Search Results (630)

Mollusks, such as bivalves, face increasing threats, such as disease, in aquaculture. Exosomes, widely derived from living cells carrying diverse bioactive molecules, affect the immune response. To overcome these challenges, bivalves utilize exosomal miRNAs as critical regulators of immune responses. This study investigates the role of exosomal miRNAs in modulating immune and metabolic responses in Pinctada fucata martensii following lipopolysaccharide (LPS) stimulation. Exosomes (75–150 nm) were isolated from hemolymph and characterized. High-throughput sequencing identified 30 differentially expressed miRNAs (DEMs) and 1349 differentially expressed genes (DEGs) in LPS-treated oysters, with significant enrichment in TNF, TLR/NF-κB, and metabolic pathways. This study revealed exosomal miRNA-mediated regulation of immune genes (IκBα, TRAF6, IRAK1, and BIRC2/3) and metabolic enzymes (PCK and CYP2J), demonstrating their role in apoptosis, inflammation, and metabolic reprogramming. Network analysis highlighted miRNA–mRNA interactions, including miR-7/IκBα (TNF pathway) and miR-34_5/IRAK1 (TLR pathway). Additionally, exosomal miRNAs (miR-92_2 and novel_mir5) were found to regulate oxidative stress (SOD1) and gluconeogenesis (PCK), linking immune defense with metabolic adaptation. These findings provide novel insights into exosomal miRNA-mediated immune regulation in bivalves, revealing conserved mechanisms with potential implications for molluscan health and disease management. Full article

Despite the oligotrophic conditions of the southeastern Levantine Sea and northern Red Sea, six lobster species—five slipper lobsters (Scyllaridae) and one spiny lobster (Palinuridae)—maintain permanent, reproducing populations in the study area. Additionally, there are isolated records of four other sporadic lobster species. In the southeastern Mediterranean, permanent species include the Mediterranean slipper lobster,Scyllarides latus, small European locust lobster, Scyllarus arctus, and pygmy locust lobster, Scyllarus pygmaeus. In the northern Red Sea, they include the clamkiller slipper lobster, Scyllarides tridacnophaga, Lewinsohn locust slipper lobster, Eduarctus lewinsohni, and pronghorn spiny lobster, Panulirus penicillatus. This review synthesizes current knowledge of their biology and ecology, including distribution, habitat, reproduction and development, feeding, predators and anti-predatory adaptations, behavior, sensory modalities, environmental impacts, threats, and conservation. Recent advances focus mainly on larger, commercially valuable species (S. latus, S. tridacnophaga, P. penicillatus), while major gaps remain for oceanic post-embryonic stages and the nektonic nisto postlarva, as well as for smaller, often cryptic species (S. arctus, S. pygmaeus, E. lewinsohni). Addressing these gaps will require targeted research, using modern methodologies, in coastal, deep, and open waters, coupled with citizen-science surveys. While many Indo-Pacific decapods have been established in the Mediterranean, no immigrant lobster species have successfully colonized Levant waters, despite rare records of three non-indigenous species (NIS). However potential NIS predators and shifts in mollusk compositions, the main prey of some native lobsters, may affect the latter. Large lobsters remain targeted by fisheries despite protective regulations, which are not always effective or obeyed. No-take marine protected areas (MPAs) or nature reserves can be effective if sufficiently large and well-managed. Habitat loss from marine construction can be partly compensated by stable, environmentally safe artificial reefs tailored to lobster behavioral ecology. The categories of the studied lobsters’ species in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, last updated over fifteen years ago, should be re-evaluated. Full article

