Mytilus Edulis Research Articles

Oil uptake via marine snow: Effects on blue mussels (Mytilus sp.)

Accidental oil spills into the ocean can lead to downward transport and settling of oil onto the seafloor as part of marine snow, as seen during the Deepwater Horizon incident in 2010 in the Gulf of Mexico. The arctic and subarctic regions may favor conditions leading to this benthic oil deposition, prompting questions about the potential impacts on benthic communities. This study investigated the effects of oil-contaminated marine snow uptake on the blue mussel (Mytilus sp.). We exposed mussels for four days to 1) oil-contaminated marine snow (MOS treatment), or to 2) chemically-enhanced water-accommodated fraction (CEWAF) of oil plus unaggregated food particles (CEWAF treatment). Both oil treatments received the same nominal concentration of oil and food. Two controls were included: 1) Clean seawater plus unaggregated food (agg-free control) and 2) clean seawater plus marine snow (marine snow control). After the exposure, mussels were allowed to recover for ten days under clean, running seawater. Samples were taken right before and after the exposure period, and after the recovery phase for the following endpoints: distribution (partitioning) of oil compounds between seawater and MOS, and between seawater and mussel tissue; DNA damage (assessed via the comet assay); clearance rate; and condition index [tissue dry weight (g) divided by shell length (mm)]. Some discernable patterns were found in the partitioning of oil compounds between seawater and MOS. However, these patterns did not translate to any significant differences in the partitioning of oil compounds into mussel tissue between the two oil treatments. DNA damage did not exceed background levels (10% tail DNA or less; to be expected in healthy, viable cells) at any sampling time point, but significantly higher DNA damage was observed in CEWAF-T compared to MOS-T mussels after the recovery phase. After the exposure, a significant difference emerged in the clearance rate between the CEWAF treatment and the agg-free control, but not between the MOS treatment and the marine snow control. All mussels except those from the CEWAF treatment exhibited an increased condition index after the exposure time. Together, these results suggest that aggregates could moderate the effects of oil exposure on blue mussels, possibly by providing better, more concentrated nutrition than unaggregated food particles.

Local differences in robustness to ocean acidification.

Ocean acidification (OA) caused by increased atmospheric carbon dioxide is affecting marine systems globally and is more extreme in coastal waters. A wealth of research to determine how species will be affected by OA, now and in the future, is emerging. Most studies are discrete and generally do not include the full life cycle of animals. Studies that include the potential for adaptation responses of animals from areas with different environmental conditions and the most vulnerable life stages are needed. Therefore, we conducted experiments with the widely distributed blue mussel, Mytilus edulis, from populations regularly exposed to different OA conditions. Mussels experienced experimental conditions prior to spawning, through embryonic and larval development, both highly vulnerable stages. Survivorship to metamorphosis of larvae from all populations was negatively affected by extreme OA conditions (pH 7.3, Ωar, 0.39, pCO2 2479.74), but, surprisingly, responses to mid OA (pH 7.6, Ωar 0.77, pCO21167.13) and low OA (pH 7.9, Ωar 1.53, pCO2 514.50) varied among populations. Two populations were robust and showed no effect of OA on survivorship in this range. One population displayed the expected negative effect on survivorship with increased OA. Unexpectedly, survivorship in the fourth population was highest under mid OA conditions. There were also significant differences in development time among populations that were unaffected by OA. These results suggest that adaptation to OA may already be present in some populations and emphasizes the importance of testing animals from different populations to see the potential for adaptation to OA.

Valorization of Baltic Sea farmed blue mussels: Chemical profiling and prebiotic potential for nutraceutical and functional food development

The severe eutrophication of the Baltic Sea requires mussel (Mytilus spp.) farming to remove nutrients, but farming in a low salinity environment results in smaller mussels that require value enhancement to be economically viable. This study evaluates the biomass valorisation of smaller Baltic mussels, focusing on the extraction of oil, protein and glycogen. It analyses the amino acid profiles, oil and fatty acid contents and glycogen levels of the mussels, as well as their prebiotic properties on beneficial gut bacteria. In addition, the study improves the extraction of bioactive compounds through enzymatic hydrolysis. Results indicate significant seasonal differences, with summer mussels having higher meat and lower ash content, and a rich content of essential fatty acids, particularly omega-3, and amino acids, underscoring the mussels' sustainability as a food source. The enzymatically treated biomass exhibited notable prebiotic activity, proposing health-promoting benefits. The study underscores the valorization of Baltic mussel biomass, highlighting its role in health, nutrition, and environmental sustainability.

