Search

Parasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide‐ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community‐level effects. Here, we investigated the effects of a common trematode parasite (Cercaria opaca) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, Spartina alterniflora, and the ribbed mussel, Geukensia demissa. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient‐rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with C. opaca was most common in mussels in areas experiencing cordgrass die‐off due to drought, and that infection intensity decreased with distance from die‐off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought‐associated die‐off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess the prevalence and genomic characteristics of Shiga-toxigenic (STEC) and Enteroaggregative E. coli (EAEC) strains in raw mussels and ready-to-eat (RTE)-stuffed mussels, focusing on potential public health implications for identifying virulence and antimicrobial resistance genes. Results: The genome sequence analysis identified the E. coli strain named 23EM as serotype O111:H12, with adhesion (fimH-54) and fumarate hydratase (fumC-11) genes. The draft genome (4.9 Mb, 50.6% GC content, 111 contigs, 4,688 genes) is available in NCBI GenBank (accession JAWXVJ000000000). The strain, classified as ST292 and CC ST10, showed high similarity to nonpathogenic E. coli MG1655 but was distinct from pathogenic strains such as EAEC and ExPEC. In silico serotyping revealed the presence of O111-antigen flippase (wzx) and H12-antigen flagellin (fliC) genes. The strain harbors an IncFII (pCoo) plasmid with 96.95% identity. PathogenFinder predicted a 92% probability of being a human pathogen, supported by 720 pathogenic protein families. CRISPR analysis identified one high-evidence sequence with nine spacers and six low-evidence sequences. Phylogenetic analysis using RAxML positioned 23EM close to nonpathogenic E. coli but distant from other pathogenic strains. Antimicrobial resistance genes across multiple classes, including macrolides, fluoroquinolones, and aminoglycosides, were identified. The strain also contains several virulence factors, such as adhesins (e.g., ECP, ELF, TIF, type IV pili), and autotransporter genes (espP, pic), highlighting its significant pathogenic potential and public health risk. Conclusions: This study highlights the ability of the detection of E. coli strains harboring virulence and antimicrobial resistance genes in mussels, thus emphasizing the importance of ongoing surveillance and careful consideration of the potential risks associated with the consumption of these shellfish. [ABSTRACT FROM AUTHOR]

Aims: To obtain preliminary data on changes in gait from the use of a green-lipped mussel (Perna canaliculus) extract product in working farm dogs with musculoskeletal abnormalities using accelerometry. Methods: New Zealand working farm dogs (n = 32) with signs of musculoskeletal abnormalities were enrolled in a double-blinded, placebo-controlled cross-over study. Each dog was allocated to one of six groups to receive three trial substances (180 mg full fat green-lipped mussel extract (GLME180); 220 mg full fat green-lipped mussel extract (GLME220); placebo) in one of the six possible different orders. Each trial substance was administered orally once a day for an 8-week period, with a 4-week washout in between each. Dogs wore a collar-mounted triaxial accelerometer for the study duration. Diet and activity were not controlled. Accelerations were recorded continuously and analysed (n = 27) in 10-second activity epochs partitioned into daytime and night-time periods. Analysis of activity during the daytime period was limited to epochs when dogs were gaiting faster than a walk. The median and IQR of activity were determined for the daytime and night-time. Additionally, the 75th and 90th percentiles of daytime activity for each 24-hour period were determined. Mixed effects linear regression models were constructed to determine if each trial substance altered the response variables. Results: During the daytime, the 90th percentile was higher when dogs were given GLME220 compared with the placebo (β coefficient 2.6; 95% CI = 0.25–4.94; p = 0.03). Dogs that started the trial with the GLME products had a higher 90th percentile activity compared with dogs that began with the placebo (β coefficient 26.26; 95% CI = 0.45–52.06; p = 0.046). The 75th percentile for activity was not affected by the GLME product. The daytime IQR was larger when dogs were given the GLME180 product compared with the placebo (β coefficient 1.25; 95% CI = 0.12–2.37; p = 0.03). Night-time median activity and the IQR was greater in dogs that started the trial with the GLME products than in dogs that began with the placebo. The night-time IQR for activity was greater for GLME180 than for the placebo. Conclusions: Administration of a low dose of the GLME-containing product increased peak activity in working farm dogs with signs of musculoskeletal abnormalities and may improve their performance. Clinical relevance: Even mildly affected working farm dogs might benefit from support of their musculoskeletal abnormalities, and this particular GLME-based product shows promise as an adjunct to other management strategies. [ABSTRACT FROM AUTHOR]

This work evaluates utilizing the native mussel Brachidontes pharaonis as a bioindicator and sentinel organism for monitoring heavy metals Cu, Zn, and Cd along the Red Sea coast of Egypt. Samples were collected from four coastal locations, and the concentrations of heavy metals in the mussels' tissues, shells, seawater, and sediments were analyzed. Subsequently, bioassay experiments were conducted by exposing the organisms to single, binary, and tertiary metal mixtures, and the accumulation of heavy metals was determined to elucidate the dynamics of metal–metal interactions. Field samples revealed significant variations in heavy metal concentrations in the mussels' soft tissues across different locations, with Zn ranging from 58.1 to 121.0 µg/g dw (dry weight), Cu ranging between 18.3 and 36.7 µg/g dw, and Cd ranging from 0.3 to 1.04 µg/g dw. Conversely, the shells exhibited minimal spatial variations, with much lower contents of Cu (ranging from 1.9 to 2.8 µg/g dw) and Zn (ranging from 1.8 to 1.9 µg/g dw). However, the shells accumulated Cd at higher levels (ranging from 1.4 to 2.1 µg/g dw) compared to the soft tissues. Following a 96-h bioassay experiment, the soft tissues displayed a linear accumulation of metals with increasing exposure dose, with Cd showing the highest accumulation rate (approximately threefold) followed by Zn (twofold) and Cu (1.7-fold). In binary and tertiary exposures, the metals exhibited a general antagonistic interaction, affecting each other's accumulation. On the other hand, the accumulation of heavy metals in the shells after the 96-h bioassay exposure did not follow a consistent linear pattern, suggesting that accumulation during this short experimental period occurs primarily through adsorption rather than the biological pathway. [ABSTRACT FROM AUTHOR]

This work presents a spatial and temporal distribution of tributyltin (TBT) and TBT pollution assessment of the Croatian Adriatic coast in the period 2016 - 2023. The monitoring of TBT pollution was carried out within the Water Framework Directive (2000/60/EC) and the Marine Strategy Framework Directive (2008/56/EC). TBT concentrations were measured at 63 sites in coastal and transitional waters in three compartments - water, sediments and mussels. The ranges of TBT concentrations were <0.06 - 6.40 ng(TBT)/L in the water column, <1 - 2546 ng (TBT)/g(d.w.) in sediments, and <1 - 655 ng(TBT)/g(d.w.) in mussels, while transitional waters were in general more polluted than coastal waters. Monitoring of TBT concentrations in water showed that 30% of monitored sites were continuously polluted with TBT with average annual concentrations exceeding AA-EQS [0.2 ng (TBT)/L], while 20% of the sites had concentrations in sediments above the proposed EQS for sediments [1.6 ng(TBT)/g(d.w.)]. In mussels, TBT was detected at 70% of the sites with more than 60% of the sites exceeding the OSPAR criteria [12.6 ng(TBT)/g (d.w.)], indicating that the occurrence of imposex in gastropods at these sites is very likely. Only a slight decrease in TBT levels was observed over the investigated period, but concentrations at most contaminated sites did not fall below the EQS. This study shows that, despite the ban of TBT-based antifouling paints more than 15 years ago (except for public and military vessels), contamination of the Croatian Adriatic coast with TBT still exists and regular monitoring is essential. The TBT distribution was primarily determined by the vicinity of the pollution source, i.e. shipping traffic, but the role of physicochemical parameters, such as dissolved organic carbon (DOC) and transparency of the water column, should not be disregarded as well as the influence of hydrodynamics in the transitional waters. Although monitoring of TBT concentrations in water is an established approach to assess recent pollution, this long-term study has shown that mussels can be the most reliable indicator of pollution in a given area over the last several months. [ABSTRACT FROM AUTHOR]

