Rapana Venosa Research Articles

Biocidal Action of Sunflower Oil Based Soaps towards Bread Mould

The antifungal action of soaps prepared from sunflower oil (pure and amended with various organic materials) was examined towards bread mould. The results show that at 2-2.5 % percent concentration, pure (without any amendment) sunflower oil-based soap can completely block the development of mould on bread, just like 70 % ethanol solution. Amendment of the soap with different organic materials like dry shells from Rapana venosa, dry mapple leaves, dry olive pits, and so on can cause differences in the action of the soap towards mould. The highest effectiveness was observed in the soaps enhanced with Rapana venosa dry shells and dry pumpkin seeds.

Recolonization behavior of rapa whelk (Rapana venosa) and common starfish (Asterias rubens) eradicated from mussel bed

ABSTRACT This study aimed to investigate the recolonization behaviour of the rapa whelk (Rapana venosa) and the common starfish (Asterias rubens) on the mussel beds in their natural habitat. The monitoring studies were carried out seasonally on an island covered by a complete mussel bed in the Sea of Marmara (Turkey) between 19 October 2020 and 9 August 2021. Inhabitant rapa whelk and common starfish on the experimental study island (ESI) were tagged, then moved 10 m away from ESI. The recolonization potential of tagged invaders was monitored for 14 days with underwater surveys after their local eradication each season. The percentage of returned rapa whelk to the ESI was higher than common starfish end of the monitoring period. Rapa whelk moved non-stop towards the mussel bed, reaching the ESI at the latest 6th hour. Common starfish reached the mussel bed much later (at the 15th hour) than rapa whelk. The common starfish began to leave the ESI at the end of the 7th day, while the rapa whelk addicted to the ESI for 14 days. Re-invasion behaviour varied significantly seasonally, and both invaders reached the ESI much later in winter. During the monitoring periods, the highest invader densities were seen in the patches with the most abundant mussels, indicating continued uninterrupted feeding. The re-invasion duration and daily feeding activities support the spread of these invaders and could be considered a threat to marine resources.

Grid-net design that successfully reduces discarded catch and damage to benthic species in the veined rapa whelk beam trawl fishery

ABSTRACT In this study, a grid-net design (GND) with three different bar spacings was compared with the commercial beam trawl used in the veined rapa whelk fishery to minimize the discarded catch amount and the loss of commercial product. In addition, the damage and mortality rates of the species that entered the tested fishing gear were determined to understand whether the tested fishing gear has a possible negative effect on benthic species. In the grid-net design, a rectangular metallic grid positioned 6 cm off the ground substituted half of the codend to allow the escape of discard species. Sea trials were carried out in the south-eastern Black Sea between 13 and 24 October 2021. Results showed that the discarded catch amount was significantly reduced by each GND (P < 0.05). Compared with the commercial fishing gear, the reductions in the discarded catch amounts (in terms of number) were 91.6%, 92.2%, and 95.0% for 22, 25, and 28 mm GNDs, respectively. The minimum commercial product loss was determined at 22 mm GND. In addition, it was seen that each GND compared to commercial gear caused statistically significantly less damage and mortality on the discarded species. In conclusion, 22 mm GND was the most successful design among the tested gears in minimizing commercial product loss and reducing the discarded catch amount. Recommendations are given for this design to be adopted by the commercial fleet.

Catch composition of non-target species escaping dredge gear of Rapana fisheries in the western coast of the Black Sea

