Search Results (184)

Bone loss represents a significant clinical burden that has driven the development of improved orthopedic graft substitutes. Although current grafting options, including autografts, allografts, and xenografts, have demonstrated considerable therapeutic potential, their widespread application is constrained by limitations such as donor scarcity, limited availability, and associated clinical risks. Consequently, biologically derived materials, including avian eggshells and marine bivalve shells, have emerged as promising alternative sources to produce bone precursor materials and next-generation bone graft substitutes. This review summarizes recent advances in avian eggshell- and marine shell-derived calcium carbonate (CaCO₃) materials for bone regeneration and examines their preclinical evaluation in diverse animal models, including critical-size defects in calvarial, femoral, radial and mandibular bone. Relevant studies published over the past ten years were systematically analyzed, focusing on natural calcium carbonate systems derived from avian eggshell and marine shells, including oyster, mussel, clam, scallop, cockle, and sea urchins. A structured literature search was conducted using PubMed, Scopus, and Google Scholar to identify studies published between 2015 and 2025 investigating eggshell- and aquatic-derived biomaterials for bone repair and regeneration. Eligible studies were screened, and data were comparatively analyzed with respect to biomaterial source, scaffold fabrication, physicochemical characteristics, mechanical performance, biocompatibility, osteogenic potential, and the use of preclinical animal studies. Eggshell-derived biomaterials currently show the strongest translational evidence, while aquatic shell-derived biomaterials remain promising but underexplored for bone regeneration. Furthermore, this review critically examines the scientific, manufacturing, and regulatory challenges that must be addressed before clinical implementation. Full article

This review analyzes how in situ environmental monitoring and satellite remote sensing (RS) can be integrated to assess the production performance of the Mediterranean mussel (Mytilus galloprovincialis). It provides a focused synthesis of the available evidence on the integration of these complementary monitoring approaches for assessing environmental conditions and mussel production performance. A systematic literature search was performed across major scientific databases, including PubMed, Scopus, Web of Science, CAB Abstracts, ASFA, and IEEE Xplore, to identify studies published between 2014 and November 2025. Following the screening process, reported in accordance with PRISMA-ScR, 28 studies met the inclusion criteria. The results showed that most studies relied exclusively on in situ environmental data (n = 24), while only one study used RS alone and three studies combined both approaches. Temperature and salinity were the most frequently monitored variables and showed the clearest associations with growth-related indicators, such as shell length and soft tissue weight. Overall, the combination of in situ monitoring and RS remains limited, while spatial analytical methods, including GIS, are still underused in this research area. Combining local and depth-specific in situ measurements with the broader spatial coverage of RS may provide a more comprehensive assessment of environmental variability relevant to mussel production and aquaculture management. These findings highlight important methodological gaps and emphasize the need for standardized and integrated monitoring schemes to support the management of mussel farming systems. Full article

Digenean of the superfamily Echinostomatoidea exhibit complex life cycles that involve up to three host species. Several echinostomatoid species have been reported in snails of the family Littorinidae. In the zebra snail Echinolittorina peruviana from central Chile, two cercarial species resembling Echinostomatoidea were recognized based in their morphological characteristics. Molecular characterization was carried out to identify the species. Key aspects of their infection dynamics were quantified and compared between the two cercarial morphologies, with particular emphasis on transmission to secondary intermediate hosts. We evaluated: (i) swimming activity, (ii) the success of cercarial settlement in a mussel host across different body sizes, and (iii) host selection among three potential secondary intermediate hosts (a mussel, a snail, and a crab). Molecular analyses, based on the 28S gene, indicated that the examined cercariae corresponded to two distinct species from the superfamily Echinostomatoidea. However, species-level identification could not be confirmed, and they were therefore designated as species 1 and species 2. Species 1 exhibited a significantly faster decline in swimming activity compared to species 2, whose active period was approximately twice as long. Mussels were successfully infested in all trials, with no significant differences among shell-size groups. In host preference experiments, all host types were selected. However, only the cercaria species 2 showed a significant preference for the crab, suggesting that this may be an alternative secondary intermediate host. Despite their similar body size, the two cercarial species displayed distinct infection dynamics and host-use strategies, indicating divergent biological traits and transmission pathways within a limited time window. Full article

