Search Results (13)

Snails at hydrothermal vents rely on symbiotic bacteria for nutrition; however, the specifics of these associations in adapting to such extreme environments remain underexplored. This study investigated the community structure and metabolic potential of bacteria associated with two Indian Ocean vent snails, Chrysomallon squamiferum and Gigantopelta aegis. Using microscopic, phylogenetic, and metagenomic analyses, this study examines bacterial communities inhabiting the foot and gland tissues of these snails. G. aegis exhibited exceptionally low bacterial diversity (Shannon index 0.14–0.18), primarily Gammaproteobacteria (99.9%), including chemosynthetic sulfur-oxidizing Chromatiales using Calvin–Benson–Bassham cycle and methane-oxidizing Methylococcales in the glands. C. squamiferum hosted significantly more diverse symbionts (Shannon indices 1.32–4.60). Its black variety scales were dominated by Campylobacterota (67.01–80.98%), such as Sulfurovum, which perform sulfur/hydrogen oxidation via the reductive tricarboxylic acid cycle, with both Campylobacterota and Gammaproteobacteria prevalent in the glands. The white-scaled variety of C. squamiferum had less Campylobacterota but a higher diversity of heterotrophic bacteria, including Delta-/Alpha-Proteobacteria, Bacteroidetes, and Firmicutes (classified as Desulfobacterota, Pseudomomonadota, Bacteroidota, and Bacillota in GTDB taxonomy). In C. squamiferum, Gammaproteobacteria, including Chromatiales, Thiotrichales, and a novel order “Endothiobacterales,” were chemosynthetic, capable of oxidizing sulfur, hydrogen, or iron, and utilizing the Calvin–Benson–Bassham cycle for carbon fixation. Heterotrophic Delta- and Alpha-Proteobacteria, Bacteroidetes, and Firmicutes potentially utilize organic matter from protein, starch, collagen, amino acids, thereby contributing to the holobiont community and host nutrition accessibility. The results indicate that host species and intra-species variation, rather than the immediate habitat, might shape the symbiotic microbial communities, crucial for the snails’ adaptation to vent ecosystems. Full article

This study evaluates the nutritional potential of two cultivated snail species, Acusta despecta and Achatina fulica, sourced from commercial farms in Korea, marking the first comprehensive analysis of A. despecta. The protein content of A. despecta (70.9 g/100 g dry matter) was significantly higher than that of A. fulica (44.2 g/100 g dry matter). Similar trends were observed for ash content (6.3 vs. 4.9 g/100 g dry matter) and crude fiber (2.9 vs. 0.4 g/100 g dry matter). Reflecting the higher protein content, A. despecta contained elevated levels of most amino acids compared to A. fulica. Glutamic acid was the most abundant amino acid, with leucine and lysine being the predominant essential amino acids in both species. The total amino acid content was 57.6 g/100 g dry matter for A. despecta and 40.4 g/100 g for A. fulica. Mineral analysis revealed significantly higher concentrations of minerals in A. despecta, except calcium and magnesium. Notably, A. despecta provided over 100% of the RDA/AI for calcium, phosphorus, copper, and manganese and met 94.5% of the iron RDA for women. These results emphasize the potential of A. despecta as a valuable dietary source for addressing protein and mineral deficiencies, particularly in nutrient-poor diets. Full article

In recent years, Pomacea canaliculata has aggressively invaded rice fields in Asia, resulting in significant agricultural losses. Biological control can effectively reduce the damage caused by P. canaliculata. This research evaluates E. sinensis as a biocontrol for P. canaliculata, focusing on its feeding preferences and optimal control density on snails of three sizes, as well as the effects on the nutritional quality of juvenile crabs post consumption. Our findings reveal that juvenile E. sinensis exhibit a strong preference for feeding on small snails, effectively managing populations at densities of 600 snails per tank. Crab feeding significantly reduces the survival and activity of snails. Furthermore, consumption of P. canaliculata meat alters the crabs’ physiology. Female crabs show elevated levels of molting hormones, total energy yield (TEY), and condition factor (CF), while males demonstrate increased lipid, moisture, and TEY levels. The amino acid profiles shift, with higher isoleucine and leucine levels in female hepatopancreas and reduced histidine in the muscles. Notably, the total Σn-3 PUFA content in female muscles fed on snail meat exceeds that of those given commodity grain. This study underscores the dual benefits of employing juvenile E. sinensis for managing P. canaliculata while enhancing crab farming practices. Full article

