Mya Arenaria Research Articles

Mya arenaria

This datasheet on Mya arenaria covers Identity, Distribution.

Two branchial pathological conditions, nuclear hypertrophy and abnormal epithelial proliferation, in Mya arenaria from northwest Russian coasts.

Histopathological analysis of soft-shell clams Mya arenaria collected from 2 northwest Russian locations disclosed high prevalence of 2 pathological gill conditions. One involved the occurrence of more or less extended gill areas in which the branchial filaments showed hyperchromatic (basophilic) epithelium with some hypertrophied nuclei, which were considered presumptive signs of viral infection. Another pathological condition involved abnormal proliferation of the branchial epithelium, which lost the main differential features of the normal branchial epithelium (ciliated and simple cell layer structure), becoming non-ciliated, pseudostratified or stratified hyperchromatic epithelium with abundant mitotic figures and frequent apoptotic cells. The most complex cases involved loss of the normal branchial filament architecture, which was replaced with tumour-like growths consisting of branching, convoluted epithelial projections with a connective stroma. Images suggesting migration (invasion) of cells from the abnormally proliferating epithelium to the subjacent connective tissue, which would involve malignancy, were observed in one individual. The occurrence of both pathological conditions in clams from both locations and their co-occurrence in one clam suggest the possibility of a common, possibly viral, aetiology. Furthermore, the high prevalence of the abnormal proliferative disorder in non-polluted areas suggests an infectious aetiology. Additional studies are needed to assess a viral aetiology for the nuclear hypertrophy and/or the abnormal epithelial proliferation as well as the malignancy of the latter condition.

Eco-valorification of marine shells by hydrothermal conversion in alkaline media

Marine shells are a natural, cheap, abundant and renewable resource, which can be used to produce useful materials, such as for the construction industry. The present study focuses on the transformation of Mya arenaria exoskeletons from the Black Sea into calcium hydroxide by using low-temperature hydrothermal synthesis. In contrast with other methods, this energy-saving process does not involve calcination of shells prior to the hydrothermal treatment. XRD results show the formation of calcium hydroxide with preferential orientation and interesting atypical morphology, which is strongly influenced by the composition of the reaction medium.

Industrialization and food safety for the Tsleil-Waututh Nation: An analysis of chemical levels in shellfish in Burrard Inlet

While Indigenous food systems remain critical for community well-being, traditionally harvested foods are a potential source of toxic exposures. The Tsleil-Waututh Nation (TWN) is seeking to restore shellfish harvesting in Burrard Inlet (British Columbia [BC], Canada), where the cumulative effects of industrial activity have nearly eliminated safe harvesting. The Trans Mountain Expansion project would triple the capacity to transport oil through the inlet, threatening TWN's progress to restore shellfish harvesting. To inform ongoing efforts we assessed contamination by heavy metals (arsenic, cadmium, lead, and mercury) and 48 polycyclic aromatic hydrocarbons (PAHs) congeners in different shellfish species (Softshell clams, Varnish clams, and Dungeness crab) in three areas. We compared our results against local screening values (SVs) established by the TWN and BC Ministry of Environment and Climate Change Strategy, as well as provincial and national benchmarks. In total, we analyzed 18 composite samples of Softshell clams and Varnish clams (5 individuals per sample), as well as 17 individual crabs. We found chemical contamination in all species at all sites. PAHs were most frequently detected in Softshell clams, highest in the site closest to the pipeline terminus. Clams presented higher levels of contamination than crabs for PAHs, but not for heavy metals. For Softshell and Varnish clams, all heavy metals across study sites exceeded at least one of the population-specific SVs. Of the 14 PAHs detected, benzo(a)pyrene presented a median concentration in Softshell clams of 3.25 μ/kg, exceeding local SV for subsistence fisher. Our results call for further assessment of human health impacts related to food harvesting within Burrard Inlet and establishing a long-term coordinated program co-led by the TWN to monitor contamination and inform future harvesting programs. The study draws attention to the need to consider locally-relevant toxicity benchmarks, and include potential health impacts of food contamination in appraising development project proposals.