Commercial production of refrigerated shucked mussels (SM) in Greece presents several challenges that are associated with short shelf-life, lack of taste and development of brown color in the filling medium. To overcome these problems an alternative mussel body recovery process in combination with different filling media, namely brines and white vinegar solutions of various concentrations, was used for the production of SM. A 2-fold to 5-fold increase in the shelf-life of the various SM products was observed when compared against control, while significant improvements were also found in both taste and visual appearance of the products. [ABSTRACT FROM AUTHOR]

Larval cryopreservation techniques have been established in Pacific oysters and Mediterranean mussels. Although initial cryopreservation protocols for both species differed slightly in Ficoll PM 70 (FIC) concentration, better post-thaw larval survivability was produced in mussels than oysters. Furthermore, the post-thaw survivability in the latter could be improved significantly by the addition of lipids and antioxidants to the cryoprotectant agent. These findings have generated a unique opportunity to investigate the cryo-functions of both endogenous and exogenous fatty acids (FAs) in bivalves as mammalian studies indicated that lipid compositions could contribute the interspecific difference in gamete and embryo cryopreservation. Our study showed that the higher survivability of post-thaw larvae in mussels (65% vs. 34% in oysters) could be attributed to their higher proportion of total polyunsaturated fatty acids (PUFAs), especially C22:6, and higher resistance of FA profiles to cryopreservation. In oysters, on the other hand, their FA profiles were very sensitive to cryopreservation, with saturated FAs and PUFAs being significantly increased (from 37 to 41%) and decreased (from 35% to ~ 32%), respectively. Although exogenous lipids could significantly improve the survivability of post-thaw oyster larvae from 34 to 51%, their supplementation did not alter the response pattern of endogenous FA profiles to cryopreservation. [ABSTRACT FROM AUTHOR]

Environmental DNA (eDNA) offers a novel approach to supplement traditional surveys and provide increased spatial and temporal information on species detection, and it can be especially beneficial for detecting at risk or threatened species with minimal impact on the target species. The transport of eDNA in lotic environments is an important component in providing more informed descriptions of where and when a species is present, but eDNA transport phenomena are not well understood. In this study, we used species-specific assays to detect eDNA from two federally endangered mussels in two geographically distinct rivers. Using the eDNA concentrations measured from field samples, we developed a one-dimensional (1D) hydrodynamic transport model to predict the downstream fate and transport of eDNA. We detected eDNA from both federally endangered mussels across several seasons and flow rates and up to 3.5 km downstream from the source populations, but the detection rates and eDNA concentrations were highly variable across and within rivers and study reaches. Our 1D transport models successfully integrated the variability of the eDNA field samples into the model predictions and overall model results were generally within ±1 standard error of the eDNA field concentration values. Overall, the results of this study demonstrate the importance of optimizing the spatial locations from where eDNA is collected downstream from a source population, and it highlights the need to improve understanding on the shedding mechanisms and magnitude of eDNA from source populations and biogeomorphic processes that influence eDNA transport. [ABSTRACT FROM AUTHOR]

Mussel byssus is an important model for bio-inspired design, due to the discovery that byssus proteins enriched in the non-canonical amino acid 3,4-dihydroxyphenylalanine (DOPA) form dynamic, load-bearing metal coordination cross-links. While it was initially assumed that cross-linking was based on DOPA–Fe coordination, recent findings challenge this assumption, suggesting that mussels preferentially utilize vanadium. Yet, the details are still unclear. Here, we performed a cross-disciplinary investigation of vanadium use by mussels for formation and function of the byssus, harnessing Raman and X-ray absorption spectroscopy, DFT modeling, and rheological studies. Our results indicate that Mytilus mussels actively uptake vanadium for the express purpose of incorporating it into the byssus, and that byssus V content is influenced by local seawater vanadium concentration. The vanadium oxidation state in the byssus appears to be a mixture of V(IV) and V(III), while the dominant coordination geometry is octahedral tris–DOPA–V. Rheological studies on model DOPA-enriched polymer hydrogels demonstrated that vanadium-reinforced gels exhibit more solid-like behavior than iron-reinforced gels at seawater pH, which may explain why mussels prefer vanadium for building their byssus. These findings offer new insights for how vanadium is used in biology, but also offer further inspiration for novel mussel-inspired adhesive, coatings, and supramolecular materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Toxoplasma gondii DNA was detected in bivalves from the Kerguelen and Galapagos archipelagos. • Its occurrence differed between sampling sites in Kerguelen but not in Galapagos. • In both archipelagos, quantitative PCR-positive bivalves were found on islands without cats. • Our finding demonstrated the waterborne transport of oocysts over at least 20 km. • Exposure to currents and giant kelp density affect T. gondii detection in bivalves. Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km2, 15.38% of the sampled oysters (Saccostrea palmula) tested positive for T. gondii by quantitative real-time PCR (qPCR) (n = 260), and positive samples were found in all eight sampling sites. In Kerguelen, with 1-3 cats per km2, 40.83% of 120 tested mussels (Mytilus edulis platensis) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of T. gondii contamination in the coastal waters of these archipelagos. Furthermore, T. gondii -positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that T. gondii oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (p = 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (p < 0.001). The detection of T. gondii in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ratio (OR) 60.2, p < 0.001) and the on-site density of giant kelp forests (OR 2.624, p < 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests. [ABSTRACT FROM AUTHOR]

Metacestode infestation of Semibalanus balanoides (L., 1767) and Balanus crenatus Bruguiеre, 1789, collected in the Barents and White Seas and in the northern part of the Sea of Okhotsk in 2020 and 2021, respectively, was studied. A total of 313 S. balanoides from Mogilnaya Bay of Kildin Island (Barents Sea) and isolated mature wrinkled barnacles B. crenatus, two and four specimens from the Pechora Sea and Kandalaksha Bay of the White Sea, respectively, were examined in 2020. Metacestodes Fimbriarioides intermedia (Fuhrmann, 1913) (Cyclophyllidea, Hymenolepididae) were found in 1.0 ± 0.6% of S. balanoides in the Barents Sea with an invasion intensity (I. I.) of 2–5 specimens, and in one of two B. crenatus from the Pechora Sea (I. I. 15 specimens). For the first time, in both B. crenatus from the Pechora Sea, taken from the valves of the mussel Mytilus edulis, metacestodes Microsomacanthus sp. I (I. I. 13 and 20 specimens) with proboscis hooks 38–41 (39.4 ± 0.1) µm long and blades of 9.5–11 (10.7 ± 0.1) µm were obtained. One of four B. crenatus from the Kandalaksha Bay was infected with another Microsomacanthus sp. II (I. I. 19 specimens) with proboscis hooks 44.0–49.5 (45.7 ± 0.5) µm long and blades 14.0–16.0 (14.8 ± 0.07) µm long. A total of 362 S. balanoides were collected and dissected in Gizhiginskaya Bay of the northern part of the Sea of Okhotsk in 2021, of which 8.0 ± 1.4% were infected with F. intermedia metacestodes (I. I. 1–19 specimens). Study results of the infestation of S. balanoides on the Koni-Pyagin coast of the Sea of Okhotsk (according to the collections of 2006–2007) were supplemented and clarified. Description of metacestodes and the taxonomic affiliation of cysticercoids Microsomacanthus spp. are given. [ABSTRACT FROM AUTHOR]