The influence of pre‐exposure to marine heatwaves on the critical thermal maxima (CTmax) of marine foundation species

Abstract Marine foundation species underpin some of the world's most diverse ecosystems but they are increasingly threatened by intensification of marine heatwaves (MHWs). Where MHWs exceed critical thermal maxima (CTmax), increased mortality and population declines can occur. CTmax is increasingly used to assess MHW population vulnerability but studies estimating CTmax across species, range edges and thermal histories in a comparable manner remain lacking. We determined the impact of MHWs on subsequent CTmax estimates of matched cool/warm affinity pairs of marine foundation species (kelp, seagrass and bivalves) in the Western English Channel. Following a 4‐week MHW simulation, individuals were subjected to a CTmax trial, where temperatures were raised by 2°C day−1 until physiological end points were reached. We found no positive effect of MHWs on CTmax but clear negative impacts were observed for some groups of foundation species. Increased MHW intensity had a stepwise negative impact on the physiology of both warm (Laminaria ochroleuca) and cool water (L. digitata) kelp species that manifested in significant reductions in CTmax. Surprisingly, this was most marked in the warm water species, which runs opposite to the assumed safety of leading‐edge populations. The physiology of warm (Zostera noltii) and cool (Z. marina) seagrasses was negatively impacted by increasing MHW intensity but no significant decrease in CTmax was observed. Both bivalve species (Mytilus edulis and Magallana gigas) showed marked resistance to exposure to MHWs, which was unexpected given the observed vulnerability of these species to stressful summertime conditions. Our results show pre‐exposure to realistic MHWs can influence CTmax values but generalities are difficult to make across groups or based on assumed thermal safety margins. We show CTmax is a labile trait and exposure to MHWs, can erode the resilience of an individual or population to subsequent thermal challenges. This leaves uncertainty within frameworks built to understand where and when MHWs will be most impactful. Further experimentation across a wider range of species and thermal challenges is needed to better understand the dynamic nature of CTmax and field validation is needed to determine the responses of individuals and populations within complex natural systems. Read the free Plain Language Summary for this article on the Journal blog.

Efficient and reliable methods for estimating the abundance of keystone coastal macrofauna over large spatial scales.

Coastal bivalves are important ecosystem engineers, and identifying critical habitats can enhance conservation outcomes for threated keystone species as well as determining hotspots for invasive species. As early action is more efficient in both conservation and mitigation of species invasions, efficient and reliable tools for mapping and monitoring species over large scales are essential. We assessed the reliability and efficiency of towed video and quadrat sampling for estimating the abundance of three keystone macrofaunal bivalve species. To assess reliability, we compared the measured density based on each of the two methods to the "true" density estimated by manually surveying an entire transect. We found that both the video and quadrat method caused underestimation of the density of bivalves, but that the amount of underestimation was comparable, and further that both methods took substantially less time than surveying an entire transect manually. The video method underestimated the abundance of Pacific oysters (Magallana gigas), European flat oysters (Ostrea edulis), and blue mussels (Mytilus spp.) by 23%, 24%, and 16%, respectively. The causes of underestimation for the two oyster species were bivalves grouped in clusters, large amounts of small individuals, and generally higher abundances. While Mytilus spp. were underestimated overall, here observer experience was important, with inexperienced observers overestimating and experienced observers underestimating. Our study found both methods to be reliable and efficient for estimating the abundance of three keystone macrofaunal species, suggesting their potential applicability to other sessile or slow-moving species. We propose that these methods, due to their efficiency, can advance scientific knowledge and enhance conservation outcomes by establishing population baselines, assessing trends over time, and identifying and protecting critical habitats.

