Mytilus Edulis Shells Research Articles

First characterization of a nursery ground for the commercial sea cucumber Cucumaria frondosa

This study characterised the nursery ground of the cold-water sea cucumber Cucumaria frondosa for the first time. New recruits and early juveniles 0.9–40 mm in length were discovered at depths of 1.8–2.5 m in Qikiqtait (traditional name of the Belcher Islands, Nunavut, Canada) at a site with salinities ≥27 psu. They were primarily attached to live individuals and empty shells of the blue mussel Mytilus edulis and to stones. Based on laboratory rearing and known spawning times, the smallest individuals (0.9–1.4 mm) found in October 2021 and June 2022 were estimated to be 3–4 and 11–12 months old, respectively (year class 0-I). Other juveniles found at the same time were mostly ≤4-year-old, likely representing subsequent anual recruitment pulses. Densities of juveniles measuring 0.9–40 mm varied between 4 and 104 ind. m−2. Recruits <2 mm occurred in complex substrata, mostly mussel byssal threads, while larger juveniles, especially those >9 mm, were on exposed surfaces of shells and stones. No adults occupied the shallow nursery site. This study draws attention to ontogenetic migration allowing the occurrence of cryptic nursery sites that may occur in shallower environments than the typical adult habitats, of particular significance for the management of commercial species.

A wind of change for soft-sediment infauna within operational offshore windfarms

In this study, “artificial reef” (AR) impacts of offshore windfarms (OWFs) on the surrounding soft-sediments were investigated. Benthic grab samples were collected at nearby (37.5 m) and distant (500 or 350 m) positions from turbines of two Belgian OWFs (Belwind: monopiles and C-Power: jackets). Higher macrobenthos abundance and species richness were found nearby jacket foundations of C-Power compared to distant positions and differences were most pronounced within deeper sediments (i.e., gullies between sandbanks) at intermediate levels of fine sand fractions (10–20%) and total organic matter (0.5–0.9%). Strong benthic enrichment (>1000 ind. m−2, >20 spp. sample−1) was also linked with higher fine sand fractions (>20%) near the jackets. Moreover, nearby sediments showed higher occurrences of coastal species and habitat diversification was promoted by Mytilus edulis shell debris and alive organisms (“biofouling drop-offs”). The lack of similar results around monopiles (Belwind) confirms that the extent of detectable AR-effects depends on site- and turbine specific factors.

Chemical compositions of bivalves shells: Anadara senilis, Crassostrea gasar, and Mytilus edulis and their potential for a sustainable circular economy

The paradigm termed circular blue economy has become a concept that is greatly associated with the utilization of marine resources to ensure continued sustainability. Several constraints and limitations related to plants and plant products means human needs to look beyond green economy. The chemical constituents of animals also allow researchers to evaluate their growth and development. This study evaluates the proximate and chemical compositions of Anadara senilis, Crassostrea gasar, and Mytilus edulis, with emphasizes on their calcium and calcium carbonate contents and industrial importance. A total of 270 live bivalve samples were collected from March to May 2021 from Lagos Lagoon harbour. Each bivalve sample collected was opened to separate the flesh from the species’ shell, sun-dried and transported to the laboratory for analysis. One-way analysis of variance was adopted to estimate the significance level at 5% (P < 0.05). Post-HOC LSD test was performed to verify the disparity of mean. The results of this study revealed that Mytilus edulis shells had the highest moisture, crude protein, and crude fat at 1.15 ± 0.05%, 4.29 ± 0.43%, and 0.96 ± 0.15%, respectively and showed significant difference (P < 0.05). Anadara senilis shells had high levels of calcium (51.00 ± 2.87 mg/kg), magnesium (0.59 ± 0.23 mg/kg) and calcium carbonate (60.91 ± 2.50 mg/kg). Due to the high Ca and CaCO3 contents obtained, these shells can be processed alongside other biomaterials into food supplements, animal feeds, dental products, plant nutrient supplements, ornamental purpose, construction, agricultural industries among others. These would enhance the development of cottage industries, promotes farming of shell animals, help to alleviate the unemployment crisis and creation of wealth from substances which would have been regarded as waste.

