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The present study investigates the history of the northern Sfax coast by means of subsurface sediments of the sebkhas El Merdessia and El Awebed through a multiproxy approach. Ostracod and mollusk assemblages, diversity index, sedimentological criteria, correspondence analysis, and radiocarbon datings together provide an overview of the development of this coast over the last 5000 years. Original data give evidence for periods of predominantly lagoonal and brackish water conditions. These data testify to the emersion of sebkha El Awebed during Holocene, while sebkha El Merdessia recorded three marine transgressions toward 4599, 2225, and 1396 years cal BP. These transgressions are indicated by the richness of sediments in lagoonal and marine ostracod assemblages coupled with marine mollusks and the high values of species richness and diversity index. Sandwiched between 2225 and 1396 years BP, a period of sea-level stability and buildup of sand barriers in front of the estuaries was evidenced. Toward 250 years cal BP, a tsunami event is evidenced by the deposition of a shelly bed containing angular and sharpened Cerithium vulgatum in coarser marine sands overlaid by silts and clays rich in charcoal particles and pottery fragments. The comparison between the proxies analyzed of the studied area and those of Skhira coast leads to the conclusion that the two coasts were subjected to the same factors. However, a time shift of sedimentation is due to the uplift of Sfax northern coast favored by the activity of the faults, unlike the southern Skhira subsidence.

The 1980s excavations at the El Collado, a large open-air Mesolithic site on the Eastern coast of Spain, revealed a sequence of human occupations consisting of a large shell midden and 14 human burials dated to the Mesolithic period. Human palaeodietary reconstructions based on bone collagen δ13C and δ15N isotope ratios, identified a variable contribution of marine proteins, ranging from fully terrestrial diets to a maximum input of 25%. Most subsequent research on Mediterranean coastal and dietary adaptations refers to the site's funerary record and palaeodietary study, but the composition of its shell midden has remained unstudied. This work reports the first systematic study of a representative sample of mollusc and a comparatively small assemblage of fish bone recovered from the different stratigraphic horizons of El Collado site. Results indicate a mixed marine–terrestrial mollusc composition of the shell midden. The edible land snail Sphincterochila candidissima and the marine bivalve Cerastoderma glaucum are the best represented species throughout the archaeological sequence. The pattern of intertidal resource exploitation is clearly dominated by bivalves (C. glaucum, Glycimeris violacescens, and Ruditapes decussatus) and gastropods (Cerithium vulgatum, Hexaplex trunculus) inhabiting mud and sand flats in coastal lagoon environments. The presence of rocky shore intertidal species is minimal, mostly related to the manufacture of pierced shell ornaments made from Columbella rustica. On the other hand, fish bone assemblages are overwhelmingly dominated by the gilthead sea bream (Sparus aurata) a coastal species frequent in brackish water coastal lagoons and estuaries, both on rocky and sandy grounds. The biometric analysis of C. glaucum records differences on shell size amongst the different layers, suggesting variations of marine productivity throughout the archaeological sequence.

8 páginas, 2 figuras., There is increasing evidence of the importance of herbivory in seagrass communities, but the factors that regulate seagrass–herbivore interactions remain largely unknown. Many terrestrial plants and marine algae chemically deter herbivores using secondary metabolites, yet their incidence and role on seagrasses have received little attention. Posidonia oceanica, the dominant seagrass in the Mediterranean Sea, suffers a high level of herbivory and produces phenolics, a type of compounds known to deter feeding in algae and terrestrial plants. We have experimentally quantified the chemical deterrence of P. oceanica against 3 types of sympatric consumers by comparing feeding on palatable agar-based foods containing aqueous and organic extracts of P. oceanica at natural concentrations with that on appropriate controls. The effect of plant chemistry was measured on the feeding of the sea urchins Spharechinus granularis, Paracentrotus lividus and Arbacia lixula, the mesograzer gastropod Cerithium vulgatum, and the general fish assemblage inhabiting P. oceanica meadows. Since these 5 experiments were run independently, we used meta-analysis to test the overall hypothesis that P. oceanica is chemically defended against multiple consumers and to compare the magnitude of their inhibition. Our results clearly showed that the seagrass extracts significantly deterred feeding, although inhibition varied between consumers. S. granularis was the most deterred organism, while the mesograzer C. vulgatum was the only species unaffected by P. oceanica extracts. These results represent the first experimental evidence for seagrass chemical deterrence against a range of consumers, and emphasise the potential importance of chemically mediated interactions between seagrass and herbivores., This work was supported by Grant REN- 2002-04020-C02 from the Spanish Ministry of Science and Education.

