Edible Gastropod Research Articles

Distribution and bioaccumulation of butyltins in the edible gastropod Odontocymbiola magellanica

ABSTRACTButyltins (BTs) were found in sediments and body tissues of the edible gastropod Odontocymbiola magellanica, in which imposex has been recorded since 2000. BTs in sediments ranged from < MDL to 174.8 ng (Sn) g−1 for TBT, < MDL to 19.2 ng (Sn) g−1 for DBT, and < MDL to 71.8 ng (Sn) g−1 for MBT. In body tissues BTs varied from < MDL to 147.1, < MDL to 77.0 and < MDL to 345.3 ng (Sn) g−1 for TBT, DBT and MBT, respectively. BT concentrations were higher in gonads and digestive glands than in the albumen gland and foot (edible). The highest concentrations of BTs in both sediments and gastropods were found in the harbour area, decreasing with distance to the harbour and areas with less maritime traffic. The Biota-Sediment Accumulation Factor (BSAF) in the different organs was between 0.02–0.42, 0.09–0.35 and 0.08–5.25 for TBT, DBT and MBT, respectively. There were positive correlations between concentrations of BTs in sediments and gastropod body tissues, suggesting that xenobiotic accumulation in O. magellanica occurs mainly through contaminated sediments, rather than water or the food chain. Considering current sediment quality guidelines, our results indicate that acute toxic effects would be expected from TBT exposure, which represents a serious environmental threat for the benthic community. Although the levels of BTs found in the foot of this edible gastropod did not exceed the recommended Tolerable Daily Intake in polluted areas, they should be monitored to ensure the safety of seafood consumers. The alternative antifouling biocides Irgarol and Diuron were not detected in sediments.

Assessment of trace metal pollution in sediments and intertidal fauna at the coast of Cameroon.

Coastal systems act as a boundary between land and sea. Therefore, assessing pollutant concentrations at the coast will provide information on the impact that land-based anthropogenic activities have on marine ecosystems. Sediment and fauna samples from 13 stations along the whole coast of Cameroon were analyzed to assess the level of trace metal pollution in sediments and intertidal fauna. Sediments showed enrichment of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn. However, pollution of greater concern was observed for Cd, Cr, Cu, Ni, and Zn at the northern stations. Some sites recorded trace metal levels higher than recommended in sediment quality guidelines. Species diversity was low, and high bioaccumulation of trace metals was observed in biological samples. Some edible gastropod species accumulated trace metals above the safety limits of the World Health Organization, European Medicine Agency, and the US Environment Protection Agency. Although industrial pollution is significant along Cameroon's coast, natural pollution from the volcano Mount Cameroon is also of concern.

Copper, zinc, and cadmium body concentrations in Hexaplex trunculus collected from the Tunisian coast

Copper, Zn, and Cd were analyzed in the soft tissues of the edible gastropod Hexaplex trunculus collected from seven localities along the Tunisian coast. The body concentration of these metals was significantly different depending on the gender and site. Copper and Zn varied, respectively, from 47.70 to 343.64 μg/g dry weight (dw) and 149.46 to 530.44 μg/g dw, being higher in males. Cadmium varied from 0.22 to 18.95 μg/g dw and was always higher in females. Overall, the highest concentrations of the three metals were all recorded in Gabès fishing harbor. Comparison of metal concentrations with the European standards compiled by the Food and Agriculture Organization showed that values exceeded standards in several localities. Imposex had been previously recorded in H. trunculus along the Tunisian coast; however, it does not seem to be related with Cu, Zn, and Cd pollution because the body concentration of these metals is not correlated with imposex degree. Nevertheless, interactive effects resulting from the combination of different pollutants and other stressors cannot be disregarded.

Checklist and Habitat Descriptions of Edible Gastropods from Sarawak, Malaysia

Sarawak comprises of vast areas of wetland which is the habitat of huge number of edible gastropods. Among the wetland faunal composition, the edible gastropod is one of the important sources of animal protein for the local communities. This diversity of edible gastropod was studied from seven Divisions of Sarawak namely Kuching, Sibu, Mukah, Bintulu, Miri, Limbang and Lawas. Samples were collected from the wet market and catches from local fishermen. A total of 21 species representing 11 families and 16 genera of edible gastropods were identified from Sarawak. Cerithidea spp. was represented by three species while both Nerita and Pomacea were made up of three and two species each. Others were each represented by one single species. Six edible gastropod species belonged to the freshwater habitat while seven and eight species were recorded from brackish and marine habitats, respectively. Cerithidea and Pomacea showed wide geography amongst the Division and also highly distributed. Edible gastropods have high market value in the state of Sarawak and contribute significantly to the livelihoods of the certain indigenous communities in the state.