Bisphenol A (BPA) and its substitutes have been identified as endocrine-disrupting chemicals (EDCs). However, little information is available on their reproductive endocrine disruptive effects in mollusks. This study cloned the full-length sequence (2434 bp) of the estrogen-related receptor (ERR) gene in the freshwater bivalve Corbicula fluminea and performed a bioinformatics analysis and tissue-specific expression analysis. We further examined the expression of the CfERR gene after exposure to E2, BPA, and their substitutes (BPS, BPF, and BPAF) at 1, 10, and 100 μg/L for 0, 1, 7, 14, 21, and 28 days. The results showed that CfERR is a nuclear protein with a typical structure. Phylogenetic analysis indicated a high degree of similarity among bivalve species. The high expression of CfERR in the gonad suggested its important role in reproductive regulation. The exposure experiment confirmed that CfERR showed a time- and dose-dependent upregulation in response to all pollutants, with BPS and BPAF exhibiting stronger estrogenic interference effects. This study facilitates a better understanding of the reproductive regulation of bivalves and provides data to support the toxicity evaluation of BPA and its substitutes. Full article

Sea turtles, particularly the opportunistic feeder species loggerhead turtles (Caretta caretta), are increasingly reported as a source of disturbance to mussel farming operations, especially in the Adriatic Sea. Despite the evident damage caused by these interactions, comprehensive national data on the phenomenon are still lacking. This study aimed to address this gap through a survey conducted among Italian mussel farmers, combined with the analysis of gastrointestinal contents from stranded sea turtles along the Adriatic and Tyrrhenian coasts, focusing on the ingestion of Mediterranean mussels (Mytilus galloprovincialis). Survey results revealed frequent turtle sightings in the northern Adriatic (Veneto and Emilia-Romagna) during summer months (June to August), while southern regions (Molise and Puglia) reported more sightings in autumn (September to October), likely influenced by seasonal water temperatures. The Mediterranean mussel was identified as the most commonly ingested mollusk in the Adriatic, with a notable increase in presence from 2018 to 2021. Although mussels are not a targeted prey, they appear to be a consistent dietary component due to adaptive feeding behavior. These interactions are increasingly and consistently reported, leading to significant management challenges for mussel farms. Based on these findings, a broader national and international assessment is recommended to evaluate the overall impact of sea turtles on shellfish aquaculture in the Mediterranean. Full article

Sharks play critical roles in marine ecosystems as apex or mesopredators, regulating trophic dynamics and ecosystem stability. However, their populations are increasingly threatened due to overexploitation caused by targeted fisheries, bycatch, and illegal activities. This study investigates the feeding ecology and reproductive biology of the shark species Mustelus mustelus, which has been heavily fished across the Mediterranean, leading to significant population declines. A total of 333 specimens were collected between October 2019 and October 2022 from Türkiye’s Aegean Sea, Sea of Marmara, and Levantine Sea coasts. The total lengths of the specimens ranged from 42.1 to 173.0 cm, with an average of 73.5 cm ± 26.8, and their weights ranged from 205 to 22,470 g, with an average of 1840.2 g ± 2525.5. Stomach content analyses revealed that M. mustelus is a benthic predator with a broad diet. Regional and size-based comparisons indicated that crustaceans were the primary food source, followed by teleost fish and mollusks. Ontogenetic dietary shifts were evident, with juveniles feeding predominantly on crustaceans, while adults consumed more teleost fish and mollusca. The reproductive biology analysis showed placental viviparity in M. mustelus, with the smallest observed mature male measuring 75 cm TL and the smallest observed pregnant female measuring 96 cm TL. The uterine fecundity of pregnant females ranged from 8 to 29 embryos. Additionally, the pupping season of M. mustelus in the Aegean Sea was found to occur in March and April. M. mustelus populations have declined dramatically in the western Mediterranean and in many other parts of their range. The scarcity of data on this species in the eastern Mediterranean basin, including Türkiye, is noteworthy. Therefore, this study investigated the populations in the study area from a bioecological perspective and provides fundamental data to support the development of conservation strategies for the species. Full article

Marine sources contain compounds that act on a wide variety of systems, including ligand-gated ion channels. This review will focus on the effectors of nicotinic acetylcholine receptors (nAChRs), for which the diversity of ligands and modulators from marine sources is determined mainly by neurotoxic peptides (α-conotoxins) from mollusks of the Conus genus. These are very selective compounds that allow the study of the role of different nAChR subtypes in the cancer cells. They have analgesic or anti-inflammatory activities associated with cholinergic transmission and have shown analgesic effect in case of chemotherapy-induced neuropathic pain. Another class of marine compounds targeting nAChRs for which cytotoxicity for cancer cells was shown is represented by low molecular organic substances found mostly in dinoflagellates and marine sponges. Some of the compounds discussed in this review show promise for developing drugs that suppress cancer growth. Full article

