Asian Green Mussel Perna Viridis Research Articles

Low-level ionizing radiation-induced DNA responses in the Asian green mussel Perna viridis

Cesium-137 (Cs-137) is a radioactive isotope present in marine environments due to the operation of nuclear power plants and weapons testing. Radiocesium poses a potential risk to marine life due to its long half-life and bioaccumulation. This study evaluated the genotoxicity of low doses of Cs-137 in the Asian green mussel Perna viridis, a sentinel species for marine pollution monitoring, by performing the comet assay and micronucleus test on hemolymph samples. Genotoxicity was assessed after exposing mussels to Cs-137 at dose rates of 0, 5, 10, and 15 μGy/h for 48 h. Cs-137's organ-specific distribution was also determined using HPGe gamma spectrometry. Even at low radiation doses, Cs-137 was found to exert genotoxic effects. Significant increases in DNA strand breaks (%Tail DNA) and micronucleus formation (MNF) were observed at all tested dose rates compared with the levels in controls, with dose-dependent responses. Cs-137 predominantly accumulated in the soft tissues, specifically the gills and digestive gland. The findings support the recommended safety level of 10 μGy/h for aquatic organisms, suggesting its appropriateness as a fundamental criterion for developing the national marine water quality standard for Cs-137 in Thailand.

Oxidative response to accumulation of trace metals in tissue of two bivalves, the Asian green mussel Perna viridis and the blood cockle Tegillarca granosa, living in Pattani Bay, Thailand.

Using bivalves to indicate aquatic pollutants was favorable for discerning the negative effects of high levels of metal accumulation in tissue. We investigated the correlation between trace metal accumulation and the tissue oxidative response of two bivalves. The Asian green mussel Perna viridis and the blood cockle Tegillarca granosa were sampled along with seawater and sediments from three locations around Pattani Bay, Thailand. Accumulation of nine trace metals (cadmium, cobalt, copper, chromium, nickel, manganese, iron, zinc, and lead) in seawater, sediments, and tissue and the oxidative tissue response were evaluated. Metal bioaccumulation factor, biota-sediment accumulation factor, and histopathology were also indicated. The present study found that P. viridis and T. granosa were macroconcentrators and bioaccumulative of cadmium, and their tissue accumulation of cadmium was strongly related to lipid peroxidation activation. Perna viridis exhibited a higher oxidative response than T. granosa, as indicated by malondialdehyde, catalase, and reduced glutathione levels. The present study indicated that P. viridis and T. granosa were macroconcentrators and bioaccumulative of cadmium, and their tissue accumulation of cadmium was strongly related to lipid peroxidation activation. Research has shown discernible negative effects of a high level of metal accumulation in tissue, and deformed and damaged tissues were present in the gills, digestive glands, intestines, and feet of P. viridis and T. granosa.

Horizon scanning for potentially invasive non-native marine species to inform trans-boundary conservation management – Example of the northern Gulf of Mexico

Prevention of non-native species introductions and establishment is essential to avoid adverse impacts of invasive species in marine environments. To identify potential new invasive species and inform non-native species management options for the northern Gulf of Mexico (Alabama, Mississippi, Louisiana, Texas), 138 marine species were risk screened for current and future climate conditions using the Aquatic Species Invasiveness Screening Kit. Species were risk-ranked as low, medium, high, and very high risk based on separate (calibrated) thresholds for fishes, tunicates, and invertebrates. In the basic screening, 15 fishes, two tunicates, and 26 invertebrates were classified as high or very high risk under current climate conditions. Whereas, under future climate conditions, 16 fishes, three tunicates, and 33 invertebrates were classified as high or very high risk. Very high risk species included: California scorpionfish Scorpaena guttata, red scorpionfish Scorpaena scrofa, purple whelk Rapana venosa, and Santo Domingo false mussel Mytilopsis sallei under both current and future climates, with weedy scorpionfish Rhinopias frondosa, Papuan scorpionfish Scorpaenopsis papuensis, daggertooth pike conger Muraenesox cinereus, yellowfin scorpionfish Scorpaenopsis neglecta, tassled scorpionfish Scorpaenopsis oxycephalus, brush-clawed shore crab Hemigrapsus takanoi, honeycomb oyster Hyotissa hyotis, carinate rock shell Indothais lacera, and Asian green mussel Perna viridis under climate change conditions only. This study provides evidence to inform trans-boundary management plans across the five Gulf of Mexico states to prevent, detect, and respond rapidly to new species arrivals.