To establish non-destructive morphometric predictors of live body weight in the endangered freshwater pearl mussel (Margaritifera dahurica), 100 wild adult individuals were randomly selected. Four phenotypic parameters, including shell height (SH), shell length (SL), shell width (SW), and body weight (BW), were measured, and the interrelationships among these traits were statistically analyzed using correlation and path analyses. The results indicated that the phenotypic correlations among all traits of M. dahurica reached a highly significant level. Shell length exhibited the greatest direct effect on body weight, with a path coefficient of 0.718. The statistical associations of shell height and shell width with body weight were primarily mediated through indirect pathways via shell length. Shell length, shell width, and shell height were identified as the key morphometric predictors of body weight, yielding a total coefficient of determination of 0.879. Shell length possessed the highest comprehensive coefficient of determination (0.911), making it an ideal target trait for selective breeding. Using stepwise regression analysis, the optimal multiple linear regression equation of morphological traits on body weight was established as Log_BW = −0.814 + 2.482Log_SL + 0.522Log_SW. Rather than directly driving genetic breeding, these findings provide a grounded, non-destructive method for predicting live body mass, facilitating rapid biomass monitoring and founder broodstock assessment in M. dahurica. Full article

This study investigates the use of mussel shells (MSs), a biogenic by-product of the food industry, as a partial replacement for ground granulated blast furnace slag (GBFS) in alkali-activated mortars. Given their high CaCO₃ content, MSs represent a sustainable secondary raw material that reduces both waste disposal burden and reliance on natural resources, while offering a low-carbon alternative to conventional cement-based binders. Alkali-activated mussel shell/slag mortars (AAMSs) were produced with MS replacement ratios of 0%, 5%, 10%, 15%, and 20% by mass of GBFS. Sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) were used as alkaline activators. Fresh specimens were cured at 60 °C for 48 h. The experimental program included workability, compressive and flexural strength, water absorption, porosity, density, capillarity, ultrasonic pulse velocity (UPV), and freeze–thaw (F-T) resistance tests. Increasing MS content slightly reduced flowability and mechanical strength, while increasing water absorption, porosity, and capillarity. The M0 series achieved the highest 28-day compressive strength (54.06 MPa), while M15 exhibited the highest flexural strength (5.23 MPa). Following F-T cycling, the 5% and 10% MS series demonstrated the best compressive strength (30 MPa). The 10% MS exhibits a relatively balanced overall performance, providing the best balance between mechanical performance, F-T resistance, and microstructural stability, as confirmed by scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) analyses showing elevated Ca/Si ratios and the formation of Ca-rich crystalline phases. Full article

Freshwater mussels (Bivalvia, Unionidae) are now among the world’s most imperiled taxonomic groups, and their diversity is under serious threat. The metamorphosis of glochidia parasitizing on a host fish into juveniles is undoubtedly the most unique and critical stage in the life cycle of freshwater mussels, but the underlying mechanisms remain unclear. Here, we integrated microscopic observation, stable isotope (δ¹³C and δ¹⁵N) tracing, and transcriptomic analysis to investigate this process in the globally distributed freshwater mussel Sinanodonta woodiana on yellow catfish (Pelteobagrus fulvidraco). Compared with glochidia, juveniles exhibited byssus abandonment and the formation of a foot, visceral mass, and new shell. The shell length (0.34 ± 0.02 mm) and height (0.31 ± 0.01 mm) of the juveniles were both larger than those of the glochidia (0.26 ± 0.01 mm and 0.30 ± 0.01 mm, respectively) (p < 0.05); however, this growth likely occurred after excystment from the host fish rather than during the parasitic phase. Juveniles showed significantly higher δ¹³C (−17.70 ± 0.26‰) and δ¹⁵N (9.80 ± 0.90‰) than glochidia (δ¹³C: −23.58 ± 0.63‰; δ¹⁵N: 6.18 ± 0.37‰) (p < 0.05), with juvenile δ¹⁵N comparable to host fish tissues. Metamorphosis generated 12,584 differentially expressed genes, mainly enriched in upregulated neuroactive ligand–receptor interaction, Ras signaling, and calcium signaling pathways. This study reveals the mechanisms of S. woodiana metamorphosis, providing valuable insights for improving breeding and thus supporting the diversity conservation of freshwater mussels. Full article

The protected fan mussel Pinna nobilis (Linnaeus, 1758) is a key ecosystem-engineering species in Mediterranean coastal ecosystems, historically providing important regulating ecosystem services—particularly nutrient removal and shell-based carbon storage—as well as the ecological function of large-scale biofiltration. Prior to the mass mortality event in 2016, the Greek population was estimated at approximately 2.66 × 10⁹ individuals. This is associated with an annual gross shell carbon storage of 13,689–108,139 t “C”, together with 304.7–2988.3 t “N” and 49.7–450.5 t “P” retained in shell material, valued at EUR 8.14–76.6 million yr⁻¹ using replacement-cost proxies. These values represent a gross shell carbon storage rather than a net ecosystem carbon sequestration, due to the fact that metabolic fluxes and remineralization may partially offset long-term retention. Furthermore, P. nobilis performed a substantial biofiltration function, filtering 6.07 × 10¹¹–6.85 × 10¹² m³ of seawater per year (2.89–32.53 turnovers of the 30 m coastal zone). The mass mortality event led the population to a decline by >81%, reducing the value of nutrient retention and gross shell carbon storage to EUR 1.31–13.47 million yr⁻¹ and filtration capacity to 1.15 × 10¹¹–1.30 × 10¹² m³ yr⁻¹. Using an illustrative order-of-magnitude replacement-cost approach, we estimate that by reproducing the lost biofiltration function through engineered systems, we would require approximately EUR 1–5.2 billion annually which indicates the magnitude of natural capital lost and the utmost importance of P. nobilis recovery for Greek coastal ecosystems. Full article