First characterisation of the populations and immune-related activities of hemocytes from two edible gastropod species, the disk abalone, Haliotis discus discus and the spiny top shell, Turbo cornutus

The disk abalone Haliotis discus discus and the spiny top shell Turbo cornutus are edible gastropod species of high economic value, mainly in Asia. Mortality outbreaks and variations in worldwide stock abundance have been reported and suggested to be associated, at least in part, with pathogenic infections. Ecology, biology and immunology of both species are currently not well documented. The characterisation of the immune systems of these species is necessary to further assess the responses of H. discus discus and T. cornutus to environmental, chemical and disease stresses. In the present study, we investigated the morphology and immune-related activities of hemocytes in both species using light microscopy and flow cytometry. Two types of hemocytes were identified in the disk abalone hemolymph, blast-like cells and hyalinocytes; whereas four main hemocyte types were distinguished in the spiny top shell, blast-like cells, type I and II hyalinocytes, and granulocytes. Flow cytometric analysis also revealed differences between cell types in immune-related activities. Three subsets of hemocytes, defined by differing lysosomal characteristics, were observed in the hemolymph of the spiny top shell, and only one in the disk abalone. Phagocytic activity was higher in H. discus discus hemocytes than in T. cornutus hemocytes, and the kinetics of PMA-stimulated oxidative activity was different between hemocytes of the disk abalone and the spiny top shell. Finally our results suggest for the first time a predominant mitochondrial origin of oxidative activity in gastropod hemocytes.

Studies on the short-term fffects of the mobil Idoho oil Spill on the Littoral Biota of Southeastern Nigeria

Quantitative surveys of the intertidal macro-fauna were conducted during September-October 1998 along transects established at various locations along the Nigeria coastline, following the rupture of a 24-inch pipeline at Idoho, off the Gulf of Guinea, southeastern Nigeria on 12 January 1998. Samples were taken within impacted areas and at control unpolluted sites approximately 5 km to the east of the Idoho off-shore platform. Spilled oil moved rapidly ashore and into river mouths, and estuaries and their mangals shortly after the spills. Biomass of macrofauna in the impacted areas tended to decrease with level of oiling, as the mean abundance decreased rapidly to about 50% of that found on the control unpolluted sites. Edible gastropod, mainly species of Tympanotomus fuscatus, and the brachyuran decapod, Ucatangeri, typically consumed by coastal inhabitants, had reduction in mean densities (up to 62%) in the oiled Bonny, Brass, Lagos and Forcados than in the non-oiled areas of Imo, Andoni and Cross River, showing partial recovery of the environment from the debacle after 9 months. The ecological implications of these findings are discussed.

TBT pollution and effects in molluscs at US Virgin Islands, Caribbean Sea

An almost ubiquitous occurrence of imposex and butyltins in the molluscs from US Virgin Islands gives evidence to a widespread contamination with the antifouling agent tributyltin (TBT), which most likely is related to a relatively intense ship traffic. Three different muricid neogastropod species Thais deltoidea, Thais rustica and Purpura patula all seem to have potential as suitable and sensitive bioindicators for assessing levels and effects of TBT pollution in coastal areas including coral reefs in the Caribbean Sea. However, considerable interspecies differences in especially accumulation potential of butyltins were seen in this study. Furthermore, a high accumulation potential of TBT in the edible gastropod West Indian topshell ( Cittarium pica) was found, despite that no signs of imposex were observed in this archaeogastropod species.