Range extension of the Asian green mussel Perna viridis (Linnaeus, 1758) into a Marine Extractive Reserve in Brazil

Range extension of the Asian green mussel Perna viridis (Linnaeus, 1758) into a Marine Extractive Reserve in Brazil

Effect of environmental variables on the growth of Asian green mussel Perna viridis (Linnaeus, 1758), in two different aquaculture systems in Goa, west coast of India

Asian Green mussel, Perna viridis (Linnaeus, 1758), is a bivalve mollusc with high market demand along India’s western coast, specifically in Goa. An experiment was conducted to compare the environmental variables, specific growth rate (SGR) and length-weight progression of the species raised in two different coastal aquaculture systems; a semi-enclosed water body (SEW) and an open-water system (OWS). The variables chlorophyll-a and plankton density were high in SEW and these variables were positively correlated with the growth rate of the species. The ‘b’ value of the length-weight relationship and SGR were found high and allometric in nature in SEW. The prediction of SGR using the generalised linear model has indicated that plankton density and nitrate are the variables that influence the growth of P. viridis. Thus, being a predominant filter-feeder on plankton, the high plankton density channeled through the rich nutrients and chlorophyll content might have triggered the growth of mussels in SEW. India is blessed with many semi-enclosed coastal water bodies lying unutilised, and the results indicate that there is scope for mussel culture in these systems, which will provide a source of secondary livelihood for the coastal fishers. Keywords: Bivalves, Coastal aquaculture, GLM, Molluscan culture, Zuari

Solution structure of recombinant Pvfp-5β reveals insights into mussel adhesion

Some marine organisms can resist to aqueous tidal environments and adhere tightly on wet surface. This behavior has raised increasing attention for potential applications in medicine, biomaterials, and tissue engineering. In mussels, adhesive forces to the rock are the resultant of proteinic fibrous formations called byssus. We present the solution structure of Pvfp-5β, one of the three byssal plaque proteins secreted by the Asian green mussel Perna viridis, and the component responsible for initiating interactions with the substrate. We demonstrate that Pvfp-5β has a stably folded structure in agreement with the presence in the sequence of two EGF motifs. The structure is highly rigid except for a few residues affected by slow local motions in the µs-ms time scale, and differs from the model calculated by artificial intelligence methods for the relative orientation of the EGF modules, which is something where computational methods still underperform. We also show that Pvfp-5β is able to coacervate even with no DOPA modification, giving thus insights both for understanding the adhesion mechanism of adhesive mussel proteins, and developing of biomaterials.

Microplastics, both non-biodegradable and biodegradable, do not affect the whole organism functioning of a marine mussel

Microplastics are ubiquitous in the marine environment, and their uptake by many organisms has been well documented. Concern about increasing plastic waste in ecosystems and organisms has led to the production of biodegradable alternatives. However, long breakdown times of biodegradable plastics in natural environments mean they still have the potential to induce ecological impacts. The impacts of microplastics on organisms remain unclear, especially as many experimental microplastic exposures employ particle concentrations orders of magnitude greater than those found in natural ecosystems. Here, we exposed the ecosystem engineer, the Asian green mussel Perna viridis, to non-biodegradable and biodegradable microplastics at two environmentally relevant concentrations (~17–20 particles L−1 and ~ 135–140 particles L−1). After four weeks of exposure, there were no significant effects of microplastic type or concentration on the mortality, oxygen consumption rate, clearance rate, or condition index of P. viridis. With the increasing body of microplastic literature, future exposure studies considering biotic effects should make efforts to employ environmentally relevant concentrations. Further, we suggest that, while a high-profile threat to ecosystems, investigating the effects of microplastics on ecosystems should be conducted alongside, and not draw focus away from, other major threats such as climate change.

Effect of Abrupt Salinity Change in the Survival of Asian Green Mussel Perna viridis (Linnaeus, 1758) Spats

Salinity is one of the key environmental factors that affects the growth and survival of marine organisms including mussels. Five different salinity levels (40, 30, 20, 10 and 5 ppt) were used to test the effect of abrupt salinity change in the survival of hatchery-produced spats of Asian green mussel Perna viridis (Linnaeus, 1758). Spats were stocked with a density of 30 individuals per 6-L tank. Salinity manipulation was conducted after 2 days from the date of stocking. Based on the results, abrupt change and prolonged exposure to lower salinities particularly of 5 and 10 ppt (up to 5 days) are detrimental to P. viridis spats. The critical time for P. viridis spats wherein they could seclude themselves from the persistent lower salinities is 28 hours from its exposure. After which, mortality could be high at about 50% and will continue in the succeeding days if low salinity persists. Critically, no single spat can survive until the 4th day of continuous exposure to very low salinity of 5 ppt. Nevertheless, surviving individuals could still recover if salinity will return to optimum levels. Additionally, spats can readily adjust to abrupt change up to 10 ppt from the optimum salinity level as seen in the high survival in 20 and 40 ppt.

