013-01-01

    ABSTRACT This study observed the spatial and temporal distributions of molluscs in a Halodule wrightii meadow, verifying if they respond satisfactorily to seasonal changes in this seagrass ecosystem. Twenty-four species were identified. Chitons were rare, bivalves had greater number of species (11), followed by gastropods (9) which were also the most abundant class (73%). All classes were more abundant in the belowground. The most common species was Tricolia affinis, especially in aboveground...

  12. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA

    OpenAIRE

    Jacquemin, Stephen J.; Jun A. Ebersole; Dickinson, William C.; Charles N Ciampaglio

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) lead...

  13. Radionuclide transfer to freshwater biota species: review of Russian language studies

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, S., E-mail: s.fesenko@iaea.or [International Atomic Energy Agency, NAAL, 1400 Vienna (Austria); Fesenko, J.; Sanzharova, N.; Karpenko, E.; Titov, I. [Russian Institute of Agricultural Radiology and Radioecology, 249020 Obninsk (Russian Federation)

    2011-01-15

    Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for {sup 241}Am (bivalve molluscs, gastropods and pelagic fish), {sup 60}Co (gastropods, benthic fish and insect larvae), {sup 90}Sr and {sup 137}Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species. - Research highlights: {yields} The paper provides information on concentration ratios to freshwater biota species for 35 radionuclides. Many of the data are for {sup 90}Sr and {sup 137}Cs. {yields} For the majority of radionuclides reviewed in this paper, the CR values are in good agreement with those given in the recent International reviews. {yields} For {sup 241}Am (bivalve molluscs, gastropods and pelagic fish), {sup 60}Co (gastropods, benthic fish and insect larvae), {sup 90}Sr and {sup 137}Cs (benthic fish and zooplankton), the mean values based on review of the Russian language publications are substantially different from those presented in the International reviews. {yields} Information presented in the paper significantly increases the availability of data on radionuclide accumulation in freshwater species.

  14. Hábitos de Vida dos Gastropoda e Bellerophontida da Formação Maecuru,Devoniano Médio, Bacia do Amazonas, Brasil

    Directory of Open Access Journals (Sweden)

    Luiza Corral Martins de Oliveira Ponciano

    2007-07-01

    Full Text Available The Maecuru Formation comprises the Devonian-Carboniferous sedimentary sequence of Amazonas Basin and consists of fluvialdeltaics and pelites layers. Its fossiliferous sediments (the uppermost part of the Lontra Member consists of hummocky cross-stratified fine-grained to very coarse sandstones beds.With the purpose of adding more information about the palaeoecology of The Maecuru Formation fossils, the life habits of gastropods and bellerophontids were inferred based on functional analysis and similarities with the living forms. The more significant features used were: (1 total frontal cross-sectional area, (2height and relative positions of pressure point and center of gravity, (3 apertural margin morphology, (4 kind of symmetry and (5surface smoothness. The species Platyceras (Orthonychia steinmanni; Platyceras (Tumbophalus hartti; Platyceras (Platyostomadarwini; Platyceras (Platyostoma (? agassizi; Platyceras (Orthonychia meerwarthi; Platyceras (Orthonychia gracilis; Platyceras (Tumbophalus coutoanus; “Platyceras” tschernischewi; “Platyceras” subconicum; “Platyceras” (Ortonychia hussaki; “Platyceras” (Ortonychia whitii; “Platyceras” (Ortonychia whitii var. curua and “Platyceras” symmetricum var. maecuruensis represent the epifaunal gastropods with low mobility (coprophagous/suspension feeders of the Maecuru Formation, living symbiotically directly over the anus of a crinoid or nearby. This coprophagous mode of life was probably a non-obligate relationship, because only the closest organisms will get all the advantages of using the crinoid host as a nutrient source. The others adult platyceratids would have a broader feeding repertoire, like as suspension feeders. The bellerophonts Plectonotus (Plectonotus derbyi, Plectonotus (? (Plectonotus salteri e Bucanella reissi would have an epifaunal medium to high mobility, showing a predator habit preferably. On the other hand Bucania freitasi, Ptomatis forbesi and

  15. Parasites and personality in periwinkles (Littorina littorea): Infection status is associated with mean-level boldness but not repeatability.