HAEMATOLOGY OF NILE TILAPIA, Oreochromis niloticus FED Mytilus edulis SHELL MEAL SUBSTITUTED FOR DI CALCIUM PHOSPHATE

The effect of the inclusion of Mytilus edulis shell collected from the Lagos Lagoon front, University of Lagos, in diets of Nile tilapia (Oreochromis niloticus) on the haematology of the fish was investigated in the Marine Research Laboratory of the University. Ten fingerlings each of O. niloticus were placed in plastic tanks and fed for 12 weeks with feed containing milled M. edulis shell substituted for Di calcium phosphate (DCP), in other to utilize locally available and abundant non conventional food materials. The substitutions were at the rate of 100% (T4), 75% (T3), 50% (T2), 25% (T1) and 0% (T0) the control diet. Each feeding regime was in triplicates. The mean water parameters during experimental period were within the normal range for tropical fishes, and were: mean temperature (27.78±0.57 28.17±0.570C); pH(4±0.07 7.49±0.10) and dissolved oxygen (6.19±0.633 6.46±0.633mg/l). The proximate analysis of M. edulis shell showedhigher crude protein content compared to DCP; this probably had a positive effect on the growth of the fish fed M. edulis shell. Fish fed with M. edulis shell showed a remarkable significant decrease (P&gt;0.05) amongst diet in haematological parameters (Hb, WBC and RBC). However, the PCV values was highest in T3 (0.363±0.465) and lowest in the control diet (T0) (0.133±0.015). In conclusion, 75% level of substitution of Di calcium phosphate with M. edulis shell in the diet O. niloticus yielded a better haematological parameter

Hard to Soft: Biogenic Absorbent Sponge-like Material from Waste Mussel Shells

Summary Mussel shells are a source of renewable CaCO3 and can be obtained from aquaculture waste streams. Valorization of waste shells relieves strain on landfills and aligns with the goals of a circular economy. Here, we present the preparation of an absorbent CaCO3 material, soft calcite (SC), prepared from waste blue mussel shells under mild conditions. Calcite is the only polymorph present in SC, despite the presence of aragonite in the shell. SC has a nest-like morphology, unlike the highly ordered calcite in the shell. SC is formed by the reassembly of calcite prisms and may be held together by the organic matrix “glue” from the original shell as evidenced by NMR spectroscopy. This inorganic sponge adsorbs dyes from aqueous solution and absorbs crude oil from seawater with good recyclability. Our results demonstrate how a natural structure can be modified in a sustainable fashion to yield a higher-value material.

Addressing critical limitations of oyster (Ostrea edulis) restoration: Identification of nature‐based substrates for hatchery production and recruitment in the field

AbstractThe European flat oyster (Ostrea edulis) is an ecosystem engineer that provides important biogenic reef habitat with associated ecosystem functions and services. Most stocks have been commercially exploited and degraded; some are functionally extinct. Ecological restoration now aims to recover these degraded, damaged or destroyed ecosystems.Availability of seed oysters and substrate for successful larval recruitment has been identified as a major limiting factor for restoration projects in Europe. In substrate‐limited areas, restoration approaches have to involve the restoration of suitable substrates.The present study provides an evaluation of such potential substrate types. Various categories were investigated through hatchery and/or field experiments: (1) marine bivalve shells; (2) inorganic materials; (3) sandy sediment; (4) 3D sandstone reefs; (5) wood materials; and (6) limed materials. The respective settlement rates (settled larvae per cm2) indicate settlement preferences.Hatchery experiments showed significant preferences for bivalve shells and inorganic materials. Best settlement rates were observed onMytilus edulisshells, followed byO.edulisshells as well as on slaked lime and on baked clay. Settlement was significantly higher on bottom‐oriented areas of bivalve shells and 3D reefs in laboratory experiments; however, this was not substantiated in the field experiments.Field experiments showed significant settlement preferences between substrate categories (bivalve shells, inorganic materials and wood materials). Best settlement rates were observed on baked clay, followed by slaked lime and bivalve shells. Wooden materials did not perform.Settlement rates and substrate preferences of larvae in controlled environments (laboratory, hatchery) differed from rates in the natural environment (field). This study provides a list of substrate types considering these specific environments. The relevance of these results for ecological restoration in the field and potential applications in seed oyster production are discussed.