Snail Bellamya purificata is not only useful for bioremediation, purifying aquaculture environments, but it is also a commercially valuable and nutritionally rich aquatic product. To analyze the effect of various stocking densities on the muscle nutritional quality and metabolic functions of B. purificata. The transcriptome and metabolome were analyzed and set up three different density groups—low (LD, 234.38 g/m²), medium (MD, 468.75 g/m²), and high (HD, 937.5 g/m²). The results of the study showed that the weight gain (WG) and specific growth rate (SGR) of B. purificata in the MD and HD groups were significantly lower compared to the LD group. High stocking density significantly reduced the oleic acid (C18:1n9c), linoleic acid (C18:2n6c), alpha-linolenic acid (C18:3n3), eicosadienoic acid (C20:2), erucic acid (C22:1n9), docosahexaenoic acid (DHA, C22:6n3), and lignoceric acid (C24:0) levels within snail foot muscle. Most of the identified differentially expressed genes (DEGs) were categorized as Signal transduction, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG); these genes were categorized into Transport and catabolism, Endocrine system, and Immune system. A total of 11 upregulated DEGs and 19 downregulated DEGs were identified and confirmed to be associated with density stress. The identified metabolites were mainly enriched in the Metabolism category, with 620 differential metabolites identified in positive ion (POS) mode and 265 differential metabolites identified in the negative ion (NEG) mode among different stocking density groups. The differential metabolites affected by stocking density were primarily amino acids, nucleic acids, vitamins, and lipid metabolites. There were 8 upregulated differential metabolites and 14 downregulated differential metabolites identified and confirmed to be associated with density stress. These findings elucidated the response mechanisms of B. purificata to adverse stocking density conditions and provide data and a theoretical basis for selecting appropriate stocking densities for B. purificata. Full article

The European Union’s (EU) agricultural self-sufficiency is challenged by its reliance on imported plant proteins, particularly soy from the Americas, contributing to deforestation and greenhouse gas emissions. Addressing the EU’s protein deficit, this study evaluates alternative protein sources for aquaculture, focusing on their nutritional value, elemental content, and polycyclic aromatic hydrocarbons (PAHs). Protein flours from gastropods (Helix pomatia, Arion lusitanicus, Arion vulgaris) and their hepatopancreas, along with plant-based proteins from food industry by-products (oilcakes, coffee grounds, spent brewer’s yeast), were analyzed. Results revealed that snail flour contained the highest protein content at 59.09%, significantly outperforming hepatopancreas flour at 42.26%. Plant-based proteins demonstrated substantial nutritional value, with coffee grounds flour exhibiting a remarkable protein content of 71.8% and spent brewer’s yeast flour at 57.9%. Elemental analysis indicated high levels of essential minerals such as magnesium in hepatopancreas flour (5719.10 mg/kg) and calcium in slug flour (48,640.11 mg/kg). However, cadmium levels in hepatopancreas flour (11.45 mg/kg) necessitate caution due to potential health risks. PAH concentrations were low across all samples, with the highest total PAH content observed in hepatopancreas flour at 0.0353 µg/kg, suggesting minimal risk of PAH-related toxicity. The analysis of plant-based protein sources, particularly oilcakes derived from sunflower, hemp, flax, and pumpkin seeds, revealed that these by-products not only exhibit high protein contents but present a promising avenue for enhancing the nutritional quality of feed. This study underscores the potential of utilizing gastropod and plant-based by-products as sustainable and nutritionally adequate alternatives to conventional feeds in aquaculture, contributing to the EU’s environmental sustainability goals. Full article

Forest-dwelling residents frequently collect non-timber forest products (NTFPs) for various reasons, such as food, medicine, firewood, religious reasons, or handicrafts. This study examines the multiple benefits derived from NTFPs and how they contribute to the livelihoods of Ghanaian communities to alleviate poverty. Resources and services provided by NTFPs have an essential role in providing economic, nutritional, medicinal, cultural, and environmental benefits. This study examines the diverse range of NTFPs locals collect, such as chewing sticks, games, herbs, honey, leaves, mushrooms, pestles, raffia and palms, snails, and straws. In addition to serving different purposes, these NTFPs contribute to income generation, food security, health care, cultural practices, and the protection of the environment. A qualitative research approach was used in this study to collect data through semi-structured interviews and focus groups with members on multiple collections of NTFPs and their multiple benefits. We interviewed 732 residents regarding their multiple NTFPs and their potential to improve the livelihood of the locals. The data for the study were analysed using descriptive statistics. As a result of the survey, the frequency and percentages of responses were analysed for each indicator related to multiple values of NTFPs. Both males and females collected a list of NTFPs during the survey. Regarding NTFPs used for sale, 275 were reported, representing 37.57% of the total. In addition to emphasising the importance of sustainable management practices and equitable distribution of benefits, the study explores the multiple benefits of NTFPs for poverty alleviation in Ghanaian communities. It is essential to ensure the conservation of forest ecosystems and promote inclusive policies to harness the potential of NTFPs and maximise their positive impact on livelihoods. NTFPs provide multiple benefits for Ghanaian communities, including income, nutrition, healthcare, cultural preservation, and environmental sustainability. To promote sustainable development, it is imperative to understand the role of NTFPs and implement appropriate strategies. Full article