    Science.gov (United States)

    Seaman, Ben; Briffa, Mark

    2015-06-01

    We demonstrate the presence of animal personality in an inter-tidal gastropod, Littorina littorea, both in a sample of individuals infected by the trematode Cryptocotyle lingua and in an uninfected sample. On average infected individuals behaved more cautiously than individuals free of infection, but the parasite did not affect repeatability. Although the parasite is not associated with greater diversity of behaviour amongst infected individuals, infection might be associated with state-dependent personality differences between infected and non-infected individuals.

  16. The use of intertidal molluscs in the monitoring of heavy metals and organotin compounds in the west coast of Peninsular Malaysia

    OpenAIRE

    Ismail, Ahmad

    2006-01-01

    Over 60% of human activities in the west coast of Peninsular Malaysia are concentrated in the coastal areas. High human activities in the coastal areas may cause hazardous chemical pollution. In this report, intertidal molluscs were used to assess heavy metals pollution in the coastal areas of the west coast of Peninsular Malaysia. Intertidal gastropods such as Thais, Cherithedia and Nerita, and bivalves such as Anadara, Isognomon alatus and Perna viridis have been studied and analysed for th...

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

    Directory of Open Access Journals (Sweden)

    Ricardo Cordeiro

    2015-02-01

    Full Text Available 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., S. ermelindoi sp. n., S. 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.

  18. Molluscan immunorecognition

    Directory of Open Access Journals (Sweden)

    E Ottaviani

    2006-06-01

    Full Text Available The immune system in molluscs, as well as in other invertebrates, is endowed with an innate immuneresponse which, however, shows in its recognition processes both molecular mechanisms andeffectors similar to those employed by vertebrates in eliminating pathogens and parasites.Furthermore, as in vertebrates, invertebrates also present a profound correlation between immuneand neuroendocrine responses. In this review, the players in the immune and neuroendocrine systemshave been examined, with particular references to gastropods and bivalves.

  19. Confirmation of the identification and establishment of the South American slipper limpet Crepipatella dilatata (Lamark 1822) (Caenogastropoda: Calyptraeidae) in Northern Spain

    OpenAIRE

    2009-01-01

    Calyptraeid gastropods have been introduced frequently in bays and ports around the world, and have become rampantly invasive in several cases. Here we confirm the identification and establishment of a recently-detected population of Crepipatella in northern Spain. Because their shells do not have many diagnostic features, introductions of calyptraeids are often accompanied by confusion about the identity and therefore origin of the species in question. We use DNA sequence data and developmen...

  20. Comparative genomic analysis reveals species-dependent complexities that explain difficulties with microsatellite marker development in molluscs

    OpenAIRE

    2010-01-01

    Reliable population DNA molecular markers are difficult to develop for molluscs, the reasons for which are largely unknown. Identical protocols for microsatellite marker development were implemented in three gastropods. Success rates were lower for Gibbula cineraria compared to Littorina littorea and L. saxatilis. Comparative genomic analysis of 47.2 kb of microsatellite containing sequences (MCS) revealed a high incidence of cryptic repetitive DNA in their flanking regions. The majority of t...

  1. Mitochondrial DNA hyperdiversity and its potential causes in the marine periwinkle Melarhaphe neritoides (Mollusca: Gastropoda)

    OpenAIRE

    2016-01-01

    We report the presence of mitochondrial DNA (mtDNA) hyperdiversity in the marine periwinkle Melarhaphe neritoides (Linnaeus, 1758), the first such case among marine gastropods. Our dataset consisted of concatenated 16S-COI-Cytb gene fragments. We used Bayesian analyses to investigate three putative causes underlying genetic variation, and estimated the mtDNA mutation rate, possible signatures of selection and the effective population size of the species in the Azores archipelago. The mtDNA hy...

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

    OpenAIRE

    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 taxonomicall...

  3. Buffalo Metropolitan Area, New York Water Resources Management Study, Tonawanda Creek Watershed. Interim Flood Management Study. Appendices.

    Science.gov (United States)

    1980-12-01

    T I t . ITLAAEIAI I-I caI’I 0 x4 20 3 40 IOSP 9 20 40 5~ 7 DNA WAGE RM bA, INSQUAE 4U PLT4A lii: or Izo Wi - I > :’’’4, . (.0 0’ Hi ,. TOAWND CRE...water scorpions), decapods (crayfish), ephemeropterans (mayflies), gastropods (snails), isopods, lepidopterans (water moths), megalopterans

  4. Distribution of heavy metals in internal organs and tissues of Korean molluscan shellfish and potential risk to human health.