Comparative phylotranscriptomics reveals putative sex differentiating genes across eight diverse bivalve species

Mollusks, especially bivalves, exhibit a great diversity of sex determining mechanisms, including both genetic and environmental sex determination. Some bivalve species can be gonochoristic (separate sexes), while others are hermaphroditic (sequential or simultaneous). Several models have been proposed for specific bivalve species, utilizing information gained from gene expression data, as well as limited RAD-seq data (e.g., from Crassostrea gigas). However, these mechanisms are not as well studied as those in model organisms (e.g., Mus musculus, Drosophila melanogaster, Caenorhabditis elegans) and many genes involved in sex differentiation are not well characterized. We used phylotranscriptomics to better understand which possible sex differentiating genes are in bivalves and how these genes relate to similar genes in diverse phyla. We collected RNAseq data from eight phylogenetically diverse bivalve species: Argopecten irradians, Ensis directus, Geukensia demissa, Macoma tenta, Mercenaria mercenaria, Mya arenaria, Mytilus edulis, and Solemya velum. Using these data, we assembled representative transcriptomes for each species. We then searched for candidate sex differentiating genes using BLAST and confirmed the identity of nine genes using phylogenetics analyses from nine phyla. To increase the confidence of identification, we included ten bivalve genomes in our analyses. From the analysis of doublesex and mab-3 related transcription factor (DMRT) genes, we confirmed the identify of a Mollusk-specific sex determining DMRT gene: DMRT1L. Based on gene expression data from M. edulis and previous research, DMRT1L and FoxL2 are key genes for male and female development, respectively.

Linear growth and yield of bivalve mollusks Mya Arenaria linnaeus, 1758 in the conditions of the littoral of the barents and white seas

Mya arenaria are large bivalve mollusks burrowing into the ground. Mollusks are widespread in the northern hemisphere. The growth patterns of M. arenaria were studied in the arctic part of the species’ geographic range. As a result of the research, it was revealed that the mollusks from the Severnaya Inlet of the Kandalaksha Bay of the White Sea have the highest growth rate. The limiting shell length is L∞=174.7 mm, and the rate of growth retardation is k=0.0518 year–1. The mollusks from the Yarnishnaya Inlet of the Barents Sea have the lowest growth rates L∞=84.27 mm, and the rate of growth retardation is k=0.0721 year-1. A positive correlation was found between the nature of the soil and the limiting shell length of mollusks (r = 0.94).

The silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams

Contaminants are ubiquitous in the environment, often reaching aquatic systems. Combinations of forestry use pesticides have been detected in both water and aquatic organism tissue samples in coastal systems. Yet, most toxicological studies focus on the effects of these pesticides individually, at high doses, and over acute time periods, which, while key for establishing toxicity and safe limits, are rarely environmentally realistic. We examined chronic (90 days) exposure by the soft-shell clam, Mya arenaria, to environmentally relevant concentrations of four pesticides registered for use in forestry (atrazine, 5 μg/L; hexazinone, 0.3 μg/L; indaziflam, 5 μg/L; and bifenthrin, 1.5 μg/g organic carbon (OC)). Pesticides were tested individually and in combination, except bifenthrin, which was tested only in combination with the other three. We measured shell growth and condition index every 30 days, as well as feeding rates, mortality, and chemical concentrations in tissue from a subset of clams at the end of the experiment to measure contaminant uptake. Indaziflam caused a high mortality rate (max. 36%), followed by atrazine (max. 27%), both individually as well as in combination with other pesticides. Additionally, indaziflam concentrations in tissue (61.70–152.56 ng/g) were higher than those of atrazine (26.48–48.56 ng/g), despite equal dosing concentrations, indicating higher tissue accumulation. Furthermore, clams exposed to indaziflam and hexazinone experienced reduced condition index and clearance rates individually and in combination with other compounds; however, the two combined did not result in significant mortality. These two compounds, even at environmentally relevant concentrations, affected a non-target organism and, in the case of the herbicide indaziflam, accumulated in clam tissue and appeared more toxic than other tested pesticides. These findings underscore the need for more comprehensive studies combining multiple compounds at relevant concentrations to understand their impacts on aquatic ecosystems.