Understanding the age structure and growth patterns of freshwater bivalve species is crucial for their conservation, and these data are still lacking for many species and locations. The main objective of this study was to gain insight into the age structure and growth patterns of the endangered mussel Unio crassus at the unpolluted and polluted sites on the Mrežnica River (Croatia), as well as construct the first-ever chronology for this species. Bivalve sampling was carried out in July 2020. The age and growth dynamics were determined by analysing internal growth lines in acetate peel replicas of shell cross sections. The length range of shells from the unpolluted station was 4.5–5.6 cm, with an estimated age range of 10 to 29 years, whereas shell length at the polluted site was 5.2–6.1 cm, with an estimated age range of 10 to 22 years. Our results indicate that industrial pollution may influence life strategies in U. crassus populations, with mussels growing faster and living shorter at polluted site. Compared to other parts of Europe, the estimated ages obtained in our study were the most similar to those in central Europe. According to growth curves, mussels grow the fastest during their first 10 years, after which their growth significantly slows down. Growth chronologies were constructed by measuring growth increments in acetate peels of shell cross-section, and some correlations between shell growth and environmental parameters have been observed, indicating the potential for further sclerochronology research on this species. [ABSTRACT FROM AUTHOR]

A major expense in the operation of bivalve nurseries is the culture of high‐quality live microalgae feeds, and efforts to develop effective alternative feeds have had limited success. Juvenile bivalves are known to be able to absorb dissolved nutrients, but this ability has received minimal attention as a route for supplementary feeding. This study assessed the capacity of juvenile green‐lipped mussels (GLMs) (Perna canaliculus) to uptake and assimilate dissolved glucose at five experimental concentrations (i.e. 10 µg mL−1, 100 µg mL−1, 1 mg mL−1, 10 mg mL−1 and 30 mg mL−1) as a supplement to cultured microalgae. Growth and survival of the mussels were measured over 3 weeks. Although all glucose concentrations improved the performance of mussel spat compared to the control, the best performing was a concentration of 1 mg mL−1 of dissolved glucose which enhanced daily spat growth 2.7 times that of the control live microalgal diet without glucose. Survival was high (i.e. >95%) for all treatments except for the highest experimental concentration of glucose, for which a concentration of 30 mg mL−1 resulted in mean mortality of 24%. Mussel spat supplemented with dissolved glucose accumulated up to 30% greater lipid and improved the carbohydrate content per mg g−1 of ash‐free dry weight as much as 3.5 times compared to those in the control treatment, indicating that they were in greater nutritional condition. This demonstration that dissolved glucose can be used to fuel growth by GLM spat at concentrations as low as 10 µg mL−1 suggests that other soluble nutrients may also act as a supplemental feed for cultured juvenile molluscs. Dissolved nutrients have the potential to improve the performance of spat in nursery systems while simultaneously reducing the reliance of cultured microalgae as a sole feed input. [ABSTRACT FROM AUTHOR]

The issue of microplastics (MPs) has emerged as a significant concern globally, with discussions surrounding the potential environmental impact of these tiny plastic particles becoming increasingly prevalent. This study aimed to identify the concentration and characteristics of MPs in hemolymph and organs (gills and hepatopancreas) of green mussels (Perna viridis) that are frequently consumed by people in Pangkajene Kepulauan, South Sulawesi Province, Indonesia. Green mussels were collected from two different sampling sites for comparison. Screening was carried out on dispensed hemolymph and dissected organs to identify the characteristics of MPs. Surface seawater sampling was added as information on MP's characteristics from the mussel habitat. Visual observation of MP's characteristics using a stereomicroscope in laminar flow is to prevent contamination. The identification of MP's polymer type is using FTIR-ATR. The results showed that hemolymph, hepatopancreas, gills, and surface water were concentrated with MPs. Small (2–3.9 cm) green mussels accumulated more MPs than medium (4–5.9 cm) and large (> 6 cm). MPs characteristics of fiber shape, transparent color, and size 0.1–0.5 mm were dominant in all samples. A total of seven polymers of MPs were identified with polyethylene and polystyrene types most frequently found from all samples. Based on this study, green mussels are good for biomonitoring of MPs. [ABSTRACT FROM AUTHOR]

Ecosystem engineers alter habitat and resource availability within ecosystems, but the magnitude of these effects depends on abiotic context and spatial scale. We examined how the effects of freshwater mussels, an ecosystem engineer, changed with spatial scale. We combined a field enclosure experiment and comparative field study to evaluate associations among mussels and macroinvertebrate communities across three spatial scales: mussel individuals (~ 0.01 m2), patches of mussels (0.25 m2), and large aggregations of many mussel patches (mussel beds, ~ 1000 m2). We used canonical correspondence analysis and variation partitioning to evaluate how mussel abundance, food availability, substrate heterogeneity, and flow influenced macroinvertebrate communities. We found that mussels' influence on macroinvertebrate communities differed among spatial scales. At the smallest scale, macroinvertebrate density increased on the shells of live mussels, likely due to mussel influences on food availability to grazers. At the patch scale, we found no mussel effects, likely because they were overridden by a flood event. At the mussel bed scale, macroinvertebrate communities were primarily controlled by flow and secondarily by food availability. As such, the continued loss of freshwater mussels means the loss of habitat creation and food provisioning for other aquatic groups, and alteration of facilitation landscapes within streams. [ABSTRACT FROM AUTHOR]

Global increase in aquaculture production has created a need to reduce its environmental impacts. Nutrients could be recycled especially at land-based recirculating aquaculture systems (RAS) by cultivating green microalgae in aquaculture effluent. However, microalgae are difficult to harvest. As a multi-trophic solution, mussels could be used in harvesting microalgae. We tested three European freshwater mussels (duck mussel Anodonta anatina, swan mussel A. cygnea, and swollen river mussel Unio tumidus) for filtering two common green microalgae (Monoraphidium griffithii and Selenastrum sp.) grown in RAS effluent. Mussels decreased microalgal concentrations in the tanks 42–83% over three consecutive trials. Algal concentrations at the end of each trial were lowest for both microalgae in tanks containing Anodonta mussels. Clearance rates were higher for Anodonta mussels than for U. tumidus. Mussels biodeposited more microalgae to tank bottoms when M. griffithii was filtered. Ammonium concentration decreased or did not change in tanks with M. griffithii, but increased in tanks containing Selenastrum sp. These results suggest that of the tested species Anodonta mussels and M. griffithii show best potential for RAS effluent bioremediation application. We conclude that a co-culture of microalgae and unionid mussels could be used for recycling nutrients in aquaculture. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) persist for long periods in the environment, causing adverse effects on aquatic and terrestrial ecosystems. The accumulation of MPs in various trophic levels mostly depends on weathering phenomena, their reduced dimensions and the improved bioavailability; this ultimately causes their ingestion by organisms living in different niches. The modern concern about MPs toxicity collides with the current unavailability of standardized and reliable methodologies to assess the risks associated with the exposure of organisms from different habitats. Hence, the identification and selection of appropriate biomonitors for MPs pollution risk assessment should focus on the identification of easy-to-implement assays, rapidly interpretable results (e.g., based on the MPs bioaccumulation capabilities in their tissues) and standardizable methodologies. The present review analyzed some emerging biomonitors exploited for MPs evaluation, selected and examined according to their potential use as specific biological indicators for diverse environments. The research was focused on plants, as biological models for airborne microfibers toxicity evaluation; mussels, as key organisms for the establishment of MPs accumulation in marine environments; land snails, representing emerging organisms selected for studies of MPs' impact on soil. Furthermore, recent findings evidenced the influence of microplastics on the composition of environmental microbiota, enhancing pathogenic biofilms formation, leading to increased water, soil, food, crops and waste contamination. Disposing of harmonized and validated methods to study MPs' impact on the environment, integrated with promising machine learning tools, might sensibly support the risk management strategies protecting human and animal health. [ABSTRACT FROM AUTHOR]