    Science.gov (United States)

    Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kim, Poong Ho; Lee, Tae Seek; Kim, Ji Hoe

    2015-09-01

    Molluscan shellfish (gastropods and bivalves) were collected from major fish markets on the Korean coast and analyzed for mercury by direct Hg analyzer and for other metals, such as cadmium, lead, chromium, silver, nickel, copper and zinc, using inductively coupled plasma mass spectrometry. Distribution of heavy metals in muscles, internal organs and whole tissues were determined and a potential risk assessment was conducted to evaluate their hazard for human consumption. Heavy metals were accumulated significantly higher (P organs than in muscles for all species. The mean Cd level, which had the highest level of three hazardous metals (Cd, Pb, and Hg) in all internal-organ samples were above the regulatory limit of Korea and the mean level in whole tissue samples of the selected gastropod species, bay scallop and comb pen shell, exceeded the limit (except in a few cases). The sum of the estimated dietary intake of Cd, Pb and Hg for each part of all tested species accounted for 1.59-16.94, 0.02-0.36, and 0.07-0.16% respectively, of the provisional tolerable daily intake adopted by the Joint FAO/WHO Expert Committee on Food Additives. The hazard index for each part of gastropods and bivalves was below 1.0, however, the maximum HI for internal organs of all analysed species was quite high (0.71). These results suggest that consumption of flesh after removing the internal organs of some molluscan shellfish (all gastropod species, bay scallop and comb pen shell) is a suitable way for reducing Cd exposure.

  5. HISTORY OF MOLLUSC COMMUNITY TYPES AND FAUNAL DYNAMICS IN CONTINENTAL SALINE ECOSYSTEMS OF THE SOUTH MEDITERRANEAN QUATERNARY

    Directory of Open Access Journals (Sweden)

    THORSTEN KOWALKE

    2006-07-01

    Full Text Available Quaternary continental aquatic ecosystems characterised by poly/eusaline waters, and without a connection to the Mediterranean Sea, are dominated by the potamidid gastropod Potamides conicus (Blainville and the cardiid bivalve Cerastoderma glaucum (Poiret. Metasaline environments are characterised by monotypic occurrences of C. glaucum. The primarily freshwater-dwelling thiarid gastropod Melanoides tuberculata (Müller, in contrast, colonised oligo/mesosaline habitats, similarly to its precursors from the Upper Messinian Lago-Mare ecosystems. In case of the establishment of saline conditions in former freshwater environments, characteristic taphocoenoses document the dynamic development in the context of progressive evaporation: the Melanoides palaeocommunity from a Holocene ecosystem at In Ecker (S Algeria is accompanied by freshwater inhabitants, which did not reach their adult size of complete development due to the temporal character of their habitats. Oligo/mesosaline conditions are reflected in oxygen isotope signatures of the Melanoides shells. High variations in carbon isotope values indicate changes in the composition of the diet during ontogeny, and may support the interpretation that the ecosystem developed progressively. In comparison to Neogene and fossil Quaternary assemblages, the composition of extant eusaline communities is considerably more diversified: larger North African lakes in Libya and Egypt are characterised by neozoan elements originating from the Mediterranean fauna. The dynamic development of these faunas was predominantly supported by anthropochory in the context of fish cultures. The mode of early ontogenetic development played an important role with regard to the introduction of gastropods to continental environments, since the entire spectrum of euryhaline coastal gastropods with planktotrophic larval development is absent from these ecosystems. The preadaptational loss of planktotrophy enabled Potamides to

  6. Nacre-like ceramic/polymer laminated composite for use in body-armor applications

    OpenAIRE

    2016-01-01

    Nacre is a biological material constituting the innermost layer of the shells of gastropods and bivalves. It consists of polygonal tablets of aragonite, tessellated to form individual layers and having the adjacent layers as well as the tablets within a layer bonded by a biopolymer. Due to its highly complex hierarchical microstructure, nacre possesses an outstanding combination of mechanical properties, the properties which are far superior to the ones that are predicted using the techniques...

  7. Phylogenetics, development, and Cenozoic paleontology of Buccinidae (Mollusca:Gastropoda)

    OpenAIRE

    2009-01-01

    The buccinid gastropods (family Buccinidae) are a species-rich clade of mostly North Pacific taxa with an abundant fossil record that dates to the Cretaceous. Here, the evolution, systematics, and biology of fossil and extant members of this family are treated using a variety of analytical and methodological approaches. In chapter one, a new fossil species of Bruclarkia, an endemic eastern Pacific buccinid from the Eocene, Oligocene, and Miocene, is described from the Astoria Formation of the...