In the present paper one population of the “large” subtidal mollusc Cerithium vulgatum Bruguiere, 1792 (Gastropoda: Cerithiidae) from the Northwestern coast of Sicily was investigated from a karyological point of view. The chromosome complement was Giemsa stained, conventionally karyotyped in 18 homomorphic chromosome pairs (10 bi-armed and 8 mono-armed), and subsequently analysed using silver, CMA3 and DAPI staining, and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [ribosomal DNA (rDNA), (TTAGGG)n and (GATA)n]. FISH with the rDNA probe consistently mapped major ribosomal sites (18S-28S rDNA) in the terminal region of the short arms of one small sized mono-armed chromosome pair. Ribosomal DNA was transciptionally active as indicated by its preferential impregnation with silver nitrate (Ag-NOR) and did not contain a high amount of GC base pairs as suggested by the lack of a bright CMA3 fluorescence. The (TTAGGG)n telomeric probe was hybridized to the termini of nearly all chromosomes, thus demonstrating that, in C. vulgatum, this sequence has been conserved during the genomic evolution. The finding of the telomeric hexanucleotide in six species belonging to the three high taxa of Gastropoda supports the notion that this sequence is widespread within this class. The (GATA)n probe did not label any chromosome regions except for a minute terminal area of a single bivalent at pachytene stage.

Results of isozyme electrophoresis were used to explore the genetic relationships between several Mediterranean morphs of Cerithium (Gastropoda: Prosobranchia), for which taxonomy is currently uncertain because of high intraspecific variability and low interspecific differentiation. The large species, classically known as C. vulgatum Bruguiere, 1789 was identified at four sites (two in the French Mediterranean and two in southern Spain). Two different larval types were found in the French sites, but poecilogony could not be demonstrated. Individuals collected from harbours were not genetically distinct from open-sea populations of classic C. vulgatum. However, a population in the Embiez lagoon (French Mediterranean) which morphologically resembles C. vulgatum did display distinct genetic traits, supporting its status as a separate species. Of the small Cerithium species usually known as C. rupestre, two sympatric species (C.“rupestre” Risso, 1826 and C. lividulum Risso, 1826) were distinguished. Genotype frequencies within the analysed populations revealed much heterozygote deficiency. F ST values (fixation index measuring the effects of population subdivision) suggest a higher genetic differentiation for C. lividulum populations than for C. vulgatum populations. We assume that a high larval dispersal capability (via planktotrophy) allows a high gene flow between populations of C. vulgatum.

Accumulation of Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn was studied in the sediments, Cymodocea nodosa leaves, roots and stems and in two gastropods from an area adjacent to a ferro-nickel smelting plant and a control site on the east coast of Greece. In the sediment, the metals, with the exception of Cu, have significantly higher concentrations in the polluted than in the clean site. There is a tendency for C. nodosa tissues in the polluted area to have higher concentrations of metals although the differences are not always statistically significant. Co, Mn, Ni and Zn are in higher concentrations in the leaves than in the other tissues, a trend more obvious in the polluted site. Concentrations of metals in the viscera of the gastropods Cerithium vulgatum and Monodonta mutabilis are higher than in the muscle (except for Cd) and significantly higher in the animals from the polluted site. It is suggested that Mn is taken up from the water by C. nodosa leaves, which in the form of detritus enter C. vulgatum. Mn concentrates in the viscera of C. vulgatum in the form of granules. Zn follows the same route with additional amounts being taken by C. vulgatum directly from the water. © 1998 Elsevier Science Ltd. All rights reserved

Şahin, Yeşim Müge (Arel Author), Biphasic bioceramic nanopowders of hydroxyapatite (HA) and ß-tricalcium phosphate (TCP) were prepared from shells of the sea snail Cerithium vulgatum (Bruguière, 1792) using a novel chemical method. Calcination of the powders produced was carried out at varying temperatures, specifically at 400°C and 800°C, in air for 4 hours. When compared to the conventional hydrothermal transformation method, this chemical method is very simple, economic, due to the fact that it needs inexpensive and safe equipment, because the transformation of the aragonite and calcite of the shells into the calcium phosphate phases takes place at 80°C under the atmospheric pressure. The powders produced were determined using infrared spectroscopy (FT-IR), X-ray diffraction, and scanning electron microscopy (SEM). The features of the powders produced along with the fact of their biological origin qualify these powders for further consideration and experimentation to fabricate nanoceramic biomaterials.