Settlement of Asian Green Mussel (Perna viridis) Spat in Tampa Bay, Florida

The Asian green mussel Perna viridis, was first detected in Tampa Bay, FL, in 1999 and quickly spread throughout the bay. The long-term population trend of P. viridis from 2002 to 2017 was assessed by monitoring settlement to collectors and bycatch of P. viridis in trawls in Tampa Bay. In addition, a suite of water-quality parameters and trends in predator abundance were modeled to evaluate the effects of these variables on P. viridis in the bay. Since 2002, settlement and bycatch of P. viridis in Tampa Bay has declined by 83% and 62%, respectively, in relation to nitrogen concentrations and productivity fluctuations limiting resource availability and energy acquisition in P. viridis. While Florida stone crab (Menippe mercenaria) landings, Atlantic blue crab (Callinectes sapidus) landings, and catch per unit effort of C. sapidus in fisheries independent monitoring trawls decreased throughout the study period, C. sapidus landings were the only biotic factor that was significantly related to P. viridis settlement. Temperature and salinity extremes, while not significant parameters in the models, likely negatively affected the distribution and persistence of P. viridis in the bay. Taken together, these findings suggest that conditions within Tampa Bay were not conducive to the large-scale dominance of P. viridis that was predicted when they were first introduced and they currently do not fit the definition of a problematic, invasive species. Conditions have been sufficient for this introduced species to remain established as a relatively minor constituent of the benthic community.

Molecular cloning and expression analysis of mytilin-like antimicrobial peptides from Asian green mussel Perna viridis

Mytilin is one of the most important CS-αβ peptides involved in innate immune response in Mytilidae. In this study, we successfully identified four mytilin-like antimicrobial peptides (pernalins) from Asian green mussel Perna viridis by aligning the P. viridis transcriptome with 186 mytilins and myticins related sequences collected from the transcriptome data of six Mytilus species. Analysis on gene structure showed that pernalin genes had high conservation with mytilin B of Mediterranean mussel Mytilus galloprovincialis. Interestingly, all pernalin genes have a similar tissue expression feature, evidenced by the highest transcription level observed in the hemocytes and followed by the mantle. The lowest transcription level was observed in the foot and gills. qRT-PCR analysis showed that all pernalin genes were significantly down-regulated at each time points from 3 h to 48 h after Vibrio parahaemolyticus infection, suggesting their timely immune responses after bacterial infection.

Recombinant mussel protein Pvfp-5β: A potential tissue bioadhesive

During their lifecycle, many marine organisms rely on natural adhesives to attach to wet surfaces for movement and self-defense in aqueous tidal environments. Adhesive proteins from mussels are biocompatible and elicit only minimal immune responses in humans. Therefore these proteins have received increased attention for their potential applications in medicine, biomaterials, and biotechnology. The Asian green mussel Perna viridis secretes several byssal plaque proteins, molecules that help anchoring the mussel to surfaces. Among these proteins, protein-5β (Pvfp-5β) initiates interactions with the substrate, displacing interfacial water molecules before binding to the surface. Here, we established the first recombinant expression in Escherichia coli of Pvfp-5β. We characterized recombinant Pvfp-5β, finding that despite displaying a CD spectrum consistent with features of a random coil, the protein is correctly folded as indicated by MS and NMR analyses. Pvfp-5β folds as a β-sheet–rich protein as expected for an epidermal growth factor-like module. We examined the effects of Pvfp-5β on cell viability and adhesion capacity in NIH-3T3 and HeLa cell lines, revealing that Pvfp-5β has no cytotoxic effects at the protein concentrations used and provides good cell-adhesion strength on both glass and plastic plates. Our findings suggest that the adhesive properties of recombinant Pvfp-5β make it an efficient surface-coating material, potentially suitable for biomedical applications including regeneration of damaged tissues.

