Distribution and Contamination of Arsenic in Fish, Gastropods and Bivalves in the Aby and Tendo Lagoons in East of Ivory Coast

Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.

The Gastropod Shell Structure as a Blueprint for a Periodic System: A New Theory for Element Configurations

The purpose of this article is to propose a new design for the periodic table of elements. The new design is based on a three-dimensional (3D) model of the gastropod shell structure and presents a mechanism of the formation of elements that reflects the laws of nature that guide the formation of the gastropod shell, electron orbitals, and element structure. The author also identifies challenges associated with the current standard periodic table, such as the positions of hydrogen, helium, lanthanides, and actinides. The author’s research is a response to the IUPAC’s request, dating back to 2016, to settle unresolved disputes surrounding the current standard periodic table. Hence, the author proposes the “Gastropod Shell Model”, which presents the periodic system in 2D and 3D snail shells based on a hypothesized unifying principle guiding the formation of elements: the universal unified theory that considers the spiral and vortex forms as the bridge between energy and matter. The author was able to position hydrogen, helium, lanthanides, and actinides uniquely in their proposed periodic system to solve problems associated with their positions in the standard periodic table. Readers will be interested in uncovering the “hypothesized unifying principle guiding the formation of elements”.

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

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/（snall.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.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 μg/g dry weight （dw）, and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 μg/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.

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

Objective:To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata(B.spirala)against nine bacterial and three fungal patliogeiis.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(FT1R)spectro photometry analysis was also studied.Results:The maximum inhibition zone(12 mm)was observed against Pseudomonas aeruginosa in the crude ethanol extract of B.spirata and the minimum inhibition zone(2 mm)was noticed against Staphylococcus aureus in the crude methanol extract of B.spirala.Water extract of B.spirala showed the highest activity against Vibrio parahaemolyticus,Staphylococcus aureus and Candida albicans.Ethanol,acetone,methanol,chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus.Compared with water extracts,ethanol and methanol extracts showed higher activity against all pathogens.The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE.FTIR analysis revealed the presence of bioactive compounds signals at different ranges.Conclusions:The research shows that the great medicinal value of the gastropod muscle of B.spirata may be due to high quality of antimicrobial compounds.

Antimicrobial secondary metabolites from marine gastropod egg capsules and egg masses

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.

Study of Possible Oil Source Rock in Southern Caspian Sea(Iranian Side) with Emphasis on Bivalves and Gastropoda

Most Maikop series,in age of upper-Oligocene to middle Miocene in Republic of Azerbaidjan(western Caspian sea) and Caspian part,is petroleum source rocks.So,considering the interpretation of results gained from correlation between the Maikop series and the Miocene sediments in southern Caspian sea (Iranian side),we suggested that these sediments are probable petroleum source rocks.Recent geochemical studies by Research Center Oil Industry of

Geographical Distribution and Diversity History of Late Cambrian and Ordovician Gastropods in China

1 Introduction Gastropods are one of the most diverse groups in the living animals.The rich,long-ranging and extensive occurrences of gastropod fossils make them a unique animal group for evolutionary,ecologic,and biogeographic studies(Fryda and Rohr,2004).As a major component of shallow-water benthic fauna.

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

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 ichnogenus. 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 define a shallow depositional environment, characteristic of a marine context with high-energy conditions.

New Discovery of Oligocene Gastropod Opercula from the Yehucheng Formation in Northwestern China

Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bithyniidae and Assimineidae,and four genera,namely Pseudemmericia,Bithynia,Mirolaminatus and Assiminea.Among them,three species are new,and they are Bithynia paramonolithic sp.nov.,B.obliquus sp.nov.,and B.disregularis sp.nov.Some of these species were first discovered in Paleogene strata of the vast Northwest China and can be compared with the opercula recovered from the Paleogene deposits in East and South China.It is inferred from the paleontology and sediment associations that the climate was slightly humid and the fauna probably inhabited the fresh or brackish water of a shallow lake in the Lanzhou Basin during the late early Oligocene period.