  8. Cyanobacteria from terrestrial and marine sources contain apoptogens able to overcome chemoresistance in acute myeloid leukemia cells

    OpenAIRE

    2014-01-01

    In this study, we investigated forty cyanobacterial isolates from biofilms, gastropods, brackish water and symbiotic lichen habitats. Their aqueous and organic extracts were used to screen for apoptosis-inducing activity against acute myeloid leukemia cells. A total of 28 extracts showed cytotoxicity against rat acute myeloid leukemia (IPC-81) cells. The design of the screen made it possible to eliminate known toxins, such as microcystins and nodularin, or known metabolites with anti-leukemi...

  9. Monitoring Stone Degradation on Coastal Structures in the Great Lakes - Summary Report

    Science.gov (United States)

    2005-06-01

    face of the quarry was logged. The west side, however, is where all armor stone has thus far been produced and therefore, is more applicable to this...echinoderm fragments, crinoid stems and gastropods . Bivalve fragments commonly align with their long axes parallel to bedding planes as evenly...particles approximately sand-sized) are more com- mon materials used in cut stone applications . Where settlement occurs, it is more likely to cause

  10. Are exploited mangrove molluscs exposed to persistent organic pollutant contamination in Senegal, West Africa ?

    OpenAIRE

    2011-01-01

    The surface sediments, two bivalves (Arca senilis and Crassostera gasar) and three gastropods (Conus spp., Hexaplex duplex and Pugilina mono) from two Senegalese stations, Falia (Sine-Saloum Estuary) and Fadiouth (Petite Cote), were analyzed for their pollutant organic persistent contamination (polychlorinated biphenyls PCBs; organochlorinated pesticides OCPs; polybrominated diphenyl ethers PBDEs). Results revealed significant levels of PCBs, DDTs and lindane in mangrove sediments ranging fro...

  11. Toxicity of Chlorophyllin against Lymnaea acuminata at Different Wavelengths of Visible Light

    OpenAIRE

    Chaturvedi, Divya; Singh, Vinay Kumar

    2016-01-01

    Fasciolosis is a water and food-borne disease caused by the liver fluke Fasciola hepatica and Fasciola gigantica. This disease is widespread in different parts of the world. Lymnaeidae and Planorbidae snails are the intermediate hosts of these flukes. Snail population management is a good tool to control fasciolosis because gastropods represent the weakest link in the life-cycle of trematodes. Chlorophyll can be extracted from any green plant. Chlorophyllin was prepared from spinach in 100% e...

  12. Canaveral Harbor, Florida, Integrated Section 203 Navigation Study Report and Final Environmental Assessment. Volume 1

    Science.gov (United States)

    2012-10-01

    Athiri 752 India 66,497 32 10-Feb-11 Citron 600 Algeria 53,388 35 14-Feb-11 Oriental Ruby 620 Venezuela 40,244 39,490 35 24-Feb-11 Cartagena 601...Brevard County. The rock and worm rock reefs provide habitat for a number of crustaceans , fish, macroalgae, sponges, and other invertebrates. In...annelids, bivalves, gastropods, and crustaceans . The coarser to fine sand habitat typically supports a more diverse benthic community than the finer

  13. Os topónimos algarvios na Paleontologia portuguesa

    OpenAIRE

    ROCHA, R. B.; Kullberg, J. C.; Caetano, P. S.

    2007-01-01

    Since the XIX century, Portuguese and foreign geologists have defined 47 new invertebrate taxa (foraminifera, ostracods, coelenterates, brachiopods, gastropods, ammonoids, echinoids), 2 new fossil plant taxa (charophyte and pteridophyte) and 1 ichnofossil, using toponymy from the Algarve; these taxa refer to 1 genera, 47 species and 2 varieties. Besides the Algarve toponym, the most used as specific name, twenty others have been used, mostly from western Algarve; these toponyms are a...