A gypsum karst sinkhole at Westeregeln (north-central Germany) was filled during the Late Pleistocene, first by fluvial flooding, then by solifluctation, and finally with wind-transported loess. Pleistocene mollusks and bones of snakes, birds, micro- and macromammals, and hyena coprolites were accumulated, often mixed in gravel or sand layers with Middle Paleolithic artifacts, whereas ice wedges reach deep into the sinkhole. The high amount of small flint debris prove on-site tool production by using 99% local Saalian transported brownish-to-dark Upper Cretaceous flint, which could have been collected from the Bode River gravels near-site. Only a single quartzite and one jasper flake prove other local gravel sources or importation. A large bifacial flaked knife of layer 4 dates to the early/middle Weichselian/Wuermian (MIS 5-4), similar to two triangular handaxes in the MTA tradition and an absolutely dated woolly rhinoceros bone (50,310 + 1580/−1320 BP). A cold period of Late Pleistocene glacial mammoth steppe megafauna is represented, but the material is mostly strongly fragmented and smashed by humans. Neanderthal camp use on the gypsum hill is indicated also by small charcoal pieces, burned bone fragments, and fire-dehydrated flint fragments. Crocuta crocuta spelaea (Goldfuss) hyenas are well known from Westeregeln, with an open-air commuting den site, which was marked with feces. Full article

Vibrio species of the Harveyi and Splendidus clades are the causative agents of vibriosis, resulting in mortality rates of up to 100% in common aquaculture species. They are primarily responsible for seafood-related illnesses in humans, causing gastroenteritis. Except for V. parahaemolyticus, the ecological behaviour of these pathogens is poorly understood. We investigated the spatial and temporal distribution of V. parahaemolyticus, V. alginolyticus, V. harveyi/V. campbellii, and V. splendidus in three Georgia (USA) grounds for Crassostrea virginica and Mercenaria mercenaria. DNA from oysters, clams, water, and sediment was collected over a year-long study and analyzed using quantitative PCR (qPCR) to assess the prevalence and concentrations of the above Vibrio species. The study targeted the tlh, VA1198230, rpoA, and recA genes using species-specific primers. Species abundance was estimated based on the concentrations of the corresponding genes. The species abundance was profiled for water parameters and concentrations of the clade-specific virulence genes toxR, luxR, srp, vhhA, vhh, and vhp that were previously detected in the study area. V. parahaemolyticus was the most common species, detected year-round in 61% and 44% of the water and sediment samples, respectively, followed by V. splendidus (67% and 17%) and V. harveyi/V. campbellii (19% and 33%). V. alginolyticus was rarely detected in water and never in sediment. In bivalves, the highest frequency was observed for V. parahaemolyticus. This species was detected in 89% of clam and 100% of oyster samples, followed by V. alginolyticus (22% and 17%) and V. splendidus at 17% in both species. No V. harveyi/V. campbellii has been detected in clams and oysters. Seasonal dynamics and concentrations varied between the species. Water temperature (r = 0.58–0.63, p ≤ 0.05), pH (r = −0.46), and dissolved oxygen (r = −0.42 to −0.56, p ≤ 0.05) were reliable predictors for the abundance of the Harveyi and Splendidus clade pathogens in bivalves and the water column, but not in sediments. In water and sediments, the abundances of V. harveyi/V. campbellii and V. parahaemolyticus were highly correlated (r = 0.80–0.99, p ≤ 0.001) to concentrations of most of the virulence genes, with some heterogeneities between the sites. The study revealed the species-specific dynamic of the Harveyi and Splendidus clade pathogens, provided the first evidence for the presence of V. harveyi/V. campbellii in the Atlantic USA waters, and identified environmental predictors for monitoring the Harveyi and Splendidus clade pathogens in mollusks and the water column. Full article