Edible snails are an attractive protein source due to their high growth rate, cost-efficiency, and nutritional value. Calcium is crucial for snail growth, reproduction, and shell formation, while magnesium plays a role in enzyme function and muscle tone. This study aimed to optimise calcium and magnesium levels in Cornu aspersum diets to optimise the production and technological characteristics of the derived animal products. Snails were fed specific diets in controlled conditions with varying calcium and magnesium levels (44.3, 66.1, 88.7, 103.5 Ca g/kg feed and 3.3, 5.6, 7.2 Mg g/kg feed) for four months. Their growth, shell characteristics, and meat composition were evaluated. As calcium in the feed increased, carcass and shell weights were higher. Also, the crushing force of the shells was higher with increasing amount of calcium in the feed. In the group with 10.35% calcium and 0.72% magnesium, snail growth significantly slowed down after three months, with lower mortality. It is suggested that a shortened fattening cycle by 3–4 weeks compared to the magnesium-free diet is possible. However, based on meat, shell, mortality, and feed intake analysis, a 0.56% magnesium concentration in the feed seems to give better results, as magnesium content at 0.72% might be toxic to snails. Further investigation is to confirm the possibility of neutralising the negative effects of magnesium in the diet through increasing calcium and phosphorus intake. Full article

Humans consume snail flesh as part of their diet. To assess its nutritional value and toxicity, chemical analyses were conducted to confirm the presence of protein, total and reduced carbohydrates, fat, fatty acid composition and mineral components. Furthermore, an acute toxicity study was carried out to determine the safety of Helix aspersa Müller snail flesh. H. aspersa Müller snail flesh exhibits a high nutritional content, a good ω3/ω6 ratio and higher levels of unsaturated fatty acids. Various minerals have been found in the flesh of H. aspersa Müller. Around 76.91 kcal, or 3.84% of the energy of a daily meal of 2000 kcal, are present in 100 g of this flesh. The evaluation of the antioxidant capacity indicated that the flesh’s extracts contained a large quantity of antioxidant biomolecules. Administration of the aqueous extract of H. aspersa Müller flesh didn’t cause death in laboratory rats, indicating that the lethal dose 50 is greater than 2000 mg·kg⁻¹ body weight. The consumption of the flesh of H. aspersa Müller is highly recommended for human consumption due to its high concentration of nutrients and essential elements, as well as unsaturated fats, and due to its safety. Full article

The human population is growing; food production is becoming insufficient, and the growing awareness of the negative impact of traditional animal husbandry on the environment means that the search for alternative methods of providing animal protein is continuously underway. The breeding of edible snails seems to be a promising option. The most popular species of edible snails in Europe include the brown garden snail Cornu aspersum (Müller, 1774) (previously divided into two subspecies: Cornu aspersum aspersum (Müller, 1774) and Cornu aspersum maxima (Taylor, 1883)), as well as the Roman Snail—Helix pomatia Linnaeus, 1758. These animals are highly productive, require relatively little space, are easy to breed and their maintenance does not require large financial outlays. This review focuses on the prospects of food snail farming in Europe. It discusses the living conditions, the nutritional value of the snails’ meat, and the way of feeding the animals, paying particular attention to issues still not scientifically resolved, such as the need for micro and macro elements, as well as fat and carbohydrates. Full article