  14. Carbonate production and deposition in a warm-temperate macroalgal environment, Investigator Strait, South Australia

    Science.gov (United States)

    James, Noel P.; Bone, Yvonne

    2011-08-01

    The prolific macroalgal forests in shallow (red algae that are grazed by herbivorous gastropods, 2) an intermediate, 5-20 cm-high community of fleshy red algae, and 3) a 20-100 cm+-high canopy of large phaeophytes (especially Ecklonia, Cystophora and Xiophora) whose blades are locally encrusted with bryozoans, such as Membranipora membranacea, and spirorbids. Concealed surfaces of subvertical rock walls and cryptic habitats behind the macroalgal curtain have two tiers; 1) a cornucopia of encrusting plants and animals, especially crustose and geniculate corallines in shallow water, that give way in water depths > 4 m to numerous bryozoans (especially fenestrates), serpulid worms, numerous and diverse demosponges, ascidians, small solitary corals, epifaunal echinoids, and gastropods, and 2) a veil of macroalgae (mainly Cystophora and Ecklonia) that drapes down and shades the rock walls. Most carbonate sediment production does not come from calcareous epiphytes on the macroalgae but comes from the coralline algae and calcareous invertebrates living on the rock walls and in concealed depressions. Mollusks (gastropods and bivalves) and geniculate coralline algae with numerous lithoclasts, crustose coralline fragments, barnacle plates, serpulid worms, bryozoans, and large benthic foraminifers (especially Amphistegina) dominate the resultant gravels and sands; but there is little or no mud. This is because carbonate sediment is the result of production not only in the macrophyte factory but also in adjacent seagrass factories. Particles produced in the macroalgal factory are shed onto the adjacent seafloor, where they form the requisite sandy substrates for quick colonization by seagrasses. Thus, over time the sediment in this shallow but hydrodynaically energetic environment becomes a mixture of materials from the two sources with seagrasses contributing gastropods, large benthic foraminifers, spirorbids, bryozoans and articulated corallines to the sediment milieu. If

  15. THE CHANGES IN THE POPULATION OF THEODOXUS FLUVIATILIS IN THE RIVER TYWA WESTERN POMERANIA (POMORZE ZACHODNIE IN THE BACKGROUND OF THE ABIOTIC HABITAT

    Directory of Open Access Journals (Sweden)

    Tadeusz Zamkowski

    2014-10-01

    Full Text Available The paper presents the research on the concentration and biomass of the gastropod Theodoxus fluviatilis found in the river Tywa (Western Pomerania. It has been stated that the strongest influence on the size of the concentration of those species had the following elements of habitat: the kind of the bed, amount of food, depth of water, degree of its transformation. However, the interrelation between the concentration of species and their biomass has not been noticed.

  16. Invasive Marine and Estuarine Animals of California

    Science.gov (United States)

    2005-08-01

    4 3 5 Porifera 5 5 5 3 7 Polychaete 7 45 13 15 47 Oligochaete 1 4 4 5 Bivalve 16 25 12 6 26 Gastropod 16 23 14 6 26 Nudibranch 2 2 2 2...ballast water, they include species of 13 hydrozoans, 7 sponges ( porifera ), 5 anemones (anthozoans), 3 barnacles, 14 bryozoans, 2 entoprocts, 15...ST SF HU Obelia geniculata Hydrozoan ST Aurelia aurita Scyphozoan NB ST SF HU Phyllorhiza punctatus Scyphozoan NB ST Cliona sp. Porifera

  17. Body size and growth of benthic invertebrates along an Antarctic latitudinal gradient

    Science.gov (United States)

    Linse, Katrin; Barnes, David K. A.; Enderlein, Peter

    2006-04-01

    Much has been made of body-size variability with latitude, and extreme body sizes in polar waters, but body size has never been investigated along a latitudinal gradient within polar waters. The Scotia arc and Antarctic Peninsula are ideal for latitudinal studies, and a number of species extend along the length of this region. We studied body size in two gastropod molluscs, Margarella antarctica and Nacella concinna, an echinoid, Sterechinus neumayeri, and two bryozoans, Celleporella bougainvillea and Inversiula nutrix, at six sites from South Georgia to Adelaide Island (54-68°S). We hypothesised that size, age, and growth would not correlate with latitude, given the uniformity of conditions (i.e. temperature, dissolved oxygen, etc.) within the Polar Frontal Zone. We found significant differences in size of all five species among our study sites, but not a linear trend, nor one that correlated with latitude. In bryozoans, this result was because growth was positively and age negatively correlated with latitude—resulting in little difference in overall size. In the grazer organisms (the two gastropods and the echinoid) a correlation with local food availability (chlorophyll a concentration) did not correlate with latitude. Fecundity in the gastropod M. antarctica was positively correlated with body size, and body size also was influenced by food availability. We conclude that variation in body size in all five study taxa was governed by local factors such as food availability and competition and not by latitude.