Are yessotoxins an emerging problem in Chile? Context and perspectives following the first report of YTX levels exceeding the regulatory limit in the Patagonian fjord system

In late summer and early autumn 2022, an intense bloom of Protoceratium reticulatum—the main yessotoxin (YTX) producer along Chilean coasts and a major threat to artisanal fisheries, the aquaculture industry, and environmental health—was recorded in the Patagonian fjord system. The high YTX levels (>3.75 mg kg−1) resulted in the first ban of shellfish collection in Chile. At Puyuhuapi Fjord, a global "hotspot" of harmful algal bloom events, the cell density of P. reticulatum determined in integrated tube samples (0–10 m) at the end of April 2022 reached 407,000 cells L−1. At the same time, YTX levels well exceeded the regulatory limit by roughly 2.5-fold, with concentrations as high as 9.42 mg kg−1 measured in native populations of the blue mussel Mytilus chilensis. Five different YTX analogues, 45-OH-YTX, COOH-45-keto-YTX, COOH-45-OH-YTX, COOH-YTX, and 45,55-diOH-YTX, were also detected in relevant amounts. While the ban lasted close to 3 months, accumulation and detoxification processes were monitored over a 1-year period. This study assessed the implications of high levels of YTXs and their analogues on the local economy and ecosystem health, given the increase in P. reticulatum blooms predicted for NW Patagonia in the context of a changing climate.

Metal concentrations in fish, crabs, and bivalve molluscs from marine waters adjacent to a multi-metals smelter and refinery

Metal concentrations were determined in tissues of finfish, crabs, and bivalve molluscs collected from marine waters near Port Pirie, South Australia, the site of a long-standing multi-metals smelter and refinery. A general trend of tissue metal concentrations in order of highest to lowest was observed in bivalves > crabs > finfish. A lead concentration of 158 ± 6.6 mg/kg (wet wt.) was observed in blue mussels (Mytilus galloprovincialis) sampled close to the smelter. Lead concentrations correlated positively with proximity to the smelter in all biota analysed. Similar relationships were observed for cadmium, copper, zinc and selenium in all biota except razorfish (Pinna bicolor; Bivalvia: Pinnidae), which showed no correlation with proximity to the smelter for these metals. Inorganic arsenic concentrations were below the limit of reporting in the majority of the analysed samples, however inorganic arsenic concentrations in blue swimmer crabs (Portunus armatus) and blue mussels correlated with proximity to the smelter. Mercury concentrations in the biota analysed were generally low and showed variable relationships with proximity to the smelter, with no significant correlation observed in finfish and razorfish, a significant positive correlation in blue mussels, and a significant negative correlation in blue swimmer crabs. This is the first major study of metal concentrations in recreationally-targeted marine species near Port Pirie species for more than two decades. Comparison with data from previous studies conducted shows little change in tissue metal concentrations in marine biota near Port Pirie over the past 40 years.

Under the cover of ice: Trematode infections affect survival and growth of wintering mussels

Parasites play many regulating roles that are increasingly recognized in different ecosystems. In coastal ecosystems, the trematode Himasthla elongata infects blue mussel Mytilus edulis, a foundation species that shapes the functioning of intertidal communities. Although the largest impacts of infections occur during the summer months, the parasites form long-lived cysts that can be harmful to their host mussels under winter conditions. Here, we experimentally show that even moderate levels of infection by H. elongata have a detrimental effect on the survival and growth rate of wintering blue mussels. These parasite-induced costs during winter may potentially affect populations of blue mussels in coastal habitats, with ramifications for the whole ecosystem.

The genome sequence of the blue mussel, Mytilus edulis Linnaeus, 1758

We present a genome assembly from an individual Mytilus edulis (the blue mussel; Mollusca; Bivalvia; Mytilida; Mytilidae). The genome sequence is 1,368.4 megabases in span. Most of the assembly is scaffolded into 14 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.75 kilobases in length.

Predicting key ectotherm population mortality in response to dynamic marine heatwaves: A Bayesian‐enhanced thermal tolerance landscape approach