Photothermal Effect-based Cytotoxic Ability of Melanin from Mytilus edulis Shells to Heal Wounds Infected with Drug-resistant Bacteria in vivo

ObjectiveOwing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed. MethodsMelanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, in vitro and in vivo, were assessed by plate counting and ratios (%) of wound areas. ResultsNatural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria in vivo and was biocompatible according to toxicity tests in vivo and in vitro. ConclusionThe present findings indicated a safe and efficient method of developing natural antibacterial agents.

Removal of odorous sulphur compounds from industrial gases by biotrickling filters

A pilot plant for the treatment of Sulphur-based odorous gases was installed in a line of a phosphoric acid plant located in Skhira, Tunisia. The air pollution control system train consisted of a first stage, including a chemical scrubber operating with an alkaline solution containing caustic soda, followed by a two-stage biotrickling filter (BTF) filled with Mytilus edulis shells. This study evaluated the performance of the dual-stage BTF in removing hydrogen sulphide (H2S), sulphur dioxide (SO2) and dimethyl sulphide (DMS) from the phosphoric acid reactor’s exhaust air current. Concentrations of H2S, SO2 and DMS at the inlet of the two-stage BTF were 10-30 ppm, &lt; 1-20 ppm and 16-30 ppm, respectively. All of the respective concentrations at the outlet of the biological step were &lt; 1 ppm, except for the H2S in the outlet during the first day of operation (10 ppm). Removal efficiencies were generally higher than 95% for all compounds, and remained high even with an increase of the off-gas flow rate. Mass-removal capacity was at least 2.0 g m-3 h-1, 0.5 g m-3 h-1 and 6.2 g m-3 h-1, for H2S, SO2 and DMS, respectively. The removal efficiencies of the process were satisfactory, especially considering the already low inlet concentrations, due to the high quality of the raw phosphate used.

Biomineral shell formation under ocean acidification: a shift from order to chaos.

Biomineral production in marine organisms employs transient phases of amorphous calcium carbonate (ACC) in the construction of crystalline shells. Increasing seawater pCO2 leads to ocean acidification (OA) with a reduction in oceanic carbonate concentration which could have a negative impact on shell formation and therefore survival. We demonstrate significant changes in the hydrated and dehydrated forms of ACC in the aragonite and calcite layers of Mytilus edulis shells cultured under acidification conditions (1000 μatm pCO2) compared to present day conditions (380 μatm pCO2). In OA conditions, Mytilus edulis has more ACC at crystalisation sites. Here, we use the high-spatial resolution of synchrotron X-ray Photo Emission Electron Microscopy (XPEEM) combined with X-ray Absorption Spectroscopy (XAS) to investigate the influence of OA on the ACC formation in the shells of adult Mytilus edulis. Electron Backscatter Diffraction (EBSD) confirms that OA reduces crystallographic control of shell formation. The results demonstrate that OA induces more ACC formation and less crystallographic control in mussels suggesting that ACC is used as a repair mechanism to combat shell damage under OA. However, the resultant reduced crystallographic control in mussels raises concerns for shell protective function under predation and changing environments.