© 2014 Elsevier Ltd. The Banded dye-murex (Hexaplex trunculus), the main component of the Purple dye, was one of the most valued marine resources in Roman times. Its ancient exploitation appears described in the written sources. Until now, the archaeological record documenting the industry of Purple dye consisted of middens of broken shells that only allowed the identification of the harvested species and the derivation of some 14C dates, while the identity of the fishing methods used remained elusive. An integrated study of a zooarchaeological assemblage recovered at the Roman city of Pollentia (Mallorca, Western Mediterranean) has thrown light on this unknown aspect of the muricid gastropod fishery. I present sound evidence supporting that at this Roman site, the gastropod Cerithium vulgatum was used at least during the 3rd century AD as bait to collect the Banded dye-murex. This is derived from the high frequency of drilled shells - especially of shells showing incomplete drills - recorded in the deposit, suggesting that these specimens were unnaturally over-exposed to predatory gastropods. This is exactly what could be expected if these cerithids were encased as bait in traps used to collect muricids., This research is included in the Research Projects CGL2012-38087 and HAR2009-08290/HIST funded by the Direccion General de Investigación, Ministerio de Ciencia y Tecnología (Madrid). The author had a JAEPredoc fellowship from the Consejo Superior de Investigaciones Científicas of the Ministerio de Educacion y Ciencia of Spain

Marine snails excrete metals via the gut. The sediment-feeding, tower shell Cerithium vulgatum, from a polluted environment, accumulates Cr and Ni to 3500 ppm dry weight in the faecal pellets. Pellets from C. vulgatum and the grazing, top shell Monodonta mutabilis were incubated in surface and deeper anoxic layers of clean and metal-polluted sediment. Pellets retained the original load of metals and in some cases gained Ti, Cr, Mn, Fe and Ni. Effects were modified by sediment properties. Pellets of C. vulgatum are durable, membrane-bound structures and they reduce metal bioavailability to food chains by compartmentalization. Intracellular, phosphate granules bind metals in digestive glands of snails and they are excreted via the gut and faecal pellets. These granules were extracted from digestive glands of both species of snail and incubated in the same sediments. Magnesium phosphate granules from M. mutabilis dissolved but calcium/metal phosphate granules from C. vulgatum remained; they had differentially retained or lost Mn, Fe, Co, Ni and Zn according to the type of sediment.

In any polluted marine environment, different invertebrate species contain markedly different concentrations of heavy metals. Primary producers take metals from seawater, but animals take additional metals from diets of animals, plants and detritus. Metals in a dietary organism of a food chain have varying reactivities and they follow different biochemical pathways. Excess metals are bound by ligands to form insoluble compounds within cytological compartments. These metabolic systems prevent the disruption of normal biochemical reactions by metals. The present work on Mediterranean invertebrates, initiated in Greece in 1993, used digestive glands from three species of marine snail,Monodonta mutabilis (Philippi),Cerithium vulgatum (Bruguiere), andMurex trunculus (Linnaeus) as prey tissue, and hermit crabsClibanarius erythropus (Latreille) as predators; the digestive glands and faecal pellets from all animals were analysed by atomic absorption spectroscopy and x-ray microanalysis. Most metals detoxified by the snails are unavailable to the crabs and they pass straight through the gut and appear in the faecal pellets. This applies to significant proportions of the manganese, nickel, copper, zinc and silver which are bound electrostatically to phosphate or covalently to sulphur within membrane-bound intracellular compartments. Cadmium and chromium are transferred to the crabs. In digestive glands of snails, cadmium is bound to soluble highsulphur protein in the cytosol; the cytology of chromium in these animals is not known.

It has been observed previously that the digestive gland of the carnivorous gastropod mollusc, Murex trunculus, does not accumulate metals which occur in high concentration in the digestive gland of its prey, the detritus-feeding gastropod, Cerithium vulgatum. It is proposed that mechanisms of metal detoxification which operate in C. vulgatum render metals biologically unavailable to M. trunculus. In the present work, this scheme is tested by feeding tissues containing detoxified metals from a gastropod, bivalve and barnacle to carnivorous gastropods. Metals in the prey are accumulated in insoluble granules in the digestive gland of the gastropod, kidney of the bivalve and gut connective tissue of the barnacle. These tissues are fed to the carnivores and the granules pass through the entire length of the gut. They are egested as clean preparations within the faecal pellets and they still contain the metals introduced by the tissues of the prey. This transfer of detoxification between species indicates that the food chain progression of material can result in the reduction of the bioavailability of metals. The observations are recorded by scanning electron microscopy and X-ray microanalysis.