First report of the Asian green mussel Perna viridis (Linnaeus, 1758) in Rio de Janeiro, Brazil: a new record for the southern Atlantic Ocean

First report of the Asian green mussel Perna viridis (Linnaeus, 1758) in Rio de Janeiro, Brazil: a new record for the southern Atlantic Ocean

Identification and characterization of a novel defensin from Asian green mussel Perna viridis

Defensin is one of the most diversified groups of antimicrobial peptides in invertebrate. In the present study, a novel defensin member referred as Pv-Def was identified and characterized from Asian green mussel Perna viridis. Using in silico survey of several EST databases released from diverse tissues of P. viridis, a single peptide referred as Pv-Def was predicted as defensin homologue with Mytilus counterparts. Further analysis on gene structure revealed that Pv-Def was 1001 nt in length and consisted of 3 exons and 2 introns. The precursor of Pv-Def was composed of a signal peptide of 19 amino acids and a mature peptide of 45 amino acids. The mature Pv-Def peptide contains 6 cysteines which formed 3 disulfide bonds at 27C1- 54C4, 40C2- 60C5 and 44C3- 62C6. Like most of the defensin family members, mature Pv-Def peptide included an alpha helix and 2 beta strands. Pv-Def showed significantly tissue-specific expression pattern, while highest transcription level was observed in hepatopancreas, which was about 900 folds to that in hemocytes. Moreover, the expression of Pv-Def mRNA in hemocytes was significantly and accurately up-regulated at different time intervals by Vibrio parahaemolyticus challenge. Interestingly, phylogenetic analysis suggested that the Pv-Def possesses closest relationships with arthropods counterparts rather than other mollusk defensins. To our knowledge, this is the first time that a defensin member was reported in Asian green mussel P. viridis.

Ports and pests: Assessing the threat of aquatic invasive species introduced by maritime shipping activity in Cuba

Aquatic invasive species (AIS) are biological pollutants that cause detrimental ecological, economic, and human-health effects in their introduced communities. With increasing globalization through maritime trade, ports are vulnerable to AIS exposure via commercial vessels. The Cuban Port of Mariel is poised to become a competitive transshipment hub in the Caribbean and the intent of this study was to evaluate present and potential impacts AIS pose with the likely future increase in shipping activity. We utilized previous assessment frameworks and publicly accessible information to rank AIS by level of threat. Fifteen AIS were identified in Cuba and one, the Asian green mussel Perna viridis (Linnaeus, 1758), had repeated harmful economic impacts. Five species associated with trade partners of Port Mariel were considered potentially detrimental to Cuba if introduced through shipping routes. The results presented herein identify species of concern and emphasize the importance of prioritizing AIS prevention and management within Cuba.

If the Asian green mussel, Perna viridis (Linnaeus, 1758), poses the greatest invasive marine species threat to Australia, why has it not invaded?

ABSTRACTA national approach has been developed to the problem of invasive marine species (IMS) in the Australian marine environment. Fifty-five species were listed as posing significant threats to Australia. A 2005 analysis of the scientific literature concluded that the Asian green mussel Perna viridis (Linnaeus, 1758) poses the greatest threat to Australia. The mussel has in fact successfully invaded many areas of the world’s oceans. Despite the numerous and varied opportunities for P. viridis to be distributed to northern Australia it has not established a known population on the continent, perhaps suggesting there are biological factors inhibiting its establishment. The invasion success of P. viridis in many parts of the world and its failure so far to establish in Australia make the species ideal for testing theories of the factors determining invasion success. Such research will allow a reconsideration of the invasion threat the species poses to the Australian marine environment.

Suspended micro-sized PVC particles impair the performance and decrease survival in the Asian green mussel Perna viridis

Marine bivalves are known to ingest microplastics, but information on the consequences for their physiological performance is limited. To investigate a potential exposure pathway that has not yet been addressed, we mimicked the resuspension of microplastics from the sediment in a laboratory exposure experiment. For this, we exposed the Asian green mussel Perna viridis to 4 concentrations (0mg/l, 21.6mg/l, 216mg/l, 2160mg/l) of suspended polyvinylchloride (PVC) particles (1–50μm) for two 2-hour-time-periods per day. After 44days, mussel filtration and respiration rates as well as byssus production were found to be a negative function of particle concentration. Furthermore, within 91days of exposure, mussel survival declined with increasing PVC abundance. These negative effects presumably go back to prolonged periods of valve closure as a reaction to particle presence. We suggest that microplastics constitute a new seston component that exerts a stress comparable to natural suspended solids.