Abstract As climate change intensifies heatwaves, quantifying associated mortality within ectothermic populations is crucial for effective conservation. Thermal tolerance landscape (TTL) models are useful predictive tools that assume exponentially decreasing survival durations in individuals with increasing temperatures. This assumption has been validated through regression analyses on data from constant temperature experiments, primarily focusing on adult‐stage individuals. However, this approach does not allow for direct model validation with data from dynamic, real‐world heatwave events and overlooks early recruitment stage vulnerabilities. This study aimed to address these gaps using the blue mussel Mytilus, a foundation species forming extensive reefs along temperate coasts, as a model organism. We monitored survival rates of mussels (juveniles and adults) under constant heatwave (CHW) conditions in a laboratory experiment and under dynamic heatwave (DHW) scenarios simulated in an outdoor mesocosm experiment. Post‐heatwaves, we also assessed recruitment rates within the mesocosms. TTL models were parametrised by employing Approximate Bayesian Computation with Sequential Monte Carlo (ABC‐SMC) on each dataset separately. The parameter distributions were similar across both experiments, and the ABC‐SMC model predictions closely matched the observed survival declines, validating these models. In comparison, we found a lower predictive performance when using a Bayesian regression approach. Additionally, our best‐fit model predicted that warming across the non‐fatal DHW regimes would increase sublethal effects on mussels. The observed impact on the recruitment stage was more pronounced, with the recruitment rate following an exponential decay as sublethal effects increased. Our model projected minor (<4%) sublethal effects in adult mussels during the century's five warmest summer temperature regimes, corresponding to 0%–32% declines in recruitment rates. Our research extends the TTL model validation, demonstrates the resilience of subtidal Baltic Mytilus to future extreme heatwaves and offers an approach to predict heatwave‐induced population mortalities, applicable to other species and sensitive systems. Read the free Plain Language Summary for this article on the Journal blog.

Shellfish CO2 excretion is modulated by seawater carbonate chemistry but largely independent of pCO2.

Four species of shellfish, blue mussel (Mytilus galloprovincialis), Pacific abalone (Haliotis discus hannai), zhikong scallops (Chlamys farreri), and Pacific oyster (Crassostrea gigas), were exposed to decoupled carbonate system variables to investigate the impacts of different seawater carbonate parameters on the CO2 excretion process of mariculture shellfish. Six experimental groups with two levels of seawater pH (pH 8.1 and pH 7.7) and three levels of total alkalinity (TA = 1000, 2300, and 3600μmol/kg, respectively) were established, while pH 8.1 and TA = 2300μmol/kg was taken as control. Results showed that the CO2 excretion rates of these tested shellfish were significantly affected by the change in carbonate chemistry (P < 0.05). At the same TA level, animals incubated in the acidified group (pH 7.7) had a lower CO2 excretion rate than those in the control group (pH 8.1). In comparison, at the same pH level, the CO2 excretion rate increased when seawater TA level was elevated. No significant correlation between the CO2 excretion rate and seawater pCO2 levels (P > 0.05) was found; however, a significant correlation (P < 0.05) between CO2 excretion rate and TA-DIC (the difference between total alkalinity and dissolved inorganic carbon) was observed. Blue mussel has a significantly higher CO2 excretion rate than the other three species in the CO2 excretions per unit mass of soft parts, with no significant difference observed among these three species. However, in terms of CO2 excretion rate per unit mass of gills, abalone has the highest CO2 excretion rate, while significant differences were found between each species. Our studies indicate that the CO2 buffering capacity impacts the CO2 excretion rate of four shellfish species largely independent of pCO2. Since CO2 excretion is related to acid-base balancing, the results imply that the effects of other carbonate parameters, particularly the CO2 buffering capacity, should be studied to fully understand the mechanism of how acidification affects shellfish. Besides, the species difference in gill to soft parts proportion may contribute to the species difference in responding to ocean acidification.

Alexandrium catenella (Group I) Causes Higher and Faster Toxicity Than A. pacificum (Group IV) in Mytilus eduis

Consuming poisoned shellfish can lead to severe health problems and even death. Alexandrium catenella (Group I) and A. pacificum (Group IV) cause paralytic shellfish poisoning (PSP) in Korea, and PSP is detected more in a wider area. However, the association between toxic dinoflagellates and shellfish poisoning is unclear. Therefore, it is necessary to understand the toxicity, detoxification, and compositional differences in PSP in Mytilus edulis exposed to PSP caused by A. catenella and A. pacificum. High-performance liquid chromatography with post-column oxidation was used to analyze PSP toxicity in poisoned M. edulis. PSP in M. edulis increased as the A. catenella and A. pacificum cell density increased. However, the cell density of A. catenella peaked faster than that of A. pacificum, and a high level of toxicity was detected. In the detoxification experiment, PSP in M. edulis decreased rapidly within 24 h in filtered seawater. However, PSP was continuously detected without decreasing below the detection limit until the last day of the experiment. In addition, the carbamate composition (GTX1+4) was detected as the main toxic composition in poisoned M. edulis, unlike in vegetative cells. GTX1+4 can poison shellfish quickly when toxic dinoflagellates appear in the marine environment. However, poisoned shellfish take a long time to be completely detoxified. Moreover, if shellfish continuously feed on poisonous dinoflagellates, their toxicity can increase rapidly due to biotransformation. Our results can help identify the mechanisms of shellfish toxicity and detoxification after PSP caused by toxic dinoflagellates.