Members of the Phylum Mollusca include shellfish such as oysters and squid but also the edible garden snail known as Helix aspersa. This snail species is consumed as a delicacy in countries including France (where they are known as petit-gris), southern Spain (where they are known as Bobe), Nigeria, Greece, Portugal and Italy but is not a traditional food in many other countries. However, it is considered an excellent protein source with a balanced amino acid profile and an environmentally friendly, sustainable protein source. The aim of this work was to develop a different dietary form of snail protein by generating protein hydrolysate ingredients from the edible snail using enzyme technology. A second aim was to assess the bioactive peptide content and potential health benefits of these hydrolysates. H. aspersa hydrolysates were made using the enzyme Alcalase^® and the nutritional profile of these hydrolysates was determined. In addition, the bioactive peptide content of developed hydrolysates was identified using mass spectrometry. The potential heart health benefits of developed snail hydrolysates were measured in vitro using the Angiotensin-I-converting Enzyme (ACE-1; EC 3.4.15.1) inhibition assay, and the ACE-1 inhibitory drug Captopril© was used as a positive control. The generated H. aspersa hydrolysates were found to inhibit ACE-1 by 95.60% (±0.011) when assayed at a concentration of 1 mg/mL (n = 9) compared to the positive control Captopril© which inhibited ACE-1 by 96.53% (±0.0156) when assayed at a concentration of 0.005 mg/mL (n = 3). A total of 113 unique peptide sequences were identified following MS analysis with peptides identified ranging from 628.35 Da (peptide GGGLVGGI—protein accession number sp|P54334|XKDO_BACSU) to 2343.14 Da (peptide GPAGVPGLPGAKGDHGFPGSSGRRGD—protein accession number sp|Q7SIB2|CO4A1_BOVIN) in size using the BIOPEP-UWM database. Full article

In mid Adriatic Sea the common sea snail is the habitual snail eaten, but over the years fishermen started to capture also the long sea snail, a possible alternative for human consumption. This study aims to compare the quality traits of the edible fraction in the common and long sea snails. In this study, common and long sea snail samples were provided by fishermen in November 2018 and March 2019. Total weight (meat and shell), fractions of meat and shell (after having extracted the edible part), fatty acid, elements in meat, and calcium content in shells were determined. Meat quality traits showed high nutritional value without significant differences between the two species. The fatty acid profile showed n3/n6 ratio significantly different both considering the season of sampling (November: 4.1; March: 2.38) and the species of sea snail (common: 4.98; long: 2.86). The long species showed a higher yield in the total body and calcium content concentrations. However, the long sea snail showed 50% lower meat yield compared with the common sea snail. In conclusion, the long sea snail can be used as an alternative to the common sea snail for human consumption. Full article

Wild animals have been used as food since ancient times and, currently, the consumption of unconventional animals is increasing worldwide. The process of cooking meat using traditional recipes includes a variety of ingredients, which can influence the total metal intake from the diet. In this study, the concentrations of eight essential (Fe, Zn, Cu, Mn, Se, Ni, Mo, and Co) and six non-essential (Pb, Cd, Hg, Al, As, and Cr) trace elements were determined in home-processed food obtained from snails and from three common species of game animals (woodcock, pheasant, and hare), seasoned with anchovies, mushrooms, and different vegetables using inductively coupled plasma mass spectrometry (ICP-MS). In general, Fe was the most abundant trace element, ranging from 18 ± 8 µg/g in pheasant to 99 ± 76 µg/g in snail, and Co was the least abundant, ranging from 0.007 ± 0.003 µg/g in hare to 0.093 ± 0.048 µg/g in snail. Regarding the non-essential trace elements, Pb concentrations showed wide variations, reaching a concentration of 17.30 µg/g in hare, while Cd concentrations were higher in snail, ranging from 0.18 to 0.46 µg/g. These alternative food sources can offer an important contribution to the human nutritional requirements of essential trace elements, in particular of Fe. The high concentrations of Pb and Cd present in some samples should be considered as potentially dangerous for the consumers. Full article

Neptunea arthritica cumingii (Nac) is a marine snail with high nutritional and commercial value; however, little is known about its active peptides. In this study, two multi-functional peptides, YSQLENEFDR (Tyr-Ser-Gln-Leu-Glu-Asn-Glu-Phe-Asp-Arg) and YIAEDAER (Tyr-Ile-Ala-Glu-Asp-Ala-Glu-Arg), were isolated and purified from meat and visceral mass extracts of Nac using a multi-bioassay-guided method and were characterized by using liquid chromatography-tandem mass spectrometry. Both peptides showed high antioxidant, angiotensin-converting enzyme (ACE)-inhibitory, and anti-diabetic activities, with half-maximal effective concentrations values less than 1 mM. Antioxidant and ACE-inhibitory activities were significantly higher for YSQLENEFDR than for YIAEDAER. In a zebrafish model, the two peptides exhibited strong scavenging ability for reactive oxygen species and effectively protected skin cells against oxidative damage without toxicity. Molecular docking simulation further predicted the interactions of the two peptides and ACE. Stability analysis study indicated that the two synthetic peptides maintained their activities under thermal stress and simulated gastrointestinal digestion conditions. The low molecular weight, high proportion of hydrophobic and negatively-charged amino acids, and specific C-terminal and N-terminal amino acids may contribute to the observed bio-activities of these two peptides with potential application for the prevention of chronic noncommunicable diseases. Full article