Species Richness and Abundance of Bivalves and Gastropods in Mangrove Forests of Casiguran, Aurora, Philippines

The diversity and abundance of bivalves and gastropods were studied from April to July 2015. Two sampling stations, Tinib and Esteves, in Casiguran, Aurora were selected based on the presence of mangrove forest, bivalves, gastropods, muddy substrate, and gleaners for the establishment of a transect line. Each station was laid with 100 meters transect line overlaid continuously with 2 m × 2 m quadrat along each transect. A total of 50 sampling units covering 0.02 ha area per sampling station were surveyed. The transect line recorded six species of bivalves distributed among five families and 12 species of gastropods belonging to eight families. Three species of bivalves and five species of gastropods were common to both sampling stations. However, Tinib station had most diverse species of bivalves (0.55) while Esteves station had most diverse species of gastropods (0.43). Both stations revealed Dendrostrea folium (43%) (bivalve) and Cerithidea cingulata (93%) (gastropods) as most frequently occurring species. Dendostrea folium also emerged as the densest (10,640 ind∙ha−1 and 6850 ind∙ha−1) and most abundant (58.52% and 77.84%) bivalve species. For gastropods, Terebralia sulcata (249,250 ind∙ha−1) was the densest and most abundant (96.97%) in Tinib while Terebralia palustris was the densest (747,050 ind∙ha−1) and most abundant (70.44%) in Esteves. Pooled results for bivalve species maintained Dendrostrea folium as the densest (8750 ind∙ha−1) and most abundant (64.81%). However, for gastropods, Terebralia palustris emerged as the densest (373,525 ind∙ha−1) and most abundant (56.70%) species. The mangrove forests of Casiguran, Aurora thus contain a variety of bivalves and gastropods with Tinib station dominated by bivalves while Esteves station dominated by gastropods.

Spatial Zonation and Diversity of Bivalves and Gastropods in Mangrove Forests of Casiguran, Aurora, Philippines

This study generally aimed to determine the spatial zonation and diversity of bivalves and gastropods in mangrove forest of Cozo, Esteves and Tinib in Casiguran, Aurora. Specifically, this aimed to determine the species composition and distribution, and determine the relationship between spatial zonation and diversity of bivalves and gastropods as influenced by ecological factors such as vegetation, soil texture, organic matter, soil salinity, and soil pH. A total of 22 taxa comprising eight species of bivalves and 14 species of gastropods were identified. The high tidal zone of Esteves had high diversity (0.66) of bivalve species compared to other tidal zones and areas. On the other hand, the diversity of gastropods was almost equal in the middle tidal zones of Cozo (0.60), Esteves (0.57), and Tinib (0.42). In terms of bivalve species’ density and abundance, Dendostrea folium was the most dense and abundant in the low tidal zone of Cozo (253,333 ind.ha−1 or 25 ind.m2-1, 97.44%) while Gafrarium tumidum in the low tidal zones of Esteves (46,666 ind.ha−1 or 4 ind.m2-1, 73.68%) and Tinib (126,666 ind.ha−1 or 12 ind.m2-1, 50%). In terms of gastropod species’ density and abundance, Cerithidea cingulata was the most dense and abundant in the low tidal zone (666,666 ind.ha−1 or 66 ind.m2-1, 65.79%) of Cozo and the middle tidal zone (5,280,000 ind.ha−1 or 528 ind.m2-1, 61.40%) of Tinib. It was Terebralia palustris in the low tidal zone (1,263,333 ind.ha−1 or 126 ind.m2-1, 63.06%) of Esteves. All tidal zones within each study area had greater dissimilarities in terms of bivalves but had greater similarities in terms of gastropod species’ compositions. On the other hand, all tidal zones between study areas had greater dissimilarities in terms of bivalve and gastropod species present. Most tidal zones had Gafrarium tumidum as common bivalve species while Neritidae sp. and Cerithidea cingulata were common gastropod species. All these species were found thriving in a wide range of vegetation, soil texture, organic matter, soil salinity and pH.

Were Late Cretaceous extinctions of gastropods selective by generic longevity?

Many gastropod taxa went extinct during the Late Cretaceous. The stratigraphic ranges of 268 genera permit to establish the longevity of extinction victims for each stage of this epoch. ＂Young＂ taxa （originated within B epochs before the extinction） prevailed among victims of the extinctions in all stages. The proportion of ＂old＂ taxa （originated before the Cretaceous） that went extinct was the highest in the Cenomanian, and it was the lowest in the Coniacian and the Maastrichtian. It appears that the end-Cretaceous mass extinction affected chiefly ＂young＂ taxa. However, the comparison with the earlier time intervals suggests that this pattern of selectivity by generic longevity was not specific for the noted catastrophe, but, in contrast, it was typical for the entire Late Cretaceous. The latest Cenomanian environmental perturbation （OAE2） caused a stronger extinction of＂old＂ taxa, and thus, this biotic crisis was less selective by generic longevity. This hypothesis, however, is not proven by the statistical test.