Unionid mussels deposit growth rings (annuli) within the shell, which can be used to estimate age and growth. Thin-sectioning is a common technique for counting annuli, wherein a cross-section of a shell valve is taken and evaluated by multiple readers. Correctly identifying annuli can be challenging because ambiguous annuli can bias growth estimates. Staining with calcein, a fluorescent chemical, is a technique that has been used with marine and freshwater species to improve accuracy of growth estimates. This method chelates calcium, causing a permanent mark that fluoresces under ultraviolet light. Calcein has seen limited testing on unionid mussels so it remains unclear if this method has adverse effects on survival and growth. We evaluated calcein against 2 concentrations (125 mg L−1 and 250 mg L−1) at 2 exposure times (12 and 24 h) on Cyclonaias pustulosa, a common North American unionid. Survivorship remained above 80% 6 months post-immersion. Mark quality and retention for 250 mg L−1 were high for both 12- and 24-h immersions, although historical annuli were not highlighted. These findings corroborate studies indicating calcein immersion is generally safe and effective in juveniles and adults and suggest it may be useful in validating new growth. [ABSTRACT FROM AUTHOR]

When moving from a very sheltered aquaculture site to a very exposed oceanic aquaculture site, the energy increases proportionally in a continuum. Lojek et al. (in review) considered the primary influential parameters (water current, wave height, wave period, wavelength and water depth) which influence the species, structure, technology, methods, and operational aspects of any aquaculture endeavour and investigated six possible indices which cover these variables. Added to advanced computer modelling, assisted by detailed and constant environmental monitoring, it may be possible to refine site selection, structure selection and design, species selection, equipment and logistic requirements and health and safety requirements. This manuscript has selected two indicative indices: Specific Exposure Energy (SEE) index and Exposure Velocity (EV) index from the potential equations provided by Lojek et al. (in review) and compared them with known operational aquaculture sites highlighting present structural capability and limitations. The two indices are also utilized to reflect on their suitability for assessing sample sites with respect to biological, technological, operational or maintenance aspects of aquaculture activities. The indices have shown themselves to be useful tools in the general assessment of the energy that will influence the species and structure selection at potential aquaculture sites. This information can help prospective fish farmers characterize their sites concisely and accurately to consultants, regulators, equipment vendors, and insurance brokers. [ABSTRACT FROM AUTHOR]

Freshwater mussels preserve valuable information about hydrology, climate, and population dynamics, but developing seasonal chronologies can be problematic. Using clumped isotope thermometry, we produced high-resolution reconstructions of modern and historic (~ 1900) temperatures and δ18Owater from mussel shells collected from an impounded river, the Brazos in Texas, before and after damming. We also performed high-resolution growth band analyses to investigate relationships between mussel growth rate, rainfall, and seasonal temperature. Reconstructed δ18Owater and temperature vary little between the modern (3R5) and historic shell (H3R). However, a positive relationship between reconstructed δ18Owater and growth rate in H3R indicates that aside from diminished growth in winter, precipitation and flow rate are the strongest controls on mussel growth in both modern and pre-dam times. Overall, our results demonstrate (1) the impact, both positive and negative, of environmental factors such as flow alteration and temperature on mussel growth and (2) the potential for clumped isotopes in freshwater mussels as a paleohydrology and paleoclimate proxies in terrestrial environments. [ABSTRACT FROM AUTHOR]

The quagga mussel, Dreissena bugensis, is an invasive freshwater bivalve that causes significant economic and ecological damage. Numerous techniques are currently being investigated to help control their spread. X-ray irradiation has been used in different techniques to help control the spread of invasive species, either through decontamination or by the production of sterile male that reduce reproductive populations (Sterile Male Release Technique). Most studies have focused on terrestrial species, fewer looking at the effects of irradiation on aquatic species. This study was designed to evaluate the effects of x-ray irradiation on quagga mussels both in its effectiveness to kill mussels or to produce sterile males. Adult mussels were irradiated with a range of exposures from 0 (control), 6, 30, to 50 Gy to determine the effect on quagga mussel survival and impact on reproduction. The results demonstrated that x-ray treated quagga mussels had lower developmental success than the control. Adult quagga mussels were highly tolerant of x-ray irradiation with high survival rates (> 95%) after treatment. Mussels from all treatments produced motile sperm and these sperm were able to bind and fuse with eggs. There was a decrease in sperm binding between treatments, but fertilization still occurred. Fertilized eggs in all treatments were able to divide and produce swimming trochophores, but irradiation appears to decrease development between zygote and trochophore stage. The current experiment was not able to produce completely sterile males, even at the highest irradiation of 50 Gy in a single 8-minute session. The current experiment did not find an x-ray dose leading to the generation of 100% sterile males. Even at higher doses, x-ray irradiation may not be realistic for implementation. [ABSTRACT FROM AUTHOR]

Qualitative and quantitative sampling efforts in the Verdigris River, OK (upstream of Lake Oologah), yielded new distributional records of 2 freshwater mussel species of conservation need: Cyprogenia aberti (Western Fanshell) and Ptychobranchus occidentalis (Ouachita Kidneyshell). The Ouachita Kidneyshell has not been documented alive during a scientific survey in the Oklahoma portion of the Verdigris River in nearly 100 years. Our observations extend the known distribution for the Western Fanshell further downstream into Oklahoma by ∼36 river km. These findings indicate an expansion in the known range and potential improvement in the populations of 2 imperiled mussel species, contrary to the prevailing global trend of mussel population decline. [ABSTRACT FROM AUTHOR]

Simple Summary: This study explores how the autumn-spawning bitterling, Acheilognathus rhombeus, reproduces and develops within its mussel host. The research highlights how these fish lay their eggs inside mussels, which then serve as a safe environment for the eggs to develop over winter. A critical phase, called diapause, allows the embryos to pause their development for about seven months, ensuring they survive the cold winter months. Once the temperature rises above 10 °C, development resumes. During this time, tiny structures on the embryos called minute tubercles help anchor them within the mussel, preventing them from being expelled prematurely. These findings provide valuable insights into the complex relationship between the bitterlings and their mussel hosts, revealing important evolutionary adaptations that aid in the reproductive success and survival of these fish. We investigated the reproductive strategies and embryonic development of Acheilognathus rhombeus (a bitterling species that spawns in autumn) within its freshwater mussel host in the Bongseo Stream, South Korea. By focusing on survival mechanisms during critical stages of embryonic development, the selective use of mussel gill demibranchs by the bitterlings and associated adaptive traits were observed over 1 year. A significant diapause phase occurs at developmental stage D, which lasts for approximately 7 months, allowing embryos to survive winter. Development resumes when the temperature exceeds 10 °C. Minute tubercles on the embryos (crucial for anchoring within the host gill demibranchs and preventing premature ejection) exhibit the largest height during diapause, and the height decreases when developmental stage E is reached, when growth resumes. Acheilognathus rhombeus embryos were observed in 30.5% of the mussels, mostly within the inner gills, thereby maximizing spatial use and oxygen access to enhance survival. These results highlight the intricate relationship between A. rhombeus and its mussel hosts, demonstrating the evolutionary adaptations that enhance reproductive success and survival. This study provides valuable insights into the ecological dynamics and conservation requirements of such symbiotic relationships. [ABSTRACT FROM AUTHOR]