Salad with Clams: Prey Choice of an Intentionally Carnivorous Turtle

Prey choice is the non-random foraging and consumption of prey species by their predators, and is therefore the basis for studies of topics as diverse as quantifying food webs, predator–prey relationships, and optimal-foraging models. Malaclemys terrapin (Diamond-back Terrapin) is a diet generalist with a large geographic distribution: the US Atlantic and Gulf coasts from Massachusetts to Texas. Individual terrapins have relatively small home ranges and feed primarily on local mollusc species. In feeding trials with 1 prey species and 2 prey species, wild-caught terrapins from New York readily consumed Mya arenaria (Soft-shelled Clam) and Geukensia demissa (Atlantic Ribbed Mussel), preferring them over a wide range of other prey species commonly eaten by terrapins at other sites. Our correlation test indicated that Ulva latuca (Sea Lettuce), common in the diets of this population, is ingested incidentally when terrapins forage for Soft-shelled Clams. The impact of consumption of algae by this primarily molluscivorous turtle is unexplored, but could have important impacts on their energy balance and contaminant intake.

SPECIFIC MICROBIOLOGY SPECTRUM OF WHITE SAND MUSSELS FROM KEY SAMPLE SPOTS FROM BULGARIAN BLACK SEA AQUATORY

The "white sand mussels" are edible bivalves inhabiting the littoral shores usually buried in the sand. Тhey are invasive species for the Bulgarian waters of the Black Sea. The samples for this study were collected from different points on the northern and southern Black Sea Bulgarian coast in the period January 2020 to December 2020. The study of different types of microorganisms was performed by using the microbial identification system model: MicroLog M® BIO45101 BiologInc and the software product GEN III. The physic-chemical parameters of the waters – temperature, pH, salinity and dissolved O2 were also determined. In the different species, we had detected specific microbiological complexes. The species Pseudomonas viridilivida and Citrobacter farmer were isolated only from Donax trunculus. The species Escherichia hermannii was found only in Mya arenaria, and Acinetobacter johnsonii was detected only in Chamelea gallina. The isolated species Acinetobacter gyllenbergii and Acinetobacter johnsonii are related to humans and are indicators for pollution of the water with channel waste waters. Our results demonstrated an increase ofhe quantity of the coliforms the region of Sveti Vlas from August, where they were 50 the norms. In the region of Arkutino in July and Ahtopol in August, the quantity of the fecal coliforms is 190 and 30 times the norms prescribed in the Ordinanceo. 4 from 20.10.2000 for the quality of fisheries water and the breeding of shellfish (the amount of fecal coliforms in the inter-shell content should be less than 300 NVB). We noticed also seriousollution of the Varna lake even months after an accident with a leaky pipe.

Продукционные характеристики поселений двустворчатого моллюска Mya arenaria Linne, 1758 Баренцева моря

The linear growth equations and production for bivalve Mya arenaria (Linne, 1758) in the intertidal zone Yarnyshnaya and Zelenetskaya bays of Barents Sea are represented. Our studies have shown that length of the shell Mya reached 26.3–62.5 mm, the highest age was 11 years. Indicators of the growth rate of mollusks from Zelenetskaya Bay are significantly higher than those of mollusks from Yarnyshnaya Bay. Linear growth is described by the Bertalanfi equations: Lt = 84.27 [1–e–0.0721 (t–0.1244)] – for mollusks from Yarnyshnaya Bay, Lt = 118.49 [1–e–0.0566 (t–0.2744)] – for mollusks from Zelenetskaya Bay. Production in the intertidal zone of the Yarnyshnaya Bay was lower (44.8 g/m2 with a biomass of 330 g/m2) than in the intertidal zone of the Zelenetskaya Bay (90.5 g/m2, with a biomass of 258 g/m2). The P/V-value is the coefficient of 0.14 and 0.35, respectively.