ABSTRACT Despite the importance of Rapana fisheries in the Black Sea region, few studies have focused on the non-target species, and determined discard rates from hauls on the deck, with no data on organisms that entered and subsequently escaped the fishing net during the dredge fishing. Rapana venosa is harvested along the entire coast of the Black Sea using dredging or beam-trawl fishing. This study adopted the cover net method to assess the composition and proportion of non-target escapees in Rapana fisheries by dredging along the western coast of the Black Sea. In this method, the dredge net bag (codend net) is covered with a second net bag that has a smaller mesh size to retain those individuals escaping from the dredge net bag. Up to 87% of the total ∼1.4×106 individuals per km (ind. km−2) cover net catches belonged to non-target species. Overall, 24 non-target species were caught in the cover net, with 46% of species belonging to the Teleostei (mostly flatfishes), 21% Malacostraca, 17% Bivalvia, 8% Gastropoda, 4% Amphibia, and 4% Ascidiacea. On the other hand, up to 6.8% of the total ∼0.16×106 ind. km−2 catches of the codend net (dredge net) belonged to non-target species. Compared to the cover net, a total of seven non-target species were retained in the codend net, and six of them belonged to Bivalvia. This study demonstrated an apparent negative impact of Rapana fisheries, particularly on escapees that often go unaccounted for their vulnerability to stress and physical damage.

Effects of escape vents on the size selection of whelk (Rapana venosa) and Asian paddle crab (Charybdis japonica) in the small-scale pot fishery of the Yellow Sea, China

Effects of escape vents on the size selection of whelk (Rapana venosa) and Asian paddle crab (Charybdis japonica) in the small-scale pot fishery of the Yellow Sea, China

Antitumour Activity of Different Bioactive Compounds from Hemolymph and Mucus of Mollusca against Human Urinary Bladder Cancer Cell Lines

In this study, we isolated different bioactive compounds and fractions from Rapana venosa (RvH), Helix aspersa (HaH) and Helix lucorum (HlH) and then we evaluated their in vitro antitumour activity on CAL-29 and T- 24 cell lines (transitional cell carcinoma). Also, we performed fluorescence staining with propidium iodide to assess nuclear changes caused by molluscan extracts. Briefly, our results have demonstrated antineoplastic activity of: subunit βc-HaH of H. aspersa hemocyanins to CAL-29 cell line, subunit βc-HaH and subunit RvH II of R. venosa hemocyanin against T-24 cells. Also, fractions from R. venosa hemolymph exerted significant cytotoxic activity against CAL- 29 cells. Furthermore, fluorescence microscopy results demonstrated chromatin condensation and nuclear morphological changes which are typical for apoptosis induction. We assume that the observed death of T-24 and CAL-29 cells is due to the interaction between the oligosaccharide structures of the proteins on the tumour cell membranes and the hemolymph from R. venosa, active components isolated from hemolymph of R. venosa, H. aspersa and H. lucorum, as well as H. aspersa mucus.

Participation of Carbohydrate Structures in the Formation of Complex Structure of Hemocyanins from Haliotis tuberculata

Glycosylation plays an important role in many important processes in organisms. Their participation in the construction of the tertiary structure and immunotherapeutic activity of the hemocyanin Rapana venosa (RvH) from the Black Sea has been presented. Based on these results, the importance of glycans in organization of the structure of hemocyanin from the abdominal mollusk Haliotis tuberculata (HtH) was also studied.&#x0D; After incubation of both isoforms HtH1 and HtH2 with yeast Saccharomyces cerevisiae and enzyme Zymolyase, fractions with lower molecular weight (MW) between 45 and 65 kDa, which corresponds to MW of functional units (FUs) of hemocyanins, was identified. A comparative analysis of 10% SDS PAGE assays confirmed the depolymerization of the subunits HtH1 and HtH2 due to the specific glycosidase in the yeast S. cerevisiae and the enzyme Zymolyase. The presented results confirm our hypothesis that glycans are involved in the formation of the structural subunits of HtH.

Elemental Compositions of Rapana Venosa (Mollusca: Muricidae) from the Eastern Black Sea Region of Turkey: Toxicology Health Risk Assessment

This study examined the level of metals, metalloids, non–metals, and mineral elements in the edible parts as well as in other organs of Rapana venosa, obtained from the Eastern Black Sea. The concentrations of Ba, Ca, Cr, Co, Cu, Fe, Ni, P, Mo, Se, Pb, Sr, and Zn within the organs showed significant variations. The operculum possessed significantly higher Ba, Co, Cr, Fe, Mo, Pb, and Se, while the hepatopancreas had higher Ca, Cu, Ni, P, Sr, and Zn concentrations. The target hazard quotient (THQ) and total THQ were < 1, indicating no potential health risk to consumers.