Due to their immobile nature and filter-feeding habits, which enable biological particles to accumulate in their tissues, mussels are recognized as vectors of foodborne diseases. Consuming these shellfish uncooked or partly processed might result in food poisoning because of accumulated bacteria originating from the culture environment and unhygienic handling. The present study aimed to assess the presence of Salmonella and Escherichia coli as well as to biochemically and serotypically confirm Salmonella spp. in mussels (Mytilus galloprovincialis) taken from two locations in Morocco: Zenata and Mansouria. A total of 90 mussel samples were collected from October 2022 to August 2023. Two methods were employed in this study: AFNOR NF EN ISO 6579-1 (2017) for the detection of Salmonella spp., and the most probable number method (MPN) using Norm ISO/TS 16649-3 (2017) for E. coli. The number of E. coli varied between 0.2/100 g and 1.7 x 103/100 g of mussels. The percentage of Salmonella spp. detected in mussel samples was 4,4%. Further analysis revealed the identification of two distinct Salmonella serotypes, namely S. kentucky (1 isolate) and S. Typhimurium (3 isolates). This research highlights the potential risks to public health due to the presence of pathogenic bacteria in mussels from two regions of Morocco where shellfish farming and coastal tourism are significant contributors to the local economy. [ABSTRACT FROM AUTHOR]

The factors shaping host–parasite interactions and epibiont communities in the variable rocky intertidal zone are poorly understood. California mussels, Mytilus californianus , are colonized by endolithic cyanobacterial parasites that erode the host shell. These cyanobacteria become mutualistic under certain abiotic conditions because shell erosion can protect mussels from thermal stress. How parasitic shell erosion affects or is affected by epibiotic microbial communities on mussel shells and the context dependency of these interactions is unknown. We used transplant experiments to characterize assemblages of epibiotic bacteria and endolithic parasites on mussel shells across intertidal elevation gradients. We hypothesized that living mussels, and associated epibacterial communities, could limit colonization and erosion by endolithic cyanobacteria compared with empty mussel shells. We hypothesized that shell erosion would be associated with compositional shifts in the epibacterial community and tidal elevation. We found that living mussels experienced less shell erosion than empty shells, demonstrating potential biotic regulation of endolithic parasites. Increased shell erosion was not associated with a distinct epibacterial community and was decoupled from the relative abundance of putatively endolithic taxa. Our findings suggest that epibacterial community structure is not directly impacted by the dynamic symbiosis between endolithic cyanobacteria and mussels throughout the rocky intertidal zone. [ABSTRACT FROM AUTHOR]

Carcasses are patchily distributed and often short‐lived resources, placing scavenging animals under pressure to locate them before they rot or are depleted by competitors. Scavengers may search for carcasses directly, or indirectly, using social information. Aggregations of feeding animals and their conspicuous competitive behaviour may be more readily detectable to searching scavengers than the carcass itself. Moreover, the actions of attendant scavengers upon the carcass, breaking it apart and releasing odour or chemical cues, may further enhance its detectability to others foraging nearby. Here we test this idea. In the first of two experiments performed in the field, we found that hermit crabs (Pagurus bernhardus) were attracted to shelled mussels (Mytilus edulis) that other hermit crabs were already feeding on. They showed no strong tendency to approach aggregations of conspecifics in the absence of food, nor conspecifics that were confined close to mussels but prevented from feeding on them. We speculated that through breaking up the carcass, the feeding hermit crabs released chemical cues and drifting particles of mussel tissue that further attracted other hermit crabs. We tested this in a second experiment, finding that finely chopped mussels attracted significantly more hermit crabs than did intact mussels. We suggest that scavenger feeding action upon carcasses makes these more detectable to others by releasing odour and particle plumes, a form of inadvertently produced social information. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the presence/abundance of microplastics and mold species in mussels and their implications for food safety and public health. Mussels, known to accumulate microplastics and mold species, were studied due to their role in the food chain. A sampling protocol covering a vast coastal area of Bursa Province along the Marmara Sea was implemented, gathering 410 raw mussel samples from 10 locations. After digestion with hydrogen peroxide, microplastics were examined using a stereomicroscope, and mold species were isolated and identified through matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis. A total of 496 microplastics were detected in the mussel samples, with fragment-type and black-colored microplastics being the predominant types. Results also revealed varying levels of microplastics contamination, with the highest rate recorded at Location 5 (28.02%). Notably, Location 5, characterized by its central yacht/boat harbor, exhibited the highest microplastics pollution, while Location 9, lacking such facilities, displayed the lowest contamination rate at 2.22%. Fragment-type microplastics were the most prevalent (26.1%), with black microplastics being the predominant color (38.51%). Among the 10 identified mold species, Penicillium and Aspergillus were the most prevalent. Notably, a remarkably high positive correlation was observed between fragment (r = .976; p < .001) and line (r = .888; p = .001) microplastics values. In the mussels collected from Location 5, where the highest microplastics were detected, three different species of mold were detected. In accordance with this result, the highest amount of mold belonging to two different genus were detected in the mussels from Location 2, where the second highest number of microplastics were detected. However, no correlation was found between the mold count and microplastics values. The presence of microplastics and mold in mussels underscores potential food safety and public health risks, emphasizing the need for ongoing monitoring and management to reduce these adverse effects. [ABSTRACT FROM AUTHOR]

Living shorelines (LS) stabilize eroding banks while providing more natural habitats and creating a gentler slope for enhanced migration of flora and fauna migration as sea levels rise. Typical LS practices include using several different materials, including oyster shell bags, to stabilize shorelines and planting marsh grasses. However, incorporating other important species interactions among marsh organisms can improve LS function and stability. For example, ribbed mussels, Guekensia demissa, benefit marsh plants by adding nutrients and stabilizing sediments. Unfortunately, mussels are not typically included in management and restoration practices. In this study, the objective was to investigate whether ribbed mussels facilitate marsh grass growth at a LS site in the southeastern US. We conducted field surveys for mussel abundance and recruitment, and a manipulative in situ experiment at an established LS site in Georgia to explore the impacts of adding mussels. Although mussel treatment did not have a significant effect on Spartina alterniflora metrics (i.e., density, height, biomass), Spartina plots with high mussel density exhibited ~300% increase in biomass relative to the start of the experiment, while plots without mussels only increased by ~100%. Some of the variability within treatments can be explained by high and sustained mussel mortality throughout the experimental period, likely due to predation, that impacted the actual mussel densities in our plots. We found that Spartina height, density, and biomass exhibited significant positive relationships with mussel biomass. Thus, ribbed mussels may be useful in living shorelines restoration projects if they are planted in sufficient densities, in aggregations, and/or with protective devices. [ABSTRACT FROM AUTHOR]

Macroalgae and phytoplankton support the base of highly productive nearshore ecosystems in cold-temperate regions. To better understand their relative importance to nearshore food webs, this study considered four regions in the northern Gulf of Alaska where three indicator consumers were collected, filter-feeding mussels (Mytilus trossulus), pelagic-feeding Black Rockfish (Sebastes melanops), and benthic-feeding Kelp Greenling (Hexagrammos decagrammus). The study objectives were to (1) estimate the proportional contributions of macroalgal and phytoplankton organic matter using carbon and nitrogen stable isotopes, (2) determine if macroalgal use affected consumer growth using annual growth rings in shells or otoliths, and (3) describe changes in organic matter use and growth during the Pacific Marine Heatwave (PMH; 2014–2016) in one consumer, mussels. Macroalgae were the major organic matter source (> 60%) to the diet for all three consumers. The relationships between macroalgal contribution and growth were neutral for both fish species and significantly positive for mussels. During the PMH, mussels had a drop (> 10%) in macroalgal contributions and grew 45% less than in other time periods. Simultaneously, the relationship between macroalgal contribution and mussel growth was strongest during the PMH, explaining 48% variation compared to 3–12% before or after the PMH. Collectively, the results suggest that macroalgae is likely more important to cold-temperate nearshore food webs than phytoplankton. Management actions aimed at conserving and expanding macroalgae are likely to benefit nearshore food webs under all climate scenarios and especially during marine heatwaves. [ABSTRACT FROM AUTHOR]