Using a Stakeholder-Engaged Approach to Understand and Address Bacterial Transport on Soft-Shell Clam Flats

Using a Stakeholder-Engaged Approach to Understand and Address Bacterial Transport on Soft-Shell Clam Flats

The truncate soft-shell clam,Mya truncata, as a biomonitor of municipal wastewater exposure and historical anthropogenic impacts in the Canadian Arctic

Municipal wastewater is a large source of pollution to Canadian waters, yet its effects on Arctic marine ecosystems remains relatively unknown. We characterized the impacts of municipal wastewater from a growing northern community, Iqaluit, Nunavut, on the Arctic truncate soft-shell clam, Mya truncata. Clams were sampled from six locations that varied in proximity to the wastewater treatment plant, and shell biogeochemical analysis revealed that clams nearest the wastewater treatment plant had slower growth rates, lower carbon and oxygen stable isotope ratios, and elevated concentrations of copper and lead. A parallel analysis on mRNA expression profiles characterized M. truncata’s physiological response to wastewater effluent. Clams nearest the wastewater treatment plant had significantly lower mRNA expression of genes associated with metabolism, antioxidants, molecular chaperones, and phase I and II detoxification, but had heightened mRNA expression in genes coding for enzymes that bind and remove contaminants. These results demonstrated a biological response to Iqaluit’s wastewater effluent and highlight M. truncata’s potential to act as a biomonitor of municipal wastewater along Arctic coastlines in Canada.

Bivalve Mya arenaria L. as a model object in demecology: dynamics of bed structure, mortality and growth in the Kandalaksha Bay of the White Sea

Bivalve Mya arenaria L. as a model object in demecology: dynamics of bed structure, mortality and growth in the Kandalaksha Bay of the White Sea

Long-Term Trends in the Occurrence of Disseminated Neoplasia in a Population of Mya arenaria (Softshell Clam) from a New Hampshire Estuary

Mya arenaria (Softshell Clam) is an important recreational and commercial bivalve in coastal New England, the mid-Atlantic, and elsewhere. The Softshell Clam is a filter feeder that provides a trophic link between planktonic food items and benthic predators. We quantified annual trends of disseminated neoplasia in Softshell Clams in the Hampton–Seabrook estuary in New Hampshire using logistic regression from 3975 individuals collected from 2002 to 2018. There was a negative trend in the incidence of Softshell Clams with non-detectable amounts of neoplastic cells, there was no significant trend in the incidence of stage 1 neoplasia (1–25% neoplastic cells), positive trends in the incidences of stages 2 and 3 (26–50% and 51–75% neoplastic cells), and no significant trends in incidence of stage 4 (76–100% neoplastic cells). The significant changes in neoplasia development suggest that the incidence of the disease is increasing. The lack of a significant trend in the terminal stage 4 neoplasia may be due to the short duration of this stage prior to death. Probabilities of acquiring stages 2 and 3 neoplasia in 2018 were 0.19 and 0.12, respectively. The mean length of Softshell Clams with stage 4 neoplasia was 66.7 mm (min–max = 53.2–78.1 mm), which indicates that terminal neoplasia occurs primarily in reproductive adults. The presence of advanced stages of the disease in sexually mature individuals can reduce the reproductive potential of that population.

Exploring Biophysical Linkages between Coastal Forestry Management Practices and Aquatic Bivalve Contaminant Exposure.

Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, yet non-point source pollution is difficult to trace and quantify. In Oregon, U.S.A., state and federal forestry pesticide regulations, designed to meet regulatory water quality requirements, differ in buffer size and pesticide applications. We deployed passive water samplers and collected riverine and estuarine bivalves Margaritifera falcata, Mya arenaria, and Crassostrea gigas from Oregon Coast watersheds to examine forestry-specific pesticide contamination. We used non-metric multidimensional scaling and regression to relate concentrations and types of pesticide contamination across watersheds to ownership and management metrics. In bivalve samples collected from eight coastal watersheds, we measured twelve unique pesticides (two herbicides; three fungicides; and seven insecticides). Pesticides were detected in 38% of bivalve samples; and frequency and maximum concentrations varied by season, species, and watershed with indaziflam (herbicide) the only current-use forestry pesticide detected. Using passive water samplers, we measured four current-use herbicides corresponding with planned herbicide applications; hexazinone and atrazine were most frequently detected. Details about types and levels of exposure provide insight into effectiveness of current forest management practices in controlling transport of forest-use pesticides.