Mussel shells of &amp;lt;i&amp;gt;Mytilus edulis&amp;lt;/i&amp;gt; as bioarchives of the distribution of rare earth elements and yttrium in seawater and the potential impact of pH and temperature on their partitioning behavior

Abstract. Mussel shells are potential bioarchives of proxies for changes in the physicochemical conditions in the bivalve's habitat. One such proxy is the distribution of rare earths and yttrium (REY) in seawater, as REY speciation in seawater is sensitive to pH and temperature variations, due to the impact of these parameters on the activity of CO32− in seawater. We present a new protocol for sample preparation and determination of ultratrace concentrations of REY in bulk bivalve shells (comprised of calcite and aragonite) that includes sample treatment with NaOCl followed by REY separation and preconcentration. The data obtained were used to calculate REY partition coefficients between bulk bimineralic shells of Mytilus edulis (calcite aragonite mix) and ambient seawater, and the results acquired were then used to investigate the potential effects of pH and temperature on REY partitioning.Shells of Mytilus edulis mussels from the North Sea show consistent shale-normalized (SN) REY patterns that increase from the light REY to the middle REY and decrease from the middle REY to the heavy REY. Despite being different from the general seawater REYSN pattern, the shells still display distinct REY features of seawater, such as a negative CeSN anomaly and small positive YSN and GdSN anomalies. Apparent REY partition coefficients between shells and seawater (appDTot.REYshell/seawater) are low and decrease strongly from the light REY (4.04 for La) to the heavy REY (0.34 for Lu). However, assuming that only the free REY3+ are incorporated into the shell, modDFreeREY3+shell/seawater values are higher and comparatively similar for all REY (102.46 for La; 113.44 for Lu) but show a slight maximum at Tb (199.18). Although the impact of vital effects, such as REY speciation in a mussel's extrapallial fluid from which the carbonate minerals precipitate, cannot be quantified yet, it appears that M. edulis shells are bioarchives of some REY features of seawater.We modeled the REYSN patterns of a hypothetical mussel shell at pH 8.2 and 7.6 and at temperatures of 25 and 5 °C, assuming that only free REY3+ are incorporated into the carbonate's crystal lattice and that vital effects do not obliterate the REY signal of the shells. The results suggest that with lower pH, REY concentrations in shells increase, but with little effect on the shape of the REYSN patterns, while a temperature change has an impact on the REYSN pattern but only minor effects on REY concentrations. Hence, after additional calibration studies, the REY systematics in mussel shells may become a valuable proxy for paleo-pH and ocean acidification.

The use of shells as tools by hunters-gatherers in the Beagle Channel (Tierra del Fuego, South America): an ethnoarchaeological experiment

This paper presents the results of the analysis of lipid residues extracted from two Aulacomya atra shells and a single Mytilus edulis shell found in the hunter-fisher-gatherer site of Lanashuaia II, a shell midden located on the Beagle Channel (Tierra del Fuego, Argentina). According to existing ethnographic information, the shells could have been used as receptacles (like spoons) or knives by the Yamana people that inhabited the region in the historical period (nineteenth and twentieth centuries). Yamana society is the final moment of a long history of hunter-fisher-gatherer societies present in the Beagle Channel and the rest of Fuegian Channels and islands. Higher concentrations of lipid residues were recovered from both A. atra shells than from the sedimentary control sample analyzed. This is consistent with existing accounts that these types of shells were used as containers to cook or melt fat-rich foods. The composition of lipids extracted from archaeological shell was significantly different from the degraded reference cooking residues prepared from modern A. atra shells.

Les amas coquilliers du site Imiwaia I (Canal Beagle, Argentine). Étude des coquilles Mytilus edulis au moyen de la FTIR-ATR

This article presents a part of conclusions of a research concerning the Mytilus edulis shells coming from a shellmidden or “conchales” of Imiwaia I site on the edges of the Beagle channel in Argentina. Our main objective was to bring further information on the method of preparation of bivalves by canoe hunter-gatherer-fishers for their alimentation (~6400 BP). The project concentrated on the comparative analysis of modern M. edulis valves collected in the region and opened by various methods, and those excavated from the archeological site Imiwaia I. The analysis of the inorganic structure of both layers of valves (calcite and aragonite) allowed to conclude on the opening technique employed and the parameters of preservation offered by the shellmidden. During the development of the study, we worked from a multidisciplinary approach of historical, ethnographical, archaeological and chemical information to better understand and interpret the opening methodology of bivalves and their effect on the state of preservation of the information carried by the archaeological specimens.