Modelling and mapping carbon capture potential of farmed blue mussels in the Baltic Sea region

This study applies a regional Dynamic Energy Budget (DEB) model, enhanced to include biocalcification processes, to evaluate the carbon capture potential of farmed blue mussels (Mytilus edulis/trossulus) in the Baltic Sea. The research emphasises the long-term capture of carbon associated with shell formation, crucial for mitigating global warming effects. The model was built using a comprehensive pan-Baltic dataset that includes information on mussel growth, filtration and biodeposition rates, and nutrient content. The study also examined salinity, temperature, and chlorophyll a as key environmental factors influencing carbon capture in farmed mussels. Our findings revealed significant spatial and temporal variability in carbon dynamics under current and future environmental conditions. The tested future predictions are grounded in current scientific understanding and projections of climate change effects on the Baltic Sea. Notably, the outer Baltic Sea subbasins exhibited the highest carbon capture capacity with an average of 55 t (in the present scenario) and 65 t (under future environmental conditions) of carbon sequestrated per farm (0.25 ha) over a cultivation cycle – 17 months. Salinity was the main driver of predicted regional changes in carbon capture, while temperature and chlorophyll a had more pronounced local effects. This research advances our understanding of the role low trophic aquaculture plays in mitigating climate change. It highlights the importance of developing location-specific strategies for mussel farming that consider both local and regional environmental conditions. The results contribute to the wider discourse on sustainable aquaculture development and environmental conservation.

Effects of mussel-phytoplankton interactions on the aquatic environment

A five-day in situ experiment was conducted in plastic enclosures to investigate the effects of different densities of the mussel Mytilus edulis, and sampling time on water variables, and phytoplankton community structure in Sanggou Bay (Shandong, China). The tested mussel densities were low (LD300: 300 g/m3), medium (MD600: 600 g/m3), high (HD900: 900 g/m3), and sampling times were at 6:00 and 17:00 h. The water variables analyzed as indicators were pH, dissolved oxygen, nutrients, carbonate system, pCO2, and chlorophyll-a (Chl-a). The results showed that density and sampling time had highly significant effects on all water parameters and phytoplankton abundance, except for dissolved oxygen (P<0.01). At the same sampling time, pH, c[CO32-] and Chl-a concentrations in the water column of LD300 treatment were much higher than those of MD600 and HD900 treatments, while c[HCO3-], c[CO2] and pCO2 were significantly lower than those of MD600 and HD900 treatments (P<0.01). Phosphate was the main limiting nutrient for phytoplankton growth. Chl-a concentrations increased and then decreased significantly in LD300 and MD600 treatments, while it diminished continuously in HD900 treatment. The higher M. edulis density showed higher correlation with picophytoplankton abundance and Chl-a concentrations. Not only the phytoplankton structure was affected, but also the condition index of the HD900 treatment was significantly reduced (P<0.05). The present study showed LD300 and MD600 treatments significantly promoted the growth of picophytoplankton. The selective filtration of M. edulis for microphytoplankton and nanophytoplankton were much higher than those for picophytoplankton. The combined decrease in competitors (micro- and nanophytoplankton) led to a substantial increase of picophytoplankton abundance in shellfish farming areas. The interactions between mussel and phytoplankton significantly affected the water environment. However, well designed integrated shellfish and algae aquaculture might mitigate the adverse impacts.