Comparative evidence for harvesting-driven enhancement of clam beds in northeastern New Brunswick, Canada

Populations of infaunal clams can be affected by natural and anthropogenic factors. Two such factors include sediment porewater pH and clam harvesting. To date, however, the potential effects of clam harvesting on sediment pH conditions and corresponding clam densities remain understudied. To fill this knowledge gap, we sampled sediment pH conditions and the densities of three clam species (Mya arenaria spat, and all life stages of Macoma balthica and Gemma gemma) in harvested and non-harvested areas at two sites (Miramichi and Point aux Carr) in eastern New Brunswick, Canada. Within sites, sediment pH conditions were higher within harvested areas and correlated with significantly higher clam densities compared to non-harvested areas. Between sites, clam abundances were significantly higher at the site with lower pH conditions, suggesting that reduced clam densities associated with low sediment pH may be restricted to small spatial scales in this region. These results add to a growing body of literature suggesting that, under certain contexts, commercial clam harvesting may enhance habitat suitability and benefit some clam populations. The ways in which commercial clam harvesting affects habitat suitability and clam densities under a wide range of ecological and anthropogenic conditions warrant future investigation.

Effects of variable oxygen regimes on mitochondrial bioenergetics and reactive oxygen species production in a marine bivalve, Mya arenaria.

Estuarine and coastal benthic organisms often experience fluctuations in oxygen levels that can negatively impact their mitochondrial function and aerobic metabolism. To study these impacts, we exposed a common sediment-dwelling bivalve, the soft-shell clam Mya arenaria, for 21 days to chronic hypoxia (PO2 ∼4.1 kPa), cyclic hypoxia (PO2 ∼12.7-1.9 kPa, mean 5.7 kPa) or normoxia (PO2 ∼21.1 kPa). pH was manipulated to mimic the covariation in CO2/pH and oxygen levels in coastal hypoxic zones. Mitochondrial respiration, including proton leak, the capacity for oxidative phosphorylation (OXPHOS), the maximum activity of the electron transport system (ETS), reactive oxygen species (ROS) production, and activity and oxygen affinity of cytochrome c oxidase (CCO) were assessed. Acclimation to constant hypoxia did not affect the studied mitochondrial traits except for a modest decrease in the OXPHOS coupling efficiency. Cyclic hypoxia had no effect on OXPHOS or ETS capacity, but increased proton leak and lowered mitochondrial OXPHOS coupling efficiency. Furthermore, mitochondria of clams acclimated to cyclic hypoxia had higher rates of ROS generation compared with the clams acclimated to normoxia or chronic hypoxia. CCO activity was upregulated under cyclic hypoxia, but oxygen affinity of CCO did not change. These findings indicate that long-term cyclic hypoxia has a stronger impact on the mitochondria of M. arenaria than chronic hypoxia and might lead to impaired ATP synthesis, higher costs of mitochondrial maintenance and oxidative stress. These changes might negatively affect populations of M. arenaria in the coastal Baltic Sea under increasing hypoxia pressure.

The patterns of elemental concentration (Ca, Na, Sr, Mg, Mn, Ba, Cu, Pb, V, Y, U and Cd) in shells of invertebrates representing different CaCO<sub>3</sub> polymorphs: a case study from the brackish Gulf of Gdańsk (the Baltic Sea)

Abstract. The shells of calcitic arthropod Amphibalanus improvisus; aragonitic bivalves Cerastoderma glaucum, Limecola balthica, and Mya arenaria; and bimineralic bivalve Mytilus trossulus were collected in the brackish waters of the southern Baltic Sea in order to study patterns of bulk elemental concentration (Ca, Na, Sr, Mg, Ba, Mn, Cu, Pb, V, Y, U and Cd) in shells composed of different crystal lattices (calcite and aragonite). The factors controlling the elemental composition of shells are discussed in the context of crystal lattice properties, size classes of organisms and potential environmental differences between locations. Clams that precipitate fully aragonitic shells have a clear predominance of Sr over Mg in shells, contrary to predominant accumulation of Mg over Sr in calcitic shells of barnacles. However, the barnacle calcite shell contains higher Sr concentration than bivalve aragonite. The elemental variability between size-grouped shells is different for each studied species, and the elemental concentrations tend to be lower in the large size classes compared to the smaller size classes. Biological differences between and within species, such as growth rate, feeding strategy (including feeding rate and assimilation efficiency or composition) and contribution of organic material, seem to be important factors determining the elemental accumulation in shells. Because specimens used in this study were obtained from different sampling sites within the gulf, the impact of location-specific environmental factors, such as sediment type, cannot be excluded.