This study investigates the reuse of mussel shell waste as a secondary raw material in bio-cement mortars designed for the additive manufacturing of artificial reefs for marine habitat restoration. The novelty of the research lies in combining a high recycled shell content (60 wt.%), low-clinker cement, and two 3D-printing techniques: Extruded Material Systems (EMS) and Powder-Based Systems (PBS). Mechanical performance was evaluated through flexural and compressive tests after 7, 28, and 91 days under both air and freshwater curing conditions, while environmental impacts were assessed through Life Cycle Assessment (LCA). The LCA evaluated both the environmental performance of shell-based mixtures compared with conventional materials and the impacts associated with the investigated fabrication techniques. The best-performing bio-mixtures achieved compressive strengths up to 46.01 MPa and flexural strengths up to 9.91 MPa after freshwater curing, demonstrating the suitability of shell-based mortars for submerged applications. LCA results showed reduced impacts in land use and mineral resource depletion compared with conventional mixtures, despite slightly higher energy and water demands associated with shell pre-treatment. The results demonstrate the technical and environmental feasibility of integrating aquaculture waste into sustainable 3D-printed marine restoration solutions. Full article

This study proposes a sustainable, integrated biorefinery approach to valorize mussel shell waste into high-value products, including chitin, chitosan, and calcium formate. Formic acid was employed as an effective demineralizing agent, enabling not only efficient mineral removal but also the direct conversion of the demineralization effluent into value-added calcium formate. The sequential extraction processes, demineralization, deproteinization, and decolorization, successfully yielded purified chitin (PCH), which was subsequently deacetylated to produce chitosan (CTS) with a degree of deacetylation of 85% and a molecular weight of 75 kDa. The physicochemical properties of all products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR and XRD analyses confirmed the successful extraction of chitin and chitosan, demonstrating the feasibility of mussel shells as an alternative biopolymer source. In parallel, calcium formate (CCF) was obtained from the demineralization effluent with a yield of 94.19%, and its formation was verified by FTIR and XRD. Elemental analysis by XRF exhibited 98.3% CaO with minimal non-toxic impurities. The TGA/DTG profiles of CCF exhibited a well-defined two-step thermal decomposition, confirming its anhydrous form. Overall, this environmentally benign process enables the simultaneous production of multiple value-added products while significantly improving resource utilization and reducing waste generation. The proposed integrated biorefinery model offers a promising, economically viable pathway for marine biomass valorization, aligned with the Bio-Circular-Green (BCG) economy concept. Full article

This study presents a green bio-upcycling strategy for converting mussel shell biowaste into three value-added products: chitin, chitosan, and calcium lactate. Mussel shells were treated chemically with lactic acid during demineralization, yielding a solid fraction rich in chitin and a liquid fraction containing calcium and lactate ions. The solid fraction was sequentially purified by deproteinization and decolorization, then deacetylated to obtain chitosan, while the liquid fraction was evaporated to obtain calcium lactate. Notably, 2.37 g of raw chitin, 2.15 g of purified chitin, and 275.87 g of calcium lactate were obtained from 100 g of mussel shells, demonstrating the efficiency of the process. FTIR spectra revealed characteristic absorption bands corresponding to α-chitin and chitosan functional groups, while XRD patterns indicated the crystalline α-chitin structure and the formation of calcium lactate pentahydrate. TGA demonstrated the high thermal stability of chitin and chitosan and confirmed the presence of crystallization water in calcium lactate. In conclusion, these results confirmed the successful preparation of α-chitin, chitosan, and calcium lactate pentahydrate, with improved purity compared to previous studies. This approach highlights the potential of the green bio-upcycling process of mussel shell waste as a renewable source for the eco-friendly production of biopolymers and calcium salts, supporting sustainable waste management and the development of the Bio-Circular-Green (BCG) economy. Full article