  18. River Floodplains as Habitat and Bio-Corridors for Distribution of Land Snails: Their Past and Present

    Directory of Open Access Journals (Sweden)

    Horáčková Jitka

    2015-12-01

    Full Text Available River floodplains of Czech rivers serve as refugia to woodland or hydrophilous gastropods, in current intensively agriculturally utilised, urbanised and largely fragmented landscape. This habitat often form one of the last refuge and replace the natural habitat of these species. River floodplains also represent linear bio-corridors in landscape and allow gastropods to spread through the landscape in both directions, up and down the stream. We showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history in comparison with those in higher altitudes. The species richness and composition of recent floodplain malacofauna arises from historical development of particular area/site and depends also on environmental factors such as an elevation, humidity gradient, vegetation type and its biomass, light conditions of the site and soil reaction. Recently, the invasive plants represent a serious problem for current floodplain ecosystems; species richness and abundances of terrestrial mollusc floodplain assemblages are changing due to their effect. The impact on gastropods is species-specific and was described for the following species: Impatiens glandulifera, Fallopia japonica subsp. japonica, F. sachalinensis, F. ×bohemica.

  19. Peripheral sensory cells in the cephalic sensory organs of Lymnaea stagnalis.

    Science.gov (United States)

    Wyeth, Russell C; Croll, Roger P

    2011-07-01

    The peripheral nervous system in gastropods plays a key role in the neural control of behaviors, but is poorly studied in comparison with the central nervous system. Peripheral sensory neurons, although known to be widespread, have been studied in a patchwork fashion across several species, with no comprehensive treatment in any one species. We attempted to remedy this limitation by cataloging peripheral sensory cells in the cephalic sensory organs of Lymnaea stagnalis employing backfills, vital stains, histochemistry, and immunohistochemistry. By using at least two independent methods to corroborate observations, we mapped four different cell types. We have found two different populations of bipolar sensory cells that appear to contain catecholamines(s) and histamine, respectively. Each cell had a peripheral soma, an epithelial process bearing cilia, and a second process projecting to the central nervous system. We also found evidence for two populations of nitric oxide-producing sensory cells, one bipolar, probably projecting centrally, and the second unipolar, with only a single epithelial process and no axon. The various cell types are presumably either mechanosensory or chemosensory, but the complexity of their distributions does not allow formation of hypotheses regarding modality. In addition, our observations indicate that yet more peripheral sensory cell types are present in the cephalic sensory organs of L. stagnalis. These results are an important step toward linking sensory cell morphology to modality. Moreover, our observations emphasize the size of the peripheral nervous system in gastropods, and we suggest that greater emphasis be placed on understanding its role in gastropod neuroethology.

  20. Priority wetland invertebrates as conservation surrogates.

    Science.gov (United States)

    Ormerod, S J; Durance, Isabelle; Terrier, Aurelie; Swanson, Alisa M

    2010-04-01

    Invertebrates are important functionally in most ecosystems, but seldom appraised as surrogate indicators of biological diversity. Priority species might be good candidates; thus, here we evaluated whether three freshwater invertebrates listed in the U.K. Biodiversity Action Plan indicated the richness, composition, and conservation importance of associated wetland organisms as defined respectively by their alpha diversity, beta diversity, and threat status. Sites occupied by each of the gastropods Segmentina nitida, Anisus vorticulus, and Valvata macrostoma had greater species richness of gastropods and greater conservation importance than other sites. Each also characterized species assemblages associated with significant variations between locations in alpha or beta diversity among other mollusks and aquatic macrophytes. Because of their distinct resource requirements, conserving the three priority species extended the range of wetland types under management for nature conservation by 18% and the associated gastropod niche-space by around 33%. Although nonpriority species indicated variations in richness, composition, and conservation importance among other organisms as effectively as priority species, none characterized such a wide range of high-quality wetland types. We conclude that priority invertebrates are no more effective than nonpriority species as indicators of alpha and beta diversity or conservation importance among associated organisms. Nevertheless, conserving priority species can extend the array of distinct environments that are protected for their specialized biodiversity and environmental quality. We suggest that this is a key role for priority species and conservation surrogates more generally, and, on our evidence, can best be delivered through multiple species with contrasting habitat requirements.