Bioavailable metals and cellular effects in the digestive gland of marine limpets living close to shallow water hydrothermal vents

The pressure exerted by shallow water hydrothermal vents on edible gastropods and their cellular responses triggered by these stresses are almost unknown. The aims of this study were to evaluate the bioavailability of metals in the Macaronesian endemic limpet Patella candei gomesii living close to shallow water hydrothermal vents, and the structural differences in their digestive gland as well as the levels of apoptosis in that organ. Limpets were sampled in four sites, two with the presence of hydrothermalism and the other two without it. Whole body concentrations of several metals (Ca, Cd, Cs, Co, Cu, Fe, Hg, Mg, Mn, Pb, Rb, Se, Sr, and Zn) were obtained, morphometry analysis of the digestive gland and TUNEL test for apoptosis were also performed. Results revealed that the presence of shallow water hydrothermal vents is a source of chronic metal stress to limpets, imposing modifications in the morphometry and cell composition of the digestive gland of those limpets that may constitute cell and tissue adaptations to the environment they live in. This study sets up new baseline data for further research on the influence of shallow water hydrothermal vents over communities living in these habitats.

Imposex in gastropods from Venezuela

The imposex phenomenon is a superimposition of male characters on gastropod females due to exposure to tributyltin (TBT). There have been no previous reports of this phenomenon in the southern Caribbean, which is inhabited by some edible and commercially exploited gastropod populations. To determine whether imposex is affecting some of these local gastropod populations, surveys were conducted at several sites with different levels of boating activity around Margarita Island and on the continental coast of Venezuela. The species affected were Chicoreus brevifrons, Chicoreus (Phylonotus) margaritensis and Leucozonia nasa; however, no females with obstructed vagina were observed. Imposex was observed in a coastal lagoon and on the coast at sites characterized by medium to high boat concentrations, but was not detected in open waters with low marine traffic. A survey of local boat operators indicated that the use of TBT had stopped 2–3 years prior to this study and had been replaced by regular application of other antifouling paints. This is the first report of imposex in Venezuela, but further studies incorporating the bioindicators identified here are needed in order to determine the full extent of TBT contamination and the biological implications in zones with marine traffic. Key words: edible gastropods, TBT, marine pollution, imposex, southern Caribbean.

Intertidal population structure of the edible mollusc Turbo sarmaticus (Vetigastropoda) at an unexploited and exploited sites along the coast of the Eastern Cape Province, South Africa

The intertidal population structure of the large edible gastropod Turbo sarmaticus was examined at four sites along the Eastern Cape Province of South Africa. One site was free from exploitation, two were subjected to low levels of exploitationand one was heavily exploited. Within the intertidal zone at all sites there was a size-related distribution, with smalleranimals being found towards the upper mid-shore and larger animals occurring in a downshore direction. The mean shore densities (1.2–animals/m2) and biomass (4.4–9.4 g/m2) of T. sarmaticus at the sites where there was no, or minimal, exploitation of animals were not significantly different (P<0.001). However, the largest animals (up to 110mmshell length) were found at the unexploited site, an offshore island. The lowest density (0.2 animals/m2) and biomass (0.4 g/m2) of T. sarmaticus was recorded at the site where the exploitation of this gastropod was intense. In addition, no animals of a legally exploitable size (>70 mm shell length) were found. It is suggested that intense over-exploitation is threatening the population at this site.

Amino-acid sequence of the cooperative dimeric myoglobin from the radular muscles of the marine gastropod Nassa mutabilis

The complete amino-acid sequence of the dimeric and cooperative myoglobin from the radular muscles of Nassa mutabilis, a common edible gastropod mollusc on the Italian coast, has been determined. The molecule is a homodimer. The monomer is composed of 147 amino-acid residues, with a molecular mass of 15 760 Da. Its sequence is homologous with those of the dimeric myoglobins of the gastropod molluscs of the Prosobranchia subclass Busycon canaliculatum (63% conserved residues) and Cerithidea rhizophorarum (46% conserved residues). The rate of autoxidation to met-myoglobin of N. mutabilis oxymyoglobin at 25°C is strongly pH-dependent with relative minimal rate values in the pH range 7 to 8.

Seasonal variations in energy and biochemical components of an edible gastropod, Turbo sarmaticus (Turbinidae)

Protein, lipid, ash, moisture and energy contents were determined for four size classes of Turbo sarmaticus every second month for a year. Protein was the major component and was negatively correlated with carbohydrate and lipid and positively correlated with energy and gonadosomatic index values. Lipid values were positively correlated with temperature. Seasonal changes in energy and biochemical components of faeces were also monitored and faecal lipid and ash values were positively correlated with temperature.

Lipids in the economy of marine invertebrates.

Lipids in the economy of marine invertebrates.