Allograft inflammatory factor-1 (AIF1) is a conserved calcium-binding protein involved in inflammatory and neuro-immune responses and expressed in Pomacea canaliculata (Pc-AIF1) during cephalic tentacle regeneration. Here, we investigated the expression and distribution of Pc-AIF1 in control conditions and during cephalic tentacle regeneration. A transcriptomic analysis of 315 RNA-seq datasets revealed maximal Pc-AIF1 expression in circulating hemocytes and hemocyte-rich tissues. Pc-AIF1 was also highly expressed in neural ganglia. Fluorescence in situ hybridization (FISH) evidenced Pc-AIF1 in circulating hemocytes and in the phagocytic hemocyte aggregates in the posterior kidney. qPCR showed the constitutive expression of Pc-AIF1 in cerebral ganglia. FISH experiments showed Pc-AIF1-positive cells within the cephalic tentacle blastema at 24 h post-amputation (hpa). Even if the amputation left them untouched, both the ipsilateral and contralateral cerebral ganglia increased Pc-AIF1 expression until 48 hpa. Immunocytochemical experiments evidenced positive cells to RCA120 (a microglial marker in mammals) among circulating hemocytes, in the connective tissue surrounding the cerebral ganglia, and within the regenerating tentacles. These findings suggest that Pc-AIF1 is a neuro-immune marker constitutively expressed in hemocyte populations and neural tissues; it is associated with the immediate hemocyte response to wounding and the neuro-immune interplay during the regeneration of sensory organs. Full article

Structural analysis of glycosphingolipids provides novel insights into organismal classification and reveals conserved functional roles that transcend taxonomic boundaries. To elucidate the structural characteristics of acidic glycosphingolipids (AGLs) in the adductor muscle of the Japanese giant scallop (Patinopecten yessoensis), AGLs were isolated and purified by column chromatography using anion exchange resin and silica gel. Structural characterization was performed using mass spectrometry, proton nuclear magnetic resonance spectroscopy, and immunological techniques. The sugar chain structure was identified as GlcA4Meβ1-4(GalNAc3Meα1-3)Fucα1-4GlcNAcβ1-2Manα1-3Manβ1-4Glcβ1-Cer, consistent with the mollu-series core reported for mollusks. In addition to uronic acid, the structure was distinguished by internal fucose and methylated sugars, features commonly found in bivalves. The presence of xylose in the sugar chains of AGLs was also suggested. In contrast, the ceramide moiety was composed primarily of fatty acids C16:0 and C18:0 and the long-chain base d16:1. This chemical structure provides valuable insights into the biological classification of P. yessoensis and the mollu-series glycolipids containing fucose and methylated sugars, which may serve as bioactive components shared across species in the phylum Mollusca and class Bivalvia. Full article

Perfluorooctane sulfonate (PFOS), which is known for its environmental persistence and bioaccumulation, poses substantial impacts to aquatic ecosystems. This study assesses the toxic effects of PFOS in the freshwater snail Lanistes carinatus using biomarkers for antioxidant activity, neurotoxicity, and tissue damage. Snails exposed to PFOS (1, 3, 10 mg/L for 14 days) displayed lipid peroxidation (LPO) levels that increased by 16.3–67.5%, and malondialdehyde (MDA) levels that rose by 10.0–58.4%, indicating oxidative damage. Enzyme activities for glutathione S-transferase (GST), glutathione peroxidase (GPx), and catalase (CAT) increased, ranging from 10.0 to 58.3%, 10.0 to 58.4%, and 10.0 to 58.4%, respectively, whereas levels of reduced glutathione (GSH) dropped by 15.0–41.5% and Superoxide dismutase (SOD) decreased by 15.0–41.4%. The activity of acetylcholinesterase (AchE) was reduced by a range of 15.0–40.0%, suggesting neurotoxic effects. Histopathological changes in the digestive gland were also noted. Further research on the effects of PFOS on mollusks is required, and investigation into sex-specific toxicity is needed. This shed light on L. carinatus as a sentinel species, providing helpful information for the monitoring and regulation of PFOS in aquatic environments. Full article