Genetic diversity and population structure of the Asian green mussel Perna viridis in South China Sea based on microsatellite markers

The green mussel, Perna viridis is ecologically and economically important in the coastal region of the South China Sea. Determining its population genetic structure at this fine geographic scale will help sustainable management of natural stocks. In this study, we examined the genetic diversity and population genetic structure of P. viridis from four locations in the South China Sea (n = 45–48) using nine microsatellite loci. The results showed moderate levels of genetic diversity in all four samples (mean A = 13.222–14.000, mean Ae = 7.092–7.571, mean Ar = 12.894–13.746, mean Ho = 0.596–0.656, mean He = 0.690–0.733) and a large effective population size estimate for the pooled sample (total Ne estimates = infinity, 95% CI = 1869.0-infinity). We did not detect any sign of recent bottleneck events in P. viridis populations in the South China Sea. The conventional and a model-based analysis reveal low, non-significant genetic divergence among the four samples (FST = − 0.001–0.005, P > 0.05/6). The results obtained from this study can provide valuable genetic information for the conservation and fishery management of P. viridis by retaining the high Ne estimates.

The invasive Asian green mussel Perna viridis in South Africa: all that is green is not viridis

The Asian green mussel Perna viridis is an invasive Indo-Pacific species recently reported from South African harbours. To verify the invasion, a phylogenetic (and morphological) analysis of green-shelled mussels (n = 39), found in six South African harbours, was conducted using the mitochondrial cytochrome c oxidase subunit I gene (COI). Estimates of genetic distances using the neighbour-joining analysis identified P. viridis only from Durban Harbour. All other green mussels were more than 3.2% divergent from P. viridis and were identified as green-shelled variants of indigenous P. perna. The only reliable morphological differences distinguishing the two species were the poorly developed mantle papillae and the wavy pallial line in P. viridis. The confirmed occurrence of P. viridis in a South African harbour suggests that there is a possible threat of the species becoming established and then spreading onto the open coast and competing with indigenous P. perna.

Food availability in an anthropogenically impacted habitat determines tolerance to hypoxia in the Asian green mussel Perna viridis

The Asian green mussel Perna viridis is tolerant to environmental stress, but its robustness varies between populations from habitats that differ in quality. So far, it is unclear whether local adaptations through stress-induced selection or phenotypic plasticity are responsible for these inter-population differences. We tested for the relevance of both mechanisms by comparing survival under hypoxia in mussels that were transplanted from an anthropogenically impacted (Jakarta Bay, Indonesia) to a natural habitat (Lada Bay, Indonesia) and vice versa. Mussels were retrieved 8 weeks after transplantation and exposed to hypoxia in the laboratory. Additional hypoxia tests were conducted with juvenile mussels collected directly from both sites. To elucidate possible relationships between habitat quality and mussel tolerance, we monitored concentrations of inorganic nutrients, temperature, dissolved oxygen, salinity, phytoplankton density and the mussels’ body condition index (BCI) for 20 months before, during and after the experiments. Survival under hypoxia depended mainly on the quality of the habitat where the mussels lived before the hypoxia tests and only to a small degree on their site of origin. Furthermore, stress tolerance was only higher in Jakarta than in Lada Bay mussels when the BCIs were substantially higher, which in turn correlated with the phytoplankton densities. We explain why phenotypic plasticity and high BCIs are more likely the causes of population-specific differences in hypoxia tolerance in P. viridis than stress-induced selection for robust genotypes. This is relevant to understanding the role of P. viridis as mariculture organism in eutrophic ecosystems and invasive species in the (sub)tropical world.

Genetic diversity and population connectivity of the Asian green mussel Perna viridis in South China Sea, inferred from mitochondria DNA markers

The Asian green mussel Perna viridis is ecologically and economically important in the coastal regions of China. In order to characterize the genetic diversity and population connectivity of P. viridis in South China Sea, a 664 bp region of mitochondrial COI gene and a 293 bp region of 16S rRNA gene were sequenced and analyzed for 78 and 92 individuals from four populations in South China Sea, respectively. A total of 15 haplotypes were defined by 14 variable nucleotide sites in COI gene, and 7 haplotypes by 6 variable nucleotide sites in 16S rRNA gene. High haplotype diversity and low nucleotide diversity were observed in COI gene, while moderate haplotype diversity and low nucleotide diversity were observed in 16S rRNA gene. Pairwise FST values of COI gene were all negative and those of 16S rRNA gene ranged from −0.01409 to 0.10289. The results showed that no significant genetic divergence (or shallow genetic structure) and high levels of population connectivity among the four populations of P. viridis in South China Sea.