The critically endangered fan mussel Pinna nobilis is under strict protection in the Mediterranean waters and exhibited a documented fishing history in Greece dating back to 19th and early of 20th centuries. The present study examined historical documentary evidence from Greek archives, technical reports, and oral testimonies to reconstruct traditional fishing methods and their ecological implications. Historical records revealed the widespread use of specialized fishing tools called “pinologos”, a Y-shaped iron attached to a wooden poles, deployed primarily in shallow waters (2–7 m depth) across various Greek coastal regions in the Ionian and Aegean Seas. Two types of fishing gear existed, a simple Y-shaped tong and a scissor-type gear, both designed to encircle and extract individual fan mussels, through quarter-turn rotation. Fishers selectively targeted only large, established individuals of fan mussel, as small specimens with thin shells were unsuitable for this method. Historical fishing pressure on the species was spatially and size-limited, unlike current basin-wide mortality events. These findings demonstrate that structured populations persisted even under traditional exploitation, suggesting potential for recovery if contemporary threats are mitigated. Management strategies should reference historical population structures as restoration targets. Full article

The climate impact of bivalve aquaculture remains inadequately quantified for China, the world’s dominant producer. Prevailing carbon footprint assessments often overlook the complexity of biological carbon flows and fail to capture effects that evolve across different timescales. To address these gaps, we developed a novel multi-temporal dual-carbon flow life cycle assessment framework that systematically quantifies both the anthropogenic (ACF) and biological (BCF) carbon footprints and evaluates the climate impacts across different time horizons. Applied to China’s largest mussel farm, the framework reveals the system’s total carbon footprint decreases from +261.7 kg CO₂-eq/t under a conventional Cradle-to-Gate perspective to +84.6 kg CO₂-eq/t over a centennial scale and further to +27.9 kg CO₂-eq/t over a geological timescale. With the ACF constant across all timescales (+256.2 kg CO₂-eq/t), the transition in total carbon footprint is driven entirely by the BCF. The BCF changes from a minor positive contribution during farming (+5.5 kg CO₂-eq/t, from enhanced sea-to-air CO₂ efflux) to a major net sink at centennial (–171.6 kg CO₂-eq/t ) and geological (–228.3 kg CO₂-eq/t) scales, primarily due to long-term carbon sequestration from shell removal, burial, and weathering. Consequently, the net carbon footprint is not a fixed attribute but a function of temporal perspective, controlled decisively by shell-waste management. Aligning the industry with climate goals thus requires not only reducing the ACF through material and energy efficiency during the production chain but, crucially, also diverting shells from incineration to burial or weathering pathways to secure their long-term sink potential. Full article

Bio-epoxy composites were fabricated by casting a resin–hardener–filler mixture into 3D-printed molds, using different sea-originated secondary raw materials: mussel shell powder (MSP) (63–83 μm) and Posidonia oceanica short fibers (POF) (1–2 mm). Monofiller composites were prepared with 5 or 10 wt.% MSP, or 5 or 10 wt.% POF. Hybrid formulations were also produced, containing both MSP and POF in two combinations, where the total amount of filler again summed up at 10 wt.%. A subset of the samples was conditioned by immersion in a 35 ‰ NaCl solution reproducing seawater composition until saturation was reached. Characterization was carried out on unconditioned and conditioned samples by Shore D hardness and Charpy impact tests while performing three-point flexural loading only on unconditioned ones. Fracture morphology was also investigated. Adding MSP slightly enhanced resin hardness, whereas impact absorption exhibited, to a variable extent, a two-phase behavior, reproducing crack initiation and propagation. The MSP6-POF4 hybrid configuration provided the greatest improvement in absorbed energy (25–30% higher), which was retained after conditioning. The introduction of fillers, first separately, then in combination, resulted in a reduction in flexural strength to a similar extent for all unconditioned configurations. Finally, composite panels containing 10 wt.% MSP, 10 wt.% POF, and a 6MSP–4POF hybrid formulation, intended for prospective boat deck applications, were fabricated and compared with neat bio-epoxy, showing satisfactory consolidation. Density and post-molding dimensional shrinkage were measured on the panels. Full article

Pearl culture has long been a major global industry. As a significant global producer, China mainly produces pearls from the freshwater mussel (Sinohyriopsis cumingii). S. cumingii with various shell colors can produce pearls of different colors; for example, mussels with a blue-white shell can produce white pearls, while those with a purple shell can produce light-purple pearls. Therefore, investigating the molecular genetics of shell color variation in S. cumingii can advance our understanding of the mechanisms underlying differences in shell and pearl coloration in these mussels. In this study, we selected juvenile S. cumingii with four differently colored inner shells and collected tissue samples for transcriptomic analysis. The results showed that many key genes involved in the regulation of pigment metabolism (such as ADAMTS, TYR, BCDO2, and FTH1), as well as those associated with metabolism and mineral absorption (such as TRPV6, HCP1, HEPH, and Zip4), exhibited significant differences. Furthermore, these DEGs (differentially expressed genes) may influence the synthesis and metabolism of melanin, carotenoids, porphyrins, and heme, thereby affecting shell color variation; they might also be one of the potential reasons why S. cumingii produces pearls of different colors. Full article