Copyright of Veterinarska Stanica is the property of Croatian Veterinary Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Improved sustainability of aquaculture can be achieved by reducing product wastage post-harvest. Aquaculture of the green-lipped mussel, Perna canaliculus, is an important industry for New Zealand, which increasingly exports to live markets. Live transport can keep mussels fresh, but mussels could also be susceptible to handling stresses. To remedy this, pre-treatments that make mussels metabolically depressed, and thus potentially less sensitive to external stressors, were explored. As indicators of depressed metabolism, heart rate (HR), inferred cardiac output (PCO), and relative gaping magnitude (RGM) were simultaneously monitored in mussels experiencing different temperatures, dissolved oxygen levels and anaesthetic (MgCl2) concentrations to compare their efficacy in inducing suppressed metabolism of adult P. canaliculus. We found complex interactions between HR, PCO, and RGM in response to these conditions; however, overall, these response variables were significantly correlated. Mussels showed depressed HR and PCO by up to 100% at 4 °C within 2 h, with correspondingly decreased RGM of up to 48%. Similarly, mussels immersed in 40 g L−1 MgCl2 suppressed HR by up to 97%, accompanied by up to 76% decrease in PCO, and a slight increase in RGM (11%) after 2 h. While responses were variable, low DO levels suppressed HR by up to 50%, yet PCO and RGM increased two- and threefold relative to control groups. The results of the present study indicated that 4 °C and 40 g MgCl2 L−1 were more effective conditions as pre-treatments than low dissolved oxygen lower the metabolism of P. canaliculus before live transport. [ABSTRACT FROM AUTHOR]

Aim: The goal of our study was to use a nested sampling design to compare the distribution of different groups of organisms with different dispersal modes and examine their responses in community composition to environmental heterogeneity at different spatial scales (local pool vs. riffle habitat, sections within a river and between rivers). Location: Upper Colorado River basin, Texas, USA. Taxon: Fishes, mussels and macroinvertebrates. Methods: We sampled 100 sites using a nested sampling design across five rivers (four tributaries and the mainstem), with four river sections and five sampling sites per section, each consisting of a pool and riffle habitat. Collected data on species abundances, local and landscape environmental variables and spatial variables were analysed using a combination of dissimilarity, redundancy and variation partitioning analysis. Results: At the river scale, environmental heterogeneity explained 28% and 34% of the variation in mussel and fish communities, respectively, and 15% for macroinvertebrates. Community changes between sections in the tributaries were highest for fishes, but similarly high for fishes and macroinvertebrates in the mainstem. Significant patterns for mussels were only detected in rivers with higher abundances. No significant differences in dissimilarity were found between mesohabitats, but a small significant effect of mesohabitat was detected for mussels with RDA after removing the river effect. Main Conclusions: Although the depauperate mussel communities made it more difficult to draw any conclusions, there were some indications that their distribution was driven by environmental heterogeneity across scales. Section and river scales were relevant for fish, whereas macroinvertebrates showed a weaker response to environmental heterogeneity at these scales. The combination of approaches detected more ecologically meaningful patterns than one analysis alone would have. This study highlights the complexity of riverine community dynamics and underscores the need for a multiscale approach to identify their distribution patterns. [ABSTRACT FROM AUTHOR]

For more than a century, bacterial infections caused by Vibrio spp. have affected various species of mussels around the world, with limited insights into the responses implemented by mussels against these infections. A combination of chemical analyses and carefully selected biological endpoints from haemolymph and tissues can be used to identify the welfare status of mussels and potentially protect aquatic ecosystems from catastrophic health threats. Recent developments in biomarker identification tools, such as omics and bioinformatics, have been successfully applied to evaluate the effect of environmental pollutants and other chemicals on mussels. However, the application of biomarkers to assess mussel health is limited. This review describes the available scientific literature on biomarker research for Vibrio-mussel interactions, and those aspects related to mussel health and disease assessment, grouped as biomarkers of exposure, effects, and susceptibility. From the review, it is clear that when integrated biomarkers are used, they can provide a deeper understanding of the relative health and potential susceptibility of mussels for better management practices. Furthermore, health biomarker data can be used to build resilience in mussels against climate change conditions, strengthen biosecurity management programs, improve farming and processing efficiency, and add value in terms of market-desirable traits. These data hold promise for advancing sustainability efforts within the aquaculture industry. [ABSTRACT FROM AUTHOR]

The Asian green mussel, Perna viridis is an important aquaculture species in the family Mytilidae contributing substantially to molluscan aquaculture. We generated a high-quality chromosome level assembly of this species by combining PacBio single molecule sequencing technique (SMRT), Illumina paired-end sequencing, high-throughput chromosome conformation capture technique (Hi-C) and Bionano mapping. The final assembly resulted in a genome of 723.49 Mb in size with a scaffold N50 of 49.74 Mb with 99% anchored into 15 chromosomes. A total of 49654 protein-coding genes were predicted from the genome. The presence of 634 genes associated with the cancer pathway and 408 genes associated with viral carcinogenesis indicates the potential of this species to be used as a model for cancer studies. The chromosome-level assembly of this species is also a valuable resource for further genomic selection and selective breeding for improving economically important aquaculture traits and augmenting aquaculture productivity. [ABSTRACT FROM AUTHOR]

The impressive adhesive capacity of marine mussels has inspired various fascinating designs in biomedical fields. Mussel-inspired injectable adhesive hydrogels, as a type of promising mussel-inspired material, have attracted much attention due to their minimally invasive property and desirable functions provided by mussel-inspired components. In recent decades, various mussel-inspired injectable adhesive hydrogels have been designed and widely applied in numerous biomedical fields. The rational incorporation of mussel-inspired catechol groups endows the injectable hydrogels with the potential to exhibit many properties, including tissue adhesiveness and self-healing, antimicrobial, and antioxidant capabilities, broadening the applications of injectable hydrogels in biomedical fields. In this review, we first give a brief introduction to the adhesion mechanism of mussels and the characteristics of injectable hydrogels. Further, the typical design strategies of mussel-inspired injectable adhesive hydrogels are summarized. The methodologies for integrating catechol groups into polymers and the crosslinking methods of mussel-inspired hydrogels are discussed in this section. In addition, we systematically overview recent mussel-inspired injectable adhesive hydrogels for biomedical applications, with a focus on how the unique properties of these hydrogels benefit their applications in these fields. The challenges and perspectives of mussel-inspired injectable hydrogels are discussed in the last section. This review may provide new inspiration for the design of novel bioinspired injectable hydrogels and facilitate their application in various biomedical fields. [ABSTRACT FROM AUTHOR]

Background: Freshwater mussels are important keystone and indicator species of aquatic ecosystems. Recent advances in sensor technology facilitate applications to individually track mussels and to record and monitor their behavior and physiology. These approaches require the attachment of sensor devices as "backpacks" to the outer shell surface. The interpretation of such data makes it necessary to understand the influence of these attachments on the horizontal and vertical movement behaviors of freshwater mussels. Over a series of mesocosm experiments, this study systematically investigated the effects of three size- and wiring-specific variants of artificially attached backpacks on the horizontal and vertical movement behavior of Anodonta anatina. Results: Across all experiments, equipping mussels with backpacks did not result in a significant influence on horizontal movement for any of the backpack variants. In contrast to this finding, the big backpacks with a high ratio between backpack volume and mussel length resulted in a significantly negative effect on vertical movement, indicating a potential for adverse effects of such devices on mussels, especially in natural settings. Conclusions: The findings of this study show that assessing the effects of attached devices on mussels requires a species-specific evaluation of potential impacts on the endpoints of interest. Especially for vertical movement patterns, selection of the smallest available devices appears mandatory. [ABSTRACT FROM AUTHOR]