Biochemical and Haematological Response of Clarias gariepinus (Burchell, 1822) Juveniles Fed with Diet Containing Mytilus edulis Shell at Varying Level

Biochemical and Haematological Response of Clarias gariepinus (Burchell, 1822) Juveniles Fed with Diet Containing Mytilus edulis Shell at Varying Level

Nano-FTIR chemical mapping of minerals in biological materials

Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone. "Nano-FTIR" spectral images result from Fourier-transform infrared (FTIR) spectroscopy combined with scattering scanning near-field optical microscopy (s-SNOM). On polished sections of Mytilus edulis shells we observe a reproducible vibrational (phonon) resonance within all biocalcite microcrystals, and distinctly different spectra on bioaragonite. Surprisingly, we discover sparse, previously unknown, 20 nm thin nanoparticles with distinctly different spectra that are characteristic of crystalline phosphate. Multicomponent phosphate bands are observed on human tooth sections. These spectra vary characteristically near tubuli in dentin, proving a chemical or structural variation of the apatite nanocrystals. The infrared band strength correlates with the mineral density determined by electron microscopy. Since nano-FTIR sensitively responds to structural disorder it is well suited for the study of biomineral formation and aging. Generally, nano-FTIR is suitable for the analysis and identification of composite materials in any discipline, from testing during nanofabrication to even the clinical investigation of osteopathies.

Rare earth elements in mussel shells of the Mytilidae family as tracers for hidden and fossil high-temperature hydrothermal systems

Bathymodiolus mussels of the Mytilidae family live in ecological niches at marine vent sites where hydrothermal fluids discharge at the seafloor and mix with ambient seawater. We report the first concentration data for rare earth elements and yttrium (REY) of Bathymodiolus shells and of low-temperature diffuse hydrothermal fluids venting in their respective habitat at three hydrothermal vent fields along the Mid-Atlantic Ridge (MAR) and for littoral Mytilus edulis shells from the western North Atlantic, Dingle Bay, Ireland, and from the southern North Sea, German Bight, Germany. Similar to high-temperature hydrothermal solutions expelled in the respective area, the low-temperature diffuse fluids from the hydrothermal vent sites display positive Eu anomalies. These indicate that the fluids carry a component previously involved in high-temperature water–rock interaction, as decoupling of Eu from neighbouring REY requires temperatures above about 200 °C. While the Bathymodiolus shells from the hydrothermal vent fields reflect these positive Eu anomalies, the littoral M. edulis shells studied for comparison, do not show Eu anomalies, consistent with the lack of any high-temperature hydrothermal activity in their coastal environments. Shells of mussels of the Mytilidae family, such as Bathymodiolus and M. edulis, therefore, are archives whose REY distribution can be used as a proxy for the Eu anomaly of the waters in which the mussels grew. Although the Ca carbonate of a mussel shell is precipitated from the extrapallial fluid of the mussel and not directly from seawater, the Eu/Eu* ratio of seawater is not significantly modified under the low-temperature conditions prevailing during vital processes and biomineralization. This allows one to use the positive Eu anomalies in the REY distribution patterns of Bathymodiolus shells as a tracer for hidden or fossil high-temperature hydrothermal systems where other indicators of high-temperature hydrothermalism are not available.

Control of crystal polymorph in microfluidics using molluscan 28 kDa Ca2+-binding protein

Biominerals produced by biological systems in physiologically relevant environments possess extraordinary properties that are often difficult to replicate under laboratory conditions. Understanding the mechanism that underlies the process of biomineralisation can lead to novel strategies in the development of advanced materials. Using microfluidics, we have demonstrated for the first time, that an extrapallial (EP) 28 kDa protein, located in the extrapallial compartment between mantle and shell of Mytilus edulis, can influence, at both micro- and nanoscopic levels, the morphology, structure and polymorph that is laid down in the shell ultrastructure. Crucially, this influence is predominantly dependent on the existence of an EP protein concentration gradient and its consecutive interaction with Ca²(+) ions. Novel lemon-shaped hollow vaterite structures with a clearly defined nanogranular assembly occur only where particular EP protein and Ca²(+) gradients co-exist. Computational fluid dynamics enabled the progress of the reaction to be mapped and the influence of concentration gradients across the device to be calculated. Importantly, these findings could not have been observed using conventional bulk mixing methods. Our findings not only provide direct experimental evidence of the potential influence of EP proteins in crystal formation, but also offer a new biomimetic strategy to develop functional biomaterials for applications such as encapsulation and drug delivery.