Gill epithelial cell nuclear virus disease is prevalent and widespread in Mya arenaria clams of Chesapeake Bay, USA.

Several historic investigations have reported intranuclear virus infections of Mya arenaria soft-shell clams from the Atlantic coast of North America, but their descriptive details are limited. Among numerous multi-clam samples of Chesapeake Bay M. arenaria that were analyzed histopathologically during clam population surveys from 2000-2009, virus replication apparently caused extreme hypertrophy among the infected nuclei of gill epithelial cells. Infected cells were often abundant within the gill epithelia of affected clams, where their nuclear abnormalities suggested compromised genetic controls of critical cellular physiological functions. Infection prevalences were generally elevated, reaching 90% in 25% of samples. A grand mean prevalence of 67% resulted for all (69) M. arenaria samples of the decadal investigation, which included 1934 individual clams. Infected nuclei of gill epithelial cells were microscopically conspicuous by their extreme hypertrophic diameters of 10 µm or more and their prominent DNA-inclusion bodies. Cells with abnormal, hypertrophic nuclei were often abundant in the epithelia of M. arenaria gills. Transmission electron microscopy revealed abundant, replicating, icosahedral viral particles of 65-85 nm diameter within such hypertrophic nuclei. Viruses frequently occurred in paracrystalline nuclear arrays, showed granular internal contents, and had radial structures that suggested capsid surface ornamentation. Normal heterochromatin of infected nuclei appeared emarginated by dense central masses of replicating virions. Large, electron-dense DNA inclusion bodies routinely occurred at the internal margins of virus-infected nuclei. These may be virus replication centers based on their ultrastructural features and close proximity to replicated viral particles.

Comparative Field Trials to Examine the Efficacy of a Traditional Management Tool—Brushing—To Enhance Local Densities of 0-Y Class Recruits in the Soft Shell Clam Mya arenaria L. Fishery in Maine, USA

The intertidal soft-shell clam Mya arenaria fishery in Maine is comanaged under a cooperative agreement, or shellfish ordinance, between coastal communities and the state. The ordinance, among other things, defines conservation tools that encourage communities to engage in activities with a goal to enhance local densities of 0-y class individuals of this infaunal bivalve. One method used by communities for over 75 y is referred to as “brushing,” which involves forcing dozens of the recently cut white spruce Picea glauca boughs (approximately 70 cm in length) vertically into the soft sediments of a mudflat so that 40–45 cm protrudes into the water column. Typically, multiple rows of boughs are deployed on flats in the spring before clam spawning where they remain through the fall after annual settlement and recruitment have ended. Brushing purportedly results in slowing down tidal currents and creating eddies that allow recently settled clams that otherwise are susceptible to bedload transport away from the flat to establish themselves in the vicinity of the boughs. During spring–fall 2019, a comparative field experiment was conducted at three intertidal flats within a 160-km stretch of the Maine Coast to test, for the first time, the efficacy of this traditional management tool versus another approach used to enhance local densities of 0-y class clams—predator-exclusion netting. At each flat, neither treatment enhanced densities when compared with controls of recruits of Mya as well as recruits of another commercially important infaunal bivalve that occurred at a single site, the northern quahog Mercenaria mercenaria. That is, neither bivalve responded positively to experimental additions of spruce boughs to soft sediments at any study site. Passive bivalve collectors demonstrated that both species settled into plots, ruling out recruitment limitation. Comparison of recruit densities between collectors and core samples from both brushed and netted plots demonstrated losses greater than 97% for Mya and greater than 93% for Mercenaria. Collectors also provided data on densities of recruits of the invasive green crab Carcinus maenas, which ranged from 1.2 to 13.9 ind. m–2 across sites, and were 3–6× more abundant in collectors within plots with brush or netting versus adjacent control plots, suggesting that this predator selects heterogeneous versus homogeneous environments during its early life history. As green crab populations in Maine vary directly with seawater temperatures, and the Gulf of Maine is warming relatively rapidly, adding potential habitat for green crabs, such as brush, to intertidal flats should be discontinued in favor of more effective methods to enhance local densities of 0-y class individuals.