Heavy Metal Concentrations in the Intertidal Gastropod Nerita lineata and Their Relationships to Those in Its Habitats:A Case Study in Dumai Coastal Waters

Concentrations of heavy metals in the intertidal gastropod Nerita lineata collected from 4 sampling stations in the intertidal zone of Dumai coastal waters have been analyzed and correlated with the respective metal concentrations in their habitat.The objective of this study was to evaluate the possible relationships between heavy metal concentrations in the N.lineata with metal concentrations in their habitat,which include seawater,algal mat,suspended particulate matter,and surface sediment.The results showed that heavy metal concentrations in the sediment,N.lineata,suspended particulate matter,algal mat and surface seawater were found to be higher in stations closed to Dumai city center which has more industrial and anthropogenic activities.The mean concentrations of Cd,Cu,Pb,Zn,Ni and Fe in the N.lineata collected from Dumai intertidal area were 4.14 μg/g,5.90 μg/g,44.43 μg/g,3.74 μg/g,20.73 μg/g,24.91 μg/g in shell;4.16 μg/g,7.31 μg/g,51.78 μg/g,17.63 μg/g,23.52 μg/g,30.60 μg/g in operculum and 0.71 μg/g,15.09 μg/g,9.41 μg/g,94.42 μg/g,5.10 μg/g,398.24 μg/g dry weight in the total soft tissue,respectively.Cd,Pb and Ni concentrations of parts of the N.lineata were in the order:that of operculum>shell>soft tissue whilst Cu,Zn and Fe concentrations of parts of the N.lineata in the order:that of soft tissue>operculum>shell.This suggested that N.lineata could be used as biomonitoring agent for Cu,Zn and Fe(soft tissues)and for Cd,Pb and Ni(operculum).However,the shell had significant correlations(P<0.05)with metal concentrations in the sediment,algal mat,suspended particulate matter and seawater.Bioconcentration factor(BCF)values of the shell also revealed greater capacity for non-essential metals bioaccumulation from all environmental phases.This might suggest that the shell of N.lineata could be better used as biomonitoring agent for heavy metal pollution.

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

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.

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

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(510μg/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 523.9μg/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.

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

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.

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

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.

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

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.

What physical habitat factors determine the distribution of gastropods in neotropical headwater streams?

Freshwater gastropods play a pivotal role in the structure and functioning of freshwater ecosystems,but despite their importance,there are still gaps in their ecology.Our goal was to understand what physical habitat factors are the most important for the distribution of freshwater gastropods in headwater stream ecosystems in the Neotropical Savanna and provide a baseline for conservation and management efforts for freshwater gastropods in this biome.We identified five taxa,each with different environmental prefferences.Littoridina presence related negatively with stream slope,Biomphalaria presence related positively with total dissolved solids and the proportions of cobble,fine sediment and organic matter.Gundlachia presence correlated positively with elevation and the proportion of pools in the site.Physa presence related negatively with total dissolved solids and positively with alkalinity.Melanoides tuberculata presence correlated positively with the proportion of coarse gravel.Our results highlight the challenge for protecting native freshwater gastropod assemblages(and managing non-native invasive species),because environmental preferences vary widely amongst taxa and most are vulnerable to common anthropogenic disturbances.

准卷螺属(Spirina)在中国的发现

一个世纪之前,Kayser(1889)在研究莱茵地区泥盆纪动物群时,发现一种壳体性状比较特殊的腹足类化石。这种化石的主要特征是壳体松旋,螺环少,并向壳口骤然扩大,具脐孔,壳面饰有同缘褶等。据此,Kayser把它命名为准卷螺。依据以往的记载,准卷螺属主要分布于欧洲的中志留世至中泥盆世地层中。本文记述的材料是张文堂教授于1950年采自黑龙江省密山县黑台地区黑台组。黑台组是我国泥盆纪北方槽区盛产化石的重要层位。腹足类产于黑台组深灰色灰岩中。