Cadmium, Co, Cr, Cu, Fe, Mn, Ni, and Zn were measured by atomic absorption spectroscopy in the digestive gland of the marine gastropods Cerithium vulgatum, Monodonta spp., Murex trunculus, Conus mediterraneus , and Patella coerulea , sampled during different seasons at four sites near a ferro-nickel smelting plant and two control sites on the east coast of Greece. Near the smelter there were higher concentrations of all metals in Cerithium (except Cu) and Murex , and of Ni and Co in Monodonta , compared with the control sites, which indicated that the plant contaminated the environment. The animals from the contaminated area showed marked differences in concentrations which were associated both with the genera and the sites, while there were no consistent seasonal variations.

The gas tropod Cerithium vulgatum plays an important role in metal cycling in shallow water marine ecosystems. C. vulgatum detoxifies metals by incorporating them into insoluble granules formed in the digestive gland. When in granular form metals become unavailable to predators and thus are removed from food chains. Granules are incorporated in the durable faecal pellets of C. vulgatum and thus are retained in the sediment. The fate of metals in granules released from the faecal pellets depends on the properties of the metals and the characteristics of the sediment, especially the state of oxidation.

Preface. List of Contributors. Geochemistry of organic carbon in the ocean E.A. Romankevich, et al. Primary production and decomposition of organic matter in coastal areas of the Northern Aral Sea, with special reference to land-sea interactions M.I. Orlova. Biogeochemistry of water and sediment in the Ob and Yenisey estuaries V.V. Gordeev. The continental-ocean boundary as a marginal filter in the world oceans A.P. Lisitzin. Unjustifiably ignored: reflections on the role of benthos in marine ecosystems W.E. Arntz, et al. Understanding small-scale processes controlling the bioavailability of organic contaminants to deposit-feeding benthos T.L. Forbes. The role of the marine gastropod Cerithium vulgatum in the biogeochemical cycling of metals A. Nicolaidou, J.A. Nott. Changes in macrozoobenthos communities induced by anthropogenic eutrophication of the Gulf of Gdansk A. Szaniawska, et al. Do benthic animals control the particle exchange between bioturbated sediments and benthic turbidity zones? G. Graf. Impact of catchment land-use on an estuarine benthic food web D. Raffaelli. Natural variability and the effects of fisheries in the North Sea: towards an integrated fisheries and ecosystem management? M.J.N. Bergman, H.J. Lindeboom. Community composition of tidal flats on Spitsbergen: consequence of disturbance? J.M. Weslawski, M. Szymelfenig. The problem of scale: uncertainties and implications for soft-bottom marine communities and the assessment of human impacts S.F. Thrush, et al. Understanding the sea floor landscape in relation to impact assessment and environmental management in coastal marine sediments R.N. Zajac. Conclusions and Recommendations J.S. Gray, et al. Index.

In the digestive glands of gastropod molluscs, metals are metabolized in the sense that they are subject to inorganic biochemical processes within the epithelial cells and lumen of the digestive tubules and the pore cells in the intervening connective tissue. These systems have been examined in the tower shell Cerithium vulgatum Bruguieres, a sediment feeder, the top shell Monodonta articulata Lam., a grazing herbivore, and in the whelk Murex trunculus L., a carnivore whose prey includes Cerithium . These animals were taken from a Mediterranean environment polluted by heavy metals. In all three species the metals are compartmentalized within mineralized granules as phosphates and within lysosomal residual bodies in association with sulphur. However, the extent to which a particular metal is accumulated and the relative proportions that are bound within the different compartments are factors that are primarily determined by the species and not the concentration available in the environment. Thus Cerithium accumulates high concentrations of a wide range of metals from the ingested sediment and these are rendered insoluble and non-toxic in the digestive gland. This unavailability is transferred to Murex when it eats Cerithium because Murex does not accumulate the full range of metals from its prey. Indeed, for some metals there appears to be bioreduction rather than bioamplification. The grazing herbivore Monodonta articulata accumulates a third distinct spectrum of metals. The accumulations in each species do not reflect the levels of all the metals in the environment. The presence of metals in the digestive glands is associated with the removal of magnesium from the phosphate granules but also with an increase in the concentration of magnesium in the tissue. It is proposed that metals induce the formation of magnesium phosphate as a source of metal-binding phosphate ions.

Seven heavy metals, Co, Cr, Cu, Fe, Mn, Ni and Zn, were measured in marine sediments, plants and invertebrates in the vicinity of a ferro-nickel smelting plant in Greece. The concentrations of metals in the sediment were higher than those found in the average unpolluted Greek coastal sediment. High levels of metals were observed in the gastropod molluscs, particularly Cerithium vulgatum, which concentrated metals more than other invertebrates.