Marine and Agro-Industrial By-Products Valorization Intended for Topical Formulations in Wound Healing Applications.

Over the past years, research attention has been focusing more on waste-derived, naturally derived, and renewable materials, in the view of a more sustainable economy. In this work, different topical formulations were obtained from the valorization of marine and agro-industrial by-products and the use of Carbopol 940 as gelling agent. In particular, the combination of extracts obtained from the marine snail, Rapanosa venosa, with Cladophora vagabunda and grape pomace extracts, was investigated for wound healing purposes. Rapana venosa has demonstrated wound healing properties and antioxidant activity. Similarly, grape pomace extracts have been shown to accelerate the healing process. However, their synergic use has not been explored yet. To this aim, four different formulations were produced. Three formulations differed for the presence of a different extract of Rapana venosa: marine collagen, marine gelatin, and collagen hydrolysate, while another formulation used mammalian gelatin as further control. Physico-chemical properties of the extracts as well as of the formulations were analyzed. Furthermore, thermal stability was evaluated by thermogravimetric analysis. Antioxidant capacity and biological behavior, in terms of cytocompatibility, wound healing, and antimicrobial potential, were assessed. The results highlighted for all the formulations (i) a good conservation and thermal stability in time, (ii) a neutralizing activity against free radicals, (iii) and high degree of cytocompatibility and tissue regeneration potential. In particular, collagen, gelatin, and collagen hydrolysate obtained from the Rapana venosa marine snail represent an important, valuable alternative to mammalian products.

Identification and characterization of olfactory receptor genes and olfactory perception in rapa whelk Rapana venosa (Valenciennes, 1846) during larval settlement and metamorphosis.

The rapa whelk Rapana venosa, an economically important marine fishery resource in China but a major invader all over the world, changes from a phytophagous to a carnivorous form following settlement and metamorphosis. However, the low settlement and metamorphosis rates (<1%) of larvae limit the abundance of R. venosa. This critical step (settlement and metamorphosis) remains poorly characterized but may be related to how larvae perceive the presence of shellfish, their new source of food. Here, we report that larvae may use olfactory perception to sense shellfish. Olfactory receptor (OR) genes are involved in odor sensing in animals. We identified a total of 463 OR genes, which could be grouped into nine clades based on phylogenetic analysis. When assessing the attraction of larvae at different developmental stages to oyster odor, R. venosa showed active settlement and metamorphosis behavior only at the J4 stage (competent larva, 1000-1500 μm shell length) and in the presence of shellfish odor at the same time. Expression of OR gene family members differed between stage 2 (four-spiral whorl stage) and stage 1 (single- to three-spiral whorl stage), indicating significant changes in the olfactory system during larval development. These findings broaden our understanding of olfactory perception, settlement, and metamorphosis in gastropods and can be used to improve R. venosa harvesting, as well as the sustainable development and utilization of this resource.

Microbial diversity and nutritional profile of processed and unprocessed Tympanotonus fuscatus (Periwinkle), Crassostrea gasar (Oyster) and Rapana venosa (Whelk)