Bathymodioline mussels dominate deep-sea methane seep and hydrothermal vent habitats and obtain nutrients and energy primarily through chemosynthetic endosymbiotic bacteria in the bacteriocytes of their gill. However, the molecular mechanisms that orchestrate mussel host-symbiont interactions remain unclear. Here, we constructed a comprehensive cell atlas of the gill in the mussel Gigantidas platifrons from the South China Sea methane seeps (1100 m depth) using single-nucleus RNA-sequencing (snRNA-seq) and whole-mount in situ hybridisation. We identified 13 types of cells, including three previously unknown ones, and uncovered unknown tissue heterogeneity. Every cell type has a designated function in supporting the gill's structure and function, creating an optimal environment for chemosynthesis, and effectively acquiring nutrients from the endosymbiotic bacteria. Analysis of snRNA-seq of in situ transplanted mussels clearly showed the shifts in cell state in response to environmental oscillations. Our findings provide insight into the principles of host-symbiont interaction and the bivalves' environmental adaption mechanisms. [ABSTRACT FROM AUTHOR]

Charru mussel, an invasive species found along the coastal areas of Baroy, Lanao del Norte, the Philippines, is commonly processed into the local delicacy known as “amahong,” with the shells often discarded as waste from this practice. This study aims to extract chitosan through demineralization of charru mussel shells using 1.25 N HCl, deproteinization using 3% NaOH yielding chitin, and deacetylation of chitin using 45% NaOH. The result shows a chitin yield of 21.27 ± 0.98% and a chitosan yield of 11.07% ± 0.66%. ATR-FTIR analysis confirmed the characteristic bands and functional groups associated with chitosan. SEM imaging revealed an amorphous and uneven particle shape, and TGA results exhibited thermal degradation at 550 °C, at which point chitosan breaks down. The synthesized chitosan displayed antibacterial activity at all concentrations (100, 200, and 300 µg/mL) against S. aureus while ineffective against E. coli. This study underscores the untapped potential of charru mussel shells as a source of chitosan, offering valuable insight for waste management. [ABSTRACT FROM AUTHOR]

This study assessed the efficacy of artificial collectors in recruiting Mytella strigata along the Amazon Macrotidal Mangrove Coast. The experiment involved three treatments (PVC plate, PET, and polyethylene screen), each repeated thrice. The study was conducted over 315 days, during which settlement density, bivalve biometry within the collectors, and environmental variables, such as temperature (°C), salinity (g.kg-1), chlorophyll-a (mg.m-3), particulate organic matter (POM), particulate inorganic matter (PIM) (mg.L-1), water transparency (determined using a Secchi disc), and rainfall data (mm), were assessed at 45-day intervals. The recruitment of M. strigata was observed predominantly during the rainy season. Both mussel shell size and average settlement density significantly varied (p < 0.05) based on the type of collector, collection period, and their interaction. Polyethylene mesh collectors demonstrated a higher settlement density compared to PET and PVC substrates (p < 0.05), but mussel shell size was lower in this treatment compared to the shell size of juveniles in PVC and PET collectors. Among the collectors, PVC ones proved more effective for collecting M. strigata, considering the quantity of fixed juveniles and the size of the individuals. Regarding the region's environmental conditions, recommendations are that producers place collectors in the water from January, with juvenile recruitment occurring February‒June. [ABSTRACT FROM AUTHOR]

Mussels (Mytilus spp.) are abundant in the North Atlantic, sessile, and sensitive to environmental change, and suitable as sentinels of environment and climate change of costal ecosystems. We aimed to determine the baseline for the Northeast Atlantic (58–70°N) Mytilus species complex, and to show the present distribution to surveys conducted 60 years ago. Baseline was obtained by investigating a total of 509 stations in the intertidal zone, in four regions comprising the environmental gradient from head of fjord to coast, and distributed over the latitudinal gradient from 58 to 70°N. The baseline shows a range in continuous abundance of mussels from 12% to 36%, patchy abundance from 26% to 57% and no or very limited mussel abundance from 26% to 46% between the four regions. The presence of mussels in the southeast and west region was visualized to previous surveys conducted 60 years ago. The data points to similar past and present presence of mussels in both regions, yet past major mussel fields in the inner section of region southeast was not detected in this study. The baseline of Mytilus spp. in the Northeast Atlantic (58–70°N) is now available for future reference. The baseline, plotted to surveys conducted 60 years ago, points to awareness of the population situated in the southeast section of the investigated region. Continued monitoring and modeling are needed to clarify drivers of temporal and spatial variation in the mussel populations along the Northeastern Atlantic coast. [ABSTRACT FROM AUTHOR]

Summary Extraordinary mechanical properties of biological materials are often not so much due to their chemical composition, but instead to the formation of hierarchical structures. This is illustrated with three examples – nacre, spider silk und holdfast structures of mussels. Selected approaches of taking inspiration from the construction principles of these natural materials for the development of new materials are presented. Although the high degree of integrating many hierarchical levels, as well as adaptability and multifuncionality of the materials, as achieved by evolutionary processes, has not (yet) been reached, bio‐inspired concepts allow developing materials with interesting specific properties. [ABSTRACT FROM AUTHOR]

In freshwater ecosystems, consumers can play large roles in nutrient cycling by modifying nutrient availability for autotrophic and heterotrophic microbes. Nutrients released by consumers directly support green food webs based on primary production and brown food webs based on decomposition. While much research has focused on impacts of consumer driven nutrient dynamics on green food webs, less attention has been given to studying the effects of these dynamics on brown food webs.Freshwater mussels (Bivalvia: Unionidae) can dominate benthic biomass in aquatic systems as they often occur in dense aggregations that create biogeochemical hotspots that can control ecosystem structure and function through nutrient release. However, despite functional similarities as filter‐feeders, mussels exhibit variation in nutrient excretion and tissue stoichiometry due in part to their phylogenetic origin. Here, we conducted a mesocosm experiment to evaluate how communities of three phylogenetically distinct species of mussels individually and collectively influence components of green and brown food webs.We predicted that the presence of mussels would elicit a positive response in both brown and green food webs by providing nutrients and energy via excretion and biodeposition to autotrophic and heterotrophic microbes. We also predicted that bottom‐up provisioning of nutrients would vary among treatments as a result of stoichiometric differences of species combinations, and that increasing species richness would lead to greater ecosystem functioning through complementarity resulting from greater trait diversity.Our results show that mussels affect the functioning of green and brown food webs through altering nutrient availability for both autotrophic and heterotrophic microbes. These effects are likely to be driven by phylogenetic constraints on tissue nutrient stoichiometry and consequential excretion stoichiometry, which can have functional effects on ecosystem processes. Our study highlights the importance of measuring multiple functional responses across a gradient of diversity in ecologically similar consumers to gain a more holistic view of aquatic food webs. [ABSTRACT FROM AUTHOR]

The freshwater snails and mussels are recognized as ecosystem engineers owing to their ability to influence the ecological processes. We investigated the effect of the snail Filopaludina bengalensis and the mussel Lamellidens marginalis alone and in interaction with the macrophyte Lemna minor on the ecological processes (nutrient dynamics, microbial account, sediment properties and periphytic algal growth) of the freshwater ecosystem through a mesocosm experiment. Both the snail and mussel promoted the growth rate of L. minor; however, the presence of snail negatively influenced the growth of periphyton. The biogeochemical process was affected by the presence of snails and mussels. Macrophyte association further influenced this biogeochemical process. Snail and mussel enhance the growth of heterotrophic bacteria and phosphate solubilising bacteria in the sediment. Likewise, the presence of macrophyte also positively influences the microbial growth. The activities of the benthic fauna like the mussels and the snails can be considered a useful process for the sustenance of the microbes and the macrophytes representing a pattern of bottom-up regulation. [ABSTRACT FROM AUTHOR]