The fossiliferous Dursunlu Lignite Quarry (DLQ) is highlighted prominently in the archeological and paleontological literature because of the study of Pleistocene fauna and lithic artifacts, being considered the oldest Paleolithic site in Türkiye. Although the fauna and flora assemblage from DLQ are reasonably well known, taxonomic studies devoted to some groups, such as ostracods, mollusks, reptiles, and amphibians, have never been carried out. Here, we describe, illustrate, and study the taxonomic composition and ecological implications of the unpublished material of said groups, together with the aquatic plants and fish, recovered from six samples taken from the palustrine and peat bog facies of the sedimentary sequence. In addition, the recovered charophytes and cyprinids refine our taxonomical knowledge of both aquatic plants and fish. Our results concur with previous paleoenvironmental inferences based on flora and fauna composition—with DLQ representing a very shallow eutrophic lake with a dense palustrine vegetation belt during the cold (glacial) stage of the late Early Pleistocene—as well as highlight the study of all available groups as pivotal for better understanding the paleolake biota. We further conclude that the wetland areas of Dursunlu and surrounding steppe areas appear to have been an excellent environment for sporadic settlement of hominins during the Early Pleistocene, given the availability of food resources and easy access to water. Full article

This study investigated whether marine toxin poisonings reported to U.S. Poison Centers changed during the height of the pandemic period (April 2020 to December 2021). The National Poison Data System was queried for single-substance human exposure calls between 1 January 2000 and 31 March 2022 pertaining to ichthyosarcotoxins. Incidence rate ratios for exposure calls were calculated using mixed-effects negative binomial regression. Call counts were aggregated by year and regressed on a binary indicator for occurrence during pandemic restrictions. During the peak pandemic period, exposure calls decreased for several toxins: ciguatera poisoning: 0.57 (0.43, 0.76); clupeotoxic fish poisoning: 0.12 (0.04, 0.39); diarrhetic shellfish poisoning: 0.28 (0.16, 0.49); paralytic shellfish poisoning: 0.23 (0.17, 0.33); scombroid fish poisoning: 0.46 (0.36, 0.57). However, palytoxin poisoning (1.94 (1.32, 2.84)) and tetrodotoxin poisoning (1.73 (1.46, 2.04)) exposure calls appear to have increased. All results were Bonferroni-significant (p ≤ 0.0009). Sensitivity analyses suggest the PLTX increase began prior to pandemic restrictions, whereas the TTX increase appeared to be directly associated with the restrictions. Both men and women reported increases in TTX exposure calls. The TTX increase could be associated with potentially increased participation in outdoor activities, as TTX exposures are linked to amphibia, echinoderms, fish, and mollusks, among other animals. Full article

Nacre, the iridescent inner layer of mollusk shells, has long been traditionally used in medicine. While we have previously demonstrated its anti-aging effects on muscle and skin, its impact on pancreatic dysfunction and glucose metabolism remains unclear. In this study, we aimed to isolate and identify an active component from nacre extract that improves glucose metabolism and to evaluate its potential to prevent or ameliorate pancreatic dysfunction and glucose metabolic abnormalities in a D-galactose-induced aging mouse model. A polysaccharide component was successfully isolated using a combination of reverse-phase and ion-exchange chromatography. Structural analyses revealed that it was primarily composed of glucose, mannose, and rhamnose, which together accounted for approximately 87% of the total monosaccharide content. Further characterization by FT-IR spectroscopy and MALDI-TOF-MS confirmed its identity as a neutral polysaccharide with glycosidic linkages and an estimated molecular weight of approximately 5000 Da. Intraperitoneal administration of this polysaccharide significantly improved glucose tolerance and prevented a decline in serum insulin levels in D-galactose-induced aging mice. Immunohistochemical analysis of pancreatic tissues revealed that the polysaccharide preserved insulin expression and suppressed the D-galactose-induced upregulation of cellular senescence and apoptosis markers. These findings suggest that this nacre-derived polysaccharide effectively mitigates pancreatic dysfunction and glucose metabolic dysfunction, indicating its potential as a natural therapeutic agent for age-related metabolic disorders. Full article