A study of the microbiological quality and proximate composition of Shellfish purchased from different markets in Rivers State. The results obtained for raw and cooked shellfish are as follows: Total Viable Bacteria Count ranged from Log10 cfu/g 3.39 -7.74, Total Salmonella Count ranged Log10 cfu/g 1.5-6.47, Total Staphylococcus Count; Log10 cfu/g 3.07 -5.58, Total Vibrio Count Log10 cfu/g0 cfu/g 0.2 – 4.3. Most samples analyzed did not meet ICMSF standards for raw and cooked samples. Twelve bacteria species were isolated from raw(unprocessed) and processed periwinkle, oyster and whelk; Salmonella sp, Proteus sp, Escherichia coli, Micrococcus sp, Vibrio cholerea, Vibrio parahaemolyticus, Enterobacter sp, Klebsiella sp, Citrobacter sp, Staphylococcus sp, Bacillus sp and Pseudomonas sp. Proximate analysis showed that cooking does minimal to insignificant damage to the nutrient content in the sea foods. Handling and consumption of seafood must be undertaken carefully and knowledgeably to avoid food borne infections.

Microbial diversity and nutritional profile of processed and unprocessed Tympanotonus fuscatus (Periwinkle), Crassostrea gasar (Oyster) and Rapana venosa (Whelk)

Microbial diversity and nutritional profile of processed and unprocessed Tympanotonus fuscatus (Periwinkle), Crassostrea gasar (Oyster) and Rapana venosa (Whelk)

Long-term investigation of heavy metal variations in mollusks along the Chinese Bohai Sea

Biomonitoring is an effective way to assess the effects of pollutants on marine ecosystems. As an important fishing region in China, the Chinese Bohai Sea has been contaminated with heavy metals, posing great risks to seafood safety and human health. Herein, the spatiotemporal variations in the concentrations of seven heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in 11 species of mollusks (658 samples) collected from the Chinese Bohai Sea were studied during 2006–2016. The concentrations of Cr, As, Cd, and Pb in approximately 41%, 100%, 71%, and 18% of the sampled mollusks exceeded the maximum permissible levels in aquatic products set by China, indicating that the mollusks were contaminated with varied concentrations of heavy metals. Except for slight fluctuations, no significant temporal variations were observed during the sampling period, suggesting a relatively stable status of these metals. Cluster analysis showed that oyster had higher bioaccumulation potential for Zn and Cu, whereas Mactra veneriformis, Rapana venosa, Meretrix meretrix, Chlamys farreri, and Mya arenaria had higher bioaccumulation potentials for Cr, As, Ni, Cd, and Pb, respectively. These findings are useful for biomonitoring and developing guidelines for seafood consumption in coastal regions. Significant relationships were observed between heavy metal concentrations in mollusks and socioeconomic indices (gross domestic product, per capita gross domestic product, and population amount), suggesting the effects of anthropogenic activities on heavy metal contamination. Our study established a good model to evaluate the risks of heavy metals and provided a sound scientific basis for controlling seafood safety in coastal regions.

Ekonomik etkinliğin belirlenmesi: Güney Karadeniz’deki deniz salyangozu (Rapana venosa) avcılığına (balıkçılığına) ilişkin bir çalışma

The inevitable increase in the numerical and technological capacity of fishing fleets in developed and developing countries has major implications for the management and distribution of limited natural resource capacity, as well as the ecological and socio-economic sustainability of fisheries. It is important to determine these effects to make the right decisions in fisheries management. This study aims to assess the fishing capacity, technical efficiency, scale efficiency, and capacity use in a specific subset of Rapa whelk fishers, those in Turkey's Black Sea. Economically efficient and inefficient boats were also compared in the study. The data obtained through face-to-face interviews with 452 boat owners constitute the main data of the study. Data were collected about the economic efficiency of the boats for one year. While economic efficiency ranged between 0.27 and 1, the average value was found to be 0.60. It was concluded that the age of the owner, the education period, and the length of the fishing boat positively affected economic efficiency (p&lt;0.05). In the boats studied, technical efficiency scores were greater than economic efficiency scores. This suggests that rather than technical information, fishers require information on selecting the optimum input combination at the data cost level.