Reproductive investment and gonad development in triploid mussels, Mytilus Edulis

The production of triploid bivalves has elicited great interest because their reproductive investment is known to be lower than that of diploids. Reduced reproductive investment is expected to improve the survival and growth of triploid bivalves compared to diploids as the energy spared from reproduction could be used for other metabolic needs. However, the reduction of triploid fertility varies among species, therefore, its impacts on survival and growth are variable. In this study, we compared the reproductive investment of diploid and triploid mussels between two age and size groups (1-year-old ˂ 30 mm, and 2-years-old ˃ 50 mm). We measured gonadosomatic index (GSI), gonad volume fraction (GVF), gonad maturation, and sex ratio. Results demonstrated that while triploid mussels do invest part of their energy in reproduction, they had lower GSI and GVF than diploids. In all tested groups, triploid gonads were less mature than those of diploids, and their sex ratio was significantly altered, with the absence of female triploids. Furthermore, triploid gonads showed signs of gamete resorption, suggesting that the gametes of triploid mussels could serve as energy reserves. This study reveals that triploid mussels invest less energy in reproduction which suggests that the spared energy could be used to improve other metabolic need and survival. We conclude that triploid mussels could be of great interest for aquaculture because they may have better resistance to post-spawning weakness and better recovery due to gametes resorption.

Technical specifications for a EU-wide baseline survey of antimicrobial resistance in bacteria from aquaculture animals.

The European Commission requested scientific and technical assistance in the preparation of a EU-wide baseline survey of antimicrobial resistance (AMR) in bacteria from aquaculture animals. It is recommended that the survey would aim at estimating the occurrence of AMR in Aeromonas spp. isolated from Atlantic Salmon (Salmo salar), European seabass (Dicentrarchus labrax) and trout (Salmo trutta, Salvelinus fontinalis, Oncorhynchus mykiss) intended to consumption, at harvesting (at farm/slaughter), at the EU level and in addition, at estimating the occurrence and diversity of AMR of Escherichia coli, Enterococcus faecium, Enterococcus faecalis, Vibrio parahaemolyticus and Vibrio alginolyticus in blue mussel (Mytilus edulis) and Mediterranean mussel (Mytilus galloprovincialis) from production areas and at dispatch centres at the EU level. These technical specifications define the target populations, the sample size for the survey, sample collection requirements, the analytical methods (for isolation, identification, phenotypic susceptibility testing and further genotypic analysis of some of the bacteria targeted) and the data reporting requirements. The data to be reported by the EU Member States to support this baseline survey are presented in three data models. The results of the survey should be reported using the EFSA reporting system.

Body Size Influence on Respiration Rate and Mitochondrial Metrics in Mytilus edulis L. Gill Tissue

Body Size Influence on Respiration Rate and Mitochondrial Metrics in Mytilus edulis L. Gill Tissue

Semibalanus balanoides (L.) and Balanus crenatus Bruguière (Balanidae) Are Intermediate Hosts of Fimbriarioides intermedia (Fuhrmann, 1913) and Two Species of the Genus Microsomacanthus (Cestoda: Hymenolepidae), Parasites of Sea Ducks from the Atlantic Sector of the Arctic and Northern Pacific.

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.

Wave of mutilation: Scavenging hermit crabs use social information to locate carcasses

AbstractCarcasses 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.

Mimicking Mytilus edulis foot protein: A versatile strategy for robust biomedical coatings

Universal coatings with versatile surface adhesion, good mechanochemical robustness, and the capacity for secondary modification are of great scientific interest. However, incorporating these advantages into a system is still a great challenge. Here, we report a series of catechol-decorated polyallylamines (CPAs), denoted as pseudo-Mytilus edulis foot protein 5 (pseudo-Mefp-5), that mimic not only the catechol and amine groups but also the backbone of Mefp-5. CPAs can fabricate highly adhesive, robust, multifunctional polyCPA (PCPA) coatings based on synergetic catechol-polyamine chemistry as universal building blocks. Due to the interpenetrating entangled network architectures, these coatings exhibit high chemical robustness against harsh conditions (HCl, pH 1; NaOH, pH 14; H2O2, 30%), good mechanical robustness, and wear resistance. In addition, PCPA coatings provide abundant grafting sites, enabling the fabrication of various functional surfaces through secondary modification. Furthermore, the versatility, multifaceted robustness, and scalability of PCPA coatings indicate their great potential for surface engineering, especially for withstanding harsh conditions in multipurpose biomedical applications.