Trace metals in the shells of blue mussels (Mytilus edulis) from the Poland coast of Baltic sea

In this study, bioaccumulation of the heavy metals (Hg, Pb, Cd, Cu, Zn, Cr, Ni, Fe, Mn, V, Li, Al) in the shells of Mytilus edulis were investigated. Shells of Mytilus edulis were collected in May to September 2005 from 12 stations on the Polish coast of Baltic Sea. At each sampling sites 17-330 different size of shells were collected during 2005, respectively. Due to heavy industrial activities in the region, the bay has the polluted coastal waters of Poland. Shells were analysed by ICP AES and Coleman MAS 50 CV atomic absorption spectrometer. As expected from the similarity found between the relationships of metal content length and dry the concentrations of the different metals in the shells did not seem to depend on the shell length. No significant differences were detected in metal concentration between different shell lengths. Given their geographical distributions, as well as their abilities to show up spatial and temporal changes in metal bioavailabilities confirmed here, it is concluded that the mussel M. edulis a suitable candidate to be used in biomonitoring surveys of the Poland coast of Baltic.

Comparison of the Crystallographic Structure of Semi Nacre and Nacre by Electron Backscatter Diffraction

Aragonite nacre is commonly found in the shells of molluscs, while semi nacre has been observed in the shells of organisms from two phyla: the Brachiopoda and the Bryozoa. Calcite semi nacre and aragonite nacre display similar morphologies with laminae composed of tablets that grow by screw dislocation. This study uses electron backscatter diffraction to compare the crystallography of calcite semi nacre from the shell of the Craniid brachiopod Novocrania huttoni with aragonite nacre from the shell of the bivalve mollusc Mytilus edulis. Semi nacre and nacre are similar in morphology but ultimately have different crystallography. In N. huttoni calcite semi nacre, the c-axis lies parallel to the laminae of the secondary layer of the shell. In comparison, the c-axis of aragonite nacre in M. edulis is orientated perpendicular to the laminae. The crystallography of calcite semi nacre in the secondary layer of N. huttoni is similar to the crystallography of skeletal ultrastructures produced by bryozoans, while it differs from the crystallography described in other brachiopod genera.

Crystallography and chemistry of the calcium carbonate polymorph switch in M. edulis shells

The control exerted by some invertebrates on the calcium carbonate polymorph produced is intriguing but not understood. Mytilus edulis shells, with the abrupt polymorph switch within their valves from an outer calcite to inner aragonite layer, are excellent examples of this phenomenon. Detailed crystallography of intact valves using Electron Backscatter Diffraction (EBSD) is considered in the context of quantitative chemical analyses by electron microprobe. Apart from the outer 40 μm, individual crystals that comprise the calcite layer of M. edulis differ from each other in terms of misorientation by less than 10°. Similar uniformity occurs in the inner aragonite layer with notable ‘mineral bridging’ between tablets of aragonite nacre. The first-formed aragonite laminae are sub-micron thickness and the subsequent laminae of uniform 1 μm thickness. Variations in chemical composition through the two valves correspond in part with the distribution of the two polymorphs. Magnesium is present in notably higher concentrations within calcite than aragonite. However, the Mg2+ concentration in calcite is not uniform and increases with growth before decreasing at the polymorph switch. Sodium concentrations decrease steadily through the calcite layer. The aragonite layer is compositionally more uniform. Sulphur is not a good proxy for organic content in this system because it does not reflect the higher organic content of the aragonite. Sector zoning is not responsible for the element distribution seen here while differences in crystal size and association with organic components remain as possible explanations.

A history of heavy metal pollution recorded in the shell of Mytilus edulis

A history of heavy metal pollution recorded in the shell of Mytilus edulis