Population dynamics and ecology of the invasive veined rapa whelk, Rapana venosa in the southern Black Sea

Spatial and temporal changes in some ecological characteristics (i.e. biomass, abundance, morphometrics, sex-composition, growth parameters and population dynamics) of the invasive veined rapa whelk (Rapana venosa) were studied off Sinop Bay, in the southern Black Sea. The whelk specimens were sampled from three depths (15 m, 25 m and 35 m) at monthly intervals between November 2005 and October 2007. Custom-made pots were deployed for the capture of R. venosa individuals. Monthly distributions in whelk biomass and abundance peaked in summer (June/July) and mid-autumn (October) and displayed no differences between 2006 and 2007. With the exception of gut weight, all morphometric variables produced three peak periods (January, June and September, respectively) over one year. Densities, morphometrics and sex composition were dictated significantly by bottom depth and monthly variation. Two stages were defined in the ovary and testis index maxima denoting longer spawning and recruitments periods starting as early as in March which is a different finding compared to previous studies from the Black Sea. For the estimation of population growth parameters, of the five morphometric variables analysed, siphon width was the best variable to produce clear size cohorts. Whelk growth in terms of shell length and width oscillated seasonally and ceased during February–March. Maximum age of the veined rapa whelk in the southern Black Sea was determined as 3.5 years corresponding to 7 cohorts. Among the environmental parameters, dissolved oxygen, temperature and salinity appeared to affect whelk densities. Results obtained here are important for better management of the whelk fishery in the Black Sea.

Heavy Metals and Arsenic in Soft Tissues of the Gastropod Rapana venosa (Valenciennes, 1846) Collected on a Mollusk Farm Off Sevastopol (Southwestern Crimea, Black Sea): Assessing Human Health Risk and Locating Regional Contamination Areas.

The gastropod Rapana venosa is an edible mollusk suitable for biomonitoring of sea shelf contamination. In this work, the contents of five elements (Cu, Zn, As, Cd, Pb) in foot and in the rest of soft tissues of this mollusk were quantified, and the element contents in the edible foot were found below the maximum permissible levels set in several national and transnational regulations. The estimated daily intake of these elements and the hazard index indicated no likely risks to consumers' health, but the long-term cancer risks due to the arsenic intake were found significant. The arsenic and cadmium contents in soft tissues of this rapawhelk were among highest observed in the Black Sea region in the 2010s, and this suggests the specific arsenic and cadmium contamination of seawater off the southwestern Crimea. For the first time, this mollusk was shown to serve as a seawater contamination bioindicator at the regional level.

Effect of Fishery Closure on Discard Composition of Rapa Whelk, Rapana venosa (Valenciennes 1846) Beam Trawl Fisheries in Black Sea

Rapa whelk has become significant commercially, as there is a market that makes it export-oriented species. It has also gained special importance because of catching this species in all riparian countries in the Black Sea basin. The various exploitation methods of this species include beam trawl and diving. Here, the experimental beam trawl survey for Rapa whelk fishing was designed monthly in one year. Catch composition was examined spatially and temporally. Differences in estimated biomass of Rapa whelk and abundance of discard species were used to evaluate the effectiveness of seasonal fishing closure. Our results indicated that, discard composition of Rapa whelk fishery strongly reflected seasonal changes. Total estimated abundance and biomass values showed significant regional, seasonal and depth-related differences, also number of species and diversity index changes regionally and seasonally. Discard ratio was found very low in biomass. At the same time, seasonal fishery closure period was benefited for discard species in spring and summer period. The lowest distribution of Rapa whelk and discard species except blood cockle were found in winter season during fishing period. It becomes apparent that seasonal fishery closure is an important management measure both for stock sustainability, species diversity, and ecosystem health. Therefore, all Black Sea countries should consider similar management.

TAFONOMÍA ACTUALISTA EN EL GASTERÓPODO INVASOR Rapana venosa (VALENCIENNES, 1846) EN EL ESTUARIO DEL RÍO DE LA PLATA

Actualistic taphonomy allows to know the environmental conditions that influence the preservation of biological remains, contributing to the reconstruction of the depositional setting of fossil assemblages. Here we explore the use of the alien gastropod Rapana venosa (Valenciennes, 1846) as a taphonomic model in the Río de la Plata.