In February 2023, a severe cold snap took place in Atlantic Canada and was followed by the mass loss of mussels at mid-to-high intertidal elevations on the southeastern Nova Scotia coast. This loss was concerning because mussels sustain upper trophic levels in coastal food webs and because mussel stands enhance local biodiversity by sheltering many small invertebrate species. Using photographs taken in the second summer after that cold snap (July 2024), this article provides visual evidence of active ongoing recolonization of intertidal mussels on this coast, including the incipient formation of new stands. These are encouraging signs of ecological resilience. Reaching historical values of abundance will likely depend on the future occurrence of weather extremes, which are becoming more frequent with the ongoing climate change. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the correlation between the levels of chromium (Cr), lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu) in surface sediment samples and those in the total soft tissues of the mussel Mytilus.galloprovincialis, collected off the northern Moroccan coast in the Mediterranean. The objective was to examine the accumulation patterns of these heavy metals in M. galloprovincialis relative to their concentrations in the sediment. Detailed sampling of sediments and Mytilus galloprovincialis mussels were carried out at three specific stations to measure trace metal concentrations. A perfect correlation was observed for Pb levels between the mussel tissues and sediment. The sampling methods were carefully planned to ensure data accuracy and consistency, following strict protocols to reduce contamination and maintain sample integrity. In contrast, Cr showed only a weak correlation. The correlations for the other trace metals (Cd, Zn, and Cu) varied from strong to weak and were both positive and negative, but none were statistically significant. These findings underscore the potential of M. galloprovincialis as an effective biomonitoring species for Pb. However, additional research and more comprehensive analyses are necessary to establish firmer conclusions regarding the correlations for the other metals. [ABSTRACT FROM AUTHOR]

The early stages of mussel farming are often inefficient with a large proportion of seed (spat) typically lost early in the production cycle. An effective approach for decreasing such losses is to grow spat to larger sizes in nursery systems prior to seeding. However, for such an approach to be commercially viable, spat must first be separated from their settlement substrates into a single seed format, that is, singulated. This study investigated the efficacy of three commercial protease enzymes (Enzidase PAP, PXT and BAP) and chlorine (NaOCl) in singulating Greenshell mussel (Perna canaliculus) spat from spat‐collector ropes. Two distinct experiments involved immersing segments of spat collector rope in seawater solutions with varying concentrations (2.5% or 5%) of each enzyme or chlorine (NaOCl) for different exposure times (10, 30 and 60 min for enzymes; 2 and 5 min for chlorine). After the singulation experiments, all spat were recovered with sieves and reintroduced into the tanks with renewed seawater. After 24 h of rearing, the recovery of alive spat was measured. Results indicate that in Experiment 1, involving spat ∼5 mm in size, the singulation rate was up to 65% for protease enzymes (i.e., in the case of 5% PAP at 30 min) and 61% for chlorine (i.e., at 5% for 2 min). In Experiment 2, involving spat ∼1.5 mm in size, the singulation rate was up to 85% for protease enzymes (i.e., in the case of 5% PXT for 60 min) and 78% for chlorine (i.e., of 2.5% for 5 min). However, these treatments generally resulted in elevated spat mortality, which was exacerbated by increasing concentrations and exposure times, resulting in recovery rates of up to 35% (i.e., for 2.5% PAP for 30 min) in Experiment 1 and 26.0% (i.e., for 5% chlorine for 2 min) in Experiment 2. These findings emphasise the necessity for consideration of chemical concentrations and exposure times to optimise the singulation process while highlighting challenges in achieving high post‐singulation survival rates. These insights contribute to ongoing efforts aimed at improving the efficiency and sustainability of mussel farming practices, demonstrating the potential utility of protease enzymes and chlorination in singulating spat from settlement substrate prior to their transfer to nursery systems for further ongrowing. For mussel spat to be grown in nursery culture systems they must first be separated from their associated settlement substrate (i.e., singualted). This work demonstrated that protease enzymes and chlorination is an effective approach for separating Greenshell mussel spat from spat‐catching ropes. [ABSTRACT FROM AUTHOR]

(1) Background: Atopic dermatitis (AD) is characterized as a chronic inflammatory skin disease with a significant incidence rate. The pathophysiological mechanisms underlying AD remain incompletely understood. However, extensive research demonstrates that a complex interplay among genetic, immune, and environmental factors contributes to the disruption of skin barrier function. Inflammation is identified as one of the pathological mechanisms in AD. Recombined mussel adhesive protein exhibits anti-inflammatory properties. However, recombinant mussel adhesive protein has been used less frequently for AD, so we explored the therapeutic effect of recombinant mussel adhesive protein for AD and the potential mechanism. (2) Methods: We established a mice model of AD in vivo and an LPS-induced inflammation model in HaCaT cells in vitro. Through assessment of skin lesion scores, itch frequency, transepidermal water loss, skin microcirculation, HE staining, Elisa assays for IL-6, IL-12, IL-13, IL-4, IL-5, IFN-γ, IgE, and TNF-α, immunohistochemical staining for filaggrin and CK14, Masson staining, and Western blot analysis of NF-κB p65, P-P65, Keap1, and Nrf2, the effects of recombined mussel adhesive protein on AD symptoms, pathology, inflammation, and its mechanisms are investigated. (3) Results: The recombined mussel adhesive protein significantly improved the compromised skin barrier, reduced scratching frequency in mice, decreased transepidermal water loss, and lowered the expression of inflammatory factors, thus ameliorating skin inflammation damage. Mechanistically, recombined mussel adhesive protein downregulated the expression of P-p65/p65 and Keap1 while upregulating the level of Nrf2. (4) Conclusions: Overall, our results demonstrate the effectiveness of recombined mussel adhesive protein in attenuating DNFB-induced AD by inhibiting NF-κB and activating the Keap1/Nrf2 signaling pathway. Thus, recombined mussel adhesive protein is a promising therapeutic candidate for the treatment of AD. [ABSTRACT FROM AUTHOR]

Acute environmental changes cause stress during conventional deep‐sea biological sampling without in situ fixation and affect gene expressions of samples collected. However, the degree of influence and underlying mechanisms are hardly investigated. Here, we conducted comparative transcriptomic analyses between in situ and onboard fixed gills and between in situ and onboard fixed mantles of deep‐sea mussel Gigantidas haimaensis to assess the effects of incidental sampling stress. Results showed that transcription, translation, and energy metabolism were upregulated in onboard fixed gills and mantles, thereby mobilizing rapid gene expression to tackle the stress. Autophagy and phagocytosis that related to symbiotic interactions between the host and endosymbiont were downregulated in the onboard fixed gills. These findings demonstrated that symbiotic gill and nonsymbiotic mantle responded differently to sampling stress, and symbiosis in the gill was perturbed. Further comparative metatranscriptomic analysis between in situ and onboard fixed gills revealed that stress response genes, peptidoglycan biosynthesis, and methane fixation were upregulated in the onboard fixed endosymbiotic Gammaproteobacteria inside the gills, implying that energy metabolism of the endosymbiont was increased to cope with sampling stress. Furthermore, comparative analysis between the mussel G. haimaensis and the limpet Bathyacmaea lactea transcriptomes resultedidentified six transcription factor orthologs upregulated in both onboard fixed mussel mantles and limpets, including sharply increased early growth response protein 1 and Kruppel‐like factor 5. They potentially play key roles in initiating the response of sampled deep‐sea macrobenthos to sampling stress. Our results clearly show that in situ fixed biological samples are vital for studying deep‐sea environmental adaptation. [ABSTRACT FROM AUTHOR]