Symbiotic microbiome and metabolism profiles reveal the effects of induction by oysters on the metamorphosis of the carnivorous gastropod Rapana venosa

Most marine mollusks have a pelagic larval phase, and they need to undergo metamorphosis to develop into adults. Metamorphosis is affected by many factors, including abiotic factors such as temperature, salinity and illumination as well as biological factors such as food and microorganisms. In our previous study, we found that the metamorphosis of Rapana venosa requires induction by juvenile oysters, which are the food source of R. venosa. However, the regulatory mechanism of this induction is largely unknown. In the present study, we evaluated the impacts of induction by juvenile oysters on competent larvae of R. venosa. Competent larvae were experimentally divided into two pools, and scallop shells without juvenile oysters and scallop shells with juvenile oysters were added for 2 h and 12 h to monitor alterations in critical gene expression, symbiotic microbiota and metabolomic responses. The carboxypeptidase gene was increased while the cellulase gene was decreased, which may mean that the food habit transition was induced by juvenile oysters. Meanwhile, critical genes in the neuroendocrine system were also significantly altered in juvenile oysters. Furthermore, dramatic changes in the symbiotic microbiota and metabolism profiles were observed, with many of them associated with the digestive system and neuroendocrine system. In conclusion, juveniles as food resources may induce metamorphosis in R. venosa by regulating the neuroendocrine system and promoting the development of the digestive system and changes in digestive enzymes. This study may provide evidence that induction by juvenile oysters can promote food habit transition and metamorphosis in R. venosa by regulating the metabolome and microbiome and further altering the digestive and neuroendocrine systems of R. venosa, which expands our understanding of the regulatory mechanism of metamorphosis in R. venosa. However, further studies are needed to explore the specific substance inducing metamorphosis released by juvenile oysters.

Assessment of Polycyclic Aromatic Hydrocarbons Content in Marine Organisms of Commercial Interest from the Romanian Black Sea Coast

The purpose of this work was to assess the levels of polycyclic aromatic hydrocarbons (PAHs) in some mollusks and fish species, collected during the summer of 2016–2018, from three sites representing the southern, middle, and northern areas of the Romanian Black Sea coast. The PAHs concentrations were determined from the edible tissues of some important seafood (Rapana venosa and Mytilus galloprovincialis mollusk species; Sprattus sprattus, Engraulis encrasicolus, and Trachurus mediterraneus ponticus pelagic fish species and Neogobius cephalarges benthic fish species). The PAHs were analyzed using gas chromatography-mass spectrometry. The average concentrations of these PAHs ranged from below detection limit of 0.0001 to 103.09 ± 11.18 µg/kg wet wt. in mollusk species, from 0.0001 to 147.45 ± 9.28 µg/kg wet wt. in pelagic fish species and from 0.0001 to 45.73 ± 5.28 µg/kg in benthic fish species. Among the two mollusks species, Rapana venosa accumulated significantly higher concentrations (p < 0.05) of PAHs, while among fish species, Trachurus mediterraneus ponticus accumulated significantly higher concentrations (p < 0.05) of total PAHs. Total PAH concentrations varied between the sites; the main presence of PAHs was observed in site 2 (middle location), the major contribution being given by the presence of phenanthrene (Ph), anthracene (An), and naphthalene (Na). PAHs contents in organisms varied according to the different species, their location in the water, their feeding habits (pelagic and benthic organisms) and differences in the quantification of LMW and HMW PAHs. PAH distribution patterns in pelagic and mollusk species are characterized by the abundance of LMW-PAHs. Most of the PAHs had a petrogenic origin, which indicates that the anthropogenic activities influenced PAH concentrations. Apart from Neogobius cephalarges species, the benzo[a]pyrene concentrations, measured in mollusks and fish species did not exceed the EU recommended limit.